Electrical and Electronics Engineering publications abstract of: 11-2017 sorted by title, page: 5

» Control of Domain Structure in Artificial Ni Wires Fabricated on an LiNbO3 Substrate
Abstract:
We demonstrated control of magnetic domain structure formation within micro-scale polycrystalline Ni wires fabricated on a single crystalline LiNbO3 substrate. We observed the domain structures using X-ray magnetic circular dichroism-photoemission electron microscopy at SPring-8 BL25SU and BL17SU. Both zebra-stripe domain and ordinary single domain structures can be formed in the Ni wire in control of alignment of the wire onto the substrate. The result suggests that magnetoelastic effects from pizoelectristic substrates can strongly influence the magnetization alignment, overwhelming their shape magnetic anisotropy. The formation of zebra-stripe domain structure can be qualitatively explained by the micromagnetic simulation under the assumption of the magnetic anisotropy perpendicular to the longitudinal axis of wire. Our finding provides a way to control the domain structure and magnetization reversal using the combination of shape magnetic anisotropy and strain-induced anisotropy.
Autors: A. Yamaguchi;T. Ohkochi;A. Yasui;T. Kinoshita;K. Yamada;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Control of Interlayer Exchange Coupling and Its Impact on Spin–Torque Switching of Hybrid Free Layers With Perpendicular Magnetic Anisotropy
Abstract:
To ensure data retention in high-density spin-transfer-torque magnetic random access memory (STT-MRAM), a [Co/Ni]-CoFeB hybrid free layer (HFL) with a high energy barrier was proposed for small-dimension magnetic tunnel junctions. Its behavior on device level, however, needs further research. In particular, the impact of the interlayer that provides magnetic coupling between the [Co/Ni] multilayers and the CoFeB on the spin-torque switching is not known. In this paper, both macrospin modeling and micromagnetic simulations are used to study the influence of interlayer exchange coupling (IEC) on the switching behavior of the HFL for different device sizes. Both methods provide the optimal value for the coupling constant () and switching current (), as well as their size dependence, to realize HFL switching with the lowest energy consumption. In addition to the simulations, control of the IEC in the HFL by introducing a TaCoFeB interlayer and a Co termination layer on the [Co/Ni] part is shown, and a broad range is achieved without compromising the magnetotransport properties of the stacks. Both simulations and experimental work show that the HFL design with adequate interlayer engineering can be a viable route for high-density STT-MRAM devices and other spintronic applications.
Autors: Enlong Liu;Adrien Vaysset;Johan Swerts;Thibaut Devolder;Sebastien Couet;Sofie Mertens;Tsann Lin;Sven Van Elshocht;Jo De Boeck;Gouri Sankar Kar;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Controls for Smart Grids: Architectures and Applications
Abstract:
Control is and will continue to be a key discipline for realizing the objectives of smart grid initiatives. Research in control science and engineering is not limited to one or a few application concepts but is pervasive across the smart grid ecosystem. The principal contribution of this paper is to review, from a system-architectural perspective, how control enables smart grid applications. Application “templates” are presented for direct load control, automated demand response, microgrid optimization, control for distribution grids, wide-area control, and market-centric control. Technological developments, including in power electronics, that are enabling smart grid control research and applications are also itemized and two cross-cutting needs/opportunities for future research discussed. We conclude with a summary of a recent status report on the progress that has been made in the United States, noting also the challenges to further progress, in renewable generation, energy efficiency, and carbon reduction.
Autors: Tariq Samad;Anuradha M. Annaswamy;
Appeared in: Proceedings of the IEEE
Publication date: Nov 2017, volume: 105, issue:11, pages: 2244 - 2261
Publisher: IEEE
 
» Convex Mapping Formulations Enabling Optimal Power Split and Design of the Electric Drivetrain in All-Electric Vehicles
Abstract:
All-electric drivetrains have been identified as a promising alternative to contemporary hybrid vehicle technology. Extending their operational range is key and can be achieved by means of design procedures based on high-fidelity models capturing the dynamical behavior of the electric drivetrain. This paper proposes a dedicated power split embodying a dual electric drive and a model-based strategy to design the drivetrain. Advancements are required in model-based design that can cope with the complexity of the computationally expensive and high-dimensional parametric design problems. We propose a nested optimization approach wherein parameter exploration is attained using an evolutionary algorithm and the optimal power flows are determined by abstracting the high-fidelity behavioral models into appropriate convex loss mappings. This allows for an accelerated design procedure based on convex optimization without compromising accuracy. We size an electric drivetrain for maximal range extension, consisting of a battery stack, buck–boost converter, inverter and mechanically coupled induction motors subjected to variable load conditions. A tractable convex formulation is obtained and optimization time is reduced by 99.3% compared to the traditional approach without convexification. Optimal control of the incorporated power split increases the operational range by 0.7% compared to the isolated operation of a single motor. The proposed methodology thus paves the way for extensive designs of drivetrains and complex mechatronic systems in a general context.
Autors: Arne De Keyser;Matthias Vandeputte;Guillaume Crevecoeur;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 9702 - 9711
Publisher: IEEE
 
» Convex Optimization-Based Signal Detection for Massive Overloaded MIMO Systems
Abstract:
This paper proposes signal detection schemes for massive multiple-input multiple-output (MIMO) systems, where the number of receive antennas is less than that of transmitted streams. Assuming practical baseband digital modulation and taking advantage of the discreteness of transmitted symbols, we formulate the signal detection problem as a convex optimization problem, called sum-of-absolute-value (SOAV) optimization. Moreover, we extend the SOAV optimization into the weighted-SOAV (W-SOAV) optimization and propose an iterative approach to solve the W-SOAV optimization with updating the weights in the objective function. Furthermore, for coded MIMO systems, we also propose a joint detection and decoding scheme, where log likelihood ratios of transmitted symbols are iteratively updated between the MIMO detector and the channel decoder. In addition, a theoretical performance analysis is provided in terms of the upper bound of the size of the estimation error obtained with the W-SOAV optimization. Simulation results show that the bit error rate performance of the proposed scheme is better than that of conventional schemes, especially in large-scale overloaded MIMO systems.
Autors: Ryo Hayakawa;Kazunori Hayashi;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7080 - 7091
Publisher: IEEE
 
» Convolutional Neural Networks for Inverse Problems in Imaging: A Review
Abstract:
In this article, we review recent uses of convolutional neural networks (CNNs) to solve inverse problems in imaging. It has recently become feasible to train deep CNNs on large databases of images, and they have shown outstanding performance on object classification and segmentation tasks. Motivated by these successes, researchers have begun to apply CNNs to the resolution of inverse problems such as denoising, deconvolution, superresolution, and medical image reconstruction, and they have started to report improvements over state-of-the-art methods, including sparsity-based techniques such as compressed sensing. Here, we review the recent experimental work in these areas, with a focus on the critical design decisions.
Autors: Michael T. McCann;Kyong Hwan Jin;Michael Unser;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 85 - 95
Publisher: IEEE
 
» Coordinated Supervisory Control of Multi-Terminal HVDC Grids: A Model Predictive Control Approach
Abstract:
A coordinated supervisory control scheme for future multi-terminal high-voltage direct-current (HVDC) grids is proposed. The purpose is to supervise the grid and take appropriate actions to ensure power balance and prevent or remove voltage or current limit violations. First, using DC current and voltage measurements, the power references of the various Voltage Source Converters are updated according to participation factors. Next, the setpoints of the converters are smoothly adjusted to track those power references, while avoiding or correcting limit violations. The latter function resorts to model predictive control and a sensitivity model of the system. The efficiency of the proposed scheme has been tested through dynamic simulations of a five-terminal HVDC grid interconnecting two asynchronous AC areas and a wind farm.
Autors: Lampros Papangelis;Marie-Sophie Debry;Patrick Panciatici;Thierry Van Cutsem;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4673 - 4683
Publisher: IEEE
 
» Core-Shell Magnetic Structure of La1–xSrxMnO $_{3+delta }$ Nanocrystallites
Abstract:
Magnetic La1–xSrxMnO particles of composition and average size of 40 nm have been prepared from the oxidizing flux of sodium nitrite at . Detailed magnetic and neutron diffraction measurements have been performed on raw nanoparticles and particles subjected to mild acid leaching. Based on these experiments and X-ray fluorescence analysis of the respective products, we conclude on the core-shell magnetic structure of the molten-salt-prepared particles, consisting of ferromagnetic (FM) ordering in the interior and A-type antiferromagnetic (AFM) ordering in the intermediate shell just below the outermost, magnetically disordered layer. The reason for such complex arrangement, unprecedented in sol-gel-prepared manganite nanoparticles of the same composition, is in a certain radial distribution of La, Sr cations, and an increased oxygen stoichiometry related to the presence of extra oxygen atoms covalently bound at the particle surface. The acid leaching, performed by consecutive treatments with ice-cold solutions of dilute nitric acid and citric acid, removes the overoxidized surface and some outer Sr-richer layers, decreasing the composition to . As a result, the AFM ordering is almost completely suppressed while FM ordering is preserved in the leached nanoparticles.
Autors: Nadezhda M. Belozerova;Sergey E. Kichanov;Denis P. Kozlenko;Ondřej Kaman;Zdeněk Jirák;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Correcting Biased Evaporation in CloudSat Warm Rain
Abstract:
The CloudSat mission’s Cloud Profiling Radar has provided the first global-scale estimates of light rainfall from warm marine clouds. Because surface radar reflection prevents hydrometeor detection below ~720 m, the CloudSat 2C-RAIN-PROFILE retrieval uses an evaporation–sedimentation model to extend its profile estimates to the surface. We use in situ radar measurements from the ship-based Marine ARM GPCI Investigation of Clouds (MAGIC) campaign in the Northeastern subtropical Pacific, which sampled a diverse set of shallow marine cloud regimes, to evaluate the evaporation–sedimentation model near the surface. We suggest an empirical bias correction, which can be applied to the 2C-RAIN-PROFILE retrieval. Before this correction, the evaporation–sedimentation model produced a mean surface rain rate bias along the MAGIC transect of 57%; after correction, this bias was effectively eliminated. We also present the evidence of the validity of this bias correction across regimes in the MAGIC region, and also in the southeast subtropical Pacific, where the magnitude of the mean bias for surface rain due to the evaporation–sedimentation model is reduced by a factor of 4.
Autors: Peter Kalmus;Matthew Lebsock;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6207 - 6217
Publisher: IEEE
 
» Correction to “Closed-Form Jones Matrix of Dual-Polarized Inverted-Vee Dipole Antennas over Lossy Ground”
Abstract:
In the Appendix of the paper [1, p. 33], the authors would like to make the following correction.
Autors: R. A. C. Baelemans;A. T. Sutinjo;P. J. Hall;A. B. Smolders;M. J. Arts;E. de Lera Acedo;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6198 - 6198
Publisher: IEEE
 
» Correction to “Cyclic Orbit Codes”
Abstract:
We would like to thank Mahdieh Hakimi Poroch and Ali Asghar Talebi for pointing out two errors in Proposition 28 and Theorem 29 of the original paper [1]. The correct formulation for these two statements is as follows.
Autors: Anna-Lena Horlemann-Trautmann;Felice Manganiello;Michael Braun;Joachim Rosenthal;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7616 - 7616
Publisher: IEEE
 
» Correction to “Cyclic Orbit Codes” [Nov 13 7386-7404]
Abstract:
We would like to thank Mahdieh Hakimi Poroch and Ali Asghar Talebi for pointing out two errors in Proposition 28 and Theorem 29 of the original paper [1]. The correct formulation for these two statements is as follows.
Autors: Anna-Lena Horlemann-Trautmann;Felice Manganiello;Michael Braun;Joachim Rosenthal;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7616 - 7616
Publisher: IEEE
 
» Corrections to “Change Detection in Full and Dual Polarization, Single- and Multi-Frequency SAR Data”
Abstract:
When the covariance matrix formulation is used for multi-look polarimetric synthetic aperture radar (SAR) data, the complex Wishart distribution applies. Based on this distribution a test statistic for equality of two complex variance-covariance matrices and an associated asymptotic probability of obtaining a smaller value of the test statistic are given. In a case study airborne EMISAR C- and L-band SAR images from the spring of 1998 covering agricultural fields and wooded areas near Foulum, Denmark, are used in single- and bi-frequency, bi-temporal change detection with full and dual polarimetry data.
Autors: Allan A. Nielsen;Knut Conradsen;Henning Skriver;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 5143 - 5144
Publisher: IEEE
 
» Corrections to “A New Efficient Unconditionally Stable Finite-Difference Time-Domain Solution of the Wave Equation”
Abstract:
In [1], , , and were mistyped. The correct values are begin{align*} r_{x}=&frac {sqrt {2} Delta t}{sqrt {varepsilon mu } Delta x} sin {left ({frac { k_{x} Delta x}{2} }right )}\ r_{y}=&frac {sqrt {2} Delta t}{sqrt {varepsilon mu } Delta y} sin {left ({frac { k_{y} Delta y}{2} }right )}\ mathbf {G_{M}}=&begin{matrix} left [{ begin{matrix} big (1+r_{x}^{2}big )(xi ^{2}+1)-2xi &quad -(2r_{x} r_{y}) xi \ -(2r_{x} r_{y}) xi &quad big (1+r_{y}^{2}big )(xi ^{2}+1)-2xi end{matrix} }right ]. end{matrix} end{align*}
Autors: Seyed-Mojtaba Sadrpour;Vahid Nayyeri;Mohammad Soleimani;Omar M. Ramahi;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6197 - 6197
Publisher: IEEE
 
