ABCelectronique : portail d'information dans le domaine de l'électronique
Pages: 0123456789101112


Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 05-2017 trié par par titre, page: 7
» Lithium-Ion Battery Charge Equalization Algorithm for Electric Vehicle Applications
Résumé:
The lithium-ion batteries are commonly used in electric vehicle (EV) applications due to their better performances as compared with other batteries. However, lithium-ion battery has some drawbacks such as the overcharged cell which has a risk of explosion, the undercharged cell eventually reduces the life cycle of the battery, and unbalanced charge in series battery gradually reduces overall charge capacity. This paper presents a battery charge equalization algorithm for lithium-ion battery in EV applications to enhance the battery's performance, life cycle, and safety. The algorithm is implemented in series-connected battery cells of 15.5 Ah and 3.7 V nominal each using a battery monitoring integrated circuit for monitoring and equalization of an 8-cell battery pack using a bidirectional flyback dc–dc converter as the channel for charging and discharging of the battery cell. The obtained results show that the developed charge equalization controller algorithm performs well in equalizing both undercharged and overcharged cells, and equalizes the cell within the safety operation range of 3.81 V. To validate the charge equalizer performance, the proposed algorithm outperforms with other studies in terms of balancing, equalization speed, low power loss, and efficiency. Thus, the proposed battery charge equalization algorithm proves an effective and automated system to modularize the battery charge that improves the safety and life cycle of battery.
Auteurs: Mohammad Abdul Hannan;Md. Murshadul Hoque;Seow Eng Peng;M. Nasir Uddin;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2541 - 2549
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Live Prefetching for Mobile Computation Offloading
Résumé:
Mobile computation offloading refers to techniques for offloading computation intensive tasks from mobile devices to the cloud so as to lengthen the formers’ battery lives and enrich their features. The conventional designs fetch (transfer) user-specific data from mobiles to the cloud prior to computing, called offline prefetching. However, this approach can potentially result in excessive fetching of large volumes of data and cause heavy loads on radio-access networks. To solve this problem, the novel technique of live prefetching, which seamlessly integrates the task-level computation prediction and prefetching within the cloud-computing process of a large program with numerous tasks, is proposed in this paper. The technique avoids excessive fetching but retains the feature of leveraging prediction to reduce the program runtime and mobile transmission energy. By modeling the tasks in an offloaded program as a stochastic sequence, stochastic optimization is applied to design fetching policies to minimize mobile energy consumption under a deadline constraint. The policies enable real-time control of the prefetched-data sizes of candidates for future tasks. For slow fading, the optimal policy is derived and shown to have a threshold-based structure, selecting candidate tasks for prefetching and controlling their prefetched data based on their likelihoods. The result is extended to design close-to-optimal prefetching policies to fast fading channels. Compared with fetching without prediction, live prefetching is shown theoretically to always achieve reduction on mobile energy consumption.
Auteurs: Seung-Woo Ko;Kaibin Huang;Seong-Lyun Kim;Hyukjin Chae;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3057 - 3071
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Load Optimization With User Association in Cooperative and Load-Coupled LTE Networks
Résumé:
We extend the problem of optimizing user association for load balancing in cellular networks along 2-dimensions. First, we consider joint transmission, which is one of the coordinated multipoint techniques with which a user may be simultaneously served by multiple base stations. Second, we account for, mathematically, the coupling relation between the base stations’ load levels that are dependent on each other due to inter-cell interference. We formulate two optimization problems, sum load minimization (MinSumL) and maximum load minimization (MinMaxL). We prove that both MinSumL and MinMaxL are $mathcal {NP}$ -hard. We propose a mixed integer linear programming based scheme by means of linearization. This approach also leads to a bounding scheme for performance benchmarking. Then, we derive a set of partial optimality conditions. Fulfillment of the conditions will guarantee performance improvement for both MinSumL and MinMaxL. A solution algorithm is then derived based on the conditions. Simulation results are provided to demonstrate the effectiveness of the approaches.
Auteurs: Lei You;Di Yuan;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3218 - 3231
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Local Controllability of the Two-Link Magneto-Elastic Micro-Swimmer
Résumé:
A recent promising technique for robotic micro-swimmers is to endow them with a magnetization and apply an external magnetic field to provoke their deformation. In this technical note, we consider a simple planar micro-swimmer model made of two magnetized segments connected by an elastic joint, controlled via a magnetic field. After recalling the analytical model, we establish a local controllability result around the straight position of the swimmer.
Auteurs: Laetitia Giraldi;Jean-Baptiste Pomet;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2512 - 2518
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Local Defect Density in Polycrystalline High-k Dielectrics: CAFM-Based Evaluation Methodology and Impact on MOSFET Variability
Résumé:
A methodology to determine with nanometer resolution the defect density in polycrystalline HfO2 layers has been developed. This methodology is based on experimental data measured with conductive atomic force microscopy and the obtained results have been validated using Kelvin prove force microscopy measurements. The local defect density ( $rho _{mathsf {ox}}$ ) and thickness ( $text{t}_{mathsf {ox}}$ ) of the gate dielectric have been included into a device simulator to evaluate their impact on the $text{I}_{mathsf {D}}text{V}_{mathsf {G}}$ curves of MOSFETs.
Auteurs: C. Couso;M. Porti;J. Martin-Martinez;A. J. Garcia-Loureiro;N. Seoane;M. Nafria;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 637 - 640
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Localization of Radial Deformation and Its Extent in Power Transformer HV Winding Using Stationary UWB Antennas
Résumé:
In this paper, three monitoring stages of detection, localization, and extent determination of radial deformation in power transformer winding using stationary ultra-wideband antennas, are investigated. For this purpose, two types of radial deformation are implemented on the actual transformer high-voltage winding. The first type is a modeled bulgy mechanical deformation, which its extent and reversibility may be changed and it can occur in different positions. The second type is an actual radial deformation applied to the winding. Hyperboloid method and 2-D locus of the winding are adopted in the localization stage. To perform a precise analysis of the received signals, matched filter technique is employed. The extent of the deformation is also determined by magnitude Euclidean distance index. The experimental results prove the effectiveness of the proposed method.
Auteurs: H. Rahbarimagham;S. Esmaeili;G. B. Gharehpetian;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3184 - 3192
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Localizing Microaneurysms in Fundus Images Through Singular Spectrum Analysis
Résumé:
Goal: Reliable recognition of microaneurysms (MAs) is an essential task when developing an automated analysis system for diabetic retinopathy (DR) detection. In this study, we propose an integrated approach for automated MA detection with high accuracy. Methods: Candidate objects are first located by applying a dark object filtering process. Their cross-section profiles along multiple directions are processed through singular spectrum analysis. The correlation coefficient between each processed profile and a typical MA profile is measured and used as a scale factor to adjust the shape of the candidate profile. This is to increase the difference in their profiles between true MAs and other non-MA candidates. A set of statistical features of those profiles is then extracted for a K-nearest neighbor classifier. Results: Experiments show that by applying this process, MAs can be separated well from the retinal background, the most common interfering objects and artifacts. Conclusion: The results have demonstrated the robustness of the approach when testing on large scale datasets with clinically acceptable sensitivity and specificity. Significance: The approach proposed in the evaluated system has great potential when used in an automated DR screening tool or for large scale eye epidemiology studies.
Auteurs: Su Wang;Hongying Lilian Tang;Lutfiah Ismail Al turk;Yin Hu;Saeid Sanei;George Michael Saleh;Tunde Peto;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 05.-2017, volume: 64, issue:5, pages: 990 - 1002
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Logic-Form-Equation-Based Active Capacitor Voltage Balancing Control Technique for Stacked Multicell Converters
Résumé:
This paper proposes a novel active capacitor voltage balancing technique for stacked multicell (SM) converters. The proposed active capacitor voltage balancing control method detects the direction of the load current and measures the voltage of flying capacitors (FCs) to generate a proper switching state in order to form the required output voltage level and regulate the FC voltages at their desired reference levels. The proposed active capacitor voltage balancing control technique can modulate the output voltage through any of the pulse-width-modulation (PWM) techniques such as the phase-shifted carrier PWM or the level-shifted-carrier PWM. The foremost advantage of the proposed active control technique is that it does not demand any complex computations because it is not based on the optimization of the FC voltage-deviation cost functions. A thorough set of simulation results and experimental measurements for the five-level and seven-level SM converters are provided to validate the proposed active capacitor voltage balancing control method.
Auteurs: Arash Khoshkbar Sadigh;Vahid Dargahi;Keith A. Corzine;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3456 - 3466
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Logical Correlation-Based Sleep Scheduling for WSNs in Ambient-Assisted Homes
Résumé:
This paper proposes a logical correlation-based sleep scheduling mechanism (LCSSM) to implement energy-efficient wireless sensor networks (WSNs) in ambient-assisted homes (AAHs). LCSSM analyzes sensory data generated by different human behaviors to detect the logical correlations between sensor nodes in an AAH. By utilizing the particular logical correlations of an AAH to predict its usage status, LCSSM deactivates sensor nodes accordingly to save energy when they are not expected to sense any valuable event. Evaluation results based on real life-logs have validated that LCSSM not only reduces the energy consumption of WSNs significantly, but also retains their quality of sensing successfully, e.g., with a moderate assumption on the duty cycling ratio and hardware configuration of sensor nodes, LCSSM successfully senses 98.7% valuable events with an average of 37.0% usual energy consumption, and extends the life time of WSNs by 63.4%.
Auteurs: Wei Liu;Yozo Shoji;Ryoichi Shinkuma;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3207 - 3218
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Longitudinal Electro-Optic Probe for the Transient Analysis of the Radial Field Surrounding a Three-Phase Cable
Résumé:
In this paper, we present the potentialities of the electro-optic technique for the radial electric field transient analysis of a three-phase power cable. A longitudinal electro-optic probe performing real time characterization of the field surrounding the cable has been developed. The measurement gives the transient evolution of the radial component of the field. The analysis provides information on amplitude, position, and phase of the conductors in the multicore cable. Theoretical analysis, simulations, and experimental measurements are in agreement and demonstrate the contactless voltage diagnostic of multicore cables.
Auteurs: Laurane Gillette;Gwenaël Gaborit;Jean Dahdah;Anne Grau;Valérie Murin;Lionel Duvillaret;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2807 - 2813
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Longitudinal Privacy Management in Social Media: The Need for Better Controls
Résumé:
This large-scale measurement study of Twitter focuses on understanding how users control the longitudinal exposure of their publicly shared social data -- that is, their tweets -- and the limitations of currently used control mechanisms. The study finds that, while Twitter users widely employ longitudinal exposure control mechanisms, they face two fundamental problems. First, even when users delete their data or account, the current mechanisms leave significant traces of residual activity. Second, these mechanisms single out withdrawn tweets or accounts, attracting undesirable attention to them. To address both problems, an inactivity-based withdrawal scheme for improved longitudinal exposure control is explored.
Auteurs: Mainack Mondal;Johnnatan Messias;Saptarshi Ghosh;Krishna P. Gummadi;Aniket Kate;
Apparue dans: IEEE Internet Computing
Date publication: 05.-2017, volume: 21, issue:3, pages: 48 - 55
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Loop Shaping of a Wide-Area Damping Controller Using HVDC
Résumé:
Insufficiently damped inter-area oscillatory behavior in large power systems may be mitigated by the application of a feedback control system. Thorough investigation of the resonant features unique to the western North American power system suggests that the modulation of active power using high-voltage dc has great impact on retaining system stability when actuation is provided by the geographically expansive pacific dc intertie transmission line. The controller is limited in bandwidth by the influences of time delay, sensor and actuator dynamics, and specific plant characteristics. While proportional feedback of the scaled difference of two disparate bus frequencies has shown to be a valid method for controlling this particular system in previous work, the authors submit that a shaped loop transmission function provides performance and noise response improvement with guaranteed stability in saturation. Results of simulations using a high fidelity model of the system show the efficacy of the approach.
Auteurs: Dakota Roberson;John F. O’Brien;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2354 - 2361
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Complexity and Low-Feedback-Rate Channel Allocation in CA MIMO Systems With Heterogeneous Channel Feedback
Résumé:
In this paper, we propose a low complexity and low-feedback-rate channel allocation for carrier aggregation (CA) MIMO systems as an application to heterogeneous networks (HetNets) with multiple component carriers (CCs) and users. The proposed channel allocation technique relies on the heterogeneous channel feedback concept due to the heterogeneous channel statistics of the different CCs. We apply the heterogeneous channel feedback, where the channel feedback granularity is provided using best-$M$ selected feedback strategy. The precoding matrix indicator (PMI) and rank indicator (RI) are designed with a low complexity so that the PMI/RI reports are calculated more efficiently per CC and user. This approach reduces the complexity significantly in a multiuser and multichannel scenario. Next, we deal with the low-feedback rate and thus devise a channel allocation problem. The problem on one hand provides the minimization of the feedback overhead and, on the other hand, it guarantees the quality-of-service request of each user for a specific target throughput. The problem is considered as a channel assignment problem; thus, the Hungarian method is first used. Next, a low complexity solution is devised using the stable matching algorithm. A complexity analysis and evaluation among the original and the proposed approach for the low-complexity and the low-feedback-rate channel allocation is carried out. This comparison reveals the benefits of the proposed solution for CA MIMO system in HetNets. The proposed approach can be considered as a proposal to the future massive CA, i.e., up to 32 CCs.
Auteurs: Christos Tsinos;Apostolos Galanopoulos;Fotis Foukalas;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4396 - 4409
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Complexity Image and Video Coding Based on an Approximate Discrete Tchebichef Transform
Résumé:
The usage of linear transformations has great relevance for data decorrelation applications, like image and video compression. In that sense, the discrete Tchebichef transform (DTT) possesses useful coding and decorrelation properties. The DTT transform kernel does not depend on the input data and fast algorithms can be developed to real-time applications. However, the DTT fast algorithm presented in literature possess high computational complexity. In this paper, we introduce a new low-complexity approximation for the DTT. The fast algorithm of the proposed transform is multiplication free and requires a reduced number of additions and bit-shifting operations. Image and video compression simulations in popular standards show good performance of the proposed transform. Regarding hardware resource consumption for FPGA shows a 43.1% reduction in configurable logic blocks and ASIC place and route realization shows a 57.7% reduction in the area-time figure compared with the 2D version of the exact DTT.
Auteurs: Paulo A. M. Oliveira;Renato J. Cintra;Fábio M. Bayer;Sunera Kulasekera;Arjuna Madanayake;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 1066 - 1076
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Complexity OSIC Equalization for OFDM-Based Vehicular Communications
Résumé:
Vehicular communication systems are usually equipped with orthogonal frequency division multiplexing (OFDM) transceivers that operate on rapidly changing radio propagation environments, which results in high Doppler and delay spreads. More specifically, in these environments, the experienced channels are doubly selective and introduce severe intercarrier interference (ICI) at the receiver. An effective ICI mitigation technique is desired as a constituent part of an ordered successive interference cancellation (OSIC) architecture, which turns out to be computationally efficient, since it may require the solution of linear systems with multiple right-hand sides. To decrease the complexity, several techniques suggest mitigating the ICI by considering only a small number of adjacent subcarriers. However, this approximation introduces an error floor, which may result in unacceptable bit error rates (BER) at high signal-to-noise ratio regimes. In this paper, we propose a new OSIC equalization technique based on an iterative Galerkin projection-based algorithm that reduces the computational cost without sacrificing the performance gains of the OSIC architecture. Furthermore, we suggest a new serial/parallel cancellation architecture that extends the OSIC and has the potential to completely cancel the experienced ICI introduced in high-mobility scenarios. Extensive Monte Carlo experiments have been carried out to validate the accuracy of our framework, revealing intriguing tradeoffs between achieved BER and complexity, and highlighting the importance of designing low-complexity OSIC schemes for OFDM systems operating over double selective channels.
Auteurs: Evangelos Vlachos;Aris S. Lalos;Kostas Berberidis;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3765 - 3776
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Cost 3-D Flow Estimation of Blood With Clutter
Résumé:
Volumetric flow rate estimation is an important ultrasound medical imaging modality that is used for diagnosing cardiovascular diseases. Flow rates are obtained by integrating velocity estimates over a cross-sectional plane. Speckle tracking is a promising approach that overcomes the angle dependency of traditional Doppler methods, but suffers from poor lateral resolution. Recent work improves lateral velocity estimation accuracy by reconstructing a synthetic lateral phase (SLP) signal. However, the estimation accuracy of such approaches is compromised by the presence of clutter. Eigen-based clutter filtering has been shown to be effective in removing the clutter signal; but it is computationally expensive, precluding its use at high volume rates. In this paper, we propose low-complexity schemes for both velocity estimation and clutter filtering. We use a two-tiered motion estimation scheme to combine the low complexity sum-of-absolute-difference and SLP methods to achieve subpixel lateral accuracy. We reduce the complexity of eigen-based clutter filtering by processing in subgroups and replacing singular value decomposition with less compute-intensive power iteration and subspace iteration methods. Finally, to improve flow rate estimation accuracy, we use kernel power weighting when integrating the velocity estimates. We evaluate our method for fast- and slow-moving clutter for beam-to-flow angles of 90° and 60° using Field II simulations, demonstrating high estimation accuracy across scenarios. For instance, for a beam-to-flow angle of 90° and fast-moving clutter, our estimation method provides a bias of −8.8% and standard deviation of 3.1% relative to the actual flow rate.
Auteurs: Siyuan Wei;Ming Yang;Jian Zhou;Richard Sampson;Oliver D. Kripfgans;J. Brian Fowlkes;Thomas F. Wenisch;Chaitali Chakrabarti;
Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Date publication: 05.-2017, volume: 64, issue:5, pages: 772 - 784
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Cost Architecture of Modified Daubechies Lifting Wavelets Using Integer Polynomial Mapping
Résumé:
This brief proposes a modified version of the popular lifting algorithm of Daubechies-4 (D4) and Daubechies-6 (D6) wavelets and its efficient implementation using integer polynomial mapping (IPM). At first, an improved polyphase matrix for D4 is presented that eliminates one filter coefficient completely without losing any accuracy. Then, IPM is applied to encode the remaining irrational coefficients. As a result, computation error due to irrational numbers in the conventional method is significantly reduced, resulting in better image reconstruction. For D6, a two-level optimization scheme combined with the resource sharing of coefficients is applied that results in simplified hardware architecture with much fewer resources.
Auteurs: Md. Mehedi Hasan;Khan A. Wahid;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 585 - 589
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-cost CDC ROADM architecture based on stacked wavelength selective switches
Résumé:
A highly flexible, stacked, switch module is proposed, wherein multiple independent 1 × N wavelength selective switches (WSSs) can be realized on a single 4k liquid crystal on silicon device. The stacked WSS module can be configured in different ways for application at either the transit side or the add/drop side of a colorless, directionless, and contentionless (CDC) reconfigurable optical add/drop multiplexer (ROADM). TwoROADMarchitectures are proposed based on the stacked WSS modules. Their costs are analyzed for both a 4-deg network node and a larger 8-deg node. The first proposed ROADM architecture with full CDC features is shown to realize a cost reduction of at least 35% in these two test network nodes, when compared with the conventional CDC ROADMarchitecture based on the standalone WSSs and multicasting switches (MCSs). The second ROADM architecture proposed has a small probability of wavelength contention, which could be prevented by a local wavelength assignment algorithm. According to our cost estimation, we are able to aggressively reduce the number of components at the add/drop side and make an overall cost reduction of >70% and >80% in the 4- and 8-deg network nodes, respectively.
Auteurs: Haining Yang;Brian Robertson;Peter Wilkinson;Daping Chu;
Apparue dans: IEEE/OSA Journal of Optical Communications and Networking
Date publication: 05.-2017, volume: 9, issue:5, pages: 375 - 384
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Cost, Direct-Fed Slot Antenna Built in Metal Cover of Notebook Computer for 2.4-/5.2-/5.8-GHz WLAN Operation
Résumé:
The slot antenna has been utilized for some recent notebook computers on the market. The FR4 substrates are usually required to print the metal patterns for coupled-feeding the 2.4 GHz (2400–2484 MHz) slot and also for contributing the 5.2 GHz (5150–5350 MHz) and 5.8 GHz (5725–5825 MHz) bands. This communication presents a simple, direct-fed slot antenna with a low profile of 7 mm to the top edge of the metal cover for 2.4-/5.2-/5.8-GHz WLAN operation. The antenna design did not require any substrate and can be implemented directly in the metal cover of a notebook computer at low cost. The design comprised two parallel-connected, 0.5-wavelength-slot portions, formed in a linear structure of length 79 mm and constant width 2 mm, and fed by a common antenna feed port using a mini-coaxial cable. The larger slot generated a 0.5-wavelength resonant mode in the 2.4-GHz band and a 1-wavelength mode for 5.2-GHz operation. The smaller slot operated in a 0.5-wavelength resonant mode, which covered the 5.8-GHz band. With a matching inductor properly set in the slot, good input impedance over the 2.4-, 5.2-, and 5.8-GHz bands can be attained.
Auteurs: Cheng-Tse Lee;Saou-Wen Su;Shu-Chuan Chen;Chen-Shuo Fu;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2677 - 2682
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Power Energy Generation Systems for Two-Phase PM Machine With Reduced-Switch-Count Controlled Switches
Résumé:
This paper investigates two power generation systems that utilize a rectifier with small number of controlled switches associated to a two-phase permanent magnet synchronous machine. The proposed topologies have as a main purpose converting wind energy into electrical energy for low-power applications, giving them large potential to be employed in urban and rural areas. Each configuration is commanded by only two controlled switches and has natural protection against short circuit on the dc link. Compared with two three-phase generation systems that use a reduced number of controlled switches, the proposed topologies permit obtaining sinusoidal machine currents, with low harmonic distortion, using a smaller number of controlled switches. At last, to investigate the proposed system and control strategy, simulation and experimental results are presented.
Auteurs: Filipe Antônio da Costa Bahia;Cursino Brandão Jacobina;Nady Rocha;Italo Roger Ferreira Moreno Pinheiro da Silva;Fabiano Salvadori;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2320 - 2328
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Rank and Adaptive Sparse Signal (LASSI) Models for Highly Accelerated Dynamic Imaging
Résumé:
Sparsity-based approaches have been popular in many applications in image processing and imaging. Compressed sensing exploits the sparsity of images in a transform domain or dictionary to improve image recovery fromundersampledmeasurements. In the context of inverse problems in dynamic imaging, recent research has demonstrated the promise of sparsity and low-rank techniques. For example, the patches of the underlying data are modeled as sparse in an adaptive dictionary domain, and the resulting image and dictionary estimation from undersampled measurements is called dictionary-blind compressed sensing, or the dynamic image sequence is modeled as a sum of low-rank and sparse (in some transform domain) components (L+S model) that are estimated from limited measurements. In this work, we investigate a data-adaptive extension of the L+S model, dubbed LASSI, where the temporal image sequence is decomposed into a low-rank component and a component whose spatiotemporal (3D) patches are sparse in some adaptive dictionary domain. We investigate various formulations and efficient methods for jointly estimating the underlying dynamic signal components and the spatiotemporal dictionary from limited measurements. We also obtain efficient sparsity penalized dictionary-blind compressed sensing methods as special cases of our LASSI approaches. Our numerical experiments demonstrate the promising performance of LASSI schemes for dynamicmagnetic resonance image reconstruction from limited k-t space data compared to recent methods such as k-t SLR and L+S, and compared to the proposed dictionary-blind compressed sensing method.
Auteurs: Saiprasad Ravishankar;Brian E. Moore;Raj Rao Nadakuditi;Jeffrey A. Fessler;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 05.-2017, volume: 36, issue:5, pages: 1116 - 1128
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Rank Spatial Channel Estimation for Millimeter Wave Cellular Systems
Résumé:
The tremendous bandwidth available in the millimeter wave frequencies above 10 GHz have made these bands an attractive candidate for next-generation cellular systems. However, reliable communication at these frequencies depends critically on beamforming with very high-dimensional antenna arrays. Estimating the channel sufficiently accurately to perform beamforming can be challenging due to both low coherence time and a large number of antennas. Also, the measurements used for channel estimation may need to be made with analog beamforming, where the receiver can “look” in only one direction at a time. This paper presents a novel method for estimation of the receive-side spatial covariance matrix of a channel from a sequence of power measurements made in different angular directions. It is shown that maximum likelihood estimation of the covariance matrix reduces to a non-negative matrix completion problem. We show that the non-negative nature of the covariance matrix reduces the number of measurements required when the matrix is low-rank. The fast iterative methods are presented to solve the problem. Simulations are presented for both single-path and multi-path channels using models derived from real measurements in New York City at 28 GHz.
Auteurs: Parisa A. Eliasi;Sundeep Rangan;Theodore S. Rappaport;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2748 - 2759
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Low-Temperature, Solution-Processed, 3-D Complementary Organic FETs on Flexible Substrate
Résumé:
Vertical stacking of thin-film transistors is an effective way to reduce the footprint of a device, thus increases transistor density in complex flexible electronic applications without reducing the feature size and resolution of the patterning tools. In this paper, we report a 3-D complementary organic FET fabricated on a plastic substrate by stacking a bottom-gate top-contact p-type transistor on a top-gate bottom-contact n-type transistor with a gate shared between the two. We used high-performance polymer semiconductors, poly [(E)-2, 7-bis (2 decyltetradecyl) 4 methyl 9 (5 (2 (5 methylthiophen 2 yl) vinyl) thiophen 2 yl) benzo [lmn] [3, 8] phenanthroline-1, 3, 6, 8 (2H, 7H)-tetraone] for n-type devices and poly [2, 5-bis (7-decylnonadecyl) pyrrolo [3, 4-c] pyrrole-1, 4 (2H, 5H)-dione-(E) 1,2 bis (5 (thiophen 2 yl) selenophen 2 yl) ethene] for p-type devices to fabricate the vertically stacked organic transistors along with a Cytop and cross-linked poly (4-vinylphenol) bilayer and Poly (Methyl Methacrylate) gate dielectric. A 3-D flexible complementary organic inverter exhibits a maximum static voltage gain of $thickapprox 18$ V/V and high noise immunity of up to 60% of ${V} _{mathrm {DD}}$ /2. The 3-D transistors show hysteresis-free $I$ $V$ characteristics despite of low-temperature processes. Moreover, we discuss the influence of cross-linker concentration and the processing temperature of the PVP dielectric film on the degree of hysteresis in $I$ $V$ characteristics.
Auteurs: Sujeong Kyung;Jimin Kwon;Yun-Hi Kim;Sungjune Jung;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 1955 - 1959
Editeur: IEEE
Document complet vers site de l'éditeur
 
