#### Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 13

» QoE-Driven Dynamic Adaptive Video Streaming Strategy With Future Information
 Abstract:DASH, the Dynamic adaptive video streaming over hypertext transfer protocol (HTTP), has become the de-facto video delivery mechanism nowadays, which takes advantage of the existing low cost and wide-spread HTTP platforms. Standards like MPEG-DASH defines the bitstreams conformance and decoding process, while leaving the bitrate adaptive algorithm open for research. So far, most DASH researches focus on the constant bitrate video delivery. In this paper, various bitrate (VBR) video delivery is investigated in the on-demand streaming scenario. Detailed instant bitrates of future segments are exploited in the proposed adaptation method to grasp the fluctuation traits of the VBR video. Meanwhile, the adaptation problem is formulated as an optimization process with the proposed internal QoE goal function, which keeps a good balance between various requirements. Besides, the parameters within the internal QoE function can be tuned to guarantee the flexibility of meeting different preferences. The experimental results demonstrate that our proposed QoE-based video adaptation method outperforms the state-of-the-art method with a good margin. Autors: Li Yu;Tammam Tillo;Jimin Xiao; Appeared in: IEEE Transactions on Broadcasting Publication date: Sep 2017, volume: 63, issue:3, pages: 523 - 534 Publisher: IEEE
» QoS-Aware Dynamic RRH Allocation in a Self-Optimized Cloud Radio Access Network With RRH Proximity Constraint
» Quantification of Additional Reinforcement Cost From Severe Three-Phase Imbalance
 Abstract:This letter is an enhancement to our previous paper that quantifies additional reinforcement costs (ARCs) for low-voltage assets under moderate degree of three-phase imbalance. The original formulas cause an overestimation of the ARCs under severe imbalance. This letter first quantifies the threshold of the severe degree of imbalance (DIB), below which the original formulas are applicable. Then, the ARC formulas are extended to account for the whole range of DIB. Case studies demonstrate that when the asset loading level is below 33.3% (50%) for a feeder (a transformer), the DIB never exceeds the threshold and the original ARC formulas are applicable; otherwise, the DIB can exceed the threshold and the extended formulas yield correct ARCs. Autors: Kang Ma;Ran Li;Ignacio Hernando-Gil;Furong Li; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4143 - 4144 Publisher: IEEE
» Quantitative EEG Evaluation During Robot-Assisted Foot Movement
 Abstract:Passiveand imagined limbmovements induce changes in cerebral oscillatory activity. Central modulatory effects play a role in plastic changes, and are of uttermost importance in rehabilitation. This has extensively been studied for upper limb, but less is known for lower limb. The aim of this study is to investigate the topographical distribution of event-related desynchronization/synchronization(ERD/ERS) and task-relatedcoherence during a robot-assisted and a motor imagery task of lower limb in healthy subjects to inform rehabilitation paradigms. 32-channels electroencephalogram (EEG) was recorded in twenty-one healthy right footed and handed subjects during a robot-assisted single-joint cyclic right ankle movement performed by the BTS ANYMOV robotic hospital bed. Data were acquired with a block protocol for passive and imagined movement at a frequency of 0.2 Hz. ERD/ERS and task related coherence were calculated in alpha1 (8–10 Hz), alpha2 (10.5–12.5 Hz) and beta (13–30 Hz) frequency ranges. During passive movement, alpha2 rhythm desynchronized overC3 and ipsilateral frontal areas (F4, FC2, FC6); betaERD was detected over the bilateral motor areas (Cz, C3, C4). During motor imagery, a significant desynchronization was evident for alpha1 over contralateral sensorimotor cortex (C3), for alpha2 over bilateral motor areas (C3 and C4), and for beta over central scalp areas. Task-related coherence decreased during passive movement in alpha2 band between contralateral central area (C3, CP5, CP1, P3) and ipsilateral frontal area (F8, FC6, T8); beta band coherence decreased between C3-C4 electrodes, and increased between C3-Cz. These data contribute to the understanding of oscillatory activity and functional neuronal interactions during lower limb robot-assisted motor performance. The final output of this line of research is to inform the design and development of neurorehabilitation protocols. Autors: Emanuela Formaggio;Stefano Masiero;Anna Bosco;Federica Izzi;Francesco Piccione;Alessandra Del Felice; Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering Publication date: Sep 2017, volume: 25, issue:9, pages: 1633 - 1640 Publisher: IEEE
» Quantized/Saturated Control for Sampled-Data Systems Under Noisy Sampling Intervals: A Confluent Vandermonde Matrix Approach
 Abstract:In this paper, a unified framework is established to investigate both the quantized and the saturated control problems for a class of sampled-data systems under noisy sampling intervals. A random variable obeying the Erlang distribution is used to describe the noisy sampling intervals. In virtue of the matrix exponential, the sampled-data control system is transformed into an equivalent discrete-time stochastic system, and the aim of this paper is to design a quantized/saturated sampled-data controller such that the resulting discrete-time stochastic system is stochastically stable when the sampling error follows the Erlang distribution. In order to deal with the case of multiple control inputs, a confluent Vandermonde matrix approach is proposed in the design process. By using the Kronecker product operation and the matrix inequality techniques, the desired quantized/saturated controller gains are designed in terms of the solution to certain matrix inequalities. Finally, a simulation example is exploited to verify the effectiveness of the proposed design approach. Autors: Bo Shen;Hailong Tan;Zidong Wang;Tingwen Huang; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4753 - 4759 Publisher: IEEE
» Quantum Well Mach–Zehnder Intensity Modulator With Enhanced Linearity for Direct Detection RF Photonic Link
 Abstract:The spurious free dynamic range (SFDR) of a direct-detection RF/photonic link is restricted by nonlinearity of the optical intensity modulation. We report a compact quantum well Mach-Zehnder (MZ) optical intensity modulator with enhanced linearity. The MZ modulator's linearity is improved by canceling the nonlinear distortions from the MZ interferometer and the optical phase modulation. The compact modulator is less than 4 mm long and has a Vπ of ~5.5 volt. In an RF photonic link, the modulator helped to achieve an SFDR of 117 dB·Hz2/3 at 1 GHz with 1.4 mA photodetector photocurrent. A down-conversion RF photonic link using this modulator demonstrated an RF-to-IF SFDR of 108.1 dB·Hz2/3. Autors: Shilei Jin;Longtao Xu;Tariq Manzur;Yifei Li; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:17, pages: 3785 - 3790 Publisher: IEEE
» Query Adaptive Fusion for Graph-Based Visual Reranking
 Abstract:Developing effective fusion schemes for multiple feature types has always been a hot issue in content-based image retrieval. In this paper, we propose a novel method for graph-based visual reranking, which addresses two major limitations in existing methods. First, in the phase of graph construction, our method introduces fine-grained measurements for image relations, by assigning the edge weights using normalized similarity. Furthermore, in the phase of graph fusion, rather than summing up all the graphs for different single features indiscriminately, we propose to estimate the reliability of each feature through a statistical model, and selectively fuse the single graphs via query-adaptive fusion weights. Fusion methods with either labeled data and unlabeled data are proposed and the performance are evaluated and compared by experiments. Our method is evaluated on five public datasets, by fusing scale-invariant feature transform (SIFT), CNN, and hue, saturation, hue (HSV), three complementary features. Experimental results demonstrate the effectiveness of the proposed method, which yields superior results than the competing methods. Autors: Muyuan Fang;Yu-Jin Zhang; Appeared in: IEEE Journal of Selected Topics in Signal Processing Publication date: Sep 2017, volume: 11, issue:6, pages: 908 - 917 Publisher: IEEE
» Queuing Approaches to Principal-Agent Communication Under Information Overload
» Quickest Detection of Parameter Changes in Stochastic Regression: Nonparametric CUSUM
 Abstract:We consider the problem of detecting abrupt parameter changes in a stochastic regression with unknown noise distribution. The process changes at some unknown point of time. Under general conditions on the regression function and unknown distributions of observations before and after the disruption, the paper develops a nonparametric cumulative sum procedure (CUSUM). Unlike likelihood-based CUSUM algorithms, constructed mostly on log-likelihood ratio statistics, we use a special system of basic statistics in Page’s procedure. By applying a sequential sampling scheme, which measures time in terms of accumulated Kullback–Leibler (K-L) divergence, we come to a system of statistics with the martingale properties close to those of the log-likelihood ratios. The proposed approach suggests also an alternative performance criterion in the analysis of the procedure by replacing the expected detection delay by the corresponding K-L divergence. We show that, under the false alarm probability constraint, the nonparametric CUSUM rule is optimal in the sense that it ensures the logarithmic asymptotic for the detection delay. Autors: Victor Konev;Sergey Vorobeychikov; Appeared in: IEEE Transactions on Information Theory Publication date: Sep 2017, volume: 63, issue:9, pages: 5588 - 5602 Publisher: IEEE
» Quickest Sequence Phase Detection
 Abstract:A phase detection sequence is a length- cyclic sequence, such that the location of any length- contiguous subsequence can be determined from a noisy observation of that subsequence. In this paper, we derive bounds on the minimal possible in the limit of , and describe some sequence constructions. We further consider multiple phase detection sequences, where the location of any length- contiguous subsequence of each sequence can be determined simultaneously from a noisy mixture of those subsequences. We study the optimal trade-offs between the lengths of the sequences, and describe some sequence constructions. We compare these phase detection problems to their natural channel coding counterparts, and show a strict separation between the fundamental limits in the multiple sequence case. Both adversarial and probabilistic noise models are addressed. Autors: Lele Wang;Sihuang Hu;Ofer Shayevitz; Appeared in: IEEE Transactions on Information Theory Publication date: Sep 2017, volume: 63, issue:9, pages: 5834 - 5849 Publisher: IEEE
» Raccoon: A Novel Network I/O Allocation Framework for Workload-Aware VM Scheduling in Virtual Environments
 Abstract:We present a network I/O allocation framework, called Raccoon, for workload-aware VM scheduling algorithm to facilitate hybrid I/O workloads in virtual environments. Raccoon combines the strengths of paravirtual I/O and SR-IOV techniques to not only minimize the network latency, but also optimize the bandwidth utilization for workload-aware VM scheduling. In Raccoon, a limited number of VFs in SR-IOV are granted to I/O-intensive VMs while the paravirtual Network Interface Cards (vNICs) are allocated to other non-I/O-intensive VMs as the default resources. With this design, Raccoonprovides latency reduction and bandwidth guarantee under the premise that I/O-intensive VMs will always be granted the VFs to facilitate their I/O operations. The types of workloads in each VM are identified at runtime by modified XenMon. By leveraging the ACPI Hotplug technique, Raccoon can adaptively plugin and plugout the SR-IOV VFs upon the changes of VM requirements so that an efficient I/O workload-aware VM scheduling algorithm can be implemented based on the bonding driver technique. The experimental results reveal that Raccoon can combine the benefits of para-virtual I/O and SR-IOV techniques to improve the overall performance of virtualized platforms with VMs that have diverse I/O workloads. Autors: Lingfang Zeng;Yang Wang;Xiaopeng Fan;Chengzhong Xu; Appeared in: IEEE Transactions on Parallel and Distributed Systems Publication date: Sep 2017, volume: 28, issue:9, pages: 2651 - 2662 Publisher: IEEE
» Radar HRRP Target Recognition Based on t-SNE Segmentation and Discriminant Deep Belief Network
 Abstract:In radar high-resolution range profile (HRRP)-based target recognition, one of the most challenging tasks is the noncooperative target recognition with imbalanced training data set. This letter presents a novel recognition framework to deal with this problem. The framework is composed of two steps: first, the t-distributed stochastic neighbor embedding (t-SNE) and synthetic sampling are utilized for data preprocessing to provide a well segmented and balanced HRRP data set; second, a discriminant deep belief network (DDBN) is proposed to recognize HRRP data. Compared with the conventional recognition models, the proposed framework not only makes better use of data set inherent structure among HRRP samples for segmentation, but also utilizes high-level features for recognition. Moreover, the DDBN shares latent information of HRRP data globally, which can enhance the ability of modeling the aspect sectors with few HRRP data. The experiments illustrate the meaning of the t-SNE, and validate the effectiveness of the proposed recognition framework with imbalanced HRRP data. Autors: Mian Pan;Jie Jiang;Qingpeng Kong;Jianguang Shi;Qinghua Sheng;Tao Zhou; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1609 - 1613 Publisher: IEEE
» Radiation-Hardened CMOS Negative Voltage Reference for Aerospace Application
 Abstract:Voltage reference is the key module in analog and mixed-signal integrated circuits. This paper presents a radiation-hardened CMOS negative voltage reference for aerospace electronics. To improve the antiradiation performance, in the circuit design, the input pair of the operational amplifier is replaced from pMOS to nMOS. An extra unity-gain amplification stage is added and the compensation network is optimized. Besides, the start-up circuit is redesigned. In the layout design, the annular-gate structure is adopted to eliminate electric leakage, while the layout technique against single-event latch-up is also used. The prototype of the proposed circuit is fabricated using a bulk CMOS 0.6- process with a chip area. By using the proposed circuit and layout optimizations, the measured temperature coefficient of reference is reduced to 13 ppm/°C and the output voltage drift is below 1.2% after 300-krad(Si) total ionizing dose. The measured single-event latch-up threshold is above 94.6 MeVcm2/mg. Autors: Fan Liu;Feng Yang;Han Wang;Xun Xiang;Xichuan Zhou;Shengdong Hu;Zhi Lin;Amine Bermak;Fang Tang; Appeared in: IEEE Transactions on Nuclear Science Publication date: Sep 2017, volume: 64, issue:9, pages: 2505 - 2510 Publisher: IEEE
