###### Accueil » Publications dans le domaines des technologies » 10-2017
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 Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 10-2017 trié par par titre, page: 7
» Grouping-Based TSV Test Architecture for Resistive Open and Bridge Defects in 3-D-ICs
 Résumé:After the 3-D stacking, 3-D-ICs based on through-silicon-vias (TSVs) must be inspected for any TSV defects such as resistive open or bridge defects. In some research studies, several effective testing techniques have been developed such as parallel or serial test architectures, which measure the voltage across a single TSV with a comparator. However, in the current test architectures, hardware overhead and test time are proportional to the number of TSVs. In this paper, we propose a new unified test architecture for screening of TSV defects in 3-D-ICs. Depending on the number of assembled TSVs, the proposed grouping-based test architecture can effectively reduce the cumulative test time and hardware overhead without compromising the test quality. Auteurs: Young-woo Lee;Hyeonchan Lim;Sungho Kang; Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems Date publication: 10.-2017, volume: 36, issue:10, pages: 1759 - 1763 Editeur: IEEE Document complet vers site de l'éditeur
» Growth Goals, Travel Grants, Chapter Awards, and Chapter Events [Chapter News]
 Résumé:Presents information on various APS Society chapters. Auteurs: Ajay K. Poddar; Apparue dans: IEEE Antennas and Propagation Magazine Date publication: 10.-2017, volume: 59, issue:5, pages: 10 - 17 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editor's Introduction: Selected Papers from ACM-BCB 2014
 Résumé: Auteurs: Ümit V. Çatalyürek; Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics Date publication: 10.-2017, volume: 14, issue:5, pages: 1000 - 1001 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial
 Résumé:This Transactions on Microwave Theory and Techniques’ Mini-Special Issue includes ten papers from the 2017 IEEE Radio and Wireless Week (RWW 2017) held in Phoenix, AZ, USA, January 15–18, 2017. The Radio and Wireless Week consists of five related conferences that focus on the intersection between wireless communication theory, systems, circuits, and device technologies: the Radio and Wireless Symposium, the Topical Conference on Power Amplifiers for Wireless and Radio Applications, the Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, the Topical Conference on Wireless Sensors and Sensor Networks, and the Topical Workshop on The Internet of Space. Radio and Wireless Week is thus a multidisciplinary event bringing together innovations that are happening across the broad wireless spectrum. A total of 214 papers were submitted to the RWW 2017 Technical Program Committee, of which 168 papers were accepted for presentation and publication online on the IEEE Xplore website. Together with the technical sessions, four workshops, one special talk on the Internet of Things powered by wireless, a plenary session on 5G hardware and system solutions, a panel session on linearization of power amplifiers for 5G, and a demo track session to show the latest innovative wireless experimental achievements were successfully held. Auteurs: Andrei Grebennikov;Nils Pohl; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 10.-2017, volume: 65, issue:10, pages: 3559 - 3560 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial - Special Section on Emerging Informatics for Risk Hedging and Decision Making in Smart Grids
 Résumé:The aim of this Special Section is to attract and report the latest advances toward the trend of applying advanced informatics techniques resolving complex problems facing power system operation and planning in the new era of smart grids. Special interests are given to the new methods that can handle various tasks of risk hedging and decision making appeared in eleven system operation and planning, though the scope has been slightly expanded to other topical issues in smart grids as well. The accepted eleven high-quality papers represent how the newadvances and solutions toward resolving complex problems facing power system operation and planning can be brought forward by continuously leveraging emerging techniques in the field of data analytics and informatics. It should be highlighted that with the increased penetration of various emerging technologies such as renewables and electric vehicles (EVs), secure and economic system operation and planning deserve continuous research efforts in producing the most up-to-date methods and solutions dealing with issues of diversified natures and complexities in future power grids. Specifically, the covered topics in this Special Section are topical and broad, concerning mainly power system security analysis and electricity market planning and operation under risks and uncertainties, which are briefly summarized. Auteurs: Zhao Xu;Loi Lei Lai;Kit Po Wong;Pierre Pinson;Fangxing Li; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2507 - 2510 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial - Special Section on Systems of Power Converters: Design, Modeling, Control, and Implementation
 Résumé:In this Special Section on Systems of Power Converters: Design, Modeling, Control, and Implementation, we have 11 high-quality papers approved for publication that cover the following three topics. 1) Converter Design and Operation. 2) Subsystem-Level Applications. 3) System-Level Applications. These topics and the corresponding papers are summarized. Auteurs: Wenxin Liu;Josep M. Guerrero;Jang-Mok Kim; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2631 - 2633 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial for Special Section on the 11th International Conference on Intelligent Computing (ICIC)
 Résumé: Auteurs: De-Shuang Huang;Vitoantonio Bevilacqua;M. Michael Gromiha; Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics Date publication: 10.-2017, volume: 14, issue:5, pages: 1104 - 1105 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial Introduction to the Special Issue on Internet of Things and Sensors Technologies for Intelligent Transportation Systems
 Résumé:The degree of modernization of transportation is currently an important criterion for urban development. Progress in communication techniques and networking, together with vehicle localization methods, have become the key enablers of innovative transportation systems. Auteurs: Reza Malekian;Kui Wu;Kris Steenhaut;Ning Ye; Apparue dans: IEEE Transactions on Intelligent Transportation Systems Date publication: 10.-2017, volume: 18, issue:10, pages: 2798 - 2801 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial ISCAS 2016 Special Issue
 Résumé: Auteurs: P. HÄFLIGER;S. CHAKRABARTTY;Z. WANG; Apparue dans: IEEE Transactions on Biomedical Circuits and Systems Date publication: 10.-2017, volume: 11, issue:5, pages: 977 - 978 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial Medical Measurements and Applications: 10 Years of Ideas and Innovation
 Résumé:The interest of industry and academia in medical measurements continues to increase, due to technology advancements that allow new sensors, measurement systems, and methodologies, supporting a wide number of medical applications. Auteurs: Luca De Vito;J. Max Cortner; Apparue dans: IEEE Transactions on Instrumentation and Measurement Date publication: 10.-2017, volume: 66, issue:10, pages: 2502 - 2504 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial Special Issue for Selected Papers from EAPPC/BEAMS/MEGAGAUSS 2016
 Résumé:The joint conference of the 6th Euro-Asian Pulsed Power Conference (EAPPC 2016), the 21st International Conference on High-Power Particle Beams (BEAMS 2016), and the 15th International Conference on Megagauss Magnetic Field Generation and Related Topics (MEGAGAUSS 2016) was held in Estoril, Portugal, on September 18–22, 2016. It was the first time that researchers from these three areas, although closely related, have come together to share their findings following an integrated scientific program. Auteurs: Joshua Leckbee;Fernando Silva;Hong-Je Ryoo;Jianqiang Yuan; Apparue dans: IEEE Transactions on Plasma Science Date publication: 10.-2017, volume: 45, issue:10, pages: 2610 - 2610 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial Special Section on Emerging Informatics for Risk Hedging and Decision Making in Smart Grids
 Résumé: Auteurs: Zhao Xu;Loi Lei Lai;Kit Po Wong;Pierre Pinson;Fangxing Li; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2507 - 2510 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial Special Section on Systems of Power Converters: Design, Modeling, Control, and Implementation
 Résumé: Auteurs: Wenxin Liu;Josep M. Guerrero;Jang-Mok Kim; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2631 - 2633 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial Target and Reverberation Experiment 2013 (TREX13)—Part II
 Résumé: Auteurs: Brian T. Hefner;Dajung Tang; Apparue dans: IEEE Journal of Oceanic Engineering Date publication: 10.-2017, volume: 42, issue:4, pages: 757 - 758 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial: Alternative Computing and Machine Learning for Internet of Things
 Résumé:The impending Internet of Things (IoT) wave is promising to affect every aspect of our daily lives, ranging from smart things to smart buildings, smart cities, and smart environments. A lot of attention has been devoted to the tsunami of data produced by IoT, and the related means of extracting useful actionable information from it, spawning efforts in Big Data processing and machine learning. Yet, all of this does little to address the need for IoT to capture, interpret, and act on this wall of (noisy) information at the right time, at the right place, and in the right form. Conventional computing systems are a poor match to the needs of this emerging massively distributed real-time system. Hence, alternative computing techniques present an attractive alternative, trading off computational resolution for significant gains in quality-of-service energy efficiency and robustness. This observation is based on the conjecture that most applications related to IoT have an inherent error resilience and are evolutionary (that is, learning-based). Alternative computing strategies may be conceived at every level of the design hierarchy, starting from the device level with novel 3-D nonvolatile memory/logic combinations, or at the architectural level by shifting away from the traditional von Neumann architecture to different computing paradigms such as neuromorphic and/or stochastic computation all the way up to the algorithmic and data representation levels. Auteurs: Farshad Firouzi;Bahar Farahani;Andrew B. Kahng;Jan M. Rabaey;Natasha Balac; Apparue dans: IEEE Transactions on Very Large Scale Integration Systems Date publication: 10.-2017, volume: 25, issue:10, pages: 2685 - 2687 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial: Special Collection of Papers Arising From UComms16
 Résumé: Auteurs: John R. Potter;João Alves;Ian F. Akyildiz; Apparue dans: IEEE Journal of Oceanic Engineering Date publication: 10.-2017, volume: 42, issue:4, pages: 754 - 756 Editeur: IEEE Document complet vers site de l'éditeur
» Guest Editorial: Video Over Future Networks
 Résumé: Auteurs: X. Zhu;S. Mao;M. Hassan;H. Hellwagner; Apparue dans: IEEE Transactions on Multimedia Date publication: 10.-2017, volume: 19, issue:10, pages: 2133 - 2135 Editeur: IEEE Document complet vers site de l'éditeur
» Hamilton Paths With Lasting Separation
 Résumé:We determine the asymptotics of the largest cardinality of a set of Hamilton paths in the complete graph with vertex set $[n]$ under the condition that for any two of the paths in the family there is a subpath of length $k$ entirely contained in only one of them and edge-disjoint from the other one. Auteurs: Emanuela Fachini;János Körner; Apparue dans: IEEE Transactions on Information Theory Date publication: 10.-2017, volume: 63, issue:10, pages: 6344 - 6346 Editeur: IEEE Document complet vers site de l'éditeur
» Harbor Water Area Extraction From Pan-Sharpened Remotely Sensed Images Based on the Definition Circle Model
 Résumé:Harbor water area extraction is a key step in nearshore environment pollution surveillance using remote sensing image processing techniques. This letter proposes the definition circle (DC) model of color gradient to describe color fluctuations in harbor water surface areas based on pan-sharpened remote sensing images. The DC model includes two steps: center setting and radius tuning. In the center setting process, labeled training set pixels are selected in the red, green, and blue color space. Then, center setting is completed in the hue, saturation, and intensity color space using the perceptron model. In the radius tuning process, positive and negative sample pixels are used to tune the radius value. After these two steps, the DC model can describe the color gradient of a water surface area and provide accurate harbor water area extraction. A series of experiments shows that the proposed DC model is robust and performs better than other extraction methods based on pan-sharpened remote sensing images. Auteurs: Yin Zhuang;Penglin Wang;Yiding Yang;Hao Shi;He Chen;Fukun Bi; Apparue dans: IEEE Geoscience and Remote Sensing Letters Date publication: 10.-2017, volume: 14, issue:10, pages: 1690 - 1694 Editeur: IEEE Document complet vers site de l'éditeur
» Hardware Trojan Detection Through Chip-Free Electromagnetic Side-Channel Statistical Analysis
 Résumé:The hardware Trojan (HT) has become a major threat for the integrated circuit (IC) industry and supply chain, and has motivated numerous developments of Trojan detection schemes. Although the side-channel method is the most promising one, nearly all of the side-channel methods require fabricated golden chips, which are very difficult to obtain in reality. In this paper, we propose a novel strategy for HT detection using electromagnetic side-channel-based spectrum modeling and analyzing. We utilize the design data at early stage of the IC lifecycle, and the generated spectrum can serve as the golden reference, and thus we do not need the fabricated golden chips anymore. Another very important feature is that our method is immune to the process variation theoretically. Experimental results on selected Advanced Encryption Standard benchmark circuits on FPGA show that our proposed method can effectively detect Trojans even with very small traces. Auteurs: Jiaji He;Yiqiang Zhao;Xiaolong Guo;Yier Jin; Apparue dans: IEEE Transactions on Very Large Scale Integration Systems Date publication: 10.-2017, volume: 25, issue:10, pages: 2939 - 2948 Editeur: IEEE Document complet vers site de l'éditeur
» Head and Media Design for Curvature Reduction in Heat-Assisted Magnetic Recording
 Résumé:Recording curvature in magnetic data-storage technology has long been one of the significant challenges impacting on recording performance. Despite curvature occurrence in the conventional recording techniques such as perpendicular magnetic recording (PMR), heat-assisted magnetic recording (HAMR) is demonstrated to induce much more severe curvature than PMR. HAMR curvature could cause poor bit error rate and limits the maximum areal density capacity. Here we have theoretically predicted and demonstrated various approaches for curvature reduction from the aspect of either altering the near-field transducer head design or recording medium design. Optical and thermal modeling have indicated that by utilizing a crown-shape peg to change the thermal source profile and compensate for thermal expansion and rounding effect, it could potentially improve curvature figure of merit (FOM) and achieve curvature reduction by ~45%. In terms of the recording media design, by altering the heat sink and internal layer media material or geometry, it could also achieve curvature cancellation of ~40% with increased thermal gradient. The combined approach from both HAMR head and media perspectives with balanced recording FOMs, could potentially realize significant curvature reduction to be of similar or better recording curvature level to PMR. Auteurs: Zhongyang Li;Weibin Chen;Chris Rea;Martin G. Blaber;Nan Zhou;Hua Zhou;Huaqing Yin; Apparue dans: IEEE Transactions on Magnetics Date publication: 10.-2017, volume: 53, issue:10, pages: 1 - 4 Editeur: IEEE Document complet vers site de l'éditeur
» Heat Transfer in Filamentary RRAM Devices
 Résumé:We study the heat transport in filamentary resistive random access memory nanosized devices by comparing the accurate results of COMSOL Multiphysics modeling with simplified analytical models for two complementary mechanisms: one neglecting the radial heat transfer from the filament to the insulating host, while the other describing the radial transport through the dielectric in the absence of the filament heat transfer. For the former, we find that the earlier assumed simplification of the electrodes being ideal heat conductors is insufficient; a more adequate approximation is derived where the heat transport is determined by the adjacent proximities of the filament tips in the electrodes. We find that both complementary mechanisms overestimate the maximum temperature yet offering acceptable results. However, the two in parallel provide a better analytical approximation. In addition, we show that the Wiedemann–Franz–Lorenz law helps the analysis when the Lorenz parameter is chosen from the actual data. We present an approximate relation between device SET voltage and SET temperature possessing a high degree of universality and predicting that filament materials with low Lorenz numbers can be good candidates for the future low set voltage devices. Auteurs: Dipesh Niraula;Victor G. Karpov; Apparue dans: IEEE Transactions on Electron Devices Date publication: 10.-2017, volume: 64, issue:10, pages: 4106 - 4113 Editeur: IEEE Document complet vers site de l'éditeur
» Hiding the Rumor Source
» Hierarchical Distributed Scheme for Demand Estimation and Power Reallocation in a Future Power Grid
 Résumé:The classical power allocation/reallocation faces difficult challenges in a future power grid with a great many distributed generators and fast power fluctuations caused by high percentage of renewable energy. To perform power reallocation fast in a future power grid with a large number of participants and disturbances, a hierarchical distributed scheme based on a partition framework is proposed. In the proposed scheme, the power grid is naturally partitioned into a certain number of regions, and the total energy demand in the power grid with disturbances is automatically estimated rather than given in advance. Besides, the centralized local optimizations in regions and the distributed global optimization among regions are coupled to solve the power reallocation problem, in which each region performs as a single agent. Thus, the agents in the proposed scheme are much fewer than the purely distributed ones, hence the communication load is greatly relieved and the reallocation process is significantly simplified. Effectiveness of the proposed scheme is verified by the cases. Auteurs: Xiong Hu;Hong Zhou;Zhi-Wei Liu;Xinghuo Yu;Chaojie Li; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2279 - 2290 Editeur: IEEE Document complet vers site de l'éditeur
» Hierarchical Place Recognition for Topological Mapping
 Résumé:In this paper, we propose a novel appearance-based approach for topological mapping based on a hierarchical decomposition of the environment. In our map, images with similar visual properties are grouped together in nodes, which are represented by means of an average global descriptor and an index of binary features based on a bag-of-words online approach. Each image is represented by means of a global descriptor and a set of local features, and this information is used in a two-level loop closure approach, where first global descriptors are employed to obtain the most likely nodes of the map and then binary image features are used to retrieve the most likely images inside these nodes. This hierarchical scheme enables us to reduce the search space when recognizing places, maintaining high accuracy when creating a map. Our approach is validated using several public datasets and compared against several state-of-the-art techniques. The accuracy and the sparsity of the generated maps are also discussed. Auteurs: Emilio Garcia-Fidalgo;Alberto Ortiz; Apparue dans: IEEE Transactions on Robotics Date publication: 10.-2017, volume: 33, issue:5, pages: 1061 - 1074 Editeur: IEEE Document complet vers site de l'éditeur
» High Mechanical Strength Thin HIT Solar Cells With Graphene Back Contact
 Résumé:It is widely known that thinner Si substrate is the main path for lower $/Watt HIT solar cells due to improved charge collection, reduced bulk and total recombination, and fewer raw material consumption (Panasonic, IEEE Journal of Photovoltaics., vol. 4, p. 96, 2014). Nonetheless, thin substrates always lead to low mechanical stability and wafer breaking. In this work, spray coated 50 nm graphene layer is used as the back electrode in Si HIT solar cells to enhance the mechanical stability. With the incorporation of graphene as the back electrode in Si HIT solar cells, remarkable improvements in substrate mechanical strength are achieved. Without the degradation of HIT solar cell efficiency, hardness is increased nearly twofold from 902 to 1747 HV. The Young's modulus is increased from 93.9 to 140.1 GPa while the ultimate tensile strength is increased from 96.71 to 273.68 MPa. Low-cost chemical exfoliation method and low-temperature (150 °C) spray coating method have been employed for the preparation and deposition of thin graphene back electrode, respectively. In addition, unlike the graphene as the substitute for ITO in OLED applications, the graphene strengthened thin silicon substrate technology here imposes no additional constraint on the graphene electrode transparency since it is used as a back electrode. We, thereby, believe that our proposed method is effective for attaining higher efficiency and lower$/Watt thin Si HIT solar cell technology with enhanced mechanical strength. Auteurs: Albert S. Lin;Parag Parashar;Chih-Chieh Yang;Wei-Ming Huang;Yi-Wen Huang;Ding-Rung Jian;Ming-Hsuan Kao;Shi-Wei Chen;Chang-Hong Shen;Jia-Min Shieh;Tseung Yuen Tseng; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 9 Editeur: IEEE Document complet vers site de l'éditeur
» High Performance CuO Nanorectangles-Based Room Temperature Flexible NH3 Sensor
 Résumé:Here, we report the fabrication of a flexible room temperature ammonia gas sensor using surfactant-free hydrothermally synthesized copper oxide (CuO) nanorectangles. The structural analysis revealed that the CuO nanorectangles possessed monoclinic structure with an average length and breadth of 950 and 450 nm, respectively. The specific surface area of CuO nanorectangles was determined to be 29 m2/g. The sensor was fabricated on a flexible polyethylene terephthalate substrate by screen printing technique. The room temperature ammonia sensing measurement exhibited significant response down to 5 ppm of ammonia with a quick response time of 90 s and recovered to baseline within 120 s. Maximum response of 0.99 was recorded for 100 ppm of ammonia. The rate constants for adsorption and desorption were estimated for 6.5 to 100 ppm of ammonia from the exponential conductance changes during response and recovery process. The sensor showed appreciable stability and reproducibility of the sensing performance over a period of three months. The fabricated flexible sensor demonstrated its ability to detect a wide range of ammonia concentrations at room temperature irrespective of the mechanical deformations applied. Thus, the fabricated sensor is promising and can be suitably employed for practical applications in environments where efficient gas sensing is vitally important. Auteurs: Bhuvaneshwari Sakthivel;Libu Manjakkal;Gopalakrishnan Nammalvar; Apparue dans: IEEE Sensors Journal Date publication: 10.-2017, volume: 17, issue:20, pages: 6529 - 6536 Editeur: IEEE Document complet vers site de l'éditeur
» High Selectivity Wideband Balanced Filters With Multiple Transmission Zeros
