Electrical and Electronics Engineering publications abstract of: 07-2017 sorted by title, page: 12

» Parameter Optimization in Waveform Relaxation for Fractional-Order $RC$ Circuits
Abstract:
The longitudinal waveform relaxation (WR) proposed by Gander and Ruehli converges faster than the classical WR method. For the former, a free parameter is contained, which has a significant effect on the convergence rate. The optimization of this parameter is thus an important issue in practice. Here, we apply this new WR method to the fractional-order RC circuits, and optimize such a parameter at the continuous and discrete levels (this gives two parameters and ). We consider three simple but widely used convolution quadrature for discretization, based on the implicit-Euler method, the two-step backward difference formula, and the trapezoidal rule, and we derive the parameter for each quadrature. Interestingly, it is found that for the former two quadratures, the optimized parameter results in a much better convergence rate than , while for the quadrature based on the trapezoidal rule, and result in the same convergence rate.
Autors: Shu-Lin Wu;Mohammad Al-Khaleel;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2017, volume: 64, issue:7, pages: 1781 - 1790
Publisher: IEEE
 
» Parametric Quality-Estimation Model for Adaptive-Bitrate-Streaming Services
Abstract:
The use of adaptive-bitrate-streaming services over networks has been increasing in recent years. The quality of adaptive-bitrate-streaming services is primarily affected by the video resolution, the audio and video bitrate, bitrate adaptation, stalling due to a lack of playout buffer, and the content length. Therefore, service providers should monitor quality in real time to confirm the normality of their services. To accurately monitor quality, a model that can be used for quality estimation should be developed. To develop such a model, we first conducted extensive subjective quality assessment tests. We then developed a model using the subjective data obtained in the tests. Finally, we verified the performance of the proposed model by applying it to unknown datasets (different from the training datasets used to develop the model) and confirmed its high quality-estimation accuracy.
Autors: Kazuhisa Yamagishi;Takanori Hayashi;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jul 2017, volume: 19, issue:7, pages: 1545 - 1557
Publisher: IEEE
 
» Parametrization and Validation of Geometry-Based Stochastic Channel Model for Urban Small Cells at 10 GHz
Abstract:
We derive a full measurement-based parametrization for a 3-D geometry-based stochastic channel model for an urban microcell type of environment at 10 GHz. The measurements were performed with a vector network analyzer and dual polarized virtual arrays at the bandwidth of 500 MHz. The proposed parametrization is validated by channel simulations. Multiple-input multiple-output channel is reconstructed from the measured data and compared with channel generated by the quasi deterministic radio channel generator using the proposed statistical parameters. The capacity and eigenvalue distribution are used as the validation metrics, showing almost perfect match between the reconstructed and simulated channels.
Autors: Antti Roivainen;Pekka Kyösti;Claudio Ferreira Dias;Veikko Hovinen;Nuutti Tervo;Marko Sonkki;Matti Latva-aho;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3809 - 3814
Publisher: IEEE
 
» Particle Collection Efficiency of Polypropylene Nonwoven Filter Media Charged by Triode Corona Discharge
Abstract:
The aim of this paper is to evaluate the collection efficiency of submicron particles using electrically charged nonwoven filter media. A triode-type electrode arrangement consisting of a high-voltage wire-type ionizing electrode, a metallic grid, and grounded plate electrode is employed to control the distribution of electric charges deposited on the media. Surface electric potential measurement is carried out to study the evolution in time and the repartition in space of deposited charges. The collection efficiency is estimated by measuring the particle concentrations downstream and upstream of the charged filter media. The main results show good correlation between the surface potential level and the collection efficiency of submicron particles for several charging conditions. In particular, filtration performance increases with increasing the corona current through the media during the charging process. Increasing the electric field between the grid and the media during corona charging has also a positive effect on the collection efficiency. Results indicate that high collection performances could not be achieved using thin monolayer media.
Autors: Ali Fatihou;Noureddine Zouzou;Lucian Dascalescu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3970 - 3976
Publisher: IEEE
 
» Particle Identification on an FPGA Accelerated Compute Platform for the LHCb Upgrade
Abstract:
The current LHCb readout system will be upgraded in 2018 to a “triggerless” readout of the entire detector at the Large Hadron Collider collision rate of 40 MHz. The corresponding bandwidth from the detector down to the foreseen dedicated computing farm (event filter farm), which acts as the trigger, has to be increased by a factor of almost 100 from currently 500 Gb/s up to 40 Tb/s. The event filter farm will preanalyze the data and will select the events on an event by event basis. This will reduce the bandwidth down to a manageable size to write the interesting physics data to tape. The design of such a system is a challenging task, and the reason why different new technologies are considered and have to be investigated for the different parts of the system. For the usage in the event building farm or in the event filter farm (trigger), an experimental field programmable gate array (FPGA) accelerated computing platform is considered and, therefore, tested. FPGA compute accelerators are used more and more in standard servers such as for Microsoft Bing search or Baidu search. The platform we use hosts a general Intel CPU and a high-performance FPGA linked via the high-speed Intel QuickPath Interconnect. An accelerator is implemented on the FPGA. It is very likely that these platforms, which are built, in general, for high-performance computing, are also very interesting for the high-energy physics community. First, the performance results of smaller test cases performed at the beginning are presented. Afterward, a part of the existing LHCb RICH particle identification is tested and is ported to the experimental FPGA accelerated platform. We have compared the performance of the LHCb RICH particle identification running on a normal CPU with the performance of the same algorithm, which is running on the Xeon-FPGA compute accelerator platform.
Autors: Christian Fäerber;Rainer Schwemmer;Jonathan Machen;Niko Neufeld;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Jul 2017, volume: 64, issue:7, pages: 1994 - 1999
Publisher: IEEE
 
» Passive BCI in Operational Environments: Insights, Recent Advances, and Future Trends
Abstract:
Goal: This minireview aims to highlight recent important aspects to consider and evaluate when passive brain–computer interface (pBCI) systems would be developed and used in operational environments, and remarks future directions of their applications. Methods: Electroencephalography (EEG) based pBCI has become an important tool for real-time analysis of brain activity since it could potentially provide covertly—without distracting the user from the main task—and objectively—not affected by the subjective judgment of an observer or the user itself—information about the operator cognitive state. Results: Different examples of pBCI applications in operational environments and new adaptive interface solutions have been presented and described. In addition, a general overview regarding the correct use of machine learning techniques (e.g., which algorithm to use, common pitfalls to avoid, etc.) in the pBCI field has been provided. Conclusion: Despite recent innovations on algorithms and neurotechnology, pBCI systems are not completely ready to enter the market yet, mainly due to limitations of the EEG electrodes technology, and algorithms reliability and capability in real settings. Significance: High complexity and safety critical systems (e.g., airplanes, ATM interfaces) should adapt their behaviors and functionality accordingly to the user’ actual mental state. Thus, technologies (i.e., pBCIs) able to measure in real time the user's mental states would result very useful in such “high risk” environments to enhance human machine interaction, and so increase the overall safety.
Autors: Pietro Aricò;Gianluca Borghini;Gianluca Di Flumeri;Nicolina Sciaraffa;Alfredo Colosimo;Fabio Babiloni;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jul 2017, volume: 64, issue:7, pages: 1431 - 1436
Publisher: IEEE
 
» Passivity Enhancement in Renewable Energy Source Based Power Plant With Paralleled Grid-Connected VSIs
Abstract:
Harmonic instability is threatening the operation of renewable energy based power plants where multiple grid connected voltage source inverters (VSIs) are connected in parallel. To analyze and improve the stability of the grid-connected VSIs, the real part of the output admittance of the VSIs is first investigated in this paper. It has been shown that the negative real part of the output admittance will make the system unstable under certain grid condition. Based on the stability analysis, this paper proposes a method to cancel the negative real parts by using VSIs with different LCL filters, sampling frequencies, and control strategies. The proposed method does not require the VSIs to have any active damping function. Three specific cases are studied where the LCL parameters, sampling frequencies, and current control strategies of the VSIs are different. The results show that the combination of different types of grid-connected VSIs can improve the stability of the renewable power plant.
Autors: Haofeng Bai;Xiongfei Wang;Frede Blaabjerg;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3793 - 3802
Publisher: IEEE
 
» Patch-Probe Excitation for Ultrahigh Magnetic Field Wide-Bore MRI
Abstract:
In this paper, we present the design of probe excitations for 7- and 10.5-T traveling-wave wide-bore magnetic resonance imaging systems. The probes are 297- and 447-MHz coaxially fed microstrip patches, designed to give a circularly polarized magnetic field when placed in the metallic bore waveguide. Images of a water phantom using the patch probes are obtained and compared with full-wave electromagnetic simulations. Additionally, periodic axial metal strip cylinders are inserted into the bore, resulting in improved field uniformity in a phantom with a simultaneous increase in SNR. The numerical analysis for nonquasi-static fields can be computationally intensive, and the numerical error for finite-element simulations is quantified using modified boundary conditions of the system. When the waveguide effects are taken into account, the mode content in the images compares well to full-wave simulations.
Autors: Patrick Bluem;Andrew Kiruluta;Pierre-Francois Van de Moortele;Allison Duh;Gregor Adriany;Zoya Popović;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2017, volume: 65, issue:7, pages: 2547 - 2557
Publisher: IEEE
 
» Path-Loss Prediction for an Industrial Indoor Environment Based on Room Electromagnetics
Abstract:
A simple approach of path-loss and root-mean-square (rms) delay spread prediction for indoor propagation environment is developed based on the room electromagnetics theory. The indoor room environment is interpreted as a lossy cavity, which is characterized by the diffuse scattering components caused by the walls and surrounding obstacles, and a possible line-of-sight component. Simply, speed of the algorithm and good accuracy are among the advantages of this approach. To apply the method, it only requires the knowledge of the dimensions of the room and the reverberation time, which can be easily obtained from one measurement of the power-delay-profile in the investigated environment. For experimental validation, path-loss measurements at two different transmission frequencies, and wideband measurements from 0.8 to 2.7 GHz were conducted in two rooms of an industrial environment. The theoretical results from the path-loss and rms delay spread prediction algorithm show good match with the measurement results.
Autors: Yun Ai;Jørgen Bach Andersen;Michael Cheffena;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3664 - 3674
Publisher: IEEE
 
» Pattern Division for Massive MIMO Networks With Two-Stage Precoding
Abstract:
In massive multiple-input multiple-output networks with two-stage precoding, the user clusters with serious angle-spreading-range (ASR) overlapping should be divided into different patterns and scheduled in orthogonal sub-channels to achieve optimal performance. In this letter, we propose one graph theory-based pattern division (GT-PD) scheme to deal with the ASR overlapping with a limited number of sub-channels. First, we depict the ASR overlapping as an undirected weighted graph, where the weight of each edge indicates the strength of the ASR overlapping between two connected clusters. Then, we separately denote each user cluster and pattern as a vertex and a color, and transform the pattern division into a graph coloring problem with limited colors. In addition, the GT-PD scheme is developed with the help of the Dsatur algorithm. Finally, numerical results are provided to corroborate the efficiency of the proposed scheme.
Autors: Jianpeng Ma;Shun Zhang;Hongyan Li;Nan Zhao;Arumugam Nallanathan;
Appeared in: IEEE Communications Letters
Publication date: Jul 2017, volume: 21, issue:7, pages: 1665 - 1668
Publisher: IEEE
 
» PbS Colloidal Quantum Dot Visible-Blind Photodetector for Early Indoor Fire Detection
Abstract:
We report on a novel optical fire detector based on a PbS colloidal quantum dot photodetector. The sensor is realized with a simple, cost effective, drop casting technique. The photodetector is characterized in terms of its electrical characteristics, responsivity, and specific detectivity to monochromatic light. We demonstrate effective indoor fire detection at a distance exceeding 20 m with a 120° field of view. We also show a twofold improvement of the detector signal to noise ratio exploiting a short focal lens.
Autors: Andrea De Iacovo;Carlo Venettacci;Lorenzo Colace;Leonardo Scopa;Sabrina Foglia;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4454 - 4459
Publisher: IEEE
 
» Pd/ZnO Schottky Ultraviolet Photodiode Fabricated on ITO Using rGO Seed Layer
Abstract:
This letter reports the high-performance ultraviolet (UV) Pd/ZnO Schottky photodiodes fabricated on indium tin oxide (ITO) using reduced graphene oxide (rGO) as seed layer. Electrophoretic deposition method has been used for the deposition of rGO layer on ITO substrate. A comparative study of Pd/ZnO devices with and without the rGO seed layer is carried out. The current–voltage (I–V) measurements of as-fabricated Schottky photodiodes having rGO as seed layer have shown responsivity ~1.32 A/W; which is around 26 times compared with responsivity ~0.05 A/W of a Pd/ZnO/ITO photodiode without rGO seed layer both measured at −2 V reverse bias voltage. Good contrast ratio (~74.91) and detectivity ( mHz) are observed for rGO seed layer-based devices when the device is illuminated by an UV source of output power at ~365 nm. Hence, this letter reports about utilizing rGO as seed layer for improving the performance of Pd/ZnO-based Schottky UV photodiodes.
Autors: Amritanshu Pandey;Aditya Bansod;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2017, volume: 29, issue:14, pages: 1191 - 1194
Publisher: IEEE
 
» Peak-Power-Limited Frequency-Domain Microwave-Induced Thermoacoustic Imaging for Handheld Diagnostic and Screening Tools
Abstract:
Coherent frequency-domain microwave-induced thermoacoustic (TA) imaging is investigated as an alternative to the traditional pulsed-based TA imaging approaches that use extremely high-energy short excitation pulses, often produced by vacuum RF sources or spark-gap generators. It is shown that under peak-power limitation of the RF source, dictated by the goals of form factor and portability of this paper, the frequency-domain approach can achieve the required signal-to-noise ratio (SNR) without sacrificing resolution or other performance metrics. Theoretical and experimental comparison of the time-domain and frequency-domain TA methods is provided with the ultimate goal of implementing the imager with solid-state hardware. Using a microwave source with 120 W of peak power, frequency-domain TA demonstrates 27-dB SNR improvement over the pulse method while the average specific absorption ratio remains below 10 W/kg. Finally, we demonstrate TA images of multilayer relatively complex muscle-fat structures. To the best of our knowledge, these are the first TA images obtained with solid-state electronic sources.
Autors: Hao Nan;Amin Arbabian;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2017, volume: 65, issue:7, pages: 2607 - 2616
Publisher: IEEE
 