» Corrections to “High-Gain Filtering Patch Antenna without Extra Circuit”
Abstract:
We would like to correct the values listed in Table I and two typos in Fig. 14 in the communication [1] as follows.
Autors: Xiu Yin Zhang;Wen Duan;Yong-Mei Pan;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6196 - 6196
Publisher: IEEE
 
» Corrections to “Relativistic Aspects of Plane Wave Scattering by a Perfectly Conducting Half-Plane With Uniform Velocity Along an Arbitrary Direction”
Abstract:
In a recent paper [1], there was a typo in (13), which should read as a scalar equation for the -component of in the form begin{equation*} tilde {E}_{ {z}} {tilde {H}_{ {z}}} = F(tilde {xi }^{i}) , tilde {E}_{ {z}}^{i} {tilde {H}_{ {z}}^{i}} + F(tilde {xi }^{r}) tilde {E}_{ {z}}^{r} {tilde {H}_{ {z}}^{r}} end{equation*} from which the remaining field components may be obtained. The full vector equation for the electric field is then given by begin{align*} tilde {mathbf {E}}=&F(tilde {xi }^{i}) tilde {mathbf {E}}^{i} + F(tilde {xi }^{r}) tilde {mathbf {E}}^{r} + frac {e^{i pi /4}}{sqrt { 2 pi tilde {k} tilde {rho } sin tilde {theta }_{0} }} e^{i tilde {k} (tilde {rho } sin tilde {theta }_{0} -tilde { {z}} cos tilde {theta }_{0})} \[3pt]× bigg { cos frac {tilde {phi }-tilde {phi }_{0}}{2} left [{ left ({ tilde {mathbf {E}}^{i}_{0} cdot hat {tilde { {z}}} }right) hat {tilde { {z}}} - tilde {mathbf {E}}^{i}_{0} }right ] +sin frac {tilde {phi }-tilde {phi }_{0}}{2} , hat {tilde { {z}}} times tilde {mathbf {E}}^{i}_{0} \[4pt]&+,cos frac {tilde {phi }+tilde {phi }_{0}}{2} left [{ left ({ tilde {mathbf {E}}^{r}_{0} cdot hat {tilde { {z}}} }right) hat {tilde { {z}}} - tilde {mathbf {E}}^{r}_{0} }right ] +sin frac {tilde {phi }+tilde {phi }_{0}}{2} , hat {tilde { {z}}} times tilde {mathbf {E}}^{r}_{0} bigg } end{align*} where denotes the incident (reflected) electric field ampli- ude at the edge of the half-plane in frame . In addition, in (24) should read as , yielding begin{align*} tilde {bar {bar {F}}}_{re}=&dfrac {tilde {Q}}{c} \× ! begin{bmatrix}! 0 !&quad ! -!tilde {B}_{e} sin dfrac {tilde {phi }}{2} !&quad ! tilde {B}_{e} cos dfrac {tilde {phi }}{2} !&quad ! 0 \ tilde {B}_{e} sin dfrac {tilde {phi }}{2} !&quad ! 0 !&quad ! 0 !&quad ! -tilde {B}_{h} sin dfrac {tilde {phi }}{2} \ -tilde {B}_{e} cos dfrac {tilde {phi }}{2} !&quad ! 0 !&quad ! 0 !&quad ! tilde {B}_{h} cos dfrac {tilde {phi }}{2} \ 0 !&quad ! tilde {B}_{h} sin dfrac {tilde {phi }}{2} !&quad ! -tilde {B}_{h} cos dfrac {tilde {phi }}{2} !&quad ! 0 end{bmatrix}!. end{align*} None of the above-mentioned remarks affect the calculations and results presented in [1].
Autors: Guilherme S. Rosa;Julio L. Nicolini;Flavio J. V. Hasselmann;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6199 - 6199
Publisher: IEEE
 
» Corrections to “Weight Distribution of Cosets of Small Codes With Good Dual Properties”
Abstract:
We provide two corrections to [1] which do not affect the validity of any of the the reported results. First, we note that Conjecture 9 on page 6497 is not correct; a counter example follows from Cohen’s theorem [2] which asserts the existence of linear codes with covering radius up to the sphere-covering bound. The second correction is related to the “Proof of Theorem 2 using Theorem 5” on page 6496. In that proof, the -point Discrete Fourier Transform (DFT) should be on points. The other steps of the proof hold without modification. We reproduce below the corrected proof with the needed modifications in bold. The issue with the -point DFT is that it makes Identity (1) below incorrect for .
Autors: Louay Bazzi;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7615 - 7615
Publisher: IEEE
 
» Correlation Between Rotor Vibration and Mechanical Stress in Ultra-High-Speed Permanent Magnet Synchronous Motors
Abstract:
This paper investigates the correlation between rotor vibration and mechanical stress in ultra-high-speed permanent magnet synchronous motors (PMSMs); the mechanical stress generated in the PM and the rotational vibration when the PMSM rotates at high speeds were evaluated. Two PM rotors that have the same performance characteristics but different shrink fits were studied, and the vibration of these two PM rotors was analyzed. Furthermore, to evaluate the correlation between mechanical stress and vibration, the rotor design parameters, such as sleeve thickness and shrink fit, were varied. Based on the analysis results, a real-world model was developed and an experiment was conducted to test the vibration of these two rotors; the validity of our results was verified by performing experiments.
Autors: Ji-Hun Ahn;Jang-Young Choi;Cheol Hoon Park;Cheol Han;Chang-Woo Kim;Tae-Gwang Yoon;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Cortical Brain–Computer Interface for Closed-Loop Deep Brain Stimulation
Abstract:
Essential tremor is the most common neurological movement disorder. This progressive disease causes uncontrollable rhythmic motions—most often affecting the patient’sdominant upper extremity—thatoccur during volitional movement and make it difficult for the patient to perform everyday tasks. Medication may also become ineffective as the disorder progresses. For many patients, deep brain stimulation (DBS) of the thalamus is an effective means of treating this condition when medication fails. In current use, however, clinicians set the patient’s stimulator to apply stimulation at all times—whether it is needed or not. This practice leads to excess power use, and more rapid depletion of batteries that require surgical replacement. In this paper, for the first time, neural sensing of movement (using chronically implanted cortical electrodes) is used to enable or disable stimulation for tremor. Therapeutic stimulation is delivered onlywhen the patient is actively using their effected limb, thereby reducing the total stimulation applied, and potentially extending the lifetime of surgically implanted batteries. This paper, which involves both implanted and external subsystems, paves the way for fully-implanted closed-loop DBS in the future.
Autors: Jeffrey A. Herron;Margaret C. Thompson;Timothy Brown;Howard Jay Chizeck;Jeffrey G. Ojemann;Andrew L. Ko;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2180 - 2187
Publisher: IEEE
 
» Cost-Aware Big Data Processing Across Geo-Distributed Datacenters
Abstract:
With the globalization of service, organizations continuously produce large volumes of data that need to be analysed over geo-dispersed locations. Traditionally central approach that moving all data to a single cluster is inefficient or infeasible due to the limitations such as the scarcity of wide-area bandwidth and the low latency requirement of data processing. Processing big data across geo-distributed datacenters continues to gain popularity in recent years. However, managing distributed MapReduce computations across geo-distributed datacenters poses a number of technical challenges: how to allocate data among a selection of geo-distributed datacenters to reduce the communication cost, how to determine the Virtual Machine (VM) provisioning strategy that offers high performance and low cost, and what criteria should be used to select a datacenter as the final reducer for big data analytics jobs. In this paper, these challenges is addressed by balancing bandwidth cost, storage cost, computing cost, migration cost, and latency cost, between the two MapReduce phases across datacenters. We formulate this complex cost optimization problem for data movement, resource provisioning and reducer selection into a joint stochastic integer nonlinear optimization problem by minimizing the five cost factors simultaneously. The Lyapunov framework is integrated into our study and an efficient online algorithm that is able to minimize the long-term time-averaged operation cost is further designed. Theoretical analysis shows that our online algorithm can provide a near optimum solution with a provable gap and can guarantee that the data processing can be completed within pre-defined bounded delays. Experiments on WorldCup98 web site trace validate the theoretical analysis results and demonstrate that our approach is close to the offline-optimum performance and superior to some representative approaches.
Autors: Wenhua Xiao;Weidong Bao;Xiaomin Zhu;Ling Liu;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3114 - 3127
Publisher: IEEE
 
» Cost-Effective Vernier Permanent-Magnet Machine With High Torque Performance
Abstract:
This paper presents a cost-effective five-phase vernier permanent-magnet (VPM) machine with fault tolerance for direct-drive applications, which has hybrid magnet material in both stator and rotor. By adopting unipolar rare-earth PM in rotor, the amount of rare-earth PM is reduced by half and the flux leakage between PMs is much reduced. Besides, the unipolar ferrite PM is assisted between flux-modulation poles to further improve the flux in stator teeth. Moreover, the torque performance and PM utilization rate are further improved due to the optimization of stator teeth in the proposed machine. The time-stepping finite-element method is used to evaluate the performance of proposed VPM machine in comparison with bipolar and unipolar ones. The results show that the proposed VPM machine not only remains the advantage of fault tolerance, but also significantly improves the torque density and reduces torque ripple simultaneously with considerable less consumption of rare-earth PM.
Autors: Gaohong Xu;Guohai Liu;Ming Chen;Xinxin Du;Meimei Xu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Coverage and Rate Analysis for Facilitating Machine-to-Machine Communication in LTE-A Networks Using Device-to-Device Communication
Abstract:
With a wide range of applications, Machine-to-Machine (M2M) communication has become an emerging technology for connecting generic machines to the Internet. To ensure ubiquity in connections across all machines, it is necessary to have a standard infrastructure, such as 3GPP LTE-A network infrastructure, that facilitates such type of communications. However, owing to the huge scale ofquery id="Q1"> machines to be deployed in near future and the nature of data transactions, ensuring ubiquitous connections among all the machines will be difficult. Solutions that not only maintain connectivity but also route machine data in a cost effective manner are the need of the hour. In this context, it has been suggested that Device-to-Device (D2D) communication can play a very important role in expanding network coverage and routing the data between source-destination machine pairs. In this paper, we conduct a feasibility study to highlight the impact of multi-hop D2D communication in increasing the network coverage and average rate of a Machine Type Communication (MTC) device. We present a stochastic geometry based framework to analyze the coverage probability and average data rate of a three-hop M2M network deployed along with User Equipments (UEs) and conduct extensive simulations to study the system performance. Our simulation results show that the three-hop M2M network formed from out-of-range MTC devices and UEs can significantly improve the coverage and average rate of the entire network. Due to the mobility of users in the network, design of robust routing mechanisms in such a time evolving network becomes difficult. Hence, we suggest the use of space-time graph built from the predicted user locations to design a cost efficient multi-hop D2D topology that enables routing of MTC data to its destination.
Autors: Siba Narayan Swain;Rahul Thakur;Siva Ram Murthy Chebiyyam;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Nov 2017, volume: 16, issue:11, pages: 3014 - 3027
Publisher: IEEE
 
» Cramér–Rao Lower Bound Derivation and Performance Analysis for Space-Based SAR GMTI
Abstract:
This paper derives the Cramér–Rao lower bound (CRLB) for a general multichannel spaceborne synthetic aperture radar system for ground moving-target indication and provides a theoretical analysis of across-track velocity estimation for RADARSAT-2 and a fictitious satellite. The signal model assumes a deterministic target signal in Gaussian clutter and noise. In estimation theory, the CRLB provides a lower bound on the achievable variance of any unbiased estimator. An estimator that achieves this bound is called efficient; however, there is no guarantee that an efficient estimator can be found. Nonetheless, the theoretical variance of the efficient estimator provides a good measure of the capability of the system and serves as a valuable system performance validation tool. Even if an efficient estimator cannot be found, for radar systems, the CRLB provides a necessary, but not sufficient design baseline for measurement parameters, such as the number of subapertures for transmit and receive, power levels, pulse-repetition frequency, and so on. CRLBs for a limited number of system configurations for RADARSAT-2 and TerraSAR-X are presented by Cerutti-Maori et al. and Ender et al.; however, the complete analytical form of CRLB for a general system, which can be readily applied to an arbitrary antenna switching configuration, has not been previously derived.
Autors: Mamoon Rashid;Richard M. Dansereau;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6031 - 6043
Publisher: IEEE
 
» Creation of an Internal Cladding in Sapphire Optical Fiber Using the $^{6}$ Li(n, $alpha)^{3}$ H Reaction
Abstract:
The focus of this work is to extend optical frequency domain reflectometry sensing to sapphire optical fiber, by creating a cladding in the fiber. A cladding was created by irradiating a sapphire optical fiber, which was surrounded by an annulus of Li-6 enriched lithium carbonate (Li2CO3) powder, in The Ohio State University Research Reactor. The 6Li(n, reaction created high energy alpha particles and tritons that irradiated the fiber simultaneously to a depth of 24 microns along the entire periphery of the sapphire fiber, thereby slightly reducing the index of refraction in the fiber’s periphery and creating a cladding within the fiber. Transmitted light intensity profiles show that the ion implanted cladding made the fiber’s intensity profile nearly single mode. The cladding survived to the highest temperature that was tested (1500 °C). The cladding made the fiber sufficiently single mode that the cladded sapphire fiber, when read out with an optical backscatter reflectometer, produced distributed temperature measurements along the entire length of the fiber.
Autors: Brandon Augustus Wilson;Thomas E. Blue;
Appeared in: IEEE Sensors Journal
Publication date: Nov 2017, volume: 17, issue:22, pages: 7433 - 7439
Publisher: IEEE
 
