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Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 02-2018 trié par par titre, page: 2
» An Artificial Neuron Based on a Threshold Switching Memristor
Résumé:
Artificial neurons and synapses are critical units for processing intricate information in neuromorphic systems. Memristors are frequently engineered as artificial synapses due to their simple structures, gradually changing conductance and high-density integration. However, few studies have designed memristors as artificial neurons. In this letter, we demonstrate an integration-and-fire artificial neuron based on a Ag/SiO2/Au threshold switching memristor. This neuron displays four critical features for action-potential-based computing: the all-or-nothing spiking of an action potential, threshold-driven spiking, a refractory period, and a strength-modulated frequency response. As a post-synaptic neuron, the designed neuron was demonstrated to be applicable to digit recognition. These results demonstrate that the developed artificial neuron can realize the basic functions of spiking neurons and has great potential for neuromorphic computing.
Auteurs: Xumeng Zhang;Wei Wang;Qi Liu;Xiaolong Zhao;Jinsong Wei;Rongrong Cao;Zhihong Yao;Xiaoli Zhu;Feng Zhang;Hangbing Lv;Shibing Long;Ming Liu;
Apparue dans: IEEE Electron Device Letters
Date publication: 02.-2018, volume: 39, issue:2, pages: 308 - 311
Editeur: IEEE
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» An Asynchronous Operation Approach to Event-Triggered Control for Fuzzy Markovian Jump Systems With General Switching Policies
Résumé:
This paper investigates the problem of event-triggered control for a class of fuzzy Markov jump systems with general switching policies. A novel event-triggered scheme is proposed to improve the transmission efficiency at each sampling instance. Each transition rate allows to be unknown, known, or only its uncertain domains value is known. With the help of a tailored technique to bind the uncertain terms and an asynchronous operation approach to tackle the fuzzy system and fuzzy controller, sufficient conditions for the resulting fuzzy Markovian jump systems are established in terms of coupled linear matrix inequalities. Finally, an example is given to illustrate the validity of the developed technique.
Auteurs: Jun Cheng;Ju H. Park;Lixian Zhang;Yanzheng Zhu;
Apparue dans: IEEE Transactions on Fuzzy Systems
Date publication: 02.-2018, volume: 26, issue:1, pages: 6 - 18
Editeur: IEEE
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» An Auto-Tuner for OpenCL Work-Group Size on GPUs
Résumé:
Tuning the kernel work-group size for GPUs is a challenging problem. In this paper, using the performance counters provided by GPUs, we characterize a large body of OpenCL kernels to identify the performance factors that affect the choice of a good work-group size. Based on the characterization, we realize that the most influential performance factors with regard to the work-group size include occupancy, coalesced global memory accesses, cache contention, and variation in the amount of workload in the kernel. By tackling the performance factors one by one, we propose auto-tuning techniques that selects the best work-group size and shape for GPU kernels. We show the effectiveness of our auto-tuner by evaluating it with a set of 54 OpenCL kernels on three different NVIDIA GPUs and one AMD GPU. On average, the auto-tuner needs to spend no more than 8 percent of the time required by an exhaustive search to find an optimal work-group size. The execution time of the selected sub-optimal work-group size is at most 1.14x slower than that of the optimal work-group size found by the exhaustive search, on average.
Auteurs: Thanh Tuan Dao;Jaejin Lee;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 02.-2018, volume: 29, issue:2, pages: 283 - 296
Editeur: IEEE
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» An Automated Microfluidic Assay for Photonic Crystal Enhanced Detection and Analysis of an Antiviral Antibody Cancer Biomarker in Serum
Résumé:
We report on the implementation of an automated platform for detecting the presence of an antibody biomarker for human papillomavirus-associated oropharyngeal cancer from a single droplet of serum, in which a nanostructured photonic crystal surface is used to amplify the output of a fluorescence-linked immunosorbent assay. The platform is comprised of a microfluidic cartridge with integrated photonic crystal chips that interfaces with an assay instrument that automates the introduction of reagents, wash steps, and surface drying. Upon assay completion, the cartridge interfaces with a custom laser-scanning instrument that couples light into the photonic crystal at the optimal resonance condition for fluorescence enhancement. The instrument is used to measure the fluorescence intensity values of microarray spots corresponding to the biomarkers of interest, in addition to several experimental controls that verify correct functioning of the assay protocol. In this paper, we report both dose-response characterization of the system using anti-E7 antibody introduced at known concentrations into serum and characterization of a set of clinical samples from which results were compared with a conventional enzyme-linked immunosorbent assay performed in microplate format. The demonstrated capability represents a simple, rapid, automated, and high-sensitivity method for the multiplexed detection of protein biomarkers from a low-volume test sample.
Auteurs: Caitlin M. Race;Lydia E. Kwon;Myles T. Foreman;Qinglan Huang;Hakan Inan;Sailaja Kesiraju;Phuong Le;Sung Jun Lim;Andrew M. Smith;Richard C. Zangar;Utkan Demirci;Karen S. Anderson;Brian T. Cunningham;
Apparue dans: IEEE Sensors Journal
Date publication: 02.-2018, volume: 18, issue:4, pages: 1464 - 1473
Editeur: IEEE
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» An Autonomous Intelligent Music Teacher
Résumé:
The attempted combination of music and artificial intelligence (AI) has been viewed as the jamming together of two puzzle pieces that are not meant to fit together. It is the opinion of some musicians that music is a purely human feat, a proficiency that computers will never be able to achieve. Several members of the AI community, however, have fought this mindset with their belief that music is, in more ways than one, founded on mathematics. What computers lack in emotions, they make up for with computational capabilities.
Auteurs: Lavanya Aprameya;
Apparue dans: IEEE Potentials
Date publication: 02.-2018, volume: 37, issue:1, pages: 10 - 14
Editeur: IEEE
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» An Effective Compensation Technique for Speed Smoothness at Low-Speed Operation of PMSM Drives
Résumé:
This paper proposes a simple and effective method to reduce speed ripples of permanent magnet synchronous machines (PMSMs) under low-speed working conditions. The treated issue is related to the periodic torque ripples, which induce speed oscillations that deteriorate the drive performance. The main idea of the proposed method is to modify a conventional PMSM controller by superposing an appropriate compensation signal to the quadratic-current reference. The proposed approach allows the reduction of speed ripples at low speed through a simple compensation signal and does not require a hard calculation cost. A theoretical analysis is presented, and both simulation and experimental results are presented to validate the proposed compensation method.
Auteurs: Azeddine Houari;Ahmed Bouabdallah;Ali Djerioui;Mohamed Machmoum;Francois Auger;Abdallah Darkawi;Jean-Christophe Olivier;Mohamed Fouad Benkhoris;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 647 - 655
Editeur: IEEE
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» An Efficient Amplitude-Preserving Generalized S Transform and Its Application in Seismic Data Attenuation Compensation
Résumé:
The time–frequency analysis tools, which are very useful for anomaly identification, reservoir characterization, seismic data processing, and interpretation, are widely used in discrete signal analysis. Among these methods, the generalized S transform (GST) is more flexible, because its analytical window can be self-adjusted according to the local frequency components of the selected discrete signal, besides there exist another two adjustable parameters to make it superior to the S transform (ST). But the amplitude-preserving ability is a little poor near the boundary because the analytical windows do not satisfy the partition of unity, which is a sufficient condition for amplitude-preserving time–frequency transforms. In order to make the GST with the amplitude-preserving ability, we first design a new analytical window, and then propose an amplitude-preserving GST (APGST), but with a higher computational cost. To accelerate the APGST, we provide two strategies: the 3 $sigma$ criterion in the probability theory is introduced to accelerate the analytical windows summation and a convolution operator is derived to accelerate the time integral or summation, which generates an efficient APGST (EAPGST). Finally, the proposed EAPGST is used for seismic data attenuation compensation to improve the vertical resolution. Detailed numerical examples are used to demonstrate the validity of the proposed EAPGST in amplitude preserving and high efficiency. Field data attenuation compensation result further proves its successful application in improving the vertical resolution. Besides, the proposed EAPGST can be easily extended into other applications in discrete signal analysis, and remote-sensing and seismology fields.
Auteurs: Benfeng Wang;Wenkai Lu;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2018, volume: 56, issue:2, pages: 859 - 866
Editeur: IEEE
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» An Efficient Dual-Band Orthogonally Polarized Transmitarray Design Using Three-Dipole Elements
Résumé:
A dual-band transmitarray is proposed for downlink/uplink frequencies (12.5/14.25 GHz) of Ku-band satellite communications. The basic building block for the dual-band transmitarray is a three-dipole element. Such two elements are interlaced in orthogonal polarization for each frequency band independently. This element overwhelms the basic phase restriction of a simple dipole element, and 360° phase range can be achieved in both bands with a four-layer configuration. However, it is explored (theoretically and experimentally) that three layers are preferred to be used instead of four layers due to a compromise between the phase range and reflection loss. A high-gain three-layer dual-band orthogonally polarized transmitarray is designed successfully. The measured results match well with simulation results, and high gains of 31.0 and 31.8 dBi are achieved with aperture efficiencies of 45.0% and 41.3% at 12.5 and 14.25 GHz, respectively. It also achieves 1 dB gain bandwidths of 7.2% and 7.0% in both the downlink and uplink frequency bands, respectively.
Auteurs: Abdul Aziz;Fan Yang;Shenheng Xu;Maokun Li;
Apparue dans: IEEE Antennas and Wireless Propagation Letters
Date publication: 02.-2018, volume: 17, issue:2, pages: 319 - 322
Editeur: IEEE
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» An Efficient Implementation of Lattice Staggered Multicarrier Faster-Than-Nyquist Signaling
Résumé:
In this letter, we investigate the lattice staggered multicarrier faster-than-Nyquist (MFTN) signaling. Specifically, we consider the time–frequency packing and optimal hexagonal lattice over additive white Gaussian noise channels. First, an efficient implementation of the lattice staggered MFTN based on the fast Fourier transform algorithm is proposed, and we show that the modulation and demodulation complexity could be substantially reduced. Furthermore, we consider, at the receiver, a low-complexity symbol-by-symbol detector. Our practical spectral efficiency and bit-error-rate performance investigation demonstrate that the MFTN with optimal hexagonal lattice outperforms the conventional rectangular lattice.
Auteurs: Siming Peng;Aijun Liu;Xinhai Tong;Giulio Colavolpe;
Apparue dans: IEEE Communications Letters
Date publication: 02.-2018, volume: 22, issue:2, pages: 240 - 243
Editeur: IEEE
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» An Efficient Integral-Based Method for Three-Dimensional MR-EPT and the Calculation of the RF-Coil-Induced ${B_z}$ Field
Résumé:
Magnetic resonance electrical property tomography (MR-EPT) has significant potential for the estimation of the electrical properties (EPs) of tissue, which are essential for the calculation of specific absorption rates (SAR), a critical safety factor requiring monitoring and controlling in applications of ultrahigh field magnetic resonance imaging. In this paper, a novel, efficient method based on integral equations is proposed for the calculation of the EPs and the RF-coil-induced ${boldsymbol{B}_{boldsymbol{z}}}$ field. An inverse problem framework is first constructed to include the forward problem operator, while the EPs are reconstructed by using a nonlinear conjugate gradient method. The RF-coil-induced ${boldsymbol{B}_{boldsymbol{z}}}$ component is then calculated based on the achieved EPs and the forward operator. The proposed MR-EPT algorithm improves upon and differs from the existing methods in three aspects. First, a three-dimensional algorithm with improved efficiency is proposed. The higher efficiency arises from using a fast integral equation solver as well as an approximation of initial solution. Second, in addition to the EP values, the proposed method calculates the RF-coil-induced ${boldsymbol{B}_{boldsymbol{z}}}$ component, which is usually neglected in the existing MR-EPT algorithms. Here, we show that considering this ${boldsymbol{B}_{boldsymbol{z}}}$ field can significantly improve the accuracy of the SAR calculation. Finally, in contrast to differential approaches, the proposed method is more robust against noisy measurement of the transmit magnetic fields, because of the nature of the integral equations. The proposed method is verified through a full- wave simulation and an anatomically accurate numerical brain model, demonstrating its accuracy and efficiency.
Auteurs: Lei Guo;Jin Jin;Chunyi Liu;Feng Liu;Stuart Crozier;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 02.-2018, volume: 65, issue:2, pages: 282 - 293
Editeur: IEEE
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» An Efficient Model-Free Setting for Longitudinal and Lateral Vehicle Control: Validation Through the Interconnected Pro-SiVIC/RTMaps Prototyping Platform
Résumé:
In this paper, the problem of tracking desired longitudinal and lateral motions for a vehicle is addressed here. Let us point out that a “good” modeling is often quite difficult or even impossible to obtain. It is due for example to parametric uncertainties, for the vehicle mass, inertia or for the interaction forces between the wheels and the road pavement. To overcome this type of difficulties, we consider a model-free control approach leading to “intelligent” controllers. The longitudinal and the lateral motions, on one hand, and the driving/braking torques and the steering wheel angle, on the other hand, are respectively the output and the input variables. An important part of this paper is dedicated to present simulation results with actual data. Actual data, used in MATLAB as reference trajectories, have been previously recorded with an instrumented Peugeot 406 experimental car. The simulation results show the efficiency of our approach. Some comparisons with a nonlinear flatness-based control in one hand, and with a classical PID control in another hand confirm this analysis. Other virtual data have been generated through the interconnected platform SiVIC/RTMaps, which is a virtual simulation platform for prototyping and validation of advanced driving assistance systems.
Auteurs: Lghani Menhour;Brigitte d’Andréa-Novel;Michel Fliess;Dominique Gruyer;Hugues Mounier;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 02.-2018, volume: 19, issue:2, pages: 461 - 475
Editeur: IEEE
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» An Efficient Recursive Multiframe Track-Before-Detect Algorithm
Résumé:
Multiframe track-before-detect (MF-TBD) usually uses sliding-window-based batch processing, where a number $N$ of the latest data frames are jointly processed at each measurement time. The sliding window mechanism compromises the operating efficiency of MF-TBD by increasing both computational costs and memory requirements, thus, heavily restricting its application in practical problems. In this paper, an improved recursive implementation for MF-TBD is proposed. Unlike the sliding-window-based implementation, the proposed method calculates the merit function, a measure of the possibility that a state is target originated, of the current batch based on an approximated recursive relationship between the merit functions of consecutive batches. As a result, instead having to process the whole batch, at any given time only the latest frame needs to be processed. The recursive relationship is first derived for any arbitrary merit function, and then explored further with several typical merit functions that are used in MF-TBD. Both the theoretical analysis and simulation results demonstrate that the proposed method can achieve almost $N$ times reduction in computational complexity and memory requirements with negligible performance loss.
Auteurs: Jinghe Wang;Wei Yi;Thia Kirubarajan;Lingjiang Kong;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 190 - 204
Editeur: IEEE
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» An Efficient Ride-Sharing Framework for Maximizing Shared Route
Résumé:
Ride-sharing (RS) has great values in saving energy and alleviating traffic pressure. Existing studies can be improved for better efficiency. Therefore, we propose a new ride-sharing model, where each driver has a requirement that if the driver shares a ride with a rider, the shared route percentage (i.e., the ratio of the shared route's distance to the driver's total travel distance) exceeds an expectation rate of the driver, e.g., 0.8. We consider two variants of this problem. The first considers multiple drivers and multiple riders and aims to compute driver-rider pairs to maximize the overall shared route percentage (SRP). We model this problem as the maximum weighted bigraph matching problem, where the vertices are drivers and riders, edges are driver-rider pairs, and edge weights are driver-rider's SRP. However, it is rather expensive to compute the SRP values for large numbers of driver-rider pairs on road networks. To address this problem, we propose an efficient method to prune many unnecessary driver-rider pairs and avoid computing the SRP values for every pair. To improve the efficiency, we propose an approximate method with error bound guarantee. The basic idea is that we compute an upper bound and a lower bound for each driver-rider pair in constant time. Then, we estimate an upper bound and a lower bound of the graph matching. Next, we select some driver-rider pairs, compute their real shortest-route distance, and update the lower and upper bounds of the maximum graph matching. We repeat above steps until the ratio of the upper bound to the lower bound is not larger than a given approximate rate. The second considers multiple drivers and a single rider and aims to find the top-$k$ drivers for the rider with the largest SRP. We first prune a large - umber of drivers that cannot meet the SRP requirements. Then, we propose a best-first algorithm that progressively selects the drivers with high probability to be in the top- $k$ results and prunes the drivers that cannot be in the top- $k$ results. Extensive experiments on real-world datasets demonstrate the superiority of our method.
Auteurs: Na Ta;Guoliang Li;Tianyu Zhao;Jianhua Feng;Hanchao Ma;Zhiguo Gong;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 02.-2018, volume: 30, issue:2, pages: 219 - 233
Editeur: IEEE
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» An Efficient Self-Powered Piezoelectric Energy Harvesting CMOS Interface Circuit Based on Synchronous Charge Extraction Technique
Résumé:
An efficient self-powered synchronous electric charge extraction CMOS interface circuit dedicated to piezoelectric harvesters is proposed in this paper. Self-powered peak detection (PKD) and switch circuits are used to reduce quiescent current so that the backup or pre-charged power can be saved. A new low phase lag (LPL) PKD circuit is designed to improve the synchronous extraction efficiency, which only requires one detection capacitor to perform positive and negative PKD. The circuit can be set at general mode (G-mode) or LPL mode (LPL-mode). Under LPL-mode, the phase lag can be reduced typically by 50%, the synchronous extraction efficiency can obtained up to 94%, while the output power can reach $659~mu text{W}$ when the piezoelectric transducer original open-circuit voltage $V_{mathrm{ oc,org}}=5$ V, which is 3.56 times of that of full-bridge rectifier standard energy harvesting circuit at the maximum power point. The minimum harvesting startup voltage is 1.7 V and is independent of the energy storage capacitor voltage $V_{mathrm{ DC}}$ . The harvesting efficiency can still reach 71.3% at $V_{mathrm{ oc,org}}=5$ V. The size of the active area is 0.5 mm2 in a 0.18- $mu text{m}$ CMOS technology. Circuit may be invoked as a functional block for energy autonomous wireless sensor network node of the Internet of Things.
Auteurs: Ge Shi;Yinshui Xia;Xiudeng Wang;Libo Qian;Yidie Ye;Qing Li;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2018, volume: 65, issue:2, pages: 804 - 817
Editeur: IEEE
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» An Efficient Technique to Assess the Convergence of the Multimode Equivalent Network for Waveguide Devices
Résumé:
Numerical methods are widely used to analyze and design microwave components for communication applications. In the implementation of any numerical technique, however, there are always a set of parameters that must be properly adjusted in order to obtain, at the same time, computational efficiency and numerical accuracy of the results. In this context, therefore, we focus in this paper on the multimode equivalent network formulation for waveguide devices, and we propose a more intuitive and efficient strategy for choosing these parameters. Following our approach, setting only one global numerical variable is sufficient to adjust automatically the specific convergence parameters of each discontinuity to give a specific level of numerical accuracy of the results. As a consequence, the computational efficiency is significantly increased. In addition, the user experience is significantly improved since our approach eliminates all lengthy convergence tests previously needed to assure good numerical accuracy. In addition to theory, we discuss in this paper a number of numerical results that clearly demonstrate how the new strategy is very effective, thereby fully validating the theoretical formulation.
Auteurs: Celia Gómez Molina;Fernando Quesada Pereira;Alejandro Alvarez Melcón;Vicente E. Boria;Marco Guglielmi;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2018, volume: 66, issue:2, pages: 651 - 659
Editeur: IEEE
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» An Eight-Element Reconfigurable Diversity Dipole System
Résumé:
In this paper, an antenna system that is composed of eight radiating elements is presented. The eight elements consist of a set of four curved dipoles and another set of four straight dipoles, providing two diversity antenna structures. Each curved and straight dipole is designed to produce a focused gain pattern toward one dedicated quadrant. A parasitic printed reflector is introduced into the center section of the top layer of the proposed antenna to enhance the matching and the gain pattern redirection capabilities of each radiating element. In addition, the printed reflector further enhances the isolation between the various elements. The assessment of the proposed diversity antenna system is performed in a rich multipath environment for various propagation scenarios. A diversity gain between 16.5 and 19.1 dB is attained for a 1% probability level and by assuming a Rayleigh fading channel for both structures. The control of the feeding of the various elements for both diversity structures is achieved through the design and incorporation of four reconfigurable feeding networks within the antenna system. Fabrication and testing of various prototypes display very good agreement between the simulation and measured results, which validate the presented designs.
Auteurs: Youssef Tawk;Joseph Costantine;Christos G. Christodoulou;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 572 - 581
Editeur: IEEE
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» An Electrically Small Planar Quasi-Isotropic Antenna
Résumé:
A singly fed, electrically small, planar antenna that generates a quasi-isotropic radiation pattern is investigated. The antenna consists of a folded dipole, a pair of capacitively loaded loops (CLLs), and a coplanar stripline (CPS), which are printed on the top and bottom surfaces of a single-layer printed circuit board. Through near-field coupling with the driven CPS, the folded dipole and CLLs are both effectively excited and behave like an electric dipole and a magnetic dipole, respectively. A quasi-isotropic radiation pattern can therefore be obtained by combining the two orthogonal dipoles with the same radiation intensities and quadrature phases. To verify the idea, a prototype operating at 2.4 GHz is designed, fabricated, and measured. It has been shown that this electrically small antenna (0.165 × 0.164 × 0.006 λ3, ka = 0.73) has a −10 dB impedance bandwidth of 0.99%, a total efficiency of ∼90%, and a nearly isotropic pattern with the difference between the maximum and minimum radiated power densities given by ∼3 dB over the entire spherical radiating surface.