» LTCC-Integrated $H$ -Plane Bends for THz Antenna-in-Package Solution
Résumé:
We present a compact terahertz antenna-in-package solution using a substrate integrated waveguide (SIW), which connects an integrated circuit (IC) to an SIW antenna. To suppress the leakage of electromagnetic waves due to bending a low-temperature cofired ceramic (LTCC) substrate, an H-plane bend SIW in the LTCC was investigated using the E-plane split-block technology. We introduced an IC with a CPW-to-waveguide transition into the hollow SIW. The insertion loss, estimated by measuring a back-to-back transition with the H-plane-bend SIW, is 1.6 dB at 300 GHz, and 49-GHz bandwidth with less than 10-dB return loss is achieved.
Auteurs: Takuro Tajima;Ho-Jin Song;Hideaki Matsuzaki;Makoto Yaita;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 05.-2017, volume: 27, issue:5, pages: 440 - 442
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Magnet Temperature Effects on the Useful Properties of Variable Flux PM Synchronous Machines and a Mitigating Method for Magnetization Changes
Résumé:
Variable flux permanent magnet synchronous machines (VF-PMSMs) use permanent magnet magnetization as an additional degree-of-freedom to reduce losses based on operating conditions (e.g., at medium to high speeds, losses are reduced by using a lower magnetization). Magnet properties are known to be dependent on temperature; therefore, the magnet temperature effects on magnetization manipulation and maximum torque properties in VF-PMSMs are investigated in this paper with FEA simulations and experiments. Increased magnet temperature changes the available range of attainable magnetization levels and makes demagnetization occur more easily; therefore, a different current angle and magnetization are needed for maximum torque operation. The temperature effects on high speed magnetization manipulation methods, which are needed for driving cycle loss reduction and full power capability, are evaluated with simulation and experiments on a prototype 80 kW traction machine. A closed loop method for magnetization manipulation that mitigates the effect of temperature is proposed.
Auteurs: Brent S. Gagas;Kensuke Sasaki;Apoorva Athavale;Takashi Kato;Robert D. Lorenz;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2189 - 2199
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Magnetic Field Analysis for 3-D Positioning Applications
Résumé:
This paper proposes an analysis of the quasi-stationary magnetic field generated by coils and its applicability to 3-D short-range positioning scenarios. Starting from a theoretical background, an approximation of the induced voltage in a sensor coil is developed and analyzed. Then, the design and performance of a short-range magnetic field-based positioning system is described. The system is realized by using three-axis field generating coils and a three-axis sensor coil. It uses resonance properties to decrease current and power consumption requirements. The system is targeted for simple and low-cost applications, requiring subdecimeter accuracies over short ranges of approximately a couple of meters. The realized prototype, validated through in-field measurements, features a positioning error in the order of 4–5 cm over an area of 1.15 m \times 1.55 m \times 0.8 m.
Auteurs: Valter Pasku;Alessio De Angelis;Guido De Angelis;Antonio Moschitta;Paolo Carbone;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 935 - 943
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Magnetic Fluid Based High Precision Temperature Sensor
Résumé:
We have developed a high precision (3.7 mK) temperature sensor using nanomagnetic fluid bearing. The device is based on the basic principle of Charles law (v $propto $ T). For this, we have prepared kerosene-based magnetic fluid for ferrofluid bearing formation with permanent magnet. The ferrofluid bearing has very low coefficient of friction ( $mu _{f} = 0.002$ ), and provides a frictionless movement and perfect sealing. The device is highly sensitive as it uses air as a working media whose coefficient of volume expansion (0.0036) is much larger (20 times) than mercury (0.00018), ethanol (0.00026), and so on usually used in expansion-based thermometers. At constant atmospheric pressure (1 atm), a temperature variation of 1 °C causes a variation of 20 mm (capillary diameter 5 mm) in the position of fluid column. The device has been calibrated and tested using standard calibrated equipment’s. The device shows the high sensitivity of 3.7 (± 0.2) mK and can be used where high accuracy in temperature measurements is required. The device sensitivity and range is easily customizable. The device is capable of finding many useful applications, viz., standards and the calibration of thermometers.
Auteurs: Saurabh Pathak;Komal Jain; Noorjahan;Vinod Kumar;Rajendra Prasad Pant;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2670 - 2675
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Magneto–Lithography, a Simple and Inexpensive Method for High Throughput, Surface Patterning
Résumé:
Magneto-lithography (ML) is based on patterning magnetic field on a substrate, using paramagnetic or diamagnetic masks, that defines the shape and strength of the magnetic field. ML is a “bottom-up” method but at the same time, it provides desired high-throughput capabilities for mass production. It is based on applying a magnetic field on the substrate using paramagnetic metal masks that define the spatial distribution and shape of the applied field. The second component in ML is ferromagnetic nanoparticles that are assembled onto the substrate according to the field induced by the mask. We demonstrate the use of various methods of ML for common microelectronic processes such as etching and deposition.
Auteurs: Amos Bardea;A. Yoffe;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 439 - 444
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Maintenance strategy based on reliability analytical models for three parallel mechanical transformation machines
Résumé:
The purpose of this article is to formulate a maintenance strategy for three parallel machines in a mechanical manufacture. The research method was the quantitative modeling, based on analytical models. Time between failures (TBF) and time-to-repair (TTR) data since April 2014 to September 2015 were modelled for the three machines. Weibull distribution fitted all the TBF data. Lognormal distribution fitted TTR for machine 3. The availability Av(t) were calculated for each machine, remaining between 97% to 98%. Based on analytical models, it was defined that the best maintenance strategy for the system is the corrective maintenance.
Auteurs: Miguel Afonso Sellitto;William Brusius Jr;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 988 - 993
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Making a Difference [From the Editor's Desk]
Résumé:
Presents the introductory editorial for this issue of the publication.
Auteurs: Lanny Floyd;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 3 - 3
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Malevolent Activity Detection with Hypergraph-Based Models
Résumé:
We propose a hypergraph-based framework for modeling and detecting malevolent activities. The proposed model supports the specification of order-independent sets of action symbols along with temporal and cardinality constraints on the execution of actions. We study and characterize the problems of consistency checking, equivalence, and minimality of hypergraph-based models. In addition, we define and characterize the general activity detection problem, that amounts to finding all subsequences that represent a malevolent activity in a sequence of logged actions. Since the problem is intractable, we also develop an index data structure that allows the security expert to efficiently extract occurrences of activities of interest.
Auteurs: Antonella Guzzo;Andrea Pugliese;Antonino Rullo;Domenico Saccà;Antonio Piccolo;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 05.-2017, volume: 29, issue:5, pages: 1115 - 1128
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Managing New Technology Using Malleable Profit Functions
Résumé:
Technological innovation drives economic growth, and the pioneering activity of scientists and engineers produce technological innovation. We provide a mathematical model of pioneering strategic choice by adopting a perspective familiar to microeconomics, but less common in the engineering management literature. Instead of focusing on the specific features of a pioneer's technology, we focus on the malleability of the profit equation involved. By considering the arguments of the profit function (i.e., entry and variable costs and potential market demand) as strategic levers, we derive propositions that identify the ranges of actions (lever pulling) available to managers to protect (and even increase) entrepreneurial rents in a simple yet robust partial equilibrium case. For each lever, we show that there are several value ranges (intervals) and that the pioneer's incentives vary across these intervals. In addition, for each lever, we identify the existence of nontrivial profit discontinuities that change the pioneer's incentives in surprising ways and lead to counterintuitive strategic choices. Lastly, we show that for some range of each lever's values, welfare-improving transfer payments are possible and, therefore, pioneers and policy-makers both have an incentive to bargain. As in the case of patents, these transfers encourage the introduction of new technologies.
Auteurs: Richard Arend;Moren Levesque;Maria Minniti;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 05.-2017, volume: 64, issue:2, pages: 120 - 133
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mapping Thermokarst Lakes on the Qinghai–Tibet Plateau Using Nonlocal Active Contours in Chinese GaoFen-2 Multispectral Imagery
Résumé:
In order to monitor the response of thermokarst lakes on the Qinghai–Tibet Plateau (QTP) to rapid climatic changes and human activities, an automated method for extracting shorelines from Chinese GaoFen-2 (GF-2) imagery is proposed. First, the water index (WI) images and the potential lake areas are calculated from the preprocessed multispectral imagery and digital elevation model data, respectively. Second, the initial segmentation obtained by global thresholding of the WI images and masking in the potential lake areas are used to implement the contour initialization of active contours models efficiently. Finally, the nonlocal active contours (NLAC) approach is applied to refine the initial segmentation of the WI images, and the final shoreline vector files are produced by some simple and automatic postprocessing steps. Experiments on the GF-2 imagery demonstrate that 1) by exploiting the capability of WI to locate the approximate shoreline effectively around the evolving contour, the processing time of the proposed method can be saved significantly; 2) the NLAC approach can efficiently identify the shoreline by integrating the nonlocal interactions between pairs of patches inside and outside the lake; and 3) the proposed method can conveniently adapt to the multitemporal and multifeature image analysis. Using the manual digitized shorelines as the reference data, an average error of less than one pixel with standard deviation of 0.1320 can be obtained. These results prove that the proposed method is feasible for the identification and monitoring of thermokarst lakes on the QTP.
Auteurs: Bangsen Tian;Zhen Li;Meimei Zhang;Lei Huang;Yubao Qiu;Zhixian Li;Panpan Tang;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 1687 - 1700
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Matchable-Observable Linear Models and Direct Filter Tuning: An Approach to Multivariable Identification
Résumé:
Identification of linear time-invariant multivariable systems can best be understood as comprising three separate problems: selection of system model structure, filter design, and parameter estimation itself. Approaching the first using matchable-observable models originally developed in the adaptive control literature and the second via direct or derivative-free optimization, effective least-squares algorithms can be used for parameter estimation. The accuracy, robustness and moderate computational demands of the methods proposed are demonstrated via simulations with randomly generated models and applied to identification using real process data. The results obtained are comparable or superior to the best results obtained using standard implementations of the algorithms described in the literature.
Auteurs: Rodrigo Alvite Romano;Felipe Pait;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2180 - 2193
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Matching Network Elimination in Broadband Rectennas for High-Efficiency Wireless Power Transfer and Energy Harvesting
Résumé:
Impedance matching networks for nonlinear devices such as amplifiers and rectifiers are normally very challenging to design, particularly for broadband and multiband devices. A novel design concept for a broadband high-efficiency rectenna without using matching networks is presented in this paper for the first time. An off-center-fed dipole antenna with relatively high input impedance over a wide frequency band is proposed. The antenna impedance can be tuned to the desired value and directly provides a complex conjugate match to the impedance of a rectifier. The received RF power by the antenna can be delivered to the rectifier efficiently without using impedance matching networks; thus, the proposed rectenna is of a simple structure, low cost, and compact size. In addition, the rectenna can work well under different operating conditions and using different types of rectifying diodes. A rectenna has been designed and made based on this concept. The measured results show that the rectenna is of high power conversion efficiency (more than 60%) in two wide bands, which are 0.9–1.1 and 1.8–2.5 GHz, for mobile, Wi-Fi, and ISM bands. Moreover, by using different diodes, the rectenna can maintain its wide bandwidth and high efficiency over a wide range of input power levels (from 0 to 23 dBm) and load values (from 200 to 2000 Ω). It is, therefore, suitable for high-efficiency wireless power transfer or energy harvesting applications. The proposed rectenna is general and simple in structure without the need for a matching network hence is of great significance for many applications.
Auteurs: Chaoyun Song;Yi Huang;Jiafeng Zhou;Paul Carter;Sheng Yuan;Qian Xu;Zhouxiang Fei;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3950 - 3961
Editeur: IEEE
Document complet vers site de l'éditeur
 
» MAVEN: An Algorithm for Multi-Parametric Automated Segmentation of Brain Veins From Gradient Echo Acquisitions
Résumé:
Cerebral vein analysis provides a chance to study, from an unusual viewpoint, an entire class of brain diseases, including neurodegenerative disorders and traumatic brain injuries. Manual segmentation approaches can be used to assess vascular anatomy, but they are observer-dependent and time-consuming; therefore, automated approaches are desirable, as they also improve reproducibility. In this paper, a new, fully automated algorithm, based on structural, morphological, and relaxometric information, is proposed to segment the entire cerebral venous system from MR images. The algorithm for multi-parametric automated segmentation of brain VEiNs (MAVEN) is based on a combined investigation of multi-parametric information that allows for rejection of false positives and detection of thin vessels. The method is tested on gradient echo brain data sets acquired at 1.5, 3, and 7 T. It is compared to previous methods against manual segmentation, and its inter-scan reproducibility is assessed. The achieved accuracy and reproducibility are good, meaning that MAVEN outperforms previous methods on both quantitative and qualitative analyses. It is usable at all the field strengths explored, showing comparable accuracy scores, with no need for algorithm parameter adjustments, and thus, it is a promising candidate for the characterization of the venous tree topology.
Auteurs: Serena Monti;Sirio Cocozza;Pasquale Borrelli;Sina Straub;Mark E. Ladd;Marco Salvatore;Enrico Tedeschi;Giuseppe Palma;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 05.-2017, volume: 36, issue:5, pages: 1054 - 1065
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Maximum Achievable Power Conversion Efficiency Obtained Through an Optimized Rectenna Structure for RF Energy Harvesting
Résumé:
High-efficiency rectennas for radio frequency (RF) energy harvesting have been studied for decades, but most of the literature straightforwardly applies the rectenna aiming at dedicated RF sources to this situation, even though the level of input power is significantly different. Since previous studies address antenna design collecting more ambient RF power, the improvement of power conversion efficiency (PCE) has emerged in a scattered way, because the theoretical limit of PCE has not yet been characterized, and the optimal rectenna structure approaching such maximum PCE is still uninvestigated. In this paper, we characterize the performance limit of rectennas with input power ranging from −20 to 0 dBm, proposing optimal rectenna design demonstrating the maximum PCE. The maximum achievable PCE is cast into a mathematical programming problem. Solving this optimization model clarifies the effect of design factors, including operational frequencies, rectifier topologies, and parameterization. To achieve the maximum PCE, our investigation shows that the optimal rectenna structure should not only optimize those design factors but also eliminate the matching circuit between an antenna and a rectifier for ultralow-power scenarios. The resultant PCE at 2.45 GHz is 61.4% and 31.8% at −5 and −15 dBm, respectively, closely approaching the theoretical bound.
Auteurs: Yen-Sheng Chen;Cheng-Wei Chiu;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2305 - 2317
Editeur: IEEE
Document complet vers site de l'éditeur
 
