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Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 05-2017 trié par par titre, page: 2
» An Overview of Dynamic-Linearization-Based Data-Driven Control and Applications
Résumé:
A brief overview on the model-based control and data-driven control methods is presented. The data-driven equivalent dynamic linearization, as a foundational analysis tool of data-driven control methods for discrete-time nonlinear systems, is introduced in detail with motivations and distinct features. The prototype model-free adaptive control schemes by using the dynamic linearization to an unknown nonlinear plant model, as well as the alternative model-free adaptive control methods by using the dynamic linearization to an unknown ideal nonlinear controller, are discussed. Furthermore, the extensions of the dynamic linearization to unknown nonlinear repetitive systems and the corresponding model-free adaptive iterative learning control methods are also overviewed and summarized. This work highlights the characteristics and comments of the different model-free adaptive control schemes in detail to facilitate the understanding of the readers. Finally, some perspectives on data-driven control methods in information-rich age are given.
Auteurs: Zhongsheng Hou;Ronghu Chi;Huijun Gao;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 4076 - 4090
Editeur: IEEE
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» An RF-Powered FDD Radio for Neural Microimplants
Résumé:
We present a radio system that could be used in millimeter-scale wireless neural implants. The system is RF-powered and demonstrates Mbps data rates required for neuromodulation and recording applications. The radio transmits at 58 Mb/s and receives at 2.5 Mb/s maximum data rates. The transceiver uses a duplexer to achieve full-duplex communication via frequency-division duplexing at 1.74 and 1.86 GHz for TX and RX, respectively. The average power consumption of the transmitter is 93 $mu text{W}$ at 58 Mb/s, while that of the receiver is 7.2 $mu text{W}$ at 2.5 Mb/s. The transceiver was fabricated using 40-nm LP CMOS process and occupies 0.8 mm2 of die area. Including the off-chip duplexer, the system occupies 2 $times $ 1.6 $times $ 0.6 mm3.
Auteurs: Yashar Rajavi;Mazhareddin Taghivand;Kamal Aggarwal;Andrew Ma;Ada S. Y. Poon;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 05.-2017, volume: 52, issue:5, pages: 1221 - 1229
Editeur: IEEE
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» An RFID Based Smartphone Proximity Absence Alert System
Résumé:
We present the design, implementation, and evaluation of an RFID-based cellphone anti-lost and anti-theft measure. The cellphone owner is given an audio-visual alert at the very instant of the lost event, and the cellphone deduces the fact that it is away from its owner and executes the safety measures. This is realized by equipping the cellphone with a low-power RFID Reader and tagging the owner with a passive RFID token to determine a private space around him, which spans within 2-10 feet. We prototype an RFID Reader from discrete components under $60 which can transmit 30 dBm with - 78 dBm sensitivity, and can also serve as an educational tool for academic learning. Our system works on automatic, timed, or accelerometer based thresholds. We interface our system with Samsung Galaxy Note2 and develop an Android User Interface. We carry out extensive indoor and outdoor experiments under static and dynamic scenarios to ascertain the Frontal and Angular ranges, energy and power consumption, and memory and computational overheads. Our salient contribution is a twofold probing scheme—a duty cycle approach that economizes battery overhead, mitigates false alarms and scans the tag for multiple times by leveraging the interrogation time and power. We argue that though our design is costly in power budget, it is highly economical on battery energy because of short interrogation cycles. We show that for 17 tag interrogations from 20-24 dBm, our scheme consumes 72.1 to 52.4 percent lower energy than a single Bluetooth device scan. For a fully embedded design, we propose System-on-Chip RFID solutions. We foresee our endeavor as a viable proximity absence detection scheme for short range applications and scenarios.
Auteurs: Muhammad Jawad Hussain;Li Lu;Shan Gao;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 05.-2017, volume: 16, issue:5, pages: 1246 - 1257
Editeur: IEEE
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» An SOI-MEMS Piezoelectric Torsional Stage With Bulk Piezoresistive Sensors
Résumé:
This paper presents a micro-electromechanical stage for out-of-plane positioning of microcantilevers designed for atomic force microscopes. The stage produces an out-of-plane displacement using a torsional mechanism that exploits piezoelectric clamped-guided beams as actuators. To measure the torsional displacement of the stage, novel differential piezoresistive sensors are implemented. These sensors feature clamped-guided beams that exploit the bulk piezoresistivity of silicon. Using this sensing concept eliminates the requirement to fabricate highly doped regions on the flexures. An analytical model is provided that describes the sensor’s linearity. The sensor, the microcantilevers, and the mechanical features of the stage are experimentally characterized. The first resonance frequency of the stage is located at 7.8 kHz, and a static out-of-plane displacement of more than 1.2 $mu text{m}$ is obtained. In addition, the piezoresistive sensor captures the dynamics of the stage within a bandwidth of 13 kHz with a $1sigma $ -resolution of 3 nm.
Auteurs: Mohammad Maroufi;S. O. Reza Moheimani;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3030 - 3040
Editeur: IEEE
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» An SQP Method Combined With Gradient Sampling for Small-Signal Stability Constrained OPF
Résumé:
Small-Signal Stability Constrained Optimal Power Flow (SSSC-OPF) can provide additional stability measures and control strategies to guarantee the system to be small-signal stable. However, due to the nonsmooth property of the spectral abscissa function, existing algorithms solving SSSC-OPF cannot guarantee convergence. To tackle this computational challenge of SSSC-OPF, we propose a Sequential Quadratic Programming (SQP) method combined with gradient sampling for SSSC-OPF. At each iteration of the proposed SQP, the gradient of the spectral abscissa function is randomly sampled at the current iterate and additional nearby points to make the search direction computation effective in nonsmooth regions. The method can guarantee SSSC-OPF is globally and efficiently convergent to stationary points with probability one. The effectiveness of the proposed method is tested and validated on WSCC 3-machine 9-bus system, New England 10-machine 39-bus system, and IEEE 54-machine 118-bus system.
Auteurs: Peijie Li;Junjian Qi;Jianhui Wang;Hua Wei;Xiaoqing Bai;Feng Qiu;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2372 - 2381
Editeur: IEEE
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» An Ultra-Low Power 1.7-2.7 GHz Fractional-N Sub-Sampling Digital Frequency Synthesizer and Modulator for IoT Applications in 40 nm CMOS
Résumé:
This paper introduces an ultra-low power 1.7-2.7-GHz fractional-N sub-sampling digital PLL (SS-DPLL) for Internet-of-Things (IoT) applications targeting compliance with Bluetooth Low Energy (BLE) and IEEE802.15.4 standards. A snapshot time-to-digital converter (TDC) acts as a digital sub-sampler featuring an increased out-of-range gain and without any assistance from the traditional counting of DCO edges, thus further reducing power consumption. With a proposed DCO-divider phase rotation in the feedback path, the impact of the digital-to-time converter’s (DTC’s) non-linearity on the PLL is reduced and improves fractional spurs by at least 8 dB across BLE channels. Moreover, a “variable-preconditioned LMS” calibration algorithm is introduced to dynamically correct the DTC gain error with fractional frequency control word (FCW) down to 1/16384. Fabricated in 40 nm CMOS, the SS-DPLL achieves phase noise performance of −109 dBc/Hz at 1 MHz offset, while consuming a record-low power of 1.19 mW.
Auteurs: Yao-Hong Liu;Johan Van Den Heuvel;Takashi Kuramochi;Benjamin Busze;Paul Mateman;Vamshi Krishna Chillara;Bindi Wang;Robert Bogdan Staszewski;Kathleen Philips;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1094 - 1105
Editeur: IEEE
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» An Unbounded Frequency Detection Mechanism for Continuous-Rate CDR Circuits
Résumé:
A continuous-rate clock and data recovery (CDR) circuit with unbounded frequency detection mechanism is proposed herein. The unbounded frequency detection mechanism combines the digital quadricorrelator frequency detection and subharmonic tone frequency detection techniques. By adopting the unbounded frequency detector, this reference-less CDR circuit has no locking range limitation and provides an automatically bidirectional frequency detection characteristic. In addition, the CDR circuit can detect the frequency-hopping information without an additional transmitted control signal. Based on the proposed frequency detection methodology, a proof-of-concept CDR circuit is implemented to demonstrate the feasibility and effectiveness of the proposed design.
Auteurs: Yen-Long Lee;Soon-Jyh Chang;Yen-Chi Chen;Yu-Po Cheng;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 500 - 504
Editeur: IEEE
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» An Upgraded ACA Algorithm in Complex Field and Its Statistical Analysis
Résumé:
An upgraded adaptive cross approximation (U-ACA) algorithm in complex field is proposed, including detailed discussion about both relative-error estimator and pivoting threshold. Two new relative-error estimators are constructed, and the range of the pivoting threshold is determined theoretically. Besides, a statistical analysis of the U-ACA algorithm for computational electromagnetics is provided to identify the credibility of existing relative-error estimators and new ones. The statistical experiments show that the U-ACA algorithm with either of the two new relative-error estimators is a more robust algorithm at present for applications in computational electromagnetics, compared with the previous ACA algorithm.
Auteurs: Hou-Xing Zhou;Guang-Yu Zhu;Wei-Bin Kong;Wei Hong;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2734 - 2739
Editeur: IEEE
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» Analysis and Control of a Novel Power Electronics Converter for Active Magnetic Bearing Drive
Résumé:
Magnetic bearing has been developed for high-speed rotational machinery and its power electronics drive is its key technology. In this paper, a novel converter with reduced switches for magnetic bearing drive is described. The principle of the magnetic bearing and its test rig were introduced and graphically illustrated at first. Then, based on the current unidirectional and phase-leg sharing principles, the novel converter topology for magnetic bearing drive together with the current control functions is introduced, including the steady state and dynamic performance. Less power electronics devices are required for this converter in comparison with conventional magnetic bearing drives. Simulation and experimental results have successfully validated the current control capability of magnetic bearing with the proposed converter. With the novel converter and the controller, magnetic bearing can deliver superior levitation and dynamic control performance. In the rotational test, the magnetic bearing has been controlled with position error less than 20% of the air gap up to 24 000 r/min on the test rig.
Auteurs: Dong Jiang;Parag Kshirsagar;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2222 - 2232
Editeur: IEEE
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» Analysis and Design of VCO-Based Phase-Domain $Sigma Delta $ Modulators
Résumé:
VCO-based phase-domain $Sigma Delta $ modulators employ the combination of a voltage-controlled-oscillator (VCO) and an up/down counter to replace the analog loop filter used in conventional $Sigma Delta $ modulators. Thanks to this highly digital architecture, they can be quite compact, and are expected to shrink even further with CMOS scaling. This paper describes the analysis and design of such converters. Trade-offs between design parameters and the impact of non-idealities, such as finite counter length and VCO non-linearity, are assessed through both theoretical analysis and behavioral simulations. The proposed design methodology is applied to the design of a phase-to-digital converter in a 40-nm CMOS process, which is used to digitize the output of a thermal-diffusivity temperature sensor, achieving ± 0.2° ( $3sigma $ ) phase inaccuracy from -40 to 125 °C and a sensor-limited resolution of 57 m° (RMS) within a 500-Hz bandwidth. Measurements on the prototype agree quite well with theoretical predictions, thus demonstrating the validity of the proposed design methodology.
Auteurs: Uğur Sönmez;Fabio Sebastiano;Kofi A. A. Makinwa;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1075 - 1084
Editeur: IEEE
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» Analysis Method of Mobile Phone Batteries Remaining State of Charge
Résumé:
The cell phone is among the electronics which have quickly attracted consumers throughout the world with an average usage time of a year and a half, generating with this, a considerable environmental impact. This paper presents a literature review on components of batteries, important factors in battery performance, state of charging and health determination. In this study, through the unloading constant current CC test, it was possible to obtain, in a fast and efficient way, the amount of energy remaining and the state of charge from the lithium-ion mobile batteries discarded by the population, showing that many of the discarded batteries could still be reused as an energy source.
Auteurs: Eduardo Luis Schneider;Rodolfo de Freitas Valle Dresch;Luiz Tiaraju dos Reis Loureiro;Renato Machado de Brito;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 854 - 860
Editeur: IEEE
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» Analysis of a Dual-Rotor, Toroidal-Winding, Axial-Flux Vernier Permanent Magnet Machine
Résumé:
In this paper, a vernier permanent magnet (VPM) machine with dual-rotor toroidal-winding axial-flux topology is analyzed. Through the combination of toroidal windings with the rotor-stator-rotor topology, the end winding length of the proposed machine is significantly reduced compared with that of the regular VPM machine. Based on the airgap permeance function, the back-EMF and torque expressions are derived and the nature of the machine is revealed. The influence of pole ratio (ratio of rotor pole pair number to stator pole pair number) and main geometric parameters, such as slot opening, magnet thickness, etc., on electromagnetic performance is then analytically investigated in detail. Both the quasi-three-dimensional (quasi-3D) finite element analysis (FEA) and 3-D FEA are applied to verify the derived equations. Finally, a prototype of the proposed machine has been manufactured and experimentally evaluated. The test results agree well with both theoretical and FEA analyses. With the current density of 5.8 A/mm 2 and slot fill factor of 0.35, the torque density of the proposed machine prototype can reach 31.9 kNm/m 3.
Auteurs: Tianjie Zou;Dawei Li;Ronghai Qu;Jian Li;Dong Jiang;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 1920 - 1930
Editeur: IEEE
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» Analysis of a Statistical Relationship Between Dose and Error Tallies in Semiconductor Digital Integrated Circuits for Application to Radiation Monitoring Over a Wireless Sensor Network
Résumé:
Mass production of widely used semiconductor digital integrated circuits (ICs) has lowered unit costs to the level of ordinary daily consumables of a few dollars. It is therefore reasonable to contemplate the idea of an engineered system that consumes unshielded low-cost ICs for the purpose of measuring gamma radiation dose. Underlying the idea is the premise of a measurable correlation between an observable property of ICs and radiation dose. Accumulation of radiation-damage-induced state changes or error events is such a property. If correct, the premise could make possible low-cost wide-area radiation dose measurement systems, instantiated as wireless sensor networks (WSNs) with unshielded consumable ICs as nodes, communicating error events to a remote base station. The premise has been investigated quantitatively for the first time in laboratory experiments and related analyses performed at the Canadian Nuclear Laboratories. State changes or error events were recorded in real time during irradiation of samples of ICs of different types in a 60Co gamma cell. From the error-event sequences, empirical distribution functions of dose were generated. The distribution functions were inverted and probabilities scaled by total error events, to yield plots of the relationship between dose and error tallies. Positive correlation was observed, and discrete functional dependence of dose quantiles on error tallies was measured, demonstrating the correctness of the premise. The idea of an engineered system that consumes unshielded low-cost ICs in a WSN, for the purpose of measuring gamma radiation dose over wide areas, is therefore tenable.
Auteurs: Karen Colins;Liqian Li;Yu Liu;
Apparue dans: IEEE Transactions on Nuclear Science
Date publication: 05.-2017, volume: 64, issue:5, pages: 1151 - 1158
Editeur: IEEE
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» Analysis of Direct-On-Line Synchronous Reluctance Machine Start-Up Using a Magnetic Field Decomposition
Résumé:
Direct-on-line synchronous reluctance machines combine the characteristics of induction machines and synchronous reluctance machines. Saturation of core materials, the eddy currents, and the asymmetry of the rotor core and cage make it difficult to predict which kind of loads a machine can synchronize. In this paper, the start-up of a direct-on-line synchronous reluctance machine is analyzed with a magnetic field decomposition that makes it possible to quantify and isolate forces between any two distinct parts of an electric machine using a transient time-stepping finite element field solution. The results show explicitly which portion of the torque is produced by the rotor core and which by the rotor cage. Compared with conventional average torque analyses (also known as pseudo-constant-speed or quasi-steady-state analyses) used to distinguish between the torque on the rotor core and cage, the proposed method makes no assumptions on the state of the machine. This results in a more detailed view of the starting transient.
Auteurs: Juha Tampio;Tero Känsäkangas;Saku Suuriniemi;Jere Kolehmainen;Lauri Kettunen;Jouni Ikäheimo;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 1852 - 1859
Editeur: IEEE
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» Analysis of Dynamic Processes in Single-Cell Electroporation and Their Effects on Parameter Selection Based on the Finite-Element Model
Résumé:
Pulsed electric fields have recently been the focus of considerable attention because of their potential application in biomedicine. However, their practical clinical applications are limited by poor understanding of the interaction mechanism between pulsed electric fields and cells, particularly in the process of electroporation and its effect on parameter selection. This paper established a multishelled dielectric model based on finite elements to simulate and analyze the processes involved in electroporation. In particular, the processes include the dynamic development of the pore radius and electroporation region: the distribution of recoverable, nonrecoverable, and nonelectroporation areas on the cell; and the influence of pulse parameters on varying degrees of electroporation. Results showed that membrane conductivity, pore density, transmembrane potential, and distribution of pore radii are functions of time and position on the cell. The electroporation areas were divided into recoverable, nonrecoverable, and no-electroporation pores. For $10~mu text{s}$ , 1.5-kV/cm pulse was observed in the regions exposed to sufficiently high transmembrane voltage (1 V), electroporation occurred, membrane conductivity and pore density (up to $10^{mathrm {16}}/text{m}^{mathrm {2}})$ rapidly increased with time, and electroporation areas increased gradually and were mainly distributed in the range 0°–70° (recoverable pore [0°, 35°], nonrecoverable pore [35°, 70°], and no-electroporation pore [70°, 90°]). Electric field strength was the major factor that induced electroporation, particularly in the recoverable pore, but it had minimal effect on pore- expansion. However, pulse duration affects the nonrecoverable pore, such that the high-intensity wide pulse is more useful in the field of irreversible electroporation. The high-intensity short pulse can increase permeability and maintain cell viability.
Auteurs: Chenguo Yao;Hongmei Liu;Yajun Zhao;Yan Mi;Shoulong Dong;Yanpeng Lv;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 05.-2017, volume: 45, issue:5, pages: 889 - 900
Editeur: IEEE
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» Analysis of Metasurfaces at Oblique Incidence
Résumé:
The theory of analytical modeling of periodic metasurfaces for normal incidence is extended to the general oblique case. The metasurface is considered as a periodic planar array with electrically small dipolar scatterers. The induced polarization currents are calculated by combining the information obtained from the response of individual scatterer to the incident wave and the interaction of scatterers with each other. All required interaction coefficients for the most general analysis of metasurfaces are analytically derived. The expressions in terms of the polarization currents are presented for the reflected/transmitted fields from metasurfaces at oblique illumination. Although theoretically known that adding normal polarization currents to the tangential ones will not provide extra degrees of freedom in the manipulation of the reflection and transmission properties of metasurfaces, in most practical applications, it is required to consider both tangential as well as normal polarization currents. Thus, the effect of oblique illumination in the modification of normal and tangential polarization currents is clarified. Our theory is used to analyze two canonical examples of bianisotropic metasurfaces composed of chiral and omega inclusions. The results of this paper provide an effective tool to push the analysis as well as the synthesis of metasurfaces one step forward.
