Electrical and Electronics Engineering publications abstract of: 11-2017 sorted by title, page: 10

» Improvement of Handheld Radar Operators’ Hazard Detection Performance Using 3-D Visualization
Abstract:
Handheld ground-penetrating radar systems are employed in both military and humanitarian demining operations. Radar system operators are given the difficult job of determining the nature of subsurface objects from signal reflections in real time. Current systems require operators to multitask both collection and classification. This letter tested a 3-D data visualization method against a 2-D method. The 3-D method attempts to separate tasks by not forcing operators to classify objects in real time. Data showed that users classifying objects with the 3-D system had better performance and also reported that this system was more user-friendly. In addition, users were able to classify underground objects quicker with the 3-D system. The results of this letter demonstrate the benefit of 3-D visualization in ground scanning systems in increasing performance and decreasing cognitive load.
Autors: Drew B. Gonsalves;Lawrence H. Winner;Joseph N. Wilson;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1888 - 1892
Publisher: IEEE
 
» Improvement of Preventing Particle Generation by Using Collision Assisted Sintering Process (CASP)
Abstract:
To suppress particle generation in a dry etching apparatus, the deposition method of Y2O3 film used as chamber wall coating was studied. The conventional Y2O3 coating is deposited by atmospheric plasma spraying. Compared to the conventional method, collision assisted sintering process (CASP) provided denser film with less defects, higher density, and less particle detachment, even after plasma exposure. By using CASP coating in the chamber, we were able to reduce particles by 67%.
Autors: Tetsuyuki Matsumoto;Rikyu Ikariyama;Makoto Saito;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Nov 2017, volume: 30, issue:4, pages: 362 - 366
Publisher: IEEE
 
» Improving BER Performance by Using V-Shaped Read Head Array in Heat-Assisted Magnetic Recording
Abstract:
Heat-assisted magnetic recording (HAMR) is the leading candidate for the next generation of magnetic recording. In HAMR, the thermal profile (with circular contours produced by the near-field transducer) combined with the current writer structures results in recording transitions with noticeable curvature, which causes edge erasure at high linear density and increased transition noise. This transition curvature affects the bit error rate (BER) and is thus important to the model. As the micromagnetic simulations are computationally demanding, in this paper we investigate a fast and simplified write model to capture the transition curvature of HAMR. As the transition curvature causes signal degradation in normally oriented read head array (NHA) having straight gaps, we propose a V-shaped read head array (VHA) by rotating the side readers at appropriate angles to follow the curvature shapes and improve the readback signal. Simulations indicate that, with 2-D signal processing, VHA can provide improved BER performance compared to the NHA in the presence of readback transition curvature on HAMR media. Also this paper indicates that the Curie temperature variance affects BER performance more severely than the anisotropy field variance.
Autors: Yao Wang;B. V. K. Vijaya Kumar;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 7
Publisher: IEEE
 
» Improving MOCVD MoS2 Electrical Performance: Impact of Minimized Water and Air Exposure Conditions
Abstract:
The effects of oxidants both in the channel and contact regions of MoS2 transistors are discussed through a systematic experimental study. This letter highlights the issues of partial instability in metal-organic chemical vapor deposition MoS2 and proposes a procedure, which considerably improves the electrical characteristics of back-gated transistors. By avoiding ambient exposure and layer oxidation, contact resistance can be reduced and intrinsic mobility increased by 50%.
Autors: Alessandra Leonhardt;Daniele Chiappe;Inge Asselberghs;Cedric Huyghebaert;Iuliana Radu;Stefan De Gendt;
Appeared in: IEEE Electron Device Letters
Publication date: Nov 2017, volume: 38, issue:11, pages: 1606 - 1609
Publisher: IEEE
 
» Improving QoS and QoE Through Seamless Handoff in Software-Defined IEEE 802.11 Mesh Networks
Abstract:
To deliver an enhanced mobility experience, wireless networks must provide seamless handoff to mobile clients. Moreover, the handoff process should preserve quality-of-service (QoS) and quality of experience (QoE) at acceptable levels. This letter presents a strategy to provide seamless mobility in wireless mesh networks, considering software-defined network-controlled handoff and passive measurements. To validate the proposal, we deployed a 802.11/OpenFlow test bed and performed extensive experiments. Experimental results demonstrated improvements of QoE up to 70% while keeping key QoS metrics below real-time applications constraints.
Autors: Italo Valcy S. Brito;Gustavo B. Figueiredo;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2484 - 2487
Publisher: IEEE
 
» Improving Secrecy Performance of a Wirelessly Powered Network
Abstract:
This paper considers the secrecy communication of a wirelessly powered network, where an energy-constrained legitimate transmitter (Alice) sends message to a legitimate receiver (Bob) with the energy harvested from a dedicated power beacon, while an eavesdropper (Eve) intends to intercept the information. A simple time-switching protocol with a time-switching ratio is used to supply power for the energy-constrained legitimate transmitter. To improve the physical layer security, we first propose a protocol that combines maximum ratio transmission with zero-forcing (ZF) jamming for the case without Eve’s channel state information (CSI), i.e., Alice has access to Bob’s CSI only. Then, we propose a protocol that uses a ZF transmitting strategy to minimize the signal-to-noise ratio (SNR) at Eve for the case that Alice is capable of obtaining partial CSI related to Eve. Closed-form expressions and simple approximations of the connection outage probability and secrecy outage probability are derived for both protocols. Furthermore, the secrecy throughput as well as the diversity orders achieved by our proposed protocols are characterized, and the optimal time-switching ratio and power allocation coefficient for secrecy throughput maximization are derived in the high SNR regime. Finally, numerical results validate the effectiveness of the proposed schemes.
Autors: Zhuo Chen;Lucinda Hadley;Zhiguo Ding;Xuchu Dai;
Appeared in: IEEE Transactions on Communications
Publication date: Nov 2017, volume: 65, issue:11, pages: 4996 - 5008
Publisher: IEEE
 
» Improving Throughput and Fairness of Convergecast in Vehicular Networks
Abstract:
Delivering data from source vehicles to infrastructures, or convergecast, is a fundamental operation in vehicular networks. However, the network capacity of vehicular network is always limited because of scarce inter-vehicle contacts. Thus, throughput maximization of convergecast in vehicular networks is of great importance. The unique characteristics of vehicular networks, however, present great challenges including frequent connection unavailability and opportunistic contacts. We propose an approach called ConvergeCode for improving the convergecast throughput in vehicular networks, which employs random linear coding for packet delivery. A vehicle randomly combines all received coded data and forwards it to any contacted vehicles. Through extensive empirical study based on the two large datasets of real GPS traces, we make the key observation that significant throughput gain can be achieved by using network coding but a serious fairness issue arises. In this paper, we study the problem of maximizing the throughput of convergecast in vehicular networks at the same time enhancing the fairness among different source nodes. We first formulate the problem of allocating inter-vehicle contacts as a lexicographical max-min multi-source flow problem, and then develop an efficient approximation algorithm with -approximation guarantee. Simulations based on real vehicular GPS traces have been performed and results show that the throughput is improved by 74-110 percent while the lexicographical max-min fairness is achieved.
Autors: Ruobing Jiang;Yanmin Zhu;Yudong Yang;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Nov 2017, volume: 16, issue:11, pages: 3070 - 3083
Publisher: IEEE
 
» In Memoriam
Abstract:
It is with great sadness that we inform you that Sergey Kharkovsky, one of the journal's Associate Editors, passed away on September 6, 2017.
Autors: Sergey Kharkovsky;Shervin Shirmohammadi;Alessandro Ferrero;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2802 - 2802
Publisher: IEEE
 
» In Situ Mechanical Characterization of Multilayer Soft Tissue Using Ultrasound Imaging
Abstract:
In this paper, we report the development of a technique to characterize layer-specific nonlinear material properties of soft tissue in situ with the potential for in vivo testing. A soft tissue elastography robotic arm system comprising of a robotically manipulated 30 MHz high-resolution ultrasound probe, a custom designed compression head, and load cells has been developed to perform compression ultrasound imaging on the target tissue and measure reaction forces. A multilayer finite element model is iteratively optimized to identify the material coefficients of each layer. Validation has been performed using tissue mimicking agar-based phantoms with a low relative error of ∼7% for two-layer phantoms and ∼10% error for three layer phantoms when compared to known ground-truth values obtained using a commercial material testing system. The technique has then been used to successfully determine the in situ layer-specific mechanical properties of intact porcine stomach. The mean C10 and C20 for a second-order reduced polynomial material model were determined for the muscularis (6.41 ± 0.60, 4.29 ± 1.87 kPa), submucosal (5.21 ± 0.57, 3.68 ± 3.01 kPa), and mucosal layers (0.06 ± 0.02, 0.09 ± 0.24 kPa). Such a system can be utilized to perform in vivo mechanical characterization, which is left as future work.
Autors: Saurabh Dargar;Ali C. Akyildiz;Suvranu De;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2595 - 2606
Publisher: IEEE
 
» In the Pursuit of Hygge Software
Abstract:
Hygge is Danish and Norwegian for well-being related to conviviality. Health and social relations are tightly bound, so how can we integrate today’s technologies to provide hygge? Two healthcare scenarios show ways to achieve hygge by integrating software and distributed technologies, using elements of the U’Ductor model. This model ubiquitously supports noncommunicable-disease care, providing a way for applications to communicate, automatically receive health status updates, and search for nearby resources and people. The ChronicDuctor and ChronicPrediction apps use U’Ductor to improve patient care.
Autors: Henrique Damasceno Vianna;Jorge Luis Victória Barbosa;Fábio Pittoli;
Appeared in: IEEE Software
Publication date: Nov 2017, volume: 34, issue:6, pages: 48 - 52
Publisher: IEEE
 
» In-DRAM Data Initialization
Abstract:
Initializing memory with zero data is essential for safe memory management. However, initializing a large memory area slows down the system significantly. The most likely cause for initialization to slow down the system is the limited DRAM initialization method. At present, the only way to initialize DRAM area is to execute multiple WRITE commands. However, the WRITE command slows the initialization because of its small granularity and data bus occupancy. In this brief, we propose an efficient in-DRAM initialization method inspired by the internal structure and operation of DRAM. The proposed method, called row reset, uses a DRAM row buffer to zero out a single DRAM row at a time. Row Reset allows for parallel initialization on multiple DRAM banks without using off-chip data transfer, thus reducing initialization time by up to 63 times. Row reset is a practical approach, because it can be implemented with existing circuitry in DRAM without additional area overhead.
Autors: Hoseok Seol;Wongyu Shin;Jaemin Jang;Jungwhan Choi;Jinwoong Suh;Lee-Sup Kim;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3251 - 3254
Publisher: IEEE
 
» In-Memory Processing Paradigm for Bitwise Logic Operations in STT–MRAM
Abstract:
In the current big data era, the memory wall issue between the processor and the memory becomes one of the most critical bottlenecks for conventional Von-Newman computer architecture. In-memory processing (IMP) or near-memory processing (NMP) paradigms have been proposed to address this problem by adding a small amount of processing units inside/near the memory. Unfortunately, although intensively studied, prior IMP/NMP platforms are practically unsuccessful because of the fabrication complexity and cost efficiency by integrating the processing units and memory on the same chip. Recently, emerging nonvolatile memories provide new possibility for efficiently implementing the IMP/NMP paradigm. In this paper, we propose a cost-efficient IMP/NMP solution in spin-transfer torque magnetic random access memory (STT–MRAM) without adding any processing units on the memory chip. The key idea behind the proposed IMP/NMP solution is to exploit the peripheral circuitry already existing inside memory (or with minimal changes) to perform bitwise logic operations. Such an IMP/NMP platform enables rather fast logic operations as the logic results can be obtained immediately through just a memory-like readout operation. Memory read and logics not, and/nand, and or/nor operations can be achieved and dynamically configured within the same STT–MRAM chip. Functionality and performance are evaluated with hybrid simulations under the 40 nm technology node.
Autors: Wang Kang;Haotian Wang;Zhaohao Wang;Youguang Zhang;Weisheng Zhao;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» In-Plane Magnetic Anisotropy Detection of Crystal Grain Orientation in Goss-Textured Ferromagnets
Abstract:
In this paper, a preliminary study about non-destructive diagnostics of crystal grain orientation in laminated Goss-textured magnetic material is presented. The reconstruction of the local lattice orientation is achieved by exploiting the surface magnetic anisotropy that is obtained by the contact-less magnetic measurements and lag angle plots elaboration. In addition, the experimental measurements are compared to the magnetic simulations of the crystal grains in order to extrapolate the local orientation of the system. The evaluation of the tilt angle between the easy axis and the rolling direction, as well as the angle of the other axes respect to the lamination plane, is carried out for different grains of an Fe–Si grain-oriented alloy specimen.
Autors: D. Candeloro;E. Cardelli;A. Faba;M. Pompei;S. Quondam Antonio;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» In-Store Pickup and Returns for a Dual Channel Retailer
Abstract:
The Internet and technology have changed how products are sold and delivered to consumers. Today, the most significant growth in online retailing comes from multichannel retailers that sell products both in stores and over the Internet. Recently, these retail/e-tail organizations have attempted to leverage their “brick” locations by allowing customers to pick up or return orders purchased online at retail store locations. Such options let online customers avoid both long carrier lead times and high shipping costs. However, these options come at a cost to the retailer. This paper develops a mathematical model for analytically examining the cost and value of providing in-store pickup and return options in multi-echelon retail/e-tail organizations. In this light, the model determines the optimal subset of a retailer/e-tailer's stores that should be set up to handle in-store pickups and online returns under stochastic channel demands. Computational results show that optimizing the set of pickup and return locations can reduce system cost by up to 20% on average over arbitrarily enabling all stores with Internet pickup/return capabilities, and firms can substantially increase customer value while maintaining cost minimization as an important selection criterion in choosing pickup and return locations.
Autors: Stephen Mahar;P. Daniel Wright;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 491 - 504
Publisher: IEEE
 