» Peak-to-Average Power Ratio Reduction in OFDM Index Modulation Through Convex Programming
Abstract:
Orthogonal frequency division multiplexing (OFDM) index modulation (IM) is a new multi-carrier modulation where the sub-carriers have two states, active and idle, and the indices of the active sub-carriers carry information. Although showing many advantages over OFDM, OFDM-IM also inherits the high peak-to-average power ratio (PAPR) problem. In this letter, utilizing the signal feature of OFDM-IM, a high-efficient PAPR reduction method is proposed. Concretely, a small dither in the idle sub-carrier is introduced to reduce the PAPR, and the design of the optimal dither signal can be solved by the convex programming. Simulation results show that the proposed method can achieve a large PAPR reduction when a proper amplitude constraint on the dither signal is employed.
Autors: Jianping Zheng;Hongmei Lv;
Appeared in: IEEE Communications Letters
Publication date: Jul 2017, volume: 21, issue:7, pages: 1505 - 1508
Publisher: IEEE
 
» Perceptual Crosstalk Prediction on Autostereoscopic 3D Display
Abstract:
Perceptual crosstalk prediction for autostereoscopic 3D displays is of fundamental importance in determining the level of quality perceived by humans in terms of the display performance and the 3D viewing experience. However, no robust framework exists to quantify perceptual crosstalk while taking into account the hardware structure of a display as well as its content characteristics via content analysis. In this paper, we present a 3D perceptual crosstalk predictor (3D-PCP) that can be used to predict crosstalk in a unique way when viewing autostereoscopic 3D displays. 3D-PCP captures hardware features using an optical Fourier transform-light measurement device and content features through content analysis based on information theory. By deriving the disparity, luminance, color, and texture maps, this approach defines the visual entropy, mutual information, and relative entropy in order to investigate the influences of the 3D scene characteristics on perceptual crosstalk. The experimental results demonstrate that the 3D-PCP output is highly correlated with subjective scores.
Autors: Taewan Kim;Jongyoo Kim;SeongYong Kim;Sungho Cho;Sanghoon Lee;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jul 2017, volume: 27, issue:7, pages: 1450 - 1463
Publisher: IEEE
 
» Perfect and Quasi-Perfect Codes Under the $l_{p}$ Metric
Abstract:
A long-standing conjecture of Golomb and Welch, raised in 1970, states that there is no perfect error correcting Lee code of length for and . In this paper, we study perfect codes in under the metric, where . We show some nonexistence results of linear perfect codes for and , . We also give an algebraic construction of quasi-perfect codes for , and .
Autors: Tao Zhang;Gennian Ge;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jul 2017, volume: 63, issue:7, pages: 4325 - 4331
Publisher: IEEE
 
» Performance Analysis and Compensation of Joint TX/RX I/Q Imbalance in Differential STBC-OFDM
Abstract:
Differential space time block coding (STBC) achieves full spatial diversity and avoids channel estimation overhead. Over highly frequency-selective channels, STBC is integrated with orthogonal frequency division multiplexing (OFDM) to efficiently mitigate intersymbol interference effects. However, low-cost implementation of STBC-OFDM with direct-conversion transceivers is sensitive to In-phase/Quadrature-phase imbalance (IQI). In this paper, we quantify the performance impact of IQI at both the transmitter and receiver radio-frequency (RF) front-ends on differential STBC-OFDM systems, which has not been investigated before in the literature. In addition, we propose a widely-linear compensation algorithm at the receiver to mitigate the performance degradation caused by the IQI at the transmitter and receiver ends. Moreover, a parameter-based generalized algorithm is proposed to extract the IQI parameters and improve the performance under high mobility. The adaptive compensation algorithms are blind and work in a decision-directed manner without using known pilots or training sequences. Numerical results show that our proposed compensation algorithms can effectively mitigate IQI in differential STBC-OFDM.
Autors: Lei Chen;Ahmed G. Helmy;Guangrong Yue;Shaoqian Li;Naofal Al-Dhahir;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6184 - 6200
Publisher: IEEE
 
» Performance Analysis for Training-Based Multipair Two-Way Full-Duplex Relaying With Massive Antennas
Abstract:
This paper considers a multipair two-way amplify-and-forward (AF) relaying system, where multiple pairs of full-duplex users are served via a full-duplex relay with massive antennas, and the relay adopts maximum-ratio combining/maximum-ratio transmission (MRC/MRT) processing. The orthogonal pilot scheme and the least square method are first exploited to estimate the channel state information (CSI). When the number of relay antennas is finite, we derive an approximate sum rate expression which is shown to be a good predictor of the ergodic sum rate, especially with a large number of antennas. Then, the corresponding achievable rate expression is obtained by adopting another pilot scheme which estimates the composite CSI for each user pair to reduce the pilot overhead of channel estimation. We analyze the achievable rates of the two pilot schemes and then show the relative advantages of the two methods. Furthermore, power allocation strategies for users and the relay are proposed based on sum rate maximization and max-min fairness criterion, respectively. Finally, numerical results verify the accuracy of the analytical results and show the performance gains achieved by the proposed power allocation.
Autors: Zhanzhan Zhang;Zhiyong Chen;Manyuan Shen;Bin Xia;Weiliang Xie;Yong Zhao;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6130 - 6145
Publisher: IEEE
 
» Performance Analysis of an All Solid-State Linear Transformer Driver
Abstract:
The performance of an all solid-state linear transformer driver (LTD) is evaluated based on experimentally verified behavior of a single stage. The single-stage LTD utilizes a low-profile design with robust thyristor switches and high-energy-density mica capacitors to minimize overall system inductance. Subnanosecond jitter is achieved with simultaneous thyristor triggering. The stage is magnetically coupled to a secondary winding through a central nanocrystalline core. A dc current source, decoupled with a large inductance, actively resets the core between pulses. The overall result is a low-impedance ( per stage) pulse generator that rivals the performance of traditional Marx systems with the improved reliability, increased lifetime, and fast rep-rate capabilities of solid-state switches. The stage is tested with charging voltages up to 8 kV into various loads and compared with simulations based on an analog behavioral thyristor switch model previously developed at Texas Tech University. The simulation is expanded into a full-scale, multistage LTD simulation and compared with a previously constructed Marx generator.
Autors: Landon Collier;James Dickens;John Mankowski;Andreas Neuber;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jul 2017, volume: 45, issue:7, pages: 1755 - 1761
Publisher: IEEE
 
» Performance Analysis of IEEE 802.11ad MAC Protocol
Abstract:
IEEE 802.11ad specifies a hybrid medium access control (MAC) protocol consisting of contention as well as non-contention-based channel access mechanisms. It also employs directional antennas to compensate for the high free-space path loss observed in 60 GHz frequency band. Therefore, it significantly differs from other IEEE 802.11(b/g/n/ac) MAC protocols and thus requires new methods to analyze its performance. We propose a new analytical model for performance analysis of IEEE 802.11ad employing a 3-D Markov chain considering all the features of IEEE 802.11ad medium access mechanisms including the presence of non-contention access and the different number of sectors due to the use of directional antennas. We show that the number of sectors has a high impact on the network throughput. We show that the MAC packet delay is significantly affected by the duration of the contention period. Our results indicate that a suitable choice of the number of sectors and contention period can improve the channel utilization and MAC delay performance.
Autors: Kishor Chandra;R. Venkatesha Prasad;Ignas Niemegeers;
Appeared in: IEEE Communications Letters
Publication date: Jul 2017, volume: 21, issue:7, pages: 1513 - 1516
Publisher: IEEE
 
» Performance Enhancement in Uniaxially Strained Germanium–Tin FinTFET: Fin Direction Dependence
Abstract:
We investigate the impact of uniaxial tensile stress on the performance of germanium–tin (GeSn) fin tunneling field-effect transistor (FinTFET) with fin rotating within (001) plane by numerical simulation. The uniaxial tensile stress with a magnitude of 1 GPa is always along the fin direction. Nonlocal empirical pseudopotential method and k p method were utilized to calculate the energy band structure of GeSn. Dynamic nonlocal band-to-band tunneling (BTBT) algorithm was used to analyze the electrical characteristics of the strained GeSn FinTFETs with point and line tunneling modes. The substantial improvement of BTBT generation rate and on-state current achieved in tensile-strained FinTFETs compared to the relaxed devices is attributed to the reduced direct bandgap in strained GeSn. The device performance enhancement induced by the stress demonstrates the obvious dependence on the fin direction and tunneling mode. Under 1 GPa uniaxial tensile stress, GeSn point-FinTFETs with fin directions demonstrate an 11.7% enhancement as compared with the relaxed devices. For the strained GeSn line-FinTFETs, the devices with fin directions obtain a 96.7% of −0.3 V.
Autors: Hongjuan Wang;Yan Liu;Genquan Han;Yao Shao;Chunfu Zhang;Qian Feng;Jincheng Zhang;Yue Hao;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 2804 - 2811
Publisher: IEEE
 
» Performance Enhancement of Parameter Estimators via Dynamic Regressor Extension and Mixing*
Abstract:
A new procedure to design parameter estimators with enhanced performance is proposed in the technical note. For classical linear regression forms, it yields a new parameter estimator whose convergence is established without the usual requirement of regressor persistency of excitation. The technique is also applied to nonlinear regressions with “partially” monotonic parameter dependence—giving rise again to estimators with enhanced performance. Simulation results illustrate the advantages of the proposed procedure in both scenarios.
Autors: Stanislav Aranovskiy;Alexey Bobtsov;Romeo Ortega;Anton Pyrkin;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3546 - 3550
Publisher: IEEE
 
» Performance Evaluation and Optimization of Single Layer MoS2 Double Gate Transistors With Schottky Barrier Contacts
Abstract:
The making use of 2-D material as transistor channel is a rapid growth field since it can provide enough gate controllability for transistors at scaling limit. Among all kinds of 2-D materials, monolayer MoS2 stands out because of its large intrinsic bandgap and moderate mobility at room temperature. Most of the simulation work assumes the source/drain contacts of monolayer MoS2 transistors are Ohmic type, while in experiment the Schottky barrier contacts are more frequently seen. In this paper, the performance of single layer MoS2 double gate transistors with Schottky barrier contacts is evaluated with nonequilibrium Green’s function method. The image force lowering effect, which is crucial for accurate simulation of Schottky barrier, is taken into account. The simulation results reveal that increasing doping concentration is the most effective way to adjust monolayer MoS2 transistor performance. Transistor performance with Schottky barrier contacts can be comparable and even outperforms those with Ohmic contacts. The dependence of subthreshold swing, drain-induced barrier lowering and intrinsic delay on Schottky barrier height, source/drain extension length, and doping concentration in source/drain extension region are also simulated and analyzed. The effect of phonon scattering on performance of monolayer MoS2 transistor with Schottky barrier contacts and Ohmic contacts is also presented.
Autors: Lang Zeng;Deming Zhang;Tianqi Gao;Fanghui Gong;Xiaowan Qin;Mingzhi Long;Youguang Zhang;Weisheng Zhao;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 2999 - 3006
Publisher: IEEE
 
» Performance Evaluation of an Ultra-Wideband Transmit Diversity in a Living Animal Experiment
Abstract:
To realize implant communications with a high data rate, ultra-wideband (UWB) transmission has gathered a lot of attention as a promising candidate. However, due to high operation frequency, the UWB communication link suffers from large attenuation. This represents the difficulty to achieve reliable communications. To mitigate such a problem, spatial diversity techniques have been proposed in the literature, where some of them work without any frequency extension. In contrast, the implant side diversity technique has been rarely discussed because of the difficulty in miniaturizing the size of the transmitter antenna. In this paper, we designed a UWB transmitter diversity antenna and evaluated its performance numerically and experimentally. First, we analyzed the antenna performance using a finite-difference time-domain simulation and physical experiment in a liquid phantom. Thereafter, we measured the path loss performance in an implant communication link using a liquid phantom and a living porcine subject. Finally, we evaluated the impact of the implant side polarization diversity system with the developed antenna on the communication performance. Based on the measured isolation between the polarization channels, our measurements show that a signal-to-noise power ratio improvement of 7 dB can be in principle achieved with a predicted outage rate of 0.01 and a range of 15 cm in typical body environments.
Autors: Yuto Shimizu;Daisuke Anzai;Raul Chavez-Santiago;Pål Anders Floor;Ilangko Balasingham;Jianqing Wang;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2017, volume: 65, issue:7, pages: 2596 - 2606
Publisher: IEEE
 
» Performance Evaluation of Wavelet-Coded OFDM on a 4.9 Gb/s W-Band Radio-Over-Fiber Link
Abstract:
Future generation mobile communications running on mm-wave frequencies will require great robustness against frequency selective channels. In this paper, we evaluate the transmission performance of 4.9 Gb/s wavelet-coded orthogonal frequency division multiplexing (OFDM) signals on a 10 km fiber plus 58 m wireless radio-over-fiber link using a mm-wave radio frequency carrier. The results show that a 2 × 128 wavelet-coded OFDM system achieves a bit-error rate of 1e-4 with nearly 2.5 dB less signal-to-noise ratio than a convolutional coded OFDM system with equivalent spectral efficiency for 8 GHz-wide signals with 512 subcarriers on a carrier frequency of 86 GHz. Our findings confirm the Tzannes' theory that wavelet coding enables high diversity gains with a low complexity receiver and, most notably, without compromising the system's spectral efficiency.
Autors: Lucas C. P. Cavalcante;Simon Rommel;Rui Dinis;L. G. Q. Silveira Junior;L. F. Q. Silveira;Idelfonso Tafur Monroy;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2803 - 2809
Publisher: IEEE
 