Auteurs: Mohammad Yazdi;Mohammad Albooyeh;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2397 - 2404
Editeur: IEEE
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» Analysis of Proportional Fair Scheduling Under Bursty On-Off Traffic
Résumé:
Proportional fair scheduling (PFS) has been adopted as a standard solution for fair resource allocation in modern wireless cellular networks. With the emergence of heterogeneous networks with widely varying user loads, it is of great importance to characterize the performance of PFS under bursty traffic, which is the case in most wireless streaming and data transfer services. In this letter, we provide the first analytical solution to the performance of PFS under bursty on-off traffic load. We use the Gaussian approximation model to derive a closed-form expression of the achievable user data rates. In order to further improve the accuracy of our baseline analytical solution for multi-cell networks, we design a hybrid approximation by employing multi-interference analysis. The simulation results verify that our model guarantees extremely low data rate estimation error, which is further insensitive to changes in session duration, traffic load and user density.
Auteurs: Fei Liu;Janne Riihijärvi;Marina Petrova;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1175 - 1178
Editeur: IEEE
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» Analysis of Recurrent Neural Networks for Probabilistic Modeling of Driver Behavior
Résumé:
The validity of any traffic simulation model depends on its ability to generate representative driver acceleration profiles. This paper studies the effectiveness of recurrent neural networks in predicting the acceleration distributions for car following on highways. The long short-term memory recurrent networks are trained and used to propagate the simulated vehicle trajectories over 10-s horizons. On the basis of several performance metrics, the recurrent networks are shown to generally match or outperform baseline methods in replicating driver behavior, including smoothness and oscillatory characteristics present in real trajectories. This paper reveals that the strong performance is due to the ability of the recurrent network to identify recent trends in the ego-vehicle's state, and recurrent networks are shown to perform as, well as feedforward networks with longer histories as inputs.
Auteurs: Jeremy Morton;Tim A. Wheeler;Mykel J. Kochenderfer;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 05.-2017, volume: 18, issue:5, pages: 1289 - 1298
Editeur: IEEE
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» Analysis of Spectral and Energy Efficiency Tradeoff in Single-Line Rate WDM Links
Résumé:
This paper investigates, through simulations, the tradeoff between energy efficiency (EE) and the overall spectral efficiency (SE) of fiber optic links for a given capacity and a link length. The comparison is made for various modulation formats, span lengths, and with/without using forward error correction (FEC). The power consumption of the different system components is estimated from the data sheets of the state-of-the-art equipment. Results show that the use of long single-mode fiber spans (i.e., more than 40 km) improves EE when coherent modulation formats are used. However, with noncoherent formats, the span length must be selected depending on SE, aggregated traffic amount needs to be transmitted, and link length. For almost all modulation formats, FEC reduces the overall energy consumption despite being one of the main power consumers in fiber optic communication systems. The power consumption of 3Rs becomes particularly important when the linear crosstalk limits the system reach. In all other cases, the power consumption of transponders and optical line amplifiers is dominating, but their contribution changes depending on the aggregated traffic amount and system reach.
Auteurs: Aleksejs Udalcovs;Richard Schatz;Lena Wosinska;Paolo Monti;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1847 - 1857
Editeur: IEEE
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» Analysis of Subchannel Correlation in Dual-Polarised MIMO Systems via a Polarisation Diversity Scheme
Résumé:
A polarisation diversity combing scheme for dual-polarised multiple-input and multiple-output channels in small cell environments introduced and evaluated. The scheme is based on post analysis of channel measurement data captured from scenarios and includes indoor-to-indoor, indoor-to-outdoor, and indoor–outdoor–indoor propagation. An analysis of link signal strength and correlation with respect to frequency and polarisation revealed profound differences between copolarised and cross-polarised links in terms of received signal strength and correlation between frequencies. Utilizing these differences, a polarisation diversity combing scheme is evaluated which is shown to produce an average of 10.6-dB polarisation diversity gain.
Auteurs: Cheng Fang;Enjie Liu;Masood Ur Rehman;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2635 - 2644
Editeur: IEEE
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» Analysis of Zeros in a Boost DC–DC Converter: State Diagram Approach
Résumé:
This brief presents the analysis of zeros present in boost dc–dc converters that are operating in continuous inductor current mode. It proposes the utilization of the concept of multiple forward pathways from input to output to analyze the origin of the resulting zeros and determine their locations. This brief provides insight into the various zeros present in the boost converter through a state diagram approach.
Auteurs: Vikas Paduvalli;R. J. Taylor;Poras T. Balsara;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 550 - 554
Editeur: IEEE
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» Analysis on Special Protection Scheme of Korea Electric Power System by Fully Utilizing STATCOM in a Generation Side
Résumé:
Increase in power demand has required providing infrastructure, such as huge power plants and transmission lines. However, the recent trends in power system planning and operation are being toward maximum utilization of existing electricity infrastructure with tight operating margins because of new constraints placed by economic, political, and environmental issues. This might cause serious stability problems when a severe fault or a sudden outage of critical lines occurs. Therefore, the special protection scheme (SPS) has been used by generator tripping and successive load shedding to prevent a large-scale blackout by the cascading effect. If the number of tripping generators in the SPS operation is reduced, the enormous cost of power outage can be saved. This paper analyzes the enhancement of SPS via the transient stability improvement by the static synchronous compensator (STATCOM) applied to a generation side of Korea electric power system. First, its characteristic related to the SPS is described. Then, the proper capacity of STATCOM is determined with the equal area criterion to reduce the number of tripping generators. Also, the new control method for STATCOM is proposed for its full utilization. Finally, its effectiveness is verified by the case study with the practical data of Korea electric power system.
Auteurs: Dong-Hee Choi;Soo Hyoung Lee;Yong Cheol Kang;Jung-Wook Park;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1882 - 1890
Editeur: IEEE
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» Analysis, Prototyping, and Experimental Characterization of an Adaptive Hybrid Electromagnetic Damper for Automotive Suspension Systems
Résumé:
In this paper, the concept of hybrid electromagnetic damping is explored and experimentally evaluated. The aim of the hybrid electromagnetic damping concept is to address the adaptive damping problem in vehicle suspension systems. In order to reach optimal performance, the damping characteristics of the vehicle suspension system must be capable of adaptively increasing or decreasing the amount of energy being absorbed by the system. For the sake of having the requisite functionality of variable damping, a multitude of solutions have been implemented, proposed, and evaluated at both the commercial and academic research levels. These solutions have met the variable damping requirements, but still, there are several crucial drawbacks associated with them. To overcome the shortcomings associated with the aforementioned variable damping solutions, a hybrid design consisting of a conventional hydraulic damper and a linear motor topology is fused together to build a hybrid variable damper. In the proposed hybrid electromagnetic design, the oil in the system acts as bias to provide fail-safe operation for the system, and the linear motor topology allows the requisite variable damping requirement to be achieved with the additional capacity for recovering energy from the system. We present an extended analysis of the electromagnetic damping component of the hybrid damper that can serve as a potent tool for the designers who seek to maximize the adaptability (and regeneration capacity) of the hybrid damper. Afterwards, based on the proposed hybrid electromagnetic concept, the design and fabrication of the first prototype are illustrated. An experimental setup and a test protocol are prepared, and different experiments are conducted to characterize the damping properties of hydraulic and electromagnetic components. Furthermore, friction forces, as well as power capacities, are scrutinized. The results indicate that the hybrid electromagnetic damper prototype is capable of prov- ding a variable damping coefficient in a range of 1302–1540 N $cdot$s/m.
Auteurs: Ehsan Asadi;Roberto Ribeiro;Mir Behrad Khamesee;Amir Khajepour;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3703 - 3713
Editeur: IEEE
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» Analytic $JV$ -Characteristics of Ideal Intermediate Band Solar Cells and Solar Cells With Up and Downconverters
Résumé:
The ideal diode equation is regularly used to describe the $textit {JV}$ -characteristic of single junction solar cells. The connection between the diode equation and fundamental physics is the application of the Boltzmann approximation to describe the fluxes of photons emitted by the cell. In this paper, this approximation is used to derive analytic $textit {JV}$ -characteristics for three photovoltaic high-efficiency concepts, intermediate band solar cells, and solar cells optically coupled to up and downconverters. These three concepts share the common feature that they allow excitation of electrons between at least three energy levels, which assures a better utilization of the solar spectrum and leads to limiting efficiencies surpassing the Shockley–Queisser limit. Although being considerablysimpler to implementand use, the resulting $textit {JV}$ -characteristics reproduce the limiting efficiencies obtained from full detailed balancemodels. The simplicity facilitates the intuitive understanding of such devices. The presented models also have the potential to serve as a useful framework for further modeling, through savings in computation time and complexity.
Auteurs: Rune Strandberg;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2275 - 2282
Editeur: IEEE
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» Analytic Approximations for Real-Time Area Light Shading
Résumé:
We introduce analytic approximations for accurate real-time rendering of surfaces lit by non-occluded area light sources. Our solution leverages the Irradiance Tensors developed by Arvo for the shading of Phong surfaces lit by a polygonal light source. Using a reformulation of the 1D boundary edge integral, we develop a general framework for approximating and evaluating the integral in constant time using simple peak shape functions. To overcome the Phong restriction, we propose a low cost edge splitting strategy that accounts for the spherical warp introduced by the half vector parametrization. Thanks to this novel extension, we accurately approximate common microfacet BRDFs, providing a practical method producing specular stretches that closely match the ground truth in real-time. Finally, using the same approximation framework, we introduce support for spherical and disc area light sources, based on an original polygon spinning method supporting non-uniform scaling operations and horizon clipping. Implemented on a GPU, our method achieves real-time performances without any assumption on area light shape nor surface roughness.
Auteurs: Pascal Lecocq;Arthur Dufay;Gaël Sourimant;Jean-Eudes Marvie;
Apparue dans: IEEE Transactions on Visualization and Computer Graphics
Date publication: 05.-2017, volume: 23, issue:5, pages: 1428 - 1441
Editeur: IEEE
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» Analytic Modeling for Nanoscale Resistive Filament Variation in ReRAM With Stochastic Differential Equation
Résumé:
Nanoscale filament is the active area in oxygen vacancy type resistance random access memory (ReRAM), which is formed stochastically during electric test after being fabricated in a clean room. That is, the filament dimension cannot be controlled with a designed mask pattern. Here, we introduce a formula to describe the current cycle-to-cycle trajectories based on a stochastic differential equation (SDE) with microscopic structure parameters: filament dimension and oxygen vacancy concentration. Since ReRAM conduction follows hopping, the filament can be described by a random resistance network (RRN). The stochastic configuration of an RRN follows the Brownian motion, which is the key parameter in the diffusion of SDE. The formula provides a practically quantitative filament characterization method, which is verified by direct observation of the filament in actual devices. Based on the formula, we can predict ReRAM endurance with the given microscopic structure parameters.
Auteurs: Zhiqiang Wei;Koji Eriguchi;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2201 - 2206
Editeur: IEEE
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» Analytical and Experimental Investigations on Mitigation of Interference in a DBF MIMO Radar
Résumé:
As driver assistance systems and autonomous driving are on the rise, radar sensors become a common device for automobiles. The high sensor density leads to the occurrence of interference, which decreases the detection capabilities. Here, digital beamforming (DBF) is applied to mitigate such interference. A DBF system requires a calibration of the different receiving channels. It is shown how this calibration completely changes the DBF beam pattern required to cancel interferences, if the system has no IQ receiver. Afterward, the application of DBF on a multiple-input multiple-output (MIMO) radar is investigated. It is shown that only the real aperture and not the virtual one can be used for interference suppression, leading to wide notches in the pattern. However, for any target the large virtual aperture can be exploited, even if interferers are blinded out. Moreover, the wide notches for interference suppression of the real aperture appear narrow in the virtual aperture for target localization. The results are verified by measurements with time-multiplexing MIMO radar.
Auteurs: Jonathan Bechter;Muhammad Rameez;Christian Waldschmidt;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1727 - 1734
Editeur: IEEE
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» Analytical Expressions for Joint Distributions in Probabilistic Load Flow
Résumé:
Adopting the Gaussian mixture model, we derive an analytical expression for the joint probability density function of active power on multiple transmission lines, in the presence of non-Gaussian stochastic power injections. The corresponding joint cumulative distribution function is further obtained by multiple integrals. Results of the proposed method coincide with that of Monte Carlo simulations.
Auteurs: Zhiwen Wang;Chen Shen;Feng Liu;Feng Gao;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2473 - 2474
Editeur: IEEE
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» Analytical Methods for Characterizing Frequency Dynamics in Islanded Microgrids With Gensets and Energy Storage
Résumé:
Microgrids with increased penetration of renewables experience serious challenges due to large frequency excursions under power system disturbances. An energy storage system can provide frequency regulation, but the effectiveness depends on whether it is configured for the grid-forming or grid-following mode of operation. For this purpose, two critical parameters are studied for frequency regulation in distribution systems; first, the initial rate-of-change-of-frequency (ROCOF), and second, the minimum value of frequency, also known as frequency nadir, following a load change. The aim of this paper is to identify analytical methods for accurately calculating the frequency parameters like ROCOF and frequency nadir. Reduced-order models are developed to determine the frequency deviation against power system disturbances. The results are verified against simulation models validated by testing at the Consortium for Electric Reliability Technology Solutions Microgrid test bed.
Auteurs: Ajit A. Renjit;Abrez Mondal;Mahesh S. Illindala;Amrit S. Khalsa;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 1815 - 1823
Editeur: IEEE
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» Analytical Model of Mid-Infrared Surface Plasmon Modes in a Cylindrical Long-Range Waveguide With Double-Layer Graphene
Résumé:
An optical waveguide for working in mid-infrared range is highly desirable. However, such a waveguide is required to yield a long propagation distance and deep subwavelength confinement. Although the graphene-based surface plasmon polariton (SPP) waveguides have exhibited some potential in this regard, their propagation lengths are currently insufficient (∼100 μm). In this paper, we propose a graphene-based cylindrical long-range SPP (LRSPP) waveguide, which is composed of a cylindrical silicon nanowire core surrounded by an inner graphene layer, a silica layer, and an outer graphene layer from inside to out. First, the electromagnetic field equation and the dispersion equation of this waveguide are derived. Then, combining these derived equations with the numerical simulation, the propagation properties of the LRSPP and the short-range SPP modes are analyzed. The results show that the proposed waveguide with the LRSPP fundamental mode has a notable advantage for simultaneously achieving a larger propagation length (∼10 μm) and a deep subwavelength confinement ( $sim10^{- 5},A_{0}$, where $A_{0}$ is the diffraction-limited mode area). This waveguide has potential for application in high-density photonic integrated circuits in the mid-infrared range.
Auteurs: Jian-Ping Liu;Xiang Zhai;Fang Xie;Ling-Ling Wang;Sheng-Xuan Xia;Hong-Ju Li;Xin Luo;Xiong-Jun Shang;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1971 - 1979
Editeur: IEEE
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» Analytical Modeling of Interturn Short Circuit for Multiphase Fault-Tolerant PM Machines With Fractional Slot Concentrated Windings
Résumé:
Interturn short-circuit faults that occur inside stator coils are difficult to cope with compared with terminal short-circuit faults. A general analytical model for interturn short-circuit faults is developed that employs a novel T-type equivalent circuit. When this model is used to investigate the impact of interturn short-circuit faults in permanent-magnet (PM) machines with fractional slot concentrated windings (FSCW), the model delivers fault response predictions that agree very well with results from the finite element analysis. The model is used to show that the 24-slot/14-pole FSCW PM machine is vulnerable to very high interturn fault currents, even when the remaining turns are shorted, offsetting its advantage of low magnetic coupling between phases. FSCW-PM machines that employ aligned coils in phase windings can effectively suppress their interturn fault currents. Experimental verifications are provided for the 24-slot/22-pole FSCW PM prototype machine (with two aligned coils per phase) under the single-turn short-circuit fault.
Auteurs: Fan Wu;Ping Zheng;Thomas M. Jahns;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 1994 - 2006
Editeur: IEEE
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» Analytical Prediction of Magnetic Field Distribution in Spoke-Type Permanent-Magnet Synchronous Machines Accounting for Bridge Saturation and Magnet Shape
Résumé:
This paper presents an analytical model for the prediction of magnetic field distribution in spoke-type permanent-magnet synchronous machines with rectangular magnets and magnetic bridges. The influence of saturation is considered. The magnetic bridges are equivalent to fan-shaped saturation regions. On the basis of the same pole-arc angle and identical magnetic energy, one rectangular magnet is simplified to two fan-shaped regions. The entire field domain is divided into eight types of simple subdomains, i.e., shaft, inner magnetic bridge, inner fan-shaped magnet, outer fan-shaped magnet, outer magnetic bridge, air gap, slot opening, and slot. The effect of magnetic field caused by armature reaction on the saturation of magnetic bridges is considered. The analytical expression of each subdomain is derived and the field solution is obtained by the boundary conditions. The analytical results at the no-load and on-load conditions are verified with the finite-element method.
Auteurs: Peixin Liang;Feng Chai;Yi Li;Yulong Pei;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3479 - 3488
Editeur: IEEE
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» Analytical Rotor Position Estimation for SRM Based on Scaling of Reluctance Characteristics From Torque-Balanced Measurement
Résumé:
In this paper, a novel analytical method is proposed for rotor position estimation of switched reluctance machine (SRM). The nonlinear reluctance characteristic of the SRM is divided into two parts, namely air gap and iron core, and analyzed in detail from the aspect of magnetic field. According to the inherent features of the reluctance characteristic, it is analytically expressed based on scaling. Two segments are considered, which are expressed as a linear function and a quadratic function, respectively. Then, the analytical expressions of rotor position are derived for each segment. The effectiveness of the proposed analytical estimation method is evaluated with detailed simulations and experiments under different operating conditions. The proposed method is accurate and just requires the reluctance characteristic at four or even two rotor positions, which can be conveniently measured by the torque-balanced method.
Auteurs: Shoujun Song;Shuo Chen;Weiguo Liu;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3524 - 3536
Editeur: IEEE
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» Analyzing Eye-Tracking Information in Visualization and Data Space: From Where on the Screen to What on the Screen
Résumé:
Eye-tracking data is currently analyzed in the image space that gaze-coordinates were recorded in, generally with the help of overlays such as heatmaps or scanpaths, or with the help of manually defined areas of interest (AOI). Such analyses, which focus predominantly on where on the screen users are looking, require significant manual input and are not feasible for studies involving many subjects, long sessions, and heavily interactive visual stimuli. Alternatively, we show that it is feasible to collect and analyze eye-tracking information in data space. Specifically, the visual layout of visualizations with open source code that can be instrumented is known at rendering time, and thus can be used to relate gaze-coordinates to visualization and data objects that users view, in real time. We demonstrate the effectiveness of this approach by showing that data collected using this methodology from nine users working with an interactive visualization, was well aligned with the tasks that those users were asked to solve, and similar to annotation data produced by five human coders. Moreover, we introduce an algorithm that, given our instrumented visualization, could translate gaze-coordinates into viewed objects with greater accuracy than simply binning gazes into dynamically defined AOIs. Finally, we discuss the challenges, opportunities, and benefits of analyzing eye-tracking in visualization and data space.