» Radio Frequency Carbon Nanotube Thin-Film Bolometer
 Abstract:A radio frequency bolometer was realized using a thermistor fabricated from a carbon nanotube thin-film deposited on a sapphire substrate. Power detection performance was characterized at room and liquid nitrogen temperatures. With the thermistor held at a temperature of 15 °C, the bolometer’s sensitivity of 915-MHz test signals was found to be 0.36 mV/mW, and power levels as low as −45 dBm could be detected with a 20-s integration time constant. The sensitivity increased to 2.3 mV/mW when the thermistor was cooled to −193 °C. Experiments over the temperature range of 15 °C–240 °C indicate that internanotube mechanisms dominate power detection at temperatures below a value of approximately 200 °C and that intrananotube mechanisms (primarily Joule-heating) dominate at higher temperatures. Autors: Michael R. Gasper;Ryan C. Toonen;Samuel G. Hirsch;Mathew P. Ivill;Henning Richter;Ramesh Sivarajan; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3278 - 3284 Publisher: IEEE
» Radio Frequency Self-Interference Cancellation With Analog Least Mean-Square Loop
 Abstract:A multitap adaptive filter with analog least mean-square (ALMS) loop is proposed in this paper for effective and low complexity self-interference cancellation implemented as part of the radio frequency frontend in a full duplex transceiver. Comprehensive analyses of the ALMS loop’s behaviors at both micro and macroscales are presented for a wireless communication system with single carrier signaling. It is revealed that there is always an irreducible residual interference due to the cyclostationary property of the transmitted signal. The interference suppression ratio (ISR) lower bound is derived accordingly, which can be used as a design rule for determining the ALMS loop parameter. Stationary analysis shows that the convergence speed and achievable ISR of the ALMS loop are determined by the loop gain and the autocorrelation function of the transmitted signal. The interference channel modeling error with the adaptive filter also accounts for part of the residual interference power. These theoretical findings are verified by simulation and experimental results. Autors: Xiaojing Huang;Y. Jay Guo; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3336 - 3350 Publisher: IEEE
 Abstract:Examines micowave and electromagnetic studies funded by DARPA. Autors: Rajeev Bansal; Appeared in: IEEE Microwave Magazine Publication date: Sep 2017, volume: 18, issue:6, pages: 16 - 18 Publisher: IEEE
» Rain Attenuation Prediction Model Based on Hyperbolic Cosecant Copula for Multiple Site Diversity Systems in Satellite Communications
 Abstract:This paper presents a novel model for prediction of site diversity system performance in millimeter-wave satellite communications. The model predicts the joint exceedance probability of rain attenuation based on a new family of Archimedean copulas, called the hyperbolic cosecant copula. Furthermore, employing the hierarchical Archimedean copula structures, the proposed methodology can be used for the prediction of joint first-order statistics of rain attenuation for dual- and multiple-site diversity satellite communication systems. The proposed method has been tested on an extensive data set of site diversity experiments with various system configurations. Moreover, in addition to the common approaches, where the dependence of rain attenuation induced on multiple links is based solely on the distance between ground stations, elevation and baseline angle are also taken into account for the modeling of the dependence parameter. Both versions of the model outperform the existing model for two-site diversity systems given in the ITU-R Recommendation P.618-12. The version, which accounts for the system’s angles, shows a better performance also in comparison with the state-of-the-art models such as the models based on the Archimedean Clayton copula and the Gaussian copula. Autors: Arsim Kelmendi;Gorazd Kandus;Andrej Hrovat;Charilaos I. Kourogiorgas;Athanasios D. Panagopoulos;Michael Schönhuber;Mihael Mohorčič;Andrej Vilhar; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4768 - 4779 Publisher: IEEE
» Ramp-Limited Optimal Dispatch Strategy for PV-Embedded Microgrid
 Abstract:This letter is focused on the issue of power imbalance caused by significant fluctuations of photovoltaic (PV) generation in a stand-alone microgrid. To exploit the flexibility of microgrid in addressing such issue, a novel rolling optimization based dispatch strategy involving a microgrid flexibility check model and a PV ramp scenario generation model is proposed. Based on the proposed strategy, the optimal operation schedule for conventional generation and energy storage system can be efficiently found. Case study demonstrates the effectiveness of the proposed model. Autors: Jian Zhao;Zhao Xu; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4155 - 4157 Publisher: IEEE
» Random Subchannel Selection of Store-Carry and Forward Transmissions in Traffic Hotspots
» Ranking Saliency
 Abstract:Most existing bottom-up algorithms measure the foreground saliency of a pixel or region based on its contrast within a local context or the entire image, whereas a few methods focus on segmenting out background regions and thereby salient objects. Instead of only considering the contrast between salient objects and their surrounding regions, we consider both foreground and background cues in this work. We rank the similarity of image elements with foreground or background cues via graph-based manifold ranking. The saliency of image elements is defined based on their relevances to the given seeds or queries. We represent an image as a multi-scale graph with fine superpixels and coarse regions as nodes. These nodes are ranked based on the similarity to background and foreground queries using affinity matrices. Saliency detection is carried out in a cascade scheme to extract background regions and foreground salient objects efficiently. Experimental results demonstrate the proposed method performs well against the state-of-the-art methods in terms of accuracy and speed. We also propose a new benchmark dataset containing 5,168 images for large-scale performance evaluation of saliency detection methods. Autors: Lihe Zhang;Chuan Yang;Huchuan Lu;Xiang Ruan;Ming-Hsuan Yang; Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence Publication date: Sep 2017, volume: 39, issue:9, pages: 1892 - 1904 Publisher: IEEE
» Rayleigh SAW-Assisted SH-SAW Immunosensor on X-Cut 148-Y LiTaO3
 Abstract:In this paper, we describe a shear horizontal surface acoustic wave (SH-SAW) immunosensor that utilizes induce agitation by a Rayleigh SAW (R-SAW) on an X-cut 148-Y LiTaO3 substrate. On this substrate, SH-SAWs and R-SAWs with different frequencies can be effectively generated at an interdigital transducer (IDT). First, to consider the power flow angles of SH-SAWs and R-SAWs on this substrate, the 360-MHz delay lines with six different tilt angles were designed and fabricated. From the experiments, an optimal power flow angle of 9° for the SH-SAW on this substrate is obtained. Second, in order to consider the immunoreactions of the SH-SAW immunosensors, a delay line with a tilt angle of 9° was designed and fabricated on this substrate. The delay line, which can generate two SAWs, namely, a 100-MHz SH-SAW and an 88.8-MHz R-SAW, has a propagation area covered with antigens of human serum albumin between transmitting and receiving IDTs. The immunoreactions caused by antigen–antibody binding events on the surface of the delay line were investigated on the basis of the velocity changes of the SH-SAWs for sensing with and without the assistance of an R-SAW. As a result, it was confirmed that the SH-SAW velocity changes due to antigen–antibody reactions can be markedly increased by the assistance of R-SAW agitation. Autors: Takashi Kogai;Hiromi Yatsuda;Jun Kondoh; Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Publication date: Sep 2017, volume: 64, issue:9, pages: 1375 - 1381 Publisher: IEEE
» Reactive-Power Coordination in VSC-HVDC Multi-Terminal Systems for Transient Stability Improvement
 Abstract:This paper proposes a new control strategy for the reactive-power injections of voltage-source converters (VSCs) in high-voltage direct-current multi-terminal systems to improve power system transient stability. A reactive-power supplementary signal is provided for each converter. Its value is proportional to the frequency deviation of its corresponding AC bus with respect to the weighed-average frequency of the multi-terminal system stations. The purpose is to increase (decrease) the electromagnetic torque of generators close to those terminals, in which the frequency is above (below) the weighed-average frequency used. The AC frequency for all VSC stations is always available locally for synchronization purposes and could be used by a central controller. Simulations have been carried out using PSS/E, and the results have shown that transient stability can be improved using this strategy. Since this approach uses global measurements of all VSC stations, the impact of the communication delays has been analyzed, concluding that the negative effect is small, for realistic latency values. Autors: Javier Renedo;Aurelio García-Cerrada;Luis Rouco; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3758 - 3767 Publisher: IEEE
» Real-Time Detection of the Dynamic Eccentricity in Permanent-Magnet Synchronous Motors by Monitoring Speed and Back EMF Induced in an Additional Winding
 Abstract:We developed a real-time method to detect the dynamic eccentricity of a rotor in a permanent-magnet (PM) motor by monitoring a fault detection signal induced in an additional winding, without performing any further postprocessing, even under a nonstationary rotational speed. After deriving a mathematical equation of the back electromotive force (EMF) induced in a tooth-coil winding, we proposed a fault detection signal, which is the back EMF in an additional winding divided by the rotational speed, when the additional winding is wound around the teeth corresponding to an even number of pole pitches. We used the 2-D finite-element model of a three-phase PM motor with eight poles and 12 slots to verify the proposed method. We also developed an experimental setup which can change the dynamic eccentricity of a PM motor and we performed the experiment for PM motors with dynamic eccentricities of 0%, 25%, and 50% to verify the proposed method. Through the mathematical equation, numerical simulation, and experiment, we confirmed that the fault detection signal proposed in this paper can successfully detect the dynamic eccentricity in a PM motor in real time. Autors: Kyungjin Kang;Jeongyong Song;Chiho Kang;Sangjin Sung;Gunhee Jang; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7191 - 7200 Publisher: IEEE
» Real-Time Hardware-in-the-Loop Simulation of Permanent-Magnet Synchronous Motor Drives Under Stator Faults
 Abstract:Hardware-in-the-loop (HIL) testing methods can facilitate the development of control strategies in a safe and inexpensive environment particularly when extreme operating conditions such as faults are considered. HIL methods rely on accurate real-time emulation of the equipment under investigation. However, no validated tools for real-time emulation of electrical drives under fault conditions are available. This paper describes the implementation of a high-fidelity real-time emulator of a permanent-magnet synchronous motor drive in a platform suitable for HIL tests. The emulator is capable of representing the drive operation under both healthy conditions and during interturn stator winding faults. Nonlinearities due to saturation, higher order harmonics, slotting effects, etc., are accounted for using four-dimensional look-up tables (LUTs) obtained by finite element analysis. The proposed model is computationally efficient and capable of running in real time in a field programmable gate array platform and is validated against simulations and experimental results in a wide range of operating conditions. Potential applications of the proposed emulation environment to the development of drive control, fault detection, and diagnostic algorithms are proposed. Autors: Fernando Alvarez-Gonzalez;Antonio Griffo;Bhaskar Sen;Jiabin Wang; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 6960 - 6969 Publisher: IEEE
» Real-Time Implementation of Calderón’s Method on Subject-Specific Domains
 Abstract:A real-time implementation of Calderón’s method for the reconstruction of a 2-D conductivity from electrical impedance tomography data is presented, in which domain-specific modeling is taken into account. This is the first implementation of Calderón’s method that accounts for correct modeling of non-symmetric domain boundaries in image reconstruction. The domain-specific Calderón’s method is derived and reconstructions from experimental tank data are presented, quantifying the distortion when correct modeling is not included in the reconstruction algorithm. Reconstructions from human subject volunteers are presented, demonstrating the method’s effectiveness for imaging changes due to ventilation and perfusion in the human thorax. Autors: Peter A. Muller;Jennifer L. Mueller;Michelle M. Mellenthin; Appeared in: IEEE Transactions on Medical Imaging Publication date: Sep 2017, volume: 36, issue:9, pages: 1868 - 1875 Publisher: IEEE
» Real-Time Multisensor Vehicle Localization: A Geographical Information System?Based Approach
 Abstract:In this article, a localization system for a mobile robot, using a top-down multisensors approach and a map of the environment, is proposed. Popular methods try to optimize a global cost, track multihypothesis, or reduce the problem by using multisensors. These approaches are bottom-up: Each sensor data is analyzed even if it is not relevant [like a global positioning system (GPS) in an indoor environment]. Autors: Claude Aynaud;Coralie Bernay-Angeletti;Romuald Aufrere;Laurent Lequievre;Christophe Debain;Roland Chapuis; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 65 - 74 Publisher: IEEE
» Real-time Triple-modal Photoacoustic, Ultrasound, and Magnetic Resonance Fusion Imaging of Humans
