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Electrical and Electronics Engineering publications abstract of: 01-2017 sorted by title, page: 2

» An Analytical Model of Drain Current in a Nanoscale Circular Gate TFET
Abstract:
This paper presents an analytical model of drain current in a silicon tunnel FET with a circular gate (CG TFET). The method involves the bifurcation of the complete geometry into a rectangular gate conventional TFET, and the CG TFET itself based on the number of solvable regions of the CG TFET. The 2-D Poisson equation is solved on the regions of focus of each structure, and both the substructures are mathematically connected through conditions of continuity to arrive at the solution for the original geometry. The effect of the circular gate is considered by segregating the circular region into a number of rectangular segments, and solving the Poisson equation on each of them. The model takes into account the effect of drain on channel potential, bandgap narrowing, and quantum correction. The model is validated by comparing the results with outputs from a TCAD simulation tool.
Autors: Rupam Goswami;Brinda Bhowmick;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 45 - 51
Publisher: IEEE
 
» An Appeal to the Employers and Volunteers [Standards]
Abstract:
Discusses the importance of standards and the work of the IEEE Volunteers and industry members in general to develop new standards and actively work to enhance current standards in the industry.
Autors: Daleep Mohla;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jan 2017, volume: 23, issue:1, pages: 82 - 82
Publisher: IEEE
 
» An Automated Design Methodology of RF Circuits by Using Pareto-Optimal Fronts of EM-Simulated Inductors
Abstract:
A new design methodology for radiofrequency circuits is presented that includes electromagnetic (EM) simulation of the inductors into the optimization flow. This is achieved by previously generating the Pareto-optimal front (POF) of the inductors using EM simulation. Inductors are selected from the Pareto front and their -parameter matrix is included in the circuit netlist that is simulated using an RF simulator. Generating the EM-simulated POF of inductors is computationally expensive, but once generated, it can be used for any circuit design. The methodology is illustrated both for a single-objective and a multiobjective optimization of a low noise amplifier.
Autors: Reinier González-Echevarría;Elisenda Roca;Rafael Castro-López;Francisco V. Fernández;Javier Sieiro;José María López-Villegas;Neus Vidal;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2017, volume: 36, issue:1, pages: 15 - 26
Publisher: IEEE
 
» An Automated Transient Stability Constrained Optimal Power Flow Based on Trajectory Sensitivity Analysis
Abstract:
This paper presents an automated transient stability constrained optimal power flow (ATSC-OPF). ATSC-OPF automates the design of linear transient stability constraints without online human interference thus is adaptive to the change of real-time operating conditions and suitable for applications in industrial dispatch programs. The design of transient stability constraints uses trajectory sensitivities to separate the integration of time-domain simulation from the online computing of optimal power flow. For identified unstable cases, a generic iterative algorithm is proposed to search corresponding stable base cases required to calculate trajectory sensitivities. ATSC-OPF identifies and limits only the key generators at critical time to minimize the extra computational burden brought by the transient stability constraints. The designed transient stability constraints are incorporated into ATSC-OPF only when needed in operation. The limits in the transient stability constraints are determined with manageable stability margin to avoid unnecessary increase of operational cost. The performance of ATSC-OPF is studied with the New England 39-bus system for a single-contingency situation and a 140-bus simplified NPCC system for a multicontingency situation.
Autors: Lei Tang;Wei Sun;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 590 - 599
Publisher: IEEE
 
» An Autonomous Water Monitoring and Sampling System for Small-Sized ASVs
Abstract:
In recent years, sensorized autonomous vehicles (either AUVs or ASVs) have been increasingly used for in situ water measurements. However, collection of water samplings at depth by small-sized ASVs and their subsequent physical/chemical analysis onboard remains difficult due to size and weight constraints. This paper addresses this issue and describes the design and testing of an autonomous water monitoring and sampling system intended for operations onboard small-sized man-portable ASVs. The system is designed to collect water samples up to 50 m in depth and to measure physical water parameters along the water column. The system is composed of a probe lowered by a winch measuring physical water parameters and able to collect water samples at different selectable depths. Once the probe is returned onboard, a water distribution system transfers the collected water samples to sensors lodged in the ASV for the monitoring of chemical parameters, or into containers to transport the samples to laboratories on the mainland. The system combines small dimensions, self-cleaning capabilities, low weight, and limited power consumption allowing it to be easily installable and used on an autonomous small-sized ASVs. The sampling system was installed and tested in a robotic small-sized catamaran belonging to the HydroNet ASV class.
Autors: Francesco Fornai;Gabriele Ferri;Alessandro Manzi;Francesco Ciuchi;Francesco Bartaloni;Cecilia Laschi;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2017, volume: 42, issue:1, pages: 5 - 12
Publisher: IEEE
 
» An Auxiliary Variable-Aided Hybrid Message Passing Approach to Joint Channel Estimation and Decoding for MIMO-OFDM
Abstract:
This letter deals with message passing receiver design for joint channel estimation and decoding in MIMO-OFDM with unknown noise variance. The conventional factor graph representation for the system involves observation factors, which are functions of a number of variables in the form of multiplication and summation. In this work, by introducing some auxiliary variables, we further break each of the observation factors into several factors, which enables the use of hybrid mean field (MF), belief propagation (BP), and expectation propagation (EP) message passing to tackle the observation factors. It turns out that our approach is much more efficient than the existing approaches, leading to remarkable performance improvement as shown by simulation results.
Autors: Zhengdao Yuan;Chuanzong Zhang;Zhongyong Wang;Qinghua Guo;Jiangtao Xi;
Appeared in: IEEE Signal Processing Letters
Publication date: Jan 2017, volume: 24, issue:1, pages: 12 - 16
Publisher: IEEE
 
» An EEG Acquisition and Biomarker-Extraction System Using Low-Noise-Amplifier and Compressive-Sensing Circuits Based on Flexible, Thin-Film Electronics
Abstract:
This paper presents an electroencephalogram (EEG) acquisition and biomarker-extraction system based on flexible, thin-film electronics. There exist commercial, single-use, flexible, pre-gelled electrode arrays; however, these are fully passive, requiring cabling to transfer sensitive, low-amplitude signals to external electronics for readout and processing. This work presents an active EEG acquisition system on flex, based on amorphous silicon (a-Si) thin-film transistors (TFTs). The system incorporates embedded chopper-stabilized a-Si TFT low-noise amplifiers, to enhance signal integrity, and a-Si TFT compressive-sensing scanning circuits, to enable reduction of EEG data from many channels onto a single interface, for subsequent processing by a CMOS IC. Further, the system uses an algorithm, by which spectral-energy features, a key EEG biomarker, are extracted directly from the compressed signals. We demonstrate a prototype, performing EEG acquisition from a human subject, and compressed EEG reconstruction and seizure detection via analog replay of patient data. The TFT amplifier achieves a noise PSD of 230 nV/Hz. Seizure detection, at up to compression, achieves error rates 8%. Reconstruction is demonstrated at up to compression.
Autors: Tiffany Moy;Liechao Huang;Warren Rieutort-Louis;Can Wu;Paul Cuff;Sigurd Wagner;James C. Sturm;Naveen Verma;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2017, volume: 52, issue:1, pages: 309 - 321
Publisher: IEEE
 
» An Efficient Approach for Filling Gaps in Landsat 7 Satellite Images
Abstract:
Landsat 7 Enhanced Thematic Mapper Plus (ETM+) satellite imagery presents an important data source for many applications related to remote sensing. However, the scan line corrector (SLC) failure has seriously limited the scientific applications of ETM+ data since SLC failed permanently on May 31, 2003, resulting in about 22% of the image data missing in each scene. In this letter, we propose to apply a new method to fill the missing information (gap) in the satellite image without any spatial or spectral constraint applied on the neighborhood of missing pixels. The method can also simultaneously remove various types of noise, including Gaussian noise and impulse noise, affected in the acquisition process. This proposed concept is formulated as a consecutive multilevel Otsu and Two-Threshold Binary Decomposition to detect the boundary of the damaged region (gaps) and then reconstruct the edge of the damaged region based on boundary restoration. In the final step, we applied the well-known matrix completion as a low-rank approximation problem guided by boundary reconstructed. We achieve better approximation of the rank by minimizing the truncated nuclear norm with accelerated proximal gradient line, a method for convex optimization problems. The results show the capability of our approach to predict the missing values accurately in terms of quality, time, and without the need of outside information. This letter also shows encouraging results on both synthetic and real visual data sets.
Autors: Salma El Fellah;Mohammed Rziza;Mohamed El Haziti;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2017, volume: 14, issue:1, pages: 62 - 66
Publisher: IEEE
 
» An Efficient Component for Designing Signed Reverse Converters for a Class of RNS Moduli Sets of Composite Form ${2^{k}, 2^{P}-1}$
Abstract:
The application of residue number system (RNS) to digital signal processing lies in the ability to operate on signed numbers. However, the available RNS-to-binary (reverse) converters have been designed for unsigned numbers, which means that they do not produce signed outputs. Usually, some additional circuits are introduced at the output of the reverse converter to map the unsigned generated output into a signed number representation. This paper proposes a novel method to design reverse converters with signed output for a class of RNS moduli sets of composite form . The structure of the modulo adder used in the last stage of the proposed converters is modified in order to reuse the internal circuits to produce the signed output. This adder component is especially designed for achieving reverse converters with signed output, imposing very low area and delay overheads compared with unsigned converters. The proposed approach is applied to design reverse converters for different moduli sets and to implement application specific integrated circuits. Experimental results show that for a 4-moduli converter, the proposed design can outperform the traditional method to obtain signed outputs by improving the delay, chip-area, and energy consumption by up to 9%, 21%, and 35%, respectively.
Autors: Azadeh Alsadat Emrani Zarandi;Amir Sabbagh Molahosseini;Leonel Sousa;Mehdi Hosseinzadeh;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2017, volume: 25, issue:1, pages: 48 - 59
Publisher: IEEE
 
» An Efficient Framework for Unconditionally Secure Multiparty Computation
Abstract:
Threshold unconditionally secure multiparty computation (MPC) allows a set of mutually distrusting parties to securely compute an agreed function over some finite field in the presence of a computationally unbounded adversary, who can maliciously corrupt any out of the parties. Most of the known efficient MPC protocols are designed in the offline–online framework introduced in a seminal work by Beaver in CRYPTO 1991. In this framework, the parties generate shared random and private multiplication-triples during the offline phase, which are used later in the online phase for securely evaluating the multiplication gates in the circuit representing . The efficiency of the MPC protocols in this framework then relies on efficient ways of implementing the offline phase. In this paper, we propose a new and simple framework for generating shared and private random multiplication triples with unconditional security. The existing protocols approach this problem by first producing shared pairs of private and random values, followed by securely computing the shared product of each pair of values. The latter task involves a multiplication protocol for shared values that are typically communication intensive. Our framework takes a completely different approach and shuns the use of multiplication protocol. Namely, we ask the parties to verifiably share random multiplication triples and then securely extract shared random multiplication triples unknown to the adversary, from the shared triples. Realizing our framework in the asynchronous and hybrid network setting,1 we present the first ever MPC protocols with a linear (in the number of parties) communication overhead per multiplication gate in the circuit representing . These are significant improvements over the best known existing MPC protocols in the asynchronous and hybrid network setting with communication complexity and , respectively. Our framework when applied to the synchronous setting results in round-efficient MPC protocols.

In a hybrid network, it is assumed that the network is synchronous up to a certain “point” and asynchronous after that point onward. We assume a hybrid network with just one synchronous round in the beginning.

Autors: Ashish Choudhury;Arpita Patra;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 428 - 468
Publisher: IEEE
 
» An Efficient Joint Formulation for Bayesian Face Verification
Abstract:
This paper revisits the classical Bayesian face recognition algorithm from Baback Moghaddam et al. and proposes enhancements tailored to face verification, the problem of predicting whether or not a pair of facial images share the same identity. Like a variety of face verification algorithms, the original Bayesian face model only considers the appearance difference between two faces rather than the raw images themselves. However, we argue that such a fixed and blind projection may prematurely reduce the separability between classes. Consequently, we model two facial images jointly with an appropriate prior that considers intra- and extra-personal variations over the image pairs. This joint formulation is trained using a principled EM algorithm, while testing involves only efficient closed-formed computations that are suitable for real-time practical deployment. Supporting theoretical analyses investigate computational complexity, scale-invariance properties, and convergence issues. We also detail important relationships with existing algorithms, such as probabilistic linear discriminant analysis and metric learning. Finally, on extensive experimental evaluations, the proposed model is superior to the classical Bayesian face algorithm and many alternative state-of-the-art supervised approaches, achieving the best test accuracy on three challenging datasets, Labeled Face in Wild, Multi-PIE, and YouTube Faces, all with unparalleled computational efficiency.
Autors: Dong Chen;Xudong Cao;David Wipf;Fang Wen;Jian Sun;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2017, volume: 39, issue:1, pages: 32 - 46
Publisher: IEEE
 
» An Efficient Semidefinite Relaxation Algorithm for Moving Source Localization Using TDOA and FDOA Measurements
Abstract:
In this letter, we address the moving source localization problem by using time-difference-of-arrival and frequency-difference-of-arrival measurements. The localization problem is first reformulated based on the robust least squares criterion and then perform semidefinite relaxation (SDR) to obtain a convex semidefinite programming problem, which can be solved efficiently via optimization toolbox. Unlike several existing SDR localization methods requiring the initial estimate, the proposed method does not require this priori knowledge. The simulation results also show the superior positioning performance of the proposed method at high noise level than other existing methods.
Autors: Yunlong Wang;Ying Wu;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 80 - 83
Publisher: IEEE
 