» In0.53Ga0.47As/InP Trench-Gate Power MOSFET Based on Impact Ionization for Improved Performance: Design and Analysis
Abstract:
A novel In0.53Ga0.47As/InP heterostructure trench-gate power MOSFET employing impact ionization at the hetero junction of n In0.53Ga0.47As drift region and n+InP drain region has been proposed. The impact ionization supports the band-to-band tunneling at heterojunction, which further increases the drain current. It results in reduced ON-state resistance and improved transconductance without compromising with the breakdown voltage as compared with the conventional silicon trench-gate MOSFET (CTGMOS). Using 2-D numerical simulations, we demonstrate that the proposed device exhibits ~440% improvement in peak transconductance, ~92% reduction in on-state resistance, ~ 10% increase in breakdown voltage, ~16% increase in switching speed, and ~93% improvement in figure of Merit (. as compared with CTGMOS.
Autors: Navneet Kaur Saini;Shubham Sahay;Raghvendra Sahai Saxena;Mamidala Jagadesh Kumar;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4561 - 4567
Publisher: IEEE
 
» InAs/InGaAsSb/GaSb Nanowire Tunnel Field-Effect Transistors
Abstract:
Tunnel field-effect transistors with ability to operate well below the thermal limit (with a demonstrated 43 mV/decade at VDS = 0.1 V) are characterized in this paper. Based on 88 devices, the impact of the low subthreshold swing on the overall performance is studied. Furthermore, correlation between parameters that are important for device characterization is determined.
Autors: Elvedin Memisevic;Johannes Svensson;Erik Lind;Lars-Erik Wernersson;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4746 - 4751
Publisher: IEEE
 
» Incentive Mechanisms for Data Dissemination in Autonomous Mobile Social Networks
Abstract:
This work focuses on the incorporation of incentive stimulations into data dissemination in autonomous mobile social networks with selfish nodes. The key challenge of enabling incentives is to effectively track the value of a message under such a unique network setting with intermittent connectivity and multiple interest data types. We propose two data dissemination models: the data pulling model where mobile users pull data from data providers, and the data pushing model where data providers generate personalized data and push them to the intended users. For data pulling, we present effective mechanisms to estimate the expected credit reward of a message that helps intermediate nodes to evaluate the potential reward of it. Nodal message communication is formulated as a two-person cooperative game, whose solution is found by a heuristic approach which achieves Pareto optimality. Under the data pushing model, “virtual checks” are introduced to eliminate the needs of accurate knowledge about whom and how many credits data providers should pay. The check buying process is formulated as an online auction model to further accelerate the circulation of credits. Extensive simulations carried out based on real-world traces show the proposed schemes achieve better performance than fully cooperative scheme, but significantly reduce communication cost.
Autors: Ting Ning;Yang Liu;Zhipeng Yang;Hongyi Wu;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Nov 2017, volume: 16, issue:11, pages: 3084 - 3099
Publisher: IEEE
 
» Incentivized Outsourced Computation Resistant to Malicious Contractors
Abstract:
With the rise of Internet computing, outsourcing difficult computational tasks became an important need. Yet, once the computation is outsourced, the job owner loses control, and hence it is crucial to provide guarantees against malicious actions of the contractors involved. One may want to ensure that both the job itself and any inputs to it are hidden from the contractors, while still enabling them to perform the necessary computation. Furthermore, one would check that the computation was carried out correctly. In this paper, we are not concerned with hiding the job or the data, but our main task is to ensure that the job is computed correctly. We also observe that not all contractors are malicious; rather, majority are rational. Thus, our approach brings together elements from cryptography, as well as game theory and mechanism design. We achieve the following results: (1) We incentivize all the rational contractors to perform the outsourced job correctly, (2) we guarantee high fraction (e.g., 99.9 percent) of correct results even in the existence of a relatively large fraction (e.g., 33 percent) of malicious irrational contractors in the system, (3) and we show that our system achieves these while being almost as efficient as running the job locally (e.g., with only 3 percent overhead). Such a high correctness guarantee was not known to be achieved with such efficiency.
Autors: Alptekin Küpçü;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Nov 2017, volume: 14, issue:6, pages: 633 - 649
Publisher: IEEE
 
» Incidence Angle Dependence of First-Year Sea Ice Backscattering Coefficient in Sentinel-1 SAR Imagery Over the Kara Sea
Abstract:
We have studied the incidence angle () dependence of the sea ice backscattering coefficient (°) for Sentinel-1 (S-1) extra wide (EW) mode dual-polarization (HH/HV) synthetic aperture radar (SAR) imagery acquired over the Kara Sea under winter and summer melting conditions. The determination of the ° versus dependence was based on SAR image pairs acquired on ascending and descending orbits over the same sea ice area with a short time difference. The SAR noise floor was subtracted from the HV images. From the image pairs 1.1 by 1.1 km windows representing level first-year ice (LFYI) and deformed first-year ice (DFYI) were manually selected, and a linear regression was fit between the resulting ° and differences of the windows to estimate the slope (dB/1°) between ° and . For example, under winter condition for DFYI at HH- and HV-polarizations was found to be −0.24 and −0.16 dB/1°, respectively, and for LFYI at HH-pol- rization was −0.25 dB/1°. It was not possible to determine a reliable for LFYI at HV due to a contamination effect of the S-1 noise floor. The values at HH compared well with previous studies. They can be used to compensate the ° incidence angle variation in the S-1 EW SAR images with good accuracy. The HH values are applicable to other S-1 imaging modes and other C-band SAR sensors like RADARSAT-2. Unfortunately, the HV values are specific to the S-1 EW mode due to the noise floor problem.
Autors: Marko Mäkynen;Juha Karvonen;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6170 - 6181
Publisher: IEEE
 
» Incorporating Open Source Data for Bayesian Classification of Urban Land Use From VHR Stereo Images
Abstract:
This study investigates the incorporation of open source data into a Bayesian classification of urban land use from very high resolution (VHR) stereo satellite images. The adopted classification framework starts from urban land cover classification, proceeds to building-type characterization, and results in urban land use. For urban land cover classification, a preliminary classification distinguishes trees, grass, and shadow objects using a random forest at a fine segmentation level. Fuzzy decision trees derived from hierarchical Bayesian models separate buildings from other man-made objects at a coarse segmentation level, where an open street map provides prior building information. A Bayesian network classifier combining commonly used land use indicators and spatial arrangement is used for the urban land use classification. The experiments were conducted on GeoEye stereo images over Oklahoma City, USA. Experimental results showed that the urban land use classification using VHR stereo images performed better than that using a monoscopic VHR image, and the integration of open source data improved the final urban land use classification. Our results also show a way of transferring the adopted urban land use classification framework, developed for a specific urban area in China, to other urban areas. The study concludes that incorporating open source data by Bayesian analysis improves urban land use classification. Moreover, a pretrained convolutional neural network fine tuned on the UC Merced land use dataset offers a useful tool to extract additional information for urban land use classification.
Autors: Mengmeng Li;Kirsten M. de Beurs;Alfred Stein;Wietske Bijker;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4930 - 4943
Publisher: IEEE
 
» Incorporating Squirrel-Cage Induction Machine Models in Convex Relaxations of OPF Problems
Abstract:
The optimal power flow (OPF) problem determines a minimum cost operating point for an electric power system. Recently developed convex relaxations are capable of globally solving certain OPF problems. Using a semidefinite relaxation of the OPF problem as an illustrative example, this letter presents a method for extending convex relaxations of the OPF problem to include steady-state squirrel-cage induction machine models.
Autors: Daniel K. Molzahn;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4972 - 4974
Publisher: IEEE
 
» Increased Red Frequency Shift in Coherent Mid-Infrared Supercontinuum Generation From Tellurite Microstructured Fibers
Abstract:
We investigate coherent broadband mid-infrared supercontinuum generation in all normal dispersion (ANDi) tellurite microstructured fibers through numerical simulations. The proposed tellurite microstructured fibers (PTMFs) have an inverted L-shaped ANDi profile in the wavelength range of < 5.2 μm. By using a 2-μm femtosecond laser as the pump source, the spectral broadening occurs in the PTMF, which is caused by self-phase modulation (SPM) and optical wave breaking. Interestingly, SPM induced spectral broadening is larger on the Stokes side than the antistokes side, since the trailing edge of laser pulse becomes smoother than its leading edge, and the effect of self-steepening (SS) on pulse shape is compensated by the effect of the dispersion in the PTMF. Such a phenomenon is inaccessible in previously reported optical fibers, since the trailing edge of output pulse is steeper than the leading edge of output pulse when SS occurs in previously reported ANDi fibers. As a result, coherent broadband mid-infrared supercontinuum light with long operating wavelength can be generated in the PTMF.
Autors: Qing Li;Lai Liu;Zhixu Jia;Guanshi Qin;Yasutake Ohishi;Weiping Qin;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4740 - 4746
Publisher: IEEE
 
» Independent Encoding Joint Sparse Representation and Multitask Learning for Hyperspectral Target Detection
Abstract:
Target detection is playing an important role in hyperspectral image (HSI) processing. Many traditional detection methods utilize the discriminative information within all the single-band images to distinguish the target and the background. The critical challenge with these methods is simultaneously reducing spectral redundancy and preserving the discriminative information. The multitask learning (MTL) technique has the potential to solve the aforementioned challenge, since it can further explore the inherent spectral similarity between the adjacent single-band images. This letter proposes an independent encoding joint sparse representation and an MTL method. This approach has the following capabilities: 1) explores the inherent spectral similarity to construct multiple sub-HSIs in order to reduce spectral redundancy for each sub-HSI; 2) takes full advantage of the prior class label information to construct reasonable joint sparse representation and MTL models for the target and the background; 3) explores the great difference between the target dictionary and background dictionary with different regularization strategies in order to better encode the task relatedness for two joint sparse representation and MTL models; and 4) makes the detection decision by comparing the reconstruction residuals under different prior class labels. Experiments on two HSIs illustrated the effectiveness of the proposed method.
Autors: Yuxiang Zhang;Wu Ke;Bo Du;Xiangyun Hu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1933 - 1937
Publisher: IEEE
 
» Indoor Localization Without a Prior Map by Trajectory Learning From Crowdsourced Measurements
Abstract:
Accommodation of a situation when a prior map is not available in an indoor localization system is valuable to cost-effective operations by removing a need for map drawing and map updating. This paper suggests a trajectory learning method using crowdsourced measurements in order to support the absence of map. A localization framework based on a particle filter is formalized by machine-learning-based feature extraction and Gaussian process (GP) regression. The feature extraction algorithm reduces dimensionality of sparse measurement vector, and it is applied to detect floor level and designated landmarks. Also, the combination of the feature extraction and the GP regression is used for modeling nonlinear relationship between location and measurement. By this combination, locations of Wi-Fi access points are not required to be known. From the field experimental results, we confirm that the detections of floor level and landmarks are accurate, the learned trajectories are close to the true map, and positioning accuracy is improved thanks to the learning-aided localization.
Autors: Jaehyun Yoo;Karl Henrik Johansson;Hyoun Jin Kim;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2825 - 2835
Publisher: IEEE
 
» Influence of Ar Pressure on the Magnetic Properties of Amorphous FeGaSiB Thin Films
Abstract:
Magnetostrictive amorphous FeSiB and FeGaSiB thin films thickness 50 nm have been grown by the co-sputtering-evaporation technique with a range of Ar pressure (4–bar) to control the Ga percentage within the films and study their effect on the magnetic, structural, and magnetostriction properties. By X-ray diffraction, it was found that all the films had an amorphous structure and the only peaks were present for Si substrate. Using a magneto-optical Kerr effect magnetometer, it was found that, for the FeSiB films, the anisotropy field ) increased slowly as the pressure increased, while for the FeGaSiB films, the saturation field A/m for all pressures. For both the film sets, the coercive field was less than 800 A/m. The magnetostriction constants of the FeSiB thin films increased with increasing pressure. While for the FeGaSiB films, the magnetostriction constant decreased with increasing the sputtering gas pressure, with the maximum ppm, at the lowest pressure bar. Thus, it was determined that the addition of Ga atoms reduced the intrinsic stress within the films, while maintaining the amorphous morphology.
Autors: Qayes A. Abbas;Nicola A. Morley;August Johansson;Thomas Thomson;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Influence of Carbon Nanotubes Saturable Absorbers Diameter on Mode-Locking Erbium-Doped Fiber Laser Performance
Abstract:
We present a study about the influence of saturable absorbers single-wall carbon nanotubes (CNT) diameter on the passive mode-locking Erbium doped fiber laser performance. We used several samples of CNT with different mean diameters (from 0.8 to 1.4 nm) and distributions to fabricated CNT/polymer films. Films with 1.0 nm mean diameter CNT showed best results in terms of larger laser bandwidths and shorter pulse durations, compared to the other CNT samples used in our experiments. This result is due to the fact that 1.0 nm diameter CNT absorption energy gap (∼0.8 eV) is close to the photon energy of operating Erbium-doped fiber laser wavelength (∼1557 nm). Laser bandwidths up to 8.7 nm and pulse durations as short as 0.55 ps were obtained.
Autors: David Steinberg;Henrique G. Rosa;Eunezio A. Thoroh de Souza;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4804 - 4808
Publisher: IEEE
 