 Abstract:Imaging that fuses multiple modes has become a useful tool for diagnosis and therapeutic monitoring. As a next step, real-time fusion imaging has attracted interest as for a tool to guide surgery. One widespread fusion imaging technique in surgery combines real-time ultrasound (US) imaging and pre-acquired magnetic resonance (MR) imaging. However, US imaging visualizes only structural information with relatively low contrast. Here, we present a photoacoustic (PA), US, and MR fusion imaging system which integrates a clinical PA and US imaging system with an optical tracking-based navigation sub-system. Through co-registration of pre-acquired MR and real-time PA/US images, overlaid PA, US, and MR images can be concurrently displayed in real time. We successfully acquired fusion images from a phantom and a blood vessel in a human forearm. This fusion imaging can complementarily delineate the morphological and vascular structure of tissues with good contrast and sensitivity, has a well-established user interface, and can be flexibly integrated with clinical environments. As a novel fusion imaging, the proposed triple-mode imaging can provide comprehensive image guidance in real time, and can potentially assist various surgeries. Autors: Sara Park;Jongseong Jang;Jeesu Kim;Young Soo Kim;Chulhong Kim; Appeared in: IEEE Transactions on Medical Imaging Publication date: Sep 2017, volume: 36, issue:9, pages: 1912 - 1921 Publisher: IEEE
» Realization Theory for LPV State-Space Representations With Affine Dependence
 Abstract:We present a Kalman-style realization theory for linear parameter-varying state-space representations whose matrices depend on the scheduling variables in an affine way (abbreviated as LPV-SSA). We show that minimality of LPV-SSAs is equivalent to observability and span-reachability rank conditions, and that minimal LPV-SSAs of the same input-output map are isomorphic. We present necessary and sufficient conditions for existence of an LPV-SSA in terms of the rank of a Hankel-matrix and a Ho-Kalman-like realization algorithm. Autors: Mihály Petreczky;Roland Tóth;Guillaume Mercère; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4667 - 4674 Publisher: IEEE
» Recurrent Neural Networks to Correct Satellite Image Classification Maps
 Abstract:While initially devised for image categorization, convolutional neural networks (CNNs) are being increasingly used for the pixelwise semantic labeling of images. However, the proper nature of the most common CNN architectures makes them good at recognizing but poor at localizing objects precisely. This problem is magnified in the context of aerial and satellite image labeling, where a spatially fine object outlining is of paramount importance. Different iterative enhancement algorithms have been presented in the literature to progressively improve the coarse CNN outputs, seeking to sharpen object boundaries around real image edges. However, one must carefully design, choose, and tune such algorithms. Instead, our goal is to directly learn the iterative process itself. For this, we formulate a generic iterative enhancement process inspired from partial differential equations, and observe that it can be expressed as a recurrent neural network (RNN). Consequently, we train such a network from manually labeled data for our enhancement task. In a series of experiments, we show that our RNN effectively learns an iterative process that significantly improves the quality of satellite image classification maps. Autors: Emmanuel Maggiori;Guillaume Charpiat;Yuliya Tarabalka;Pierre Alliez; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 4962 - 4971 Publisher: IEEE
» Reduced Junction Leakage by Hot Phosphorus Ion Implantation of NiGe-Contacted Germanium n+/p Shallow Junction
 Abstract:Effects of hot phosphorus (P) implantation on the NiGe-contacted Ge n+/p junction are studied in this work. At an adequately high ion-implantation temperature (150°C), the P depth profiles of the hot-implanted samples are similar to that of the room-temperature implanted ones. Hot P implantation is demonstrated effectively in reducing ion implantation induced defect formation and suppressing nickel atoms diffusion. Therefore, hot P implantation is efficient in lowering junction leakage and excellent junction characteristics exhibiting ratio is achieved. Autors: Yi-Ju Chen;Bing-Yue Tsui;Hung-Ju Chou;Ching-I. Li;Ger-Pin Lin;Shao-Yu Hu; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1192 - 1195 Publisher: IEEE
» Reduced-Complexity Iterative Receiver for Improving the IEEE 802.15.7 Convolutional-Coded Color Shift Keying Mode
 Abstract:In this letter, we conceive novel symbol-based color-shift keying (CSK)-aided concatenated coding schemes, which provide attractive performance gains over the comparable bit-based systems. Quantitatively, our 4 CSK-aided and 16 CSK-aided symbol-based concatenated systems require 0.8 and 0.45 dB lower SNR than the equivalent bit-based schemes. In terms of decoding complexity, the 4 CSK-aided and 16 CSK-aided systems reduce the decoding complexity by 67% and 33%, respectively. We have also analyzed the convergence behavior of our system with the aid of non-binary extrinsic information transfer charts adapted for symbol-based iterative CSK-assisted systems. Autors: Zunaira Babar;Chuan Zhu;Hung Viet Nguyen;Panagiotis Botsinis;Dimitrios Alanis;Daryus Chandra;Soon Xin Ng;Lajos Hanzo; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 2005 - 2008 Publisher: IEEE
» Reducing Arc-Flash Hazards: Installing MV-Controllable Fuses on the Secondary Side of the Transformer in a Pumped Storage Plant
 Abstract:The Mitigation of arc-flash incident energy is important to increase safety. One method is to reduce the duration of the arc flash by using protective relays to sense an arc-flash fault. This method requires a supply-side switching device that will respond to the protective relaying fast enough to mitigate the incident energy. In many existing installations, medium-voltage (MV) controllable fuses are already installed to provide transformer protection. Before the development of an MV-controllable fuse, the MV fuse would have to be replaced with an MV circuit breaker or circuit switcher to have relay control of the MV protective device. This replacement would have significant equipment and construction costs and require extensive equipment outage time. The MV-controllable-fuse method uses the existing fusegear protecting the primary side of the transformer. The protective relay senses the arc fault and signals the controllable fuse to change to a fasteracting time-current response. The incident energies can be reduced from 200 cal/cm2 to lower than 8 cal/cm2 on the secondary side of the transformer. This article reviews an installation using an MV-controllable fuse to mitigate the incident energy on the equipment connected to the secondary side of the transformer. Autors: Peter R. Walsh;Michael M. Price; Appeared in: IEEE Industry Applications Magazine Publication date: Sep 2017, volume: 23, issue:5, pages: 21 - 27 Publisher: IEEE
» Reducing Energy Waste Due to Idle Network Devices
 Abstract:The number of end-user network devices in the world is increasing at a rapid rate. Today, the most frequently used devices include smartphones, tablets, laptops, and desktop personal computers (PCs). The U.S. Environmental Protection Agency (EPA) investigated energy usage of PCs in the United States and revealed that they consume approximately 2% of overall generated electricity every year. Furthermore, Lawrence Berkeley National Laboratory announced in a study that about 60% people never switch off computers in offices (even when idle). Autors: Rafiullah Khan;Sarmad Ullah Khan; Appeared in: IEEE Potentials Publication date: Sep 2017, volume: 36, issue:5, pages: 37 - 45 Publisher: IEEE
» Reduction of Power System Dynamic Models Using Sparse Representations
 Abstract:This paper proposes a model reduction technique that simplifies the dynamic equations of complex power networks, using sparse representations of the system matrices. Instead of removing components from the state vector, elements from the system matrices are eliminated such that these matrices become sparse. This is achieved by three different numeric algorithms that approximate the original system model using fewer nonzero elements. These algorithms lead to simpler models, since the complexity of operations involving sparse matrices is primarily affected by the matrices density. Furthermore, this approach enables to identify significant dynamic relations between units in the network. The proposed methods are demonstrated on several test-case systems with 9 and 2383-buses. In these examples, more than % of the elements in the system matrices are eliminated. Autors: Yoash Levron;Juri Belikov; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3893 - 3900 Publisher: IEEE
» Redundant-Configuration Scrubbing of SRAM-Based FPGAs
 Abstract:Static RAM-based field programmable gate arrays (SRAM-based FPGAs) are widely adopted in trigger and data acquisition systems of high-energy physics detectors for implementing fast logic due to their reconfigurability, large real-time processing capabilities and embedded high-speed serial IOs. These devices are sensitive to radiation-induced upsets, which may alter the functionality of the implemented circuit. Presently, their usage on-detector is limited and there is a strong interest in finding solutions for improving their tolerance to radiation-induced upsets. In this paper, we show a novel configuration-redundancy generation and scrubbing technique for SRAM-based FPGAs. It leads to a power saving with respect to other solutions in the literature. Moreover, our technique is compatible with several Xilinx FPGA families. Our solution does not require neither the usage of external memories nor third-party layout tools. We describe an example of our solution applied to a benchmark design implemented in a Xilinx Kintex-7 FPGA. In order to prove the effectiveness of the solution, we present results from a proton irradiation test. Autors: Raffaele Giordano;Sabrina Perrella;Vincenzo Izzo;Giuliana Milluzzo;Alberto Aloisio; Appeared in: IEEE Transactions on Nuclear Science Publication date: Sep 2017, volume: 64, issue:9, pages: 2497 - 2504 Publisher: IEEE
» Regularized Speaker Adaptation of KL-HMM for Dysarthric Speech Recognition
 Abstract:This paper addresses the problem of recognizing the speech uttered by patients with dysarthria, which is a motor speech disorder impeding the physical production of speech. Patients with dysarthria have articulatory limitation, and therefore, they often have trouble in pronouncing certain sounds, resulting in undesirable phonetic variation. Modern automatic speech recognition systems designed for regular speakers are ineffective for dysarthric sufferers due to the phonetic variation. To capture the phonetic variation, Kullback–Leibler divergence-based hidden Markov model (KL-HMM) is adopted, where the emission probability of state is parameterized by a categorical distribution using phoneme posterior probabilities obtained from a deep neural network-based acoustic model. To further reflect speaker-specific phonetic variation patterns, a speaker adaptation method based on a combination of L2 regularization and confusion-reducing regularization, which can enhance discriminability between categorical distributions of the KL-HMM states while preserving speaker-specific information is proposed. Evaluation of the proposed speaker adaptation method on a database of several hundred words for 30 speakers consisting of 12 mildly dysarthric, 8 moderately dysarthric, and 10 non-dysarthric control speakers showed that the proposed approach significantly outperformed the conventional deep neural network-based speaker adapted system on dysarthric as well as non-dysarthric speech. Autors: Myungjong Kim;Younggwan Kim;Joohong Yoo;Jun Wang;Hoirin Kim; Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering Publication date: Sep 2017, volume: 25, issue:9, pages: 1581 - 1591 Publisher: IEEE
» Regulating the Collective Charging Load of Electric Taxi Fleet via Real-Time Pricing
 Abstract:This paper investigates the problem of how to regulate the collective charging load of a large fleet of plug-in electric taxies (PETs) in a metropolis from the viewpoint of utility company. Because the charging load of PET is much higher and less predictable compared with common private electric vehicle, the unregulated charging load of PET fleet can potentially bring large and unpredictable peaks to the distribution system and cause severe damage. To address this problem, this paper proposes a real-time pricing mechanism that can successfully regulate the collective charging load to track a given load profile. The mechanism design consists of three steps. First, we propose two aggregated models for PET fleet to characterize, separately, the relationship between charging decisions of the fleet and real time prices, and the relationship between energy dynamics and charging decisions of the fleet. Then, an optimization problem is designed to calculate the optimal charging load profile that can be accomplished by the fleet. Finally, an efficient online method is launched to calculate proper real time prices, such that the collective charging load of fleet can track the desired value as the response to the prices. Simulation results validate the effectiveness of the proposed mechanism. Autors: Jinfeng Yang;Yinliang Xu;Zaiyue Yang; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3694 - 3703 Publisher: IEEE
» Reinforcement Learning With Network-Assisted Feedback for Heterogeneous RAT Selection
 Abstract:Future wireless networks (e.g., 5G) will consist of multiple radio access technologies (RATs). In these networks, deciding which RAT users should connect to is not a trivial problem. Current fully distributed algorithms although guaranteeing convergence to equilibrium states, are often slow, require high exploration times and may converge to undesirable equilibria. To overcome these limitations, this paper develops a network feedback framework that uses limited network-assisted information to improve efficiency of distributed algorithms for RAT selection problem. We prove theoretically that a fully distributed algorithm developed within this framework is guaranteed to converge to a set of correlated equilibria. Our framework guarantees convergence in self-play even when only a single user applies the algorithm. Simulation results demonstrate that our solution: 1) is highly efficient with fast convergence time and low signaling overheads while achieving competitive, if not better, performance both in fairness and utility, as well as achieving lower per-user switchings than state-of-the-art algorithms; and 2) can flexibly support a wide range of network-assisted feedback. The simulations demonstrate the effectiveness of our solution in a heterogeneous environment, where users may potentially apply a number of different RAT selection procedures. Autors: Duong D. Nguyen;Hung X. Nguyen;Langford B. White; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 6062 - 6076 Publisher: IEEE
» Relational Joins on GPUs: A Closer Look
