#### Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 5

» Coordinated Multi-Area Economic Dispatch via Critical Region Projection
 Abstract:A coordinated economic dispatch method for multiarea power systems is proposed. Choosing boundary phase angles as coupling variables, the proposed method exploits the structure of critical regions in local problems defined by active and inactive constraints. For a fixed boundary state given by the coordinator, local operators compute the coefficients of critical regions containing the boundary state and the optimal value functions then communicate them to the coordinator who in turn optimizes the boundary state to minimize the overall cost. By iterating between local operators and the coordinator, the proposed algorithm converges to the global optimal solution in finite steps, and it requires limited information sharing. Autors: Ye Guo;Lang Tong;Wenchuan Wu;Boming Zhang;Hongbin Sun; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3736 - 3746 Publisher: IEEE
» Coordination Over Multi-Agent Networks With Unmeasurable States and Finite-Level Quantization
 Abstract:In this note, the coordination of linear discrete-time multi-agent systems over digital networks is investigated with unmeasurable states in agents' dynamics. The quantized-observer based communication protocols and Certainty Equivalence principle based control protocols are proposed to characterize the inter-agent communication and the cooperative control in an integrative framework. By investigating the structural and asymptotic properties of the equations of stabilization and estimation errors, which are nonlinearly coupled by the finite-level quantization scheme, some necessary conditions and sufficient conditions are given for the existence of such communication and control protocols to ensure the inter-agent state observation and cooperative stabilization. It is shown that these conditions come down to the simultaneous stabilizability and the detectability of the dynamics of agents and the structure of the communication network. Autors: Yang Meng;Tao Li;Ji-Feng Zhang; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4647 - 4653 Publisher: IEEE
» CoRQ: Enabling Runtime Reconfiguration Under WCET Guarantees for Real-Time Systems
 Abstract:Real-time systems have an increasing demand for predictable performance. Only recently novel models and analyses were proposed that make the performance benefits of runtime-reconfigurable architectures accessible for optimized worst-case execution time (WCET) guarantees. However, the implicit assumption in these works is that the process of reconfiguration itself complies with execution time guarantees. The realization of a reconfiguration controller that fulfills these assumptions and that is amenable to WCET guarantees is so far unavailable. In this letter, we detail the challenges of runtime reconfiguration in real-time systems and show that conflicts while accessing a shared main memory during reconfiguration can lead to a slowdown of more than in reconfiguration bandwidth. We present concepts that enable runtime reconfiguration under WCET guarantees and release our implementation of these concepts as open source. Autors: Marvin Damschen;Lars Bauer;Jörg Henkel; Appeared in: IEEE Embedded Systems Letters Publication date: Sep 2017, volume: 9, issue:3, pages: 77 - 80 Publisher: IEEE
» Correcting Instrumental Variation and Time-Varying Drift Using Parallel and Serial Multitask Learning
 Abstract:When instruments and sensor systems are used to measure signals, the posterior distribution of test samples often drifts from that of the training ones, which invalidates the initially trained classification or regression models. This may be caused by instrumental variation, sensor aging, and environmental change. We introduce transfer-sample-based multitask learning (TMTL) to address this problem, with a special focus on applications in machine olfaction. Data collected with each device or in each time period define a domain. Transfer samples are the same group of samples measured in every domain. They are used by our method to share knowledge across domains. Two paradigms, parallel and serial transfer, are designed to deal with different types of drift. A dynamic model strategy is proposed to predict samples with known acquisition time. Experiments on three real-world data sets confirm the efficacy of the proposed methods. They achieve good accuracy compared with traditional feature-level drift correction algorithms and typical labeled-sample-based MTL methods, with few transfer samples needed. TMTL is a practical algorithm framework which can greatly enhance the robustness of sensor systems with complex drift. Autors: Ke Yan;David Zhang;Yong Xu; Appeared in: IEEE Transactions on Instrumentation and Measurement Publication date: Sep 2017, volume: 66, issue:9, pages: 2306 - 2316 Publisher: IEEE
» Correction to “Automatic Quality Assessment of Echocardiograms Using Convolutional Neural Networks: Feasibility on the Apical Four-Chamber View”
 Abstract:In the above paper [1], the first footnote should have indicated the following information: A. H. Abdi and C. Luong are joint first authors. Autors: A. H. Abdi;C. Luong;T. Tsang;G. Allan;S. Nouranian;J. Jue;D. Hawley;S. Fleming;K. Gin;J. Swift;R. Rohling;P. Abolmaesumi; Appeared in: IEEE Transactions on Medical Imaging Publication date: Sep 2017, volume: 36, issue:9, pages: 1992 - 1992 Publisher: IEEE
» Correction to “Fast Mode Selection for HEVC Intra-Frame Coding With Entropy Coding Refinement Based on a Transparent Composite Model”
 Abstract:After our internal code cross-check, we have recently found some mistakes in [1, Table VIII] and [1, Figs. 12 and 13]. As such, we have reimplemented the ideas and methods stated in [1]. The corrected Table VIII and Figs. 12 and 13 are now shown in this correction. Our code is also available from http://multicom.uwaterloo.ca. To reflect this correction, the following changes have to be made accordingly throughout the paper [1]. Autors: Nan Hu;En-Hui Yang; Appeared in: IEEE Transactions on Circuits and Systems for Video Technology Publication date: Sep 2017, volume: 27, issue:9, pages: 2055 - 2056 Publisher: IEEE
» Corrections on “Symbol Flipping Decoding Algorithms Based on Prediction for Non-Binary LDPC Codes”
 Abstract:Due to a production error, an equation in the above paper [1] appeared incorrectly. Below is the correct version. Autors: S. Wang;Q. Huang;Z. Wang; Appeared in: IEEE Transactions on Communications Publication date: Sep 2017, volume: 65, issue:9, pages: 4099 - 4099 Publisher: IEEE
» Corrections to “A 10/20/30/40 MHz Feed-Forward FIR DAC Continuous-Time $\Delta \Sigma$ ADC With Robust Blocker Performance for Radio Receivers”
 Abstract:In [1], Table I compares the state of the art in CT ADCs. Unfortunately, due to a mistake, the FOM [Schreier] (dB) reported is 3 dB below its actual value. Table I in [1] is reprinted as Table I. The authors regret their mistake. Autors: Sebastian Loeda;Jeffrey Harrison;Franck Pourchet;Andrew Adams; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2515 - 2515 Publisher: IEEE
» Corrections to “Multilevel MVDC Link Strategy of High-Frequency-Link DC Transformer Based on Switched Capacitor for MVDC Power Distribution”
 Abstract:Presents corrections to the paper, “Multilevel MVDC Link Strategy of High-Frequency-Link DC Transformer Based on Switched Capacitor for MVDC Power Distribution,” (Wang, Y., et al), IEEE Trans. Ind. Electron. vol. 64, no. 4, pp. 2829–2835, Apr. 2017. Autors: Yu Wang;Qiang Song;Qianhao Sun;Biao Zhao;Jianguo Li;Wenhua Liu; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7280 - 7280 Publisher: IEEE
» Corrections to “Fundamental Efficiency Limits for Small Metallic Antennas”
 Abstract:In [1], it was stated that “An attempt to establish bounds on the maximum achievable gain and efficiency using a “loss merit factor” is reported in [2]. However, the results are clearly unphysical, since a single turn loop antenna can surpass these fundamental limits when ” [3]. Autors: Carl Pfeiffer; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4958 - 4958 Publisher: IEEE
» Corrections to “Resource Allocation for D2D-Enabled Vehicular Communications”
 Abstract:In the above paper [1], the text discussion of several equations were misrepresented. Below is the corrected text of Sections III and IV, in which the errors appear. Autors: L. Liang;G. Y. Li;W. Xu; Appeared in: IEEE Transactions on Communications Publication date: Sep 2017, volume: 65, issue:9, pages: 4096 - 4098 Publisher: IEEE
» Correntropy Maximization via ADMM: Application to Robust Hyperspectral Unmixing
 Abstract:In hyperspectral images, some spectral bands suffer from low signal-to-noise ratio due to noisy acquisition and atmospheric effects, thus requiring robust techniques for the unmixing problem. This paper presents a robust supervised spectral unmixing approach for hyperspectral images. The robustness is achieved by writing the unmixing problem as the maximization of the correntropy criterion subject to the most commonly used constraints. Two unmixing problems are derived: the first problem considers the fully constrained unmixing, with both the nonnegativity and sum-to-one constraints, while the second one deals with the nonnegativity and the sparsity promoting of the abundances. The corresponding optimization problems are solved using an alternating direction method of multipliers (ADMM) approach. Experiments on synthetic and real hyperspectral images validate the performance of the proposed algorithms for different scenarios, demonstrating that the correntropy-based unmixing with ADMM is particularly robust against highly noisy outlier bands. Autors: Fei Zhu;Abderrahim Halimi;Paul Honeine;Badong Chen;Nanning Zheng; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 4944 - 4955 Publisher: IEEE
» Cost-Effective Enhancement on Both Yield and Reliability for Cache Designs Based on Performance Degradation Tolerance
 Abstract:Guaranteeing functional correctness of cache memories is crucial for computer designs. In the literature, there have been several works addressing this issue. However, fault tolerability of these methods may be limited. In this paper, we present a new cache architecture that has flexible tolerability. Moreover, by using the proposed architecture, both yield and reliability of the cache can be enhanced simultaneously. In our cache, a particular type of cache blocks called tolerable block is further identified among the faulty ones. Such blocks can still be used during cache access in our architecture, while accessing to intolerable blocks will result in additional cache misses, and therefore performance degradation. The number of tolerable cache blocks is thus critical for the achievable yield and reliability enhancement, as well as the incurred cost on performance. In this work, error correcting code (ECC) methods are employed to increase the number of tolerable blocks. In particular, we propose to embed the required check bits in one of the cache ways. Analysis results show that this embedding method only incurs minor performance degradation, while the incurred area overhead due to ECC can thus be significantly reduced from 5.92% to only 0.92%. General applicability of the embedding method to ordinary ECC methods is also investigated. Experimental results show that the performance degradation can be reduced from 16% to only 1.53% by using the proposed cache. This leads to great tolerability improvement, and thus the yield and reliability are enhanced very significantly when compared with the previous work. Autors: Tong-Yu Hsieh;Tsung-Liang Chih;Mei-Jung Wu; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2434 - 2448 Publisher: IEEE
 Abstract:This paper investigates a cellular network powered by a micro-grid (MG) in the context of green communications, which integrates the conventional generators, energy storage devices, and renewable energy generators, so as to supply electricity to base stations (BSs). Under this model, we study the efficiency aspect of the MG-powered cellular network from the economical perspective. Specifically, the concept of cost efficiency (CE) is employed to measure the sum rate delivered per dollar. Then, our goal is to maximize this CE subject to a series of constraints, including multi-variable coupling and time coupling constraints. Particularly, we assume the zero-forcing beamforming scheme employed by the BSs. To address this established fractional CE optimization problem, we first apply the Dinkelbach method, and then propose a low-complexity algorithm based on the alternating direction method of multipliers approach to jointly schedule power generation in the MG and optimize transmit power for BSs. We introduce a number of auxiliary variables to design a special variable splitting scheme so that the coupling inequality constraints can be separable among two variable sets. Consequently, the proposed algorithm only incorporates simple updates in each step and thus can be implemented in a parallel and completely distributed fashion. Simulation results demonstrate the convergence and energy scheduling performance of the proposed algorithm. Autors: Ling Zhang;Yunlong Cai;Qingjiang Shi;Guanding Yu;Geoffrey Ye Li; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 6047 - 6061 Publisher: IEEE
» Coupled Split-Ring Resonator Circular Polarization Selective Surface
 Abstract:A novel class of circular polarization selective surfaces (CPSSs) consisting of a pair of planar split-ring resonator arrays is proposed. A significant advantage of the proposed structure over existing designs is its manufacturing simplicity compatible with standard printed technology processes. Its operating principle is reviewed alongside that of the Pierrot cell and in light of the linear polarization reflection and transmission characteristics of CPSSs. Guidelines for the initial design of the proposed CPSS concept are thus derived. Further design considerations and tradeoffs are also discussed. The validity of the concept is confirmed by means of a design example entailing a right-hand CPSS at 20 GHz. Full-wave simulation results and experimental testing on a fabricated prototype are presented and agree well with the theoretical predictions. Autors: Wenxing Tang;George Goussetis;Nelson J. G. Fonseca;Hervé Legay;Elena Sáenz;Peter de Maagt; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4664 - 4675 Publisher: IEEE
» Coupling Quality [Enigmas, etc.]