» May the Force Be with You: The Future of Force-Sensitive Authentication
Résumé:
Modern smartphones provide a rich set of possible touchscreen interactions, but most authentication schemes still rely on simple digit or character input. Previous studies examined the shortcomings of such schemes (digit-PINs, for example). Here, the authors discuss the potential of a new PIN type called force-PINs. The idea behind this approach is to augment the security of digit-PINs by assigning a binary pressure value to each digit in the sequence. By adding this (practically) invisible pressure component, force-PINs help users select stronger PINs that are harder to observe. The authors also discuss implications for future research on force-sensitive authentication.
Auteurs: Katharina Krombholz;Thomas Hupperich;Thorsten Holz;
Apparue dans: IEEE Internet Computing
Date publication: 05.-2017, volume: 21, issue:3, pages: 64 - 69
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mean-Field Dynamics of Inter-Switching Memes Competing Over Multiplex Social Networks
Résumé:
This letter characterizes the intertwined behavior of a susceptible-infected-susceptible epidemic model involving multiple mutually exclusive memes, each competing over distinct contact planes of an undirected multi-layer social network, with the possibility of inter-switching. Based on the mean-field theory, we contrast and derive closed-form analytical expressions for the steady-state thresholds that govern the transitions between extinction, co-existence, and absolute dominance of the inter-switchable memes. Moreover, a non-linear optimization formulation is presented to determine the optimal budget allocation for controlling the switching rates to a particular co-existing meme. Validated by simulations, the impact of switching on the tipping thresholds and their implications in reality are demonstrated using data extracted from online social networks.
Auteurs: Aresh Dadlani;Muthukrishnan Senthil Kumar;Manikanta Gowtham Maddi;Kiseon Kim;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 967 - 970
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Measurement and Modeling of Angular Spreads of Three-Dimensional Urban Street Radio Channels
Résumé:
By utilizing planar antenna arrays, a base station (BS) by the roadside can exploit two-dimensional (2-D) sectorization and beamforming to connect dense pedestrians and vehicles in a street. The azimuth and elevation angular spreads of the street radio channels are critical for the spatial multiplexing performance. In this paper, by utilizing a multiple-input–multiple-output (MIMO) channel sounder equipped with two uniformed planar antenna arrays, the three-dimensional (3-D) multipath propagations in urban macrocellular street canyon environments were measured and modeled, with the focus on the dynamics of the angular spreads along the streets. The transmitter (emulating a user equipment, UE) was placed at 100 and 95 positions in two streets for the line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios, respectively. The azimuth/elevation angle-of-arrival (AoA/EoA) and the root-mean-square azimuth/elevation spread of arrivals (ASA/ESA) at each position were measured. Contrary to the expected monotonous change of the angular spreads with respect to the UE–BS distance, the measurement results show that, in the LOS scenario, ASA and ESA have a positive correlation with the UE–BS distance in an open street but a negative correlation in a closed street. In the NLOS scenario, the correlation is positive when the UE is close to a building without the over-rooftop diffraction, but the correlation is reversed if such a Quasi-LOS path exists. The 2-D arrival profiles of the ray clusters have been observed, and their impacts on the angular spreads are analyzed in different propagation environments. By comparing multiple candidate fitting functions, the lognormal distribution models for ASA and ESA are proposed. In addition, the channel delay spread (DS) was also measured along the streets and positive correlations among ASA, ESA, and DS have been found. This work can help to est- blish the 3-D spatial channel models for advanced MIMO technologies and is also valuable for future channel measurements.
Auteurs: Ruonan Zhang;Xiaofeng Lu;Jianping Zhao;Lin Cai;Jiao Wang;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3555 - 3570
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Measurement of the Mass Flow and Velocity Distributions of Pulverized Fuel in Primary Air Pipes Using Electrostatic Sensing Techniques
Résumé:
Online measurement of pulverized fuel (PF) distribution between primary air pipes on a coal-fired power plant is of great importance to achieve balanced fuel supply to the boiler for increased combustion efficiency and reduced pollutant emissions. An instrumentation system using multiple electrostatic sensing heads is developed and installed on 510-mm bore primary air pipes on the same mill of a 600-MW coal-fired boiler unit for the measurement of PF mass flow and velocity distributions. An array of electrostatic electrodes with different axial widths is housed in a sensing head. An electrode with a greater axial width and three narrower electrodes are used to derive the electrostatic signals for the determination of PF mass flow rate and velocity, respectively. The PF velocity is determined by multiple cross correlation of the electrostatic signals from the narrow electrodes. The measured PF velocity is applied on the root-mean-square magnitude of the measured electrostatic signal from the wide electrode for the calibration of PF mass flow rate. On-plant comparison trials of the developed system were conducted under five typical operating conditions after a system calibration test. Isokinetic sampling equipment is used to obtain reference data to evaluate the performance of the developed system. Experimental data demonstrate that the developed system is effective and reliable for the online continuous measurement of the mass flow and velocity distributions between the primary air pipes of the same mill.
Auteurs: Xiangchen Qian;Yong Yan;Xiaobin Huang;Yonghui Hu;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 944 - 952
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Measurement-Directed Reduction of Dynamic Models in Power Systems
Résumé:
The paper describes a new model reduction procedure tailored to power systems. It uses measurement data to devise a family of reduced order nonlinear models while retaining physical interpretability of parameters and equations. The manifold boundary approximation method (MBAM) uses the Fisher information matrix calculated from measurements to identify the least relevant parameter combination in the original model. Next, it numerically constructs a geodesic on the corresponding statistical manifold originating from the initial parameters in the least relevant parameter direction until a manifold boundary is found. MBAM then identifies a limiting approximation in the mathematical form of the model and removes one parameter combination. The simplified model is recalibrated by fitting its behavior to that of the original model, and the process is repeated as appropriate. MBAM is demonstrated on the example of a synchronous generator (SG), which has been treated extensively in the literature. Implications of the proposed model reduction procedure on large power system models are illustrated on a 441-bus, 72-SG dynamical model.
Auteurs: Mark K. Transtrum;Andrija T. Sarić;Aleksandar M. Stanković;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2243 - 2253
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Measuring and Understanding RRC State Machine Optimization in Light of Recent Advancements
Résumé:
Broadband mobile networks utilize a radio resource control (RRC) state machine to allocate scarce radio resources. Current implementations introduce high latencies and cross-layer degradation. Recently, the RRC enhancements, continuous packet connectivity (CPC), and the enhanced forward access channel (Enhanced FACH), have emerged in UMTS. We measure the availability and performance of these enhancements on a network serving a market with a population in the millions. We demonstrate that these enhancements offer significant reductions in latency, mobile device energy consumption, and improved end user experience. We develop new over-the-air measurements that resolve existing limitations in measuring RRC parameters. We find CPC provides significant benefits with minimal resource costs, prompting us to rethink past optimization strategies. We examine the cross-layer performance of CPC and Enhanced FACH, concluding that CPC provides reductions in mobile device energy consumption for many applications. While the performance increase of HS-FACH is substantial, cross-layer performance is limited by the legacy uplink random access channel (RACH), and we conclude full support of Enhanced FACH is necessary to benefit most applications. Given that UMTS growth will exceed LTE for several more years and the greater worldwide deployment of UMTS, our quantitative results should be of great interest to network operators adding capacity to these networks. Finally, these results provide new insights for application developers wishing to optimize performance with these RRC enhancements.
Auteurs: Xuetao Wei;Theodore Stoner;Joseph Knight;Lei Guo;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 05.-2017, volume: 16, issue:5, pages: 1330 - 1342
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Measuring Azimuth Deformation With L-Band ALOS-2 ScanSAR Interferometry
Résumé:
We analyze the methods for measuring azimuth deformation with the L-band Advanced Land Observing Satellite-2 (ALOS-2) scanning synthetic aperture radar (ScanSAR) interferometry. To implement the methods, we extract focused bursts from the ALOS-2 full-aperture product, which is the only product available for ScanSAR interferometry at present. The extracted bursts are properly processed to measure azimuth deformation using interferometric phase. We apply the range split-spectrum method to ScanSAR to estimate the differential ionospheric phase of the interferogram, and take the azimuth derivative of the differential ionospheric phase to mitigate the relative azimuth shift caused by ionosphere. For the first time, azimuth deformation of a large earthquake (April 25, 2015 Nepal earthquake) is nearly completely measured by the L-band ScanSAR interferometry with moderate precision. The result is validated by the azimuth deformation measured by incoherent cross correlation using a pair of high-resolution RADARSAT-2 images. In addition to the final azimuth deformation, we show the possibility of processing full-aperture ScanSAR product using a burst-by-burst approach to form regular interferograms. We also show the recent strong large-scale ionospheric effects on the L-band ALOS-2 ScanSAR interferograms. Other possible applications of this paper include measuring the movement of glaciers.
Auteurs: Cunren Liang;Eric J. Fielding;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2725 - 2738
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Measuring Vehicle Velocity in Real Time Using Modulated Motion Blur of Camera Image Data
Résumé:
In this paper, a novel sensor system is presented for estimating the velocity using a modulated motion blur. By moving a camera mounted on the vehicle body with a specific pattern when the vehicle is moving, the blurred image includes the information of the vehicle velocity of the camera itself. It will be shown that the inclinations of motion blur in a scene are directly related to the velocity vector of the vehicle and the modulation speed. The proposed approach invariant to the exposure time provides the magnitude and direction of the velocity vector with high accuracy and high reliability. In contrast to other approaches using a camera image, our approach requires only 256 × 192 [pixel], and the proposed algorithm is simple and fast. The efficacy of the proposed method is demonstrated through simulations and experiments. The experimental results present empirical evidence to support that the proposed system is robust to climate changes such as rainy or snowy weather. The proposed system is expected to be applicable to vehicular technologies such as the vehicle dynamics controlling system or the vehicle positioning system.
Auteurs: Minyoung Lee;Kyung-Soo Kim;Soohyun Kim;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3659 - 3673
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mechanomyography Assisted Myoeletric Sensing for Upper-Extremity Prostheses: A Hybrid Approach
Résumé:
The myoelectric upper-limb prosthetic manipulation is inherently limited by the unreliable sensor-skin interface. This paper presents a hybrid approach to overcome the limitation of electromyography (EMG) through mechanomyography (MMG) assisted myoelectric sensing. An integrated hybrid sensor system was developed for simultaneous EMG and MMG measurement. The hybrid system formed a platform to capture muscular activations in different frequencies. To evaluate the effectiveness of hybrid EMG-MMG sensing, hand motion experiments have been carried out on seven able-bodied and two transradial amputee subjects. It convincingly demonstrated, a significantly ( ${p} <0.01$ ) improved classification accuracy (CA). Furthermore, the CA was compensated by 8.7% ~ 33.7% in the presence of 2 ~ 3 fault EMG channels. These results suggest that MMG assisted myoelectric sensing can improve the control performance and robustness. It has great potential to promote the clinical application of multi-functional prosthetic hand with hybrid EMG-MMG sensor system.
Auteurs: Weichao Guo;Xinjun Sheng;Honghai Liu;Xiangyang Zhu;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3100 - 3108
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Meetings Calendar
Résumé:
The following list of meetings, conferences, and symposia is provided as a reader service and does not constitute endorsement by the IEEE or the IEEE Dielectrics and Electrical Insulation Society. This calendar can also be found at http://sites.ieee.org/deis.
Auteurs: Davide Fabiani;
Apparue dans: IEEE Electrical Insulation Magazine
Date publication: 05.-2017, volume: 33, issue:3, pages: 46 - 47
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Method of Generating Femtosecond Cylindrical Vector Beams Using Broadband Mode Converter
Résumé:
We experimentally obtain femtosecond cylindrical vector beams based on a mode-locked fiber laser (MLFL) by using a fused few-mode coupler. Pulses of 300 fs duration with radially and azimuthally polarized modes are directly delivered at the central wavelength of 1566 nm. The fused few-mode fiber coupler inserted inside the cavity acts as a mode converter from LP01 mode to LP11 mode with a wide bandwidth over 100 nm. The proof-of-concept generation of femtosecond cylindrical vector beams is efficient and useful in MLFLs.
Auteurs: Feng Wang;Fan Shi;Teng Wang;Fufei Pang;Tingyun Wang;Xianglong Zeng;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 747 - 750
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mg Doping to Simultaneously Improve the Electrical Performance and Stability of MgInO Thin-Film Transistors
Résumé:
In this paper, we have fabricated the magnesium-doped indium oxide (MgInO) thin-film transistors (TFTs) by solution process and evaluate the electrical characteristics and stability under temperature stress and positive bias stress. The MgInO TFTs show a decrease of off-state current ( ${text {I}}_{{mathrm{scriptscriptstyle off}}})$ and an increase of threshold voltage ( ${text {V}}_{mathrm {TH}})$ with the increase of Mg doping concentration. For MgInO TFT with 0.75 mol% Mg doping concentration, it shows an excellent electrical characteristic (the field effectmobility of 13.77 cm $^{2} {text {V}}^{-1}~text{s}^{-1}$ , the threshold voltage of 2.84 V, and subthreshold swing value of 0.85 V/decade) and a good stability of temperature stress and positive bias stress. The performance enhancement of MgInO TFTs is attributed to the reduced density of states and the lower interface trap density by the optimized Mg doping concentration, which is first verified by the temperature-dependent field effect measurement and capacitance–voltage method.
Auteurs: Cheng-Yu Zhao;Jun Li;De-Yao Zhong;Chuan-Xin Huang;Jian-Hua Zhang;Xi-Feng Li;Xue-Yin Jiang;Zhi-Lin Zhang;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2216 - 2220
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Microplasma Actuator for EHD Induced Flow
Résumé:
Dielectric barrier discharge microplasma actuator was used for flow modification. The actuator was energized at a relatively low discharge voltage of about 1 kV. The movement of incense particles was tracked by the high-speed camera. A modulated ac voltage was applied to electrodes. It was observed using a high-speed camera how the flow velocity and direction was changed at different duty ratios of the applied voltage. The numerical simulation of the flow was carried out using the fluid model, which considers the electric potential to be the combination of the potential due the external electric field and the charge density of plasma. Based on these potentials, the body force was calculated. Furthermore, the body force was implemented in the Navier–Stokes equations and the simulated flow was obtained. The numerical results matched the obtained results in experiments.
Auteurs: Marius Blajan;Yoshinori Mizuno;Akihiko Ito;Kazuo Shimizu;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2409 - 2415
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Microscopic Origin of Electron Transport Properties and Ultrascalability of Amorphous Phase Change Material Germanium Telluride
Résumé:
The electron transport in prototypical amorphous ( ${a}$ -) phase change material (PCM) germanium telluride is investigated using density functional theory, ab initio molecular dynamics, nonequilibriumGreen’s function, and quantum hydrodynamics. It is found that the measured peculiar electron transport properties of ${a}$ -PCM are governed by bias-dependent dynamics of local current swirls, which originate from defects-induced electron backscattering and localization. The microscopic balance between defects-induced electron localization and field-induced electron delocalization is the origin of the linear, exponential, and S-shape snapback current–voltage curve shapes. It is revealed that the threshold switching is a manifestation of quantum percolation. It is shown that the local current swirls are well confined in Å-scale, leading to the promising single-digit nanometer scalability of related device technologies.
Auteurs: Jie Liu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2207 - 2215
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Microwave Characteristics of an Independently Biased 3-Stack InGaP/GaAs HBT Configuration
Résumé:
This paper investigates various important microwave characteristics of an independently biased 3-stack InGaP/GaAs heterojunction bipolar transistor (HBT) monolithic microwave integrated circuit (MMIC) chip at both small-signal and large-signal operation. By taking the advantage of the independently biased functionality, bias condition for individual transistor can be adjusted flexibly, resulting in the ability of independent control for both small-signal and large-signal performances. It was found that at small-signal operation stability and isolation characteristics of the proposed configuration can be significantly improved by controlling bias condition of the second-stage and the third-stage transistors while at large-signal operation its linearity and power gain can be improved through controlling the bias condition of the first-stage and the third-stage transistors. To demonstrate the benefits of using such an independently biased configuration, a measured optimum large-signal performance at an operation frequency of 1.6 GHz under an optimum bias condition for the high gain, low distortion were obtained as: $text {PAE} = 23.5,,%$ , ${text {P}}_{text {out}}= 12$ dBm; ${text {Gain}}= 32.6$ dB at IMD3 = −35 dBc. Moreover, to demonstrate the superior advantage of the proposed configuration, its small-signal and large-signal performance were also compared to that of a single stage common-emitter, a conventional 2-stack, an independently biased 2-stack and a conventional 3-stack configuration. The compared results showed that the independently biased 3-stack is the best candidate among the configurations for various wireless communications applications.
Auteurs: Manh Duy Luong;Ryo Ishikawa;Yoichiro Takayama;Kazuhiko Honjo;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1140 - 1151
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Microwave Voltage-Controlled Oscillator With Harmonic-Suppressed Stepped-Impedance-Resonator Filter
Résumé:
This brief proposes a new low-phase-noise microwave voltage-controlled oscillator (VCO) with a harmonic-suppressed stepped-impedance-resonator (SIR) filter. Since the filter is synthesized by multiple resonators, it can provide a high-quality factor to improve the phase-noise performance. In addition, the harmonic-suppressed property of the filter adopted in this brief can alleviate the noise contributed from the oscillation harmonics. By applying the two techniques mentioned, the proposed VCO is designed at 2.4 GHz with a three-pole Butterworth filter, which is synthesized by the parallel transmission-line SIRs to reduce the circuit size. The proposed VCO using a three-pole filter has a measured phase noise of −147 dBc/Hz at 1-MHz offset frequency with a corresponding figure-of-merit of −203.18 dBc/Hz.
Auteurs: Chao-Hsiung Tseng;Tien-Sheng Huang;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 520 - 524
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Microwaves-Based High Sensitivity Sensors for Crack Detection in Metallic Materials
Résumé:
This paper presents a highly sensitive sensor for crack detection in metallic surfaces. The sensor is inspired by complementary split-ring resonators which have dimensions much smaller than the excitation’s wavelength. The entire sensor is etched in the ground plane of a microstrip line and fabricated using printed circuit board technology. Compared to available microwave techniques, the sensor introduced here has key advantages including high sensitivity, increased dynamic range, spatial resolution, design simplicity, selectivity, and scalability. Experimental measurements showed that a surface crack having 200- $mu text{m}$ width and 2-mm depth gives a shift in the resonance frequency of 1.5 GHz. This resonance frequency shift exceeds what can be achieved using other sensors operating in the low GHz frequency regime by a significant margin. In addition, using numerical simulation, we showed that the new sensor is able to resolve a 10- $mu text{m}$ -wide crack (equivalent to $lambda $ /4000) with 180-MHz shift in the resonance frequency.
Auteurs: Ali M. Albishi;Omar M. Ramahi;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1864 - 1872
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mid-Infrared Waveguide Array Inter-Chip Coupling Using Optical Quilt Packaging
Résumé:
A MEMS-based mid-infrared (MIR) chip-to-chip optical coupling technique, optical quilt packaging (OQP), is described. Numerical simulations are performed to predict performance and establish fabrication tolerances. The OQP fabrication process is described in detail and MIR inter-chip optical coupling between two waveguide arrays joined by OQP is characterized. The coupling loss between Ge-on-Si passive MIR waveguides is found to be ~ 4.1 dB, which is the lowest butt-coupling loss reported between two chips.
Auteurs: Tahsin Ahmed;Tian Lu;Thomas P. Butler;Jason M. Kulick;Gary H. Bernstein;Anthony J. Hoffman;Douglas C. Hall;Scott S. Howard;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 755 - 758
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Migration From Fixed to Flexible Grid Optical Networks With Sub-Band Virtual Concatenation
Résumé:
A novel strategy is presented to operate a mixed fixed/flexible grid optical network which may be used to gradually migrate from a fixed to a flexible mode of operation. Routing and spectrum allocation (RSA) in an optical network where fixed and flexible grids co-exist using a multi-path sub-band virtual concatenation (VCAT) or split spectrum (SS) technique is considered. Mixed integer linear programming models and an efficient heuristic algorithm based on spectrum window planes are proposed for the RSA optimization. The results obtained for the static traffic demand indicate that it is operationally more convenient to use the multi-path VCAT only by itself in a mixed grid optical network to guarantee performance comparable to that of the joint multi-path and single-path VCAT case. Network performance is also evaluated in terms of bandwidth blocking probability (BBP) under a dynamic traffic demand. Simulation results show that the multi-path VCAT scheme can efficiently utilize the overall spectrum resources with low blocking. The results of studies with both static and dynamic traffic demands also confirm that migration from a pure fixed grid optical network to a pure flexible grid will be desirable for better network capacity utilization.
Auteurs: Ya Zhang;Yao Zhang;Sanjay K. Bose;Gangxiang Shen;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1752 - 1765
Editeur: IEEE
Document complet vers site de l'éditeur
 