 Abstract:The problem of scaling out relational join performance for large data sets in the database management system (DBMS) has been studied for years. Although in-memory DBMS engines can reduce load times by storing data in the main memory, join queries still remain computationally expensive. Modern graphics processing units (GPUs) provide massively parallel computing and may enhance the performance of such join queries; however, it is not clear yet in what condition relational joins perform well on GPUs. In this paper, we identify the performance characteristics of GPU computing for relational joins by implementing several well-known GPU-based join algorithms under various configurations. Experimental results indicate that the speedup ratio of GPU-based relational joins to CPU-based counterparts depends on the number of compute cores, the size of data sets, join conditions, and join algorithms. In the best case, the speedup ratios are up to 6.67 times for non-index joins, 9.41 times for sort index joins, and 2.55 times for hash joins. The execution time of GPU-based implementation for index joins, on the other hand, is only about 0.696 times less than the execution time of the CPU’s counterparts. Autors: Makoto Yabuta;Anh Nguyen;Shinpei Kato;Masato Edahiro;Hideyuki Kawashima; Appeared in: IEEE Transactions on Parallel and Distributed Systems Publication date: Sep 2017, volume: 28, issue:9, pages: 2663 - 2673 Publisher: IEEE
» Relative Humidity Sensing Using a PMMA Doped Agarose Gel Microfiber
 Abstract:Humidity sensors rely on humidity-induced refractive index change in the sensing material despite the sensor configuration. Polymer-based microwires can absorb water vapor molecules and detect humidity changes without the need of further coating. However, the sensitivity-simplicity trade-off is still a challenge. Sophisticated coating methods, complex resonating structures, and nanostructured films are reported as methods to enhance the device sensitivity. A simple technique, to build a high sensitivity RH sensor based on an agarose-doped Poly Methyl Methacrylate (PMMA) sensor head, is demonstrated. The waist diameter and uniform length of the PMMA doped agarose gel microfiber were measured to be 6 μm and 10 mm, respectively. The sensor can achieve power variation of up to 2.9 μW in a wide relative humidity range (50–80%), and display linear response with a correlation coefficient of 98.29%, sensitivity of 0.421 dB/%RH, and resolution of 0.431%RH. This agarose-based optical sensor provides a beneficial complement to the existing electrical ones, and will promote the employment of agarose in chemical sensing techniques. Autors: Ninik Irawati;Husna Abdul Rahman;Moh Yasin;Shadi Al-Askari;Belal Ahmed Hamida;Harith Ahmad;Sulaiman Wadi Harun; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:18, pages: 3940 - 3944 Publisher: IEEE
» Relativistic Aspects of Plane Wave Scattering by a Perfectly Conducting Half-Plane With Uniform Velocity Along an Arbitrary Direction
 Abstract:The scattering of time-harmonic plane waves by a perfectly electrically conducting (PEC) half-plane (H-P) in relativistic uniform motion is discussed. The problem is formulated using the special theory of relativity by means of the Lorentz transformation applied to the classic Sommerfeld solution. Exact fields are obtained for the 3-D vector problem of scattering of an obliquely incident and arbitrarily polarized plane wave by a PEC H-P in relativistic translational motion. The total fields are then presented as the relativistic analog of their motionless counterparts and an association with the uniform asymptotic theory of diffraction framework is inferred. In addition to recovering known features such as the relativistic Doppler effect and shadow boundary shifts, it is herein depicted a polarization coupling effect due to motion that can give rise to a 3-D scattered field with all components present even for a linearly polarized incident wave. Validating results and illustrative examples are also presented. Autors: Guilherme Simon da Rosa;Julio L. Nicolini;Flavio J. V. Hasselmann; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4759 - 4767 Publisher: IEEE
» Relaxed Conditions for the Input-to-State Stability of Switched Nonlinear Time-Varying Systems
 Abstract:This technical note considers the problem of input-to-state stability (ISS) for switched nonlinear time-varying systems. First, a sufficient condition is proposed to verify the ISS of nonlinear time-varying systems by using an improved Lyapunov function. Then, the results obtained are extended to study the ISS of switched nonlinear time-varying systems. Three relaxed conditions are given by using the methods of multiple Lyapunov functions, minimum dwell time, and infinite switchings, respectively. Comparing with the existing results, the conditions obtained have two relaxations, i.e., the derivative of Lyapunov functions of subsystems are allowed to be indefinite, and all subsystems are allowed to be unstable in the case of infinite switchings. All results obtained also be used to study the uniformly asymptotic stability (UAS) of systems. Finally, a numerical example is given to illustrate the theoretical results. Autors: Guopei Chen;Ying Yang; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4706 - 4712 Publisher: IEEE
» Reliability and Failure Analysis of UHF RFID Passive Tags Under Thermal Storage
 Abstract:This paper proposes studying the effects of thermal storage on the reliability of passive ultra-high frequency radio-frequency identification tags. Two types of tags M1 and M2 from two different manufacturers are aged under two high temperatures equal to 408 K and 433 K. Tested tags are put into thermal storage oven hang fixed terms. The performances of these tags are measured after each aging phase to determine the power loss caused by high-temperature storage. Then, a mathematical approach is used to estimate for both tags from the two manufacturers the law of reliability under nominal conditions. Statistical and physical analyses of the results allow us to study and analyze the mechanisms of aging. It is observed that the failure mechanisms depend on the type of passive tags and the values of selected storage temperatures for the tests. The scale parameters of M1 tags aged at 408 K are around 280 h, whereas the scale parameters of the M2 tags aged at the same temperature are around 360 h. Cracks on the antenna are observed with the higher temperature equal to 433 K for M1 tags. However, the changes of the performance of others tags are probably caused by changes in the matching of the impedance between the antenna and the radio-frequency integrated circuit. From this study, various failure mechanisms demonstrate the necessity of determining the type of passive tags and the used temperature. Autors: Sanae Taoufik;Pascal Dherbécourt;Ahmed El Oualkadi;Farid Temcamani; Appeared in: IEEE Transactions on Device and Materials Reliability Publication date: Sep 2017, volume: 17, issue:3, pages: 531 - 538 Publisher: IEEE
» Reliability Effects of Maintenance on TNEP Considering Preventive and Corrective Repairs
 Abstract:The aim of this paper is to investigate maintenance effects on system reliability and transmission network expansion planning considering line loading and repairs. For this purpose, the maintenance cost is formulated taking into account transient and permanent forced outage rates, as well as durations of planned and forced outage. Also, transmission reliability is modeled considering load shedding (LS) and energy not supplied (ENS) criteria. LS index is calculated for transient forced outages and ENS criterion is computed for permanent forced outages, and planned outage rates and durations. Furthermore, the effects of line loadings on transmission system reliability are formulated through the transient and permanent forced outage rates. The proposed model was tested on the IEEE 24-bus and 30-bus test systems, and the results are discussed. Autors: Meisam Mahdavi;Hassan Monsef;Rubén Romero; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3768 - 3781 Publisher: IEEE
» Reliability Evaluation for Demand-Based Warm Standby Systems Considering Degradation Process
 Abstract:Warm standby redundancy is a fault-tolerant technique balancing the low economical efficiency of hot standby and the long recovery time of cold standby. In this paper, motivated by practical engineering systems, a general demand-based warm standby system (DB-WSS) considering component degradation process is studied. A series of intermediate states exists between perfect functionality and complete failure because of degradation processes. A lot of existing analytical reliability assessment techniques are focused on conventional binary-state models or exponential state transition distributions for a system or its components. In this paper, a novel reliability evaluation approach based on the multistate decision diagram for DB-WSS is proposed. The proposed technique can handle arbitrary distributions of degradation processes for multistate components or systems. Moreover, considering the imperfect switch of the warm standby component, the start failure probability is taken into account in the warm standby system. Numerical studies are given to illustrate the proposed approach. Autors: Heping Jia;Yi Ding;Rui Peng;Yonghua Song; Appeared in: IEEE Transactions on Reliability Publication date: Sep 2017, volume: 66, issue:3, pages: 795 - 805 Publisher: IEEE
» Reliability of nand-Based SSDs: What Field Studies Tell Us
 Abstract:Solid-state drives (SSDs) based on NAND flash are making deep inroads into data centers as well as the consumer market. In 2016, manufacturers shipped more than 130 million units totaling around 50 Exabytes of storage capacity. As the amount of data stored on solid state drives keeps increasing, it is important to understand the reliability characteristics of these devices. For a long time, our knowledge about flash reliability was derived from controlled experiments in lab environments under synthetic workloads, often using methods for accelerated testing. However, within the last two years, three large-scale field studies have been published that report on the failure behavior of flash devices in production environments subjected to real workloads and operating conditions. The goal of this paper is to provide an overview of what we have learned about flash reliability in production, and where appropriate contrasting it with prior studies performing controlled experiments. Autors: Bianca Schroeder;Arif Merchant;Raghav Lagisetty; Appeared in: Proceedings of the IEEE Publication date: Sep 2017, volume: 105, issue:9, pages: 1751 - 1769 Publisher: IEEE
» Reliability of Solid-State Drives Based on NAND Flash Memory
 Abstract:This paper reviews the reliability of solid-state drives (SSDs) based on NAND Flash memory from the perspectives of failure mechanisms, design mitigations, qualification methods, and field failure rates. NAND reliability is dominated by gradual memory-cell degradation in late life and defects such as interconnect shorts earlier in life. Design mitigations exist for these mechanisms. Qualification methods standardized in JEDEC JESD218 are designed to evaluate the mechanisms and mitigations, over a full drive lifetime, in the laboratory. Full-lifetime qualification provides confidence in the long-term reliability of SSDs that cannot be achieved by the early-life qualifications performed on hard disk drives. If NAND mechanisms are sufficiently suppressed, field reliability will be dominated by non-NAND mechanisms such as firmware bugs, power-loss events, radiation-induced soft errors, and failures in non-NAND components. A wide range of design validation and qualification tests are necessary to evaluate these non-NAND mechanisms. Published field reliability statistics indicate that SSDs are more reliable on average than HDDs, but they are not immune to failure, and there is wide variation among models. The NAND and non-NAND mechanisms are illustrated through new case studies of SSD internal qualification and field reliability data. Autors: Neal R. Mielke;Robert E. Frickey;Ivan Kalastirsky;Minyan Quan;Dmitry Ustinov;Venkatesh J. Vasudevan; Appeared in: Proceedings of the IEEE Publication date: Sep 2017, volume: 105, issue:9, pages: 1725 - 1750 Publisher: IEEE
» Reliability-Aware Circuit Design Methodology for Beyond-5G Communication Systems
 Abstract:This paper focuses on efficient reliability analysis methodologies applicable for beyond-5G communication systems demonstrated on prospective terahertz (THz) technologies. Recently, a lot of the research interests have grown on optoelectronic integration which requires simultaneous management of electronic and optical modules. These technologies are evolving very rapidly, providing higher complexity, thereby increasing their susceptibility to stress environments (i.e., mutual self-heating) and finally requiring both robustness assessment and lifetime prediction under different operating conditions. Consequently, long-time reliability is a major issue. Extensive reliability assessment needs novel design methodologies that can provide reliability-aware optimization at the design level. This review discusses an extensive physics-based methodology for reliability prediction and analysis of degradation mechanisms in integrated-circuit technologies. Circuit-level design and optimization methodologies are illustrated by taking into account reliability-aware design techniques. Application examples and results are presented for an InP DHBT process, a viable technological solution for beyond-5G and THz applications. Autors: Chhandak Mukherjee;Bertrand Ardouin;Jean-Yves Dupuy;Virginie Nodjiadjim;Muriel Riet;Thomas Zimmer;François Marc;Cristell Maneux; Appeared in: IEEE Transactions on Device and Materials Reliability Publication date: Sep 2017, volume: 17, issue:3, pages: 490 - 506 Publisher: IEEE
» Reliability-Enhanced Separated Pre-Charge Sensing Amplifier for Hybrid CMOS/MTJ Logic Circuits
 Abstract:Benefitting from its non-volatility, low power, high speed, nearly infinite endurance, good scalability, and great CMOS compatibility, magnetic tunnel junction (MTJ) embedded in conventional CMOS logic circuits has been proposed as one potentially powerful solution to introduce non-volatility in today’s programmable logic circuits, which is envisioned to extend Moore’s law. However, a critical issue in such hybrid CMOS/MTJ logic circuit is the reliable transmission of MTJ electric signals to the CMOS electronics, i.e., the requirement of nearly zero read/write error for logic applications. In this paper, a reliability-enhanced separated pre-charge sensing amplifier (RESPCSA) is proposed for hybrid CMOS/MTJ logic circuits. By adding two feedback paths with only two transistors between its discharge and evaluation terminal, such proposed RESPCSA can achieve a more and more larger dynamic resistance difference between its two discharge branches with the MTJs during the discharge phase, thereby obtaining a large sensing margin. By using a commercial CMOS 40 nm design kit and a physics-based MTJ compact model, hybrid CMOS/MTJ transient and Monte-Carlo statistic simulations have been conducted to demonstrate its functionality and evaluate its performance, respectively. Autors: Deming Zhang;Lang Zeng;Tianqi Gao;Fanghui Gong;Xiaowan Qin;Wang Kang;Yue Zhang;Youguang Zhang;Jacques Olivier Klein;Weisheng Zhao; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 5 Publisher: IEEE