Auteurs: J. Ouyang;Y. M. Pan;S. Y. Zheng;P. F. Hu;
Apparue dans: IEEE Antennas and Wireless Propagation Letters
Date publication: 02.-2018, volume: 17, issue:2, pages: 303 - 306
Editeur: IEEE
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» An EM Simulation-Based Design Flow for Custom-Built MR Coils Incorporating Signal and Noise
Résumé:
Developing custom-built MR coils is a cumbersome task, in which an a priori prediction of the coils’ SNR performance, their sensitivity pattern, and their depth of penetration helps to greatly speed up the design process by reducing the required hardware manufacturing iterations. The simulation-based design flow presented in this paper takes the entire MR imaging process into account. That is, it includes all geometric and material properties of the coil and the phantom, the thermal noise as well as the target MR sequences. The proposed simulation-driven design flow is validated using a manufactured prototype coil, whose performance was optimized regarding its SNR performance, based on the presented design flow, by comparing the coil’s measured performance against the simulated results. In these experiments, the mean and the standard deviation of the relative error between the simulated and measured coil sensitivity pattern were found to be $mu ={1.79}%$ and $sigma ={3.15}%$ . Moreover, the peak deviation between the simulated and measured voxel SNR was found to be less than 4%, indicating that simulations are in good accordance with the measured results, validating the proposed software-based design approach.
Auteurs: Andreas Horneff;Michael Eder;Erich Hell;Johannes Ulrici;Jörg Felder;Volker Rasche;Jens Anders;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2018, volume: 37, issue:2, pages: 527 - 535
Editeur: IEEE
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» An Embedded, Eight Channel, Noise Canceling, Wireless, Wearable sEMG Data Acquisition System With Adaptive Muscle Contraction Detection
Résumé:
Wearable technology has gained increasing popularity in the applications of healthcare, sports science, and biomedical engineering in recent years. Because of its convenient nature, the wearable technology is particularly useful in the acquisition of the physiological signals. Specifically, the (surface electromyography) sEMG systems, which measure the muscle activation potentials, greatly benefit from this technology in both clinical and industrial applications. However, the current wearable sEMG systems have several drawbacks including inefficient noise cancellation, insufficient measurement quality, and difficult integration to customized applications. Additionally, none of these sEMG data acquisition systems can detect sEMG signals (i.e., contractions), which provides a valuable environment for further studies such as human machine interaction, gesture recognition, and fatigue tracking. To this end, we introduce an embedded, eight channel, noise canceling, wireless, wearable sEMG data acquisition system with adaptive muscle contraction detection. Our design consists of two stages, which are the sEMG sensors and the multichannel data acquisition unit. For the first stage, we propose a low cost, dry, and active sEMG sensor that captures the muscle activation potentials, a data acquisition unit that evaluates these captured multichannel sEMG signals and transmits them to a user interface. In the data acquisition unit, the sEMG signals are processed through embedded, adaptive methods in order to reject the power line noise and detect the muscle contractions. Through extensive experiments, we demonstrate that our sEMG sensor outperforms a widely used commercially available product and our data acquisition system achieves 4.583 dB SNR gain with $98.9784%$ accuracy in the detection of the contractions.
Auteurs: Mert Ergeneci;Kaan Gokcesu;Erhan Ertan;Panagiotis Kosmas;
Apparue dans: IEEE Transactions on Biomedical Circuits and Systems
Date publication: 02.-2018, volume: 12, issue:1, pages: 68 - 79
Editeur: IEEE
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» An Energy Efficient VM Management Scheme with Power-Law Characteristic in Video Streaming Data Centers
Résumé:
As cloud computing services have gained popularity, users view videos on websites (e.g., YouTube) to generate high CPU resource utilization and bandwidth for video streaming data centers. However, popular videos result in power-law features to cause imbalanced resource utilization. In addition, hotspot and idle servers generate extra power consumption in data centers. Previous studies considered to satisfy the requirements of users, provide faster access rates and save power consumption. However, fewer studies considered resource utilization with different popularity videos. Therefore, this paper proposes an energy efficient virtual machine (VM) management scheme with power-law features (VMPL). VMPL predicts the resource utilization of the video in the future based on the popularity, ensures enough resources for upcoming videos, and turns off idle servers for power saving. Simulation results validated by mathematical analysis show that VMPL has the best resource utilization and the lowest power consumption compared with Nash and Best-Fit algorithms.
Auteurs: Hsueh-Wen Tseng;Ting-Ting Yang;Kai-Cheng Yang;Pei-Shan Chen;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 02.-2018, volume: 29, issue:2, pages: 297 - 311
Editeur: IEEE
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» An Energy-Based Model Encoding Nonlocal Pairwise Pixel Interactions for Multisensor Change Detection
Résumé:
Image change detection (CD) is a challenging problem, particularly when images come from different sensors. In this paper, we present a novel and reliable CD model, which is first based on the estimation of a robust similarity-feature map generated from a pair of bitemporal heterogeneous remote sensing images. This similarity-feature map, which is supposed to represent the difference between the multitemporal multisensor images, is herein defined, by specifying a set of linear equality constraints, expressed for each pair of pixels existing in the before-and-after satellite images acquired through different modalities. An estimation of this overconstrained problem, also formulated as a nonlocal pairwise energy-based model, is then carried out, in the least square sense, by a fast linear-complexity algorithm based on a multidimensional scaling mapping technique. Finally, the fusion of different binary segmentation results, obtained from this similarity-feature map by different automatic thresholding algorithms, allows us to precisely and automatically classify the changed and unchanged regions. The proposed method is tested on satellite data sets acquired by real heterogeneous sensor, and the results obtained demonstrate the robustness of the proposed model compared with the best existing state-of-the-art multimodal CD methods recently proposed in the literature.
Auteurs: Redha Touati;Max Mignotte;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2018, volume: 56, issue:2, pages: 1046 - 1058
Editeur: IEEE
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» An Energy-Efficient Architecture for Binary Weight Convolutional Neural Networks
Résumé:
Binary weight convolutional neural networks (BCNNs) can achieve near state-of-the-art classification accuracy and have far less computation complexity compared with traditional CNNs using high-precision weights. Due to their binary weights, BCNNs are well suited for vision-based Internet-of-Things systems being sensitive to power consumption. BCNNs make it possible to achieve very high throughput with moderate power dissipation. In this paper, an energy-efficient architecture for BCNNs is proposed. It fully exploits the binary weights and other hardware-friendly characteristics of BCNNs. A judicious processing schedule is proposed so that off-chip I/O access is minimized and activations are maximally reused. To significantly reduce the critical path delay, we introduce optimized compressor trees and approximate binary multipliers with two novel compensation schemes. The latter is able to save significant hardware resource, and almost no computation accuracy is compromised. Taking advantage of error resiliency of BCNNs, an innovative approximate adder is developed, which significantly reduces the silicon area and data path delay. Thorough error analysis and extensive experimental results on several data sets show that the approximate adders in the data path cause negligible accuracy loss. Moreover, algorithmic transformations for certain layers of BCNNs and a memory-efficient quantization scheme are incorporated to further reduce the energy cost and on-chip storage requirement. Finally, the proposed BCNN hardware architecture is implemented with the SMIC 130-nm technology. The postlayout results demonstrate that our design can achieve an energy efficiency over 2.0TOp/s/W when scaled to 65 nm, which is more than two times better than the prior art.
Auteurs: Yizhi Wang;Jun Lin;Zhongfeng Wang;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 02.-2018, volume: 26, issue:2, pages: 280 - 293
Editeur: IEEE
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» An Extended Moving Target Detection Approach for High-Resolution Multichannel SAR-GMTI Systems Based on Enhanced Shadow-Aided Decision
Résumé:
This paper develops a framework based on enhanced shadow-aided decision for multichannel synthetic aperture radar-based ground moving target indication system according to the relationships between the moving target and its shadow information in position, dimensions, and intensity. As a sort of feature information available, the moving target shadow may improve the ground target detection performance. A critical precondition for shadow utilization is to obtain the good detection performance for the moving target shadow. However, shadow detection performance will deteriorate inevitably as a result of target motion that blurs its shadow. To address this issue, a knowledge-aided shadow detection algorithm with adaptive thresholds is proposed to improve the shadow detection performance in the developed framework. Furthermore, the theoretical performance analysis is performed, which indicates that the proposed knowledge-aided shadow detection algorithm has a better performance than that of the conventional shadow detection algorithm with a fixed threshold. Finally, numerical simulation experiments are presented to demonstrate that the developed framework can obtain good results for extended ground moving target detection.
Auteurs: Huajian Xu;Zhiwei Yang;Min Tian;Yongyan Sun;Guisheng Liao;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2018, volume: 56, issue:2, pages: 715 - 729
Editeur: IEEE
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» An Extrapolation Method for Efficient and Accurate Numerical Dosimetry of Resonant Exposure Setups
Résumé:
An extrapolation method was proposed to increase the calculation efficiency and the accuracy of the incident power and specific absorption rate (SAR) in resonant exposure setups. The stable incident power and SAR were derived by observing the oscillating ${E}$ -field envelope recorded during the finite-difference time-domain calculation. The extrapolation method was validated when applied to a waveguide loaded with two or four 35-mm-diameter Petri dishes at the ${H}$ -field maximum for the resonant exposure at 1800 MHz. With the extrapolation, the computational time was reduced by 80% to derive the incident power with the error reduction of 93%, as compared to the calculation with the current mechanism until the accepted wave stability. For the SAR, the computational time was reduced by 77%. With the proper position and weighting of the ${E}$ -field samples, the error of the averaged SAR in the cell monolayer was reduced from 4.62% to 1.31%. The proposed method applies to the scenario where the resonant frequency of the loaded setup drifts away from the driven frequency so that an oscillating ${E}$ -field envelope is available.
Auteurs: Jianxun Zhao;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2018, volume: 66, issue:2, pages: 774 - 783
Editeur: IEEE
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» An HDR Pixel With Over 60-dB Dynamic Range Enhancement Using In-Pixel Parametric Amplification
Résumé:
This paper discusses a method to enhance the dynamic range (DR) of a conventional CMOS image sensor in low- and high-light environment using in-pixel parametric amplification. The parametric amplification gives a linear and noiseless gain. The source follower in a conventional 4T pixel is used as a capacitor for charge amplification by varying its capacitance periodically. This reconfiguration helps in signal amplification without affecting the pixel fill factor drastically. The simulation results show that over 60-dB DR extension in the low and high illuminations can be achieved enhancing the total DR of the pixel to 120 dB.
Auteurs: Gaurav Musalgaonkar;Neha Priyadarshini;Mukul Sarkar;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2018, volume: 65, issue:2, pages: 555 - 563
Editeur: IEEE
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» An Identification Method Based on Mathematical Morphology for Sympathetic Inrush
Résumé:
Sympathetic interaction between transformers is a quite normal phenomenon in power systems. For the purpose of preventing transformer differential protection relays from malfunction, this paper proposes a morphological method for the identification of sympathetic inrush, which is the first time when mathematical morphology is applied in this field. Since the waveform of differential current is symmetrical in an internal fault case while asymmetrical in a sympathetic inrush case, the proposed method uses a morphological operator to extract the peaks and valleys of the differential current to distinguish sympathetic inrush. Considering the possible current-transformer (CT) saturation conditions, this paper combines a morphological gradient with a weighted mathematical morphological operator to improve the effectiveness of the proposed method. The proposed method is evaluated on data collected from simulation cases established in PSCAD/EMTDC and from laboratory experiments, respectively. Identification results have verified that by comparing with the traditional second harmonic restrain method, the proposed method can distinguish sympathetic inrush from an internal fault current more accurately and more effectively, even when the CT is fully saturated.
Auteurs: A. Q. Zhang;T. Y. Ji;M. S. Li;Q. H. Wu;L. L. Zhang;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 12 - 21
Editeur: IEEE
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» An Imaging Dictionary Based Multipath Suppression Algorithm for Through-Wall Radar Imaging
Résumé:
This paper considers the problem of multipath ghosts elimination for the through-wall radar imaging. We formulate a discrete signal model in the presence of first-order multipath, and propose an imaging dictionary based algorithm to suppress the multipath ghosts. Specifically, first, several estimated images are obtained via two different kinds of imaging dictionaries for the focus delays related to the direct propagation path and the multipaths, respectively. We find that all the estimated images possess large values around the genuine target positions and the multipath ghosts of them do not overlap with each other. Then, based on this feature, these images are fused via incoherent multiplication image fusion method to yield a multipath ghosts free image. Finally, the simulation and real data are used to prove the validity of the proposed approach.
Auteurs: Shisheng Guo;Guolong Cui;Lingjiang Kong;Xiaobo Yang;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 269 - 283
Editeur: IEEE
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» An Improved 2-D Subdomain Model of Squirrel-Cage Induction Machine Including Winding and Slotting Harmonics at Steady State
Résumé:
This paper proposes an improved subdomain model of squirrel-cage induction machines (SCIMs) with imposed stator currents. This new model enables to accurately compute electromagnetic quantities such as air-gap flux density, instantaneous torque and forces, and electromotive force including all harmonic contents. The first improvement is to explicitly account for rotor motion with time-stepping technique. The second improvement consists in modeling the skin effect in rotor bars by considering each space harmonic of the stator magnetomotive force separately. Eddy currents in rotor bars are therefore “skin limited” and not “resistance limited.” The results are then validated with linear transient finite-element analysis for both no-load and load cases, taking a topology of squirrel-cage machine already used in the previous references. The time and spatial harmonic content of all electromagnetic quantities is also validated by comparison with analytical expressions. The computation time is a hundred times lower than finite element as it does not require achieving a numerical transient first, and the resolution for a time step is shorter. Thanks to its computational efficiency and intrinsic mesh insensitivity, this method is particularly suited to magnetic forces computation and vibroacoustic analysis of SCIMs.
Auteurs: Emile Devillers;Jean Le Besnerais;Thierry Lubin;Michel Hecquet;Jean-Philippe Lecointe;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 02.-2018, volume: 54, issue:2, pages: 1 - 12
Editeur: IEEE
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» An Improved Adjustable Step Adaptive Neuron-Based Control Approach for the Grid-Supportive SPV System
Résumé:
A grid-supportive two-stage three-phase three-wire solar photovoltaic (SPV) system is presented in this paper, wherein a boost converter is used as a first stage to serve the function of maximum power point tracking and a three-leg voltage source converter is used to feed the extracted SPV energy, along with the supporting distribution system for improvement in the power quality. The harmonics elimination, grid currents balancing, and compensation for nonactive part of the load currents are extra features offered by the proposed system other than conventional features of the solar inverter. The true power reflecting part of the load current is estimated using an improved adjustable step adaptive neuron-based control approach. Moreover, a feed-forward term is added as photovoltaic (PV) array contribution to grid currents, which helps in fast dynamic response due to ambience changes. The output of which is a current component reflected on grid side to instantaneously regulate the dc-link voltage. In the proposed approach, the load, PV array, and loss contributions are kept decoupled. The feasibility of the proposed control algorithm is confirmed via experimental results.
Auteurs: Bhim Singh;Chinmay Jain;Anmol Bansal;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 563 - 570
Editeur: IEEE
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» An Improved Measure of AC System Strength for Performance Analysis of Multi-Infeed HVdc Systems Including VSC and LCC Converters
Résumé:
A small signal model of a multi-infeed high-voltage direct current (HVdc) transmission system containing a line commutated converter (LCC) and a voltage source converter (VSC) is developed. This model represents the LCC and VSC converters as operational impedances as seen from the converter ac busbar. This permits the converters to be included in the effective short-circuit ratio (ESCR) calculations. The resulting ESCR is referred to in this paper as the “Impedance based Effective Short Circuit Ratio” (IESCR). It is shown that the maximum power transfer limit (referred to as the maximum available power or MAP) of the converters is better predicted by this index compared to the conventional ESCR which ignores the operational impedances of the converters. The question also arises as to how close to this theoretical maximum power transfer limit can the HVdc system operate. Using the small-signal model, it is shown that with commonly used control strategies, the predicted MAP can only be achieved by reducing the controller gains. The results are validated using detailed electromagnetic transients simulation of the multi-infeed VSC-LCC system.
Auteurs: Xiaojun Ni;Aniruddha M. Gole;Chengyong Zhao;Chunyi Guo;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 169 - 178
Editeur: IEEE
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» An Improved Optical Fiber Remote Sensing Method Based on Polarized Low-Coherence Interferometry
Résumé:
We proposed an improved phase-based method by using a filtering window on the low-coherence interferogram. Through theoretical derivation and numerical simulation, we prove the correction of our proposed method that the fringe phase can be demodulated nondestructively after applying a symmetrical filtering window nearby the envelope peak, and our method can enhance system SNR. Since fringe overlap phenomenon arising from narrow bandwidth occurs frequently in single-mode sensing system, this method is especially applicable to remote sensing wherein the localization of interference fringe is difficult using traditional phase-based methods. To verify this method, an experiment with a single-mode fiber Fabry-Perot air pressure sensing system was carried out. The experiment results showed that the precision using our method decreased to less than 0.053$%$ in full 280 kPa pressure scale and the sensing distance extended to 20 km, which were apparently superior to traditional phase-based methods.
Auteurs: Kun Liu;Dongdong Ju;Shuang Wang;Junfeng Jiang;Mengnan Xiao;Xue Wang;Tiegen Liu;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 9
Editeur: IEEE
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» An Improved RF MOSFET Model Accounting Substrate Coupling Among Terminals
Résumé:
An RF CMOS model incorporating an improved substrate coupling network is developed. The proposed model focuses on characterizing the nonlinear phase of S12 when a transistor is under zero-bias condition. In addition, a corresponding parameter extraction technique of the model is proposed. To validate this model, a set of transistors fabricated in a commercial 90-nm CMOS process is investigated under multibias conditions. Comparison between measurement and calculation results shows that good agreement has been achieved, which indicates that the proposed model can accurately characterize the performance of transistors up to 66 GHz.
Auteurs: Yunqiu Wu;Qinghe Xu;Chenxi Zhao;Jun Liu;Yiming Yu;Wenyan Yin;Kai Kang;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2018, volume: 28, issue:2, pages: 138 - 140
Editeur: IEEE
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» An In–Laboratory Validity and Reliability Tested System for Quantifying Hand–Arm Tremor in Motions
Résumé:
Despite the advancement of the tremor assessment systems, the current technology still lacks a method that can objectively characterize tremors in relative segmental movements. This paper presents a measurement system, which quantifies multi-degrees-of-freedom coupled relative motions of hand–arm tremor, in terms of joint angular displacement. In-laboratory validity and reliability tests of the system algorithm to provide joint angular displacement was carried out by using the two-degrees-of-freedom tremor simulator with incremental rotary encoder systems installed. The statistical analyses show that the developed system has high validity results and comparable reliability performances using the rotary encoder system as the reference. In the clinical trials, the system was tested on 38 Parkinson’s disease patients. The system readings were correlated with the observational tremor ratings of six trained medical doctors. The moderate to very high clinical correlations of the system readings in measuring rest, postural and task-specific tremors add merits to the degree of readiness of the developed tremor measurement system in a routine clinical setting and/or intervention trial for tremor amelioration.
Auteurs: Ping Yi Chan;Zaidi Mohd Ripin;Sanihah Abdul Halim;John Tharakan;Mustapha Muzaimi;Kwang Sheng Ng;Muhammad Imran Kamarudin;Gaik Bee Eow;Jyh Yung Hor;Kenny Tan;Chun Fai Cheah;Nelson Soong;Linda Then;Ahmad Shukri Yahya;
Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Date publication: 02.-2018, volume: 26, issue:2, pages: 460 - 467
Editeur: IEEE
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» An Information-Theoretic Analysis of the Gaussian Multicast Channel With Interactive User Cooperation
Résumé:
We consider the transmission of a common message from a transmitter to three receivers over a broadcast channel, referred to as a multicast channel in this case. All the receivers are allowed to cooperate with each other over full-duplex non-orthogonal cooperation links. We investigate the information-theoretic upper and lower bounds on the transmission rate. In particular, we propose a three-receiver fully interactive cooperation scheme (3FC) based on superpositions of compress-forward (CF) and decode-forward (DF) at the receivers. In the 3FC scheme, the receivers interactively perform CF simultaneously to initiate the scheme, and then DF sequentially to allow a correlation of each layer of the DF superposition in cooperation with the transmitter toward the next receiver in the chain to improve the achievable rate. The analysis leads to a closed-form expression that allows for numerical evaluation, and also gives some insight on key points to design interactive schemes. The numerical results provided in the Gaussian case show that the proposed scheme outperforms the existing schemes and show the benefits of interaction.
Auteurs: Victor Exposito;Sheng Yang;Nicolas Gresset;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 02.-2018, volume: 17, issue:2, pages: 899 - 913
Editeur: IEEE
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» An Innovative Electro-Optical Chaotic System Using Electrical Mutual Injection With Nonlinear Transmission Function
Résumé:
In the purpose of improving the complexity and the security of chaotic communication system, a novel electro-optical intensity chaotic system using electrical mutual injection with nonlinear transmission function is proposed. The electro-optical intensity chaotic system consisting of two delay feedback branches in a serial configuration extends keys space scale. The dynamic characteristics of the proposed system are investigated by means of the bifurcation diagram, the largest Lyapunov exponents, and the permutation entropy, and the security are also analyzed through the autocorrelation function and the delayed mutual information. The simulation results show that the proposed system can acquire higher complexity and the better security, compared with the recent ones. The scheme allows the system to enter chaos with a low gain and the time-delay concealed effectively due to a nonlinear transmission function. Besides, the communication synchronization on basis of the proposed system is discussed. It comes to a conclusion that the proposed chaotic system has potential applications in secure communications.