» Criterion for the Electrical Resonance Stability of Offshore Wind Power Plants Connected Through HVDC Links
Abstract:
Electrical resonances may compromise the stability of HVDC-connected offshore wind power plants (OWPPs). In particular, an offshore HVDC converter can reduce the damping of an OWPP at low-frequency series resonances, leading to the system instability. The interaction between offshore HVDC converter control and electrical resonances of offshore grids is analyzed in this paper. An impedance-based representation of an OWPP is used to analyze the effect that offshore converters have on the resonant frequency of the offshore grid and on system stability. The positive-net-damping criterion, originally proposed for subsynchronous analysis, has been adapted to determine the stability of the HVDC-connected OWPP. The reformulated criterion enables the net damping of the electrical series resonance to be evaluated and establishes a clear relationship between electrical resonances of the HVDC-connected OWPPs and stability. The criterion is theoretically justified, with analytical expressions for low-frequency series resonances being obtained and stability conditions defined based on the total damping of the OWPP. Examples are used to show the influence that HVDC converter control parameters and the OWPP configuration have on stability. A root locus analysis and time-domain simulations in PSCAD/EMTDC are presented to verify the stability conditions.
Autors: Marc Cheah-Mane;Luis Sainz;Jun Liang;Nick Jenkins;Carlos Ernesto Ugalde-Loo;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4579 - 4589
Publisher: IEEE
 
» Crop Biophysical Properties Estimation Based on LiDAR Full-Waveform Inversion Using the DART RTM
Abstract:
This paper presents the results of a three-dimensional (3-D) model inversion in order to demonstrate the potential of small footprint light detection and ranging (LiDAR) waveforms for estimating crop biophysical properties. For such, we consider the height, leaf area index (LAI), and ground spectral reflectance of two maize and wheat fields. Crop structure spatial variability that is observed per measured waveform is a source of inaccuracy for the inversion of LiDAR small footprint waveforms. For example, in the maize field, standard deviation is 0.16 m for height and 0.6 for LAI. To mitigate this issue, all measured waveforms are first classified into maize and wheat clusters. Then, biophysical properties are assessed per cluster using a look-up table of waveforms that are simulated by the discrete anisotropic radiative transfer model that works with the LiDAR configuration and realistic crop 3-D mock-ups with varied properties. Results were tested against in situ measurements. Crop height is very well estimated, with root-mean-square error (RMSE) and 0.04 m for maize and wheat, respectively. LAI estimate is also accurate (RMSE = 0.17) for maize except for wheat last growth stage (RMSE = 0.5), possibly due to the wheat low LAI value. Finally, the field spatial heterogeneity justifies the selection of many clusters to get accurate results.
Autors: Sahar Ben Hmida;Abdelaziz Kallel;Jean-Philippe Gastellu-Etchegorry;Jean-Louis Roujean;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4853 - 4868
Publisher: IEEE
 
» Cross-Convolutional-Layer Pooling for Image Recognition
Abstract:
Recent studies have shown that a Deep Convolutional Neural Network (DCNN) trained on a large image dataset can be used as a universal image descriptor and that doing so leads to impressive performance for a variety of image recognition tasks. Most of these studies adopt activations from a single DCNN layer, usually a fully-connected layer, as the image representation. In this paper, we proposed a novel way to extract image representations from two consecutive convolutional layers: one layer is used for local feature extraction and the other serves as guidance to pool the extracted features. By taking different viewpoints of convolutional layers, we further develop two schemes to realize this idea. The first directly uses convolutional layers from a DCNN. The second applies the pre-trained CNN on densely sampled image regions and treats the fully-connected activations of each image region as a convolutional layer's feature activations. We then train another convolutional layer on top of that as the pooling-guidance convolutional layer. By applying our method to three popular visual classification tasks, we find that our first scheme tends to perform better on applications which demand strong discrimination on lower-level visual patterns while the latter excels in cases that require discrimination on category-level patterns. Overall, the proposed method achieves superior performance over existing approaches for extracting image representations from a DCNN. In addition, we apply cross-layer pooling to the problem of image retrieval and propose schemes to reduce the computational cost. Experimental results suggest that the proposed method achieves promising results for the image retrieval task.
Autors: Lingqiao Liu;Chunhua Shen;Anton van den Hengel;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Nov 2017, volume: 39, issue:11, pages: 2305 - 2313
Publisher: IEEE
 
» Cross-Polarization Amplitudes of Obliquely Orientated Buildings With Application to Urban Areas
Abstract:
Buildings that are rotated with respect to the sensor trajectory could be erroneously classified as vegetated areas in the Pauli basis, and subsequently in many decomposition theorems despite the considerable amount of work done to solve that issue. This misjudgement is linked to the high level of their cross-polarized contribution. Using electromagnetic simulation tools and image analysis, we study the value of these cross-polarization components. We show that forested areas and cities exhibit significantly different cross-polarization levels; indeed, the origin of these components is actually distinct. Based on that, to discriminate between the two environments, we introduce an extension to the Pauli basis where the cross polarization is split into two classes, one for rotated dihedrals and the other for random scatterers. This approach is then tested on two synthetic aperture radar images: the first acquired at C-band using RADARSAT-2 over Downtown San Francisco and the second using RAMSES at X-band over an industrial area near Paris.
Autors: R. Guinvarc’h;L. Thirion-Lefevre;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1913 - 1917
Publisher: IEEE
 
» Cross-Validated Variable Selection in Tree-Based Methods Improves Predictive Performance
Abstract:
Recursive partitioning methods producing tree-like models are a long standing staple of predictive modeling. However, a fundamental flaw in the partitioning (or splitting) rule of commonly used tree building methods precludes them from treating different types of variables equally. This most clearly manifests in these methods’ inability to properly utilize categorical variables with a large number of categories, which are ubiquitous in the new age of big data. We propose a framework to splitting using leave-one-out (LOO) cross validation (CV) for selecting the splitting variable, then performing a regular split (in our case, following CART's approach) for the selected variable. The most important consequence of our approach is that categorical variables with many categories can be safely used in tree building and are only chosen if they contribute to predictive power. We demonstrate in extensive simulation and real data analysis that our splitting approach significantly improves the performance of both single tree models and ensemble methods that utilize trees. Importantly, we design an algorithm for LOO splitting variable selection which under reasonable assumptions does not substantially increase the overall computational complexity compared to CART for two-class classification.
Autors: Amichai Painsky;Saharon Rosset;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Nov 2017, volume: 39, issue:11, pages: 2142 - 2153
Publisher: IEEE
 
» Crowd-Based Ambient Assisted Living to Monitor the Elderly’s Health Outdoors
Abstract:
Ambient assisted living (AAL) technologies can help the elderly maintain their independence while keeping them safer. Sensors monitor their activities to detect situations in which they might need help. Most research in this area has targeted indoor environments, but outdoor activities are just as important; many risky situations might occur outdoors. SafeNeighborhood (SN) is an AAL system that combines data from multiple sources with collective intelligence to tune sensor data. It merges mobile, ambient, and AI technologies with old-fashioned neighborhood ties to create safe outdoor spaces. The initial results indicate SN’s potential use and point toward new opportunities for care of the elderly.
Autors: Ana Cristina Bicharra Garcia;Adriana Santarosa Vivacqua;Nayat Sánchez-Pi;Luis Martí;José M. Molina;
Appeared in: IEEE Software
Publication date: Nov 2017, volume: 34, issue:6, pages: 53 - 57
Publisher: IEEE
 
» Cryptanalysis of a Privacy-Preserving Aggregation Protocol
Abstract:
Privacy-preserving aggregation protocols allow an untrusted aggregator to evaluate certain statistics over a population of individuals without learning each individual’s privately owned data. In this note, we show that a recent protocol for computing an aggregate sum due to Jung, Li, and Wan (IEEE Transactions on Dependable and Secure Computing, 2015) is universally breakable, that is, anyone is able to recover each individual’s private data from the corresponding ciphertext. We also describe an alternate collusion attack against their companion product protocol.
Autors: Marc Joye;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Nov 2017, volume: 14, issue:6, pages: 693 - 694
Publisher: IEEE
 
» Crystal Orientation Dependence of Magnetization and Magnetostriction Behaviors in Highly Textured Galfenol and Alfenol Thin Sheets
Abstract:
Highly textured rolled sheets of Fe–Ga and Fe–Al alloys behave like single crystal, exhibiting magnetostriction values that are equal to ~ 80%–95% of those of single crystal along the axes. In this paper, we investigate the crystal orientation dependence of anisotropic magnetization and magnetostriction properties in highly textured disks of Fe–Ga and Fe–Al alloys. The highly textured samples are composed of a single (011) plane and small isolated grains, aside from the (011) grain, which exhibit three different cubic crystal orientations, such as , , and directions. Measured magnetostriction values strongly depend on a deviation angle of the direction from the rolling direction, well matched with the predicted values based on the anisotropic magnetostriction equation in the (011) plane. Of particular interest is the observation that measured values at the deviation angles over ~20° are higher than the predicted ones as much as the fraction of island grains with principal and directions along the strain measurement direction. In addition, it seems to be averaged out for magnetization behaviors along the three different direction- in comparison with those of the single crystal Fe–Ga.
Autors: Suok-Min Na;Joshua Eng-Morris;Julia Downing;Alison B. Flatau;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Crystallographic Orientation and Microstructure-Dependent Magnetic Behaviors in Arrays of Ni Nanowires
Abstract:
The magnetic behavior of a material is determined by its microstructure, or more precisely, by the configuration of electrons and their interactions with lattices. It has been difficult to control the microstructures of polycrystalline metallic nanowires through electrochemical deposition. Here, we report the synthesis, microstructure, and magnetic properties of nickel (Ni) nanowires from the viewpoints of crystallographic orientation and grain size. Changes in both the Ni precursor and buffer solution result in a remarkable modification of crystallographic orientation and magnetocrystalline anisotropy energy, and consequently, a difference in magnetic susceptibility is observed. In addition, a significant enlargement in grain size with a [220] texture is observed when raising the temperature during electrochemical deposition and subsequently brings a decrease in experimental coercivities.
Autors: Min Jun Ko;Su Hyo Kim;Young Keun Kim;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» CSI-Based Device-Free Wireless Localization and Activity Recognition Using Radio Image Features
Abstract:
Device-free wireless localization and activity recognition is an emerging technique, which could estimate the location and activity of a person without equipping him/her with any device. It deduces the state of a person by analyzing his/her influence on surrounding wireless signals. Therefore, how to characterize the influence of human behaviors is the key question. In this paper, we explore and exploit a radio image processing approach to better characterize the influence of human behaviors on Wi-Fi signals. Traditional methods deal with channel state information (CSI) measurements on each channel independently. However, CSI measurements on different channels are correlated, and thus lots of useful information involved with channel correlation may be lost. This motivates us to look on CSI measurements from multiple channels as a radio image and deal with it from the two-dimensional perspective. Specifically, we transform CSI measurements from multiple channels into a radio image, extract color and texture features from the radio image, adopt a deep learning network to learn optimized deep features from image features, and estimate the location and activity of a person using a machine learning approach. Benefits from the informative and discriminative deep image features and experimental results in two clutter laboratories confirm the excellent performance of the proposed system.
Autors: Qinhua Gao;Jie Wang;Xiaorui Ma;Xueyan Feng;Hongyu Wang;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10346 - 10356
Publisher: IEEE
 
» Current Reconstruction of Bundle Conductors Based on Tunneling Magnetoresistive Sensors
Abstract:
The current monitoring of bundle conductors is essential for precisely locating operation failures in transmission lines, leading to a more stable and reliable power grid. This paper proposed a novel method for current reconstruction of bundle conductors, utilizing tunneling magnetoresistive (TMR) sensors. Both the normal and abnormal situations are discussed. The optimal and sub-optimal measurement points for sensors were obtained for concise current measurement with only one uniaxial TMR sensor. The current in each bundle conductor was calculated separately based on the comprehensive algorithm. Validation experiment indicated the error of the measurement and calculation system was no more than 10%, proving the robustness and feasibility of the measurement system and the algorithm. The reconstruction process takes full advantages of TMR sensors and provides a promising solution for transmission line monitoring in power grid.
Autors: Gen Zhao;Jun Hu;Shuai Zhao;Zhongxu Wang;Shan X. Wang;Jinliang He;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Curvature Sensor Based on In-Fiber Mach–Zehnder Interferometer Inscribed With Femtosecond Laser
Abstract:
In this paper, an in-fiber Mach-Zehnder interferometer inscribed by femtosecond laser for curvature sensing has been designed and manufactured. Its operating principle consists of a secondary waveguide inscription working as a sensing arm. This waveguide has been manufactured using asymmetric structures with an average refractive index change of 1.1 × 10-2 in its guiding section measured by refracted near-field profilometry. The overall arm/cladding index difference is higher than its core/cladding counterpart, which is a suggested condition for device operation following preliminary simulations. The manufactured Mach-Zehnder interferometer exhibits a linear response to bending radius that is also dependent on an established bending axis. Sensitivity has been measured up to 9.49 nm/m-1 for curvature ranges from 0 to 14 m-1. Simulation results using the beam propagation method and conformal mapping transformation to convert bending action into a tilt refractive index agree with experimental results for the same index parameters. Preliminary temperature test shows a remarkable cross sensitivity of 0.0024(3) m-1/°C up to 180 °C.
Autors: David Pallarés-Aldeiturriaga;Luis Rodríguez-Cobo;Antonio Quintela;José M. López-Higuera;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4624 - 4628
Publisher: IEEE
 