» Reliable Beamspace Channel Estimation for Millimeter-Wave Massive MIMO Systems with Lens Antenna Array
 Abstract:Millimeter-wave (mm-wave) massive MIMO with lens antenna array can considerably reduce the number of required radio-frequency (RF) chains by beam selection. However, beam selection requires the base station to acquire the accurate information of beamspace channel. This is a challenging task as the size of beamspace channel is large, while the number of RF chains is limited. In this paper, we investigate the beamspace channel estimation problem in mm-wave massive MIMO systems with lens antenna array. Specifically, we first design an adaptive selecting network for mm-wave massive MIMO systems with lens antenna array, and based on this network, we further formulate the beamspace channel estimation problem as a sparse signal recovery problem. Then, by fully utilizing the structural characteristics of the mm-wave beamspace channel, we propose a support detection (SD)-based channel estimation scheme with reliable performance and low pilot overhead. Finally, the performance and complexity analyses are provided to prove that the proposed SD-based channel estimation scheme can estimate the support of sparse beamspace channel with comparable or higher accuracy than conventional schemes. Simulation results verify that the proposed SD-based channel estimation scheme outperforms conventional schemes and enjoys satisfying accuracy even in the low SNR region as the structural characteristics of beamspace channel can be exploited. Autors: Xinyu Gao;Linglong Dai;Shuangfeng Han;Chih-Lin I;Xiaodong Wang; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 6010 - 6021 Publisher: IEEE
» Reliable RF B/E-Field Probes for Time-Domain Monitoring of EM Exposure During Medical Device Testing
 Abstract:This paper presents electric and magnetic probes to measure radio frequency (RF) electric and magnetic fields for measuring the time-varying RF fields used in magnetic resonance imaging (MRI). A small single loop (2 cm) and short dipole antenna (2 cm) were developed to monitor the near field magnetic and electric exposure during the medical device testing. Theoretical analysis for each designed probe was performed to convert the real time receive signals to the exposed electric and magnetic field. Probes in this paper were tuned and matched at center frequency of 127.6 MHz for 3T MRI scanners to improve the accuracy and sensitivity. Different cables were designed to reduce the E-field pick up and achieving the most accurate measurement setup. Probes were fabricated on a single sided printed circuit board, FR4 of thickness 1.57 mm and a copper thickness of . The measured S-parameters of the magnetic and electric field probes show less than −44 and −45 dB return loss at 127.6-MHz center frequency of the RF Birdcage. Autors: Ali Attaran;William Bradfield Handler;Krzysztof Wawrzyn;Ravi S. Menon;Blaine A. Chronik; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4815 - 4823 Publisher: IEEE
» Remaining Discharge Time Prognostics of Lithium-Ion Batteries Using Dirichlet Process Mixture Model and Particle Filtering Method
 Abstract:A new approach using Dirichlet process mixture model (DPMM) and particle filtering (PF) method to predict remaining discharge time (RDT) of ongoing discharge processes of lithium-ion batteries is proposed. Different voltage trajectory patterns are proposed to describe the discharge process at different periods of a battery’s life. Each pattern is represented by the same empirical model based on the physical discharge behavior of lithium-ion batteries, with different parameters to distinguish itself. A DPMM is developed to automatically discover these voltage trajectory patterns from historical monitoring data, without specifying the number of patterns in advance. The trajectory parameters for each pattern can also be learned simultaneously, which are used as the initial parameters for online prognostics. The developed DPMM is able to discover new patterns as more trajectory data become available. During online prognostics, voltage trajectory pattern is constantly identified with new voltage data, then initial parameters for identified pattern and PF-based method are combined to predict the RDT of the ongoing discharge process. A case study demonstrating the proposed approach is presented. It also demonstrates that this approach improves accuracy of RDT prediction compared with benchmark PF-based method. Autors: Yu Jinsong;Liang Shuang;Tang Diyin;Liu Hao; Appeared in: IEEE Transactions on Instrumentation and Measurement Publication date: Sep 2017, volume: 66, issue:9, pages: 2317 - 2328 Publisher: IEEE
» Remaining Useful Life Prediction for Degradation Processes With Memory Effects
 Abstract:Some practical systems such as blast furnaces and turbofan engines have degradation processes with memory effects. The term of memory effects implies that the future states of the degradation processes depend on both the current state and the past states because of the interaction with environments. However, most works generally used a memoryless Markovian process to model the degradation processes. To characterize the memory effects in practical systems, we develop a new type of degradation model, in which the diffusion is represented as a fractional Brownian motion (FBM). FBM is actually a special non-Markovian process with long-term dependencies. Based on the monitored data, a Monte Carlo method is used to predict the remaining useful life (RUL). The unknown parameters in the proposed model can be estimated by the maximum likelihood algorithm, and then the distribution of the RUL is predicted. The effectiveness of the proposed model is fully verified by a numerical example and a practical case study. Autors: Xiaopeng Xi;Maoyin Chen;Donghua Zhou; Appeared in: IEEE Transactions on Reliability Publication date: Sep 2017, volume: 66, issue:3, pages: 751 - 760 Publisher: IEEE
» Remedial Strategies of T-NPC Three-Level Asymmetric Six-Phase PMSM Drives Based on SVM-DTC
 Abstract:In this paper, novel remedial direct torque control (DTC) schemes are proposed for open-circuit faults in T-type neutral-point-clamping (T-NPC) three-level asymmetric six-phase permanent-magnet synchronous motor (PMSM) drives. First, a simplified space vector modulation (SVM) is designed and applied for DTC-controlled asymmetric six-phase drive, in such a way that both good current harmonic performance and fast dynamic response are available. Based on the SVM-DTC scheme, a remedial strategy is proposed for the open-circuit faults in phase windings. The key is to derive the relationship between the stator fluxes and the stator voltages of all phases under faulty condition. Then, a derived perturbation term is compensated for normal voltage references, and the fault-tolerant scheme is, thus, implemented without changing control structure of normal condition. The remedial DTC schemes are also studied and proposed for open-switch faults in T-NPC six-phase drives. The modulation methods are redesigned for the faults in half-bridge switches and NPC switches. The experiments are carried out on a laboratory prototype to verify the validity and performance of the proposed fault-tolerant control schemes. Autors: Xueqing Wang;Zheng Wang;Ming Cheng;Yihua Hu; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 6841 - 6853 Publisher: IEEE
» Remote Sensing Image Classification Using Genetic-Programming-Based Time Series Similarity Functions
 Abstract:In several applications, the automatic identification of regions of interest in remote sensing images is based on the assessment of the similarity of associated time series, i.e., two regions are considered as belonging to the same class if the patterns found in their spectral information observed over time are somewhat similar. In this letter, we investigate the use of a genetic programming (GP) framework to discover an effective combination of time series similarity functions to be used in remote sensing classification tasks. Performed experiments in a Forest–Savanna classification scenario demonstrated that the GP framework yields effective results when compared with the use of traditional widely used similarity functions in isolation. Autors: Alexandre E. Almeida;Ricardo da S. Torres; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1499 - 1503 Publisher: IEEE
» Remote Sensing Scene Classification by Unsupervised Representation Learning
 Abstract:With the rapid development of the satellite sensor technology, high spatial resolution remote sensing (HSR) data have attracted extensive attention in military and civilian applications. In order to make full use of these data, remote sensing scene classification becomes an important and necessary precedent task. In this paper, an unsupervised representation learning method is proposed to investigate deconvolution networks for remote sensing scene classification. First, a shallow weighted deconvolution network is utilized to learn a set of feature maps and filters for each image by minimizing the reconstruction error between the input image and the convolution result. The learned feature maps can capture the abundant edge and texture information of high spatial resolution images, which is definitely important for remote sensing images. After that, the spatial pyramid model (SPM) is used to aggregate features at different scales to maintain the spatial layout of HSR image scene. A discriminative representation for HSR image is obtained by combining the proposed weighted deconvolution model and SPM. Finally, the representation vector is input into a support vector machine to finish classification. We apply our method on two challenging HSR image data sets: the UCMerced data set with 21 scene categories and the Sydney data set with seven land-use categories. All the experimental results achieved by the proposed method outperform most state of the arts, which demonstrates the effectiveness of the proposed method. Autors: Xiaoqiang Lu;Xiangtao Zheng;Yuan Yuan; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 5148 - 5157 Publisher: IEEE
» Renewable Energy Microgrids in Northern Remote Communities
 Abstract:If you consider community electricity access issues and their environmental impact, you might not think Canada would have communities where these are major concerns. Canada has abundant dispersed natural resources providing sufficient electrical capacity with a relatively low environmental footprint. In general terms, the country has enough generation capacity to supply electricity for the vast majority of the population and for foreseeable growth. In addition, since 2002, Canada has reduced its environmental footprint from the electricity sector, mainly due to the retirement of coal plants. So, what is the problem? Autors: Mariano Arriaga;Ehsan Nasr;Hayley Rutherford; Appeared in: IEEE Potentials Publication date: Sep 2017, volume: 36, issue:5, pages: 22 - 29 Publisher: IEEE
» Repairing Reed-Solomon Codes
 Abstract:We study the performance of Reed–Solomon (RS) codes for the exact repair problem in distributed storage. Our main result is that, in some parameter regimes, Reed–Solomon codes are optimal regenerating codes, among maximum distance separable (MDS) codes with linear repair schemes. Moreover, we give a characterization of MDS codes with linear repair schemes, which holds in any parameter regime, and which can be used to give non-trivial repair schemes for RS codes in other settings. More precisely, we show that for -dimensional RS codes whose evaluation points are a finite field of size , there are exact repair schemes with bandwidth bits, and that this is optimal for any MDS code with a linear repair scheme. In contrast, the naive (commonly implemented) repair algorithm for this RS code has bandwidth bits. When the entire field is used as evaluation points, the number of nodes is much larger than the number of bits per node (which is ), and so this result holds only when the degree of sub-packetization is small. However, our method applies in any parameter regime, and to illustrate this for high levels of sub-packetization, we give an improved repair scheme for a specific (14,10)-RS code used in the facebook hadoop analytics cluster. Autors: Venkatesan Guruswami;Mary Wootters; Appeared in: IEEE Transactions on Information Theory Publication date: Sep 2017, volume: 63, issue:9, pages: 5684 - 5698 Publisher: IEEE
» Reporting Usability Defects: A Systematic Literature Review
 Abstract:Usability defects can be found either by formal usability evaluation methods or indirectly during system testing or usage. No matter how they are discovered, these defects must be tracked and reported. However, empirical studies indicate that usability defects are often not clearly and fully described. This study aims to identify the state of the art in reporting of usability defects in the software engineering and usability engineering literature. We conducted a systematic literature review of usability defect reporting drawing from both the usability and software engineering literature from January 2000 until March 2016. As a result, a total of 57 studies were identified, in which we classified the studies into three categories: reporting usability defect information, analysing usability defect data and key challenges. Out of these, 20 were software engineering studies and 37 were usability studies. The results of this systematic literature review show that usability defect reporting processes suffer from a number of limitations, including: mixed data, inconsistency of terms and values of usability defect data, and insufficient attributes to classify usability defects. We make a number of recommendations to improve usability defect reporting and management in software engineering. Autors: Nor Shahida Mohamad Yusop;John Grundy;Rajesh Vasa; Appeared in: IEEE Transactions on Software Engineering Publication date: Sep 2017, volume: 43, issue:9, pages: 848 - 867 Publisher: IEEE
» Representation Learning Based Speech Assistive System for Persons With Dysarthria
 Abstract:An assistive system for persons with vocal impairment due to dysarthria converts dysarthric speech to normal speech or text. Because of the articulatory deficits, dysarthric speech recognition needs a robust learning technique. Representation learning is significant for complex tasks such as dysarthric speech recognition. We focus on robust representation for dysarthric speech recognition that involves recognizing sequential patterns of varying length utterances. We propose a hybrid framework that uses a generative learning based data representation with a discriminative learning based classifier. In this hybrid framework, we propose to use Example Specific Hidden Markov Models (ESHMMs) to obtain log-likelihood scores for a dysarthric speech utterance to form fixed dimensional score vector representation. This representation is used as an input to discriminative classifier such as support vector machine.The performance of the proposed approach is evaluatedusingUA-Speechdatabase.The recognitionaccuracy is much better than the conventional hidden Markov model based approach and Deep Neural Network-Hidden Markov Model (DNN-HMM). The efficiency of the discriminative nature of score vector representation is proved for “very low” intelligibility words. Autors: S. Chandrakala;Natarajan Rajeswari; Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering Publication date: Sep 2017, volume: 25, issue:9, pages: 1510 - 1517 Publisher: IEEE