» Performance Improvement of HfS2 Transistors by Atomic Layer Deposition of HfO2
Abstract:
Hafnium disulfide (HfS2) is one of the transition metal dichalcogenides which is expected to have the high electron mobility and the finite bandgap. However, the fabrication process for HfS2-based electron devices is not established, and it is required to bring out the superior transport properties of HfS2. In this report, we have investigated the effects of the atomic layer deposited HfO2 passivation on the current properties of HfS2 transistors. HfO2 passivation of the HfS2 surface enhanced the drain current and significantly reduced the hysteresis. Moreover, HfO2 passivation allows the use of a higher annealing temperature and further improvement of the drain current.
Autors: Toru Kanazawa;Tomohiro Amemiya;Vikrant Upadhyaya;Atsushi Ishikawa;Kenji Tsuruta;Takuo Tanaka;Yasuyuki Miyamoto;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jul 2017, volume: 16, issue:4, pages: 582 - 587
Publisher: IEEE
 
» Performance Improvement of Model-Predictive Current Control of Permanent Magnet Synchronous Motor Drives
Abstract:
Model-predictive current control (MPCC) is widely recognized as a high-performance control strategy of permanent magnet synchronous machine (PMSM) drives due to its quick response and simple principle. It uses a cost function to select the best voltage vector minimizing the current error between the reference value and the feedback value. However, as only one voltage vector is applied during one control period, it fails to give satisfactory performance due to the limited voltage vectors, especially in the case of two-level converters. This paper proposes an improved MPCC strategy for PMSM drives, which first estimates the back electromotive force (EMF) based on the past value of stator voltage and currents and then applies the estimated EMF in the stator current prediction. To achieve steady-state performance improvement, a null vector along with the active vector obtained from conventional MPCC is applied during one control period. Two methods are proposed to achieve optimal vector selection and vector duration. The first one requires six predictions and the calculation of current differentiation, while the second one only requires one prediction to obtain the best voltage vector and its optimal duty can be obtained in a very efficient way. The proposed methods are comparatively studied and compared to conventional MPCC and deadbeat control with space vector modulation. Both simulation and experimental results confirm the effectiveness of the proposed methods in achieving good steady-state performance while maintaining quick dynamic response.
Autors: Yongchang Zhang;Donglin Xu;Jiali Liu;Suyu Gao;Wei Xu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3683 - 3695
Publisher: IEEE
 
» Periodic Stabilization of Discrete-Time Switched Linear Systems
Abstract:
The goal of this paper is to study the exponential stabilization problem for autonomous discrete-time switched linear systems (SLSs), where only the discrete mode can be controlled. Our approach is based on periodic control Lyapunov functions whose value decreases periodically instead of at each time step as in the classical control Lyapunov functions. Using periodic control Lyapunov functions, we develop stabilizability analysis and controller synthesis conditions that are less conservative than existing results in that they apply to a larger class of SLSs. Utilizing recent results on the switched optimal control problems, a constructive way to find periodic control Lyapunov functions is presented.
Autors: Donghwan Lee;Jianghai Hu;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3382 - 3394
Publisher: IEEE
 
» Persistent and Nonpersistent Error Optimization for STT-RAM Cell Design
Abstract:
Rapidly increasing demands for memory capacity and severe technical scaling challenges of conventional memory technologies motivated recent investments on next-generation nonvolatile memory technologies. As a promising candidate, spin-transfer torque random access memory (STT-RAM) has demonstrated many attractive properties, such as nanosecond access time, high integration density, nonvolatility, and excellent CMOS integration compatibility. However, similar to all other nano-devices, the performance and reliability of STT-RAM cells are greatly affected by process variations, device operating uncertainties, and environmental fluctuations. As a result, the read and write operations of STT-RAM demonstrate some variabilities and errors. In this paper, we systematically analyze the impacts of CMOS and magnetic tunneling junction (MTJ) process variations, MTJ resistance switching randomness that are induced by intrinsic thermal fluctuations, and working temperature changes on STT-RAM cell designs. The STT-RAM cell reliability issues in both read and write operations are first investigated. A combined circuit and magnetic simulation platform is then established to quantitatively study the persistent and nonpersistent errors in STT-RAM cell operations. Our analysis proved the importance of a full statistical design method in STT-RAM designs for design pessimism minimization.
Autors: Yaojun Zhang;Bonan Yan;Xiaobin Wang;Yiran Chen;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2017, volume: 36, issue:7, pages: 1181 - 1192
Publisher: IEEE
 
» Personal Web Revisitation by Context and Content Keywords with Relevance Feedback
Abstract:
Getting back to previously viewed web pages is a common yet uneasy task for users due to the large volume of personally accessed information on the web. This paper leverages human's natural recall process of using episodic and semantic memory cues to facilitate recall, and presents a personal web revisitation technique called WebPagePrev through context and content keywords. Underlying techniques for context and content memories' acquisition, storage, decay, and utilization for page re-finding are discussed. A relevance feedback mechanism is also involved to tailor to individual's memory strength and revisitation habits. Our 6-month user study shows that: (1) Compared with the existing web revisitation tool Memento, History List Searching method, and Search Engine method, the proposed WebPagePrev delivers the best re-finding quality in finding rate (92.10 percent), average F1-measure (0.4318), and average rank error (0.3145). (2) Our dynamic management of context and content memories including decay and reinforcement strategy can mimic users' retrieval and recall mechanism. With relevance feedback, the finding rate of WebPagePrev increases by 9.82 percent, average F1-measure increases by 47.09 percent, and average rank error decreases by 19.44 percent compared to stable memory management strategy. Among time, location, and activity context factors in WebPagePrev, activity is the best recall cue, and context+content based re-finding delivers the best performance, compared to context based re-finding and content based re-finding.
Autors: Li Jin;Ling Feng;Gangli Liu;Chaokun Wang;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Jul 2017, volume: 29, issue:7, pages: 1508 - 1521
Publisher: IEEE
 
» Phosphorene: A Promising Candidate for Highly Sensitive and Selective SF6 Decomposition Gas Sensors
Abstract:
Phosphorene is a promising candidate for gas sensing materials. This letter describes our study of the adsorption of SF6 and SF6 decomposition gases (SO2 and H2 S) on phosphorene. We used first principles calculations to explore phosphorene’s potential applications as gas sensor to diagnose the state of online gas insulated switchgear (GIS). The calculation results showed that only the adsorption of SO2 induced a moderate adsorption energy and apparent charge transfer. We further investigated the current–voltage (–) relationships before and after gas absorption through the non-equilibrium Green’s function method. It was found that only SO2 induced a dramatic change in the – relationships. Therefore, phosphorene appears to be a promising candidate for highly sensitive and selective SF6 decomposition gas sensors for online GIS diagnosis.
Autors: Ai-Jun Yang;Da-Wei Wang;Xiao-Hua Wang;Ji-Feng Chu;Pin-Lei Lv;Yang Liu;Ming-Zhe Rong;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 963 - 966
Publisher: IEEE
 
» Photoresponse Performance Evaluation of ZnO UV Photodetector Based on Noise Analysis
Abstract:
The ZnO film photosensitive chips prepared by sputtering method were post-treated by air-anneal at different temperatures and Ar or air-plasma treatments for different time. Then, photosensitive chips were packaged into UV photodetectors with a standard TO-5 package to meet the sensitivity, selectivity, and stability standards. Noise analysis was used as an efficient tool to evaluate the quality and reliability of ZnO UV photodetectors, and the overall performance evaluation based on 1/f noise physical model is made to build the relationship between photoresponse and surface defect state density. The 1/f noise comes from defect-related carriers’ number fluctuation, which are trap and detrap processes of free electrons from oxygen vacancies at the surface of ZnO. This can be analyzed semi-quantitatively by the surface trap energy density obtained by voltage power spectral density. For the photosensitive chip treated by 300° air-anneal, we can obtain the largest responsivity 6.7 A/W, the smallest noise equivalent power W, and the largest specific detectivity Jones at 300 nm under the bias of 5 V. The excellent photoresponse performance is also indicated by large linear dynamic range and fast response and recovery speeds.
Autors: Zhi Yang;Mingnan Le;Minqiang Wang;Ke Zhang;Xiangming Li;Jinyou Shao;Wenhao Chen;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4447 - 4453
Publisher: IEEE
 
» Physical Models of Planar Spiral Inductor Integrated on the High-Resistivity and Trap-Rich Silicon-on-Insulator Substrates
Abstract:
High-resistivity(HR) silicon-on-insulator (SOI) substrates provide low substrate loss, so planar spiral inductors integrated on them presenting higher quality factor () than those on traditional Si substrates. However, the parasitic surface conduction (PSC) effect in the SOI substrate constitutes a conductive layer underneath the buried oxide layer, which deteriorates the inductors performance. This effect can be effectively eliminated by introducing a trap-rich layer. In this paper, physical models that can accurately characterize the behavior of inductors integrated on the HR and radio frequency enhanced signal integrity (RFeSI) SOI substrates are presented, and the analysis and evaluation of PSC effect on the performance of inductors, i.e., the inductance, the quality factor, the self-resonant frequency, and the frequency, where peaks, are shown. Planar spiral inductors integrated on HR and RFeSI SOI substrates are fabricated and measured, validating the feasibility of the models we use. The experiment results show that the value of and the frequency where it peaks can be improved significantly by eliminating the PSC effect. The temperature effects are also explored, showing that the PSC effect gets worse with raising temperature and accelerates the degradation rate of .
Autors: Shuangke Liu;Lei Zhu;Frederic Allibert;Ionut Radu;Xinen Zhu;Yumin Lu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 2775 - 2781
Publisher: IEEE
 
» Physical-Layer Authentication Based on Extreme Learning Machine
Abstract:
Most physical-layer authentication techniques use hypothesis tests to compare the radio channel information with the channel record of Alice to detect spoofer Eve in wireless networks. However, the test threshold in the hypothesis test is not always available, especially in dynamic networks. In this letter, we propose a physical-layer authentication scheme based on extreme learning machine that exploit multi-dimensional characters of radio channels and use the training data generated from the spoofing model to improve the spoofing detection accuracy. Simulation results show that our proposed technique can significantly improve the authentication accuracy compared with the state-of-the-art method.
Autors: Ning Wang;Ting Jiang;Shichao Lv;Liang Xiao;
Appeared in: IEEE Communications Letters
Publication date: Jul 2017, volume: 21, issue:7, pages: 1557 - 1560
Publisher: IEEE
 
» Physically Unclonable Function Using an Initial Waveform of Ring Oscillators
Abstract:
A silicon physically unclonable function (PUF) is considered to be one of the key security system solutions for local devices in an era in which the Internet is pervasive. Among many proposals, a PUF using ring oscillators (RO-PUF) has the advantage of easy application to a field-programmable gate array (FPGA). In the conventional RO-PUF, the frequency difference between two ROs is used as one bit of identification (ID). Thus, in order to obtain an ID of long bit length, the corresponding number of RO pairs are required and, consequently, power consumption is large, leading to difficulty in implementing RO-PUF in local devices. Here, we provide an RO-PUF using the initial waveform of the ROs. Because a waveform constitutes a part of the ID, the number of ROs is greatly reduced, and the time needed to generate the ID is finished in a couple of system clocks. We also propose a solution to a change of PUF performance attributable to temperature or voltage change.
Autors: Tetsufumi Tanamoto;Shinich Yasuda;Satoshi Takaya;Shinobu Fujita;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jul 2017, volume: 64, issue:7, pages: 827 - 831
Publisher: IEEE
 
» Pilot Precoding and Combining in Multiuser MIMO Networks
Abstract:
Although the benefits of precoding and combining data signals are widely recognized, the potential of these techniques for pilot transmission is not fully understood. This is particularly relevant for multiuser multiple-input multiple-output (MU-MIMO) cellular systems using millimeter-wave (mmWave) communications, where multiple antennas have to be used both at the transmitter and the receiver to overcome the severe path loss. In this paper, we characterize the gains of pilot precoding and combining in terms of channel estimation quality and achievable data rate. Specifically, we consider three uplink pilot transmission scenarios in an mmWave MU-MIMO cellular system: 1) non-precoded and uncombined; 2) precoded but uncombined; and 3) precoded and combined. We show that a simple precoder that utilizes only the second-order statistics of the channel reduces the variance of the channel estimation error by a factor that is proportional to the number of user equipment (UE) antennas. We also show that using a linear combiner design based on the second-order statistics of the channel significantly reduces multiuser interference and provides the possibility of reusing some pilots. Specifically, in the large antenna regime, pilot precoding and combining help to accommodate a large number of UEs in one cell, significantly improve channel estimation quality, boost the signal-to-noise ratio of the UEs located close to the cell edges, alleviate pilot contamination, and address the imbalanced coverage of pilot and data signals.
Autors: Nima N. Moghadam;Hossein Shokri-Ghadikolaei;Gabor Fodor;Mats Bengtsson;Carlo Fischione;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jul 2017, volume: 35, issue:7, pages: 1632 - 1648
Publisher: IEEE
 
» Planar High-efficiency Antenna Array Using New Printed Ridge Gap Waveguide Technology
Abstract:
High-efficiency millimeter wave antenna array is proposed. A cooperate feeding network is designed using the new printed ridge gap waveguide technology, which is self-packaged with low loss. The feeding network is designed to couple to narrow slots arranged in a planar array that is coupled to printed broadband magnetoelectric (ME) dipoles. An array of ME dipoles is designed. The simulated results are verified with measurements. The measured reflection coefficient is less than −10 dB over 16.5% bandwidth (28.8–34 GHz). The measured antenna gain is higher than 19 dBi, and the cross polarization measured gain is around −35 dB within the main beam. Furthermore, the measured total radiation efficiency is 70%, and the measured aperture efficiency corresponds to 90% at 30.2 GHz.
Autors: Milad Sharifi Sorkherizi;Abdolmehdi Dadgarpour;Ahmed A. Kishk;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3772 - 3776
Publisher: IEEE
 