 Résumé:Two novel high selectivity wideband balanced filters based on open/shorted stubs with multiple transmission zeros are proposed in this brief. Two and four transmission zeros near each passband for the differential mode (DM) can be easily achieved for two balanced filters. In addition, the common mode can be suppressed with three and five transmission zeros with an insertion loss greater than 15 dB/20 dB over a wide frequency band. Two prototypes with 3-dB fractional bandwidths of 67.6% and 37.8% for the DM with an insertion loss greater than 15 dB (7.0–12.7 GHz) are designed and fabricated. A good agreement can be observed between the measured results and the theoretical expectations. Auteurs: Wenjie Feng;Xin Gao;Wenquan Che;Wanchen Yang;Quan Xue; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 10.-2017, volume: 64, issue:10, pages: 1182 - 1186 Editeur: IEEE Document complet vers site de l'éditeur
» High-Accuracy Impedance Detection to Improve Transient Stability in Microgrids
» High-Brightness Multimode Fiber Lasers for Resonant Pumping
 Résumé:We present multimode fiber lasers for tandem pumping of high power Er-, Tm-, and Yb-doped lasers. These pump sources are based on especially developed multimode Er- and Yb-doped double-clad fibers. Er-doped lasers with record pump conversion efficiency >48% at 1565 nm and more than 41% at 1535 and 1590 nm were realized. Yb-doped fiber laser at 1020 nm with record high 85% pump conversion efficiency was demonstrated. Also, we propose novel design of compact and cost-effective multimode laser scheme. The potential of power scaling of proposed lasers to the 1–10-kW level and their advantages as resonant pump sources are discussed. Auteurs: Leonid V. Kotov;Svetlana S. Aleshkina;Maksim M. Khudyakov;Mikhail M. Bubnov;Oleg I. Medvedkov;Denis S. Lipatov;Aleksei N. Guryanov;Mikhail M. Likhachev; Apparue dans: Journal of Lightwave Technology Date publication: 10.-2017, volume: 35, issue:20, pages: 4540 - 4546 Editeur: IEEE Document complet vers site de l'éditeur
» High-Level Energy Estimation for Submicrometric TSV Arrays
 Résumé:The 3-D integration using through silicon vias (TSVs) is one of the most promising approaches to overcome the interconnect delay problem of current CMOS technologies. Nevertheless, the TSV energy consumption is not negligible due to the high capacitive coupling. This paper presents an abstract and yet accurate model to estimate the pattern-dependent energy consumption in arrays of TSVs; it is the first high-level model including the effects of the voltage-dependent metal–oxide–semiconductor (MOS) capacitances surrounding each TSV and a possible temporal misalignment between the input signals. We propose a regression method to estimate the dynamic size of the coupling capacitances as a function of the bit probabilities. Experimental results for real and synthetic data streams, a submicrometer 9-bit TSV array and a 65-nm technology show that the presented TSV energy model exhibits a maximum error of 5.53%, while the traditional high-level model shows errors of up to 79.77%. Furthermore, the new insights provided by our model reveal a possibility to easily boost the efficiency of existing low-power codes for TSV structures by over 10% without affecting the coding efficiency for the planar metal wires or the encoder complexity. Auteurs: Lennart Bamberg;Alberto Garcia-Ortiz; Apparue dans: IEEE Transactions on Very Large Scale Integration Systems Date publication: 10.-2017, volume: 25, issue:10, pages: 2856 - 2866 Editeur: IEEE Document complet vers site de l'éditeur
» High-Order Dual-Band Superconducting Bandpass Filter With Controllable Bandwidths and Multitransmission Zeros
 Résumé:In this paper, a compact dual-mode hairpin ring resonator (HRR) with two controllable resonances is proposed to design high-order dual-band high-temperature superconducting (HTS) bandpass filters. Its noncoupled dual-mode resonant characteristics and the mechanism for inherent transmission zero (TZ) production are studied. Moreover, a general dual-path coupling scheme is introduced for high-order coupling realization and applied to the third-order and eighth-order dual-band filter design. Also, two coupling structures for the adjacent HRRs with different orientations are proposed to excite TZs between the passbands for high selectivity. Besides, dual-parallel input–output feeding structure is adopted to tune the external quality factors of the dual-mode HRR individually so that the two passband are realized easily using high-order structure. For demonstration, an eighth-order dual-band HTS filter both operating at 1.9 and 2.6 GHz for mobile communications application are designed and analyzed. Compared with the third-order one, the selectivity of the eighth-order filter has at least 4.2 times improvement and five TZs are produced for high band-edge selectivity. Finally, the eighth-order dual-band filter is fabricated on MgO substrate with YBCO thin films. Measured results agree well with the simulations and show the excellent performance with 0.12-dB minimum insertion loss and better than −75-dB rejection level up to 5 GHz. In addition, the nonlinear characteristics of the fabricated HTS filter is observed by experiment, which shows the temperature dependence of filter center frequency performance and microwave insertion loss. Auteurs: Haiwen Liu;Baoping Ren;Shuangxi Hu;Xuehui Guan;Pin Wen;Jiaming Tang; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 10.-2017, volume: 65, issue:10, pages: 3813 - 3823 Editeur: IEEE Document complet vers site de l'éditeur
» High-Performance Compact Diplexers for Ku/K-Band Satellite Applications
 Résumé:In this paper, two novel compact diplexers for satellite applications are presented. The first covers the Ku-band with two closely spaced channels (Ku-transmission band: 10.7–13 GHz and Ku-reception band: 13.75–14.8 GHz). The second is wider than the first (overall bandwidth up to 50%) achieves the suppression of the higher order modes, and covers the Ku/K-band with a reception channel between 17.2 and 18.5 GHz. Both diplexers are composed of two novel bandpass filters, joined together with an E-plane T-junction. The bandpass filters are designed by combining a low-pass filtering function (based on $\lambda$ /4-step-shaped band-stop elements separated by very short waveguide sections) and a high-pass filtering structure (based on the waveguide propagation cutoff effect). The novel diplexers show a very compact footprint and very relaxed fabrication tolerances, and are especially attractive for wideband applications. A prototype Ku/K-band diplexer has also been fabricated by milling. Measurements show a very good agreement with simulations, thereby demonstrating the validity and manufacturing robustness of the proposed topology. Auteurs: Fernando Teberio;Ivan Arregui;Pablo Soto;Miguel A. G. Laso;Vicente E. Boria;Marco Guglielmi; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 10.-2017, volume: 65, issue:10, pages: 3866 - 3876 Editeur: IEEE Document complet vers site de l'éditeur
» High-Performance of Al Nanoparticle Enhanced 4H-SiC MSM Photodiodes for Deep Ultraviolet Detection
 Résumé:The size controlled Al nanoparticles (NPs) were prepared by magnetron sputtering and subsequent rapid thermal annealing. Significant deep ultraviolet (DUV) detection enhancement is demonstrated on 4H-SiC metal–semiconductor–metal (MSM) ultraviolet photodiodes (PDs) by introducing the coupling of localized surface plasmon resonance (LSPR) from Al NPs. The peak responsivity of 165 mA/W and quantum efficiency of 93% at 220-nm wavelength are achieved under deuterium lamp illumination when 10-V bias is applied, which is 3.93 times than that without Al NPs. LSPR at wavelength as low as 220 nm is the shortest one ever reported in Al NPs. Auteurs: Shao-Xiong Liu;Tao Wang;Zhi-Zhan Chen; Apparue dans: IEEE Electron Device Letters Date publication: 10.-2017, volume: 38, issue:10, pages: 1405 - 1408 Editeur: IEEE Document complet vers site de l'éditeur
» High-Power and High-Efficiency Millimeter-Wave Harmonic Oscillator Design, Exploiting Harmonic Positive Feedback in CMOS
 Résumé:Based on time-variant behavior of metal-oxide–semiconductor field-effect transistors in large-signal operations, harmonic translations and their mutual effects are analyzed. Large amplitudes at terminal voltages of these transistors push them into different regions of operation. In this paper, harmonic translations are derived as a result of such changes in operation region of transistors. Operation in triode region for a portion of oscillation cycle results in iterative harmonic translations between fundamental frequency and second harmonic. They boost each other constructively for significantly stronger oscillation, more second harmonic output power, and enhanced dc-to-RF efficiency. Based on this analysis, a 215-GHz signal source, implemented in a TSMC 65-nm CMOS LP is presented. The proposed oscillator achieves a maximum output power of 5.6 dBm and a dc-to-RF efficiency of 4.6%. The measured phase noise is −94.6 dBc/Hz at 1-MHz offset. The proposed oscillator occupies only 0.08 mm2 of chip area. Auteurs: Rouzbeh Kananizadeh;Omeed Momeni; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 10.-2017, volume: 65, issue:10, pages: 3922 - 3936 Editeur: IEEE Document complet vers site de l'éditeur
» High-Power Narrow-Linewidth Tunable 670.8-nm Master Oscillator Power Amplifier With High Efficiency
 Résumé:A highly efficient 670.8-nm high-power narrow-linewidth wavelength-tunable laser source with master oscillator power amplifier structure is demonstrated, which yielded CW output power of 4.5 W with spectral linewidth of 0.3 pm and mode-hop free tuning range of 52 pm (35 GHz). The total conversion efficiency of 20% was achieved. The developed narrow-linewidth tunable laser source can provide better performance than others ever reported at 670.8 nm for many applications, such as laser isotope separation, Bose–Einstein condensation experiments, and mid-infrared laser generation. Auteurs: Hao Wu;Hangyu Peng;Jun Zhang;Jinlong Zhang;Hongbo Zhu;Yongqiang Ning; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 6 Editeur: IEEE Document complet vers site de l'éditeur
» High-Precision Hydraulic Pressure Control Based on Linear Pressure-Drop Modulation in Valve Critical Equilibrium State
 Résumé:High precision and fast response are of great significance for hydraulic pressure control in automotive braking systems. In this paper, a novel sliding mode control based high-precision hydraulic pressure feedback modulation is proposed. Dynamical models of the hydraulic brake system including valve dynamics are established. An open loop load pressure control based on the linear relationship between the pressure-drop and coil current in valve critical open equilibrium state is proposed, and also experimentally validated on a hardware-in-the-loop test rig. The control characteristics under different input pressures and varied coil currents are investigated. Moreover, the sensitivity of the proposed modulation on valve's key structure parameters and environmental temperatures are explored with some unexpected drawbacks. In order to achieve better robustness and precision, a sliding mode control based closed loop scheme is developed for the linear pressure-drop modulation. Comparative tests between this method and the existing methods are carried out. The results validate the effectiveness and superior performance of the proposed closed loop modulation method. Auteurs: Chen Lv;Hong Wang;Dongpu Cao; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 10.-2017, volume: 64, issue:10, pages: 7984 - 7993 Editeur: IEEE Document complet vers site de l'éditeur
» High-Precision Printing Force Control System for Roll-to-Roll Manufacturing
 Résumé:High-precision printing machines are essential for the fabrication of more sophisticated printed electronics. In particular, roll-to-roll printing with flexible substrates and nonideal rolls, which exhibit cylindricity, misalignment, and run-outs, produces nonlinear effects that are hard to manage with conventional control systems. For instance, printing rolls with cylindricity and run-outs cause large perturbations in the printing forces. In this paper, we propose a hybrid printing force control system that provides uniform printing conditions in the regions where printing occurs. The unique parallel arrangement of two force components provides excellent regulation of the printing force; this system also consumes less power. Our experimental results verify that the force control performance of the hybrid force control system is better than that of a conventional system. We also report the results of in situ printing quality tests with a pressure-sensitive film that confirm the effectiveness of the proposed system. Auteurs: Young-Man Choi;Dongwoo Kang;Sungsoo Lim;Moon Gu Lee;Seung-Hyun Lee; Apparue dans: IEEE/ASME Transactions on Mechatronics Date publication: 10.-2017, volume: 22, issue:5, pages: 2351 - 2358 Editeur: IEEE Document complet vers site de l'éditeur
» High-Quality Plane Wave Compounding Using Convolutional Neural Networks
 Résumé:Single plane wave (PW) imaging produces ultrasound images of poor quality at high frame rates (ultrafast). High-quality PW imaging usually relies on the coherent compounding of several successive steered emissions (typically more than ten), which in turn results in a decreased frame rate. We propose a new strategy to reduce the number of emitted PWs by learning a compounding operation from data, i.e., by training a convolutional neural network to reconstruct high-quality images using a small number of transmissions. We present experimental evidence that this approach is promising, as we were able to produce high-quality images from only three PWs, competing in terms of contrast ratio and lateral resolution with the standard compounding of 31 PWs ( $10\times$ speedup factor). Auteurs: Maxime Gasse;Fabien Millioz;Emmanuel Roux;Damien Garcia;Hervé Liebgott;Denis Friboulet; Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Date publication: 10.-2017, volume: 64, issue:10, pages: 1637 - 1639 Editeur: IEEE Document complet vers site de l'éditeur
» High-R Poly Resistance Deviation Improvement From Suppressions of Back-End Mechanical Stresses
 Résumé:This paper investigates techniques for N-type high-resistance polysilicon resistors to reduce the resistance deviation which is caused by the back-end mechanical stress. In the back-end layers of the wafer, a top metal thickness equal to $3~\mu \text{m}$ is provided to increase the heat allowing current density in the metal routes of power ICs. The top metal processing yields the mechanical stress to increase the resistance by the piezoresistance effect. To eliminate the mechanical stresses, a new layout is proposed with the full passivation cutting (FPC). The resistor with an FPC uses the passivation film separation to create a physical empty room for suppressing the mechanical stresses on the polysilicon. The proposed layout has been verified in the 0.4- $\mu \text{m}$ bipolar-CMOS-DMOS process, and the resistance shifts were compared with other four-type layouts. Compared to those original layouts, the proposed layout exhibits the improvements in the resistance deviation reduction in the maximum ratio 20.80%. Auteurs: Tingyou Lin;Yingchieh Ho;Chauchin Su; Apparue dans: IEEE Transactions on Electron Devices Date publication: 10.-2017, volume: 64, issue:10, pages: 4233 - 4241 Editeur: IEEE Document complet vers site de l'éditeur
» High-Resolution Real-Time Underwater 3-D Acoustical Imaging Through Designing Ultralarge Ultrasparse Ultra-Wideband 2-D Arrays
 Résumé:Acoustical imaging systems are an important kind of instrumentation for underwater investigation. Currently, angular resolutions of most existing real-time underwater 3-D imaging systems are around 1°, which cannot meet the high-quality imaging requirement in a relatively far distance. Enhancing the angular resolution of a real-time 3-D imaging system needs enlarging the aperture size of its receiving 2-D array. However, the huge number of elements is not affordable for a traditional fully sampled uniform large 2-D array with half-wavelength interelement spacing to achieve a high angular resolution. This paper proposes the concept of ultralarge ultrasparse ultra-wideband (UUU) 2-D arrays for achieving the high angular resolution of underwater 3-D acoustical imaging systems. The design method of UUU 2-D arrays is demonstrated through the example of designing an annular 2-D array with only 100 elements. The capabilities of the designed annular UUU 2-D array are evaluated, showing that it can achieve a 0.1° angular resolution and a −32 dB maximum sidelobe level. The imaging simulations of complicated targets also demonstrate that the designed annular UUU 2-D array can satisfy the requirement of high-resolution underwater 3-D acoustical imaging. The element number of the designed annular UUU 2-D array is 4 orders of magnitude lower than that of a fully sampled uniform 2-D array, which provides a viable choice for developing high-resolution real-time underwater 3-D acoustical imaging systems. Auteurs: Cheng Chi;Zhaohui Li; Apparue dans: IEEE Transactions on Instrumentation and Measurement Date publication: 10.-2017, volume: 66, issue:10, pages: 2647 - 2657 Editeur: IEEE Document complet vers site de l'éditeur
» High-Resolution SAR ADC With Enhanced Linearity
 Résumé:This brief proposes two digital-to-analog converter switching techniques for binary-weighted capacitor array successive approximation register (SAR) analog-to-digital converter (ADC), rotating&averaging without redundancy technique and rotating&averaging with redundancy technique. The rotating&averaging without redundancy technique can improve the signal-to-noise ratio (SNR) and spurious free dynamic range (SFDR) of conventional SAR ADCs by averaging four samples for one input voltage, while the rotating&averaging with redundancy has better static linearity improvement but less SNR improvement than the rotating&averaging without redundancy technique. The application of these two methods to 14-bit SAR ADC is demonstrated by Monte-Carlo runs, results show that with a mismatch error typical of modern technology, the proposed rotating&averaging with redundancy scheme can improve the root-mean-square of integral nonlinearity from 2.08 to 0.57 LSB, and the SFDR is more than 15 dB better. On the other hand, the averaged SNR of 7.7 dB is improved by using the proposed rotating&averaging without redundancy technique for a 14-bit SAR ADC. Furthermore, the schemes proposed require only small additional circuit on a typical SAR ADC configuration, which are more feasible to implement high-resolution SAR ADC compared with the traditional calibration schemes. Auteurs: Hua Fan;Franco Maloberti; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 10.-2017, volume: 64, issue:10, pages: 1142 - 1146 Editeur: IEEE Document complet vers site de l'éditeur
» High-Resolution Satellite Observations of a New Hazard of Golden Tides Caused by Floating Sargassum in Winter in the Yellow Sea
 Résumé:A new marine hazard of golden tides caused by floating brown macroalgae-Sargassum occurred in the Yellow Sea in December 2016. An economic loss of 0.5 billion CNY (about U.S. $73 million) was estimated due to the damaged seaweed aquaculture in the Jiangsu Shoal, China. In this letter, images from the new Chinese satellite of Gaofen (GF) with high-resolution optical cameras are used to retrieve the drifting path of floating Sargassum and its origin. A southward drifting path of floating Sargassum in the western Yellow Sea is identified for the first time, and the initial site of bloom occurrence is near the eastern end of the Shandong Peninsula, China, implying the origin of this hazard of floating Sargassum. The scale of this Sargassum bloom event in the Jiangsu Shoal is also evaluated using a linear-mixing model suitable for high-resolution images. The result shows that the total area of Sargassum-containing pixels in the GF-1 wide-field-of-view images on December 31, 2016 was more than 46 km2, and according to the estimation by the linear-mixing model, the total area of sea surface completely covered by Sargassum was above 8.8 km2. The approach and the results presented in this letter should contribute to the future study and management of golden tides in Chinese coastal waters. Auteurs: Qianguo Xing;Ruihong Guo;Lingling Wu;Deyu An;Ming Cong;Song Qin;Xuerong Li; Apparue dans: IEEE Geoscience and Remote Sensing Letters Date publication: 10.-2017, volume: 14, issue:10, pages: 1815 - 1819 Editeur: IEEE Document complet vers site de l'éditeur » High-Resolution Spaceborne SAR Processing Using the Decomposed Transfer Function  Résumé:In this paper, a new analytic decomposed transfer function (DTF) for spaceborne synthetic aperture radar processing is calculated using the stationary phase approximation and Taylor's series expansion. The DTF copes with large Doppler centroid variations and executes range cell migration correction, secondary range compression, azimuth compression, and higher order effects. A fourth-order (DTF4) and fifth-order (DTF5) algorithms have been implemented using segmented block processing. It is shown that the DTF4 yields high quality 3-look target responses at azimuth resolution 0.3 m and range resolution 0.5 m at low squint (yaw = 0.3°) for X-band. At higher squint (yaw = 7.5°) the DTF5 has to be used to obtain adequate image quality. Auteurs: Knut Eldhuset; Apparue dans: IEEE Transactions on Aerospace and Electronic Systems Date publication: 10.-2017, volume: 53, issue:5, pages: 2187 - 2198 Editeur: IEEE Document complet vers site de l'éditeur » High-Temperature Characteristics of 3-kV 4H-SiC Reverse Blocking MOSFET for High-Performance Bidirectional Switch  Résumé:Novel 3-kV 4H-SiC reverse blocking (RB) metal–oxide–semiconductor field-effect transistors (MOSFETs) have been demonstrated for high-voltage bidirectional switching applications. To achieve RB capability, a series Schottky barrier diode structure was introduced onto the backside of the 4H-SiC MOSFET. The developed SiC RB MOSFET exhibits bidirectional blocking voltage over 3 kV and a differential specific on-resistance of 20$\text{m}\Omega ~\cdot $cm2 at room temperature. In an inductive-load switching measurement, the RB MOSFET showed good turn-ON/-OFF characteristics at 1 kV. The bidirectional switch configured by the developed RB MOSFETs exhibited lower ON-state power loss than the series connection of the standard SiC MOSFETs at wide range of temperature and operation current, demonstrating the advantage of the SiC RB MOSFET as a high-performance bidirectional switch. Auteurs: Seigo Mori;Masatoshi Aketa;Takui Sakaguchi;Yuichiro Nanen;Hirokazu Asahara;Takashi Nakamura;Tsunenobu Kimoto; Apparue dans: IEEE Transactions on Electron Devices Date publication: 10.-2017, volume: 64, issue:10, pages: 4167 - 4174 Editeur: IEEE Document complet vers site de l'éditeur » Highly Efficient and Reliable SiC-Based DC–DC Converter for Smart Transformer  Résumé:The series-resonant converter (SRC) has been used in several application and it recently became popular for smart transformers (STs). In this application, the efficiency and reliability are of paramount importance. Although many papers have addressed the design challenges to improve the converter efficiency, discussions about the reliability are still missing in the literature. In this context, this paper presents a design procedure focusing on the efficiency and reliability improvement of the SRC for ST application. High efficiency is achieved through the use of silicon-carbide MOSFETs, reducing conduction and switching losses, and the detail design procedure based on accurate losses modeling. High reliability is achieved through a fault-tolerant topology and reliability-oriented design of the resonant circuit passive components. Experimental results obtained for the optimized 10 kW SRC has shown an efficiency of 98.61%. Auteurs: Levy Ferreira Costa;Giampaolo Buticchi;Marco Liserre; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 10.-2017, volume: 64, issue:10, pages: 8383 - 8392 Editeur: IEEE Document complet vers site de l'éditeur » Highly Efficient Chip-Scale Package LED Based on Surface Patterning  Résumé:Chip-scale package (CSP) light-emitting diodes (LEDs) are considered as the next generation of highly efficient package LED. However, they suffer from total internal reflection that limits their light extraction efficiency (LEE). In this letter, surface patterning, in terms of microstructures, as a well-controlled surface roughness method is designed and applied on CSP-LED to improve the LEE. Based on simulation results, pyramid and flat top pyramid structures have been designed and optimized. Four types of layouts, including tightly, interlaced, distant and chessboard layout, are also compared. A LEE enhancement of more than 20% is achieved. Furthermore, the four layouts with pyramid structures are fabricated using nano-imprint technology. The experimental results match the simulated results well with only a mismatch of 2.9%. The fabricated layout shows an enhancement of 20.31% when pyramid structures are fully filling the surface. Surface patterned CSP-LED, therefore, exhibits a great potential for high efficient LED. Auteurs: Tianqi Zhang;Haodong Tang;Shang Li;Zuoliang Wen;Xiangtian Xiao;Yulong Zhang;Fei Wang;Kai Wang;Dan Wu; Apparue dans: IEEE Photonics Technology Letters Date publication: 10.