 Abstract:Various puzzles, games, humorous definitions, or mathematical that should engage the interest of readers. Autors: Takashi Ohira; Appeared in: IEEE Microwave Magazine Publication date: Sep 2017, volume: 18, issue:6, pages: 154 - 154 Publisher: IEEE
» Covert Communication in the Presence of an Uninformed Jammer
 Abstract:Recent work has established that when transmitter Alice wishes to communicate reliably to recipient Bob without detection by warden Willie, with additive white Gaussian noise (AWGN) channels between all parties, communication is limited to bits in channel uses. However, this assumes that Willie has an accurate statistical characterization of the channel. When Willie has uncertainty about such and his receiver is limited to a threshold test on the received power, Alice can transmit covertly with a power that does not decrease with , thus conveying bits covertly and reliably in uses of an AWGN channel. Here, we consider covert communication of bits in channel uses while generalizing the environment and removing any restrictions on Willie’s receiver. We assume that an uninformed “jammer” is present to help Alice, and we consider AWGN and block fading channels. In some scenarios, Willie’s optimal detector is a threshold test on the received power. When the channel between the jammer and Willie has multiple fading blocks per codeword, a threshold test on the received power is not optimal. However, we establish that Alice can remain covert with a transmit power that does not decrease with even when Willie employs an optimal detector. Autors: Tamara V. Sobers;Boulat A. Bash;Saikat Guha;Don Towsley;Dennis Goeckel; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 6193 - 6206 Publisher: IEEE
» Critical Analysis of Model-Based Incoherent Polarimetric Decomposition Methods and Investigation of Deorientation Effect
 Abstract:This paper critically analyzes several incoherent model-based decomposition methods for assessing the effect of deorientation in characterization of various land covers. It has been found that even after performing decomposition, ambiguity still occurs in scattering response from various land covers, such as urban and vegetation. Researchers introduced the concept of deorientation to remove this ambiguity. Therefore, in this paper, a critical analysis has been carried out using seven different three- and four-component decomposition methods with and without deorientation and two Eigen decomposition-based methods to investigate the scattering response on various land covers, such as urban, vegetation, bare soil, and water. The comprehensive evaluation of decomposition and deorientation effect has been performed by both visual and quantitative analyses. Two types of quantitative analysis have been performed; first, by observing percentage of scattering power and second, by analyzing the variation in the number of pixels in different land covers for each scattering contribution. The analysis shows that deorientation increases not only the power but also the number of pixels for surface and double bounce scattering. The number of pixels representing volume scattering remain almost the same for all the methods with or without deorientation, whereas volume scattering power reduces after deorientation. Eigen decomposition-based methods are observed to solve the problem of overestimation of volume scattering power. Autors: Pooja Mishra;Akanksha Garg;Dharmendra Singh; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 4868 - 4877 Publisher: IEEE
» Critical Bus Voltage Support in Distribution Systems With Electric Springs and Responsibility Sharing
 Abstract:With the development of a new smart load device, the electric spring (ES), the operation of distribution systems with high renewable penetration becomes more flexible. The ESs can be installed at noncritical loads for grid support. This paper proposes a two-level voltage management scheme to optimize the voltage profiles of the network, especially at chosen critical buses. In the upper level, the tap positions of load tap changer and capacitor banks switching are optimized to prevent the voltages along the feeder from being out of limits. The model predictive control technique is applied to handle the uncertainties in renewable energy and demand. In the lower level, the responsibility of maintaining the voltages of the critical buses is shared among the ES in a distributed way via consensus control which is suitable for systems with limited communication and calculation capabilities. The proposed management scheme is verified on a modified IEEE 15-bus distribution network. The results show that different voltage regulation devices can work together to maintain the voltage of critical buses by sharing the responsibility in the proposed scheme. Autors: Yu Zheng;David John Hill;Ke Meng;S. Y. Hui; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3584 - 3593 Publisher: IEEE
» Cross-Range Resolution Enhancement for DBS Imaging in a Scan Mode Using Aperture-Extrapolated Sparse Representation
 Abstract:This letter addresses the problem of cross-range superresolution in Doppler beam sharpening (DBS). The coherence of echoes in the azimuth direction and the sparsity of the DBS image in the Doppler domain are fully exploited; thus, a superresolution DBS imaging framework using aperture-extrapolated sparse representation (SR) is proposed. In this framework, aperture extrapolation based on the autoregressive model is utilized to predict the forward and backward information in the azimuth direction, and SR is exploited to extract the Doppler spectrum information. In addition, the resolution ability with different coherent processing intervals is analyzed. The sharpening ratio in this proposed algorithm can be improved by a factor of two or four theoretically in comparison with the conventional DBS imaging method. Experimental results demonstrate that the proposed framework can lead to noticeable performance improvement. Autors: Hongmeng Chen;Ming Li;Zeyu Wang;Yunlong Lu;Runqing Cao;Peng Zhang;Lei Zuo;Yan Wu; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1459 - 1463 Publisher: IEEE
» Crystallinity of Silicon-Shells Deposited onto Germanium and Silicon Nanowires for Core-Shell Nanostructures and Nanotubes
 Abstract:Core-shell nanowires are an essential component of numerous nanoscale device concepts. In this study, germanium and silicon nanowires were synthesized bottom-up using the vapor-liquid-solid technique and successively modified with a silicon shell. The shell synthesis was studied with focus to the crystallinity but includes as well the electrical characteristics of n- and p-doped radial core-shell nanowire devices. Furthermore, the influence of certain post-annealing procedures on the crystallinity of the core-shell nanowires are discussed. We demonstrate that the crystallinity of the silicon shell can be tuned from single-crystalline to amorphous in a controlled manner, independent on a p- or n-type doping, by deliberate adjustment of the growth parameters. Autors: Ardeshir Moeinian;Nicolas Hibst;Dorin Geiger;Johannes Biskupek;Steffen Strehle; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 736 - 740 Publisher: IEEE
» Current-Mode Triline Transceiver for Coded Differential Signaling Across On-Chip Global Interconnects
 Abstract:This paper presents a current-mode triline ternary-level coded differential signaling scheme for high-speed data transmission across on-chip global interconnects. An energy efficient current-mode triline transceiver pair suitable for this signaling scheme has been proposed. Compared with a voltage mode receiver with resistive termination, the proposed active terminated current-mode receiver reduces the signal current by 7.8 times and the signaling power by 2.6 times. Two data transmission schemes are proposed for using this transceiver pair. In the first scheme, two data streams are directly transmitted over the three lines link, thereby having a wire efficiency of 67%. In the second scheme, five data streams at half rate are encoded and serialized to send over the three lines, thereby having a wire efficiency of 83%. A prototype design has been implemented in a UMC 0.18- technology for an interconnect of length 5 mm. The measured energy efficiency of the triline transceiver in a direct transmission scheme for the data rate of 7.4 Gb/s is 0.61 pJ/bit. With the encoding scheme, the energy efficiency is 1.24 pJ/bit for a total data transmission of 9.25 Gb/s. Autors: Nijwm Wary;Pradip Mandal; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2575 - 2587 Publisher: IEEE
» Customers seek 100-percentrenewable grids [News]
 Abstract:In June, energy experts were clashing in both tweets and peer-reviewed journals over the feasibility of the United States achieving a 100-percent-renewable power grid in 2050. Many governments, utilities, and big consumers, however, appear unwilling to wait for the engineers' all clear: An increasing number of jurisdictions and institutions are setting deadlines for a jump to a 100- percent-renewable electricity grid or even beyond, to fossil- fuel-free heating and roadways as well. Autors: Peter Fairley; Appeared in: IEEE Spectrum Publication date: Sep 2017, volume: 54, issue:9, pages: 12 - 13 Publisher: IEEE
» CW Experiments With the EU 1-MW, 170-GHz Industrial Prototype Gyrotron for ITER at KIT
 Abstract:The European 1-MW, 170-GHz continuous wave industrial prototype gyrotron for electron cyclotron resonance heating and current drive on international thermonuclear experimental reactor was during 2016 under test at the Karlsruhe Institute of Technology (KIT) test facility. In order to optimize the gyrotron operation, the tube was at first thoroughly tested in the short-pulse regime, with pulses that did not exceed 10 ms, for a wide range of operational parameters. Then, and after proper conditioning of the tube, the operation was extended to longer pulses with duration up to 180 s, which is the maximum pulselength possible at the KIT test facility. In this paper, we present in detail the achievements of the long-pulse experimental campaign. Autors: Zisis C. Ioannidis;Tomasz Rzesnicki;F. Albajar;S. Alberti;Konstantinos A. Avramidis;William Bin;T. Bonicelli;Alessandro Bruschi;Ioannis Chelis;P.-E. Frigot;Gerd Gantenbein;V. Hermann;J.-P. Hogge;Stefan Illy;Jianbo Jin;John Jelonnek;W. Kasparek;G. Lat Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3885 - 3892 Publisher: IEEE
» Cyber-Medical Systems: Requirements, Components and Design Examples
 Abstract:Cyber-medical systems will produce a major revolution in health care, by both raising the quality of care and reducing its cost, thus reaching an important social and economic goal. The evolution of electronic devices and systems has already enabled societal changes. Inroads in the quantification of medicine, in the discovery and applications of biosensors in connection with integrated circuit technology, in the analysis of large-scale real-time biomedical data are strong indicators that cyber-medical systems will redesign health care in the years to come. To sustain this thesis, this paper presents three aspects of cyber-medical systems, describes their medical significance and potentials, and then delves in the detailed technology required to realize such systems. Specifically, this paper describes state of the art sensing devices and their integration into platforms, data processing for ultrasound medical imaging and system correctness approaches for drug administration support systems. The paper concludes with a brief outlook on the evolution of this emerging field in the years to come. Autors: Giovanni De Micheli; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2226 - 2236 Publisher: IEEE
» Cybersecurity and Rural Electric Power Systems: Considering Competing Requirements for Implementing a Protection Plan
 Abstract:Cybersecurity is a topic of increasing importance and interest to small utility operators like rural electric associations. Cyberattacks are a threat to our society's functioning, and cybersecurity is an urgent need in areas that include national security, business operations, and regulatory compliance. Several fundamental concepts can guide an operator when implementing a cybersecurity plan. Operators must consider the competing requirements of confidentiality, integrity, availability (CIA), and cost. They must also consider the potential of impact levels for an incident. While implementing a cybersecurity plan, operators will constantly identify adversaries, threats, vulnerabilities, consequences, and risks. They will implement physical, technical, and administrative controls to protect networks and other assets, detect attacks, respond to those attacks, and recover from any damage. The process will be continuous as operators respond to the changing environment. Autors: Paul Kaster;Pankaj P.K. Sen; Appeared in: IEEE Industry Applications Magazine Publication date: Sep 2017, volume: 23, issue:5, pages: 14 - 20 Publisher: IEEE
» Cybersecurity in Power Systems
 Abstract:Did you know that cyberattackers have already created outages in Ukraine, not once but twice? On 23 December 2015, cyberintruders at three electric distribution companies in Ukraine opened breakers, creating a power outage that affected 225,000 people. Power was restored in approximately 6 h, as field personnel manually closed the breakers. Autors: Michael F. Ahern; Appeared in: IEEE Potentials Publication date: Sep 2017, volume: 36, issue:5, pages: 8 - 12 Publisher: IEEE
» Cyclostationary Stochastic Jitter Measurement Method With Uncertainty Prediction
 Abstract:This paper presents a completely new approach to measure the jitter at the output of a sample-and-hold circuit. A cyclostationary stochastic process is used to model the entire noise of the measurement system. This approach relies on the calculation of a cyclostationary variance, representing a complete description of the noise of the measurement system. This provides the basis for conducting powerful analyses of how the various noise sources contribute to the cyclostationary variance, enabling the user to gain a deep insight into the noise behavior of the system. A new jitter estimator is derived that provides some new and unprecedented features. First, it is robust against the second harmonic of the input signal, and second, it allows for the elimination of cyclostationary noise contributed by the data acquisition device. A stochastic model of the method is derived and a thorough analysis of the uncertainty of the proposed estimator is presented. This results in a formula that allows for the prediction of the measurement uncertainty and another formula that allows for the calculation of the required number of samples in order to meet a given uncertainty. The method proved to be accurate in Monte Carlo simulations and in measurements as well. A jitter in the range of 22 fs out of a 10-GS/s sample-and-hold integrated circuit was successfully measured with a standard deviation of 230 as. Autors: Thomas Schweiger;Benjamin Krüger;Frank Wiedmann; Appeared in: IEEE Transactions on Instrumentation and Measurement Publication date: Sep 2017, volume: 66, issue:9, pages: 2371 - 2379 Publisher: IEEE
» D2D-Aware Device Caching in mmWave-Cellular Networks
 Abstract:In this paper, we propose a novel policy for device caching that facilitates popular content exchange through high-rate device-to-device (D2D) millimeter-wave (mmWave) communication. The D2D-aware caching policy splits the cacheable content into two content groups and distributes it randomly to the user equipment devices, with the goal to enable D2D connections. By exploiting the high bandwidth availability and directionality of mmWaves, we ensure high rates for the D2D transmissions, while mitigating the co-channel interference that limits the throughput gains of the D2D communication in the sub-6-GHz bands. Furthermore, based on a stochastic-geometry modeling of the network topology, we analytically derive the offloading gain that is achieved by the proposed policy and the distribution of the content retrieval delay considering both half- and full-duplex modes for the D2D communication. The accuracy of the proposed analytical framework is validated through Monte Carlo simulations. In addition, for a wide range of a content popularity indicator, the results show that the proposed policy achieves higher offloading and lower content-retrieval delays than existing state-of-the-art approaches. Autors: Nikolaos Giatsoglou;Konstantinos Ntontin;Elli Kartsakli;Angelos Antonopoulos;Christos Verikoukis; Appeared in: IEEE Journal on Selected Areas in Communications Publication date: Sep 2017, volume: 35, issue:9, pages: 2025 - 2037 Publisher: IEEE