» An Empirical Comparison of Model Validation Techniques for Defect Prediction Models
Abstract:
Defect prediction models help software quality assurance teams to allocate their limited resources to the most defect-prone modules. Model validation techniques, such as -fold cross-validation, use historical data to estimate how well a model will perform in the future. However, little is known about how accurate the estimates of model validation techniques tend to be. In this paper, we investigate the bias and variance of model validation techniques in the domain of defect prediction. Analysis of 101 public defect datasets suggests that 77 percent of them are highly susceptible to producing unstable results– - selecting an appropriate model validation technique is a critical experimental design choice. Based on an analysis of 256 studies in the defect prediction literature, we select the 12 most commonly adopted model validation techniques for evaluation. Through a case study of 18 systems, we find that single-repetition holdout validation tends to produce estimates with 46-229 percent more bias and 53-863 percent more variance than the top-ranked model validation techniques. On the other hand, out-of-sample bootstrap validation yields the best balance between the bias and variance of estimates in the context of our study. Therefore, we recommend that future defect prediction studies avoid single-repetition holdout validation, and instead, use out-of-sample bootstrap validation.
Autors: Chakkrit Tantithamthavorn;Shane McIntosh;Ahmed E. Hassan;Kenichi Matsumoto;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Jan 2017, volume: 43, issue:1, pages: 1 - 18
Publisher: IEEE
 
» An Event-Triggered Approach for Load Frequency Control With Supplementary ADP
Abstract:
The modern power system is evolving towards a new generation of smart grid, with significant benefits from the latest computer-based communication network technologies. Furthermore, as the incremental deployment of phase measurements units (PMUs) and the use of Smart Meters, there will be a substantial increase of the real-time system measurements. Under this trend, event-triggered control (ETC) will play an important role in reducing the communication and computation cost. In this paper, a novel ETC architecture design for load frequency control (LFC) with supplementary adaptive dynamic programming (ADP) is presented. The primary proportional-integral (PI) controller uses different proportional and integral thresholds for updating the actions, while the supplementary ADP controller is updated in an aperiodic manner. A strategy for the parameters calculation is introduced in a systematic way, and theoretical analysis of the ultimate boundedness for the closed-loop event-triggered system is also included. Simulation studies are carried out on one-area and three-area IEEE LFC benchmarks, and the results demonstrate the efficiency and effectiveness of the proposed design.
Autors: Lu Dong;Yufei Tang;Haibo He;Changyin Sun;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 581 - 589
Publisher: IEEE
 
» An Expectation Maximization Method for Joint Estimation of Emission Activity Distribution and Photon Attenuation Map in PET
Abstract:
A maximum likelihood expectation maximization (MLEM) method is proposed for joint estimation of emission activity distribution and photon attenuation map from positron emission tomography (PET) emission data alone. The method is appealing since: (i) it guarantees monotonic likelihood increase to a local extremum, (ii) does not require arbitrary parameters, and (iii) guarantees the positivity of the estimated distributions. Moreover, we propose a discrete Poisson data acquisition model and numerical algorithm for: (i) efficient graphics processing unit (GPU) based formulation, and (ii) a closed form exact solution for the MLEM update equations, which is essential for accurate and robust estimation. Numerical experiments indicate that in the presence of noise, joint EMAA estimation converges to the true emission activity distribution with root mean square errors of 4% and 0.5% respectively in estimation of lung- and myocardial emission activity distributions for a computational XCAT thorax phantom.
Autors: Alexander Mihlin;Craig S Levin;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 214 - 224
Publisher: IEEE
 
» An Extended Shared Logarithmic Unit for Nonlinear Function Kernel Acceleration in a 65-nm CMOS Multicore Cluster
Abstract:
Energy-efficient computing and ultralow-power computing are strong requirements for various application areas, such as internet of things and wearables. While for some applications integer and fixed-point arithmetic suffice, others require a larger dynamic range, typically obtained using floating-point (FP) numbers. Logarithmic number systems (LNSs) have been proposed as energy-efficient alternative, since several complex FP operations translate into simple integer operations. However, additions and subtractions become nonlinear operations, which have to be approximated via interpolation. Even efficient LNS units (LNUs) are still larger than standard FP units (FPUs), rendering them impractical for most general-purpose processors. We show that, when shared among several cores, LNUs become a very attractive solution. A series of compact LNUs is developed, which provide significantly more functionality (such as transcendental functions) than other state-of-the-art designs. This allows, for example, to evaluate the atan2 function with three instructions for only 183.2 pJ/op at 0.8 V. We present the first shared-LNU architecture where these LNUs have been integrated into a multicore system with four 32-b-OpenRISC cores and show measurement results demonstrating that the shared-LNU design can be up to 4.1 more energy-efficient in common nonlinear processing kernels, compared with a similar area design with four private FPUs.
Autors: Michael Gautschi;Michael Schaffner;Frank K. Gürkaynak;Luca Benini;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2017, volume: 52, issue:1, pages: 98 - 112
Publisher: IEEE
 
» An FMCW Radar Transceiver Chip for Object Positioning and Human Limb Motion Detection
Abstract:
This letter proposes a frequency modulated continuous wave radar transceiver chip and a method to position objects as well as detect human limb motions. Implemented in 65-nm CMOS, the chip presents 2-GHz bandwidth centered at 15 GHz and consumes only 210 mW, with performance among the best of the state of the art. Using the chip, imaging experiments for moving targets and human arm raisings are carried out. In addition, the demonstration of both object positioning and human limb-motion detection by the FMCW radar mode is believed to be the first time. This letter is beneficial for navigation systems, surveillance applications, and more.
Autors: Yong Wang;Yuanjin Zheng;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 236 - 237
Publisher: IEEE
 
» An Impedance Transfer Function Formulation for Reduced-Order Macromodels of Subgridded Regions in FDTD
Abstract:
Recently, model order reduction was applied to the macromodel of a subgridded region in the method of finite-difference time domain (FDTD), where an admittance transfer function formulation was used to model materials with electric conductivity. In this communication, we develop an impedance transfer function formulation for the reduced-order macromodel of a subgridded region; this formulation may be used to model materials exhibiting magnetic conductivity. The two macromodel types may be used together, in a complementary fashion, to model fine-featured subgridded regions in FDTD that contain materials exhibiting both electric and magnetic conductivity. Additionally, this communication greatly extends the range of both the deterministic and the stochastic macromodeling techniques recently developed in FDTD, thus enabling the solution of a much wider range of problems in computational electromagnetics.
Autors: Ata Zadehgol;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 401 - 404
Publisher: IEEE
 
» An Improved Analytical Model for Carrier Multiplication Near Breakdown in Diodes
Abstract:
The charge carrier contributions to impact ionization and avalanche multiplication are analyzed in detail. A closed-form analytical model is derived for the ionization current before the onset of breakdown induced by both injection current components. This model shows that the ratio of both injection current components affects the multiplication factor at relatively low fields before breakdown, but does not affect the reverse breakdown voltage. Furthermore, the model indicates that in case the ionization coefficients of electrons and holes are quite different in value, which depends upon the semiconductor material, the ionization coefficient of the charge carrier with the highest value can be extracted at those low fields. The one with the lowest value can be obtained by fitting the current close to breakdown. The model is compared and verified with TCAD simulations, and to some extent with experimental data, for silicon p-i-n diodes.
Autors: Raymond J. E. Hueting;Anco Heringa;Boni K. Boksteen;Satadal Dutta;Alessandro Ferrara;Vishal Agarwal;Anne Johan Annema;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 264 - 270
Publisher: IEEE
 
» An Improved Azimuth Reconstruction Method for Multichannel SAR Using Vandermonde Matrix
Abstract:
To overcome the contradiction between wide swath and high resolution in synthetic aperture radar systems, a multichannel azimuth reconstruction method is investigated to unambiguously recover the Doppler spectrum. The proposed method is derived from the least squares principle by exploiting a Vandermonde component of the system matrix. The Vandermonde matrix is Doppler independent and data independent. Reconstruction filter weightings can be easily achieved, and performance, including signal-to-noise ratio (SNR) and azimuth ambiguity-to-signal ratio, can be explicitly expressed. By well-conditioning the Vandermonde matrix and coherent processing of all channels, the proposed method improves the reconstruction performance. In simulated reconstruction, compared with the conventional matrix inversion method, the SNR increases by approximately 30 dB.
Autors: Pu Cheng;Jianwei Wan;Qin Xin;Zhan Wang;Mi He;Yongjian Nian;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2017, volume: 14, issue:1, pages: 67 - 71
Publisher: IEEE
 
» An Improved Bound on the Fraction of Correctable Deletions
Abstract:
We consider codes over fixed alphabets against worst case symbol deletions. For any fixed , we construct a family of codes over alphabet of size with positive rate, which allow efficient recovery from a worst case deletion fraction approaching . In particular, for binary codes, we are able to recover a fraction of deletions approaching . Previously, even non-constructively, the largest deletion fraction known to be correctable with positive rate was , and around 0.17 for the binary case. Our result pins down the largest fraction of correctable deletions for -ary codes as , since is an upper bound even for the simpler model of erasures where the locations of the missing symbols are known. Closing the gap between and 1/2 for the limit of worst case deletions correctable by binary codes remains a tantalizing open question.
Autors: Boris Bukh;Venkatesan Guruswami;Johan Håstad;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 93 - 103
Publisher: IEEE
 
» An Improved Ku-band MILO With Tapered Choke Cavity and Enlarged First Interaction Cavity
Abstract:
In order to further enhance the power capacity, and speed up the microwave start-up and saturation, an improved Ku-band magnetically insulated transmission line oscillator (MILO) with tapered choke cavity and enlarged first interaction cavity is proposed and investigated in this paper. The simplified plate model of MILO is analyzed to investigate the movement of individual electron. According to the theoretical analysis, the Ku-band MILO is optimized designed. In order to make the electrons emitted from the launch point of the cathode closer to the slow wave structure (SWS), especially the surface of the first interaction cavity, help to speed up the microwave start-up and saturation, the launch point of the cathode is optimized and designed 1.5 cm in front of the second choke vane. A tapered choke cavity is used to replace traditional uniform choke cavity, which helps further speed up the microwave start-up and saturation. An enlarged first interaction cavity with increased cavity gap is introduced to enhance the power capacity. Typical particle simulation results show that the improved Ku-band MILO can generate a microwave with a power of 1.65 GW and a frequency of 12.3 GHz under the diode voltage of 474 kV and the beam current of 42 kA. Compared with the traditional Ku-band MILO, the microwave start-up and saturation of the improved one are 2.5 and 5.5 ns faster, respectively. The power capacity of the improved Ku-band MILO is enhanced greatly due to that the RF electric field is decreased much from 1.3 to 1 MV/cm. At last, the experimental investigation of the improved Ku-band MILO is conducted. The device achieves a microwave output with a power of 1.2 GW, a frequency of 12.36 GHz, and a pulsewidth of 35 ns in the experiment. Both the power and the pulsewidth are enhanced significantly.
Autors: Tao Jiang;Juntao He;Jiande Zhang;Zhiqiang Li;Junpu Ling;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 286 - 292
Publisher: IEEE
 
» An Improved Line-Reflect-Reflect-Match Calibration With an Enhanced Load Model
Abstract:
An improved line-reflect-reflect-match calibration with an enhanced load model is proposed. Different from load models used by existing LRRM algorithms, the load model used in the proposed algorithm takes into account both the parasitic capacitance and inductance. Using the same calibration standards as the classical LRRM and the enhanced LRRM, the proposed algorithm can accurately determine the load parasitics from raw measurements. Measurement results from 0.5 GHz to 110 GHz on a commercial impedance standards substrate show that the proposed LRRM outperforms the classical LRRM and the enhanced LRRM, and gives multiline TRL quality on-wafer calibrations.
Autors: Song Liu;Ilja Ocket;Arkadiusz Lewandowski;Dominique Schreurs;Bart Nauwelaers;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 97 - 99
Publisher: IEEE
 
» An Improved Uplink Sparse Coded Multiple Access
Abstract:
Sparse coded multiple access (SCMA) has received considerable attention recently as a candidate multiple access scheme for 5G cellular systems. This letter proposes an improved uplink SCMA scheme where instead of the multi-dimensional constellation (MDC) mapping and a fixed number of nonzero elements per sparse codeword, a varying number of coded symbols from each user are directly mapped onto the resource elements. We show that the proposed SCMA scheme outperforms the MDC-SCMA scheme in terms of both error rate performance and receiver complexity when the user load is high.
Autors: Ming Zhao;Shengli Zhou;Wuyang Zhou;Jinkang Zhu;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 176 - 179
Publisher: IEEE
 
» An Intensity Gradient/Vegetation Fractional Coverage Approach to Mapping Urban Areas From DMSP/OLS Nighttime Light Data
Abstract:
Many studies have demonstrated the efficient extraction of the spatial extent of urban areas from Defense Meteorological Satellite Program/Operational Linescan System imagery using a fixed thresholding technique. These studies may underestimate and overestimate the extents of small and large cities, respectively. To overcome this problem, a new intensity gradient (IG) and vegetation fractional coverage (VFC) method is developed for identifying cities or towns, principally based on the assumption that there is a border around a city at which the nighttime light intensity decreases sharply. Using this method, the spatial extents of urban areas for two of the biggest countries in the world, namely China and the United States, were extracted in 2010. The urban areas thus identified are compared with the urban areas interpreted from Landsat Thematic Mapper imagery, and the results show that there is a significant linear relationship between the former and latter areas. This demonstrates that the IG/VFC model is effective for efficiently extracting the extent of urban areas from nighttime light imagery.
Autors: Minghong Tan;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 95 - 103
Publisher: IEEE
 