» MIMO Energy Harvesting in Full-Duplex Multi-User Networks
Résumé:
This paper considers the efficient design of precoding matrices for sum throughput maximization under throughput quality of service (QoS) constraints and energy harvesting (EH) constraints for energy-constrained devices in a full-duplex (FD) multicell multi-user multiple-input-multiple-output network. Both time splitting (TS) and power splitting are considered to ensure practical EH and information decoding. These problems are quite complex due to non-concave objectives and nonconvex constraints. Especially, with TS, which is implementation-wise quite simple, the problem is even more challenging because the time splitting variable is not only coupled with the downlink throughput function but also coupled with the self-interference in the uplink throughput function. New path-following algorithms are developed for their solutions, which require only a single convex quadratic program for each iteration and ensure rapid convergence. Moreover, the FD EH maximization problem under throughput QoS constraints with TS is also considered. The performance of the proposed algorithms is compared with that of the modified problems assuming half-duplex systems. Finally, the merit of the proposed algorithms is demonstrated through extensive simulations.
Auteurs: Ho Huu Minh Tam;Hoang Duong Tuan;Ali Arshad Nasir;Trung Q. Duong;H. Vincent Poor;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3282 - 3297
Editeur: IEEE
Document complet vers site de l'éditeur
 
» MIMO Sphere Decoding With Successive Interference Cancellation for Two-Dimensional Non-Uniform Constellations
Résumé:
Non-uniform constellations (NUCs) have been introduced to improve the performance of quadrature amplitude modulation constellations. 1D-NUCs keep the squared shape, while 2D-NUCs break that constraint to provide robustness. An impending problem with multiple-input multiple-output (MIMO) is the optimum demapping complexity, which grows exponentially with the number of antennas and the constellation order. Some well-known sub-optimum MIMO demappers, such as soft fixed-complexity sphere decoders (SFSD), can reduce that complexity. However, SFSD demappers do not work with the 2D-NUCs, since they perform a quantization step in separated I/Q components. In this letter, we provide an efficient solution for the 2D-NUCs based on Voronoi regions. Both complexity implications and SNR performance are also analyzed.
Auteurs: Carlos Barjau;Manuel Fuentes;Takuya Shitomi;David Gómez-Barquero;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1015 - 1018
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Miniature Low-Cost Carbon Dioxide Sensor for Mobile Devices
Résumé:
We present our recent advances on developing a miniature sensor for carbon dioxide that may be used in mobile devices. Until now, limiting factors for the implementation of gas sensors in mobile devices, such as smartphones, include their production costs and large size, which is associated with the comparatively poor sensitivity. To overcome these constraints, we employ a photoacoustic-based infrared detection technology to gauge the light intensity of a mid-infrared LED. The photoacoustic detector mainly consists of a commercially available microphone inside a hermetically sealed, carbon dioxide filled cell. To save space and minimize intensity losses, a novel waveguide is used to direct the LED radiation to the detector. The waveguide simultaneously forms the measuring chamber. Because of the high sensitivity of our device, the overall size can be reduced to a level where it is compatible with standard IC sockets. Gas measurements were performed that demonstrate the suitability of the sensor. While providing high sensitivity, the influence of humidity on the sensor signal is insignificant and influences due to temperature shifts may be compensated for.
Auteurs: Louisa Scholz;Alvaro Ortiz Perez;Benedikt Bierer;Ponkanok Eaksen;Jürgen Wöllenstein;Stefan Palzer;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2889 - 2895
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Miniaturization of Frequency Selective Surfaces Using 2.5-D Knitted Structures: Design and Synthesis
Résumé:
This paper explores the potential of using vias for the miniaturization of frequency selective surfaces (FSSs). A new concept of knitting the loop-type FSS elements in 2.5-D is proposed, where successive segments of the loop are placed alternately on the two surfaces of the substrate and then interconnected through vias. A 2.5-D square-loop FSS (2.5-D SL-FSS) based on the proposed method is designed with the inclusion of ten vias at each side and characterized by a full-wave simulator. The transmission curves indicate a significant size reduction with a figure-of-merit $lambda _{0}/p = 16$ , where $lambda _{0}$ is the free-space wavelength of resonant frequency and $p$ is the periodicity of unit element. In addition, the frequency response of this miniaturized FSS is also stable for various incident angles and polarizations. Furthermore, a general equivalent circuit model (ECM) is developed for 2.5-D SL-FSS by combining the prevailing electrical models of planar square loop and through-silicon vias. A wide set of parametric simulations for various element sizes, substrate thicknesses, and via counts are carried out with this ECM. Then, its performance is assessed on the basis of root-mean-square error (RMSE) criteria by comparing the results with appropriate electromagnetic simulations. The findings suggest that the ECM has sufficient accuracy for estimating the resonant frequency of 2.5-D SL-FSS with the RMSE values close to 3%. Moreover, the proposed concept of knitting is further validated by measuring two physical prototypes of the 2.5-D SL-FSS and the experimental results show a good consistency with full-wave simulations.
Auteurs: Tauseef Hussain;Qunsheng Cao;Jahangir Khan Kayani;Irfan Majid;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2405 - 2412
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Miniaturized Millimeter-Wave Radar Sensor for High-Accuracy Applications
Résumé:
A highly miniaturized and commercially available millimeter wave (mmw) radar sensor working in the frequency range between 121 and 127 GHz is presented in this paper. It can be used for distance measurements with an accuracy in the single-digit micrometer range. The sensor is based on the frequency modulated continuous wave (CW) radar principle; however, CW measurements are also possible due to its versatile design. An overview of the existing mmw radar sensors is given and the integrated radar sensor is shown in detail. The radio frequency part of the radar, which is implemented in SiGe technology, is described followed by the packaging concept. The radar circuitry on chip as well as the external antennas is completely integrated into an 8 mm $times ,, 8$ mm quad flat no leads package that is mounted on a low-cost baseband board. The packaging concept and the complete baseband hardware are explained in detail. A two-step approach is used for the radar signal evaluation: a coarse determination of the target position by the evaluation of the beat frequency combined with an additional determination of the phase of the signal. This leads to an accuracy within a single-digit micrometer range. The measurement results prove that an accuracy of better than $pm 6~mu text{m}$ can be achieved with the sensor over a measurement distance of 35 mm.
Auteurs: Mario Pauli;Benjamin Göttel;Steffen Scherr;Akanksha Bhutani;Serdal Ayhan;Wolfgang Winkler;Thomas Zwick;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1707 - 1715
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Miniaturized Transparent Metallodielectric Resonator Antennas Integrated With Amorphous Silicon Solar Cells
Résumé:
Miniaturized transparent metallodielectric resonator antennas are developed and integrated on amorphous silicon solar cells. The horizontal metallic strips attached on the sidewalls of transparent low-profile dielectric resonators are used to manipulate electric near-fields and achieve novel dominant modes that represent miniaturized narrowband, wideband, or multiband antennas with various far-field properties. The radiation properties of each mode can also be adjusted to suit a prospective application by a simple change in position and/or size of the strip. The horizontal strip on the sidewall can be as narrow as one twelfth of the resonator height, and the top wall of the resonator is always kept clear to maximize the solar cell efficiency. A comprehensive comparison including far-field, near-field, and impedance properties of different modes is presented. Several prototypes of the integrated antennas were fabricated and tested. The experimental results are along with the theoretical achievements showing miniaturized antennas with maximum dimension as small as $0.18lambda $ and multimode operation with realized gain higher than 6 dBi.
Auteurs: Atabak Rashidian;Lotfollah Shafai;Cyrus Shafai;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2265 - 2275
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Minimal Load Shedding Using the Swing Equation
Résumé:
Load shedding constitutes the very last resort for preventing total blackouts and cascading events. Conventional load shedding schemes, which are massively applied in industrial practice, adopt a step-wise approach that usually causes overshedding or fails to prevent frequency decay above the allowable limits. Recently proposed schemes based on real time intelligent control and neural networks achieve the control objective, but fail to minimize the amount of load to be shed due to the delay incurred in consecutive control decisions. This letter proposes a new load shedding scheme, decoupled from the conventional scheme. This scheme, based on the equivalent swing equation of the system, determines the minimal amount of load that should be shed immediately (in a single step) after the load event/disturbance occurs, in order to guarantee system stability.
Auteurs: Yiannis Tofis;Stelios Timotheou;Elias Kyriakides;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2466 - 2467
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Minimax Compression and Large Alphabet Approximation Through Poissonization and Tilting
Résumé:
This paper introduces a convenient strategy for coding and predicting sequences of independent, identically distributed random variables generated from a large alphabet of size $m$ . In particular, the size of the sample is allowed to be variable. The employment of a Poisson model and tilting method simplifies the implementation and analysis through independence. The resulting strategy is optimal within the class of distributions satisfying a moment condition, and it is close to optimal for the class of all i.i.d distributions on strings of a given length. The method also can be used to code and predict strings with a condition on the tail of the ordered counts, and it can be applied to distributions in an envelope class. Moreover, we show that our model permits exact computation of the minimax optimal code, for all alphabet sizes, when conditioning on the size of the sample.
Auteurs: Xiao Yang;Andrew R. Barron;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 2866 - 2884
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Minimization of Waiting Time Variation in a Generalized Two-Machine Flowshop With Waiting Time Constraints and Skipping Jobs
Résumé:
Wafer quality issues are becoming essential concerns in semiconductor manufacturing industry. It is becoming increasingly important for fab managers to raise the wafer quality level. Quality variation across wafers and wafer lots is also recognized as of vital importance. Wafer waiting times, which occur between consecutive wafer processing steps, are critical for the quality and quality variation of wafers. To resolve these quality issues, we consider waiting time constraints and variation in a flowshop. To follow the actual operating features of the fab, we define a two-machine flowshop with jobs that can skip the first process step and are ready to enter the second step from the beginning of scheduling. This research thus examines a machine scheduling problem that minimizes the variation in job waiting times in a generalized two-machine flowshop with skipping jobs and waiting time constraints. The mathematical properties of the problem such as the dominance properties and feasibility conditions are vigorously analyzed. These analyses provide profound insights into reduction of the search space in the solution procedure. We also observe that the derived properties are intuitively consistent with the well-known principles of queueing theory. From these, we develop efficient approximation algorithms and present their computational performance.
Auteurs: Tae-Sun Yu;Hyun-Jung Kim;Tae-Eog Lee;
Apparue dans: IEEE Transactions on Semiconductor Manufacturing
Date publication: 05.-2017, volume: 30, issue:2, pages: 155 - 165
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Minimizing Coefficients Wordlength for Piecewise-Polynomial Hardware Function Evaluation With Exact or Faithful Rounding
Résumé:
Piecewise polynomial interpolation is a well-established technique for hardware function evaluation. The paper describes a novel technique to minimize polynomial coefficients wordlength with the aim of obtaining either exact or faithful rounding at a reduced hardware cost. The standard approaches employed in literature subdivide the design of piecewise-polynomial interpolators into three steps (coefficients calculation, coefficients quantization and arithmetic hardware optimization) and estimate conservatively the overall approximation error as the sum of the error components arising in each step. The proposed technique, using Integer Linear Programming (ILP), optimizes the polynomial coefficients taking into account all error components simultaneously. This gives two advantages. Firstly, we can obtain exactly rounded approximations; secondly, for faithfully rounded interpolators, we avoid any overdesign due to pessimistic assumptions on error components, optimizing in this way the resulting hardware. The proposed ILP based algorithm requires an acceptable CPU time (from few seconds to tens of minutes) and is suited for approximations up to, maximum, 24 input bits. The results compare favorably with previously published data. We present synthesis results in 28 nm and 90 nm CMOS technologies, to further assess the effectiveness of the proposed approach.
Auteurs: Davide De Caro;Ettore Napoli;Darjn Esposito;Gerardo Castellano;Nicola Petra;Antonio G. M. Strollo;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1187 - 1200
Editeur: IEEE
Document complet vers site de l'éditeur
 