» Damping Methods for Resonances Caused by LCL-Filter-Based Current-Controlled Grid-Tied Power Inverters: An Overview
 Abstract:Grid-tied voltage source inverters using LCL filter have been widely adopted in distributed power generation systems (DPGSs). As high-order LCL filters contain multiple resonant frequencies, switching harmonics generated by the inverter and current harmonics generated by the active/passive loads would cause the system resonance, and thus the output current distortion and oscillation. Such phenomenon is particularly critical when the power grid is weak with the unknown grid impedance. In order to stabilize the operation of the DPGS and improve the waveform of the injected currents, many innovative damping methods have been proposed. A comprehensive overview on those contributions and their classification on the inverter- and grid-side damping measures are presented. Based on the concept of the impedance-based stability analysis, all damping methods can ensure the system stability by modifying the effective output impedance of the inverter or the effective grid impedance. Classical damping methods for industrial applications will be analyzed and compared. Finally, the future trends of the impedance-based stability analysis, as well as some promising damping methods, will be discussed. Autors: Weimin Wu;Yuan Liu;Yuanbin He;Henry Shu-Hung Chung;Marco Liserre;Frede Blaabjerg; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7402 - 7413 Publisher: IEEE
» DASC: Robust Dense Descriptor for Multi-Modal and Multi-Spectral Correspondence Estimation
 Abstract:Establishing dense correspondences between multiple images is a fundamental task in many applications. However, finding a reliable correspondence between multi-modal or multi-spectral images still remains unsolved due to their challenging photometric and geometric variations. In this paper, we propose a novel dense descriptor, called dense adaptive self-correlation (DASC), to estimate dense multi-modal and multi-spectral correspondences. Based on an observation that self-similarity existing within images is robust to imaging modality variations, we define the descriptor with a series of an adaptive self-correlation similarity measure between patches sampled by a randomized receptive field pooling, in which a sampling pattern is obtained using a discriminative learning. The computational redundancy of dense descriptors is dramatically reduced by applying fast edge-aware filtering. Furthermore, in order to address geometric variations including scale and rotation, we propose a geometry-invariant DASC (GI-DASC) descriptor that effectively leverages the DASC through a superpixel-based representation. For a quantitative evaluation of the GI-DASC, we build a novel multi-modal benchmark as varying photometric and geometric conditions. Experimental results demonstrate the outstanding performance of the DASC and GI-DASC in many cases of dense multi-modal and multi-spectral correspondences. Autors: Seungryong Kim;Dongbo Min;Bumsub Ham;Minh N. Do;Kwanghoon Sohn; Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence Publication date: Sep 2017, volume: 39, issue:9, pages: 1712 - 1729 Publisher: IEEE
» Data Improving in Time Series Using ARX and ANN Models
 Abstract:Anomalous data can negatively impact energy forecasting by causing model parameters to be incorrectly estimated. This paper presents two approaches for the detection and imputation of anomalies in time series data. Autoregressive with exogenous inputs (ARX) and artificial neural network (ANN) models are used to extract the characteristics of time series. Anomalies are detected by performing hypothesis testing on the extrema of the residuals, and the anomalous data points are imputed using the ARX and ANN models. Because the anomalies affect the model coefficients, the data cleaning process is performed iteratively. The models are re-learned on “cleaner” data after an anomaly is imputed. The anomalous data are reimputed to each iteration using the updated ARX and ANN models. The ARX and ANN data cleaning models are evaluated on natural gas time series data. This paper demonstrates that the proposed approaches are able to identify and impute anomalous data points. Forecasting models learned on the unclean data and the cleaned data are tested on an uncleaned out-of-sample dataset. The forecasting model learned on the cleaned data outperforms the model learned on the unclean data with 1.67% improvement in the mean absolute percentage errors and a 32.8% improvement in the root mean squared error. Existing challenges include correctly identifying specific types of anomalies such as negative flows. Autors: Hermine N. Akouemo;Richard J. Povinelli; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3352 - 3359 Publisher: IEEE
» Data Reconstruction Using Subspace Analysis for Gas Classification
 Abstract:We propose a data reconstruction method using subspace analysis for gas classification in an electronic nose system. A noise generated by defects in sensors or by environmental factors in the process of data sampling significantly degrades data classification performance. In this paper, an electronic nose system more robust to data errors is designed by reconstructing lost or damaged values of data samples based on a statistical learning method that exploits the principal components. Diverse types of volatile organic compounds were employed in the classification experiments, which were conducted to reconstruct the lost or damaged data through the proposed method. The applied method prevented the degradation of classification performance and enhanced the discriminative power in the PCA+LDA feature space. Autors: Sang-Il Choi;Hong-Min Jeon;Gu-Min Jeong; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 5954 - 5962 Publisher: IEEE
» Data-Dependent Convergence for Consensus Stochastic Optimization
 Abstract:We study a distributed consensus-based stochastic gradient descent (SGD) algorithm and show that the rate of convergence involves the spectral properties of two matrices: The standard spectral gap of a weight matrix from the network topology and a new term depending on the spectral norm of the sample covariance matrix of the data. This data-dependent convergence rate shows that distributed SGD algorithms perform better on datasets with small spectral norm. Our analysis method also allows us to find data-dependent convergence rates as we limit the amount of communication. Spreading a fixed amount of data across more nodes slows convergence; for asymptotically growing datasets, we show that adding more machines can help when minimizing twice-differentiable losses. Autors: Avleen S. Bijral;Anand D. Sarwate;Nathan Srebro; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4483 - 4498 Publisher: IEEE
» Data-Driven DG Capacity Assessment Method for Active Distribution Networks
 Abstract:This paper proposes a data-driven method based on distributionally robust optimization to determine the maximum penetration level of distributed generation (DG) for active distribution networks. In our method, the uncertain DG outputs and load demands are formulated as stochastic variables following some ambiguous distributions. In addition to the given expectations and variances, the polyhedral uncertainty intervals are employed for the construction of the probability distribution set to restrict possible distributions. Then, we decide the optimal sizes and locations of DG to maximize the total DG hosting capacity under the worst-case probability distributions among this set. Since more information is utilized, our proposed model is expected to be less conservative than the robust optimization method and the traditional distributionally robust method. Using the CVaR (Conditional Value at Risk) reformulation technique and strong duality, we transform the proposed model into an equivalent bilinear matrix inequality problem, and a sequential convex optimization algorithm is applied for solution. Our model guarantees that the probability of security constraints being violated will not exceed a given risk threshold. Besides, the predefined risk level can be tuned to control the conservativeness of our model in a physically meaningful way. The effectiveness and robustness of this proposed method are demonstrated numerically on the two modified IEEE test systems. Autors: Xin Chen;Wenchuan Wu;Boming Zhang;Chenhui Lin; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3946 - 3957 Publisher: IEEE
» Data-Driven Robust RVFLNs Modeling of a Blast Furnace Iron-Making Process Using Cauchy Distribution Weighted M-Estimation
 Abstract:Optimal operation of a practical blast furnace (BF) iron-making process depends largely on a good measurement of molten iron quality (MIQ) indices. However, measuring the MIQ online is not feasible using the available techniques. In this paper, a novel data-driven robust modeling is proposed for an online estimation of MIQ using improved random vector functional-link networks (RVFLNs). Since the output weights of traditional RVFLNs are obtained by the least squares approach, a robustness problem may occur when the training dataset is contaminated with outliers. This affects the modeling accuracy of RVFLNs. To solve this problem, a Cauchy distribution weighted M-estimation-based robust RFVLNs are proposed. Since the weights of different outlier data are properly determined by the Cauchy distribution, their corresponding contribution on modeling can be properly distinguished. Thus, robust and better modeling results can be achieved. Moreover, given that the BF is a complex nonlinear system with numerous coupling variables, the data-driven canonical correlation analysis is employed to identify the most influential components from multitudinous factors that affect the MIQ indices to reduce the model dimension. Finally, experiments using industrial data and comparative studies have demonstrated that the obtained model produces a better modeling and estimating accuracy and stronger robustness than other modeling methods. Autors: Ping Zhou;Youbin Lv;Hong Wang;Tianyou Chai; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7141 - 7151 Publisher: IEEE
» Data-Driven Stochastic Transmission Expansion Planning
 Abstract:Due to the significant improvements of power generation technologies and the trend of replacing traditional power plants with renewable generation resources, the generation portfolio will experience dramatic changes in the near future. The uncertainty and variability of renewable energy and their sitting call for strategic and economic plans for expanding the transmission capacities. In this study, we develop a data-driven two-stage stochastic transmission expansion planning with uncertainties. In the proposed approach, purely by learning from the historical data, we first construct a confidence set for the unknown distribution of the uncertain parameters. Then, we develop a two-stage data-driven transmission expansion framework, by considering the worst-case distribution within the constructed confidence set, so as to provide a reliable while economic transmission planning decision. Furthermore, to tackle the model complexity, we propose a decomposition framework embedded with Benders’ and Column-and-Constraint generation methods. We implement our approach on 6-bus and 118-bus systems to test its effectiveness. Finally, we show as the amount of historical data grows, the conservativeness of the model decreases. Autors: Ali Bagheri;Jianhui Wang;Chaoyue Zhao; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3461 - 3470 Publisher: IEEE
» Day-Ahead Financial Loss/Gain Modeling and Prediction for a Generation Company
 Abstract:In an electricity market, the main goal of a generation company (GenCo) is to maximize its profit, while encountering the uncertainty of the electricity price forecast. Different risk measures have been proposed to cope with this source of uncertainty. However, those are usually before-the-fact performance indices and cannot give a measure for the financial loss/gain (FLG) of a GenCo considering the electricity prices actually realized in the market. This paper focuses on this matter. The time series of FLG is first constructed given the real conditions of the electricity market. Then, the FLG time series is quantized using Silhouette criterion and k-means clustering approach. Subsequently, based on the historical values of the quantized FLG time series and relevant exogenous variables, its day-ahead values are predicted. The method proposed for day-ahead FLG prediction consist of conditional mutual information and sequential forward search as the feature selection technique and extreme learning machine as the forecasting engine. The effectiveness of the whole proposed approach, including the FLG time series construction, quantization approach, and the prediction method, is shown for a typical GenCo using the real data of the PJM and Ontario electricity markets. Autors: Ali Doostmohammadi;Nima Amjady;Hamidreza Zareipour; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3360 - 3372 Publisher: IEEE
» DC 30-GHz DPDT Switch Matrix Design in High Resistivity Trap-Rich SOI
 Abstract:This paper presents low insertion loss, high isolation, ultra-wideband double-pole-double-throw (DPDT) switch matrix designed in a 0.13- commercial high resistivity trap-rich silicon-on-insulator (SOI) CMOS process for the first time. The switches are designed using series–shunt–series configuration in a ring-type structure with input and output matching networks. Transistor width and transistor channel length effects on the wideband DPDT switch performance are thoroughly investigated. The designed switches achieve widest bandwidth from dc to 30 GHz with a low insertion loss of 2.5 dB and a high isolation of 32 dB up to 30 GHz. The measured input P1dB of designed switches is higher than 18 dBm. It was found both second and third harmonics can be improved by widening switch transistor channel width, and third harmonic can be improved by shortening channel length. The active chip area of designed switch matrix is very small size of only 0.28 mm mm. Autors: Bo Yu;Kaixue Ma;Fanyi Meng;Kiat Seng Yeo;Parthasarathy Shyam;Shaoqiang Zhang;Purakh Raj Verma; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3548 - 3554 Publisher: IEEE
» DC Bias Reversal Behavior of Spin–Torque Ferromagnetic Resonance Spectra in CoFeB/MgO/CoFeB Perpendicular Magnetic Tunnel Junction
 Abstract:Spin–torque ferromagnetic resonance (ST-FMR) spectra of nano-scaled CoFeB/MgO/CoFeB full perpendicular magnetic tunnel junctions (p-MTJs) were investigated, especially in detail at low dc-bias voltage region. Usually in in-plane magnetized MTJs (i-MTJs), the ST-FMR spectrum line shape reverses its symmetry as switching dc-bias voltage polarities; however, it is found that in the p-MTJs the line shape reversal behaves differently, that not only the spectrum shows anti-symmetric line shape at zero dc bias but also the dependence of reversal symmetry on dc bias is broken. Based on the framework of homodyne-detected ST-FMR, we extracted the parameters characterizing the spectra and discussed the possible factors resulting these differences. Autors: Tian Yu;Hiroshi Naganuma;Mikihiko Oogane;Yasuo Ando; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 5 Publisher: IEEE
» Decoupled 2-D Direction of Arrival Estimation in L-Shaped Array
 Abstract:In this letter, we propose a novel decoupled method for 2-D direction of arrival (2-D DOA) estimation in L-shaped array. Specifically, in the proposed method, the Jacobi-Anger expansion is utilized to decouple the elevation angle from the azimuth angle, which means that the reconstructed manifold of the L-shaped array is the product of the two matrices of elevation and azimuth angles. Although the traditional 2-D MUSIC algorithm can estimate the elevation and azimuth angles without pair matching, it requires the complex 2-D spectrum peaks search. In order to simplify the searching procedure, the new formulation of the array manifold is applied in the Root-MUSIC algorithm, in which only 1-D elevation searching is needed to estimate the 2-D DOA and the azimuth estimates can be paired automatically with the elevation estimates. Simulation results are presented to confirm the effectiveness of the proposed method, and demonstrate that our proposed method achieves a better tradeoff between the performance and complexity than other existing methods. Autors: Zhi Zhang;Wenjie Wang;Yuzhen Huang;Shang Liu; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 1989 - 1992 Publisher: IEEE