Auteurs: Sayeed Safayet Alam;Radu Jianu;
Apparue dans: IEEE Transactions on Visualization and Computer Graphics
Date publication: 05.-2017, volume: 23, issue:5, pages: 1492 - 1505
Editeur: IEEE
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» Anatomical Directional Dissimilarities in Tri-axial Swallowing Accelerometry Signals
Résumé:
Swallowing accelerometry is a noninvasive approach currently under consideration as an instrumental screening test for swallowing difficulties, with most current studies focusing on the swallowing vibrations in the anterior–posterior (A-P) and superior–inferior (S-I) directions. However, the displacement of the hyolaryngeal structure during the act of swallowing in patients with dysphagia involves declination of the medial–lateral (M-L), which suggests that the swallowing vibrations in the M-L direction have the ability to reveal additional details about the swallowing function. With this motivation, we performed a broad comparison of the swallowing vibrations in all three anatomical directions. Tri-axial swallowing accelerometry signals were concurrently collected from 72 dysphagic patients undergoing videofluoroscopic evaluation of swallowing (mean age: 63.94 ± 12.58 years period). Participants swallowed one or more thickened liquids with different consistencies including thin–thick liquids, nectar-thick liquids, and pudding-thick liquids with either a comfortable self-selected volume from a cup or a controlled volume by the examiner from a 5-ml spoon. Swallows were grouped based on the viscosity of swallows and the participant’s stroke history. Then, a comprehensive set of features was extracted in multiple signal domains from 881 swallows. The results highlighted inter-axis dissimilarities among tri-axial swallowing vibrations including the extent of variability in the amplitude of signals, the degree of predictability of signals, and the extent of disordered behavior of signals in time-frequency domain. First, the upward movement of the hyolaryngeal structure, representing the S-I signals, were actually more variable in amplitude and showed less predictable behavior than the sideways and forward movements, representing the A-P and M-L signals, duri- g swallowing. Second, the S-I signals, which represent the upward movement of the hyolaryngeal structure, behaved more disordered in the time-frequency domain than the sideways movement, M-L signals, in all groups of study except for the pudding swallows in the stroke group. Third, considering the viscosity and the participant’s pathology, thin liquid swallows in the nonstroke group presented the most directional differences among all groups of study. In summary, despite some directional dissimilarities, M-L axis accelerometry characteristics are similar to those of the two other axes. This indicates that M-L axis characteristics, which cannot be observed in videofluoroscopic images, can be adequately derived from the A-P and S-I axes.
Auteurs: Faezeh Movahedi;Atsuko Kurosu;James L. Coyle;Subashan Perera;Ervin Sejdić;
Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Date publication: 05.-2017, volume: 25, issue:5, pages: 447 - 458
Editeur: IEEE
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» Angled 3D Glass-to-Silicon Photonics Coupling Interface
Résumé:
A numerical study on the design of a novel low-loss, low-cost, and low fabrication complexity, angled 3D Glass-to-SiPh coupling interface is demonstrated. The interface is composed of a 2° angled 3D glass waveguide and a thin-silicon-on-insulator platform flip-chip assembled in close proximity. The overall structure is designed and optimized based on the maximization of the coupling strength ( $kappa )$ as well as the calculation of a constant loss taper (CLT) silicon taper. The reported maximum conversion efficiency is 85.7% for 1.55- $mu text{m}$ central wavelength and is almost flat across the entire $C$ -band. The results were obtained using a 3D eigenmode expansion (3D-EME) propagation solver and were verified through the 3D finite-difference time-domain (3D-FDTD) simulation method.
Auteurs: G. Poulopoulos;D. Kalavrouziotis;J. R. Macdonald;P. Mitchell;N. Psaila;H. Avramopoulos;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 763 - 766
Editeur: IEEE
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» Anomaly Detection in Traffic Scenes via Spatial-Aware Motion Reconstruction
Résumé:
Anomaly detection from a driver's perspective when driving is important to autonomous vehicles. As a part of Advanced Driver Assistance Systems (ADAS), it can remind the driver about dangers in a timely manner. Compared with traditional studied scenes such as a university campus and market surveillance videos, it is difficult to detect an abnormal event from a driver's perspective due to camera waggle, abidingly moving background, drastic change of vehicle velocity, etc. To tackle these specific problems, this paper proposes a spatial localization constrained sparse coding approach for anomaly detection in traffic scenes, which first measures the abnormality of motion orientation and magnitude, respectively, and then fuses these two aspects to obtain a robust detection result. The main contributions are threefold, as follows. 1) This work describes the motion orientation and magnitude of the object, respectively, in a new way, which is demonstrated to be better than the traditional motion descriptors. 2) The spatial localization of an object is taken into account considering the sparse reconstruction framework, which utilizes the scene's structural information and outperforms the conventional sparse coding methods. 3) Results of motion orientation and magnitude are adaptively weighted and fused by a Bayesian model, which makes the proposed method more robust and able to handle more kinds of abnormal events. The efficiency and effectiveness of the proposed method are validated by testing on nine difficult video sequences that we captured ourselves. Observed from the experimental results, the proposed method is more effective and efficient than the popular competitors and yields a higher performance.
Auteurs: Yuan Yuan;Dong Wang;Qi Wang;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 05.-2017, volume: 18, issue:5, pages: 1198 - 1209
Editeur: IEEE
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» Antenna Cross-Polar Requirements for 3-PolD Weather Radar Measurements
Résumé:
The analysis and correction of the bias occurring in weather radar polarimetric measurements is a challenging problem. Polarization coupling due to the cross-polar radiation pattern of the radar's antenna is known to be responsible for errors in the estimation of the polarimetric covariance matrix, and consequently in the hydrometeor classification and quantification, either when using the ATSR or the SHV method. An alternative method for Doppler and polarimetric measurements based on transmitting three different polarizations (3-PolD) has been proven to provide accurate polarimetric covariance matrix estimates without making any hypothesis about the target polarimetric response or its Doppler spectrum. This method does not reduce the Doppler capabilities or the unambiguous range of the radar despite alternately transmitting 3-PolD. These characteristics have encouraged evaluating the polarimetric parameter biases due to cross-polar radiation when this method is used. Biases are calculated considering reflector antenna systems as well as phased-array antenna systems. The results show that this method may guarantee a tolerable bias level even with a poor co- to cross-polar antenna pattern ratio.
Auteurs: José M. Pidre;María Vera Isasa;Verónica Santalla del Río;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2682 - 2692
Editeur: IEEE
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» Antenna Selection in MIMO Cognitive AF Relay Networks With Mutual Interference and Limited Feedback
Résumé:
This letter studies antenna selection in amplify-and-forward multiple-input multiple-output cooperative cognitive radio system under mutual primary-secondary interference. Two power allocation methods are adopted at the secondary transmitters, assuming perfect and limited feedback from the primary receiver. For both methods, outage, and error performance analysis is conducted, where simple, closed-form expressions are derived over Rayleigh fading channels. In addition, asymptotic analysis is performed to get insights about the diversity gain and the effects of key parameters, including the primary receiver feedback and the number of the antennas. Our analytical results, which are validated with simulations, show the effective impact of the proposed model on enhancing the overall system performance.
Auteurs: Eylem Erdogan;Ali Afana;Salama Ikki;Halim Yanikomeroglu;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1111 - 1114
Editeur: IEEE
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» Antenna Selection in RF-Chain-Limited MIMO Interference Networks Under Interference Alignment
Résumé:
In multiple-input multiple-output (MIMO) systems, the deployment of multiple radio-frequency (RF) chains is much more expensive than that of multiple antennas. Antenna selection (AS) is a low-cost low-complexity method to exploit the diversity gain in MIMO systems with sufficient antennas but limited RF chains. Among the AS algorithms, decremental AS has been shown to be near-optimal compared with exhaustive search. In this paper, we study AS in MIMO interference networks applying the interference alignment (IA) scheme. IA aligns and zero-forces the interference via transmitter–receiver beamforming and achieves a maximum degree of freedom. The feasibility and alignment topology of IA is dependent on the active antenna configuration. For users in tightly feasible systems, IA can be resumed after AS by adapting the beamformers locally, and the exact transmission rate can be known. For users in superfeasible systems, we derive the expected rate under IA conditioned on local channel state information (CSI). Adopting the rate or expected rate as selection criterion, we propose the decremental AS algorithms achieving a twofold complexity reduction. Simulation results and complexity analysis show that the algorithms achieve near-optimal performance at low complexity.
Auteurs: Mengjie Xie;Tat-Ming Lok;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3856 - 3870
Editeur: IEEE
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» Application of Infrared Thermography to Failure Detection in Industrial Induction Motors: Case Stories
Résumé:
Infrared thermography has been extensively applied over decades to areas such as maintenance of electrical installations. Its use in electrical machinery has been mainly circumscribed to the detection of faults in static machines, such as power transformers. However, with regard to the predictive maintenance of rotating electrical machines, its use has been much more limited. In spite of this fact, the potential of this tool, together with the progressive decrease in the price of infrared cameras, makes this technique a very interesting option to at least complement the diagnosis provided by other well-known techniques, such as current or vibration data analysis. In this context, infrared thermography has recently shown potential for the detection of motor failures including misalignments, cooling problems, bearing damages, or connection defects. This work presents several industrial cases that help to illustrate the effectiveness of this technique for the detection of a wide range of faults in field induction motors. The data obtained with this technique made it possible to detect the presence of faults of diverse nature (electrical, mechanical, thermal, and environmental); these data were very useful to either diagnose or complement the diagnosis provided by other tools.
Auteurs: David López-Pérez;Jose Antonino-Daviu;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 1901 - 1908
Editeur: IEEE
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» Application of the Thermal Fin Approximation to Modeling Voice Coil Magnetic Fields and Performance
Résumé:
This paper develops an approximate analytical model to describe the magnetic fluxes, forces, and armature reaction in cylindrical voice coil actuators and related electric machines. Magnetic flux is assumed to either lie in an inner region of the actuator and parallel to its axis, or in an outer region of the actuator and oriented radially. A differential reluctance model is derived for this set of assumptions, with a structure and solution set similar to those involved in extended-surface heat transfer (“fins”) and lossy transmission lines. Particular solutions for the force constant, motor constant, coil inductance, and variable-reluctance force are found for a symmetric motor with opposed axial permanent magnets on either side of an iron flux concentrator. The model results for this topology are validated using finite-element analysis and experimental measurements from a prototype.
Auteurs: Bryan P. Ruddy;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 8
Editeur: IEEE
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» Application of VPM for Scattering From Tapered Cylindrical Components of Vegetation
Résumé:
To advance the investigation of vegetated terrain using polarimetric remote sensing techniques, it is important to determine the electromagnetic properties of key constituents, such as branches and trunks, which may be realistically modeled by tapered cylinders. To this end, we apply our previously proposed virtual partition method (VPM). Numerical simulations demonstrate that VPM possesses the desired features, such as high fidelity prediction of the scattering amplitude function and fulfillment of energy conservation as well as the reciprocity theorem. It thus may be helpful in the pursuit of better coherent scattering models of vegetated terrain, a finer understanding of PolInSAR imagery, and a better characterization of scattering mechanisms.
Auteurs: Chao Yang;Yang Du;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 654 - 658
Editeur: IEEE
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» Apply or Die: On the Role and Assessment of Application Papers in Visualization
Résumé:
Application-oriented papers provide an important way to invigorate and cross-pollinate the visualization field, but the exact criteria for judging an application paper's merit remain an open question. This article builds on a panel at the 2016 IEEE Visualization Conference entitled "Application Papers: What Are They, and How Should They Be Evaluated?" that sought to gain a better understanding of prevalent views in the visualization community. This article surveys current trends that favor application papers, reviews the benefits and contributions of this paper type, and discusses their assessment in the review process. It concludes with recommendations to ensure that the visualization community is more inclusive to application papers.
Auteurs: Gunther H. Weber;Sheelagh Carpendale;David Ebert;Brian Fisher;Hans Hagen;Ben Shneiderman;Anders Ynnerman;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 05.-2017, volume: 38, issue:3, pages: 96 - 104
Editeur: IEEE
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» Approaches to Co-Evolution of Metamodels and Models: A Survey
Résumé:
Modeling languages, just as all software artifacts, evolve. This poses the risk that legacy models of a company get lost, when they become incompatible with the new language version. To address this risk, a multitude of approaches for metamodel-model co-evolution were proposed in the last 10 years. However, the high number of solutions makes it difficult for practitioners to choose an appropriate approach. In this paper, we present a survey on 31 approaches to support metamodel-model co-evolution. We introduce a taxonomy of solution techniques and classify the existing approaches. To support researchers, we discuss the state of the art, in order to better identify open issues. Furthermore, we use the results to provide a decision support for practitioners, who aim to adopt solutions from research.
Auteurs: Regina Hebig;Djamel Eddine Khelladi;Reda Bendraou;
Apparue dans: IEEE Transactions on Software Engineering
Date publication: 05.-2017, volume: 43, issue:5, pages: 396 - 414
Editeur: IEEE
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» Approximate MMSE Estimator for Linear Dynamic Systems With Gaussian Mixture Noise
Résumé:
In this work, we propose an approximate minimum mean-square error filter for linear dynamic systems with Gaussian Mixture (GM) noise. The proposed estimator tracks each component of the GM posterior with an individual filter and minimizes the trace of the covariance matrix of the bank of filters, as opposed to minimizing the MSE of individual filters filters in the commonly used Gaussian sum filter (GSF). Hence, the spread of means in the proposed method is smaller than that of GSF which makes it more robust to removing components. Consequently, reduction schemes with lower computational complexity can be used with the proposed filter without losing estimation accuracy and precision. This is supported through simulations on synthetic data as well as experimental data related to an indoor localization system. Additionally, we show that in two limit cases the state estimation provided by our proposed method converges to that of GSF, and we provide simulation results supporting this in other cases.
Auteurs: Leila Pishdad;Fabrice Labeau;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2457 - 2463
Editeur: IEEE
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» Arc Fault Detection Method Based on CZT Low-Frequency Harmonic Current Analysis
Résumé:
This paper presents a method for the detection of series arc faults in electrical circuits, which has been developed starting from an experimental characterization of the arc fault phenomenon and an arcing current study in several test conditions. Starting from this, the authors have found that is it possible to suitably detect arc faults by means of a high-resolution low-frequency harmonic analysis of current signal, based on chirp zeta transform, and a proper set of indicators. The proposed method effectiveness is shown by means of experimental tests, which were carried in both arcing and nonarcing conditions and in the presence of different loads, chosen according to the UL 1699 standard requirements.
Auteurs: Giovanni Artale;Antonio Cataliotti;Valentina Cosentino;Dario Di Cara;Salvatore Nuccio;Giovanni Tinè;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 888 - 896
Editeur: IEEE
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» Arc-Flash Mitigation: A Systematic Approach for Company Standard Power System Schemes
Résumé:
Arc-flash hazard assessment studies involving a very large oil and gas company's equipment rated 38 kV and below revealed locations with excessive arcflash incident energy. After conducting many additional studies of power distribution systems for various plants (e.g., refineries, gas plants, gas-oil separation plants, and natural gas liquid plants), we realized that dangerous locations (greater than 40 cal/cm<sup>2</sup>) are somewhat consistent among various plant types. This knowledge makes planning and budgeting for implementing arc-flash mitigation predictable from a corporate perspective. Specific arc-flash mitigation techniques can be embedded in the specifications of new projects as well as company material standards to avoid unnecessary retrofit activities after installation. Maintenance personnel can also be effectively trained on arc-flash mitigation and safe work practices when consistent solutions are implemented. This article demonstrates a systematic approach to address dangerous arc-flash locations for corporate planning purposes and provides practical mitigation solutions that can be applied at many company facilities.
Auteurs: Rakan El-Mahayni;Jamal Bugshan;Ritchie Pragale;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 24 - 32
Editeur: IEEE
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» Architectural Principles for Energy-Aware Internet-Scale Applications
Résumé:
Optimizing the energy consumption of today's Internet-scale systems will require a radical approach that considers the whole system. To address system-level energy efficiency, software architects can follow three simple design principles. A case study illustrates the possible savings.
Auteurs: Rabih Bashroush;Eoin Woods;
Apparue dans: IEEE Software
Date publication: 05.-2017, volume: 34, issue:3, pages: 14 - 17
Editeur: IEEE
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» Are There Many Real Innovators Nowadays?
Résumé:
Academia struggles to produce innovative work leading to highimpact publications. In the meantime, the goal of every researcher is to make as significant an impact as is possible, gauged mainly by a high number of citations. Another parameter is the visibility of the conferences or journals that researchers choose to publish their findings.
Auteurs: Vasileios Theodosiadis;
Apparue dans: IEEE Potentials
Date publication: 05.-2017, volume: 36, issue:3, pages: 41 - 43
Editeur: IEEE
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» ARFTG 2017
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Peter H. Aaen;Nick Ridler;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 98 - 100
Editeur: IEEE
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» ASRQ: Automatic Segment Repeat Request for IEEE 802.15.4-Based WBAN
Résumé:
In a wireless body area network (WBAN), high data reliability and long operating time are important requirements. The retransmission process of the default Automatic Repeat reQuest (ARQ) mechanism in IEEE 802.15.4 is a suitable method to ensure the data reliability of WBAN communications, where frame loss can occur frequently. However, retransmitting the entire DATA frame is energy inefficient due to the fact that the most of payload data within lost frames are only partially corrupted. Therefore, this paper proposes the automatic segment repeat request scheme for the IEEE 802.15.4-based WBANs. The proposed scheme partitions the data payload into segments when the channel condition is bad, and retransmits only the corrupted segment(s). This reduces the size of the retransmitted frames, which improves frame reception rate and decreases the amount of transmitted traffic, and thus energy consumption. Our experiments using a real IEEE 802.15.4-based WBAN test bed show that the proposed method provides higher transmission reliability and lower power consumption than the default IEEE 802.15.4 ARQ mechanism.
Auteurs: Byoungseon Kim;Ben Lee;Jinsung Cho;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2925 - 2935
Editeur: IEEE
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» Assessment of the Electrical Performance of Short Channel InAs and Strained Si Nanowire FETs
Résumé:
We present a numerical study aimed to benchmark short gate InAs nanowire-FETs (NW-FETs) against their strained Si (sSi) counterpart. Our full-quantum simulations focus on both gate-length scaling and device variability and include the impact of electron–phonon scattering and surface roughness (SR). Interestingly, we found that SR improves the subthreshold-voltage swing (SS) of short gate-length InAs devices by inducing a reduced source-to-drain tunneling. Hence, InAs NW-FETs exhibit a larger immunity to the roughness-induced degradation of the ON-current, whereas they suffer froma larger OFF-current and SS variabilitywith respect to the sSi ones. According to our results, InAs NW-FETs could compete with sSi NW-FETs only for very short gate lengths, when the device performance is significantly degraded, while for longer devices sSi NW-FETs remain a more effective and reliable choice due to the higher gate overdrive charge.
Auteurs: Corentin Grillet;Demetrio Logoteta;Alessandro Cresti;Marco G. Pala;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2425 - 2431
Editeur: IEEE
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» Asymmetric Junctions in Metallic–Semiconducting–Metallic Heterophase MoS2
Résumé:
Symmetry of the source–channel and drain–channel junction is a unique property of a metal-oxide-semiconductor field effect transistor (MOSFET), which needs to be preserved while realizing sub-decananometer channel length devices using advanced technology. Employing experimental-findings-driven atomistic modeling techniques, we demonstrate that such symmetry might not be preserved in an atomically thin phase-engineered MoS2-based MOSFET. It originates from the two distinct atomic patterns at phase boundaries ( $beta $ and $beta $ *) when the semiconducting phase (channel) is sandwiched between the two metallic phases (source and drain). We develop a geometrically optimized atomic model of two independent heterophase structures comprising $beta $ and $beta $ * interfaces and study their electrical characteristics using density functional theory-nonequilibriumGreen’s function formalism. We further study the effect of semiconductor doping on the transmission of those planar devices and show that irrespective of the doping concentration, these heterophase structures exhibit asymmetric barrier heights. Our findings could be useful for designing integrated circuits using such advanced transistors.