Auteurs: Yizhao Huang;Hanping Hu;Feilong Xie;Jun Zheng;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 12
Editeur: IEEE
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» An INS Monitor to Detect GNSS Spoofers Capable of Tracking Vehicle Position
Résumé:
In this paper, we describe and evaluate a new monitor that uses inertial navigation system (INS) measurements to detect spoofing attacks on global navigation satellite system (GNSS) receivers. Spoofing detection is accomplished by monitoring the Kalman filter innovations in a tightly coupled INS/GNSS mechanization. Monitor performance is evaluated against worst case spoofing attacks, including spoofers capable of tracking vehicle position. There are two main contributions of this paper. The first is a mathematical framework to quantify postmonitor spoofing integrity risk. The second is an analytical expression of the worst case sequence of spoofed GNSS signals. We then apply these to an example spoofing attack on a Boeing 747 on final approach. The results show that GNSS spoofing is easily detected, with high integrity, unless the spoofer's position-tracking devices have unrealistic, near-perfect accuracy, and no delays.
Auteurs: Çağatay Tanıl;Samer Khanafseh;Mathieu Joerger;Boris Pervan;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 131 - 143
Editeur: IEEE
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» An Integrated Approach for IC Design R&D Portfolio Decision and Project Scheduling and a Case Study
Résumé:
Research and development (R&D) projects are crucial for semiconductor companies to maintain growth, profitability, and competitiveness. Integrated circuit (IC) design is capital intensive and continuously migrates to new technologies to meet various market demands. Moreover, the scheduling of selected R&D projects that enables technology roadmap involving complicated interrelationships, while competing for similar resources. Focusing on realistic needs, this paper aims to propose an integrated approach for selecting IC design projects for R&D portfolios and scheduling the selected projects simultaneously. In particular, a hybrid autotuning multiobjective genetic algorithm was developed to solve large sized problem instances. An empirical study was conducted at a leading IC design service company in Taiwan to test the validity of the proposed approach. The proposed algorithm was compared with conventional approaches for both convergence and diversity. The results have shown the practical viability of this approach in efficiently and effectively generating near-optimal portfolio alternatives for portfolio selection. The approach also enables the scheduling of the selected projects to achieve R&D portfolio objectives. The developed solution was fully implemented and adopted by the company.
Auteurs: Chen-Fu Chien;Nhat-To Huynh;
Apparue dans: IEEE Transactions on Semiconductor Manufacturing
Date publication: 02.-2018, volume: 31, issue:1, pages: 76 - 86
Editeur: IEEE
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» An Integrated Four-Element Slot-Based MIMO and a UWB Sensing Antenna System for CR Platforms
Résumé:
This communication presents a novel integrated antenna system for cognitive radio (CR) applications. The design consists of a compact four-element reconfigurable annular slot-based multiple-input-multiple-output (MIMO) antenna system integrated within an ultrawideband (UWB) sensing antenna. All the antenna elements are planar in structure and designed on a single substrate (RO-4350) with dimensions $60times 120times 1.5$ mm3. The frequency reconfigurable slot-based MIMO antenna system is tuned over a wide frequency band from 1.77 to 2.51 GHz while the UWB sensing antenna is covering from 0.75 to 7.65 GHz The proposed antenna system is suitable for CR enabled wireless devices. The envelop correlation coefficient did not exceed 0.248 in the entire operating band of the MIMO antenna part. The maximum measured gain of the MIMO antenna is 3.2 dBi with a maximum efficiency of 81%.
Auteurs: Rifaqat Hussain;Mohammad S. Sharawi;Atif Shamim;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 978 - 983
Editeur: IEEE
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» An Integrated Ka-Band Diplexer-Antenna Array Module Based on Gap Waveguide Technology With Simple Mechanical Assembly and No Electrical Contact Requirements
Résumé:
This paper presents the integration of a diplexer with a corporate feed network of a high gain slot array antenna at the Ka-band. A hybrid diplexer-splitter with a novel architecture is proposed to have compatibility for its direct integration with the feed network of the array antenna. A seventh-order hybrid diplexer-splitter is successfully integrated into a corporate feed network of a $16times 16$ slot array antenna. The proposed integrated diplexer-antenna module consists of three distinct metal layers without the need of electrical contacts between the different layers based on the recently introduced gap waveguide technology. The designed module has two channels of 650-MHz bandwidths each with center frequencies 28.21 and 29.21 GHz. The fabricated prototype provides good radiation and input impedance characteristics. The measured input reflection coefficients for both Tx/Rx ports are better than −13 dB with the measured antenna efficiency better than 60% in the designed passband, which includes the losses in the diplexer.
Auteurs: Abbas Vosoogh;Milad Sharifi Sorkherizi;Ashraf Uz Zaman;Jian Yang;Ahmed A. Kishk;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2018, volume: 66, issue:2, pages: 962 - 972
Editeur: IEEE
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» An Integration-Friendly Regrowth-Free Tunable Laser
Résumé:
This letter presents a single-mode tunable laser operating in the $L$ -band. The facetless design, along with a regrowth-free fabrication that does not require high-resolution lithography techniques, contributes to make the laser a suitable candidate for monolithic integration with other components. Tuning is demonstrated over a range of 47 nm, with side-mode suppression ratio values over 30 dB and a linewidth of 800 kHz.
Auteurs: Ludovic Caro;Mohamad Dernaika;Niall P. Kelly;Padraic E. Morrissey;Justin K. Alexander;Frank H. Peters;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 02.-2018, volume: 30, issue:3, pages: 270 - 272
Editeur: IEEE
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» An Inter-Cloud Meta-Scheduling (ICMS) Simulation Framework: Architecture and Evaluation
Résumé:
Inter-cloud is an approach that facilitates scalable resource provisioning across multiple cloud infrastructures. In this paper, we focus on the performance optimization of Infrastructure as a Service (IaaS) using the meta-scheduling paradigm to achieve an improved job scheduling across multiple clouds. We propose a novel inter-cloud job scheduling framework and implement policies to optimize performance of participating clouds. The framework, named as Inter-Cloud Meta-Scheduling (ICMS), is based on a novel message exchange mechanism to allow optimization of job scheduling metrics. The resulting system offers improved flexibility, robustness and decentralization. We implemented a toolkit named “Simulating the Inter-Cloud” (SimIC) to perform the design and implementation of different inter-cloud entities and policies in the ICMS framework. An experimental analysis is produced for job executions in inter-cloud and a performance is presented for a number of parameters such as job execution, makespan, and turnaround times. The results highlight that the overall performance of individual clouds for selected parameters and configuration is improved when these are brought together under the proposed ICMS framework.
Auteurs: Stelios Sotiriadis;Nik Bessis;Ashiq Anjum;Rajkumar Buyya;
Apparue dans: IEEE Transactions on Services Computing
Date publication: 02.-2018, volume: 11, issue:1, pages: 5 - 19
Editeur: IEEE
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» An Interactive Visual Analytics Platform for Smart Intelligent Transportation Systems Management
Résumé:
The reduction of road congestion requires intuitive urban congestion-control platforms that can facilitate transport stakeholders in decision making. Interactive ITS visual analytics tools can be of significant assistance, through their real-time interactive visualizations, supported by advanced data analysis algorithms. In this paper, an interactive visual analytics platform is introduced that allows the exploration of historical data and the prediction of future traffic through a unified interactive interface. The platform is backed by several data analysis techniques, such as road behavioral visualization and clustering, anomaly detection, and traffic prediction, allowing the exploration of behavioral similarities between roads, the visual detection of unusual events, the testing of hypotheses, and the prediction of traffic flow after hypothetical incidents imposed by the human operator. The accuracy of the prediction algorithms is verified through benchmark comparisons, while the applicability of the proposed toolkit in facilitating decision making is demonstrated in a variety of use case scenarios, using real traffic and incident data sets.
Auteurs: Ilias Kalamaras;Alexandros Zamichos;Athanasios Salamanis;Anastasios Drosou;Dionysios D. Kehagias;Georgios Margaritis;Stavros Papadopoulos;Dimitrios Tzovaras;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 02.-2018, volume: 19, issue:2, pages: 487 - 496
Editeur: IEEE
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» An Investigation of Justice, Conflict, and Moderating Effects of Supplier Autonomy and Cultural Distance in Buyer–Supplier Relationships
Résumé:
In this paper, we examine the relationship between justice dimensions (procedural, distributive, and interactional justice) and conflict (task and relationship) in buyer–supplier relationships. We develop a nuanced understanding of how justice dimensions reduce task and relationship conflict in buyer–supplier relationships. In addition, we hypothesize that task conflict mediates the relationship between justice dimensions and relationship conflict. We also hypothesize that the effect of justice dimensions on conflict is contingent on the buyer–supplier cultural distance and the degree of autonomy provided to the supplier. Based on primary data on buyer–supplier relationships, our results show that procedural and interactional justice dimensions are more important than distributive fairness. Furthermore, managers can reduce the relationship conflict by mitigating task conflict, which has not been asserted in the buyer–supplier relationship literature. Our results suggest that supplier autonomy and cultural distance, as contextual variables, influence the relationship between interactional justice and conflict dimensions, but they do not influence the relationship between procedural or distributive justice and conflict dimensions. We discuss the relative importance and role of the three justice dimensions in mitigating relational conflicts in buyer–supplier relationships, and implications of our results to theory as well as practice.
Auteurs: Ravi Srinivasan;Sriram Narayanan;Ram Narasimhan;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 02.-2018, volume: 65, issue:1, pages: 6 - 20
Editeur: IEEE
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» An Isolated Multi-Input ZCS DC–DC Front-End-Converter Based Multilevel Inverter for the Integration of Renewable Energy Sources
Résumé:
A new isolated current-fed zero-current switched (ZCS) front-end dc/dc converter based multilevel inverter is proposed for multi-input applications. The proposed front-end converter with only two controllable switches integrates two different renewable energy sources, resulting in an advantageous compact structure and low conduction losses. The ZCS turn-off is achieved in both the controllable switches with the proposed modulation scheme. The converter maintains ZCS turn-off under a wide load, as well as input voltage variations by employing frequency modulation along with a variable duty ratio technique. Simple structure, soft switching, high gain, and automatic load regulation make the converter structure novel for simultaneous power management in multi-input renewable energy applications. Converter operation and design guidelines have been outlined. A laboratory prototype of the proposed converter is developed and tested at 300-W power level. Simulations and experimental results demonstrate the robust performance of the converter under load, as well as input source voltage variations.
Auteurs: Naresh Kumar Reddi;Manoj R. Ramteke;Hiralal M. Suryawanshi;Koteswararao Kothapalli;Snehal P. Gawande;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 494 - 504
Editeur: IEEE
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» An Isolated Resonant Mode Modular Converter With Flexible Modulation and Variety of Configurations for MVDC Application
Résumé:
The dc tap or dc transformer will play an important role in interfacing different voltages of dc links in dc grids. This paper presents an isolated resonant mode modular converter (RMMC) with flexible modulation and assorted configurations to satisfy a wide variety of interface requirements for medium-voltage dc (MVdc) networks. The transformerless RMMC, as introduced in the literature, implemented a restricted modulation scheme leading to a very limited range of step ratio and the diode rectifier resulted in unidirectional power flow. Both of these limitations are removed in this proposal and galvanic isolation has also been added. Moreover, this new RMMC approach can serve as a building block for variety of configurations. Two such derived topologies are given, which inherently balance the voltage and current between different constituent circuits and realize the high power rating conversion for very low or very high step-ratio application. The theoretical analysis is validated by a set of full-scale simulations and a downscaled experimental prototype. The results illustrate that this isolated RMMC and its derivatives have promising features for dc taps or dc transformers in MVdc applications.
Auteurs: Xin Xiang;Xiaotian Zhang;Geraint P. Chaffey;Timothy C. Green;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 508 - 519
Editeur: IEEE
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» An Iterative Method for Detecting and Localizing Islands Within Sparse Matrixes Using DSSim-RT
Résumé:
Nowadays, the simulation tools used to perform power system analysis are evolving into the many-core computation era; some of these techniques propose to tear the power system network into several subnetworks (islands) for its parallel processing. The island's detection is an issue considered by the power flow analysis due to management activities such as feeder reconfiguration, fault detection, and isolation, among others, that generate topological changes. These methods include graph theory, checking the circuit breaker status and on-site measurements, decision trees, frequency deviation, and pattern recognition, among other techniques, which are focused to detect topology changes that may generate islands and affect the state estimation of the system. In contrast, other techniques such as the approximate minimum degree perform a reorganization of the $Y_{{text{BUS}}}$ matrix that describes the network components and their connectivity, looking to factorizing the $Y_{{text{Bus}}}$ matrix to solve the power flow problem. These techniques are very functional and efficient; however, some of them require detailed information of the network, and are addressed to cover meshed and radial network configurations separately. This paper presents an iterative algorithm that uses the compressed coordinate branch-to-node matrix for detecting, classifying, and grouping islands within sparse matrixes, describing mesh or radial networks. This algorithm is a valuable tool to simplify islands location and can be implemented using any programing language due to its simplicity. This method is used in Distribution System Simulator - Real Time Version (DSSim-RT), which is a simulator based in OpenDSS, for tearing the power system network to allow the multithread power flow analysis of distribution sys- ems in real time.
Auteurs: Davis Montenegro;Gustavo A. Ramos;Seddik Bacha;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 675 - 684
Editeur: IEEE
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» An L-Shaped Array With Nonorthogonal Axes—Its Cramér–Rao Bound for Direction Finding
Résumé:
If a nominally L-shaped sensor-array's two legs are not exactly perpendicular, its azimuth-polar direction-of-arrival estimation would be degraded. This paper quantifies this degradation via a deterministic Cramér–Rao bound analysis of the direction-finding error variance.
Auteurs: Dominic Makaa Kitavi;Kainam Thomas Wong;Chun-Chiu Hung;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 486 - 492
Editeur: IEEE
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» An On-Chip Learning Neuromorphic Autoencoder With Current-Mode Transposable Memory Read and Virtual Lookup Table
Résumé:
This paper presents an IC implementation of on-chip learning neuromorphic autoencoder unit in a form of rate-based spiking neural network. With a current-mode signaling scheme embedded in a 500 × 500 6b SRAM-based memory, the proposed architecture achieves simultaneous processing of multiplications and accumulations. In addition, a transposable memory read for both forward and backward propagations and a virtual lookup table are also proposed to perform an unsupervised learning of restricted Boltzmann machine. The IC is fabricated using 28-nm CMOS process and is verified in a three-layer network of encoder–decoder pair for training and recovery of images with two-dimensional ${text{16}}times {text{16}}$ pixels. With a dataset of 50 digits, the IC shows a normalized root mean square error of 0.078. Measured energy efficiencies are 4.46 pJ per synaptic operation for inference and 19.26 pJ per synaptic weight update for learning, respectively. The learning performance is also estimated by simulations if the proposed hardware architecture is extended to apply to a batch training of 60 000 MNIST datasets.
Auteurs: Hwasuk Cho;Hyunwoo Son;Kihwan Seong;Byungsub Kim;Hong-June Park;Jae-Yoon Sim;
Apparue dans: IEEE Transactions on Biomedical Circuits and Systems
Date publication: 02.-2018, volume: 12, issue:1, pages: 161 - 170
Editeur: IEEE
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» An On-Line Fourier Transform Infrared Spectrometer Used for Biological Process Measurement
Résumé:
In order to real-time online monitoring the reaction substrates for biological processes, we designed an on-line Fourier transform infrared spectrometer measurement system, which has the advantages of low cost, simple and compact structure, good reliability, and strong shock resistance compared with the traditional Fourier transform infrared spectrometer. This system consists of two core components, i.e., a high-performance interferometer and an attenuated total reflectance (ATR) probe. In the interferometer, we 1) combined corner cube mirrors and flat mirrors to avoid tilting of the moving mirror; 2) set 60° incident angle to the ZnSe beam splitter to improve the luminous flux; 3) shared folded optical path with both the infrared light and the reference laser to improve compactness in structure; and 4) drive the moving mirror by a parallelogram swing flexible support module to make it move smoothly. In the ATR probe, we utilized two large diameter and inner coating light pipes to transmit the incident and outgoing light to enhance the luminous flux further. We also simulated the optical system and did some off-line and online measurement experiments. The results show the spectrometer has satisfactory reliability, large luminous flux, and online measurement capability. It can be real-time online monitoring the biological process through measuring the concentration of the related bioreactor reactant. The online analysis has wide application prospects in biological, chemical testing, material analysis, and many other fields.
Auteurs: Sha Huang;Bangsheng Yin;Libo Zeng;Qiongshui Wu;
Apparue dans: IEEE Sensors Journal
Date publication: 02.-2018, volume: 18, issue:4, pages: 1723 - 1730
Editeur: IEEE
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» An Optimal Design Methodology for Yield-Improved and Low-Power Pipelined ADC
Résumé:
An energy-efficient, high-performance, and yield-improved analog to digital converter (ADC) design using a multi-objective evolutionary algorithm is demonstrated. The proposed ADC design algorithm incorporates several techniques to enable simultaneous improvement of yield and performance. With the same accuracy, the proposed approach can achieve a significant reduction of computational burden compared with the modified Monte-Carlo (MC)-based yield improvement methods integrating Latin-hypercube sampling or trimmed-sample MC. A prototype chip based on the proposed design is fabricated in a 0.13- $boldsymbol {mu }text{m}$ CMOS process at 150 MS/s. The results show the ADC achieves an SFDR of 65.48 dB and SNDR of 58.15 dB while dissipating 12 mW from a 1-V power supply. The results also yield a figure of merit of 121 fJ/conversion step.
Auteurs: Nahid Mirzaie;Gyung-Su Byun;
Apparue dans: IEEE Transactions on Semiconductor Manufacturing
Date publication: 02.-2018, volume: 31, issue:1, pages: 130 - 135
Editeur: IEEE
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» An Optimization Model for Electric Vehicle Battery Charging at a Battery Swapping Station
Résumé:
A new model for a viable battery swapping station is proposed to minimize its cost by determining the optimized charging schedule for swapped electric vehicle (EV) batteries. The aim is to minimize an objective function considering three factors: the number of batteries taken from stock to serve all the swapping orders from incoming EVs, potential charging damage with the use of high-rate chargers, and electricity cost for different time period of the day. A mathematical model is formulated for the charging process following the constant-current/constant-voltage charging strategy. An integrated algorithm is proposed to determine an optimal charging schedule, which is inspired by genetic algorithm, differential evolution, and particle swarm optimization. A series of simulation studies are executed to assess the feasibility of the proposed model and compare the performance between the proposed algorithm and the typical evolutionary algorithms.
Auteurs: Hao Wu;Grantham Kwok Hung Pang;King Lun Choy;Hoi Yan Lam;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 02.-2018, volume: 67, issue:2, pages: 881 - 895
Editeur: IEEE
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» An Optimized Drude's Equation For Polarization Measurement in the Visible Region and Concentrations Estimation
Résumé:
Drude's equation, a classical equation, can be used to express the properties of optic polarization. In the paper, an optimized two-term Drude's equation is introduced for expressing the specific rotation. The optical rotation angle for each wavelength is measured by a charge-coupled device. In order to verify the precision and versatility of the equation, we compare the obtained specific rotation with published analysis at a wavelength of 589.3 nm. Moreover, the two-term Drude's equation is translated into calculate the approximatively individual concentration of the molecules in aqueous solution. The calculation is based on the linear functional relation and fitting parameters of total rotation without knowing the ranges of concentrations and setting constraints. The viability and flexibility of this method demonstrate the potential applications in optics.
Auteurs: Yu Lei;Hongzhi Jia;Xun Xu;Shixin Jiang;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 9
Editeur: IEEE
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» An Ultra-Wide-Band Tightly Coupled Dipole Reflectarray Antenna
Résumé:
A novel ultra-wide-band tightly coupled dipole reflectarray (TCDR) antenna is presented in this paper. This reflectarray antenna consists of a wideband feed and a wideband reflecting surface. The feed is a log-periodic dipole array antenna. The reflecting surface consists of $26 times 11$ unit cells. Each cell is composed of a tightly coupled dipole and a delay line. The minimum distance between adjacent cells is 8 mm, which is about 1/10 wavelength at the lowest operating frequency. By combining the advantages of reflectarray antennas and those of tightly coupled array antennas, the proposed TCDR antenna achieves ultra-wide bandwidth with reduced complexity and fabrication cost. A method to minimize the phase errors of the wideband reflectarray is also developed and the concept of equivalent distance delay is introduced to design the unit cell elements. To verify the design concept, a prototype operating from 3.4 to 10.6 GHz is simulated and fabricated. Good agreement between simulated and measured results is observed. Within the designed frequency band, the radiation pattern of the TCDR antenna is stable and the main beam of the antenna is not distorted or split. The side lobe levels of the radiation patterns are below −11.7 dB in the entire operating band. It is the first time a tightly coupled reflectarray is reported.
Auteurs: Wenting Li;Steven Gao;Long Zhang;Qi Luo;Yuanming Cai;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 533 - 540
Editeur: IEEE
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» Analog Frontend for Tribo-Current-Based Fly-Height Sensor for Magnetic Hard Disk Drive
Résumé:
This paper presents an analog front end for measuring the triboelectric current flow between the triboelectric current sensor attached to the magnetic recording head and the media in a hard-disk-drive (HDD) system. The magnitude of the triboelectric current serves as a measure of the proximity between the head and the media and can be optimized for better performance in the next generation HDDs. The analog front end employs a novel current-divert circuit to create two separate signal paths with high and low gain that together provide a linear measure of the triboelectric current over a large dynamic range. A 42.6- $text{M}Omega $ dc-coupled, low leakage transimpedance amplifier is designed for the high gain path. It employs an area-efficient, floating, gate-voltage controlled MOS resistor with a novel open-loop temperature compensation scheme. A gain variation of <10% and an input current offset drift of < ±35 pA are measured over a temperature range of −40 °C to 120 °C. With the help of the low gain path, an overall input dynamic range of tens of picoamps to 50 nA is achieved. The high accuracy and large dynamic range measurement of tribocurrent serves the dual purpose of accurate fly-height estimation and tracking of the topography of the hard-disk media.