» Deep Boltzmann Regression With Mimic Features for Oscillometric Blood Pressure Estimation
 Abstract:Oscillometric blood pressure (BP) devices are among the standard automatic monitors, now readily available for the home, office, and hospital. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) are obtained at fixed ratios of the envelope of the maximum amplitude of the oscillometric wave signal. However, these fixed ratios can cause overestimation or underestimation of the real SBP and DBP in oscillometric BP measurements. In this paper, we propose a new regression technique using a deep Boltzmann regression with mimic features based on the bootstrap technique to learn the complex nonlinear relationships between the mimic features vectors acquired from the oscillometric signals and the target BPs. The performance of the proposed model is compared with those of conventional and auscultatory techniques. Our regression model with mimic features provides lower standard deviation of error, mean error, mean absolute error, and standard error of estimates than the conventional techniques, along with a similar fit for the SBP and DBP. Autors: Soojeong Lee;Joon-Hyuk Chang; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 5982 - 5993 Publisher: IEEE
» Deep Learning-Based Large-Scale Automatic Satellite Crosswalk Classification
 Abstract:High-resolution satellite imagery has been increasingly used on remote sensing classification problems. One of the main factors is the availability of this kind of data. Despite the high availability, very little effort has been placed on the zebra crossing classification problem. In this letter, crowdsourcing systems are exploited in order to enable the automatic acquisition and annotation of a large-scale satellite imagery database for crosswalks related tasks. Then, this data set is used to train deep-learning-based models in order to accurately classify satellite images that contain or not contain zebra crossings. A novel data set with more than 240000 images from 3 continents, 9 countries, and more than 20 cities was used in the experiments. The experimental results showed that freely available crowdsourcing data can be used to accurately (97.11%) train robust models to perform crosswalk classification on a global scale. Autors: Rodrigo F. Berriel;André Teixeira Lopes;Alberto F. de Souza;Thiago Oliveira-Santos; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1513 - 1517 Publisher: IEEE
» Definition of Accurate Reference Synchrophasors for Static and Dynamic Characterization of PMUs
 Abstract:The calibration of phasor measurement units (PMUs) consists of comparing coordinated universal time time-aligned phasors (synchrophasors) measured by the PMU under test, against reference synchrophasors generated through a PMU calibrator. The IEEE Standard C37.118–2011 and its latest amendment (IEEE Std) describe compliance tests for static and dynamic conditions, and indicate the relative limits in terms of accuracy. In this context, this paper focuses on the definition and accuracy assessment of the reference synchrophasors in the test conditions defined by the above IEEE Std. In the first part of this paper, we describe the characterization of a nonlinear least-squares fitting algorithm used to determine the parameters of these reference synchrophasors. For this analysis, we deploy the proposed algorithm in a PMU calibrator and characterize the algorithm performance within the actual hardware implementation for both static and dynamic test conditions. More specifically, we generate reference waveforms through a highly stable high-resolution digital-to-analog converter and evaluate how the algorithm parameters (observation interval length and sampling frequency) affect the solution accuracy. In the second part, we discuss on the appropriateness of the synchrophasor model in the evaluation of PMU performance under step test conditions. In this regard, we propose an alternative time-domain approach to assess the synchrophasor estimate during transient events. Autors: Guglielmo Frigo;Daniele Colangelo;Asja Derviškadić;Marco Pignati;Claudio Narduzzi;Mario Paolone; Appeared in: IEEE Transactions on Instrumentation and Measurement Publication date: Sep 2017, volume: 66, issue:9, pages: 2233 - 2246 Publisher: IEEE
» Degrees of Freedom of the Two-User MIMO Broadcast Channel With Private and Common Messages Under Hybrid CSIT Models
 Abstract:We establish the degree of freedom (DoF) regions of the two-user multiple-input multiple-output (MIMO) broadcast channel with a general message set (BC-GM), that includes private and common messages, under fast fading. Nine different channel state knowledge assumptions—collectively known as hybrid channel state information at the transmitter (CSIT) models—are considered wherein the transmitter has either perfect/instantaneous, delayed, or no CSI from each of the two receivers. General antenna configurations are addressed wherein the three terminals have arbitrary numbers of antennas. The DoF regions are established for the five hybrid CSIT models in which either both channels are unknown at the transmitter or each of the two channels is known perfectly or with delay. In the four remaining cases in which exactly one of the two channels is unknown at the transmitter, the DoF regions under the restriction of linear encoding strategies—also known as the linear DoF (LDoF) regions—are established. As the key to the converse proofs of the LDoF region of the MIMO BC-GM under such hybrid CSIT assumptions, we show that, when only considering linear encoding strategies, the CSI from the receiver with more antennas does not help if there is no CSI available from the receiver with fewer antennas. This result is conjectured to be true even without the restriction on the encoding strategies to be linear. If true, the LDoF regions obtained for the four hybrid CSIT cases herein will also be the DoF regions for those cases. Many of the results of this paper when specialized to even the two-message problems are new. These include the LDoF regions, when one of the two channels is not known, of the MIMO BC-GM when specialized to the MIMO BC with private messages. They also include the DoF/LDoF regions for all the hybrid CSIT models obtained by specializing the corresponding regions for the MIMO BC-GM to the cas- with degraded messages. Autors: Yao Wang;Mahesh K. Varanasi; Appeared in: IEEE Transactions on Information Theory Publication date: Sep 2017, volume: 63, issue:9, pages: 6004 - 6019 Publisher: IEEE
» Demonstration of AlN Schottky Barrier Diodes With Blocking Voltage Over 1 kV
 Abstract:This letter reports the first demonstration of 1-kV-class AlN Schottky barrier diodes on sapphire substrates by metal organic chemical vapor deposition. The device structure mimics the silicon-on-insulator (SOI) technology, consisting of thin -AlN epilayer as the device active region and thick resistive AlN underlayer as the insulator. At room temperature, the devices show outstanding performances with a low turn-ON voltage of 1.2 V, a high ON/OFF ratio of , a low ideality factor of 5.5, and a low reverse leakage current below 1 nA. The devices also exhibit excellent thermal stability over 500 K owing to the ultra-wide bandgap of AlN. The breakdown voltage of the devices can be further improved by employing field plate, edge termination technologies, and optimizing the SOI-like device structure. This letter presents a cost-effective route to high performance AlN-based Schottky barrier diodes for high-power, high-voltage, and high-temperature applications. Autors: Houqiang Fu;Izak Baranowski;Xuanqi Huang;Hong Chen;Zhijian Lu;Jossue Montes;Xiaodong Zhang;Yuji Zhao; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1286 - 1289 Publisher: IEEE
» Denoising of Hyperspectral Images Using Nonconvex Low Rank Matrix Approximation
 Abstract:Hyperspectral image (HSI) denoising is challenging not only because of the difficulty in preserving both spectral and spatial structures simultaneously, but also due to the requirement of removing various noises, which are often mixed together. In this paper, we present a nonconvex low rank matrix approximation (NonLRMA) model and the corresponding HSI denoising method by reformulating the approximation problem using nonconvex regularizer instead of the traditional nuclear norm, resulting in a tighter approximation of the original sparsity-regularised rank function. NonLRMA aims to decompose the degraded HSI, represented in the form of a matrix, into a low rank component and a sparse term with a more robust and less biased formulation. In addition, we develop an iterative algorithm based on the augmented Lagrangian multipliers method and derive the closed-form solution of the resulting subproblems benefiting from the special property of the nonconvex surrogate function. We prove that our iterative optimization converges easily. Extensive experiments on both simulated and real HSIs indicate that our approach can not only suppress noise in both severely and slightly noised bands but also preserve large-scale image structures and small-scale details well. Comparisons against state-of-the-art LRMA-based HSI denoising approaches show our superior performance. Autors: Yongyong Chen;Yanwen Guo;Yongli Wang;Dong Wang;Chong Peng;Guoping He; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 5366 - 5380 Publisher: IEEE
» Dense Multipath Component Characteristics in 11-GHz-Band Indoor Environments
 Abstract:In the next-generation mobile communication system, the higher frequency bands from C-band to V-band are expected to be utilized because it has the potential to improve network capacity drastically by the available wideband spectrum. Since the characteristics of reflected and scattered radio waves from surrounding environments in those bands are thought to be quite different than at lower frequencies, the clarification of its influence on the multiple-input multiple-output (MIMO) transmission performance is a critical issue. In this paper, we focused on the characteristics of diffuse scattering in X-band, and conducted the MIMO channel measurements in indoor environments in the 11-GHz band. The frequency, angular, and polarization domain dense multipath component (DMC) propagation parameters were jointly estimated by using the RiMAX-based estimator. The measurement result showed the existence of significant DMC, which is thought to have originated from the floor, the ceiling as well as the walls. The angular spreads of the DMC tended to increase, and their decay factor tended to decrease as the room size decreased. It is also shown that the existence of DMC significantly affected the eigenvalue structure of the MIMO channel, which defines the MIMO transmission performance. The result is expected to be utilized for novel MIMO channel modeling in X-band that includes the DMC contribution. Autors: Kentaro Saito;Jun-Ichi Takada;Minseok Kim; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4780 - 4789 Publisher: IEEE
» Dense Semantic 3D Reconstruction
 Abstract:Both image segmentation and dense 3D modeling from images represent an intrinsically ill-posed problem. Strong regularizers are therefore required to constrain the solutions from being ‘too noisy’. These priors generally yield overly smooth reconstructions and/or segmentations in certain regions while they fail to constrain the solution sufficiently in other areas. In this paper, we argue that image segmentation and dense 3D reconstruction contribute valuable information to each other’s task. As a consequence, we propose a mathematical framework to formulate and solve a joint segmentation and dense reconstruction problem. On the one hand knowing about the semantic class of the geometry provides information about the likelihood of the surface direction. On the other hand the surface direction provides information about the likelihood of the semantic class. Experimental results on several data sets highlight the advantages of our joint formulation. We show how weakly observed surfaces are reconstructed more faithfully compared to a geometry only reconstruction. Thanks to the volumetric nature of our formulation we also infer surfaces which cannot be directly observed for example the surface between the ground and a building. Finally, our method returns a semantic segmentation which is consistent across the whole dataset. Autors: Christian Häne;Christopher Zach;Andrea Cohen;Marc Pollefeys; Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence Publication date: Sep 2017, volume: 39, issue:9, pages: 1730 - 1743 Publisher: IEEE
» Dermoscopic Image Segmentation via Multistage Fully Convolutional Networks
 Abstract:Objective: Segmentation of skin lesions is an important step in the automated computer aided diagnosis of melanoma. However, existing segmentation methods have a tendency to over- or under-segment the lesions and perform poorly when the lesions have fuzzy boundaries, low contrast with the background, inhomogeneous textures, or contain artifacts. Furthermore, the performance of these methods are heavily reliant on the appropriate tuning of a large number of parameters as well as the use of effective preprocessing techniques, such as illumination correction and hair removal. Methods: We propose to leverage fully convolutional networks (FCNs) to automatically segment the skin lesions. FCNs are a neural network architecture that achieves object detection by hierarchically combining low-level appearance information with high-level semantic information. We address the issue of FCN producing coarse segmentation boundaries for challenging skin lesions (e.g., those with fuzzy boundaries and/or low difference in the textures between the foreground and the background) through a multistage segmentation approach in which multiple FCNs learn complementary visual characteristics of different skin lesions; early stage FCNs learn coarse appearance and localization information while late-stage FCNs learn the subtle characteristics of the lesion boundaries. We also introduce a new parallel integration method to combine the complementary information derived from individual segmentation stages to achieve a final segmentation result that has accurate localization and well-defined lesion boundaries, even for the most challenging skin lesions. Results: We achieved an average Dice coefficient of 91.18% on the ISBI 2016 Skin Lesion Challenge dataset and 90.66% on the PH2 dataset. Conclusion and Significance: Our extensive experimental results on two well-established public b- nchmark datasets demonstrate that our method is more effective than other state-of-the-art methods for skin lesion segmentation. Autors: Lei Bi;Jinman Kim;Euijoon Ahn;Ashnil Kumar;Michael Fulham;Dagan Feng; Appeared in: IEEE Transactions on Biomedical Engineering Publication date: Sep 2017, volume: 64, issue:9, pages: 2065 - 2074 Publisher: IEEE
» Design and Analysis of an Always-ON Input-Biased pA-Current Sub-nW mV-Threshold Hysteretic Comparator for Near-Zero Energy Sensing
 Abstract:This paper presents the design and analysis of an always-ON comparator capable of detecting mV-range input voltage signals reliably with sub-nW power consumption. The comparator compares the two pA currents generated by current mirrors biased by the mV-range input signal. With the input signal near zero at the standby mode, the comparator consumes near-zero energy. A positive feedback is introduced to accelerate the output signal transition to the supply or the ground and to generate the hysteresis to tolerate the noise in the input signal. The comparator threshold and the amount of hysteresis are programmed using control signals to adjust the current mirror transistor sizes. Analytic expressions of comparator characteristics are derived using circuit theory and subthreshold transistor models, and have been validated using simulation and measurement. A prototype comparator implementing these ideas was designed and fabricated in a standard 65-nm CMOS process. Chip measurements have shown that the comparator achieved programmable thresholds from 27 to 46.5 mV with energy per switching from 1.9 to 2.4 nJ using four control bits. The measured power consumption is 270 pW at the input signal of 0.1 mV with the frequency of 10 Hz. Autors: Aili Wang;Chixiao Chen;Chuanjin Richard Shi; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2284 - 2294 Publisher: IEEE
» Design and Evaluation of a Data-Driven Scenario Generation Framework for Game-Based Training