Auteurs: Dipankar Saha;Santanu Mahapatra;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2457 - 2460
Editeur: IEEE
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» Asymptotic Stability of Perturbation-Based Extremum-Seeking Control for Nonlinear Plants
Résumé:
We introduce a perturbation-based extremum-seeking controller for general nonlinear dynamical plants with an arbitrary number of tunable plant parameters. The controller ensures asymptotic convergence of the plant parameters to their performance-optimizing values for any initial plant condition under the assumptions in this work. The key to this result is that the amplitude and the frequencies of the perturbations, as well as other tuning parameters of the controller, are time varying. Remarkably, the time-varying tuning parameters can be chosen such that asymptotic convergence is achieved for all plants that satisfy the assumptions, thereby guaranteeing stability of the resulting closed-loop system of plant and controller regardless of tuning.
Auteurs: Mark Haring;Tor Arne Johansen;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2302 - 2317
Editeur: IEEE
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» Asynchronous Distributed Optimization Via Randomized Dual Proximal Gradient
Résumé:
In this paper we consider distributed optimization problems in which the cost function is separable, i.e., a sum of possibly non-smooth functions all sharing a common variable, and can be split into a strongly convex term and a convex one. The second term is typically used to encode constraints or to regularize the solution. We propose a class of distributed optimization algorithms based on proximal gradient methods applied to the dual problem. We show that, by choosing suitable primal variable copies, the dual problem is itself separable when written in terms of conjugate functions, and the dual variables can be stacked into non-overlapping blocks associated to the computing nodes. We first show that a weighted proximal gradient on the dual function leads to a synchronous distributed algorithm with local dual proximal gradient updates at each node. Then, as main paper contribution, we develop asynchronous versions of the algorithm in which the node updates are triggered by local timers without any global iteration counter. The algorithms are shown to be proper randomized block-coordinate proximal gradient updates on the dual function.
Auteurs: Ivano Notarnicola;Giuseppe Notarstefano;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2095 - 2106
Editeur: IEEE
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» Attention-Weighted Texture and Depth Bit-Allocation in General-Geometry Free-Viewpoint Television
Résumé:
In a free-viewpoint television network, each viewer chooses its point of view from which to watch a scene. We use the concept of total observed distortion, wherein we aim to minimize the distortion of the view observed by the viewers as opposed to the distortion of each camera, to develop an optimized bit-rate allocation for each camera. Our attention-weighted approach effectively gives more bits to the cameras that are more watched. The more concentrated the viewer distribution, the larger the bit-rate savings, for a given total observed distortion, compared with the uniform rate allocation. We analyze and model the distortion of a synthesized view as a function of the distortions (both in texture and/or depth) of the nearby cameras. Based on such models, we develop optimal rate-allocation methods for texture images, considering a uniform bit allocation for depth, and for both texture and depth simultaneously. Simulation results are shown, demonstrating not only the correctness of the optimized solution, but also measuring its improvement against uniform rate allocation for a few viewer distributions.
Auteurs: Camilo Dorea;Ricardo L. de Queiroz;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 1055 - 1065
Editeur: IEEE
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» Attentive Contexts for Object Detection
Résumé:
Modern deep neural network-based object detection methods typically classify candidate proposals using their interior features. However, global and local surrounding contexts that are believed to be valuable for object detection are not fully exploited by existing methods yet. In this work, we take a step towards understanding what is a robust practice to extract and utilize contextual information to facilitate object detection in practice. Specifically, we consider the following two questions: “how to identify useful global contextual information for detecting a certain object?” and “how to exploit local context surrounding a proposal for better inferring its contents?” We provide preliminary answers to these questions through developing a novel attention to context convolution neural network (AC-CNN)-based object detection model. AC-CNN effectively incorporates global and local contextual information into the region-based CNN (e.g., fast R-CNN and faster R-CNN) detection framework and provides better object detection performance. It consists of one attention-based global contextualized (AGC) subnetwork and one multi-scale local contextualized (MLC) subnetwork. To capture global context, the AGC subnetwork recurrently generates an attention map for an input image to highlight useful global contextual locations, through multiple stacked long short-term memory layers. For capturing surrounding local context, the MLC subnetwork exploits both the inside and outside contextual information of each specific proposal at multiple scales. The global and local context are then fused together for making the final decision for detection. Extensive experiments on PASCAL VOC 2007 and VOC 2012 well demonstrate the superiority of the proposed AC-CNN over well-established baselines.
Auteurs: Jianan Li;Yunchao Wei;Xiaodan Liang;Jian Dong;Tingfa Xu;Jiashi Feng;Shuicheng Yan;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 05.-2017, volume: 19, issue:5, pages: 944 - 954
Editeur: IEEE
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» Attributed Scattering Center Extraction Algorithm Based on Sparse Representation With Dictionary Refinement
Résumé:
Compared with the point-scattering model, the attributed scattering center model (ASCM) is able to describe the frequency and aspect dependence of canonical scattering objects using solutions from both physical optics and the geometric theory of diffraction. As the ASCM is complicated, it may increase the dimension of the parameterized dictionary, which will increase the cost of computation and storage significantly. Aiming at this problem, a novel sparse representation-based algorithm, combined with an alternative optimization and dictionary refinement, is proposed. Utilizing the orthogonal matching pursuit algorithm combined with relaxation algorithm, the solution to the sparse signal recovery problem can be obtained. Numerical results on both electromagnetic computation data and measured SAR data verify the validity of the proposed algorithm.
Auteurs: Hongwei Liu;Bo Jiu;Fei Li;Yinghua Wang;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2604 - 2614
Editeur: IEEE
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» Attribution Mechanisms for Ancillary Service Costs Induced by Variability in Power Delivery
Résumé:
The increased penetration of renewable energy sources in existing power systems has led to necessary developments in electricity market mechanisms. Most importantly, renewable energy generation is increasingly made accountable for deviations between scheduled and actual energy generation. However, there is no mechanism to enforce accountability for the additional costs induced by power fluctuations. These costs are socialized and eventually supported by electricity customers. We propose some metrics for assessing the contribution of all market participants to power regulation needs, as well as an attribution mechanism for fairly redistributing related power regulation costs. We discuss the effect of various metrics used by the attribution mechanisms, and we illustrate, in a game-theoretical framework, their consequences on the strategic behavior of market participants. We also illustrate, by using the case of Western Denmark, how these mechanisms may affect revenues of the various market participants.
Auteurs: Francesca Bona;Nicolas Gast;Jean-Yves Le Boudec;Pierre Pinson;Dan-Cristian Tomozei;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1891 - 1901
Editeur: IEEE
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» Auditory-Inspired Speech Envelope Extraction Methods for Improved EEG-Based Auditory Attention Detection in a Cocktail Party Scenario
Résumé:
This paper considers the auditory attention detection (AAD) paradigm, where the goal is to determine which of two simultaneous speakers a person is attending to. The paradigm relies on recordings of the listener’s brain activity, e.g., from electroencephalography (EEG). To perform AAD, decoded EEG signals are typically correlated with the temporal envelopes of the speech signals of the separate speakers. In this paper, we study how the inclusion of various degrees of auditory modelling in this speech envelope extraction process affects the AAD performance, where the best performance is found for an auditory-inspired linear filter bank followed by power law compression. These two modelling stages are computationally cheap, which is important for implementation in wearable devices, such as future neuro-steered auditory prostheses. We also introduce a more natural way to combine recordings (over trials and subjects) to train the decoder, which reduces the dependence of the algorithm on regularization parameters. Finally, we investigate the simultaneous design of the EEG decoder and the audio subband envelope recombination weights vector using either a norm-constrained least squares or a canonical correlation analysis, but conclude that this increases computational complexity without improving AAD performance.
Auteurs: Wouter Biesmans;Neetha Das;Tom Francart;Alexander Bertrand;
Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Date publication: 05.-2017, volume: 25, issue:5, pages: 402 - 412
Editeur: IEEE
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» Auto-configurable optical amplifier for simple network operation and flexible access network design of a passive optical network
Résumé:
In this paper, we propose an auto-configurable optical amplifier (AC-OA) for passive optical networks (PONs); the value of optical attenuation is automatically controlled to prevent optical overloading of the OA. The AC-OA has a variable optical attenuator (VOA) at the input and a controller synchronized with an external facility database (FDB). The controller obtains the infrastructure information of each ONU and calculates the optimum setting for the input VOA. This structure enables the AC-OA to autonomously react to the spectrum being used. We simulate AC-OA operation based on the parameters of a commercial access network and evaluate the installation-cost reduction possible.
Auteurs: Takuya Tsutsumi;Yu Nakayama;Shunsuke Kanai;Manabu Kubota;Akihiro Otaka;
Apparue dans: IEEE/OSA Journal of Optical Communications and Networking
Date publication: 05.-2017, volume: 9, issue:5, pages: 446 - 455
Editeur: IEEE
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» Autocalibrated Sampling Rate Conversion in the Frequency Domain [Tips & Tricks]
Résumé:
Frequency-domain sampling rate conversion (SRC) can be conveniently implemented by manipulating the discrete Fourier transform (DFT) of the input signal. This method has achieved the advantages of using less computation to obtain more accurate converted output. Conversion errors are mainly produced from the formulation process of the DFT of the output signal. This article presents a sparsity-based scheme to appropriately and automatically calibrate the conversion errors to make further improvement on the conversion accuracy at the cost of more computational complexity. The experimental results demonstrate that the proposed scheme can significantly decrease the meansquare errors (MSEs) and is particularly effective on minimizing the MSEs of phase spectrum.
Auteurs: Lifan Zhao;Xiumei Li;Lu Wang;Guoan Bi;
Apparue dans: IEEE Signal Processing Magazine
Date publication: 05.-2017, volume: 34, issue:3, pages: 101 - 106
Editeur: IEEE
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» Autofocusing and Polar Body Detection in Automated Cell Manipulation
Résumé:
Autofocusing and feature detection are two essential processes for performing automated biological cell manipulation tasks. In this paper, we have introduced a technique capable of focusing on a holding pipette and a mammalian cell under a bright-field microscope automatically, and a technique that can detect and track the presence and orientation of the polar body of an oocyte that is rotated at the tip of a micropipette. Both algorithms were evaluated by using mouse oocytes. Experimental results show that both algorithms achieve very high success rates: 100% and 96%. As robust and accurate image processing methods, they can be widely applied to perform various automated biological cell manipulations.
Auteurs: Zenan Wang;Chen Feng;Wei Tech Ang;Steven Yih Min Tan;Win Tun Latt;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 05.-2017, volume: 64, issue:5, pages: 1099 - 1105
Editeur: IEEE
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» Automated Assessment of Disease Progression in Acute Myeloid Leukemia by Probabilistic Analysis of Flow Cytometry Data
Résumé:
Objective: Flow cytometry (FC) is a widely acknowledged technology in diagnosis of acute myeloid leukemia (AML) and has been indispensable in determining progression of the disease. Although FC plays a key role as a posttherapy prognosticator and evaluator of therapeutic efficacy, the manual analysis of cytometry data is a barrier to optimization of reproducibility and objectivity. This study investigates the utility of our recently introduced nonparametric Bayesian framework in accurately predicting the direction of change in disease progression in AML patients using FC data. Methods: The highly flexible nonparametric Bayesian model based on the infinite mixture of infinite Gaussian mixtures is used for jointly modeling data from multiple FC samples to automatically identify functionally distinct cell populations and their local realizations. Phenotype vectors are obtained by characterizing each sample by the proportions of recovered cell populations, which are, in turn, used to predict the direction of change in disease progression for each patient. Results: We used 200 diseased and nondiseased immunophenotypic panels for training and tested the system with 36 additional AML cases collected at multiple time points. The proposed framework identified the change in direction of disease progression with accuracies of 90% (nine out of ten) for relapsing cases and 100% (26 out of 26) for the remaining cases. Conclusions: We believe that these promising results are an important first step toward the development of automated predictive systems for disease monitoring and continuous response evaluation. Significance: Automated measurement and monitoring of therapeutic response is critical not only for objective evaluation of disease status prognosis but also for timely assessment of treatment strategies.
Auteurs: Bartek Rajwa;Paul K. Wallace;Elizabeth A. Griffiths;Murat Dundar;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 05.-2017, volume: 64, issue:5, pages: 1089 - 1098
Editeur: IEEE
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» Automated Disease Identification With 3-D Optical Imaging: A Medical Diagnostic Tool
Résumé:
Digital holographic microscopy is an ideal tool for 3-D cell imaging and characterization. It provides a host of cell parameters based on cell morphology and its temporal dynamics or time variation. These parameters can be used to study and quantify cell growth and cell physiology. When coupled with classification algorithms, this technique can also be used to identify and classify cells such as blood cells for automated disease identification. A compact, portable version of this 3-D optical imaging system has the potential to become a device for compact field portable biological data collection, analysis, and cell identification leading to disease diagnosis with mobile devices, low cost instruments for deployment in remote areas with limited access to healthcare to combat disease. In this paper, we present an overview of our reported work on the development of digital holographic microscopes and their applications in 3-D cell imaging, cell parameter extraction and cell classification for potential automated disease identification.
Auteurs: Arun Anand;Inkyu Moon;Bahram Javidi;
Apparue dans: Proceedings of the IEEE
Date publication: 05.-2017, volume: 105, issue:5, pages: 924 - 946
Editeur: IEEE
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» Automatic Detection of 3D Quality Defects in Stereoscopic Videos Using Binocular Disparity
Résumé:
The 3D video quality issues that may disturb the human visual system and negatively impact the 3D viewing experience are well known and become more relevant as the availability of 3D video content increases, primarily through 3D cinema, but also through 3D television. In this paper, we propose four algorithms that exploit available stereo disparity information, in order to detect disturbing stereoscopic effects, namely, stereoscopic window violations, bent window effects, uncomfortable fusion object objects, and depth jump cuts on stereo videos. After detecting such issues, the proposed algorithms characterize them, based on the stress they cause to the viewer’s visual system. Qualitative representative examples, quantitative experimental results on a custom-made video data set, a parameter sensitivity study, and comments on the computational complexity of the algorithms are provided, in order to assess the accuracy and the performance of stereoscopic quality defect detection.
Auteurs: Sotirios Delis;Ioannis Mademlis;Nikos Nikolaidis;Ioannis Pitas;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 977 - 991
Editeur: IEEE
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» Automatic Detection of Ship Targets Based on Wavelet Transform for HF Surface Wavelet Radar
Résumé:
High-frequency surface wave radar (HFSWR) has a vital civilian and military significance for continuous maritime surveillance of activities within exclusive economic zone. However, HFSWR has lower spatial and temporal resolutions and the received signals are strongly polluted by different clutter and background noise. Therefore, ship target detection by HFSWR has become a challenging task. This letter presents an automatic ship target detection algorithm based on discrete wavelet transform (DWT). First, a peak signal-to-noise ratio-based algorithm is proposed to automatically determine the optimal scale of DWT for extraction of ship targets. Second, the high-frequency coefficients of DWT at the optimal scale are processed by a fuzzy set-based method to enhance the useful target information and depress the unwanted background noises. Third, a target-highlighted image is reconstructed by ignoring all the low-frequency coefficients and performing inverse DWT only to the enhanced high-frequency coefficients. Finally, the targets are extracted by adaptive threshold segmentation of the final target-highlighted image. Experimental results show that the proposed approach can automatically extract ship targets effectively for range Doppler images with complex background, and has a better target detection performance than the previous wavelet-based algorithm, thereby providing a new reliable image processing-based method of ship target detection for HFSWR.
Auteurs: Qingzhong Li;Wandong Zhang;Ming Li;Jiong Niu;Q. M. Jonathan Wu;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 714 - 718
Editeur: IEEE
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» Automatic Gauge Control under Laterally Asymmetric Rolling Conditions Combined with Feedforward
Résumé:
The most common and well proven control strategy for thickness control in industrial rolling mills is the automatic gauge controller (AGC). However, it is still unclear how to use AGC for the control of asymmetries in lateral direction. How should the controller react to different thickness estimations at both sides of the mill? Such laterally asymmetric rolling conditions may originate from strip track-off, asymmetric friction in the mill stand, or a wedge-shaped entry profile of the strip thickness. In this paper, three control approaches are discussed. Two different setups of AGC are compared and a feedforward (FF) approach is developed for lateral asymmetries of the entry thickness profile. Simulation studies based on a validated mill stand model demonstrate the benefit of combining AGC with a feedforward controller to compensate for asymmetries.
Auteurs: Katharina Prinz;Andreas Steinboeck;Martin Müller;Andreas Ettl;Andreas Kugi;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2560 - 2568
Editeur: IEEE
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» Automatic Reference Image Selection for Color Balancing in Remote Sensing Imagery Mosaic
Résumé:
Selection of a reference image is an important step in color balancing. However, the past research and currently available methods do not focus on it, leading to the lack of an effective way to select the reference image for color balancing in remote sensing imagery mosaic. This letter proposes a novel automatic reference image selection method that aims to select the reference images by assessing multifactors according to the land surface types of the target images. The proposed method addresses the limitations caused by the use of a single assessment factor as well as the selection of a single image as the reference in traditional methods. In addition, the proposed method has a wider range of applications than those requiring no reference image. The visual experimental results indicate that the proposed method can select the suitable reference images, which benefits the color balancing result, and outperforms the other comparative methods. Moreover, the absolute mean value of skewness metric of the proposed method is 0.0831, which is lower than the values of the other comparison methods. It indicates that the result of the proposed method had the best performance in the color information. The quantitative analyses with the metric of absolute difference of mean value indicate that the proposed method has a good ability in maintaining the spectral information, and the spectral changing rates had been reduced at least 10.66% by the proposed method when compared with the other methods.
Auteurs: Lei Yu;Yongjun Zhang;Mingwei Sun;Yihui Lu;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 729 - 733
Editeur: IEEE
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» Automotive Software
Résumé:
This theme issue addresses automotive IT and software development. What technologies and principles deliver value, and how can you introduce them at a fast pace?
Auteurs: Christof Ebert;John Favaro;
Apparue dans: IEEE Software
Date publication: 05.-2017, volume: 34, issue:3, pages: 33 - 39
Editeur: IEEE
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» Autonomous System for Interpretation of Measurements Based on Adaptive Device
Résumé:
The monitoring and interpretation of electrical signals have been evolving nowadays. In this paper, an autonomous system based on the concepts of adaptivity has been developed with the goal to perform signal interpretation. The method consists in to receive signals acquired in the field through the sensors installed. From the processing carried out by the knowledge base deployed, the method is able to detect anomalies in the measured point and emits alarms or even actions to be accomplished by the engineer team. The experimental results validate the application of the adaptive method for monitoring and interpretation of signals.
Auteurs: Sidnei Nicoli;Jose Antonio Jardini;Romulo Goncalves Lins;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 861 - 868
Editeur: IEEE
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» AZO Thin Film Transistor Performance Enhancement by Capping an Aluminum Layer
Résumé:
Coplanar bottom-gate aluminum-zinc-oxide (AZO) thin film transistors (TFTs) with aluminum (Al) capping layers were fabricated in this work. The influences of the Al capping layer thickness and the post-annealing condition on the performance of the AZO-TFTswere investigated. Results show that the performance of the AZO-TFTs are enhanced significantly by introducing the Al capping layer on back channel, with saturation mobility increasing dramatically from 0.128 to 12.6 cm2/ $text {V}cdot text {s}$ . The enhancement is ascribed to the diffusion of Al atoms into the AZO thin film and thus induced crystallization improvement.