» Curvature-Eliminating Head Field and Track Edge Characteristics in Heat-Assisted Magnetic Recording
Abstract:
Transition curvature in heat-assisted magnetic recording can be eliminated by appropriately varying head field amplitude across recording track width. In this paper, we present a systematic micromagnetic study on the effects of non-vanishing field beyond track edges in practical head designs, focusing on the recording characteristics beyond track edges. It is found that a uniform field amplitude beyond track edges will create wing-like patterns beyond straightened transitions, forming erase bands at high linear densities. The width of the erase band decreases if the head field diminishes beyond track edges. However, for practical field reduction gradients beyond track edges, the width of the erase band still remains significant.
Autors: Yuwei Qin;Hai Li;Jian-Gang Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Cutting Latency Tail: Analyzing and Validating Replication without Canceling
Abstract:
Response time variability in software applications can severely degrade the quality of the user experience. To reduce this variability, request replication emerges as an effective solution by spawning multiple copies of each request and using the result of the first one to complete. Most previous studies have mainly focused on the mean latency for systems implementing replica cancellation, i.e., all replicas of a request are canceled once the first one finishes. Instead, we develop models to obtain the response-time distribution for systems where replica cancellation may be too expensive or infeasible to implement, as in “fast” systems, such as web services, or in legacy systems. Furthermore, we introduce a novel service model to explicitly consider correlation in the processing times of the request replicas, and design an efficient algorithm to parameterize the model from real data. Extensive evaluations on a MATLAB benchmark and a three-tier web application (MediaWiki) show remarkable accuracy, e.g., 7 (4 percent) average error on the 99th percentile response time for the benchmark (respectively, MediaWiki), the requests of which execute in the order of seconds (respectively, milliseconds). Insights into optimal replication levels are thereby gained from this precise quantitative analysis, under a wide variety of system scenarios.
Autors: Zhan Qiu;Juan F. Pérez;Robert Birke;Lydia Chen;Peter G. Harrison;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3128 - 3141
Publisher: IEEE
 
» Cyber Threats Facing Autonomous and Connected Vehicles: Future Challenges
Abstract:
Vehicles are currently being developed and sold with increasing levels of connectivity and automation. As with all networked computing devices, increased connectivity often results in a heightened risk of a cyber security attack. Furthermore, increased automation exacerbates any risk by increasing the opportunities for the adversary to implement a successful attack. In this paper, a large volume of publicly accessible literature is reviewed and compartmentalized based on the vulnerabilities identified and mitigation techniques developed. This review highlighted that the majority of studies are reactive and vulnerabilities are often discovered by friendly adversaries (white-hat hackers). Many gaps in the knowledge base were identified. Priority should be given to address these knowledge gaps to minimize future cyber security risks in the connected and autonomous vehicle sector.
Autors: Simon Parkinson;Paul Ward;Kyle Wilson;Jonathan Miller;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Nov 2017, volume: 18, issue:11, pages: 2898 - 2915
Publisher: IEEE
 
» Cyclic Scheduling of Multi-Cluster Tools Based on Mixed Integer Programming
Abstract:
Multi-cluster tools are automated equipment which is increasingly used in semiconductor manufacturing. The scheduling of multi-cluster tools is much more challenging than single-cluster tools due to multi-robot coordination and increasing chambers. In this paper, we develop a mixed integer programming (MIP) model which manages to formulate the multi-robot coordination for cyclic scheduling of multi-cluster tools. Three reformulations of the model are implemented: 1) linearization; 2) eliminating integer variables; and 3) tightening constraints. The first reformulation is designed to make the MIP model solvable by commercial solvers while the other two are intended for promoting computational efficiency which is critical when chambers increase. The proposed model can meet various practical scheduling requirements such as dual-armed robots, wafer residency time constraints, parallel and reentrant processes in multi-cluster tools. Experimental results demonstrate the efficiency of the proposed method.
Autors: Tianpeng Bao;Huangang Wang;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Nov 2017, volume: 30, issue:4, pages: 515 - 525
Publisher: IEEE
 
» Damping Representation for the Fifth-Order Generator Model in Transient Behaviors
Abstract:
An expression of the compensation torque is derived to reduce the difference between the fifth-order generator model and the seventh-order model. It is appended to the swing equation in the fifth-order model, with the voltage equations and the flux linkage equations unchanged. Based on the singular perturbation theory, the stator transients are approximated. The fast current components of three rotor windings are represented by equivalent d- and q-axis stator current increments that create the same stator flux linkage. The relationship between this torque and damping is clarified from a physical viewpoint. Simulations on two systems show that the compensation torque reduces the model difference. The proposed damping preserving model overcomes the difficulty in determining the damping torque coefficient and is applicable to online transient stability analysis.
Autors: Ningqiang Jiang;Hsiao-Dong Chiang;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4924 - 4933
Publisher: IEEE
 
» Data Glove System Embedded With Inertial Measurement Units for Hand Function Evaluation in Stroke Patients
Abstract:
This paper proposes a data glove system integrated with six-axis inertial measurement unit sensors for evaluating the hand function of patients who have suffered a stroke. The modular design of this data glove facilitates its use for stroke patients. The proposed system can use the hand’s accelerations, angular velocities, and joint angles as calculated by a quaternion algorithm, to help physicians gain new insights into rehabilitation treatments. A clinical experiment was performed on 15 healthy subjects and 15 stroke patients whose Brunnstrom stages (BSs) ranged from 4 to 6. In this experiment, the participants were subjected to a grip task, thumb task, and card turning task to produce raw data and three features, namely, the average rotation speed, variation of movement completion time, and quality of movement; these features were extracted from the recorded data to form 2-D and 3-D scatter plots. These scatter plots can provide reference information and guidance to physicians who must determine the BSs of stroke patients. The proposed system demonstrated a hit rate of 70.22% on average. Therefore, this system can effectively reduce physicians’ load and provide them with detailed information about hand function to help them adjust rehabilitation strategies for stroke patients.
Autors: Bor-Shing Lin;Pei-Chi Hsiao;Shu-Yu Yang;Che-Shih Su;I-Jung Lee;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2204 - 2213
Publisher: IEEE
 
» Data Handling in EAST Remote Participation
Abstract:
International collaboration has become increasingly frequent in fusion research. It improves the quality and efficiency of the research in Experimental Advanced Superconducting Tokamak (EAST) facility. The traditional face-to-face collaborative way has been proven inadequate in current situation. The remote participation system (RPS) for EAST (EAST RPS) will play an important role in EAST operation experiment. Data handling for remote access through Internet are a critical issue for EAST RPS. There are three types of data in EAST RPS: engineer data, scientific raw data, and camera data. This paper presents the technical solutions for data handling in EAST RPS including the system architecture, data compression technologies, protocols, and a new experimental physics and industrial control system data archiving Engine.
Autors: Xiaoyang Sun;Feng Wang;Yong Wang;Shi Li;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Nov 2017, volume: 64, issue:11, pages: 2891 - 2894
Publisher: IEEE
 
» Data Rate Effects on Transition and Remanence Noise in a Modeled Heat-Assisted Magnetic Recording System
Abstract:
The heat-assisted magnetic recording performance at varying data rate conditions is investigated using an ensemble waveform analysis method. This method decouples the transition signal-to-noise ratio (SNR) and the remanence SNR from the total spatial media SNR. For data rates below 2200 Mbpsi, transition and remanence noises are largely independent of writer field rise time (RT) values less than 150 ps. Above a data rate of 2200 Mbpsi, the transition SNR is significantly degraded for the slowest RTs considered. For all data rate values, the remanence SNR sees minimal degradation with increasing RT. At the highest data rate, at least a 1 dB loss is observed compared with the lowest data rate, across the RT range considered. For comparison, spin-stand data were also collected. The modeled results were contrasted to bit error rate (BER) trends obtained from the measurement. The spin-stand data show a significant BER degradation as a function of increasing RT at higher data rates. This trend is likely explained with the increase in transition noise observed in the model. These results suggest that moderate writer field RTs do not degrade either transition or remanence noise significantly. If RTs can be kept low, higher data rates may be allowable from a media noise perspective.
Autors: Stephanie Hernández;Steven Granz;Pavol Krivosik;Pin-Wei Huang;Walt Eppler;Tim Rausch;Edward Gage;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Data Rate for Distributed Consensus of Multiagent Systems With High-Order Oscillator Dynamics
Abstract:
Distributed consensus under data rate constraint is an important research topic of multiagent systems. Some results have been obtained for consensus of multiagent systems with integrator dynamics, but it remains challenging for general high-order systems, especially in the presence of unmeasurable states. In this paper, we study the quantized consensus problem for a special kind of high-order critical systems and investigate the corresponding data rate required for achieving consensus. The state matrix of each agent is a th order real Jordan block admitting identical pairs of conjugate poles on the unit circle; each agent has a single input, and only the first state variable can be measured. The case of harmonic oscillators () is first investigated under a directed communication topology which contains a spanning tree, while the general case of is considered for a connected and undirected network. In both cases, the sufficient number of communication bits to guarantee the exponentially fast consensus is shown to be an integer between and , depending on the location of the poles.
Autors: Zhirong Qiu;Lihua Xie;Yiguang Hong;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 6065 - 6072
Publisher: IEEE
 
» Decentralized Caching and Coded Delivery With Distinct Cache Capacities
Abstract:
Decentralized proactive caching and coded delivery is studied in a content delivery network, where each user is equipped with a cache memory, not necessarily of equal capacity. Cache memories are filled in advance during the off-peak traffic period in a decentralized manner, i.e., without the knowledge of the number of active users, their identities, or their particular demands. User demands are revealed during the peak traffic period, and are served simultaneously through an error-free shared link. The goal is to find the minimum delivery rate during the peak traffic period that is sufficient to satisfy all possible demand combinations. A group-based decentralized caching and coded delivery scheme is proposed, and it is shown to improve upon the state of the art in terms of the minimum required delivery rate when there are more users in the system than files. Numerical results indicate that the improvement is more significant as the cache capacities of the users become more skewed. A new lower bound on the delivery rate is also presented, which provides a tighter bound than the classical cut-set bound.
Autors: Mohammad Mohammadi Amiri;Qianqian Yang;Deniz Gündüz;
Appeared in: IEEE Transactions on Communications
Publication date: Nov 2017, volume: 65, issue:11, pages: 4657 - 4669
Publisher: IEEE
 
» Decentralized Frank–Wolfe Algorithm for Convex and Nonconvex Problems
Abstract:
Decentralized optimization algorithms have received much attention due to the recent advances in network information processing. However, conventional decentralized algorithms based on projected gradient descent are incapable of handling high-dimensional constrained problems, as the projection step becomes computationally prohibitive. To address this problem, this paper adopts a projection-free optimization approach, a.k.a. the Frank–Wolfe (FW) or conditional gradient algorithm. We first develop a decentralized FW (DeFW) algorithm from the classical FW algorithm. The convergence of the proposed algorithm is studied by viewing the decentralized algorithm as an inexact FW algorithm. Using a diminishing step size rule and letting be the iteration number, we show that the DeFW algorithm's convergence rate is for convex objectives; is for strongly convex objectives with the optimal solution in the interior of the constraint set; and is toward a stationary point for smooth but nonconvex objectives. We then show that a consensus-based DeFW algorithm meets the above guarantees with two communication rounds per iteration. We demonstrate the advantages of the proposed DeFW algorithm on low-complexity robust matrix completion and communication efficient sparse learning. Numerical results on synthetic and real data are presented to support our findings.
Autors: Hoi-To Wai;Jean Lafond;Anna Scaglione;Eric Moulines;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5522 - 5537
Publisher: IEEE
 
» Decentralized Prediction-Correction Methods for Networked Time-Varying Convex Optimization
Abstract:
We develop algorithms that find and track the optimal solution trajectory of time-varying convex optimization problems that consist of local and network-related objectives. The algorithms are derived from the prediction-correction methodology, which corresponds to a strategy where the time-varying problem is sampled at discrete time instances, and then, a sequence is generated via alternatively executing predictions on how the optimizers at the next time sample are changing and corrections on how they actually have changed. Prediction is based on how the optimality conditions evolve in time, while correction is based on a gradient or Newton method, leading to decentralized prediction-correction gradient and decentralized prediction-correction Newton. We extend these methods to cases where the knowledge on how the optimization programs are changing in time is only approximate and propose decentralized approximate prediction-correction gradient and decentralized approximate prediction-correction Newton. Convergence properties of all the proposed methods are studied and empirical performance is shown on an application of a resource allocation problem in a wireless network. We observe that the proposed methods outperform existing running algorithms by orders of magnitude. The numerical results showcase a tradeoff between convergence accuracy, sampling period, and network communications.
Autors: Andrea Simonetto;Alec Koppel;Aryan Mokhtari;Geert Leus;Alejandro Ribeiro;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5724 - 5738
Publisher: IEEE
 
» Decoding Kinematics Using Task-Independent Movement-Phase-Specific Encoding Models
Abstract:
Neural decoders of kinematic variables have largely relied on task-dependent (TD) encoding models of the neural activity. TD decoders, though, require prior knowledge of the tasks, which may be unavailable, lack scalability as the number of tasks grows, and require a large number of trials per task to reduce the effects of neuronal variability. The execution of movements involves a sequence of phases (e.g., idle, planning, and so on) whose progression contributes to the neuronal variability. We hypothesize that information about the movement phase facilitates the decoding of kinematics and compensates for the lack of prior knowledge about the task. We test this hypothesis by designing a task-independent movement-phase-specific (TI-MPS) decoding algorithm. The algorithm assumes that movements proceed through a consistent sequence of phases regardless of the specific task, and it builds one model per phase by combining data from different tasks. Phase transitions are detected online from neural data and, for each phase, a specific encoding model is used. The TI-MPS algorithm was tested on single-unit recordings from 437 neurons in the dorsal and ventral pre-motor cortices from two nonhuman primates performing 3-D multi-object reach-to-grasp tasks. The TI-MPS decoder accurately decoded kinematics from tasks it was not trained for and outperformed TD approaches (one-way ANOVA with Tukey’s post-hoc test and -value <0.05). Results indicate that a TI paradigm with MPS models may help decoding kinematics when prior information about the task is unavailable and pave the way toward clinically viable prosthetics.
Autors: Stefan L. Sumsky;Marc H. Schieber;Nitish V. Thakor;Sridevi V. Sarma;Sabato Santaniello;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2122 - 2132
Publisher: IEEE
 