» Plasma-Catalytic Reforming of Biofuels and Diesel Fuel
Abstract:
The replacement of fossil hydrocarbons with the renewable biomass alternatives is an inevitable requirement in our transition toward a sustainable economy. However, traditional petrochemical technologies are not designed to operate using biomass raw materials. Thus, the development of new hydrocarbon processing methods is essential. This paper deals with the study of the hybrid plasma-catalytic reforming of liquid hydrocarbons. The system for the reforming of liquid hydrocarbons, which used low-power rotating gliding discharge as a plasma generator, was studied. Sunflower oil (C17H33COOH) and ethanol (C2H5OH) have been used as model oxygen-containing hydrocarbons and diesel fuel (C16H34) has been used as a model hydrocarbon without oxygen. Reforming products have been analyzed using mass spectrometry and gas chromatography, and the combustion of produced syngas was studied. The values of the reforming efficiency, the ratio between the chemical energy of the produced syngas and the electric energy spent on the plasma generation, and the efficiency of the produced syngas combustion in the standard water heaters were obtained.
Autors: Oleg A. Nedybaliuk;Valeriy Ya. Chernyak;Igor I. Fedirchyk;Valentina P. Demchina;Volodymyr S. Popkov;Mykola V. Bogaenko;Vitaliy V. Iukhymenko;Nikolay V. Klochok;Evgen V. Martysh;Valeriy A. Bortyshevsky;Raisa V. Korzh;Semen V. Dragnev;Olena V. Prysiazh
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jul 2017, volume: 45, issue:7, pages: 1803 - 1811
Publisher: IEEE
 
» Plotting a Moore's law for flexible electronics [News]
Abstract:
At a meeting in mid-town Manhattan, Kris Myny picks up what looks like an ordinary paper business card and, with little fanfare, holds it to his smartphone. The details of the card appear almost immediately on the screen inside a custom app.
Autors: Rachel Courtland;
Appeared in: IEEE Spectrum
Publication date: Jul 2017, volume: 54, issue:7, pages: 7 - 8
Publisher: IEEE
 
» Polar Scale-Invariant Feature Transform for Synthetic Aperture Radar Image Registration
Abstract:
Obtaining high accuracy in orientation assignment for Synthetic Aperture Radar (SAR) image registration is a great challenge because of the serious speckle noise and geometrical distortion. In this letter, a polar scale-invariant feature transform (PSIFT) descriptor is proposed for SAR image registration. The novel descriptor is invariant to rotation, skipping the dominant orientation assignment. In PSIFT, a polar-transformed support region is adopted to calculate the gradient magnitudes and orientations and further sampled in the radial and angular directions with different scales. The final descriptor is then built with the orientation bins covering the omnidirectional space. Furthermore, an improved dual-matching method is proposed to achieve sufficiently correct matches. Extensive experiments confirm that the PSIFT descriptor is suitable for SAR image registration because of its excellent performance.
Autors: Lina Zeng;Deyun Zhou;Junli Liang;Kun Zhang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 1101 - 1105
Publisher: IEEE
 
» Polarization-Tracking-Free IFoF Mobile Fronthaul With Adaptively Modulated PDM Multiband DDO-OFDM
Abstract:
This letter proposes a polarization-tracking-free polarization division multiplexing (PDM) in an intermediate frequency over fiber mobile fronthaul system based on multiband direct detection optical orthogonal frequency division multiplexing (DDO-OFDM) with adaptive modulation. The use of two orthogonally polarized optical carriers with a simple optical filter at each radio access unit is sufficient to perform passive demultiplexing of the corresponding multiband signals in PDM schemes without transmission efficiency loss in training signal, which is commonly found in conventional PDM demultiplexing schemes. We experimentally achieved a multiband OFDM signal with adaptive modulation, which maximizes signal capacity, in a PDM scheme with the data rate of 49.64 Gb/s, which doubles that of corresponding single polarization schemes, over a 25-km single mode fiber. We also achieved a 6-dB power margin which is sufficient for the wireless transmission part.
Autors: Shing-Jiuan Liu;Jhih-Heng Yan;Chen-Yao Tseng;Kai-Ming Feng;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2017, volume: 29, issue:14, pages: 1211 - 1214
Publisher: IEEE
 
» Polarized Remote Sensing: A Note on the Stokes Parameters Measurements From Natural and Man-Made Targets Using a Spectrometer
Abstract:
Polarized light has been studied over the past four decades as a useful signal to enhance the information from a variety of remote sensing applications. In the measurement process, the Stokes parameters are usually used to describe the state of polarization of light reflected from target surfaces. However, there is no research concerning the influence of extinction of the polarizer on the polarization properties derived from the Stokes parameters when we perform the polarimetric measurements of target surfaces using a spectrometer. In this paper, we measured the Stokes parameters of six natural surfaces (two soil samples, three vegetation covers, and a single leaf) and two man-made targets over a wide range of viewing directions at different incident zenith angles in the laboratory under two measurement conditions: considering and without considering the extinction of the polarizer. The comparison of these measured results indicated that the extinction of the polarizer, which was taken from the Spectralon panel, decreased the parameter and the bidirectional polarized reflectance factor of all the samples. Moreover, it is safe to use the parameter to represent the total reflected intensity of all our samples when we considered the extinction of the polarizer. Thus, the polarimetric measurements of target surfaces can not only give us the polarization information but also provide a reliable intensity signal.
Autors: Zhongqiu Sun;Yanhua Huang;Yulong Bao;Di Wu;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jul 2017, volume: 55, issue:7, pages: 4008 - 4021
Publisher: IEEE
 
» Position Control of Asymmetric Nonlinearities for a Cable-Conduit Mechanism
Abstract:
Cable-conduit mechanism (CCM) is widely used in robotic hands, rescue robots, rehabilitation robots, and surgical robots because it offers efficient transmission of forces/torques from the external actuator to the end effector with lightweight and high flexibility. However, the accurate position control is challenging in such mechanism due to friction and backlash-like hysteresis between the cable and the conduit. In this paper, a new control approach is proposed to enhance the trajectory tracking performances of the CCM. Unlike current approaches for the CCM in the literature, the proposed scheme considers the position transmission of the CCM as an approximation of backlash-like hysteresis nonlinearities without requiring the exact values of model parameters and their bounds. Online approximation-based robust control laws, which have the capabilities of estimating unknown system parameters, are also established. In addition, the deigned controller can adapt to any changes of the cable-conduit configuration and it is stable. The results of the proposed control techniques have been experimentally validated on a flexible robotic system using a flexible endoscope. Experimental validations show substantial improvements on the performances of position tracking for the use of CCM regardless of the arbitrary changes of the cable-conduit configurations.
Autors: Thanh Nho Do;Tegoeh Tjahjowidodo;Michael Wai Shing Lau;Soo Jay Phee;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jul 2017, volume: 14, issue:3, pages: 1515 - 1523
Publisher: IEEE
 
» Power Electronics Based Active Load for Unintentional Islanding Testbenches
Abstract:
The paper discusses the emulation of a parallel resonant load by means of an electronic power converter. The main application of the analyzed approach is in the testing of grid connected resources (e.g., renewable sources), where it allows us to ease testing procedure, minimize wasted power, and reduce test-bench size. To this end, an effective control system is proposed, analyzed, and designed considering a current-controlled inverter as the basis of emulator development. The limitations of the control system are explored, highlighting the requirements of the controller in order to achieve desired emulation accuracies and avoid instability. The reported studies are verified by means of both simulations and experimental tests performed on a laboratory prototype. In particular, the proposed modeling is able to predict the presence of resonant peaks close to the current control bandwidth, giving in this way useful guidelines to minimize such an undesired effect, which is detrimental for stability when the load is connected to other systems. Finally, the experimental results from an unintentional islanding test are reported to show the equivalence of the developed active load with respect to a passive one.
Autors: Tommaso Caldognetto;Luca Dalla Santa;Paolo Magnone;Paolo Mattavelli;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3831 - 3839
Publisher: IEEE
 
» Power Grid Resilience [Scanning the Issue]
Abstract:
Hurricane Sandy and other recent extreme weather events, which have caused significant service interruptions including power outages, have revealed that our power grid is not sufficiently planned and operated to be resilient to large-scale events. Power grid resilience is a generic term that covers many aspects of power grid planning and operation. A resilient power grid should be capable of executing preventive measures, mitigating the impact of extreme events, responding optimally by automated control procedures, reducing the time needed to restore service to consumers, and potentially leading to significant economic savings. In addition, due to the growing usage of information and communication technologies (ICT), power grids are being increasingly exposed to cyber attacks. The recent blackout in Ukraine serves as a good example to illustrate the severe consequence that cyber attacks on the power grid can entail. Extensive reports and media coverage indicate the urgency to improve our power grid resilience. Maintaining resilience of the power grid is crucial to our nation’s energy security and sustainability.
Autors: Jianhui Wang;Hamid Gharavi;
Appeared in: Proceedings of the IEEE
Publication date: Jul 2017, volume: 105, issue:7, pages: 1199 - 1201
Publisher: IEEE
 
» Power Scaling of Full-Duplex Two-Way Massive MIMO Relay Systems With Correlated Antennas and MRC/MRT Processing
Abstract:
In this paper, the performance of full-duplex (FD) two-way massive multiple-input multiple-output (MIMO) relay systems is analyzed. One popular linear relaying scheme, i.e., maximum ratio combining/maximum ratio transmission relaying, is particularly investigated. Different from prior analyses, multi-pair of MIMO users and antenna correlation at both the relay and the users are considered. Asymptotic sum-rate under a general case is first derived. Four special power scaling cases are then discussed and the corresponding asymptotic sum-rates are derived in simple forms with clear insights. The analytical results clearly quantify the impacts of self-loop interference, intra-group interference and antenna correlation, and discover the power scaling laws under various cases. It is found that the transmission powers at both the MIMO users and the relay can be scaled down inversely proportional to the number of antennas at the relay while maintaining a desirable sum-rate when the number of antennas at the relay grows large. The FD two-way massive MIMO relay system is finally compared with the half-duplex (HD) counterpart. It is revealed that under two special power scaling cases, the FD system can achieve double sum-rate when compared with the HD system. However, under the other two power scaling cases, self-loop interference and intra-group interference degrade the asymptotic sum-rate and the FD system may perform worse than the HD system. The maximum allowable self-loop interference for the FD system to outperform the HD system is given explicitly. In addition, the impact of antenna correlation at the users and the relay is analyzed. The results show that the antenna correlation at the users has complicate impact on the sum-rate, while the antenna correlation at the relay may not affect the sum-rate under certain power scaling cases.
Autors: Junjuan Feng;Shaodan Ma;Guanghua Yang;Bin Xia;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2017, volume: 16, issue:7, pages: 4738 - 4753
Publisher: IEEE
 
» Power System Sensitivity Identification—Inherent System Properties and Data Quality
Abstract:
The increasing amount of data recorded during power system operations and recently developed data-driven methods make online sensitivity identification (SI) a possibility. However, due to the inherent properties of power systems—nonlinearity, time variance, and collinearity—the effective data that carry the sensitivity information are insufficient. Consequently, the online SI information collected with existing methods may result in unexpected estimates. In this paper, a sufficient effective data condition that guarantees the success of online SI is proposed. The inherent properties of power systems and their impacts on this condition are then investigated. A series of metrics to qualify online whether the data meet the condition is put forward to assess the online SI results. A method is also proposed to select the effective data to improve the online computational efficiency. Finally, the findings and methods are validated in an eight-generator 36-node bus system with operations data recorded from actual power systems.
Autors: Junbo Zhang;Xiangtian Zheng;Zejing Wang;Lin Guan;C. Y. Chung;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2756 - 2766
Publisher: IEEE
 
» Power Systems Resilience Assessment: Hardening and Smart Operational Enhancement Strategies
Abstract:
Power systems have typically been designed to be reliable to expected, low-impact high-frequency outages. In contrast, extreme events, driven for instance by extreme weather and natural disasters, happen with low-probability, but can have a high impact. The need for power systems, possibly the most critical infrastructures in the world, to become resilient to such events is becoming compelling. However, there is still little clarity as to this relatively new concept. On these premises, this paper provides an introduction to the fundamental concepts of power systems resilience and to the use of hardening and smart operational strategies to improve it. More specifically, first the resilience trapezoid is introduced as visual tool to reflect the behavior of a power system during a catastrophic event. Building on this, the key resilience features that a power system should boast are then defined, along with a discussion on different possible hardening and smart, operational resilience enhancement strategies. Further, the so-called resilience assessment framework is presented, which includes a set of resilience metrics capable of modeling and quantifying the resilience performance of a power system subject to catastrophic events. A case study application with a 29-bus test version of the Great Britain transmission network is carried out to investigate the impacts of extreme windstorms. The effects of different hardening and smart resilience enhancement strategies are also explored, thus demonstrating the practicality of the different concepts presented.
Autors: Mathaios Panteli;Dimitris N. Trakas;Pierluigi Mancarella;Nikos D. Hatziargyriou;
Appeared in: Proceedings of the IEEE
Publication date: Jul 2017, volume: 105, issue:7, pages: 1202 - 1213
Publisher: IEEE
 
» Power-Electronics-Enabled Autonomous Power Systems
Abstract:
The eleven papers in this special section focus on power electronics-enabled autonomous systems. Power systems are going through a paradigm change from centralized generation to distributed generation and further onto smart grid. Millions of relatively small distributed energy resources (DER), including wind turbines, solar panels, electric vehicles and energy storage systems, and flexible loads are being integrated into power systems through power electronic converters. This imposes great challenges to the stability, scalability, reliability, security, and resiliency of future power systems. This section joins the forces of the communities of control/systems theory, power electronics, and power systems to address various emerging issues of power-electronics-enabled autonomous power systems, paving the way for large-scale deployment of DERs and flexible loads.
Autors: Qing-Chang Zhong;Frede Blaabjerg;Carlo Cecati;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5904 - 5906
Publisher: IEEE
 
» Power-Electronics-Enabled Autonomous Power Systems: Architecture and Technical Routes
Abstract:
Power systems are going through a paradigm change from centralized generation to distributed generation and further on to smart grids. In this paper, it is shown that future power systems will be power electronics based, instead of electric machines based, with a huge number of incompatible players and that the fundamental challenge behind this paradigm change is how to make sure these players could work together and maintain system stability. Then, a lateral architecture based on the synchronization mechanism of synchronous machines (SM), which has underpinned the growth and operation of power systems for over 100 years, is proposed to unify the integration and interaction of these players with the grid by operating power electronic converters to behave like virtual synchronous machines (VSM), which are coined cyber synchronous machines (CSM) here. Thus, all the suppliers and the majority of loads can follow the same mechanism to regulate system stability. This paves the way for autonomous operation of future power systems. Moreover, two technical routes, one based on the synchronverter technology and the other based on the robust droop control technology, are proposed to implement the architecture. Real-time simulation results are presented to illustrate the operation of such a system.
Autors: Qing-Chang Zhong;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5907 - 5918
Publisher: IEEE
 