Auteurs: Wen Yu;Dedong Han;Junchen Dong;Yingying Cong;Guodong Cui;Yi Wang;Shengdong Zhang;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2228 - 2232
Editeur: IEEE
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» Bag-of-Discriminative-Words (BoDW) Representation via Topic Modeling
Résumé:
Many of the words in a given document either deliver facts (objective) or express opinions (subjective), respectively, depending on the topics they are involved in. For example, given a bunch of documents, the word “bug” assigned to the topic “order Hemiptera” apparently remarks one object (i.e., one kind of insects), while the same word assigned to the topic “software” probably conveys a negative opinion. Motivated by the intuitive assumption that different words have varying degrees of discriminative power in delivering the objective sense or the subjective sense with respect to their assigned topics, a model named as discriminatively objective-subjective LDA (dosLDA) is proposed in this paper. The essential idea underlying the proposed dosLDA is that a pair of objective and subjective selection variables are explicitly employed to encode the interplay between topics and discriminative power for the words in documents in a supervised manner. As a result, each document is appropriately represented as “bag-of-discriminativewords” (BoDW). The experiments reported on documents and images demonstrate that dosLDA not only performs competitively over traditional approaches in terms of topic modeling and document classification, but also has the ability to discern the discriminative power of each word in terms of its objective or subjective sense with respect to its assigned topic.
Auteurs: Yueting Zhuang;Hanqi Wang;Jun Xiao;Fei Wu;Yi Yang;Weiming Lu;Zhongfei Zhang;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 05.-2017, volume: 29, issue:5, pages: 977 - 990
Editeur: IEEE
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» Balancing Security and Usability in Encrypted Email
Résumé:
End-to-end encryption is the best way to protect digital messages. Historically, end-to-end encryption has been extremely difficult for people to use, but recent tools have made it more broadly accessible, largely by employing key-directory services. These services sacrifice some security properties for convenience. The authors wanted to understand how average users think about these tradeoffs. They conducted a 52-person user study and found that participants could learn to understand properties of different encryption models. Users also made coherent assessments about when different tradeoffs might be appropriate. Participants recognized that the less-convenient exchange model was more secure overall, but considered the registration model's security sufficient for most everyday purposes.
Auteurs: Wei Bai;Doowon Kim;Moses Namara;Yichen Qian;Patrick Gage Kelley;Michelle L. Mazurek;
Apparue dans: IEEE Internet Computing
Date publication: 05.-2017, volume: 21, issue:3, pages: 30 - 38
Editeur: IEEE
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» Baltic Sea Ice Concentration Estimation Using SENTINEL-1 SAR and AMSR2 Microwave Radiometer Data
Résumé:
Sea ice concentration (SIC) is an important sea ice parameter for sea ice navigation, environmental research, and weather and ice forecasting. We have developed and tested a method for estimation of the Baltic Sea SIC using SENTINEL-1 synthetic aperture radar (SAR) and Advanced Microwave Scanning Radiometer 2 passive microwave radiometer (MWR) data. Here, we present the method and results for January 2016. Ice concentration grids of Finnish Meteorological Institute daily ice charts have been used as reference data in this paper. We present a comparison of four SIC estimation methods with our reference data. In addition to the combined SAR/MWR SIC estimation method, we also compare SIC estimates produced using SAR alone and two MWR-based methods. The main target of this paper was to develop and test a high-resolution SIC estimation method suitable for operational use.
Auteurs: Juha Karvonen;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2871 - 2883
Editeur: IEEE
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» Band Assignment Approaches for Hyperspectral Sharpening
Résumé:
Classical pansharpening algorithms constitute a class of image fusion methods that have been widely investigated in the literature. They have been developed for combining a single- and a multichannel image (panchromatic (PAN) and multispectral (MS), respectively), but can be adapted to the sharpening of hyperspectral (HS) data, both through companion PAN and MS images. We focus in this letter on the HS/MS fusion, showing that the assignation of the MS channel to each HS band is a key step, and investigate several alternatives to make this choice. The assignment algorithms are tested in conjunction with both component substitution and multiresolution analysis pansharpening methods and assessed on images acquired by the Hyperion and ALI sensors. The numerical evaluation shows that the best results can be obtained by optimizing the spectral angle mapper metric confirming that classical methods represent a reliable basis for the development of novel sharpening algorithms.
Auteurs: Daniele Picone;Rocco Restaino;Gemine Vivone;Paolo Addesso;Mauro Dalla Mura;Jocelyn Chanussot;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 739 - 743
Editeur: IEEE
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» Bathymetry Determination From Marine Radar Image Sequences Using the Hilbert Transform
Résumé:
This letter presents an image processing technique based on the theory of the Hilbert transform to determine the coastal bathymetry from marine radar image sequences. Use of the Hilbert transform enables the difficulties and complications of inhomogeneous image analysis to be avoided. In addition, a number of steps and complex computations can be avoided using the numerical algorithm of the Hilbert transform. Because the Hilbert transform is suitable for only monocomponent signals, we first applied the image procedure to decompose the irregular wave patterns into different single wave period images. Analysis of the simulated wave field and radar image sequences demonstrated that there was a high correlation between the estimated depths and reference depths. The causes for errors in the bathymetry estimations are also discussed.
Auteurs: Li-Chung Wu;Dong-Jiing Doong;Jong-Hao Wang;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 644 - 648
Editeur: IEEE
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» Bayesian Time-of-Flight for Realtime Shape, Illumination and Albedo
Résumé:
We propose a computational model for shape, illumination and albedo inference in a pulsed time-of-flight (TOF) camera. In contrast to TOF cameras based on phase modulation, our camera enables general exposure profiles. This results in added flexibility and requires novel computational approaches. To address this challenge we propose a generative probabilistic model that accurately relates latent imaging conditions to observed camera responses. While principled, realtime inference in the model turns out to be infeasible, and we propose to employ efficient non-parametric regression trees to approximate the model outputs. As a result we are able to provide, for each pixel, at video frame rate, estimates and uncertainty for depth, effective albedo, and ambient light intensity. These results we present are state-of-the-art in depth imaging. The flexibility of our approach allows us to easily enrich our generative model. We demonstrate this by extending the original single-path model to a two-path model, capable of describing some multipath effects. The new model is seamlessly integrated in the system at no additional computational cost. Our work also addresses the important question of optimal exposure design in pulsed TOF systems. Finally, for benchmark purposes and to obtain realistic empirical priors of multipath and insights into this phenomena, we propose a physically accurate simulation of multipath phenomena.
Auteurs: Amit Adam;Christoph Dann;Omer Yair;Shai Mazor;Sebastian Nowozin;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 05.-2017, volume: 39, issue:5, pages: 851 - 864
Editeur: IEEE
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» Beehive: Erasure Codes for Fixing Multiple Failures in Distributed Storage Systems
Résumé:
In distributed storage systems, erasure codes have been increasingly deployed to tolerate server failures without loss of data. Traditional erasure codes, such as Reed-Solomon codes, suffer from a high volume of network transfer and disk I/O to recover unavailable data at failed storage servers. Typically, unavailable data at different failed storage servers in a distributed storage system are fixed separately. It has been shown that it is possible to reduce the volume of network transfer significantly by reconstructing data from multiple storage servers at the same time. However, there has been no construction of erasure codes to achieve it without imposing strict constraints on system parameters. In this paper, we propose Beehive codes, designed for optimizing the volume of network transfers to fix the data on multiple failed storage servers. Beehive codes can be constructed over a wide range of system parameters at code rate no more than 0.5, while incurring slightly more storage overhead than Reed-Solomon codes. To achieve the optimal storage overhead as Reed-Solomon codes, we further extend vanilla Beehive codes to MDS Beehive codes, which incurs near-optimal volumes of network transfers during reconstruction. We implement both Beehive and MDS Beehive Codes in C++ and evaluate their performance on Amazon EC2. Our evaluation results have clearly shown that the volume of both network transfers and disk I/O can be conserved by a substantial margin.
Auteurs: Jun Li;Baochun Li;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 05.-2017, volume: 28, issue:5, pages: 1257 - 1270
Editeur: IEEE
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» Being a Supercook: Joint Food Attributes and Multimodal Content Modeling for Recipe Retrieval and Exploration
Résumé:
This paper considers the problem of recipe-oriented image-ingredient correlation learning with multi-attributes for recipe retrieval and exploration. Existing methods mainly focus on food visual information for recognition while we model visual information, textual content (e.g., ingredients), and attributes (e.g., cuisine and course) together to solve extended recipe-oriented problems, such as multimodal cuisine classification and attribute-enhanced food image retrieval. As a solution, we propose a multimodal multitask deep belief network ( $mathrm{M}^{3}$TDBN) to learn joint image-ingredient representation regularized by different attributes. By grouping ingredients into visible ingredients (which are visible in the food image, e.g., “chicken” and “mushroom”) and nonvisible ingredients (e.g., “salt” and “oil”), $mathrm{M}^{3}$ TDBN is capable of learning both midlevel visual representation between images and visible ingredients and nonvisual representation. Furthermore, in order to utilize different attributes to improve the intermodality correlation, $mathrm{M}^{3}$TDBN incorporates multitask learning to make different attributes collaborate each other. Based on the proposed $mathrm{M}^{3}$TDBN, we exploit the derived deep features and the discovered correlations for three extended novel applications: 1) multimodal cuisine classification; 2) attribute-augmented cross-modal recipe image retrieval; and 3) ingredient and attribute inference from food images. The proposed approach is evaluated on the construct- d Yummly dataset and the evaluation results have validated the effectiveness of the proposed approach.
Auteurs: Weiqing Min;Shuqiang Jiang;Jitao Sang;Huayang Wang;Xinda Liu;Luis Herranz;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 05.-2017, volume: 19, issue:5, pages: 1100 - 1113
Editeur: IEEE
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» Benefit Points: The Best Part of the Story
Résumé:
Delivering valuable software to your customer is the first priority in agile management and development. The product owner is involved along the way, and backlogs are prioritized, with the best of intentions to maximize business value early and eliminate waste. Yet in many IT development projects, bewilderment remains as to how to express business value in process decisions and the delivered system. Also, projects continue to implement functionality that's off the mark or never used. This situation occurs because there isn't sufficient methodological support to determine and monitor business value or to link business value decisions to the development project's mechanics. However, researchers have developed a bundle of easy-to-use core practices that help systematize a project's evolving knowledge. Although these practices are simple, they provide powerful support for monitoring project progress on both the realized business value and the realized costs.
Auteurs: Jo Erskine Hannay;Hans Christian Benestad;Kjetil Strand;
Apparue dans: IEEE Software
Date publication: 05.-2017, volume: 34, issue:3, pages: 73 - 85
Editeur: IEEE
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» Bespoke Lenses Based on Quasi-Conformal Transformation Optics Technique
Résumé:
In this paper, a systematic method to design a quasi-optimum lens profile based on quasi-conformal transformation optics technique for a given excitation is presented. This method is applied to a number of conventional antennas, such as an aperture and a log-spiral slot. In all these configurations, an increase of the directivity is observed. Furthermore, using this method, a quasi-optimum graded index lens for a broadband enhanced leaky slot excitation is designed and the results are compared with a hyperhemispherical lens with and without matching layers. Our proposed methodology demonstrates to be able to increase the directivity, to reduce the sidelobes and the cross polarization in a broad bandwidth from 20 to 70 GHz. Due to the continuously changed dielectric constant of the lens profile, reflections are also reduced considerably inside the lens.
Auteurs: Mahsa Ebrahimpouri;Oscar Quevedo-Teruel;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2256 - 2264
Editeur: IEEE
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» Better Now Than Later: Managing Technical Debt in Systems Development
Résumé:
Technical debt is incurred when development project tasks are deferred either unintentionally or deliberately. Detecting and mitigating this debt, including controlling it through risk management techniques, can help avoid or address common project pitfalls, such as late delivery, team burnout, and cost overruns.
Auteurs: Richard E. Fairley;Mary Jane Willshire;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 80 - 87
Editeur: IEEE
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» Blind Estimation of the HPA Operating Point in Multicarrier Satellite Transponders
Résumé:
Satellite operators need to know the operating point of a transponder to provide a good transmission quality. Especially in satellite networks with many small carriers in one transponder, the estimation is challenging because of gain compression, capture effects or unknown attenuation in the transmission channel. We propose a blind estimator based on signal statistics to overcome these problems. The new estimator is independent of a-priori information about the carrier modulation and the absolute power of the received signal. The method is applicable to existing satellites because we only use a simulation model of the transponder together with the sampled receive signal for the estimation process.
Auteurs: Matthias G. Schraml;Andreas Knopp;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1051 - 1054
Editeur: IEEE
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» Blind Interference Alignment for Multiuser MISO Indoor Visible Light Communications
Résumé:
A filter-pair-based blind interference alignment scheme is proposed to improve the achievable degree of freedom (DoF) in multiuser multiple-input single-output indoor visible light communications. In the proposed scheme, the transmitter does not need to know channel state information. Different transmit sub-channels employ different pulse-shaping filters, and each user is equipped with multiple receive filters. The transmitter sends signals according to the predesigned strategy, and each user sets the receive mode by choosing the corresponding receive filter. Optical orthogonal frequency division multiplexing is employed in the proposed scheme to combat the intersymbol interference in high-speed transmissions, and the maximum achievable spectrum efficiency (SE) of the proposed scheme is analyzed. Simulation results validate that the proposed scheme can achieve higher SE and more DoF than the orthogonal multiple access schemes.
Auteurs: Liang Wu;Zaichen Zhang;Jian Dang;Huaping Liu;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1039 - 1042
Editeur: IEEE
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» Blind Sharpness Prediction for Ultrahigh-Definition Video Based on Human Visual Resolution
Résumé:
We explore a no-reference sharpness assessment model for predicting the perceptual sharpness of ultrahigh-definition (UHD) videos through analysis of visual resolution variation in terms of viewing geometry and scene characteristics. The quality and sharpness of UHD videos are influenced by viewer perception of the spatial resolution afforded by the UHD display, which depends on viewing geometry parameters including display resolution, display size, and viewing distance. In addition, viewers may perceive different degrees of quality and sharpness according to the statistical behavior of the visual signals, such as the motion, texture, and edge, which vary over both spatial and temporal domains. The model also accounts for the resolution variation associated with fixation and foveal regions, which is another important factor affecting the sharpness prediction of UHD video over the spatial domain and which is caused by the nonuniform distribution of the photoreceptors. We calculate the transition of the visually salient statistical characteristics resulting from changing the display’s screen size and resolution. Moreover, we calculated the temporal variation in sharpness over consecutive frames in order to evaluate the temporal sharpness perception of UHD video. We verify that the proposed model outperforms other sharpness models in both spatial and temporal sharpness assessments.
Auteurs: Haksub Kim;Jongyoo Kim;Taegeun Oh;Sanghoon Lee;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 951 - 964
Editeur: IEEE
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» Block-Matching Distortion Correction of Echo-Planar Images With Opposite Phase Encoding Directions
Résumé:
By shortening the acquisition time of MRI, Echo Planar Imaging (EPI) enables the acquisition of a large number of images in a short time, compatible with clinical constraints as required for diffusion or functional MRI. However such images are subject to large, local distortions disrupting their correspondence with the underlying anatomy. The correction of those distortions is an open problem, especially in regions where large deformations occur. We propose a new block-matching registration method to perform EPI distortion correction based on the acquisition of two EPI with opposite phase encoding directions (PED). It relies on new transformations between blocks adapted to the EPI distortion model, and on an adapted optimization scheme to ensure an opposite symmetric transformation. We present qualitative and quantitative results of the block-matching correction using different metrics on a phantom dataset and on in-vivo data. We show the ability of the block-matching to robustly correct EPI distortion even in strongly affected areas.
Auteurs: Renaud Hédouin;Olivier Commowick;Elise Bannier;Benoit Scherrer;Maxime Taquet;Simon K. Warfield;Christian Barillot;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 05.-2017, volume: 36, issue:5, pages: 1106 - 1115
Editeur: IEEE
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» BlockPy: An Open Access Data-Science Environment for Introductory Programmers
Résumé:
Non-computer science majors often struggle to find relevance in traditional computing curricula that tend to emphasize abstract concepts, focus on nonpractical entertainment, or rely on decontextualized settings. BlockPy, a web-based, open access Python programming environment, supports introductory programmers in a data-science context through a dual block/text programming view. The web extra at https://youtu.be/RzaOPqOpMoM illustrates BlockPy features discussed in the article.
Auteurs: Austin Cory Bart;Javier Tibau;Eli Tilevich;Clifford A. Shaffer;Dennis Kafura;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 18 - 26
Editeur: IEEE
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» Book Reviews [7 Books Reviewed]
Résumé:
Books reviewed are: Photovoltaic Laboratory-Safety, Code-Compliance,and Commercial Off-the-Shelf Equipment, by P. T. Parrish, CRC Press Taylor & Francis Group; Dielectrics in Electric Fields,2nd Edition by, G. G. Raju CRC Press Taylor & Francis Group; Advanced Piezoelectric Materials-Science and Technology by K. Uchino, editor Woodhead Publishing; Introduction to Modern Power Electronics, 3rd Edition, by A. M. Trzynadlowski John Wiley & Sons Inc.; Engineering Electrodynamics, by J. Turowski and M. Turowski CRC Press Taylor & Francis Group; Discharge in Long Air Gaps-Modeling and Applications, by A. Beroual and I. Fofana IOP Publishing; Impedance Source Power Electronic Converters by Y. Liu, H. Abu-Rub, F. Blaabjerg, O.Ellabban, and P. C. Loh, John Wiley & Sons Inc.
Auteurs: John J. Shea;
Apparue dans: IEEE Electrical Insulation Magazine
Date publication: 05.-2017, volume: 33, issue:3, pages: 42 - 47
Editeur: IEEE
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» Breezing My Way as a Solution Architect: A Retrospective on Skill Development and Use
Résumé:
Solution architecture is a team effort balancing various forces. Solution architects must consciously cultivate skills cutting across technical, social, and behavioral domains. In this article, Raghuraman Krishnamurthy discusses eight such skills that will likely be helpful.
Auteurs: Raghuraman Krishnamurthy;
Apparue dans: IEEE Software
Date publication: 05.-2017, volume: 34, issue:3, pages: 9 - 13
Editeur: IEEE
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» Brevity, Clarity, Engagement: The IMS2017 Three Minute Thesis Competition
Résumé:
Presents information on the IMS 2017 Conference.
Auteurs: John W. Bandler;Erin M. Kiley;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 85 - 87
Editeur: IEEE
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» Broadband Analog Network Coding With Robust Processing for Two-Way Relay Networks
Résumé:
In this letter, we study the robust processing for a single carrier two-way relay network with broadband analog network coding and imperfect channel state information. Based on a statistical model for channel estimation error, we derive the optimal coefficients of self interference cancellation and linear frequency domain equalization in the sense of minimizing the conditional mean square error given a channel estimate. Simulation results show that the proposed robust design can achieve better bit error rate performance than the conventional non-robust scheme.
Auteurs: Jiejun Qin;Yu Zhu;Pengfei Zhe;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1115 - 1118
Editeur: IEEE
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» Broadband and Wavelength-Dependent Chalcogenide Optical Fiber Couplers
Résumé:
We present optical fiber couplers made of As2Se3 glass. Broadband and wavelength-dependent couplers are fabricated from fibers of engineered core/cladding diameter ratios. Coupling ratios at the through-cross ports ranging from 50%–50% down to 1%–99% are achieved. The transparency of As2Se3 glass over the spectral range of 1.5–12.0 $mu text{m}$ makes it a material of prime interest for the fabrication of mid-infrared couplers.