-2017, volume: 29, issue:20, pages: 1703 - 1706 Editeur: IEEE Document complet vers site de l'éditeur » Highly Sensitive Microfluidic Chip Sensor for Biochemical Detection  Résumé:Chip calorimetry offers a power tool for fast and high throughput analysis of biochemical process. However, it is challenging to realize an inexpensive, easy to fabricate microfluidic chip-based calorimeter with high sensitivity. This paper describes the design of a novel, highly sensitive, and continuous flow microfluidic chip sensor with an integrated antimony (Sb)–bismuth (Bi) thin-film thermopile heat detection element. The geometry and the design of the microfluidic device facilitate hydrodynamic flow focusing, and the integration and design of the thermopile sensor into the microfluidic device eliminates the need for reference temperature control. The device contains a single flow channel that is$120~\mu \text{m}$high and 10-mm wide with two fluid inlets and one fluid outlet. An Sb-Bi thin film thermopile is fabricated on the inner surface of the bottom channel wall using thermal evaporation and was passivized with a$3~\mu \text{m}$SU-8 photoresist layer. The device has been successfully used to measure the dynamic temperature changes resulting from heat generation following the mixing of glycerol and water. The effect of flow rates on the sensor’s response was measured. The sensor can detect dynamic temperature changes in the order of 10-6 K. The limit of detection of heat power of the device was calculated to be 8.8 pW. With the obtained remarkable sensitivity and heat power detection limit, the microfluidic chip sensor can potentially be used to investigate biochemical processes, such as enzyme-catalysed reactions, and metabolic activity of cells. Auteurs: Varun Lingaiah Kopparthy;Eric J. Guilbeau; Apparue dans: IEEE Sensors Journal Date publication: 10.-2017, volume: 17, issue:20, pages: 6510 - 6514 Editeur: IEEE Document complet vers site de l'éditeur » Highly Stable Atomic Layer Deposited Zinc Oxide Thin-Film Transistors Incorporating Triple O2 Annealing  Résumé:Top-gate zinc oxide thin-film transistors have been fabricated by thermal atomic layer deposition, and the effective process steps to improve the device stability have been investigated in detail. In particular, the incorporation of triple rapid thermal annealing steps in oxygen ambient has been proposed to shift the turn-ON voltage toward the positive direction, reduce interface defects, and suppress gate leakage current. Such devices exhibited near zero turn-ON voltage and significantly enhanced electrical and environmental stability. Repeated${I} _{D}$–${V} _{\text {GS}}$sweeping over 900 times in air ambient only caused a shift of the transfer characteristics as low as 0.08 V. Both positive and negative gate bias stress tests on such devices exhibited superior stability performance. Furthermore, ring oscillators based on these devices were found to be capable of highly stable continuous operation over 10 000 s, indicating the devices’ suitability for practical circuits-on-glass applications. Auteurs: Zhi Ye;Hua Xu;Tengfei Liu;Ni Liu;Ying Wang;Ning Zhang;Yang Liu; Apparue dans: IEEE Transactions on Electron Devices Date publication: 10.-2017, volume: 64, issue:10, pages: 4114 - 4122 Editeur: IEEE Document complet vers site de l'éditeur » Historical-Data-Based Energy Management in a Microgrid With a Hybrid Energy Storage System  Résumé:In a microgrid, due to potential reverse power profiles between the renewable energy source (RES) and the loads, energy storage devices are employed to achieve high self-consumption of RES and to minimize power surplus flowing back into the main grid. This paper proposes a variable charging/discharging threshold method to manage the energy storage system. In addition, an adaptive intelligence technique (AIT) is put forward to raise the power management efficiency. A battery–ultra-capacitor hybrid energy storage system (HESS) with merits of high energy and power density is used to evaluate the proposed method with on-site-measured RES output data. Compared with the particle swarm optimization (PSO) algorithm based on the precise predicted data of the load and the RES, the results show that the proposed method can achieve better load smoothing and self-consumption of the RES without the requirement of precise load and RES forecasting. Auteurs: Ke Jia;Yiru Chen;Tianshu Bi;Yaoqi Lin;David Thomas;Mark Sumner; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2597 - 2605 Editeur: IEEE Document complet vers site de l'éditeur » History of the Endoscope [Scanning Our Past]  Résumé:Endoscopy is a technique allowing inspection, manipulation, and treatment of internal organs using devices to enhance visualization from a distance of the target organs without the need of an incision large enough to allow the hand or fingers of the surgeon to enter the surgical field. As can be expected, endoscopy developed in areas where hollow organs were connected to the exterior via natural orifices: the urethra, the vagina, the rectum, the ear canal, and the throat and pharynx. Entry of natural orifices was safe, devoid of wounds, and thus with little risk of infection and death. As also can be expected in the early days without radio, TV, telephone, or internet, numerous physicians and nonphysician scientists invented smaller or larger contributions to the field, sometimes at the same time unaware of the inventions of others. Not all who contributed published their inventions or the application of their inventions, and for others records were lost or destroyed at times of war. As a result the history of the endoscope is not an exact science where each advancement can be placed on a reputable time line and assigned with confidence to a single inventor. The limited space assigned to this summary of the history of the endoscope will not allow any details or nuances; instead it will focus on a number of well-regarded and generally accepted important contributions and its inventors in the early phases of endoscopy and mostly on the technology of the more recent history of endoscopy (Table 1). In addition, rather than focus on the people behind the inventions, this history is aimed mostly at the engineering concepts and subsequent applications in the medical field. For those who desire a more detailed and nuanced history of endoscopy, the reader is referred to books, manuscripts, and websites that cover the entire field or specific subspecialty areas: there are many including cystoscopy, colposcopy, bronchosco- y, thoracoscopy, gastrointestinal endoscopy, laparoscopy, arthroscopy, laryngoscopy, and otoscopy [1]–[10]. Auteurs: Piet C. De Groen; Apparue dans: Proceedings of the IEEE Date publication: 10.-2017, volume: 105, issue:10, pages: 1987 - 1995 Editeur: IEEE Document complet vers site de l'éditeur » Histotripsy Treatment of S. Aureus Biofilms on Surgical Mesh Samples Under Varying Pulse Durations  Résumé:Prior studies demonstrated that histotripsy generated by high-intensity tone bursts to excite a bubble cloud adjacent to a medical implant can destroy the bacteria biofilm responsible for the infection. The goal of this paper was to treat Staphylococcus aureus (S. aureus) biofilms on surgical mesh samples while varying the number of cycles in the tone burst to minimize collateral tissue damage while maximizing therapy effectiveness. S. aureus biofilms were grown on 1-cm square surgical mesh samples. The biofilms were then treated in vitro using a spherically focused transducer (1.1 MHz, 12.9-cm focal length, 12.7-cm diameter) using either a sham exposure or histotripsy pulses with tone burst durations of 3, 5, or 10 cycles (pulse repetition frequency of 333 Hz, peak compressional pressure of 150 MPa, peak rarefactional pressure of 17 MPa). After treatment, the number of colony forming units (CFUs) on the mesh and the surrounding gel was independently determined. The number of CFUs remaining on the mesh for the sham exposure (4.8 ± 0.9–log10) (sample mean ± sample standard deviation-log10 from 15 observations) was statistically significantly different from the 3-cycle (1.9 ± 1.5–log10), 5-cycle (2.2 ± 1.1–log10), and 10-cycle exposures (1 ± 1.5–log10) with an average reduction in the number of CFUs of 3.1–log10. The numbers of CFUs released into the gel for both the sham and exposure groups were the same within a bound of 0.86–log10, but this interval was too large to deduce the fate of the bacteria in the biofilm following the treatment. Auteurs: Timothy A. Bigelow;Clayton L. Thomas;Huaiqing Wu;Kamal M. F. Itani; Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Date publication: 10.-2017, volume: 64, issue:10, pages: 1420 - 1428 Editeur: IEEE Document complet vers site de l'éditeur » hMuLab: A Biomedical Hybrid MUlti-LABel Classifier Based on Multiple Linear Regression  Résumé:Many biomedical classification problems are multi-label by nature, e.g., a gene involved in a variety of functions and a patient with multiple diseases. The majority of existing classification algorithms assumes each sample with only one class label, and the multi-label classification problem remains to be a challenge for biomedical researchers. This study proposes a novel multi-label learning algorithm, hMuLab, by integrating both feature-based and neighbor-based similarity scores. The multiple linear regression modeling techniques make hMuLab capable of producing multiple label assignments for a query sample. The comparison results over six commonly-used multi-label performance measurements suggest that hMuLab performs accurately and stably for the biomedical datasets, and may serve as a complement to the existing literature. Auteurs: Pu Wang;Ruiquan Ge;Xuan Xiao;Manli Zhou;Fengfeng Zhou; Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics Date publication: 10.-2017, volume: 14, issue:5, pages: 1173 - 1180 Editeur: IEEE Document complet vers site de l'éditeur » Homogeneous Rational Lyapunov Functions for Performance Analysis of Switched Systems With Arbitrary Switching and Dwell Time Constraints  Résumé:This paper addresses the problems of determining the${\mathcal {H}_2}$norm and the root mean square (RMS) gain of continuous-time switched linear systems. A novel class of Lyapunov functions is proposed for reaching this goal, called homogeneous rational Lyapunov functions (HRLFs). It is shown that sufficient conditions for establishing upper bounds of the sought performance indexes in the case of arbitrary switching can be given in terms of linear matrix inequality (LMI) feasibility tests by searching for an HRLF of chosen degree. Moreover, it is shown that these conditions are also necessary by searching for an HRLF of degree sufficiently large. It is worth mentioning that necessary and sufficient LMI conditions have not been proposed yet in the literature for the considered problems. Hence, the paper continues by considering the case of switching with dwell time constraints, showing that analogous LMI conditions can be obtained for this case by searching for a family of HRLFs mutually constrained by the dwell time specification. Some numerical examples illustrate the proposed methodology and highlight the advantages with respect to the existing works. Auteurs: Graziano Chesi;Patrizio Colaneri; Apparue dans: IEEE Transactions on Automatic Control Date publication: 10.-2017, volume: 62, issue:10, pages: 5124 - 5137 Editeur: IEEE Document complet vers site de l'éditeur » Homography Propagation and Optimization for Wide-Baseline Street Image Interpolation  Résumé:Wide-baseline street image interpolation is useful but very challenging. Existing approaches either rely on heavyweight 3D reconstruction or computationally intensive deep networks. We present a lightweight and efficient method which uses simple homography computing and refining operators to estimate piecewise smooth homographies between input views. To achieve the goal, we show how to combine homography fitting and homography propagation together based on reliable and unreliable superpixel discrimination. Such a combination, other than using homography fitting only, dramatically increases the accuracy and robustness of the estimated homographies. Then, we integrate the concepts of homography and mesh warping, and propose a novel homography-constrained warping formulation which enforces smoothness between neighboring homographies by utilizing the first-order continuity of the warped mesh. This further eliminates small artifacts of overlapping, stretching, etc. The proposed method is lightweight and flexible, allows wide-baseline interpolation. It improves the state of the art and demonstrates that homography computation suffices for interpolation. Experiments on city and rural datasets validate the efficiency and effectiveness of our method. Auteurs: Yongwei Nie;Zhensong Zhang;Hanqiu Sun;Tan Su;Guiqing Li; Apparue dans: IEEE Transactions on Visualization and Computer Graphics Date publication: 10.-2017, volume: 23, issue:10, pages: 2328 - 2341 Editeur: IEEE Document complet vers site de l'éditeur » Horizontal Directional Coupler Formed With Waveguides of Different Heights for Mode-Division Multiplexing  Résumé:We propose a horizontal directional coupler formed with two parallel waveguides of different heights. By breaking the symmetry in both the horizontal and the vertical direction, this directional coupler can be designed to allow us coupling between any two spatial modes of a few-mode waveguide, regardless of their symmetry properties, whereas a conventional directional coupler formed with planar waveguides of equal heights only allows us coupling between two spatial modes of the same symmetry in the vertical direction. As an example, we design and fabricate such a directional coupler with polymer material for the (de)multiplexing of the LP01 and the LP11b mode, which have a symmetric and an antisymmetric field distribution in the vertical direction, respectively. Our typical fabricated device shows a coupling ratio higher than 95% in the wavelength range from 1530 to 1560 nm. The insertion losses for the LP01 and LP11b modes are 9.6 and 12.8 dB, respectively. The performance of the device is weakly sensitive to temperature variations. The proposed directional coupler is easy to fabricate and can be used as a basic structure for the implementation of mode-controlling devices for mode-division-multiplexing applications. Auteurs: Wei Ke Zhao;Kai Xin Chen;Jie Yun Wu;Kin Seng Chiang; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 9 Editeur: IEEE Document complet vers site de l'éditeur » How synchronization evolved from analog to digital in the TLC world  Résumé:We are back in the 1960s and 1970s, and the world is still analog: the home phone, with its reliable “hard dialer” that most people today have probably never seen (Fig. 1), is connected with a twisted pair cable to the public exchange. In Italy, it was the Società Italiana per l’Esercizio Telefonico (SIP Society), which has now become Telecom Italia Mobile (TIM). If we try to connect with a client on the same exchange, our call will be handled by a Strowger switch, from the inventor Almon Brown Strowger, which connects us directly to the desired subscriber (Fig. 2). Auteurs: Franco Baroncini;Simona Salicone; Apparue dans: IEEE Instrumentation & Measurement Magazine Date publication: 10.-2017, volume: 20, issue:5, pages: 30 - 34 Editeur: IEEE Document complet vers site de l'éditeur » HRO-OFDM Scheme Design and Optimization for a Hybrid RF/VLC Baseband System  Résumé:A hybrid radio frequency (RF) and visible light communication (VLC) system can provide better data rate performance and user experience, and only the hybrid RF/VLC systems that use independent RF access points (APs) and VLC APs have been currently considered. However, a hybrid design in baseband can more centrally allocate various resources. In this paper, a new hybrid RF/VLC orthogonal frequency division multiplexing (OFDM) baseband is presented. Different from conventional OFDM baseband, the new baseband combines both RF link and VLC link in the physical layer. IQ modulation is used in RF link, whereas intensity modulation and direct detection are used in VLC link. Furthermore, the proposed hybrid of radio and optical OFDM (HRO-OFDM) scheme can better combine the different features in RF and VLC link. Based on the new hybrid baseband and HRO-OFDM, we improve the conventional optimization and consider both power allocation and bandwidth allocation. Compared with some conventional designs like RF OFDM baseband design, VLC OFDM baseband design and hybrid RF/VLC design, results show that our new design can achieve better performance and adaptively allocate bandwidth in RF/VLC links under the different distances between user and the baseband. Auteurs: Fangzhou Wu;Li Chen;Weidong Wang; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 13 Editeur: IEEE Document complet vers site de l'éditeur » Human Behavior Recognition Using Wi-Fi CSI: Challenges and Opportunities  Résumé:Human behavior recognition (HBR) has emerged as a core research area in human-computer interaction. In this article, we give a comprehensive introduction to HBR using Wi-Fi channel state information. We first comprehensively review the state-of-art of HBR, based on the two techniques that drove recent progress in Wi-Fi channel-state-information-based HBR -- fingerprint-based and model-based. Specifically, we describe their corresponding characteristics, general architectures, and provide a performance comparison of the two mechanisms. We then provide insights into the future directions of HBR research, and propose two possible new schemes, and the technical challenges coming with them. Auteurs: Lili Chen;Xiaojiang Chen;Ligang Ni;Yao Peng;Dingyi Fang; Apparue dans: IEEE Communications Magazine Date publication: 10.-2017, volume: 55, issue:10, pages: 112 - 117 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid Backscatter Communication for Wireless-Powered Heterogeneous Networks  Résumé:In this paper, we propose hybrid backscatter communication for wireless-powered communication networks (WPCNs) to increase transmission range and provide uniform rate distribution in the heterogeneous network (HetNet) environment. In such HetNet, where the TV tower or high-power base station (macrocell) coexists with densely deployed small-power access points (e.g., small-cells or WiFi), users can operate in either bistatic scatter or ambient backscatter, or a hybrid of them, given that the harvested energy from the dedicated or ambient RF signals may not be sufficient enough to support the existing harvest-then-transmit protocol for WPCN, which is extended to the wireless-powered heterogeneous network (WPHetNet). Considering the hybrid and dual mode operation, we formulate a throughput maximization problem depending on the user location, namely Macro-zone or WiFi-zone. After performing the optimal time allocation for the above operation, we show that the proposed hybrid backscatter communication can increase the transmission range of WPHetNet, while achieving uniform rate distribution. Auteurs: Sung Hoon Kim;Dong In Kim; Apparue dans: IEEE Transactions on Wireless Communications Date publication: 10.-2017, volume: 16, issue:10, pages: 6557 - 6570 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid conventional and quantum security for software defined and virtualized networks  Résumé:Today's networks are quickly evolving toward more dynamic and flexible infrastructures and architectures. This software-based evolution has seen its peak with the development of the software-defined networking (SDN) and network functions virtualization (NFV) paradigms. These new concepts allow operators to automate the setup of services, thus reducing costs in deploying and operating the required infrastructure. On the other hand, these novel paradigms expose new vulnerabilities, as critical information travels through the infrastructure fromcentral offices, down to remote data centers and network devices. Quantum key distribution (QKD) is a state-of-the-art technology that can be seen as a source of symmetric keys in two separated domains. It is immune to any algorithmic cryptanalysis and is thus suitable for long-term security. This technology is based on the laws of physics, which forbids us from copying the quantum states exchanged between two endpoints from which a secret key can be extracted. Thus, even though it has some limitations, a correct implementation can deliver keys of the highest security. In this paper, we propose the integration of QKDsystems with well-known protocols and methodologies to secure the network’s control plane in an SDN and NFV environment. Furthermore, we experimentally demonstrate a workflow where QKD keys are used together with classically generated keys to encrypt communications between cloud and SDN platforms for setting up a service via secure shell, while showcasing the applicability to other cryptographic protocols. Auteurs: Alejandro Aguado;Victor Lopez;Jesus Martinez-Mateo;Thomas Szyrkowiec;Achim Autenrieth;Momtchil Peev;Diego Lopez;Vicente Martin; Apparue dans: IEEE/OSA Journal of Optical Communications and Networking Date publication: 10.-2017, volume: 9, issue:10, pages: 819 - 825 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid CS-DMRI: Periodic Time-Variant Subsampling and Omnidirectional Total Variation Based Reconstruction  Résumé:Compressive sensing (CS) has been used to accelerate dynamic magnetic resonance imaging (DMRI). Currently, the online CS-DMRI is faster, whereas the offline CS-DMRI provides higher accuracy for image reconstruction. To achieve good image reconstruction performance in terms of both speed and accuracy, we propose a hybrid CS-DMRI method using periodic time-variant subsampling for different frames. In each period, there is one reference frame that is sampled at a higher subsampling ratio. The two nearby reference frames with good reconstruction quality can be used to provide rough predictions of the other frames between them. To finely recover the current frame, one structural regularization in the optimization model for reconstruction is a 2-D omnidirectional total variation (OTV) for exploiting the sparsity of the difference between the predicted and estimated frames, and the other is a 3-D OTV as a regularization term for exploiting the bilateral spatio-temporal coherence between the forward reference frame, current frame, and backward reference frame. Compared with classical total variation, the proposed OTV fully utilizes the correlations of all the possible directions of the data. The formulated optimization model can be solved using iterative reweighted least squares with the pre-conditioned conjugate gradient method. Numerical experiments demonstrate that the proposed method has better reconstruction accuracy than all the existing methods and low computational complexity that is comparable to the existing online methods. Auteurs: Yipeng Liu;Shan Wu;Xiaolin Huang;Bing Chen;Ce Zhu; Apparue dans: IEEE Transactions on Medical Imaging Date publication: 10.-2017, volume: 36, issue:10, pages: 2148 - 2159 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid Dynamic Moving Obstacle Avoidance Using a Stochastic Reachable Set-Based Potential Field  Résumé:One of the primary challenges for autonomous robotics in uncertain and dynamic environments is planning and executing a collision-free path. Hybrid dynamic obstacles present an even greater challenge as the obstacles can change dynamics without warning and potentially invalidate paths. Artificial potential field (APF)-based techniques have shown great promise in successful path planning in highly dynamic environments due to their low cost at runtime. We utilize the APF framework for runtime planning but leverage a formal validation method, Stochastic Reachable (SR) sets, to generate accurate potential fields for moving obstacles. A small number of SR sets are computed a priori, then used to generate a potential field that represents the obstacle's stochastic motion for online path planning. Our method is novel and scales well with the number of obstacles, maintaining a relatively high probability of reaching the goal without collision, as compared to other traditional Gaussian APF methods. Here, we demonstrate our method with up to 900 hybrid dynamic obstacles and show that it outperforms the traditional Gaussian APF method by up to 60% in the holonomic case and up to 20% in the unicycle case. Auteurs: Nick Malone;Hao-Tien Chiang;Kendra Lesser;Meeko Oishi;Lydia Tapia; Apparue dans: IEEE Transactions on Robotics Date publication: 10.