 Abstract:Generating suitable game scenarios that can cater for individual players has become an emerging challenge in procedural content generation. In this paper, we propose a data-driven scenario generation framework for game-based training. An evolutionary scenario generation process is designed with a fitness evaluation methodology that integrates the processes of AI player modeling, simulation and model training based on artificial neural networks. The fitness function for scenario evaluation can be automatically constructed based on the proposed methodology. To further enhance the evaluation of scenarios, we specifically study the impact of the timing of events in a scenario and propose a generic scenario representation model that characterizes individual scenario based on the types and timing of events in the scenario. We present an extensive evaluation of our framework by validating our AI player model, demonstrating the impact of timing of events in a scenario and comparing the effectiveness of our data-driven framework with our previous heuristic-based approach and a random baseline. The results show that it is necessary to consider the timing of events for scenario evaluation and the proposed framework works well in generating scenarios for game-based training. Autors: Linbo Luo;Haiyan Yin;Wentong Cai;Jinghui Zhong;Michael Lees; Appeared in: IEEE Transactions on Computational Intelligence and AI in Games Publication date: Sep 2017, volume: 9, issue:3, pages: 213 - 226 Publisher: IEEE
» Design and Experimental Demonstration of a Compact Silicon Photonic Interleaver Based on an Interfering Loop With Wide Spectral Range
 Abstract:We present the design and experimental demonstration of a compact tunable silicon photonic interleaver with a wide spectral range. The interleaver consists of an interfering loop containing a Fabry-Perot cavity formed by two Sagnac loops. The transmission coefficients of the directional couplers are calculated based on the maximally flat criterion. The impacts of the transmission coefficient variations on the extinction ratio and filter sharpness are investigated. The wavelength dependences of the directional couplers are analyzed to increase the spectral range of the interleaver. The device was fabricated on a silicon-on-insulator platform. The spectral ranges of the measured transmission and reflection spectra are increased to 60 nm. By thermal tuning the waveguide connecting the two Sagnac loops, the central wavelength can be shifted over one free spectral range with a wavelength-tuning efficiency of ~0.08 nm/mW. Autors: Xinhong Jiang;Yuxing Yang;Hongxia Zhang;Jizong Peng;Yong Zhang;Ciyuan Qiu;Yikai Su; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:17, pages: 3765 - 3771 Publisher: IEEE
» Design and Implementation of an Optical Receiver for Angle-of-Arrival-Based Positioning
 Abstract:Optical wireless (OW) technology has attracted significant interest for indoor positioning in the past decade. An emerging form of this technology makes use of angle-of-arrival (AOA) measurements to carry out positioning via triangulation off of an optical beacon grid. Such AOA-based OW positioning systems can yield accurate position estimates—but only given sufficient attention to the optical receiver. The design, operation, and implementation of such a receiver are presented in this work. The optical receiver is designed to have a sufficiently small AOA error, being σAOA = 1°, over a wide angular field-of-view (FOV), being 100°. The design allows the optical receiver to carry out positioning based off a 3 × 3 grid of optical beacons, where each optical beacon is uniquely identified using multiple frequency and color channels. The optical beacons are widely spaced to fully utilize the optical receiver's wide angular FOV. The overall AOA-based OW positioning system exhibits a position error of 1.7 cm, which is comparable to those obtained by more complex positioning systems. Thus, the presented AOA-based technologies can play a role in emerging indoor positioning systems. Autors: Mark H. Bergen;Xian Jin;Daniel Guerrero;Hugo A. L. F. Chaves;Naomi V. Fredeen;Jonathan F. Holzman; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:18, pages: 3877 - 3885 Publisher: IEEE
» Design and Psychophysical Evaluation of the HapSticks: A Novel Non-Grounded Mechanism for Presenting Tool-Mediated Vertical Forces
 Abstract:Force feedback in tool-mediated interactions with the environment is important for the successful performance of complex tasks in daily life as well as in specialized fields such as medicine. Most stylus-based haptic devices require either grounding or attachment to the user’s body. Recently, non-grounded haptic devices have attracted a growing interest. In this study, we propose a non-grounded rotation mechanism to represent the vertical forces applied on the tip of a tool by mimicking the cutaneous sensations that are caused by such forces. As an example of an application of our method, we developed a non-grounded haptic device called HapSticks, which mimicked the sensation of manipulating objects using chopsticks. First, using an adjustment paradigm, we directly compared a virtual weight rendered by our device and a real weight to investigate the relation of real weight and virtual weight. Next, we used a forced choice constant stimuli paradigm in a virtual and a real weight discrimination task. We conclude that our novel device renders a reliable illusion of sensed weight that leads to a discrimination ability that is typical of virtual-reality applications but worse than the discrimination between real weights. Autors: Ginga Kato;Yoshihiro Kuroda;Ilana Nisky;Kiyoshi Kiyokawa;Haruo Takemura; Appeared in: IEEE Transactions on Haptics Publication date: Sep 2017, volume: 10, issue:3, pages: 338 - 349 Publisher: IEEE
» Design and Simulation of a Novel Graded-Channel Heterojunction Tunnel FET With High ${I} _{\scriptscriptstyle\text {ON}}/{I} _{\scriptscriptstyle\text {OFF}}$ Ratio and Steep Swing
 Abstract:In this letter, a novel graded-channel heterojunction tunnel field-effect transistor (GCH-TFET) is proposed and studied by simulation. The novel TFET adopts a near broken-gap heterojunction at the source/channel interface to enhance the tunnel efficiency. Besides, it employs a graded component channel which works as an electron barrier to block up the leakage current at the OFF-state and can be removed with the increased gate voltage at the ON-state for high ON/ OFF-current () ratio. Such graded channel also allows a sudden turn-on of band-to-band tunneling, resulting in a reduced sub-threshold swing (SS) compared with conventional heterojunction TFETs. The GCH-TFET demonstrates an ratio of more than seven decades with up to 225 at V, more than two decades lower than a near broken-gap heterojunction TFET and SS lower than 30 mV/decade for more than five decades, exhibiting excellent potential for ultra-low power applications. Autors: Jiadi Zhu;Yang Zhao;Qianqian Huang;Cheng Chen;Chunlei Wu;Rundong Jia;Ru Huang; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1200 - 1203 Publisher: IEEE
» Design Automation of Cyber-Physical Systems: Challenges, Advances, and Opportunities
 Abstract:A cyber-physical system (CPS) is an integration of computation with physical processes whose behavior is defined by both computational and physical parts of the system. In this paper, we present a view of the challenges and opportunities for design automation of CPS. We identify a combination of characteristics that define the challenges unique to the design automation of CPS. We then present selected promising advances in depth, focusing on four foundational directions: combining model-based and data-driven design methods; design for human-in-the-loop systems; component-based design with contracts, and design for security and privacy. These directions are illustrated with examples from two application domains: smart energy systems and next-generation automotive systems. Autors: Sanjit A. Seshia;Shiyan Hu;Wenchao Li;Qi Zhu; Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems Publication date: Sep 2017, volume: 36, issue:9, pages: 1421 - 1434 Publisher: IEEE
» Design Consideration of SAW/BAW Band Reject Filters Embedded in Impedance Converter
 Abstract:This paper discusses design of surface acoustic wave/bulk acoustic wave (SAW/BAW)-based band reject filters composed of the impedance converters, where capacitive elements are replaced with SAW/BAW resonators. First, basic properties of the unit cell are studied. It is shown how basic properties of a unit cell change with the design. It is also shown that when two notches caused by the resonators are placed in proximity, two synergy effects occur: 1) an extra matching point appears on one side of the transition band. This makes the insertion loss at the point smaller and the transition band steeper and 2) the dip level becomes deeper, and the total rejection level improves. Then, two resonators are fabricated, measured, and combined with inductors in circuit simulator to demonstrate functionality of the basic cell design. Finally, the wide rejection band filter is designed by cascading multistages, and effectiveness of the device configurations is demonstrated. Autors: Yulin Huang;Jingfu Bao;Gongbin Tang;Qiaozhen Zhang;Tatsuya Omori;Ken-ya Hashimoto; Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Publication date: Sep 2017, volume: 64, issue:9, pages: 1368 - 1374 Publisher: IEEE
» Design of a Full Solid Angle Scanning Cylindrical-and-Conical Phased Array Antennas
 Abstract:In this paper, a full solid angle scanning cylindrical-and-conical (CYLCON) conformal phased array antenna (PAA) is designed. First, a microstrip Yagi antenna with low profile and small size is proposed and discussed. Second, a cylindrical conformal Yagi antenna array consisting of 24 aforementioned 8-element Yagi antennas is designed and optimized. Simulation results show that the Yagi antenna array can realize low-elevation beam scanning in the region of , with low sidelobe levels and sharp beams. Third, CYLCON conformal microstrip antenna arrays are developed to realize the broadside beam scanning. Afterwards, an integrated PAA by combining the aforementioned conformal arrays along with feeding networks is constructed to achieve full solid angle scanning. Finally, a prototype is fabricated, the measured results show that it can realize beam scanning in the regions of , , and , , which meet well with those of the simulated. By arranging proper number of arrays along the perimeter accompanied with the switchable feeding configurations, a full solid angle scanning can be achieved. Autors: Yulong Xia;Badar Muneer;Qi Zhu; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4645 - 4655 Publisher: IEEE
» Design of a Miniaturized On-Chip Bandpass Filter Using Edge-Coupled Resonators for Millimeter-Wave Applications
 Abstract:A unique miniaturization technique for on-chip passive device implemented in gallium arsenide (GaAs)-based technology is presented, which is based on edge-coupled cells (ECCs). The principle of an ECC is first studied by means of the equivalent LC circuits. Then, using the ECC as a baseline, a combination of different shorting-ground and tapping methods is fully investigated in terms of their impact on frequency responses. By directly shorting the specific edge-coupled fingers to the ground, an ECC can be converted into a resonator without increasing any physical size. To further demonstrate the feasibility of using this technique for miniaturized monolithic microwave integrated circuit design, an on-chip bandpass filter (BPF) is implemented and fabricated in a commercial 0.1- GaAs technology. The measurement results show that the 3-dB bandwidth of the filter is from 21.2 to 26.5 GHz, while the insertion loss is less than 2.9 dB at 23 GHz. In addition, more than 30 dB of suppression is achieved from 0 to 15 GHz and from 44 to 54 GHz. The size of the BPF is only , excluding the pads, which is equivalent to . ( is the guided wavelength at 23.5 GHz.) Autors: Yang Yang;Xi Zhu;Eryk Dutkiewicz;Quan Xue; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3822 - 3828 Publisher: IEEE
» Design of a Wavelength-Tunable Optical Tweezer Using a Graded-Index Multimode Optical Fiber
 Abstract:A wavelength-tunable optical fiber tweezer based on a graded index multimode fiber with a flat endface is proposed. The design offers a noncontact optical fiber tweezer generating a stable optical trap that can be tuned precisely over a large range using a common wavelength-tunable laser. This property comes from the wavelength dependence of the graded index multimode fiber design parameters, such as the numerical aperture. Using an optical fiber tweezer with a flat endface is also more desirable than the tapered one because of the easier fabrication process. Our analysis also shows that the setup can form a stable three-dimensional optical trap in the Rayleigh regime in the absence of any microfluidic flow force. Autors: Esmaeil Mobini;Arash Mafi; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:18, pages: 3854 - 3861 Publisher: IEEE
» Design of Absorptive/Transmissive Frequency-Selective Surface Based on Parallel Resonance
 Abstract:This communication presents a novel frequency-selective surface (FSS) with high in-band transmission at high frequency and wideband absorption at low frequency. It consists of a resistive sheet and a metallic bandpass FSS separated by a foam spacer. The resistive element is realized by inserting a strip-type parallel (PLC) structure into the center of a lumped-resistor-loaded metallic dipole. The PLC resonates at the passband of the bandpass FSS and exhibits an infinite impedance, which splits the resistive dipole into two short sections per the surface current; this setup allows for high in-band transmission at high frequency. Below the resonance frequency, the PLC becomes finite inductive and the entire FSS performs as an absorber with the metallic FSS as a ground plane. The surface current distribution on the resistive element can be controlled at various frequencies via the PLC structure. The wideband absorption and high in-band transmission of the proposed design are verified by both numerical simulation and experimental measurements. The potential extension to polarization-insensitive designs is also discussed. Autors: Qiang Chen;Shilin Yang;Jiajun Bai;Yunqi Fu; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4897 - 4902 Publisher: IEEE
» Design of All-Normal Dispersion Microstructured Optical Fiber on Silica Platform for Generation of Pulse-Preserving Supercontinuum Under Excitation at 1550 nm
 Abstract:We investigated numerically the possibility of all normal dispersion fiber design for near-infrared supercontinuum generation based on a standard air-silica microstructure. The design procedure includes finding of target dispersion profile and subsequent finding of appropriate geometrical fiber design by inverse dispersion engineering. It was shown that the tailoring of dispersion profile could increase the spectral width of generated supercontinuum while maintaining perfect spectral flatness. Conditions necessary for wide and flat supercontinuum generation as well as restrictions imposed by chosen materials were discussed. As a result of design and optimization procedure, an air-silica design was found providing normal dispersion up to 3 μm. Simulation results with 10 nJ, 100 fs pulses demonstrate supercontinuum generation up to 1.3 octave; whereas pumping with 30 nJ, 100 fs pulses could provide 1.8 octavse supercontinuum. Autors: Igor A. Sukhoivanov;Sergii O. Iakushev;Oleksiy V. Shulika;Enrique Silvestre;Miguel V. Andrés; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:17, pages: 3772 - 3779 Publisher: IEEE
» Design of an Area-Effcient Million-Bit Integer Multiplier Using Double Modulus NTT
 Abstract:This brief proposes a double modulus number theoretical transform (NTT) method for million-bit integer multiplication in fully homomorphic encryption. In our method, each NTT point is processed simultaneously under two moduli, and the final result is generated through the Chinese reminder theorem. The employment of double modulus enlarges the permitted NTT sample size from 24 to 32 bits and thus improves the transform efficiency. Based on the proposed double modulus method, we accomplish a VLSI design of million-bit integer multiplier with the Schönhage–Strassen algorithm. Implementation results on Altera Stratix-V FPGA show that this brief is able to compute a product of two 1024k-bit integers every 4.9 ms at the cost of only 7.9k ALUTs and 3.6k registers, which is more area-efficient when compared with the current competitors. Autors: Xiang Feng;Shuguo Li; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2658 - 2662 Publisher: IEEE