Auteurs: Farzan Tavakoli;Alexandre Rekik;Martin Rochette;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 735 - 738
Editeur: IEEE
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» Broadband CMOS Schottky-Diode Star Mixer Using Coupled-CPW Marchand Dual-Baluns
Résumé:
A broadband CMOS Marchand dual-balun using stacked broadside couplers for low odd-mode impedance with surrounded ground planes for high even-mode impedance is employed to achieve a high coupling coefficient needed for a Marchand dual-balun. The demonstrated Marchand dual-balun using 0.18- $mu text{m}$ CMOS technology is designed at 30-GHz center frequency with an insertion loss of 11.5- and 10-dB input return loss bandwidth of over 120%. The bandwidth of 1-dB amplitude imbalance and 10° phase difference are over 100%. A broadband CMOS Schottky-diode star mixer is implemented with two Marchand dual-baluns at RF and local oscillator (LO) ports. As a result, the Schottky-diode star mixer shows conversion loss of 14 dB, LO-to-RF isolation of 26 dB, LO-to-IF isolation of 45 dB, and RF-to-IF isolation of 42 dB within 27-GHz operating bandwidth, respectively.
Auteurs: Yu-Chih Hsiao;Chinchun Meng;Yong-Hao Peng;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 05.-2017, volume: 27, issue:5, pages: 500 - 502
Editeur: IEEE
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» Broadband Dual-Port Intermodulation Generator for Passive Intermodulation Measurements
Résumé:
A dual-port tunable intermodulation (IM) generator is reported. This IM generator employs a coupling network to distribute carrier waves and IM. The proposed coupling network is constructed by cascading four parallel-coupled directional couplers, while a Schottky diode is working as a tunable IM source. By adjusting the IM performance of diode using bias voltage and distributing IM along symmetrical IM paths, a pair of tunable IM signals is introduced into passive IM (PIM) test loop simultaneously, they can serve as bidirectional IM reference in dual-port PIM measurements. The provided IM3 can be tuned to be lower than −112 dBm at $2 times 43$ dBm at either 710 or 2550 MHz, while their dynamic IM3 range can reach about 20 dB at $2 times 43$ dBm. The work promotes the application of IM predistortion techniques and provides a solution to realize dual-port dynamic IM calibration in PIM test.
Auteurs: Xiong Chen;Yongning He;Wanzhao Cui;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 05.-2017, volume: 27, issue:5, pages: 518 - 520
Editeur: IEEE
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» Broadband Microwave Signal Processing Based on Photonic Dispersive Delay Lines
Résumé:
The development of communications technologies has led to an ever-increasing demand for a higher speed and wider bandwidth of microwave signal processors. To overcome the inherent electronic speed limitations, photonic techniques have been developed for processing of ultrabroadband microwave signals. A dispersive delay line (DDL) is a key photonic device that can be used to implement signal processing functions, such as time reversal, time delay, dispersion compensation, Fourier transformation, and pulse compression. Compared with an electrical delay line, a photonic DDL has a much wider bandwidth and can be used for processing a microwave signal with a much wider bandwidth. In this paper, we review our recent work using photonic DDLs for processing of broadband microwave signals. Two types of DDLs are to be discussed, a linearly chirped fiber Bragg grating-based DDL and an optical dispersive loop-based DDL. Signal processing functions including microwave time reversal, microwave temporal convolution, time-stretched sampling, microwave waveform generation with an extended temporal duration, and wideband true-time delay beamforming are discussed.
Auteurs: Jiejun Zhang;Jianping Yao;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1891 - 1903
Editeur: IEEE
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» Broadcast Erasure Channel With Feedback and Message Side Information, and Related Index Coding Result
Résumé:
We consider the $N$ -receiver broadcast erasure channel with feedback and message side information at the receivers prior to beginning of transmission. Specifically, the transmitter must deliver different, independent messages to each of the receivers, and each receiver knows a function of these messages before transmission begins. This situation can arise in multi-hop wireless networks, where a receiver may overhear transmissions consisting of possibly encoded combinations of messages (e.g., encoded using a network coding technique) prior to beginning of transmission over a given broadcast channel. We provide an outer bound to the capacity region of this system. For the case, where each message consists of a number of symbols taking values in a finite field and each receiver knows linear combinations of these symbols, the outer bound is given in terms of ranks of matrices expressing the linear combinations. For the latter case and when $N=2$ , the outer bound is tight under mild conditions on the limiting behavior of the ranks of matrices expressing the side information. We provide a capacity achieving code for this case. The special case, where each receiver either knows the entire message of another receiver or has no information about it, constitutes a generalization of the index coding problem that incorporates channel erasures. For this instance, and when there are no channel errors, we show that the outer bound reduces to the known maximum weighted acyclic induced subgraph bound.
Auteurs: Athanasios Papadopoulos;Leonidas Georgiadis;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 3161 - 3180
Editeur: IEEE
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» Buckle Up: The Smart Grid Rollout Begins [In My View]
Résumé:
A valuable set of matured smart grid concepts has emerged from the significant trial-and-demonstration programs around the world. An investment in rollout programs is now required to deliver the full value of these initial investments to electricity customers. Managing the risks and making an effective transition to the smarter grid are significant challenges but a growing body of experience, strong principles, and effective solutions to the issues are helping to make smart grids business as usual. Innovative grid solutions trials create real operating environments for assessing the technical and commercial performance of solutions to industry problems. They also enhance basic technological understanding, leading to improved design and production quality of rollout-ready solutions.
Auteurs: Graham Ault;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 05.-2017, volume: 15, issue:3, pages: 104 - 100
Editeur: IEEE
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» Build your own Amazon Echo - Turn a PI into a voice controlled gadget [Resources_Hands on]
Résumé:
As a young man, I yearned for a machine like the ship's computer on Star Trek: a gadget that can listen and obey a human voice, and answer in kind. Fifteen years ago, after reading about university researchers who had gotten voice-controlled artificial intelligence systems working, I taught myself Linux and set up a server in my attic in the hope that the technology had arrived to let me build such a thing myself. It had not.
Auteurs: W. Wayt Gibbs;
Apparue dans: IEEE Spectrum
Date publication: 05.-2017, volume: 54, issue:5, pages: 20 - 21
Editeur: IEEE
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» Burst-Erasure Correcting Codes With Optimal Average Delay
Résumé:
The objective of low-delay codes is to protect communication streams from erasure bursts by minimizing the time between the packet erasure and its reconstruction. Previous work has concentrated on the constant-delay scenario, where all erased packets need to exhibit the same decoding delay. We consider the case of heterogeneous delay, where the objective is to minimize the average delay across the erased packets in a burst. We derive delay lower bounds for the average case, and show that they match the constant-delay bounds only at a single rate point $R=0.5$ . We then construct codes with optimal average delays for the entire range of code rates. The construction for rates $Rleq 0.5$ achieves optimality for every erasure instance, while the construction for rates $R>0.5$ is optimal for a $(1-R)/R$ fraction of all burst instances and close to optimal for the remaining fraction. The paper also studies the benefits of delay heterogeneity within the application of sensor communications. It is shown that a carefully designed code can significantly improve the temporal precision at the receiving node following erasure-burst events.
Auteurs: Nitzan Adler;Yuval Cassuto;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 2848 - 2865
Editeur: IEEE
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» C-Vine Copula Mixture Model for Clustering of Residential Electrical Load Pattern Data
Résumé:
The ongoing deployment of residential smart meters in numerous jurisdictions has led to an influx of electricity consumption data. This information presents a valuable opportunity to suppliers for better understanding their customer base and designing more effective tariff structures. In the past, various clustering methods have been proposed for meaningful customer partitioning. This paper presents a novel finite mixture modeling framework based on C-vine copulas (CVMM) for carrying out consumer categorization. The superiority of the proposed framework lies in the great flexibility of pair copulas toward identifying multidimensional dependency structures present in load profiling data. CVMM is compared to other classical methods by using real demand measurements recorded across 2613 households in a London smart-metering trial. The superior performance of the proposed approach is demonstrated by analyzing four validity indicators. In addition, a decision tree classification module for partitioning new consumers is developed and the improved predictive performance of CVMM compared to existing methods is highlighted. Further case studies are carried out based on different loading conditions and different sets of large numbers of households to demonstrate the advantages and to test the scalability of the proposed method.
Auteurs: Mingyang Sun;Ioannis Konstantelos;Goran Strbac;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2382 - 2393
Editeur: IEEE
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» Calibration of Nonlinear Crosstalk in MIMO Transmitter
Résumé:
Multiple-input multiple-output (MIMO) techniques have been extensively used in modern wireless communications. The front-end nonlinearity coupled with crosstalk in a MIMO transmitter is much more complex than that in a single-input single-output (SISO) system. In this paper, we propose a nonlinear crosstalk calibration algorithm with the corresponding reference signal design. We start with the nonlinear crosstalk model of the MIMO transmitter and derive its corresponding inverse compensation model. The proposed model characterizes the nonlinearity and the crosstalk in separated blocks. We then propose specifically designed reference signals that utilize the model structure. The nonlinear crosstalk model can be reorganized and simplified with the reference signal. Thus, the complexity of the model coefficients estimation is greatly reduced without compromising the model accuracy. In addition, with the proposed algorithm, the compensation of the nonlinearity and crosstalk can be done separately. Simulations show a satisfactory calibration results with low computational complexity.
Auteurs: Hua Qian;Xin Cheng;Xiliang Luo;Weifeng Feng;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3739 - 3748
Editeur: IEEE
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» Camera Self-Calibration Based on Nonlinear Optimization and Applications in Surveillance Systems
Résumé:
This paper presents a new approach for self-calibration of static cameras in the context of surveillance applications. Initially, a pedestrian detector is applied and the responses are validated using background removal. Then, foreground-related pixels within the detection results are used to estimate the feet-head line segments of each person (called poles), which are used to find a linear estimate for the camera matrix. Finally, a nonlinear cost function is used to refine the initial estimate, aiming to mostly improve the orientation of the reprojected poles. We also present different applications of self-calibration in tasks related to video surveillance itself, such as improvements to pedestrian detection and tracking algorithms, and augmented reality applications, such as the insertion of virtual cameras to aid the placement of real cameras in the scene.
Auteurs: Gustavo Führ;Cláudio Rosito Jung;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 1132 - 1142
Editeur: IEEE
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» Can Affective Computing Save Lives? Meet Mobile Health
Résumé:
This installment of Computer's series highlighting the work published in IEEE Computer Society journals comes from IEEE Transactions on Affective Computing.
Auteurs: Björn Schuller;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 13 - 13
Editeur: IEEE
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» Capabilities of CdTe-Based Detectors With ${mathrm {MoO}}_{x}$ Contacts for Detection of X- and $gamma$ -Radiation
Résumé:
The charge transport mechanism and spectrometric properties of the X-ray and $gamma $ -ray detectors, fabricated by the deposition of molybdenum oxide thin films onto semi-insulating p-CdTe crystals were studied. The current transport processes in the ${mathrm {Mo}}{-}{mathrm {MoO}}_{x}/{mathrm {p}}{-}{mathrm {CdTe/MoO}}_{x}{-}{mathrm {Mo}}$ structure are well described in the scope of the carrier’s generation in the space-charge region and the space-charge-limited current models. The lifetime of charge carriers, the energy of hole traps, and the density of discrete trapping centers were determined from the comparison of the experimental data and calculations. Spectrometric properties of ${mathrm {Mo}}{-}{mathrm {MoO}}_{x}/{mathrm {p}}{-}{mathrm {CdTe/MoO}}_{x}{-}{mathrm {Mo}}$ structures were also investigated. It is shown that the investigated heterojunctions have demonstrated promising characteristics for practical application in X-ray and $gamma $ -ray detector fabrication.
Auteurs: O. L. Maslyanchuk;M. M. Solovan;V. V. Brus;V. V. Kulchynsky;P. D. Maryanchuk;I. M. Fodchuk;V. A. Gnatyuk;T. Aoki;C. Potiriadis;Y. Kaissas;
Apparue dans: IEEE Transactions on Nuclear Science
Date publication: 05.-2017, volume: 64, issue:5, pages: 1168 - 1172
Editeur: IEEE
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» Capacity Analysis of FBMC-OQAM Systems
Résumé:
This letter presents a capacity analysis of filter bank multicarrier offset quadrature amplitude modulation (FBMC-OQAM) systems. In FBMC-OQAM receivers, it is common to preserve the real part of the demodulated signal samples for information recovery. The imaginary part of these samples, which are called intrinsic interference, is simply ignored. This letter provides a theoretical answer to the following fundamental question. Does the ignored imaginary interference in FBMC-OQAM contain any information beyond what could be obtained from the preserved real parts?
Auteurs: Ahmad RezazadehReyhani;Behrouz Farhang-Boroujeny;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 999 - 1002
Editeur: IEEE
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» Capacity Bounds for the Gaussian IM-DD Optical Multiple-Access Channel
Résumé:
Optical wireless communications (OWC) is a promising technology for closing the mismatch between the growing number of connected devices and the limited wireless network capabilities. Similar to downlink, uplink can also benefit from OWC for establishing connectivity between such devices and an optical access point. In this context, the incoherent intensity-modulation and direct-detection (IM-DD) scheme is desirable in practice. Hence, it is important to understand the fundamental limits of communication rates over an OWC uplink employing IM-DD, i.e., the channel capacity. This uplink, modeled as a Gaussian multiple-access channel (MAC) for indoors OWC, is studied in this paper, under the IM-DD constraints, which form the main difference with the standard Gaussian MAC commonly studied in the radio-frequency context. Capacity region outer and inner bounds for this channel are derived. The bounds are fairly close at high signal-to-noise ratio (SNR), where a truncated-Gaussian input distribution achieves the capacity region within a constant gap. Furthermore, the bounds coincide at low SNR showing the optimality of ON–OFF keying combined with successive cancellation decoding in this regime. At moderate SNR, an optimized uniformly spaced discrete input distribution achieves fairly good performance.
Auteurs: Anas Chaaban;Omer Mahmoud S. Al-Ebraheemy;Tareq Y. Al-Naffouri;Mohamed-Slim Alouini;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3328 - 3340
Editeur: IEEE
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» Carbon Nanotube Interconnects for Nanoelectronic Integrated Systems
Résumé:
A perspective study about the effect of carbon nanotube compared with copper interconnects in the H-tree distributed clock network - used for routing clock signals inside a chip - in nanoelectronic systems will be developed based on simulation models. Important features for circuit design, such as low logic level, high logic level, rise time, slew rate, attenuation, delay time, dissipated power and delay-power product will be evaluated by computer simulations. Results will show that distributed networks based on carbon nanotube interconnects are able to operate at terahertz frequencies.
Auteurs: Camila Peixoto da Silva Madeira Nogueira;Janaina Goncalves Guimaraes;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 813 - 818
Editeur: IEEE
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» Cardiac Image Reconstruction via Nonlinear Motion Correction Based on Partial Angle Reconstructed Images
Résumé:
Even though the X-ray Computed Tomography (CT) scan is considered suitable for fast imaging, motion-artifact-free cardiac imaging is still an important issue, because the gantry rotation speed is not fast enough compared with the heart motion. To obtain a heart image with less motion artifacts, a motion estimation (ME) and motion compensation (MC) approach is usually adopted. In this paper, we propose an ME/MC algorithm that can estimate a nonlinear heart motion model from a sinogram with a rotation angle of less than 360°. In this algorithm, we first assume the heart motion to be nonrigid but linear, and thereby estimate an initial 4-D motion vector field (MVF) during a half rotation by using conjugate partial angle reconstructed images, as in our previous ME/MC algorithm. We then refine the MVF to determine a more accurate nonlinear MVF by maximizing the information potential of a motion-compensated image. Finally, MC is performed by incorporating the determined MVF into the image reconstruction process, and a time-resolved heart image is obtained. By using a numerical phantom, a physical cardiac phantom, and an animal data set, we demonstrate that the proposed algorithm can noticeably improve the image quality by reducing motion artifacts throughout the image.
Auteurs: Seungeon Kim;Yongjin Chang;Jong Beom Ra;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 05.-2017, volume: 36, issue:5, pages: 1151 - 1161
Editeur: IEEE
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» Catch the Wave! [From the Guest Editors' Desk]
Résumé:
Auteurs: Aditya Singh;Isar Mostafanezhad;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 12 - 14
Editeur: IEEE
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» Causal Boxes: Quantum Information-Processing Systems Closed Under Composition
Résumé:
Complex information-processing systems, for example, quantum circuits, cryptographic protocols, or multi-player games, are naturally described as networks composed of more basic information-processing systems. A modular analysis of such systems requires a mathematical model of systems that is closed under composition, i.e., a network of these objects is again an object of the same type. We propose such a model and call the corresponding systems causal boxes. Causal boxes capture superpositions of causal structures, e.g., messages sent by a causal box $A$ can be in a superposition of different orders or in a superposition of being sent to box $B$ and box $C$ . Furthermore, causal boxes can model systems whose behavior depends on time. By instantiating the abstract cryptography framework with causal boxes, we obtain the first composable security framework that can handle arbitrary quantum protocols and relativistic protocols.
Auteurs: Christopher Portmann;Christian Matt;Ueli Maurer;Renato Renner;Björn Tackmann;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 3277 - 3305
Editeur: IEEE
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» Cellular Offloading in Heterogeneous Mobile Networks With D2D Communication Assistance
Résumé:
The next-generation mobile communication system [fifth-generation (5G)] needs to address the challenges stemming from the performance requirements in diverse technical scenarios, such as seamless wide-area coverage, high-capacity hot-spots, and low-power massive connections. It is widely recognized that traditional single-tier cellular network architecture is not adequate to meet these requirements, and thus, the heterogeneous cellular network (HetNet) has been identified as a promising network architecture for 5G. In HetNets, traffic offloading can be exploited to effectively improve network capacity by utilizing complementary network communication techniques. In this paper, we propose a device-to-device (D2D) communication assisted mobile traffic offloading (DATO) scheme, with focus on massive connections for machine type communications (MTC). DATO determines access mode for user equipments (UEs) to offload UEs from macro base stations (MBSs) to small base stations via D2D communications to improve the overall network capacity and mitigate the traffic congestion at MBSs. We formulate the DATO problem as a 0–1 linear programing and prove it to be NP-hard. We resort to dynamic programing to provide the optimal solution, as well as the theoretical performance upper bound of DATO. We develop an efficient algorithm to solve the DATO problem while preserving the optimality by making use of the location relationship of BSs and UEs. We apply our proposed DATO scheme to a series of typical network scenarios to validate its effectiveness. Numerical results reveal that DATO significantly outperforms traditional UE access mode in terms of network capacity and UE energy consumption, which are important to massive MTC.
Auteurs: Wei Cao;Gang Feng;Shuang Qin;Mu Yan;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4245 - 4255
Editeur: IEEE
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» Centralized Collaborative Sparse Unmixing for Hyperspectral Images
Résumé:
Spectral unmixing is very important in hyperspectral image analysis and processing, which aims at identifying the constituent spectra (i.e., endmembers) and estimating their fractional abundances from the mixed pixels. In recent years, sparse unmixing has received considerable interest. However, the acquired hyperspectral images are generally degraded by the noise, making sparse unmixing not faithful enough. To address this issue, this paper proposes a novel framework to couple sparse hyperspectral unmixing and abundance estimation error reduction together. Specifically, with the definition of abundance estimation error, a centralized constraint is incorporated into the collaborative sparse unmixing framework by exploiting the nonlocal redundancy of abundance map. This way we suppress the abundance estimation error, and improve the unmixing accuracy. Meanwhile, the alternating direction method of multipliers is introduced to solve the underlying constrained model. Experimental results on both synthetic and real hyperspectral data demonstrate the effectiveness of our proposed algorithm.