» Powering the Future: New Initiatives for the Society [Leaders' Corner]
Abstract:
Reports on new initatives, areas of project development, and activities planned for PES society members.
Autors: Tommy Mayne;Shay Bahramirad;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 8 - 14
Publisher: IEEE
 
» Precision Packet-Based Frequency Transfer Based on Oversampling
Abstract:
Frequency synchronization of a distributed measurement system requires the transfer of an accurate frequency reference to all nodes. The use of a general-purpose packet-based network for this aim is analyzed in this paper, where oversampling is considered as a means to counter the effects of packet delay variation on time accuracy. A comprehensive analysis that includes the stability of the local clock is presented and shows that frequency transfer through a packet network of this kind is feasible, with an accuracy level that can be of interest to a number of distributed measurement applications.
Autors: Giada Giorgi;Claudio Narduzzi;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1856 - 1863
Publisher: IEEE
 
» Precoding and Power Optimization in Cell-Free Massive MIMO Systems
Abstract:
Cell-free Massive multiple-input multiple-output (MIMO) comprises a large number of distributed low-cost low-power single antenna access points (APs) connected to a network controller. The number of AP antennas is significantly larger than the number of users. The system is not partitioned into cells and each user is served by all APs simultaneously. The simplest linear precoding schemes are conjugate beamforming and zero-forcing. Max–min power control provides equal throughput to all users and is considered in this paper. Surprisingly, under max–min power control, most APs are found to transmit at less than full power. The zero-forcing precoder significantly outperforms conjugate beamforming. For zero-forcing, a near-optimal power control algorithm is developed that is considerably simpler than exact max–min power control. An alternative to cell-free systems is small-cell operation in which each user is served by only one AP for which power optimization algorithms are also developed. Cell-free Massive MIMO is shown to provide five- to ten-fold improvement in 95%-likely per-user throughput over small-cell operation.
Autors: Elina Nayebi;Alexei Ashikhmin;Thomas L. Marzetta;Hong Yang;Bhaskar D. Rao;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2017, volume: 16, issue:7, pages: 4445 - 4459
Publisher: IEEE
 
» Predicting Upcoming Values of Stress While Driving
Abstract:
The levels of stress while driving affect the way we drive and have an impact on the likelihood of having an accident. Different types of sensors, such as heart rate or skin conductivity sensors, have been previously used to measure stress related features. Estimated stress levels could be used to adapt the driver’s environment to minimize distractions in high cognitive demanding situations and to promote stress-friendly driving behaviors. The way we drive has an impact on how stressors affect the perceived cognitive demands by drivers, and at the same time, the perceived stress has an impact on the actions taken by the driver. In this paper, we evaluate how effectively upcoming stress levels can be predicted considering current stress levels, current driving behavior, and the shape of the road. We use features, such as the positive kinetic energy and severity of curves on the road to estimate how stress levels will evolve in the next minute. Different machine learning techniques are evaluated and the results for both intra and inter-city driving and for both intra and inter driver data are presented. We have used data from four different drivers with three different car models and a motorbike and more than 220 test drives. Results show that upcoming stress levels can be accurately predicted for a single user (correlation r = 0.99 and classification accuracy 97.5%) but prediction for different users is more limited (correlation r = 0.92 and classification accuracy 46.9%).
Autors: Mario Muñoz-Organero;Victor Corcoba-Magaña;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jul 2017, volume: 18, issue:7, pages: 1802 - 1811
Publisher: IEEE
 
» Prediction of Losses and Efficiency for Three-Phase Induction Machines Equipped With Combined Star–Delta Windings
Abstract:
Combined star–delta windings in electrical machines result in a higher fundamental winding factor and cause a smaller spatial harmonic content. This leads to lower I2R losses in the stator and the rotor windings, and thus to an increased efficiency. However, compared with an equivalent six-phase winding, additional spatial harmonics are generated due to the different magnetomotive forces in the star and the delta parts of the winding. In this paper, a complete theory and analysis method for the analytical calculation of the efficiency for induction motors equipped with combined star–delta windings is developed. The method takes into account the additional harmonic content due to the different magnetomotive forces in the star and delta parts. To check the analysis’ validity, an experimental test is reported both on a cage induction motor equipped with a combined star–delta winding in the stator and on a reference motor with the same core, but with a classical three-phase winding.
Autors: Onur Misir;Seyed Morteza Raziee;Nabil Hammouche;Christoph Klaus;Rainer Kluge;Bernd Ponick;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3579 - 3587
Publisher: IEEE
 
» Predictive Analysis of Microgrid Reliability Using a Probabilistic Model of Protection System Operation
Abstract:
Protection continues to be an important factor in the development of microgrids. In this paper, an evaluation strategy is proposed to quantify the effects of deficient protection scheme on reliability indices in a microgrid. In particular, the evaluation strategy takes into account the trigger probability of protective actions under abnormal operating conditions, such as warranted trips, rejections, and malfunctions. This trigger probability in per unit time is defined as dynamic outage rate to distinguish the static outage rate (i.e., random outage rate). A probabilistic model is constructed by simulating system operating conditions to determine the trigger probability. The model can be characterized by the previously proposed virtual setting value, which can be determined by a predictive analysis to minimize the probability of incorrect protective actions under different operating conditions. With the proposed evaluation strategy, the significance of the impacts of the protection system, in terms of dynamic outage rate and static outage rate, on the operational reliability are demonstrated with a 400 V microgrid system.
Autors: Xufeng Xu;Tingting Wang;Longhua Mu;Joydeep Mitra;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 3176 - 3184
Publisher: IEEE
 
» Preventive Maintenance for Electrical Reliability: A Proposed Metric Using Mean Time Between Failures Plus Finds
Abstract:
Electrical reliability can be measured by taking a systematic approach to documenting preventive maintenance (PM) records with a metric derived from its discovery finds. These finds, however minor, are leading indicators of equipment failures. Therefore, documenting and reviewing them can justify electrical PM programs, measure PM effectiveness, and optimize PM intervals. The investigation of a refinery process upset brought on by electrical equipment failure due to inadequate maintenance is often required for the benefits of electrical PM to be realized as a good business practice. When electrical repairs and PM results are consistently collected and effectively reviewed, the measure of a refinery’s electrical reliability is realized. The result is a data set that is presentable and understandable to refinery leadership. When this metric is introduced to other refineries enterprisewide as a comparative key performance indicator (KPI), electrical PM becomes a supported and institutionalized program that leadership identifies as paramount to business reliability.
Autors: John R. Duenckel;Robert Soileau;Jerry D. Pittman;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jul 2017, volume: 23, issue:4, pages: 45 - 56
Publisher: IEEE
 
» Priority Ranking of Critical Uncertainties Affecting Small-Disturbance Stability Using Sensitivity Analysis Techniques
Abstract:
This paper critically evaluates a number of sensitivity analysis (SA) techniques to identify the most influential parameters affecting power system small-disturbance stability. SA of uncertain parameters has attracted increased attention with the adoption of deregulated market structure, intermittent energy resources, and new types of loads. Identification of the most influential parameters affecting system stability using SA techniques will facilitate better operation and control with reduced monitoring (only of the parameters of interest) by system operators and stakeholders. In total, nine SA techniques have been described, implemented, and compared in this paper. These can be categorized into three different types: local, screening, and global SA. This comparative analysis highlights their computational complexity and simulation time. The methods have been illustrated using a two-area power system and 68 bus NETS-NYPS test system. The priority ranking of all uncertain parameters has been evaluated, identifying the most critical parameters with respect to the small-signal stability of the test systems. It is shown that for many applications, the Morris screening approach is most suitable, providing a good balance between accuracy and efficiency.
Autors: Kazi Nazmul Hasan;Robin Preece;Jovica V. Milanović;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2629 - 2639
Publisher: IEEE
 
» Probabilistic Forecast of PV Power Generation Based on Higher Order Markov Chain
Abstract:
This paper presents a method to forecast the probability distribution function (PDF) of the generated power of PV systems based on the higher order Markov chain (HMC). Since the output power of the PV system is highly influenced by ambient temperature and solar irradiance, they are used as important features to classify different operating conditions of the PV system. The classification procedure is carried out by applying the pattern discovery method on the historical data of the mentioned variables. An HMC is developed based on the categorized historical data of PV power in each operating point. The 15-min ahead PDF of the PV output power is forecasted through the Gaussian mixture method (GMM) by combining several distribution functions and by using the coefficients defined based on parameters of the HMC-based model. In order to verify the proposed method, the genetic algorithm is applied to minimize a well-defined objective function to achieve the optimal GMM coefficients. Numerical tests using real data demonstrate that the forecast results follow the real probability distribution of the PV power well under different weather conditions.
Autors: Mohammad Javad Sanjari;H. B. Gooi;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2942 - 2952
Publisher: IEEE
 
» Probabilistic Framework for Transient Stability Assessment of Power Systems With High Penetration of Renewable Generation
Abstract:
This paper introduces a probabilistic framework for transient stability assessment (TSA) of power systems with high penetration of renewable generation. The critical generators and areas of the system are identified using a method based on hierarchical clustering. Furthermore, statistical analysis of several transient stability indices is performed to assess their suitability for TSA of reduced inertia systems. The proposed framework facilitates robust assessment of transient stability of uncertain power systems with reduced inertia.
Autors: Panagiotis N. Papadopoulos;Jovica V. Milanović;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 3078 - 3088
Publisher: IEEE
 
» Probabilistic Jamming/Eavesdropping Attacks to Confuse a Buffer-Aided Transmitter–Receiver Pair
Abstract:
We assume that a buffer-aided transmitter communicates with a receiving node in the presence of an attacker. We investigate the impact of a radio-frequency energy-harvesting attacker that probabilistically operates as a jammer or an eavesdropper. We show that even without the need for an external energy source, the attacker can still degrade the security of the legitimate system. We show that the random data arrival behavior at the transmitter and the channel randomness of the legitimate link can improve the system’s security. We design a jamming scheme for the attacker and investigate its impact on the secure throughput of the legitimate system. The attacker designs his power splitting parameter and jamming/eavesdropping probability based on the energy state of the attacker’s battery to minimize the secure throughput of the legitimate system.
Autors: Ahmed El Shafie;Kamel Tourki;Zhiguo Ding;Naofal Al-Dhahir;
Appeared in: IEEE Communications Letters
Publication date: Jul 2017, volume: 21, issue:7, pages: 1549 - 1552
Publisher: IEEE
 
» Probabilistic Models and Algorithms for Data Synchronization/Broadcast Via Network Coding
Abstract:
We investigate the problem of data synchronization in which a sender has a set of packets to be distributed to all the receivers via a broadcast channel. Initially, each receiver has some fraction of the packets. At each time slot, the sender might broadcast a packet to all the receivers. The goal is to find a broadcast scheme that minimizes the number of time slots until all the receivers successfully obtain all the packets. We propose two probabilistic models on how the initial fractions of packets at receivers are distributed. These models arise naturally in many large-scale systems, such as peer-to-peer networks, data centers, and distributed storage systems. Based on these models, we establish probabilistic bounds and asymptotic results on the minimum number of time slots to successfully transmit all the packets to all the receivers. Next, we propose and analyze a number of random network coding algorithms for finding the approximately optimal solution. Theoretical analysis and simulations are provided to verify the probabilistic bounds and the proposed algorithms.
Autors: Duong Nguyen-Huu;Thinh Nguyen;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6075 - 6088
Publisher: IEEE
 
» Probabilistic Prediction of Bus Headway Using Relevance Vector Machine Regression
Abstract:
Bus headway regularity heavily affects transit riders’ attitude for choosing public transportation and also serves as an important indicator for transit performance evaluation. Therefore, an accurate estimate of bus headway can benefit both transit riders and transit operators. This paper proposed a relevance vector machine (RVM) algorithm to predict bus headway by incorporating the time series of bus headways, travel time, and passenger demand at previous stops. Different from traditional computational intelligence approaches, RVM can output the probabilistic prediction result, in which the upper and lower bounds of a predicted headway within a certain probability are yielded. An empirical experiment with two bus routes in Beijing, China, is utilized to confirm the high precision and strong robustness of the proposed model. Five algorithms [support vector machine (SVM), genetic algorithm SVM, Kalman filter, k-nearest neighbor, and artificial neural network] are used for comparison with the RVM model and the result indicates that RVM outperforms these algorithms in terms of accuracy and confidence intervals. When the confidence level is set to 95%, more than 95% of actual bus headways fall within the prediction bands. With the probabilistic bus headway prediction information, transit riders can better schedule their trips to avoid late and early arrivals at bus stops, while transit operators can adopt the targeted correction actions to maintain regular headway for bus bunching prevention.
Autors: Haiyang Yu;Zhihai Wu;Dongwei Chen;Xiaolei Ma;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jul 2017, volume: 18, issue:7, pages: 1772 - 1781
Publisher: IEEE
 
» Procrustean Normal Distribution for Non-Rigid Structure from Motion
Abstract:
A well-defined deformation model can be vital for non-rigid structure from motion (NRSfM). Most existing methods restrict the deformation space by assuming a fixed rank or smooth deformation, which are not exactly true in the real world, and they require the degree of deformation to be predetermined, which is impractical. Meanwhile, the errors in rotation estimation can have severe effects on the performance, i.e., these errors can make a rigid motion be misinterpreted as a deformation. In this paper, we propose an alternative to resolve these issues, motivated by an observation that non-rigid deformations, excluding rigid changes, can be concisely represented in a linear subspace without imposing any strong constraints, such as smoothness or low-rank. This observation is embedded in our new prior distribution, the Procrustean normal distribution (PND), which is a shape distribution exclusively for non-rigid deformations. Because of this unique characteristic of the PND, rigid and non-rigid changes can be strictly separated, which leads to better performance. The proposed algorithm, EM-PND, fits a PND to given 2D observations to solve NRSfM without any user-determined parameters. The experimental results show that EM-PND gives the state-of-the-art performance for the benchmark data sets, confirming the adequacy of the new deformation model.
Autors: Minsik Lee;Jungchan Cho;Songhwai Oh;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jul 2017, volume: 39, issue:7, pages: 1388 - 1400
Publisher: IEEE
 