» Decomposition of Multi-Channel Intramuscular EMG Signals by Cyclostationary-Based Blind Source Separation
Abstract:
We propose a novel decomposition method for electromyographic signals based on blind source separation. Using the cyclostationary properties of motor unit action potential trains (MUAPt), it is shown that the MUAPt can be decomposed by joint diagonalization of the cyclic spatial correlation matrix of the observations. After modeling the source signals, we provide the proof of orthogonality of the sources and of their delayed versions in a cyclostationary context. We tested the proposed method on simulated signals and showed that it can decompose up to six sources with a probability of correct detection and classification >95%, using only eight recording sites. Moreover, we tested the method on experimental multi-channel signals recorded with thin-film intramuscular electrodes, with a total of 32 recording sites. The rate of agreement of the decomposed MUAPt with those obtained by an expert using a validated tool for decomposition was >93%.
Autors: Julien Roussel;Philippe Ravier;Michel Haritopoulos;Dario Farina;Olivier Buttelli;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2035 - 2045
Publisher: IEEE
 
» Deep CNNs With Spatially Weighted Pooling for Fine-Grained Car Recognition
Abstract:
Fine-grained car recognition aims to recognize the category information of a car, such as car make, car model, or even the year of manufacture. A number of recent studies have shown that a deep convolutional neural network (DCNN) trained on a large-scale data set can achieve impressive results at a range of generic object classification tasks. In this paper, we propose a spatially weighted pooling (SWP) strategy, which considerably improves the robustness and effectiveness of the feature representation of most dominant DCNNs. More specifically, the SWP is a novel pooling layer, which contains a predefined number of spatially weighted masks or pooling channels. The SWP pools the extracted features of DCNNs with the guidance of its learnt masks, which measures the importance of the spatial units in terms of discriminative power. As the existing methods that apply uniform grid pooling on the convolutional feature maps of DCNNs, the proposed method can extract the convolutional features and generate the pooling channels from a single DCNN. Thus minimal modification is needed in terms of implementation. Moreover, the parameters of the SWP layer can be learned in the end-to-end training process of the DCNN. By applying our method to several fine-grained car recognition data sets, we demonstrate that the proposed method can achieve better performance than recent approaches in the literature. We advance the state-of-the-art results by improving the accuracy from 92.6% to 93.1% on the Stanford Cars-196 data set and 91.2% to 97.6% on the recent CompCars data set. We have also tested the proposed method on two additional large-scale data sets with impressive results observed.
Autors: Qichang Hu;Huibing Wang;Teng Li;Chunhua Shen;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Nov 2017, volume: 18, issue:11, pages: 3147 - 3156
Publisher: IEEE
 
» Deep Convolutional Neural Models for Picture-Quality Prediction: Challenges and Solutions to Data-Driven Image Quality Assessment
Abstract:
Convolutional neural networks (CNNs) have been shown to deliver standout performance on a wide variety of visual information processing applications. However, this rapidly developing technology has only recently been applied with systematic energy to the problem of picture-quality prediction, primarily because of limitations imposed by a lack of adequate ground-truth human subjective data. This situation has begun to change with the development of promising data-gathering methods that are driving new approaches to deep-learning-based perceptual picture-quality prediction. Here, we assay progress in this rapidly evolving field, focusing, in particular, on new ways to collect large quantities of ground-truth data and on recent CNN-based picture-quality prediction models that deliver excellent results in a large, real-world, picture-quality database.
Autors: Jongyoo Kim;Hui Zeng;Deepti Ghadiyaram;Sanghoon Lee;Lei Zhang;Alan C. Bovik;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 130 - 141
Publisher: IEEE
 
» Deep Learning for Image-to-Text Generation: A Technical Overview
Abstract:
Generating a natural language description from an image is an emerging interdisciplinary problem at the intersection of computer vision, natural language processing, and artificial intelligence (AI). This task, often referred to as image or visual captioning, forms the technical foundation of many important applications, such as semantic visual search, visual intelligence in chatting robots, photo and video sharing in social media, and aid for visually impaired people to perceive surrounding visual content. Thanks to the recent advances in deep learning, the AI research community has witnessed tremendous progress in visual captioning in recent years. In this article, we will first summarize this exciting emerging visual captioning area. We will then analyze the key development and the major progress the community has made, their impact in both research and industry deployment, and what lies ahead in future breakthroughs.
Autors: Xiaodong He;Li Deng;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 109 - 116
Publisher: IEEE
 
» Deep Learning for Visual Understanding [From the Guest Editors]
Abstract:
Autors: Fatih Porikli;Shiguang Shan;Cees Snoek;Rahul Sukthankar;Xiaogang Wang;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 24 - 25
Publisher: IEEE
 
» Deep Metric Learning for Visual Understanding: An Overview of Recent Advances
Abstract:
Metric learning aims to learn a distance function to measure the similarity of samples, which plays an important role in many visual understanding applications. Generally, the optimal similarity functions for different visual understanding tasks are task specific because the distributions for data used in different tasks are usually different. It is generally believed that learning a metric from training data can obtain more encouraging performances than handcrafted metrics [1]-[3], e.g., the Euclidean and cosine distances. A variety of metric learning methods have been proposed in the literature [2]-[5], and many of them have been successfully employed in visual understanding tasks such as face recognition [6], [7], image classification [2], [3], visual search [8], [9], visual tracking [10], [11], person reidentification [12], cross-modal matching [13], image set classification [14], and image-based geolocalization [15]-[17].
Autors: Jiwen Lu;Junlin Hu;Jie Zhou;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 76 - 84
Publisher: IEEE
 
» Deep Multimetric Learning for Shape-Based 3D Model Retrieval
Abstract:
Recently, feature-learning-based 3D shape retrieval methods have been receiving more and more attention in the 3D shape analysis community. In these methods, the hand-crafted metrics or the learned linear metrics are usually used to compute the distances between shape features. Since there are complex geometric structural variations with 3D shapes, the single hand-crafted metric or learned linear metric cannot characterize the manifold, where 3D shapes lie well. In this paper, by exploring the nonlinearity of the deep neural network and the complementarity among multiple shape features, we propose a novel deep multimetric network for 3D shape retrieval. The developed multimetric network minimizes a discriminative loss function that, for each type of shape feature, the outputs of the network from the same class are encouraged to be as similar as possible and the outputs from different classes are encouraged to be as dissimilar as possible. Meanwhile, the Hilbert-Schmidt independence criterion is employed to enforce the outputs of different types of shape features to be as complementary as possible. Furthermore, the weights of the learned multiple distance metrics can be adaptively determined in our developed deep metric network. The weighted distance metric is then used as the similarity for shape retrieval. We conduct experiments with the proposed method on the four benchmark shape datasets. Experimental results demonstrate that the proposed method can obtain better performance than the learned deep single metric and outperform the state-of-the-art 3D shape retrieval methods.
Autors: Jin Xie;Guoxian Dai;Yi Fang;
Appeared in: IEEE Transactions on Multimedia
Publication date: Nov 2017, volume: 19, issue:11, pages: 2463 - 2474
Publisher: IEEE
 
» Deep Multimodal Learning: A Survey on Recent Advances and Trends
Abstract:
The success of deep learning has been a catalyst to solving increasingly complex machine-learning problems, which often involve multiple data modalities. We review recent advances in deep multimodal learning and highlight the state-of the art, as well as gaps and challenges in this active research field. We first classify deep multimodal learning architectures and then discuss methods to fuse learned multimodal representations in deep-learning architectures. We highlight two areas of research–regularization strategies and methods that learn or optimize multimodal fusion structures–as exciting areas for future work.
Autors: Dhanesh Ramachandram;Graham W. Taylor;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 96 - 108
Publisher: IEEE
 
» Deep Reinforcement Learning: A Brief Survey
Abstract:
Deep reinforcement learning (DRL) is poised to revolutionize the field of artificial intelligence (AI) and represents a step toward building autonomous systems with a higherlevel understanding of the visual world. Currently, deep learning is enabling reinforcement learning (RL) to scale to problems that were previously intractable, such as learning to play video games directly from pixels. DRL algorithms are also applied to robotics, allowing control policies for robots to be learned directly from camera inputs in the real world. In this survey, we begin with an introduction to the general field of RL, then progress to the main streams of value-based and policy-based methods. Our survey will cover central algorithms in deep RL, including the deep Q-network (DQN), trust region policy optimization (TRPO), and asynchronous advantage actor critic. In parallel, we highlight the unique advantages of deep neural networks, focusing on visual understanding via RL. To conclude, we describe several current areas of research within the field.
Autors: Kai Arulkumaran;Marc Peter Deisenroth;Miles Brundage;Anil Anthony Bharath;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 26 - 38
Publisher: IEEE
 
» Deep-Depletion Mode Boron-Doped Monocrystalline Diamond Metal Oxide Semiconductor Field Effect Transistor
Abstract:
A p-type deep-depletion mode monocrystalline diamond MOSFET is demonstrated, with a 190-nm-thick controllable channel. Such a device offers new opportunities for a better optimization of the bulk doping versus designed breakdown voltage and the resulting figure of merit. Diamond MOSFETs with Boron doping of and using 20-nm ALD deposited Al2O3 as the gate oxide show promising IV characteristics, with a clear ON and OFF state operation. The MOSFETs have a normally-ON operation with typical threshold voltages of V and a ON-state drain current of /mm at V and V, at room temperature. A high hole mobility (1000±200 cm2/()) has been evaluated. Just before the experimental voltage breakdown at 200 V, the gate leakage is still below 0.6 nA/mm at room temperature and the peak electric field in diamond at the gate edge is simulated at 4 MV/cm. Beyond this experimental proof of concept, these combined values show the high potential of deep-depletion mode Boron doped diamond MOSFETs.
Autors: Thanh-Toan Pham;Julien Pernot;Gaetan Perez;David Eon;Etienne Gheeraert;Nicolas Rouger;
Appeared in: IEEE Electron Device Letters
Publication date: Nov 2017, volume: 38, issue:11, pages: 1571 - 1574
Publisher: IEEE
 
» Deep-Learning Systems for Domain Adaptation in Computer Vision: Learning Transferable Feature Representations
Abstract:
Domain adaptation algorithms address the issue of transferring learning across computational models to adapt them to data from different distributions. In recent years, research in domain adaptation has been making great progress owing to the advancements in deep learning. Deep neural networks have demonstrated unrivaled success across multiple computer vision applications, including transfer learning and domain adaptation. This article outlines the latest research in domain adaptation using deep neural networks. It begins with an introduction to the concept of knowledge transfer in machine learning and the different paradigms of transfer learning. It provides a brief survey of nondeep-learning techniques and organizes the rapidly growing research in domain adaptation based on deep learning. It also highlights some drawbacks with the current state of research in this area and offers directions for future research.
Autors: Hemanth Venkateswara;Shayok Chakraborty;Sethuraman Panchanathan;
Appeared in: IEEE Signal Processing Magazine
Publication date: Nov 2017, volume: 34, issue:6, pages: 117 - 129
Publisher: IEEE
 
» Deep-Reinforcement-Learning-Based Optimization for Cache-Enabled Opportunistic Interference Alignment Wireless Networks
Abstract:
Both caching and interference alignment (IA) are promising techniques for next-generation wireless networks. Nevertheless, most of the existing works on cache-enabled IA wireless networks assume that the channel is invariant, which is unrealistic considering the time-varying nature of practical wireless environments. In this paper, we consider realistic time-varying channels. Specifically, the channel is formulated as a finite-state Markov channel (FSMC). The complexity of the system is very high when we consider realistic FSMC models. Therefore, in this paper, we propose a novel deep reinforcement learning approach, which is an advanced reinforcement learning algorithm that uses a deep network to approximate the value-action function. We use Google TensorFlow to implement deep reinforcement learning in this paper to obtain the optimal IA user selection policy in cache-enabled opportunistic IA wireless networks. Simulation results are presented to show that the performance of cache-enabled opportunistic IA networks in terms of the network's sum rate and energy efficiency can be significantly improved by using the proposed approach.
Autors: Ying He;Zheng Zhang;F. Richard Yu;Nan Zhao;Hongxi Yin;Victor C. M. Leung;Yanhua Zhang;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10433 - 10445
Publisher: IEEE
 
» DeepSleepNet: A Model for Automatic Sleep Stage Scoring Based on Raw Single-Channel EEG
Abstract:
This paper proposes a deep learning model, named DeepSleepNet, for automatic sleep stage scoring based on raw single-channel EEG. Most of the existing methods rely on hand-engineered features, which require prior knowledge of sleep analysis. Only a few of them encode the temporal information, such as transition rules, which is important for identifying the next sleep stages, into the extracted features. In the proposed model, we utilize convolutional neural networks to extract time-invariant features, and bidirectional-long short-term memory to learn transition rules among sleep stages automatically from EEG epochs. We implement a two-step training algorithm to train our model efficiently. We evaluated our model using different single-channel EEGs (F4-EOG (left), Fpz-Cz, and Pz-Oz) from two public sleep data sets, that have different properties (e.g., sampling rate) and scoring standards (AASM and R&K). The results showed that our model achieved similar overall accuracy and macro F1-score (MASS: 86.2%−81.7, Sleep-EDF: 82.0%−76.9) compared with the state-of-the-art methods (MASS: 85.9%−80.5, Sleep-EDF: 78.9%−73.7) on both data sets. This demonstrated that, without changing the model architecture and the training algorithm, our model could automatically learn features for sleep stage scoring from different raw single-channel EEGs from different data sets without utilizing any hand-engineered features.
Autors: Akara Supratak;Hao Dong;Chao Wu;Yike Guo;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 1998 - 2008
Publisher: IEEE
 