» Influence of Ce Content on the Mechanical Properties of Sintered (Ce, Nd)–Fe–B Magnets
Abstract:
The (R,Ce)–Fe–B magnets have been successfully industrialized in recent years. The mechanical property of sintered permanent magnets is one important aspect of their comprehensive performances, which directly influences the service reliability and the production cost. In this paper, the bending strength, fracture toughness, Vickers hardness, and brittleness index of commercial (R1–xCex)30.5–31.5Febal.B1M1 magnets with different cerium contents have been investigated. The micro-fractures of the magnets were observed by a scanning electron microscopy equipped with energy dispersive X-ray analysis system. It shows that the bending strength and the fracture toughness of (R,Ce)–Fe–B magnets have a downward tendency with increasing Ce content x, while the Vickers hardness of the magnets varies irregularly with Ce contents in this paper. The optimum mechanical properties have been obtained in the (R1–xCex)30.5–31.5Febal.B1M1 magnet with ; the bending strength, fracture toughness and brittleness index of the magnet with are obviously superior to those of the ordinary sintered Nd–Fe–B magnets. Some flocculent oxide phases have been discovered in the (R,Ce)–Fe–B magnet with . The flocculent phases may absorb the crack propagating energy, and reduce the stress concentration at a crack tip, which is b- neficial to strengthening and toughening of (R,Ce)–Fe–B magnets. However, the mechanical properties are obviously worse for the magnet with (Ce/RE = 45%). That is probably because the microstructures of the magnet with become deteriorated, in which abnormally large grains have been observed.
Autors: Anhua Li;Yueming Zhang;Wei Li;Haibo Feng;Yang Zhao;Minggang Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Influence of End Effects on Direct- and Quadrature-Axis Inductances in Linear Electromagnetic Actuators
Abstract:
This paper presents an analysis of the direct- and quadrature-axis inductances for linear tubular actuators with permanent magnet arrays, highlighting and featuring how they are affected by the end effects. A semi-analytical and an experimental analysis are performed to prove the influence of end effects on self- and mutual inductances. The synchronous parameters, i.e., - and -axis inductances of the actuator, are determined using a semi-analytical method and an experimental method. Once the synchronous parameters are all identified, high performance control methods (such as direct force control and vector control) may be implemented.
Autors: Ben Hur B. Boff;Ana P. Zanatta;David G. Dorrell;Paulo R. Eckert;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 7
Publisher: IEEE
 
» Influence of External Current on Yokeless Electric Current Transducers
Abstract:
Yokeless electric current transducers have compact size, but they are sensitive to external magnetic fields, including those caused by electric currents in their vicinity. It is often believed that this unwanted sensitivity can be effectively suppressed by using a differential sensor. In this paper, we investigate the effect of external current with arbitrary position on busbar differential current sensor. We show the main disadvantage of the differential current sensor: increased sensitivity to currents in the transversal direction, which are not sensed by a single sensor. We analyze by finite element method simulation also the influence of real conductor size and uneven density of ac currents. The results were verified on 1000 A current transducer using a pair of microfluxgate sensors. The realistic suppression of close currents depends on the conductor angular position and in 10 cm distance it can be as low as 50, but it can be corrected if the geometry is known.
Autors: Pavel Ripka;Andrey Chirtsov;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Influence of Inductance Properties on a Magnetic Levitation for Thin-Steel Plates
Abstract:
There are many studies on magnetic levitation, some of which were already realized in railways. The authors in our laboratory now try to apply the magnetic levitation techniques to the steel processing industry. Therefore, we aim at the construction of magnetic levitation system for very thin steel plates. However, it is extremely difficult to levitate them perfectly, because of its vibratory properties and awkward electromagnetic properties. We have already studied the elasticity of the thin steel plate mechanically and shown its control methodology. In this research, we carry out many measurements about “the magnetic saturation and the magnetic leakage” and formulate its influence. Last, with a controller designed by considering the influence, we accomplish a stable levitation for a very thin steel plate.
Autors: Yusuke Takada;Toshiki Kimura;Toshiko Nakagawa;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Influence of Interlocking on Magnetic Properties of Electrical Steel Laminations
Abstract:
Interlocking is a suitable method to fix iron cores made of electrical steel sheets along the stack direction. However, this will increase iron loss of the core and, as a result, lower the efficiency and power density of electrical machines. In this paper, the influence of interlocking on the magnetic properties of ring cores is studied and evaluated by measurements. A linear increase of the inverse of magnetic field and iron loss with increasing number of interlocks shows that the influence of interlocking is local. This behavior coincides with the proposed model. Interlaminar eddy currents have no serious impact on the iron-loss properties. Averaged magnetic properties of the magnetically deteriorated regions are calculated according to the magnetic model. These data will be useful for accurate finite-element method calculations of iron losses in electrical machines.
Autors: Satoshi Imamori;Simon Steentjes;Kay Hameyer;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Influence of Noise on the Determination of Curie Temperature From Magnetocaloric Analysis
Abstract:
In this paper, we study the effect of the signal-to-noise ratio of magnetization measurements on the determination of the Curie temperature from the analysis of the magnetocaloric response. The procedure has been compared with the method of the inflection point of the magnetization versus temperature curves. Magnetization data have been simulated using the Arrott–Noakes equation of state, with the addition of different noise levels (either 1% of the measured signal or 0.3% of the measurement range). It is shown that the obtained values of the Curie temperature are more accurate in the case of the magnetocaloric procedure, although this method requires more data analysis than the inflection point method. Moreover, the field independence of the Curie temperature obtained from the magnetocaloric procedure allows us to perform a statistical analysis of the obtained values, reducing the associated error in the Curie temperature determination.
Autors: L. M. Moreno-Ramírez;V. Franco;M. Pękała;A. Conde;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Influence of Shape Anisotropy and Temperature on Magnetostrictive Behavior in Single-Crystal Galfenol Alloys
Abstract:
Fe–Ga (Galfenol) is a rare-earth-free alloy with useful magnetostrictive properties of nominal cost and robust mechanical properties advantageous for sensing, actuating, and energy harvesting. Understanding magnetostriction and magnetization behaviors under stress while at temperatures up to +250 °C is needed to explore the potential of harsh environment applications for magnetostrictive non-contact sensors, for use in applications such as monitoring torque changes in engines and rotorcraft shafts. Galfenol thin patches have the potential to operate in these applications, but alloy performance at these temperatures while under stress has not been studied. Thus, in this paper, we investigate simultaneous effects of temperature and compressive stresses on magnetic and magnetostrictive behaviors of single crystal Fe–Ga samples at temperatures from +25 °C to +250 °C while under compressive stresses of 0, 15, and 23 MPa. The samples are also subjected to temperatures up to +250 °C and no stress to acquire simultaneous magnetostriction and magnetization values. Building upon this experimental data, this paper attempts to relate temperature dependence and shape anisotropy to determine the effect on magnetic susceptibility at elevated temperatures. Understanding the roles of temperature and compressive stress as well as shape anisotropy on magnetostrictive, Fe–Ga alloys can provide an advanced understanding of the material properties and thus facilitate their use in a wider range of applications.
Autors: Allison Orr;Julia Downing;Hyunsoo Kim;Johnpierre Paglione;Joey Cozzo;Suok-Min Na;Alison Flatau;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Influence of Skin Effect on the Current Distribution of Grounded-Gate NMOS Device
Abstract:
For the first time, the influence of fast pulse induced skin effect on the current distribution inside the grounded-gate NMOS (GGNMOS) is reported. The skin effect results in the current crowding at the finger edges of the GGNMOS, leading to the high photoemission and high substrate potential at those regions. This report comprehensively explains some of the decades-old unexplained physical phenomena.
Autors: Jian-Hsing Lee;Natarajan Mahadeva Iyer;Haojun Zhang;
Appeared in: IEEE Electron Device Letters
Publication date: Nov 2017, volume: 38, issue:11, pages: 1583 - 1585
Publisher: IEEE
 
» Influence of the Distributed Air Gap on the Parameters of an Industrial Inductor
Abstract:
Air gaps are often used in a design of power inductors. Different arrangements of air gap in a magnetic circuit influence the parameters of an inductor. Understanding this dependence allows a design of more efficient inductors. In this paper, the influence of different air-gap arrangements on the distribution of the magnetic flux density, the value of saturation current, and the power losses is presented. The 3-D finite-element analyses and laboratory measurements were realized for the exemplary inductor made of grain-oriented steel and copper foil. Additionally, the main rules of the design of inductors with distributed air-gap arrangement are also given.
Autors: Radoslaw Jez;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Information Complexity Density and Simulation of Protocols
Abstract:
Two parties observing correlated random variables seek to run an interactive communication protocol. How many bits must they exchange to simulate the protocol, namely to produce a view with a joint distribution within a fixed statistical distance of the joint distribution of the input and the transcript of the original protocol? We present an information spectrum approach for this problem whereby the information complexity of the protocol is replaced by its information complexity density. Our single-shot bounds relate the communication complexity of simulating a protocol to tail bounds for information complexity density. As a consequence, we obtain a strong converse and characterize the second-order asymptotic term in communication complexity for independent and identically distributed observation sequences. Furthermore, we obtain a general formula for the rate of communication complexity, which applies to any sequence of observations and protocols. Connections with results from theoretical computer science and implications for the function computation problem are discussed.
Autors: Himanshu Tyagi;Shaileshh Bojja Venkatakrishnan;Pramod Viswanath;Shun Watanabe;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 6979 - 7002
Publisher: IEEE
 
» Information Seeking in Online Healthcare Communities: The Dual Influence From Social Self and Personal Self
Abstract:
The use of online healthcare communities to acquire health-related information and reduce uncertainty over illnesses is currently hampered by the lack of understanding of how health information-seeking behavior can be stimulated in such environments. By drawing upon the theoretical notion of social self and personal self, and conducting a field survey among 101 online healthcare community users, this study investigates how social identity in online healthcare communities and individual users’ perceived disease severity jointly influence the health information-seeking propensity. This study contributes to the literature on health information seeking by investigating the influence of social self (social identity), personal self (perceived disease severity), and their interplay in online communities. The findings can guide healthcare providers and community managers in formulating strategic plans for promoting health information-seeking behavior.
Autors: Na Liu;Yu Tong;Hock Chuan Chan;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 529 - 538
Publisher: IEEE
 
» Information Theoretic Cutting of a Cake
Abstract:
Cutting a cake is a metaphor for the problem of dividing a resource (cake) among several agents. The problem becomes non-trivial when the agents have different valuations for different parts of the cake (i.e., one agent may like chocolate, while the other may like cream). A fair division of the cake is one that takes into account the individual valuations of agents and partitions of the cake based on some fairness criterion. Fair division may be accomplished in a distributed or centralized way. Due to its natural and practical appeal, it has been a subject of study in economics. To the best of our knowledge, the role of partial information in fair division has not been studied so far from an information theoretic perspective. Given the diversity of problems in fair division, we consider certain specific (yet important) problems that capture different aspects of information exchange in a fair division setting. From the class of distributed algorithms, we consider the classical divide and choose (DC) problem between two parties. Here, we study the effect of partial spying and voluntarily sharing of information in both one-shot and asymptotic scenarios. Furthermore, we consider implicit information transmission through actions for the repeated version of the problem. While identifying subgame perfect Nash equilibrium in repeated games with incomplete information on both sides is very difficult in general, for the special case of division of two items, we find a more stringent trembling hand perfect equilibrium. Next, from the class of centralized algorithms, we consider the Adjusted Winner (AW) algorithm between two players Alice and Bob. Brams and Taylor showed that if Alice can fully spy on Bob, she can trick the algorithm. We consider the same setup when partial spying is allowed and study the growth rate of Alice’s utility per spying bit. Via a transformation from AW to DC, it is shown that the problem reduces to the one studied- earlier for DC. However, if Alice is forced to only spy certain simple structured functions of Bob’s valuation, an upper bound on the growth rate of utility per spying bit is derived. This bound is shown to be tight in some cases. We also consider a centralized algorithm for maximizing the overall welfare of the agents under the Nash collective utility function (CUF). This corresponds to a clustering problem. By observing a link between this problem and the portfolio selection problem in stock markets, we provide an upper bound on the increase of the Nash CUF for a clustering refinement.
Autors: Payam Delgosha;Amin Gohari;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 6950 - 6978
Publisher: IEEE
 
» Information-Theoretic Caching: The Multi-User Case
Abstract:
In this paper, we consider a cache aided network in which each user is assumed to have individual caches, while upon users’ requests, an update message is sent through a common link to all users. First, we formulate a general information theoretic setting that represents the database as a discrete memoryless source, and the users’ requests as side information that is available everywhere except at the cache encoder. The decoders’ objective is to recover a function of the source and the side information. By viewing cache aided networks in terms of a general distributed source coding problem and through information theoretic arguments, we present inner and outer bounds on the fundamental tradeoff of cache memory size and update rate. Then, we specialize our general inner and outer bounds to a specific model of content delivery networks: file selection networks, in which the database is a collection of independent equal-size files and each user requests one of the files independently. For file selection networks, we provide an outer bound and two inner bounds (for centralized and decentralized caching strategies). For the case when the user request information is uniformly distributed, we characterize the rate versus cache size tradeoff to within a multiplicative gap of 4. By further extending our arguments to the framework of Maddah-Ali and Niesen, we also establish a new outer bound and two new inner bounds in which it is shown to recover the centralized and decentralized strategies, previously established by Maddah-Ali and Niesen. Finally, in terms of rate versus cache size tradeoff, we improve the previous multiplicative gap of 72 to 4.7 for the average case with uniform requests.
Autors: Sung Hoon Lim;Chien-Yi Wang;Michael Gastpar;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7018 - 7037
Publisher: IEEE
 