» An Interior-Point Method for Modified Total Variation Exploiting Transform-Domain Sparsity
Abstract:
The total variation (TV) minimization can be utilized in a compressive sensing framework to recover a signal from a small number of measurements by searching for a signal with a sparse gradient. However, many natural signals of interest, such as natural images, generally have sparse representations in known transforms. Hence, the performance of the signal reconstruction procedure can be improved by also taking into account this transform-domain sparsity of the signal. Thus, the TV minimization problem can be modified by introducing an -norm penalty term. The -regularized TV minimization problem searches for a signal with a sparse gradient and a sparse representation in the given transform. The main contribution of this paper is the derivation of a customized interior-point method for solving the -regularized TV minimization problem that computes the search direction of the Newton method efficiently by exploiting the specific structure of the Hessian.
Autors: Uditha Lakmal Wijewardhana;Marian Codreanu;Matti Latva-aho;
Appeared in: IEEE Signal Processing Letters
Publication date: Jan 2017, volume: 24, issue:1, pages: 56 - 60
Publisher: IEEE
 
» An Investigation of Motor Topology Impacts on Magnet Defect Fault Signatures
Abstract:
This paper presents a study on the topology-dependent magnet defect fault signatures in permanent-magnet motors. A new analytical approach is introduced to characterize the fault signatures in stator back electromotive force (EMF) and current waveforms using magnetic equivalent circuit. Stator winding configuration, winding connection type and location of damaged rotor magnets are some of the physical properties affecting the fault signature characteristics. Several cases with different number of pole and slot are investigated through the proposed method. In addition, different winding connections (including star and delta connection), different winding configurations (including single and double layer, fractional and full coil pitch), and different magnet defect number and location are scrutinized. It is shown that there are some cases exhibiting different fault patterns than the ones obtained through well-known fault models defined in the literature. It is essential to take these discrepancies into account in order to avoid false alarms. In addition, it is observed that some of the fault signatures show up in the stator back EMF spectrum but not in the current spectrum due to location and severity of magnet defect, and design specs. Comparative 2-D finite-element simulations and experimental results justify the theoretical magnet defect fault analysis and show the efficacy of the proposed approach.
Autors: Mohsen Zafarani;Taner Goktas;Bilal Akin;Stephen E. Fedigan;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 32 - 42
Publisher: IEEE
 
» An Iterative Method for Nonlinear Stochastic Optimal Control Based on Path Integrals
Abstract:
This paper proposes a new iterative solution method for nonlinear stochastic optimal control problems based on path integral analysis. First, we provide an iteration law for solving a stochastic Hamilton-Jacobi-Bellman (SHJB) equation associated to this problem, which is a nonlinear partial differential equation (PDE) of second order. Each iteration procedure of the proposed method is represented by a Cauchy problem for a linear parabolic PDE, and its explicit solution is given by the Feynman-Kac formula. Second, we derive a suboptimal feedback controller at each iteration by using the path integral analysis. Third, the convergence property of the proposed method is investigated. Here, some conditions are provided so that the sequence of solutions for the proposed iteration converges, and the SHJB equation is satisfied. Finally, numerical simulations demonstrate the effectiveness of the proposed method.
Autors: Satoshi Satoh;Hilbert J. Kappen;Masami Saeki;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 262 - 276
Publisher: IEEE
 
» An On-Chip Triplexer Based on Silicon Bragg Grating-Assisted Multimode Interference Couplers
Abstract:
A silicon triplexer based on Bragg grating-assisted multimode interference (MMI) couplers is designed and experimentally demonstrated. Compared with the conventional MMI-based triplexers, the device length is not required to be the common multiple of beat length of different wavelengths. The simulated bandwidth is over 100 nm for 1310-nm band with the 3-D finite-different time-domain method. Experimental results of the fabricated on-chip triplexer show extinction ratios higher than 15 dB and insertion losses around 1 dB in all output ports. The total device size is only , which is the smallest size over the experimentally demonstrated triplexers ever reported.
Autors: Jingye Chen;Yuguang Zhang;Yaocheng Shi;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 63 - 65
Publisher: IEEE
 
» An Optimal Service Strategy for Grouped Machine-Type Communications in Cellular Networks
Abstract:
Machine-type communication devices (MTCDs) served as groups are an efficient way to solve device management and resource allocation problems in cellular networks. We propose an MTCD group model based on the traffic of devices in the network. A group state transition matrix and revenue and constraint vectors are introduced and the optimal service solution is derived that the best service strategy is to serve devices in only two groups. Results can be used as a guide for cellular base stations to efficiently manage resources for MTCD applications.
Autors: Zebing Feng;Zhiyong Feng;Wei Li;T. Aaron Gulliver;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 140 - 143
Publisher: IEEE
 
» An Outer-Rotor Flux-Switching Permanent-Magnet-Machine With Wedge-Shaped Magnets for In-Wheel Light Traction
Abstract:
This paper proposes a novel outer-rotor flux-switching permanent-magnet (OR-FSPM) machine with specific wedge-shaped magnets for in-wheel light-weight traction applications. First, the geometric topology is introduced. Then, the combination principle of stator slots and rotor poles for OR-FSPM machines is investigated. Furthermore, to demonstrate the relationship between performance specifications (e.g., torque and speed) and key design parameters and dimensions (e.g., rotor outer diameter and stack length) of OR-FSPM machines at preliminary design stage, an analytical torque-sizing equation is proposed and verified by two-dimensional (2-D) finite-element analysis (FEA). Moreover, optimizations of key dimensions are conducted on an initially designed proof-of-principle three-phase 12-stator-slot/22-rotor-pole prototyped machine. Then, based on 2-D-FEA, a comprehensive comparison between a pair of OR-FSPM machines with rectangular- and wedge-shaped magnets and a surface-mounted permanent-magnet (SPM) machine is performed. The results indicate that the proposed OR-FSPM machine with wedge-shaped magnets exhibits better flux-weakening capability, higher efficiency, and wider speed range than the counterparts, especially for torque capability, where the proposed wedge-shaped magnets-based one could produce 40% and 61.5% more torque than the rectangular-shaped magnets-based machine and SPM machine, respectively, with the same rated current density (5 A/mm2). Finally, the predicted performance of the proposed OR-FSPM machine is verified by experiments on a prototyped machine.
Autors: Wei Hua;Hengliang Zhang;Ming Cheng;Jianjian Meng;Chuang Hou;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 69 - 80
Publisher: IEEE
 
» An OVT Based on Conoscopic Interference and Position Sensitive Detector
Abstract:
The measurement mode of the existing optical voltage transducer (OVT) is mostly based on light intensity detection. In such a way, the OVT has some big issues, such as a light intensity dependency, a temperature drift, an additional birefringence in the crystal and a half-wave voltage limitation to its measurement range. A new OVT based on conoscopic interference and bi-dimensional position sensitive detector (PSD) is proposed in the paper, which can convert the electro-optical phase delay of the crystal to a rotation angle of spot pattern, and therefore, a high voltage can be measured by the PSD. Compared with the existing OVT, the measurement mode of the new one is independent of light intensity, capable of measuring the electro-optical phase delay from 0° to 180° linearly and directly, and has a wide measurement range with no restriction of the half-wave voltage. The rotation angle of the spot pattern is positioned by a bi-dimensional PSD and the new OVT has a good linearity better than 0.5%.
Autors: Yifan Huang;Qi Feng Xu;Qiao Tan;Zhikun Xu;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 340 - 346
Publisher: IEEE
 
» An RFID-Enabled Wireless Strain Gauge Sensor for Static and Dynamic Structural Monitoring
Abstract:
Strain gauge measurements are widely used in structural health monitoring and damage detection of existing infrastructures as well as in laboratory prototyping tests of new structures and materials. Wireless sensing of strain gauge is desirable in many practical applications because of the difficulty to access at the measurement point or to handle wired sensors. In this paper, we show a semi-passive wireless strain gauge sensor, which allows a high level of measurement accuracy comparable with that of wired strain sensors. It overcomes the limits and drawbacks of devices based on wireless sensor networks and those based on similar RFID-based sensors. The ability to perform measurements over long distances and to handle fast time-varying phenomena (e.g., vibration) makes the proposed device practical in realistic scenarios.
Autors: Emidio DiGiampaolo;Alessandro DiCarlofelice;Amedeo Gregori;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 286 - 294
Publisher: IEEE
 
» An Ultralow-Voltage Energy-Efficient Level Shifter
Abstract:
This brief presents an energy-efficient level shifter (LS) able to convert extremely low level input voltages to the nominal voltage domain. To obtain low static power consumption, the proposed architecture is based on the single-stage differential-cascode-voltage-switch scheme. Moreover, it exploits self-adapting pull-up networks to increase the switching speed and to reduce the dynamic energy consumption, while a split input inverting buffer is used as the output stage to further improve energy efficiency. When implemented in a commercial 180-nm CMOS process, the proposed design can up-convert from the deep subthreshold regime (sub-100 mV) to the nominal supply voltage (1.8 V). For the target voltage level conversion from 0.4 to 1.8 V, our LS exhibits an average propagation delay of 31.7 ns, an average static power of less than 60 pW, and an energy per transition of 173 fJ, as experimentally measured across the test chips.
Autors: Marco Lanuzza;Felice Crupi;Sandro Rao;Raffaele De Rose;Sebastiano Strangio;Giuseppe Iannaccone;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2017, volume: 64, issue:1, pages: 61 - 65
Publisher: IEEE
 
» Analysis and Design of a Passive Switched-Capacitor Matrix Multiplier for Approximate Computing
Abstract:
A switched-capacitor matrix multiplier is presented for approximate computing and machine learning applications. The multiply-and-accumulate operations perform discrete-time charge-domain signal processing using passive switches and 300 aF unit capacitors. The computation is digitized with a 6 b asynchronous successive approximation register analog-to-digital converter. The analyses of incomplete charge accumulation and thermal noise are discussed. The design was fabricated in 40 nm CMOS, and experimental measurements of multiplication are illustrated using matched filtering and image convolutions to analyze noise and offset. Two applications are highlighted: 1) energy-efficient feature extraction layer performing both compression and classification in a neural network for an analog front end and 2) analog acceleration for solving optimization problems that are traditionally performed in the digital domain. The chip obtains measured efficiencies of 8.7 TOPS/W at 1 GHz for the first application and 7.7 TOPS/W at 2.5 GHz for the second application.
Autors: Edward H. Lee;S. Simon Wong;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2017, volume: 52, issue:1, pages: 261 - 271
Publisher: IEEE
 
» Analysis and Design of an Electronic On-Load Tap Changer Distribution Transformer for Automatic Voltage Regulation
Abstract:
Current solutions for voltage regulation close to the consumers usually require technicians for manually changing the taps of the transformer, which may entail high maintenance costs and uncontrolled voltage levels. In this context, electronic on-load tap changers (OLTCs) are a prospective solution for present-day and future power grids, since they provide automatic voltage regulation. This paper presents the analysis and design guidelines for an electronic OLTC applied to a distribution transformer, encompassing the physical layout design for external access to the transformer tap terminals, the evaluation of current and voltage transients during the commutation process, and the dimensioning of the electronic switches and protection system. The dielectric withstand of the proposed physical layout is also analyzed through the finite-element approach, guaranteeing adequate insulation for the electronic circuits located outside the transformer tank, which facilitates circuitry maintenance and provides high modularity. The electronic switches and the protection circuit of the electronic OLTC are experimentally tested under normal and faulty operational conditions in a 5 kVA, 7.69 kV/220 V, single-phase earth return distribution transformer.
Autors: Josemar de Oliveira Quevedo;Fabricio Emmanuel Cazakevicius;Rafael Concatto Beltrame;Tiago Bandeira Marchesan;Leandro Michels;Cassiano Rech;Luciano Schuch;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 883 - 894
Publisher: IEEE
 
» Analysis and Experimental Implementation of Grid Frequency Regulation Using Behind-the-Meter Batteries Compensating for Fast Load Demand Variations
Abstract:
This paper proposes a new grid frequency regulation (GFR) scheme using behind-the-meter battery energy storage systems (BESSs). The fast dynamic responses of the electrical BESSs enable buildings to compensate for the high-frequency components of load demand variations, through direct load control (DLC). An electrical system in a building, along with its building-level and device-level controllers, is considered to address the difficulties in the application of DLC, especially in communicating with several small-scale BESSs. A small-signal analysis is carried out using the aggregated responses of the generators and the DLC-enabled buildings to investigate the proposed GFR scheme, particularly with respect to the feedback controllers for the buildings. Simulation studies are performed using a test grid for various penetrations of the DLC-enabled buildings, and the test grid is implemented using a laboratory-scale microgrid. The proposed GFR is effective in reducing the frequency deviations and required reserve capacity of the generators, which is achieved by making small variations in the state-of-charge of the behind-the-meter battery.
Autors: Young-Jin Kim;Gerard Del-Rosario-Calaf;Leslie K. Norford;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 484 - 498
Publisher: IEEE
 
» Analysis and Implementation of an Ultra-Wide Tuning Range CMOS Ring-VCO With Inductor Peaking
Abstract:
A novel ring voltage controlled oscillator (VCO) topology is proposed which uses monolithic inductors as a peaking load. Four design examples have been fabricated and tested to verify the proposed circuit structure. The highest measured oscillation frequency is 25.07 GHz, with a tuning range of more than four octaves, and the active area is 0.0085 mm2. The design has the highest combined frequency and tuning range with the best figure of merit () comparable to previously published work.
Autors: Ke Li;Fanfan Meng;Dave J. Thomson;Peter Wilson;Graham. T. Reed;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 49 - 51
Publisher: IEEE
 