» MISO Networks With Imperfect CSIT: A Topological Rate-Splitting Approach
Résumé:
Recently, the Degrees-of-Freedom (DoFs) region of multiple-input-single-output (MISO) networks with imperfect channel state information at the transmitter (CSIT) has attracted significant attention. An achievable scheme, known as rate-splitting (RS), integrates common-message-multicasting and private-message-unicasting. In this paper, focusing on the general $K$ -cell MISO IC with an arbitrary CSIT quality of each interfering link, we first identify the DoF region achieved by RS. Second, we introduce a novel scheme, so called topological RS (TRS), whose novelties compared with RS lie in a multi-layer structure and in transmitting multiple common messages to be decoded by groups of users rather than all users. The design of TRS is motivated by a novel interpretation of the $K$ -cell IC with imperfect CSIT as a weighted sum of a series of partially connected networks. We show that the DoF region achieved by TRS yields the best known result so far, and we find the maximal sum DoF via hypergraph fractional packing. Finally, for a realistic scenario where each user is connected to three dominant transmitters, we identify the sufficient condition where TRS strictly outperforms conventional schemes, and show that TRS is optimal for some CSIT qualities.
Auteurs: Chenxi Hao;Bruno Clerckx;
Apparue dans: IEEE Transactions on Communications
Date publication: 05.-2017, volume: 65, issue:5, pages: 2164 - 2179
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mixed Iterative Adaptive Dynamic Programming for Optimal Battery Energy Control in Smart Residential Microgrids
Résumé:
In this paper, a novel mixed iterative adaptive dynamic programming (ADP) algorithm is developed to solve the optimal battery energy management and control problem in smart residential microgrid systems. Based on the data of the load and electricity rate, two iterations are constructed, which are $P$ -iteration and $V$ -iteration, respectively. The $V$-iteration is implemented based on value iteration, which aims to obtain the iterative control law sequence in each period. The $P$-iteration is implemented based on policy iteration, which updates the iterative value function according to the iterative control law sequence. Properties of the developed mixed iterative ADP algorithm are analyzed. It is shown that the iterative value function is monotonically nonincreasing and converges to the solution of the Bellman equation. In each iteration, it is proven that the performance index function is finite under the iterative control law sequence. Finally, numerical results and comparisons are given to illustrate the performance of the developed algorithm.
Auteurs: Qinglai Wei;Derong Liu;Frank L. Lewis;Yu Liu;Jie Zhang;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 4110 - 4120
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mobility Aware Virtual Network Embedding
Résumé:
Over the last years, network virtualization has become one of the most promising solutions for sustainability towards the ongoing increase of data demand in mobile networks. Within that context, the virtual network embedding problem has recently been studied extensively and many different solutions have been proposed; but, mainly these studies have focused on wired networks. The main purpose of this paper is to provide an optimization framework for optimal virtual network embedding, including a heuristic algorithm with low computational complexity, by explicitly considering the effect of supporting the actual user mobility, assuming the emerging Distributed Mobility Management (DMM) scheme as well as a traditional Centralized Mobility Management (CMM) scheme. In addition to that, service differentiation is introduced, giving higher priority to time-critical over-the-top (OTT) services compared to more traditional elastic Internet applications. The performance of the proposed framework is compared to mobility agnostic greedy algorithms as well as virtual network embedding algorithms from the literature. Numerical investigations reveal that the effect of user mobility has a significant impact on the design of virtual networks. Additionally, the mobility aware scheme can provide tangible gains in the overall performance compared with the previous proposed schemes that do not take explicitly into account the effect of user mobility.
Auteurs: Giorgos Chochlidakis;Vasilis Friderikos;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 05.-2017, volume: 16, issue:5, pages: 1343 - 1356
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Model-Based Self-Aware Performance and Resource Management Using the Descartes Modeling Language
Résumé:
Modern IT systems have increasingly distributed and dynamic architectures providing flexibility to adapt to changes in the environment and thus enabling higher resource efficiency. However, these benefits come at the cost of higher system complexity and dynamics. Thus, engineering systems that manage their end-to-end application performance and resource efficiency in an autonomic manner is a challenge. In this article, we present a holistic model-based approach for self-aware performance and resource management leveraging the Descartes Modeling Language (DML), an architecture-level modeling language for online performance and resource management. We propose a novel online performance prediction process that dynamically tailors the model solving depending on the requirements regarding accuracy and overhead. Using these prediction capabilities, we implement a generic model-based control loop for proactive system adaptation. We evaluate our model-based approach in the context of two representative case studies showing that with the proposed methods, significant resource efficiency gains can be achieved while maintaining performance requirements. These results represent the first end-to-end validation of our approach, demonstrating its potential for self-aware performance and resource management in the context of modern IT systems and infrastructures.
Auteurs: Nikolaus Huber;Fabian Brosig;Simon Spinner;Samuel Kounev;Manuel Bähr;
Apparue dans: IEEE Transactions on Software Engineering
Date publication: 05.-2017, volume: 43, issue:5, pages: 432 - 452
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Model-Free Optimal Control Based Intelligent Cruise Control with Hardware-in-the-Loop Demonstration [Research Frontier]
Résumé:
It is difficult to implement optimal control for a system whose model is unknown and operation environment is uncertain, such as the intelligent cruise control of vehicles. This article will address the problem from the perspective of reinforcement learning by learning the optimal policy from the state transition data. The model-free optimal control algorithm is employed to approximate the optimal control policy for the intelligent cruise control system, which considers the comfort performance and the safety performance comprehensively by setting up a total performance index. The algorithm is implemented by two multi-layer neural networks which are the critic network and the actor network. The critic and actor networks are employed to approximate the stateaction value function and the control action, respectively. In addition, a data collecting strategy is proposed to obtain the state transition data distributed uniformly in the state action space from the running trajectory of the host car. The critic network and the action network are trained alternatively by the collected data until converging. The convergent action network is used to obtain the optimal control policy. At last, the policy is tested on a hardware-in-the-loop simulator built upon dSPACE by comparing with a linear quadratic regulator (LQR) controller and a proportion integration differentiation (PID) controller. Results show its excellent performance on both aspects of the safety and the comfort.
Auteurs: Dongbin Zhao;Zhongpu Xia;Qichao Zhang;
Apparue dans: IEEE Computational Intelligence Magazine
Date publication: 05.-2017, volume: 12, issue:2, pages: 56 - 69
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling and Characterization of Vertical GaN Schottky Diodes With AlGaN Cap Layers
Résumé:
A new gallium nitride (GaN) Schottky device structure suitable for power electronic applications is discussed. A GaN Schottky diode with an ultrathin AlGaN cap layer was fabricated using an Ni/Au metal stack as the Schottky electrode. ${C}$ ${V}$ measurements at various temperatures were used to calculate a barrier height of 0.65 V with a free electron concentration of $5 times 10^{15}$ cm $^{-3}$ both of which appear temperature independent. A forward conduction model based on a thermionic emission–diffusion process with tunneling through the AlGaN barrier was developed and compared favorably to experimental data. A reverse conduction model utilizing thermionic field emission (TFE) with a triangular energy barrier is presented and then improved upon with a scaling factor that modifies the barrier thickness. This TFE model compares more favorably with the experimental data than the standard thermionic emission model typically used in Schottky diodes. Both the forward conduction and reverse conduction characteristics were assessed at room temperature and elevated temperature. The model can be used to predict how the physical parameters of the device affect its ${I}$ ${V}$ characteristics.
Auteurs: Michael R. Hontz;Yu Cao;Mary Chen;Ray Li;Austin Garrido;Rongming Chu;Raghav Khanna;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2172 - 2178
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling and Dimensioning of a Virtualized MME for 5G Mobile Networks
Résumé:
Network function virtualization is considered one of the key technologies for developing future mobile networks. In this paper, we propose a theoretical framework to evaluate the performance of a Long-Term Evolution (LTE) virtualized mobility management entity (vMME) hosted in a data center. This theoretical framework consists of 1) a queuing network to model the vMME in a data center and 2) analytic expressions to estimate the overall mean system delay and the signaling workload to be processed by the vMME. We validate our mathematical model by simulation. One direct use of the proposed model is vMME dimensioning, i.e., to compute the number of vMME processing instances to provide a target system delay given the number of users in the system. Additionally, the paper includes a scalability analysis of the system. In our study, we consider the billing model and a data center setup of Amazon Elastic Compute Cloud service and estimate the processing time of MME processing instances for different LTE control procedures experimentally. For the considered setup, our results show that the vMME is scalable for signaling workloads up to 37 000 LTE control procedures per second for a target mean system delay of 1 ms. The system design and database performance assumed imposes this limit in the system scalability.
Auteurs: Jonathan Prados-Garzon;Juan J. Ramos-Munoz;Pablo Ameigeiras;Pilar Andres-Maldonado;Juan M. Lopez-Soler;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4383 - 4395
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling and Exploration of the Voltage-Controlled Magnetic Anisotropy Effect for the Next-Generation Low-Power and High-Speed MRAM Applications
Résumé:
Spin transfer torque magnetic random access memory (STT-MRAM) has been widely regarded as a potential nonvolatile memory candidate in the next-generation computer architectures. Nevertheless, the write energy consumption and delay are two significant concerns for STT-MRAM, blocking its applications for working memories. Recently, magnetic tunnel junction (MTJ) based on voltage-controlled magnetic anisotropy (VCMA) effect shows tremendous superiority in terms of dynamic write energy and delay over the STT-based one, attracting much attention for advanced low-power and high-speed MRAM designs. In this paper, we evaluate the prospects and challenges of the VCMA-MTJ devices for advanced MRAM applications. First, the magnetization dynamics of the free layer of VCMA-MTJ devices are studied by solving a modified Landau–Lifshitz–Gilbert equation. Afterward, a VCMA-MTJ electrical model is built by integrating the VCMA effect, Slonczewski STT model, Brinkman resistance model, and tunnel magnetoresistance model. Finally, three MTJ switching strategies, including precessional VCMA, STT-assisted precessional VCMA and STT-assisted thermally-activated VCMA, are studied for MRAM applications. Our results show that the STT-assisted precessional VCMA strategy is the most potential one for high-speed and low-power VCMA-MRAM design. This paper provides models, strategies, and guidelines for VCMA-MRAM design and application.
Auteurs: Wang Kang;Yi Ran;Youguang Zhang;Weifeng Lv;Weisheng Zhao;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 387 - 395
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling and Parameter Extraction of CMOS On-Chip Spiral Inductors With Ground Shields
Résumé:
A new simple $pi $ -equivalent model with parameter extraction method is presented in this letter, to develop accurate models for spiral inductors on low-resistance CMOS substrate with ground shield structure. C-L-R network is introduced to model the ground loop in the lower metal strips, replacing the conventional C-R-C network. This model contains only ten frequency-independent components with explicit physical meaning, which has fewer elements and is easy to be extracted. Frequency responses of the extracted results are in excellent agreement with the measurements and EM simulations of inductors with different ground shields and layout designs up to 40 GHz. This proves the validity of the proposed model and parameter extraction method. Finally, extracted results of the inductors with different ground shields are compared and investigated.
Auteurs: Bowen Ding;Shengyue Yuan;Chen Zhao;Tong Tian;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 05.-2017, volume: 27, issue:5, pages: 431 - 433
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling Fading Channels With Binary Erasure Finite-State Markov Channels
Résumé:
Finite-state Markov channels (FSMCs) are commonly used to characterize the memory of binary (binary-input, binary-output) discrete fading channels (DFCs). This paper proposes a new FSMC model, called the ternary Markov channel (TMC), to characterize ternary (binary-input, ternary-output) discrete channels with memory and soft-information. The TMC is used to model a DFC with the simplest soft-decision quantizer that labels low reliable received symbols as erasure symbols. This paper also proposes an enumerative technique to analytically evaluate the performance of a linear block code over the TMC. A new recurrence expression is developed for calculating the probability of codeword error for bounded distance error and erasure decoding.
Auteurs: Igor Moreira;Cecilio Pimentel;Felipe P. Barros;Daniel P. B. Chaves;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4429 - 4434
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling Nanoelectromechanical Switches With Random Surface Roughness
Résumé:
Surface roughness is an important physical feature of nanometer-scale electromechanical (NEM) devices but typically is not considered in their numerical analysis. In this paper, computer simulations of a single-pole double-throw NEM switch with surface roughness are presented. Roughness is shown to modify the eigenfrequencies of the system, and also to make it possible for the switch to not close successfully. The importance of avoiding a free-standing cantilever is demonstrated.
Auteurs: Daniel Connelly;Tsu-Jae King Liu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2409 - 2416
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling of CMOS Devices and Circuits on Flexible Ultrathin Chips
Résumé:
The field of flexible electronics is rapidly evolving. The ultrathin chips are being used to address the high-performance requirements of many applications. However, simulation and prediction of changes in response of device/circuit due to bending induced stress remains a challenge as of lack of suitable compact models. This makes circuit designing for bendable electronics a difficult task. This paper presents advances in this direction, through compressive and tensile stress studies on transistors and simple circuits such as inverters with different channel lengths and orientations of transistors on ultrathin chips. Different designs of devices and circuits in a standard CMOS 0.18- $mu text{m}$ technology were fabricated in two separated chips. The two fabricated chips were thinned down to $20~mu text{m}$ using standard dicing-before-grinding technique steps followed by post-CMOS processing to obtain sufficient bendability (20-mm bending radius, or 0.05% nominal strain). Electrical characterization was performed by packaging the thinned chip on a flexible substrate. Experimental results show change of carrier mobilities in respective transistors, and switching threshold voltage of the inverters during different bending conditions (maximum percentage change of 2% for compressive and 4% for tensile stress). To simulate these changes, a compact model, which is a combination of mathematical equations and extracted parameters from BSIM4, has been developed in Verilog-A and compiled into Cadence Virtuoso environment. The proposed model predicts the mobility variations and threshold voltage in compressive and tensile bending stress conditions and orientations, and shows an agreement with the experimental measurements (1% for compressive and 0.6- ; for tensile stress mismatch).
Auteurs: Anastasios Vilouras;Hadi Heidari;Shoubhik Gupta;Ravinder Dahiya;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2038 - 2046
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling of FinFET Parasitic Source/Drain Resistance With Polygonal Epitaxy
Résumé:
In this paper, we introduce a new compact model of the parasitic resistance of a FinFET with a hexagonal-shaped raised source–drain (S/D) structure. In contrast to previous models that divided the extrinsic S/D region into three parts, we redefined the region boundaries and modeled them as a series connection of accumulation resistance, gradient resistance, bulk resistance, and contact resistance. The newly added bulk resistance model accounts for the highly doped silicon region. We also significantly improved the contact resistance model to reflect the contact area and contact resistivity for better accuracy in the raised S/D region. We validated the accuracy of our model by varying the gate voltage, doping diffusion length, epitaxy silicon height, and contact resistivity, finding the model errors to be within 2% of the 3-D technology CAD device simulation results.
Auteurs: JungHun Kim;Hai Au Huynh;SoYoung Kim;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2072 - 2079
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling of the Change of Impedance of an Eddy Current Probe Due to Small Changes in Host Conductivity
Résumé:
Two different approximation techniques for predicting the response of an eddy current coil in the presence of small changes in conductivity were developed. The small changes in conductivity are the result of changes in the orientation of individual anisotropic crystals in a polycrystalline aggregate. Orientation information from electron backscatter diffraction was imported directly into the modeling domain and the simulations were run to map orientations into an approximated eddy current response. These approximated responses were compared with experimental data obtained with commercially available eddy current equipment, and the approximations were found to be in good agreement with experiment. Further verification was performed with other existing numerical and analytical models to demonstrate the accuracy of the approximations made in deriving the eddy current response. This paper shows these results and demonstrates the viability of using low-fidelity approximations in predicting the eddy current response when the change in conductivity is low.
Auteurs: Matthew R. Cherry;Shamachary Sathish;Ryan D. Mooers;Adam L. Pilchak;Ramana Grandhi;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 10
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling of Via Resistance for Advanced Technology Nodes
Résumé:
We investigate the dependence of Cu via resistance on via dimensions, shape, misalignment, and Co via prefill level by means of a novel resistivity model, calibrated to actual wires on silicon and integrated into the Synopsys Raphael tool. For this paper, we consider the case of 16 and 12nm self-aligned vias, which are representative for the 7 and 5nm logic technology nodes, respectively. Process emulations are performed by using the Synopsys Sentaurus Process Explorer tool in order to generate 3-D models of the investigated via structures. Finally, via resistance is extracted through current simulations in Raphael, that is, by taking into account the actual conductive path from the wires into the via. We predict that via resistance could increase by more than a factor of 2 from node to node. We show that chamfered vias can exhibit up to 56% less resistance than standard (87° tapered) vias because of the larger cross section at the via top. For the same reason, via resistance sensitivity to via width variations along the direction of the connecting (i.e. upper) wire is smaller for chamfered vias. As far as via misalignment to the connected (i.e. lower) wire is concerned, we demonstrate that in the range of interest, the induced resistance increase is not severe (e.g. 20% or lower), and in particular, via resistance is not inversely proportional to the contact area between the via and the connected wire. If side contact to the connected wire is enabled upon misalignment, the via resistance increase is further reduced. If vias are fully self-aligned, that is, self-aligned to both connecting and connected wires, the impact of misalignment can be neutralized in a certain range by properly oversizing the via mask in the direction along the connecting wire. Finally, we show that Co via prefill can enable a substantial reduction (up to 45%) of via resistance for chamfered vias, where the bottom ba- rier surface can be significantly increased when raised to the via top by means of the prefill step.
Auteurs: Ivan Ciofi;Philippe J. Roussel;Yves Saad;Victor Moroz;Chia-Ying Hu;Rogier Baert;Kristof Croes;Antonino Contino;Kevin Vandersmissen;Weimin Gao;Philippe Matagne;Mustafa Badaroglu;Christopher J. Wilson;Dan Mocuta;Zsolt Tőkei;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2306 - 2313
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling the Dual-Slope Behavior of in-Quad EL-FEXT in Twisted Pair Quad Cables
Résumé:
It is well known that the ratio between received crosstalk and received signal in telephony cabling increases with the frequency until both levels become about equal. Transmission systems like VDSL and G.fast are designed to cope with that. But the awareness that the increase of EL-FEXT (equal level – far end cross talk) becomes much stronger above a certain frequency (increases with 40 dB instead of 20 dB per decade) was raised only recently in ITU and BBF standardization bodies for G.fast. This second order effect became known under the name “dual slope” effect, was initially not well understood, and resulted in a number of conjectured explanations. This paper demonstrates that this second order effect in far end crosstalk between opposite wire pairs in the same quad is deterministic in nature. It is caused by the interaction of the twist in a quad and its metallic surroundings (e.g., shield). The twist of these quads reduces this second order crosstalk effect significantly, but what remains causes a slope of 40 dB/decade. This paper shows via a model that this second order effect scales linearly with the cable length and twist length, and validates that via measurements. It quantifies how sensitive this effect is to cable design parameters like twist length and capacitance to shield. In addition, an extension is proposed to a commonly used simplified system model for describing the far end cross talk as a function of the frequency and cable length.
Auteurs: Rob F. M. van den Brink;
Apparue dans: IEEE Transactions on Communications
Date publication: 05.-2017, volume: 65, issue:5, pages: 2153 - 2163
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modeling, Simulation, and Comparison of Control Techniques for Energy Storage Systems
Résumé:
This paper describes the modeling and formulation of a variety of deterministic techniques for energy storage devices, namely the PI, H-infinity, and sliding mode controllers. These techniques are defined based on a general, yet detailed, energy storage device model, which is accurate for transient stability analysis. The paper also presents a thorough statistical comparison of the performance and robustness of the considered control techniques, using stochastic dynamic models and a variety of disturbances and scenarios. The case study is based on a 1479-bus model of the all-island Irish transmission system and an energy storage device actually installed in the system.
Auteurs: Álvaro Ortega;Federico Milano;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2445 - 2454
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modernizing the Grid: Challenges and Opportunities for a Sustainable Future
Résumé:
In Addition To Their Age, Particularly in large metropolitan areas, electric power systems throughout the industrialized world face challenges brought on by new technology trends, environmental concerns, evolving weather patterns, a multiplicity of consumer needs, and regulatory requirements. New technology trends include the development of more efficient, reliable, and cost-effective renewable generation and distributed energy resources (DERs), energy storage technologies, and electric vehicles (EVs), along with monitoring, protection, automation, and control devices and communications that offer significant opportunities for realizing a sustainable energy future. The medium- to long-term vision for the electrical grid is to transition away from carbon-based fuels toward increased penetration of renewable DERs and use of energy storage and electric transportation.
Auteurs: Julio Romero Aguero;Erik Takayesu;Damir Novosel;Ralph Masiello;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 05.-2017, volume: 15, issue:3, pages: 74 - 83
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Modular and Asynchronous Backpressure in Multihop Networks: Model and Optimization
Résumé:
It is well known that backpressure routing and scheduling can achieve optimal operation in multihop networks. However, the joint routing and scheduling nature of backpressure imposes challenges for practical implementation since many off-the-shelf network nodes cannot be easily changed to match the synchronous scheduling and routing functionality of backpressure. Toward this end, we propose a two-tier data queue structure to separate routing from scheduling and design a novel modular and asynchronous backpressure (MAB) based on the Lyapunov optimization technique. In MAB, source rate control, routing selection, and session scheduling can be asynchronously and independently implemented, which performs at the transport/network/link layer, respectively. Thus, MAB is readily deployed with current infrastructure, and all network nodes can easily employ MAB partially or fully. Simulation results show that MAB maintains optimal performance of the classic backpressure.
Auteurs: Weiqiang Xu;Fansong Sun;Qingjiang Shi;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4486 - 4491
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Monitoring Physiological Variables of Mining Workers at High Altitude
Résumé:
Miners working at high altitude must handle extreme climatic and physiological hazards without specialized medical supervision. For this reason, the mining industry is constantly looking for improvements to existing occupational safety and health programs in order to enhance working conditions for people and equipment. This paper presents the design and implementation of a continuous monitoring device to measure the physiological variables of miners at high altitudes (>2000 m.a.s.l.). Extreme environmental conditions are detrimental for human health; therefore, a continuous control of the workers’ vital signs is necessary. The proposed system includes physiological variables such as electrocardiogram, respiratory activity, and body temperature, and environmental variables such as ambient temperature and relative humidity. The noninvasive sensors of the proposed system are embedded all throughout a T-shirt (first layer of protecting clothing) to achieve a functional device and maximum comfort for the users. The device is able to continuously calculate heart and respiration rate, and establish a wireless data transmission to a central monitoring station.
Auteurs: Pablo Aqueveque;Christopher Gutiérrez;Francisco Saavedra Rodríguez;Esteban J. Pino;Anibal S. Morales;Eduardo P. Wiechmann;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2628 - 2634
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Morphing Origami Conical Spiral Antenna Based on the Nojima Wrap
Résumé:
A two-arm Nojima origami conical spiral antenna (CSA) is designed. The antenna is based on the origami Nojima wrap pattern that enables the antenna to morph from a planar dipole to a conical spiral. The design equations of the Nojima origami CSA are presented and its performance is studied using simulations and measurements. The reflection coefficient, input impedance, gain, and axial ratio of this antenna are investigated over a wide frequency band. The radiation patterns of this antenna are also examined. A prototype of an origami Nojima CSA with 1.5 turns is manufactured and measured.
Auteurs: Shun Yao;Xueli Liu;Stavros V. Georgakopoulos;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2222 - 2232
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Morphology, Structure, and Gas Sensing Performance of Conductive Polymers and Polymer/Carbon Black Composites Used for Volatile Compounds Detection
Résumé:
In this paper, we present fabrication, characterization, and sensing performance of four sensor elements, including two conducting polymers (polypyrrole and polyaniline), and two polymer/carbon black (CB) composites consisting ethyl cellulose (EC) and poly(caprolactone) (PCL). The identifications of four different vapors (methanol, ethanol, acetone, and ammonia) by these four sensors have been successfully demonstrated by using the principal component analysis. The sensing mechanisms of the examined sensors were investigated and a discussion on the similarity of gas sensor responses and the creep behavior has also been given. It was found that the response/recovery behavior of gas sensors can be presented by the Kelvin–Voigt rheological model. The effect of CB content on polymer/carbon sensor performance was investigated in the range of 15–20 wt. %. The increase of CB wt. %, led to increase the sensor response. The morphology of the produced EC/CB and PCL/CB composite sensors has been characterized by scanning electron microscopy and atomic force microscopy. Polyaniline indicated the highest response to ammonia due to effect of ${p}$ -phenylene resonance on deprotonation process. The PCL/CB sensor response was more pronounced as compared with EC/CB, due to its higher porous structure.
Auteurs: Farnoosh Miramirkhani;Amir H. Navarchian;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 2992 - 3000
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Motion and Switching of Dual-Vortex Cores in Elliptical Permalloy Nanodisk Stimulated by a Gaussian Magnetic Field Pulse
Résumé:
Magnetic nanostructures have potential applications in ultrahigh-density magnetic storage. In this paper, the dynamics of the dual magnetic vortices in elliptical Permalloy nanodisk are investigated using micromagnetic modeling. Under the stimulation of the short-axis ( $y$ -axis) Gaussian field pulse and long-axis ( $x$ -axis) constant field, the equilibrium positions of dual-vortex cores can be driven away from the initial positions. The displacement in the $y$ -direction is proportional to the magnitude of the $x$ -axis constant field. The displacement in the $x$ -direction exhibit periodic reliance on the pulsewidth of the $y$ -axis Gaussian field pulse. The threshold value of pulse strength for dual-vortex motion increases with the magnitude of the $x$ -axis constant field. The mechanism of polarity and chirality switching in dual-vortex cores are studied through analyzing the trajectories of vortex cores in the annihilation and nucleation processes. The switching of polarity exhibits an oscillatory dependence on the pulsewidth and strength. The minimum pulse strength required for chirality switching is 120 mT, while the corresponding pulsewidth is influenced by the $x$ -axis constant field. This paper provides insights on the magnetization dynamics of nanostructures containing dual vortices subject to external excitations.
Auteurs: X. Li;Y. Zhou;T. Zeng;K. -W. Lin;P. T. Lai;Philip W. T. Pong;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 6
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Motion Classification-Based Fast Motion Estimation for High-Efficiency Video Coding
Résumé:
High efficiency video coding (HEVC), the latest video coding standard, is becoming popular due to its excellent coding performance. However, the significant gain in performance is achieved at the cost of substantially higher encoding complexity than its precedent H.264/AVC, in which motion estimation (ME) is the most time-consuming module that effectively removes temporal redundancy. Test zone search (TZS) is adopted as the default fast ME method in the reference software of HEVC; however, its computational complexity is still too high for real-time applications. Several fast ME algorithms have been recently proposed to further reduce ME complexity; however, these approaches typically lead to non-negligible performance loss. To address this problem, this paper proposes a motion classification-based fast ME algorithm. By exploring the motion relationship of neighboring blocks and the coding cost characteristic, the prediction unit (PU) is first categorized into one of three classes, namely, motion-smooth PU, motion-medium PU and motion-complex PU. Then different search strategies are carefully designed for PUs of each class according to their respective motion and content characteristics. Furthermore, a fast search priority-based partial internal termination scheme is presented to rapidly skip impossible positions that speeds up cost computation during the ME process. Extensive experimental results demonstrate that the proposed algorithm achieves as much as 12.47% and 20.25% reductions in total encoder complexity when compared with TZS under low delay P and random access configuration, respectively, with negligible rate-distortion degradation; thus, it outperforms state-of-the-art fast ME algorithms in terms of both coding performance and complexity reduction.
Auteurs: Rui Fan;Yongfei Zhang;Bo Li;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 05.-2017, volume: 19, issue:5, pages: 893 - 907
Editeur: IEEE
Document complet vers site de l'éditeur
 