» Infrared Energy Harvesting in Millimeter-Scale GaAs Photovoltaics
Abstract:
The design and characterization of millimeter-scale GaAs photovoltaic (PV) cells are presented and demonstrate highly efficient energy harvesting in the near infrared (NIR). Device performance is improved dramatically by optimizing the device structure for the NIR spectral region and improving surface and sidewall passivation with the ammonium sulfide treatment and subsequent silicon nitride deposition. The power conversion efficiency of a 6.4-mm2 cell under 660-nW/mm2 NIR illumination at 850 nm is greater than 30%, which is higher than commercial crystalline silicon solar cells under similar illumination conditions. Critical performance limiting factors of submillimeter-scale GaAs PV cells are addressed and compared to theoretical calculations.
Autors: Eunseong Moon;David Blaauw;Jamie D. Phillips;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4554 - 4560
Publisher: IEEE
 
» Initial Rotor Position Detection for Sensorless Interior PMSM With Square-Wave Voltage Injection
Abstract:
In order to resolve the starting problem for position sensorless interior permanent magnet synchronous motor, an improved initial rotor position estimation method based on square-wave signal injection is presented in this paper. Instead of the conventional sinusoidal voltage injection, square-wave voltage signals are injected into stator windings to obtain magnet pole position. On the basis of saturation and saliency principle, the voltage pulse injection method was adopted to identify the magnet polarity. Detecting the magnet pole position by using the square-wave voltage injection, the error signal can be calculated without low-pass filters and time delays. The proposed method is verified via a 1.5 kW interior permanent magnet synchronous motor drive platform.
Autors: Xuan Wu;Yaojing Feng;Xiao Liu;Shouddao Huang;Xiaofang Yuan;Jian Gao;Jian Zheng;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Installation and Maintenance of Synchronous Motors: What Separates the Best Motors from the Ordinary Ones
Abstract:
Synchronous motors are installed in numerous applications within the pulp and paper industry, and their reliability is essential to the successful operation of a mill. Critical steps in the installation of synchronous motors are frequently misunderstood, and maintenance practices often overlook the most common causes of motor failure. Limitations on time and resources may exacerbate these deficiencies, but a carefully planned installation and maintenance program should not burden a mill with excessive work and will ultimately increase reliability of the equipment.
Autors: Sean Orchuk;Matt Florczykowski;
Appeared in: IEEE Industry Applications Magazine
Publication date: Nov 2017, volume: 23, issue:6, pages: 54 - 61
Publisher: IEEE
 
» Instantaneous Frequency Estimation for Nonlinear FM Signal Based on Modified Polynomial Chirplet Transform
Abstract:
Time-frequency analysis (TFA) is an effective tool to identify the signal frequency components and to reveal their time variant features. In this paper, a new instantaneous frequency (IF) estimation method is proposed for signals with heavy noise, which is based on a polynomial chirplet transform and a ridge curve extraction scheme. Based on this method, an iterative stepwise refinement algorithm is developed to generate a time-frequency distribution (TFD) with satisfactory energy concentration. Both simulated signals and experimental vibration signals are used to validate the performance of the proposed methods. The results demonstrate that the proposed TFA method is more effective in processing the nonstationary signals with heavy noise. Further, it can perform an accurate evaluation of the IF and obtain a clear TFD.
Autors: Xiaotong Tu;Yue Hu;Fucai Li;Saqlain Abbas;Yang Liu;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2898 - 2908
Publisher: IEEE
 
» Integral Control of Port-Hamiltonian Systems: Nonpassive Outputs Without Coordinate Transformation
Abstract:
In this paper we present a method for the addition of integral action to nonpassive outputs of a class of port-Hamiltonian (pH) systems. The proposed integral controller is a dynamic extension, constructed from the open-loop system, such that the closed loop preserves the pH form. It is shown that the controller is able to reject the effects of both matched and unmatched disturbances, preserving the regulation of the nonpassive outputs. Previous solutions to this problem have relied on a change of coordinates whereas the presented solution is developed using the original state vector and, therefore, retains its physical interpretation. In addition, the resulting closed-loop dynamics have a natural interpretation as a control by interconnection scheme.
Autors: Joel Ferguson;Alejandro Donaire;Richard H. Middleton;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5947 - 5953
Publisher: IEEE
 
» Integrated Cooperative Adaptive Cruise and Variable Speed Limit Controls for Reducing Rear-End Collision Risks Near Freeway Bottlenecks Based on Micro-Simulations
Abstract:
Freeway bottlenecks lead to traffic congestion and speed reduction, resulting in increased risks of rear-end collision. This paper aimed to develop a control strategy of an integrated system of cooperative adaptive cruise control (CACC) and variable speed limit (VSL) to reduce rear-end collision risks near freeway bottlenecks. A microscopic simulation testbed was first constructed, in which the realistic PATH CACC models and surrogate safety measures of the time exposed time-to-collision (TET) and time integrated time-to-collision (TIT) were used. A feedback control algorithm was then developed for the proposed vehicle to infrastructure system of CACC and VSL. The simulation results showed that the proposed integration system with 100% CACC penetration rate can reduce the rear-end collision risks effectively, with the TIT and TET declined by 98%. The average travel time was also decreased by 33%, compared with the manual vehicles without any control. Moreover, the safety improvements of the proposed integrated system are quite stable at the various bottlenecks with different magnitudes of speed reductions. The sensitivity analyses suggested that the penetration rate of CACC has significant impact on safety performance. The VSL control plays an important role in reducing rear-end collision risks when the penetration rate of CACC is low. The combination of CACC and VSL controls mitigates the negative effects of the mixed traffic flow of the manual and CACC vehicles.
Autors: Ye Li;Chengcheng Xu;Lu Xing;Wei Wang;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Nov 2017, volume: 18, issue:11, pages: 3157 - 3167
Publisher: IEEE
 
» Integrated Planning of Distribution Networks Considering Utility Planning Concepts
Abstract:
This paper presents a methodology for integrated planning of real-life medium-voltage networks based on the utility planning concepts. The research is motivated by the need to develop a methodology that would line-up with utility day-to-day businesses and could be applied in real-life. Its core is a two-stage optimization process, where the first stage solves the static investment optimization and the second stage considers operational problem. A probabilistic decision tree approach is proposed for the solution of the entire problem to consider uncertainties in the planning period. The overall formulation is given first, which is followed by details of the investment model and outlines of the proposed operation planning. The novelty of the investment problem, which determines optimal network reinforcements, is explicit modeling of network security constraints of radially operated networks, whilst considering different operating regimes. Additional novel features include modeling of real-life supply restoration rules through network reconfiguration and optimal placement of new switching devices, as well as consideration of “customer flows” on the network. Connection of new distributed generation and demand centers and construction of circuits on new corridors are also included. Two investment models are formulated as mixed-integer nonlinear optimization problems, tested on several MV networks and compared with established methods. The proposed operational problem is solved in two stages, quality-of-supply and operation cost optimization. Computational aspects are also presented.
Autors: Nurulafiqah Nadzirah Mansor;Victor Levi;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4656 - 4672
Publisher: IEEE
 
» Integrated Planning of Electricity and Natural Gas Transportation Systems for Enhancing the Power Grid Resilience
Abstract:
Power systems are exceedingly faced with extreme events such as natural disasters and deliberate attacks. In comparison, the underground natural gas system is considered less vulnerable to such extreme events. We consider that the overhead power grid can be hardened by replacing segments of electric power grid with underground natural gas pipelines as an energy transportation system to countereffect extreme events which can damage interdependent infrastructures severely. In this paper, an integrated electricity and natural gas transportation system planning algorithm is proposed for enhancing the power grid resilience in extreme conditions. A variable uncertainty set is developed to describe the interactions among power grid expansion states and extreme events. The proposed planning problem is formulated as a two-stage robust optimization problem. First, the influence of extreme events representing natural disasters is described by the proposed variable uncertainty set and the proposed robust model for the integrated planning is solved with the grid resilience represented by a set of constraints. Second, the investment decisions are evaluated iteratively using the conditional events. The integrated electricity and natural gas planning options are analyzed using the modified IEEE-RTS 1979 for enhancing the power grid resilience. The numerical results point out that the proposed integrated planning is an effective approach to improving the power grid resilience.
Autors: Chengcheng Shao;Mohammad Shahidehpour;Xifan Wang;Xiuli Wang;Biyang Wang;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4418 - 4429
Publisher: IEEE
 
» Integrated Predictive Analytics and Optimization for Opportunistic Maintenance and Operations in Wind Farms
Abstract:
This paper proposes an integrated framework for wind farm maintenance that combines i) predictive analytics methodology that uses real-time sensor data to predict future degradation and remaining lifetime of wind turbines, with ii) a novel optimization model that transforms these predictions into profit-optimal maintenance and operational decisions for wind farms. To date, most applications of predictive analytics focus on single turbine systems. In contrast, this paper provides a seamless integration of the predictive analytics with decision making for a fleet of wind turbines. Operational decisions identify the dispatch profiles. Maintenance decisions consider the tradeoff between sensor-driven optimal maintenance schedule, and the significant cost reductions arising from grouping the wind turbine maintenances together—a concept called opportunistic maintenance. We focus on two types of wind turbines. For the operational wind turbines, we find an optimal fleet-level condition-based maintenance schedule driven by the sensor data. For the failed wind turbines, we identify the optimal time to conduct corrective maintenance to start producing electricity. The economic and stochastic dependence between operations and maintenance decisions are also considered. Experiments conducted on i) a 100-turbine wind farm case, and ii) a 200-turbine multiple wind farms case demonstrate the advantages of our proposal over traditional policies.
Autors: Murat Yildirim;Nagi Z. Gebraeel;Xu Andy Sun;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4319 - 4328
Publisher: IEEE
 
» Integrating Social Grouping for Multitarget Tracking Across Cameras in a CRF Model
Abstract:
Tracking multiple targets across nonoverlapping cameras aims at estimating the trajectories of all targets, and maintaining their identity labels consistent while they move from one camera to another. Matching targets from different cameras can be very challenging, as there might be significant appearance variation and the blind area between cameras makes the target’s motion less predictable. Unlike most of the existing methods that only focus on modeling the appearance and spatiotemporal cues for inter-camera tracking, this paper presents a novel online learning approach that considers integrating high-level contextual information into the tracking system. The tracking problem is formulated using an online learned conditional random field (CRF) model that minimizes a global energy cost. Besides low-level information, social grouping behavior is explored in order to maintain targets’ identities as they move across cameras. In the proposed method, pairwise grouping behavior of targets is first learned within each camera. During inter-camera tracking, track associations that maintain single camera grouping consistencies are preferred. In addition, we introduce an iterative algorithm to find a good solution for the CRF model. Comparison experiments on several challenging real-world multicamera video sequences show that the proposed method is effective and outperforms the state-of-the-art approaches.
Autors: Xiaojing Chen;Bir Bhanu;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Nov 2017, volume: 27, issue:11, pages: 2382 - 2394
Publisher: IEEE
 
» Integration of Preventive and Emergency Responses for Power Grid Resilience Enhancement
Abstract:
Boosting the resilience of power systems is one of the core requirements of smart grid. In this paper, an integrated resilience response framework is proposed, which not only links the situational awareness with resilience enhancement, but also provides effective and efficient responses in both preventive and emergency states. The core of the proposed framework is a two-stage robust mixed-integer optimization model, whose mathematical formulation is presented in this paper as well. To solve the above model, an algorithm based on the nested column-and-constraint generation decomposition is provided, and computational efficiency improvement techniques are proposed. Preventive response in this paper considers generator re-dispatch and topology switching, while emergency response includes generator re-dispatch, topology switching and load shedding. Several numerical simulations validate the effectiveness of the proposed framework and the efficiency of the solution methodology. Key findings include the following: 1) in terms of enhancing power grid resilience, the integrated resilience response is preferable to both independent preventive response and independent emergency response; 2) the power grid resilience could be further enhanced by utilizing topology switching in the integrated resilience response.
Autors: Gang Huang;Jianhui Wang;Chen Chen;Junjian Qi;Chuangxin Guo;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4451 - 4463
Publisher: IEEE
 
» Intelligent Multi-Area Power Control: Dynamic Knowledge Domain Inference Concept
Abstract:
This paper presents an intelligent multi-area power control with dynamic knowledge domain inference concept. The ongoing operational shift leads to unacceptable states variation, which may result in power oscillations, and if the controllers are not suitably designed, the system may be interactive and oscillations can aggravate. The study reports a new concept of updating control parameters, which is linked with operational shift, initially in an offline mode in building respective knowledge domain that fits into the framework of changing situations, to ensure states regulation. The proposed concept also provides flexibility to update the knowledge domain over and above offline data with newer dataset combining the nearest data clusters to derive an averaged data (controller parameter) within predefined boundary to change the controller functioning. The knowledge retrieval, as operational shift proceeds, has been mapped utilizing dynamical inference concept. The control so derived, effectively ensures the best damping well within time for the large network reliability and security. The structure of the controller so obtained is termed as the intelligent controller. In the present investigation, parameters of the respective controllers are stored in their respective knowledge domain on the modular basis. Firefly Algorithm (FA) with integral time multiplied by absolute error has been used as the objective function to be minimized. FA is then used to develop knowledge domain structure by way of deriving optimal controller parameters for corresponding operational shift to ensure oscillation damping with minimum settling time as well as overshoot/undershoot. The study is performed on six area sample power system. The proposed concept demonstrates an intelligent control concept for quick oscillation damping as the operating condition changes. Unified power flow controller has been used as an ancillary device as power system stabilizer approaches to the onset of unaccepta- le response.
Autors: Rajendra Kumar Pandey;Deepak Kumar Gupta;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4310 - 4318
Publisher: IEEE
 