» Analysis and Implementation of Hologram Lenses for See-Through Head-Mounted Display
Abstract:
We introduce an approach to implementation of see-through head-mounted displays using hologram lenses, which are categorized by holographic optical elements. The hologram lenses magnify displayed images and superimpose the magnified images on the real-world simultaneously, which allows system configuration to be compact. Here, we investigate imaging properties and optical issues of hologram lenses using the spectral analysis of light field. Also, the astigmatism of hologram lenses is analyzed and its compensation method is proposed and verified. We conclude by describing display results and a practical application of the proposed method.
Autors: Seungjae Lee;Byounghyo Lee;Jaebum Cho;Changwon Jang;Jonghyun Kim;Byoungho Lee;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 82 - 85
Publisher: IEEE
 
» Analysis and Optimization of Caching and Multicasting in Large-Scale Cache-Enabled Heterogeneous Wireless Networks
Abstract:
Heterogeneous wireless networks (HetNets) provide a powerful approach to meeting the dramatic mobile traffic growth, but also impose a significant challenge on backhaul. Caching and multicasting at macro and pico base stations (BSs) are two promising methods to support massive content delivery and reduce backhaul load in HetNets. In this paper, we jointly consider caching and multicasting in a large-scale cache-enabled HetNet with backhaul constraints. We propose a hybrid caching design consisting of identical caching in the macro-tier and random caching in the pico-tier, and a corresponding multicasting design. By carefully handling different types of interferers and adopting appropriate approximations, we derive tractable expressions for the successful transmission probability in the general signal-to-noise ratio (SNR) and user density region as well as the high SNR and user density region, utilizing tools from stochastic geometry. Then, we consider the successful transmission probability maximization by optimizing design parameters, which is a very challenging mixed discrete-continuous optimization problem. By exploring structural properties, we obtain a near optimal solution with superior performance and manageable complexity. This solution achieves better performance in the general region than any asymptotically optimal solution, under a mild condition. The analysis and optimization results provide valuable design insights for practical cache-enabled HetNets.
Autors: Ying Cui;Dongdong Jiang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 250 - 264
Publisher: IEEE
 
» Analysis and Performance EnhancementPub _newline of Vector-Controlled VSC in HVDC Links Connected to Very Weak Grids
Abstract:
Voltage source converter (VSC)-based high-voltage direct current (HVDC) transmission systems have been employed widely in recent years. However, connecting a VSC-HVDC link to a very weak grid (a high-impedance grid) is challenging. A vector-controlled VSC is incapable of injecting/absorbing its maximum theoretical active power in such grids. A simple yet effective control system for a standard vector-controlled VSC in a very weak grid condition has not been reported in the literature. This paper, benefiting from a comprehensive small-signal model, presents a detailed analysis of the VSC dynamics and shows how the assumptions made for designing VSC regulators in strong grids are no longer valid in very weak grids. The paper then proposes and compares two straightforward solutions: retuning the control parameters and using an artificial bus for converter-grid synchronization. Both methods enable the VSC to operate at the maximum theoretical active power at a very weak grid condition (i.e., at unity short-circuit ratio) by minimal modification in the widely accepted vector control method. The advantages and disadvantages of each method are discussed. The analytical results are verified by detailed nonlinear time-domain simulation results.
Autors: Mohammadreza Fakhari Moghaddam Arani;Yasser Abdel-Rady I. Mohamed;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 684 - 693
Publisher: IEEE
 
» Analysis and Verification of DLL-Based GFSK Demodulator Using Multiple-IF-Period Delay Line
Abstract:
This brief presents a delay-locked-loop-based Gaussian frequency-shift keying (FSK) demodulator using a multiple-IF-period delay line. Theoretical analysis of the bit error rate (BER) performance is developed. The analysis result implies that the BER can be improved when a multiple-IF-period delay line is used instead of a single-IF-period delay line. To verify the analysis, a prototype chip was fabricated in a 0.11- CMOS process. When a binary Gaussian FSK (GFSK) signal carries 1-Mb/s data on a 3-MHz center frequency with a 160-kHz frequency deviation, the minimum required signal-to-noise ratio for 0.1% BER is reduced from 17.5 to 12.5 dB when a triple-IF-period delay line is used instead of a single-IF-period delay line. The implemented GFSK demodulator consumes 0.8 mA from a 1.2-V supply voltage.
Autors: Sangjin Byun;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2017, volume: 64, issue:1, pages: 6 - 10
Publisher: IEEE
 
» Analysis of Crosstalk Effects for Multiwalled Carbon Nanotube Bundle Interconnects in Ternary Logic and Comparison With Cu Interconnects
Abstract:
In this study, the crosstalk-induced effects are investigated in ternary logic by using the three-line bus architecture. The worst case crosstalk delays for both repeated and unrepeated interconnect and the peak crosstalk noise voltage on the victim net are investigated. Analyses have been done for global level multiwalled carbon nanotube (MWCNT) bundle and copper interconnects with carbon nanotube FET-based drivers and receivers at 22 nm node. According to the HSPICE simulations, the crosstalk delay and noise area in the MWCNT bundle interconnects are much smaller than the Cu wires for the ternary logic. In addition, the MWCNT bundle interconnects require a lower number of repeaters as compared to the Cu wires, which results in lower complexity and power consumption. The results indicate that utilizing the MWCNT interconnects instead of Cu wires in ternary systems leads to 63% shorter crosstalk delay without repeater insertion and 65% lower crosstalk noise area and 75% lower power consumption with repeater insertion. It is concluded from the results that the MWCNT bundle global wires are more suitable for ternary very large scale integration systems as compared to the Cu wires.
Autors: Maryam Rezaei Khezeli;Mohammad Hossein Moaiyeri;Ali Jalali;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2017, volume: 16, issue:1, pages: 107 - 117
Publisher: IEEE
 
» Analysis of Encoding Degradation in Spiking Sensors Due to Spike Delay Variation
Abstract:
Spiking sensors such as the silicon retina and cochlea encode analog signals into massively parallel asynchronous spike train output where the information is contained in the precise spike timing. The variation of the spike timing that arises from spike transmission degrades signal encoding quality. Using the signal-to-distortion ratio (SDR) metric with nonlinear spike train decoding based on frame theory, two particular sources of delay variation including comparison delay and queueing delay are evaluated on two encoding mechanisms which have been used for implementations of silicon array spiking sensors: asynchronous delta modulation and self-timed reset. As specific examples, is obtained from a 2T current-mode comparator, and is obtained from an M/D/1 queue for 1-D sensors like the silicon cochlea and an /D/1 queue for 2-D sensors like the silicon retina. Quantitative relations between the SDR and the circuit and system parameters of spiking sensors are established. The analysis method presented in this work will be useful for future specifications-guided designs of spiking sensors.
Autors: Minhao Yang;Shih-Chii Liu;Tobi Delbruck;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jan 2017, volume: 64, issue:1, pages: 145 - 155
Publisher: IEEE
 
» Analysis of High-Field Hole Transport in Germanium and Silicon Nanowires Based on Boltzmann's Transport Equation
Abstract:
In this paper, high-field hole transport in germanium nanowires was studied by using Boltzmann's transport equation in an atomistic framework. The scattering mechanisms taken into account are phonon and surface roughness. The hole drift velocities of [110], [111], and [112]-oriented germanium nanowires showed negative-differential characteristics, while that of the [001] nanowire did not. The behavior of hole drift velocity was analyzed based on the highly nonparabolic and orientation-dependent valence band structure. High-field hole transport properties in silicon nanowires were also calculated, and the differences between germanium and silicon nanowires were discussed, focusing mainly on momentum and energy relaxation times. The [110], [111], and [112] silicon nanowires showed faster hole drift velocity at high field than the germanium nanowires with the same orientation. This was attributed to faster energy relaxation in silicon nanowires, which mitigates the negative differential mobility in silicon nanowires compared to germanium nanowires.
Autors: Hajime Tanaka;Jun Suda;Tsunenobu Kimoto;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2017, volume: 16, issue:1, pages: 118 - 125
Publisher: IEEE
 
» Analysis of Knee Strength Measurements Performed by a Hand-Held Multicomponent Dynamometer and Optoelectronic System
Abstract:
The quantification of muscle weakness is useful to evaluate the health status and performance of patients and athletes. In this paper, we proposed a novel methodology to investigate and to quantify the effects induced by inaccuracy sources occurring when using a hand-held dynamometer (HHD) for knee strength measurements. The validation methodology is based on the comparison between the output of a one-component commercial HHD and the outputs of a six-component load cell, comparable in dimension and mass. An optoelectronic system was used to measure HHD positioning angles and displacements. The setup allowed to investigate the effects induced by: 1) the operator’s ability to place and to hold still the HHD and 2) ignoring the transversal components of the force exchanged. The main finding was that the use of a single component HHD induced an overall inaccuracy of 5% in the strength measurements if the angular misplacements are kept within the values found in this paper (≤15°) and with a knee range of motion ≤22°. Extension trials were the most critical due to the higher force exerted, i.e., 249.4 ± 27.3 versus 146.4 ± 23.9 N of knee flexion. The most relevant source of inaccuracy was identified in the angular displacement on the horizontal plane.
Autors: Andrea Ancillao;Stefano Rossi;Paolo Cappa;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2017, volume: 66, issue:1, pages: 85 - 92
Publisher: IEEE
 
» Analysis of Negatively Focused Ultrasound Detectors in Optoacoustic Tomography
Abstract:
In optoacoustic tomography, negatively focused transducers may be used for improving the tangential image resolution while preserving a high signal-to-noise ratio. Commonly, image reconstruction in such scenarios is facilitated by the use of the virtual-detector approach. Although the validity of this approach has been experimentally verified, it is based on an approximation whose effect on optoacoustic image reconstruction has not yet been studied. In this paper, we analyze the response of negatively focused acoustic detectors in 2D in both time and frequency domains. Based on this analysis, tradeoffs between the detector size, curvature, and sensitivity are formulated. In addition, our analysis reveals the geometrical underpinning of the virtual-detector approximation and quantifies its deviation from the exact solution. The error involved in the virtual-detector approximation is studied in image reconstruction simulations and its effect on image quality is shown. The theoretical tools developed in this work may be used in the design of new optoacoustic detection geometries as well as for improved image reconstruction.
Autors: Gilad Drozdov;Amir Rosenthal;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 301 - 309
Publisher: IEEE
 
» Analysis of the Meyer-Neldel Rule Based on a Temperature-Dependent Model for Thin-Film Transistors
Abstract:
Based on the Pao–Sah model and considering the double exponential distribution of traps density of states (DOS) in the bandgap, a unified drain current model is derived for thin-film transistors (TFTs). It is verified by fitting experimental – characteristics of both a-InGaZnO TFTs and two types of polycrystalline Si TFTs of different technologies, measured at different drain voltages and temperatures with a set of model parameters independent of temperature. Temperature dependence of TFT subthreshold current follows the well-known Meyer–Neldel rule (MNR). It is clarified that the proposed – model is inherently consistent with the MNR, without any intentionally introduced assumptions or parameters. Key parameter, the MN energy, is associated with the inverse slope of the deep traps DOS distribution, while another key parameter, the activation energy, is the averaged energy difference between the band edge and the quasi Fermi-level along the channel depth.
Autors: Zhiyuan Han;Mingxiang Wang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 145 - 152
Publisher: IEEE
 
» Analysis of the Probability of Sync-Words in Reed–Solomon Codes
Abstract:
Given binary data transmission encoded using a Reed–Solomon (RS) code and employing binary sync-words (markers) for synchronization, we calculate the probability of finding the sync-word in the codewords of the RS code as . We give analytical expressions for calculating , which is applicable to RS codes. Knowledge of can be used to calculate the probability of finding a sync-word that is used as a marker in RS encoded data, . The probability is called the false acquisition probability in the synchonization of RS encoded data.
Autors: Thokozani Shongwe;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 36 - 39
Publisher: IEEE
 
» Analysis of the Spatial Correlation of Indoor MIMO PLC Channels
Abstract:
In this letter, an analysis of the spatial correlation of multiple-input multiple-output (MIMO) power line communications (PLC) channels in the frequency range 1–80 MHz is provided, where the term spatial correlation refers to the relation between the paths that form the MIMO channel matrix. The study is based on a large set of MIMO channels measured in four different countries. The presented statistical analysis of the condition number reveals three important facts. First, the spatial correlation is almost independent of frequency, which has important implications in the development of top-down MIMO PLC channel models. Second, the use of an alternative injection method can notably reduce the spatial correlation and, consequently, increase the system bit-rate. Third, there exist countries whose channels have larger spatial correlation values than others. Since spatial correlation plays a key role in the performance of MIMO PLC systems, a hypothesis relating the type of wiring deployed in the indoor power grid to the spatial correlation is given and supported by simulations.
Autors: Julio A. Corchado;José A. Cortés;Francisco J. Cañete;Antonio Arregui;Luis Díez;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 40 - 43
Publisher: IEEE
 