» Design of Closely Packed Pattern Reconfigurable Antenna Array for MIMO Terminals
 Abstract:In this communication, a compact pattern reconfigurable dual-antenna array is designed at 2.65 GHz for multiple-input multiple-output (MIMO) terminal applications, such as laptops. Each antenna is composed of two layers, i.e., the monopole layer and the planar inverted-F antenna (PIFA) layer. By switching the p-i-n diodes on each layer, its radiation patterns can be varied between conical and boresight patterns. Two such identical antennas are placed side by side on a common ground plane for MIMO application, providing altogether four operating modes. The center-to-center separation between the antennas is 0.25 wavelength, to keep the overall array compact. To facilitate an isolation of above 17 dB over all the modes for this compact array, two decoupling techniques based on the decoupling slits and the shielding wall are effectively combined. The envelope correlation coefficients (ECCs) of the far-field patterns in the four modes are below 0.05 in free space, and below 0.1 for most cases in the indoor and outdoor scenarios. The only exception is the monopole-PIFA mode in the outdoor scenario, but the ECC is still below 0.3 for this case. The measured efficiencies of the antennas are between −1.7 (68%) and −0.7 dB (85%) for all the modes. Therefore, good diversity and MIMO performances are expected for the proposed design. Autors: Hui Li;Buon Kiong Lau;Sailing He; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4891 - 4896 Publisher: IEEE
» Design of Hybrid SSDs With Storage Class Memory and NAND Flash Memory
 Abstract:NAND flash memory-based solid-state drives (SSDs) are increasingly being used in both consumer and enterprise storage markets, due to their superior performance over hard disk drives (HDDs) and continuous bit cost reductions. With multiple-level cell technology memory device is capable of trading off the performance and endurance with bit density. The more bits per cell there are, the longer latency and shorter lifetime. On the other hand, the performance of such SSDs is limited due to NAND flash access speed as well as the need of garbage collection. Recently, storage class memories (SCMs) like resistive RAM (ReRAM) and phase change RAM (PRAM) have been developed to fill the bandwidth gap between DRAM and NAND flash memory. SCMs are nonvolatile and byte addressable, which are much faster and durable than NAND flash. Therefore, with SCMs, the storage performance would be significantly improved. Hybrid SSDs are promising cost-efficient storage solutions. Various types of memories like single-level cell (SLC), multiple-level cell (MLC), triple-level cell (TLC) NAND flash memories, and SCMs create lots of opportunities for new system architectures and algorithms. In this paper, the architecture and algorithm design overview of three types of hybrid drives including MLC/TLC NAND flash hybrid, SCM/MLC NAND flash hybrid, and SCM/MLC/TLC NAND flash tri-hybrid are presented. From the evaluation results, hybrid drives demonstrate better performance, endurance, and power consumption, compared to the MLC NAND flash only SSD. Furthermore, the relationship between device reliability and performance of the SCM/NAND flash hybrid SSD has been understood at a system level. There is a tradeoff between acceptable bit error rate of SCM and NAND flash. In addition, the decoding latency of SCM affects the performance of hybrid SSD more than that of NAND flash. Autors: Chihiro Matsui;Chao Sun;Ken Takeuchi; Appeared in: Proceedings of the IEEE Publication date: Sep 2017, volume: 105, issue:9, pages: 1812 - 1821 Publisher: IEEE
» Design of Integral Controllers for Nonlinear Systems Governed by Scalar Hyperbolic Partial Differential Equations
 Abstract:The paper deals with the control and regulation by integral controllers for the nonlinear systems governed by scalar quasi-linear hyperbolic partial differential equations. Both the control input and the measured output are located on the boundary. The closed-loop stabilization of the linearized model with the designed integral controller is proved first by using the method of spectral analysis and then by the Lyapunov direct method. Based on the elaborated Lyapunov function, we prove local exponential stability of the nonlinear closed-loop system with the same controller. The output regulation to the set-point with zero static error by the integral controller is shown upon the nonlinear system. Numerical simulations by the Preissmann scheme are carried out to validate the robustness performance of the designed controller to face to unknown constant disturbances. Autors: Ngoc-Tu Trinh;Vincent Andrieu;Cheng-Zhong Xu; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4527 - 4536 Publisher: IEEE
» Design of Modified Droop Controller for Frequency Support in Microgrid Using Fleet of Electric Vehicles
 Abstract:Droop control has been extensively used by academia and industry for managing frequency fluctuations at microgrid (MG). This controller generates series of reference signals to different distributed energy sources (DES) such as diesel generator, PV, and wind system based on their respective maximum capacities. However, the combination of inertial and noninertial DES leads to frequency fluctuations at MG. Therefore, this paper proposes a novel frequency support strategy by controlling the operation of DES and controllable loads, i.e., electric vehicles (EVs). Moreover, fleet of EVs batteries maximum capacity depends upon constraints, such as state of charge (SoC), random arrival, and departure patterns. Hence, to accomodate EVs’ batteries with droop controller, it has been enhanced with communication links and feedback mechanism and referred as modified droop controller (MDC). This MDC would be now able to dispatch reference signals to both DES and EVs. However, for meeting reference signal given to fleet of EVs, an aggregator (AG) is proposed. AG can alter the charging and discharging rates of EVs’ thereby satisfying EVs’ needs in terms of battery's SoC. Extensive simulations have been done using the proposed scheme on data available from Santa Rita Jails’ MG. Autors: Rubi Rana;Mukesh Singh;S. Mishra; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3627 - 3636 Publisher: IEEE
» Design of MRAM-Based Magnetic Logic Circuits
 Abstract:Emerging technologies are gaining an increasing attention due to the slowdown of CMOS development. NanoMagnet Logic (NML), among emerging technologies, increases the potentials for developing fully magnetic circuits. Using a magnet as a building block for logic circuits has the advantage to merge logic and memory in the same device. Moreover, circuits have low dynamic and no stand-by power consumption. Even though demonstrations exist for small circuits, the experimental feasibility of complex NML circuits still represents a critical point for this technology. In this paper, we outline the possibility to design NML circuits based on the technological structure of magnetic RAMs (MRAMs). NML circuits based on MRAMs rely on a well-developed technology that provides a natural interface with CMOS world. To study this new NML implementation a novel tool, NANOcom, was developed to easily design complex circuits. Simulations were then performed using an high-level behavioral model described using VHDL language. Two types of circuit layouts, based on different technological constraints, are investigated. To evaluate the performance of this new NML implementation, a 4-bit Galois multiplier is used as a testbench. The Galois multiplier is the basic block of cryptographic circuits, an ideal target for this technology. Results obtained are encouraging and can unlock interesting options for the future development of NML technology. Autors: Giovanna Turvani;Matteo Bollo;Marco Vacca;Fabrizio Cairo;Maurizio Zamboni;Mariagrazia Graziano; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 851 - 859 Publisher: IEEE
» Design of Multioctave Bandwidth Power Amplifier Based on Resistive Second-Harmonic Impedance Continuous Class-F
 Abstract:In this letter, a generic method is presented for multioctave power amplifier (PA) based on extended version of the continuous class-F. The theory allows resistive second-harmonic impedance and sacrifices part of efficiency to get a bandwidth over one octave. A high-voltage GaN HEMT is adopted to achieve high output power and drain efficiency. Finally, a 0.2–2.5 GHz miniature multioctave PA is designed and fabricated. Experimental results show the drain efficiency of 55.5%–70.3% and the output power of 43.7–46.9 dBm across 0.2–2.5 GHz (170%). The compact size of the proposed PA can also be observed with only 2.6 cm cm, which is greatly reduced compared with other PAs with similar performances. Autors: Hang Huang;Bo Zhang;Cuiping Yu;Jinchun Gao;Yongle Wu;Yuanan Liu; Appeared in: IEEE Microwave and Wireless Components Letters Publication date: Sep 2017, volume: 27, issue:9, pages: 830 - 832 Publisher: IEEE
» Design of Smart LED Streetlight System for Smart City With Web-Based Management System
 Abstract:Smart LED streetlight system is one of the enabling technologies for a smart city, giving low-cost, low power outdoor lighting also with benefits for vehicle users as well as pedestrians. Integration of sensors and ZigBee-based wireless sensor modules can furnish an optimal platform for an innovative LED streetlight application. Psychological studies suggest that a different level of color temperature can significantly affect human circadian rhythm. For this reason, correlated color temperature (CCT)-based illumination gives a significant lighting performance both in terms of energy efficiency and in overcoming traffic accidents in low visibility areas. Previous works usually assume only specific platform and did not consider CCT-based illumination toward smart LED streetlight system. In this paper, we consider the importance of CCT-based illumination and propose a novel integration of public weather data awareness, ZigBee-based wireless communication, and dynamic web-based management system for the state-of-art of smart LED streetlight system applicable to smart city. In particular, we design a central web server that can receive weather information and real-time sensor data from each LED streetlights and provides a dynamic and flexible web interface for authorized users. Furthermore, real-time implementation of the proposed system shows perfect transmission-reception parameters, such as throughput and signal strength among the different LED streetlights, which fulfills the wireless communication range and signal quality between each LED streetlights. Autors: Philip Tobianto Daely;Haftu Tasew Reda;Gandeva Bayu Satrya;Jin Woo Kim;Soo Young Shin; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 6100 - 6110 Publisher: IEEE
» Design Procedure and Optimal Guidelines for Overall Enhancement of Steady-State and Transient Performances of Line Start Permanent Magnet Motors
 Abstract:This paper proposes a design procedure in addition to some optimal design guidelines for line start permanent magnet (LSPM) motors, independent from their ratings. Major transient and steady-state characteristics of LSPM motors, including magnet braking torque, synchronizing torque, efficiency, and power factor, are analyzed with respect to the main motor design parameters, i.e., motor back electromotive force, reactances, and saliency ratio. The contradicting behaviors of the motor characteristics with respect to the motor parameters are fully investigated. Design guidelines are developed to wisely compromise the performance characteristics by selecting optimal parameters. A design procedure considering the guidelines is proposed. By following the procedure and guidelines, an LSPM motor is designed and optimal values of the motor parameters are determined. Accordingly, a prototype LSPM motor is built and tested. The finite element method (FEM)-based simulation results in close agreement with the experimental results confirm superior steady-state and transient performance characteristics of the motor, thus validating the developed guidelines and the proposed design procedure. Autors: Esmaeil Sarani;Sadegh Vaez-Zadeh; Appeared in: IEEE Transactions on Energy Conversion Publication date: Sep 2017, volume: 32, issue:3, pages: 885 - 894 Publisher: IEEE
» Design Procedure of the Leakage Inductance for a Pulse Transformer Considering Winding Structures
 Abstract:The pulse transformer is used in many applications to provide high-voltage pulses. In order to obtain high and narrow output pulses, it is necessary to reduce the leakage inductance of the pulse transformer. The circuit of a high-voltage power supply is analyzed and simulated to study the effect of the leakage inductance on the pulse waveform. Afterwards, the winding structure is analyzed. Three transformer models were built based on the asymmetric parallel winding, the traditional parallel winding, and the taper winding. Their leakage inductances and parasitic capacitances are calculated and compared. The 3-D finite element simulation is adopted to compute the leakage inductance precisely. The simulation results demonstrate that the asymmetric parallel winding in this paper reduces the leakage inductance effectively with small parasitic capacitances. In addition, using the asymmetric parallel winding, a pulse transformer prototype is manufactured and tested. The experimental results verify the accuracy of the simulation method and the feasibility of the asymmetric parallel winding. Autors: Feifei Pan;Long Jin;Peng Pan;Zhike Xu; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2504 - 2510 Publisher: IEEE
» Designing of a Microelectrode Sensor-Based Label Free Milk Adulteration Testing System
 Abstract:A novel hand held micro-electrode sensor based on a label free impedance spectroscopy is fabricated for the detection of adulteration in milk. The results showed remarkable impedance change for different concentrations of starch and detergent in the milk sample in the frequency range of 0.05–5 kHz. The impedance of reference milk sample at resonant frequency 4.75 kHz was found to be 8.01E and that of model milk sample adulterated with 10% (w/v) detergent was found to be 56% of the original value while the impedance of milk sample adulterated with 10% (w/v) starch was found to be ~160% of the original value of 8.01E . Also, it was found that the change in the concentration of starch and detergent in milk samples changes the overall impedance of the sensor remarkably. The measured impedance values were inversely proportional to the concentration of detergent and directly proportional to the concentration of starch in the model milk samples. The observed trend is explained and highlights the selectivity and sensitivity of the device. The device requires only 0.2 mL of the sample and gives response within 10 s. The real and simulated data were fitted in an ac equivalent circuit model of the device operation. Autors: Rathin Gupta;Shikha Wadhwa;Ashish Mathur;Ashwani Kumar Dubey; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 6050 - 6055 Publisher: IEEE
» Designing Optimal Interlink Patterns to Maximize Robustness of Interdependent Networks Against Cascading Failures
 Abstract:In this paper, we consider the optimal design of interlinks for an interdependent system of networks. In contrast to existing literature, we explicitly exploit the information of intra-layer node degrees to design interdependent structures such that their robustness against cascading failures, triggered by randomized attacks, is maximized. Utilizing percolation theory-based system equations relating the robustness of the network to its degree sequence, we characterize the optimal design for the one-to-one structure, with complete interdependence and partial interdependence, under randomized attack. We also extend our study to the one-to-many interdependence structure and the targeted attack model. The theoretically derived optimal interdependence structures have been verified using simulations on scale-free networks. Autors: Srinjoy Chattopadhyay;Huaiyu Dai;Do Young Eun;Seyyedali Hosseinalipour; Appeared in: IEEE Transactions on Communications Publication date: Sep 2017, volume: 65, issue:9, pages: 3847 - 3862 Publisher: IEEE
» Detecting Stress Based on Social Interactions in Social Networks