» Research of Segmentation Method on Image of Lingwu Long Jujubes Based on a New Extraction Model of Hue
 Abstract:This paper studies on the image segmentation method of Lingwu Long Jujubes based on a new extraction model of hue to improve the accuracy of extracting images of Lingwu Long Jujubes. According to the characteristics that color components of Lingwu Long Jujubes in RGB color space have different distribution in a shadow environment or others, a extraction model of hue aiming at images of Lingwu Long Jujubes based on stage treatment of R component is built to extract hue information. And the difference between the target object and the background object is increased by using color difference. Then, the image is segmented by optimal threshold obtained by combining the maximum entropy and the mathematical criteria to achieve the adaptive adjustment of the segmentation threshold. Finally, the segmented image will be obtained through dealing with mathematical morphology. By comparing the segmentation effect of 30 Lingwu Long Jujubes images with artificial methods and other methods, it proves that the color image segmentation method of Lingwu Long Jujubes based on a new extraction model of hue has good effect to extract the object region. The accuracy of the segmentation rate is up to 92.6883%. The time that the algorithm run is 1.3107 s. Autors: Yingpeng Dai;Yutan Wang;Junrui Xue;Xiangnan Liu;Bohan Liu;Xiaoyun Guo; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 6029 - 6036 Publisher: IEEE
» Research of the Monolithic Integrated 3-D Magnetic Field Sensor Based on MEMS Technology
 Abstract:A monolithic-integrated 3-D magnetic field sensor is proposed in this paper, which is composed of four silicon magnetic sensitive transistors and a Hall magnetic field sensor. Using microelectromechanical system (MEMS) technology, the chip of the sensor was designed and fabricated on a p-type silicon wafer with a higher resistivity. At the room temperature, the magnetic sensitivities and on the - and -directions are 77.5 and 78.6 mV/T at power supply V and base injection current mA, respectively. In addition, the magnetic sensitivity on the -axis is 77.4 mV/T at V. The experimental results show that the proposed sensor has a good uniformity of magnetic sensitivity, besides achieving the measurement to 3-D magnetic fields and the cross sensitivities are less than 3% at T. Autors: Xiaofeng Zhao;Yunjia Bai;Qi Deng;Chunpeng Ai;Xianghong Yang;Dianzhong Wen; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 5849 - 5856 Publisher: IEEE
» Resilient Event-Triggering $H_{\infty }$ Load Frequency Control for Multi-Area Power Systems With Energy-Limited DoS Attacks
 Abstract:This paper investigates a resilient event-triggering load frequency control (LFC) for multi-area power systems with energy-limited Denial-of-Service (DoS) attacks. The LFC design specifically takes the presence of DoS attacks into account. First, an area control error dependent time delay model is delicately constructed for multi-area closed-loop power systems. Second, a resilient event-triggering communication (RETC) scheme is well designed, which allows a degree of packet losses induced by DoS attacks and has the advantage of improving the transaction efficiency. Then, by using the Lyapunov theory, two stability and stabilization criteria for the multi-area power systems are derived under consideration of the energy-limited DoS attacks. In these criteria, the relationship between the allowable DoS attack duration and the resilient event-triggering communication parameters are clearly revealed. Moreover, an algorithm is also provided to obtain the RETC parameters and the LFC gains simultaneously. Finally, a case study shows the effectiveness of the proposed method. Autors: Chen Peng;Jicai Li;Minrui Fei; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4110 - 4118 Publisher: IEEE
» Resistive RAM-Centric Computing: Design and Modeling Methodology
 Abstract:Memory-centric computing with on-chip non-volatile memories provides unique opportunities for native and local information processing in an energy-efficient manner. Design and modeling methodology based on resistive random access memory (RRAM) is presented in this paper. A hierarchical RRAM SPICE model having different levels of physics realism is described, where the incorporated stochasticity provides a more accurate representation of RRAM operations. Three in-memory operation schemes are developed and experimentally verified for reconfigurable in-memory logic, using RRAM built in 3-D vertical structure (i.e., 3-D RRAM). As a case study for RRAM-centric computing systems, we evaluate the Please note that there were discrepancies between the accepted pdf [TCAS_R1_combined.pdf] and the [TCAS_RRAM-centric computing_hli_FINAL_submit.docx] in the lines 12 and 70. We have followed [TCAS_RRAM-centric computing_hli_FINAL_submit.docx]. use of 3-D RRAMs for a language recognition system using the hyperdimensional (HD) computing model. Utilizing the inherent properties of 3-D RRAM, we demonstrate, using fabricated 3-D RRAM integrated with FinFET, the essential kernels for HD operations: multiplication, addition, and permutation (MAP). RRAM-centric HD systems exhibit strong resilience to hard errors induced by RRAM endurance failures, making a promising case for using various types of RRAM for memory-centric HD systems. Autors: Haitong Li;Tony F. Wu;Subhasish Mitra;H.-S. Philip Wong; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2263 - 2273 Publisher: IEEE
» Resistive Random Access Memory for Future Information Processing System
 Abstract:Resistive random access memory (RRAM) is regarded as one of the most promising emerging memory technologies for next-generation embedded, standalone nonvolatile memory (NVM), and storage class memory (SCM) due to its speed, density, cost, and scalability. Considerable progress has been made in recent years on the manufacturability of RRAM, with low-density RRAM products now in production and the path to higher density parts becoming clearer. This review updates the learning on the fundamental materials and process integration needed for high-volume manufacturing and summarizes very recent progress on array level performance improvement methodology using novel techniques, and circuit level contributions for different applications. The device performance, array integration, and device/circuit codesign for memory systems are discussed. Novel applications besides embedded memory and standalone memory are addressed, including hardware security, neuromorphic computing, and nonvolatile logic systems. Autors: Huaqiang Wu;Xiao Hu Wang;Bin Gao;Ning Deng;Zhichao Lu;Brent Haukness;Gary Bronner;He Qian; Appeared in: Proceedings of the IEEE Publication date: Sep 2017, volume: 105, issue:9, pages: 1770 - 1789 Publisher: IEEE
» Resistive Switching Characteristic of Low-Temperature Top-Electrode-Free Tin-Oxide Memristor
 Abstract:This brief investigated bipolar resistive switching (RS) characteristic of a top-electrode-free sol-gel SnOx resistive memory, which was fabricated at a low temperature of 120 °C. The RS characteristic was obtained by directly using a probe tip to make an electrical point contact with the SnOx surface. The SnOx memristor exhibited a remarkable memory window of 103 and it can operate over 500 dc cycles without noticeable degradation. Oxygen ion storage and release from a chemically active top-electrode, which were commonly used to explain RS, seem not applicable to this SnOx memristor. The SnOx film was characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. The physical mechanisms of the conduction current and the RS behavior were also explored. Autors: Chih-Chieh Hsu;Po-Yang Chuang;Yu-Ting Chen; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3951 - 3954 Publisher: IEEE
» Resolution Independent Real-Time Vector-Embedded Mesh for Animation
 Abstract:High-resolution textures are determinant of not only high rendering quality in gaming and movie industries, but also of burdens in memory usage, data transmission bandwidth, and rendering efficiency. Therefore, it is desirable to shade 3D objects with vector images such as scalable vector graphics (SVG) for compactness and resolution independence. However, complicated geometry and high rendering cost limit the rendering effectiveness and efficiency of vector texturing techniques. In order to overcome these limitations, this paper proposes a real-time resolution-independent vector-embedded shading method for 3D animated objects. Our system first decomposes a vector image consisting of layered close coloring regions into unifying-coloring units for mesh retriangulation and 1D coloring texture construction, where coloring denotes color determination for a point based on an intermediate medium such as a raster/vector image, unifying denotes the usage of the same set of operations, and unifying coloring denotes coloring with the same-color computation operations. We then embed the coloring information and distances to enclosed unit boundaries in retriangulated vertices to minimize embedded information, localize vertex-embedded shading data, remove overdrawing inefficiency, and ensure fixed-length shading instructions for data compactness and avoidance of indirect memory accessing and complex programming structures when using other shading and texturing schemes. Furthermore, stroking is the process of laying down a fixed-width pen-centered element along connected curves, and our system also decomposes these curves into segments using their curve-mesh intersections and embeds their control vertices as well as their widths in the intersected triangles to avoid expensive distance computation. Overall, our algorithm enables high-quality real-time Graphics Processing Unit (GPU)-based coloring for real-time 3D animation rendering through our efficient SVG-embedded rendering pi- eline while using a small amount of texture memory and transmission bandwidth. Autors: Chih-Yuan Yao;Kuang-Yi Chen;Hong-Nian Guo;Cheng-Chi Li;Yu-Chi Lai; Appeared in: IEEE Transactions on Circuits and Systems for Video Technology Publication date: Sep 2017, volume: 27, issue:9, pages: 1974 - 1986 Publisher: IEEE
» Resonant Frequency Tuning Technique for Selective Detection of Alcohols by TiO2 Nanorod-Based Capacitive Device
 Abstract:Selective detection of vapor species, especially belonging to the same group, is a crucial bottleneck for resistive sensor devices. In this paper, methanol, ethanol, and 2-propanol detection by Pd/TiO2 nanorod array/Ti device in capacitive mode was achieved, with improved selectivity, employing a resonant frequency tuning technique. The optimal capacitive response of the device was obtained by identifying the resonant frequency over the frequency range of 0.01–200 kHz. The imaginary part of the impedance (−|Z| sinθ as a function of frequency) in air and in alcohols revealed a shift in resonant frequency towards lower frequency regime upon exposure to alcohols. Moreover, the difference in the resonant frequencies (Δf ) from one alcohol to another were found to be almost constant which facilitated the frequency-selective sensing even for varying concentrations of target species (1, 50, and 100 ppm in present case). Such frequency selective nature of the device possibly originated from different degree of polarization of different alcohol molecules at different frequencies which was duly correlated to the corresponding equivalent circuit model. However, for real selective detection, when the target species is unknown, the proposed device does not work properly and an array of devices is necessary. Autors: Koushik Dutta;Basanta Bhowmik;Partha Bhattacharyya; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 820 - 825 Publisher: IEEE
» Resource Allocation for D2D Wireless Networks With Asymmetric Social Weighted Graph
 Abstract:Different from the existing symmetric social relation graph, we first utilize a new asymmetric social weighted graph to study the problem of resource allocation for Device-to-Device (D2D) wireless social networks. We propose a social-aware cluster-based game theoretical scheme for resource allocation in which clusters are formatted based on the new defined weighted social interference degree and the physical interference graph. In the proposed cluster-based game scheme, we shrink action spaces of players (clusters) through a determined channel allocation rule. Simulation results show that the proposed cluster action selection algorithm has a higher convergence speed and a better social network interference performance. Autors: Ducheng Wu;Yuhua Xu;Qihui Wu; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 2085 - 2088 Publisher: IEEE
 Abstract:The extension of long term evolution (LTE) networks in unlicensed spectrum areas under the licensed assisted access concept aims at achieving higher transmission rates via the aggregation of the aforementioned bands along with the licensed ones within the 3G Partnership Project framework. A prospect carrier aggregation (CA) scheme should handle efficiently the coexistence of the LTE systems that compete for the same unlicensed spectrum areas along with their incumbent users (i.e., Wi-Fi). In this paper, a novel CA scheme is proposed for licensed/unlicensed MIMO LTE systems that allocates optimally the resources (power and resource blocks) of an evolved Node B to user equipments. Furthermore, the proposed approach handles the coexistence matters within the unlicensed bands with an efficient decentralized way. The new scheme involves the solution to a mixed integer nonlinear programming problem and thus, an optimal low complexity method is proposed based on the Lagrange dual decomposition. Furthermore, the proposed technique is extended to the imperfect channel state information (CSI) case. To that end, a novel listen-before-talk scheme is developed via which the required unlicensed bands CSI are estimated in a blind manner. The performance of all of the proposed techniques is verified via indicative simulations. Autors: Christos G. Tsinos;Fotis Foukalas;Theodoros A. Tsiftsis; Appeared in: IEEE Transactions on Communications Publication date: Sep 2017, volume: 65, issue:9, pages: 3765 - 3779 Publisher: IEEE
» Responsivity Enhancement of Metal-Insulator-Semiconductor Photodetectors on Silicon-on-Insulator Substrates by Plasmonic Nanoantennas