» Analysis of the Transmission “Window” Formation in the Electrooptical Switch of Laser Pulses With Plasma Electrodes
Abstract:
A process of plasma electrodes and optical transmission “window” formation in electrooptical switch (Pockels cell) of high-power laser radiation pulses is studied experimentally and analyzed numerically. A 2-D computer model of a gas discharge, forming the electrodes and allowing for the charged particles transport and reactions kinetics in self-consistent electric field is developed. A time dependence of the optical transmission in various points of the cross section of the cell operating in the two-pulse mode is computed. In the cell center, the calculated dependence is consistent with the optical transmission oscilloscope trace.
Autors: Leonid P. Babich;Evgeniĭ I. Bochkov;Sergeĭ G. Garanin;Yuriĭ. V. Dolgopolov;Igor M. Kutsyk;Nikolaĭ F. Andreev;Aleksandr Z. Matveev;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 85 - 90
Publisher: IEEE
 
» Analysis of Uplink ICI and IBI in Heterogeneous Cellular Networks With Multiple Macrocells
Abstract:
This letter analyzes the effects of inter-carrier interference (ICI) and inter-block interference (IBI) on uplink reception of small cells (SCs) in orthogonal frequency division multiple access heterogeneous cellular networks. Tight upper and lower bounds of the power of ICI and IBI plus co-channel interference from nearby SCs, average rate, and symbol error rate (SER) per SC subcarrier are derived. Results show that the theoretical analysis is close to simulation. Importantly, the average rate and SER are seriously degraded by the interference at high signal-to-noise ratio.
Autors: Hong Wang;Shu-Hung Leung;Rongfang Song;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 212 - 215
Publisher: IEEE
 
» Analysis of Vibratory Gyroscopes: Drive and Sense Mode Resonance Shift by Coriolis Force
Abstract:
In this paper, we demonstrate the analysis of coupling between drive and sense systems of vibratory gyroscopes. Vibratory gyroscopes have attracted a lot of interest recently with the development of MEMS gyroscopes. These gyroscopes made their way through portable devices and smart phones. Novel gyroscope architectures have been proposed and analyzed in detail. However, in most of these analyses, coupling between the sense and drive systems was ignored. We analytically show that drive and sense systems are coupled together via Coriolis and centrifugal force. As a result, system resonances shift as the rotation rate increase for linear and torsional gyroscope systems. Starting from a simple gyro system, we calculated the sense and drive resonant frequency shifts in various configurations. Then, for more complex systems where analytical solution is difficult to obtain, we used commercially available FEM tools to determine corresponding frequency shift. In general, we found that the shift is small and can be ignored for linear vibratory gyroscopes where of the sense system is less than 2500 for mode matched gyros. But for higher systems, the frequency shift may affect the linearity of these gyroscopes. This sets a fundamental limit for the linearity of vibratory gyroscopes. Based on our calculations the non-linearity is above 1% for linear 2-DOF mode-matched vibratory gyroscopes where is above 3000 and for torsional 2-DOF vibratory gyroscopes where is above 600. Multi-DOF and ring vibratory gyroscopes are also examined. We find that the effect is less pronounced for Multi-DOF gyros, whereas there is a large effect on the linearity of ring gyroscop s.
Autors: Hakan Cetin;Goksen G. Yaralioglu;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 347 - 358
Publisher: IEEE
 
» Analytical Drain Current Compact Model in the Depletion Operation Region of Short-Channel Triple-Gate Junctionless Transistors
Abstract:
A new charge-based analytical compact model for the drain current of junctionless (JL) triple-gate MOSFETs is presented, which includes the short-channel effects, the saturation velocity overshoot, the series resistance, and the mobility degradation effects. The proposed model consists of a single analytical equation that covers the depletion operation region in which the bulk conduction determines the drain current. The model is supported by experimental measurements in JL nanowire transistors with channel length varying from 95 to 25 nm and doping concentration cm. The overall results reveal the very good accuracy of the proposed analytical compact model, making it suitable for circuit simulation tools.
Autors: Theodoros A. Oproglidis;Andreas Tsormpatzoglou;Dimitrios H. Tassis;Theano A. Karatsori;Sylvain Barraud;Gérard Ghibaudo;Charalabos A. Dimitriadis;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 66 - 72
Publisher: IEEE
 
» Analytical Performance Evaluation of VDSL2
Abstract:
In this letter, we model the downstream bit rate per user for VDSL2-based access systems as normal random variable. Its statistics are expressed in closed analytic forms explicitly accounting for FEXT fluctuation and for the access network geometry. The considered approximation is obtained assuming log-normal statistics for the signal-to-interference plus noise ratio per sub-carrier. The validity of this model has been assessed by computer calculation showing a very good agreement between the exact and the approximated bit rates.
Autors: Franco Mazzenga;Romeo Giuliano;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 44 - 47
Publisher: IEEE
 
» Ancillary Services Through Demand Scheduling and Control of Commercial Buildings
Abstract:
Prior work showed building Heating, Ventilation, Air Conditioning (HVAC) systems can provide ancillary services to the power grid without sacrificing occupant comfort if the reference power variation is of high frequency (seconds to a few minutes). This paper addresses the question of how to do that when the reference power variation is of lower frequency, e.g., periods of a few minutes to an hour. The proposed control system to do so uses a two-layer architecture. An optimizer schedules the baseline cooling and heating power of a building based on load forecasts. A lower level controller is then used to track the scheduled baseline plus ancillary service reference signal. The schedule is periodically updated based on indoor measurements to ensure quality of service in spite of load forecasting error. The algorithm is tested in simulation. Results show that ancillary services in the frequency range of can be extracted from commercial building HVAC systems while still maintaining a comfortable indoor climate.
Autors: Yashen Lin;Prabir Barooah;Johanna L. Mathieu;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 186 - 197
Publisher: IEEE
 
» Anger Management [MicroBusiness]
Abstract:
Discusses approaches to deal with anger management in the workplace.
Autors: Fred Schindler;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2017, volume: 18, issue:1, pages: 18 - 20
Publisher: IEEE
 
» Angle Correction in Optopalatographic Tongue Distance Measurements
Abstract:
Optopalatography (OPG) is an optical technique to measure the distance between the hard palate and the tongue surface inside the mouth during articulation. The conventional way to measure this distance is only accurate for the special case that the tongue surface is oriented perpendicular to the optical axes of the optical sensors. It introduces an error in the much more common case that the tongue is angled with respect to the sensor axes. In this paper, we present a technique to compensate that error by using a newly devised complete model of light propagation for arbitrary source-reflector-detector setups that considers the complex reflective properties of the tongue surface due to sub-surface scattering. Optimal parameters for our model are found by fitting it to a data set of real-world measurements. For any given arrangement of sensors, simulations of this model can be used to obtain optimal coefficients for a distance error correction term. This term reduces the mean distance error of in vivo data recorded with our electrooptical stomatography (EOS, a multi-modal technique that includes OPG) hardware prototype from 7.38% to 2.25% and the standard deviation from 2.79% to 1.9%. The results are used to significantly improve the precision and accuracy of the distance measurements in real-time EOS recordings and example tongue contours of five German vowels are presented.
Autors: Simon Stone;Peter Birkholz;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 459 - 468
Publisher: IEEE
 
» Angle Difference Method for Vehicle Navigation in Multilevel Road Networks With a Three-Dimensional Transport GIS Database
Abstract:
Multilevel road networks such as grade-separated interchanges and elevated roads have been increasingly used to solve traffic congestion in large cities. When navigating a vehicle in a multilevel road network, identifying the location of the vehicle in different road levels is of equal importance to identifying its planar location, particularly for overlapping and parallel roads. Although they can be represented and visualized in the existing navigation system, at present, it is difficult to guide a vehicle through such a multilevel road network because the existing vehicle positioning system uses consumer-grade GPS, and the transport geographic information system (GIS-T) database is mainly 2-D-based. The location of a vehicle on diffrent road levels in multilevel road networks is often overlooked. This paper examines the deficiency of existing approaches in supporting vehicle navigation in multilevel road networks with consumer-grade GPS. It proposes to use an angle difference method that compares the vehicle pitch angle with the inclination angles of different road levels calculated from road elevations stored in the proposed GIS-T database to snap the vehicle to the appropriate road level when the vehicle is entering or exiting a multilevel road network. The angle difference method is implemented based on consumer-grade assisted GPS (A-GPS) and onboard vehicle pitch angle measurement with smartphone. Experiment results prove that the angle difference method have high accuracy in determining the road level when the vehicle is driving in a parallel multilevel road network.
Autors: Anthony Gar-On Yeh;Teng Zhong;Yang Yue;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2017, volume: 18, issue:1, pages: 140 - 152
Publisher: IEEE
 
» Anisotropic Conductivity Tensor Imaging of In Vivo Canine Brain Using DT-MREIT
Abstract:
We present in vivo images of anisotropic electrical conductivity tensor distributions inside canine brains using diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT). The conductivity tensor is represented as a product of an ion mobility tensor and a scale factor of ion concentrations. Incorporating directional mobility information from water diffusion tensors, we developed a stable process to reconstruct anisotropic conductivity tensor images from measured magnetic flux density data using an MRI scanner. Devising a new image reconstruction algorithm, we reconstructed anisotropic conductivity tensor images of two canine brains with a pixel size of 1.25 mm. Though the reconstructed conductivity values matched well in general with those measured by using invasive probing methods, there were some discrepancies as well. The degree of white matter anisotropy was 2 to 4.5, which is smaller than previous findings of 5 to 10. The reconstructed conductivity value of the cerebrospinal fluid was about 1.3 S/m, which is smaller than previous measurements of about 1.8 S/m. Future studies of in vivo imaging experiments with disease models should follow this initial trial to validate clinical significance of DT-MREIT as a new diagnostic imaging modality. Applications in modeling and simulation studies of bioelectromagnetic phenomena including source imaging and electrical stimulation are also promising.
Autors: Woo Chul Jeong;Saurav Z. K. Sajib;Nitish Katoch;Hyung Joong Kim;Oh In Kwon;Eung Je Woo;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 124 - 131
Publisher: IEEE
 
» Antenna on Cavity Backed High Impedance Surface
Abstract:
A low profile (), lightweight, linearly polarized antenna has been designed for 0.9 GHz applications using a double layered via-less high impedance surface (HIS). The weight of the antenna is reduced by removing the dielectric layer between the HIS and the ground plane. In order to suppress the back lobe, we propose the use of a cavity. Since the entire structure lies below the surface of the ground, the proposed antenna can be used on moving platforms, especially for airborne applications.
Autors: Gaurangi Gupta;A. R. Harish;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 374 - 379
Publisher: IEEE
 
» Application of a Phasor-Only State Estimator to a Large Power System Using Real PMU Data
Abstract:
This paper applies a phasor-only state estimator (PSE) to a large power system consisting of two control regions, using synchrophasor data from 56 765/345/230 kV substations. Although the technique has been previously developed, this paper describes a topology processor to determine the redundant clusters of connected buses such that the PSE can be used in real time. This PSE allows corrections for phase biases, transformer taps, and current magnitude scaling. The ability to simultaneously solve the PSE for the two control regions is due to a PMU monitoring a tie-line between these two regions. The results show that with this method, the total vector errors of the measured voltage phasor data in these two control regions average to less than 0.5% under ambient conditions. The PSE also computes virtual phasor measurements on 70 buses that do not have PMUs, including large steam generator and wind-turbine generator substations.
Autors: Emily R. Fernandes;Scott G. Ghiocel;Joe H. Chow;Daniel E. Ilse;De D. Tran;Qiang Zhang;David B. Bertagnolli;Xiaochuan Luo;George Stefopoulos;Bruce Fardanesh;Russell Robertson;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 411 - 420
Publisher: IEEE
 
» Approximate Area-to-Point Regression Kriging for Fast Hyperspectral Image Sharpening
Abstract:
Area-to-point regression kriging (ATPRK) is an advanced image fusion approach in remote sensing In this paper, ATPRK is considered for sharpening hyperspectral images (HSIs), based on the availability of a fine spatial resolution panchromatic or multispectral image. ATPRK can be used straightforwardly to sharpen each coarse hyperspectral band in turn. This scheme, however, is computationally expensive due to the large number of bands in HSIs, and this problem is exacerbated for multiscene or multitemporal analysis. Thus, we extend ATPRK for fast HSI sharpening with a new approach, called approximate ATPRK (AATPRK), which transforms the original HSI to a new feature space and image fusion is performed for only the first few components before back transformation. Experiments on two HSIs show that AATPRK greatly expedites ATPRK, but inherits the advantages of ATPRK, including maintaining a very similar performance in sharpening (both ATPRK and AATPRK can produce more accurate results than seven benchmark methods) and precisely conserving the spectral properties of coarse HSIs.
Autors: Qunming Wang;Wenzhong Shi;Peter M. Atkinson;Qi Wei;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 286 - 295
Publisher: IEEE
 
» Approximate Safety Verification and Control of Partially Observable Stochastic Hybrid Systems
Abstract:
Assuring safety in stochastic hybrid systems is particularly difficult when only noisy or partial observations of the state are available. We first review a formulation of the probabilistic safety problem under partial hybrid observations as a dynamic program over an equivalent information state. Two methods for approximately solving the dynamic program are presented. The first approximates the hybrid system as a finite state Markov decision process, so that the information state is a probability mass function. The second method approximates an indicator function over the safe region using radial basis functions, to represent the information state as a Gaussian mixture. In both cases we discretize the hybrid observation process, then use point-based value iteration to under-approximate the safety probability and synthesize a safety-preserving control policy. We obtain error bounds and convergence results in both cases, assuming switched affine dynamics and additive Gaussian noise on the continuous states and observations. We compare the performance of the finite state and Gaussian mixture approaches on a simple numerical example.
Autors: Kendra Lesser;Meeko Oishi;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 81 - 96
Publisher: IEEE
 