Auteurs: Arup Polley;Pankaj Pandey;Bryan E. Bloodworth;Costin Cazana;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2018, volume: 65, issue:2, pages: 556 - 566
Editeur: IEEE
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» Analog Models Manipulation for Effective Integration in Smart System Virtual Platforms
Résumé:
Analog components are fundamental blocks of smart systems, as they allow a tight interaction with the environment, in terms of both sensing/actuation and communication. This impacts on the design of the overall system, and mainly on the validation phase, that thus requires the joint simulation of digital and analog aspects. In this scenario, this paper proposes the automatic conversion of analog models to C++-based languages, to remove the overhead of co-simulation with traditional virtual platform tools. The proposed methodology allows to convert a given analog description to either: 1) a fully equivalent description or 2) an abstract representation for faster simulation which models only the aspects of interest. Effectiveness and correctness have been proved on a number of case studies that highlight the effectiveness and potentiality of the proposed methodology.
Auteurs: Michele Lora;Sara Vinco;Enrico Fraccaroli;Davide Quaglia;Franco Fummi;
Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Date publication: 02.-2018, volume: 37, issue:2, pages: 378 - 391
Editeur: IEEE
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» Analysis and Background Self-Calibration of Comparator Offset in Loop-Unrolled SAR ADCs
Résumé:
In conventional charge redistribution successive approximation register (SAR) ADCs that use a single comparator, the comparator offset causes no distortion but a dc shift in the transfer curve. In loop-unrolled (LU) SAR ADCs, on the other hand, mismatched comparator offset voltages introduce input-level-dependent errors to the conversion result, which deteriorates the linearity and limits the resolution. Still, the literature lacks a quantitative analysis on this phenomenon, and the resolution of most reported SAR ADCs of this kind, until recently, has been limited to 6 bit. In this paper, we analyze the effects of comparator offset voltage mismatch in LU-SAR ADCs, and establish the quantitative relation between individual offsets and the signal-to-noise-and-distortion ratio (SNDR) and the effective-number-of-bits. A statistical linearity model is proposed for yield estimation. Finally, an on-line deterministic calibration technique for auto-zeroing dynamic comparator offset is presented to treat the offsets mismatch and improve linearity. A 150-MS/s 8-bit LU-SAR ADC is fabricated in a 130-nm CMOS technology to validate the concept. The measured result shows that the calibration improves the SNDR from 33.7 to 42.9 dB. The ADC consumes $640~mu text{W}$ from a 1.2-V supply with a figure-of-merit of 37.5 fJ/conv-step.
Auteurs: Shaolong Liu;Taimur Rabuske;Jeyanandh Paramesh;Lawrence Pileggi;Jorge Fernandes;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2018, volume: 65, issue:2, pages: 458 - 470
Editeur: IEEE
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» Analysis and Behavioral Modeling of Monolithic Digital Potentiometers
Résumé:
This paper focuses on analysis and modeling of complementary metal-oxide semiconductor (CMOS) resistive digital-to-analog converter (RDAC) potentiometers based on string digital-to-analog converter or Kelvin divider architecture. The model is developed by using very-high hardware description language (VHDL) analog and mixed-signal language, and accurately simulates basic static and dynamic parameters, integral nonlinearity, terminal voltage operating range, and leakage current at various operational modes for linear and nonlinear changing of the middle point (wiper). The model is implemented in the SystemVision simulation platform, using a style combining structural and behavioral elements. For verification of the model parameters are extracted for single-stage AD5235 and triple-stage AD5143 RDACs from analog devices as examples. The workability of the proposed models is validated by simulation and experimental testing of sample digitally controlled analog circuits. The comparative analysis shows that the achieved relative error, between the simulation and the experimental results at the maximum value of the nominal resistance equal to ${25,rm{k}Omega }$ , is less than 5%. Moreover, an error of 5% is quite acceptable, considering the technological tolerances of the parameters.
Auteurs: Ivailo M. Pandiev;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 416 - 425
Editeur: IEEE
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» Analysis and Design of a Broadband Multifeed Tightly Coupled Patch Array Antenna
Résumé:
In this letter, a multifeed tightly coupled patch array antenna capable of broadband operation is analyzed and designed. First, an antenna array composed of infinite elements with each element excited by a feed is proposed. To produce specific polarized radiation efficiently, a new patch element is proposed, and its characteristics are studied based on a 2-port network model. Full-wave simulation results show that the infinite antenna array exhibits both a high efficiency and desirable radiation pattern in a wide frequency band (10 dB bandwidth) from 1.91 to 5.35 GHz (94.8%). Second, to validate its outstanding performance, a realistic finite 4 × 4 antenna prototype is designed, fabricated, and measured in our laboratory. The experimental results agree well with simulated ones, where the frequency bandwidth (VSWR < 2) is from 2.5 to 3.8 GHz (41.3%). The inherent compact size, light weight, broad bandwidth, and good radiation characteristics make this array antenna a promising candidate for future communication and advanced sensing systems.
Auteurs: Xi Yang;Pei-Yuan Qin;Yao Liu;Ying-Zeng Yin;Yingjie Jay Guo;
Apparue dans: IEEE Antennas and Wireless Propagation Letters
Date publication: 02.-2018, volume: 17, issue:2, pages: 217 - 220
Editeur: IEEE
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» Analysis and Design of a Passive Receiver Front-End Using an Inductive Antenna Impedance
Résumé:
This paper presents the analysis and design of a passive front-end (PFE) for low-power receivers. The freedom of the antenna impedance is observed and exploited to propose an inductive-antenna-based PFE. Analytical methods for the desired signal transfer and noise behavior of the proposed PFE are presented to offer insight into the proposed technique and facilitate the design. The analysis suggests that the inductive-antenna-based PFE offers higher voltage gain and lower noise figure than a standard $50~Omega $ -based PFE does, which is confirmed by simulations. The proposed PFE and a baseband bandpass amplifier are designed in 0.18- $mu text{m}$ CMOS technology for the 402–405 MHz band of the IEEE 802.15.6 WBAN standard. Their combination exhibits a passive voltage gain of 11.6 dB, a NF of 14.7 dB, and an in-band IIP3 of 3.6 dBm, while dissipating 1.1 mW from a 1.2 V supply.
Auteurs: Yao Liu;Wouter A. Serdijn;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2018, volume: 65, issue:2, pages: 733 - 744
Editeur: IEEE
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» Analysis and Design of Broadband LC-Ladder FET LNAs Using Noise Match Network
Résumé:
A noise match network for the LC-ladder input network of a broadband inductively source-degenerated common-source (CS) field effect transistor (FET) low-noise amplifier (LNA) is established through noise transformation matrix to derive the noise parameters of a broadband LNA. Analytical formulas for the noise factors of a CS FET LNA with a three-section LC-ladder input network are thus obtained based on the design algorithm of optimal noise and input match developed in this paper. Two 3.7–10.5 GHz two-stage LNAs of the same topology are demonstrated using 0.15- $mu text{m}$ pHEMT technology to validate the design methodology. One LNA has all the fully integrated inductors and the other uses two on-chip inductors replaced by two high-Q bondwire inductors for better noise performance. The measurement results show 11-dB power gain with 2.1-dB noise figure for the LNA with the fully integrated inductors and 11-dB power gain with 1.6-dB noise figure for the LNA with two bondwire inductors, respectively.
Auteurs: Yu-Chih Hsiao;Chinchun Meng;Meng-Che Li;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2018, volume: 66, issue:2, pages: 987 - 1001
Editeur: IEEE
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» Analysis and Design of Functionally Weighted Single-Input-Rule-Modules Connected Fuzzy Inference Systems
Résumé:
The single-input-rule-modules (SIRMs) connected fuzzy inference method can efficiently solve the fuzzy rule explosion phenomenon, which usually occurs in the multivariable modeling and/or control applications. However, the performance of the SIRMs connected fuzzy inference system (SIRM-FIS) is limited due to its simple input–output mapping. In this paper, to further enhance the performance of SIRM-FIS, a functionally weighted SIRM-FIS (FWSIRM-FIS), which adopts multivariable functional weights to measure the important degrees of the SIRMs, is presented. Then, in order to show the fundamental differences of the SIRMs methods, properties of the traditional SIRM-FIS, the type-2 SIRM-FIS (T2SIRM-FIS), the functional SIRM-FIS (FSIRM-FIS), the SIRMs model with single-variable functional weights (SIRM-FW), and FWSIRM-FIS are explored. These properties demonstrate that the proposed FWSIRM-FIS has more general and complex input–output mapping than the existing SIRMs methods. Such properties theoretically guarantee that better performance can be achieved by FWSIRM-FIS. Furthermore, based on the least-squares method, a novel data-driven optimization method is presented for the parameter learning of FWSIRM-FIS. It can also be used to optimize the parameters of SIRM-FIS, T2SIRM-FIS, FSIRM-FIS, and SIRM-FW. Due to the properties of the least-squares method, the proposed parameter learning algorithm can overcome the drawbacks of the gradients-based parameter learning methods and obtain both smallest training errors and smallest parameters. Finally, to show the effectiveness and superiority of FWSIRM-FIS and the proposed optimization method, six examples and detailed comparisons are given. Simulation results show that FWSIRM-FIS can obtain better performance than the other SIRMs methods, and, compared with some well-known methods, FWSIRM-FIS can achieve similar or better performance but has much less parameters and faster training speed.
Auteurs: Chengdong Li;Junlong Gao;Jianqiang Yi;Guiqing Zhang;
Apparue dans: IEEE Transactions on Fuzzy Systems
Date publication: 02.-2018, volume: 26, issue:1, pages: 56 - 71
Editeur: IEEE
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» Analysis and Design of Triple-Rotor Axial-Flux Spoke-Array Vernier Permanent Magnet Machines
Résumé:
This paper focuses on the analysis and design of a triple-rotor axial-flux spoke-array vernier permanent magnet (TR-AFSAVPM) machine. By cooperating with spoke-array rotor and coil-wounded winding, power factor and torque density of the proposed machine are much improved and its copper utilization is reduced comparing with conventional vernier machines. First, the machine structure and its operation principles are reviewed. After that, analytical equations of its back-electromotive force and torque are derived to reveal the machine characteristics. Based on both quasi-3-D finite element analysis (FEA) and 3-D FEA, its high torque density performance is verified and a set of optimized machine sizing specifications is ultimately settled. A fractional slot axial-flux permanent magnet (VPM) machine and an axial-flux surface VPM machine are designed to compare with the proposed configuration. Analysis results show that the TR-AFSAVPM machine has high power factor viz., 0.96 and high torque density viz., 24.2 kNm/m3. A prototype has been designed and tested to validate the results. No-load test result is illustrated in this paper and the rated load experiment will be added in the future.
Auteurs: Rui Zhang;Jian Li;Ronghai Qu;Dawei Li;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 244 - 253
Editeur: IEEE
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» Analysis and Design of Zero-Current Switching Switched-Capacitor Cell Balancing Circuit for Series-Connected Battery/Supercapacitor
Résumé:
To overcome the problem that the balancing performance of existing switched-capacitor (SC) cell balancing systems drops along with the increase in the number of series-connected battery cells, a novel SC cell balancing circuit is presented in this paper. The same as other SC balancing systems, only a pair of complementary square-wave signals is required to control the proposed circuit. With resonant SC design, all switches employed in the proposed balancing circuit operate under zero-current switching. The equivalent model is derived to reveal the balancing performance of the proposed balancing circuit. The system feasibility and theoretical analysis are verified by both of simulation and experimental results.
Auteurs: Yuanmao Ye;Ka Wai Eric Cheng;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 02.-2018, volume: 67, issue:2, pages: 948 - 955
Editeur: IEEE
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» Analysis and Implementation of Closed-Loop Control of Electrolytic Capacitor-Less Six-Pulse DC-Link Bidirectional Three-Phase Grid-Tied Inverter
Résumé:
Cascaded bidirectional dc–ac converters are commonly used in uninterruptible power supply applications and battery chargers for electric vehicles. Power conversion units for such applications employ a large electrolytic capacitor at high-voltage dc bus, which not only reduces the lifetime but also adds to the weight of the converter. In this paper, a novel bidirectional dual active bridge cascaded three-phase converter (DABCC) with six-pulse dc link is proposed. Also, a new closed-loop control scheme to implement the six-pulse modulation (SPM) technique in DABCC is proposed. The advantages of the proposed control scheme in DABCC are that the electrolytic capacitor is eliminated and is replaced with a low-value film capacitor resulting in increased reliability, compactness, and reduced cost. SPM technique also increases the dc bus utilization and decreases the inverter average switching frequency to 33% when compared with the conventional sine pulse-width modulation (SPWM). Harmonic components introduced in the pole voltages of the SPM-modulated DABCC due to inverter dead time are analyzed, and a resonant controller is designed to mitigate them. Also, root mean square current stress for high-voltage dc-link capacitor is studied, and it is shown that the capacitor requirement for SPM modulation is lower than the conventional SPWM. To validate the proposed control scheme, an 800-W proof-of-concept laboratory hardware prototype is fabricated and experimental results are demonstrated.
Auteurs: V. K. Kanakesh;Dorai Babu Yelaverthi;Anirban Ghoshal;Akshay Kumar Rathore;Ranjit Mahanty;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 539 - 550
Editeur: IEEE
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» Analysis and Modeling of Thermal-Electric Coupling Effect of High-Power Monolithically Integrated Light-Emitting Diode
Résumé:
A 2-D thermal-electric coupling model has been developed, which enables us to evaluate the current distribution of monolithically integrated light-emitting diode (MI-LED). Based on the experimental IR images, the current distributions have been evaluated for the MI-LEDs on two types’ heat sinks. For the MI-LED on poor thermal conductive chip-on-board heat sink, although there is a large junction temperature variation of 40 °C all over the chip, the current only varies from −16% to 11% due to the high parasitic series resistance and the topological design of MI-LED. The experiments show that the impact of the heat-crowding-induced uneven current distribution on the wall-plug efficiency is negligible at a power density of 1 W/mm2. The average junction temperature is still the dominant issue. With a high thermal conductive copper heat sink, the average junction temperature could be suppressed below 50 °C, and there is no obvious heat crowding and uneven current distribution observed.
Auteurs: Yibin Zhang;Mingdi Ding;Desheng Zhao;Hongjuan Huang;Longjie Huang;Yunzhen Lin;Difei Bian;Baoshun Zhang;Yong Cai;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2018, volume: 65, issue:2, pages: 564 - 571
Editeur: IEEE
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» Analysis of a Silicon Dual-Coupled-Ring Resonator Modulator Based on Push–Pull Coupling Tunings
Résumé:
We present a silicon dual-coupled-ring resonator modulator with push–pull coupling tunings. The basic idea of this scheme is to construct a dual-coupled-ring resonator structure in which the coupling coefficients of all coupling regions are tunable through Mach–Zehnder interferometers operated in push–pull modes. Two coupling coefficients are tuned jointly for optical bandwidth shaping and tuning while another coupling coefficient is tuned for high speed and chirp-free modulation. The fundamental analytical expressions for the intensity transmittance, the critical and the resonance conditions of the proposed dual-coupled-ring resonator modulator are derived. In addition, the performance simulations and optimization are presented and compared with those of the single-ring resonator modulator. The proposed dual-coupled-ring resonator modulator is more likely to achieve wide optical bandwidth tuning range and narrow channel spacing simultaneously, which are suitable for future optical processing and interconnects.
Auteurs: Zhen Zhou;Li Shuang Feng;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 12
Editeur: IEEE
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» Analysis of Cross-Borehole Pulse Radar Signatures on a Terminated Tunnel With Various Penetration Lengths
Résumé:
A cross-borehole pulse radar system was operated to detect an intrusive man-made tunnel terminated just 1.2 m away from the line of sight between a newly drilled borehole pair at a tunnel test site. Unlike conventional radar signatures on a fully penetrated air-filled tunnel, the relatively fast arrival in the measured time-of-arrival (TOA) profile was highly suppressed at the depth of the terminated tunnel. To analyze the TOA contraction at a terminated tunnel without drilling additional borehole pairs, a finite-difference time-domain (FDTD) simulator is implemented using the accurately measured location information on the terminated tunnel and borehole pair. The relation curves between the time advance in the TOA profile and the penetration length of the terminated tunnel are plotted in the high and low limits of electrical properties of background rock. To verify the accuracy of our FDTD simulated results, the wideband complex permittivity profiles of the core rock samples’ boring at the tunnel test site are measured using an open-ended coaxial probe method. The calculated time advances agree well with the measured values in both cases of fully penetrated and closely terminated borehole pairs in the test site. The presented time advance curves for various penetration lengths will be a valuable guideline on detection of a terminated tunnel in site.
Auteurs: Jae-Hyoung Cho;Ji-Hyun Jung;Se-Yun Kim;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2018, volume: 56, issue:2, pages: 799 - 807
Editeur: IEEE
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» Analysis of Data Acquisition Time on Soil Moisture Retrieval From Multiangle L-Band Observations
Résumé:
This paper investigated the sensitivity of passive microwave L-band soil moisture (SM) retrieval from multiangle airborne brightness temperature data obtained under morning and afternoon conditions from the National Airborne Field Experiment conducted in southeast Australia in 2006. Ground measurements at a dryland focus farm including soil texture, soil temperature, and vegetation water content were used as ancillary data to drive the retrieval model. The derived SM was then in turn evaluated with the ground-measured near-surface SM patterns. The results of this paper show that the Soil Moisture and Ocean Salinity target accuracy of 0.04 $text{m}^{3}cdot text{m}^{-3}$ for single-SM retrievals is achievable irrespective of the 6 A.M. and 6 P.M. overpass acquisition times for moisture conditions $le 0.15~text{m}^{3}cdot text{m}^{-3}$ . Additional tests on the use of the air temperature as proxy for the vegetation temperature also showed no preference for the acquisition time. The performance of multiparameter retrievals of SM and an additional parameter proved to be satisfactory for SM modeling—independent of the acquisition time—with root-mean-square errors less than 0.06 $text{m}^{3}cdot text{m}^{-3}$ for the focus farm.
Auteurs: Sandy Peischl;Jeffrey P. Walker;Dongryeol Ryu;Yann H. Kerr;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2018, volume: 56, issue:2, pages: 966 - 971
Editeur: IEEE
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» Analysis of DFT-Based Channel Estimation for Uplink Massive MIMO Systems
Résumé:
To reduce the edge effect in discrete Fourier transform-based channel estimation, various schemes have been proposed to estimate the channel response at the non-allocated subcarriers. However, it is not easy to estimate the channel response accurately at the non-allocated subcarriers, particularly at low signal-to-noise ratio (SNR). Moreover, the estimation places an additional computational burden on the receiver. The analysis in this letter shows that the edge effect is not serious in uplink massive multiple-input multiple-output systems. Zero padding at the non-allocated subcarriers is asymptotically optimal in the low SNR regime. We can also use fast Fourier transform/inverse fast Fourier transform pruning to reduce the computational complexity dramatically.
Auteurs: Hao Wu;Yuan Liu;Kai Wang;
Apparue dans: IEEE Communications Letters
Date publication: 02.-2018, volume: 22, issue:2, pages: 328 - 331
Editeur: IEEE
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» Analysis of Electrothermal and Impact-Ionization Effects in Bipolar Cascode Amplifiers
Résumé:
This paper is aimed at the analysis of the influence of electrothermal and impact-ionization effects on the dc behavior of bipolar cascode amplifiers. A simple physics-based relationship is derived to predict the limit of the safe operating area in the output diagram. Experiments and circuit simulations are performed on amplifiers in GaAs and SiGe technologies to examine and explain the distortion in the dc ${I}$ ${V}$ curves induced by these positive-feedback mechanisms, as well as to predict the temperatures of the individual devices.
Auteurs: Vincenzo d’Alessandro;Rosario D’Esposito;Andre G. Metzger;Kai H. Kwok;Klaus Aufinger;Thomas Zimmer;Niccolò Rinaldi;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2018, volume: 65, issue:2, pages: 431 - 439
Editeur: IEEE
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» Analysis of Energy Savings of CVR Including Refrigeration Loads in Distribution Systems
Résumé:
Conservation voltage reduction (CVR) plays an important role in energy savings and shaving peak demand. This paper quantifies energy savings for refrigeration loads (RLs) with experimentally validated air conditioner and refrigerator models. It is demonstrated that peak demand reduction and energy savings exist simultaneously during the implementation of CVR. A 1666-bus real meshed network with residential, small, and large commercial customers is simulated for the calculation of energy savings. Different working patterns: weekday and weekend; weather conditions: hottest and average summer days during peak load of the year; and load types: mixed load (ZIP and RLs) and ZIP load are studied. In addition, the IEEE 8500-node radial system with 100% residential customers is also used to show the energy savings of CVR. It is concluded that the economic benefits of CVR are larger for meshed networks than for radial systems. It is also shown experimentally and by simulation that CVR produces significant savings for both utilities and customers.
Auteurs: Jun Wang;Ashhar Raza;Tianqi Hong;Adriana Cisco Sullberg;Francisco de León;Qi Huang;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 158 - 168
Editeur: IEEE
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» Analysis of Faults in Multiterminal HVDC Grid for Definition of Test Requirements of HVDC Circuit Breakers
Résumé:
This paper provides a detailed analysis of the temporal development of fault currents in a multiterminal high-voltage direct-current (MT-HVDC) grid composed of a bipolar converter configuration. The sequence of events following the occurrence of a pole-to-ground fault is identified, divided into three distinct periods; namely, submodule capacitor discharge, arm current decay, and ac in-feed periods. The critical parameters that have a significant impact on the fault current in each period are discussed. The impacts of various parameters of the HVDC grid such as the size of the current limiting reactor, ac grid strength, as well as the location of the fault within the grid are studied through PSCAD/EMTDC simulation. Then, a fault current interruption process using models of various HVDC circuit breaker technologies and the resulting stresses are studied. Both serve as important inputs to define test procedures. It is found that the HVDC circuit breakers are subjected to not only dc current and voltage stresses but also energy stress. These stresses are translated into test requirements.