Auteurs: Rui Wang;Heng-Chao Li;Wenzhi Liao;Xin Huang;Wilfried Philips;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 1949 - 1962
Editeur: IEEE
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» Change Detection Based on Gabor Wavelet Features for Very High Resolution Remote Sensing Images
Résumé:
In this letter, we propose a change detection method based on Gabor wavelet features for very high resolution (VHR) remote sensing images. First, Gabor wavelet features are extracted from two temporal VHR images to obtain spatial and contextual information. Then, the Gabor-wavelet-based difference measure (GWDM) is designed to generate the difference image. In GWDM, a new local similarity measure is defined, in which the Markov random field neighborhood system is incorporated to obtain a local relationship, and the coefficient of variation method is applied to discriminate contributions from different features. Finally, the fuzzy c-means cluster algorithm is employed to obtain the final change map. Experiments employing QuickBird and SPOT5 images demonstrate the effectiveness of the proposed approach.
Auteurs: Zhenxuan Li;Wenzhong Shi;Hua Zhang;Ming Hao;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 783 - 787
Editeur: IEEE
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» Changes to the Editorial Board
Résumé:
It is my pleasure to welcome Dr. Brian S. Doyle to the Editorial Board of the IEEE Electron Device Letters. A biography and sketch of Dr. Doyle’s research interests can be found below. His subject areas are Emerging Technologies and Devices and Embedded Memory Devices and Technology.
Auteurs: Tsu-Jae King Liu;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 539 - 539
Editeur: IEEE
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» Changing Lives in EPICS Fashion
Résumé:
Founded at Purdue University in 1995, Engineering Projects in Community Service (EPICS) in IEEE empowers teams of university and high school students to collaborate on socially innovative projects that will have a lasting impact on local humanitarian organizations and community members. Not only does this program give students a unique platform to experience a career in the engineering field, which many of them are already pursuing, but it also enables them to develop and broaden their technical skills to address critical community issues while transforming lives.
Auteurs: Lindsey Moses;
Apparue dans: IEEE Potentials
Date publication: 05.-2017, volume: 36, issue:3, pages: 6 - 17
Editeur: IEEE
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» Channel Correlation Modeling and its Application to Massive MIMO Channel Feedback Reduction
Résumé:
In this paper, we propose a feedback information reduction technique for massive multiple-input multiple-output (MIMO) systems. To this end, we analytically derive a covariance matrix of spatially correlated Rayleigh fading channels in closed form. The covariance matrix is expressed based on its statistics, including transmit and receive antennas’ correlation factors, channel variance, and channel delay profile. The closed-form expression enables a principal component analysis (PCA)-based compression of channel state information (CSI), which allows the feedback overhead to be efficiently reduced. We also analyze the compression feedback error, bit-error-rate (BER) performance, and the spectral efficiency (SE) of the system using the PCA-based compression. Under our proposed model, numerical results verify that the PCA-based compression method significantly reduces the feedback overhead of the massive MIMO systems with marginal performance degradation from full-CSI feedback. Furthermore, we propose a new design framework by numerically showing that there exists the optimal number of transmit antennas in terms of SE for a given limited feedback amount.
Auteurs: Jingon Joung;Ernest Kurniawan;Sumei Sun;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3787 - 3797
Editeur: IEEE
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» Channel Selection Algorithm for Cognitive Radio Networks with Heavy-Tailed Idle Times
Résumé:
We consider a multichannel Cognitive Radio Network (CRN), where secondary users sequentially sense channels for opportunistic spectrum access. In this scenario, the Channel Selection Algorithm (CSA) allows secondary users to find a vacant channel with the minimal number of channel switches. Most of the existing CSA literature assumes exponential ON-OFF time distribution for primary user's (PU) channel occupancy pattern. This exponential assumption might be helpful to get performance bounds; but not useful to evaluate the performance of CSA under realistic conditions. An in-depth analysis of independent spectrum measurement traces reveals that wireless channels have typically heavy-tailed PU OFF times. In this paper, we propose an extension to the Predictive CSA framework and its generalization for heavy tailed PU OFF time distribution, which represents realistic scenarios. In particular, we calculate the probability of channel being idle for hyper-exponential OFF times to use in CSA. We implement our proposed CSA framework in a wireless test-bed and comprehensively evaluate its performance by recreating the realistic PU channel occupancy patterns. The proposed CSA shows significant reduction in channel switches and energy consumption as compared to Predictive CSA which always assumes exponential PU ON-OFF times. Through our work, we show the impact of the PU channel occupancy pattern on the performance of CSA in multichannel CRN.
Auteurs: Senthilmurugan Sengottuvelan;Junaid Ansari;Petri Mähönen;T.G. Venkatesh;Marina Petrova;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 05.-2017, volume: 16, issue:5, pages: 1258 - 1271
Editeur: IEEE
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» Channel-Aware Polling-Based MAC Protocol for Body Area Networks: Design and Analysis
Résumé:
Body area networks (BANs) enable wearable/implanted devices to exchange information or collect monitored data. The channel quality of a link in a BAN is typically highly dynamic, since sensors equipped on a human body usually move with gesture, posture, or mobility. Therefore, existing sleep-wake-up scheduling mechanisms used in traditional static sensor networks could be very inefficient in a BAN, because they do not consider channel fluctuation of body sensors. Sensors might be waked up to transmit during bad channel conditions, leading to transmission failures and energy waste. To remedy this inefficiency, this paper proposes a Channel-aware Polling-based MAC protocol CPMAC. Our design only wakes sensors up and triggers them to transmit when the channel is strong enough to ensure fast and reliable transmissions. We further analyze the energy consumption and derive a queueing model to estimate the probability of completing all data transmissions of all sensors in our CPMAC. Benefiting from these analyses, we are able to optimize energy efficiency of our CPMAC by adapting the number of polling periods in a superframe to dynamic traffic demands and channel fluctuation. Our simulation results show that, as compared with TDMA-based scheduling and the IEEE 802.15.6 CSMA/CA protocol, CPMAC significantly improves energy efficiency and, meanwhile, keeps the latency short.
Auteurs: Chi-Han Lin;Kate Ching-Ju Lin;Wen-Tsuen Chen;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2936 - 2948
Editeur: IEEE
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» Characteristic Mode Analysis of Plasmonic Nanoantennas
Résumé:
The theory of characteristic modes (TCMs) based on the surface integral equation (SIE) formalism is presented for the analysis of plasmonic nanostructures. With TCM, excitation-independent characteristic solutions of the underlying electromagnetic field problem are obtained. Both single and multiple particle nanostructures are analyzed using the conventional SIE approach and the TCM formalism. By comparing these results, the modes that are responsible of the observed scattering and absorption characteristics can be identified. These solutions can be further utilized in the design and tuning nanoantenna configurations for specific application purposes.
Auteurs: Pasi Ylä-Oijala;Dimitrios C. Tzarouchis;Elias Raninen;Ari Sihvola;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2165 - 2172
Editeur: IEEE
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» Characteristics of Needle-Disk Electrodes Atmospheric Pressure Discharges Applied to Modify PET Wettability
Résumé:
In the atmospheric pressure discharge with arran- gement of a syringe needle, a capillary, and an external disk, it was observed different operation modes according to the relative position of the electrodes. With external electrode over the shaft of the needle, a stable and steady plume is formed from the tip of the needle to the exterior of the capillary. The breakdown is governed by filamentary discharges that evolve randomly on time in the gap between the needle and the capillary. This mechanism changes to bullet-like discharge when the external disk is located off needle. The breakdown generates a large amount of charge that rises quickly and varies with the distance between the electrodes. The mean power is higher than that of the previous case and the plume generated, in interaction with external metallic surface, is more unstable to arc transition. Independently of the operation mode, high electric field at the bevel of the needle plays an important role on the evolution of the plume. The application of the plume to change the wettability properties of the polyethylene terephthalate indicated rapid augment of the hydrophilicy and treated area larger than the plume dimension.
Auteurs: Milton Eiji Kayama;Lucas José da Silva;Vadym Prysiazhnyi;Konstantin G. Kostov;Mauricio Antonio Algatti;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 05.-2017, volume: 45, issue:5, pages: 843 - 848
Editeur: IEEE
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» Characterization and Optimization of Unrepeatered Coherent Transmission Systems Using DRA and ROPA
Résumé:
We present a detailed investigation of the singe-channel 100G polarization-multiplexed quadrature-phase-shift-keying-based unrepeatered coherent transmissions using various order distributed Raman amplifiers (DRAs). The impact of main factors on the system performance is discussed including intrachannel nonlinearity, amplified spontaneous emission, double Rayleigh backscattering, and pump relative intensity noise (RIN)-induced impairments. After optimizing the pump power configuration, it is found that compared to a first- and a third-order DRA, a second-order DRA can provide the best performance owing to relative high optical signal-to-noise ratio (OSNR) and low pump RIN-induced penalty. By using the Giles model, the optimization of a remote optically pumped amplifier is performed in terms of the Erbium-doped fiber length and its farthest position, with given input signal's power and OSNR.
Auteurs: Jingchi Cheng;Ming Tang;Songnian Fu;Perry Ping Shum;Deming Liu;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1830 - 1836
Editeur: IEEE
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» Characterization of Defects in AlGaN/GaN HEMTs Based on Nonlinear Microwave Current Transient Spectroscopy
Résumé:
This paper presents a new nonlinear microwave-based characterization methodology for the study of the deep levels proprieties in gallium nitride (GaN)-based high electron mobility transistors (HEMTs). Currently, it is unique measurement method allowing the extraction of time constants of HEMTs operating under large signal RF conditions. This method improves the conventional dc techniques, since it employs RF excitation during the filling condition to investigate the impact of “real-life” RF excitation on the trapping mechanisms. The experimental results demonstrate that, beyond the presence of Poole–Frenkel effect, the slow detrapping time constant is accelerated by the power dissipation of the trapping bias point. Moreover, it is possible to distinguish the impact of dc and RF conditions on the trapping phenomena. The temperature measurements allow identifying the 0.75-eV deep level, attributed to extended defects in GaN, when ionized under dc excitation. This deep level trap is probably located in the buffer layer and contributes to the RF trapping phenomenon.
Auteurs: Agostino Benvegnù;Sylvain Laurent;Olivier Jardel;Jean-Luc Muraro;Matteo Meneghini;Denis Barataud;Gaudenzio Meneghesso;Enrico Zanoni;Raymond Quéré;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2135 - 2141
Editeur: IEEE
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» Characterization of Iron Loss for Integral-Slot Interior Permanent Magnet Synchronous Machine During Flux Weakening
Résumé:
Iron loss resistance is widely used for rapid motor design and maximum efficiency control. However, the harmonic loss obviously increases during flux weakening, and even dominates in total iron loss, especially in deep flux weakening region. This paper presents an analytical calculation method of iron loss for an integral-slot interior permanent magnet synchronous machine (IPMSM) by iron loss resistance, considering harmonic effect during flux weakening. To predict the harmonic loss, both a harmonic loss voltage and a harmonic loss coefficient are employed into an iron loss resistance model, and the relation of harmonic loss to the harmonic voltage and coefficient are studied. The iron loss and efficiency of an integral-slot IPMSM are, respectively, obtained by the proposed model, the conventional model, the experiment, and finite-element analysis (FEA). The proposed model is validated by the comparison with FEA and experimental results.
Auteurs: Qi Li;Tao Fan;Xuhui Wen;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 8
Editeur: IEEE
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» Characterization of the Spatial Variability of In-Situ Soil Moisture Measurements for Upscaling at the Spatial Resolution of RADARSAT-2
Résumé:
This study characterizes the spatial variability of soil moisture measurements using statistical and geostatistical analyses for the transferability of the ground measurements to the scale of the spatial resolution of RADARSAT-2 images. It aims to better interpret synthetic aperture radar backscattering relationships to soil moisture. Coincident with RADARSAT-2 overpasses, soil and crop parameters were measured in July 2008 and August 2009 over two Canadian agricultural sites (Kenaston, Saskatchewan, and Lennoxville, Québec). The measured soil moisture was used to determine the theoretical semivariogram models that fit the experimental semivariograms. An inverse correlation is obtained between the soil moisture coefficient of variation (CV) and the range (spatial correlation) of the semivariogram, which can assess the degree of the spatial correlation between the samples of each field. Soil moisture measurements with high values of CV (20%–40%) are correlated within a distance less than 10 m and those with lower CV (10%–20%) are correlated within a larger distance varying between 12 and 46 m. The soil moisture measurements of each field were upscaled to the spatial resolution of RADARSAT-2 images ( $text{6}times text{5}$ and ${text{9}}times {text{5 m}}^{2}$) using either simple kriging or ordinary kriging. The results were cross validated using the surface scattering component, which is extracted from the Freeman–Durden decomposition applied to fully polarimetric RADARSAT-2 images. They show that the kriging-based soil moisture better represents RADARSAT-2 surface scattering with strong clustered linear regressions (R2 greater than ∼0.6, RMSE lower than ∼0.9 dB, and p-value of slope less than 0.05) than the nonkriged soil moisture samples.
Auteurs: Imen Gherboudj;Ramata Magagi;Aaron A. Berg;Brenda Toth;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 1813 - 1823
Editeur: IEEE
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» Characterizing the Instantaneous Connectivity of Large-Scale Urban Vehicular Networks
Résumé:
Understanding of the network topology is a basic building block towards the design of efficient networking solutions. In the context of vehicular networks, such a step is especially crucial due to the highly dynamic nature of vehicles that can lead to strong instantaneous variations in the structure of the network. This notwithstanding, and despite the soon-to-come real-world deployment of vehicle-to-vehicle communication technologies, we still lack a clear understanding of vehicular network topological properties. In this paper, we present a complex network analysis of the instantaneous topology of a realistic vehicular network in Cologne, Germany. Our study unveils a poorly connected topology, with very limited availability, reliability, and navigability. We also examine the vehicular network topology in a second scenario, i.e., Zurich, Switzerland. The comparative analysis shows how simplistic mobility models can lead to unrealistic overly connected topologies.
Auteurs: Diala Naboulsi;Marco Fiore;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 05.-2017, volume: 16, issue:5, pages: 1272 - 1286
Editeur: IEEE
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» Choosing Bootstrap Method for the Estimation of the Uncertainty of Traffic Noise Measurements
Résumé:
The environmental acoustic noise is considered as a big risk for today’s population health. Consequently, the regulations in many countries commit themselves to control the exposition of people, imposing limits to the noise level. In the comparison between the measured value and the threshold, the uncertainty of the measured value has to be taken into account. In this paper, a procedure for the evaluation of the uncertainty of traffic noise measurements due to the variability of the measurand is proposed. A deep analysis of five bootstrap (normal, basic percentile, t-student, bias corrected percentile, and bias corrected and accelerated percentile) methods is performed to obtain accurate confidence intervals for the indicator L_{math\rm{ eq},A} without necessity to make normal theory assumptions. From the comparison with the classical method (according to Guide to the Expression of Uncertainty in Measurement (ISO GUM)), the novel approach reveals to be more effective for estimating both the expected value and the uncertainty of the short-term equivalent sound pressure level when a large data set is not available.
Auteurs: Consolatina Liguori;Alessandro Ruggiero;Paolo Sommella;Domenico Russo;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 869 - 878
Editeur: IEEE
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» Ciphertext-Only Attack on Linear Feedback Shift Register-Based Esmaeili-Gulliver Cryptosystem
Résumé:
Esmaeili and Gulliver recently proposed a secret key cryptosystem based on error-correcting codes in which a codeword modified by random insertions, deletions, and errors is used as a ciphertext. The secret keys used in this cryptosystem consist of random numbers generated by synchronized random number generators that are implemented using two distinct linear feedback shift registers (LFSRs) in each encryptor and decryptor, respectively. In this letter, we propose a ciphertext-only attack to break the Esmaeili-Gulliver cryptosystem based on LFSRs. The proposed attack requires $O(n)$ consecutive ciphertexts, where $n$ is the number of shift registers in the LFSR, which is the secret key size. The proposed attack consists of two steps, and the time complexity of the first step is linear in the secret key size while the second step is a polynomial-time algorithm.
Auteurs: Yongwoo Lee;Young-Sik Kim;Jong-Seon No;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 971 - 974
Editeur: IEEE
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» Circuit Designs of High-Performance and Low-Power RRAM-Based Multiplexers Based on 4T(ransistor)1R(RAM) Programming Structure
Résumé:
Routing multiplexers based on pass-transistors or transmission gates are an essential components in many digital integrated circuits. However, whatever structure is employed, CMOS multiplexers have two major limitations: 1) their delay is linearly related to the input size; 2) their performance degrades seriously when operated in near- $V_{t}$ regime. Resistive Random Access Memory (RRAM) technology brings opportunities of overcoming these limitations by exploiting the properties of RRAMs and associated programming structures. In this paper, we propose new one-level, two-level and tree-like multiplexers circuit designs using 4T(ransistors)1R(RAM) elements and we compare them to naive one-level multiplexers. We consider the main physical design aspects associated with 4T1R-based multiplexers, such as the layout implications using a 7 nm FinFET technology, and the co-integration of low-voltage nominal power supply and high-voltage programming supply. Electrical simulations show that using a 7 nm FinFET transistor technology, the proposed 4T1R-based multiplexers reduce delay by $2times $ and energy by $2.8times $ over naive 4T1R and 2T1R counterparts. At nominal working voltage, considering an input size ranging from 2 to 50, the proposed 4T1R-based multiplexers reduces Area-Delay and Power-Delay products by $2.6times $ and $3.8times $ respectively, as compared to best CMOS multiplexers. In the near- $V_{t}$ regime, the proposed 4T1R-based multiplexer demonstrates - 2times $ larger delay efficiency over the best CMOS multiplexer. The proposed 4T1R-based multiplexers operating at near- $V_{t}$ regime can still achieve up to 22% delay improvement when compared to best CMOS multiplexers working at nominal voltage.
Auteurs: Xifan Tang;Edouard Giacomin;Giovanni De Micheli;Pierre-Emmanuel Gaillardon;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1173 - 1186
Editeur: IEEE
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» Circuit Implementation of Data-Driven TSK-Type Interval Type-2 Neural Fuzzy System With Online Parameter Tuning Ability
Résumé:
This paper proposes a new circuit for implementing a reduced-interval type-2 neural fuzzy system using weighted bound-set boundaries (RIT2NFS-WB) with online tuning ability. The antecedent and consequent parts of the RIT2NFS-WB use interval type-2 fuzzy sets and Takagi-Sugeno-Kang (TSK) rules with interval combination parameters, respectively. In the software implementation, the structure and parameters of the RIT2NFS-WB are learned through firing-strength-based rule generation and gradient descent algorithms, respectively. The software-designed RIT2NFS-WB is then transferred to a circuit implementation with online parameter-tuning ability; the hardware version is called the RIT2NFS-WB(HL). The RIT2NFS-WB(HL) is characterized by its online tuning ability with updatable consequent and weighting parameters. To the best of our knowledge, the RIT2NFS-WB(HL) is the first TSK-type interval type-2 neural fuzzy circuit with online parameter tuning ability in the literature. To take advantage of the inherent parallel processing property of the rules, a parallel processing technique is utilized in the RIT2NFS-WB(HL) to achieve computational speedup. The RIT2NFS-WB(HL) is applied to examples of online system modeling and sequence prediction to demonstrate the system's functionality.