» Area Spectral Efficiency Analysis of Multi-Antenna Two-Tier Cellular Networks
Abstract:
This letter investigates the area spectral efficiency (ASE) of a two-tier network with multi-antenna base stations (BSs). Based on a tractable approximation, some key properties of ASE are analytically revealed. We demonstrate that the additional deployment of small-cell BSs is efficient for improving ASE. For the purpose of ASE maximization, the optimal number of active users is derived for each tier, which has a linear relationship with the number of antennas. Furthermore, under the optimal condition, ASE will increase linearly with the number of antennas. Different from single-antenna networks, we observe that range expansion can have either a positive or a negative effect on ASE.
Autors: Zheng Chen;Ling Qiu;Xiao Wen Liang;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 108 - 111
Publisher: IEEE
 
» Artificial-Noise-Aided Secure Transmission Scheme With Limited Training and Feedback Overhead
Abstract:
We design a novel artificial-noise-aided secure ON–OFF transmission scheme in a wiretap channel. We consider a practical scenario, where the multi-antenna transmitter only obtains partial channel knowledge from the single-antenna receiver through limited training and feedback but has no channel knowledge about the single-antenna eavesdropper. In the design, we first propose a three-period block transmission protocol to capture the practical training and quantization features. We then characterize the statistics of the received signal-to-noise ratios at the receiver and the eavesdropper. Under the secrecy outage constraint, we exploit the ON–OFF scheme to perform secure transmission and derive a closed-form expression for the secrecy throughput. Moreover, we investigate the optimization problem of maximizing the secrecy throughput by proposing an iterative algorithm to determine the optimal power allocation between the information signal and artificial noise, as well as the optimal codeword transmission rate. Furthermore, we define the net secrecy throughput (NST), which takes the signaling overhead into account and address the problem of optimally allocating the block resource to the training and feedback overhead. Numerical results clearly demonstrate how the optimal signaling overhead changes with the number of transmit antennas, and there exists an optimal number of antennas that maximizes the NST.
Autors: Jianwei Hu;Yueming Cai;Nan Yang;Xiangyun Zhou;Weiwei Yang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 193 - 205
Publisher: IEEE
 
» Assessment of Scalable and Fast 1310-nm Optical Switch for High-Capacity Data Center Networks
Abstract:
The development of high-capacity 1310-nm optical interconnects and the limitation of the electrical switches have necessitated the investigation of 1310-nm optical switches for flat data center networks. We have performed an experimental assessment of the scalable and fast 1310-nm optical switching system with three types of traffic, namely, the waveband Gb/s on–off keying (OOK), 28 Gb/s 4-level pulse-amplitude modulation (PAM4), and 40 Gb/s discrete multi-tone (DMT) by using the prototyped 1310-nm optical switch. 10-dB input power dynamic range has been achieved at 16 ports for waveband Gb/s, 28-Gb/s PAM4, and 40-Gb/s DMT with power penalty of 1, 3, and 3.3 dB, respectively. Waveband Gb/s OOK traffic shows the most promising results with port-count scaling up to 64 ports with limited penalty and allows for the potential scaling to larger port-count and more wavelength channels.
Autors: Wang Miao;Huug de Waardt;Robbert van der Linden;Nicola Calabretta;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 98 - 101
Publisher: IEEE
 
» Assistive Intelligent Robotic Wheelchairs
Abstract:
In a world where technological achievements and breakthroughs are astonishing and where computers and all kinds of electronic devices have become one with their users, there are still people that need assistance. This type of aid often has to come through technology and the implementation of ideas. People with disabilities and the elderly usually require diligent monitoring and help to complete their daily tasks.
Autors: Iosif Papadakis Ktistakis;Nikolaos G. Bourbakis;
Appeared in: IEEE Potentials
Publication date: Jan 2017, volume: 36, issue:1, pages: 10 - 13
Publisher: IEEE
 
» Asymmetrical Operation Analysis for Dual Stator-Winding Induction Generator Variable Frequency AC Generating System With Unbalanced Loads
Abstract:
In this paper, the performance of the dual stator-winding induction generator (DWIG) variable frequency ac (VFAC) generating system with unbalanced loads is analyzed, and an asymmetrical operation analysis method based on a three-port load network model is proposed. This method has four key steps: (1) deriving the three-port load network model for three-phase four-line unbalanced loads; (2) establishing the positive sequence, negative sequence, and zero sequence equivalent circuits for the DWIG; (3) combining the above model and circuits together to obtain the system whole equivalent model; and (4) writing the corresponding equations and solving them. The experimental results and the calculation results are almost consistent, which proves that the proposed method is correct and valid, and the DWIG VFAC generating system with unbalanced loads has a good performance.
Autors: Feifei Bu;Shenglun Zhuang;Wenxin Huang;Ning Su;Yuwen Hu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 52 - 59
Publisher: IEEE
 
» Asymptotically Stable Electromagnetic Shock Waves in Relativistic Plasmas
Abstract:
The behavior of electromagnetic (EM) waves in a relativistic plasma is investigated. The governing equations of such dynamical plasma system are derived from the basic fluid model equations, and the vector and electrostatic potential are analyzed using Maxwell’s equations. A system of first-order, ordinary but nonlinear differential equations, is obtained from the two coupled second-order differential equations. Numerical results are found using the fourth order Runge–Kutta method. It is seen that EM shock waves are emerged for subsonic case, and on the other hand, periodic oscillatory solution as well as asymptotically stable state is obtained for supersonic case. The present investigation is important to extrapolate in different plasma backgrounds, like laboratory and astroplasma environments, viz., in laboratory biomedicine, biophysics, genetic engineering, laboratory astrophysics, and at different stages of stellar evolution.
Autors: G. Mandal;U. N. Ghosh;M. Asaduzzaman;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 148 - 153
Publisher: IEEE
 
» Atmospheric Correction of Landsat-8/OLI Imagery in Turbid Estuarine Waters: A Case Study for the Pearl River Estuary
Abstract:
Several methods have been proposed for atmospheric correction over turbid waters, including near-infrared (NIR) band based or short-wave infrared (SWIR) band-based where the signal in turbid waters can be assumed zero. Here, we adopt a new infrared extrapolation method to extend the existing turbid water atmospheric correction of the operational land imager (OLI) data on Landsat-8 platform. The atmospheric correction uses the extrapolated Rayleigh-corrected reflectance at NIR and SWIR bands to derive the ratios of NIR to SWIR and visible aerosol single-scattering contributions (aerosol epsilon). Taking the Pearl River Estuary as an example, the magnitude and spatial distribution of reflectance from OLI compare well with those of concurrent moderate resolution imaging spectroradiometer /Aqua based on SWIRE atmospheric correction method. The linear regression coefficients between the resampled OLI and Aqua data have demonstrated the proposed atmospheric correction method can provide robust and realistic reflectance. The advantages of the high spatial resolution made the OLI data a good source for applications in coastal and estuarine waters.
Autors: Haibin Ye;Chuqun Chen;Chaoyu Yang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 252 - 261
Publisher: IEEE
 
» Augmenting Human Intellect and Amplifying Perception and Cognition
Abstract:
This first installment of the new Human Augmentation department looks at various technologies designed to augment the human intellect and amplify human perception and cognition. Linking back to early work in interactive computing, Albrecht Schmidt considers how novel technologies can create a new relationship between digital technologies and humans.
Autors: Albrecht Schmidt;
Appeared in: IEEE Pervasive Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 6 - 10
Publisher: IEEE
 
» Automated Detection of Uninformative Frames in Pulmonary Optical Endomicroscopy
Abstract:
Significance: Optical endomicroscopy (OEM) is a novel real-time imaging technology that provides endoscopic images at a microscopic level. The nature of OEM data, as acquired in clinical use, gives rise to the presence of uninformative frames (i.e., pure-noise and motion-artefacts). Uninformative frames can comprise a considerable proportion (up to > 25%) of a dataset, increasing the resources required for analyzing the data (both manually and automatically), as well as diluting the results of any automated quantification analysis. Objective: There is, therefore, a need to automatically detect and remove as many of these uninformative frames as possible while keeping frames with structural information intact. Methods: This paper employs Gray Level Cooccurrence Matrix texture measures and detection theory to identify and remove such frames. The detection of pure-noise and motion-artefacts frames is treated as two independent problems. Results: Pulmonary OEM frame sequences of the distal lung are employed for the development and assessment of the approach. The proposed approach identifies and removes uninformative frames with a sensitivity of 93% and a specificity of 92.6%. Conclusion: The detection algorithm is accurate and robust in pulmonary OEM frame sequences. Conditional to appropriate model refinement, the algorithms can become applicable in other organs.
Autors: Antonios Perperidis;Ahsan Akram;Yoann Altmann;Paul McCool;Jody Westerfeld;David Wilson;Kevin Dhaliwal;Stephen McLaughlin;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2017, volume: 64, issue:1, pages: 87 - 98
Publisher: IEEE
 
» Automatic Generation of Five-Axis Continuous Inspection Paths for Free-Form Surfaces
Abstract:
Continuous five-axis sweep scanning is an emerging technology for free-form surface inspection, which, unlike the traditional three-axis inspection that works in a point-by-point manner, keeps the stylus tip in constant contact with the surface during the scanning, and thus could tremendously improve the inspection efficiency. However, at present, it mostly depends on humans to plan a five-axis inspection path, which severely affects the potential use of this new technology. In this paper, we report a practical algorithm, which is able to automatically generate a five-axis inspection path for an arbitrary free-form surface. The crux of this algorithm is that the unique kinematic characteristics of the five-axis inspection machine are fully considered and utilized when a path is planned. As a direct result of this consideration and utilization, the inspection efficiency is tremendously increased, often 20–30 times better than an inspection path obtained by any traditional path planning algorithm that disregards the inspection machine itself. The experiments performed by us have fully validated this point.
Autors: Pengcheng Hu;Rong Zhang;Kai Tang;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 83 - 97
Publisher: IEEE
 
» Automatic Identification of Space-Frequency Block Coding for OFDM Systems
Abstract:
Signal identification has emerged as an enabling technology for intelligent wireless communication systems with applications in military and commercial fields. One of recent trends in this research topic is to propose identification algorithms for multiple antenna (MA) systems with multi-carrier (MC) transmissions. The previously reported investigations are limited to space-time block code (STBC) systems with MC transmissions. However, practical systems include also space-frequency block code (SFBC) schemes with MC transmissions. In this paper, we develop and analyze an SFBC identification algorithm for MA orthogonal frequency-division multiplexing (OFDM) transmission for the first time in the literature. Analytical expressions for the time-domain properties of the Alamouti and spatial multiplexing SFBC-OFDM signals are derived as the basis of the identification process. The proposed algorithm is divided into two steps. The first step estimates the cross-correlation function of pairs of signals received from different antennas, while the second step employs a false-alarm based test for decision making. The proposed algorithm avoids the need for a priori knowledge of the modulation format, channel coefficients, signal-to-noise ratio (SNR) value, and the starting time of OFDM symbols. Simulation results show the ability of the proposed algorithm to provide an acceptable identification performance in the presence of transmission impairments, even at relatively low SNR values. These favorable results are achieved with acceptable computational cost.
Autors: Mohamed Marey;Octavia A. Dobre;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 117 - 128
Publisher: IEEE
 
» Azimuth Motion Compensation With Improved Subaperture Algorithm for Airborne SAR Imaging
Abstract:
Conventional motion compensation (MOCO) under beam-center approximation is usually insufficient to correct severe track deviations for high-resolution synthetic aperture radar imaging. In this paper, a novel MOCO approach is developed for correction of the azimuth-variant motion errors by exploiting a precise angle-to-Doppler relationship within subapertures. The corruption from the residual motion errors to the angle-to-Doppler mapping is investigated and overcome by a compensation scheme of the scaled Fourier transform. Inheriting the high efficiency, the proposed azimuth MOCO approach has dramatically improved precision over the conventional subaperture MOCO method by reducing high side-lobe peaks of the point spread function. Extensive comparisons with other MOCO algorithms are given to show the superiority of the proposed algorithm. Moreover, real-data experiments are provided for a clear demonstration of our proposed approach.
Autors: Lei Zhang;Guanyong Wang;Zhijun Qiao;Hongxian Wang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 184 - 193
Publisher: IEEE
 
» Balanced MSM-2DEG Varactors Based on AlGaN/GaN Heterostructure With Cutoff Frequency of 1.54 THz
Abstract:
AlGaN/GaN high-electron mobility transistor structures were utilized to fabricate metal–semiconductor–metal (MSM) two-dimensional electron gas (2DEG) varactors for application as a terahertz (THz) capacitive switch. By adopting an asymmetric MSM structure composed of nanoscale gates and micron-scale gates, the cutoff frequency of the MSM-2DEG varactors was dramatically improved, up to the THz range, by reducing series resistance. The balanced MSM-2DEG varactor, in which a nanoscale gate is sandwiched between two micron-scale gates exhibited a capacitance switching ratio ( of 2.64, a cutoff frequency of 1.54 THz, and a figure of merit of 4.06 THz.
Autors: Ji Hyun Hwang;Kye-Jeong Lee;Sung-Min Hong;Jae-Hyung Jang;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 107 - 110
Publisher: IEEE
 