» Profile: Plex.AI [Resources_Startups]
Abstract:
If Internet-connected cars, the blockchain, and machine learning are each going to change the world in its own unique way, what happens when all three are combined? One startup company, based in Kitchener, Ont., Canada, is exploring this question in the unlikely arena of insurance.
Autors: Mark Anderson;
Appeared in: IEEE Spectrum
Publication date: Jul 2017, volume: 54, issue:7, pages: 19 - 19
Publisher: IEEE
 
» Profiling Entities over Time in the Presence of Unreliable Sources
Abstract:
To harness the rich amount of information available on the web today, many organizations aggregate public (and private) data to derive knowledge repositories for real-world entities. This paper aims to build historical profiles of real-world entities by integrating temporal records collected from different sources. This problem is challenging not only because entities may change their attribute values over time, but also because information provided by the sources could be unreliable. In this paper, we present a new solution for profiling entities over time. To understand the evolution of entities, we describe a novel transition model which gives the probability that an entity will change to a particular attribute value after some time period. Next, a set of quality metrics are defined for the data sources to capture the exactness and timeliness of their provided values. The transition model and the quality metrics are then built into a source-aware temporal matching algorithm that can link temporal records to entities at the right time and augment entity profiles with correct values. Our suite of experiments demonstrate that the proposed approach is able to outperform the state-of-the-art techniques by constructing more complete and accurate profiles for entities.
Autors: Furong Li;Mong Li Lee;Wynne Hsu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Jul 2017, volume: 29, issue:7, pages: 1522 - 1535
Publisher: IEEE
 
» Prognostics-Based LED Qualification Using Similarity-Based Statistical Measure With RVM Regression Model
Abstract:
Light-emitting diodes (LEDs) are widely used for general lighting and display applications. As the demand for LEDs has grown, the need to quickly qualify them has emerged. To address this issue, this paper introduces a prognostics-based qualification method using an efficient relevance vector machine (RVM) regression model that reduces the qualification testing time of LEDs from 6000 h (as recommended by industry standards) to 210 h. The developed method predicts LED remaining useful life (RUL) by calculating the accumulated sum of products of similarity weights and historical LED RUL values at the 210th hour. Specifically, a similarity weight, defined as the degree of affinity between two different LED's degradation trends, is derived from the difference between a test unit's degradation trend and a training unit's degradation trend. Likewise, the RVM is used to represent a unit's degradation behavior and facilitates the reduction of unit-to-unit variations by precisely capturing transient degradation dynamics.
Autors: Moon-Hwan Chang;Myeongsu Kang;Michael Pecht;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5667 - 5677
Publisher: IEEE
 
» Projective Networks: Topologies for Large Parallel Computer Systems
Abstract:
The interconnection network comprises a significant portion of the cost of large parallel computers, both in economic terms and power consumption. Several previous proposals exploit large-radix routers to build scalable low-distance topologies with the aim of minimizing these costs. However, they fail to consider potential unbalance in the network utilization, which in some cases results in suboptimal designs. Based on an appropriate cost model, this paper advocates the use of networks based on incidence graphs of projective planes, broadly denoted as Projective Networks. Projective Networks rely on generalized Moore graphs with uniform link utilization and encompass several proposed direct (PN and demi-PN) and indirect (OFT) topologies under a common mathematical framework. Compared to other proposals with average distance between 2 and 3 hops, these networks provide very high scalability while preserving a balanced network utilization, resulting in low network costs.
Autors: Cristóbal Camarero;Carmen Martínez;Enrique Vallejo;Ramón Beivide;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jul 2017, volume: 28, issue:7, pages: 2003 - 2016
Publisher: IEEE
 
» Propagating Uncertainty in Power-System DAE Models With Semidefinite Programming
Abstract:
This paper outlines a convex-optimization-based method to estimate maximum and minimum bounds on states of differential algebraic equations (DAEs) that describe the electromechanical dynamics of power systems while acknowledging parametric and input uncertainty in the model. The method is based on a second-order Taylor-series approximation of the DAE-model state trajectories as a function of the uncertainties. A key contribution in this regard is the derivation of a DAE model that governs the second-order trajectory sensitivities of states to uncertainties in the model. Bounds on the states are then obtained by solving semidefinite programs, where the objective is to maximize/minimize the Taylor-series approximations subject to constraints that describe the uncertainty space. While the computed bounds are approximate (since they are derived from a Taylor-series approximation of the state trajectories) the method nevertheless is an efficient system-theoretic approach to uncertainty propagation for power-system DAE models. Numerical case studies are presented for a DAE model of the IEEE 39-bus New England system to demonstrate scalability and validate the approach.
Autors: Hyungjin Choi;Peter J. Seiler;Sairaj V. Dhople;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 3146 - 3156
Publisher: IEEE
 
» Prototype of Field Waveform Digitizer for BaF2 Detector Array at CSNS-WNS
Abstract:
At the China spallation neutron source-white neutron sources (CSNS-WNS), the BaF2 (barium fluoride) detector array in planning is designed for neutron capture cross section measurements with high accuracy and efficiency. Once proton beam collides with the spallation target, the neutrons will fly from the target to specimen surrounded by BaF2 array and produce cascaded rays eventually. The time of flight (TOF) corresponds to the neutron energy. To identify signals from the high -particle background, pulse shape discrimination (PSD) technique is usually used according to the ratio of fast to slow component in the signal. Waveform digitization is a valid supporting technology for PSD. In order to precisely obtain the wave and time information carried by detector signal, and to maximally cover the signal dynamic range, a universal digitizer with 1 GSps sampling rate and 12-b resolution has been designed based on a 3U PXIe platform in this paper. Besides waveform digitization, this customized digitizer also measures TOF precisely based on the digitized waveform data and technique of time-to-digital converting on field-programming gate array. Test results show that this digitizer can achieve good static and dynamic performance. The specification of effective number of bits is better than 9.43 b within 198 MHz. Digitizer proposed in this paper can meet the requirements for BaF2 spectrum at CSNS-WNS.
Autors: Qi Wang;Ping Cao;Deliang Zhang;Xincheng Qi;Tao Yu;Di Jiang;Bing He;Yaxi Zhang;Qi An;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Jul 2017, volume: 64, issue:7, pages: 1988 - 1993
Publisher: IEEE
 
» Pulse Biasing Scheme for the Fast Recovery of FET-Type Gas Sensors for Reducing Gases
Abstract:
The promotive effect of a pre-bias condition on the recovery speed of a field-effect transistor-type gas sensor, which has a horizontal control gate (CG) and floating gate (FG), is investigated in this letter. To verify the pre-bias effect in the recovery phase after the detection of H2S gas, a type of reducing gas, a 200-nm-thick layer of SnOx is deposited on top of the interdigitated CG and FG as a sensing material. A pulse measurement method is proposed to improve the recovery speed of the sensor for H2S gas sensing by applying a negative pre-bias condition to the CG before the read operation of the sensor. This method greatly accelerates the recovery and reduces the recovery time by 74% with a pre-bias of −3 V at 180° C. The mechanism is explained in terms of energy band theory. The pre-biasing method used with our gas sensor is beneficial for the continuous monitoring and for the rapid detection of various gases.
Autors: Meile Wu;Jongmin Shin;Yoonki Hong;Xiaoshi Jin;Jong-Ho Lee;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 971 - 974
Publisher: IEEE
 
» Pump Power Reduction in Optical Fiber Amplifier for WDM-Interleaved Multi-Core/Multi-Fiber System
Abstract:
The effect of reducing the pump power in a multi-core erbium-doped fiber amplifier (MC-EDFA) designed for a wavelength-division-multiplexing-interleaved multi-core/multi-fiber system is investigated. An analysis of the asymptotic behavior of the pump power ratio of the MC-EDFA and discrete single-core EDFAs, derived by using the analytical EDFA model with an average inversion level, shows a remarkable effect of the pump power reduction in an MC-EDFA when the input signal power or the amplifier gain is small. Experimental results are consistent with the analysis of the pump efficiency. The allowable excess losses of optical components in an MC-EDFA are also investigated by using the analytical expression of an EDFA.
Autors: Hirotaka Ono;Makoto Yamada;Hiroji Masuda;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2017, volume: 29, issue:14, pages: 1163 - 1166
Publisher: IEEE
 
» Putting Magic Into a Hat
Abstract:
New students at Hogwarts School of Witchcraft and Wizardry approached the Sorting Hat with equal parts excitement and trepidation. How different would the story of "the boy who lived" have been had Harry Potter been sorted into the more sinister house of Slytherin rather than with the courageous crew in Gryffindor?
Autors: Craig Causer;
Appeared in: IEEE Potentials
Publication date: Jul 2017, volume: 36, issue:4, pages: 11 - 14
Publisher: IEEE
 
» QoE-Driven Channel Allocation and Handoff Management for Seamless Multimedia in Cognitive 5G Cellular Networks
Abstract:
Cognitive radio (CR) is among the promising solutions for overcoming the spectrum scarcity problem in the forthcoming fifth-generation (5G) cellular networks, whereas mobile stations are expected to support multimode operations to maintain connectivity to various radio access points. However, particularly for multimedia services, because of the time-varying channel capacity, the random arrivals of legacy users, and the on-negligible delay caused by spectrum handoff, it is challenging to achieve seamless streaming leading to minimum quality of experience (QoE) degradation. The objective of this paper is to manage spectrum handoff delays by allocating channels based on the user QoE expectations, minimizing the latency, providing seamless multimedia service, and improving QoE. First, to minimize the handoff delays, we use channel usage statistical information to compute the channel quality. Based on this, the cognitive base station maintains a ranking index of the available channels to facilitate the cognitive mobile stations. Second, to enhance channel utilization, we develop a priority-based channel allocation scheme to assign channels to the mobile stations based on their QoE requirements. Third, to minimize handoff delays, we employ the hidden markov model (HMM) to predict the state of the future time slot. However, due to sensing errors, the scheme proactively performs spectrum sensing and reactively acts handoffs. Fourth, we propose a handoff management technique to overcome the interruptions caused by the handoff. In such a way that, when a handoff is predicted, we use scalable video coding to extract the base layer and transmit it during a certain interval time before handoff occurrence to be shown during handoff delays, hence providing seamless service. Our simulation results highlight the performance gain of the proposed framework in terms of channel utilization and received video quality.
Autors: Md. Jalil Piran;Nguyen H. Tran;Doug Young Suh;Ju Bin Song;Choong Seon Hong;Zhu Han;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6569 - 6585
Publisher: IEEE
 
» Quadband Rectifier Using Resonant Matching Networks for Enhanced Harvesting Capability
Abstract:
A multiband rectifier was designed according to multiple resonator networks by simultaneously matching the rectifier at different frequencies (1.3, 1.7, 2.4, and 3.6 GHz). The rectifier can simultaneously harvest energy from RF sources at the L-band (1–2 GHz), GSM1800, Wi-Fi bands, and long-term evolution. Through sequential application of the resonator networks during the rectifier-matching process, the resonance characteristic of the resonator facilitates the nearly independent design of each matching frequency. A fabricated prototype showed a 1-V output voltage when the input power was set at −11 dBm for each of the four RF bands with a 3- load.
Autors: Chih-Yuan Hsu;Shih-Cheng Lin;Zuo-Min Tsai;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2017, volume: 27, issue:7, pages: 669 - 671
Publisher: IEEE
 
» Quantification of Storage Necessary to Firm Up Wind Generation
Abstract:
This paper proposes a method to quantitatively determine the sizes of energy storage systems that are intended to mitigate negative impacts of integrating wind energy into power systems. Although the integration of wind power has several advantages, it poses several technical challenges such as variability and uncertainty of wind speed and failures of wind turbine generators (WTGs), which may deteriorate the reliability of power systems. One of the most practical solutions to mitigate these drawbacks is the use of energy storage systems. The method proposed in this paper determines the sizes of the energy storage systems considering the effect of wind power uncertainty and variability, failures of WTGs, wind speed temporal resolution, and correlation with system load. Sizes of energy storage systems are determined based on composite system reliability analysis under operational and technical constraints using the ac power flow model. Monte Carlo simulation is used to emulate the behavior of the system. The proposed method is demonstrated on the IEEE reliability test system and the results are provided. The results show that the size of an energy storage system is dependent on wind farm characteristics, as well as the connectivity with the rest of the system.
Autors: Samer Sulaeman;Yuting Tian;Mohammed Benidris;Joydeep Mitra;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3228 - 3236
Publisher: IEEE
 
» Quantifying Backscatter Anisotropy Using the Reference Phantom Method
Abstract:
Acoustic properties can be exploited to infer and evaluate tissue microstructure. However, common assumptions are that the medium of interest is homogeneous and isotropic, and that its underlying physical properties cause diffuse scattering. In this paper, we describe how we developed and tested novel parameters designed to address isotropy/anisotropy in backscattered echo signal power in complex biological tissues. Specifically, we explored isotropy/anisotropy in backscattered power in isotropic phantoms (spherical glass beads), an anisotropic phantom (dialysis phantom with rodlike fibers), and an in vivo human tissue with well-described anisotropy (bicep muscle). Our approach uses the reference phantom method to compensate for system transfer and diffraction losses when electronically beamsteering a linear array transducer. We define three parameters to quantify the presence and orientation of anisotropic scatterers, as well as address magnitude of anisotropy. We found that these parameters can detect and sense the degree of anisotropy in backscatter in both phantoms and bicep muscle. Bias of the summary anisotropy parameters, induced through a speed of sound mismatch of sample media and reference phantom, was less than 0.2 dB if the speed of sound was within ±20 m/s of the sample media. In summary, these new parameters may be useful for testing the assumption of isotropy as well as providing more detailed information about the underlying microstructural sources of backscatter in complex biological tissues.
Autors: Quinton W. Guerrero;Ivan M. Rosado-Mendez;Lindsey C. Drehfal;Helen Feltovich;Timothy J. Hall;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Jul 2017, volume: 64, issue:7, pages: 1063 - 1077
Publisher: IEEE
 