» Defect Modes Control in Coupled Magnonic Crystals
Abstract:
We report on the theoretical study of magnetostatic surface wave propagation through the two side-coupled 1-D magnonic crystals (MCs) with broken translational symmetry. Using the transfer matrix method, we obtained transmission and reflection coefficients. Existence of two defect modes in such four-port planar structure was shown. We consider the possibility of controlling the position of defect modes by changing coupling between MCs. Comparison between investigated structure with coupled defect-free magnonic crystals was provided.
Autors: Anna Yu. Sharaevskaya;Evgenii N. Beginin;Yurii P. Sharaevskii;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Defectivity and Yield Impact From the AMC Inside the FOUP in Advanced Technologies
Abstract:
Historically, much attention has been given to the unit processes and the integration of those unit processes to improve product yield. Less attention has been given to the wafer mini environment, either during processing or post processing. This paper contains a detailed discussion on how particles and airborne molecular contaminants (AMCs) from the wafer mini environment interact and produce undesired effects on the wafer which in turn cause devices to fail. Sources of wafer environmental contamination are the processes themselves, ambient environment, outgassing from wafers, and front open unified pod (FOUP) contamination. Establishing a strategy that reduces contamination inside the FOUP mini environment will decrease defect variability and thus increase yield. In manufacturing ecosystem, changing the FOUP or moving the wafers faster or purging with nitrogen to reduce the impact from mini environment is not always an option. Alternative to having a stop gap, it is desired to understand the AMCs and thus exploring sustainable solutions to minimize them below certain thresholds that would cause impact on wafer. NH3-based contamination, extensively discussed in this paper, is observed to cause wafer defects. Thus, explicit knowledge of AMC type is critical, as the most optimized methodology to control various AMCs might not always be the same. Three primary variables that greatly impact this strategy are FOUP contamination mitigation, FOUP material, FOUP metrology, and cleaning method.
Autors: John Barker;Stephen Miner;Wei Zhao;Jong Soo Kim;Joshua Moore;Eswar Ramanathan;Sara Case;Stephanie Waite;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Nov 2017, volume: 30, issue:4, pages: 434 - 439
Publisher: IEEE
 
» Deferred Warping
Abstract:
Deferred warping is a novel approach for real-time deformation of 3D objects attached to an animated or manipulated surface. The target application is virtual prototyping of garments, where 2D pattern modeling is combined with 3D garment simulation, allowing for an immediate validation of the design. This technique can directly handle complex topology changes within a surface. The authors demonstrate a fast implementation in the vertex shading stage, allowing the use of highly decorated surfaces with millions of triangles in real time.
Autors: Martin Knuth;Jan Bender;Michael Goesele;Arjan Kuijper;
Appeared in: IEEE Computer Graphics and Applications
Publication date: Nov 2017, volume: 37, issue:6, pages: 76 - 87
Publisher: IEEE
 
» Delay Optimal Scheduling for ARQ-Aided Power-Constrained Packet Transmission Over Multi-State Fading Channels
Abstract:
In this paper, we study the delay optimal scheduling policy for a multi-state wireless fading channel, by taking bursty packet arrivals and automatic repeat request-based packet transmission into account. In our system, the average delay each packet experiences includes the time it waits in the queue and the time it may take to retransmit due to packet delivery failure. To reduce the average delay, we propose a joint channel-aware and queue-aware stochastic scheduling policy to determine whether and with which probability the source should transmit based on channel and buffer states, subject to an average power constraint at the transmitter. To find the optimal scheduling probabilities, we formulate a non-linear power-constrained delay minimization problem with the aid of controlled Markov decision processes. The optimization problem is then converted into an equivalent linear programming problem by introducing new variables from the steady-state probabilities of the underlying Markov chain and transmission probabilities. By analyzing its property, we derive the structure of the optimal solution, and exploit it to obtain the optimal probabilities analytically. It is found that the optimal scheduling policy has a double threshold structure, and can significantly reduce the average delay.
Autors: Juan Liu;Wei Chen;Khaled B. Letaief;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7123 - 7137
Publisher: IEEE
 
» Demagnetizing Field Effect on the Detection Range of a Galfenol-Based Magnetic Field Sensor
Abstract:
This paper investigates the new developments of a class of magnetic field sensors based on the integration of Iron–Gallium magnetostrictive alloys (Galfenol) and fiber Bragg gratings used to detect the magneto-induced mechanical strain. This kind of sensor has the advantage of being able to work also in harsh environments, but on the other hand cannot detect fields beyond 10 kA/m, because of the magnetic softness of the active material. A simple solution consists in the exploitation of the demagnetizing field experienced by the ferromagnetic alloy by effect of its magnetization, generated by the application of the external magnetic field. Since the demagnetizing field effect depends only on geometrical parameters, the use of samples with different aspect ratios allows us to check how the shape of the active material can be used as a control parameter of the sensor detection range.
Autors: Valerio Apicella;Michele Arturo Caponero;Cesidio Cianfarani;Daniele Davino;Andrea Polimadei;Ciro Visone;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Demonstration of 3-D SRAM Cell by 3-D Monolithic Integration of InGaAs n-FinFETs on FDSOI CMOS With Interlayer Contacts
Abstract:
In this paper, we demonstrate, for the first time, 3-D Monolithic integration of short-channel replacement metal gate InGaAs n-FinFETs on fully-depleted silicon-on-insulator CMOS, with TiN/W interlayer contacts. Top layer InGaAs nFETs feature raised source–drain and bottom layer CMOS has Si raised source–drain for nFETs, SiGe raised source–drain for pFETS, implants, silicide, and TiN/W plug contacts. Scaled gate length () of 15 nm is achieved on bottom layer Si n- and pFETs, while the top layer InGaAs n-FinFETs are scaled to of 25 nm. A densely integrated 3-D 6T-static random access memory circuit with planar InGaAs nFETs stacked on Si pFETs is demonstrated by taking advantage of the interlayer contacts. This yields significant area reduction when compared with 2-D layouts.
Autors: Veeresh Deshpande;H. Hahn;E. O’Connor;Y. Baumgartner;D. Caimi;M. Sousa;H. Boutry;J. Widiez;L. Brévard;C. Le Royer;M. Vinet;J. Fompeyrine;L. Czornomaz;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4503 - 4509
Publisher: IEEE
 
» Demonstration of Polarization-Insensitive Superconducting Nanowire Single-Photon Detector With Si Compensation Layer
Abstract:
Polarization sensitivity is an intrinsic characteristic of the superconducting nanowire single-photon detector (SNSPD). It is caused by the periodical meander structure of the SNSPD, and may severely limit the scope of the SNSPD's applications. In this study, we have designed and fabricated a SNSPD with much reduced polarization sensitivity, based on a previously published theoretical result that involves high refractive index compensation materials. Using a home-built broadband automatic measurement system, the device detection efficiencies of the fabricated SNSPD have been measured for wavelengths ranging from 1200 to 1700 nm. The measurement results show that the polarization sensitivity of the fabricated device is greatly reduced, with the device detection efficiencies at 1550 nm being 61% and 56% for cases of parallel and perpendicular polarizations, respectively. The measurement results are in good agreement with the numerical simulations.
Autors: Ruiying Xu;Fan Zheng;Defeng Qin;Xiachao Yan;Guanghao Zhu;Lin Kang;Labao Zhang;Xiaoqing Jia;Xuecou Tu;Biaobing Jin;Weiwei Xu;Jian Chen;Peiheng Wu;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4707 - 4713
Publisher: IEEE
 
» Dependency Analysis of Accuracy Estimates in k-Fold Cross Validation
Abstract:
A standard procedure for evaluating the performance of classification algorithms is k-fold cross validation. Since the training sets for any pair of iterations in k-fold cross validation are overlapping when the number of folds is larger than two, the resulting accuracy estimates are considered to be dependent. In this paper, the overlapping of training sets is shown to be irrelevant in determining whether two fold accuracies are dependent or not. Then a statistical method is proposed to test the appropriateness of assuming independence for the accuracy estimates in k-fold cross validation. This method is applied on 20 data sets, and the experimental results suggest that it is generally appropriate to assume that the fold accuracies are independent. The cross validation of non-overlapping training sets can make fold accuracies to be dependent. However, this dependence almost has no impact on estimating the sample variance of fold accuracies, and hence they can generally be assumed to be independent.
Autors: Tzu-Tsung Wong;Nai-Yu Yang;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Nov 2017, volume: 29, issue:11, pages: 2417 - 2427
Publisher: IEEE
 
» Depolarized Backscattering of Rough Surface by AIEM Model
Abstract:
This paper presents a new expression for multiple scattering by including the upward and downward propagation waves in the medium 1 and medium 2. Unlike the single scattering, the multiple scattering accounts for the interactions, up to second order, among all the spectral components of surface roughness spectrum. Though the derivation is mathematically intricate, but yet manageable, the final expression is compact and easy for numerical implementation, which only involves a series of two-dimensional integration. Some of special cases in depolarized backscattering are also derived and compared with known analytical model to partly validate the update AIEM model. Then, extensive comparisons with numerical simulations and field measurements are conducted to illustrate the model accuracy.
Autors: Ying Yang;Kun-Shan Chen;Leung Tsang;Liu Yu;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4740 - 4752
Publisher: IEEE
 
» Design and Analysis of a Double-Layer Magnetic Circuit Structure for High-Force Density Hybrid Fuel Injector
Abstract:
This paper proposes the design and analysis of a double-layer magnetic circuit structure for a high-force density hybrid fuel injector. In general, fuel injector models have disadvantages such as a significant leakage flux and magnetic saturation; therefore, a finite-element method is used to detail the model design and reduce the leakage flux from the electromagnet pole to the lead pipe. This change can help improve the fuel injector performance. In addition, a permanent magnet (PM) is inserted to increase the force density. Moreover, the no-load performance and demagnetization characteristic of the injector are analyzed according to the injector’s working environment. The optimized hybrid fuel injector model with a PM shows substantially improved performance compared to a conventional design.
Autors: Huai-Cong Liu;Sooyoung Cho;Hyun-Seok Hong;Ju Lee;Ho-Joon Lee;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Design and Analysis of a New HTS Electromagnetic Screw
Abstract:
The high-temperature superconductor (HTS) machines are more attractive due to the advantages of high power density and efficiency. This paper introduces a new HTS electromagnetic screw (HTS-EMS) that is developed for artificial heart. Two helical-shaped slots are introduced to the translator; the key to the HTS-EMS is that the HTS coils carrying dc currents are placed in the helical-shaped slots. The permanent-magnet array is placed in the rotor. Due to the high current density of the HTS coil, the power density of the HTS-EMS can be improved effectively. The electromagnetic performance of the HTS-EMS is analyzed, including the flux, thrust force, as well as torque. The proposed HTS-EMS is evaluated compared with the existing magnetic screw using time-stepping finite-element method, verifying the advantages of the proposed structure.
Autors: Zhijian Ling;Wenxiang Zhao;Jinghua Ji;Jihong Zhu;Jingfeng Mao;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Design and Analysis of a Novel Lightweight Translator Permanent Magnet Linear Generator for Oceanic Wave Energy Conversion
Abstract:
At present, most of the linear generators contain a heavy translator for converting wave power from the ocean into electrical power. As the translator is connected to the buoy, the buoy dynamic performance is reduced by the large mass and, as a result, low velocity of the translator would degrade the electricity generation of the linear generator. This problem has been minimized by the new design in this paper, where the translator is clipped off at first and split into two separate portions to minimize its weight. The secondary stator is magnetically coupled with a special m-shaped main stator which is used to flow the necessary magnetic flux. The weight of the proposed translator is 21.82% lower than that of conventional one and 49.1% by using a recently available permanent magnet with higher specifications. The finite-element method is applied in ANSYS simulation environment for the analysis and comparison between the proposed and conventional designs. Different parameters of the conventional and the proposed linear generator have been discussed in this paper. The simulation results show that the proposed design can generate the same amount of electricity as the existing one with almost half of the translator size. According to the mathematical model, it is understood that the dynamics of the translator would be higher for its lower mass and vice versa. Therefore, minimizing the translator size would result in decrease of mass, which increases the dynamics of the buoy connected to the translator.
Autors: O. Farrok;M. R. Islam;M. R. I. Sheikh;Y. G. Guo;J. G. Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Design and Analysis of a Spoke-Type Hybrid Permanent Magnet Motor for Electric Vehicles
Abstract:
This paper proposes a new spoke-type hybrid permanent magnet brushless (H-PMBL) motor for potential applications in electric vehicles, where the high-energy rare-earth PM and the cost-effective ferrite-PM are combined. In order to realize low-cost design and improve the operating points of the rare-earth PM and the ferrite-PM, the proposed motor is designed based on the calculation of PM cost and analysis on the operating points. Moreover, to fairly estimate electromagnetic performances of the H-PMBL motor, a conventional spoke-type non-rare-earth ferrite-PMBL motor with the same overall dimensions is also analyzed and compared using the finite element method. The simulation results indicate that the H-PMBL motor cannot only retain low PM cost, but also exhibit better flux-weakening ability and enhanced demagnetization withstand capability.
Autors: Xiaoyong Zhu;Xue Wang;Chao Zhang;Lin Wang;Wenye Wu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Design and Analysis of BICM-ID for Two-Way Relay Channels With Physical-Layer Network Coding
Abstract:
This paper proposes a general iterative demapping–decoding approach for two-way relay (TWR) communications with physical-layer network coding, where the relay node performs decode-and-forward. The bit-interleaved coded modulation (BICM) with high-order quadrature amplitude modulation is considered. The iterative decoding, namely the BICM-ID for TWR channels, is introduced. Based on a joint trellis, BICM-ID estimates the end nodes’ coded bits, leading to an estimation of the transmitted symbol pair probability, which is crucial for achieving iterative decoding gains in bit error rate (BER). The end nodes’ constellation design criterion is proposed to optimize the BICM-ID performance over the TWR fading channel. The EXtrinsic Information Transfer analysis is also performed, showing the iterative system's convergence behavior and providing information on code design. Our simulation results show the proposed BICM-ID scheme can achieve significant performance gains, yielding an asymptotic tendency of approaching the cut-set BER performance limit.
Autors: Zichao Sun;Li Chen;Xiaojun Yuan;Yushan Yakufu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10170 - 10182
Publisher: IEEE
 