» MoZo: A Moving Zone Based Routing Protocol Using Pure V2V Communication in VANETs
Résumé:
Vehicular Ad-hoc Networks (VANETs) are an emerging field, whereby vehicle-to-vehicle communications can enable many new applications such as safety and entertainment services. Most VANET applications are enabled by different routing protocols. The design of such routing protocols, however, is quite challenging due to the dynamic nature of nodes (vehicles) in VANETs. To exploit the unique characteristics of VANET nodes, we design a moving-zone based architecture in which vehicles collaborate with one another to form dynamic moving zones so as to facilitate information dissemination. We propose a novel approach that introduces moving object modeling and indexing techniques from the theory of large moving object databases into the design of VANET routing protocols. The results of extensive simulation studies carried out on real road maps demonstrate the superiority of our approach compared with both clustering and non-clustering based routing protocols.
Auteurs: Dan Lin;Jian Kang;Anna Squicciarini;Yingjie Wu;Sashi Gurung;Ozan Tonguz;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 05.-2017, volume: 16, issue:5, pages: 1357 - 1370
Editeur: IEEE
Document complet vers site de l'éditeur
 
» MPPT in Wireless Sensor Nodes Supply Systems Based on Electromagnetic Vibration Harvesters for Freight Wagons Applications
Résumé:
The starting point for the proper design of an efficient wireless sensor node (WSN) supply system that is based on the adoption of a resonant electromagnetic vibration energy harvester (REVEH) is represented by the choice of a REVEH with a proper resonance frequency. But further likewise important design guidelines need to be also taken into account especially if, as in the case of freight wagons applications, vibrations are nonsinusoidal and their characteristics change with time. In this paper, the guidelines leading to the development of a smart power electronics interface between the REVEH and the WSN are provided with reference to freight wagons applications. In particular, for the most widely used double stage ac/dc architecture for REVEH applications, such guidelines not only allow the choice of the proper dc/dc converter topology, but they also allow the development of a suitable maximum power point tracking control strategy that allows to avoid the waste of energy and the consequent necessity to oversize the REVEH.
Auteurs: Marco Balato;Luigi Costanzo;Massimo Vitelli;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3576 - 3586
Editeur: IEEE
Document complet vers site de l'éditeur
 
» MRCP-RM: A Technique for Resource Allocation and Scheduling of MapReduce Jobs with Deadlines
Résumé:
Resource allocation and scheduling on clouds are required to harness the power of the underlying resource pool such that the service provider can meet the quality of service requirements of users, which are often captured in service level agreements (SLAs). This paper focuses on resource allocation and scheduling on clouds and clusters that process MapReduce jobs with SLAs. The resource allocation and scheduling problem is modelled as an optimization problem using constraint programming, and a novel MapReduce Constraint Programming based Resource Management algorithm (MRCP-RM) is devised that can effectively process an open stream of MapReduce jobs where each job is characterized by an SLA comprising an earliest start time, a required execution time, and an end-to-end deadline. A detailed performance evaluation of MRCP-RM is conducted for an open system subjected to a stream of job arrivals using both simulation and experimentation on a real system. The experiments on a real system are performed on a Hadoop cluster (deployed on Amazon EC2) that runs our new Hadoop Constraint Programming based Resource Management algorithm (HCP-RM) that incorporates a technique for handling data locality. The results of the performance evaluation demonstrate the effectiveness of MRCP-RM/HCP-RM in generating a schedule that leads to a low proportion of jobs missing their deadlines (P) and also provide insights into system behaviour and performance. In the simulation experiments, it is observed that MRCP-RM achieves on average an 82 percent lower P compared to a technique from the existing literature when processing a synthetic workload from Facebook. Furthermore, in the experiments performed on a Hadoop cluster deployed on Amazon EC2, it is observed that HCP-RM achieved on average a 63 percent lower P compared to an EDF-Scheduler for a wide variety of workload and system parameters experimented with.
Auteurs: Norman Lim;Shikharesh Majumdar;Peter Ashwood-Smith;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 05.-2017, volume: 28, issue:5, pages: 1375 - 1389
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Agent-Based Technique for Fault Location, Isolation, and Service Restoration
Résumé:
This paper proposes a communication-assisted fault localization, isolation, and restoration method for microgrids based on a multi-agent system. The proposed system comprises distributed agents, located in the middle and at the two ends of a protection section, which will detect a fault through phase angle comparison of current signals at both sides of a given distribution line. The agents then send trips signal to corresponding circuit breakers accordingly. The importance of the proposed protection technique is twofold. First, it eliminates the use of voltage transformers and thus reduces costs. Second, it does not require transfer of data along long distances, which decreases the delay time for fault isolation. Power restoration processes following the fault clearance considering voltage, frequency, and power flow constraints in the microgrid under study were also performed. Simulation of the proposed protection methodology was presented followed by experimental verification. The experimental results showed excellent agreement with the simulated protection scheme.
Auteurs: Hany F. Habib;Tarek Youssef;Mehmet H. Cintuglu;Osama A. Mohammed;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 1841 - 1851
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Bit Flipping Decoding of LDPC Codes for NAND Storage Systems
Résumé:
This letter presents a new multi-bit flipping decoding algorithm for low-density parity-check codes, which can enhance hard-information-based decoding performance for NAND storage systems. Since the conventional enhancement techniques developed for bit-flipping decoding require soft information, the long latency taken to generate the soft information, makes it hard to apply them to practical NAND storage systems. The proposed algorithm requires only hard information and achieves the better performance than previous hard-information-based algorithms. The proposed method flips multiple bits in each iteration, but the maximum number of bits to be flipped in an iteration is restricted to prevent overcorrection. To relax the hardware complexity of sorting, in addition, an efficient approximation method is proposed, reducing the hardware complexity of a 512-input sorter by 48.3% without degrading the performance noticeably.
Auteurs: Jaehwan Jung;In-Cheol Park;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 979 - 982
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Hop Cooperative Relaying With Energy Harvesting From Cochannel Interferences
Résumé:
A novel multi-hop cooperative relaying transmission is proposed, where neither the source nor the relays have constant power supplies but rather scavenge energy from cochannel interferences (CCIs) and then use it for subsequent data transmission. The results show that, larger CCIs, usually detrimental to system performance, offer higher transmit power to each node and benefit improving system performance. Given a prescribed end-to-end (e2e) outage threshold, this letter identifies the largest number of hops that energy harvesting from CCIs can support. Moreover, the e2e outage probability is shown to be dominated by the quality of the desired channels along with the relaying link, almost regardless of the CCIs.
Auteurs: Erhu Chen;Minghua Xia;Daniel B. da Costa;Sonia Aïssa;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1199 - 1202
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Indenter Device for in Vivo Biomechanical Tissue Measurement
Résumé:
Biomechanical tissue properties have been hypothesized to play a critical role in the quantification of prosthetic socket production for individuals with limb amputation. In this investigation, a novel indenter platform is presented and its performance evaluated for the purposes of residual-limb tissue characterization. The indenter comprised 14 position- and force-controllable actuators that circumferentially surround a biological residuum to form an actuator ring. Each indenter actuator was individually controllable in position ( ${{97.1}}~mu {text {m}}$ accuracy) and force (330 mN accuracy) at a PC controller feedback rate of 500 Hz, allowing for a range of measurement across a residual stump. Data were collected from 162 sensors over an EtherCAT fieldbus to characterize the mechanical hyperviscoelastic tissue response of two transtibial residual-limbs from a study participant with bilateral amputations. At five distinct anatomical locations across the residual-limb, force versus deflection data—including hyperviscoelastic tissue properties—are presented, demonstrating the accuracy and versatility of the multi-indenter platform for residual-limb tissue characterization.
Auteurs: Arthur Petron;Jean-François Duval;Hugh Herr;
Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Date publication: 05.-2017, volume: 25, issue:5, pages: 426 - 435
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Level Random Walk for Software Test Suite Reduction
Résumé:
Software testing is important and time-consuming. A test suite, i.e., a set of test cases, plays a key role in validating the expected program behavior. In modern test-driven development, a test suite pushes the development progress. Software evolves over time; its test suite is executed to detect whether a new code change adds bugs to the existing code. Executing all test cases after each code change is unnecessary and may be impossible due to the limited development cycle. On the one hand, multiple test cases may focus on an identical piece of code; then several test cases cannot detect extra bugs. On the other hand, even executing a test suite once in a large project takes around one hour [1]; frequent code changes require much time for conducting testing. For instance, in Hadoop, a framework of distributed computing, 2,847 version commits are accepted within one year from September 2014 with a peak of 135 commits in one week [2].
Auteurs: Zongzheng Chi;Jifeng Xuan;Zhilei Ren;Xiaoyuan Xie;He Guo;
Apparue dans: IEEE Computational Intelligence Magazine
Date publication: 05.-2017, volume: 12, issue:2, pages: 24 - 33
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Linear Probabilistic Energy Flow Analysis of Integrated Electrical and Natural-Gas Systems
Résumé:
The deep interdependence between electrical and gas systems entails a potential threat to the security (or reliability) of both systems. It is imperative to investigate the impacts of massive uncertainties on the overall secure and economical operation of both systems. In this paper, a probabilistic energy flow framework of integrated electrical and gas systems is initially proposed considering correlated varying energy demands and wind power. Three aspects of couplings between electrical and gas systems are considered: gas-fired generators, electric-driven compressors, and energy hubs integrated with power to gas (P2G) units. Furthermore, a multilinear method is specially designed to produce a deterministic energy flow solution for each sample generated by Monte Carlo simulation (MCS). Finally, test results have verified that the proposed multilinear MCS method prevails over the nonlinear MCS. In addition, P2G effectively benefits the operation of both electrical and gas networks.
Auteurs: Sheng Chen;Zhinong Wei;Guoqiang Sun;Kwok W. Cheung;Yonghui Sun;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1970 - 1979
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Method Data Delivery for Green Sensor-Cloud
Résumé:
Delivering sensory data to users anytime and anywhere if there is network connection, sensor-cloud (SC), which integrates WSNs and cloud computing, is attracting growing interest from both academia and industry. This article discusses the potential applications and recent work about SC and observes two issues regarding green SC. Further, motivated by solving these two issues, this article proposes a Multi-Method Data Delivery (MMDD) scheme for SC users. MMDD strategically incorporates four kinds of delivery: delivery from cloud to SC users; delivery from WSN to SC users; delivery from SC users to SC users; and delivery from cloudlet to SC users. Compared to exclusive data delivery from cloud to SC users, evaluation results show that MMDD could achieve lower delivery cost or less delivery time for SC users.
Auteurs: Chunsheng Zhu;Victor C. M. Leung;Kun Wang;Laurence T. Yang;Yan Zhang;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 176 - 182
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multi-Scenario Parameter Estimation for Synchronous Generation Systems
Résumé:
Parameter estimation of synchronous generation systems is vital to the validation of power system dynamic analysis. Compared with the substantially investigated single-scenario parameter estimation, multi-scenario estimation is more advantageous in terms of estimation accuracy. This study proposes a systematic method for solving the challenges of implementing multi-scenario parameter estimation through four crucial steps. First, a novel method using trajectory sensitivity is proposed for multi-scenario parameter identifiability analysis. Scenarios are then ranked based on the scenario identifiability index with respect to the identifiable parameters. Third, a scenario decomposition strategy is developed by using the reduced-space interior point method to accelerate the parameter estimation procedure. Finally, a method based on Chi-square test is proposed for bad scenario detection and identification. In the case study, numerical experiments and field measurements are used to validate the effectiveness of the proposed method.
Auteurs: Zexiang Zhu;Guangchao Geng;Quanyuan Jiang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1851 - 1859
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiagent-Based Distributed State of Charge Balancing Control for Distributed Energy Storage Units in AC Microgrids
Résumé:
In this paper, a multiagent-based distributed control algorithm has been proposed to achieve state of charge (SoC) balance of distributed energy storage (DES) units in an ac microgrid. The proposal uses frequency scheduling instead of adaptive droop gain to regulate the active power. Each DES unit is taken as an agent and it schedules its own frequency reference given of the real power droop controller according to the SoC values of all other DES units. Further, to obtain the average SoC value of DES, the dynamic average consensus algorithm is utilized by each agent. A generalized small-signal model of the proposed frequency scheduling for the proposed frequency scheduling is developed in order to verify the stability of the control system and to guide control parameters design. The convergence characteristics for the dynamic consensus adopted in the multiagent system are also analyzed to choose the proper control parameter. Experimental results verified the effectiveness, the robustness against communication topology changes, and capability of “plug & play” for the proposed multiagent system through different case studies.
Auteurs: Chendan Li;Ernane Antônio Alves Coelho;Tomislav Dragicevic;Josep M. Guerrero;Juan C. Vasquez;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2369 - 2381
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiband and Broadband Wireless Power Transfer Systems Using the Conformal Strongly Coupled Magnetic Resonance Method
Résumé:
Novel multiband and broadband wireless power transfer (WPT) systems based on conformal strongly coupled magnetic resonance (CSCMR) are presented in this paper. An analytical model for CSCMR systems is developed in order to study their performance. Optimal multiband and broadband CSCMR systems are designed and their performance is validated using simulations and measurements. A broadband CSCMR system, which exhibits seven times broader bandwidth than conventional SCMR and CSCMR systems operating at the same frequency, is designed and prototyped.
Auteurs: Hao Hu;Stavros V. Georgakopoulos;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3595 - 3607
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multidimensional Optical Sensing and Imaging System (MOSIS): From Macroscales to Microscales
Résumé:
Multidimensional optical imaging systems for information processing and visualization technologies have numerous applications in fields such as manufacturing, medical sciences, entertainment, robotics, surveillance, and defense. Among different three-dimensional (3-D) imaging methods, integral imaging is a promising multiperspective sensing and display technique. Compared with other 3-D imaging techniques, integral imaging can capture a scene using an incoherent light source and generate real 3-D images for observation without any special viewing devices. This review paper describes passive multidimensional imaging systems combined with different integral imaging configurations. One example is the integral-imaging-based multidimensional optical sensing and imaging systems (MOSIS), which can be used for 3-D visualization, seeing through obscurations, material inspection, and object recognition from microscales to long range imaging. This system utilizes many degrees of freedom such as time and space multiplexing, depth information, polarimetric, temporal, photon flux and multispectral information based on integral imaging to record and reconstruct the multidimensionally integrated scene. Image fusion may be used to integrate the multidimensional images obtained by polarimetric sensors, multispectral cameras, and various multiplexing techniques. The multidimensional images contain substantially more information compared with two-dimensional (2-D) images or conventional 3-D images. In addition, we present recent progress and applications of 3-D integral imaging including human gesture recognition in the time domain, depth estimation, mid-wave-infrared photon counting, 3-D polarimetric imaging for object shape and material identification, dynamic integral imaging implemented with liquid-crystal devices, and 3-D endoscopy for healthcare applications.
Auteurs: Bahram Javidi;Xin Shen;Adam S. Markman;Pedro Latorre-Carmona;Adolfo Martínez-Uso;José Martinez Sotoca;Filiberto Pla;Manuel Martínez-Corral;Genaro Saavedra;Yi-Pai Huang;Adrian Stern;
Apparue dans: Proceedings of the IEEE
Date publication: 05.-2017, volume: 105, issue:5, pages: 850 - 875
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multidisciplinary Learning through Implementation of the DVB-S2 Standard
Résumé:
Telecommunication standards are documents that contain consolidated knowledge about communication systems and implementation best practices. They are created based on long consensus processes in order to meet practical constraints. This article describes how the DVB-S2 standard is used in the electrical engineering curricula at KU Leuven within a design and implementation course called EAGLE. The goal of the course is to teach third-year Bachelor students how to apply the abstract knowledge gathered in the theoretical courses (control theory, communication theory, software, and hardware) to the design of a complex and real engineering project. Based on their progress during the academic year, we illustrate how standards can be used to teach a broad skill set and act as an accelerator to abstract system implementation complexity. We give an overview of the objectives of the EAGLE project and the relevance of the DVB-S2 standard, the design and implementation task that the students need to accomplish, and how they finally learn to master the complexity of a real communication standard, VHDL coding, and system verification and integration.
Auteurs: Yuri Murillo;Bertold Van den Bergh;Jona Beysens;Alexander Bertrand;Wim Dehaene;Panagiotis Patrinos;Tinne Tuytelaars;Ruth Vazquez Sabariego;Marian Verhelst;Patrick Wambacq;Sofie Pollin;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 124 - 130
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multifrequency Radar Imagery and Characterization of Hazardous and Noxious Substances at Sea
Résumé:
The increase in maritime traffic, particularly the transport of hazardous and noxious substances (HNSs), requires advanced methods of identification and characterization in environmental chemical spills. Knowledge about HNS monitoring using radar remote sensing is not as extensive as for oil spills; however, any progress on this issue would likely advance the monitoring of both chemical and oil-related incidents. To address the need for HNS monitoring, an experiment was conducted in May 2015 over the Mediterranean Sea during which controlled releases of HNS were imaged by a multifrequency radar system. The aim of this experiment was to establish a procedure for collecting evidence of illegal maritime pollution by noxious liquid substances using airborne radar sensors. In this paper, we demonstrate the ability of radar imagery to detect and characterize chemicals at sea. A normalized polarization difference parameter is introduced to quantify both the impacts of released product on the ocean surface and the relative concentration of the substance within the spill. We show that radar imagery can provide knowledge of the involved HNS. In particular, one can distinguish a product that forms a film on the top of the sea surface from another that mixes with seawater, the information that is critical for efficient cleanup operations.
Auteurs: Sébastien Angelliaume;Brent Minchew;Sophie Chataing;Philippe Martineau;Véronique Miegebielle;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 3051 - 3066
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multilevel Reduced Controlled Switches AC–DC Power Conversion Cells
Résumé:
This paper presents multilevel ac–dc single-phase power conversion cells for applications in which the regenerative operation is either not required or prohibited. The ac primary power source is a single phase from a permanent magnet generator or from an electrical grid. The cells are composed of two h-bridges in cascade: 1) an unidirectional high-voltage h-bridge with two controlled switches; and 2) two power diodes, processing the active power, and a low-voltage h-bridge with four controlled switches and a floating capacitor. These cells can be part of multiphase systems, in which it is required one cell for each phase. Some examples of application for three-phase systems are given, exploring different ways of connection between the single-phase cells. Simulation and experimental results regarding the proposed cells and conventional h-bridge based ac–dc converters are shown for validation and comparison purposes.
Auteurs: João Paulo Ramos Agra Méllo;Cursino Brandão Jacobina;Italo Roger Ferreira Moreno Pinheiro da Silva;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2233 - 2244
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multimodal Imaging Based on Digital Holography
Résumé:
Digital holography provides a method of the 3-D recording and numerical reconstruction by a simple optical system and a computer. Quantitative measurement and numerical refocusing are major characteristics. So far, many physical parameters such as amplitude, phase, polarization, fluorescence, and spectra can be obtained independently. Recently, multimodal imaging that can obtain simultaneously two or more physical parameters by combining digital holographic microscope and other optical microscopes such as a fluorescence optical microscope and a Raman scattering microscope has emerged. In this review, physical parametric imaging techniques based on digital holography are presented and then these techniques are enhanced to develop multimodal imaging based on digital holography.
Auteurs: Osamu Matoba;Xiangyu Quan;Peng Xia;Yasuhiro Awatsuji;Takanori Nomura;
Apparue dans: Proceedings of the IEEE
Date publication: 05.-2017, volume: 105, issue:5, pages: 906 - 923
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multimodal KB Harvesting for Emerging Spatial Entities
Résumé:
New entities are being created daily. Though the novelty of these entities naturally attracts mentions, due to lack of prior knowledge, it is more challenging to collect knowledge about such entities than pre-existing entities, whose KBs are comprehensively annotated through LBSNs and EBSNs. In this paper, we focus on knowledge harvesting for emerging spatial entities (ESEs), such as new businesses and venues, assuming we have only a list of ESE names. Existing techniques for knowledge base (KB) harvesting are primarily associated with information extraction from textual corpora. In contrast, we propose a multimodal method for event detection based on the complementary interaction of image, text, and user information between multi-source platforms, namely Flickr and Twitter. We empirically validate our harvesting approaches improve the quality of KB with enriched place and event knowledge.
Auteurs: Jinyoung Yeo;Hyunsouk Cho;Jin-Woo Park;Seung-Won Hwang;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 05.-2017, volume: 29, issue:5, pages: 1073 - 1086
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multimode Interference Power-Splitter Using InP-Based Deeply Etched Hybrid Plasmonic Waveguide
Résumé:
The present study proposes a novel nanoscale multimode interference (MMI) power splitter utilizing an InP-based hybrid plasmonic waveguide at an optical communication wavelength. The layer stack has the potential to realize monolithic integrated hybrid plasmonic passive and active components. The 1 × 2, 1 × 3, and 2 × 2 MMI power splitters were simulated and optimized using a three-dimensional finite difference time domain method. The effect of MMI length, width, and wavelength on optical power transmission was investigated. Transmission was higher than 90% at 1.55 μm wavelengths. This study also presents an ultracompact shallow to deep transition between shallow-etched conventional waveguide and a hybrid plasmonic waveguide on an InP-substrate. It was shown that shallow to deep transition with a length of 2 μm has a coupling efficiency of 87.5%.
Auteurs: Mahmoud Nikoufard;Masoud Kazemi Alamouti;Soheil Pourgholi;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 477 - 483
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiobjective Beampattern Optimization in Collaborative Beamforming via NSGA-II With Selective Distance
Résumé:
Collaborative beamforming is usually characterized by high, asymmetrical sidelobe levels due to the randomness of node locations. Previous works have shown that the optimization methods aiming to reduce the peak sidelobe level (PSL) alone do not guarantee the overall sidelobe reduction of the beampattern, especially when the nodes are random and cannot be manipulated. Hence, this paper proposes a multiobjective amplitude and phase optimization technique with two objective functions: PSL minimization and directivity maximization, in order to improve the beampattern. A novel selective Euclidean distance approach in the nondominated sorting genetic algorithm II (NSGA-II) is proposed to steer the candidate solutions toward a better solution. Results obtained by the proposed NSGA with selective distance (NSGA-SD) are compared with the single-objective PSL optimization performed using both GA and particle swarm optimization. The proposed multiobjective NSGA provides up to 40% improvement in PSL reduction and 50% improvement in directivity maximization and up to 10% increased performance compared to the legacy NSGA-II. The analysis of the optimization method when considering mutual coupling between the nodes shows that this improvement is valid when the inter-node Euclidean separations are large.
Auteurs: Suhanya Jayaprakasam;Sharul Kamal Abdul Rahim;Chee Yen Leow;Tiew On Ting;Akaa A. Eteng;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2348 - 2357
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiobjective Discrete Artificial Bee Colony Algorithm for Multiobjective Permutation Flow Shop Scheduling Problem With Sequence Dependent Setup Times
Résumé:
The multiobjective permutation flow shop scheduling problem with sequence dependent setup times has been an object of investigations for decades. This widely studied problem from the scheduling theory links the sophisticated solution algorithms with the moderate real world applications. This paper presents a novel multiobjective discrete artificial bee colony algorithm based decomposition, called MODABC/D, to solve the sequence dependent setup times multiobjective permutation flowshop scheduling problem with the objective to minimize makespan and total flowtime. First, in order to make the standard artificial bee colony algorithm to solve the scheduling problem, a discrete artificial bee colony algorithm is proposed to solve the problem based on the perturbation operation. Then, a problem-specific solution builder heuristic is used to initialize the population to enhance the quality of the initial solution. Finally, a further local search method are comprised of a single local search procedures based on the insertion neighborhood structures to find the better solution for the nonimproved individual. The performance of the proposed algorithms is tested on the well-known benchmark suite of Taillard. The highly effective performance of the multiobjective discrete artificial bee colony algorithm-based decomposition is compared against the state of art algorithms from the existing literature in terms of both coverage value and hypervolume indicator.
Auteurs: Xiangtao Li;Shijing Ma;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 05.-2017, volume: 64, issue:2, pages: 149 - 165
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiple Solutions of Optimal PMU Placement Using Exponential Binary PSO Algorithm for Smart Grid Applications
Résumé:
For smart grid execution, one of the most important requirements is fast, precise, and efficient synchronized measurements, which are possible by phasor measurement unit (PMU). To achieve fully observable network with the least number of PMUs, optimal placement of PMU (OPP) is crucial. In trying to achieve OPP, priority may be given at critical buses, generator buses, or buses that are meant for future extension. Also, different applications will have to be kept in view while prioritizing PMU placement. Hence, OPP with multiple solutions (MSs) can offer better flexibility for different placement strategies as it can meet the best solution based on the requirements. To provide MSs, an effective exponential binary particle swarm optimization (EBPSO) algorithm is developed. In this algorithm, a nonlinear inertia-weight-coefficient is used to improve the searching capability. To incorporate previous position of particle, two innovative mathematical equations that can update particle's position are formulated. For quick and reliable convergence, two useful filtration techniques that can facilitate MSs are applied. Single mutation operator is conditionally applied to avoid stagnation. The EBPSO algorithm is so developed that it can provide MSs for various practical contingencies, such as single PMU outage and single line outage for different systems.
Auteurs: Tapas Kumar Maji;Parimal Acharjee;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2550 - 2559
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiple-Frequency DBIM-TwIST Algorithm for Microwave Breast Imaging
Résumé:
A novel distorted Born iterative method (DBIM) algorithm is proposed for microwave breast imaging based on the two-step iterative shrinkage/thresholding method. We show that this implementation is more flexible and robust than using traditional Krylov subspace methods such as the CGLS as solvers of the ill-posed linear problem. This paper presents several strategies to increase the algorithm’s robustness: a hybrid multifrequency approach to achieve an optimal tradeoff between imaging accuracy and reconstruction stability; a new approach to estimate the average breast tissues properties, based on sampling along their range of possible values and running a few DBIM iterations to find the minimum error; and finally, a new regularization strategy for the DBIM method based on the $L^{1}$ norm and the Pareto curve. We present reconstruction examples which illustrate the benefits of these optimization strategies, which have resulted in a DBIM algorithm that outperforms our previous implementations for microwave breast imaging.
Auteurs: Zhenzhuang Miao;Panagiotis Kosmas;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2507 - 2516
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiport Interferometer-Enabled 2-D Angle of Arrival (AOA) Estimation System
Résumé:
A systematic scheme for finding the direction of arrival (DOA) or 2-D angle of arrival (AOA) of an electromagnetic beam is proposed and demonstrated in this paper. This system estimates the respective angle of propagation vector of an incoming plane wave in either horizontal or vertical plane. It consists of three main parts, namely, an antenna, a multiport wave interferometric receiver or phase discriminator, and a signal processor. The antenna is composed of four receiving elements located in the same plane, which is arranged in a diamond-shaped configuration. The received signals manifest relative phase differences that contain information about the beam’s DOA. With the proposed eight-port junction topology, the interferometer extracts these informative phase differences and leaves them for a simple signal processing algorithm to estimate the two angles. The theoretical analysis of the proposed scheme is presented along with system-level simulation results for the proof of concept. In addition, an appropriate calibration technique is formulated to deal with nonidealities and consecutive errors in practice. One of the main applications of such a system is related to the angular detection of an antenna-to-antenna misalignment in pencil beam millimeter-wave systems. Therefore, implementation of the presented system scheme for millimeter wave applications is briefly discussed for its prototyping over 60-GHz range (V-band). Finally, the performance of the prototype system is assessed through a set of system-level measurements. Excellent results are obtained, thus validating the outstanding functionality of the proposed system. Simplicity, low cost, compact size, and operational accuracy make this system a superior candidate for 2-D angle detection applications.
Auteurs: Jaber Moghaddasi;Tarek Djerafi;Ke Wu;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1767 - 1779
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multiscale Simulation of Power System Transients Based on the Matrix Exponential Function
Résumé:
Power system electro-magnetic transient programs (EMTP) have been popular among researchers and practitioners due to their detailed component modeling and high simulation accuracy for complex system operations. Despite broad applications in simulations with wide range of timescales, the small discretization step of these programs makes their use very time-consuming for system studies with long time span. Facing the increasingly complex power system transient characteristics and simulation demands, a multiscale algorithm that integrates the simulations of the electromagnetic and slower electromechanical transients is desirable. The multiscale simulation algorithm preserves the high fidelity of the EMTP and attains higher efficiency for the overall transient simulation. In this paper, we achieve this goal by exploiting the unique properties of the matrix exponential function. The proposed algorithm is capable of utilizing large step sizes to speed up the simulation of slow dynamics, whereas the fast transients are accurately reconstructed through efficient dense output mechanism, which is built upon the matrix exponential function computation. Numerical studies including a large-scale wind farm simulation are conducted to demonstrate the effectiveness of the proposed multiscale algorithm.
Auteurs: Chengshan Wang;Xiaopeng Fu;Peng Li;Jianzhong Wu;Liwei Wang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1913 - 1926
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multisensor Coupled Spectral Unmixing for Time-Series Analysis
Résumé:
We present a new framework, called multisensor coupled spectral unmixing (MuCSUn), that solves unmixing problems involving a set of multisensor time-series spectral images in order to understand dynamic changes of the surface at a subpixel scale. The proposed methodology couples multiple unmixing problems based on regularization on graphs between the time-series data to obtain robust and stable unmixing solutions beyond data modalities due to different sensor characteristics and the effects of nonoptimal atmospheric correction. Atmospheric normalization and cross calibration of spectral response functions are integrated into the framework as a preprocessing step. The proposed methodology is quantitatively validated using a synthetic data set that includes seasonal and trend changes on the surface and the residuals of nonoptimal atmospheric correction. The experiments on the synthetic data set clearly demonstrate the efficacy of MuCSUn and the importance of the preprocessing step. We further apply our methodology to a real time-series data set composed of 11 Hyperion and 22 Landsat-8 images taken over Fukushima, Japan, from 2011 to 2015. The proposed methodology successfully obtains robust and stable unmixing results and clearly visualizes class-specific changes at a subpixel scale in the considered study area.
Auteurs: Naoto Yokoya;Xiao Xiang Zhu;Antonio Plaza;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2842 - 2857
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multispectral and Hyperspectral Image Fusion Using a 3-D-Convolutional Neural Network
Résumé:
In this letter, we propose a method using a 3-D convolutional neural network to fuse together multispectral and hyperspectral (HS) images to obtain a high resolution HS image. Dimensionality reduction of the HS image is performed prior to fusion in order to significantly reduce the computational time and make the method more robust to noise. Experiments are performed on a data set simulated using a real HS image. The results obtained show that the proposed approach is very promising when compared with conventional methods. This is especially true when the HS image is corrupted by additive noise.
Auteurs: Frosti Palsson;Johannes R. Sveinsson;Magnus O. Ulfarsson;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 639 - 643
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Multistage Robust Unit Commitment With Dynamic Uncertainty Sets and Energy Storage
Résumé:
The deep penetration of wind and solar power is a critical component of the future power grid. However, the intermittency and stochasticity of these renewable resources bring significant challenges to the reliable and economic operation of power systems. Motivated by these challenges, we present a multistage adaptive robust optimization model for the unit commitment (UC) problem, which models the sequential nature of the dispatch process and utilizes a new type of dynamic uncertainty sets to capture the temporal and spatial correlations of wind and solar power. The model also considers the operation of energy storage devices. We propose a simplified and effective affine policy for dispatch decisions, and develop an efficient algorithmic framework using a combination of constraint generation and duality-based reformulation with various improvements. Extensive computational experiments show that the proposed method can efficiently solve multistage robust UC problems on the Polish 2736-bus system under high dimensional uncertainty of 60 wind farms and 30 solar farms. The computational results also suggest that the proposed model leads to significant benefits in both costs and reliability over robust models with traditional uncertainty sets as well as deterministic models with reserve rules.
Auteurs: Álvaro Lorca;Xu Andy Sun;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1678 - 1688
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mutual Interference Analysis of FBMC-Based Return Channel for Bidirectional T-DMB System
Résumé:
In this paper, we investigate an effective scheme for implementing the return channel by exploiting the guard band between orthogonal frequency-division multiplexing (OFDM) blocks for uplink transmission, which enables guaranteeing compatibility with legacy systems. In order to resolve the interference problem between the conventional broadcast channel and the return channel, we employ the filter bank-based multicarrier (FBMC) system. Toward this goal, the mutual interference between the return and OFDM channels is derived as a closed form through numerical analysis. Based on the mutual interference analysis and the channel condition, an adaptive modulation scheme is applied to increase data throughput. Through the simulation, it can be seen that more than 350 (500) kb/s/Channel can be achieved for the channel signal-to-noise ratio (SNR) of 20 dB (30 dB) when the quality of service constraint is lower than a bit error rate of ${text 10}^-{text 2}$ ( $10^-{text 4}$). Consequently, the additional throughput above can be achieved in a given resource without the adverse effect to the legacy systems.
Auteurs: Hojae Lee;Beom Kwon;Donghyun Jeon;Seonghyun Kim;Sanghoon Lee;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3829 - 3842
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Mutual Outage Probability
Résumé:
The performance of any multiuser wireless communications system is strongly affected by interference. Consequently, the design of such systems must comply with some outage probability criteria. Although interference occurs in a mutual entangled basis, with wireless devices interfering with each other, outage is commonly considered on an individual per-device basis. This approach, however, is a simplified solution to a more intricate multidimensional and system-wide problem, in which several mutually interfering devices may be experiencing an outage simultaneously. The true outage probability across several devices is given by a set of mutual entangled boundary conditions to be fulfilled. This paper presents useful novel formulations for outage probability in multiuser wireless settings, here named mutual outage probability (MOP), for the interference-limited environment. Several scenarios are envisaged, in which some signals are in outage, whereas others are not and still for some others these conditions are irrelevant, all at the same time. We introduce a general framework for calculating the MOP, and present closed-form formulas for the Rayleigh case. Finally, we illustrate the practical use of these formulations in a call admission control application.
Auteurs: Flavio du Pin Calmon;Álvaro Augusto Machado de Medeiros;Michel Daoud Yacoub;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3138 - 3150
Editeur: IEEE
Document complet vers site de l'éditeur
 