» Interaction of Perceived Frequency and Intensity in Fingertip Electrotactile Stimulation: Dissimilarity Ratings and Multidimensional Scaling
Abstract:
Sensations elicited by electrical stimulation of touch are multidimensional, varying in perceived intensity and quality in response to changes in stimulus current or waveform timing. This paper manipulated both current and frequency, while volunteer participants estimated the dissimilarity of all non-identical pairs of 16 stimulus conditions. Multidimensional scaling analysis revealed that a model having two perceptual dimensions was adequate in representing the electrotactile (electrocutaneous) sensations. The two dimensions were identified as perceptual frequency and intensity, and were strongly correlated with the two stimulus variables, frequency and current, although not in a 1:1 correspondence. Perception of frequency differences increased monotonically with stimulus intensity, which is consistent with other human sensory systems, such as hearing and vision. Our results are consistent with previously-reported research using a different methodology and cutaneous locus. Congruence across different methods and laboratories suggests similar underlying perceptual mechanisms.
Autors: Kurt A. Kaczmarek;Mitchell E. Tyler;Uchechukwu O. Okpara;Steven J. Haase;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2067 - 2074
Publisher: IEEE
 
» Intercore Crosstalk in Homogeneous Multicore Fibers: Theoretical Characterization of Stochastic Time Evolution
Abstract:
A time-varying phase shift associated with each phase matching point of homogeneous weakly coupled multicore fibers is proposed to describe the stochastic time evolution of the intercore crosstalk (ICXT) observed experimentally. This model for the stochastic ICXT time evolution represents a generalization of current ICXT theoretical models and potentiates the development of new time-adaptive ICXT mitigation techniques. The model is first proposed considering a single polarization scheme, and is then generalized to a dual polarization scheme and to account for the polarization coupling between cores. Comparison between spectrograms of the crosstalk transfer function (XTTF) amplitude evaluated using the single polarization model and measured experimentally shows excellent agreement for short (few minutes) decorrelation times. For large decorrelation times (above 1 h), some differences in the behavior of the time evolution of the XTTF amplitude are observed. Nevertheless, excellent match between the mean and variance of the XTTF amplitude evaluated from the model and from analytical expressions proposed in the literature is observed for short and large decorrelation times. It is also shown that the decorrelation time of the short-term average crosstalk remains unchanged when the dual polarization scheme is considered. Similar spectrograms of the XTTF obtained with the single and dual polarization ICXT models are also shown.
Autors: Tiago M. Ferreira Alves;Adolfo V. T. Cartaxo;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4613 - 4623
Publisher: IEEE
 
» Interface Prostheses With Classifier-Feedback-Based User Training
Abstract:
It is evident that user training significantly affects performance of pattern-recognition-based myoelectric prosthetic device control. Despite plausible classification accuracy on offline datasets, online accuracy usually suffers from the changes in physiological conditions and electrode displacement. The user ability in generating consistent electromyographic (EMG) patterns can be enhanced via proper user training strategies in order to improve online performance. This study proposes a clustering-feedback strategy that provides real-time feedback to users by means of a visualized online EMG signal input as well as the centroids of the training samples, whose dimensionality is reduced to minimal number by dimension reduction. Clustering feedback provides a criterion that guides users to adjust motion gestures and muscle contraction forces intentionally. The experiment results have demonstrated that hand motion recognition accuracy increases steadily along the progress of the clustering-feedback-based user training, while conventional classifier-feedback methods, i.e., label feedback, hardly achieve any improvement. The result concludes that the use of proper classifier feedback can accelerate the process of user training, and implies prosperous future for the amputees with limited or no experience in pattern-recognition-based prosthetic device manipulation.
Autors: Yinfeng Fang;Dalin Zhou;Kairu Li;Honghai Liu;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2575 - 2583
Publisher: IEEE
 
» Interferometer Scanning Microwave Microscopy: Performance Evaluation
Abstract:
A systematic and quantitative comparison of electrical detection systems in scanning microwave microscopy is reported. Scanning microwave microscopy (SMM) is capable of investigating nanoscale electrical properties with high accuracy over a broad frequency range of 1–20 GHz. However, due to the passive matching network only discrete frequencies can be used every 1 GHz with varying signal-to-noise ratio (SNR). Here we study in detail the impedance matching mechanism using an interferometric network where a two-port measurement is implemented with a reduction of the trace noise due to signal subtraction. The interferometer setup shows superior performance resulting in a 2–8 fold increased SNR with respect to the standard shunt solution, in addition to stable broadband performance over the full frequency range. We perform a comparison of the electrical sensitivity obtained using a direct connection from the network analyser to probe, the typically implemented shunt-resonator impedance matching network, and the proposed interferometer setup. The interferometer SMM allows us also for calibrated impedance measurements, which we demonstrate on Tobacco mosaic viruses with 18-nm diameter, with a capacitance resolution of 0.67 attoFarads at 10 ms acquisition time per pixel.
Autors: Silviu-Sorin Tuca;Manuel Kasper;Ferry Kienberger;Georg Gramse;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 991 - 998
Publisher: IEEE
 
» Internal Solitary Waves in the Laptev Sea: First Results of Spaceborne SAR Observations
Abstract:
The first results of internal solitary wave (ISW) observations over the ice-free Laptev Sea derived from 354 ENVISAT Advanced Synthetic Aperture Radar (ASAR) images acquired in May–October 2011 are reported. Analysis of the data reveals the key regions of ISW distribution that are primarily found over the outer shelf/slope regions poleward the M2 critical latitude. Most of the ISWs are observed in regions where enhanced tide-induced vertical mixing and heat fluxes have been previously reported. This suggests that spaceborne SAR observations may serve as a tool to infer local mixing hot spots over the ice-free Arctic Ocean.
Autors: Igor E. Kozlov;Evgenia V. Zubkova;Vladimir N. Kudryavtsev;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 2047 - 2051
Publisher: IEEE
 
» Interpolation of Noisy Measurements in a Coarse Grid: Creating Waveforms for Intermediate Points on “747” Curves
Abstract:
In some situations, only a limited number of measurements under a limited number of conditions may be available for analysis. This paper describes an approach for creating additional interpolated measurements in which both measurement noise as well as signal have appropriate values. This is important, for example, when evaluating the behavior of advanced readback channels where quantities, such as sector failure rate (SFR), change very abruptly from 0% to 100% in response to relatively small parameter changes. This means that a smooth interpolation of SFR between coarse measurement points is little help in determining the actual boundary of good performance. If, instead, interpolated waveforms are fed into the channel, the boundary of the region of good performance can be clearly identified. This paper formulates a solution for the general problem of noisy measurement (waveform) interpolation and then applies this approach specifically to the situation, where a series of spin-stand waveforms were captured at various reader positions and with various written track squeeze positions (i.e., a set of “747s”). Using this approach, realistic waveforms can now be created and the SFR evaluated at any arbitrary intermediate reader and writer positions.
Autors: Rick Galbraith;Jana Jarrell;Roger Wood;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Introduction to the Special Bio-Section of the 2017 International Solid-State Circuits Conference (ISSCC)
Abstract:
The Bio-Section of this issue of the IEEE Journal of Solid-State Circuits (JSSC) includes some of the highlights of the outstanding papers from the 2017 International Solid-State Circuits Conference (ISSCC), which was held in San Francisco, CA, USA, in February 2017.
Autors: Peng Cong;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Nov 2017, volume: 52, issue:11, pages: 2791 - 2792
Publisher: IEEE
 
» Investigating FinFET Sidewall Passivation Using Epitaxial (100)Ge and (110)Ge Metal–Oxide–Semiconductor Devices on AlAs/GaAs
Abstract:
Device-quality crystallographically oriented epitaxial (100)Ge and (110)Ge were grown on GaAs substrates using a large bandgap AlAs buffer. Electrical characteristics of p-type metal–oxide–semiconductor (pMOS) capacitors, fabricated from the aforementioned material stacks, are presented for the first time. High-resolution cross-sectional transmission electron microscopy analysis demonstrated atomically abrupt heterointerfaces between Al2O3/Ge as well as Ge/AlAs for both (100) and (110) orientations. Various process conditions were implemented during MOS capacitor fabrication to study their impact on the Al2O3/Ge interface. The fabricated pMOS devices demonstrated excellent electrical characteristics with efficient modulation of the Fermi level from midgap to the conduction band edge, corresponding to a minimum value of cmev−1 on (100)Ge, indicative of a high-quality oxide/Ge heterointerface, and an effective electrical passivation of the Ge surface. Postdeposition annealing under O2 was found to be less effective at reducing oxide trap density ( as compared to forming gas or O2 postmetallization anneals (PMA), indicating that metal-induced bandgap states at the gate metal/dielectric interface have a notable impact on Ge pMOS . On the other hand, a tradeoff must be made between and the eq- ivalent oxide thickness when performing PMA under O2 or forming gas ambient.
Autors: Peter D. Nguyen;Michael B. Clavel;Jheng-Sin Liu;Mantu K. Hudait;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4457 - 4465
Publisher: IEEE
 
» Investigating Synchronous Oscillation and Deep Brain Stimulation Treatment in A Model of Cortico-Basal Ganglia Network
Abstract:
Altered firing properties and increased pathological oscillations in the basal ganglia have been proven to be hallmarks of Parkinson’s disease (PD). Increasing evidence suggests that abnormal synchronous oscillations and suppression in the cortex may also play a critical role in the pathogenic process and treatment of PD. In this paper, a new closed-loop network including the cortex and basal ganglia using the Izhikevich models is proposed to investigate the synchrony and pathological oscillations in motor circuits and their modulation by deep brain stimulation (DBS). Results show that more coherent dynamics in the cortex may cause stronger effects on the synchrony and pathological oscillations of the subthalamic nucleus (STN). The pathological beta oscillations of the STN can both be efficiently suppressed with DBS applied directly to the STN or to cortical neurons, respectively, but the underlying mechanisms by which DBS suppresses the beta oscillations are different. This research helps to understand the dynamics of pathological oscillations in PD-related motor regions and supports the therapeutic potential of stimulation of cortical neurons.
Autors: Meili Lu;Xile Wei;Kenneth A. Loparo;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 1950 - 1958
Publisher: IEEE
 
» Investigation and Analysis of a New Shaded-Pole Main Exciter for Aircraft Starter–Generator
Abstract:
In this paper, a new shaded-pole main exciter (ME) with additional short-circuited coils for aircraft three-stage starter–generator (SG) is proposed and investigated. The basic structure, winding configurations, operating principle, and start system structure of the presented shaded-pole ME are illustrated in detail. The comparative study between the original ME and the shaded-pole ME with respect to the starting mode performances is conducted by 2-D finite-element method (FEM). A prototype SG with original ME has been developed, and the experimental results are essentially consistent with the simulation results by the FEM utilized in the predictions in this paper. Simulation data and waveforms verify that the proposed shaded-pole ME is a good candidate for aircraft machines to satisfy the dual function of starter and generator.
Autors: Jincai Li;Zhuoran Zhang;Jiawei Lu;Hejie Li;Zhihui Chen;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Investigation of a Ka-Band High-Power Sheet Beam Relativistic Extended Interaction Oscillator
Abstract:
The sheet beam relativistic extended interaction oscillator (REIO) is a very important high-power millimeter-wave source for many actual and potential applications. A Ka-band sheet beam REIO is designed by means of particle-in-cell (PIC) simulation. In the design, we adopt a sheet electron beam with dimensions of 45 mm mm to reduce the space charge effect and the extended interaction cavities to increase the power capacity. The results of the PIC simulation demonstrate the device can generate an output power of 404 MW at 30 GHz with an efficiency of 20%. In addition, we develop the experiment on a short-pulse accelerator. In the experiment, the oscillator generates a millimeter-wave power of 125 MW with a beam current of 4 kA, a beam voltage of 500 kV, and guiding magnetic field of 1 T. The frequency of the output millimeter wave is 30.6 GHz and the pulsewidth is 16 ns. The experiment proves that millimeter wave of over 100 MW can be generated with the sheet beam REIO.
Autors: Zhenbang Liu;Hua Huang;Lurong Lei;Xiao Jin;Shifeng Li;Lele Li;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4671 - 4677
Publisher: IEEE
 