 Abstract:We report metal-insulator-semiconductor photodetectors fabricated on a silicon-on-insulator substrate, exhibiting an enhanced responsivity in the near-infrared due to the incorporation of Au-nanoantennas at the optical input port. The optimal antenna design and the photoresponse enhancements have been calculated using detailed finite-difference time-domain simulations. These nanoantennas modify the propagation of the input optical signals. In this regime, strong plasmonic local field enhancements are observed. The maximum responsivity enhancement, 40%, was obtained at 780 nm; while at wavelengths shorter than 720 nm, the responsivity is reduced due to absorption losses in the Au-nanoantennas. Autors: Revathy Padmanabhan;Ofir Sorias;Ori Eyal;Vissarion Mikhelashvili;Meir Orenstein;G. Eisenstein; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 778 - 783 Publisher: IEEE
» Retreat to Move Forward : Alleviating Allostatic Load for the Brave [Last Word]
 Abstract: Autors: Christina Perakslis; Appeared in: IEEE Technology and Society Magazine Publication date: Sep 2017, volume: 36, issue:3, pages: 88 - 88 Publisher: IEEE
» Retrieval From and Understanding of Large-Scale Multi-modal Medical Datasets: A Review
 Abstract:Content-based multimedia retrieval (CBMR) has been an active research domain since the mid 1990s. In medicine visual retrieval started later and has mostly remained a research instrument and less a clinical tool. The limited size of data sets due to privacy constraints is often mentioned as reason for these limitations. Nevertheless, much work has been done in CBMR, including the availability of increasingly large data sets and scientific challenges. Annotated data sets and clinical data for images have now become available and can be combined for multi-modal retrieval. Much has been learned on user behavior and application scenarios. This text is motivated by the advances in medical image analysis and the availability of public large data sets that often include clinical data. It is a systematic review of recent work (concentrating on the period 2011–2017) on multi-modal CBMR and image understanding in the medical domain, where image understanding includes techniques such as detection, localization, and classification for leveraging visual content. With the objective of summarizing the current state of research for multimedia researchers outside the medical field, the text provides ways to get data sets and identifies current limitations and promising research directions. The text highlights advances in the past six years and a trend to use larger scale training data and deep learning approaches that can replace/complement hand-crafted features. Using images alone will likely only work in limited domains but combining multiple sources of data for multi-modal retrieval has the biggest chances of success, particularly for clinical impact. Autors: Henning Müller;Devrim Unay; Appeared in: IEEE Transactions on Multimedia Publication date: Sep 2017, volume: 19, issue:9, pages: 2093 - 2104 Publisher: IEEE
» Reverse and Forward Engineering of Frequency Control in Power Networks
 Abstract:We lay out a general framework for reverse-engineering frequency dynamics with general primary frequency control and frequency response, by showing that it is a distributed algorithm to solve a well-defined optimization problem. We further characterize the role of deadband in control, and show that if the aggregated uncontrolled load deviation is nonzero the frequencies will be synchronized, and if however it is zero the frequencies may oscillate but within the deadband. The optimization based model does not only provide a way to characterize the equilibrium and establish the convergence of the frequency dynamics, but also suggests a principled way to engineer frequency control. By leveraging the optimization problem and insights from reverse engineering, we design a distributed realtime frequency control scheme that maintains the frequency to the nominal value while achieves economic efficiency. This work presents a further step towards developing a new foundation—network dynamics as optimization algorithms—for distributed realtime control and optimization of future power networks. Autors: Lijun Chen;Seungil You; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4631 - 4638 Publisher: IEEE
» Reviewing the Evolution of the NAND Flash Technology
 Abstract:This paper reviews the recent historical trends of the NAND Flash technology, highlighting the evolution of its main parameters and explaining what allowed it to become not only the most important integrated solution for nonvolatile storage of high volumes of data but also a strong rival eroding the market share of hard-disk drives. The scaling trend followed by planar arrays will be discussed with close attention, along with the major physical constraints impacting the performance and the reliability of modern deca-nanometer technologies. This will make clear why the development of further planar nodes with feature size below ~15 nm, representing today’s state of the art, can be considered less favorable than turning all the efforts toward the integration of 3-D arrays. The most promising 3-D architectures will then be reviewed, discussing their benefits and issues and addressing the impact of the change of the integration paradigm from the standpoint of the major NAND applications. Autors: Christian Monzio Compagnoni;Akira Goda;Alessandro S. Spinelli;Peter Feeley;Andrea L. Lacaita;Angelo Visconti; Appeared in: Proceedings of the IEEE Publication date: Sep 2017, volume: 105, issue:9, pages: 1609 - 1633 Publisher: IEEE
» Risk communication and miscommunication: case studies in science, technology, engineering, government, and community organizations (boiarsky, c.r.; 2016) [book review]
» Road-Terrain Classification for Land Vehicles: Employing an Acceleration-Based Approach
 Abstract:The perception of the environment around a land vehicle plays a crucial role for its driving assistant system. Knowledge of the road terrain is useful for handling its characteristics while driving the vehicles and improving passengers' safety and comfort. In this article, an approach to classifying road-terrain vehicles is presented. An accelerometer is mounted on the suspension of the vehicle to measure the vibration that represents the characteristics of the road terrain, and the road profile can be calculated by knowing the speed and one-quarter-dynamic model of the vehicle. The optimized classifier and features, speed independency, and the effect of employing principal component analysis (PCA) are investigated, and the simulation shows that this acceleration-based approach is feasible for land vehicles in a range of outdoor scenarios. Autors: Shifeng Wang;Sarath Kodagoda;Lei Shi;Hualin Wang; Appeared in: IEEE Vehicular Technology Magazine Publication date: Sep 2017, volume: 12, issue:3, pages: 34 - 41 Publisher: IEEE
» Robird: A Robotic Bird of Prey
 Abstract:Ever since the start of aviation, birds and airplanes have posed a mutual risk: Birds are killed when struck by aircraft, but, in return, bird strikes cause billions in damage to the aviation industry. Airports employ bird-control methods such as audiovisual deterrents (like scarecrows, lasers, and noise), weapons, and chemicals to relocate, suffocate, or otherwise terminate the birds [2]. While the latter methods work, they are ethically questionable. The problem of audiovisual deterrents is that they quickly lose effectiveness due to habituation. The approach that works consistently is the use of predator birds to scare off the prey birds and permanently relocate them away from runways. However, the predators themselves cannot be precisely controlled and, in turn, also pose a threat to airplanes. Autors: Gerrit Adriaan Folkertsma;Wessel Straatman;Nico Nijenhuis;Cornelis Henricus Venner;Stefano Stramigioli; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 22 - 29 Publisher: IEEE
» Robot Choreography: The Use of the Kinetography Laban System to Notate Robot Action and Motion
 Abstract:Roboticists aim to segment robot actions into a sequence of motion primitives to simplify the robot programming phase. Choreographers aim to capture the essence of human body movements within a sequence of symbols that can be understood by dancers. To that extent, roboticists and choreographers pursue the same quest. We have undertaken a pluridisciplinary approach, combining a dance notation system (the Kinetography Laban system) with a robot programming system [the Stack of Task (SoT)]. Motion scores are used instead of quantitative data to compare and enlighten differences in robot and human movements. We then discuss plausible origins of these differences, taking into account the implicit rules of the Kinetography Laban system on how a movement is executed by humans. This comparison, in the light of the Kinetography Laban system, opens some challenging questions related to motion segmentation and motion naturalness. Autors: Paolo Salaris;Naoko Abe;Jean-Paul Laumond; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 30 - 40 Publisher: IEEE
» Robot Manipulator Capability in MATLAB: A Tutorial on Using the Robotics System Toolbox [Tutorial]
 Abstract:ï»¿The Robotics System Toolbox for MATLAB provides a wide and growing set of functionalities for creating robotic systems: Robot Operating System (ROS) integration, mobile robotics, and robot manipulator arms. This capability increases with each release and is targeted at industrial developers as well as academic teaching and research. This tutorial is concerned with the robot manipulator kinematic functionality that has been available since MATLAB release 2016b. Autors: Peter Corke; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 165 - 166 Publisher: IEEE
» Robust Beamforming Design in C-RAN With Sigmoidal Utility and Capacity-Limited Backhaul
 Abstract:In this paper, we study the robust beamforming design in cloud radio access networks, where remote radio heads (RRHs) are connected to a cloud server that performs signal processing and resource allocation in a centralized manner. Different from traditional approaches adopting a concave increasing function to model the utility of a user, we model the utility by a sigmoidal function of the signal-to-interference-plus-noise ratio (SINR) to capture the diminishing utility returns for very small and very large SINRs in real-time applications (e.g., video streaming). Our objective is to maximize the aggregate utility of the users while considering the imperfection of channel state information (CSI), limited backhaul capacity, and minimum quality of service requirements. Because of the sigmoidal utility function and some of the constraints, the formulated problem is non-convex. To efficiently solve the problem, we introduce a maximum interference constraint, transform the CSI uncertainty constraints into linear matrix inequalities, employ convex relaxation to handle the backhaul capacity constraints, and exploit the sum-of-ratios form of the objective function. This leads to an efficient resource allocation algorithm, which outperforms several baseline schemes, and closely approaches a performance upper bound for large CSI uncertainty or large number of RRHs. Autors: Zehua Wang;Derrick Wing Kwan Ng;Vincent W. S. Wong;Robert Schober; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 5583 - 5598 Publisher: IEEE
» Robust Beamforming Techniques for Non-Orthogonal Multiple Access Systems with Bounded Channel Uncertainties
 Abstract:We propose a robust beamforming design for non-orthogonal multiple access-based multiple-input single-output downlink systems. In particular, the robust power minimization problem is studied with imperfect channel state information, where the beamformers are designed by incorporating norm-bounded channel uncertainties to provide the required quality of service at each user. This robust scheme is developed based on the worst-case performance optimization framework. In terms of beamforming vectors, the original robust design is not convex; therefore, the robust beamformers cannot be obtained directly. To circumvent this non-convex issue, the original intractable problem is reformulated into a convex problem, where the non-convex constraint is converted into a linear matrix inequality by exploiting S-Procedure. Simulation results are provided to demonstrate the effectiveness of the proposed robust design. Autors: Faezeh Alavi;Kanapathippillai Cumanan;Zhiguo Ding;Alister G. Burr; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 2033 - 2036 Publisher: IEEE
» Robust Output Regulation for Continuous-Time Periodic Systems
 Abstract:We consider controller design for robust output tracking and disturbance rejection for continuous-time periodic linear systems with periodic reference and disturbance signals. As our main results, we present four different controllers: a feedforward control law and a discrete-time dynamic error feedback controller for output tracking and disturbance rejection, a robust discrete-time feedback controller, and finally a discrete-time feedback controller that achieves approximate robust output tracking and disturbance rejection. The presented constructions are also new for time-invariant finite and infinite-dimensional systems. The results are illustrated with two examples: a periodically time-dependent system of harmonic oscillators and a nonautonomous two-dimensional heat equation with boundary disturbance. Autors: Lassi Paunonen; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4363 - 4375 Publisher: IEEE
» Robust Spatial Filtering With Graph Convolutional Neural Networks
 Abstract:Convolutional neural networks (CNNs) have recently led to incredible breakthroughs on a variety of pattern recognition problems. Banks of finite-impulse response filters are learned on a hierarchy of layers, each contributing more abstract information than the previous layer. The simplicity and elegance of the convolutional filtering process makes them perfect for structured problems, such as image, video, or voice, where vertices are homogeneous in the sense of number, location, and strength of neighbors. The vast majority of classification problems, for example in the pharmaceutical, homeland security, and financial domains are unstructured. As these problems are formulated into unstructured graphs, the heterogeneity of these problems, such as number of vertices, number of connections per vertex, and edge strength, cannot be tackled with standard convolutional techniques. We propose a novel neural learning framework that is capable of handling both homogeneous and heterogeneous data while retaining the benefits of traditional CNN successes. Recently, researchers have proposed variations of CNNs that can handle graph data. In an effort to create learnable filter banks of graphs, these methods either induce constraints on the data or require preprocessing. As opposed to spectral methods, our framework, which we term Graph-CNNs, defines filters as polynomials of functions of the graph adjacency matrix. Graph-CNNs can handle both heterogeneous and homogeneous graph data, including graphs having entirely different vertex or edge sets. We perform experiments to validate the applicability of Graph-CNNs to a variety of structured and unstructured classification problems and demonstrate state-of-the-art results on document and molecule classification problems. Autors: Felipe Petroski Such;Shagan Sah;Miguel Alexander Dominguez;Suhas Pillai;Chao Zhang;Andrew Michael;Nathan D. Cahill;Raymond Ptucha; Appeared in: IEEE Journal of Selected Topics in Signal Processing Publication date: Sep 2017, volume: 11, issue:6, pages: 884 - 896 Publisher: IEEE