» Bandwidth Enhancement of a Differential-Fed Equilateral Triangular Patch Antenna via Loading of Shorting Posts
Abstract:
A comprehensive study on the mechanism of bandwidth enhancement for an equilateral triangular microstrip patch antenna (MPA) under differential excitation is presented in this paper. Attributing to the way of differential excitation, the radiation directivity of TM11 mode in such a patch has been improved a lot, and field distributions for both TM10 and TM11 modes are found to be simultaneously excited for radiation. Next, two shorting posts are introduced to thisMPA so as to generate an additional mode, i.e., zero mode, which resonates in a frequency between TM10 and TM11 modes. With the proper arrangement of these three modes in proximity to each other, a wide bandwidth for radiation can be satisfactorily achieved. To demonstrate the validity of the proposed concept, a prototype antenna is finally designed and fabricated. As theoretically expected, the impedance bandwidth of the final designed patch antenna has been increased to 50.46% and the gain is around 6.5 dBi. Both simulated and measured results exhibit wide bandwidth and good performance of radiation.
Autors: Jianpeng Wang;Qianwen Liu;Lei Zhu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 36 - 43
Publisher: IEEE
 
» Banking on Availability
Abstract:
Combating the growing threat to banks of distributed denial-of-service attacks will demand more than keeping pace in a technological arms race; it will also require greater information sharing among banks and other cybersecurity entities.
Autors: Nir Kshetri;Jeffrey Voas;
Appeared in: Computer
Publication date: Jan 2017, volume: 50, issue:1, pages: 76 - 80
Publisher: IEEE
 
» Basis-Adaptive Sparse Polynomial Chaos Expansion for Probabilistic Power Flow
Abstract:
This paper introduces the basis-adaptive sparse polynomial chaos (BASPC) expansion to perform the probabilistic power flow (PPF) analysis in power systems. The proposed method takes advantage of three state-of-the-art uncertainty quantification methodologies reasonably: the hyperbolic scheme to truncate the infinite polynomial chaos (PC) series; the least angle regression (LARS) technique to select the optimal degree of each univariate PC series; and the Copula to deal with nonlinear correlations among random input variables. Consequently, the proposed method brings appealing features to PPF, including the ability to handle the large-scale uncertainty sources; to tackle the nonlinear correlation among the random inputs; to analytically calculate representative statistics of the desired outputs; and to dramatically alleviate the computational burden as of traditional methods. The accuracy and efficiency of the proposed method are verified through either quantitative indicators or graphical results of PPF on both the IEEE European Low Voltage Test Feeder and the IEEE 123 Node Test Feeder, in the presence of more than 100 correlated uncertain input variables.
Autors: Fei Ni;Phuong H. Nguyen;Joseph F. G. Cobben;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 694 - 704
Publisher: IEEE
 
» Bayesian Approach in the Modal Analysis of Electromechanical Oscillations
Abstract:
This paper presents a Bayesian approach for identifying the modal parameters (i.e., frequency, damping ratio, and modal excitation) of electromechanical modes. The proposed approach identifies the modal parameters and calculates their uncertainty using ambient phasor measurement unit (PMU) measurements from a power system. The method is applied in the frequency domain on a selected frequency band, which significantly simplifies the identification. The performance of the method is studied with simulated data from the IEEE New England test system and the Nordic power system simulation model. In addition, measured PMU data from the Nordic power system are used. The results indicate that the modal parameters of electromechanical modes can be identified reliably and their identification uncertainty can be fundamentally calculated using the proposed method. Thus, the Bayesian approach is a promising identification method for wide-area monitoring of electromechanical oscillations.
Autors: Janne Seppänen;Siu-Kui Au;Jukka Turunen;Liisa Haarla;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 316 - 325
Publisher: IEEE
 
» Behind the Scenes of IEEE 1683: A Look into the Creation of a Standard
Abstract:
Electrical equipment installations and system designs that comply with well-known consensus standards and national codes will meet or exceed minimum guidelines for safety and reliability. However, many within the industry believe that further attention should be paid to the principles of safety by design and prevention through design. In response, IEEE Standard 1683 [1], has been written to address electrical safety for low-voltage motor control centers (MCs), and similar standards are in development for other types of equipment. IEEE 1683 is the first IEEE standard developed to specifically address equipment design, selection, and installation practices with an emphasis on methods to reduce exposure to shock and arc-flash hazards. This article summarizes the history and reasons that led to the development of IEEE Standard 1683 and provides an introduction to its application for safer, low-voltage MCs.
Autors: Marcelo E. Valdes;Rachel M. Bugaris;Craig M. Wellman;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jan 2017, volume: 23, issue:1, pages: 26 - 33
Publisher: IEEE
 
» Beijing Converters: Bridge Converters With a Capacitor Added to Reduce Leakage Currents, DC-Bus Voltage Ripples, and Total Capacitance Required
Abstract:
Isolation transformers and bulky electrolytic capacitors are often used in power electronic converters to reduce leakage currents and voltage ripples but this leads to low power density and reduced reliability. In this paper, an auxiliary capacitor is added to the widely used conventional full-bridge converter to provide a path for, and hence significantly reduce, the leakage current. The operation of the full-bridge converter is split into the operation of a half-bridge converter and a dc–dc converter so that the ripple energy can be diverted from the dc-bus capacitor to the auxiliary capacitor. Hence, the dc-bus capacitor can be significantly reduced while maintaining very low voltage ripples on the dc bus because it is only required to filter out switching ripples. The auxiliary capacitor is designed to allow high voltage ripples because its voltage is not supplied to any load. Accordingly, the auxiliary capacitor can also be very small as well. As a result, the total required capacitance becomes very small. The reduction ratio of the total capacitance is significant, which makes it cost-effective to use film capacitors instead of electrolytic capacitors. The proposed converters can be also operated as an inverter without any restriction on power factor because the adopted four switches are all bidirectional in terms of power flow. Experimental results for both rectification and inversion modes are presented to demonstrate the performance of the proposed converter in reducing the ripples, the leakage currents, and the total capacitance needed, with comparison to the conventional bridge converter without the auxiliary capacitor.
Autors: Qing-Chang Zhong;Wen-Long Ming;Wanxin Sheng;Yongsheng Zhao;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 325 - 335
Publisher: IEEE
 
» Benchmark Models for the Analysis and Control of Small-Signal Oscillatory Dynamics in Power Systems
Abstract:
This paper summarizes a set of six benchmark systems for the analysis and control of electromechanical oscillations in power systems, recommended by the IEEE Task Force on Benchmark Systems for Stability Controls of the Power System Dynamic Performance Committee. The benchmark systems were chosen for their tutorial value and particular characteristics leading to control the system design problems relevant to the research community. For each benchmark, the modeling guidelines are provided, along with eigenvalues and time-domain results produced with at least two simulation softwares, and one possible control approach is provided for each system as well. Researchers and practicing engineers are encouraged to use these benchmark systems when assessing new oscillation damping control strategies.
Autors: C. Canizares;T. Fernandes;E. Geraldi;L. Gerin-Lajoie;M. Gibbard;I. Hiskens (TF Past Chair);J. Kersulis;R. Kuiava;L. Lima;F. DeMarco;N. Martins;B. C. Pal;A. Piardi;R. Ramos (TF Chair);J. dos Santos;D. Silva;A. K. Singh;B. Tamimi;D. Vowles;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 715 - 722
Publisher: IEEE
 
» Benchmarking of Mask Fracturing Heuristics
Abstract:
Aggressive resolution enhancement techniques such as inverse lithography (ILT) often lead to complex, nonrectilinear mask shapes which make mask writing extremely slow and expensive. To reduce shot count of complex mask shapes, mask writers allow overlapping shots, due to which the problem of fracturing mask shapes with minimum shot count is NP-hard. The need to account for e-beam proximity effect makes mask fracturing even more challenging. Although a number of fracturing heuristics have been proposed, there has been no systematic study to analyze the quality of their solutions. In this paper, we first propose a method to generate tight upper and lower bounds for actual ILT mask shapes by formulating mask fracturing as an integer linear program and solving it using branch and price. Since the integer program requires significant computational resources to compute reasonable bounds, we propose a new method to generate benchmarks with known optimal solutions, that can be used to evaluate the suboptimality of mask fracturing heuristics. To make the generated benchmark shapes realistic, we further propose a novel automated benchmark generation method that takes any ILT shape as input and returns a benchmark shape which looks similar to the input shape and for which the optimal fracturing solution is known. Using these methods, we compare the suboptimality of four mask fracturing heuristics. Our results show that even a state-of-the-art prototype (version of) capability within a commercial EDA tool for e-beam mask shot decomposition can be suboptimal by as much as for real ILT shapes and by for generated benchmarks.
Autors: Tuck-Boon Chan;Puneet Gupta;Kwangsoo Han;Abde Ali Kagalwalla;Andrew B. Kahng;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2017, volume: 36, issue:1, pages: 170 - 183
Publisher: IEEE
 
» Beyond Overlay: Reaping Mutual Benefits for Primary and Secondary Networks Through Node-Level Cooperation
Abstract:
Existing spectrum sharing paradigms have set clear boundaries between the primary and secondary networks. There is either no or very limited node-level cooperation between the primary and secondary networks. In this paper, we develop a new and bold spectrum-sharing paradigm beyond the state of the art for future wireless networks. We explore network cooperation as a new dimension for spectrum sharing between the primary and secondary users. Such network cooperation can be defined as a set of policies under which different degrees of cooperation are to be achieved. The benefits of this paradigm are numerous, as they allow integrating resources from two networks. There are many possible node-level cooperation policies that one can employ under this paradigm. For the purpose of performance study, we consider a specific policy called United cooperation of Primary and Secondary (UPS) networks. UPS allows a complete cooperation between the primary and secondary networks at the node level to relay each other's traffic. As a case study, we consider a problem with the goal of supporting the rate requirement of the primary network traffic while maximizing the throughput of the secondary sessions. For this problem, we develop an optimization model and formulate a combinatorial optimization problem. We also develop an approximation solution based on a piece-wise linearization technique. Simulation results show that UPS offers significantly better throughput performance than that under the interweave paradigm.
Autors: Xu Yuan;Yi Shi;Xiaoqi Qin;Y. Thomas Hou;Wenjing Lou;Sastry Kompella;Scott F. Midkiff;Jeffrey H. Reed;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 2 - 15
Publisher: IEEE
 
» Bilevel Feature Extraction-Based Text Mining for Fault Diagnosis of Railway Systems
Abstract:
A vast amount of text data is recorded in the forms of repair verbatim in railway maintenance sectors. Efficient text mining of such maintenance data plays an important role in detecting anomalies and improving fault diagnosis efficiency. However, unstructured verbatim, high-dimensional data, and imbalanced fault class distribution pose challenges for feature selections and fault diagnosis. We propose a bilevel feature extraction-based text mining that integrates features extracted at both syntax and semantic levels with the aim to improve the fault classification performance. We first perform an improved statistics-based feature selection at the syntax level to overcome the learning difficulty caused by an imbalanced data set. Then, we perform a prior latent Dirichlet allocation-based feature selection at the semantic level to reduce the data set into a low-dimensional topic space. Finally, we fuse fault features derived from both syntax and semantic levels via serial fusion. The proposed method uses fault features at different levels and enhances the precision of fault diagnosis for all fault classes, particularly minority ones. Its performance has been validated by using a railway maintenance data set collected from 2008 to 2014 by a railway corporation. It outperforms traditional approaches.
Autors: Feng Wang;Tianhua Xu;Tao Tang;MengChu Zhou;Haifeng Wang;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2017, volume: 18, issue:1, pages: 49 - 58
Publisher: IEEE
 
» BiRank: Towards Ranking on Bipartite Graphs
Abstract:
The bipartite graph is a ubiquitous data structure that can model the relationship between two entity types: for instance, users and items, queries and webpages. In this paper, we study the problem of ranking vertices of a bipartite graph, based on the graph's link structure as well as prior information about vertices (which we term a query vector). We present a new solution, BiRank, which iteratively assigns scores to vertices and finally converges to a unique stationary ranking. In contrast to the traditional random walk-based methods, BiRank iterates towards optimizing a regularization function, which smooths the graph under the guidance of the query vector. Importantly, we establish how BiRank relates to the Bayesian methodology, enabling the future extension in a probabilistic way. To show the rationale and extendability of the ranking methodology, we further extend it to rank for the more generic -partite graphs. BiRank's generic modeling of both the graph structure and vertex features enables it to model various ranking hypotheses flexibly. To illustrate its functionality, we apply the BiRank and TriRank (ranking for tripartite graphs) algorithms to two real-world applications: a general ranking scenario that predicts the future popularity of items, and a personalized ranking scenario that recommends items of interest to users. Extensive experiments on both synthetic and real-world datasets demonstrate BiRank's soundness (fast convergence), efficiency (linear in the number of graph edges), and effectiveness (achieving state-of-the-art in the two real-world tasks).
Autors: Xiangnan He;Ming Gao;Min-Yen Kan;Dingxian Wang;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Jan 2017, volume: 29, issue:1, pages: 57 - 71
Publisher: IEEE
 
» Blessing of Dimensionality: Recovering Mixture Data via Dictionary Pursuit
Abstract:
This paper studies the problem of recovering the authentic samples that lie on a union of multiple subspaces from their corrupted observations. Due to the high-dimensional and massive nature of today’s data-driven community, it is arguable that the target matrix (i.e., authentic sample matrix) to recover is often low-rank. In this case, the recently established Robust Principal Component Analysis (RPCA) method already provides us a convenient way to solve the problem of recovering mixture data. However, in general, RPCA is not good enough because the incoherent condition assumed by RPCA is not so consistent with the mixture structure of multiple subspaces. Namely, when the subspace number grows, the row-coherence of data keeps heightening and, accordingly, RPCA degrades. To overcome the challenges arising from mixture data, we suggest to consider LRR in this paper. We elucidate that LRR can well handle mixture data, as long as its dictionary is configured appropriately. More precisely, we mathematically prove that LRR can weaken the dependence on the row-coherence, provided that the dictionary is well-conditioned and has a rank of not too high. In particular, if the dictionary itself is sufficiently low-rank, then the dependence on the row-coherence can be completely removed. These provide some elementary principles for dictionary learning and naturally lead to a practical algorithm for recovering mixture data. Our experiments on randomly generated matrices and real motion sequences show promising results.
Autors: Guangcan Liu;Qingshan Liu;Ping Li;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2017, volume: 39, issue:1, pages: 47 - 60
Publisher: IEEE
 