» Investigation of a New Hybrid Excitation Machine With Auxiliary Winding for Energy Recycling
Abstract:
From a new stator-flux perspective, a comparative study between the series and parallel hybrid excitation machine (PHEM) is conducted and it is revealed that in PHEMs there still exist distinct stator-flux harmonic components during high-speed flux weakening operation, which could be further utilized to improve the torque capability at high-speed range. Inspired by this idea, an auxiliary winding is creatively introduced into PHEMs to recycle and utilize the magnetic field energy generated during the field regulation. A new design case is presented in this paper, in which two sets of armature windings with different pole pair numbers are arranged to realize the function of flux weakening operation and energy recycling, respectively. The feasibility of this new hybrid solution is evaluated by using the finite-element analysis. Furthermore, a prototype is manufactured and relevant experiments are performed. The experimental results agree well with the theoretical analysis and simulation results, which verify that the recycled energy can be effectively used to boost the output torque and power of PHEMs in the high-speed region.
Autors: Xing Zhao;Shuangxia Niu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Investigation of Bending Stress Effect on the Diagonal and Off-Diagonal Impedances for GMI Sensor Implementation
Abstract:
Electrical current measurement by a giant magnetoimpedance (GMI) sensor may require the sensitive element (amorphous wire) to be aligned with the magnetic field produced by the conductor (toroidal configuration), which involves a bending stress. In this paper, a first study is made to investigate the impact of bending stress on a GMI sensor. For practical GMI sensor implementation, the offset and intrinsic sensitivity are crucial parameters. This is why these quantities have been evaluated in both diagonal and off-diagonal configurations. A Co-rich amorphous wire (from Unitika Ltd.) of diameter and 15 cm length was used. The off-diagonal voltage was measured through a pick-up coil. The wire was bent over a cylinder with a radius of 2.5 cm. The excitation frequency was 800 kHz. In the diagonal configuration, the sensitivity at a given bias field was decreased by 50% in the bent position compared to the straight position. The offset also decreased by 25%. In the off-diagonal configuration, the sensitivity around zero decreased by about 28%. The offset stayed quasi-null during the test. These results showed that the off-diagonal configuration seems to be best suited for an application as a current sensor that involves bending. The reversibility and repeatability of the bending effect have been evaluated under ten successive bending stresses. It was shown that the effect is quite reversible and repetitive.
Autors: Julie Nabias;Aktham Asfour;Jean-Paul Yonnet;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 8
Publisher: IEEE
 
» Investigation of Copper–Carbon Nanotube Composites as Global VLSI Interconnects
Abstract:
Applicability of copper–carbon nanotube (Cu-CNT) composites as on-chip global VLSI interconnects is investigated comprehensively. Electrical modeling of Cu-CNT composite interconnects is carried out by virtue of effective complex conductivity. The performances, including time delay and step response, are characterized based on the equivalent circuit model. Finally, the crosstalk effect between coupled Cu-CNT composite interconnects is analyzed.
Autors: Zi-Han Cheng;Wen-Sheng Zhao;Linxi Dong;Jing Wang;Peng Zhao;Haijun Gao;Gaofeng Wang;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 891 - 900
Publisher: IEEE
 
» Investigation of Electromigration Degradation Mechanism in Ti/Pt/Au Ohmic Contacts to p-GaAs Under High Current Density Stress
Abstract:
The degradation mechanism of Ti/Pt/Au ohmic contacts to p-GaAs was identified experimentally under high direct-current density stress in detail. A revised measuring structure was designed based on the circular transfer length method (CTLM), in which the high current density of A/cm2 was applied vertically, while the contact resistance was measured horizontally between two contact electrodes. According to revised CTLM, the specific contact resistance was measured during stress. The results indicated that specific contact resistance showed an exponential dependence on the aging time. The depth profiling results obtained from the Auger electron spectroscopy showed that Pt penetrated into the Au layer during stress. Furthermore, some voids were observed at the Au/Pt interface, and intermixing began to form within metal layer during stress. These results demonstrated that the degradation of Ti/Pt/Au ohmic contacts to p-GaAs was attributed mainly to the electromigration and Joule heating along the current direction under high current density.
Autors: Yanbin Qiao;Dongyan Zhao;Yanning Chen;Jin Shao;Haifeng Zhang;Xiaoke Tang;Yidong Yuan;Jianqiang Li;Yang Zhao;Qiang Ma;Chunsheng Guo;Yamin Zhang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4581 - 4586
Publisher: IEEE
 
» Investigation of Frequency-Selective Surfaces for a THz Gyromultiplier Output System
Abstract:
The recent development of some high-power THz vacuum electronic devices calls for the application of space filters such as frequency-selective surfaces (FSSs) and polarization dividers. This paper presents the comparative study of two types of FSSs for a THz gyromultiplier output system, one with high-pass characteristic while the other one with low-pass functionality. Both FSSs are designed, fabricated, and experimentally tested between 200 and 1600 GHz to verify their capability of separating the dual-frequency output from the gyromultiplier. The high-power operation capability of the FSSs is also characterized by taking both the corona discharge and volumetric breakdown into consideration at the frequencies of interest. Based on the comparative study of the performance, the fabrication challenge and the high-power capability between the two FSSs, a generalized conclusion is given regarding the choice of the FSSs for high-power THz application.
Autors: Xiang Li;Xiaoming Liu;Kevin Ronald;Wenlong He;Yang Zeng;Yasir Alfadhl;Robert Donnan;Adrian Cross;Xiaodong Chen;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4678 - 4685
Publisher: IEEE
 
» Investigation of LP- and Vector-Modes for the Analysis of Space-Division Multiplexed Systems in the Nonlinear Regime
Abstract:
Space-division multiplexing in multimode fibers is a very promising approach to overcome the shortcoming of capacity in long-haul optical transmission systems. In this paper, we present an analysis of different mode representations in multimode fibers. We resume the properties and the interrelations of linearly polarized and vectorial modes. We take a look at the coupled nonlinear Schrödinger equation and Manakov equations for strongly coupled mode groups. The nonlinear coupling coefficient of the Manakov equation is investigated for both mode bases, in order to verify if the approximated linearly polarized modes are a valid representation for the analysis of nonlinearities in space-division multiplexed systems. Even though the effective mode areas differ considerably between LP- and vector modes, the simulated coupling coefficient shows a good agreement between both models. The results indicate that the mode basis does not affect the nonlinear parameter. For the analysis the field distributions of the modes are numerically calculated with a vector finite difference modesolver. Finally the simulated results are verified analytically.
Autors: Friederike Schmidt;Klaus Petermann;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:22, pages: 4859 - 4864
Publisher: IEEE
 
» Investigation of Self-Heating Effects in Gate-All-Around MOSFETs With Vertically Stacked Multiple Silicon Nanowire Channels
Abstract:
The self-heating effects (SHEs) in gate-all-around (GAA) MOSFETs with vertically stacked silicon nanowire (SiNW) channels are investigated. Direct observations using thermal images, electrical proof measurements, and supportive numerical simulations are carried out to verify the SHEs. This paper examines the location of hot spots as well as heat dissipation paths (heat sink) depending on the device geometry, and the electrical degradation produced by the SHEs. It also includes the estimation of the surface temperature of the GAA MOSFET and the average temperature across the bulk channel. Design parameters for improved management of the heat dissipation in a device are suggested. This investigation can contribute to improve the device performance and reliability of a 3-D stacked structure.
Autors: Jun-Young Park;Byung-Hyun Lee;Ki Soo Chang;Dong Uk Kim;Chanbae Jeong;Choong-Ki Kim;Hagyoul Bae;Yang-Kyu Choi;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4393 - 4399
Publisher: IEEE
 
» Ionospheric Decontamination for HF Hybrid Sky-Surface Wave Radar on a Shipborne Platform
Abstract:
This letter describes a method of correcting ionospheric frequency modulation for a high-frequency hybrid sky-surface wave radar mounted on a shipborne platform. In the proposed method, azimuth-dependent sea clutter signals are first decomposed into monocomponent signals based on distinguishable differences in their directions of incidence. Afterward, based on the decomposed monocomponent signals, the statistical mean of the time derivatives of the signal phases, weighted by the signal amplitudes, is used to estimate the ionospheric frequency modulation. Finally, the estimated result is applied to the received data to compensate for the ionospheric contamination. Numerical results on simulated data demonstrate the effectiveness of the proposed algorithm.
Autors: Yongpeng Zhu;Yinsheng Wei;Lei Yu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 2162 - 2166
Publisher: IEEE
 
» Iron Loss Characteristics Evaluation Using a High-Frequency GaN Inverter Excitation
Abstract:
Recently, novel magnetic materials have been developed for high-efficiency and high power density electric motors. In addition, next-generation semiconductor devices, like silicon carbide (SiC) or gallium nitride (GaN), have been introduced for power converters due to their high-frequency operation. Therefore, high-frequency operation of new magnetic materials is possible when they are driven by GaN or SiC inverters. Nevertheless, iron loss characterization of magnetic materials when they are excited by high-frequency signals have not been conducted yet. This paper introduces the iron losses characterization of a magnetic material at high carrier frequency excitation using a GANFET inverter. This characterization was carried out by the experimental evaluation of iron losses at carrier frequencies from 5 to 500 kHz at different deadtimes. As a result of the measurements, iron losses seem to have a trend to increase at high carrier frequencies and large deadtimes. In addition, filtering is introduced and it seems to be an effective technique for reducing iron losses.
Autors: Wilmar Martinez;Shunya Odawara;Keisuke Fujisaki;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 7
Publisher: IEEE
 
» Iron Loss Model for Electrical Machine Fed by Low Switching Frequency Inverter
Abstract:
In this paper, the investigation is focused on the iron loss prediction for electrical machines fed by low switching frequency inverter. An improved iron loss model is developed after reviewing various existing iron loss models considering pulse-width modulation (PWM) influence. In order to validate the improved iron loss model, iron loss tests are carried out on an electrical machine. The predicted iron loss results match well with the measured results, which shows that the improved iron loss model is able to predict iron loss in electrical machine fed by an inverter. The comparison between the predicted iron losses with and without considering the PWM influence shows that the iron loss can be significantly increased due to the influence of PWM, especially when the switching frequency is low.
Autors: Shaoshen Xue;Jianghua Feng;Shuying Guo;Zhichu Chen;Jun Peng;W. Q. Chu;P. L. Xu;Z. Q. Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Iron Loss Model Under DC Bias Flux Density Considering Temperature Influence
Abstract:
In this paper, the temperature dependencies of iron loss under different flux densities, frequencies, and dc bias flux densities are systematically investigated. The temperature dependence of the hysteresis loss varies significantly with the dc bias flux density while that of the eddy current loss is independent of the dc bias flux density. Based on these different characteristics of the hysteresis and the eddy current iron losses, an improved iron loss model is developed. The temperature dependence of iron loss under dc bias condition can be considered by utilizing the improved iron loss model. The developed iron loss model is validated by both tests on laminations and an electrical machine.
Autors: Shaoshen Xue;Jianghua Feng;Shuying Guo;Zhichu Chen;Jun Peng;W. Q. Chu;L. R. Huang;Z. Q. Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Iron Loss Reduction in Permanent Magnet Synchronous Motor by Using Stator Core Made of Nanocrystalline Magnetic Material
Abstract:
This paper presents the results of experimental trials carried out on a permanent magnet synchronous motor (PMSM) that uses a stator core made of a nanocrystalline magnetic material (FINEMET). It is demonstrated that the manufactured stator can reduce the PMSM total iron loss by 64% to 75% compared with an equivalent motor using a stator made of conventional non-oriented silicon steel. The experimental results are confirmed by 2-D finite-element analysis.
Autors: Nicolas Denis;Masaki Inoue;Keisuke Fujisaki;Hiromitsu Itabashi;Tomoaki Yano;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Ironless Machine Design for Wind-Based Microgeneration
Abstract:
This paper puts forward the design and analysis of an ironless permanent magnet machine for a micro wind power application. The proposed methodology includes comprehensive geometric, magnetic, and electrical dimensioning followed by detailed 2-D finite-element modeling of a synchronous generator. The configuration investigated in this paper shows the generators rotor fixed in the tip of the blades and illustrates the advantages of a large diameter for a microgeneration application.
Autors: Valdirene Verdum;Roberto P. Homrich;Aly F. Flores Filho;David G. Dorrell;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Is E-Band Satellite Communication Viable?: Advances in Modern Solid-State Technology Open Up the Next Frequency Band for SatCom
Abstract:
The Russians launched the first artificial Earth satellite, Sputnik 1, into an elliptical low-Earth orbit (LEO) in October 1957. Through its four external antennas, Sputnik 1 broadcast radio beacons at 20.005 and 40.01 MHz to study the density of the atmosphere and the radio-wave propagation through the ionosphere. This historic event represents the advent of the satellite age. Since then, satellites have become an integral part of global navigation, Earth observation, broadcasting, and communication systems. The latter complements conventional wired and wireless terrestrial communication and provides an effective platform to relay radio signals between two arbitrary points on or near the Earth. Satellite communication offers end users a high level of flexibility. Irrespective of the geological coordinate, the user can benefit from a broad spectrum for various applications, from two-way voice and data communication to video conferencing.
Autors: Parisa Harati;Benjamin Schoch;Axel Tessmann;Dirk Schwantuschke;Ralf Henneberger;Harald Czekala;Thomas Zwick;Ingmar Kallfass;
Appeared in: IEEE Microwave Magazine
Publication date: Nov 2017, volume: 18, issue:7, pages: 64 - 76
Publisher: IEEE
 
» Is this the ultimate grid battery?
Abstract:
Inside, it's brightly lit and filled with humming machinery, a mammoth futuristic manufactory. Robot arms grab components from bins and place each part with precision, while conveyor belts move the assembled pieces smoothly down production lines. Finished products enter testing stations for quality checks before being packed for shipping. It has been called a gigafactory, and it does indeed produce vast quantities of advanced batteries. But this gigafactory is in China, not Nevada. It doesn't make batteries for cars, and it's not part of the Elon Musk empire.
Autors: Z. Gary Yang;
Appeared in: IEEE Spectrum
Publication date: Nov 2017, volume: 54, issue:11, pages: 36 - 41
Publisher: IEEE
 
» It's Indisputable: Five Facts About Planning and Operating Modern Power Systems
Abstract:
An indisputable fact cannot be rebutted. It is supported by theory and experience. Over the past 25 years, wind and solar generation has undergone dramatic growth, resulting in a variety of experiences that model the integration of wind and solar into the planning and operation of modern electric power systems. In this article, we bring together examples from Europe, North America, and Australia to identify five indisputable facts about planning and operating modern power systems. Taken together, we hope these experiences can help build consensus among the engineering and public policy communities about the current state of wind and solar integration and also facilitate conversations about evolving future challenges.
Autors: Aaron Bloom;Udi Helman;Hannele Holttinen;Kate Summers;Jordan Bakke;Gregory Brinkman;Anthony Lopez;
Appeared in: IEEE Power and Energy Magazine
Publication date: Nov 2017, volume: 15, issue:6, pages: 22 - 30
Publisher: IEEE
 