» Robust Stochastic Stability Analysis Method of DFIG Integration on Power System Considering Virtual Inertia Control
 Abstract:Concerning the stochastic excitation caused by wind power fluctuation and the stochastic parameter of virtual inertia caused by wind speed uncertainty, a power system stability analysis method considering the Wiener noise is proposed in this paper. First, based on the reduced-order model of DFIG retaining virtual inertia control and phase-locked loop (phase-locked loop) dynamics, the analytic function relationship between stochastic parameters and elements in the state matrix is derived using the sensitivity analysis method; thus, the model of interconnected system with stochastic parameters considering the Wiener noise is established. And by constructing the Lyapunov functional containing the model of stochastic parameters, the linear matrix inequality (LMI) that satisfies the robust stochastic stability criterion is derived. Furthermore, by transforming the solving of LMI to a feasibility problem, the stability of system is identified. And then, by calculating online system instability probability under the current operating condition, the probability stability analysis method is proposed. On this basis, a system stochastic stability degree index is defined in this paper, which quantifies the effect of stochastic parameters on system small-signal stability, and could provide more effective information for the safe and stable operation of power system. Simulation tests on the IEEE four-generator two-area system and the New England 10-machine 39-bus system verify that the proposed method could effectively identify the small-signal stability of power system under the joint influence of stochastic parameter and stochastic external excitation, and is applicable to complex system with multiple generators. Autors: Jing Ma;Zhanxiang Song;Yongxin Zhang;Yu Zhao;James S. Thorp; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4069 - 4079 Publisher: IEEE
» Robust Tracking Commitment
 Abstract:Many engineering problems that involve hierarchical control applications, such as demand-side ancillary service provision to the power grid, can be posed as a robust tracking commitment problem. In this setting, the lower level controller commits a set of possible reference trajectories over a finite horizon to an external entity in exchange for a reward corresponding to the size of the reference set and the allowed margin of tracking error. If the commitment is accepted, the lower level system is required to track any reference trajectory that can be sampled from the committed set. This paper presents the framework of robust tracking commitment and a method to solve the optimal commitment problem for constrained linear systems subject to uncertain disturbance and reference signals. The proposed method allows tractable computations via convex optimization for conic representable uncertainty sets and lends itself to distributed solution methods. We demonstrate the proposed method in a simulation based case study with a commercial building that offers frequency regulation service to the power grid. Autors: Altuğ Bitlislioğlu;Tomasz T. Gorecki;Colin N. Jones; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4451 - 4466 Publisher: IEEE
» Robust Transport Over Networks
 Abstract:We consider transportation over a strongly connected, directed graph. The scheduling amounts to selecting transition probabilities for a discrete-time Markov evolution which is designed to be consistent with initial and final marginal constraints on mass transport. We address the situation where initially the mass is concentrated on certain nodes and needs to be transported over a certain time period to another set of nodes, possibly disjoint from the first. The evolution is selected to be closest to a prior measure on paths in the relative entropy sense–such a construction is known as a Schrödinger bridge between the two given marginals. It may be viewed as an atypical stochastic control problem where the control consists in suitably modifying the prior transition mechanism. The prior can be chosen to incorporate constraints and costs for traversing specific edges of the graph, but it can also be selected to allocate equal probability to all paths of equal length connecting any two nodes (i.e., a uniform distribution on paths). This latter choice for prior transitions relies on the so-called Ruelle-Bowen random walker and gives rise to scheduling that tends to utilize all paths as uniformly as the topology allows. Thus, this Ruelle-Bowen law taken as prior, leads to a transportation plan that tends to lessen congestion and ensures a level of robustness. We also show that the distribution on paths, which attains the maximum entropy rate for the random walker given by the topological entropy, can itself be obtained as the time-homogeneous solution of a maximum entropy problem for measures on paths (also a Schrödinger bridge problem, albeit with prio- that is not a probability measure). Finally we show that the paradigm of Schrödinger bridges as a mechanism for scheduling transport on networks can be adapted to graphs that are not strongly connected, as well as to weighted graphs. In the latter case, our approach may be used to design a transportation plan which effectively compromises between robustness and other criteria such as cost. Indeed, we explicitly provide a robust transportation plan which assigns maximum probability to minimum cost paths and therefore compares favorably with Optimal Mass Transportation strategies. Autors: Yongxin Chen;Tryphon Georgiou;Michele Pavon;Allen Tannenbaum; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4675 - 4682 Publisher: IEEE
» Routing in Wireless Networks With Interferences
 Abstract:We consider dynamic routing in multi-hop wireless networks with adversarial traffic. The model of wireless communication incorporates interferences caused by packets’ arrivals into the same node that overlap in time. We consider two classes of adversaries: balanced and unbalanced. We demonstrate that, for each routing algorithm and an unbalanced adversary, the algorithm is unstable against this adversary in some networks. We develop a routing algorithm that has bounded packet latency against each balanced adversary. Autors: Bogdan S. Chlebus;Vicent Cholvi;Paweł Garncarek;Tomasz Jurdziński;Dariusz R. Kowalski; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 2105 - 2108 Publisher: IEEE
» Sample-Optimal Tomography of Quantum States
 Abstract:It is a fundamental problem to decide how many copies of an unknown mixed quantum state are necessary and sufficient to determine the state. Previously, it was known only that estimating states to error in trace distance required copies for a -dimensional density matrix of rank . Here, we give a theoretical measurement scheme (POVM) that requires copies to estimate to error in infidelity, and a matching lower bound up to logarithmic factors. This implies copies suffice to achieve error in trace distance. We also prove that for independent (product) measurements, copies are necessary in order to achieve error in infidelity. For fixed , our measurement can be implemented on a quantum computer in time polynomial in . Autors: Jeongwan Haah;Aram W. Harrow;Zhengfeng Ji;Xiaodi Wu;Nengkun Yu; Appeared in: IEEE Transactions on Information Theory Publication date: Sep 2017, volume: 63, issue:9, pages: 5628 - 5641 Publisher: IEEE
» Sampling Rate and ADC Resolution Requirements in Digital Front-End Electronics for TOF PET
 Abstract:In the context of the development of an in-beam time-of-flight positron emission tomography demonstrator dedicated to the in vivo monitoring of delivered dose in hadrontherapy, we evaluate the potential performance of front-end architectures based on sampling and digital pulse processing to reconstruct the energy and time of event. In this paper, we evaluate the requirements for sampling frequency and analog-to-digital converter (ADC) resolution. The timing algorithm is a digital adaptation of the constant fraction discriminator principle, with a step of interpolation using a low-pass filter based on the cubic spline technique. We demonstrate the interest of the interpolation to lower the sampling frequency requirement, by improving the signal reconstruction compared with a simple linear interpolation. Experimental tests were performed on pulse libraries acquired from a set up composed of LYSO and LaBr3 scintillators coupled to H6533 photomultipliers, and a sampling oscilloscope operating at 10 GHz. By offline processing of the signals with variable parameters (initial frequency, interpolator bandwidth, resampling frequency, and ADC resolution), we examined the impact of these parameters on time resolution. Results for the tested detectors suggest a minimal required sampling rate of 1.5 GHz, while the ADC resolution can be as small as 5 b. A logarithmic ADC could be more efficient, with a strict minimum of 4 b. Autors: Baptiste Joly;Gérard Montarou;Pierre-Etienne Vert; Appeared in: IEEE Transactions on Nuclear Science Publication date: Sep 2017, volume: 64, issue:9, pages: 2543 - 2550 Publisher: IEEE
» Satellite Applications of Electromagnetic Cloaking
 Abstract:We discuss the possibility to exploit electromagnetic cloaking for enhancing the performances of communication antennas installed on nanosatellite platforms. As a case study, we consider a CubeSTAR system and show that properly designed metasurfaces can be effectively used to minimize the impact of its deployable payload sensors on both radiation and electrical characteristics of the antennas. The results discussed here pave the way to new strategies for the design of extremely compact nanosatellite platforms equipped with multifunctional antennas and sensors. Autors: Stefano Vellucci;Alessio Monti;Mirko Barbuto;Alessandro Toscano;Filiberto Bilotti; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4931 - 4934 Publisher: IEEE
» Saturation Power-Based Simple Energy Efficiency Maximization Schemes for MISO Broadcast Channel Systems
 Abstract:In this paper, we investigate an energy efficiency (EE) maximization problem in multiple input single output broadcast channels. The optimization problem in this system model is difficult to solve in general, since it is in non-convex fractional form. Hence, conventional algorithms have addressed the problem in an iterative manner for each channel realization, which leads to high computational complexity. To tackle this complexity issue, we propose a new simple method by utilizing the fact that EE maximization becomes identical to spectral efficiency (SE) maximization for the region of the power below a certain transmit power termed as saturation power. In order to calculate the saturation power, we first introduce upper and lower bounds of the EE performance by adopting a maximal ratio transmission beamforming strategy. Then, we propose an efficient way to compute the saturation power for the EE maximization problem. Once we determine the saturation power in advance, we can transform the EE maximization problem into a simplified sub-optimal EE problem, which can be solved by the SE maximization schemes with low complexity. The derived saturation power is parameterized by employing random matrix theory, which relies only on the second-order channel statistics. Hence, this approach needs much lower computational complexity compared with a conventional scheme, which requires instantaneous channel state information. Numerical results validate that the proposed algorithm achieves near optimal EE performance with significantly reduced complexity. Autors: Jaehoon Jung;Sang-Rim Lee;Inkyu Lee; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 6022 - 6031 Publisher: IEEE
» SBS Threshold Dependence on Pulse Duration in a 2053 nm Single-Mode Fiber Amplifier
 Abstract:Stimulated Brillouin scattering (SBS) is the first nonlinear effect that limits power scaling of narrow linewidth fiber lasers. Nonlinearities typically have a reduced impact when operating at longer wavelengths. However, the SBS gain is considered wavelength independent. To investigate this further, a pulsed 2053 nm source with MHz-linewidth is amplified to >100 W peak powers in single-mode, thulium-doped fiber. The SBS thresholds were measured while varying the pulse duration. Analyzing the SBS threshold measurements suggests that the peak Brillouin gain coefficient is ∼12.2 pm/W with a spontaneous Brillouin bandwidth of ∼17.5 MHz in the passive single-mode fiber at 2053 nm. While the peak Brillouin gain coefficient is comparable to those reported at shorter wavelengths, the spontaneous Brillouin bandwidth is significantly narrower. This indicates that long wavelength sources can inhibit the onset of SBS more readily than short wavelength sources. Autors: Alex Sincore;Nathan Bodnar;Joshua Bradford;Ali Abdulfattah;Lawrence Shah;Martin C. Richardson; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:18, pages: 4000 - 4003 Publisher: IEEE
» Scalable Phased Array Architectures With a Reduced Number of Tunable Phase Shifters
 Abstract:A new architecture for scalable phased array design is presented. A vector summation technique is used in a new feed network in order to reduce the number of tunable phase shifters in the phased array. As a result, phased array front-end’s complexity is reduced. In this architecture, one tunable phase shifter and variable gain amplifiers (VGAs) adjust the phase and amplitude of the signal at each antenna element in an -element subarray. The technique allows a number of subarrays to be connected together to form a larger array providing a narrow beamwidth. An optimum design based on a particle swarm optimization algorithm is presented for an -element subarray. As a proof of concept, an eight-element transmit phased array consisting of two four-element subarrays is designed and tested at the Ku-band based on the described method. Measurement results for the eight-element phased array are presented. The eight-element phased array controlled by two phase shifters and eight VGAs provides approximately 37° of scan range. Autors: Fatemeh Akbar;Amir Mortazawi; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3428 - 3434 Publisher: IEEE
» Scanning the Issue
 Abstract:A MPTCP-Based Network Architecture for Intelligent Train Control and Traffic Management Operations Autors: Petros Ioannou; Appeared in: IEEE Transactions on Intelligent Transportation Systems Publication date: Sep 2017, volume: 18, issue:9, pages: 2285 - 2289 Publisher: IEEE
» Scheduling for Workflows with Security-Sensitive Intermediate Data by Selective Tasks Duplication in Clouds