Auteurs: Nadew Adisu Belda;Cornelis Arie Plet;Rene Peter Paul Smeets;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 403 - 411
Editeur: IEEE
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» Analysis of Hexadecane Decomposition by Atmospheric Microplasma
Résumé:
Atmospheric microplasma has the potential to be one of the technologies used to purify indoor air. For example, plasma is used for pollutant decomposition or sterilization. In this study, we examined the removal of hexadecane by using microplasma. Hexadecane is contained in diesel oil and it is discharged to the air as exhaust gas. A decrease in the concentration of hexadecane from 3000 to 105 ppm was observed after 120 min of plasma processing. The removal energy efficiency of hexadecane was evaluated to 19.8 μg/W·h. Several by-products were obtained with the plasma process and were analyzed by detector tubes, Fourier transform infrared spectroscopy, and gas chromatograph–mass spectrometer. According to the analysis of the products, hexadecane was decomposed to alkane or alkene, which contains less carbon number 16, and finally, it was decomposed to CO. It became apparent that plasma can cut carbon bonds.
Auteurs: Kazuo Shimizu;Saho Muramatsu;Jaroslav Kristof;Marius Blajan;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 605 - 610
Editeur: IEEE
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» Analysis of Power System Oscillations From PMU Data Using an EPLL-Based Approach
Résumé:
Recently, the application of the adaptive notch filter (ANF) concept to the analysis of damped oscillations and the estimation of frequency and damping factor of such oscillations was introduced. This paper presents the application of the enhanced phase-locked loop (EPLL) to the same problem. A modified version of the EPLL is developed that includes the estimation of damping factor in addition to the already estimated variables of amplitude, phase angle, and frequency. The structure, mathematical formulation, and theoretical stability analysis of the proposed method, including guidelines for its parameter tuning, are presented. Simulation results verify the analytical derivations and the desirable performance of the proposed method. This paper concludes that the EPLL-based approach can address the problem as efficient as the ANF approach while offering more robust and accurate results at low sampling rate applications.
Auteurs: Hossein Zamani;Masoud Karimi-Ghartemani;Mohsen Mojiri;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 02.-2018, volume: 67, issue:2, pages: 307 - 316
Editeur: IEEE
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» Analysis of Ranging Precision in an FMCW Radar Measurement Using a Phase-Locked Loop
Résumé:
The standard deviation in a frequency modulated continuous wave radar distance measurement using a charge pump phase-locked loop (PLL) is calculated analytically. The phase noise of the PLL is modeled as an Ornstein–Uhlenbeck process resulting in a Lorentzian spectrum. We calculate the distance error as a function of the receiver noise bandwidth and the target distance. Depending on the frequency estimation algorithm and the target distance, the rms distance error due to PLL phase noise increases by about 6–9 dB with doubling the target distance. By contrast, the white noise in the radar receiver raises the distance error by about 12 dB in the far field with distance doubling, making this error contribution dominant for large target distances. These findings are verified by measurements on a scalable 61/122-GHz radar sensor platform.
Auteurs: Frank Herzel;Dietmar Kissinger;Herman Jalli Ng;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2018, volume: 65, issue:2, pages: 783 - 792
Editeur: IEEE
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» Analysis of Short-Circuit Current Characteristics and Its Distribution of Artificial Grounding Faults on DC Transmission Lines
Résumé:
Grounding faults are common faults on dc transmission lines. Characteristics of the short-circuit current, such as amplitude and frequency, and its following distribution are very important for analyzing the influence of the fault. Based on the ±500 kV Yongfu dc transmission project in China, several artificial grounding short-circuit tests at the terminal or middle of the dc transmission line were carried out. This paper reports the measurement and analysis of the short-circuit current and its distribution in a dc system for the first time. The short-circuit current distribution includes currents in the ground wires of the fault tower and currents in ground wires, which are connected to the converter station grounding grid, such as the optical ground wire (OPGW) currents of ac outgoing lines, neutral point currents of different transformers, and the grounding electrode bus arrester current. In addition, the frequency components of the fault currents are analyzed. Based on the PSCAD/EMTDC software, the current distribution is simulated and discussed. The simulation results are in good agreement with the test results.
Auteurs: Caowei Huang;Bo Zhang;Yutang Ma;Fangrong Zhou;Jinliang He;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 520 - 528
Editeur: IEEE
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» Analysis on Location Accuracy for the Binocular Stereo Vision System
Résumé:
Binocular stereo vision (BSV) system has been widely used in various fields, such as intelligent manufacture, smart robot, and so on. However, the location accuracy of the current BSV still cannot fully satisfy industry requirements due to lack of a parameters optimization BSV system. In this paper, a high accuracy BSV system is proposed. This is achieved through analyzing the seven parameters of the BSV system, which are classified into two groups: system structure parameters (SSPs) and camera calibration parameters (CCPs). For the SSPs, an improved analysis model is designed to expose the possible errors caused by three parameters. Furthermore, a new correlation model among them is also proposed to analyze the errors caused by their correlation. On the other hand, for the CCPs, the orthogonal experiment model is employed for selecting the optimal combination of the four calibration parameters. Meanwhile, the weight among the four parameters is also analyzed for reducing errors. Finally, the effectiveness of our proposed method is demonstrated by a large number of experiments. It gives a useful reference to the BSV system used in applied optics research and application fields.
Auteurs: Lu Yang;Baoqing Wang;Ronghui Zhang;Haibo Zhou;Rongben Wang;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 16
Editeur: IEEE
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» Analysis, Design, and Implementation of Passivity-Based Control for Multilevel Railway Power Conditioner
Résumé:
In recent years, railway power conditioner (RPC) has been used to improve the power quality of a traction power system. In engineering application of RPC, mismatches between parameters used in controller and actual values are inevitable, which will increase the difficulty of current controller design and deteriorate compensation performance. In this paper, a passivity-based control (PBC) system is studied for multilevel RPC to enhance its tolerance for mismatches. According to the topology of multilevel RPC, equivalent electrical and mathematical models are developed. To employ PBC, Euler–Lagrange system model of RPC is established by Park (αβ/dq) transformation, and the passivity of RPC and stability of PBC are proved. On this basis, the robustness of PBC is analyzed and criteria for damping selection are derived. Finally, simulation and experiments have been carried out to verify the structure and control method in the paper.
Auteurs: Jun Min;Fujun Ma;Qianming Xu;Zhixing He;An Luo;Alfio Spina;
Apparue dans: IEEE Transactions on Industrial Informatics
Date publication: 02.-2018, volume: 14, issue:2, pages: 415 - 425
Editeur: IEEE
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» Analytic Evaluation of Fine Alignment for Velocity Aided INS
Résumé:
Coarse attitude initialization procedure is used to determine the initial attitude of the inertial navigation system. To improve the accuracy of the attitude to a desired value, fine alignment (FA) process is employed. In stationary conditions, zero velocity updates are usually used to achieve such goal. In this paper, an analytic evaluation of the steady-state properties of the FA process is presented. The contribution of this paper is twofold: 1) closed-form analytic solutions to the error-state covariance of the FA process are derived and 2) semianalytic solutions to the convergence time of the error-state covariance are shown. With such closed-form solutions at hand, insight can be gained into the parameters involved in the FA process in preliminary design process. Simulation and field experiments are given to support the analytical expressions.
Auteurs: Alexander Tsukerman;Itzik Klein;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 376 - 384
Editeur: IEEE
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» Analytical Algorithm for 3-D Localization of a Single Source With Uniform Circular Array
Résumé:
This letter presents an analytical algorithm for estimating three-dimensional (3-D) localization of a single source with uniform circular arrays (UCAs). Fourier transforms are exploited to expand the phase distribution of a single source, and the localization problem is reformulated as an equivalent spectrum manipulation problem. 3-D parameters are decoupled to different spectrums in the Fourier domain. Algebraic relations are established between 3-D parameters and Fourier spectrums. Fourier sampling theorem ensures that the minimum element number for 3-D localization with a UCA is five. Accuracy analysis provides mathematical insights into the function of a center sensor. Numerical simulations and experimental results verify the effectiveness and appealing performance of the proposed 3-D localization algorithm.
Auteurs: Le Zuo;Jin Pan;Zhongxiang Shen;
Apparue dans: IEEE Antennas and Wireless Propagation Letters
Date publication: 02.-2018, volume: 17, issue:2, pages: 323 - 326
Editeur: IEEE
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» Analytical Derivation of the AC-Side Input Admittance of a Modular Multilevel Converter With Open- and Closed-Loop Control Strategies
Résumé:
This paper deals with the derivation of the ac-side input admittance of a grid-connected modular multilevel converter (MMC) under both open- and closed-loop ac-side current control strategies. The contribution of the internal dynamics of the MMC on the input admittance depends on the type of ac-side controllers implemented. For this reason, the input admittance is first derived with the MMC operating in open loop on the ac side. The results are then modified to include various ac-side controllers in order to analyze the impact of the internal dynamics of the MMC on the total input admittance. Based on the findings, recommendations are given on modeling the input admittance of the MMC. Finally, the derived analytical models are verified using a detailed switching model of the MMC in the frequency domain.
Auteurs: Mebtu Beza;Massimo Bongiorno;Georgios Stamatiou;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 248 - 256
Editeur: IEEE
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» Analytical Formulas for Mean Gain and Excess Noise Factor in InAs Avalanche Photodiodes
Résumé:
It has been known that McIntyre’s local multiplication theory for avalanche photodiodes (APDs) does not fully explain the experimental results for single-carrier InAs APDs, which exhibit excess noise factor values below 2. While it has been established that the inclusion of the dead-space effect in the nonlocal multiplication theory resolves this discrepancy, no closed-form formulas for the mean gain and excess noise factor have been specialized to InAs APDs in a nonlocal setting. Upon utilizing prior analytical formulation of single-carrier avalanche multiplication based on age-dependent branching theory in conjunction with nonlocal ionization coefficients and thresholds for InAs, closed-form solutions of the mean gain and the excess noise factor for InAs APDs are provided here for the first time. The formulas are validated against published experimental data from InAs APDs across a variety of multiplication region widths and are shown to be applicable for devices with multiplication widths of 500 nm and larger.
Auteurs: Erum Jamil;Majeed M. Hayat;Gordon A Keeler;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2018, volume: 65, issue:2, pages: 610 - 614
Editeur: IEEE
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» Analyzing Home Automation and Networking Technologies
Résumé:
Due to the rapid advancements in networking and automation technologies, the concept of smart homes has started taking shape. AT&T Digital Life, Schneider's Wiser homes, and Qualcomm's M2M communication, among others, are examples of ventures by conglomerates into the business of home automation. Three-quarters of homes in the United States possess computers, and more than two-thirds of those are connected to the Internet. Wireless networking in the form of Wi-Fi is present in 17% of homes.
Auteurs: Eshan Shailendra;Praneet Kaur Bhatia;
Apparue dans: IEEE Potentials
Date publication: 02.-2018, volume: 37, issue:1, pages: 27 - 33
Editeur: IEEE
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» Anatomically Constrained Neural Networks (ACNNs): Application to Cardiac Image Enhancement and Segmentation
Résumé:
Incorporation of prior knowledge about organ shape and location is key to improve performance of image analysis approaches. In particular, priors can be useful in cases where images are corrupted and contain artefacts due to limitations in image acquisition. The highly constrained nature of anatomical objects can be well captured with learning-based techniques. However, in most recent and promising techniques such as CNN-based segmentation it is not obvious how to incorporate such prior knowledge. State-of-the-art methods operate as pixel-wise classifiers where the training objectives do not incorporate the structure and inter-dependencies of the output. To overcome this limitation, we propose a generic training strategy that incorporates anatomical prior knowledge into CNNs through a new regularisation model, which is trained end-to-end. The new framework encourages models to follow the global anatomical properties of the underlying anatomy (e.g. shape, label structure) via learnt non-linear representations of the shape. We show that the proposed approach can be easily adapted to different analysis tasks (e.g. image enhancement, segmentation) and improve the prediction accuracy of the state-of-the-art models. The applicability of our approach is shown on multi-modal cardiac data sets and public benchmarks. In addition, we demonstrate how the learnt deep models of 3-D shapes can be interpreted and used as biomarkers for classification of cardiac pathologies.
Auteurs: Ozan Oktay;Enzo Ferrante;Konstantinos Kamnitsas;Mattias Heinrich;Wenjia Bai;Jose Caballero;Stuart A. Cook;Antonio de Marvao;Timothy Dawes;Declan P. O‘Regan;Bernhard Kainz;Ben Glocker;Daniel Rueckert;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2018, volume: 37, issue:2, pages: 384 - 395
Editeur: IEEE
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» Angle Estimation With Polarization Filtering: A Single Snapshot Approach
Résumé:
When a monopulse radar is subjected to main-lobe barrage interference, the target and the interference source are both located within the 3 dB beamwidth of the radar; the target returns are subsumed by the interference, which results in incorrect detection, erroneous angle measurements, and tracking error. Based on a hybrid polarimetric monopulse radar with six channels, a new approach is presented for estimating the target angle from a single snapshot in the presence of main-lobe barrage interference. By means of polarization filtering and polarization synthesis of signals from multiple channels with two orthogonal polarizations, a new pair of sum and difference signals is formed that represents the angle difference between the target and the interference source. After standard monopulse processing of these new signals and additional compensation, the estimate of the target angle is derived with low computational complexity.
Auteurs: Jiazhi Ma;Longfei Shi;Yongzhen Li;Shunping Xiao;Xuesong Wang;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 257 - 268
Editeur: IEEE
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» Angular Momentum-Dependent Transmission of Circularly Polarized Vortex Beams Through a Plasmonic Coaxial Nanoring
Résumé:
In this paper, we report on the theoretical and numerical study of the transmission of circularly polarized vortex beams through a plasmonic coaxial nanoring. We show that the transmission peak wavelength of an incident circularly polarized vortex beam is dominantly governed by the total angular momentum, which determines the coupling to the plasmonic eigenmode supported by the coaxial nanoring with a given geometry and ultimately the transmitted beam in the far field. In addition, our study shows that the total angular momentum of the incident circularly polarized vortex beam can be conserved, where the far field of the transmitted beam contains both left- and right-handed circular polarization components with correspondingly modulated orbital angular momentum preserving the same total angular momentum. Our work can be potentially useful to advanced nanophotonic devices harnessing light's angular momentum division.
Auteurs: Shuai Wang;Zi-Lan Deng;Yaoyu Cao;Dejiao Hu;Yi Xu;Boyuan Cai;Long Jin;Yuan Bao;Xiaolei Wang;Xiangping Li;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 9
Editeur: IEEE
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» Angular-Dependent Radius Measurements at Rotating Objects Using Underdetermined Sensor Systems
Résumé:
Precise and contactless shape measurements of rotating objects is important, e.g., for monitoring and controlling the manufacturing quality in lathes. For this purpose, multisensor and single-sensor approaches based on optical distance and surface velocity measurements are state-of-the-art techniques. Two- and single-sensor systems are particularly promising to measure the angular-dependent radius of the cross section of the rotating object in a scanning regime with minimal optical access. Since a comparison between the different sensor systems is missing, the potential of these underdetermined sensor systems is unclear. In addition, displacements of the rotational axis and sensor misalignments are suspected to be crucial error sources, but the error is unknown. For this reason, an error analysis is performed regarding the resulting systematic error and the random error for the two- and single-sensor systems. As a result, the different sensor systems have an equal cross-sensitivity with respect to lateral displacements of the rotational axis from the sensor axes, but the two-sensor approach has the lowest sensitivity regarding sensor misalignments. For the studied measurement conditions, the systematic error dominates the sensor noise for the two-sensor system and the single-sensor system with combined distance and velocity measurement at an object mean radius >6 mm. The smallest total measurement uncertainty is obtained with the two-sensor system. Finally, the relevance of systematic error depends on the utilization, i.e., for instance on the absolute rotor radius, the stability of the rotor axis, the sensor position, the accuracy of the sensor alignment, and the uncertainty of the distance and/or velocity measurements.
Auteurs: Andreas Fischer;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 02.-2018, volume: 67, issue:2, pages: 425 - 430
Editeur: IEEE
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» Angularly Stable Frequency Selective Surface Combined With a Wide-Scan Phased Array
Résumé:
A five-layer frequency selective surface (FSS) composed of subwavelength elements with large harmonic rejection bandwidth is presented. The FSS design is based on an equivalent circuit model, where the interlayer interaction is only described with a single transmission line representing the fundamental Floquet wave. A prototype of the designed FSS is fabricated, and the measured response exhibits good stability over a wide conical incidence range up to 45°. The FSS is combined with a wide-scanning connected array of dipoles to implement a phased array with integrated filtering properties. A dispersion analysis is performed to define the distance between the array and the FSS that avoids the propagation of surface waves between the combined structures, allowing to maximize the radiation efficiency. The performance of the array combined with the FSS is experimentally characterized, showing high-order harmonic rejection better than 17 dB over a large bandwidth.
Auteurs: Cristina Yepes;Daniele Cavallo;Erio Gandini;Stefania Monni;Andrea Neto;Frank E. van Vliet;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 1046 - 1051
Editeur: IEEE
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» Anomaly Detection and Array Diagnosis in Wireless Networks with Multiple Antennas: Framework, Challenges and Tools
Résumé:
Anomaly detection and array diagnosis in wireless networks are both important technologies and have many applications ranging from discovering malicious traffic and identifying abnormal nodes, to detecting faulty antennas and so on. In general, anomaly detection mainly depends on relational data, which denotes the links between nodes of the networks, to decide whether abnormal networks caused by intentional attack or array failure are embedded in large wireless networks. Additionally, the typical scheme of array diagnosis is to measure signals radiating from the array antennas under test to detect the faulty elements by using a centralized method. However, in largescale wireless networks, a centralized strategy results in a communication bottleneck because of transmitting all signals to a center node. Moreover, since faulty elements are only a tiny proportion for the whole networks, the method that all antennas are under test is unnecessary and also causes huge computational complexity to identify the failure of elements. Aiming to mitigate these problems, this article provides a novel framework to monitor networks and detect faulty antennas by fusing relational data and measured signals. In this article, we first review the algorithms related to anomaly detection and survey the array diagnosis problem. In particular, we discuss the relationship between anomaly detection and array diagnosis in the new framework and highlight the importance of data fusion. Finally, the main challenges are presented and mathematical tools are introduced to solve the corresponding problems.
Auteurs: Bo Wang;Fengye Hu;Yanping Zhao;Terry N. Guo;
Apparue dans: IEEE Network
Date publication: 02.-2018, volume: 32, issue:1, pages: 152 - 159
Editeur: IEEE
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» Anonymity Leakage in Private VoIP Networks
Résumé:
Private communication detection (PCD) is a traffic-analysis technique whereby an ordinary user of a communication network exploits side channels in end-point devices to observe the busy/idle activity status of targeted users. Correlations of users’ activity status allows collection of communication records that reveal private relationships. PCD techniques have been demonstrated for a number of communication technologies, such as Wi-Fi and VoIP, and their effectiveness shown even when the communication network is private; i.e., it provides content confidentiality, flow anonymity, and user pseudonymity. In this paper, we present a mathematical model of PCD that captures the activity status of two targets in a private VoIP network, including the probing process of an attacker that aims to breach their communication anonymity. Using this model, we a) develop fundamental bounds on PCD accuracy; b) measure the anonymity leakage in terms of the amount of call record information obtained in an attack; and c) provide performance guarantees and compare the efficacy of different PCD countermeasures, such as resource randomization and use of firewalls.
Auteurs: Saurabh Shintre;Virgil Gligor;Jo ao Barros;
Apparue dans: IEEE Transactions on Dependable and Secure Computing
Date publication: 02.-2018, volume: 15, issue:1, pages: 14 - 26
Editeur: IEEE
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» Antenna Miniaturization Techniques: A Review of Topology- and Material-Based Methods
Résumé:
Antenna miniaturization has been the subject of numerous studies for almost 70 years [1]-[4]. Early studies showed that a decrease in the size of an antenna results in a direct reduction in its bandwidth and efficiency (hr) [1], [2]. The size limitation translates into a lower boundary on the achievable radiation quality factor (Q factor) and consequently on the maximum achievable impedance bandwidth. Recently, many new investigations have been conducted to reduce the form factor (or the overall size) of different types of antennas while trying to maintain acceptable matching properties and operating bandwidth. These miniaturization techniques are generally related to changing the electrical and physical properties of an antenna.
Auteurs: Mojtaba Fallahpour;Reza Zoughi;
Apparue dans: IEEE Antennas and Propagation Magazine
Date publication: 02.-2018, volume: 60, issue:1, pages: 38 - 50
Editeur: IEEE
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» Antenna System Composed of T-Shaped Elements Coupled to an Open Radial Waveguide
Résumé:
An antenna system composed of an activated open radial waveguide (RadWG) and parasitic T-shaped elements is proposed as a high-gain antenna, where the radiation beam is steerable around the system axis. The T-shaped elements are proximity-coupled to the RadWG. It is found that the upper round plate for the RadWG contributes to forming a desirable beam and increasing the gain. The beam steering with a gain of greater than targeted 9 dBi in 16 azimuthal directions is obtained by changing the location of open-state T-shaped elements whose height is 0.18 wavelength. Effects on the radiation characteristics of the system parameters, including the RadWG height, upper round plate diameter, ground plane diameter, and number of open-state T-shaped elements, are also analyzed and discussed.
Auteurs: Hisamatsu Nakano;Yuhei Kameta;Toru Kawano;Amit Mehta;Arpan Pal;Andrew Skippins;Junji Yamauchi;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 550 - 563
Editeur: IEEE
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» Antennas for Autonomy [Editor's Comments]
Résumé:
Auteurs: Mahta Moghaddam;
Apparue dans: IEEE Antennas and Propagation Magazine
Date publication: 02.-2018, volume: 60, issue:1, pages: 4 - 4
Editeur: IEEE
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» AntMapper: An Ant Colony-Based Map Matching Approach for Trajectory-Based Applications
Résumé:
Many trajectory-based applications require an essential step of mapping raw GPS trajectories onto the digital road network accurately. This task, commonly referred to as map matching, is challenging due to the measurement error of GPS devices in critical environment and the sampling error caused by long sampling intervals. Traditional algorithms focus on either a local or a global perspective to deal with the problem. To further improve the performance, this paper develops a novel map matching model that considers local geometric/topological information and a global similarity measure simultaneously. To accomplish the optimization goal in this complex model, we adopt an ant colony optimization algorithm that mimics the path finding process of ants transporting food in nature. The algorithm utilizes both local heuristic and global fitness to search the global optimum of the model. Experimental results verify that the proposed algorithm is able to provide accurate map matching results within a relatively short execution time.