» Iterative Channel Detection With LDPC Product Code for Bit-Patterned Media Recording
Abstract:
Because of the explosion in data growth, the requirement for high-density storage systems has increased. Bit-patterned media recording (BPMR) is a candidate for the next-generation magnetic recording systems, and its many advantages facilitate the achievement of recording densities of 1 Tb/in2 and beyond. In BPMR, each information bit is represented by a magnetic island; however, due to the small spacings between the along- and across-track islands that are for the achievement of a high areal density, severe extents of the inter-symbol interference and inter-track interference appear. These error factors degrade the system performance of the recording system. In this paper, an iterative channel detection scheme with a low-density parity check (LDPC) product code for which the extrinsic information between the soft output Viterbi algorithm and the LDPC product code is used for the BPMR is proposed. For the improvement of the BPMR performance, the modified extrinsic information data are exploited.
Autors: Seongkwon Jeong;Jaejin Lee;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Iterative Weighted Recovery for Block-Based Compressive Sensing of Image/Video at a Low Subrate
Abstract:
In compressive sensing (CS) of images or videos, a block-based sensing or recovery scheme can facilitate low-cost sampling or recovery in memory and computation. However, its recovery with small block size and small subrate suffers greatly from its lack of information of the measurement data essential to recover a unique solution among many candidates. This study, based on prior knowledge of the signal to be sensed, namely, the relative magnitude difference of signal entries, designs a weighting process to limit the solution space of the recovered signal and combines it with much simplified Landweber iterations to deliver a complete recovery algorithm, called iterative weighted recovery (IWR). We theoretically verify the performance of the proposed IWR, including error bound, convergence rate, and stopping criterion. Application of the proposed IWR to block-based CS of images or videos confirms the quality improvement of the recovered images or videos and reduction of recovery time.
Autors: Khanh Quoc Dinh;Byeungwoo Jeon;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Nov 2017, volume: 27, issue:11, pages: 2294 - 2308
Publisher: IEEE
 
» Joint Beamforming and Resource Allocation for Wireless-Powered Device-to-Device Communications in Cellular Networks
Abstract:
In this paper, we develop wireless-powered device-to-device (D2D) communications underlaying a time-division duplex cellular network, where D2D users (DUs) coexist with cellular users (CUs) and harvest energy from a base station during the downlink time for sustaining communications during the uplink time. Two spectrum access modes, coexistence and hybrid, are considered for the DUs. Our goal is to maximize the sum rate of the DUs by jointly designing beamforming and time allocation as well as DU transmit power, while maintaining the quality-of-service for the CUs. In a single DU scenario, the joint design problems in the downlink and uplink are decoupled and solved in sequence. By doing so, the optimal downlink beamforming is found via a semi-definite relaxation (SDR) approach. From a DU power control perspective, a scheme is proposed for obtaining the optimal solution of the remaining uplink design in the coexistence and hybrid modes. For a scenario with multiple DUs, a converted SDR problem is considered to attain the optimal solution of the original problem when the uplink receive beamforming is appropriately predetermined to null out the DU interference. We present simulation results to quantify the impact of various network parameters on the performance of the proposed schemes.
Autors: Meng-Lin Ku;Jyun-Wei Lai;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7290 - 7304
Publisher: IEEE
 
» Joint Channel and Impulsive Noise Estimation in Underwater Acoustic OFDM Systems
Abstract:
Impulsive noise is one key factor that limits the performance of underwater acoustic (UA) communications. In this paper, two pilot-subcarrier based algorithms are proposed to improve the performance of channel estimation and impulsive noise mitigation for UA orthogonal frequency-division multiplexing (OFDM) systems. The first algorithm jointly estimates the channel and the impulsive noise based on the least-squares principle. The second algorithm is developed with the aim to reduce the computational complexity, where the expectation-maximization principle is applied to estimate the channel and the impulsive noise iteratively. We compare the proposed algorithms by simulations and apply them to process the data collected during an experiment conducted in December 2015 in the estuary of the Swan River, Western Australia. The results show that both proposed algorithms have better performance than existing methods in mitigating impulsive noise in UA OFDM systems.
Autors: Peng Chen;Yue Rong;Sven Nordholm;Zhiqiang He;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10567 - 10571
Publisher: IEEE
 
» Joint Channel Decoding and State Estimation in Cyber-Physical Systems
Abstract:
Combined with a quickest detection algorithm for error propagation prevention in joint channel decoding and state estimation, a decoding procedure based on Pearl’s belief propagation is proposed to exploit the redundancy of system states in time domain for cyber-physical systems. By applying the proposed scheme to a linear model of electric generator dynamic system, numerical simulations have demonstrated that a better performance of state estimation will be obtained by the joint channel decoding and state estimation, and the error propagation can be successfully eliminated by the error propagation detection algorithm during the state estimation process.
Autors: Shuping Gong;Liang Li;Ju Bin Song;Husheng Li;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7560 - 7573
Publisher: IEEE
 
» Joint Design of Optimal Precoding and Cooperative Jamming for Multiuser Secure Broadcast Systems
Abstract:
A multiuser secure broadcast system is considered, where there are one multiantenna base station (BS), multiple single-antenna legitimate users, one multiantenna friendly jammer (FJ), and one multiantenna eavesdropper (Eve). We jointly design the optimal precoding matrix at the BS and the jamming covariance matrix at the FJ by minimizing the total transmit power of the BS and FJ under the signal-to-interference-plus-noise ratio constraints at the users and Eve. To solve this challenging problem, when the FJ has more antennas than the users and Eve, we first find the optimal structure of the jamming covariance matrix and, then, convert the problem into its equivalent convex form. Also, we propose an iterative algorithm to jointly design the precoding and jamming covariance matrices in all scenarios. The solution obtained by this algorithm is shown to be asymptotically optimal when the FJ has more antennas than the users and Eve. Numerical results show that the proposed schemes considerably outperform the existing schemes.
Autors: Jae-Mo Kang;Jun Yang;Jeongseok Ha;Il-Min Kim;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10551 - 10556
Publisher: IEEE
 
» Joint Dictionary Learning-Based Non-Negative Matrix Factorization for Voice Conversion to Improve Speech Intelligibility After Oral Surgery
Abstract:
Objective: This paper focuses on machine learning based voice conversion (VC) techniques for improving the speech intelligibility of surgical patients who have had parts of their articulators removed. Because of the removal of parts of the articulator, a patient's speech may be distorted and difficult to understand. To overcome this problem, VC methods can be applied to convert the distorted speech such that it is clear and more intelligible. To design an effective VC method, two key points must be considered: 1) the amount of training data may be limited (because speaking for a long time is usually difficult for postoperative patients); 2) rapid conversion is desirable (for better communication). Methods: We propose a novel joint dictionary learning based non-negative matrix factorization (JD-NMF) algorithm. Compared to conventional VC techniques, JD-NMF can perform VC efficiently and effectively with only a small amount of training data. Results: The experimental results demonstrate that the proposed JD-NMF method not only achieves notably higher short-time objective intelligibility (STOI) scores (a standardized objective intelligibility evaluation metric) than those obtained using the original unconverted speech but is also significantly more efficient and effective than a conventional exemplar-based NMF VC method. Conclusion: The proposed JD-NMF method may outperform the state-of-the-art exemplar-based NMF VC method in terms of STOI scores under the desired scenario. Significance: We confirmed the advantages of the proposed joint training criterion for the NMF-based VC. Moreover, we verified that the proposed JD-NMF can effectively improve the speech intelligibility scores of oral surgery patients.
Autors: Szu-Wei Fu;Pei-Chun Li;Ying-Hui Lai;Cheng-Chien Yang;Li-Chun Hsieh;Yu Tsao;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2584 - 2594
Publisher: IEEE
 
» Joint Energy-Bandwidth Allocation for Multiuser Channels With Cooperating Hybrid Energy Nodes
Abstract:
In this paper, we consider the energy-bandwidth allocation for a network of multiple users, where the transmitters each powered by both an energy harvester and conventional grid, access the network orthogonally on the assigned frequency band. We assume that the energy harvesting state and channel gain of each transmitter can be predicted for time slots a priori. The different transmitters can cooperate by donating energy to each other. The tradeoff among the weighted sum throughput, the use of grid energy, and the amount of energy cooperation is studied through an optimization objective, which is a linear combination of these quantities. This leads to an optimization problem with O() constraints, where is the total number of transmitter–receiver pairs, and the optimization is over seven sets of variables that denote energy and bandwidth allocation, grid energy utilization, and energy cooperation. To solve the problem efficiently, an iterative algorithm is proposed by using the Proximal Jacobian alternating direction method of multipliers (ADMM). The optimization subproblems corresponding to Proximal Jacobian ADMM steps are solved in the closed form. We show that this algorithm converges to the optimal solution with an overall complexity of O(). Numerical results show that the proposed algorithms can make efficient use of the harvested energy, grid energy, energy cooperation, and the available bandwidth.
Autors: Vaneet Aggarwal;Mark R. Bell;Anis Elgabli;Xiaodong Wang;Shan Zhong;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 9880 - 9889
Publisher: IEEE
 
» Joint Source-Channel Secrecy Using Uncoded Schemes: Towards Secure Source Broadcast
Abstract:
This paper investigates a joint source-channel secrecy problem for the Shannon cipher broadcast system. We suppose list secrecy is applied, i.e., a wiretapper is allowed to produce a list of reconstruction sequences and the secrecy is measured by the minimum distortion over the entire list. For discrete communication cases, we propose a permutation-based uncoded scheme, which cascades a random permutation with a symbol-by-symbol mapping. Using this scheme, we derive an inner bound for the admissible region of secret key rate, list rate, wiretapper distortion, and distortions of legitimate users. For the converse part, we easily obtain an outer bound for the admissible region from an existing result. Comparing the outer bound with the inner bound shows that the proposed scheme is optimal under certain conditions. Besides, we extend the proposed scheme to the scalar and vector Gaussian communication scenarios, and characterize the corresponding performance as well. For these two cases, we also propose another uncoded scheme, orthogonal-transform-based scheme, which achieves the same performance as the permutation-based scheme. Interestingly, by introducing the random permutation or the random orthogonal transform into the traditional uncoded scheme, the proposed uncoded schemes, on one hand, provide a certain level of secrecy, and on the other hand, do not lose any performance in terms of the distortions for legitimate users.
Autors: Lei Yu;Houqiang Li;Weiping Li;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7442 - 7463
Publisher: IEEE
 
» Joint Subcarrier Pairing and Power Allocation for Cooperative Nonorthogonal Multiple Access
Abstract:
In this correspondence, a downlink cooperative nonorthogonal multiple access transmission scheme is considered in the multicarrier scenario, where the user equipment (UE) with strong channel conditions acts as a relay to help the UE with weak channel conditions. A joint optimization of subcarrier pairing and power allocation is formulated as a mixed-integer nonconvex problem, with the objective to minimize the transmit power of the base station and the relay (strong UE) under the quality of service requirements of both UEs. We first explore the inherent property of power allocation for a single subcarrier pair. Then, in light of the property, we employ the Lagrange dual method and the Hungarian algorithm, in an asymptotically optimal manner, to solve the joint subcarrier pairing and power allocation problem. Numerical results show that our proposed algorithm outperforms other schemes with or without cooperation.
Autors: Xunan Li;Chong Li;Ye Jin;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10577 - 10582
Publisher: IEEE
 
» Joint Subchannel and Power Allocation for NOMA Enhanced D2D Communications
Abstract:
In this paper, a novel non-orthogonal multiple access (NOMA) enhanced device-to-device (D2D) communication scheme is considered. Our objective is to maximize the system sum rate by optimizing subchannel and power allocation. We propose a novel solution that jointly assigns subchannels to D2D groups and allocates power to receivers in each D2D group. For the subchannel assignment, a novel algorithm based on the many-to-one two-sided matching theory is proposed for obtaining a suboptimal solution. Since the power allocation problem is non-convex, sequential convex programming is adopted to transform the original power allocation problem to a convex one. The power allocation vector is obtained by iteratively tightening the lower bound of the original power allocation problem until convergence. Numerical results illustrate that: 1) the proposed joint subchannel and power allocation algorithm are an effective approach for obtaining near-optimal performance with acceptable complexity and 2) the NOMA enhanced D2D communication scheme is capable of achieving promising gains in terms of network sum rate and the number of accessed users, compared to a traditional OMA-based D2D communication scheme.
Autors: Jingjing Zhao;Yuanwei Liu;Kok Keong Chai;Yue Chen;Maged Elkashlan;
Appeared in: IEEE Transactions on Communications
Publication date: Nov 2017, volume: 65, issue:11, pages: 5081 - 5094
Publisher: IEEE
 