 Abstract:Psychological stress is threatening people’s health. It is non-trivial to detect stress timely for proactive care. With the popularity of social media, people are used to sharing their daily activities and interacting with friends on social media platforms, making it feasible to leverage online social network data for stress detection. In this paper, we find that users stress state is closely related to that of his/her friends in social media, and we employ a large-scale dataset from real-world social platforms to systematically study the correlation of users’ stress states and social interactions. We first define a set of stress-related textual, visual, and social attributes from various aspects, and then propose a novel hybrid model - a factor graph model combined with Convolutional Neural Network to leverage tweet content and social interaction information for stress detection. Experimental results show that the proposed model can improve the detection performance by 6-9 percent in F1-score. By further analyzing the social interaction data, we also discover several intriguing phenomena, i.e., the number of social structures of sparse connections (i.e., with no delta connections) of stressed users is around 14 percent higher than that of non-stressed users, indicating that the social structure of stressed users’ friends tend to be less connected and less complicated than that of non-stressed users. Autors: Huijie Lin;Jia Jia;Jiezhong Qiu;Yongfeng Zhang;Guangyao Shen;Lexing Xie;Jie Tang;Ling Feng;Tat-Seng Chua; Appeared in: IEEE Transactions on Knowledge and Data Engineering Publication date: Sep 2017, volume: 29, issue:9, pages: 1820 - 1833 Publisher: IEEE
» Detection of Motor Impairment in Parkinson's Disease Via Mobile Touchscreen Typing
 Abstract:Mobile technology is opening a wide range of opportunities for transforming the standard of care for chronic disorders. Using smartphones as tools for longitudinally tracking symptoms could enable personalization of drug regimens and improve patient monitoring. Parkinson's disease (PD) is an ideal candidate for these tools. At present, evaluation of PD signs requires trained experts to quantify motor impairment in the clinic, limiting the frequency and quality of the information available for understanding the status and progression of the disease. Mobile technology can help clinical decision making by completing the information of motor status between hospital visits. This paper presents an algorithm to detect PD by analyzing the typing activity on smartphones independently of the content of the typed text. We propose a set of touchscreen typing features based on a covariance, skewness, and kurtosis analysis of the timing information of the data to capture PD motor signs. We tested these features, both independently and in a multivariate framework, in a population of 21 PD and 23 control subjects, achieving a sensitivity/specificity of for the best performing feature and for the best multivariate method. The results of the alternating finger-tapping, an established motor test, measured in our cohort are . This paper contributes to the development of a home-based, high-compliance, and high-frequency PD motor test by analysis of routine typing on touchscreens. Autors: Teresa Arroyo-Gallego;María Jesus Ledesma-Carbayo;Álvaro Sánchez-Ferro;Ian Butterworth;Carlos S. Mendoza;Michele Matarazzo;Paloma Montero;Roberto López-Blanco;Verónica Puertas-Martín;Rocío Trincado;Luc Appeared in: IEEE Transactions on Biomedical Engineering Publication date: Sep 2017, volume: 64, issue:9, pages: 1994 - 2002 Publisher: IEEE
» Deterioration of R-Wave Detection in Pathology and Noise: A Comprehensive Analysis Using Simultaneous Truth and Performance Level Estimation
 Abstract:Objective: For long-term electrocardiography (ECG) recordings, accurate R-wave detection is essential. Several algorithms have been proposed but not yet compared on large, noisy, or pathological data, since manual ground-truth establishment is impossible on such large data. Methods: We apply the simultaneous truth and performance level estimation (STAPLE) method to ECG signals comparing nine R-wave detectors: Pan and Tompkins (1985), Chernenko (2007), Arzeno et al. (2008), Manikandan et al. (2012), Lentini et al. (2013), Sartor et al. (2014), Liu et al. (2014), Arteaga-Falconi et al. (2015), and Khamis et al. (2016). Experiments are performed on the MIT-BIH database, TELE database, PTB database, and 24/7 Holter recordings of 60 multimorbid subjects. Results: Existing approaches on R-wave detection perform excellently on healthy subjects (F-measure above 99% for most methods), but performance drops to a range of F = 90.10% (Khamis et al.) to F = 30.10% (Chernenko) when analyzing the 37 million R-waves of multimorbid subjects. STAPLE improves existing approaches (ΔF = 0.04 for the MIT-BIH database and ΔF = 0.95 for the TELE database) and yields a relative (not absolute) scale to compare algorithms’ performances. Conclusion: More robust R-wave detection methods or flexible combinations are required to analyze continuous data captured from pathological subjects or that is recorded with dropouts and noise. Significance: STAPLE algorithm has been adopted from image to signal analysis to compare algori- hms on large, incomplete, and noisy data without manual ground truth. Existing approaches on R-wave detection weakly perform on such data. Autors: Muhammad Kashif;Stephan M. Jonas;Thomas M. Deserno; Appeared in: IEEE Transactions on Biomedical Engineering Publication date: Sep 2017, volume: 64, issue:9, pages: 2163 - 2175 Publisher: IEEE
» Determination of Nash Equilibrium Based on Plausible Attack-Defense Dynamics
 Abstract:In the critical infrastructure domain, there exist two distinct players, i.e., attackers and defenders, with contradictory strategies to achieve their winnings. This paper proposes a game-theoretic approach to capture the plausible attack-defense dynamics for power transmission grids in a controlled environment. The stratagems of attackers and defenders can be modeled with unique attributes of their motives and emergency responses. The behaviors of attackers include observation and disruptive actions that can disturb operation while defenders can establish multiple levels of defense with remedial actions for risk mitigation. With an assumption of complete information, the defenders can minimize expected loss of load and generator tripping with load generation adjustment based on current conditions. The attackers, which represent the other force, can maximize their payoff by deploying persistent agents to target on the specific points within a power operation network. The boundary between these two, referred as subgame perfect Nash equilibrium, is proposed in the dynamic game model. This model initiates an original infinite game tree that is converted into a finite structure, which is solved using a backward induction approach with multiple scenario validations. Autors: Chong Wang;Yunhe Hou;Chee-Wooi Ten; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3670 - 3680 Publisher: IEEE
» Determining the Convergence of Synchronous Measurements for Embedded Industrial Applications
 Abstract:One technique which may be employed in certain types of sensing application is the phase-sensitive or lock-in method. Since this method essentially trades off longer measurement time for a greater accuracy, it is sometimes necessary to capture samples over a long time period to ensure sufficient stability in the calculated parameter estimate. This may adversely affect safety-critical systems, and some method of determining the relative stability of the measured parameter is needed to permit this useful approach to be more widely employed. In this paper, we propose and evaluate a novel entropy-based method for ascertaining stability. The contributions of this paper are to first highlight the need for a convergence measure which is reliable, automatic, and easily computed; second, we propose one such measure, and place it on a theoretical footing; finally, we give results both with simulated Gaussian noise having a typical sensor power spectrum, as well as experimental results using the type of optical sensor which would benefit from the proposed method. It is demonstrated that this approach produces a reliable asymptotic figure for convergence, both under simulated noise conditions as well as with real measurements in the field. Autors: John Leis;David Buttsworth; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7392 - 7398 Publisher: IEEE
» Deterministic Methodology for Electrical Simulation of BTI Induced Pulse Broadening
 Abstract:This paper presents an analysis of the bias temperature instability (BTI) induced pulse broadening of single event transients (SETs) in inverter chains. A novel deterministic simulation methodology for BTI, using the trapping/de-trapping framework, is proposed and implemented in a commercial SPICE tool. The developed simulator properly predicts the possibility that an SET pulse may suffer propagation-induced pulse broadening (PIPB). The PIPB was analyzed in terms of supply voltage and input signal frequency. The simulations results are in agreement with experimental results from the literature. Autors: Gabriela Firpo Furtado;Thiago H. Both;Michele Vieira;Gilson I. Wirth; Appeared in: IEEE Transactions on Device and Materials Reliability Publication date: Sep 2017, volume: 17, issue:3, pages: 507 - 513 Publisher: IEEE
» Development of a 1 kW direct methanol fuel cell system [News from Japan]
 Abstract:Global warming is a matter of primary concern in the world, and therefore suppression of CO2 emission is an urgent task. It follows that mass consumption of petroleum, coal, and natural gas must be reduced, and therefore development of renewable energy sources such as wind power, solar power, and fuel cells, with less CO2 emission, is necessary. Autors: Y. Ohki; Appeared in: IEEE Electrical Insulation Magazine Publication date: Sep 2017, volume: 33, issue:5, pages: 52 - 55 Publisher: IEEE
» Development of a Mechanical Scanning Device With High-Frequency Ultrasound Transducer for Ultrasonic Capsule Endoscopy
 Abstract:Wireless capsule endoscopy has opened a new era by enabling remote diagnostic assessment of the gastrointestinal tract in a painless procedure. Video capsule endoscopy is currently commercially available worldwide. However, it is limited to visualization of superficial tissue. Ultrasound (US) imaging is a complementary solution as it is capable of acquiring transmural information from the tissue wall. This paper presents a mechanical scanning device incorporating a high-frequency transducer specifically as a proof of concept for US capsule endoscopy (USCE), providing information that may usefully assist future research. A rotary solenoid-coil-based motor was employed to rotate the US transducer with sectional electronic control. A set of gears was used to convert the sectional rotation to circular rotation. A single-element focused US transducer with 39-MHz center frequency was used for high-resolution US imaging, connected to an imaging platform for pulse generation and image processing. Key parameters of US imaging for USCE applications were evaluated. Wire phantom imaging and tissue phantom imaging have been conducted to evaluate the performance of the proposed method. A porcine small intestine specimen was also used for imaging evaluation in vitro. Test results demonstrate that the proposed device and rotation mechanism are able to offer good image resolution () of the lumen wall, and they, therefore, offer a viable basis for the fabrication of a USCE device. Autors: Xingying Wang;Vipin Seetohul;Ruimin Chen;Zhiqiang Zhang;Ming Qian;Zhehao Shi;Ge Yang;Peitian Mu;Congzhi Wang;Zhihong Huang;Qifa Zhou;Hairong Zheng;Sandy Cochran;Weibao Qiu; Appeared in: IEEE Transactions on Medical Imaging Publication date: Sep 2017, volume: 36, issue:9, pages: 1922 - 1929 Publisher: IEEE
» Development of a Paper-Based Plasmonic Test Strip for Visual Detection of Methiocarb Insecticide
 Abstract:This paper describes a simple and low-cost test strip for on-site monitoring of methiocarb insecticide. Hydrophilic filter paper soaked in agarose solution was bounded by hydrophobic solid wax and then was coated with unmodified gold nanoparticles (AuNPs). AuNPs aggregation caused by methiocarb served as colorimetric response. We demonstrated detection capability of methiocarb both in solution- and substrate-based sensor. A good linear relationship was obtained between the colorimetric response and the concentration of methiocarb ranging from 20 to 80 ng mL with a limit of detection of 5 ng mL. Excellent selectivity toward methiocarb was observed among various pesticides and cationic and anionic ions. Furthermore, the proposed assay could successfully detect methiocarb in paddy and tap water with satisfactory results. It would be of interest for use as rapid, portable, and technically simple test strip in water quality monitoring. Autors: Aliakbar Mohammadi;Forough Ghasemi;Mohammad Reza Hormozi-Nezhad; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 6044 - 6049 Publisher: IEEE
» Development of Cnoidal Waves in Positively Charged Dusty Plasmas
 Abstract:The dust-acoustic nonlinear periodic (cnoidal) waves are investigated in a positively charged dusty plasma that interacts with streaming electrons and ions. Different nonlinear evolution equations are derived using the reductive perturbation method, and their cnoidal wave solutions are obtained. The dependence of the dust-acoustic speed and the streaming densities of the ions and electrons on the cnoidal wave profiles are examined. The present model may be of interest to recognize the nonlinear waves in the magnetosphere of Jupiter. Autors: R. E. Tolba;W. M. Moslem;A. A. Elsadany;N. A. El-Bedwehy;S. K. El-Labany; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2552 - 2560 Publisher: IEEE
» Development of Low $\beta$ Single-Spoke Resonators for the Front End of the Proton Improvement Plan-II at Fermilab
 Abstract:A total of ten jacketed single-spoke resonators type 1 (SSR1) have been fabricated for Fermilab’ injection experiment (PIP2IT). PIP2IT is a test bed for Fermilab’s future accelerator named proton improvement plan II that is currently under development. SSR1 cavities operate at 325 MHz to accelerate a proton beam at a relative (to speed of light) velocity (). In this paper, we present Fermilab’s experience in developing those spoke resonators starting from the design and analysis phase, to fabrication and extensive testing to qualify cavities for cryomodule assembly. Autors: Mohamed H. Awida;Donato Passarelli;Paolo Berrutti;Ivan Gonin;Sergei Kazakov;Timergali Khabiboulline;Jeremiah Holzabauer;Thomas Nicol;Joseph Ozelis;Mattia Parise;Yuriy Pischalnikov;Oleg Pronitchev;Leonardo Ristori;Gennady Romanov;Allan Rowe;Warren Sch Appeared in: IEEE Transactions on Nuclear Science Publication date: Sep 2017, volume: 64, issue:9, pages: 2450 - 2464 Publisher: IEEE
» Device Instability of ReRAM and a Novel Reference Cell Design for Wide Temperature Range Operation
 Abstract:This letter addresses two difficult challenges for transition metal oxide resistive random access memories (ReRAMs)—sensitivity to operation temperature and random fluctuation of resistance value. A careful study of a WOx ReRAM array reveals that these devices are unstable and their read currents fluctuate with time due to random telegraph noise and structure relaxation. Consequently, even after careful programming, the current distribution can broaden with time and tail bit population grows. Furthermore, ReRAM state is sensitive to temperature and a reference cell made of the same device material must be used. Thus, although the broadening of read current distribution may be tolerated by creating a larger RESET/SET memory window, the current fluctuation still makes it impossible to predict the output of the reference cell, leading to array malfunction. This letter investigates the current (resistance) instability in detail and proposes a reference array with a novel trimming method that can stabilize the reference current level. The proposed reference array has very good dc stress reliability as well as wide-range temperature tracking performance from −40 °C to 85 °C. Autors: Y. H. Lin;Y. Y. Lin;F. M. Lee;Y. H. Ho;K. C. Hsu;M. H. Lee;D. Y. Lee;K. H. Chiang;C. C. Yang;C. H. Li;S. W. Wu;C. Y. Lei;C. M. Lin;C. J. Chen;K. H. Chen;H. L. Lung;K. C. Wang;T. Y. Tseng;C. Y. Lu; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1224 - 1227 Publisher: IEEE
» Dictionary-Based Principal Component Analysis for Ground Moving Target Indication by Synthetic Aperture Radar