Auteurs: Yue-Jiao Gong;En Chen;Xinglin Zhang;Lionel M. Ni;Jun Zhang;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 02.-2018, volume: 19, issue:2, pages: 390 - 401
Editeur: IEEE
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» Application of Acoustoelasticity to Evaluate Nonlinear Modulus in Ex Vivo Kidneys
Résumé:
Currently, dynamic elastography techniques estimate the linear elastic shear modulus of different body tissues. New methods that investigate other properties of soft tissues such as anisotropy, viscosity, and shear nonlinearity would provide more information about the structure and function of the tissue and might provide a better contrast than tissue stiffness and hence provide more effective diagnostic tools for some diseases. It has previously been shown that shear wave velocity in a medium changes due to an applied stress, a phenomenon called acoustoelasticity (AE). Applying a stress to compress a medium while measuring the shear wave velocity versus strain provides data with which the third-order nonlinear shear modulus $A$ can be estimated. To evaluate the feasibility of estimating $A$ , we evaluated ten ex vivo porcine kidneys embedded in 10% porcine gelatin to mimic the case of a transplanted kidney. Under assumptions of an elastic incompressible medium for AE measurements, the shear modulus was quantified at each compression level and the applied strain was assessed by measuring the change in the thickness of the kidney cortex. Finally, $A$ was calculated by applying the AE theory. Our results demonstrated that it is possible to estimate a nonlinear shear modulus by monitoring the changes in strain and ${mu }$ due to kidney deformation. The magnitudes of $A$ are higher when the compression is performed progressively and when using a plate attached to the transducer. Nevertheless, the values obtained for $A$ <- inline-formula> are similar to those previously reported in the literature for breast tissue.
Auteurs: Sara Aristizabal;Carolina Amador Carrascal;Ivan Z. Nenadic;James F. Greenleaf;Matthew W. Urban;
Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Date publication: 02.-2018, volume: 65, issue:2, pages: 188 - 200
Editeur: IEEE
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» Application of Genetic Programming (GP) Formalism for Building Disease Predictive Models from Protein-Protein Interactions (PPI) Data
Résumé:
Protein-protein interactions (PPIs) play a vital role in the biological processes involved in the cell functions and disease pathways. The experimental methods known to predict PPIs require tremendous efforts and the results are often hindered by the presence of a large number of false positives. Herein, we demonstrate the use of a new Genetic Programming (GP) based Symbolic Regression (SR) approach for predicting PPIs related to a disease. In this case study, a dataset consisting of 135 PPI complexes related to cancer was used to construct a generic PPI predicting model with good PPI prediction accuracy and generalization ability. A high correlation coefficient (CC) magnitude of 0.893, and low root mean square error (RMSE), and mean absolute percentage error (MAPE) values of 478.221 and 0.239, respectively, were achieved for both the training and test set outputs. To validate the discriminatory nature of the model, it was applied on a dataset of diabetes complexes where it yielded significantly low CC values. Thus, the GP model developed here serves a dual purpose: (a) a predictor of the binding energy of cancer related PPI complexes, and (b) a classifier for discriminating PPI complexes related to cancer from those of other diseases.
Auteurs: Renu Vyas;Sanket Bapat;Purva Goel;Muthukumarasamy Karthikeyan;Sanjeev S. Tambe;Bhaskar D. Kulkarni;
Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Date publication: 02.-2018, volume: 15, issue:1, pages: 27 - 37
Editeur: IEEE
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» Application of Predictor Feedback to Compensate Time Delays in Connected Cruise Control
Résumé:
In this paper, we investigate a vehicular string traveling on a single lane, where vehicles use connected cruise control to regulate their longitudinal motion based on data received from other vehicles via wireless vehicle-to-vehicle communication. Assuming digital controllers, the sample-and-hold units introduce time-periodic time delays in the control loops and the delays increase when data packets are lost. We investigate the effect of packet losses on plant and string stability while varying the control gains and determine the minimum achievable time gap below which stability cannot be achieved. We propose two predictor feedback control strategies that overcome the destabilizing effect of the time delay caused by the sample-and-hold unit and packet losses.
Auteurs: Tamás G. Molnár;Wubing B. Qin;Tamás Insperger;Gábor Orosz;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 02.-2018, volume: 19, issue:2, pages: 545 - 559
Editeur: IEEE
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» Application of Updated Landau–Lifshitz–Bloch Equations to Heat-Assisted Magnetic Recording
Résumé:
Previously, we applied analysis of macro-spin magnetization dynamics described by the Landau–Lifshitz–Bloch (LLB) equation to issues in the future magnetic recording which combined heat-assisted magnetic recording (HAMR) with bit-patterned media (BPM). In this paper, we use updated versions of the LLB equation to revisit the magnetic switching reliability as an HAMR head is passed over a single, isolated grain of a bit-patterned medium. Areal density was varied, while the packing density of the BPM was set to 0.4 or 0.5. LLB writing reliability is also assessed with the Arrhenius–Nèel theory that has been upgraded with recent work related to the Stoner–Wohlfarth model to add understanding of the role of thermodynamics in thermomagnetic recording and the long-time stability of magnetic reversal.
Auteurs: Terry W. McDaniel;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 02.-2018, volume: 54, issue:2, pages: 1 - 11
Editeur: IEEE
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» Applying Metamaterial-Based Repeater in LC Passive Wireless Sensors to Enhance Readout
Résumé:
Inductor–capacitor (LC) passive wireless sensors allow for a continuous, real-time monitoring for various parameters of interest in situations, where wired connections are difficult or even impossible. However, geometrical constraints reduce the magnetic coupling between the sensor and the readout coil, resulting in a limited interrogation distance. Here, we propose a left-handed metamaterial as a repeater to enhance the readout of the LC passive wireless sensors. The left-handed metamaterial consists of double-side square spirals and possesses negative relative permeability. The operating frequency of the left-metamaterial is designed adjustable to cover the frequency spectrum of the sensor. By monitoring the relative humidity as an example, we have demonstrated that the readout distance with the left-handed metamaterial can achieve nearly 1.8 times as long as that without metamaterial, while keeping their signal strength and sensitivity the same. Overall, this strategy through the metamaterials-based repeaters represents an effective approach for enhancing the readout.
Auteurs: Lei Dong;Li-Feng Wang;Qing-An Huang;
Apparue dans: IEEE Sensors Journal
Date publication: 02.-2018, volume: 18, issue:4, pages: 1755 - 1760
Editeur: IEEE
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» Applying Software Engineering Standards in Very Small Entities: From Startups to Grownups
Résumé:
Very small entities (VSEs) are organizations with up to 25 people. The ISO/IEC 29110 series of standards and guides target VSEs with little or no experience or expertise in selecting the appropriate processes from lifecycle standards and tailoring them to a project’s needs. This article gives an overview of ISO/IEC 29110, some examples of VSEs that have implemented it, and those implementations’ results.
Auteurs: Claude Y. Laporte;Mirna Munoz;Jezreel Mejia Miranda;Rory V. O’Connor;
Apparue dans: IEEE Software
Date publication: 02.-2018, volume: 35, issue:1, pages: 99 - 103
Editeur: IEEE
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» Approximate Relations of Admittance for Symmetrically Arranged Dipoles
Résumé:
We previously proposed an approximate relation between admittance $Y_{mn}$ and $Y^prime _{mn}$ , where $Y_{mn}$ is the admittance of a set of dipoles whose ports are located at their centers and $Y^prime _{mn}$ is the admittance of the same set of dipoles with one is removed. Based on the relation, approximate expressions of $Y_{mn}$ were derived for the case that dipoles are symmetrically arranged. Their validity is examined by simulations and experiments in this communication.
Auteurs: Kyoichi Iigusa;Hirokazu Sawada;Fumihide Kojima;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 984 - 989
Editeur: IEEE
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» ARC Flash KPI Compliance at a Large Oil and Gas Company
Résumé:
An oil and gas company's arc flash electrical safe operations program is a corporate initiative to prevent electrical arc flash injuries. The program implements the company general instruction—electrical arc flash hazard mitigation, which provides minimum safe work requirements for protection of personnel in the workplace against electrical arc flash hazards in accordance with the National Fire Protection Agency 70E. The program tracks five key performance indicators (KPIs) to protect employees from arc flash hazards in all company facilities, which are as follows: 1) technology deployment; 2) training and certification; 3) operation and maintenance delineation; 4) operation and maintenance unified procedures; and 5) arc flash analysis. To verify compliance, the company initiated field-based assessments conducted by a specialized team of Power Systems Compliance and Electrical Engineers. The assessments are designed to validate each facility's compliance as well as to identify any opportunities for improvement in the application of arc flash mitigation. The assessors utilized a standardized checklist to determine the level to which established KPIs have been implemented. The checklists are weighted and scored to validate compliance in a consistent manner. This paper demonstrates a structured approach to measure arc flash KPI compliance and highlights some findings and practical examples that can be applied at many oil and gas facilities.
Auteurs: Ritchie Pragale;Amar Patel;Roger Bresden;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 889 - 894
Editeur: IEEE
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» Arc Lighting Systems: The First Electrical Distribution Systems [History]
Résumé:
From about 1885 to 1915, the most common means of lighting streets was the use of arc lamps. These lamps and the systems by which they were supplied power were very technologically sophisticated. These were the first electrical distribution systems. The manufacturing companies that made the equipment for arc lighting went on to be the companies that launched the so-called electrical age.
Auteurs: Robert D. Barnett;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 02.-2018, volume: 16, issue:1, pages: 56 - 64
Editeur: IEEE
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» Arena Function: A Framework for Computing Capacity Bounds in Wireless Networks
Résumé:
Bounds on the capacity of wireless networks often rely on simplifying assumptions and are given in terms of coarse network parameters, such as the number of nodes. While useful due to their simplicity, such bounds can significantly overestimate the achievable capacity in real-world situations, ignoring actual network topology and traffic patterns. The results of this paper improve such analytical results on network capacity in several ways. At the heart of our methodology lies the concept of transmission arenas, which indicates the presence of active transmissions near any given location in the network. This novel space-based approach is well-suited to untangle the interactions of simultaneous transmissions. Avoiding a graph-based model of the network, it opens new avenues of studying capacities. For homogeneous networks, we recover classical bounds. However, our methodology applies to arbitrary networks and can, thus, inform placing and activating of nodes also in the presence of clustering. Our method works with all classical channel models and dimensions. It provides bounds on the transport capacity which involve only high-level knowledge of node locations, such as the length of Euclidean minimum spanning tree. As an additional novelty, we establish bounds on wireless unicast and multicast capacities.
Auteurs: Alireza Keshavarz-Haddad;Rudolf H. Riedi;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 02.-2018, volume: 17, issue:2, pages: 1134 - 1146
Editeur: IEEE
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» Array Waveguide Probe Loaded With Split-Ring Resonators for Sizing the Cracks in Metal Surface
Résumé:
Microwave nondestructive testing (NDT) technology developed rapidly, but crack detection in metal surface is facing many troubles, such as hard quantitation and low sensitivity. To solve these problems, this letter proposes a two-cell array waveguide microwave NDT probe with an array of split-ring resonators which operates at 12.5 GHz. It detects quantitatively tiny crack (as low as 0.5 mm) in metal surface. Maximum difference between simulation and experimental results is just 9%. Result shows that the peak distance of $S_{21}$ has a sensitive and quantitative link with the width and depth of crack. It is shown that the probe is capable of determining the location and dimension of surface cracks of a few millimeter depths and widths.
Auteurs: Xiaoqing Yang;Yang Yin;Di Zhang;Shiyue Wu;Kama Huang;Jianping Yuan;Zhanxia Zhu;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2018, volume: 28, issue:2, pages: 171 - 173
Editeur: IEEE
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» Artificial-Noise-Aided Zero-Forcing Synthesis Approach for Secure Multi-Beam Directional Modulation
Résumé:
Great attention has been paid to wireless communication security in recent years. Directional modulation (DM) is one of the promising secure wireless communication techniques. Multi-beam DM has the capability of sending multiple data streams to cooperative users in different desired directions while distorting signal constellations in all other directions. Dynamic multi-beam DM has been proven to be more secure in real communication scenarios. However, previous synthesis approaches for dynamic multi-beam DM are relatively complex and demand a lot of computations. Therefore, an artificial-noise-aided zero-forcing synthesis approach is proposed. The calculation process of the baseband-weighted vector is simplified using the zero-forcing method, which is closely related to the concept of pseudo-inverse. The dynamic property of multi-beam DM is achieved by randomly changing the artificial noise vector. Compared with previous classical dynamic multi-beam DM synthesis approaches, the proposed approach is more efficient and easier to implement in practical systems with tolerable performance loss.
Auteurs: Tao Xie;Jiang Zhu;Yang Li;
Apparue dans: IEEE Communications Letters
Date publication: 02.-2018, volume: 22, issue:2, pages: 276 - 279
Editeur: IEEE
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» Arya: Operating System Support for Securely Augmenting Reality
Résumé:
Augmented reality (AR) applications capture sensor input from a user’s surroundings and overlay virtual output on their perception of the world, enabling new, immersive experiences. However, this technology raises serious security and privacy risks such as malicious or buggy AR output.
Auteurs: Kiron Lebeck;Kimberly Ruth;Tadayoshi Kohno;Franziska Roesner;
Apparue dans: IEEE Security & Privacy
Date publication: 02.-2018, volume: 16, issue:1, pages: 44 - 53
Editeur: IEEE
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» Assessment of Rigid Registration Quality Measures in Ultrasound-Guided Radiotherapy
Résumé:
Image guidance has become the standard of care for patient positioning in radiotherapy, where image registration is often a critical step to help manage patient motion. However, in practice, verification of registration quality is often adversely affected by difficulty in manual inspection of 3-D images and time constraint, thus affecting the therapeutic outcome. Therefore, we proposed to employ both bootstrapping and the supervised learning methods of linear discriminant analysis and random forest to help robustly assess registration quality in ultrasound-guided radiotherapy. We validated both approaches using phantom and real clinical ultrasound images, and showed that both performed well for the task. While learning-based techniques offer better accuracy and shorter evaluation time, bootstrapping requires no prior training and has a higher sensitivity.
Auteurs: Roozbeh Shams;Yiming Xiao;François Hébert;Matthew Abramowitz;Rupert Brooks;Hassan Rivaz;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2018, volume: 37, issue:2, pages: 428 - 437
Editeur: IEEE
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» Asset-Based Dynamic Impact Assessment of Cyberattacks for Risk Analysis in Industrial Control Systems
Résumé:
With the evolution of information, communications, and technologies, modern industrial control systems (ICSs) face more and more cybersecurity issues. This leads to increasingly severe risks in critical infrastructure and assets. Therefore, risk analysis becomes a significant yet not well investigated topic for prevention of cyberattack risks in ICSs. To tackle this problem, a dynamic impact assessment approach is presented in this paper for risk analysis in ICSs. The approach predicts the trend of impact of cybersecurity dynamically from full recognition of asset knowledge. More specifically, an asset is abstracted with properties of construction, function, performance, location, and business. From the function and performance properties of the asset, object-oriented asset models incorporating with the mechanism of common cyberattacks are established at both component and system levels. Characterizing the evolution of behaviors for single asset and system, the models are used to analyze the impact propagation of cyberattacks. Then, from various possible impact consequences, the overall impact is quantified based on the location and business properties of the asset. A special application of the approach is to rank critical system parameters and prioritize key assets according to impact assessment. The effectiveness of the presented approach is demonstrated through simulation studies for a chemical control system.
Auteurs: Xuan Li;Chunjie Zhou;Yu-Chu Tian;Naixue Xiong;Yuanqing Qin;
Apparue dans: IEEE Transactions on Industrial Informatics
Date publication: 02.-2018, volume: 14, issue:2, pages: 608 - 618
Editeur: IEEE
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» Asymmetric Bimanual Control of Dual-Arm Exoskeletons for Human-Cooperative Manipulations
Résumé:
In this paper, two upper limbs of an exoskeleton robot are operated within a constrained region of the operational space with unidentified intention of the human operator's motion as well as uncertain dynamics including physical limits. The new human-cooperative strategies are developed to detect the human subject's movement efforts in order to make the robot behavior flexible and adaptive. The motion intention extracted from the measurement of the subject's muscular effort in terms of the applied forces/torques can be represented to derive the reference trajectory of his/her limb using a viable impedance model. Then, adaptive online estimation for impedance parameters is employed to deal with the nonlinear and variable stiffness property of the limb model. In order for the robot to follow a specific impedance target, we integrate the motion intention estimation into a barrier Lyapunov function based adaptive impedance control. Experiments have been carried out to verify the effectiveness of the proposed dual-arm coordination control scheme, in terms of desired motion and force tracking.
Auteurs: Zhijun Li;Bo Huang;Arash Ajoudani;Chenguang Yang;Chun-Yi Su;Antonio Bicchi;
Apparue dans: IEEE Transactions on Robotics
Date publication: 02.-2018, volume: 34, issue:1, pages: 264 - 271
Editeur: IEEE
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» Asymptotic Comparison of ML and MAP Detectors for Multidimensional Constellations
Résumé:
A classical problem in digital communications is to evaluate the symbol error probability (SEP) and bit error probability (BEP) of a multidimensional constellation over an additive white Gaussian noise channel. In this paper, we revisit this problem for nonequally likely symbols and study the behavior of the optimal maximum a posteriori (MAP) detector at asymptotically high signal-to-noise ratios. Exact closed-form asymptotic expressions for SEP and BEP for arbitrary constellations and input distributions are presented. The well-known union bound is proven to be asymptotically tight under general conditions. The performance of the practically relevant maximum likelihood (ML) detector is also analyzed. Although the decision regions with MAP detection converge to the ML regions at high signal-to-noise ratios, the ratio between the MAP and ML detectors in terms of both SEP and BEP approaches a constant, which depends on the constellation and a priori probabilities. Necessary and sufficient conditions for asymptotic equivalence between the MAP and ML detectors are also presented.
Auteurs: Alex Alvarado;Erik Agrell;Fredrik Brännström;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 02.-2018, volume: 64, issue:2, pages: 1231 - 1240
Editeur: IEEE
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» Asymptotically Optimum Perfect Universal Steganography of Finite Memoryless Sources
Résumé:
A solution to the problem of asymptotically optimum perfect universal steganography of finite memoryless sources with a passive warden is provided, which is then extended to contemplate a distortion constraint. The solution rests on the fact that Slepian’s Variant I permutation coding implements first-order perfect universal steganography of finite host signals with optimum embedding rate. The duality between perfect universal steganography with asymptotically optimum embedding rate and lossless universal source coding with asymptotically optimum compression rate is evinced in practice by showing that permutation coding can be implemented by means of adaptive arithmetic coding. Next, a distortion constraint between the host signal and the information-carrying signal is considered. Such a constraint is essential whenever real-world host signals with memory (e.g., images, audio, or video) are decorrelated to conform to the memoryless assumption. The constrained version of the problem requires trading off embedding rate and distortion. Partitioned permutation coding is shown to be a practical way to implement this trade-off, performing close to an unattainable upper bound on the rate-distortion function of the problem.
Auteurs: Félix Balado;David Haughton;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 02.-2018, volume: 64, issue:2, pages: 1199 - 1216
Editeur: IEEE
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» Asynchronous Distributed Algorithms for Solving Linear Algebraic Equations
Résumé:
Two asynchronous distributed algorithms are presented for solving a linear equation of the form $Ax=b$ with at least one solution. The equation is simultaneously and asynchronously solved by $m$ agents assuming that each agent knows only a subset of the rows of the partitioned matrix $[A b]$, the estimates of the equation's solution generated by its neighbors, and nothing more. Neighbor relationships are characterized by a time-dependent directed graph whose vertices correspond to agents and whose arcs depict neighbor relationships. Each agent recursively updates its estimate of a solution at its own event times by utilizing estimates generated by its neighbors which are transmitted with delays. The event time sequences of different agents are not assumed to be synchronized. It is shown that for any matrix-vector pair $(A, b)$ for which the equation has a solution and any repeatedly jointly strongly connected sequence of neighbor graphs defined on the merged sequence of all agents’ event times, the algorithms cause all agents’ estimates to converge exponentially fast to the same solution to $Ax=b$ . The first algorithm requires a specific initialization step at each agent, and the second algorithm works for arbitrary initializations. Explicit expressions for convergence rates are provided, and a relation between local initializations and limiting consensus solutions is established, which is used to solve the least 2-norm solution.
Auteurs: Ji Liu;Shaoshuai Mou;A. Stephen Morse;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 02.-2018, volume: 63, issue:2, pages: 372 - 385
Editeur: IEEE
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» Asynchronous Passive Multisensor System Observability With Unknown Sensor Position
Résumé:
A method is derived for forming composite measurements when the line-of-sight measurements from multiple sensors are asynchronous and the position(s) of one or more passive sensors is (are) unknown. Using the composite measurement, the target position, velocity, and unknown sensor location are estimated. Additionally, general analytical observability conditions are derived.