» My Best Decision [Memoirs]
Résumé:
Reports on the author's work with the IEEE P1584 Working Group to make the workplace a safer place.
Auteurs: Wei-Jen Lee;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 80 - 80
Editeur: IEEE
Document complet vers site de l'éditeur
 
» My First Lecture and Other Lessons in Teaching
Résumé:
I recently started teaching a course on programmable system-on-chip design for senior undergraduates and full-time and parttime master's degree students. The undergraduate students come from the Bachelor in Computer Engineering program while the master's degree students are in the Master in Embedded Systems program. At the time you are reading this article, it will have been almost two months since my first lecture.
Auteurs: Sharad Sinha;
Apparue dans: IEEE Potentials
Date publication: 05.-2017, volume: 36, issue:3, pages: 30 - 32
Editeur: IEEE
Document complet vers site de l'éditeur
 
» My L-3 Internship: The Power of Positivity
Résumé:
Ever since I was a little girl, I've known that my sole purpose was to accomplish one very simple goal: to enjoy life and be happy. So far, I've found happiness with a lot of different things; whether it be from dance, music, or going on adventures. But what trumps all of these activities is my mission: I want to live a life where I'll know that I have made a positive impact on the lives of other people. I am currently at the point in my life where I need to make some clear choices for what I would like to pursue with my career. I knew that one of the best ways for me to find some direction would be to gain as much hands-on experience as I could through projects and internships.
Auteurs: Hamna Kahn;
Apparue dans: IEEE Potentials
Date publication: 05.-2017, volume: 36, issue:3, pages: 36 - 37
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Nanocrystalline CopperNickelZinc Ferrite: Efficient Sensing Materials for Ethanol and Acetone at Room Temperature
Résumé:
Nanostructured CuNiZnFe2O4 in varied molar concentrations is synthesized by the rate-controlled co-precipitation method. The powder X-ray diffraction pattern and the analysis of their micrographs have confirmed the Single-phase structure of the prepared samples. Field emission scanning electron microscopy study reveals the surface morphology of the samples with nanosized grains and open pores. The average grain size of both the prepared samples is found to be 24 and 25 nm, which is obtained by the histogram analysis of high-resolution transmission electron microscopy micrographs. The dc magnetic measurements and Mössbauer spectroscopic studies together reveal that both the samples are magnetically well ordered at the room temperature with superparamagnetic relaxation due to finite size effect. The ethanol and acetone sensing characteristics of the prepared samples are studied at room temperature by conductive measurements. The maximum sensitivity of 77% is observed for 500 ppm of acetone vapor by Cu0.5Ni0.25Zn0.25Fe2O4 (CNZ1), whereas a sensitivity of 75% is observed for 500 ppm of ethanol vapor by Cu0.25Ni0.5Zn0.25Fe2O4 (CNZ2). Moreover, a quick and good response of acetone vapors by CNZ1 and ethanol vapor by CNZ2 within 10 min is also noticeable. The sensor responses are quite stable and highly reproducible.
Auteurs: Chandra Mukherjee;R. Mondal;S. Dey;S. Kumar;Jayoti Das;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2662 - 2669
Editeur: IEEE
Document complet vers site de l'éditeur
 