 Abstract:This letter addresses an efficient algorithm for ground moving target detection and estimation of motion parameters by synthetic aperture radar (SAR). The proposed method outperforms the conventional robust principal component analysis (RPCA)–based ground moving target indication (GMTI) methods that were proposed in the literature. The ability to estimate the radial and along-track velocities of ground moving targets is provided. The rank constraint in the conventional RPCA problem will be automatically relaxed by employing a dictionary matrix for clutter representation. Thus, the new optimization problem will be solved easier with lower degrees of freedom. Furthermore, this dictionary helps to suppress the clutter of higher Doppler frequencies in case of wind blowing scenarios and intrinsic clutter motion modeling. By employing another dictionary matrix for all possible moving targets with different location and velocity, each solution of the optimization problem will be reasonable as it corresponds to a moving target. Although, the two dictionary matrices impose extra computational burden, this load will be prepared prior to other GMTI processing by the information of the SAR system and scenario parameters. Moreover, the algorithm is proposed for the single-channel SAR configurations and has lower computational load than the conventional RPCA-GMTI methods that have to process the recorded data of multichannel systems. Numerical and experimental results are used to evaluate the performance of the proposed method and validate the theoretical discussions. Autors: Amir Hosein Oveis;Mohammad Ali Sebt; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1594 - 1598 Publisher: IEEE
» Dielectric Inversion of Lunar PSR Media with Topographic Mapping and Comment on “Quantification of Water Ice in the Hermite-A Crater of the Lunar North Pole”
 Abstract:Dielectric inversion of lunar permanently shadowed region (PSR) of moon poles has been studied for estimation of possible water–ice content. The Campbell model was directly applied to mini-SAR data for inversion on the Hermite-A crater region. However, this letter presents quantitative analysis that the lunar surface topography, i.e., surface roughness and slopes, and underlying dielectric media, and so on, can significantly affect this inversion. The model is actually degenerated into a half-space model without topographic account. This letter presents a two-layer model of Kirchhoff-approximation surface/small perturbation approximation subsurface to take account of all these topographic factors for PSR dielectric inversion. Autors: Niutao Liu;Hongxia Ye;Ya-Qiu Jin; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1444 - 1448 Publisher: IEEE
» Differential Protection in Low-Voltage Buses: An Exploration of Principles and Models
 Abstract:Current-differential principles are well known and commonly used for the protection of medium and large transformers, large motors, medium-voltage (MV) generators, MV and high-voltage buses, and any type of important power equipment with measurable input and output currents. However, is it practical to protect low-voltage (LV) distribution buses using differential protection? This article describes bus differential protection principles as well as interlocking principles for overcurrent protection. We discuss specific issues in applying differential protection in LV systems. Additionally, we present a concept of partial differential (PD) protection, which can be used in conjunction with zone-selective interlocking (ZSI) or as backup to traditional overcurrent protection to achieve high-speed and selective fault clearance. Additional concepts for the implementation of bus differential protection using networked data in LV systems are introduced. Autors: Lubomir Sevov;Marcelo Valdes; Appeared in: IEEE Industry Applications Magazine Publication date: Sep 2017, volume: 23, issue:5, pages: 28 - 39 Publisher: IEEE
 Abstract:Quadrature spatial modulation (QSM) is a recent multiple input multiple output transmission scheme that attracted significant research interest. QSM expands the spatial constellation diagram of spatial modulation (SM) to enhance the overall spectral efficiency while retaining all SM inherent advantages. In this paper, differential QSM (DQSM) is proposed to alleviate the requirement of channel knowledge at the receiver side. Receiver channel knowledge is crucial in QSM as part of the data are encoded in the Euclidean difference among different channel paths. Time dimension and orthogonal in-phase and quadrature spatial dimensions of QSM are exploited to facilitate differential modulation and demodulation while maintaining single RF-chain transmitters. In addition, a systematic design of the transmission blocks is provided for arbitrary number of transmit and receive antennas. Besides, a novel analytical framework for analyzing the performance of DQSM is derived and shown to predict accurate performance for differential SM and differential space shift keying systems as well. Analytical and simulation results are shown to match closely over a wide range of signal to noise ratios and for different system parameters. Autors: Raed Mesleh;Saud Althunibat;Abdelhamid Younis; Appeared in: IEEE Transactions on Communications Publication date: Sep 2017, volume: 65, issue:9, pages: 3810 - 3817 Publisher: IEEE
» Digital Integrated Circuits on an E-Mode GaN Power HEMT Platform
 Abstract:GaN-based digital integrated circuits (ICs) are realized on a 6-inch GaN-on-Si power high-electron-mobility transistor (HEMT) platform by monolithic integration of enhancement/depletion-mode HEMTs using a 0.5- gate technology. A direct-coupled FET logic inverter and a 101-stage ring oscillator are fabricated and characterized. The inverter exhibits a large input voltage swing, wide noise margin, and high temperature stability, while the ring oscillator features a small propagation delay of 0.1 ns/stage under a supply voltage of 4 V. These digital ICs can operate properly up to at least 200 °C and show great potential for GaN smart power IC applications. Autors: Gaofei Tang;Alex M. H. Kwan;Roy K. Y. Wong;Jiacheng Lei;R. Y. Su;F. W. Yao;Y. M. Lin;J. L. Yu;Tom Tsai;H. C. Tuan;Alexander Kalnitsky;Kevin J. Chen; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1282 - 1285 Publisher: IEEE
» Dimensionality Reduction by Spatial–Spectral Preservation in Selected Bands
 Abstract:Dimensionality reduction (DR) has attracted extensive attention since it provides discriminative information of hyperspectral images (HSI) and reduces the computational burden. Though DR has gained rapid development in recent years, it is difficult to achieve higher classification accuracy while preserving the relevant original information of the spectral bands. To relieve this limitation, in this paper, a different DR framework is proposed to perform feature extraction on the selected bands. The proposed method uses determinantal point process to select the representative bands and to preserve the relevant original information of the spectral bands. The performance of classification is further improved by performing multiple Laplacian eigenmaps (LEs) on the selected bands. Different from the traditional LEs, multiple Laplacian matrices in this paper are defined by encoding spatial–spectral proximity on each band. A common low-dimensional representation is generated to capture the joint manifold structure from multiple Laplacian matrices. Experimental results on three real-world HSIs demonstrate that the proposed framework can lead to a significant advancement in HSI classification compared with the state-of-the-art methods. Autors: Xiangtao Zheng;Yuan Yuan;Xiaoqiang Lu; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 5185 - 5197 Publisher: IEEE
» Direct Current Plasma Electron Source for Electric Propulsion Applications Using Atomic and Molecular Propellants
 Abstract:The design and performance of a novel direct current (dc) neutralizer for electric propulsion applications are presented. The neutralizer exploits an discharge to enhance ionization via electron-neutral collisions. Tests are performed with helium, argon, xenon, air, and water vapor as working gases. The – characteristics and extraction parameters are measured for both atomic and molecular gases. The maximum partial power efficiency is 4.2 mA/W in argon, 2.7 mA/W in air, and 2 mA/W in water vapor. The typical utilization factor is below 1 and the power consumption is less than 120 W. A semiempirical model is derived to predict the performance of dc plasma cathodes using atomic gas. A comparison with existing plasma cathodes and conventional LaB6 cathodes is presented, and design optimizations aimed at improving the performance are proposed. Autors: Antonio Gurciullo;Andrea Lucca Fabris;Aaron Knoll; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2472 - 2480 Publisher: IEEE
» Direct Position Estimation of GNSS Receivers: Analyzing main results, architectures, enhancements, and challenges
 Abstract:This article discusses theoretical and practical aspects of direct position estimation (DPE) of global navigation satellite system (GNSS) receivers. DPE is an alternative approach to the well-established positioning method, where time delays and Doppler shifts to the visible satellites are estimated to solve for a geometrical problem to compute the receiver's position. In contrast, DPE infers position directly from the sampled data without intermediate steps. This approach has been seen, both theoretically and experimentally, to substantially increase the receiver's accuracy and reliability. Autors: Pau Closas;Adria Gusi-Amigo; Appeared in: IEEE Signal Processing Magazine Publication date: Sep 2017, volume: 34, issue:5, pages: 72 - 84 Publisher: IEEE
» Directed Information Between Connected Leaky Integrate-and-Fire Neurons
 Abstract:The connectivity structure between neurons is useful for determining how groups of neurons perform tasks. Directed information is a measure that can be used to infer connectivity between neurons using their recorded time series. In this paper, we develop a method of calculating the directed information rate from one neuron to another neuron it is connected to, given a particular neuronal topology. We assume a leaky integrate-and-fire (LIF) neuron model with independent and identically distributed random spike train inputs, which governs how the membrane potential of the output neuron evolves. We use this neuron model to find the dynamics of the resulting output spike train from its membrane potential dynamics, both for when the past of the input neuron is observed and when it is not. We show that an action potential in the LIF model causes a conditional independence of the activity before and after it, and we capture this conditional independence via a Markov model. We use these spike train dynamics to then calculate the directed information between the spike train of the input neuron to the spike train generated by the LIF model. In addition, we show how changing the refractory period of the LIF model affects the directed information, and also how the spike train dynamics are affected by memory constraints, which are commonly imposed in estimators of directed information. Autors: Nima Soltani;Andrea J. Goldsmith; Appeared in: IEEE Transactions on Information Theory Publication date: Sep 2017, volume: 63, issue:9, pages: 5954 - 5967 Publisher: IEEE
» Directional Derivative-Based Transient Stability-Constrained Optimal Power Flow
 Abstract:This paper proposes a novel active power redispatch sequential approach to solve the transient stability-constrained optimal power flow (TSC-OPF) problem for the preventive control of transient stability. Based on an independent transient stability assessment of the power system for a given contingency scenario, two proposed power redispatch constraints are formulated and embedded into a conventional OPF formulation. Since these two new constraints only depend on steady-state variables, the dimension of the resulting TSC-OPF model is similar to that of a conventional OPF model and can be solved by standard optimization methods to perform a nonheuristic active power redispatch. The stabilization process is performed by sequentially solving the optimization and the transient stability problems until a suitable generation dispatch that provides a transiently stable equilibrium point is assessed. The validity and the effectiveness of the proposed method are numerically demonstrated in the WSCC three-machine, nine-bus system and an equivalent model of the Mexican power system. Autors: Alejandro Pizano-Martínez;Claudio R. Fuerte-Esquivel;Enrique Arnoldo Zamora-Cárdenas;José Merced Lozano-García; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3415 - 3426 Publisher: IEEE
» Discrete Multimodal Hashing With Canonical Views for Robust Mobile Landmark Search
 Abstract:Mobile landmark search (MLS) recently receives increasing attention for its great practical values. However, it still remains unsolved due to two important challenges. One is high bandwidth consumption of query transmission, and the other is the huge visual variations of query images sent from mobile devices. In this paper, we propose a novel hashing scheme, named as canonical view based discrete multimodal hashing (CV-DMH), to handle these problems. First, a submodular function is designed to measure visual representativeness and redundancy of a view set. With it, canonical views, which capture key visual appearances of landmark with limited redundancy, are efficiently discovered with an iterative mining strategy. Second, multimodal sparse coding is applied to transform visual features from multiple modalities into an intermediate representation. It can robustly and adaptively characterize visual contents of varied landmark images with certain canonical views. Finally, compact binary codes are learned on intermediate representation within a tailored discrete binary embedding model which preserves visual relations of images measured with canonical views and removes the involved noises. In this part, we develop a new augmented Lagrangian multiplier (ALM) based optimization method to directly solve the discrete binary codes. We can not only explicitly deal with the discrete constraint, but also consider the bit-uncorrelated constraint and balance constraint together. The proposed solution can desirably avoid accumulated quantization errors in conventional optimization method which simply adopts two-step relaxing+rounding' framework. Experiments on real world landmark datasets demonstrate the superior performance of CV-DMH over several state-of-the-art methods. Autors: Lei Zhu;Zi Huang;Xiaobai Liu;Xiangnan He;Jiande Sun;Xiaofang Zhou; Appeared in: IEEE Transactions on Multimedia Publication date: Sep 2017, volume: 19, issue:9, pages: 2066 - 2079 Publisher: IEEE
» Discrete Nonnegative Spectral Clustering
 Abstract:Spectral clustering has been playing a vital role in various research areas. Most traditional spectral clustering algorithms comprise two independent stages (e.g., first learning continuous labels and then rounding the learned labels into discrete ones), which may cause unpredictable deviation of resultant cluster labels from genuine ones, thereby leading to severe information loss and performance degradation. In this work, we study how to achieve discrete clustering as well as reliably generalize to unseen data. We propose a novel spectral clustering scheme which deeply explores cluster label properties, including discreteness, nonnegativity, and discrimination, as well as learns robust out-of-sample prediction functions. Specifically, we explicitly enforce a discrete transformation on the intermediate continuous labels, which leads to a tractable optimization problem with a discrete solution. Besides, we preserve the natural nonnegative characteristic of the clustering labels to enhance the interpretability of the results. Moreover, to further compensate the unreliability of the learned clustering labels, we integrate an adaptive robust module with loss to learn prediction function for grouping unseen data. We also show that the out-of-sample component can inject discriminative knowledge into the learning of cluster labels under certain conditions. Extensive experiments conducted on various data sets have demonstrated the superiority of our proposal as compared to several existing clustering approaches. Autors: Yang Yang;Fumin Shen;Zi Huang;Heng Tao Shen;Xuelong Li; Appeared in: IEEE Transactions on Knowledge and Data Engineering Publication date: Sep 2017, volume: 29, issue:9, pages: 1834 - 1845 Publisher: IEEE

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