Auteurs: Chia-Feng Juang;Kai-Jie Juang;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 4266 - 4275
Editeur: IEEE
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» CIS Publication Spotlight [Publication Spotlight]
Résumé:
Presents a synopsis of the latest books in the area of computational intelligence.
Auteurs: Haibo He;Jon Garibaldi;Kay Chen Tan;Graham Kendall;Yaochu Jin;Yew Soon Ong;
Apparue dans: IEEE Computational Intelligence Magazine
Date publication: 05.-2017, volume: 12, issue:2, pages: 20 - 22
Editeur: IEEE
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» Classification and Prediction of Clinical Improvement in Deep Brain Stimulation From Intraoperative Microelectrode Recordings
Résumé:
We present a random forest (RF) classification and regression technique to predict, intraoperatively, the unified Parkinson's disease rating scale (UPDRS) improvement after deep brain stimulation (DBS). We hypothesized that a data-informed combination of features extracted from intraoperative microelectrode recordings (MERs) can predict the motor improvement of Parkinson's disease patients undergoing DBS surgery. We modified the employed RFs to account for unbalanced datasets and multiple observations per patient, and showed, for the first time, that only five neurophysiologically interpretable MER signal features are sufficient for predicting UPDRS improvement. This finding suggests that subthalamic nucleus (STN) electrophysiological signal characteristics are strongly correlated to the extent of motor behavior improvement observed in STN-DBS.
Auteurs: Kyriaki Kostoglou;Konstantinos P. Michmizos;Pantelis Stathis;Damianos Sakas;Konstantina S. Nikita;Georgios D. Mitsis;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 05.-2017, volume: 64, issue:5, pages: 1123 - 1130
Editeur: IEEE
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» Classification of Three Types of Walking Activities Regarding Stairs Using Plantar Pressure Sensors
Résumé:
In this letter, we propose a novel method for classifying ambulatory activities using eight plantar pressure sensors within smart shoes. Using these sensors, pressure data of participants can be collected regarding level walking, stair descent, and stair ascent. Analyzing patterns of the ambulatory activities, we present new features with which to describe the ambulatory activities. After selecting critical features, a multi-class support vector machine algorithm is applied to classify these activities. Applying the proposed method to the experimental database, we obtain recognition rates up to 95.2% after six steps.
Auteurs: Gu-Min Jeong;Phuc Huu Truong;Sang-Il Choi;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2638 - 2639
Editeur: IEEE
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» Closed-Form BER Expressions for HSV-Based ${M}$ PSK-CSK Systems
Résumé:
The analysis of hybrid phase shift keying-color shift keying ( ${M}$ PSK-CSK) systems under the additive white Gaussian noise model is presented. ${M}$ PSK-CSK systems are formed by mapping phase shift keying symbols to color shift keying using hue-saturation-value color space. Analytical expressions of bit error rate are given for ${M} =2$ , 4, 8, and 16, to validate the simulation results published previously.
Auteurs: Alain Richard Ndjiongue;Thokozani Shongwe;Hendrik C. Ferreira;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1023 - 1026
Editeur: IEEE
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» Cloud Computing
Résumé:
Technologies and market players will change over time, but the bottom line is that cloud computing is here to stay.
Auteurs: Grace A. Lewis;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 8 - 9
Editeur: IEEE
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» CloudScout: A Non-Intrusive Approach to Service Dependency Discovery
Résumé:
Nowadays, numerous enterprises are migrating their applications into cloud computing environments. Typically, the applications are composed of several dependent service components that span many hosts and network devices. In light of this, exploring the dependency between service components can be beneficial for achieving fast network application response time. Moreover, it is significant to consolidate service components according to resource constraints, service dependency, and network structure. However, it is a tedious task to discover the dependency among service components without expert knowledge of the running application. In this paper, we propose CloudScout, a non-intrusive approach that is capable of automatically discovering dependent service components. CloudScout analyzes the correlation among service components based on the time-series information from system monitoring logs. We address two key challenges in CloudScout: service distance calculation and dependent service clustering. We conduct experiments on five applications with 290 service components that span 20 physical hosts across two data centers. The experimental results demonstrate that CloudScout can successfully discover the dependency among service components and facilitate reducing the network latency of network applications and distributed applications.
Auteurs: Jianwei Yin;Xinkui Zhao;Yan Tang;Chen Zhi;Zuoning Chen;Zhaohui Wu;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 05.-2017, volume: 28, issue:5, pages: 1271 - 1284
Editeur: IEEE
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» Clutch Judder Classification and Prediction: A Multivariate Statistical Analysis Based on Torque Signals
Résumé:
Judder is the term used in the automotive industry to describe the longitudinal oscillation in a vehicle during its clutch system engagement. Past research has shown that judder can be explained using a behavior of slip speed and temperature captured by the clutch torque. This paper proposes and implements an innovative learning system for better characterization of the judder phenomenon. It is based on a multivariate data-driven analysis from torque signals. Our experimental results have been carried out using the following main resources: dry clutch system, passenger car, test bench, and six different organic facing materials. The multivariate statistical analysis implemented has allowed the development of a computationally efficient and highly accurate learning model to discriminate the torque signals from different facings, using few features and a regularized version of a standard linear classifier. Given this multivariate framework and calculating the correlation pairwisely to a known gold material, it has also been possible to predict judder problem in the vehicle based on a standard test bench in laboratory. We believe that the findings of this paper might reduce significantly the time of development and the cost of testing new friction materials for allowing judder-free performance on vehicles.
Auteurs: Ivan R. S. Gregori;Ivandro Sanches;Carlos E. Thomaz;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 4287 - 4295
Editeur: IEEE
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» Co-Channel Interference and Background Noise in $kappa$ - $mu$ Fading Channels
Résumé:
In this letter, we derive novel analytical and closed form expressions for the outage probability, when the signal-of-interest (SoI) and the interferer experience $kappa $ $mu $ fading in the presence of Gaussian noise. Most importantly, these expressions hold true for independent and non-identically distributed $kappa $ $mu $ variates, without parameter constraints. We also find the asymptotic behaviour when the average signal to noise ratio of the SoI is significantly larger than that of the interferer. It is worth highlighting that our new solutions are very general owing to the flexibility of the $kappa $ $mu $ fading model.
Auteurs: Nidhi Bhargav;Carlos Rafael Nogueira da Silva;Young Jin Chun;Simon L. Cotton;Michel Daoud Yacoub;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1215 - 1218
Editeur: IEEE
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» Co-Design Strategies for Energy-Efficient UWB and UHF Wireless Systems
Résumé:
This paper reviews the most recent methods, combining nonlinear harmonic-balance-based analysis with electromagnetic (EM) simulation, for optimizing, at the circuit level, modern radiative RF/microwave systems. In order to maximize the system efficiency, each subsystem must be designed layoutwise, accounting for the presence of the others, that is, accounting for its actual terminations, rather than the ideal ones ( $50~Omega$ ). In this way, the twofold goal of minimizing size and losses of the system is obtained by reducing intersystem matching networks. Indeed, terminations are complex, frequency-dispersive, and variable with the signal level, if active operations are concerned, and are responsible for performance degradation if not properly optimized. This approach is nowadays necessary, given the ever increased spread of pervasively distributed RF microsystems adopting miniaturized antennas, such as radio frequency identification (RFID) or wireless sensor networks, that must be low-cost, low-profile, low-power, and must simultaneously perform localization, identification, and sensing. For the design of a transmitter and a receiver connected with the respective antennas, suitable figures of merit are considered, encompassing radiation and nonlinear performance. Recent representative low-profile realizations, adopting ultra-wideband (UWB) excitations are used to highlight the benefit of the proposed nonlinear/EM approach for next generation energy autonomous microsystem, such as UWB-RFID tags.
Auteurs: Alessandra Costanzo;Diego Masotti;Marco Fantuzzi;Massimo Del Prete;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1852 - 1863
Editeur: IEEE
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» Co-Saliency Detection via a Self-Paced Multiple-Instance Learning Framework
Résumé:
As an interesting and emerging topic, co-saliency detection aims at simultaneously extracting common salient objects from a group of images. On one hand, traditional co-saliency detection approaches rely heavily on human knowledge for designing handcrafted metrics to possibly reflect the faithful properties of the co-salient regions. Such strategies, however, always suffer from poor generalization capability to flexibly adapt various scenarios in real applications. On the other hand, most current methods pursue cosaliency detection in unsupervised fashions. This, however, tends to weaken their performance in real complex scenarios because they are lack of robust learning mechanism to make full use of the weak labels of each image. To alleviate these two problems, this paper proposes a new SP-MIL framework for co-saliency detection, which integrates both multiple instance learning (MIL) and self-paced learning (SPL) into a unified learning framework. Specifically, for the first problem, we formulate the co-saliency detection problem as a MIL paradigm to learn the discriminative classifiers to detect the co-saliency object in the “instance-level”. The formulated MIL component facilitates our method capable of automatically producing the proper metrics to measure the intra-image contrast and the inter-image consistency for detecting co-saliency in a purely self-learning way. For the second problem, the embedded SPL paradigm is able to alleviate the data ambiguity under the weak supervision of co-saliency detection and guide a robust learning manner in complex scenarios. Experiments on benchmark datasets together with multiple extended computer vision applications demonstrate the superiority of the proposed framework beyond the state-of-the-arts.
Auteurs: Dingwen Zhang;Deyu Meng;Junwei Han;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 05.-2017, volume: 39, issue:5, pages: 865 - 878
Editeur: IEEE
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» CO2 Concentration Using Adsorption and Nonthermal Plasma Desorption
Résumé:
Air-pollutant and greenhouse gas emissions typically have high gas flow rates and low concentrations (in ppm ∼ % levels, 1% = 10 000 ppm). The bulky equipment required for direct treatment of high-flow-rate low-concentration exhaust gases result in high-energy consumption and prohibitive operating costs. As such, the objective of this study is to convert high-flow-rate low-concentration exhaust gases into low-flow-rate high-concentration gases. This is achieved by desorbing the gas from an adsorbent by applying an atmospheric plasma inside a nonthermal plasma (NTP) reactor. This paper focuses on carbon dioxide (CO2) concentration (condensation) via this method. The adsorbent consists of spherical ∼2-mm-diameter molecular-sieve pellets of zeolite. Plasma desorption is performed by applying nanosecond high-voltage pulses (peak voltage ∼35 kV, pulse frequency = 140–350 Hz, and pulse width ∼600 ns) to the plasma reactor. A gas flow rate of 4 L/min is used and the concentrations of CO2, O2, H2O, and N2 gases are 2.75%, 18%, 1%, and the balance, respectively. The results reveal that CO2 can be desorbed effectively and more rapidly in a repeated adsorption and NTP desorption process than during the thermal process. Moreover, for the same electric power, the peak concentrations (typically 13%) are higher in the NTP desorption process than in the thermal process at equal electric power. These results indicate that the efficient NTP dissociation of CO2 to CO, which can be utilized in the production of combustion fuels, is possible.
Auteurs: Masaaki Okubo;Tomoyuki Kuroki;Hideaki Yamada;Keiichiro Yoshida;Takuya Kuwahara;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2432 - 2439
Editeur: IEEE
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» CO2 Laser Applications in Optical Fiber Components Fabrication and Treatment: A Review
Résumé:
CO2 laser has been widely used in material processing, manufacturing, and medical and military applications since its invention in 1964. Typically for optical fiber components fabrication and treatment, CO2 laser has been reported intensively in stress and birefringence modification, long period grating fabrication, thermal regeneration, optical device fabrication, surface polishing, photosensitivity enhancement, and so on. The reason behind this is due to the advantages of high absorption, fast thermal response, low contamination, dynamic control, and focused heating area owned by the CO2 laser treatment technique. In this paper, a wide variety of CO2 laser applications in optical fiber components fabrication and treatment are reviewed in terms of procedure and principle. The advantages of using CO2 laser and the supremacy of the optical fiber components fabricated or treated by CO2 laser are discussed as well.
Auteurs: Man-Hong Lai;Kok-Sing Lim;Dinusha Serandi Gunawardena;Yen-Sian Lee;Harith Ahmad;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 2961 - 2974
Editeur: IEEE
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» Code Design for Flicker Mitigation in Visible Light Communications Using Finite State Machines
Résumé:
The IEEE 802.15.7 standard for visible light communication (VLC) includes the use of run-length-limited codes to mitigate modulation-induced flickering and the further use of coding to improve bit error rate performance. In this paper, we introduce algorithms to design codes using finite-state machines, which provide simultaneously a coding gain while also mitigating flicker. The codes have the additional advantage of being optimally soft-decision decodable using the Viterbi algorithm. To compare the flicker mitigation performance of different codes, we further introduce a mathematical measure of flicker based on the power spectrum of the transmitted signals. We discuss tradeoffs between flicker mitigation, code rate, and coding gain, design several codes, and compare their error rate and flicker mitigation performance to some codes in the VLC standard.
Auteurs: Carlos E. Mejia;Costas N. Georghiades;Mohamed M. Abdallah;Yazan H. Al-Badarneh;
Apparue dans: IEEE Transactions on Communications
Date publication: 05.-2017, volume: 65, issue:5, pages: 2091 - 2100
Editeur: IEEE
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» Code-Aided DOA Estimation From Turbo-Coded QAM Transmissions: Analytical CRLBs and Maximum Likelihood Estimator
Résumé:
In this paper, we address the problem of direction of arrival (DOA) estimation from turbo-coded square-QAM-modulated transmissions. We devise a new code-aware direction finding concept, derived from maximum likelihood (ML) theory, wherein the soft information provided by the soft-input soft-output decoder, in the form of log-likelihood ratios, is exploited to assist the estimation process. At each turbo iteration, the decoder output is used to refine the ML DOA estimate. The latter is in turn used to perform a more focused receiving beamforming thereby providing more reliable information-bearing sequences for the next turbo iteration. In order to benchmark the new estimator, we also derive the analytical expressions for the exact Cramer-Rao lower bounds (CRLBs) of code-aided (CA) DOA estimates. Simulation results will show that the new CA direction finding scheme lies between the two traditional schemes of completely non-data-aided and data-aided (DA) estimations. Huge performance improvements are achieved by embedding the direction finding and receive beamforming tasks into the turbo iteration loop. Moreover, the new CA DOA estimator reaches the new CA CRLBs over a wide range of practical SNRs thereby confirming its statistical efficiency. As expected intuitively, its performance further improves at higher coding rates and/or lower modulation orders.
Auteurs: Faouzi Bellili;Chaima Elguet;Souheib Ben Amor;Sofiène Affes;Alex Stéphenne;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2850 - 2865
Editeur: IEEE
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» Coded Caching for Multi-level Popularity and Access
Résumé:
To address the exponentially rising demand for wireless content, the use of caching is emerging as a potential solution. It has been recently established that joint design of content delivery and storage (coded caching) can significantly improve performance over conventional caching. Coded caching is well suited to emerging heterogeneous wireless architectures which consist of a dense deployment of local-coverage wireless access points (APs) with high data rates, along with sparsely-distributed, large-coverage macro-cell base stations (BS). This enables design of coded caching-and-delivery schemes that equip APs with storage, and place content in them in a way that creates coded-multicast opportunities for combining with macro-cell broadcast to satisfy users even with different demands. Such coded-caching schemes have been shown to be order-optimal with respect to the BS transmission rate, for a system with single-level content, i.e., one where all content is uniformly popular. In this paper, we consider a system with non-uniform popularity content which is divided into multiple levels, based on varying degrees of popularity. The main contribution of this paper is the derivation of an order-optimal scheme which judiciously shares cache memory among files with different popularities. To show order-optimality we derive new information-theoretic lower bounds, which use a sliding-window entropy inequality, effectively creating a non-cut-set bound. We also extend the ideas to when users can access multiple caches along with the broadcast. Finally, we consider two extreme cases of user distribution across caches for the multi-level popularity model: a single user per cache (single-user setup) versus a large number of users per cache (multi-user setup), and demonstrate a dichotomy in the order-optimal strategies for these two extreme cases.
Auteurs: Jad Hachem;Nikhil Karamchandani;Suhas N. Diggavi;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 3108 - 3141
Editeur: IEEE
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» Coding for Classical-Quantum Channels With Rate Limited Side Information at the Encoder: Information-Spectrum Approach
Résumé:
We study the hybrid classical-quantum version of the channel coding problem for the famous Gel’fand–Pinsker channel. In the classical setting for this channel the conditional distribution of the channel output given the channel input is a function of a random parameter called the channel state. We study this problem when a rate limited version of the channel state is available at the encoder for the classical-quantum Gel’fand–Pinsker channel. We establish the capacity region for this problem in the information-spectrum setting. The capacity region is quantified in terms of spectral-sup classical mutual information rate and spectral-inf quantum mutual information rate.
Auteurs: Naqueeb Ahmad Warsi;Justin P. Coon;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 3322 - 3331
Editeur: IEEE
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» Coil-Shaped Electrodes to Reduce the Current Variation of Drop-Casted OTFTs
Résumé:
Coil-shaped structures are proposed to reduce the impact of variable grain alignment on the drive current of the polycrystalline organic thin-film transi-stors (OTFT). Top-gate, bottom-contact polycrystalline OTFT is fabricated with the drop-casted semiconducting layer to verify the proposed structures. The relative standard deviation (RSD) defined as the ratio of standard deviation, and the average of drive current is used for comparing variations between different structures. Coil-shaped transistors have a significantly lower (22%) RSD, compared with the conventional structures (61%). Finally, we present a technique for designing symmetric coil-shaped OTFTs of any arbitrary W/L ratio (>1) with reduced current variation.
Auteurs: H. M. Dipu Kabir;Zubair Ahmed;Lining Zhang;Mansun Chan;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 645 - 648
Editeur: IEEE
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» Color Image-Guided Boundary-Inconsistent Region Refinement for Stereo Matching
Résumé:
Cost computation, cost aggregation, disparity optimization, and disparity refinement are the four main steps for stereo matching. While the first three steps have been widely investigated, few efforts have been taken on disparity refinement. In this paper, we propose a color image-guided disparity refinement method to further remove the boundary-inconsistent regions on disparity map. First, the origins of boundary-inconsistent regions are analyzed. Then, these regions are detected with the proposed hybrid-superpixel-based strategy. Finally, the detected boundary-inconsistent regions are refined by a modified weighted median filtering method. Experimental results on various stereo matching conditions validate the effectiveness of the proposed method. Furthermore, depth maps obtained by active depth acquisition devices like Kinect can also be well refined with our proposed method.
Auteurs: Jianbo Jiao;Ronggang Wang;Wenmin Wang;Dagang Li;Wen Gao;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 1155 - 1159
Editeur: IEEE
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» ColorSketch: A Drawing Assistant for Generating Color Sketches from Photos
Résumé:
A color sketch creates a vivid depiction of a scene using sparse pencil strokes and casual colored brush strokes. The interactive drawing system ColorSketch can help novice users generate color sketches from photos. To preserve artistic freedom and expressiveness, the proposed system gives users full control over pencil strokes, while automatically augmenting pencil sketches using color mapping, brush stroke rendering, and blank area creation. Experimental and user study results demonstrate that users, especially novices, can create better color sketches with our system than when using traditional manual tools.
Auteurs: Guanbin Li;Sai Bi;Jue Wang;Yingqing Xu;Yizhou Yu;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 05.-2017, volume: 38, issue:3, pages: 70 - 81
Editeur: IEEE
Document complet vers site de l'éditeur
 


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