Auteurs: Itzik Klein;Yeshaya Lipman;Yaakov Bar-Shalom;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 369 - 375
Editeur: IEEE
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» Asynchronous Task-Based Polar Decomposition on Single Node Manycore Architectures
Résumé:
This paper introduces the first asynchronous, task-based formulation of the polar decomposition and its corresponding implementation on manycore architectures. Based on a new formulation of the iterative $QR$ dynamically-weighted Halley algorithm (QDWH) for the calculation of the polar decomposition, the proposed implementation replaces the original and hostile LU factorization for the condition number estimator by the more adequate $QR$ factorization to enable software portability across various architectures. Relying on fine-grained computations, the novel task-based implementation is also capable of taking advantage of the identity structure of the matrix involved during the QDWH iterations, which decreases the overall algorithmic complexity. Furthermore, the artifactual synchronization points have been weakened compared to previous implementations, unveiling look-ahead opportunities for better hardware occupancy. The overall QDWH-based polar decomposition can then be represented as a directed acyclic graph (DAG), where nodes represent computational tasks and edges define the inter-task data dependencies. The StarPU dynamic runtime system is employed to traverse the DAG, to track the various data dependencies and to asynchronously schedule the computational tasks on the underlying hardware resources, resulting in an out-of-order task scheduling. Benchmarking experiments show significant improvements against existing state-of-the-art high performance implementations (i.e., Intel MKL and Elemental) for the polar decomposition on latest shared-memory vendors’ systems (i.e., Intel Haswell/Broadwell/Knights Landing, NVIDIA K80/P100 GPUs and - BM Power8), while maintaining high numerical accuracy.
Auteurs: Dalal Sukkari;Hatem Ltaief;Mathieu Faverge;David Keyes;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 02.-2018, volume: 29, issue:2, pages: 312 - 323
Editeur: IEEE
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» At the Heart of a Sustainable Energy Transition: The Public Acceptability of Energy Projects
Résumé:
Public acceptability is at the heart of changing the energy system toward a more sustainable way of energy production and use. Without public acceptability and support for changes, a sustainable energy transition is unlikely to be viable. We argue that public acceptability is often addressed too late and should be incorporated into the planning process from the start. Moreover, engineers, policy makers, and project developers tend to misjudge the complexity and causes of public resistance, trying to find the magic bullet to "solve" the lack of public acceptability. Such attempts are likely to be ineffective, or even counterproductive, if they fail to address people's key concerns surrounding energy projects. There is not a one-size-fits-all solution: public acceptability is a dynamic process that depends on the context, the specific project at stake, and the parties involved.
Auteurs: Goda Perlaviciute;Geertje Schuitema;Patrick Devine-Wright;Bonnie Ram;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 02.-2018, volume: 16, issue:1, pages: 49 - 55
Editeur: IEEE
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» Atmospheric Humidity Sounding Using Differential Absorption Radar Near 183 GHz
Résumé:
A tunable G-band frequency-modulated continuous-wave radar system has been developed and used to perform differential absorption atmospheric humidity measurements for the first time. The radar’s transmitter uses high- power-handling GaAs Schottky diodes to generate between 15–23 dBm over a 10-GHz bandwidth near 183 GHz. By virtue of a high-isolation circular polarization duplexer, the monostatic radar’s receiver maintains a noise figure of about 7 dB even while the transmitter is on. With an antenna gain of 40 dB, high-SNR detection of light rain is achieved out to several hundred meters distance. Owing to the strong spectral dependence of the atmospheric absorption over the upper flank of the 183-GHz water absorption line, range-resolved measurements of absolute humidity can be obtained by ratioing the rain echoes over both range and frequency. Absorption measurements obtained are consistent with models of atmospheric millimeter-wave attenuation, and they demonstrate a new method for improving the accuracy of humidity measurements inside of clouds.
Auteurs: Ken B. Cooper;Raquel Rodriguez Monje;Luis Millán;Matthew Lebsock;Simone Tanelli;Jose V. Siles;Choonsup Lee;Andrew Brown;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 02.-2018, volume: 15, issue:2, pages: 163 - 167
Editeur: IEEE
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» Attention Recognition in EEG-Based Affective Learning Research Using CFS+KNN Algorithm
Résumé:
The research detailed in this paper focuses on the processing of Electroencephalography (EEG) data to identify attention during the learning process. The identification of affect using our procedures is integrated into a simulated distance learning system that provides feedback to the user with respect to attention and concentration. The authors propose a classification procedure that combines correlation-based feature selection (CFS) and a k-nearest-neighbor (KNN) data mining algorithm. To evaluate the CFS+KNN algorithm, it was test against CFS+C4.5 algorithm and other classification algorithms. The classification performance was measured 10 times with different 3-fold cross validation data. The data was derived from 10 subjects while they were attempting to learn material in a simulated distance learning environment. A self-assessment model of self-report was used with a single valence to evaluate attention on 3 levels (high, neutral, low). It was found that CFS+KNN had a much better performance, giving the highest correct classification rate (CCR) of $80.84 pm 3.0$ % for the valence dimension divided into three classes.
Auteurs: Bin Hu;Xiaowei Li;Shuting Sun;Martyn Ratcliffe;
Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Date publication: 02.-2018, volume: 15, issue:1, pages: 38 - 45
Editeur: IEEE
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» Authenticating Users Through Fine-Grained Channel Information
Résumé:
User authentication is the critical first step in detecting identity-based attacks and preventing subsequent malicious attacks. However, the increasingly dynamic mobile environments make it harder to always apply cryptographic-based methods for user authentication due to their infrastructural and key management overhead. Exploiting non-cryptographic based techniques grounded on physical layer properties to perform user authentication appears promising. In this work, the use of channel state information (CSI), which is available from off-the-shelf WiFi devices, to perform fine-grained user authentication is explored. Particularly, a user-authentication framework that can work with both stationary and mobile users is proposed. When the user is stationary, the proposed framework builds a user profile for user authentication that is resilient to the presence of a spoofer. The proposed machine learning based user-authentication techniques can distinguish between two users even when they possess similar signal fingerprints and detect the existence of a spoofer. When the user is mobile, it is proposed to detect the presence of a spoofer by examining the temporal correlation of CSI measurements. Both office building and apartment environments show that the proposed framework can filter out signal outliers and achieve higher authentication accuracy compared with existing approaches using received signal strength (RSS).
Auteurs: Hongbo Liu;Yan Wang;Jian Liu;Jie Yang;Yingying Chen;H. Vincent Poor;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 02.-2018, volume: 17, issue:2, pages: 251 - 264
Editeur: IEEE
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» Automated Detection of Postictal Generalized EEG Suppression
Résumé:
Although there is no strict consensus, some studies have reported that Postictal generalized EEG suppression (PGES) is a potential electroencephalographic (EEG) biomarker for risk of sudden unexpected death in epilepsy (SUDEP). PGES is an epoch of EEG inactivity after a seizure, and the detection of PGES in clinical data is extremely difficult due to artifacts from breathing, movement and muscle activity that can adversely affect the quality of the recorded EEG data. Even clinical experts visually interpreting the EEG will have diverse opinions on the start and end of PGES for a given patient. The development of an automated EEG suppression detection tool can assist clinical personnel in the review and annotation of seizure files, and can also provide a standard for quantifying PGES in large patient cohorts, possibly leading to further clarification of the role of PGES as a biomarker of SUDEP risk. In this paper, we develop an automated system that can detect the start and end of PGES using frequency domain features in combination with boosting classification algorithms. The average power for different frequency ranges of EEG signals are extracted from the prefiltered recorded signal using the fast fourier transform and are used as the feature set for the classification algorithm. The underlying classifiers for the boosting algorithm are linear classifiers using a logistic regression model. The tool is developed using 12 seizures annotated by an expert then tested and evaluated on another 20 seizures that were annotated by 11 experts.
Auteurs: Wanchat Theeranaew;James McDonald;Bilal Zonjy;Farhad Kaffashi;Brian D. Moseley;Daniel Friedman;Elson So;James Tao;Maromi Nei;Philippe Ryvlin;Rainer Surges;Roland Thijs;Stephan Schuele;Samden Lhatoo;Kenneth A. Loparo;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 02.-2018, volume: 65, issue:2, pages: 371 - 377
Editeur: IEEE
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» Automated Integrated Robotic Systems for Diagnostics and Test of Electric and Micropropulsion Thrusters
Résumé:
An integrated microcontroller-based data acquisition and robotic actuation suite comprising digital electronics, microcontrollers, custom-made hardware, and accessorial software for diagnostics, and characterization of electric propulsion thrusters in a large vacuum space environment simulator is designed, built, and tested. The components of the characterization suite have been aggregated into modular add-on units for rapid rearrangement and easy customization to suit various applications. The modules include a force calibration system for accurate thrust measurements in various thrust stands, and spatially resolved measurements in a multiprobe array comprising Langmuir and Faraday probes for plume diagnostics of plasma thrusters. Plume and thrust characteristics of a miniaturized Hall-type thruster were successfully measured in situ, enabling users to vary process controls and efficiently optimize the thruster performance. The system revealed a further potential for real-time flight mission diagnostics and control.
Auteurs: J. W. M. Lim;S. Y. Huang;L. Xu;J. S. Yee;R. Z. Sim;Z. L. Zhang;I. Levchenko;S. Xu;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 02.-2018, volume: 46, issue:2, pages: 345 - 353
Editeur: IEEE
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» Automated Test Case Generation as a Many-Objective Optimisation Problem with Dynamic Selection of the Targets
Résumé:
The test case generation is intrinsically a multi-objective problem, since the goal is covering multiple test targets (e.g., branches). Existing search-based approaches either consider one target at a time or aggregate all targets into a single fitness function (whole-suite approach). Multi and many-objective optimisation algorithms (MOAs) have never been applied to this problem, because existing algorithms do not scale to the number of coverage objectives that are typically found in real-world software. In addition, the final goal for MOAs is to find alternative trade-off solutions in the objective space, while in test generation the interesting solutions are only those test cases covering one or more uncovered targets. In this paper, we present Dynamic Many-Objective Sorting Algorithm (DynaMOSA), a novel many-objective solver specifically designed to address the test case generation problem in the context of coverage testing. DynaMOSA extends our previous many-objective technique Many-Objective Sorting Algorithm (MOSA) with dynamic selection of the coverage targets based on the control dependency hierarchy. Such extension makes the approach more effective and efficient in case of limited search budget. We carried out an empirical study on 346 Java classes using three coverage criteria (i.e., statement, branch, and strong mutation coverage) to assess the performance of DynaMOSA with respect to the whole-suite approach (WS), its archive-based variant (WSA) and MOSA. The results show that DynaMOSA outperforms WSA in 28 percent of the classes for branch coverage (+8 percent more coverage on average) and in 27 percent of the classes for mutation coverage (+11 percent more killed mutants on average). It outperforms WS in 51 percent of the classes for statement coverage, leading to +11 percent more coverage on average. Moreover, DynaMOSA outperforms its predecessor MOSA for all the three coverage criteria in 19 percent of the classes with +8 percent more code coverage o- average.
Auteurs: Annibale Panichella;Fitsum Meshesha Kifetew;Paolo Tonella;
Apparue dans: IEEE Transactions on Software Engineering
Date publication: 02.-2018, volume: 44, issue:2, pages: 122 - 158
Editeur: IEEE
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» Automated Wavelength Alignment in a 4 × 4 Silicon Thermo-Optic Switch Based on Dual-Ring Resonators
Résumé:
We propose and experimentally demonstrate an automated resonance wavelength alignment scheme for an O -band 4 × 4 thermo-optic optical switch using dual-ring resonators. In this scheme, a new control algorithm based on saddle point searching is employed to align dual-input switching elements (SEs) and therefore the 4 × 4 switch. The proposed scheme is proven effective by demonstrating eight routing configurations for two 10-Gb/s data channels. The insertion losses of the three-stage SEs are ≤6.9 dB, and the crosstalk values are below −13.6 dB. Besides, the tolerance of the switch to the wavelength misalignment between the two optical input signals is measured. Negligible performance degradations are observed when the two channels are spaced by 0.05 nm.
Auteurs: Qingming Zhu;Xinhong Jiang;Yanping Yu;Ruiyuan Cao;Hongxia Zhang;Danping Li;Yanbo Li;Li Zeng;Xuhan Guo;Yong Zhang;Ciyuan Qiu;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 11
Editeur: IEEE
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» Automatic 2-D/3-D Vessel Enhancement in Multiple Modality Images Using a Weighted Symmetry Filter
Résumé:
Automated detection of vascular structures is of great importance in understanding the mechanism, diagnosis, and treatment of many vascular pathologies. However, automatic vascular detection continues to be an open issue because of difficulties posed by multiple factors, such as poor contrast, inhomogeneous backgrounds, anatomical variations, and the presence of noise during image acquisition. In this paper, we propose a novel 2-D/3-D symmetry filter to tackle these challenging issues for enhancing vessels from different imaging modalities. The proposed filter not only considers local phase features by using a quadrature filter to distinguish between lines and edges, but also uses the weighted geometric mean of the blurred and shifted responses of the quadrature filter, which allows more tolerance of vessels with irregular appearance. As a result, this filter shows a strong response to the vascular features under typical imaging conditions. Results based on eight publicly available datasets (six 2-D data sets, one 3-D data set, and one 3-D synthetic data set) demonstrate its superior performance to other state-of-the-art methods.
Auteurs: Yitian Zhao;Yalin Zheng;Yonghuai Liu;Yifan Zhao;Lingling Luo;Siyuan Yang;Tong Na;Yongtian Wang;Jiang Liu;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2018, volume: 37, issue:2, pages: 438 - 450
Editeur: IEEE
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» Automatic 3D Design for Efficiency Optimization of a Class E Power Amplifier
Résumé:
A design tool, which exploits a state–space model description for the automatic design of a class E power amplifier (PA), is here proposed. The tool provides an automatic optimization of the filter components, just by inserting the design specifications and the starting values. The second step of the automatic iterative tuning allows preserving the highest value of power efficiency. All specifications realize a 3 D matrix, which is able to converge (with 60 iterations in about 3 s) to an optimal solution by using the cross-check of the specifications. Finally, as a case study, an ${eta }$ -optimal design has been implemented by using the proposed tool. We compare the analytical design of the class-E PA implemented in TSMC 65 nm CMOS technology, with the state space model technique here described. The new design reaches an efficiency of 87% in simulation, with an ${eta }$ increment of 12% respect the original design.
Auteurs: Daniela De Venuto;Giovanni Mezzina;Jan Rabaey;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2018, volume: 65, issue:2, pages: 201 - 205
Editeur: IEEE
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» Automatic Calcium Scoring in Low-Dose Chest CT Using Deep Neural Networks With Dilated Convolutions
Résumé:
Heavy smokers undergoing screening with low-dose chest CT are affected by cardiovascular disease as much as by lung cancer. Low-dose chest CT scans acquired in screening enable quantification of atherosclerotic calcifications and thus enable identification of subjects at increased cardiovascular risk. This paper presents a method for automatic detection of coronary artery, thoracic aorta, and cardiac valve calcifications in low-dose chest CT using two consecutive convolutional neural networks. The first network identifies and labels potential calcifications according to their anatomical location and the second network identifies true calcifications among the detected candidates. This method was trained and evaluated on a set of 1744 CT scans from the National Lung Screening Trial. To determine whether any reconstruction or only images reconstructed with soft tissue filters can be used for calcification detection, we evaluated the method on soft and medium/sharp filter reconstructions separately. On soft filter reconstructions, the method achieved F1 scores of 0.89, 0.89, 0.67, and 0.55 for coronary artery, thoracic aorta, aortic valve, and mitral valve calcifications, respectively. On sharp filter reconstructions, the F1 scores were 0.84, 0.81, 0.64, and 0.66, respectively. Linearly weighted kappa coefficients for risk category assignment based on per subject coronary artery calcium were 0.91 and 0.90 for soft and sharp filter reconstructions, respectively. These results demonstrate that the presented method enables reliable automatic cardiovascular risk assessment in all low-dose chest CT scans acquired for lung cancer screening.
Auteurs: Nikolas Lessmann;Bram van Ginneken;Majd Zreik;Pim A. de Jong;Bob D. de Vos;Max A. Viergever;Ivana Išgum;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2018, volume: 37, issue:2, pages: 615 - 625
Editeur: IEEE
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» Automatic Correction of Dynamic Power Management Architecture in Modern Processors
Résumé:
The increasing demand for lower power forces designers to use sophisticated power management strategies such as multivoltage and power gating which are often accompanied with many design bugs. Correcting such bugs can be a time-consuming process that requires considerable manual efforts. In this paper, we propose a scalable automated method for correcting dynamic power management architectures by an incremental SAT-based mechanism. First, an initial counterexample (CEX) is generated by checking the equivalency between the specification model of the processor and its buggy implementation model. Then, we find two candidate solutions instead of one to satisfy this CEX. If two solutions are not equivalent, we generate new CEX in an iterative process which effectively converges into the final solution. The proposed method enables designers to correct multiple bugs such as missing isolation cells between two power domains, disordering in the sequence of control signals, error in the data restoring or saving, and powering off in always-on domains which are not addressed by existing methods. We have shown the effectiveness of our method on modern processors supporting complex power management mechanisms. The results confirm that our proposed method, respectively, reduces symbolic simulation steps and runtime by $2.33times $ and $47.93times $ compared to the state-of-the-art methods.
Auteurs: Reza Sharafinejad;Bijan Alizadeh;Zainalabedin Navabi;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 02.-2018, volume: 26, issue:2, pages: 308 - 318
Editeur: IEEE
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» Automatic Defect Detection of Fasteners on the Catenary Support Device Using Deep Convolutional Neural Network
Résumé:
The excitation and vibration triggered by the long-term operation of railway vehicles inevitably result in defective states of catenary support devices. With the massive construction of high-speed electrified railways, automatic defect detection of diverse and plentiful fasteners on the catenary support device is of great significance for operation safety and cost reduction. Nowadays, the catenary support devices are periodically captured by the cameras mounted on the inspection vehicles during the night, but the inspection still mostly relies on human visual interpretation. To reduce the human involvement, this paper proposes a novel vision-based method that applies the deep convolutional neural networks (DCNNs) in the defect detection of the fasteners. Our system cascades three DCNN-based detection stages in a coarse-to-fine manner, including two detectors to sequentially localize the cantilever joints and their fasteners and a classifier to diagnose the fasteners’ defects. Extensive experiments and comparisons of the defect detection of catenary support devices along the Wuhan–Guangzhou high-speed railway line indicate that the system can achieve a high detection rate with good adaptation and robustness in complex environments.
Auteurs: Junwen Chen;Zhigang Liu;Hongrui Wang;Alfredo Núñez;Zhiwei Han;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 02.-2018, volume: 67, issue:2, pages: 257 - 269
Editeur: IEEE
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» Automatic Identification of Driver’s Smartphone Exploiting Common Vehicle-Riding Actions
Résumé:
Texting or browsing the web on a smartphone while driving, called distracted driving, significantly increases the risk of car accidents. There have been a number of proposals for the prevention of distracted driving, but none of them has addressed its important challenges completely and effectively. To remedy this deficiency, we present an event-driven solution, called Automatic Identification of Driver’s Smartphone (AIDS), which identifies a driver’s smartphone by analyzing and fusing the phone’s sensory information related to common vehicle-riding activities, such as walking toward the vehicle, standing near the vehicle while opening a vehicle door, entering the vehicle, closing the door, and starting the engine. AIDS extracts features useful for identification of the driver’s phone from diverse sensors available in commodity smartphones. It identifies the driver’s phone before the vehicle leaves its parked spot, and differentiates seated (front or rear) rows in a vehicle by analyzing the subtle electromagnetic field spikes caused by the starting of the engine. To evaluate the feasibility and adaptability of AIDS, we have conducted extensive experiments: a prototype of AIDS was distributed to 12 participants, both males and females in their 20 and 30s, who have driven seven different vehicles for three days in real-world environments. Our evaluation results show that AIDS identified the driver’s phone with an 83.3-93.3 percent true positive rate while achieving a 90.1-91.2 percent true negative rate at a marginal increase of the phone’s energy consumption.
Auteurs: Homin Park;DaeHan Ahn;Taejoon Park;Kang G. Shin;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 02.-2018, volume: 17, issue:2, pages: 265 - 278
Editeur: IEEE
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» Avoiding Matrix Inversion in Takagi–Sugeno-Based Advanced Controllers and Observers
Résumé:
Many of the recent advances on control and estimation of systems described by Takagi–Sugeno (TS) fuzzy models are based on matrix inversion, which could be a trouble in the case of real-time implementation. This paper is devoted to the development of alternative solutions to this matrix inversion problem in the discrete-time case. Two different methods are proposed: The first one relies on replacing the matrix inversion by multiple sums and the second methodology is based on an estimation of the matrix inversion by an observer structure. For the first methodology, a new class of controllers and observers are introduced which are called, respectively, the counterpart of an advanced TS-based (CATS) controller and the replica of an advanced TS-based (RATS) observer. Instead of relaxations for the linear matrix inequalities conditions, an original use of the membership functions is presented. In the second methodology, it is proposed the estimation-based control law for approximating TS-based (ECLATS) controller that uses a fuzzy state observer. The Lyapunov theory is used to ensure stability conditions for either the closed-loop system as well as the estimation error. Numerical examples and comparisons highlight the efficiency of the procedures that can be used to replace any inverted matrix in any advanced fuzzy controller or observer. Finally, advantages and drawbacks of the proposed method are discussed.
Auteurs: Thomas Laurain;Jimmy Lauber;Reinaldo Martinez Palhares;
Apparue dans: IEEE Transactions on Fuzzy Systems
Date publication: 02.-2018, volume: 26, issue:1, pages: 216 - 225
Editeur: IEEE
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» Bad Data Detection Using Linear WLS and Sampled Values in Digital Substations
Résumé:
Smart Grids employ intelligent control applications that require high quality data: fast, secure, and error free. Several researchers have focused on providing techniques for low latency and secured data links for these applications. Bad data detection is however generally provided only at the central level due to limitations in legacy technologies employed in many substations. With the introduction of IEC61850 data sharing within the substation becomes more flexible and transparent allowing more sophisticated management of data quality. Hence, this paper proposes a substation level bad data detection algorithm to facilitate also these types of requirements from applications. The algorithm is based on automatically detecting the substation topology by parsing standard substation description files and online state of circuit breakers and disconnectors. By applying linear weighted least square based state estimation algorithm, bad data from failing current transformers (CT) can be detected. By conducting the verification of different types of bad data, the results show the output of bad data detection algorithm provides higher accuracy than output from both measurement and protective CT in both static and faulty situations.