» Design and Analysis of Electromagnetic Gears With Variable Gear Ratios
Abstract:
In this paper, the electromagnetic gear (EMG) with variable gear ratios has been proposed. With proper excitation of dc field windings, various pole pairs or gear ratios can be obtained, while its transmitting torque can be also adjusted in response to different applications. Hence, the proposed EMG takes definite advantage over the recently developed magnetic variable gear in terms of gear-changing controllability and torque capability. Meanwhile, with the field-modulated topology, the proposed EMG enjoys the merit of overloading protection compared with the conventional mechanical variable gear. Both steady-state and transient performances are simulated, which well verifies the validity of the proposed EMG.
Autors: Libing Cao;K. T. Chau;Christopher H. T. Lee;Wenlong Li;Hua Fan;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Design and Application of the Distributed Ionospheric Coherent Scatter Radar
Abstract:
In this letter, a newly designed distributed coherent scatter radar for localization of ionospheric irregularities is presented. It is composed of a detection network that can detect ionospheric irregularities with the help of a time synchronization module. To achieve a fairly narrow beam with high directive gain, an antenna array is used in this transmitter module. The frequency band is from high frequency (HF) to very HF to detect irregularities at different scales. In addition, the radar uses a universal serial bus to reduce its size, which allows it to be easily moved to different areas. An iterative ray tracing method is also applied to localize the ionospheric irregularities. The results indicate that the radar can effectively track ionospheric irregularity in 3-D space.
Autors: Lei Qiao;Gang Chen;Jin Wang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 2042 - 2046
Publisher: IEEE
 
» Design and Experimental Implementation of a Low Frequency Pulsed Magnetic Field Generator
Abstract:
Pulsed magnetic field generation is a critical aspect of all nuclear magnetic resonance (NMR) experiments. In this paper, a novel design for a low field, low frequency (less than 5 MHz), pulsed magnetic field generation circuit suited for unilateral NMR applications is presented. A pulsed sinusoidal current is generated at an inductive load connected to an FET-based switch. The inductive load resonates at a frequency of approximately 2 MHz, which is also the precession frequency of protons in an external magnetic flux density of 500 G. The designed circuit can be tuned to operate at resonant frequencies of other chemical species as well. In this paper, the design parameters and operation of the prototype pulsed field generator will be discussed.
Autors: Neelam Prabhu Gaunkar;Jayaprakash Selvaraj;Leif Bauer;Mani Mina;Robert Weber;David Jiles;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Design and Experimental Validation of a Stable Two-Stage Estimator for Automotive Sideslip Angle and Tire Parameters
Abstract:
This paper proposes and experimentally validates a two-stage approach for coupled lateral vehicle state and tire model estimation. In a first stage, an extended Kalman filter is employed which provides vehicle slip angles and lateral tire forces from commercial low-cost vehicle sensors. The obtained estimates are exploited in the second stage, where a (quasi-static) tire model is fitted to this data. A major issue in this estimation process is the typical instability of these estimators for situations with (prolonged) straight driving. This issue is traced back to a lack of local observability. The use of a variable model covariance is introduced as a practical method to obtain a stable estimator, irrespective of the unobservability. The developed methodology has a low computational load and the Kalman estimator is able to run in real time, whereas the tire model parameter fitting is cheap enough to run online. The proposed methodology is validated experimentally and provides reliable results in variable driving conditions.
Autors: Frank Naets;Sebastiaan van Aalst;Boulaid Boulkroune;Norddin El Ghouti;Wim Desmet;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 9727 - 9742
Publisher: IEEE
 
» Design and Fabrication of a High-Power Air-Coupled Capacitive Micromachined Ultrasonic Transducer Array With Concentric Annular Cells
Abstract:
One shortcoming of capacitive micromachined ultrasonic transducers (CMUTs) for commercial use is the weak output power relative to traditional ultrasonic transducers. Recently, we reported an annular CMUT cell with an improved transmit efficiency over a conventional circular cell in air. Extending this paper, we designed and fabricated a nine-element concentric CMUT array to enhance the transmit power and offer depth focusing. The proposed 200-kHz array has an aperture diameter of 2.13 cm and a fill factor of 81%. A pillar-free etching process was developed to create the deep large-area cavities of the proposed wafer-bonded CMUT. The fabricated device was characterized for the static and dynamic performance using a profilometer and a laser Doppler vibrometer, respectively. The average maximum plate dynamic displacements of the CMUT driven by 20-Vpp ac excitation voltage at dc biases of 100 and 150 V were measured to be 1.28 and , respectively. Accordingly, the surface output power densities were calculated to be 0.40 and 0.96 KW/m2. We investigated the crosstalk between neighboring cells and the plate-cracking phenomenon, and provided relative suggestions for improvement. This paper demonstrates the feasibility of the concentric annular-cell CMUT array design for air-coupled applications.
Autors: Shuai Na;Zhou Zheng;Albert I-Hsiang Chen;Lawrence L. P. Wong;Zhenhao Li;John T. W. Yeow;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4636 - 4643
Publisher: IEEE
 
» Design and Investigation of Dielectric Engineered Dopant Segregated Schottky Barrier MOSFET With NiSi Source/Drain
Abstract:
In this paper, to solve an important issue of low ON-state current in the nickel silicide (NiSi) metal source/drain Schottky barrier (SB) MOSFET (SBMOS), we have reported a novel dielectric engineered (DE) dopant segregated (DS) SBMOS structure using gate dielectric engineering. In a proposed device, we employ two different gate dielectric materials. The high-k gate dielectric is used at the source side and low-k gate dielectric at the drain side. Beneath the high-k gate dielectric, electron accumulation increases due to large gate dielectric capacitance density. As a result, reduction in depletion of source side dopant segregation layer further decreases the SB tunneling width for the electron injection. Consequently, improvement in ON-state current () is obtained. In addition, the low-k gate dielectric and drain side dopant segregation layer increases the effective SB height and tunneling width for the hole injection. Thus, the OFF-state current () is suppressed. The optimization of proposed device has been performed by modulating the length of high-k and the low-k gate dielectric. In addition, we have compared the performance of the proposed device in terms of ON to OFF current ratio , subthreshold swing (SS), transconductance , transconductance generation factor , cut-off frequency , and gain-bandwidth product $({f}_{ {A}})$ to the SBMOS, DS SBMOS, and DS SBMOS with the full high-k gate dielectric. Moreover, we have proposed the possible process flow for the DE DS SBMOS fabrication.
Autors: Sumit Kale;Pravin N. Kondekar;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4400 - 4407
Publisher: IEEE
 
» Design and Investigation on Bioinverter and Bioring-Oscillator for Dielectrically Modulated Biosensing Applications
Abstract:
In this work, an inverter-based biomolecule detection strategy has been introduced for dielectrically modulated biosensing applications that show a clear output logic-state transition after conjugation. Subsequently, a bioring-oscillator has been realized based on such bioinverters, where biomolecules can be detected from the oscillation frequency amplification with conjugation. To optimize the detection efficiency, a dielectrically modulated fringing field effect transistor based transducer has been incorporated as the pull-up/pull-down elements of such bioinverter. The underlying physics of such structure has been investigated and subsequent electrical response has been estimated for various biomolecule sample specifications. This work explores different bioinverter configurations, and subsequently the suitable choice of bioinverter has been indicated for charged and charge-neutral biomolecule detection. Similar studies have been performed for bioring oscillator, and the roles of supply voltage scaling and oscillator stage enhancement have been investigated in this context.
Autors: Sayan Kanungo;Sabir Ali Mondal;Sanatan Chattopadhyay;Hafizur Rahaman;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 974 - 981
Publisher: IEEE
 
» Design and Optimization of Piezoelectric MEMS Vibration Energy Harvesters Based on Genetic Algorithm
Abstract:
Low-power electronic applications are normally powered by batteries, which have to deal with stringent lifetime and size constraints. To enhance operational autonomy, energy harvesting from ambient vibration by microelectromechanical systems (MEMS) has been identified as a vivid solution to this universal problem. This paper proposes an automated design and optimization methodology with minimum human efforts for MEMS-based piezoelectric energy harvesters. The analytic equations for estimating the harvested voltage by the unimorph piezoelectric energy harvesters are presented with their accuracy validated by using the finite element method (FEM) simulation and prototype measurement. Thanks to their high accuracy, we use these analytic equations as fitness functions of genetic algorithm (GA), an evolutionary computation method for optimization problems by mimicking biological evolution. Our experimental results show that the GA is capable of optimizing multiple physical parameters of piezoelectric energy harvesters to considerably enhance the output voltage. This harvesting efficiency improvement is also desirably coupled with physical size reduction as preferred for the MEMS design process. To demonstrate capability of the proposed optimization method, we have also included a commercial optimization product (i.e., COMSOL optimization module) in our comparison study. The experiments show that our proposed GA-based optimization methodology offers higher effectiveness in the magnitude improvement of harvested voltage along with less runtime compared with the other optimization approaches. Furthermore, the effects of geometry optimization on mechanical and electrical properties (e.g., resonant frequency, stiffness, and internal impedance) are also studied and an effective solution to producing maximum power from unimorph piezoelectric harvesters is proposed.
Autors: Seyedfakhreddin Nabavi;Lihong Zhang;
Appeared in: IEEE Sensors Journal
Publication date: Nov 2017, volume: 17, issue:22, pages: 7372 - 7382
Publisher: IEEE
 
» Design and Performance Analysis of a Differentially Spatial Modulated Chaos Shift Keying Modulation System
Abstract:
In this brief, a new differentially spatial modulated chaos shift keying modulation communication system is proposed, in which the transceiver has not accessed channel state information. In the transmitter, the symbol can be mapped into the dependently selected antenna by the differential matrix in each interval. Meanwhile, in the receiver, the maximum received signal is used to retrieve the block of transmitted bits by the maximum likelihood estimation. By employing the spatial modulation, the proposed scheme offers a higher spectrum efficiency and the energy efficiency compared to the conventional multiple-input multiple-output differential chaos shift keying system. Lastly, the theoretical upper bounds on the average bit error probability, analyzed and derived, are in good agreement with the simulation results.
Autors: Wei Hu;Lin Wang;Georges Kaddoum;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Nov 2017, volume: 64, issue:11, pages: 1302 - 1306
Publisher: IEEE
 
» Design and Performance Analysis of a Self-Start Radial Flux-Hysteresis Interior Permanent Magnet Motor
Abstract:
A self-start interior permanent magnet (IPM) motor can be a potential replacement of the conventional induction motor because of its high torque density, smaller size, higher efficiency, and power factor. Traditional self-start IPM motors are equipped with cage windings in the rotor for providing the starting as well as the damping torque. Cage-quipped IPM motors have limited starting and synchronization capabilities. This paper introduces a novel self-start radial flux (RF) hysteresis IPM motor. The rotor of the hysteresis IPM motor has a cylindrical hysteresis ring made of semi-hard magnetic material. High energy density Nd–B–Fe magnets are buried inside the rotor hysteresis ring. The ring is supported by a laminated steel sleeve, allowing the flux to travel radially inside the hysteresis ring. In this paper, the design and performance analysis of a 3-phase 4-pole 1-HP RF-hysteresis IPM motor is carried out using finite-element analysis. The performance of the designed RF-hysteresis IPM motor is compared with similar 1-HP circumferential flux type hysteresis and cage-equipped IPM motors. Based on analysis and simulation, the RF-hysteresis IPM motor demonstrates higher starting and synchronization capabilities than conventional self-start IPM motors.
Autors: S. F. Rabbi;P. Zhou;M. A. Rahman;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Design and Performance of a High- $Q$ Narrow Bandwidth Bandpass Filter in Empty Substrate Integrated Coaxial Line at $K_{u}$ -Band
Abstract:
This letter presents the design and performance of a planar narrow bandwidth bandpass filter with high quality factor. The structure is composed of an empty substrate integrated coaxial line with the center conductor suspended in air. The component dimensions have been calculated by means of classical microwave filter design theory. The filter has been manufactured using standard printed circuit board fabrication processes. A measured insertion loss of 1.59 dB, 2.93% fractional bandwidth, and a -factor of 1505 have been obtained at 15 GHz. A -factor comparison with other substrate and empty substrate integrated technologies shows the advantages of the solution considered in this letter. The proposed filter proves to be suitable for the implementation of integrated microwave or millimeter-wave subsystems with severe restrictions, i.e., low in-band losses, very narrow bandpass responses, low frequency dispersion, high out-of-band rejection, and low manufacturing cost.
Autors: Alejandro L. Borja;Angel Belenguer;Hector Esteban;Vicente E. Boria;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 977 - 979
Publisher: IEEE
 