-2017, volume: 33, issue:5, pages: 1124 - 1138 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid Fuzzy Adaptive Fault-Tolerant Control for a Class of Uncertain Nonlinear Systems With Unmeasured States  Résumé:In this paper, a hybrid adaptive output feedback fault-tolerant control is investigated for a class of uncertain nonlinear systems with unmeasured states. The generalized fuzzy hyperbolic model is used to approximate the unknown nonlinear functions, and the fuzzy state estimator (FSE) is established for estimating the unmeasured states. Based on the backstepping and dynamic surface control technique, a novel adaptive control method is proposed by introducing the prediction errors between FSE and serial–parallel estimation model. It is proved that all the variables of the closed-loop systems are semi-globally uniformly ultimately bounded by Lyapunov approach, and the tracking errors can converge to a small neighborhood. Two simulation examples are used to illustrate the effectiveness of the proposed control method. Auteurs: Huaguang Zhang;Yang Cui;Yingchun Wang; Apparue dans: IEEE Transactions on Fuzzy Systems Date publication: 10.-2017, volume: 25, issue:5, pages: 1041 - 1050 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid Robust Boundary and Fuzzy Control for Disturbance Attenuation of Nonlinear Coupled ODE-Beam Systems With Application to a Flexible Spacecraft  Résumé:This paper introduces a hybrid robust boundary and fuzzy control design for disturbance attenuation of a class of coupled systems described by nonlinear ordinary differential equations (ODEs) and two nonlinear beam equations. Initially, a Takagi–Sugeno (T–S) model is employed to exactly represent the nonlinear ODE subsystem. Then, a fuzzy controller is designed for the ODE subsystem based on the T–S fuzzy model, and a robust boundary controller via beam boundary measurements is proposed for the nonlinear beam subsystem. Such a hybrid robust boundary and fuzzy controller is developed in terms of a set of space-dependent bilinear matrix inequalities (BMIs) by Lyapunov's direct method, which can exponentially stabilize the coupled system in the absence of disturbances and achieve an prescribed$H_{\infty }$performance of disturbance attenuation in the presence of disturbances. Furthermore, in order to make the level of disturbance attenuation as small as possible, a suboptimal$H_{\infty }$control problem is formulated as a BMI optimization problem. A two-step procedure is subsequently presented to solve this BMI optimization problem by the existing linear matrix inequality optimization techniques. Finally, the proposed control method is applied to the control of a flexible spacecraft to illustrate its effectiveness. Auteurs: Shuang Feng;Huai-Ning Wu; Apparue dans: IEEE Transactions on Fuzzy Systems Date publication: 10.-2017, volume: 25, issue:5, pages: 1293 - 1305 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid Thin Film Antenna for Automotive Radar at 79 GHz  Résumé:A novel hybrid approach to designing multilayer antennas for automotive radar using a thin single layer printed circuit board and multilayer thin films is presented in this paper. A new substrate integrated waveguide (SIW) slot fed stacked grid antenna element is designed using this approach. The flexibility of this approach in designing antenna arrays is shown by integrating the same antenna element with three different feed networks based on SIW, grounded coplanar waveguide (GCPW), and microstrip (MS) transmission lines. The antenna is designed to operate in the frequency band between 77 and 81 GHz for automotive radar. Measurement results on$1\times 4$arrays show an impedance matching bandwidth and a realized gain of 7.8% (76.3–82.5 GHz) and 9.2 dBi, respectively, for SIW feed antenna, 11.3% (76.3–85.5 GHz) and 10.7 dBi, respectively, for GCPW feed antenna, and 11.3% (75.7–84.8 GHz) and 12.1 dBi, respectively, for MS feed antennas. The proposed antenna can be used for medium- and short-range automotive radar applications. Auteurs: Osama Khan;Johannes Meyer;Klaus Baur;Christian Waldschmidt; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 10.-2017, volume: 65, issue:10, pages: 5076 - 5085 Editeur: IEEE Document complet vers site de l'éditeur » Hybrid Wavelength Switched-TDMA High Port Count All-Optical Data Centre Switch  Résumé:The physical layer data plane design of an all-optical network switch capable of scaling to 1024 ports at 25 Gb/s per port is presented and experimentally evaluated. Fast-tuning DSDBR lasers modulated with line-coded bipolar data allow combined wavelength switching and time-division multiple access to provide packet switch-like functionality with over 2 Tb/s of total switch bandwidth. A passive fiber star coupler core with high sensitivity DSP-free coherent receivers creates a low complexity easily upgradeable building block for data center networks. Auteurs: Adam Christopher Funnell;Kai Shi;Paolo Costa;Philip Watts;Hitesh Ballani;Benn Charles Thomsen; Apparue dans: Journal of Lightwave Technology Date publication: 10.-2017, volume: 35, issue:20, pages: 4438 - 4444 Editeur: IEEE Document complet vers site de l'éditeur » Hyperspectral and Multispectral Image Fusion Based on Local Low Rank and Coupled Spectral Unmixing  Résumé:Hyperspectral images (HSIs) usually have high spectral and low spatial resolution. Conversely, multispectral images (MSIs) usually have low spectral and high spatial resolution. The fusion of HSI and MSI aims to create spectral images with high spectral and spatial resolution. In this paper, we propose a fusion algorithm by combining linear spectral unmixing with the local low-rank property. By taking advantage of the local low-rank property, we first partition the corresponding spectral image into patches. For each patch pair, we cast the fusion problem as a coupled spectral unmixing problem that extracts the abundance and the endmembers of MSI and HSI, respectively. It then updates the abundance and the endmember through an alternating update algorithm. In fact, the convergence of the alternative update algorithm can be mathematically and empirically supported. We also propose a multiscale postprocessing procedure to combine fusion results obtained under different patch sizes. In experiments on three data sets, the proposed fusion algorithms outperformed state-of-the-art fusion algorithms in both spatial and spectral domains. Auteurs: Yuan Zhou;Liyang Feng;Chunping Hou;Sun-Yuan Kung; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5997 - 6009 Editeur: IEEE Document complet vers site de l'éditeur » Hyperspectral Anomaly Detection With Attribute and Edge-Preserving Filters  Résumé:A novel method for anomaly detection in hyperspectral images is proposed. The method is based on two ideas. First, compared with the surrounding background, objects with anomalies usually appear with small areas and distinct spectral signatures. Second, for both the background and the objects with anomalies, pixels in the same class are usually highly correlated in the spatial domain. In this paper, the pixels with specific area property and distinct spectral signatures are first detected with attribute filtering and a Boolean map-based fusion approach in order to obtain an initial pixel-wise detection result. Then, the initial detection result is refined with edge-preserving filtering to make full use of the spatial correlations among adjacent pixels. Compared with other widely used anomaly detection methods, the experimental results obtained on real hyperspectral data sets including airport, beach, and urban scenes demonstrate that the performance of the proposed method is quite competitive in terms of computing time and detection accuracy. Auteurs: Xudong Kang;Xiangping Zhang;Shutao Li;Kenli Li;Jun Li;Jón Atli Benediktsson; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5600 - 5611 Editeur: IEEE Document complet vers site de l'éditeur » Hyperspectral Image Restoration Using Low-Rank Tensor Recovery  Résumé:This paper studies the hyperspectral image (HSI) denoising problem under the assumption that the signal is low in rank. In this paper, a mixture of Gaussian noise and sparse noise is considered. The sparse noise includes stripes, impulse noise, and dead pixels. The denoising task is formulated as a low-rank tensor recovery (LRTR) problem from Gaussian noise and sparse noise. Traditional low-rank tensor decomposition methods are generally NP-hard to compute. Besides, these tensor decomposition based methods are sensitive to sparse noise. In contrast, the proposed LRTR method can preserve the global structure of HSIs and simultaneously remove Gaussian noise and sparse noise.The proposed method is based on a new tensor singular value decomposition and tensor nuclear norm. The NP-hard tensor recovery task is well accomplished by polynomial time algorithms. The convergence of the algorithm and the parameter settings are also described in detail. Preliminary numerical experiments have demonstrated that the proposed method is effective for low-rank tensor recovery from Gaussian noise and sparse noise. Experimental results also show that the proposed LRTR method outperforms other denoising algorithms on real corrupted hyperspectral data. Auteurs: Haiyan Fan;Yunjin Chen;Yulan Guo;Hongyan Zhang;Gangyao Kuang; Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Date publication: 10.-2017, volume: 10, issue:10, pages: 4589 - 4604 Editeur: IEEE Document complet vers site de l'éditeur » Hyperspectral Image Super-Resolution by Spectral Difference Learning and Spatial Error Correction  Résumé:A hyperspectral image (HSI) super-resolution (SR) is a highly attractive topic in computer vision. However, most existed methods require an auxiliary high-resolution (HR) image with respect to the input low-resolution (LR) HSI. This limits the practicability of these HSI SR methods. Moreover, these methods often destroy the important spectral information. This letter presents a deep spectral difference convolutional neural network (SDCNN) with the combination of a spatial-error-correction (SEC) model for HSI SR. This method allows for full exploration of the spectral and spatial correlations, which achieves a good spatial information enhancement and spectral information preservation. In the proposed method, the key band is automatically selected and super-resolved with the boundary bands. Meanwhile, spectral difference mapping between the LR and HR HSIs can be learned by the SDCNN, and then be transformed according to the SEC model, which aims at correcting the spatial error while preserving the spectral information. The rest nonkey bands will be super-resolved under the guidance of the transformed spectral difference. Experimental results on synthesized and real-scenario HSIs suggest that the proposed method: 1) achieves comparable performance without requiring any auxiliary images of the same scene and 2) requires less computation time than the state-of-the-art methods. Auteurs: Jing Hu;Yunsong Li;Weiying Xie; Apparue dans: IEEE Geoscience and Remote Sensing Letters Date publication: 10.-2017, volume: 14, issue:10, pages: 1825 - 1829 Editeur: IEEE Document complet vers site de l'éditeur » Hysteresis Bearingless Slice Motors With Homopolar Flux-Biasing  Résumé:We present a new concept of bearingless slice motor that levitates and rotates a ring-shaped solid rotor. The rotor is made of a semi-hard magnetic material exhibiting magnetic hysteresis, such as D2 steel. The rotor is radially biased with a homopolar permanent-magnetic flux, on which the stator can superimpose two-pole flux to generate suspension forces. By regulating the suspension forces based on position feedback, the two radial rotor degrees of freedom are actively stabilized. The two tilting degrees of freedom and the axial translation are passively stable due to the reluctance forces from the bias flux. In addition, the stator can generate a torque by superimposing six-pole rotating flux, which drags the rotor via hysteresis coupling. This six-pole flux does not generate radial forces in conjunction with the homopolar flux or two-pole flux, and therefore the suspension force generation is in principle decoupled from the driving torque generation. We have developed a prototype system as a proof of concept. The stator has 12 teeth, each of which has a single-phase winding that is individually driven by a linear transconductance power amplifier. The system has four reflective-type optical sensors to differentially measure the two radial degrees of freedom of the rotor. The suspension control loop is implemented such that the phase margin is 25$^circ$at the cross-over frequency of 110 Hz. The prototype system can levitate the rotor and drive it up to about 1730 r/min. The maximum driving torque is about 2.7 mNm. Auteurs: Minkyun Noh;Wolfgang Gruber;David L. Trumper; Apparue dans: IEEE/ASME Transactions on Mechatronics Date publication: 10.-2017, volume: 22, issue:5, pages: 2308 - 2318 Editeur: IEEE Document complet vers site de l'éditeur » IAS Annual Meeting: Colocation with ECCE [President's Message]  Résumé:Presents the President’s message for this issue of the publication. Auteurs: Tomy Sebastian; Apparue dans: IEEE Industry Applications Magazine Date publication: 10.-2017, volume: 23, issue:5, pages: 4 - 13 Editeur: IEEE Document complet vers site de l'éditeur » ICESAT/GLAS Altimetry Measurements: Received Signal Dynamic Range and Saturation Correction  Résumé:NASA’s Ice, Cloud, and land Elevation Satellite (ICESat), which operated between 2003 and 2009, made the first satellite-based global lidar measurement of earth’s ice sheet elevations, sea-ice thickness, and vegetation canopy structure. The primary instrument on ICESat was the Geoscience Laser Altimeter System (GLAS), which measured the distance from the spacecraft to the earth’s surface via the roundtrip travel time of individual laser pulses. GLAS utilized pulsed lasers and a direct detection receiver consisting of a silicon avalanche photodiode and a waveform digitizer. Early in the mission, the peak power of the received signal from snow and ice surfaces was found to span a wider dynamic range than anticipated, often exceeding the linear dynamic range of the GLAS 1064-nm detector assembly. The resulting saturation of the receiver distorted the recorded signal and resulted in range biases as large as ~50 cm for ice- and snow-covered surfaces. We developed a correction for this “saturation range bias” based on laboratory tests using a spare flight detector, and refined the correction by comparing GLAS elevation estimates with those derived from Global Positioning System surveys over the calibration site at the salar de Uyuni, Bolivia. Applying the saturation correction largely eliminated the range bias due to receiver saturation for affected ICESat measurements over Uyuni and significantly reduced the discrepancies at orbit crossovers located on flat regions of the Antarctic ice sheet. Auteurs: Xiaoli Sun;James B. Abshire;Adrian A. Borsa;Helen Amanda Fricker;Donghui Yi;John P. DiMarzio;Fernando S. Paolo;Kelly M. Brunt;David J. Harding;Gregory A. Neumann; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5440 - 5454 Editeur: IEEE Document complet vers site de l'éditeur » Identification and Experimental Validation of an Induction Motor Thermal Model for Improved Drivetrain Design  Résumé:The ability of an electric powertrain to perform according to mechanical specifications is equally important as assessing its thermal protection limits, which are affected by its electrical and thermal properties. Although rated parameters (such as power, torque, etc.) are easily accessible in catalogs of equipment producers, more specific properties like mass/length of copper winding, heat dissipation factor, etc., are not available to customers. Therefore, an effective selection of drivetrain components is limited due to the lack of sufficient data and the need to consult critical design decisions with suppliers. To overcome this limitation, we propose a method to estimate the temperature rise of motor drives based on popular loadability curves, which are provided in catalogs. A simple first-order thermal model is applied to represent heating/cooling phenomenon of motor drives. The parameters’ identification process is formulated as a nonlinear optimization problem and solved using commercial software products. Within the proposed approach, it becomes possible to include the effect of reduced torque availability at low speeds in self-ventilated motors during design of electric actuation systems. Contrary to using a discrete set of permissible overload conditions from the catalogs, the current methodology allows for evaluating a temperature rise of a motor drive for any overload magnitude, duty cycle, and ambient temperature. This greatly improves flexibility of the design process and facilitates communication in a supplier–customer dialog. The discussed method is verified against reference overload recommendations, yielding the same thermal protection levels, and validated using the experimental results, producing identical motor temperature rise profiles as the ones measured on the laboratory test bench. Auteurs: Witold Pawlus;Jan Thomas Birkeland;Huynh Van Khang;Michael R. Hansen; Apparue dans: IEEE Transactions on Industry Applications Date publication: 10.-2017, volume: 53, issue:5, pages: 4288 - 4297 Editeur: IEEE Document complet vers site de l'éditeur » Identification of LOCA and Estimation of Its Break Size by Multiconnected Support Vector Machines  Résumé:Nuclear power plants (NPPs) are composed of very large complex systems. During transient occurrences in NPPs, operators determine the transients of the NPP through information acquired from various measuring instruments. A support vector machine (SVM) based on serial and parallel connections, termed as a multiconnected SVM, is introduced in this paper. The loss of coolant accidents (LOCAs) was identified and their break sizes are estimated using the multiconnected SVM model. The optimal parameter values of the multiconnected SVM models are obtained using a genetic algorithm. In this paper, the modular accident analysis program code was used to simulate the severe accidents occurring due to a variety of design basis accidents. The proposed algorithm uses the short time-integrated simulated sensor signals just after the reactor trip. The results show that the multiconnected SVM model can identify LOCAs and estimate their break sizes accurately. It is expected that the LOCA identification and the accurate estimation of the break size are useful for NPP operators when they try to manage severe accidents. Auteurs: Kwae Hwan Yoo;Young Do Koo;Ju Hyun Back;Man Gyun Na; Apparue dans: IEEE Transactions on Nuclear Science Date publication: 10.-2017, volume: 64, issue:10, pages: 2610 - 2617 Editeur: IEEE Document complet vers site de l'éditeur » Identification of partial discharges in power transformers: An approach driven by practical experience  Résumé:High voltage power transformers are the most challenging equipment for asset managers in that their failures are often due to thermal, electrical, ambient, and mechanical stresses that interact in a synergic way. An accurate failure mode analysis is often prevented by the compound nature of the insulation (partly solid, partly liquid, self-regenerative, and highly flammable) and by the high probability that failures involve explosions. Insulation failure is, by far, the costlier event with an average cost of about$150,000 (1999) per outage [1]. Therefore, it is worthwhile to understand better the symptoms that indicate an imminent failure. The aim of this article is to provide practical information for partial discharge source identification for oil-immersed transformers. The features of some common manufacturing defects rarely discussed in the literature are presented. Creeping discharges are also investigated through a setup intended to improve partial discharge identification. Auteurs: S. Ganeshan;J. Murugesan;A. Cavallini;F. Negri;B. Valecillos;U. Piovan; Apparue dans: IEEE Electrical Insulation Magazine Date publication: 10.-2017, volume: 33, issue:5, pages: 23 - 31 Editeur: IEEE Document complet vers site de l'éditeur
» Identification of the Uncertainty Structure to Estimate the Acoustic Release of Chemotherapeutics From Polymeric Micelles
 Résumé:This paper estimates the acoustic drug release from micelles after accurately identifying the underlying statistical noise characteristics in experimental data. The drug release is measured as a change in fluorescence as ultrasound is applied. First, the noise structure affecting the process dynamics and the measurement process is identified in terms of statistical covariance of the aforementioned quantities. Then, the identified covariance magnitudes are utilized to estimate the dynamics of drug release. The performance of different filters is investigated. The identified a priori knowledge is used to implement an optimal Kalman filter, a multi-hypothesis Kalman filter, and a variant of the full information estimator (moving horizon estimator) to the problem at hand. The proposed algorithms are initially deployed in a simulation environment, and then the experimental data sets are fed into the algorithms to validate their performance. Experiments span a number of ultrasonic power densities for both non-targeted and targeted polymeric micelles (the targeting being accomplished using the folate moiety). The results suggest that the proposed algorithm, the optimal Kalman filter, performs better than the other two in all tests performed. Auteurs: Ali Wadi;Mamoun Abdel-Hafez;Ghaleb A. Husseini; Apparue dans: IEEE Transactions on NanoBioscience Date publication: 10.-2017, volume: 16, issue:7, pages: 609 - 617 Editeur: IEEE Document complet vers site de l'éditeur
» Identifying Extract Method Refactoring Opportunities Based on Functional Relevance
 Résumé:‘Extract Method’ is considered one of the most frequently applied and beneficial refactorings, since the corresponding Long Method smell is among the most common and persistent ones. Although Long Method is conceptually related to the implementation of diverse functionalities within a method, until now, this relationship has not been utilized while identifying refactoring opportunities. In this paper we introduce an approach (accompanied by a tool) that aims at identifying source code chunks that collaborate to provide a specific functionality, and propose their extraction as separate methods. The accuracy of the proposed approach has been empirically validated both in an industrial and an open-source setting. In the former case, the approach was capable of identifying functionally related statements within two industrial long methods (approx. 500 LoC each), with a recall rate of 93 percent. In the latter case, based on a comparative study on open-source data, our approach ranks better compared to two well-known techniques of the literature. To assist software engineers in the prioritization of the suggested refactoring opportunities the approach ranks them based on an estimate of their fitness for extraction. The provided ranking has been validated in both settings and proved to be strongly correlated with experts’ opinion. Auteurs: Sofia Charalampidou;Apostolos Ampatzoglou;Alexander Chatzigeorgiou;Antonios Gkortzis;Paris Avgeriou; Apparue dans: IEEE Transactions on Software Engineering Date publication: 10.-2017, volume: 43, issue:10, pages: 954 - 974 Editeur: IEEE Document complet vers site de l'éditeur
» Identifying Stages of Kidney Renal Cell Carcinoma by Combining Gene Expression and DNA Methylation Data