» Joint Time Allocation and Power Control in Multicell Networks With Load Coupling: Energy Saving and Rate Improvement
Abstract:
In this paper, we consider the problems of minimizing sum power and maximizing sum rate for multicell networks with load coupling, where coupling relation occurs among cells due to intercell interference. This coupling relation is characterized by the signal-to-interference-plus-noise ratio (SINR) coupling model with cell load vector and cell power vector as the variables. Due to the nonlinear SINR coupling model, the optimization problems for multicell networks with load coupling is nonconvex. To solve these nonconvex problems, we first consider the optimization problems for single-cell networks. Through variable transformations, the optimization problems can be equivalently transformed into convex problems. By solving the Karush–Kuhn–Tucker, the optimal solutions to power minimization and rate maximization problems can be obtained in closed form. Based on the theoretical findings of optimization problems for single-cell networks, we develop a distributed time allocation and power control algorithm with low complexity for the sum power minimization in multicell networks. This algorithm is proved to be convergent and globally optimal by using the properties of standard interference function. For sum rate optimization in multicell networks, we also provide a distributed algorithm that yields suboptimal solution. Besides, the convergence for this distributed algorithm is proved. Numerical results illustrate the theoretical findings, showing the superiority of our solutions compared to the conventional solution of allocating uniform power for users in the same cell.
Autors: Zhaohui Yang;Cunhua Pan;Wei Xu;Hao Xu;Ming Chen;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10470 - 10485
Publisher: IEEE
 
» Jointly Learning Heterogeneous Features for RGB-D Activity Recognition
Abstract:
In this paper, we focus on heterogeneous features learning for RGB-D activity recognition. We find that features from different channels (RGB, depth) could share some similar hidden structures, and then propose a joint learning model to simultaneously explore the shared and feature-specific components as an instance of heterogeneous multi-task learning. The proposed model formed in a unified framework is capable of: 1) jointly mining a set of subspaces with the same dimensionality to exploit latent shared features across different feature channels, 2) meanwhile, quantifying the shared and feature-specific components of features in the subspaces, and 3) transferring feature-specific intermediate transforms (i-transforms) for learning fusion of heterogeneous features across datasets. To efficiently train the joint model, a three-step iterative optimization algorithm is proposed, followed by a simple inference model. Extensive experimental results on four activity datasets have demonstrated the efficacy of the proposed method. A new RGB-D activity dataset focusing on human-object interaction is further contributed, which presents more challenges for RGB-D activity benchmarking.
Autors: Jian-Fang Hu;Wei-Shi Zheng;Jianhuang Lai;Jianguo Zhang;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Nov 2017, volume: 39, issue:11, pages: 2186 - 2200
Publisher: IEEE
 
» Kalman Predictor-Based Proactive Dynamic Thermal Management for 3-D NoC Systems With Noisy Thermal Sensors
Abstract:
Thermal sensor noise has a great impact on the efficiency and effectiveness of a dynamic thermal management (DTM) strategy. To address the problem of forecasting temperature based on noisy thermal sensors, we first propose a Kalman-based runtime thermal prediction scheme. To obtain accurate temperature predictions, a multivariate linear power model and a physically-based state space thermal model for 3-D network-on-chip are also proposed. Simulation results show that it reduces the standard deviations of the prediction error by 46%–53% compared with the auto-regressive based one under sensor noise with . Conventional reactive DTM techniques suffer from significant performance degradation due to their pessimistic reaction, thus, based on the proposed prediction scheme, we further propose a proactive DTM strategy that primarily consists of a thermal-aware routing algorithm and a proactive throttling scheme: 1) to take into account both thermal and congestion issues, we propose a proactive congestion and thermal aware routing algorithm. Simulation results demonstrate that it can achieve better throughput as well as approach better thermal balance. Specifically, under uniform traffic, the proposed scheme reduces the maximum chip temperature by about 3.9 °C and achieves 78.3% higher throughput compared with the competing thermal optimization approach based on dynamic programming network and 2) when the temperature exceeds the threshold, existing coarse-grained reactive throttling schemes cool down the overheated nodes at the penalty of significant performance loss. In this paper, a proactive quota-based throttling scheme is proposed. Simulation results show that it improves the throughput up to 11.1% compared with the reactive throttling schemes.
Autors: Yuxiang Fu;Li Li;Kun Wang;Chuan Zhang;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Nov 2017, volume: 36, issue:11, pages: 1869 - 1882
Publisher: IEEE
 
» Key Effects and Process Parameters Extraction on the CD of Reactive Ion Etching (RIE) Based on DOE Modeling
Abstract:
The critical dimension (CD) is highly influenced by the reactive ion etching (RIE) of silicon in the CMOS technology. The CD has to be well-controlled since it is one of the most important features related to process stability and product quality. However, the RIE process involves a lot of parameters which are highly confounded and entangled and thus it is very difficult to analyze the process. To study and extract the influences of these parameters in terms of CD variation, screening experiments are carried out to obtain the necessary factors to develop a CD-related model. An elaborated model, based on the selected parameters, is then built up via applying the design of experiments and response surface optimization. This model is validated to be capable of characterizing the process as well as predicting the CD.
Autors: Maria Rizquez;Agnès Roussy;Jakey Blue;Laurent Bucelle;Jacques Pinaton;Julien Pasquet;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Nov 2017, volume: 30, issue:4, pages: 539 - 546
Publisher: IEEE
 
» Kinetic Velocity Model to Account for Ballistic Effects in the Drift-Diffusion Transport Approach
Abstract:
This paper proposes a novel kinetic velocity model (KVM) for the drift-diffusion (DD) transport approach to describe ballistic effects. It also presents a simulation study of the ballistic effect in short-channel InGaAs and silicon FETs. Monte Carlo and subband Boltzmann transport equation results as well as DD simulations using the simple gate length-dependent ballistic mobility proposed in the literature and the KVM model are compared and discussed. Basic concepts, such as the Matthiessen rule and Fermi-Dirac statistics, are analyzed with a view on ballistic transport in devices in the linear and saturation regimes.
Autors: Oleg Penzin;Lee Smith;Axel Erlebach;Munkang Choi;Ko-Hsin Lee;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4599 - 4606
Publisher: IEEE
 
» Knowledge Transfer Through Machine Learning in Aircraft Design
Abstract:
The modern aircraft has evolved to become an important part of our society. Its design is multidisciplinary in nature and is characterized by complex analyses of mutually interdependent disciplines and large search spaces. Machine learning has, historically, played a significant role in aircraft design, primarily by approximating expensive physics-based numerical simulations. In this work, we summarize the current role of machine learning in this application domain, and highlight the opportunity of incorporating recent advances in the field to further its impact. Specifically, regression models (or surrogate models) that represent a major portion of the current efforts are generally built from scratch assuming a zero prior knowledge state, only relying on data from the ongoing target problem of interest. However, due to the incremental nature of design processes, there likely exists relevant knowledge from various related sources that can potentially be leveraged. As such, we present three relatively advanced machine learning technologies that facilitate automatic knowledge transfer in order to improve design performance. Subsequently, we demonstrate the efficacy of one of these technologies, i.e. transfer learning, on two use cases of aircraft engine design yielding noteworthy results. Our aim is to unveil this new application as a well-suited arena for the salient features of knowledge transfer in machine learning to come to the fore, thereby encouraging future research efforts.
Autors: Alan Tan Wei Min;Ramon Sagarna;Abhishek Gupta;Yew-Soon Ong;Chi Keong Goh;
Appeared in: IEEE Computational Intelligence Magazine
Publication date: Nov 2017, volume: 12, issue:4, pages: 48 - 60
Publisher: IEEE
 
» Kronecker-Markov Prior for Dynamic 3D Reconstruction
Abstract:
Recovering dynamic 3D structures from 2D image observations is highly under-constrained because of projection and missing data, motivating the use of strong priors to constrain shape deformation. In this paper, we empirically show that the spatiotemporal covariance of natural deformations is dominated by a Kronecker pattern. We demonstrate that this pattern arises as the limit of a spatiotemporal autoregressive process, and derive a Kronecker Markov Random Field as a prior distribution over dynamic structures. This distribution unifies shape and trajectory models of prior art and has the individual models as its marginals. The key assumption of the Kronecker MRF is that the spatiotemporal covariance is separable into the product of a temporal and a shape covariance, and can therefore be modeled using the matrix normal distribution. Analysis on motion capture data validates that this distribution is an accurate approximation with significantly fewer free parameters. Using the trace-norm, we present a convex method to estimate missing data from a single sequence when the marginal shape distribution is unknown. The Kronecker-Markov distribution, fit to a single sequence, outperforms state-of-the-art methods at inferring missing 3D data, and additionally provides covariance estimates of the uncertainty.
Autors: Tomas Simon;Jack Valmadre;Iain Matthews;Yaser Sheikh;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Nov 2017, volume: 39, issue:11, pages: 2201 - 2214
Publisher: IEEE
 
» Label-Free Highly Sensitive Hybrid Plasmonic Biosensor for the Detection of DNA Hybridization
Abstract:
A highly sensitive hybrid plasmonic slot-waveguide (HPSW) biosensor based on silicon-on-insulator is proposed and analyzed for DNA hybridization detection. The reported design is based on increasing the light interaction with the sensing region by using slot waveguide with plasmonic material. Due to the high index contrast and plasmonic effect, an ultrahigh optical confinement is achieved in the low-index regions, which enables the detection of the smallest change in the analyte refractive index with high sensitivity. The normalized power confinement, power density, and effective index of the supported modes by the HPSW are analyzed to achieve high-power confinement through the suggested biosensor and hence high sensitivity can be obtained. The HPSW is also incorporated with straight slotted resonator to calculate the sensitivity of the proposed design. The simulation results are calculated using full vectorial finite element method. The reported biosensor has high sensitivity of 1890.4 nm/RIU (refractive index unit), which is the highest in the literature to the best of our knowledge with a detection limit of 2.65 × 10 –6 RIU.
Autors: Mohamed Farhat O. Hameed;Ahmed Samy Saadeldin;Essam M. A. Elkaramany;Salah S. A. Obayya;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:22, pages: 4851 - 4858
Publisher: IEEE
 
» Land Surface Temperature Retrieval From FY-3C/VIRR Data and Its Cross-Validation With Terra/MODIS
Abstract:
Accurate inversion of land surface temperature (LST) from remote sensing data is an essential and challenging topic for earth observation applications. This paper successfully retrieves the LST from FY-3C/VIRR data with split-window method. With the simulated data, the algorithm coefficients are acquired with root mean square errors lower than 1.0 K for all subranges when view zenith angle (VZA) < 30° and the water vapor content (WVC) < 4.25 g/cm2 , as well as those in which the VZA < 30° and the LST < 307.5 K. In addition, a detailed sensitivity analysis is carried out. The analysis result indicates that the total LST uncertainty caused by the standard error of the algorithm, the uncertainties of land surface emissivity and WVC, and the instrument noise would be 1.22 K and 0.94 K for dry and wet atmosphere, respectively. Furthermore, LST retrieval method is applied to the visible and infrared radiometer measurements over the study area covering the geographical latitude of 31.671°N to 44.211°N and longitude of 10.739°W to 1.898°E, and the derived LST is cross-validated with Terra/MODIS LST product. The preliminary validation result shows that the split-window method determines the LST within 2.0 K for vegetation and soil areas.
Autors: Caixia Gao;Shi Qiu;En-Yu Zhao;Chuanrong Li;Ling-Li Tang;Ling-Ling Ma;Xiaoguang Jiang;Yonggang Qian;Yongguang Zhao;Ning Wang;Lu Ren;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4944 - 4953
Publisher: IEEE
 
» Landsat 8/OLI Two Bands Ratio Algorithm for Chlorophyll-A Concentration Mapping in Hypertrophic Waters: An Application to West Lake in Hanoi (Vietnam)
Abstract:
Monitoring chlorophyll-a concentration (Chl-a) in inland waters, particularly hypertrophic lake waters in megacities, is a critically important environmental issue. To enable long-term Chl-a monitoring using Landsat series sensors, development of a Chl-a estimation algorithm for the new Landsat sensor is requisite. This study aims to identify the most accurate algorithm for Chl-a estimation in hypertrophic waters using Landsat 8 images and in situ Chl-a data from West Lake and nine other hypertrophic lakes in Hanoi (Vietnam's capital). The best estimation was obtained by the ratio of two reflectances at 562 and 483 nm, corresponding to the ratio of the OLI band 3 versus band 2, termed the GrB2 algorithm. The GrB2 values using the reflectances of water samples and the Landsat images were correlated with the Chl-a by an exponential function (r2 = 0.64 to 0.82), and the estimated Chl-a were verified by the smallness of standard error (smaller than 10%) and degree of conformity with recent fish-kill phenomena that commonly occur in those lakes in summer and early spring. Because the availability of GrB2 is limited to waters with low levels of inorganic suspended matter, its extension to waters with much higher levels requires further investigation.
Autors: Nguyen Thi Thu Ha;Katsuaki Koike;Mai Trong Nhuan;Bui Dinh Canh;Nguyen Thien Phuong Thao;Michael Parsons;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4919 - 4929
Publisher: IEEE
 
» Language Inclusion Checking of Timed Automata with Non-Zenoness
Abstract:
Given a timed automaton modeling an implementation and a timed automaton as a specification, the problem of language inclusion checking is to decide whether the language of is a subset of that of . It is known to be undecidable. The problem gets more complicated if non-Zenoness is taken into consideration. A run is Zeno if it permits infinitely many actions within finite time. Otherwise it is non-Zeno. Zeno runs might present in both and . It is necessary to check whether a run is Zeno or not so as to avoid presenting Zeno runs as counterexamples of language inclusion checking. In this work, we propose a zone-based semi-algorithm for language inclusion checking with non-Zenoness. It is further improved with simulation reduction based on LU-simulation. Though our approach is not guaranteed to terminate, we show that it does in many cases through empirical study. Our approach has been incorporated into the PAT model checker, and applied to multiple systems to show its usefulness.
Autors: Xinyu Wang;Jun Sun;Ting Wang;Shengchao Qin;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Nov 2017, volume: 43, issue:11, pages: 995 - 1008
Publisher: IEEE
 

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