» Quantifying the Interaction and Contribution of Multiple Datasets in Fusion: Application to the Detection of Schizophrenia
Abstract:
The extraction of information from multiple sets of data is a problem inherent to many disciplines. This is possible by either analyzing the data sets jointly as in data fusion or separately and then combining as in data integration. However, selecting the optimal method to combine and analyze multiset data is an ever-present challenge. The primary reason for this is the difficulty in determining the optimal contribution of each data set to an analysis as well as the amount of potentially exploitable complementary information among data sets. In this paper, we propose a novel classification rate-based technique to unambiguously quantify the contribution of each data set to a fusion result as well as facilitate direct comparisons of fusion methods on real data and apply a new method, independent vector analysis (IVA), to multiset fusion. This classification rate-based technique is used on functional magnetic resonance imaging data collected from 121 patients with schizophrenia and 150 healthy controls during the performance of three tasks. Through this application, we find that though optimal performance is achieved by exploiting all tasks, each task does not contribute equally to the result and this framework enables effective quantification of the value added by each task. Our results also demonstrate that data fusion methods are more powerful than data integration methods, with the former achieving a classification rate of 73.5 % and the latter achieving one of 70.9 %, a difference which we show is significant when all three tasks are analyzed together. Finally, we show that IVA, due to its flexibility, has equivalent or superior performance compared with the popular data fusion method, joint independent component analysis.
Autors: Yuri Levin-Schwartz;Vince D. Calhoun;Tülay Adalı;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jul 2017, volume: 36, issue:7, pages: 1385 - 1395
Publisher: IEEE
 
» Quantitative Approach for Thickness and Conductivity Measurement of Monolayer Coating by Dual-Frequency Eddy Current Technique
Abstract:
A new approach is proposed to measure the coating material's thickness and its conductivity simultaneously by using the eddy current technique. The proposed approach can be used for a coating material with unknown or inhomogeneous conductivity. This is achieved by exploring an inverse algorithm to investigate the relationship between the thickness and the perpendicular component of the magnetic flux density for different coating conductivities. The measured average relative error is less than 10%, which makes the monitoring of the coating thickness possible under variation of the conductivity due to the applied loads and the manufacturing process.
Autors: Yating Yu;Dejun Zhang;Chao Lai;Guiyun Tian;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1874 - 1882
Publisher: IEEE
 
» Query Expansion with Enriched User Profiles for Personalized Search Utilizing Folksonomy Data
Abstract:
Query expansion has been widely adopted in Web search as a way of tackling the ambiguity of queries. Personalized search utilizing folksonomy data has demonstrated an extreme vocabulary mismatch problem that requires even more effective query expansion methods. Co-occurrence statistics, tag-tag relationships, and semantic matching approaches are among those favored by previous research. However, user profiles which only contain a user's past annotation information may not be enough to support the selection of expansion terms, especially for users with limited previous activity with the system. We propose a novel model to construct enriched user profiles with the help of an external corpus for personalized query expansion. Our model integrates the current state-of-the-art text representation learning framework, known as word embeddings, with topic models in two groups of pseudo-aligned documents. Based on user profiles, we build two novel query expansion techniques. These two techniques are based on topical weights-enhanced word embeddings, and the topical relevance between the query and the terms inside a user profile, respectively. The results of an in-depth experimental evaluation, performed on two real-world datasets using different external corpora, show that our approach outperforms traditional techniques, including existing non-personalized and personalized query expansion methods.
Autors: Dong Zhou;Xuan Wu;Wenyu Zhao;Séamus Lawless;Jianxun Liu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Jul 2017, volume: 29, issue:7, pages: 1536 - 1548
Publisher: IEEE
 
» Radiation Hardness of dSiPM Sensors in a Proton Therapy Radiation Environment
Abstract:
In vivo verification of dose delivery in proton therapy by means of positron emission tomography (PET) or prompt gamma imaging is mostly based on fast scintillation detectors. The digital silicon photomultiplier (dSiPM) allows excellent scintillation detector timing properties and is thus being considered for such verification methods. We present here the results of the first investigation of radiation damage to dSiPM sensors in a proton therapy radiation environment. Radiation hardness experiments were performed at the AGOR cyclotron facility at the KVI-Center for Advanced Radiation Technology, University of Groningen. A 150-MeV proton beam was fully stopped in a water target. In the first experiment, bare dSiPM sensors were placed at 25 cm from the Bragg peak, perpendicular to the beam direction, a geometry typical for an in situ implementation of a PET or prompt gamma imaging device. In the second experiment, dSiPM-based PET detectors containing lutetium yttrium orthosilicate scintillator crystal arrays were placed at 2 and 4 m from the Bragg peak, perpendicular to the beam direction; resembling an in-room PET implementation. Furthermore, the experimental setup was simulated with a Geant4-based Monte Carlo code in order to determine the angular and energy distributions of the neutrons and to determine the 1-MeV equivalent neutron fluences delivered to the dSiPM sensors. A noticeable increase in dark count rate (DCR) after an irradiation with about 108 1-MeV equivalent neutrons/cm2 agrees with observations by others for analog SiPMs, indicating that the radiation damage occurs in the single photon avalanche diodes and not in the electronics integrated on the sensor chip. It was found that in the in situ location, the DCR becomes too large for successful operation after the equivalent of a few weeks of use in a proton therapy treatment room (about 103 protons). For PET detectors in an in-room setup, detector performance was unchanged even after an irradiation equivalent to three years of use in a treatment room ( 1015 protons).
Autors: Faruk Diblen;Tom Buitenhuis;Torsten Solf;Pedro Rodrigues;Emiel van der Graaf;Marc-Jan van Goethem;Sytze Brandenburg;Peter Dendooven;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Jul 2017, volume: 64, issue:7, pages: 1891 - 1896
Publisher: IEEE
 
» Rail Flatness Measurement Method Based on Virtual Rules
Abstract:
This paper deals with the problem of measuring the flatness of rails in the final stage of their manufacturing. The flatness must be measured repeatedly along the total length of the rails. Controlling the flatness of manufactured rails is very important; only rails with very good flatness can be used in high-speed railways. Rails with moderate flatness defects can be used in standard railways, but if the flatness defects are greater than specific tolerances, the rails must undergo a straightening process or be discarded. To measure flatness, we propose a method based on emulation of the manual measurement process: the placement of virtual rules along the entire length of rails. The goal of using virtual rules is to measure potential rail defects. The results indicate which of the rails meets the minimum quality conditions required and which need to be re-manufactured or even discarded. The proposed method is based on an official standard: the European Standard EN-13674-1-2011. An extensive dataset of rails has been measured to test the performance of the proposed method. Results indicate the proposed method is robust and accurate.
Autors: Pedro Manso Bernal;Daniel F. García;Rubén Usamentiaga;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 4116 - 4124
Publisher: IEEE
 
» Random Access and Virtual Resource Allocation in Software-Defined Cellular Networks With Machine-to-Machine Communications
Abstract:
Machine-to-machine (M2M) communications have attracted great attention from both academia and industry. In this paper, with recent advances in wireless network virtualization and software-defined networking (SDN), we propose a novel framework for M2M communications in software-defined cellular networks with wireless network virtualization. In the proposed framework, according to different functions and quality-of-service (QoS) requirements of machine-type communication devices, a hypervisor enables the virtualization of the physical M2M network, which is abstracted and sliced into multiple virtual M2M networks. In addition, we develop a decision-theoretic approach to optimize the random access process of M2M communications. Furthermore, we develop a feedback and control loop to dynamically adjust the number of resource blocks that are used in the random access phase in a virtual M2M network by the SDN controller. Extensive simulation results with different system parameters are presented to show the performance of the proposed scheme.
Autors: Meng Li;F. Richard Yu;Pengbo Si;Enchang Sun;Yanhua Zhang;Haipeng Yao;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6399 - 6414
Publisher: IEEE
 
» Random Access for M2M Communications With QoS Guarantees
Abstract:
We propose a novel random access (RA) scheme with the quality of service (QoS) guarantees for machine-to-machine (M2M) communications. We consider a slotted uncoordinated data transmission period during which machine type communication (MTC) devices transmit over the same radio channel. Based on the latency requirements, MTC devices are divided into groups of different sizes, and the transmission frame is divided into sub-frames of different lengths. In each sub-frame, each group is assigned an access probability based on which an MTC device decides to transmit replicas of its packet or remain silent. The base station employs successive interference cancellation to recover all the superposed packets. We derive the closed-form expressions for the average probability of device resolution for each group, and we use these expressions to design the access probabilities. The accuracy of the expressions is validated through Monte Carlo simulations. We show that the designed access probabilities can guarantee the QoS requirements with high reliability and high energy efficiency. Finally, we show that RA can outperform standard coordinated access schemes as well as some of the recently proposed M2M access schemes for cellular networks.
Autors: Rana Abbas;Mahyar Shirvanimoghaddam;Yonghui Li;Branka Vucetic;
Appeared in: IEEE Transactions on Communications
Publication date: Jul 2017, volume: 65, issue:7, pages: 2889 - 2903
Publisher: IEEE
 
» Random Triggering-Based Sub-Nyquist Sampling System for Sparse Multiband Signal
Abstract:
We propose a novel random triggering-based modulated wideband compressive sampling (RT-MWCS) method to facilitate efficient realization of sub-Nyquist rate compressive sampling systems for sparse wideband signals. Under the assumption that the signal is repetitively (not necessarily periodically) triggered, RT-MWCS uses random modulation to obtain measurements of the signal at randomly chosen positions. It uses multiple measurement vector method to estimate the nonzero supports of the signal in the frequency domain. Then, the signal spectrum is solved using least square estimation. The distinct ability of estimating sparse multiband signal is facilitated with the use of level triggering and time-to-digital converter devices previously used in random equivalent sampling scheme. Compared to the existing compressive sampling (CS) techniques, such as modulated wideband converter (MWC), RT-MWCS is with simple system architecture and can be implemented with one channel at the cost of more sampling time. Experimental results indicate that, for sparse multiband signal with unknown spectral support, RT-MWCS requires a sampling rate much lower than Nyquist rate, while giving great quality of signal reconstruction.
Autors: Yijiu Zhao;Yu Hen Hu;Jingjing Liu;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1789 - 1797
Publisher: IEEE
 
» Randomly Perturbed B-Splines for Nonrigid Image Registration
Abstract:
B-splines are commonly utilized to construct the transformation model in free-form deformation (FFD) based registration. B-splines become smoother with increasing spline order. However, a higher-order B-spline requires a larger support region involving more control points, which means higher computational cost. In general, the third-order B-spline is considered as a good compromise between spline smoothness and computational cost. A lower-order function is seldom used to construct the transformation model for registration since it is less smooth. In this research, we investigated whether lower-order B-spline functions can be utilized for more efficient registration, while preserving smoothness of the deformation by using a novel random perturbation technique. With the proposed perturbation technique, the expected value of the cost function given probability density function (PDF) of the perturbation is minimized by a stochastic gradient descent optimization. Extensive experiments on 2D synthetically deformed brain images, and real 3D lung and brain scans demonstrated that the novel randomly perturbed free-form deformation (RPFFD) approach improves the registration accuracy and transformation smoothness. Meanwhile, lower-order RPFFD methods reduce the computational cost substantially.
Autors: Wei Sun;Wiro J. Niessen;Stefan Klein;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jul 2017, volume: 39, issue:7, pages: 1401 - 1413
Publisher: IEEE
 
» Rapid, User-Transparent, and Trustworthy Device Pairing for D2D-Enabled Mobile Crowdsourcing
Abstract:
Mobile Crowdsourcing is a promising service paradigm utilizing ubiquitous mobile devices to facilitate large-scale crowdsourcing tasks (e.g., urban sensing and collaborative computing). Many applications in this domain require Device-to-Device (D2D) communications between participating devices for interactive operations such as task collaborations and file transmissions. Considering the private participating devices and their opportunistic encountering behaviors, it is highly desired to establish secure and trustworthy D2D connections in a fast and autonomous way, which is vital for implementing practical Mobile Crowdsourcing Systems (MCSs). In this paper, we develop an efficient scheme, Trustworthy Device Pairing (TDP), which achieves user-transparent secure D2D connections and reliable peer device selections for trustworthy D2D communications. Through rigorous analysis, we demonstrate the effectiveness and security intensity of TDP in theory. The performance of TDP is evaluated based on both real-world prototype experiments and extensive trace-driven simulations. Evaluation results verify our theoretical analysis and show that TDP significantly outperforms existing approaches in terms of pairing speed, stability, and security.
Autors: Cong Zhao;Shusen Yang;Xinyu Yang;Julie A. McCann;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jul 2017, volume: 16, issue:7, pages: 2008 - 2022
Publisher: IEEE
 
» Rate-Power-Interference Optimization in Underlay OFDMA CRNs with Imperfect CSI
Abstract:
Achieving higher transmission rate while reducing transmission power and induced interference on neighboring receivers is deemed necessary for the advancement of future generation networks and is particularly challenging, since these directions could be conflicting in nature. This letter adopts a multiobjective optimization (MOOP) approach to settle the tradeoffs between these three conflicting objectives in orthogonal frequency-division multiple access-based cognitive radio networks. Besides, unlike most of the work in the literature that studied the imperfect channel side information (CSI) of the link between the secondary transmitter and the primary receiver to evaluate ergodic capacity, the MOOP formulation considers the imperfect CSI of cross links between secondary and primary, which makes the formulated MOOP difficult to solve, since traditional water-filling-in-time solution does not directly apply to this problem. Hence, to solve this MOOP, a dummy power allocation is first used, and then obtained MOOP is solved by using a weighted Tchebycheff method.
Autors: Mohammad Robat Mili;Leila Musavian;Derrick Wing Kwan Ng;
Appeared in: IEEE Communications Letters
Publication date: Jul 2017, volume: 21, issue:7, pages: 1657 - 1660
Publisher: IEEE
 