 Résumé:In this study, in order to take advantage of complementary information from different types of data for better disease status diagnosis, we combined gene expression with DNA methylation data and generated a fused network, based on which the stages of Kidney Renal Cell Carcinoma (KIRC) can be better identified. It is well recognized that a network is important for investigating the connectivity of disease groups. We exploited the potential of the network's features to identify the KIRC stage. We first constructed a patient network from each type of data. We then built a fused network based on network fusion method. Based on the link weights of patients, we used a generalized linear model to predict the group of KIRC subjects. Finally, the group prediction method was applied to test the power of network-based features. The performance (e.g., the accuracy of identifying cancer stages) when using the fused network from two types of data is shown to be superior to that when using two patient networks from only one data type. The work provides a good example for using network based features from multiple data types for a more comprehensive diagnosis. Auteurs: Su-Ping Deng;Shaolong Cao;De-Shuang Huang;Yu-Ping Wang; Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics Date publication: 10.-2017, volume: 14, issue:5, pages: 1147 - 1153 Editeur: IEEE Document complet vers site de l'éditeur
» IEEE Administrative Meeting and Technical Talk in Abu Dhabi [Around the Globe]
 Résumé:Presents information on the IEEE Administrative Meeting and Technical Talk in Abu Dhabi. Auteurs: Nazih Khaddaj Mallat; Apparue dans: IEEE Microwave Magazine Date publication: 10.-2017, volume: 18, issue:6, pages: 136 - 137 Editeur: IEEE Document complet vers site de l'éditeur
» IEEE Technical Talk at Al Ain University [Around the Globe]
 Résumé:On 1 June 2016, the College of Engineering at Al Ain University of Science and Technology (AAU), in conjunction with the Joint Chapter of the UAE IEEE Microwave Theory and Techniques Society and IEEE Instrumentation and Measurement Society along with the IEEE AAU student branch, organized a technical talk, "The Engineering of the Human Joint: Advances in Orthopedics Research and Computer Navigation" presented by Dr. Farid Amirouche of the University of Illinois at Chicago, United States. Auteurs: Nazih Khaddaj Mallat; Apparue dans: IEEE Microwave Magazine Date publication: 10.-2017, volume: 18, issue:6, pages: 139 - 139 Editeur: IEEE Document complet vers site de l'éditeur
» Image Matting for Automatic Target Recognition
 Résumé:Features used in the classification of targets are generally based on the shape or gray-level information of the preprocessed target chip. Consequently, the performance of an automatic target recognition (ATR) system critically depends on the preprocessing result. In this paper, we propose to apply recent advances in image matting to address these challenges. First, a trimap is automatically generated in an adaptive manner to assign appropriate known foreground and background constraints. Then modified geometric clustering, which estimates the target center robustly, is performed on the estimated trimap. Then propagation-based matting is used to remove nontarget regions while retaining target information. The proposed framework is evaluated using visual examination, ATR performance comparison, and constraints dependency analysis. Our method has robust capabilities and outperforms conventional schemes. Auteurs: Hyun-Woong Cho;Young-Rae Cho;Woo-Jin Song;Byoung-Kwang Kim; Apparue dans: IEEE Transactions on Aerospace and Electronic Systems Date publication: 10.-2017, volume: 53, issue:5, pages: 2233 - 2250 Editeur: IEEE Document complet vers site de l'éditeur
» Image Registration and Change Detection under Rolling Shutter Motion Blur
 Résumé:In this paper, we address the problem of registering a distorted image and a reference image of the same scene by estimating the camera motion that had caused the distortion. We simultaneously detect the regions of changes between the two images. We attend to the coalesced effect of rolling shutter and motion blur that occurs frequently in moving CMOS cameras. We first model a general image formation framework for a 3D scene following a layered approach in the presence of rolling shutter and motion blur. We then develop an algorithm which performs layered registration to detect changes. This algorithm includes an optimisation problem that leverages the sparsity of the camera trajectory in the pose space and the sparsity of changes in the spatial domain. We create a synthetic dataset for change detection in the presence of motion blur and rolling shutter effect covering different types of camera motion for both planar and 3D scenes. We compare our method with existing registration methods and also show several real examples captured with CMOS cameras. Auteurs: Vijay Rengarajan;Ambasamudram Narayanan Rajagopalan;Rangarajan Aravind;Guna Seetharaman; Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence Date publication: 10.-2017, volume: 39, issue:10, pages: 1959 - 1972 Editeur: IEEE Document complet vers site de l'éditeur
» Image Retrieval in Spatial and Temporal Domains With a Quadrant Detector
 Résumé:To retrieve an N pixel image of a scene, conventional digital cameras record the information using an N pixelated detector with one measurement, while single-pixel imaging achieves it by sampling the image in a particular basis and recording the light intensities of N temporal measurements with a single-pixel detector. Besides these two schemes, it is also possible to obtain the same spatial information with an X pixels detector and N/X measurements, where the pressure of information retrieval is distributed to both spatial and temporal domains, rather than condensed in one domain. In this paper, we investigate this possibility and present a 4-pixels imaging scheme, which retrieves an image partially in spatial domain and partially in temporal domain, by adopting a quadrant detector to a single-pixel imaging system. While yielding images with equal quality, the proof-of-principle system we built is four times faster than a standard single-pixel imaging system, demonstrating the feasibility of the proposed scheme. Our work exploits the flexibility of space-time information retrieval and can be useful for applications where comprise between spatial and temporal domains is needed. Auteurs: Ming-Jie Sun;Wen Chen;Teng-Fei Liu;Li-Jing Li; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 6 Editeur: IEEE Document complet vers site de l'éditeur
» Image Segmentation Using Linked Mean-Shift Vectors and Global/Local Attributes
 Résumé:This paper proposes novel noniterative mean-shift-based image segmentation that uses global and local attributes. The existing mean-shift-based methods use a fixed range bandwidth, and hence their accuracy is dependent on the range spectrum of an image. To resolve this dependency, this paper proposes to modify the range kernel in the mean-shift process to be anisotropic. The modification is conducted using a global attribute defined as the range covariance matrix of the image. Further, to alleviate oversegmentation, the proposed method merges the segments having similar local attributes more aggressively than other segments. The local attribute for each segment is defined as the sum of the variances of the chromatic components. Finally, to expedite the processing, the proposed method uses a region adjacency graph (RAG) for the merging process, thus differing from the existing linked mean-shift-based methods. In the experiments on the Berkeley segmentation data set, the use of the global and local attributes improved segmentation accuracy; the proposed method outperformed the state-of-the-art linked mean-shift-based method by showing an improvement of 2.15%, 3.16%, 3.32%, and 1.90% in probability rand index, segmentation covering, variation of information, and F-measure, respectively. Further, compared with the benchmark method, which uses the dilating and merging scheme, the proposed method improved the speed of the merging process 42 times by applying the RAG. Auteurs: Hanjoo Cho;Suk-Ju Kang;Young Hwan Kim; Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology Date publication: 10.-2017, volume: 27, issue:10, pages: 2132 - 2140 Editeur: IEEE Document complet vers site de l'éditeur
» Image Super-Resolution via Block Extraction and Sparse Representation
 Résumé:Super-Resolution (SR) has many applications in several issues of the image processing by obtaining High-Resolution (HR) images from Low-Resolution (LR) images. In this paper, a SR technique that can increase the resolution in images of different nature is proposed. Our approach in obtaining SR image, first uses Lanczos interpolation of initial LR image, then edge features are extracted via convolution of an image with two different filters; following, the most informative features are performed employing principal component analysis (PCA). In next step, preprocessed image presented in blocks is used, where for an each block its sparse representation is performed using LR dictionary and another HR dictionary. In final step, the SR blocks are reconstructed resulting in improved SR image. Experimental results demonstrate the effectiveness of our method in comparison to state-of-the art techniques in terms of objective criteria PSNR, MAE and SSIM values as well as in subjective visual performance. Additionally, the proposed technique significantly reduces computational time in SR reconstruction. Auteurs: Valentin Alvarez Ramos;Volodymyr Ponomaryov;Yuriy Shkvarko;Rogelio Reyes Reyes; Apparue dans: IEEE Latin America Transactions Date publication: 10.-2017, volume: 15, issue:10, pages: 1977 - 1982 Editeur: IEEE Document complet vers site de l'éditeur
» Imbalance Learning Machine-Based Power System Short-Term Voltage Stability Assessment
 Résumé:In terms of machine learning-based power system dynamic stability assessment, it is feasible to collect learning data from massive synchrophasor measurements in practice. However, the fact that instability events rarely occur would lead to a challenging class imbalance problem. Besides, short-term feature extraction from scarce instability seems extremely difficult for conventional learning machines. Faced with such a dilemma, this paper develops a systematic imbalance learning machine for online short-term voltage stability assessment. A powerful time series shapelet (discriminative subsequence) classification method is embedded into the machine for sequential transient feature mining. A forecasting-based nonlinear synthetic minority oversampling technique is proposed to mitigate the distortion of class distribution. Cost-sensitive learning is employed to intensify bias toward those scarce yet valuable unstable cases. Furthermore, an incremental learning strategy is put forward for online monitoring, contributing to adaptability and reliability enhancement along with time. Simulation results on the Nordic test system illustrate the high performance of the proposed learning machine and of the assessment scheme. Auteurs: Lipeng Zhu;Chao Lu;Zhao Yang Dong;Chao Hong; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2533 - 2543 Editeur: IEEE Document complet vers site de l'éditeur
» Impact of 2D-Graphene on SiN Passivated AlGaN/GaN MIS-HEMTs Under Mist Exposure
 Résumé:The effect of a 2D graphene layer (GL) on top of the silicon nitride (SiN) passivation layer of AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors has been systematically analyzed. Results showed that in the devices without the GL, the maximum drain current density ( $\text{I}_{\text {D,max}}$ ) and the maximum transconductance ( $\text{g}_{\text {m,max}}$ ) decreased gradually as the mist exposure time increased, up to 23% and 10%, respectively. Moreover, the gate lag ratio increased around 10% during mist exposure. In contrast, devices with a GL showed a robust behavior and not significant changes in the electrical characteristics in both dc and pulsed conditions. The origin of these behaviors has been discussed and the results pointed to the GL as the key factor for improving the moisture resistance of the SiN passivation layer. Auteurs: M. Fátima Romero;Alberto Boscá;Jorge Pedrós;Javier Martínez;Rajveer Fandan;Tomás Palacios;Fernando Calle; Apparue dans: IEEE Electron Device Letters Date publication: 10.-2017, volume: 38, issue:10, pages: 1441 - 1444 Editeur: IEEE Document complet vers site de l'éditeur
» Impact of Interface Traps and Surface Roughness on the Device Performance of Stacked-Nanowire FETs
 Résumé:In stacked-nanowire field-effect transistors (stacked-NW FETs), the effect of nanowire surface roughness (NWSR) and random interface traps (RIT) on device performance variation is investigated. The 3-D NWSR profile is applied to the surface of the nanowires, and then, the interface traps are generated and randomly placed in the interfacial layer between the silicon and high-k. First, the interaction between NWSR and RIT in a single-NW FET is investigated; the NWSR-induced performance varia- tion is not independent on the RIT-induced variation. Then, the correlation of NWSR profiles and RIT in stacked-NW FETs is explored. The degree of correlation between the NWSR profiles of stacked-NWs is varied in three cases: 1) positively correlated; 2) negatively correlated; and 3) uncorrelated. Without RITs, the NWSR-induced performance variation of the stacked-NW FETs dramatically increases as the NWSR profiles of the nanowires become positively correlated. However, with RITs, the more positively correlated the NWSR profiles of the nanowires, the larger is the ${V}_{T}$ variation that the interface traps induce. Interface traps barely affect the ${V}_{T}$ variation of the negatively correlated NWSR profiles. The variation of current slightly decreases because interface charge scattering degrades the mobility of the carriers. Auteurs: Jinyoung Park;Changhwan Shin; Apparue dans: IEEE Transactions on Electron Devices Date publication: 10.-2017, volume: 64, issue:10, pages: 4025 - 4030 Editeur: IEEE Document complet vers site de l'éditeur
» Impact of metro-embedded data centers on metropolitan network design and traffic profile
 Résumé:Traditional data centers (DCs) that are located in distant areas usually lack flexibility and also have long service latency for metro users. On the other hand, the recently introduced and implemented metro-embedded data center (ME-DC) architecture, based on micro-data centers (mDCs), delivers more flexible services with less access latency. Hierarchical software-defined network control is employed to virtualize and holistically coordinate the distributed mDCs and metro network slices into a reconfigurable virtual data center. Such an approach improves the overall resourcemobility and access to the service;however, the impact on the metro network traffic profile induced by user/mDC and inter-mDC connections due to the dispersion of mDCs has not been evaluated. In this paper, we develop a mixed integer linear programmingmodel that optimizes the total DC traffic, taking into consideration the intra-, inter-, and externalDCcommunications. Furthermore,we numerically assess the changes in the metro network traffic induced by ME-DC architecture, considering different types of DCs and their corresponding traffic profile. Simulation shows that the distribution of the mDCs has a beneficial effect, leading to a fourfold reduction in the total traffic load. Auteurs: Ion Popescu;Xiaoyuan Cao;Gang Chen;Hongxiang Guo;Noboru Yoshikane;Takehiro Tsuritani;Jian Wu;Itsuro Morita; Apparue dans: IEEE/OSA Journal of Optical Communications and Networking Date publication: 10.-2017, volume: 9, issue:10, pages: 900 - 908 Editeur: IEEE Document complet vers site de l'éditeur
» Impact of Mobility on the Uplink Sum Rate of MIMO-OFDMA Cellular Systems
 Résumé:With the fast development of vehicular technologies, the number of mobile terminals as well as their moving speeds has increased conspicuously, making it meaningful to re-examine the impact of mobility on communication performance of the existing cellular systems. In this paper, the uplink sum rate of a multiple-input multiple-output orthogonal frequency-division multiple access (MIMO-OFDMA) cellular system with nodes moving randomly at different speeds is studied. In such a multi-user environment, mobility not only causes inter sub-carrier interferences (ICI) among different users, but also brings the so-called channel aging which together with the above interferences incur outdated and inaccurate channel estimation and thus entail additional pilot overhead. Here, we first derive the relationship between the users’ mobility and the ICI power, characterize the channel aging, and derive the overall multi-user interference caused by the outdated and inaccurate channel state information as a function of mobility. Then, by capitalizing on the above results, the sum rate of the MIMO-OFDMA uplink is theoretically analyzed. Moreover, an adaptive transmission scheme in which the users adjust the pilot percentage according to mobility statistics is proposed to maximize the sum rate. Finally, numerical results are provided to validate our analyses. Auteurs: Zhaoyang Zhang;Chunxu Jiao;Caijun Zhong; Apparue dans: IEEE Transactions on Communications Date publication: 10.-2017, volume: 65, issue:10, pages: 4218 - 4231 Editeur: IEEE Document complet vers site de l'éditeur
» Impact of Non-Linear High-Power Amplifiers on Cooperative Relaying Systems
 Résumé:In this paper, we investigate the impact of the high-power amplifier non-linear distortion on multiple relay systems by introducing the soft envelope limiter, traveling wave tube amplifier, and solid-state power amplifier to the relays. The system employs amplify-and-forward either fixed or variable gain relaying and uses the opportunistic relay selection with outdated channel state information to select the best relay. The results show that the performance loss is small at low rates; however, it is significant for high rates. In particular, the outage probability and the bit error rate are saturated by an irreducible floor at high rates. The same analysis is pursued for the capacity and shows that it is saturated by a detrimental ceiling as the average signal-to-noise ratio becomes higher. This result contrasts the case of the ideal hardware where the capacity grows indefinitely. Moreover, the results show that the capacity ceiling is proportional to the impairment’s parameter and for some special cases the impaired systems practically operate in acceptable conditions. Closed-forms and high SNR asymptotes of the outage probability, the bit error rate, and the capacity are derived. Finally, analytical expressions are validated by the Monte Carlo simulation. Auteurs: Elyes Balti;Mohsen Guizani; Apparue dans: IEEE Transactions on Communications Date publication: 10.-2017, volume: 65, issue:10, pages: 4163 - 4175 Editeur: IEEE Document complet vers site de l'éditeur
» Impact of Selfishness in Device-to-Device Communication Underlying Cellular Networks
 Résumé:In a device-to-device (D2D) communication underlying cellular network, a user equipment is desired to operate cooperatively and unselfishly to transmit data as relays. However, most users more or less behave in a selfish way, which makes user selfishness a key factor that affects the performance of the whole communication system. We focus on the impact of user selfishness on D2D communications. First, we distinguish user selfishness into two types in accordance with D2D transmission modes, namely the connected transmission and opportunistic transmission modes. The user selfishness in these two types of transmissions are modeled separately. Then, we propose a time-varying graph model that characterizes the impacts of both individual and social selfishness on the D2D communications. Simulation results obtained under the realistic networking settings indicate that the interaction between connected and opportunistic selfishness worsens the impairment caused by individual selfishness. Additionally, when concerning social selfishness, inside-community selfishness can be ignored in some occasions, while otherwise its role is heavily influenced by community numbers. Auteurs: Chuhan Gao;Haoming Zhang;Xinlei Chen;Yong Li;Depeng Jin;Sheng Chen; Apparue dans: IEEE Transactions on Vehicular Technology Date publication: 10.-2017, volume: 66, issue:10, pages: 9338 - 9349 Editeur: IEEE Document complet vers site de l'éditeur
» Impact-Time-Control Guidance Law With Constraints on Seeker Look Angle
 Résumé:An impact-time-control guidance (ITCG) law is required for simultaneous attack of multiple missiles. In application of ITCG, the limit of seeker look angle should be regarded as an important factor in homing engagement scenarios. To avoid the loss of target tracking during engagement, the seeker's look angle should be confined to the seeker's field-of-view limit. This paper suggests a new ITCG law for a realistic situation with constraints on seeker look angle driven by the exact nonlinear equations of motion in plane. The proposed guidance law ensures the seeker's look angle to reduce monotonically from the initial value to zero at the intercept point. The resulting solution is presented in the form of proportional navigation guidance law with a time-varying navigation gain. The closed-form navigation gain can be obtained from information on the current missile-to-target range and heading angle. Auteurs: In-Soo Jeon;Jin-Ik Lee; Apparue dans: IEEE Transactions on Aerospace and Electronic Systems Date publication: 10.-2017, volume: 53, issue:5, pages: 2621 - 2627 Editeur: IEEE Document complet vers site de l'éditeur
» Impedance-Dependent Wideband Digital Predistortion of Solid-State Radar Amplifiers
 Résumé:Spectral regrowth and waveform distortion caused by wideband signals input into active phased array antenna systems is the problem this paper addresses. The paper's unique contribution is the development of the impedance-dependent memory polynomial model, capable of solving nonlinear predistortion model parameters for a solid-state high power amplifier with varying load impedance resulting from active electronic beamsteering. Wideband load impedance mismatched tests demonstrate the effectiveness of this technique on a 2.7 GHz, 8 W amplifier. Auteurs: Zachary Dunn;Mark Yeary;Caleb Fulton;Rafael Rincon; Apparue dans: IEEE Transactions on Aerospace and Electronic Systems Date publication: 10.-2017, volume: 53, issue:5, pages: 2290 - 2303 Editeur: IEEE Document complet vers site de l'éditeur
» Implementation of an 8-bit ADC using successive subtraction technique
 Résumé:In this article, an 8-bit ADC circuit is proposed, using op amps in successive subtraction method. This circuit does not require any clock signal, internal DAC or decoder, etc. because it performs the conversion process completely in the analog domain. Applying a supply voltage of ±6 V, it consumes 242 mW power and the settling time is measured as 156 μs. Auteurs: Sayantan Sinha; Apparue dans: IEEE Instrumentation & Measurement Magazine Date publication: 10.-2017, volume: 20, issue:5, pages: 35 - 38 Editeur: IEEE Document complet vers site de l'éditeur
» Implementation of an Active-Clamped Current-Fed Push–Pull Converter Employing Parallel-Inductor to Extend ZVS Range for Fuel Cell Application
 Résumé:This paper proposes a wide-range zero-voltage-switching (ZVS) active-clamped current-fed push-pull converter for fuel cell application. The presented converter achieves ZVS for all of the primary switches and ZCS for secondary diodes from rated load to 10% full load over the wide input voltage variation, improving the overall efficiency. The ZVS of switches is realized by the energy stored in the transformer leakage inductance aided by the secondary parallel inductor. An additional active clamping circuit suppresses the voltage spike as well as assists in realizing ZVS of switches. Low-voltage-rated switches with low on-state resistance can be used. Moreover, the voltage-doubler rectifier is adopted to release the reverse-recovery problem of rectifier diodes and reduce turns ratio of the high-frequency transformer. Detailed steady-state operation, analysis, design, control, comparative study, and experimental results are discussed in depth in this paper. Finally, a 200-W prototype has been built in the laboratory to verify the effectiveness of the proposed converter. Auteurs: Qunfang Wu;Qin Wang;Jialin Xu;Lan Xiao; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 10.-2017, volume: 64, issue:10, pages: 7919 - 7929 Editeur: IEEE Document complet vers site de l'éditeur
» Implementation of High-Precision Quadrature Control for Single-Stage SECS