Auteurs: Yiming Wu;Yong Xiao;Fabian Hohn;Lars Nordström;Jianping Wang;Wei Zhao;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2018, volume: 33, issue:1, pages: 150 - 157
Editeur: IEEE
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» Balanced Filter With Wideband Common-Mode Suppression in Groove Gap Waveguide Technology
Résumé:
This letter is focused on the design and realization of balanced bandpass filters (BPFs) in gap waveguide technology. The procedure of filter design and resonance-mode selection to achieve the desired differential bandpass behavior with intrinsic deep and wideband common-mode suppression is explained. A third-order differential BPF is designed and fabricated for demonstration. Agreement between the computed and measured results validates the concept and the design procedure.
Auteurs: Ali K. Horestani;Mahmoud Shahabadi;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2018, volume: 28, issue:2, pages: 132 - 134
Editeur: IEEE
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» Balanced Power Amplifier Protection Against Load Mismatch
Résumé:
This letter presents a new approach for balanced power amplifier protection against load mismatch under pulsed-RF operation. The proposed protection mechanism completely eliminates the reflected power under severe mismatch conditions while not affecting nominal operating condition. The concept is based on detection, comparison, and switching technique. The proposed protection circuit offers full protection against open and short at the output. This protection mechanism has been demonstrated on a 10-W $X$ -band power amplifier, intended to be used in space borne radar payloads. The reaction time of the proposed protection mechanism is <100 ns.
Auteurs: Shruti Sinha;Ch. V. N. Rao;Dhaval Pujara;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2018, volume: 28, issue:2, pages: 165 - 167
Editeur: IEEE
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» Bandwidth Analysis of RF-DC Converters Under Multisine Excitation
Résumé:
The use of multisine signals to improve the efficiency of wireless power transfer (WPT) for low average received power was proposed recently. Several measurement-based studies illustrated the gain that can be achieved for different circuit or waveform instances, focusing on the impact of a time-varying amplitude on the rectifying efficiency. This paper first establishes a model enabling a thorough analysis of the multisine-based WPT system focusing on the bandwidth of the signal and the rectifier. This model enables a codesign of signal and rectifier for optimal WPT. The proposed model provides insight into the output voltage and power, as a function of the input waveform for different circuit models. By including the input matching and the clamper, our model is generic and can include a wide range of rectifiers with different voltage multiplication approaches. The key insight gained from our analysis is that there is a tradeoff between the frequency spacing of the tones of the multisine signal and the cut-off frequency of the low-pass RC filter, as a main property of the rectifier circuit. Our model predicts the measured power conversion efficiency and voltage with an error below 0.1 and 0.2 V, respectively.
Auteurs: Ning Pan;Daniel Belo;Mohammad Rajabi;Dominique Schreurs;Nuno Borges Carvalho;Sofie Pollin;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2018, volume: 66, issue:2, pages: 791 - 802
Editeur: IEEE
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» Bandwidth Enhancement to Continuous-Time Input Pipeline ADCs
Résumé:
This paper presents design analysis and insights for a new continuous-time input pipeline (CTIP) analog-to-digital converter (ADC) architecture that has enhanced bandwidth. An all-pass filter-based analog delay in the signal path allows bandwidth extension to Nyquist signal bandwidths. A resetting integrator gain stage provides a signal path delay helping to increase the bandwidth while reducing the power cost. The noise filtering property of the resetting integrator gain stage preserves the medium resistive input benefit of CTIP ADCs. The resetting integrator allows the architecture to be implemented with a feedforward compensated op-amp using low-voltage CMOS processes. This paper has been verified by simulation results of a CTIP ADC with 1.2-V supply voltage designed in TSMC’s 65-nm CMOS technology.
Auteurs: Daniel O’Hare;Anthony G. Scanlan;Eric Thompson;Brendan Mullane;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 02.-2018, volume: 26, issue:2, pages: 404 - 415
Editeur: IEEE
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» Barium Zirconate Nickelate as the Gate Dielectric for Low-Leakage Current Organic Transistors
Résumé:
High- $kappa $ barium zirconate nickelate (BZN) gate dielectric layer was prepared through the low-temperature sol–gel method and was used in pentacene-based organic thin-film transistor (OTFT) applications. In comparison with its barium zirconate oxide (BZO) counterpart, experimental results show that the threshold voltage of the BZN-based OTFTs decreases from −2 to −1.1 V, the gate leakage decreases from 10−8 to 10−12 A, the carrier mobility increases from 2.1 to 5.2 cm2/Vs, and the subthreshold swing decreases from 2.4 to 0.4 V/decade. The effect of Ni on device characteristics is discussed in this paper. Ni(II) acetylacetone possesses two pairs of symmetrical bidentate ligands, which can chelate with Zr ion to smoothen surface roughness. The dielectric constant can be increased. The enhancement of mobility is partly attributed to the smoother surface to reduce the scattering effects of the carrier. In addition, the improved film quality may also increase the barrier height and reduce the leakage current, which enhances the ON/ OFF ratio through the chelate effect due to the addition of Ni in BZO. Furthermore, excellent operation stability can be achieved.
Auteurs: Cheng-Jung Lee;Ke-Jing Lee;Yu-Chi Chang;Li-Wen Wang;Der-Wei Chou;Yeong-Her Wang;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2018, volume: 65, issue:2, pages: 680 - 686
Editeur: IEEE
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» Battery-Less Short-Term Smoothing of Photovoltaic Generation Using Sky Camera
Résumé:
There is a growing concern over addressing the adverse effects of variations in the output power of distributed generators such as photovoltaic generation (PVG) systems that continue to be widely introduced into power networks. Nowadays, most network operators are requiring these intermittent energy resources to seek compliance with new regulations pertaining to the restriction of their export power fluctuations. This paper aims to investigate the smoothing of the export power fluctuations primarily attributed to clouds passing over the PVG plant, which are traditionally compensated by integrating a battery storage (BS) system. The idea of incorporating short-term solar prediction information into the conventional smoothing approach is examined to indicate how it affects the engagement of BS in the smoothing process. Afterward, an enhanced solar forecasting scheme based on whole-sky imaging is proposed and its performance is demonstrated through several real-time experiments complemented with simulation studies. The results reveal that the proposed PVG smoothing strategy is capable of successfully filtering rapid export power fluctuations to an acceptable extent and the conventional generation reserves will experience a negligible amount of remaining undesired power variation. This clearly bears out the hypothesis of battery-less PVG regulation.
Auteurs: Mojtaba Saleh;Lindsay Meek;Mohammad A. S. Masoum;Masoud Abshar;
Apparue dans: IEEE Transactions on Industrial Informatics
Date publication: 02.-2018, volume: 14, issue:2, pages: 403 - 414
Editeur: IEEE
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» Bayesian Particle Tracking of Traffic Flows
Résumé:
We develop a Bayesian particle filter for tracking traffic flows that is capable of capturing non-linearities and discontinuities present in flow dynamics. Our model includes a hidden state variable that captures sudden regime shifts between traffic free flow, breakdown, and recovery. We develop an efficient particle learning algorithm for real time online inference of states and parameters. This requires a two-step approach, first resampling the current particles with a mixture predictive distribution and second propagation of states using the conditional posterior distribution. Particle learning of parameters follows from updating recursions for conditional sufficient statistics. To illustrate our methodology, we analyze the measurements of daily traffic flow from the Illinois Interstate I-55 highway system. We demonstrate how our filter can be used to infer the change of traffic flow regime on a highway road segment based on a measurement from freeway single-loop detectors. Finally, we conclude with directions for future research.
Auteurs: Nicholas Polson;Vadim Sokolov;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 02.-2018, volume: 19, issue:2, pages: 345 - 356
Editeur: IEEE
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» Bayesian Test for Detecting False Data Injection in Wireless Relay Networks
Résumé:
We develop the Bayesian test for detecting the relay misbehavior (false data injection) at the packet level in lossy one-way wireless relay networks. The proposed approach exploits overheard erroneous packet from the source as a reference in verifying the correctness of relayed packet at the destination. We derive the probability of false alarm and missed detection as a function of the overhearing error rate, the number of bits modified in a packet, and the packet length. We show that the probability of false alarm and missed detection decreases as the packet length increases and converges to zero, regardless of the overhearing error rate, if the packet length is sufficiently long.
Auteurs: Xudong Liu;Yong Guan;Sang Wu Kim;
Apparue dans: IEEE Communications Letters
Date publication: 02.-2018, volume: 22, issue:2, pages: 380 - 383
Editeur: IEEE
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» Beam Shaping Freeform Lens Design With Modified Optical Flux Partition
Résumé:
A freeform lens design strategy that performs directivity transformation is proposed. In principle, arbitrary beam pattern can be achieved with this method, which uses a modified flux partition method. Taking a Lambertian light source as the example, this method successfully give different required intensity distributions, such as the isotropic and exponential ones. Also, the isotropic directivity lens is fabricated and the beam pattern is measured to verify the effectiveness. With a real Lambertian top emitting white light LED as the source, the experimental results agree well with the simulation ones, which provides high directivity isotropy (more than 80%). This scheme takes Fresnel loss of the lens into consideration and can also predict the efficiency of the lens; it may find applications in lighting or illumination engineering where directivity transformation are required.
Auteurs: Pin Han;Hsun-Ching Hsu;Cheng-Mu Tsai;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2018, volume: 10, issue:1, pages: 1 - 13
Editeur: IEEE
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» Beam Switching Antenna Based on a Reconfigurable Cascaded Feeding Network
Résumé:
In this paper, a beam switching antenna (BSA) based on a reconfigurable cascaded feeding network (RCFN) is presented. The RCFN is engineered by cascading several varactor-loaded quasi-lumped couplers (QLCs). As the output port of the RCFN, the coupled port of every QLC is connected to an endfire radiator. BSAs based on two types of RCFN, the open-loop RCFN and closed-loop RCFN, are designed, simulated, and measured. The open-loop design features flexible beam switching strategies with the dynamic control of operation modes allocating the input power to the intended radiator(s), and single-/multibeam switching is achieved. In the case of the closed-loop RCFN, a power-recycling circuit is introduced to improve the efficiency of the single-beam switching mode of the BSA. Measured results show that the BSA operating in single-beam mode is able to radiate six switched beams each with a 3 dB beamwidth of 60°, covering 360° in the azimuth plane. The return losses and gain fluctuation of both prototypes are better than 15 dB and less than 1 dB, respectively. The corresponding experiments agree well with both the theoretical analysis and the simulation results.
Auteurs: Peng-Yuan Wang;Tao Jin;Fan-Yi Meng;Yue-Long Lyu;Daniel Erni;Qun Wu;Lei Zhu;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 627 - 635
Editeur: IEEE
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» Beam-Shaping Technique Based on Generalized Laws of Refraction and Reflection
Résumé:
In this paper, we present a new beam-shaping technique based on the use of a flat lens comprised of phase shift structures (PSSs), designed to reshape the primary beam into a desired one. The beam impinging upon the input port of the lens is regarded as a set of ray tubes, whose refraction characteristics are modified by the PSSs based on the generalized law of refraction to form the desired shaped beam. The proposed method is straightforward to implement and is general purpose in nature. The design procedure of the beam-shaping flat lens is discussed in detail, and two example designs are presented. The simulation and measured results of these case examples confirm that the BSFLs can reshape the primary beams of the feed antennas to the desired flattop or isoflux patterns, for instance. Finally, extensions of the proposed technique to other potential applications are discussed.
Auteurs: Pengfei Zhang;Shuxi Gong;Raj Mittra;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2018, volume: 66, issue:2, pages: 771 - 779
Editeur: IEEE
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» Beampattern Synthesis for Frequency Diverse Array via Reweighted $ell _1$ Iterative Phase Compensation
Résumé:
This paper addresses the issue of beampattern synthesis with flexible magnitude response and low sidelobe in a frequency diverse array radar. It is formulated as an optimization problem in terms of $ell _1$-norm minimization, which encourages the sparsity of array pattern. An $ell _1$ iterative phase compensation (IPC) technique is employed to transform the nonconvex constraint to phase compensation form. Then, to further reduce the sidelobe level, a reweighted $ell _1$ -IPC algorithm is devised, in which a sparsity-enhanced scheme is utilized to convert the $ell _1$-norm to a new cost function that more closely resembles $ell _0$-norm. Numerical results are presented to demonstrate the effectiveness of the proposed approach in different scenarios.
Auteurs: Qiang Li;Lei Huang;Peichang Zhang;Hing Cheung So;Huifeng Xue;
Apparue dans: IEEE Transactions on Aerospace and Electronic Systems
Date publication: 02.-2018, volume: 54, issue:1, pages: 467 - 475
Editeur: IEEE
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» Benchmarking of Constant Power Generation Strategies for Single-Phase Grid-Connected Photovoltaic Systems
Résumé:
With a still increase of grid-connected photovoltaic (PV) systems, challenges have been imposed on the grid due to the continuous injection of a large amount of fluctuating PV power, like overloading the grid infrastructure (e.g., transformers) during peak power production periods. Hence, advanced active power control methods are required. As a cost-effective solution to avoid overloading, a constant power generation (CPG) control scheme by limiting the feed-in power has been introduced into the currently active grid regulations. In order to achieve a CPG operation, this paper presents three CPG strategies based on a power control method (P-CPG), a current limit method (I-CPG), and the perturb and observe algorithm (P&O-CPG). However, the operational mode changes (e.g., from the maximum power point tracking to a CPG operation) will affect the entire system performance. Thus, a benchmarking of the presented CPG strategies is also conducted on a 3-kW single-phase grid-connected PV system. Comparisons reveal that either the P-CPG or I-CPG strategies can achieve fast dynamics and satisfactory steady-state performance. In contrast, the P&O-CPG algorithm is the most suitable solution in terms of high robustness, but it presents poor dynamic performance.
Auteurs: Ariya Sangwongwanich;Yongheng Yang;Frede Blaabjerg;Huai Wang;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 447 - 457
Editeur: IEEE
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» Bi-level and Bi-objective p-Median Type Problems for Integrative Clustering: Application to Analysis of Cancer Gene-Expression and Drug-Response Data
Résumé:
Recent advances in high-throughput technologies have given rise to collecting large amounts of multidimensional heterogeneous data that provide diverse information on the same biological samples. Integrative analysis of such multisource datasets may reveal new biological insights into complex biological mechanisms and therefore remains an important research field in systems biology. Most of the modern integrative clustering approaches rely on independent analysis of each dataset and consensus clustering, probabilistic or statistical modeling, while flexible distance-based integrative clustering techniques are sparsely covered. We propose two distance-based integrative clustering frameworks based on bi-level and bi-objective extensions of the p-median problem. A hybrid branch-and-cut method is developed to find global optimal solutions to the bi-level p-median model. As to the bi-objective problem, an $varepsilon$ -constraint algorithm is proposed to generate an approximation to the Pareto optimal set. Every solution found by any of the frameworks corresponds to an integrative clustering. We present an application of our approaches to integrative analysis of NCI-60 human tumor cell lines characterized by gene expression and drug activity profiles. We demonstrate that the proposed mathematical optimization-based approaches outperform some state-of-the-art and traditional distance-based integrative and non-integrative clustering techniques.
Auteurs: Anton V. Ushakov;Xenia Klimentova;Igor Vasilyev;
Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Date publication: 02.-2018, volume: 15, issue:1, pages: 46 - 59
Editeur: IEEE
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» Biased Constrained Hybrid Kalman Filter for Range-Based Indoor Localization
Résumé:
The range-based localization method is widely used in wireless sensor localization systems. Many existing localization algorithms are unbiased estimators. However, the estimation performance presents biased features in the real localization systems. On the other hand, many biased location estimators show some essential advantages over unbiased estimators, e.g., robust to the noise, more accurate estimation, and low complexity. In this paper, we deeply investigate the performance of biased estimator, min–max, to achieve a new accuracy limit, and propose a hybrid Kalman filtering algorithm, which recursively locates the target based on biased feature. The first contribution is that we formulate the biased Cramér-Rao lower bound of the min–max algorithm to indicate that the biased localization algorithm can outperform the unbiased algorithms, e.g., maximum likelihood, as if the estimation bias were attained. The second contribution is that we propose a hybrid Kalman filtering algorithm while employing the min–max to construct a constrain region and using the dynamic Gaussian model for calculation in non-Gaussian environments. Our algorithm is robust to complicated environments with high accuracy. And, we implement it in an IoT target tracking platform. Both theoretical analysis and experimental evaluation indicate that the proposed algorithm outperform the unbiased optimal estimation methods. And our algorithm can control the estimation error in only 1 m.
Auteurs: Yubin Zhao;Xiaofan Li;Yang Wang;Cheng-Zhong Xu;
Apparue dans: IEEE Sensors Journal
Date publication: 02.-2018, volume: 18, issue:4, pages: 1647 - 1655
Editeur: IEEE
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» Bilateral LSTM: A Two-Dimensional Long Short-Term Memory Model With Multiply Memory Units for Short-Term Cycle Time Forecasting in Re-entrant Manufacturing Systems
Résumé:
Forecasting short-term cycle time (CT) of wafer lots is crucial for production planning and control in the wafer manufacturing. A novel recurrent neural network called “bilateral long short-term memory (bilateral LSTM)” is proposed to model a short-term cycle time forecasting (CTF) of each re-entrant period of a wafer lot. First, a two-dimensional (2-D) architecture is designed to transmit the wafer and layer correlations by using wafer and layer connections. Subsequently, aiming to store various error signals caused by the diverse CT data, a multiply memory structure is presented to extend the capacity of constant error carousel (CEC) in the LSTM model. The experiment results indicate that the proposed model outperforms conventional models in the accuracy and stability for the short-term CTF. Further comparative experiments reveal that the 2-D architecture can enhance the prediction accuracy and the multi-CEC structure can improve the forecasting stability for the short-term CTF of wafer lots.
Auteurs: Junliang Wang;Jie Zhang;Xiaoxi Wang;
Apparue dans: IEEE Transactions on Industrial Informatics
Date publication: 02.-2018, volume: 14, issue:2, pages: 748 - 758
Editeur: IEEE
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» Bilevel Multiview Latent Space Learning
Résumé:
Different kinds of features describe different aspects of image data, and each feature can be treated as a view when we take it as a particular understanding of images. Leveraging multiple views provides a richer and comprehensive description than using only a single view. However, multiview data are often represented by high-dimensional heterogeneous features, so it is meaningful to find a low-dimensional consensus representation from multiple views. In this paper, we propose an unsupervised multiview dimensionality reduction method for images based on bilevel latent space learning. As different views have different physical meanings and statistical properties, they are not directly comparable. Therefore, we learn the comparable representation for each view in the first level. The shared and the private nature of multiview data are exploited to accurately preserve the information of each view. Then, we fuse different views into a low-dimensional representation by conducting joint matrix factorization in the second level. To guarantee the low-dimensional representation to be compact and discriminative, the intrinsic geometric structure of data is utilized. Besides, our method considers resisting the outliers and noise contained in multiview data, which may influence the learned representation and deteriorate its semantic consistency. We design appropriate optimization objectives to learn the latent spaces in different levels. Compared with the existing methods, our method could provide a more flexible multiview learning strategy that not only accurately captures the information of each view but also is robust to outliers and noise, which can obtain a more discriminative and compact low-dimensional representation. Experiments on two real-world image data sets demonstrate the advantages of our method over the existing multiview dimensionality reduction methods.
Auteurs: Zhe Xue;Guorong Li;Shuhui Wang;Weigang Zhang;Qingming Huang;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 02.-2018, volume: 28, issue:2, pages: 327 - 341
Editeur: IEEE
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» Black Phosphorus: A New Platform for Gaseous Sensing Based on Surface Plasmon Resonance
Résumé:
We numerically demonstrate and propose sensitivity enhancement of surface plasmon resonance (SPR)-based conventional gaseous sensor using few layers of black phosphorous (BP), as compared with other 2D material such as graphene and molybdenum disulphide (MoS2). Results of our optimized numerical study show that with implementation of bilayer BP over a conventional gaseous sensor, sensitivity enhances by ~35%, which is further increased up to ~73% by addition of a monolayer MoS2 at an operating wavelength $lambda =633$ nm. Therefore, the proposed SPR gaseous sensor could potentially open a new platform for high-performance gaseous sensing in the visible region.
Auteurs: Triranjita Srivastava;Rajan Jha;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 02.-2018, volume: 30, issue:4, pages: 319 - 322
Editeur: IEEE
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» BLDC Motor Drive Based on Bridgeless Landsman PFC Converter With Single Sensor and Reduced Stress on Power Devices
Résumé:
The Landsman converter based on a power factor correction (PFC) in bridgeless (BL) configuration feeding a brushless dc motor (BLDCM) drive is proposed for low-power household appliances. The conduction losses associated with diodes are reduced by BL configuration and switching losses of solid-state switches of voltage source inverter are reduced by the use of low frequency switching signals in electronic commutation for the BLDCM. The front-end BL PFC based Landsman converter operating in the discontinuous inductor current mode is used for controlling the dc link voltage, and PFC is attained naturally with reduced conduction losses and switch stress. A single voltage sensor is used for controlling the dc bus voltage. A prototype is developed to study performance of the system for wide range speed control and power quality improvement. The experimental performance of BLDCM is presented for its functions at varying voltages of ac mains (90–265 V) to adhere to the limits defined by IEC61000-3-2 standard.
Auteurs: Praveen Kumar Singh;Bhim Singh;Vashist Bist;Kamal Al-Haddad;Ambrish Chandra;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2018, volume: 54, issue:1, pages: 625 - 635
Editeur: IEEE
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