» Block Kriging With Measurement Errors: A Case Study of the Spatial Prediction of Soil Moisture in the Middle Reaches of Heihe River Basin
Abstract:
Block kriging (BK) is a common method of predicting the true value at the pixel scale when validating remote sensing retrieval products. However, measurement errors (MEs) increase the prediction uncertainty. In this letter, an extended interpolation technique—BK with MEs (BKMEs)—is developed. The properties of BKME are proven through derivation and demonstrated in a case study of soil moisture (SM) upscaling. Three prediction scenarios—one without MEs (BK), BK with homogeneous MEs (BKHOME), and BK with heterogeneous MEs (BKHEME)—are considered for the upscaling of SM data observed by a distributed wireless sensor network, and the results are compared. Both BK and BKHOME yield the same upscaling results, which differ from those of BKHEME, and the prediction results of BKHEME show less bias than those of the other scenarios. Because both BKHOME and BKHEME consider MEs, their prediction results show smaller kriging variances than do the BK results. Three primary conclusions are drawn. The first is that the optimal kriging coefficients assigned to the observations are affected not only by spatial distance but also by the MEs when the MEs of the samples are unequal. The second is that when the MEs are equal, it may not be necessary to consider the MEs to predict the value for an unobserved location. The third is that although the prediction uncertainty can be reduced by considering MEs, it is more meaningful to consider unequal MEs than equal MEs in the prediction process. BKME is an advanced upscaling method that achieves improved prediction accuracy by considering MEs.
Autors: Jian Kang;Rui Jin;Xin Li;Yang Zhang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2017, volume: 14, issue:1, pages: 87 - 91
Publisher: IEEE
 
» Bounds for Low Probability of Detection for Underwater Acoustic Communication
Abstract:
Most military underwater activities require stealth operations, and hydroacoustic transmissions might temper the mission. For this reason, military underwater acoustic transmission aims for low probability of detection (LPD). LPD communication systems are characterized by low transmission power and reception at low signal-to-noise power ratio (SNPR). As a side effect, LPD decreases acoustic noise pollution. In this paper, we study the LPD capability of underwater acoustic communication (UWAC) systems. We consider an interceptor with target false alarm and detection probabilities and a legitimate receiver with required detection and packet error probabilities. For the interceptor, we focus on an energy detector and calculate the minimal SNPR which satisfies its required performance. For the legitimate communication link, we consider spread-spectrum signaling with several modulation techniques, and calculate the minimal required SNPR to allow reliable detection and decoding of a data packet. Based on these minimal SNPR terms and using bounds on power attenuation in the channel, we quantify the LPD capability of the system and analyze the effect of channel and communication parameters. We also present results from a sea trial conducted in the Saanich Inlet off the coast of Vancouver Island, where we conducted LPD experiments for different transmission powers and carrier frequencies. We provide bounds for the minimal bandwidth and maximal transmission rate for LPD communication. Our results also show that LPD UWAC performs better in shallow and warm water, and for transmission at low carrier frequencies.
Autors: Roee Diamant;Lutz Lampe;Emmett Gamroth;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2017, volume: 42, issue:1, pages: 143 - 155
Publisher: IEEE
 
» Braking Torque Due to Cross Magnetization in Unsaturated IPM BLDC Machines and Its Mitigation
Abstract:
Cross magnetization (CM) is an inevitable phenomenon in electrical machines. It is more prominent in interior permanent magnet (IPM) brushless dc (BLDC) machines. This is because PMs demagnetize in overloaded and saturated conditions. It leads to cross coupling between the direct and quadrature-axes quantities, and a decrease in the resultant air-gap flux-density distribution under saturated conditions. In this paper, it is shown that CM leads to braking torque even in unsaturated IPM BLDC machines. Furthermore, the effect of CM on flux linkage, electromotive force, and dynamic torque is presented. Its mitigation using suitable selection of slot–pole combination is presented. It is observed that odd slot–pole combinations are least affected, and even slot–pole combinations are severely affected by CM. Furthermore, it is found that the overlap area of rotor pole arc with the stator pole arc influences the severity of CM, more particularly in fractional slot–pole combination machines. To verify these claims, finite-element method is used for modeling and analyzing various slot–pole combinations of a spoke-type IPM BLDC motor. The results obtained from these simulations are validated with a fabricated reference prototype, which support the claims.
Autors: S. Sashidhar;B. G. Fernandes;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 9
Publisher: IEEE
 
» Bridge Displacements Monitoring Using Space-Borne X-Band SAR Interferometry
Abstract:
The development of interferometric methodologies for deformation monitoring that are able to deal with long time series of synthetic aperture radar (SAR) images made the detection of seasonal effects possible by decomposing the differential SAR phase. In the case of monitoring of man-made structures, particularly bridges, the use of high-resolution X-band SAR data allows the determination of three major components with significant influence on the SAR phase: the linear deformation trend, the height of structures over terrain, and the thermal expansion. In the case of stable metallic or (reinforced) concrete structures, this last effect can reach a magnitude comparable to or even exceeding the other phase components. In this review, we present two case studies that confirm the feasibility of InSAR techniques for bridge deformation monitoring and our original approach to refine the thermal expansion component.
Autors: Milan Lazecky;Ivana Hlavacova;Matus Bakon;Joaquim J. Sousa;Daniele Perissin;Gloria Patricio;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 205 - 210
Publisher: IEEE
 
» Bristol Ridge: A 28-nm $times$ 86 Performance-Enhanced Microprocessor Through System Power Management
Abstract:
Power management techniques can be effective at extracting more performance and energy efficiency out of mature systems on chip (SoCs). For instance, the peak performance of microprocessors is often limited by worst case technology (Vmax), infrastructure (thermal/electrical), and microprocessor usage assumptions. Performance/watt of microprocessors also typically suffers from guard bands associated with the test and binning processes as well as worst case aging/lifetime degradation. Similarly, on multicore processors, shared voltage rails tend to limit the peak performance achievable in low thread count workloads. In this paper, we describe five power management techniques that maximize the per-part performance under the before-mentioned constraints. Using these techniques, we demonstrate a net performance increase of up to 15% depending on the application and TDP of the SoC, implemented on “Bristol Ridge,” a 28-nm CMOS, dual-core x86 accelerated processing unit.
Autors: Sriram Sundaram;Aaron Grenat;Samuel Naffziger;Tom Burd;Stephen Kosonocky;Steve Liepe;Ravinder Rachala;Miguel Rodriguez;Michael Austin;Sriram Sambamurthy;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2017, volume: 52, issue:1, pages: 89 - 97
Publisher: IEEE
 
» Broadband Carpet Cloak Designed Using Nanocomposite Metamaterials for 3–5-μm Wavelength Range
Abstract:
In this paper, a broadband carpet cloak using nanocomposite layers to operate in whole 3–5-μm wavelength band is designed successfully. For this purpose, spherical nanometals or doped semiconductors with desired plasma frequency are proposed. In this way, the refractive index of the cloak as an analytic function is considered by optical conformal mapping. In a two-dimensional structure, we approximated the obtained refractive index inside each pixel to be constant. Each pixel is considered as an effective medium that possesses nanoparticles with desired plasma frequency. Therefore, plasma frequency of nanoparticles should be adjusted proportional to the desired value of refractive index in each two-dimensional pixels, which is approximated to be constant (two-dimensional layers approximation). The cloak region is compacted for broadband performance. To compact the cloak region, refractive index values should be greater than 1 and realization of these required values is possible by designing nonresonant structures.
Autors: Saba Khosravi;Ali Rostami;Mahboubeh Dolatyari;Ghasem Rostami;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2017, volume: 16, issue:1, pages: 44 - 48
Publisher: IEEE
 
» Building on the Past with an Eye to the Future [President's Column]
Abstract:
Presents the President's message for this issue of the publication.
Autors: Dylan Williams;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2017, volume: 18, issue:1, pages: 14 - 14
Publisher: IEEE
 
» Calculation of PM Eddy Current Loss in IPM Machine Under PWM VSI Supply With Combined 2-D FE and Analytical Method
Abstract:
A hybrid method combining 2-D finite-element (FE) method and analytical model is proposed for permanent magnet (PM) eddy current loss calculation in interior PM machines under pulsewidth modulation (PWM) voltage source inverter (VSI) supply, in which the PM eddy current reaction effect and PM axial segmentation are taken into consideration. First, the 2-D time-stepping (TS) FE analysis results considering and neglecting PM eddy current under PWM VSI supply are compared so that the cause of PM eddy current loss, the increase of high-order armature current components due to PM eddy current effect, and the decrease of the high-order components in average flux density due to leakage flux are revealed. Second, an analytical model for PM eddy current loss calculation using voltage input is deduced with the average flux density as input and a leakage flux factor is introduced in the model to meet the real case in PM machine. Moreover, the 3-D frequency FE analysis is used to verify the derived model. Third, the ratio between the average flux density and the imposed flux density is defined as a key parameter to reflect the PM eddy current reaction effect quantitatively, for both 2-D and 3-D cases. A functional relationship is established to describe the variation of the average flux density with and without considering the PM eddy current, where the parameter is obtained with nonlinear fitting of the 2-D FEA results. At last, the calculation procedure of the hybrid method is presented and a flux-concentrating field-modulated PM machine is taken as an example for calculation. The results are verified by an FE analysis. The proposed method is more efficient compared with the 3-D TS FE method while maintaining rather good accuracy.
Autors: Ming Cheng;Sa Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 12
Publisher: IEEE
 
» Capacity of the Two-Hop Relay Channel With Wireless Energy Transfer From Relay to Source and Energy Transmission Cost
Abstract:
In this paper, we investigate a communication system comprised of an energy harvesting (EH) source, which harvests radio frequency (RF) energy from an out-of-band full-duplex relay node and exploits this energy to transmit data to a destination node via the relay node. We assume two scenarios for the battery of the EH source. In the first scenario, we assume that the EH source is not equipped with a battery and thereby cannot store energy. As a result, the RF energy harvested during one symbol interval can only be used in the following symbol interval. In the second scenario, we assume that the EH source is equipped with a battery having unlimited storage capacity in which it can store the harvested RF energy. As a result, the RF energy harvested during one symbol interval can be used in any of the following symbol intervals. For both system models, we derive the channel capacity subject to an average power constraint at the relay and an additional energy transmission cost at the EH source. We compare the derived capacities to the achievable rates of several benchmark schemes. Our results show that using the optimal input distributions at both the EH source and the relay is essential for high performance. Moreover, we demonstrate that neglecting the energy transmission cost at the source can result in a severe overestimation of the achievable performance.
Autors: Nikola Zlatanov;Derrick Wing Kwan Ng;Robert Schober;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 647 - 662
Publisher: IEEE
 
» CarrierMix: How Much Can User-side Carrier Mixing Help?
Abstract:
Energy consumption for cellular communication is increasingly gaining importance in smartphone battery lifetime as the bandwidth of wireless communication and the demand for mobile traffic increase. For energy-efficient cellular communication, we tackle two energy characteristics of cellular networks: (1) transmission energy highly varies upon channel condition, and (2) transmission of a packet accompanies unnecessary tail energy waste. Under the objective of transmitting packets when the best channel is provided as well as a number of packets are accumulated, we propose a new mobile collaboration framework “CarrierMix” that aggregates smart devices across multiple heterogeneous cellular carriers. Compared to the standalone operation, even without a buffering delay, CarrierMix allows better channel and reduces more tail energy in a statistical point of view. To maximize the energy benefit while maintaining the fairness among the nodes in collaboration, we further develop a dynamic programming framework providing the optimal algorithm of CarrierMix and its approximated heuristic. Trace-driven simulations on our experimental HSPA/EVDO/LTE network traces show that CarrierMix of five devices achieves up to 42 percent of energy reduction.
Autors: Joohyun Lee;Kyunghan Lee;Yeongjin Kim;Song Chong;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 16 - 29
Publisher: IEEE
 
» Cartoon and Texture Decomposition-Based Color Transfer for Fabric Images
Abstract:
A color design process for fabric images can resort to a solution of a color transfer problem based on given color themes. Usually, the color transfer process contains an image segmentation phase and an image construction phase. In this paper, a novel color transfer method for fabric images is proposed. Compared with classical color transfer methods, the new method has the following three main innovations. First, the new method, in its image segmentation phase, follows an assumption that a fabric image can be decomposed into cartoon and texture components, which means the new color transfer method, in its image segmentation, phase incorporates an image decomposition process. The advantage of the innovation is that the cartoon component is more suitable than the original image to be used to partition the fabric image. Second, the new color transfer method can generate more vivid color transfer results since the above texture component is used to describe yarn texture details in the image construction phase. Third, the total generalized variation (TGV) regularizer is used to further improve the performance of image decomposition. Here, the TGV regularizer is good at estimating the weak lightness variation of the cartoon component with the CIELab color scheme. In addition, by using the augmented Lagrange multiplier method, we derive an efficient algorithm to search for the solutions to the proposed color transfer problem. Numerical results demonstrate that the proposed color transfer method can generate better results for fabric images.
Autors: Yu Han;Chen Xu;George Baciu;Min Li;Md. Robiul Islam;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jan 2017, volume: 19, issue:1, pages: 80 - 92
Publisher: IEEE
 

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