» Design and Simulation of Intermediate Band Solar Cell With Ultradense Type-II Multilayer Ge/Si Quantum Dot Superlattice
Abstract:
We studied the miniband dependence on the structural parameters and shape in type-II multilayer germanium (Ge)/silicon (Si) quantum dot superlattice (QDSL) solar cell. A maximum tunable range of ground-state energy is 19% by tuning layer distance down to 0.5 nm, whereas 24.5% is achieved by adjusting the horizontal dot-to-dot spacing down to 0.3 nm. The reduction of effective bandgap is severe for cylindrical QDs than ellipsoidal and conical QDs in the ultradense QDSL, thus leading to a relatively lower conversion efficiency. On average, the thickness of QD shows a negative correlation to conversion efficiency. We observed a high conversion efficiency of 27.22% in a bilayer conical QDSL under an AM1.5 spectral irradiance and one sun illumination.
Autors: Yi-Chia Tsai;Ming-Yi Lee;Yiming Li;Seiji Samukawa;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4547 - 4553
Publisher: IEEE
 
» Design Consideration on Converged Rx SAW Duplexer Module for Multiband RF Front End
Abstract:
This paper presents the design consideration on a converged Rx surface acoustic wave (SAW) duplexer module for integrated RF front end. Two different matching-circuit and notch-circuit configurations were examined with importance placed on electrical characteristics (insertion loss and isolation of duplexer) and simplification of module, respectively. From circuit simulations and examinations, we verified that a simplified design was best in terms of both characteristics and space in the case of a finite inductor’s Q. We also fabricate a quad-band converged Rx module (Band I + II, V + VIII) using an SAW duplexer and verified that its electrical characteristics agree well with our simulation results.
Autors: Masafumi Iwaki;Tabito Tanaka;Masanori Ueda;Yoshio Satoh;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4629 - 4635
Publisher: IEEE
 
» Design Criteria in Sizing Phase-Change RF Switches
Abstract:
This paper presents design criteria for four-terminal phase-change (PC) RF switches as a function of their dimensions, (heater width, RF gap, and barrier thickness), materials, and connection topology. Reducing heater width is shown to reduce switch actuation power, with this reduction ultimately being limited by the maximum allowed heater current density, as set by projected reliability. Narrower RF gaps are shown to increase switch cut-off frequency , because they decrease on-state resistance more than they increase off-state capacitance. The balance of this increased versus the estimated reduction in power handling as the RF gap shrinks is quantified. Barrier layers of AlN thicker than 200 nm are shown to be sufficient to electrically decouple the switch from the heater trace. Coupling to heater pads can also be significant unless pad sizes are reduced as in a monolithically integrated switch. Finally, it is demonstrated that division of the switch into multiple parallel segments is a viable approach for lowering the heater actuation voltage for CMOS integration. A 12.5% increase in (~1.5 fF) was observed and 35% increase in actuation power at temperature was needed in a two-segment parallel switch, as compared to a single segment switch.
Autors: Gregory Slovin;Min Xu;Rahul Singh;T. E. Schlesinger;Jeyanandh Paramesh;James A. Bain;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4531 - 4540
Publisher: IEEE
 
» Design of 3-Times Magnetizer and Rotor of Spoke-Type PMSM Considering Post-Assembly Magnetization
Abstract:
Unlike the existing bar-type permanent magnets, it is difficult to magnetize the ferrite spoke-type permanent magnet synchronous motor (PMSM), because the permanent magnet is placed deep inside the shaft. In order to magnetize permanent magnet, a high magnetic field intensity is required. However, the high magnetic field intensity may cause demagnetization of surrounding permanent magnets. It has a bad effect on the magnetization of the permanent magnet and the performance of the spoke-type PMSM. In this paper, we proposed magnetizer models for magnetization of spoke-type 10 pole rotor and the inter-pole winding to reduce the demagnetization of surrounding permanent magnets. Finally, the optimally designed model was manufactured and the performance of the magnetizer was verified.
Autors: Hyun-Soo Seol;Tae-Chul Jeong;Hyun-Woo Jun;Ju Lee;Dong-Woo Kang;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Design of a New Electromagnetic Brake for Actuator Locking Mechanism in Aerospace Vehcile
Abstract:
Electromagnetic (EM) brakes are gaining importance in aerospace vehicles for various critical applications. In guided missiles, they are primarily used for locking the actuator when the missile is in carriage either by road or by air such that the position of the actuator is not changed when servo is in the off condition. In this paper, a new EM brake is designed which is more energy efficient and reliable compared to a conventional solenoid operated brake. The nonlinear magnetic analysis is carried out on the brake, and the hardware is realized and tested. The test results are promising and this topology can be adapted for aerospace and other critical applications.
Autors: B. V. Ravi Kumar;K. Sivakumar;Y. Srinivas Rao;S. Karunanidhi;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Design of a New Enhanced Torque In-Wheel Switched Reluctance Motor With Divided Teeth for Electric Vehicles
Abstract:
This paper presents a new switched reluctance motor (SRM) with wide speed range for the application of electric vehicles. It has an in-wheel structure for direct drive and multiple teeth per stator pole to enhance output torque. Also, the number of rotor poles is more than that of stator teeth. A 6/16 three-phase in-wheel SRM with the concepts of multi-teeth per stator pole and more rotor poles than stator teeth has been proposed for analysis. The torque performance of the topology with multi-teeth per stator pole is proven by theoretical analysis. Moreover, a new design formula is introduced for a novel combination of stator and rotor poles. The parameters of the motor are optimized by genetic algorithm method for the maximum torque output. Then the torque performance is computed by finite-element method (FEM) and compared with its counterparts, including three-phase 6/8 and 6/10 SRMs. The FEM results exhibit higher torque density for the proposed topology.
Autors: Jingwei Zhu;Ka Wai Eric Cheng;Xiangdang Xue;Yu Zou;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Design of a Novel Consequent-Pole Transverse-Flux Machine With Improved Permanent Magnet Utilization
Abstract:
Severe leakage flux is a long-existed drawback in the transverse-flux permanent magnet machines (TFPMs), which results in a low permanent magnet (PM) utilization rate and prominent cogging torque in TFPMs. Aiming to solve this problem, this paper presents a novel consequent-pole transverse-flux machine (CP-TFM). The key is to artificially shift the upper and lower salient-pole rotors with a half-pole pitch and connect them with a ring-shaped core. Therefore, a complementary magnetic circuit is constructed to reduce the flux leakage between the adjacent poles as well as improve the PM utilization rate. To verify the feasibility of design, a 3-D finite-element model is established and its electromagnetic performance is evaluated. With the same peripheral dimension and copper loss, a quantitative comparison is carried out between the proposed CP-TFM and conventional TFPM. Finite-element simulation results reveal that compared to its contrast, the proposed solution can almost double the PM utilization ratio and effectively reduce the cogging torque.
Autors: Xing Zhao;Shuangxia Niu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Design of a Scanning Seebeck Coefficient Apparatus: A Tool for Testing Inhomogeneities in Thermoelectric Materials
Abstract:
In this paper, we present a simple, 2-D Seebeck coefficient measurement system for scanning thermoelectric samples at several points over its surface. The measuring setup has been tested with a homogeneous constantan (Cu55Ni45 alloy) foil in a temperature range from room temperature to 35 °C. Results show good agreement with the literature reported data with an error less than 7%. In order to test the inhomogeneities detection capability of the system, the sample surface was intentionally modified with a rectangular layer made of nickel-based ink and the system was able to detect this defect. With this setup, temperature measurement is not used directly for the Seebeck coefficient evaluation of the sample, although temperature readings are necessary for calculation of mean Seebeck coefficients of thermocouples used and for determination of mean sample temperature. The system uses a heater and a heat sink to minimize the heat flux through the scanning probe, reducing in this way the measurement error. The developed Seebeck coeffiecient scanning method allows automated measurements in a maximum region of 15 mm × 5 mm with 1-mm steps. The statistical analysis of the Seebeck coefficient through a maximum number of 75 recorded data points can be useful in the detection of inhomogeneities and defective regions along the sample.
Autors: Luis Felipe Ramírez-García;Oscar Luis Arnache-Olmos;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 3007 - 3011
Publisher: IEEE
 
» Design of Distributed Protograph LDPC Codes for Multi-Relay Coded-Cooperative Networks
Abstract:
This paper studies protograph low-density parity-check coded cooperation (CC) schemes for two-hop multi-relay systems with relays over Nakagami- quasi-static fading (QSF) channels. We propose two CC schemes, namely schemes I and II, with different maximum code rates to satisfy different transmission requirements. We further design a family of distributed rate-compatible root-protograph (RCRP) codes to achieve full diversity in CC-based multi-relay QSF channels. In particular, our RCRP codes with sub-codewords can realize full diversity in scheme I, and our RCRP codes with two sub-codewords can achieve full diversity in scheme II with a maximum-ratio combiner. In addition, we estimate the asymptotic word error rate and bit error rate of our RCRP codes using a generalized protograph extrinsic information transfer algorithm, which is able to characterize the error performance of finite-length codewords accurately. Analysis and simulation show that our RCRP codes can achieve outage-limit-approaching performance in both multi-relay CC architectures. This makes the RCRP coding framework extremely attractive for multi-relay cooperative communication applications with slow-varying fading.
Autors: Yi Fang;Soung Chang Liew;Taotao Wang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7235 - 7251
Publisher: IEEE
 
» Design of LDPC Codes for Unequal ISI Channels
Abstract:
In this paper, we design an irregular low-density parity-check (LDPC) codes for unequal inter-symbol interference channels based on the modified extrinsic information transfer chart. During transmission, each LDPC codeword will be divided and transmitted to the different channels. The aim of this scheme is to avoid transmitting the whole codeword in a high error rate channel. The simulation results show that the proposed code optimized for both PR1 and PR2 channels can achieve a 0.2 coding gain over the codes designed specifically for each individual channel. When this simple code is applied to a perpendicular channel with these two targets, the coding gains of the proposed code is about 0.08 dB at the frame error rate of .
Autors: Watid Phakphisut;Pornchai Supnithi;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Design of Low-Power DSP-Free Coherent Receivers for Data Center Links
Abstract:
Coherent detection offers high spectral efficiency and receiver sensitivity, but digital signal processing (DSP)-based coherent receivers may be prohibitively power hungry for data centers even when optimized for short-reach applications, where fiber propagation impairments are less severe. We propose and evaluate low-power DSP-free homodyne coherent receiver architectures for dual-polarization quadrature phase shift keying (DP-QPSK) for inter- and intradata center links. We propose a novel optical polarization demultiplexing technique, for DP-QPSK and higher-order modulation formats, with three cascaded phase shifters driven by marker tone detection circuitry. We consider carrier recovery based on either optical or electrical phase-locked loops (PLLs). We propose a novel multiplier-free phase detector based on XOR gates, which exhibits less than 0.5 dB power penalty relative to a conventional Costas loop phase detector. We also study the relative performance of homodyne DP-differential QPSK, for which carrier phase recovery is unnecessary. Our proposed DSP-free architectures exhibit ~1 dB power penalty at small chromatic dispersion compared to their DSP-based counterparts. We estimate conservatively that the high-speed analog electronics of an electrical PLL-based coherent receiver consume nearly 4 W for 200 Gbit/s DP-QPSK, assuming a 90-nm complementary metal-oxide semiconductor process.
Autors: Jose Krause Perin;Anujit Shastri;Joseph M. Kahn;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4650 - 4662
Publisher: IEEE
 
» Design of Plug-In Electric Vehicle's Frequency-Droop Controller for Primary Frequency Control and Performance Assessment
Abstract:
This paper describes a novel strategy to design the frequency-droop controller of plug in electric vehicles (PEVs) for primary frequency control (PFC). To be able to properly compare the frequency response of control system with and without PEVs, the design is done to guarantee the same stability margin for both systems in the worst case scenario. To identify the worst case, sensitivity analyses are conducted on a large set of system parameters performing eigenvalue analysis and bode plots. Three main contributions are included in this work: 1) we demonstrate that PEVs using the well-design droop controller significantly improve the PFC response while successfully preserving the frequency stability, 2) since the fast response of PEVs may cause to mask the governor-turbine response in conventional units, a novel control scheme is developed to replace some portion of PEV's reserve after a certain time by the reserve of conventional units during PFC, and 3) a method is proposed to evaluate the positive economic impact of PEV's participation in PFC. For the latter, the system PFC cost savings mainly through the avoidance of under frequency load shedding by PEVs are calculated. A large-scale power system and an islanded network are evaluated and compared through dynamic simulations, which illustrate the validity and effectiveness of the proposed methodologies.
Autors: Seyedmahdi Izadkhast;Pablo Garcia-Gonzalez;Pablo Frías;Pavol Bauer;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4241 - 4254
Publisher: IEEE
 
» Design of Position Estimation Strategy of Sensorless Interior PMSM at Standstill Using Minimum Voltage Vector Injection Method
Abstract:
This paper presents a new initial rotor position estimation method for an interior permanent magnet synchronous motor. The proposed method includes two steps. First, the minimum voltage vectors are injected to estimate the rotor position. Second, in order to identify the magnet polarity accurately, two opposite voltage pulses are injected on the estimated d-axis. In the proposed method, no filter is needed to draw the high frequency current signal for position estimation and no low-pass filter is required in the current control loop for extracting the fundamental current component for field-oriented control. The fast and reliable feature of this proposed method allows starting the motor with 100% load torque. The effectiveness of the proposed method is verified experimentally and the maximum position estimation error is around 6 electrical degrees.
Autors: Xuan Wu;Shoudao Huang;Xiao Liu;Kaiyuan Lu;Jian Gao;Jian Zheng;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 

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