» Reach-Avoid Verification for Nonlinear Systems Based on Boundary Analysis
Abstract:
In this technical note, we propose a set-boundary based method to verify reach-avoid properties of non-linear dynamical systems with parametric uncertainty, which works under the assumption that the initial set is a compact set. In comparison to the conventional approach employing safely overapproximating state extrapolation on the full volume of the initial set, our boundary-based method applies such state extrapolation only to the initial set's boundary, and thus to a set of significantly smaller volume. This can help enhance precision and reduce computational burden when solving reach-avoid verification problems, especially for cases with large initial sets and/or large time horizons. Furthermore, our boundary-based method lifts existing reachability-analysis techniques with their often confined geometric representations of reachable sets (like interval boxes, zonotopes, polyhedra, ellipsoids) to considerably more complex geometric shapes, where the boundary of the set is representable as a finite union of such shapes. The resulting benefits brought by our boundary-based method in reach-avoid verification are illustrated through several examples.
Autors: Bai Xue;Arvind Easwaran;Nam-Joon Cho;Martin Fränzle;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3518 - 3523
Publisher: IEEE
 
» Reactive Power Compensation in Electric Arc Furnaces Using Prediction Intervals
Abstract:
This paper proposes a probabilistic method to model the uncertainty of reactive power compensation by static VAr compensators (SVCs) in electric arc furnaces (EAFs). The time-varying characteristics of EAF accentuate the voltage fluctuations and produce flicker in power lines as well as neighboring loads. In order to solve this issue, quick and accurate response of SVC within a half-cycle ahead is required. This paper proposes a nonparametric approach based on lower upper bound estimation method to construct prediction intervals (PIs) for the reactive power in EAFs. Due to the nonlinear nature of reactive power signals in EAFs, a set of PIs are produced and combined to find an optimal aggregated PI. The proposed prediction method provides a faster-than-real-time monitoring of SVC, which aims at high speed and efficient reactive power compensation. In order to find the most satisfying PIs with high coverage probability and low average width, an optimization algorithm is developed to improve the training process of neural networks. The appropriate performance of the proposed method is examined on the practical data gathered from the Mobarakeh Steel Company, Iran.
Autors: Abdollah Kavousi-Fard;Abbas Khosravi;Saeid Nahavandi;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5295 - 5304
Publisher: IEEE
 
» Real-Time Condition Monitoring of LOCA via Time–Frequency Domain Reflectometry
Abstract:
The maintenance of control and instrumentation (C&I) cables is crucial to safety of operating nuclear power plants. Therefore, when an accident occurs, there is a need for an accurate assessment of the impact on the cable's integrity. Unfortunately, most cable diagnostic methods are destructive and real-time assessment of the effect of accidents is not possible. Thus, in this paper, we present an analysis of a specific type of accident, a loss of coolant accident (LOCA), on C&I cables in real-time, based on time-frequency domain reflectometry (TFDR). Because the TFDR is sensitive to the signal-to-noise ratio and distortion of a reflected signal, we apply postprocessing techniques that compensate the dispersion based on the estimated propagation constant and a denoising method using singular value decomposition. The approach is verified by experimentally monitoring condition changes of localized LOCA hot spot in different C&I cables. The results are also validated by comparing with elongation at break test results.
Autors: Chun-Kwon Lee;Gu-Young Kwon;Seung Jin Chang;Moon Kang Jung;Jin Bae Park;Han-Soo Kim;Yong-June Shin;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1864 - 1873
Publisher: IEEE
 
» Real-Time Contingency Analysis With Corrective Transmission Switching
Abstract:
Transmission switching (TS) has gained significant attention recently. However, barriers still remain and must be overcome before the technology can be adopted by the industry. The state-of-the-art challenges include AC feasibility, computational complexity, the ability to handle large-scale real power systems, and dynamic stability. This paper investigates these challenges by developing an AC corrective TS (CTS) based real-time contingency analysis (RTCA) tool that can handle large-scale systems within a reasonable time. The tool quickly proposes multiple high-quality corrective switching actions for contingencies with potential violations. To reduce the computational complexity, three heuristic algorithms are proposed to generate a small set of candidate switching actions. Parallel computing is implemented to further speed up the solution time. Moreover, time-domain simulations are performed to check for dynamic stability of the proposed CTS solutions. The promising results, tested on the Tennessee Valley Authority (TVA) system and actual energy management system snapshots from the PJM Interconnection (PJM) and the Electric Reliability Council of Texas (ERCOT), show that the tool effectively reduces post-contingency violations. It is concluded that CTS is ripe for industry adoption for RTCA application.
Autors: Xingpeng Li;Pranavamoorthy Balasubramanian;Mostafa Sahraei-Ardakani;Mojdeh Abdi-Khorsand;Kory W. Hedman;Robin Podmore;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2604 - 2617
Publisher: IEEE
 
» Real-Time Ionospheric Threat Adaptation Using a Space Weather Prediction for GNSS-Based Aircraft Landing Systems
Abstract:
The use of ground-based augmentation systems (GBASs) is increasing in the national airspace system and also in many nations to support aircraft precision approaches and landing. An anomalous ionospheric event if undetected can cause a potential threat to users of single-frequency-based global navigation satellite system augmentation systems. Current GBAS utilize the pre-defined “worst case” ionospheric threat model in their computation of user position errors to consider all possible ionospheric conditions. This could lead to an excessive availability penalty by adding conservatism on the resulting error bounds. This paper proposes a methodology of real-time ionospheric threat adaptation that adjusts the ionospheric threat model in real time instead of always using the same threat model. This is done by using predicted values of space weather indices for determining the corresponding threat model based on an established relationship between space weather indices and ionospheric threats. Since space weather prediction itself is not reliable due to prediction errors, an uncertainty model was derived from 17 years of historical data. When applied to Category I GBAS in the Conterminous United States, this method lowered the upper bound of the current threat model about 95% of the time during the 17 years (from 1995 to 2011) using the bounded prediction value of the disturbance-storm time index.
Autors: Jinsil Lee;Sam Pullen;Seebany Datta-Barua;Jiyun Lee;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jul 2017, volume: 18, issue:7, pages: 1752 - 1761
Publisher: IEEE
 
» Real-Time Mitigation of Short-Range Leakage in Automotive FMCW Radar Transceivers
Abstract:
Frequency-modulated continuous wave radar systems suffer from permanent leakage of the transmit signal into the receive path. Besides leakage within the radar device itself, an unwanted object placed in front of the antennas causes so-called short-range (SR) leakage. In an automotive application, for instance, it originates from signal reflections of the car’s own bumper. Particularly the residual phase noise of the downconverted SR leakage signal causes a severe degradation of the achievable sensitivity. In an earlier work, we proposed an SR leakage cancellation concept that is feasible for integration in a monolithic microwave integrated circuit. In this brief, we present a hardware prototype that holistically proves our concept with discrete components. The fundamental theory and properties of the concept are proven with measurements. Further, we propose a digital design for real-time operation of the cancellation algorithm on a field programmable gate array. Ultimately, by employing measurements with a bumper mounted in front of the antennas, we show that the leakage canceller significantly improves the sensitivity of the radar.
Autors: Alexander Melzer;Florian Starzer;Herbert Jäger;Mario Huemer;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jul 2017, volume: 64, issue:7, pages: 847 - 851
Publisher: IEEE
 
» Real-Time Model-Based Fault Detection of Continuous Glucose Sensor Measurements
Abstract:
Objective: Faults in subcutaneous glucose concentration readings with a continuous glucose monitoring (CGM) may affect the computation of insulin infusion rates that can lead to hypoglycemia or hyperglycemia in artificial pancreas control systems for patients with type 1 diabetes (T1D). Methods: Multivariable statistical monitoring methods are proposed for detection of faults in glucose concentration values reported by a subcutaneous glucose sensor. A nonlinear first principle glucose/insulin/meal dynamic model is developed. An unscented Kalman filter is used for state and parameter estimation of the nonlinear model. Principal component analysis models are developed and used for detection of dynamic changes. K-nearest neighbor classification algorithm is used for diagnosis of faults. Data from 51 subjects are used to assess the performance of the algorithm. Results: The results indicate that the proposed algorithm works successfully with 84.2% sensitivity. Overall, 155 (out of 184) of the CGM failures are detected with a 2.8-min average detection time. Conclusion: A novel algorithm that integrates data-driven and model-based methods is developed. The proposed method is able to detect CGM failures with a high rate of success. Significance: The proposed fault detection algorithm can decrease the effects of faults on insulin infusion rates and reduce the potential for hypo- or hyperglycemia for patients with T1D.
Autors: Kamuran Turksoy;Anirban Roy;Ali Cinar;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jul 2017, volume: 64, issue:7, pages: 1437 - 1445
Publisher: IEEE
 
» Real-Time Traffic State Estimation With Connected Vehicles
Abstract:
A novel framework is developed in this paper, to increase the real-time roadway traffic condition assessment accuracy, which integrates connected vehicle technology (CVT) with artificial intelligence (AI) paradigm forming a CVT-AI method. Traffic density is a major indicator of traffic conditions. In this paper, the traffic operational condition is assessed based on traffic density. A simulated network of Interstate 26 in South Carolina is developed to investigate the effectiveness of the method. The assumption is that the vehicle onboard units will forward the CV generated data to the edge devices (e.g., roadside units) for further processing. CV generated distance headway and number of stops, and speed data are used to estimate traffic density. This paper reveals that, with 20% and greater CV penetration levels, the accuracy of the density information with the AI-aided CVT is a minimum of 85%. Moreover, this paper demonstrates that the integrated CVT-AI method yields a higher accuracy with the increase of CV penetration levels. Level of service (LOS) is the indicator of traffic congestion level on highways and is described with traffic density in terms of passenger car/mile/lane for a specific free flow speed. LOS estimated using the CVT-AI density estimation method is compared with the density estimation algorithm used by the Caltrans Performance Measurement System (PeMS), which relies on the occupancy and flow data collected by the freeway inductive loop detectors. With a 10% or more CV penetration, higher accuracy is achieved using the CVT-AI algorithm compared with the PeMS density estimation algorithm.
Autors: Sakib Mahmud Khan;Kakan C. Dey;Mashrur Chowdhury;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jul 2017, volume: 18, issue:7, pages: 1687 - 1699
Publisher: IEEE
 
» Realization of Large Dielectric Resonator Antenna ESPAR
Abstract:
A large array of dielectric resonator antenna (DRA) is designed in -band based on electrically steerable parasitic array radiator (ESPAR) concept. This large array consists of 240 perforated DRAs, which are uniformly excited by a parallel-series feeding network. By employing the perforation technique, the need for aligning and bonding individual DRA is eliminated. The subarrays are placed in an interleaved arrangement to suppress the grating lobes. To best explore the differences and advantages of our approach, the proposed ESPAR is compared with the beam steerable reflectarray antenna and traditional phased array antenna. The present large ESPAR can incredibly reduce the number of phase shifter by 80% in comparison with the conventional phased array, which makes it inexpensive. A prototype is fabricated, which achieves a maximum boresight realized a gain of 22.4 dBi. The agreement between measured and simulated results is very good.
Autors: Reza Movahedinia;Mohammad Reza Chaharmir;Abdel R. Sebak;Mohammad Ranjbar Nikkhah;Ahmed A. Kishk;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3744 - 3749
Publisher: IEEE
 
» Realization of Low Scattering for a High-Gain Fabry–Perot Antenna Using Coding Metasurface
Abstract:
We present a novel method to design a conventional Fabry–Perot (F-P) antenna but with low scattering. Combining a coding metasurface and an F-P antenna together could effectively reduce the scattering and keep high gain simultaneously. The coding element consists of two layers of square metallic patches printed on both sides of a dielectric substrate. The bottom metallic patch helps form a partially reflecting surface (PRS) for the F-P antenna, while the upper metallic patch is utilized to construct the coding metasurface with an optimized coding sequence, aiming to reduce the scattering of the F-P antenna by redirecting electromagnetic energies in all directions. Based on the specially designed coding metasurface, a good scattering reduction without degrading the radiation performance of the F-P antenna is achieved. Both simulated and experimental results demonstrate the excellent performance of the proposed antenna, with a peak measured gain of 19.8 dBi and a significant scattering reduction in the frequency range of 8–12 GHz.
Autors: Lei Zhang;Xiang Wan;Shuo Liu;Jia Yuan Yin;Qian Zhang;Hao Tian Wu;Tie Jun Cui;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3374 - 3383
Publisher: IEEE
 
» Reasoning About Job Completion Time in Vehicular Clouds
Abstract:
In order to enhance dependability and availability, it is common practice in conventional clouds to assign two servers to each job. In this paper, we investigate the effect of such a redundancy-based job assignment strategy on job completion time in vehicular clouds. We offer a heuristic analysis of the expected job completion time under this strategy. A comprehensive set of simulations confirmed the accuracy of our analytical predictions.
Autors: Ryan Florin;Puya Ghazizadeh;Aida Ghazi Zadeh;Samy El-Tawab;Stephan Olariu;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jul 2017, volume: 18, issue:7, pages: 1762 - 1771
Publisher: IEEE
 
» Receding Horizon Control of Wind Power to Provide Frequency Regulation
Abstract:
With the increased penetration of wind generation in power systems, there is a rising interest in the provision of frequency regulation by wind turbines in order to relieve the burden on remaining conventional generation units. As a first step, the possible contribution of wind power to frequency regulation by optimally anticipating load imbalances in the power system is investigated. This ability is studied by implementing a receding horizon control which takes future load and wind variations into account. In this way, the available energy reserves of the wind turbine over a certain time horizon are optimally exploited to damp frequency oscillations while keeping the energy losses within defined limits. Results indicate that the receding horizon controller will mainly damp overfrequencies as its upward regulation capability is restricted to the available kinetic energy in the turbines. Moreover, it is shown that load forecast errors only slightly influence the results as the controller iteratively determines the optimal trajectory. Even if no load forecast is available, the proposed controller is still capable of damping frequency variations resulting from the simulated load profile by 25%, while keeping the energy yield above 97% compared to optimal power point tracking.
Autors: Pieter Tielens;Dirk Van Hertem;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2663 - 2672
Publisher: IEEE
 

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