 Résumé:In this paper, a high precision quadrature control for a single-stage solar energy conversion system (SECS) is presented with power quality improvement capabilities. The SECS uses a voltage source converter (VSC) which performs multifunctions. It harvests maximum energy from the solar photovoltaic (SPV) string and it integrates the extracted energy to the grid. In addition, it utilizes a SPV feed-forward loop to improve the dynamic response and reduces the burden on the proportional-integral controller by regulating dc bus voltage. To control the switching sequences of VSC, a high precision quadrature control is used which extracts the fundamental current from the contaminated load current. The mathematical formulation of quadrature control is corroborated by the experimental results of SECS under different operating conditions. Auteurs: Shailendra Kumar;Bhim Singh; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2726 - 2734 Editeur: IEEE Document complet vers site de l'éditeur
» Improved Lower Bounds on the Size of Balls Over Permutations With the Infinity Metric
 Résumé:We study the size (or volume) of balls in the metric space of permutations, $S_{n}$ , under the infinity metric. We focus on the regime of balls with radius $r = \rho \cdot (n\!-\!1)$ , $\rho \in [{0,1}]$ , i.e., a radius that is a constant fraction of the maximum possible distance. We provide new lower bounds on the size of such balls. These new lower bounds reduce the asymptotic gap to the known upper bounds to at most 0.029 bits per symbol. Additionally, they imply an improved ball-packing bound for error-correcting codes, and an improved upper bound on the size of optimal covering codes. Auteurs: Moshe Schwartz;Pascal O. Vontobel; Apparue dans: IEEE Transactions on Information Theory Date publication: 10.-2017, volume: 63, issue:10, pages: 6227 - 6239 Editeur: IEEE Document complet vers site de l'éditeur
» Improved Model Based on the Modified Steinmetz Equation for Predicting the Magnetic Losses in Non-Oriented Electrical Steels That is Valid for Elevated Temperatures and Frequencies
 Résumé:In this paper, four different grades of fully finished, non-oriented (NO) electrical steels, i.e., M530-50A, M400-50A, M350-50A, and M290-50A, were selected. Their measured magnetic properties were the basis for the derived and validated magnetic-loss prediction model. Based on the experimental data and the modified Steinmetz equation, a simplified predictive model valid at temperatures up to 230 °C, in the frequency range 30–2000 Hz, and magnetic flux densities up to 1.0 T, is proposed. The model’s prediction coefficients are proposed for the eddy current, hysteresis, and excess loss components. An empirical equation for predicting the magnetic losses, valid up to 1.0 T, highlighting the changes in the magnetic losses with temperature is derived. The equation leads to excellent agreement between the measured and predicted magnetic losses for four grades of NO electrical steel. Auteurs: G. Novak;J. Kokošar;M. Bricelj;M. Bizjak;D. Steiner Petrovič;A. Nagode; Apparue dans: IEEE Transactions on Magnetics Date publication: 10.-2017, volume: 53, issue:10, pages: 1 - 5 Editeur: IEEE Document complet vers site de l'éditeur
» Improved Modeling of Geomagnetically Induced Currents Utilizing Derivation Techniques for Substation Grounding Resistance
 Résumé:This paper focuses on estimating the substation grounding resistance to improve the modeling of geomagnetically induced currents (GICs). Grounding resistances are not included in the standard power flow models, and their approximate values are often used for performing GIC studies. This paper provides an algorithm to estimate the resistances from the GIC measurements. This algorithm calculates the linear sensitivity factors of the GICs around the local grounding resistive components and uses linear regression to solve for the resistances. The effectiveness of the proposed algorithm is demonstrated using both a small test case as well as a 62 500-bus model of the North American Eastern Interconnection. Auteurs: Maryam Kazerooni;Hao Zhu;Thomas J. Overbye; Apparue dans: IEEE Transactions on Power Delivery Date publication: 10.-2017, volume: 32, issue:5, pages: 2320 - 2328 Editeur: IEEE Document complet vers site de l'éditeur
» Improved Multitrack Detection With Hybrid 2-D Equalizer and Modified Viterbi Detector
 Résumé:Increasing track density in magnetic recording systems increases inter-track interference (ITI). One way to handle the increased ITI is to apply 2-D equalization to the signals from multiple tracks. Usually the equalizer coefficients and the corresponding partial response (PR) targets are fixed after training using a pseudo-random bit sequence. We denote such an equalizer as a fixed equalizer. In this paper, we propose and investigate a variable 2-D equalizer for bit patterned media recording (BPMR). In the proposed approach, the equalizer coefficients and corresponding PR targets vary with ITI patterns. These variable equalizer coefficients are determined and stored by training with sequences representing different ITI patterns. In the proposed approach for BPMR, during data detection, these variable equalizer coefficients and corresponding PR targets are embedded into the parallel branches of a modified Viterbi (MV) detector in response to estimated ITI patterns. We term this new approach as V2DEMV [i.e., variable 2-D equalizer with 2-D PR target followed by MV detector] algorithm. Furthermore, we propose to simplify the implementation of the V2DEMV algorithm by identifying the survivor branch among the branches corresponding to the dominant erroneous ITI patterns. Then this survivor branch and other branches corresponding to remaining possible ITI patterns are processed by an F2DEMV (i.e., fixed 2-D equalizer with 2-D PR target followed by MV detector) algorithm to estimate the bits. We term this reduced-complexity approach as an H2DEMV (i.e., hybrid 2-D equalizer with 2-D PR target followed by MV detector) algorithm. Our simulations indicate that for both two readers detecting two tracks and three readers detecting three tracks, at target bit error rate of $10^{-3}$ , the proposed H2DEMV algorithm can provide noticeable signal-to-noise ratio (SNR) gains com- ared to F2DE1DV algorithm (i.e., fixed 2-D equalizer with 1-D PR target followed by 1-D Viterbi detector) and F2DEMV algorithm. Auteurs: Yao Wang;B. V. K. Vijaya Kumar; Apparue dans: IEEE Transactions on Magnetics Date publication: 10.-2017, volume: 53, issue:10, pages: 1 - 10 Editeur: IEEE Document complet vers site de l'éditeur
» Improved Neutral Current Compensation With a Four-Leg PV Smart VSI in a LV Residential Network
 Résumé:Loads in low voltage (LV) residential areas are mainly single-phase types which are supplied from a delta/wye connected distribution transformer with a grounded neutral conductor creating a three-phase (3P) four-wire (4W) distribution system. The unbalanced single-phase load distributions in traditional 3P-4W LV networks cause significant neutral currents which can result in the overloading of the neutral conductor and electrical safety concerns for customers. In this paper, the dependency of the load generated neutral current on the distribution line variable zero sequence R/X ratios is developed, and a new decentralized robust active neutral compensation method is proposed using a multifunctional transformerless 3P four-leg (4L) photovoltaic (PV) smart voltage source inverter (SVSI). System stability is verified from the bode analysis and the improved neutral compensation is evaluated from the circuitry model analysis. Actual single-phase customer loads with real sun irradiance and temperature profiles are used with an urban 3P-4W LV network model from Australia and implemented in simulation using the PSCAD/EMTDC software to verify the efficacy of the proposed controller in real world distribution networks. Different transient faults analyses and point of common coupling dynamic voltage regulation are also performed and faster fault recovery, better neutral compensation, and optimized voltage profile are achieved from the designed PV-SVSI. Auteurs: Fida Hasan Md Rafi;M. Jahangir Hossain;Junwei Lu; Apparue dans: IEEE Transactions on Power Delivery Date publication: 10.-2017, volume: 32, issue:5, pages: 2291 - 2302 Editeur: IEEE Document complet vers site de l'éditeur
» Improved Single-Element Resistive Sensor-to-Microcontroller Interface
 Résumé:Direct resistive sensor interface to a microcontroller has several advantages but has one prominent disadvantage, namely, the measurement is affected by the resistances of: 1) wires that connect the sensor to the port pins and 2) the internal resistances of the port pins of the microcontroller. A direct sensor-to-microcontroller interface scheme that compensates the effect due not only to resistances of lead wires but also the effect of microcontroller port pin’s internal resistance and any offset present in those pins is presented in this paper. Since the resistances of lead wires are compensated, automatic temperature compensation (temperature effect of lead wires) is also obtained. Simulation study and results obtained from a prototype built and tested establish the efficacy of the proposed method. A maximum error of 0.06% was observed from the prototype developed, when it was tested under room temperature, after interfacing it with the sensor Pt100, with a lead wire resistance $R_{\mathrm {LD}} = 21~\Omega$ . The error increased to a maximum of 0.08%, when the $R_{\mathrm {LD}}$ varied from 0 to $100~\Omega$ . When the same prototype was tested under elevated room temperature of 30 °C to 100 °C, the maximum error observed was 0.18%. Auteurs: Ponnalagu Ramanathan Nagarajan;Boby George;V. Jagadeesh Kumar; Apparue dans: IEEE Transactions on Instrumentation and Measurement Date publication: 10.-2017, volume: 66, issue:10, pages: 2736 - 2744 Editeur: IEEE Document complet vers site de l'éditeur
» Improved Single-Event Transient Hardness in Tunnel-Diode Body-Contact SOI nMOS
 Résumé:Single-event transient (SET) responses are compared for floating-body contact, T-gate body-contact (TB), and tunnel-diode body-contact (TDBC) silicon-on-insulator (SOI) MOSFETs. The influence of three body-contact schemes on SET sensitivity is examined via irradiations as functions of position, bias voltage, and device size. The mechanisms of SET in SOI devices are discussed. Although both TB and TDBC schemes suppress floating body effects (FBEs), the TDBC scheme has superior SET hardness because it effectively eliminates charge enhancement due to bipolar amplification originating from FBEs. Thus, TDBC-structure SOI devices can lead to improved single-event upset hardness in static random access memory cells. Auteurs: Lingda Xu;Jiexin Luo;Jing Chen;Zhan Chai;Weiwei He;En Xia Zhang;Daniel M. Fleetwood; Apparue dans: IEEE Transactions on Nuclear Science Date publication: 10.-2017, volume: 64, issue:10, pages: 2669 - 2672 Editeur: IEEE Document complet vers site de l'éditeur
» Improvement in Device Performance of Vertical Thin-Film Transistors Using Atomic Layer Deposited IGZO Channel and Polyimide Spacer
 Résumé:Technical strategies for improving the device characteristics of the In–Ga–Zn-O (IGZO) vertical channel thin-film transistors (VTFTs) were presented and investigated. The vertical sidewall was constructed by dry-etch process and subsequently covered with IGZO, Al2O3, and AZO as active, gate insulator, and gate electrode layers by means of conformal atomic-layer-deposition. An abrupt profile and flat back-channel were achieved by employing the spin-coated polyimide (PI) spacer. The Off-current was additionally alleviated simply by cutting the area of an active layer. The fabricated IGZO VTFT using PI spacer with an “active-cut” structure exhibited an On/off ratio of $10^{3}$ , a linear mobility of 7.1 cm2/Vs, and a subthreshold swing of 1.2 V/decade. Auteurs: Yeo-Myeong Kim;Han-Byeol Kang;Gi-Heon Kim;Chi-Sun Hwang;Sung-Min Yoon; Apparue dans: IEEE Electron Device Letters Date publication: 10.-2017, volume: 38, issue:10, pages: 1387 - 1389 Editeur: IEEE Document complet vers site de l'éditeur
» Improvement of Back-EMF Self-Sensing For Induction Machines When Using Deadbeat-Direct Torque and Flux Control
 Résumé:Back-electromotive force (back-EMF) self-sensing is commonly used in induction machine (IM) drive systems for its maintenance cost and safety considerations. In recent years, compared with standard indirect field oriented control, deadbeat-direct torque and flux control (DB-DTFC) has been shown to be a highly effective method for IM control with a fixed switching frequency. It has advantages such as fast torque dynamics with one step dynamic response for torque and flux with no current regulator. This paper evaluates the synergy between back-EMF self-sensing technology and DB-DTFC for IM drive systems. In this paper, an observer-based closed-loop back-EMF tracking self-sensing control in an IM DB-DTFC drive system is presented. It includes a back-EMF state filter, back-EMF tracking observer, and cascaded motion observer. Back-EMF harmonic decoupling is explored to improve the low-speed performance. The band-pass filter method (BPF) for back-EMF self-sensing is also presented. Finally, the closed loop system dynamic stiffness at very low speeds, with and without the BPF method, is experimentally evaluated. Auteurs: Kang Wang;Robert D. Lorenz;Noor Aamir Baloch; Apparue dans: IEEE Transactions on Industry Applications Date publication: 10.-2017, volume: 53, issue:5, pages: 4569 - 4578 Editeur: IEEE Document complet vers site de l'éditeur
» Improvement of Device Reliability by Introducing a BEOL-Compatible TiN Barrier Layer in CBRAM
 Résumé:Negative-SET behavior, induced by nano-filament overgrowth phenomenon, takes major responsibility to the reset failure phenomenon in conductive bridge random access memory (CBRAM). The unexpected negative-SET behavior in CBRAM devices can result in serious reliability issues and has been an obstacle on the way to mass production. In this letter, we have proposed a back-end-of-line (BEOL) compatible TiN barrier layer to improve the device reliability in CBRAM devices by eliminating the nano-filament overgrowth phenomenon and negative-SET behavior. Thus, a higher reset voltage can be applied to the TiN barrier layer devices to achieve more complete reset process and obtain better resistive switching performance. The results show that the Cu/HfO2/TiN/Ru device with one transistor structure has excellent comprehensive memory properties, including high reliability, fast switching speed, high resistance state uniformity, high endurance, long retention, and multi-level storage ability. Auteurs: Rongrong Cao;Sen Liu;Qi Liu;Xiaolong Zhao;Wei Wang;Xumeng Zhang;Facai Wu;Quantan Wu;Yan Wang;Hangbing Lv;Shibing Long;Ming Liu; Apparue dans: IEEE Electron Device Letters Date publication: 10.-2017, volume: 38, issue:10, pages: 1371 - 1374 Editeur: IEEE Document complet vers site de l'éditeur
» Improvement of Lake Ice Thickness Retrieval From MODIS Satellite Data Using a Thermodynamic Model
 Résumé:Observations of ice thickness are limited in high latitude regions, at a time when they are increasingly being requested by operational ice centers. This study aims to improve the retrieval of lake ice thickness using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua (P.M.) and Terra (A.M.) satellites. The accuracy of ice thickness retrievals based on MODIS lake ice surface temperature (LIST) is investigated using a commonly used heat balance equation and the retrieved ice thicknesses are compared to in situ measurements from the Canadian Ice Service. The accuracy of ice thickness estimates is improved when using snow depth from the 1-D thermodynamic lake ice model Canadian Lake Ice Model (CLIMo) rather than an empirical relationship between snow depth and ice thickness utilized in the recent investigations. Taking into account all data over the study period (2002–2014), the mean bias error and the root-mean-square error are reduced from −0.42 to 0.07 m and 0.58 to 0.17 m, respectively, with the novel approach proposed herein. However, this approach is limited to ice thickness estimations of less than ca. 1.7 m. Auteurs: Homa Kheyrollah Pour;Claude R. Duguay;K. Andrea Scott;Kyung-Kuk Kang; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5956 - 5965 Editeur: IEEE Document complet vers site de l'éditeur
» Improvement of Subthreshold Characteristic of Gate-Recessed AlGaN/GaN Transistors by Using Dual-Gate Structure
 Résumé:The subthreshold characteristic of gate-recessed high-electron-mobility transistors (HEMTs) using dual-gate (DG) architectures is systematically studied. The recessed DG structure can effectively shift the threshold voltage ( ${V}_{\text {th}}$ ) in the positive direction. Different from the complex function expression between ${V}_{\text {th}}$ and AlGaN thickness ( $\text{t}_{b}$ ) in the recessed single-gate (SG) device, the variation of $\text{V}_{\text {th}}$ with ${t}_{b}$ is monotonic in the recessed DG devices. Recessed DG device exhibits a low off-state leakage current of $\sim {3}\times {10}^{{-10}}$ A/mm and gate induced drain leakage is effectively improved. A higher $I_{ \mathrm{\scriptscriptstyle ON}}/I_{ \mathrm{\scriptscriptstyle OFF}}$ range of recessed DG devices broadens about 2 times and provide a wider range of ${t}_{b}$ than that of recessed SG devices. The DG structure has a stronger modulation effect on drain–source resistance ( ${R}_{\text {ds}}$ ) and gate–drain resistance ( ${R}_{\text {gd}}$ ) than the SG devices. A lower subthreshold swing (SS) of ~100 mV/dec is obtained by recessed DG design. Due to the second gate inducing the lateral extension of depletion - egion between the first gate and drain, the off-state leakage and first gate reverse leakage have been significantly improved. Therefore, the recessed DG architecture design can effectively improve the fluctuation of SS and off-state current versus the different AlGaN barrier thickness. Auteurs: Ling Yang;Minhan Mi;Bin Hou;Jiejie Zhu;Meng Zhang;Yunlong He;Yang Lu;Qing Zhu;Xiaowei Zhou;Ling Lv;Yanrong Cao;Xiaohua Ma;Yue Hao; Apparue dans: IEEE Transactions on Electron Devices Date publication: 10.-2017, volume: 64, issue:10, pages: 4057 - 4064 Editeur: IEEE Document complet vers site de l'éditeur
» Improvement of visibility under foggy conditions
 Résumé:Light scattering produced for bad weather conditions produces outdoor images with poor contrast and faded colors, these effects can be critical in applications such as video surveillance, driving assistance or autonomous navigation. This article introduces a novel algorithm to restore the contrast of images under adverse weather conditions e.g.; fog, mist or haze. The proposed method combines several techniques in order to provide a fast algorithm able to work with color as well as gray images. Although other deweathering methods require multiple images of the scene or information about the weather conditions or the scene structure the proposed method only requires a single image of the foggy scene and assumes heterogeneous atmospheric conditions which is a common feature in images affected for weather conditions. Experiment results on real-world datasets validate the effectiveness of the proposed method. Auteurs: Juan Andrade; Apparue dans: IEEE Latin America Transactions Date publication: 10.-2017, volume: 15, issue:10, pages: 1983 - 1987 Editeur: IEEE Document complet vers site de l'éditeur
» Improving Dynamic Response of AMB Systems in Control Moment Gyros Based on a Modified Integral Feedforward Method
 Résumé:During gimbal maneuvering, the dynamic characteristics of the active magnetic bearing (AMB) rotor system is an important concern for the applications of the magnetically suspended double-gimbal control moment gyro (MSDGCMG). Both the static torques caused by the gimbal motions and the dynamic torques by the rotor twisting motion will have an impact on the dynamic performance of the magnetically suspended high-speed rotor. This paper explores a modified current integral feedforward (CIF) control scheme to improve its dynamic response. Using a dynamic regulator, the CIF method is applied to supply the static torque by the permanent magnets and simultaneously improve the stability margin of the AMB rotor system. Then, the multiple compensation method is proposed to compensate the dynamic torque to further improve the response speed. The influence of rotor tilting on the output torque precision of MSDGCMG is also analyzed. Finally, the experimental results on a developed MSDGCMG prototype validate the effectiveness of the proposed method. The modified CIF combined with dynamic torque compensation resulted in a step response settling time of 0.13 s as compared with the traditional method with a settling time of 2.5 s. Auteurs: Shiqiang Zheng;Jinjin Xie;Chen Ma;He Liao;Cheng Chen; Apparue dans: IEEE/ASME Transactions on Mechatronics Date publication: 10.-2017, volume: 22, issue:5, pages: 2111 - 2120 Editeur: IEEE Document complet vers site de l'éditeur
» Improving IBM POWER8 Performance Through Symbiotic Job Scheduling
 Résumé:Symbiotic job scheduling, i.e., scheduling applications that co-run well together on a core, can have a considerable impact on the performance of processors with simultaneous multithreading (SMT) cores. SMT cores share most of their microarchitectural components among the co-running applications, which causes performance interference between them. Therefore, scheduling applications with complementary resource requirements on the same core can greatly improve the throughput of the system. This paper enhances symbiotic job scheduling for the IBM POWER8 processor. We leverage the existing cycle accounting mechanism to build an interference model that predicts symbiosis between applications. The proposed models achieve higher accuracy than previous models by predicting job symbiosis from throttled CPI stacks, i.e., CPI stacks of the applications when running in the same SMT mode to consider the statically partitioned resources, but without interference from other applications. The symbiotic scheduler uses these interference models to decide, at run-time, which applications should run on the same core or on separate cores. We prototype the symbiotic scheduler as a user-level scheduler in the Linux operating system and evaluate it on an IBM POWER8 server running multiprogram workloads. The symbiotic job scheduler significantly improves performance compared to both an agnostic random scheduler and the default Linux scheduler. Across all evaluated workloads in SMT4 mode, throughput improves by 12.4 and 5.1 percent on average over the random and Linux schedulers, respectively. Auteurs: Josué Feliu;Stijn Eyerman;Julio Sahuquillo;Salvador Petit;Lieven Eeckhout; Apparue dans: IEEE Transactions on Parallel and Distributed Systems Date publication: 10.-2017, volume: 28, issue:10, pages: 2838 - 2851 Editeur: IEEE Document complet vers site de l'éditeur
» Improving Identification of Key Players in Aging via Network De-Noising and Core Inference
 Résumé:Current “ground truth” knowledge about human aging has been obtained by transferring aging-related knowledge from well-studied model species via sequence homology or by studying human gene expression data. Since proteins function by interacting with each other, analyzing protein-protein interaction (PPI) networks in the context of aging is promising. Unlike existing static network research of aging, since cellular functioning is dynamic, we recently integrated the static human PPI network with aging-related gene expression data to form dynamic, age-specific networks. Then, we predicted as key players in aging those proteins whose network topologies significantly changed with age. Since current networks are noisy , here, we use link prediction to de-noise the human network and predict improved key players in aging from the de-noised data. Indeed, de-noising gives more significant overlap between the predicted data and the “ground truth” aging-related data. Yet, we obtain novel predictions, which we validate in the literature. Also, we improve the predictions by an alternative strategy: removing “redundant” edges from the age-specific networks and using the resulting age-specific network “cores” to study aging. We produce new knowledge from dynamic networks encompassing multiple data types, via network de-noising or core inference, complementing the existing knowledge obtained from sequence or expression data. Auteurs: Boyoung Yoo;Fazle Elahi Faisal;Huili Chen;Tijana Milenković; Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics Date publication: 10.-2017, volume: 14, issue:5, pages: 1056 - 1069 Editeur: IEEE Document complet vers site de l'éditeur
» Improving Performance for Flash-Based Storage Systems through GC-Aware Cache Management
 Résumé:Flash-based SSDs have been extensively deployed in modern storage systems to satisfy the increasing demand of storage performance and energy efficiency. However, Garbage Collection (GC) is an important performance concern for flash-based SSDs, because it tends to disrupt the normal operations of an SSD. This problem continues to plague flash-based storage systems, particularly in the high performance computing and enterprise environment. An important root cause for this problem, as revealed by previous studies, is the serious contention for the flash resources and the severe mutually adversary interference between the user I/O requests and GC-induced I/O requests. The on-board buffer cache within SSDs serves to play an essential role in smoothing the gap between the upper-level applications and the lower-level flash chips and alleviating this problem to some extend. Nevertheless, the existing cache replacement algorithms are well optimized to reduce the miss rate of the buffer cache by reducing the I/O traffic to the flash chips as much as possible, but without considering the GC operations within the flash chips. Consequently, they fail to address the root cause of the problem and thus are far from being sufficient and effective in reducing the expensive I/O traffic to the flash chips that are in the GC state. To address this important performance issue in flash-based storage systems, particularly in the HPC and enterprise environment, we propose a Garbage Collection aware Replacement policy, called GCaR, to improve the performance of flash-based SSDs. The basic idea is to give higher priority to caching the data blocks belonging to the flash chips that are in the GC state. This substantially lessens the contentions between the user I/O operations and the GC-induced I/O operations. To verify the effectiveness of GCaR, we have integrated it into the SSD extended Disksim simulator. The simulation results show that GCaR can significantly improve the storage performan- e by up to 40.7 percent in terms of the average response times. Auteurs: Suzhen Wu;Bo Mao;Yanping Lin;Hong Jiang; Apparue dans: IEEE Transactions on Parallel and Distributed Systems Date publication: 10.-2017, volume: 28, issue:10, pages: 2852 - 2865 Editeur: IEEE Document complet vers site de l'éditeur
» Improving Supervised Learning Classification Methods Using Multigranular Linguistic Modeling and Fuzzy Entropy
 Résumé:Obtaining good classification results using supervised learning methods is critical if we want to obtain a high level of precision in the classification processes. The training data used for the learning process play a very important role in achieving this objective. Therefore, it is important to represent the data in a way that best expresses its meaning. For this purpose, we propose to apply linguistic modeling methods in order to obtain a linguistic representation. With the help of multigranular linguistic modeling, data can be transformed and expressed using different (unbalanced) linguistic label sets. Expressing the data using linguistic expressions instead of numbers increases the readability and reduces the complexity of the problem, and data recovering methods allow us to manually control the level of precision. In this paper, several datasets are transformed and utilized for classification tasks using several supervised learning algorithms. For each combination of datasets and algorithms, the data have been expressed using several linguistic label sets that have different granularity values. After carrying out the testing processes, we can conclude that, in some cases, reducing data complexity leads to better classification results. Therefore, it is found that linguistic representation of the training data with just the necessary and sufficient precision can improve the reliability of the classification process. Auteurs: Juan Antonio Morente-Molinera;József Mezei;Christer Carlsson;Enrique Herrera-Viedma; Apparue dans: IEEE Transactions on Fuzzy Systems Date publication: 10.-2017, volume: 25, issue:5, pages: 1078 - 1089 Editeur: IEEE Document complet vers site de l'éditeur
» Improving the Algorithm of Extracting Regional Total Precipitable Water Vapor Over Land From MODIS Images
 Résumé:Precise estimation of total precipitable water vapor (TPW) with high temporal and spatial resolutions is of great importance in different disciplines. Moderate-Resolution Imaging Spectroradiometer (MODIS) is one of the sensors which have absorption and nonabsorption bands of water vapor. There is a standard algorithm to produce TPW product of MODIS (MOD05/MYD05) which uses the ratios of reflectances in strong, moderate, and weak absorption bands of water vapor to nonabsorption ones (transmission). This paper aims to present a method based on this algorithm to optimize TPW estimation in local scale. To do so, the western part of Iran was chosen as the study region. Terra MODIS images and MOD05 in clear-sky conditions related to the 100 days in four seasons of 2015–2016 were provided as the selected data. To validate and improve the results, TPW measured in six radiosonde stations and interpolated for overpass time of Terra was utilized. Four procedures were performed. In the first procedure, the coefficients of transmissions were extracted using linear least-squares technique, separately. For the second procedure, the coefficients were calculated in terms of the highest atmospheric transmission sensitivity to TPW for each absorption band separately, and in the third procedure, they were calculated simultaneously. In the last procedure, the errors from third one were modeled with a linear relationship between reflectance ratios of absorption bands. Based on the results, in highest accuracy, the coefficient of determination ${{{\text{R}}}}^{2}$ and Root Mean Square Error was 0.878 and 2.702 mm, respectively, which were acceptable comparing those of other researchers. Auteurs: Mohammad Hossein Merrikhpour;Majid Rahimzadegan; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5889 - 5898 Editeur: IEEE Document complet vers site de l'éditeur
» Improving the Speed of Center of Sets Type Reduction in Interval Type-2 Fuzzy Systems by Eliminating the Need for Sorting
 Résumé:In the deployment of interval type-2 fuzzy systems, one of the most important steps is the type reduction. The commonly used center of sets type reducer requires the solution of two nonlinear constrained optimization problems. Frequently used approaches to solve them are the Karnik–Mendel algorithms and their variants. However, these algorithms suffer from the need for sorting, which is known to be computationally very expensive. Using the reformulations proposed in this paper for center of sets type reducer, it is possible to eliminate the need for sorting. This makes interval type-2 fuzzy systems more appropriate for cost-sensitive real-time applications. Extensive simulations are presented to illustrate the faster convergence speed of the proposed method over six other enhanced variants of the Karnik–Mendel algorithm as applied to center of sets type reduction of interval type-2 fuzzy systems. Auteurs: Mojtaba Ahmadieh Khanesar;Alireza Jalalian Khakshour;Okyay Kaynak;Huijun Gao; Apparue dans: IEEE Transactions on Fuzzy Systems Date publication: 10.-2017, volume: 25, issue:5, pages: 1193 - 1206 Editeur: IEEE Document complet vers site de l'éditeur
» Impulse Response Measurement of Few-Mode Fiber Systems by Coherence-Recovered Linear Optical Sampling
 Résumé:This paper presents impulse response measurements of few-mode optical fibers and transmission lines that were obtained by using coherence-recovered linear optical sampling or a two-comb interferometer. When performing a measurement, the probe pulse source and the sampling pulse source may be far from each other, particularly when the fibers are installed in the field, and the fiber length may exceed several tens kilometers. In this paper, by modifying a previously proposed referencing technique, the coherence between two pulse lasers is equivalently maintained by canceling out the phase noise caused both by the light sources and perturbations in the fiber. Hence, the amplitude averaging is used to enhance the signal-to-noise ratio. As a result, we can measure the impulse responses of multimode fibers with a dynamic range of 80 dB and a time resolution of a few picoseconds, over tens nanoseconds of differential mode delay. Auteurs: Naoto Kono;Fumihiko Ito;Daisuke Iida;Tetsuya Manabe; Apparue dans: Journal of Lightwave Technology Date publication: 10.-2017, volume: 35, issue:20, pages: 4392 - 4398 Editeur: IEEE Document complet vers site de l'éditeur
» In Situ Shape Estimation of Triangular Moored Hydrophone Arrays Using Ambient Signals
 Résumé:In this paper, a method is presented for correcting relative errors in the locations of individual sensors in a three-element bottom-moored array, using ambient signal arrivals recorded by the array. It has the benefit that knowledge of absolute source positions is not required to determine the relative shape of the array. The procedure is demonstrated using episodic ambient signal arrivals recorded by the southern array of the Wake Island hydrophone station, which is a component of the Comprehensive Nuclear-Test Ban Treaty Organization's (CTBTO) International Monitoring System (IMS). The original coordinates of sensors 2 and 3 were adjusted by 75 and 115 m, respectively, removing approximately 4$^{\circ}$ of error in estimating the arrival angles of signals. The estimated coordinates compared favorably with the results of a position revision by the CTBTO a year after the triad installation. Auteurs: Stephen M. Nichols;David L. Bradley; Apparue dans: IEEE Journal of Oceanic Engineering Date publication: 10.-2017, volume: 42, issue:4, pages: 923 - 935 Editeur: IEEE Document complet vers site de l'éditeur
» In-Network Compression for Multiterminal Cascade MIMO Systems
» In-Plane-Gate GaN Transistors for High-Power RF Applications
 Résumé:In-plane-gate field-effect transistors (IPGFETs) offer an innovative device architecture in which the channel conductivity is modulated by the electric field from the 2D electron gas in the two adjacent in-plane gates, isolated by etched trenches. The planar nature of the gate electrode yields a huge reduction in parasitic gate capacitance, which can lead to much higher frequency. Moreover, the fabrication process for these devices is extremely simple and with inherently self-aligned gates. Here, we combine for the first time the promising architecture of IPGFETs with the exceptional properties of III-Nitrides, such as large carrier density and breakdown field, to reveal their enormous potential for high-power RF devices. AlGaN/GaN IPGFETs demonstrated large drain current up to 1.4 A/mm and transconductance up to 665 mS/mm, which are, respectively, nine times- and five times-larger than the best IPGFETs demonstrated in other semiconductors. These devices presented excellent gate control with ON–OFF ratio up to $10^{7}$ along with ultra-low capacitances down to 0.7 aF, leading to an estimated $f_{T}$ up to 0.89 THz. Extremely large breakdown voltage of 500 V was observed despite their nanoscale dimensions, with small leakage current below 1 nA up to 300 V. These results reveal that III-Nitride IPGFETs offer a promising pathway for future terahertz devices delivering large output powers. Auteurs: Giovanni Santoruvo;Elison Matioli; Apparue dans: IEEE Electron Device Letters Date publication: 10.-2017, volume: 38, issue:10, pages: 1413 - 1416 Editeur: IEEE Document complet vers site de l'éditeur
» Inactivation Decoding of LT and Raptor Codes: Analysis and Code Design
 Résumé:In this paper, we analyze Luby transform (LT) and Raptor codes under inactivation decoding. A first-order analysis is introduced, which provides the expected number of inactivations for an LT code, as a function of the output distribution, the number of input symbols, and the decoding overhead. The analysis is then extended to the calculation of the distribution of the number of inactivations. In both cases, random inactivation is assumed. The developed analytical tools are then exploited to design LT and Raptor codes, enabling a tight control on the decoding complexity versus failure probability tradeoff. The accuracy of the approach is confirmed by numerical simulations. Auteurs: Francisco Lázaro;Gianluigi Liva;Gerhard Bauch; Apparue dans: IEEE Transactions on Communications Date publication: 10.-2017, volume: 65, issue:10, pages: 4114 - 4127 Editeur: IEEE Document complet vers site de l'éditeur
» Inband Full-Duplex Radio Transceivers: A Paradigm Shift in Tactical Communications and Electronic Warfare?
» Incentivizing Crowdsensing With Location-Privacy Preserving
 Résumé:Crowd sensing systems enable a wide range of data collection, where the data are usually tagged with private locations. How to incentivize users to participate in such systems while preserving location-privacy is coming up as a critical issue. To this end, we consider location-privacy protection when motivating users to sense data instead of viewing them separately. Without loss of generality, $k$ -anonymity is utilized to reduce the risk of location-privacy disclosure. Specifically, we propose a location aggregation method to cluster users into groups for $k$ -anonymity preserving, and meanwhile mitigating the incurred information loss. After that, an incentive mechanism is carefully designed to select efficient users and calculate rational compensations based on clustered groups obtained in location aggregation, where the influences of both the information loss and $k$ -anonymity in location-privacy preserving are captured into group values and sensing costs. Through theoretical analysis and extensive performances evaluated on real and synthetic data, we find out that the incentive payment increases sharply with more stringent privacy protection and the information loss can be further mitigated compared with conventional methods. Auteurs: Xiong Wang;Zhe Liu;Xiaohua Tian;Xiaoying Gan;Yunfeng Guan;Xinbing Wang; Apparue dans: IEEE Transactions on Wireless Communications Date publication: 10.-2017, volume: 16, issue:10, pages: 6940 - 6952 Editeur: IEEE Document complet vers site de l'éditeur
» Incoherent Tensor Norms and Their Applications in Higher Order Tensor Completion
 Résumé:In this paper, we investigate the sample size requirement for a general class of nuclear norm minimization methods for higher order tensor completion. We introduce a class of tensor norms by allowing for different levels of coherence, which allows us to leverage the incoherence of a tensor. In particular, we show that a $k$ th-order tensor of multilinear rank $r$ and dimension $d \times \cdots \times d$ can be recovered perfectly from as few as $O((r^{(k-1)/2}d^{3/2}+r^{k-1}d)(\log (d))^{2})$ uniformly sampled entries through an appropriate incoherent nuclear norm minimization. Our results demonstrate some key differences between completing a matrix and a higher order tensor: they not only point to potential room for improvement over the usual nuclear norm minimization but also highlight the importance of explicitly accounting for incoherence, when dealing with higher order tensors. Although our focus is primarily on the theoretical guarantees for nuclear norm minimization, such insights may prove useful for understanding performance of other related methods and developing improved practical algorithms. Auteurs: Ming Yuan;Cun-Hui Zhang; Apparue dans: IEEE Transactions on Information Theory Date publication: 10.-2017, volume: 63, issue:10, pages: 6753 - 6766 Editeur: IEEE Document complet vers site de l'éditeur
» Incorporating Intelligence in Fog Computing for Big Data Analysis in Smart Cities
 Résumé:Data intensive analysis is the major challenge in smart cities because of the ubiquitous deployment of various kinds of sensors. The natural characteristic of geodistribution requires a new computing paradigm to offer location-awareness and latency-sensitive monitoring and intelligent control. Fog Computing that extends the computing to the edge of network, fits this need. In this paper, we introduce a hierarchical distributed Fog Computing architecture to support the integration of massive number of infrastructure components and services in future smart cities. To secure future communities, it is necessary to integrate intelligence in our Fog Computing architecture, e.g., to perform data representation and feature extraction, to identify anomalous and hazardous events, and to offer optimal responses and controls. We analyze case studies using a smart pipeline monitoring system based on fiber optic sensors and sequential learning algorithms to detect events threatening pipeline safety. A working prototype was constructed to experimentally evaluate event detection performance of the recognition of 12 distinct events. These experimental results demonstrate the feasibility of the system's city-wide implementation in the future. Auteurs: Bo Tang;Zhen Chen;Gerald Hefferman;Shuyi Pei;Tao Wei;Haibo He;Qing Yang; Apparue dans: IEEE Transactions on Industrial Informatics Date publication: 10.-2017, volume: 13, issue:5, pages: 2140 - 2150 Editeur: IEEE Document complet vers site de l'éditeur
» Incremental Deployment of Segment Routing Into an ISP Network: a Traffic Engineering Perspective
 Résumé:Segment routing (SR) is a new routing paradigm to provide traffic engineering (TE) capabilities in an IP network. The main feature of SR is that no signaling protocols are needed, since extensions of the interior gateway protocol routing protocols are used. Despite the benefit that SR brings, introducing a new technology into an operational network presents many difficulties. In particular, the network operators consider both capital expenditure and performance degradation as drawbacks for the deployment of the new technology; for this reason, an incremental approach is preferred. In this paper, we face the challenge of managing the transition between a pure IP network to a full SR one while optimizing the network performances. We focus our attention on a network scenario where: 1) only a subset of nodes are SR-capable and 2) the TE objective is the minimization of the maximum link utilization. For such a scenario, we propose an architectural solution, named SR domain (SRD), to guarantee the proper interworking between the IP routers and the SR nodes. We propose a mixed integer linear programming formulation to solve the SRD design problem, consisting in identifying the subset of SR nodes; moreover, a strategy to manage the routing inside the SRD is defined. The performance evaluation shows that the hybrid IP/SR network based on SRD offers TE opportunities comparable to the one of a full SR network. Finally, a heuristic method to identify nodes to be inserted in the set of nodes composing the SRD is discussed. Auteurs: Antonio Cianfrani;Marco Listanti;Marco Polverini; Apparue dans: IEEE/ACM Transactions on Networking Date publication: 10.-2017, volume: 25, issue:5, pages: 3146 - 3160 Editeur: IEEE Document complet vers site de l'éditeur
» Incremental SAT-Based Reverse Engineering of Camouflaged Logic Circuits
 Résumé:Layout-level gate or routing camouflaging techniques have attracted interest as countermeasures against reverse engineering of combinational logic. In order to minimize area overhead, typically only a subset of gate or routing components are camouflaged, and each camouflaged component layout can implement one of a few different functions or connections. The security of camouflaging relies on the difficulty of learning the overall combinational logic function without knowing the functions implemented by the individual camouflaged components of the circuit. In this paper, we expand our previous work on using incremental SAT solving to reconstruct the logical function of a circuit with camouflaged components. Our algorithm uses the standard attacker model in which an adversary knows only the noncamouflaged component functions, and has the ability to query the circuit to learn the correct output vector for any input vector. Our results demonstrate a $10.5\times$ speedup in average runtime over the best known existing deobfuscation algorithm prior to this technique. The results presented go beyond our previous work by showing that this technique, previously applied only to a particular style of gate camouflaging, is general and can be used to deobfuscate three different proposed styles of camouflaging. We give results to quantify the effectiveness of camouflaging techniques on a variety of ISCAS-85 benchmark circuits. Auteurs: Cunxi Yu;Xiangyu Zhang;Duo Liu;Maciej Ciesielski;Daniel Holcomb; Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems Date publication: 10.-2017, volume: 36, issue:10, pages: 1647 - 1659 Editeur: IEEE Document complet vers site de l'éditeur
» Indirect-Reciprocity Data Fusion Game and Application to Cooperative Spectrum Sensing
 Résumé:Data sharing is one critical step to implement data fusion, and how to encourage sensors to share their data is an important issue. In this paper, we propose a reputation-based incentive framework, where the data sharing stimulation problem is modeled as an indirect reciprocity game. In the proposed game, sensors choose how to report their results to the fusion center and gain reputations, based on which they can obtain certain benefits in the future. Taking the sensing and fusion accuracy into account, reputation distribution is introduced in the proposed game, where we prove theoretically the Nash equilibrium of the game and its uniqueness. Furthermore, we apply the proposed scheme to the cooperative spectrum sensing. We show that within an appropriate cost-to-gain ration, the optimal strategy for the secondary users is to report when the average received energy is above a given threshold and keep silence otherwise. Such an optimal strategy is also proved to be a desirable evolutionarily stable strategy. Finally, simulation results are shown to verify the theoretical results and demonstrate that compared with the existing schemes, our proposed scheme achieves better operating characteristic curve and higher system throughput with convincing performance on fairness. Auteurs: Biling Zhang;Yan Chen;Jung-Lang Yu;Bin Chen;Zhu Han; Apparue dans: IEEE Transactions on Wireless Communications Date publication: 10.-2017, volume: 16, issue:10, pages: 6571 - 6585 Editeur: IEEE Document complet vers site de l'éditeur
» Inference and Learning in Evidential Discrete Latent Markov Models
 Résumé:We present the Evidential Hidden Markov Models (EvHMM), an extension of probabilistic HMM for time-series modeling, where conditional belief functions are used in place of probabilities to manage uncertainty on discrete latent variables. Inference and learning mechanisms are described and allow to solve the three problems initially defined for HMM, namely, the classification problem (find the most plausible model), the decoding problem (finding the best sequence of hidden states), and the learning problem based on incomplete and uncertain data (estimate the parameters). Exact inference mechanisms based on the GBT are proposed which allows one to recover standard HMM when probabilities are considered. An EM-like procedure is developed for parameter learning, relying on some approximations suggested to make the solutions tractable. Relationships are discussed with both the learning criterion conjectured by Vannoorenberghe and Smets and the formulation of EMCs by Pieczynski et al. A comparison with standard HMM on simulated data confirms the interest of considering random disjunctive sets to represent data incompleteness in evidential temporal graphical models. Auteurs: Emmanuel Ramasso; Apparue dans: IEEE Transactions on Fuzzy Systems Date publication: 10.-2017, volume: 25, issue:5, pages: 1102 - 1114 Editeur: IEEE Document complet vers site de l'éditeur
» Influence of MOCVD Growth Pressure on Magnetoresistance of Nanostructured La-Ca-Mn-O Films Used for Magnetic Field Sensors
 Résumé:The results of structure and magnetoresistance (MR) of nanostructured La1–xCaxMnyO3 (LCMO) films, grown at different gas pressure (from 3 to 7 Torr) by pulse injection metal–organic chemical vapor deposition (MOCVD) technique, are presented. The MR was investigated in pulsed magnetic fields up to 60 T in the temperature range 1.5–294 K. The results were analyzed from the perspective of using these films for magnetic field sensors operating at low temperatures. It was demonstrated that with the increase of Ar + O2 gas pressure, the surface morphology of the films becomes rougher and grain size increases. Also, the ratio of Mn/(La + Ca) increases with the increase of the pressure. Large MR of the films was observed in a wide temperature range below the ferromagnetic–paramagnetic phase transition. It was shown that at cryogenic temperatures, the films grown at gas pressure of 3 Torr have higher sensitivity in lower magnetic field range (<10 T), while in high magnetic fields (20–60 T), the properties of films grown at higher gas pressure 5–7 Torr are favored. The obtained results allow evaluating the influence of MOCVD growth pressure on MR and sensitivity to the magnetic field of LCMO manganites used for pulsed magnetic field sensors. Auteurs: Nerija Žurauskienė;Dainius Pavilonis;Jonas Klimantavičius;Saulius Balevičius;Voitech Stankevič;Skirmantas Keršulis;Valentina Plaušinaitienė;Adulfas Abrutis;Rasuolė Lukošė;Ma Apparue dans: IEEE Transactions on Plasma Science Date publication: 10.-2017, volume: 45, issue:10, pages: 2780 - 2786 Editeur: IEEE Document complet vers site de l'éditeur
» Influence of Radar Targets on the Accuracy of FMCW Radar Distance Measurements
 Résumé:Distance measurement tasks in micromachine tools need to be performed with micrometer accuracy. For such tasks, frequency-modulated continuous-wave (FMCW) radars with a combination of frequency and phase evaluations are a good choice. However, the accuracy cannot be indefinitely increased as there are constraints on the target size and placement imposed by the limited space inside micromachines. This paper investigates the influence of target geometry and position on the accuracy of its range estimation using a W-band FMCW radar with a bandwidth of 25 GHz. A relation between target geometry and accuracy is established through the Cramér–Rao lower bound (CRLB). Based on the measurements of different targets, an optimal shape and size is proposed, which provides an average accuracy in the single digit micrometer range. Furthermore, the influence of different bandwidths on the accuracy is investigated. It is also demonstrated how the CRLB can be used to optimize the size of a target, when a certain accuracy is needed. In addition, antenna field regions are analyzed for suitable target placements. Finally, the radar system is implemented in a machine tool and measurements with accuracies in the micrometer range are carried out. Auteurs: Steffen Scherr;Rifat Afroz;Serdal Ayhan;Sven Thomas;Timo Jaeschke;Sören Marahrens;Akanksha Bhutani;Mario Pauli;Nils Pohl;Thomas Zwick; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 10.-2017, volume: 65, issue:10, pages: 3640 - 3647 Editeur: IEEE Document complet vers site de l'éditeur
» Influence of Surface Roughness Measurement Scale on Radar Backscattering in Different Agricultural Soils
 Résumé:Soil surface roughness strongly affects the scattering of microwaves on the soil surface and determines the backscattering coefficient ( $\sigma ^{0})$ observed by radar sensors. Previous studies have shown important scale issues that compromise the measurement and parameterization of roughness especially in agricultural soils. The objective of this paper was to determine the roughness scales involved in the backscattering process over agricultural soils. With this aim, a database of 132 5-m profiles taken on agricultural soils with different tillage conditions was used. These measurements were acquired coinciding with a series of ENVISAT/ASAR observations. Roughness profiles were processed considering three different scaling issues: 1) influence of measurement range; 2) influence of low-frequency roughness components; and 3) influence of high-frequency roughness components. For each of these issues, eight different roughness parameters were computed and the following aspects were evaluated: 1) roughness parameters values; 2) correlation with $\sigma ^{0}$ ; and 3) goodness-of-fit of the Oh model. Most parameters had a significant correlation with $\sigma ^{0}$ especially the fractal dimension, the peak frequency, and the initial slope of the autocorrelation function. These parameters had higher correlations than classical parameters such as the standard deviation of surface heights or the correlation length. Very small differences were observed when longer than 1-m profiles were used as well as when small-scale roughness components (<5 cm) or large-scale roughness components (>100 cm) were disregarded. In conclusion, the medium-frequency roughness components (scal- of 5–100 cm) seem to be the most influential scales in the radar backscattering process on agricultural soils. Auteurs: Alex Martinez-Agirre;Jesús Álvarez-Mozos;Hans Lievens;Niko E. C. Verhoest; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5925 - 5936 Editeur: IEEE Document complet vers site de l'éditeur
» Influence of the Manufacturing Process of a Claw-Pole Alternator on Its Stator Shape and Acoustic Noise
 Résumé:This paper shows the influence of the manufacturing process of a claw-pole alternator on its acoustic noise. First, the stator welds and the assembly of the stator in the brackets are linked to deformations of the inner diameter of the stator. Then, the influences of these deformations on the magnetic forces and the subsequent acoustic noise are investigated. Results show that the deformations caused by the manufacturing process significantly increase the sound power level of particular orders. Auteurs: Antoine Tan-Kim;Nicolas Hagen;Vincent Lanfranchi;Stéphane Clénet;Thierry Coorevits;Jean-Claude Mipo;Jérôme Legranger;Frédéric Palleschi; Apparue dans: IEEE Transactions on Industry Applications Date publication: 10.-2017, volume: 53, issue:5, pages: 4389 - 4395 Editeur: IEEE Document complet vers site de l'éditeur
» Information Entropy and Fuzzy Logic Based Equalizer for PolMux QAM Coherent Optical Communication Systems
 Résumé:In polarization-multiplexed (PolMux) coherent optical communication systems, adaptive blind equalizer is efficient in demultiplexing and mitigating intersymbol interference (ISI). A novel blind algorithm based on Information Entropy and fuzzy logic is proposed, in which the Renyi's $\alpha$ entropy is adopted to measure the uncertainty of error between the desired and estimated probability density function (PDF). The nonparametric PDF estimator of Parzen window method is employed to estimate the PDF of symbols. Meantime, a fuzzy-logic tuning unit is designed to adjust the kernel size of Parzen window, which leads to fast convergence rate and small steady mean-square error. By simulation in PolMux-16 quadrature amplitude modulation (QAM) coherent systems, the correctness and effectiveness of the proposed algorithm are verified. Auteurs: Zhili Zhou;Yiju Zhan;Qingling Cai;Xiukai Ruan;Guihua Cui;Yuxing Dai;Haiyong Zhu; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 16 Editeur: IEEE Document complet vers site de l'éditeur
» Information Transfer of Control Strategies: Dualities of Stochastic Optimal Control Theory and Feedback Capacity of Information Theory
 Résumé:The control-coding capacity of stochastic control systems is introduced, and its operational meaning is established using randomized control strategies, which simultaneously control output processes encode information, and communicate information from control processes to output processes. The control-coding capacity is the analog Shannon's coding-capacity of noisy channels. Furthermore, duality relations to stochastic optimal control problems with deterministic and randomized control strategies are identified including the following. First, extremum problems of stochastic optimal control with directed information payoff are equivalent to feedback capacity problems of information theory, in which the control system act as a communication channel. Second, for Gaussian linear decision models with average quadratic constraints, it is shown that optimal randomized strategies are Gaussian, and decompose into a deterministic part and a random part. The deterministic part is precisely the optimal strategy of the linear quadratic Gaussian stochastic optimal control problem, whereas the random part is the solution of an water-filling information transmission problem that encodes information, which is estimated by a decoder. Auteurs: Charalambos D. Charalambous;Christos K. Kourtellaris;Ioannis Tzortzis; Apparue dans: IEEE Transactions on Automatic Control Date publication: 10.-2017, volume: 62, issue:10, pages: 5010 - 5025 Editeur: IEEE Document complet vers site de l'éditeur
» Information-Assisted Density Peak Index for Hyperspectral Band Selection
 Résumé:Band selection has become an effective method to reduce hyperspectral dimensionality. In this letter, an information-assisted density peak index (IaDPI) is proposed to prioritize the bands. Based on a clustering method by finding density peaks, IaDPI introduces the intraband information entropy into the local density and intercluster distance to ensure cluster centers with a high quality. Also, the band distance is integrated with channel proximity to control the compactness of local density. Owing to the intraband entropy and the interband weighted dissimilarity, the selected band set with top-ranked IaDPI scores can hold high local density, clear global distinction, and good informative quality. Experimental results on real hyperspectral data indicate the advantages of the proposed IaDPI in good selection quality, robust noise immunity, and high classification accuracy. Auteurs: Xiaoyan Luo;Rui Xue;Jihao Yin; Apparue dans: IEEE Geoscience and Remote Sensing Letters Date publication: 10.-2017, volume: 14, issue:10, pages: 1870 - 1874 Editeur: IEEE Document complet vers site de l'éditeur
» Infrared Absorption at 300 K in InGaN/GaN Disk-in-Nanowire Arrays Grown on (001) Silicon
 Résumé:In0.34Ga0.66N/GaN disk-in-nanowire arrays have been grown on (001) Si substrates by molecular beam epitaxy and their infrared absorption spectra have been measured at room temperature. The average diameter and area density of the nanowires are 60 nm and $2\times 10^{10}$ cm $^{-2}$ , respectively. The room temperature photoluminescence spectrum is characterized by peak emission at 540 nm. The absorption spectra measured with a Fourier transform infrared spectrometer in transmission and reflection modes exhibit multiple absorption peaks ranging from 1.6 to $20~\mu \text{m}$ . The peak energies have been compared with those for intersubband transitions calculated with a simple model and there is agreement in some cases. Auteurs: Arnab Hazari;Alexander Soibel;Sarath D. Gunapala;Pallab Bhattacharya; Apparue dans: IEEE Photonics Technology Letters Date publication: 10.-2017, volume: 29, issue:20, pages: 1751 - 1754 Editeur: IEEE Document complet vers site de l'éditeur
» Infrared Dim and Small Target Detection Based on Stable Multisubspace Learning in Heterogeneous Scene
 Résumé:Infrared (IR) dim and small target detection in a highly complex background play an important role in many applications, and remain a challenging problem. In this paper, a novel method named stable multisubspace learning is presented to deal with this problem. The new method takes into account the inner structure of actual images so that it overcomes the shortage of the traditional method. First, by analyzing the multisubspace structure of heterogeneous background data, a corresponding image model is proposed using subspace learning strategy. This model is also stable to noise interference. Second, an efficient optimization algorithm is designed to solve the proposed IR image model. By adding the proper postprocessing procedure, we can get the detection result. Experiments on simulation scenes and real scenes show that the proposed method has superior detection ability under heterogeneous background. Auteurs: Xiaoyang Wang;Zhenming Peng;Dehui Kong;Yanmin He; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5481 - 5493 Editeur: IEEE Document complet vers site de l'éditeur
» Infrared Small Target Detection via Nonnegativity-Constrained Variational Mode Decomposition
 Résumé:Infrared small target detection is one of the key techniques in the infrared search and track system. Frequency differences among target, background, and noise are often important information for target detection. In this letter, a nonnegativity-constrained variational mode decomposition (NVMD) method is proposed. Unlike the traditional frequency-domain methods, the proposed method can adaptively decompose the input signal into several separated band-limited subsignals, with the nonnegativity constraint. First, a bandpass filter is used as a preprocessing step. Second, by exploring the frequency and nonnegativity properties of the small target, the NVMD model is constructed. The potential target subsignal can be obtained by solving the NVMD model. By performing threshold segmentation on the potential target subsignal, we can obtain the detection result of the infrared small target. Experiments on six real infrared image sequences demonstrate that the proposed method has a good performance in target enhancement and background suppression. Additionally, the proposed method shows strong robustness under various backgrounds. Auteurs: Xiaoyang Wang;Zhenming Peng;Ping Zhang;Yanmin He; Apparue dans: IEEE Geoscience and Remote Sensing Letters Date publication: 10.-2017, volume: 14, issue:10, pages: 1700 - 1704 Editeur: IEEE Document complet vers site de l'éditeur
» Infrastructure-Assisted Message Dissemination for Supporting Heterogeneous Driving Patterns
 Résumé:With the advances of Internet of Things technologies, individual vehicles can now exchange information to improve traffic safety, and some vehicles can further improve safety and efficiency by coordinating their mobility via cooperative driving. To facilitate these applications, many studies have been focused on the design of inter-vehicle message dissemination protocols. However, most existing designs either assume individual driving pattern or consider cooperative driving only. Moreover, few of them fully exploit infrastructures, such as cameras, sensors, and road-side units. In this paper, we address the design of message dissemination that supports heterogeneous driving patterns. Specifically, we first propose an infrastructure-assisted message dissemination framework that can utilize the capability of infrastructures. We then present a novel beacon scheduling algorithm that aims at guaranteeing the timely and reliable delivery of both periodic beacon messages for cooperative driving and event-triggered safety messages for individual driving. To evaluate the performance of the protocol, we develop both theoretical analysis and simulation experiments. Extensive numerical results confirm the effectiveness of the proposed protocol. Auteurs: Bingyi Liu;Dongyao Jia;Kejie Lu;Haibo Chen;Rongwei Yang;Jianping Wang;Yvonne Barnard;Libing Wu; Apparue dans: IEEE Transactions on Intelligent Transportation Systems Date publication: 10.-2017, volume: 18, issue:10, pages: 2865 - 2876 Editeur: IEEE Document complet vers site de l'éditeur
» Initial Phase and Modulation Factor Optimization for Structured Illumination Microscopy
 Résumé:Structured illumination microscopy (SIM) is a widefield super-resolution technique in fluorescent imaging. For an artifact-free reconstruction, some crucial parameters should be known with high accuracy. However, the initial phase and modulation factor of illumination pattern cannot be guaranteed with enough precision experimentally, so they have to be retrieved from the acquired data. We propose a fast and robust method to compute these two parameters and then the coefficients of frequency components can be normalized. We analyze the performance of this method using simulated data and experimental data. The results demonstrate that the coefficients normalization has important effect on the improvement of reconstruction image. Compared with widefield resolution (216 nm), the lateral resolution of SIM can achieve 97 nm. Auteurs: Yanwei Zhang;Cong Luo;Hongwei Wang;Song Lang;Yan Gong;Yuguo Tang; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 9 Editeur: IEEE Document complet vers site de l'éditeur
» Injection With Negative Wavelength Detuning for Multispectrum Frequency Generation and Hopping Using SMFP-LD
 Résumé:We propose and demonstrate a novel method to generate multispectrum frequency and hopping from one frequency spectrum to another using a single external cavity based Fabry–Pérot laser diode (FP-LD) subjected to a single optical injection with negative wavelength detuning. The external cavity based FP-LD has a single dominant mode, single-mode FP-LD (SMFP-LD), and hence the beating of the dominant mode and the injected beam, and the beating of the injected beam and the corresponding side mode of SMFP-LD are possible with a single optical injection. The generated frequency can be tuned to a wide range of GHz to several THz. Individual or simultaneous RF signals generation and hopping between microwave and millimeter wave spectrum are reported. The effect of the injected beam power on generating and hopping of RF frequency is analyzed in the case of negative wavelength detuning with the input beam injected on different modes of SMFP-LD. Also, the stability of beating wavelengths, power variations of beating wavelengths for an interval of 1 hour, and linewidth of RF signals are observed. Auteurs: Bikash Nakarmi;Hao Chen;Muyong Lee;Yong Hyub Won;Shilong Pan; Apparue dans: IEEE Photonics Journal Date publication: 10.-2017, volume: 9, issue:5, pages: 1 - 11 Editeur: IEEE Document complet vers site de l'éditeur
» Innovative Antenna Front Ends from L-Band to Ka-Band [Antenna Applications Corner]
 Résumé:We provide an overview of several high-tech antenna apertures and antenna front ends, developed and realized by IMST (in some cases in cooperation with partners) over a time span of more than 15 years. These front ends have become key components for bandwidth-hungry applications such as mobile/nomadic satellite communication terminals (satcom-onthe-move) and radar systems. Satcom terminal data throughput for multimedia services provided via satellite links is increasing rapidly. Such terminals require highly complex radio-frequency (RF) systems capable of tracking satellites despite movements of the mobile terminal platform. Depending on the type of platform (land mobile, maritime, or aeronautical), the requirements for these front ends and the resulting complexity can vary. This also applies to radar sensors for automotive applications and unmanned aerial vehicle (UAV) platforms, for example. In all of these front ends, the antenna architecture is always based on a phased/steerable array topology. Such systems are, in general, complex configurations: they require not only RF circuitry but also complex baseband processing and highly accurate sensor platforms to perform adequate beam steering and tracking. The overall design must be cost-effective, a very demanding requirement. Through the years, IMST has developed a customized set of highly specialized skills to address all of these challenges. Auteurs: Rens Baggen;Sybille Holzwarth;Martin Bottcher;Simon Otto; Apparue dans: IEEE Antennas and Propagation Magazine Date publication: 10.-2017, volume: 59, issue:5, pages: 116 - 129 Editeur: IEEE Document complet vers site de l'éditeur
» Innovative Contactless Energy Transfer Accessory for Rotary Ultrasonic Machining and Its Circuit Compensation Based on Coil Turns
 Résumé:An innovative concentric rotary ultrasonic machining (RUM) device based on local induction is proposed. The device is used as a machine tool accessory that can add the RUM to any machining center. Rather than using a complete ring, a portion of a ring is used as the primary core in the proposed rotary transformer, which eliminates spindle speed limits. The simplified configuration provides increased safety and is convenient for material processing applications. Additionally, a circuit compensation method based on coil turns is proposed. It takes the whole circuit, reliability of electronic components, transmission efficiency, and output power into consideration. We use this method to choose the optimal number of coil turns and compensation elements required to achieve increased and safe power transmission performance. This paper also demonstrates the performance of the device through experimentation. Finally, practicability is discussed. Auteurs: Yujia Luan;Bin Lin;Xingru Ma;Xueming Zhu; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 10.-2017, volume: 64, issue:10, pages: 7810 - 7818 Editeur: IEEE Document complet vers site de l'éditeur
» Input–Output Based Fault Estimation for T-S Fuzzy Systems With Local Nonlinear Parts
 Résumé:This paper is concerned with the problem of fault estimation for a class of Takagi–Sugeno fuzzy systems with local nonlinear parts and actuator faults. The system matrices in consideration contain unknown components, whereas in most of the literature, the system matrices are required to be known completely. An input–output based fault-estimation approach for the fuzzy system is proposed, by which, the estimation error for time-varying faults can asymptotically converge to zero in the absence of disturbances. The estimation convergence is proved theoretically. Based on the information of fault estimation, the design of fault-tolerant controller can be updated online to compensate the fault effect on systems so as to maintain the original performance of the system. Numerical examples are given to show the effectiveness and merits of the proposed method. Auteurs: Sheng-Juan Huang;Guang-Hong Yang; Apparue dans: IEEE Transactions on Fuzzy Systems Date publication: 10.-2017, volume: 25, issue:5, pages: 1320 - 1328 Editeur: IEEE Document complet vers site de l'éditeur
» InSAR Time-Series Estimation of the Ionospheric Phase Delay: An Extension of the Split Range-Spectrum Technique
 Résumé:Repeat pass interferometric synthetic aperture radar (InSAR) observations may be significantly impacted by the propagation delay of the microwave signal through the ionosphere, which is commonly referred to as ionospheric delay. The dispersive character of the ionosphere at microwave frequencies allows one to estimate the ionospheric delay from InSAR data through a split range-spectrum technique. Here, we extend the existing split range-spectrum technique to InSAR time-series. We present an algorithm for estimating a time-series of ionospheric phase delay that is useful for correcting InSAR time-series of ground surface displacement or for evaluating the spatial and temporal variations of the ionosphere’s total electron content (TEC). Experimental results from stacks of L-band SAR data acquired by the ALOS-1 Japanese satellite show significant ionospheric phase delay equivalent to 2 m of the temporal variation of InSAR time-series along 445 km in Chile, a region at low latitudes where large TEC variations are common. The observed delay is significantly smaller, with a maximum of 10 cm over 160 km, in California. The estimation and correction of ionospheric delay reduces the temporal variation of the InSAR time-series to centimeter levels in Chile. The ionospheric delay correction of the InSAR time-series reveals earthquake-induced ground displacement, which otherwise could not be detected. A comparison with independent GPS time-series demonstrates an order of magnitude reduction in the root mean square difference between GPS and InSAR after correcting for ionospheric delay. The results show that the presented algorithm significantly improves the accuracy of InSAR time-series and should become a routine component of InSAR time-series analysis. Auteurs: Heresh Fattahi;Mark Simons;Piyush Agram; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 10.-2017, volume: 55, issue:10, pages: 5984 - 5996 Editeur: IEEE Document complet vers site de l'éditeur
» Insider Privileges
 Résumé:How does standard textbook economics analyze insider status in technology markets? It takes one of two perspectives. The first perspective stresses the cold logic of market competition, and the second stresses the ambiguities of the government’s influence. This essay summarizes the implications of each perspective and the troubling questions raised. Auteurs: Shane Greenstein; Apparue dans: IEEE Micro Date publication: 10.-2017, volume: 37, issue:5, pages: 70 - 72 Editeur: IEEE Document complet vers site de l'éditeur

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