» NaPer: A TSV Noise-Aware Placer
Résumé:
Through-silicon-via (TSV)-to-TSV coupling issue can degrade the signal integrity in 3-D integrated circuit designs. This paper develops a 3-D partitioning-based force-directed placer, NaPer, to reduce the total coupling noise between TSVs and alleviate the maximum coupling noise between them. We introduce two denoise forces: TSV decoupling force and TSV density force. The TSV decoupling force is determined by the coupling noise between TSVs for separating strong coupling TSVs, and the TSV density force is determined by the TSV density for evenly distributing TSVs. The experimental results show that NaPer can effectively reduce 15.0% total TSV coupling noise and 42.7% maximum TSV coupling noise on average with only 4.5% wirelength overhead. Besides, NaPer also shows great performance in wirelength that is competitive to the state-of-the-art 3-D placer.
Auteurs: Yu-Min Lee;Kuan-Te Pan;Chun Chen;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 05.-2017, volume: 25, issue:5, pages: 1703 - 1713
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Nasal Patches and Curves for Expression-Robust 3D Face Recognition
Résumé:
The potential of the nasal region for expression robust 3D face recognition is thoroughly investigated by a novel five-step algorithm. First, the nose tip location is coarsely detected and the face is segmented, aligned and the nasal region cropped. Then, a very accurate and consistent nasal landmarking algorithm detects seven keypoints on the nasal region. In the third step, a feature extraction algorithm based on the surface normals of Gabor-wavelet filtered depth maps is utilised and, then, a set of spherical patches and curves are localised over the nasal region to provide the feature descriptors. The last step applies a genetic algorithm-based feature selector to detect the most stable patches and curves over different facial expressions. The algorithm provides the highest reported nasal region-based recognition ranks on the FRGC, Bosphorus and BU-3DFE datasets. The results are comparable with, and in many cases better than, many state-of-the-art 3D face recognition algorithms, which use the whole facial domain. The proposed method does not rely on sophisticated alignment or denoising steps, is very robust when only one sample per subject is used in the gallery, and does not require a training step for the landmarking algorithm.
Auteurs: Mehryar Emambakhsh;Adrian Evans;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 05.-2017, volume: 39, issue:5, pages: 995 - 1007
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Near Optimal Control Based on the Tensor-Product Technique
Résumé:
This brief investigates the near optimal control problem and targets at the rigid body attitude dynamic system that are characterized by its typical nonlinearity. In order to apply the linear matrix inequality-based optimization, a second-order linear-parameter-varying model is specifically derived from the attitude system by means of the tensor-product transformation. Furthermore, an adaptive attitude tracking control law is designed to achieve both the offline optimization and online control simplification. The final control law is provided in a combined form. As a result, the dynamic response of the system mainly depends on the near optimal virtual controller and the stability can be further guaranteed by the adaptive tracking controller. Numerical simulations are conducted to verify the effectiveness of the proposed algorithms.
Auteurs: Xiangdong Liu;Xing Xin;Zhen Li;Zhen Chen;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 560 - 564
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Network Slicing for 5G with SDN/NFV: Concepts, Architectures, and Challenges
Résumé:
The fifth generation of mobile communications is anticipated to open up innovation opportunities for new industries such as vertical markets. However, these verticals originate myriad use cases with diverging requirements that future 5G networks have to efficiently support. Network slicing may be a natural solution to simultaneously accommodate, over a common network infrastructure, the wide range of services that vertical- specific use cases will demand. In this article, we present the network slicing concept, with a particular focus on its application to 5G systems. We start by summarizing the key aspects that enable the realization of so-called network slices. Then we give a brief overview on the SDN architecture proposed by the ONF and show that it provides tools to support slicing. We argue that although such architecture paves the way for network slicing implementation, it lacks some essential capabilities that can be supplied by NFV. Hence, we analyze a proposal from ETSI to incorporate the capabilities of SDN into the NFV architecture. Additionally, we present an example scenario that combines SDN and NFV technologies to address the realization of network slices. Finally, we summarize the open research issues with the purpose of motivating new advances in this field.
Auteurs: Jose Ordonez-Lucena;Pablo Ameigeiras;Diego Lopez;Juan J. Ramos-Munoz;Javier Lorca;Jesus Folgueira;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 80 - 87
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Network Slicing in 5G: Survey and Challenges
Résumé:
5G is envisioned to be a multi-service network supporting a wide range of verticals with a diverse set of performance and service requirements. Slicing a single physical network into multiple isolated logical networks has emerged as a key to realizing this vision. This article is meant to act as a survey, the first to the authors� knowledge, on this topic of prime interest. We begin by reviewing the state of the art in 5G network slicing and present a framework for bringing together and discussing existing work in a holistic manner. Using this framework, we evaluate the maturity of current proposals and identify a number of open research questions.
Auteurs: Xenofon Foukas;Georgios Patounas;Ahmed Elmokashfi;Mahesh K. Marina;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 94 - 100
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Network Slicing to Enable Scalability and Flexibility in 5G Mobile Networks
Résumé:
We argue for network slicing as an efficient solution that addresses the diverse requirements of 5G mobile networks, thus providing the necessary flexibility and scalability associated with future network implementations. We elaborate on the challenges that emerge when designing 5G networks based on network slicing. We focus on the architectural aspects associated with the coexistence of dedicated as well as shared slices in the network. In particular, we analyze the realization options of a flexible radio access network with focus on network slicing and their impact on the design of 5G mobile networks. In addition to the technical study, this article provides an investigation of the revenue potential of network slicing, where the applications that originate from this concept and the profit capabilities from the network operator�s perspective are put forward.
Auteurs: Peter Rost;Christian Mannweiler;Diomidis S. Michalopoulos;Cinzia Sartori;Vincenzo Sciancalepore;Nishanth Sastry;Oliver Holland;Shreya Tayade;Bin Han;Dario Bega;Danish Aziz;Hajo Bakker;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 72 - 79
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Network Utility Maximization in Wireless Networks Over Fading Channels With Uncertain Distribution
Résumé:
In this the network utility maximization problem is investigated for wireless networks when only channel mean and variance are known. Due to the randomness of wireless channel, link outage will happen and a traffic flow’s rate will gradually decrease along its routing path. When only channel mean and variance are known, channel distribution is uncertain and it is harder to control the rate loss caused by link outage. We take into account this feature of rate loss and target at maximizing the network utility of multiple traffic flows’ rates at their destinations. An optimization problem is formulated, which is non-convex. Global optimal solution is achieved with the aid of bilevel optimization method and monotonic optimization method. Numerical results are presented to verify the effectiveness of our proposed method.
Auteurs: Song Jin;Rongfei Fan;Gongpu Wang;Xiangyuan Bu;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1107 - 1110
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Network Virtualization in Spectrum Sliced Elastic Optical Path Networks
Résumé:
The recent decade has witnessed an evolution toward virtualization of everything for the IT industry. Resources, from utility resources to networking components and functions, are abstracted as logical or virtual services. Virtualization results in elastic, agile, and automated resource provision, and facilitates the resource pricing in a pay-as-you-go model. Among this wave, the optical community has made parallel efforts in virtualizing resources in optical networks including both optical node and link resources. A virtualized optical network can not only seamlessly support automated resource provision, but also supply high-bandwidth any-to-any connectivity for network virtualization. In this paper, we overview the motivations and architecture for optical-based network virtualization. Among candidate optical networking paradigms, we argue that spectrum-sliced elastic optical path (SLICE) networks can be considered as a promising substrate choice, and study the key enabling problem, namely optical virtual network embedding over SLICE networks (OVNE-SLICE). We prove the NP-completeness of the OVNE-SLICE problem, and propose two mathematical models for this problem based on a concept named path-channel. The models are evaluated in our simulation, and compared with alternative models proposed in the literature.
Auteurs: Yang Wang;Zachary McNulty;Hung Nguyen;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1962 - 1970
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Network-Based Data-Driven Filtering With Bounded Noises and Packet Dropouts
Résumé:
This paper is concerned with the problem of a network-based data-driven filter design for discrete-time linear systems with bounded noises and packet dropouts. One favorable feature is that the designed filter can be directly employed without identifying the unknown system model. To compensate the negative effects of packet dropouts, an output predictor is first designed to reconstruct the missing data based on the received outputs and the inputs of the system. The asymptotic convergence of the output prediction error is established, of which the rate can be adjusted by the parameter. Then utilizing the predicted outputs and the received measurements, an almost-optimal data-driven filter with tractability is proposed within the set membership (SM) framework and the bound on the worst case estimation error is derived. Finally, two illustrative examples, including a comparison example and an application example, are presented to show the advantages of the proposed design and the effectiveness of the theoretical results.
Auteurs: Yuanqing Xia;Li Dai;Wen Xie;Yulong Gao;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 4257 - 4265
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Network-Centric Versus User-Centric Multihoming Strategies in LTE/WiFi Networks
Résumé:
In this paper, we consider the interworking between multiple wireless access networks and study the multihomed users’ performance for different fourth-generation (4G)/WiFi multihoming techniques. We specifically compare two points of view for multihoming: network centric—wherein the scheduler is controlled by the network—versus user centric—where each user chooses a splitting policy for its packets. In the former, we study two proportional fairness strategies: a global one applied to the whole network and a local one applied to each wireless access network apart. In the user-centric approach, we study user policies based on the information received from the network and consider two variants: a simple one in which the user has only information on the peak rates of the radio interfaces and an optimized selfish policy in which the user receives complete information on the interfaces peak rates and traffic intensities. We then prove that this optimal selfish strategy achieves a global optimum for the system. Our numerical results show that network-centric strategies are better than user-centric ones in terms of achievable throughput but are worse in terms of computational complexity.
Auteurs: Ghina Dandachi;Salah Eddine Elayoubi;Tijani Chahed;Nada Chendeb;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4188 - 4199
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Networked Control Under Random and Malicious Packet Losses
Résumé:
We study cyber security issues in networked control of a linear dynamical system. Specifically, the dynamical system and the controller are assumed to be connected through a communication channel that face malicious attacks as well as random packet losses due to unreliability of transmissions. We provide a probabilistic characterization for the link failures which allows us to study combined effects of malicious and random packet losses. We first investigate almost sure stabilization under an event-triggered control law, where we utilize Lyapunov-like functions to characterize the triggering times at which the plant and the controller attempt to exchange state and control data over the network. We then provide a look at the networked control problem from the attacker's perspective and explore malicious attacks that cause instability. Finally, we demonstrate the efficacy of our results with numerical examples.
Auteurs: Ahmet Cetinkaya;Hideaki Ishii;Tomohisa Hayakawa;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2434 - 2449
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Networks on Chips: 15 Years Later
Résumé:
The authors of a Computer article from 2002 reflect on their proposal to use networks on chips to address scalable communications on silicon VLSI chips.
Auteurs: Giovanni De Micheli;Luca Benini;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 10 - 11
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Neuro-Adaptive Fault-Tolerant Tracking Control of Lagrange Systems Pursuing Targets With Unknown Trajectory
Résumé:
In this paper, we address the problem of steering Lagrange system to track targets with unknown trajectory in the presence of modeling uncertainties and actuation faults. Artificial neural network technique is employed to reconstruct the behavior of the targets with unknown trajectory, with which robust adaptive fault-tolerant tracking control algorithms are developed. The developed control scheme is able to cope with unknown desired trajectory, attenuate modeling uncertainties and accommodate actuation faults. The proposed control scheme is shown to be able to maintain close target tracking despite actuation ineffectiveness and desired trajectory uncertainty. The benefits and feasibility of the developed control are also confirmed by simulations.
Auteurs: Yongduan Song;Junxia Guo;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3913 - 3920
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New Active Capacitor Voltage Balancing Method for Flying Capacitor Multicell Converter Based on Logic-Form-Equations
Résumé:
This paper presents a new active capacitor voltage balancing control method for the flying capacitor multicell (FCM) converters which is fully implemented using logic-form equations. The proposed active capacitor voltage balancing control technique, measures output current and flying capacitor (FC) voltages to generate the switching states in order to produce the required output voltage level and to balance FCs’ voltages at their reference values. Output voltage of the FCM converter controlled with proposed active capacitor voltage balancing method can be modulated with any pulse width modulation (PWM) technique such as the phase-shifted-carrier PWM or level-shifted-carrier PWM. An advantage of the proposed active capacitor voltage balancing control method is its simplicity as it does not require any complex computations and tedious optimization calculations. Simulation results and experimental measurements of a three-cell four-level and four-cell five-level FCM converters are presented to verify the performance of the proposed active capacitor voltage balancing control technique.
Auteurs: Arash Khoshkbar Sadigh;Vahid Dargahi;Keith A. Corzine;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3467 - 3478
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New and Optimized Magnetization Scheme for the Baby Magnetized Iron Neutrino Detector at J-PARC
Résumé:
The Baby-MIND (magnetized iron neutrino detector) collaboration is building a muon detector to be installed downstream of the WAGASCI experiment at J-PARC (Japan). Due to the challenging timeline and space constraints for the installation in the ND280 pit, an innovative magnetization scheme has been developed for the iron plates. The magnetization scheme optimizes flux return for minimum stray field and operating current, while maximizing the useful tracking area with $B > 1.5$ T. The 33 iron plates of the detector are individually magnetized by coils wound on their surface by “sewing” an aluminum conductor through slits cut in the plates. In this paper, we present the details of the magnetization scheme and coil winding procedure as well as the results of magnetization tests performed on a prototype module and the first eighteen detector plates.
Auteurs: Gabriella Rolando;Philippe Benoit;Alain Blondel;Alexey Dudarev;Etam Noah;Helder Pais Da Silva;Mark Rayner;Herman H. J. ten Kate;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 6
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New Beamforming Designs for Joint Spatial Division and Multiplexing in Large-Scale MISO Multi-User Systems
Résumé:
In this paper, we study a joint spatial division multiplexing (JSDM) beamforming scheme, which enables large-scale spatial multiplexing gains for massive multi-input multi-output downlink systems. In contrast to the conventional JSDM, which employs a block diagonalization method as a pre-beamformer, we aim to maximize sum-rate by applying minimum-mean-squared error (MMSE) approaches when designing a pre-beamformer and a multi-user precoder sequentially. First, to suppress inter-group interference, we design the pre-beamformer, which minimizes an upper bound of the sum mean-squared-error in the large-scale array regime. Then, to mitigate same-group interference, we present the multi-user precoder based on the weighted MMSE (WMMSE) optimization method, which requires the same channel state information overhead as the conventional JSDM. Also, in order to reduce the computational complexity, we compute deterministic equivalents of the WMMSE beamforming parameters to generate the beamformers by employing asymptotic results of large system analysis. Through simulation results, we confirm that the proposed two-step beamforming methods bring substantial performance gains in terms of sum-rate over the conventional JSDM schemes especially in a low and medium signal-to-noise ratio regime with comparable complexity.
Auteurs: Younghyun Jeon;Changick Song;Sang-Rim Lee;Seungjoo Maeng;Jaehoon Jung;Inkyu Lee;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3029 - 3041
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New Design of a Variable Impedance Based on Polarized Diodes at Microwave Frequency
Résumé:
In this letter, we present a new variable impedance termination consisting of two polarized diodes. To generate a complex-valued impedance, two controlled current sources polarize the diodes, which are interconnected with a Wilkinson power divider through transmission lines of different electric lengths. Because of the reduced number of diodes, this structure presents low power consumption and simple control. We validated the proposed design by implementing a prototype at the operating frequency of 1575.42 MHz. Mapping the measured results in the Smith chart, the impedance can produce reflection coefficients with full-phase coverage within the circle of magnitude 0.35 over a frequency range of 1.5–1.6 GHz.
Auteurs: Alejandro J. Venere;Martín Hurtado;Ramón Lopéz La Valle;Carlos H. Muravchik;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 05.-2017, volume: 27, issue:5, pages: 470 - 472
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New Directions in Navigation and Positioning: Signal processing-enabled technologies pinpoint people, places, and things [Special Reports]
Résumé:
In an era of same-day product deliveries, interplanetary space probes, and autonomous vehicles, transporting something—or someone—from here to there quickly, directly, and precisely is becoming increasingly important. An array of navigation and positioning technologies are now available to help guide and locate vehicles, people, and almost endless number of objects. The satellite-based global positioning system (GPS), for instance, now lies at the heart of an almost endless array of location, navigation, timing, mapping, and tracking tools. Real-time location system (RTLS) technologies, meanwhile, rely on resources such as GPS, Wi-Fi, Bluetooth, near-field communication (NFC), and radio-frequency identification (RFID) to detect the current location of a target, which may be anything from a vehicle to an item in a manufacturing plant to a person.
Auteurs: John Edwards;
Apparue dans: IEEE Signal Processing Magazine
Date publication: 05.-2017, volume: 34, issue:3, pages: 10 - 13
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New for IMS2017: Exhibitor Workshops
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Bryan Wu;Susie Horn;Lee Wood;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 68 - 76
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New Hybrid Surface–Volume Dielectric Barrier Discharge Reactor for Ozone Generation
Résumé:
Dielectric barrier discharge (DBD) is the most efficient way used in industry for ozone generation. In the last decades, many papers were published on such DBD-based ozone generators. Several geometric configurations can be used to generate ozone. They can be classified into two types depending on the discharge form: volume DBD, which is the common one in ozone industry, and surface DBD. Many studies have been conducted to analyze the ozone generation efficiency of both reactors to get maximum ozone production with the lowest possible power consumption. The aim of this paper is to carry out an experimental analysis of a patent-pending new reactor, of hybrid configuration, in which occur simultaneously a volume and a surface DBD. The hybrid reactor comprises a ground stainless steel cylindrical electrode, within which is placed a glass tube separated by an interval of 1 mm in which the volume DBD occurs. A second mesh stainless steel electrode connected to the high voltage is placed inside the glass tube wherein the surface discharge occurs. The obtained results showed a clear superiority of the hybrid reactor compared with both volume and surface DBD in terms of the ozone concentration. The difference in the ozone concentration reaches up to 50% compared with the volume DBD and 30% compared with the surface DBD.
Auteurs: Kamel Nassour;Mostefa Brahami;Said Nemmich;Nacera Hammadi;Noureddine Zouzou;Amar Tilmatine;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2477 - 2484
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New Normal Mode dv/dt Filter With a Built-In Resistor Failure Detection Circuit
Résumé:
Insulated gate bipolar transistors (IGBTs) will soon be replaced by wide band gap devices (SiC and GaN) as the choice for power semiconductor switch in voltage source inverters. These devices have extremely fast rise time and fall time compared with IGBT devices. The high dv/dt of pulse-width modulation outputs create excessive voltage stress in the insulation system of ac motors due to voltage reflection issues associated with motors at large distances from the drive. In many oil field applications, the distance between the motor and the variable frequency drive approaches 300 m. In walking rig applications, it is common to use multiple smaller sized conductors per phase, bunched together, to achieve the desired ampacity. This practice results in higher than usual value of the cable parasitic capacitance. Traditional dv/dt filters used for mitigating over-voltage at motor terminals have been found to be inadequate in reducing the over voltage at the motor terminals in such oil field installations. The damping resistor often experiences high voltage and gets damaged. A new dv/dt filter suitable for use with high power ac motors at distances nearing 300 m with a built-in resistor failure detection circuit is proposed here. Test results are given to demonstrate its efficacy.
Auteurs: Mahesh M. Swamy;Mark A. Baumgardner;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2149 - 2158
Editeur: IEEE
Document complet vers site de l'éditeur
 
» New Propeller-Type Tribocharging Device With Application to the Electrostatic Separation of Granular Insulating Materials
Résumé:
The aim of this paper is the development and functional optimization of a new propeller-type aerodynamic tribocharging device with application in the field of electrostatic separation. The originality of the system consists of its modular structure: one or several propellers can be stacked in the same device to provide appropriate tribocharging conditions to a wide variety of granular mixtures containing two or more of insulating materials. The study is conducted with samples of the following various insulating materials: polycarbonate, polyamide, acrylonitrile butadiene styrene, polyvinyl chloride, and high-impact polystyrene, grain sizes up to 4 mm in diameter, for several values of the propeller rotation speed, and of the mass of the particles in the tribocharging device, the wall of which are made of acetate, Polymethyl methacrylate (PMMA), or aluminum. The efficiency of the device is tested by processing the charged granular mixture in a metal-belt conveyor-type electrostatic separator. The aluminum-wall device enables better charging that PMMA and acetate. The mass introduced in the device has no significant effect on the outcome of the process, but the speed of the propellers does. Successful separation of a mixture of three insulating materials is reported.
Auteurs: Djamel Eddine Fekir;Mohamed Miloudi;Farid Miloua;Karim Medles;Lucian Dascalescu;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2416 - 2422
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Newly Elected CIS Administrative Committee Members (2017-2019) [Society Briefs]
Résumé:
Presents a listing of newly elected CIS administrative committee members.
Auteurs: Pablo A. Estevez;
Apparue dans: IEEE Computational Intelligence Magazine
Date publication: 05.-2017, volume: 12, issue:2, pages: 11 - 12
Editeur: IEEE
Document complet vers site de l'éditeur
 
» NLMS Algorithm Based on a Variable Parameter Cost Function Robust Against Impulsive Interferences
Résumé:
The conventional step-size scaler (SSS) normalized least-mean-square algorithm is robust against impulsive noise. However, the constant parameter in the SSS needs to be controlled to satisfy the conflicting requirements of fast convergence rate and low steady-state misadjustment. Therefore, to address this problem, an adaptive approach for the parameter in the cost function is proposed in this brief. The proposed approach is then tested in system identification and acoustic echo-cancelation scenarios, which have demonstrated that the proposed approach is effective and robust against non-Gaussian impulsive interferences.
Auteurs: Fuyi Huang;Jiashu Zhang;Sheng Zhang;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 600 - 604
Editeur: IEEE
Document complet vers site de l'éditeur
 
» No Downlink Pilots Are Needed in TDD Massive MIMO
Résumé:
We consider the Massive Multiple-Input Multiple-Output downlink with maximum-ratio and zero-forcing processing and time-division duplex operation. To decode, the users must know their instantaneous effective channel gain. Conventionally, it is assumed that by virtue of channel hardening, this instantaneous gain is close to its average and hence that users can rely on knowledge of that average (also known as statistical channel information). However, in some propagation environments, such as keyhole channels, channel hardening does not hold. We propose a blind algorithm to estimate the effective channel gain at each user, that does not require any downlink pilots. We derive a capacity lower bound of each user for our proposed scheme, applicable to any propagation channel. Compared with the case of no downlink pilots (relying on channel hardening), and compared with training-based estimation using downlink pilots, our blind algorithm performs significantly better. The difference is especially pronounced in environments that do not offer channel hardening.
Auteurs: Hien Quoc Ngo;Erik G. Larsson;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2921 - 2935
Editeur: IEEE
Document complet vers site de l'éditeur
 


Publication archives by date
    2017:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2016:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2015:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2014:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2013:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2012:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2011:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2010:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2009:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre