Electrical and Electronics Engineering publications abstract of: 11-2017 sorted by title, page: 7

» Dual Capacity Upper Bounds for Noisy Runlength Constrained Channels
Abstract:
Binary-input memoryless channels with a run length constrained input are considered. Upper bounds to the capacity of such noisy run length constrained channels are derived using the dual capacity method with Markov test distributions satisfying the Karush-Kuhn-Tucker conditions for the capacity-achieving output distribution. Simplified algebraic characterizations of the bounds are presented for the binary erasure channel and the binary symmetric channel. These upper bounds are very close to achievable rates, and improve upon previously known feedback-based bounds for a large range of channel parameters. For the binary-input additive white Gaussian noise channel, the upper bound is simplified to a small-scale numerical optimization problem. These results provide some of the simplest upper bounds for an open capacity problem that has theoretical and practical relevance.
Autors: Andrew Thangaraj;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7052 - 7065
Publisher: IEEE
 
» Dual Delta Bank TCR for Harmonic Reduction in Three-Phase Static Var Controllers
Abstract:
The conventional “Delta” connected thyristor-controlled reactor (TCR) bank used for static var compensation and other applications is proposed to be split into two identical “Delta” banks each having kvar capacity half of the total TCR capacity. The study presented shows that such combination of two identical “Delta” connected reactor banks, one with phase switching by thyristors and the other with line switching thyristor arrangement can effectively reduce the harmonic generation of the TCR. Since both the three-phase banks are connected in delta, the zero sequence triplen harmonics generated due to phase control of thyristors remain trapped inside the delta, thus reducing the harmonic injection into the power system. Further, some other major characteristic harmonics are also minimized in the TCR line current. Thus, the proposed TCR yields a low current THD which meets the requisite harmonics standards and it can therefore be used as an economic solution for reactive power control over a reasonable range in high power grid without using any external harmonic filter or special phase shifting transformer. This paper describes in detail the modeling, analysis, and performance assessment of the proposed scheme. Simulation results are furnished to evaluate the output characteristics of the scheme under varying operating conditions. Finally, experimental results are presented, which proves the theoretical proposition.
Autors: Susovan Mukhopadhyay;Dipten Maiti;Ambarnath Banerji;Sujit K. Biswas;Nirmal K. Deb;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5164 - 5172
Publisher: IEEE
 
» Dual Tuning of Doubly Hybridized Spin-Electromagnetic Waves in All-Thin-Film Multiferroic Multilayers
Abstract:
Theoretical investigation of dual (electric and magnetic) tuning of dispersion characteristics has been studied for the doubly hybridized spin-electromagnetic waves (SEWs) propagating perpendicularly to the direction of static magnetization in tangentially magnetized all-thin-film multiferroic multilayers. The multilayers consisted of two thin ferrite films separated by a thin ferroelectric film. The SEW spectrum was formed as the result of the double hybridization among one electromagnetic mode and two spin-wave modes. Such hybridization took place if the initial dispersion characteristics of these modes were degenerated. The electric tuning was realized owing to the changing of the magneto-dipole interaction between the magnetic films caused by a variation of dielectric constant of the ferroelectric film. It was shown that a decrease in permittivity of the ferroelectric film of micrometer thickness by a factor of two induces change of the SEW wavenumber up to tens of radian per centimeter.
Autors: Aleksei A. Nikitin;Vitaliy V. Vitko;Andrey A. Nikitin;Alexandr V. Kondrashov;Alexey B. Ustinov;Alexander A. Semenov;Erkki Lähderanta;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Dual-Band Magnetoelectric Dipole Antenna With Dual-Sense Circularly Polarized Character
Abstract:
In this paper, a dual-band dual-sense circularly polarized (CP) magnetoelectric dipole antenna is proposed. The antenna consists of a cavity reflector, two pairs of vertical and horizontal copper plates, and a crossed -shaped feeding structure. The shorted vertical plates work as quasi-magnetic dipoles (M-dipoles), while the connected horizontal plates work as electric dipoles (E-dipoles). Two M-dipoles and E-dipoles are designed to possess different heights and lengths, and thus they are able to achieve separate operation bands. To generate dual-sense CP performance, the M-dipoles and E-dipoles are placed in parallel and the adjacent E-dipoles extend along the opposite directions. Benefiting from the intrinsic 90° phase difference between the M-dipole and E-dipole, the left-hand CP is achieved within the lower operation band (2.15–3.4 GHz) and the right-hand CP is achieved within the upper band (4–6.3 GHz). The proposed antenna possesses a unidirectional radiation pattern with high front-to-back ratio ( dB). Furthermore, high gain ( dBi) and radiation efficiency (%) are also achieved.
Autors: Jun Tao;Quanyuan Feng;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 5677 - 5685
Publisher: IEEE
 
» Dual-Band Microstrip Balun With Flexible Frequency Ratio and High Selectivity
Abstract:
A new planar microstrip balun with two operation bands is presented and investigated in this letter. Originated from the traditional Marchand balun, the proposed dual-band balun is designed on a symmetrical four-port network with one short-circuited port. Derived equations and design charts show that the frequency ratio () of these two bands could be flexibly controlled in a wide range of 2.0–4.6. Moreover, inherent transmission zeros nearby each band have been introduced into this dual-band balun, aiming to improve the frequency selectivity. For verification, a prototype dual-band balun operating at 2.4 and 5.2 GHz () is implemented and measured. Both simulation and measured results are recorded with good agreement.
Autors: Feng Huang;Jianpeng Wang;Lei Zhu;Quangang Chen;Wen Wu;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 962 - 964
Publisher: IEEE
 
» Dual-Band Orthogonally Polarized Single-Layer Reflectarray Antenna
Abstract:
Design and implementation of a dual-band and orthogonally polarized single-layer microstrip reflectarray are presented in this communication. The proposed reflectarray operates in two separated broad frequency bands within - and -bands. The reflectarray element consists of a circular patch surrounded by a microstrip ring. Two curved phase delay lines are attached to the patch and two curved phase delay lines are attached to the ring. The ring and patch are designed for the operation at - and -bands, respectively. Phase delay lines attached to the ring are spatially rotated by 90° with respect to the delay lines attached to the patch. This produces a linear polarization at -band, which is perpendicular to the linear polarization produced at -band. This also provides a high polarization isolation, which enables by adjusting the phase of the elements at each band independent of the phase at the other bands. At both operation bands, the required phase shifts are obtained by varying the lengths of the phase delay lines. The proposed element provides more than 450° linear phase range over the bands 8.7–10.7 GHz (-band) and 18–20.4 GHz (-band). Measurement results show the maximum gain of 27.7 dB at 9.7 GHz with 25% 1 dB gain bandwidth and the maximum gain of 31.8 dB at 19.2 GHz wit- 18% 1 dB gain bandwidth. By proper arrangement of the elements in the array, the cross polarization is reduced. The measured efficiency is 63% at 9.7 GHz and 42% at 19.2 GHz with a center-fed design for the reflectarray.
Autors: R. Shamsaee Malfajani;B. Abbasi Arand;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6145 - 6150
Publisher: IEEE
 
» Dual-Layer Dielectric Stack for Thermally Isolated Low-Energy Phase-Change Memory
Abstract:
High reset energy is an ongoing issue for phase-change memory (PCM) devices. Prior work demonstrates that smaller PCM switching volume and thermal isolation can reduce the reset energy. In this paper, we fabricate and measure a planar confined PCM device with a multilayer dual-layer stack (DLS) of SiO2/Al2O3 insulator. Devices with contact area of 500 20 nm and lengths of show exceptionally low reset energies of 18.25 ± 15.8 pJ and low reset current densities of 0.94 ± 0.51 MA/cm2. Implementing the DLS enables a 60% reduction in reset energy compared with SiO2-isolated devices.
Autors: Scott W. Fong;Christopher M. Neumann;Eilam Yalon;Miguel Muñoz Rojo;Eric Pop;H.-S. Philip Wong;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4496 - 4502
Publisher: IEEE
 
» Dual-Port Planar Antenna for Implantable Inductively Coupled Sensors
Abstract:
Passive implantable sensors have received considerable attention for wireless in vivo measurement of physiological parameters in challenging locations of the human body. They are considered promising alternatives to the existing catheter-based biomedical transducers and battery powered implants. In this paper, we report a novel planar reader antenna for wireless interrogation of -based passive implantable sensors. The antenna utilizes two planar, electromagnetically isolated loops for wireless detection of the resonance frequency of the sensors. 2-D and 3-D versions of the antenna with the identical geometry were developed for a comparative study. A comprehensive analysis of the antenna together with in vitro evaluation of the antenna performance is presented. With the proposed antenna topology, the isolation level of 58 dB within the frequency range of 1–50 MHz, and at least 37 dB up to 100 MHz was achieved. The 3-D version of the antenna demonstrated improved performance by the T/R isolation of at least 64 and 44 dB within the frequency bands of 1–50 and 50–100 MHz, respectively.
Autors: Mohammad H. Behfar;Lauri Sydänheimo;Shuvo Roy;Leena Ukkonen;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 5732 - 5739
Publisher: IEEE
 
» Duration-Variable Participant Recruitment for Urban Crowdsourcing With Indeterministic Trajectories
Abstract:
For urban crowdsourcing applications, the data sensing tasks can be achieved by vehicles traveling on the roads, which can save the expenses on constructing dedicated infrastructures. In this paper, to efficiently handle the crowdsourcing recruitment problem, we propose to recruit participants with the duration-variable principle and prove that it performs better compared to the strategy that recruits vehicles for all required time periods. The duration-variable principle enables recruitment of vehicular sensing resources across different time epochs to maximize the crowdsourcing profits. To ensure the utilization of limited budget, we formulate the duration-variable participant recruitment (DPR) problem with the consideration of indeterministic trajectories to determine which vehicle subset is chosen and how many epochs are provided for each selected vehicle. Since the formulated problem is NP-hard, we propose a two-step DPR algorithm by maximizing the available sensing resource utilization efficiency in each recruitment round, which is shown to be near-optimal and has low computational complexity. Experiments on real traces show that the proposed DPR scheme exceeds three other solutions in providing higher spatial coverage for urban crowdsourcing applications.
Autors: Miao Hu;Zhangdui Zhong;Yong Niu;Minming Ni;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10271 - 10282
Publisher: IEEE
 
» DVFS-Based Long-Term Task Scheduling for Dual-Channel Solar-Powered Sensor Nodes
Abstract:
Solar-powered sensor nodes (SCSNs) with energy storages have the greatest potential and are widely used in the coming era of the Internet of Things, since they avoid tedious battery maintenance tasks. However, because the solar energy source is unstable and limited, the sensor nodes suffer from high deadline miss ratio (DMR). To achieve better DMR, the existing scheduling algorithms find the best scheduling scheme in a single period of the recurring task queue and, hence, ignore the long-term performance. To tackle this challenge, this paper proposes a three-level dynamic voltage–frequency scaling (DVFS)-based scheduling strategy to minimize long-term DMR for dual-channel SCSNs. This approach includes a day-level scheduler to achieve a coarse-grained task arrangement, two artificial neural networks to determine the task priorities, and a DVFS-based task selection algorithm for slot-level execution. Experiments show that the proposed scheduler reduces DMR by over 30% on average.
Autors: Tongda Wu;Yongpan Liu;Daming Zhang;Jinyang Li;Xiaobo Sharon Hu;Chun Jason Xue;Huazhong Yang;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 2981 - 2994
Publisher: IEEE
 
» Dynamic Analysis of High-Speed Three-Degree-of-Freedom Electromagnetic Actuator for Image Stabilization
Abstract:
Recently, a high-quality image has been obtained by a video camera because of its improved imaging performance. However, image quality deteriorations due to vibration have become a problem. In order to solve this problem, various image stabilization technologies have been developed. A lens-unit-swing system which consists of a lens and an imaging device is one of the image stabilization technologies that generate an inverse motion and correct images from camera shakes over a wide range of rotation angles around three axes. However, the lens-unit-swing system has some problems such as an increase in size and weight. On the other hand, recently, various multiple-degree-of-freedom (DOF) actuators have been developed. These actuators are expected to simplify the system. In this paper, we propose a high-speed three-DOF electromagnetic actuator for image stabilization which can be controlled by a simple control system. The basic structure and operating principle of the actuator are described. Moreover, the frequency characteristics are calculated by the transfer function and 3-D finite-element method. In addition, the dynamic characteristics under the position feedback control are analyzed and the effectiveness of the actuator is verified.
Autors: Akira Heya;Katsuhiro Hirata;Noboru Niguchi;Takamichi Yoshimoto;Tomohiro Ota;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Dynamic Capability and Firm Performance: The Role of Marketing Capability and Operations Capability
Abstract:
Scholars have argued that dynamic capability can influence firm performance through a variety of means and mechanisms. However, the empirical test of the relationship between dynamic capability, marketing capability, and operations capability on firm performance has remained scant. We contribute to resolving this issue by proposing a research model that links dynamic capability with marketing and operations capabilities on new product development performance specifically and firm performance generally. First, the model suggests that marketing capability and operations capability act as mediating mechanisms that transmit the positive influences of dynamic capability to new product development performance specifically and firm performance generally. Second, the model proposes the relationship between marketing capability, operations capability, and firm performance (new product development performance) be stronger if firms have adequate dynamic capability. Drawing on a dataset of multiyear longitudinal survey data of Chinese high-tech firms, we find support for the proposed model. The findings help us better explain the different ways in which dynamic capability affect performance.
Autors: Jifeng Mu;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 554 - 565
Publisher: IEEE
 
» Dynamic Control Allocation for Damping of Inter-Area Oscillations
Abstract:
Use of actuator redundancy to achieve higher reliability is a widely accepted engineering design technique and is used in this study to build resiliency and ensure power system stability in the presence of high levels of renewables. This paper presents a new design method for fault-tolerant wide-area damping controllers (WADCs) using modal-based control allocation (MB-CA), which coordinates a set of actuators to contribute to damping of inter-area oscillations. In our proposed method, when an actuator fails or is unavailable (e.g., due to communication failure), the supervisory MB-CA distributes the control signals to the remaining healthy actuators based on effects on the modal system, desired control actions, and actuator constraints. Our proposed block offers the benefits of modular design where it is independent of the nominal WADC. The proposed method consists of mainly two design steps. The first step is to design a WADC based on a fault-free model using robust control methods. The second step is to design an MB-CA to manage actuator availability and constraints. To validate the feasibility and demonstrate the design principles, a set of comprehensive case studies are conducted on a modified 192-bus Western Electricity Coordinating Council system. Numerical results verify the effectiveness of the proposed approach in ensuring resiliency to different actuator failures and actuator availability.
Autors: M. Ehsan Raoufat;Kevin Tomsovic;Seddik M. Djouadi;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4894 - 4903
Publisher: IEEE
 
» Dynamic Magnetization Properties of Platelet Ferromagnetic Nanoparticles and Their Heat Generation Injected in Tumors of Mice
Abstract:
Development of high-heat-generating materials is essential for magnetic nanoparticle hyperthermia therapy. As a candidate, oval platelet Fe oxide nanoparticles of sizes 30–100 nm were synthesized, and their surfaces were decorated with tetraethylene glycol block polymer. The water-based suspension showed good dispersion properties, suggesting high applicability for medical usage. High-frequency hysteresis measurement, which is helpful for understanding the mechanism of specific loss power, was carried out at the same frequency and magnetic field amplitude () range as heating. Frequency-independent ferromagnetic hysteresis was observed, and this supported the ferromagnetic heating mechanism. The suspension was directly injected into the cancerous tumor of mice and subjected to 114 kHz alternating current magnetic field below 51 kA/m, which was sufficient for elevating the local temperature to approximately 50 °C. The tumor size decreased upon heating at an early stage and was restored to nearly the original size after 14 days. Distinguished differences were observed between the platelet Fe and superparamagnetic particles with respect to temperature rise and the resulting damaging effects to the tumor.
Autors: Eiji Kita;Hideto Yanagihara;Mikio Kishimoto;Kouji Ota;Ryoichi Miyamoto;Tatsuya Oda;Nobuhiro Ohkohchi;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Dynamic Phasor Estimation Through DSTKF Under Transient Conditions
Abstract:
This paper presents a double suboptimal-scaling-factor adaptive strong tracking Kalman filter (DSTKF)-based phasor measurement unit algorithm which can meet the accuracy requirement of the IEEE standard C37.118.1 under the dynamic condition. This method uses a kth Taylor polynomial to linearize the complex exponential of the signal model, and estimates the dynamic phasor using DSTKF. The antialias filter unit for DSTKF algorithm is included to suppress high-order harmonics which will augment computing burden. By applying double suboptimal-scaling factors, DSTKF adjusts the process noise covariance matrix and the prediction covariance matrix in real time. Thereafter, amplitude and frequency measurement performances under various dynamic conditions are assessed in detail. Theoretical analysis and comprehensive experimental results validate the effectiveness of the proposed method.
Autors: Chun Huang;Xing Xie;Hui Jiang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2929 - 2936
Publisher: IEEE
 
» Dynamic Resizing on Active Warps Scheduler to Hide Operation Stalls on GPUs
Abstract:
This paper conducts a detailed study of the factors affecting the operation stalls in terms of the fetch group size on the warp scheduler of GPUs. Throughout this paper, we reveal that the size of a fetch group is highly involved for hiding various types of operation stalls: short latency stalls, long latency stalls, and Load/Store Unit (LSU) stalls. The scheduler with a small fetch group cannot hide short latency stalls due to the limited number of warps in a fetch group. In contrast, the scheduler with a large fetch group cannot hide long latency and LSU stalls due to the limited number of fetch groups and the lack of memory subsystems, respectively. To hide various types of stalls, this paper proposes a Dynamic Resizing on Active Warps (DRAW) scheduler which adjusts the size of a fetch group dynamically based on the execution phases of applications. For the applications that have the best performance at LRR (one fetch group), the DRAW scheduler matches the performance of LRR and outperforms TL (multiple fetch groups) by 22.7 percent. In addition, for the applications that have the best performance at TL, our scheduler achieves 11.0 and 5.5 percent better performance compared to LRR and TL, respectively.
Autors: Myung Kuk Yoon;Yunho Oh;Seung Hun Kim;Sangpil Lee;Deokho Kim;Won Woo Ro;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3142 - 3156
Publisher: IEEE
 
» Dynamic Scheduling Decoding of LDPC Codes Based on Tabu Search
Abstract:
The informed dynamic scheduling (IDS) strategy decoding algorithms performed exceptionally well for low-density parity-check codes in terms of the error-rate performance. However, the IDS decoding algorithm is greedy because of the unfair computation resources allocation among different variables nodes, which leads to poor convergence performance. In order to reduce the greediness of the IDS algorithm, the tabu search (TS) algorithm is introduced to the dynamic scheduling-based decoding in this paper. In the TS-based dynamic scheduling (TSDS) algorithm, the variable nodes in the Tanner graph are temporarily stored in a tabu list. In the decoding process with the TSDS algorithm, variable nodes stored in the tabu list will not be selected and updated until they are shifted out of the tabu list. Besides, an improved updating order is provided for the TSDS algorithm, by which the computational complexity can be decreased without the loss of error correction performance. Simulation results show that the proposed algorithm outperforms other decoding algorithms of interest in terms of bit error rate and convergence performance over the additive white Gaussian noise channel.
Autors: Xingcheng Liu;Chunlei Fan;Xuechen Chen;
Appeared in: IEEE Transactions on Communications
Publication date: Nov 2017, volume: 65, issue:11, pages: 4612 - 4621
Publisher: IEEE
 
» Dynamic State Aware Adaptive Source Coding for Networked Control in Cyberphysical Systems
Abstract:
A source coding (quantization) scheme is studied for the feedback of discrete-time and continuous-state cyber-physical systems (CPSs). It is formulated as a sequential coding optimization problem. The goal is to find a deterministic but adaptive policy, as a series of mappings from the historical information to the quantization strategy. In particular, an optimization problem is formulated, and then solved by the Bellman equation in dynamic programming (DP). To overcome the challenge of continuous state space, a practical solution is proposed by leveraging the approximate DP (ADP). The performance of the proposed strategy is examined for both scalar and vector dynamical systems in two practical applications. It shows that the designed policy can significantly outperform the simple fixed quantization strategies in CPSs and can be applied to the mobile/vehicle communication.
Autors: Liang Li;Ju Bin Song;Husheng Li;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10000 - 10010
Publisher: IEEE
 
» Dynamically Adaptable Software Is All about Modeling Contextual Variability and Avoiding Failures
Abstract:
Contextual-variability modeling is integral to dealing with dynamically adaptable software. Several techniques support this task using dynamic-software-product-line engineering, which enables runtime management of software variants. In particular, context-aware feature modeling (CFM) has been considered suitable for dealing with contextual variability. However, it has limited expressiveness to specify real-world constraints related to context information. To tackle this limitation, this article proposes eCFM, an extended form of CFM. In addition, it presents an approach using eCFM and model checking to identify common design faults that could lead to runtime failures. A comparison of CFM and eCFM showed that eCFM was more expressive and easier to use.
Autors: Ismayle de Sousa Santos;Magno Luã de Jesus Souza;Michelle Larissa Luciano Carvalho;Thalisson Alves Oliveira;Eduardo Santana de Almeida;Rossana Maria de Castro Andrade;
Appeared in: IEEE Software
Publication date: Nov 2017, volume: 34, issue:6, pages: 72 - 77
Publisher: IEEE
 
» Dynamics of Laser-Induced Magnetostructural Phase Transitions in MnAs/GaAs (001) Epitaxial Layers
Abstract:
We have investigated by time-resolved X-ray diffraction the manganese arsenide structure dynamics in MnAs/GaAs (001) epitaxial films, when the magnetostructural phase transition is triggered by an ultra-fast optical laser pulse. Understanding the photo-induced phase transition dynamics is relevant for applications of MnAs/GaAs (001) as a magnetically active template in laser-induced magnetization switching processes. The main goal of our experiment is to determine the timescales of the structural changes that are likely to play a role in laser-driven magnetization reversal.
Autors: Lounès Lounis;Yunlin Zheng;Carlo Spezzani;Eugenio Ferrari;Mahmoud Edrrief;Alessandra Ciavardini;Horia Popescu;Enrico Allaria;Claire Laulhé;Franck Vidal;Maurizio Sacchi;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Early Fault Diagnosis of Rotating Machinery by Combining Differential Rational Spline-Based LMD and K–L Divergence
Abstract:
First, an improved local mean decomposition (LMD) method called differential rational spline-based LMD (DRS) is developed for signal decomposition. Differential and integral operations are introduced in LMD, which can weaken the mode mixing problem. Meanwhile, an optimized rational spline interpolation is proposed to calculate the envelope functions aiming to reduce the large errors caused by moving average in the traditional LMD. A series of product functions (PFs) is obtained after the application of the proposed DRS-LMD. Then, Kullback-Leibler (K-L) divergence is adopted to select main PF components that contain most fault information. The machine fault can be easily identified from the amplitude spectrum of the selected PF component. The effectiveness of the proposed DRS-LMD and K-L strategy is tested on simulated vibration signals and experimental vibration signals. Results show that the proposed method can increase the decomposition accuracy of the signals and can be used to detect early faults on the gears and rolling bearings.
Autors: Yongbo Li;Xihui Liang;Yuantao Yang;Minqiang Xu;Wenhu Huang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 3077 - 3090
Publisher: IEEE
 
» Economic, Environmental, and Social Impact of Remanufacturing in a Competitive Setting
Abstract:
This paper studies the environmental and social trade-offs of remanufacturing for product+service firms under competition. We use an analytical model and a behavioral study that together incorporate demand cannibalization from multiple customer segments across the competing firms’ product lines. We measure firms’ profits, consumer surpluses, environmental impacts, and environmental costs along the products lifecycles in the resultant equilibria with and without remanufacturing. We show that competition intensifies the tension between increased profit and worsened environmental impact from market expansions caused by remanufacturing identified by prior research in the case of monopoly. However, bringing in the social dimension leads to an overall positive assessment: remanufacturing creates additional consumer surplus, which compensates for the cost of the environmental impact. In other words, we found strong support that remanufacturing is beneficial for the society.
Autors: Gal Raz;Anton Ovchinnikov;Vered Blass;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 476 - 490
Publisher: IEEE
 
» Economics- and Reliability-Based Design for an Offshore Wind Farm
Abstract:
This study examines the optimal layout of an offshore wind farm for a fixed number of wind turbines (WTs) and a fixed area of coverage. After the optimal layout of the turbines is determined, the topology of the cable connections is optimized. The wind decay that is associated with the wake effect is considered and the charged system search algorithm is utilized to obtain the optimal WT layout that maximizes the power output of the wind farm. The Wind Atlas Analysis and Application Program software is utilized to verify the optimality of the layout. Mixed integer linear programming is utilized to optimize the topology of radial cable connections. The system reliabilities of the proposed layout and the traditional regular layout are considered. Finally, the optimal wind-farm layout that maximizes wind power output, minimizes cable cost, and maximizes reliability is obtained.
Autors: Yuan-Kang Wu;Po-En Su;Yu-Sheng Su;Ting-Yi Wu;Wen-Shan Tan;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5139 - 5149
Publisher: IEEE
 
» Eddy Current Brake With a Two-Layer Structure: Calculation and Characterization of Braking Performance
Abstract:
This paper presents a new method for calculating the braking force of a drum-type eddy current brake with a two-layer structure. The drum-type eddy current brake should have a structure that improves the braking force by applying a material with high conductivity inside the drum because the eddy current loss generated from the drum is used as the braking force. In addition, because the eddy current brake operates at various speeds while braking the vehicle, it is necessary to grasp the braking force according to the speed. Furthermore, because the material of the drum is composed of non-laminated iron having conductivity, the skin effect and the armature reaction phenomenon appear, and the skin depth and the air-gap flux density are different depending on the braking speed. In this paper, the value of the eddy current loss of the eddy current brake with a copper coating inside the drum is newly presented and compared with the finite-element analysis results. In addition, the change in the speed–torque curve according to the conductivity value of the drum and inner coating material are shown. Finally, an experiment was conducted to compare and verify the characteristic curve of the eddy current brake obtained from the newly derived equations.
Autors: Sooyoung Cho;Huai-Cong Liu;Hanwoong Ahn;Ju Lee;Hyung-Woo Lee;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Eddy Current Non-Destructive Evaluation for Healthiness of Radiator Structure
Abstract:
This paper presents a non-destructive evaluation study on a radiator with cooling fins as a kind of complex shaped specimen. An eddy current testing method, namely multi-frequency excitation and spectrogram method, was employed to detect a removal of radiator cooling fin. Experimental results brought remarkable signal when a fin was removed. Furthermore, the authors discuss the relation between the fin signal and specimen thickness, and concludes the availability for the estimation of thickness of radiator structures.
Autors: Shoichiro Nagata;Masaaki Numachi;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Editor's Note
Abstract:
Autors: Elisa Bertino;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Nov 2017, volume: 14, issue:6, pages: 577 - 577
Publisher: IEEE
 
» Editor's Note
Abstract:
Autors: Nei Kato;
Appeared in: IEEE Network
Publication date: Nov 2017, volume: 31, issue:6, pages: 2 - 2
Publisher: IEEE
 
» Editorial
Abstract:
In February 2017 Science magazine reported widespread concern among US graduate programs in engineering over the "sharp drop this year in the number of applications from international students." The cause of the observed drop was suspected to be the anti-immigrant rhetoric of President Donald Trump during his campaign and election. The Council of Graduate Schools is still in the process of compiling final statistics on international applications for 2017, but this potential recruiting crisis has prompted me to reflect upon the highly intricate nature of graduate education in the United States, from my perspective.
Autors: Nicola Bowler;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Nov 2017, volume: 33, issue:6, pages: 4 - 5
Publisher: IEEE
 
» Editorial 2016 Best Paper Award
Abstract:
High quality scholarship requires technical excellence but also connects the work to the primary references in the field. In this way the reader advances their knowledge and gains perspective. The Transactions on Semiconductor Manufacturing supports these goals by recognizing the best paper chosen by the Associate Editors and reviewers. The winning paper was selected from 51 papers published by TSM in 2016. The winner is “Risk-Controlled Product Mix Planning in Semiconductor Manufacturing Using Simulation Optimization” by Dr. Kuo-Hao Chang published in the November 2016 issue of IEEE Transactions on Semiconductor Manufacturing (10.1109/TSM.2016.2602388). Dr. Chang is a professor of Industrial Engineering and Engineering Manufacturing at National Tsing Hua University in Hsinchu, Taiwan. The paper applies a method developed in another domain to find the optimal product mix in a semiconductor manufacturing line. On behalf of the associate editors, I congratulate Dr. Chang on being selected.
Autors: Anthony J. Muscat;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Nov 2017, volume: 30, issue:4, pages: 314 - 314
Publisher: IEEE
 
» Editorial for November 2017 Issue
Abstract:
This issue of the IEEE Transactions on Engineering Management includes 15 research articles. The relevance and usefulness of the articles is summarized. In addition, various Society-related matters are announced.
Autors: Rajiv Sabherwal;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 433 - 436
Publisher: IEEE
 
» Editorial Kudos to Our Reviewers
Abstract:
The people that we depend on to review the manuscripts published in the Transactions on Semiconductor Manufacturing ensure that work of the highest quality ends up in each finished paper. Often this requires multiple detailed readings of a manuscript separated by several weeks from one another. The reviewers are all recognized experts in their fields. Despite the demands to fulfill the duties of their employers they set aside time to support the broad dissemination of the latest results on factory and manufacturing integration, process control, yield enhancement and modeling, metrology, photolithography, factory modeling and control, and equipment technology—all of the areas that go into a modern semiconductor manufacturing facility. I personally thank all of the contributions that our reviewers have made in 2017. We would not have a journal that is a leading source of information on semiconductor manufacturing without this selfless effort.
Autors: Anthony J. Muscat;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Nov 2017, volume: 30, issue:4, pages: 313 - 313
Publisher: IEEE
 
» EEG-Based User Reaction Time Estimation Using Riemannian Geometry Features
Abstract:
Riemannian geometry has been successfully used in many brain–computer interface (BCI) classification problems and demonstrated superior performance. In this paper, for the first time, it is applied to BCI regression problems, an important category of BCI applications. More specifically, we propose a new feature extraction approach for electroencephalogram (EEG)-based BCI regression problems: a spatial filter is first used to increase the signal quality of the EEG trials and also to reduce the dimensionality of the covariance matrices, and then Riemannian tangent space features are extracted. We validate the performance of the proposed approach in reaction time estimation from EEG signals measured in a large-scale sustained-attention psychomotor vigilance task, and show that compared with the traditional powerband features, the tangent space features can reduce the root mean square estimation error by 4.30%–8.30%, and increase the estimation correlation coefficient by 6.59%–11.13%.
Autors: Dongrui Wu;Brent J. Lance;Vernon J. Lawhern;Stephen Gordon;Tzyy-Ping Jung;Chin-Teng Lin;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2157 - 2168
Publisher: IEEE
 
» Effect of a Platinum Buffer Layer on the Magnetization Dynamics of Sputter Deposited YIG Polycrystalline Thin Films
Abstract:
The present investigation deals with the effect of thickness and a platinum (Pt) buffer layer on the dynamic magnetic properties of polycrystalline yttrium iron garnet (YIG) films fabricated after post-annealing to recrystallize from the amorphous state. The dynamic magnetic properties of films without a buffer layer deteriorate as the thickness decreases as indicated by the increased line-widths in the ferromagnetic resonance spectra. On the other hand, a strong rejuvenation in the static and dynamic magnetic properties of the films is observed when a Pt buffer layer is used. The Pt buffer layer decreases the Gilbert damping parameter from and for a 100 nm-thick YIG film. These observations mainly originate from controlling the microstructure or the surface morphology of the films.
Autors: Satya Prakash Pati;Muftah Al-Mahdawi;Yohei Shiokawa;Masashi Sahashi;Yasushi Endo;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Effect of Ammonium Chloride in Plating Baths on Soft Magnetic Properties of Electroplated Fe–Ni Films
Abstract:
We electroplated Fe–Ni films in plating baths with ammonium chloride (NH4Cl) and evaluated the magnetic properties of the films. The amount of NH4Cl did not affect the current efficiency of the plating process and the Fe content in the film. The obtained current efficiency of approximately 95% is much higher than our previous study. The coercivity dramatically decreased with increasing NH4Cl from 0 to 15 g/L, and we obtained Fe22Ni78 films with very low coercivity (10 A/m). The Cl concentration in the plating bath affected the coercivity, and we found that a plating bath with moderate low concentration of Cl is preferred for obtaining the Fe22Ni78 films with low coercivity.
Autors: T. Yanai;K. Koda;K. Eguchi;K. Takashima;T. Morimura;M. Nakano;H. Fukunaga;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 3
Publisher: IEEE
 
» Effect of Amorphous/Crystalline Material Doping on the Microstructure and Magnetic Properties of FePt Thin Films
Abstract:
The effects of various doping materials (amorphous phases: TiO2, SiO2, MgO, and C and crystalline phases: HfO2 and ZrO2) on the microstructure and magnetic properties of FePt thin films have been investigated. It is found that FePt films with amorphous doping materials especially MgO and C have better (001) texture and grain isolation than doping with crystalline materials. Nevertheless, doping with crystalline materials, FePt films were preferred to form columnar structures with a larger aspect ratio compared with semi-spherical grain shape for amorphous doping materials. Moreover, all the FePt-X films exhibit better perpendicular anisotropy except for FePt-ZrO2 films due to some FePt (200) textured films epitaxial grown directly on tetragonal (002) textured ZrO2. For crystalline materials doping, the (001) texture and perpendicular anisotropy could be improved by tuning crystalline oxide materials with appropriate lattice structure, which may offer a method for application in FePt in heat-assisted magnetic recording media.
Autors: K. F. Dong;F. Jin;W. Q. Mo;J. L. Song;W. M. Cheng;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effect of Annealing on Domain Wall Mass in Amorphous FeCoMoB Microwires
Abstract:
The effect of annealing on the domain wall mass in amorphous FeCoMoB microwires has been studied. Annealing at 300 °C for 1 h leads to the relaxation of strong stresses from production process and to the homogenization of its amorphous structure. As a result of such annealing, the domain wall mass decreases from kg in the as-cast state to kg in the annealed state, while the thickness of the domain wall exhibits opposite tendency and increases from 493 nm in the as-cast state to 808 nm in the annealed sample.
Autors: P. Klein;J. Onufer;J. Ziman;G. A. Badini-Confalonieri;M. Vazquez;R. Varga;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effect of Arbitrary Shear Stress on Vector Magnetic Properties of Non-Oriented Electrical Steel Sheets
Abstract:
The magnetic properties of electrical steel sheets, which are used as core materials in numerous electric-powered machines, tend to deteriorate due to residual stress and external loads during manufacturing processes. Previously, we reported our measurement results for the residual stress distribution in a motor core and clarified that sheer stress, along with tensile and compressive stress, exists in the core’s plate and surface, which makes it necessary to evaluate the magnetic properties of the core material under various stress conditions. In this paper, we report the results of an investigation into the effects of an arbitrary shear stress on the vector magnetic properties of a non-oriented electrical steel sheet under both alternating and rotating conditions.
Autors: Yuichiro Kai;Masato Enokizono;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effect of Buffer Layer Annealing on the Growth of (001)-Textured MnGa Ultrathin Films With Perpendicular Magnetic Anisotropy
Abstract:
The effect of buffer layer annealing on the growth of (001)-textured 3 nm thick MnGa films with perpendicular magnetic anisotropy (PMA) was investigated. The film stacking of Si/SiO2 substrate/MgO/Cr/CoGa/MnGa was fabricated by magnetron sputtering. It was found that the CoGa buffer layer crystallized with a (001) orientation and B2 chemical ordering even without any thermal treatments. Interestingly, the 3 nm thick MnGa grown on the un-annealed CoGa buffer layer showed PMA, indicating that the CoGa buffer layer promoted the growth of (001)-textured MnGa films with chemical ordering even without the annealing process. Annealing the CoGa buffer layer above 400 °C improved the (001) orientation of the CoGa buffer and MnGa layers. The effective PMA constant was about 4 Merg/cm3 without the annealing and was slightly reduced with increasing the annealing temperature, whereas the PMA dispersion was improved by the annealing. These results can help to obtain (001)-oriented MnGa ultrathin films with high PMA.
Autors: Kazuya Z. Suzuki;Atsuo Ono;Reza Ranjbar;Atsushi Sugihara;Shigemi Mizukami;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effect of Carbon Addition on Magnetic Order in Mn–Al–C Alloys
Abstract:
The near-equiatomic Mn–Al alloys are considered for possible applications as rare-earth-free permanent magnets due to the existence of a ferromagnetic -phase with crystal structure and other attractive physical properties. However, this tetragonal phase is metastable and can only be obtained from a hexagonal -phase enriched in manganese. The partial atomic disorder can results in antiferromagnetic coupling of the Mn atoms occupying different sublattices. Moreover, the carbon addition, used to improve phase stability and coercivity, leads to the deformation of the unit cell and can affect the Mn–Mn coupling. To clarify this question, a series of magnetic measurements and neutron diffraction (ND) experiments in a wide temperature range was carried out on the Mn55Al45 alloys doped with a small quantity of C. The materials were prepared by melt-spinning and subsequent annealing. Different methods of carbon introduction were tried, the best results were obtained by melting Mn and Al with Mn23C6. The structural and magnetic properties of the ferromagnetic and paramagnetic -phase as well as the precursor -phase were determined. The average magnetic moments on two sublattices were analyzed using the Weiss plot of the magnetometric data and the Rietveld refinement of the ND data. The dependence of the magnetic moments on the C content and temperature is reported. Ferrimagnetic behavior of the Mn–Al alloys with excess of manganese, caused by antiferromagnetic couplin- and responsible for the decrease of magnetization with increase of Mn content, was confirmed.
Autors: Muriel Tyrman;Alexandre Pasko;Loïc Perrière;Victor Etgens;Olivier Isnard;Frédéric Mazaleyrat;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Effect of Film Thickness on the High Frequency Magnetic Properties of Polycrystalline Fe–Ga Films
Abstract:
This paper describes the effect of film thickness on the high frequency magnetic properties of polycrystalline Fe–Ga films. The damping constant ( increases markedly from approximately 0.015 to 0.081 for a film thickness below 20 nm, reaches a maximum value of 0.084 at a thickness of 30 nm, and then decreases to 0.068 as the thickness further increases to 100 nm. All the values are much larger than those of a single crystal Fe–Ga film, indicating that the extrinsic damping overlaps with the intrinsic damping. The inhomogeneous broadening in a zero field [(0)] significantly increases with the film thickness due to the magnetic inhomogeneities, such as anisotropy dispersion and other effects. In addition, increases markedly as the saturation magnetostriction ( increases. This behavior is very similar to those of Ni–Fe and Ni–Fe–M films. Therefore, these results demonstrate that is correlated with regardless of the film thickness, and also sensitive to magnetic inhomogeneities.
Autors: Yasushi Endo;Takumi Sakai;Takamichi Miyazaki;Yutaka Shimada;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Effect of Finite Tunneling Magnetoresistance for the Switching Dynamics in the Spin Transfer Torque Magnetic Tunneling Junctions
Abstract:
We investigate the effect of tunneling magnetoresistance (TMR) on the spin transfer-torque (STT) switching behaviors in magnetic tunneling junctions. In most of the micromagnetic simulations for STT switching, a uniform current density has been assumed, which is not realistic in the high TMR devices. The local STT is proportional to the local current density, and the local current density will be determined by the local resistivity. Since higher than 150% of TMR values is required in the real STT-magnetoresistive random access memory devices, the local resistance is dramatically changed as a function of the relative spin orientation between the fixed and free layers under the constant voltage operation mode. By employing non-uniform current density in STT switching simulations using the “embedded object-oriented micromagnetic framework” scheme, we found that the details of switching behaviors such as switching time and critical current density are significantly influenced by the TMR values.
Autors: Chun-Yeol You;Hyungsuk Kim;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effect of Gamma-Ray and Neutron Heating as Interfering Input for the Measurement of Temperature Using Optical Fiber Sensor System
Abstract:
This paper accounts for gamma-ray and neutron heating of an optical fiber/capillary tube temperature sensor by including current sources in the fiber and capillary tube in the electrical analog of the capillary tube/fiber sensor system. The resulting model is examined to determine the conditions for which gamma-ray and neutron heating of the capillary tube/fiber sensor system is a significant interfering input for the measurement of the steady-state temperature of the medium in which the capillary tube/fiber sensor system is immersed, or the temperature of the component to which the capillary tube/fiber sensor system is attached. The model predicts that gamma-ray and neutron heating may result in a discrepancy, on the order of tens of degrees centigrade, in the sensed temperature, in comparison to the temperature of the medium, for a bare fiber in stagnant air for a power reactor. However, for the case of bonding of a capillary tube/fiber sensor system to metal, or the placement of the sensor in a liquid for which the heat transfer coefficient exceeds approximately , the discrepancy in the sensed temperature is predicted to be negligible for power reactor neutron and gamma-ray absorbed dose rates.
Autors: Thomas E. Blue;Brandon Augustus Wilson;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Nov 2017, volume: 64, issue:11, pages: 2774 - 2781
Publisher: IEEE
 
» Effect of Interface Trap Charges on Performance Variation of Heterogeneous Gate Dielectric Junctionless-TFET
Abstract:
In this paper, we investigate the effect of interface trap charges on the variation of heterogeneous gate dielectric junctionless-tunnel FET (JL-TFET) by introducing both donor and acceptor type of localized charges at the semiconductor/insulator interface. In this regard, we have analyzed dc and analog/RF performance parameters for conventional and heterogeneous gate dielectric JL-TFET (HD JL-TFET) in terms of electric field, transfer characteristics, transconductance (), output transconductance (), parasitic capacitances, device efficiency, cutoff frequency (), gain bandwidth product, and transconductance frequency product. Apart from these, linearity distortion parameters are also analyzed in the form of higher order transconductance coefficients (, , ), VIP2, VIP3, IMD3, and IIP3. For this, high-K gate dielectric material (HfO2) is used in the case of the HD JL-TFET to improve the performance of the device. All the simulations for both devices have been performed with the help of an ATLAS device simulator.
Autors: Sarthak Gupta;Kaushal Nigam;Sunil Pandey;Dheeraj Sharma;Pravin N. Kondekar;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4731 - 4737
Publisher: IEEE
 
» Effect of Magnetic Ordering on the Stability of Ni–Mn–Ga(–Co–Cu) Alloys Along the Tetragonal Deformation Path
Abstract:
The influence of magnetic ordering on the stability of Ni–Mn–Ga(–Co–Cu) Heusler alloys is investigated using the first-principles exact muffin-tin orbital method in combination with the coherent-potential approximation. The paramagnetic (PM) state is described by disordered local moment approach. In stoichiometric Ni2MnGa alloy, the total energy profile along the tetragonal deformation path differs between ferromagnetic (FM) ground state and PM state with high energy, where cubic structure of austenite exhibits lower total energy than tetragonally distorted structure of martensite. Martensitic structure is stabilized in ground state by FM interaction. In PM state it can be stabilized by partial substitution of Ni by Co or by partial substitution of Mn/Ga by Cu. Energy difference between PM and FM state can be used for qualitative estimation of Curie temperature . Since Co doping to Ni sublattice slightly increases , the should also increase, which corresponds to experimental findings. Analogically, Cu doping to Mn sublattice strongly decreases , which corresponds to strong decrease of , also confirmed experimentally. For Cu doping in Ga sublattice the decrease in is weaker.
Autors: Martin Zelený;Alexei Sozinov;Torbjörn Björkman;Ladislav Straka;Oleg Heczko;Risto M. Nieminen;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Effect of Nanogap-Based Light-Matter Colocalization on the Surface Plasmon Resonance Detection
Abstract:
A nanoscale gap aperture has been used as a fundamental tool for diverse applications. In this paper, we investigate the effect of nanogap aperture parameters on optical sensors, primarily based on surface plasmon resonance. A simple 2-D model was used for DNA immobilization and hybridization, in which nanogap enables light-matter colocalization to amplify detection signatures, thereby enhancing performance characteristics. Interestingly, the optimum gap geometry that produces maximum light-matter overlap and the largest resonance shift was not associated with the smallest gap size. Highest sensitivity was observed to correlate with negative resonance shift due to increased damping as well as the excitation of higher order surface plasmon polariton modes. Zero-shift nanogap was also discussed. The results suggest that careful design of nanogap apertures should be carried out to make the most of what they can achieve.
Autors: Changhun Lee;Eunji Sim;Donghyun Kim;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4721 - 4727
Publisher: IEEE
 
» Effect of Particle Shape, Density, and Inhomogeneity on the Microwave Optical Properties of Graupel and Hailstones
Abstract:
Atmospheric ice particles can be rimed and contaminated (e.g., by soot attachments). Previous optical property calculations usually assume rimed particles such as graupel and hailstones to be homogeneous spheres with fixed densities. The relevant dielectric constants are estimated with the effective medium approximation (EMA), although such particles are predominately nonspherical, porous, and contain small interior grains. This paper assesses the effects of nonsphericity, density, and inhomogeneity of graupel and hailstones on their optical properties. The bicontinuous medium approximation (BMA) is employed to simulate the particle internal structure. Conical shapes are compared with spherical and spheroidal shapes to assess the effect of nonsphericity. At frequencies lower than 89 GHz, the optical properties are more sensitive to particle’s mass density than to overall particle shape, and the internal structure plays an insignificant role when the particle effective diameter (a quantity involving the particle size distribution) is smaller than approximately 10 mm, and the internal grain size is smaller than 0.2 mm. With a small grain size, the BMA phase function converges to the EMA phase function with an effective refractive index calculated with the Bruggeman formulation. Simulated top of atmosphere radiances at three microwave frequencies, 18.7, 36.5, and 89 GHz, are quite sensitive to ice particle effective diameter between 1 and 5 mm, ice fraction between 0.1 and 0.9, and ice water path between 1 and 5 kg/. Thus, these frequencies are suitable for retrieving the microphysical properties.
Autors: Guanglin Tang;Ping Yang;Patrick G. Stegmann;R. Lee Panetta;Leung Tsang;Benjamin Johnson;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6366 - 6378
Publisher: IEEE
 
» Effect of Pole–Slot Combination on Eddy-Current Formation in PMSM Rotor Assembly Including Retaining Plate Structure
Abstract:
The results of the 3-D finite-element method electromagnetic analysis of the constant speed variable output permanent magnet synchronous motor including the rotor retaining plate structure confirmed that the eddy current flow was induced in the rotor part. Eddy current flows from the permanent magnet to the rotor retaining plate, and it was found that there is induced voltage that generates eddy currents in the retaining plate from the aspect of eddy-current distribution. The eddy current flow from the permanent magnet to the retaining plate is related to the change in magnetic resistance during rotation and is also related to the effect of slot harmonics on the air-gap magnetic flux density. In this paper, the characteristics of the eddy current flow in the rotor assembly were investigated when the retaining plate is included for various slot combinations. The eddy-current generation according to the slot combination is analyzed and the cause of such tendency was investigated. Furthermore, from the pattern of eddy-current formation, it was noted that the aperiodic pole–slot combination models may have a larger eddy-current loss increase when combined with the retaining plate.
Autors: Hyun-Woo Jun;Hyun-Soo Seol;Ju Lee;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Effect of Position Sensor Error on the Performance of Permanent Magnet Machine Drives
Abstract:
Accurate knowledge of motor position is required in the motor drive application where smooth torque performance is needed. The error in position causes ripple in the developed current and thereby produce torque ripple. This paper analyzes the various effects of position sensor error in the current developed and in the torque generated in a current controlled permanent magnet synchronous motor drive. This research is focused on analyzing effect of position error on smooth production of torque in an interior permanent magnet synchronous motor (IPMSM) drive due to various inaccuracies. The analysis is verified through simulation and test results by measuring torque and torque ripple performances of an IPMSM drive. The results can be easily extended to surface mount permanent magnet motor drive also.
Autors: Ramakrishnan Raja;Tomy Sebastian;Mengqi Wang;Abraham Gebregergis;Mohammad S. Islam;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5518 - 5526
Publisher: IEEE
 
» Effect of Rotor Geometry on Peak and Average Torque of External-Rotor Synchronous Reluctance Motor in Comparison With Switched Reluctance Motor for Low-Speed Direct-Drive Domestic Application
Abstract:
This paper deals with the feasibility of developing an external-rotor synchronous reluctance motor for a low-speed direct-drive domestic application. Here, an attempt is made to identify the rotor geometry which provides high peak, average torque, and the saliency ratio in comparison with those of equivalent external-rotor switched reluctance motor (Ex-R SRM) which has already been developed and tested for the same application. In this context, six different rotor geometries are considered for the feasibility study and their performance characteristics are predicted using finite-element analysis. These results are compared with the equivalent size of Ex-R SRM, and finally, a feasible rotor geometry is proposed for further investigation and for the prototype designing.
Autors: M. Azhagar Raj;A. Kavitha;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 8
Publisher: IEEE
 
» Effect of Stress on Magnetic Properties of Annealed Glass-Coated Co71Fe5B11Si10Cr3 Amorphous Microwires
Abstract:
Various thermal treatments have long been known to be effective in tailoring structural and magnetic properties of amorphous ferromagnetic wires, consequently, a desired magnetic anisotropy can be controlled for specific sensing applications. This paper deals with the effects of annealing and applied stresses on the magnetization processes and magnetoimpedance (MI) in Co71Fe5B11Si10Cr3 glass-coated microwires having amorphous or partially crystalline structure. The alloy under study has a small positive magnetostriction (approximately ) in its amorphous unstressed state. By applying a tensile stress to amorphous microwires, an abrupt transformation of the hysteresis loop is observed owing to the anisotropy type change due to stress-dependent magnetostriction which changes sign. The modification in the anisotropy type greatly enhances the stress sensitivity of higher frequency harmonics induced during re-magnetization and MI. The wires with a partially crystalline structure did not exhibit a noticeable stress dependence of magnetic properties, but after annealing a significant increase in coercivity was observed after applying a tensile stress. The obtained results were investigated in terms of a magnetostrictive model of magnetic anisotropy offering a reasonable explanation.
Autors: M. G. Nematov;M. M. Salem;A. M. Adam;M. Ahmad;N. A. Yudanov;L. V. Panina;A. T. Morchenko;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Effect of Temperature in Hysteretic Synchronization of Magnetic Vortex Spin-Torque Nano-Oscillators
Abstract:
The synchronization of vortex spin-transfer nano-oscillators (both nanopillar and nanocontact structures) with external microwave excitations is considered. A collective variables description is used to derive an analytical reduced-order model for the vortex core dynamics, which is able to predict all the possible oscillation regimes and hysteretic transitions among them. The influence of thermal fluctuations on hysteretic synchronization is studied by full micromagnetic simulations. The numerical results are in good agreement with the theory.
Autors: M. d’Aquino;S. Perna;A. Quercia;V. Scalera;C. Serpico;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Effect of Transcranial Magnetic Stimulation of Acupuncture Point on Brain Network
Abstract:
Transcranial magnetic stimulation (TMS), as a new therapy, has been proven to be efficient in inducing electric fields in the neuronal tissues and modulating brain activity in the applications to stimulate different positions of human body such as the brain, peripheral nerves, and acupuncture points (acupoint) in the last decade. Acupuncture, an ancient therapeutic technique, is gaining popularity in Western medicine, but the underlying regulation mechanism of acupuncture has not been well understood and still needs to be further investigated. By using electroencephalogram, signals before and following stimulation of Shenmen acupoint (HT7) were acquired noninvasively. Then, we adopted a network model analysis from graph theory to construct a network and evaluate network measures of brain connectivity among multiple brain regions before and following stimulation. An analysis of the resulting brain functional network found that the parietal lobe and parietal-occipital lobe shared lower degree and strength following stimulation than before and the frontal lobe shared higher betweenness centrality than before. The network measures with significant differences were distributed over the brain areas contralateral to the stimulated hand, which has probable association with the regulation mechanism of TMS of HT7 acupoint.
Autors: Lingdi Fu;Guizhi Xu;Hongli Yu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effect of Transcranial Magnetic Stimulation on Demyelinated Neuron Populations
Abstract:
Transcranial magnetic stimulation (TMS) is non-invasive neuromodulation therapy which uses time-varying magnetic fields to induce electric fields within the patient’s brain, thus allowing for neural stimulation of the targeted region. While past studies have used finite-element analysis (FEA) to model the effects of stimulation on brain tissue, there have been limited studies which analyze the effects of the same stimulation on the neuron responses. We use a python package called NEST to model the populations of neurons which are healthy as well as those that have diminished or absent myelin sheath. We model diminished myelin sheath by increasing the capacitance of the neuron. We study the effects of TMS on the synaptic activity of these populations by utilizing clinical parameters specific to TMS. Furthermore, we compare our results to the models of brain tissue stimulation using the FEA software Sim4Life. Our results indicate that all neuron populations, regardless of their myelination state, retain some stimulation threshold which increases discretely as the myelin sheath diminishes. Using tissue analysis, we also computed the range of TMS current necessary to reach these stimulation thresholds for demyelinated populations. Furthermore, we find that the maximum-induced E-field on the cortical surface does not exceed 220 V/m for stimulation of highly demyelinated neuron populations. Therefore our study finds that although demyelinated neurons exhibit much lower nominal synaptic activity than healthy neurons, they are nevertheless responsive to TMS, and these stimulation thresholds can be reached without inducing an unsafe maximum E-field on the cortex.
Autors: F. Syeda;A. Pandurangi;A. A. El-Gendy;R. L. Hadimani;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effect of Underlying Bi2Se3 Surface on Magnetic Properties of Ni Films
Abstract:
We have investigated magnetic properties of Ni film specimens deposited either on GaAs or on Bi2Se3 surfaces. The magnetization saturation field along the out-of-plane direction observed in the Hall data was weaker for the Ni/Bi2Se3 sample than for the Ni/GaAs sample. On the other hand, planar Hall resistance measurements showed the larger in-plane coercive field for Ni/Bi2Se3 than for Ni/GaAs. These changes of magnetic hardness observed along the out-of-plane and in-plane directions in the Ni/Bi2Se3 specimen are consistent with effects arising from spin–orbit interaction at the surface of the Bi2Se3 topological insulator.
Autors: Alviu Rey Nasir;Taehee Yoo;Seul-Ki Bac;Hakjoon Lee;Sangyeop Lee;Seonghoon Choi;Sanghoon Lee;Xinyu Liu;M. Dobrowolska;Jacek K. Furdyna;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effects of 3-D Printed Structural Characteristics on Magnetic Properties
Abstract:
Additive manufacturing, particularly 3-D printing, allows for completely customizable designs with relatively no limits on geometric complexities. In order to ensure optimal part design for potential magnetic applications, it is crucial to study how the different 3-D printer settings impact the magnetic properties of the printed part. Specifically, in this paper, it was determined how three structural print parameters (outer shell thickness, internal fill factor, and internal layer orientation) affect the resulting magnetic properties of 3-D printed cubic samples. The samples are made using fused deposition modeling of an iron–polymer composite filament. Hysteresis loops were gathered for fields applied along the [100], [110], and [001] directions of the printed cubes. From this, it was determined which combination of print settings should be used to achieve the most desirable magnetic response in terms of magnetic susceptibility, net magnetic moment, and mass-normalized saturation magnetization.
Autors: Lindsey M. Bollig;Michael V. Patton;Greg S. Mowry;Brittany B. Nelson-Cheeseman;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» Effects of Cu Addition on Magnetic Properties and Microstructures of Annealed Zr–Co–Cu–B Ribbons
Abstract:
The magnetic properties and microstructures of Zr18Co82−xCuxB2 (, 1, 2, 3, and 4) ribbons fabricated by melt-spinning technique were investigated to analyze the effects of Cu addition on the stabilization of a hard magnetic rhombohedral Zr2Co11 phase. In as-spun ribbons, the proportion of the rhombohedral Zr2Co11 phase increased up to . In addition, it was found that the Cu addition inhibited the decomposition of the rhombohedral Zr2Co11 phase into Co and ZrCo5 phases during the post-annealing process. In particular, annealed Zr18Co79Cu3B2 ribbons showed that the recrystallized grains having rhombohedral Zr2Co11 phase were grown as aligned rod-shaped grains with lengths of 200 nm. Thus, the Cu addition increased the coercivity of both as-spun and annealed ribbons. A maximum coercivity of 4.7 kOe was obtained in Zr18Co80Cu2B2 ribbons annealed at 550 °C.
Autors: Gyutae Lee;Jongryoul Kim;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effects of DC Bias Current on Behavior and Sensitivity of Thin-Film Magnetoimpedance Element
Abstract:
We investigated the behaviors and sensitivity of thin-film magnetoimpedance elements having an easy axis angle of 0°–45° when applying dc bias current directly to the elements. All elements show symmetric impedance profiles with respect to the impedance axis without dc bias current, while their profiles become asymmetric with dc bias current. This appearance of the asymmetric property on the impedance profiles indicates that the shape of cross section of the element has asymmetric configuration. On the other hand, when the easy axis angle is relatively small, the sensitivity for field detection is enhanced with a small dc bias level, while a stronger bias level is required for the element with a larger easy axis angle. The obtained results show a potential to optimize the sensor properties by dc bias current with small intensity in case that design properties are not obtained in the fabrication process.
Autors: H. Kikuchi;C. Sumida;T. Nakai;S. Hashi;K. Ishiyama;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effects of Electrical and Optogenetic Deep Brain Stimulation on Synchronized Oscillatory Activity in Parkinsonian Basal Ganglia
Abstract:
Conventional deep brain stimulation of basal ganglia uses high-frequency regular electrical pulses to treat Parkinsonian motor symptoms but has a series of limitations. Relatively new and not yet clinically tested, optogenetic stimulation is an effective experimental stimulation technique to affect pathological network dynamics. We compared the effects of electrical and optogenetic stimulation of the basal gangliaon the pathologicalParkinsonian rhythmic neural activity. We studied the network response to electrical stimulation and excitatory and inhibitory optogenetic stimulations. Different stimulations exhibit different interactions with pathological activity in the network. We studied these interactions for different network and stimulation parameter values. Optogenetic stimulation was found to be more efficient than electrical stimulation in suppressing pathological rhythmicity. Our findings indicate that optogenetic control of neural synchrony may be more efficacious than electrical control because of the different ways of how stimulations interact with network dynamics.
Autors: Shivakeshavan Ratnadurai-Giridharan;Chung C. Cheung;Leonid L. Rubchinsky;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2188 - 2195
Publisher: IEEE
 
» Effects of Glycine in DES-Based Plating Baths on Structural and Magnetic Properties of Fe–Ni Films
Abstract:
We have already reported that a deep eutectic solvent is one of hopeful solvents to obtain an electroplated Fe-based soft magnetic film since the plating process shows high current efficiency. In this paper, we employed glycine as an additive to improve surface roughness and soft magnetic properties of electroplated Fe–Ni films. The coercivity of the Fe-rich films (>70 at.%) prepared from the glycine-used bath showed lower values compared with those for the no-glycine baths. From the evaluations for the surface roughness and the crystal structure of the as-plated Fe75Ni25 films, we considered that the reductions in the coercivity of the Fe-rich films for the glycine-used baths are attributed to the smooth surface and the reduction in the effective crystalline anisotropy by increase in the volume fraction of an amorphous magnetic phase in the film.
Autors: T. Yanai;T. Yamaguchi;T. Akiyoshi;K. Takashima;M. Nakano;H. Fukunaga;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effects of Liner Thickness on the Reliability of AgTe/TiO2-Based Threshold Switching Devices
Abstract:
The effects of liner thickness on the reliability of AgTe/TiO2-based threshold switching (TS) devices were investigated. The off-state current of an AgTe/TiO2/Pt TS device was found to be significantly increased by in-diffusion of Ag into the TiO2 layer during the annealing process. Therefore, 3-, 5- and 7-nm TiN liners were introduced and compared to prevent the in-diffusion of Ag. While the 3-nm TiN liner was shown to be incapable of blocking Ag in-diffusion into the TiO2 layer, the 5- and 7-nm liners effectively suppressed in-diffusion and maintained high off-state resistance. However, the TS device with the 7-nm TiN liner exhibited wide threshold voltage distribution and poor endurance characteristics owing to a lack of Ag sources. The TS device with a 5-nm TiN liner, by contrast, was found to have an adequate amount of Ag sources and to demonstrate thermally stable and electrically reliable characteristics. The effects of TiN liner on Ag diffusion were also directly confirmed using energy dispersive spectrometry line profiles, transmission electron microscopy imaging, and mapping analyses.
Autors: Jeonghwan Song;Jiyong Woo;Jongmyung Yoo;Solomon Amsalu Chekol;Seokjae Lim;Changhyuck Sung;Hyunsang Hwang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Nov 2017, volume: 64, issue:11, pages: 4763 - 4767
Publisher: IEEE
 
» Effects of Pt Buffer Layer and Sr Content on Multiferroic (Bi, Sr)FeO3 Polycrystalline Thin Films on Glass Substrates
Abstract:
Effects of Pt buffer layer and Sr content on the structure, surface morphology, ferroelectric, and magnetic properties of Bi1-xSrxFeO3 (BSFO) polycrystalline films on glass substrates at reduced temperature of 450 °C have been investigated. Perovskite single phase is present in the studied BSFO films (–0.15) on 10–30 nm thick Pt(111) electrodes. The grain size and surface roughness of BSFO films is closely related to the morphology of Pt(111) electrodes. Further refined microstructure with reduced surface roughness is found with the increase of Sr content . BSFO polycrystalline thin films display good ferroelectric properties with the remanent polarization (2Pr) of 77–103 /cm2 and electrical coercive field ( of 380–490 kV/cm. In addition, the enhanced ferromagnetic properties with magnetization () of 8.7–11.2 emu/cm3 and coercivity () of 1211–1299 Oe are attained.
Autors: H. W. Chang;C. Y. Shen;F. T. Yuan;Y. C. Lo;S. Y. Lin;C. F. Chang;C. R. Wang;C. S. Tu;S. U. Jen;W. C. Chang;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Effects of Silicon Content on the Properties of Gas-Atomized Fe–Si–Cr Powders
Abstract:
Fe-7%, 8%, 9%, and 11%Si–Cr powders were gas atomized and then annealed at 25 °C–750 °C to investigate the effects of Si content, DO3 phase, and B2 phase on the high-frequency permeability of the powders. The formation of the B2 phase could not be suppressed during the atomization process of all the powders. The evolution temperatures of the DO3 phase in the Fe-7%, 8%, and 9%Si–Cr powders as measured by X-ray diffractometer were 550 °C, 550 °C, and 450 °C, respectively. As the annealing temperature was increased, the DO3 phase grew rapidly, and the lattice parameters of the powders were decreased except for those of the Fe-11%Si–Cr powder. The coercivity of all powders decreased with increasing temperature; however, the coercivity of the Fe-8%, 9%Si–Cr powders increased sharply after annealing at 450 °C. Permeability decreased rapidly with increasing temperature except for the Fe-11%Si–Cr powder; thus, the highest real permeability was obtained for the as-atomized Fe-8%Si–Cr powder. The changes in the coercivity and permeability of the powders with annealing temperature could be attributed to the evolution of the DO3 phase, Si segregation, and changes in electrical resistivity.
Autors: Pyungwoo Jang;Gwangbo Choi;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» Efficiency, Stability, and Reliability Implications of Unbalanced Current Sharing Among Distributed On-Chip Voltage Regulators
Abstract:
Power delivery networks with distributed on-chip voltage regulators (VRs) serve as an effective way for fast localized voltage regulation within modern microprocessors. Without careful consideration of the interactions among the distributed VRs and the power grid, unbalanced current sharing (CS) among those regulators may, however, lead to efficiency degradations, stability, and reliability issues, and even malfunctions of the regulators. This paper is a first attempt to investigate the efficiency, stability, and reliability implications of unbalanced CS among distributed on-chip VRs. Benefits of balanced CS are demonstrated with concrete examples, showing the necessity of an appropriate current balancing scheme. An adaptive reference voltage control method and the corresponding control algorithms specifically for distributed on-chip VRs are proposed to balance the CS among regulators at different locations. The proposed techniques successfully balance the CS among distributed VRs and can be applied to different regulator types. Simulation results based on practical microprocessor setups confirm the efficiency, stability, and reliability implications.
Autors: Longfei Wang;S. Karen Khatamifard;Orhun Aras Uzun;Ulya R. Karpuzcu;Selçuk Köse;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3019 - 3032
Publisher: IEEE
 
» Efficient Data Center Flow Scheduling Without Starvation Using Expansion Ratio
Abstract:
Existing data center transport protocols are usually based on the Processor Sharing (PS) policy and/or the Shortest Remaining Processing Time (SRPT) policy. PS divides link bandwidth equally between competing flows, thus it fails to achieve optimal average flow completion time (FCT). SRPT prioritizes flows that have the shortest remaining processing time and provides near-optimal average FCT, but it may cause long flows to suffer unfair delays, or even starve them. In fact, these two types of policies represent two directions in the design space: PS prefers fairness (in terms of starvation freedom) while SRPT favors efficiency (in terms of average FCT). In this paper, we propose a novel metric, expansion ratio, which enables us to strike a balance between SRPT and PS. We design MERP that achieves efficient flow scheduling without starvation. MERP takes care of both average and tail FCTs by minimizing the expansion ratio of competing flows in a lexicographically manner. MERP controls the sending rate of competing flows via synchronized virtual deadlines and routes flows in a downstream-aware manner that reacts quickly to link failures. We evaluate MERP using extensive NS2-based simulations. Results show that, under various traffic loads, MERP reduces the tail FCT significantly with a negligible increase of average FCT compared with pFabric, and MERP reduces the average FCT notably compared with ECMP and CONGA when link failures occur.
Autors: Sheng Zhang;Zhuzhong Qian;Hao Wu;Sanglu Lu;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3157 - 3170
Publisher: IEEE
 
» Efficient Evaluation of Multichannel SAR Data Recombination Filters
Abstract:
Synthetic aperture radar (SAR) is a well-established technique for observing the Earth on a global scale. As applications become more demanding, it is desirable to overcome the limitations imposed by the SAR principle, one of which is the tradeoff between the swath width and the instantaneous azimuth bandwidth, determining the resolution. Recombination of multiple channels with displaced phase centers has been proposed as a convenient way to create high resolution wide-swath images. We analyze various approximations made in the channel transfer functions and their impact on the reconstruction result using examples inspired by current imaging modes of the TerraSAR-X and TanDEM-X missions. In order to do so, we introduce an efficient method to assess the quality of reconstruction filters for an arbitrary number of channels without the need of full time-domain simulations.
Autors: Moritz Kiemer;Helko Breit;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6277 - 6286
Publisher: IEEE
 
» Efficient Management and Fast Handovers in Software Defined Wireless Networks Using UAVs
Abstract:
Compared to traditional networking, SDN has better controllability and visibility for network components, which enable better management by using the common controller. In this article, the standard architecture of SDN is enhanced to utilize UAVs as on-demand forwarding switches. The proposed approach can achieve efficient management and fast handovers by decreasing the handover latency, E2E delay, and signaling overheads. The illustrated scenarios will help in understanding the impact of existing handover approaches in the next generation wireless networks, especially the upcoming 5G, which includes small cells, UAVs, UEs, and so on. The simulation study shows that scenarios with both UAVs and small cells perform better than scenarios with only small cells. The results in this article show that the proposed SDNbased handover scenarios perform better than the existing 4G-LTE handover for UAVs.
Autors: Vishal Sharma;Fei Song;Ilsun You;Han-Chieh Chao;
Appeared in: IEEE Network
Publication date: Nov 2017, volume: 31, issue:6, pages: 78 - 85
Publisher: IEEE
 
» Efficient Method for Scattering From Cylindrical Components of Vegetation and Its Potential Application to the Determination of Effective Permittivity
Abstract:
Reliable and efficient analysis of electromagnetic scattering by cylindrical components of vegetation is important for microwave remote sensing of vegetated terrain. It allows for the characterization of anistropicity of the effective permittivity for vegetation or tree canopy, where averaging operation over distribution of cylinder orientation is needed in general. In this paper, we propose a T-matrix formulation based on our virtual partition method (VPM) for the whole cylindric component of either homogeneous or inhomogeneous nature. Numerical simulations demonstrate that the proposed T-matrix preserves all the desirable features of the VPM method, including high fidelity prediction of the scattering amplitude function and fulfillment of energy conservation as well as the reciprocity theorem. More importantly, in the evaluation of averaging over orientation distribution, the proposed method is usually faster than the VPM by two orders of magnitude. The predicted effective permittivity for an exemplary orientation distribution shows appreciable difference from that of the infinite cylinder approximation. With its qualitatively characterized region of validity, the proposed method is expected to be helpful in multiband coherent scattering models of vegetated terrain.
Autors: Dejun Li;Chao Yang;Yang Du;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6120 - 6127
Publisher: IEEE
 
» Efficient Next Generation Emergency Communications over Multi-Access Edge Computing
Abstract:
Traditionally, emergency communications between citizens and public authorities relied on legacy telecommunication technologies unable to cope with the agile, rich-media-content communications that mobile users are already using. This is due to the lack of harmonization and interoperable IP-based networking solutions. With the operators currently migrating to broadband IP infrastructures, emergency systems also need to follow this path and adapt their emergency communication platforms to fulfill next generation emergency services regulatory requirements. This becomes even more evident in light of the forthcoming 5G networks, which are envisioned to support an amalgam of diverse applications and services with heterogeneous performance requirements, including mission-critical IoT communication, massive machine-type communication, and gigabit mobile connectivity. Emergency service operators face an enormous challenge in order to synchronize their model of operation with the 5G paradigm. This article studies the challenges that next generation emergency services need to overcome in order to fulfill the requirements for rich-content, real-time, location-specific communications. The concept for next generation emergency communications as described in the project EMYNOS is presented, along with a vision of how this concept can fulfill the 5G requirements for ultra-reliable and ultra-low-latency emergency communications.
Autors: Evangelos K. Markakis;Ilias Politis;Asimakis Lykourgiotis;Yacine Rebahi;George Mastorakis;Constandinos X. Mavromoustakis;Evangelos Pallis;
Appeared in: IEEE Communications Magazine
Publication date: Nov 2017, volume: 55, issue:11, pages: 92 - 97
Publisher: IEEE
 
» Efficient Resource Allocation in Device-to-Device Communication Using Cognitive Radio Technology
Abstract:
Device-to-device (D2D) communication is developed as a new paradigm to enhance network performance according to LTE and WiMAX advanced standards. The D2D communication may have dedicated spectrum (overlay) or shared spectrum (underlay). However, the allocated dedicated spectrum may not be effectively used in the overlay mode, while interference between the D2D users and cellular users cause impairments in the underlay mode. Can the resource allocation of a D2D system be optimized using the cognitive approach where the D2D users opportunistically access the underutilized radio spectrum? That is the focus of this paper. In this paper, the transmission rate of the D2D users is optimized while simultaneously satisfying five sets of constraints related to power, interference, and data rate, modeling D2D users as cognitive secondary users. Furthermore, a two-stage approach is considered to allocate the radio resources efficiently. A new adaptive subcarrier allocation scheme is designed first, and then, a novel power allocation scheme is developed utilizing geometric water-filling approach that provides optimal solution with low computation complexity for this nonlinear problem. Numerical results show that the proposed approach achieved significant performance enhancement than the existing schemes.
Autors: Ajmery Sultana;Lian Zhao;Xavier Fernando;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10024 - 10034
Publisher: IEEE
 
» Elastic versus WDM networks with dedicated multicast protection
Abstract:
We consider the routing and spectrum allocation (RSA) problem of protecting all-optical multicast sessions against a single link failure in elastic optical networks (EONs). A tree is derived to support a multicast session and can be considered as a set of paths originating from a common source. We use a scheme to protect each of the paths by an arc-disjoint backup path in the case of any link failure. For this problem, we provide a node-arc integer linear programming (ILP) formulation and propose a heuristic algorithm for this protection scheme. We evaluate the improvement achieved by the flexible grids adopted in EONs over the fixed-grid wavelength-division multiplexing (WDM) networks. The evaluation is done by considering static modeling based on ILP and heuristics as well as dynamic simulations. We consider two approaches for heuristic algorithms: one is a two-step (TS) approach that computes the routing trees then allocates spectrum. The other uses the spectrum window plane (SWP) and constructs auxiliary graphs for the relevant range of spectrum to jointly solve the RSA problem. We evaluate the performances of the proposed algorithms under static and dynamic traffic models. Based on the studied scenarios, we observe consistent improvement in efficiency of flexible grid EONs over fixed-grid WDM networks. Moreover, we demonstrate that the network size (likely because of the availability of more alternative routes) can significantly affect the benefit in efficiency achieved by the SWP-based approaches over the TS approaches.
Autors: Anliang Cai;Zheyu Fan;Kai Xu;Moshe Zukerman;Chun-Kit Chan;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Nov 2017, volume: 9, issue:11, pages: 921 - 933
Publisher: IEEE
 
» Electric Field Tuning Ferromagnetic Resonance Frequency Shift in Oblique Sputtered Fe42Co46Hf12/PZN-PT Multiferroic Heterostructures
Abstract:
Strong inverse magnetoelectric (ME) coupling was observed in Fe42Co46Hf12/Lead Zinc Niobate–Lead Titanate multiferroic heterostructure, which produced a large electric field (E-field) tunability on microwave magnetic properties. With the increase of the E-field from 0 to 8 kV/cm, the E-field-dependent linearly increases from 175 to 411 Oe, equivalent to a large ME tunability of /kV, which further leads to a significant enhancement of ferromagnetic resonance frequency from 4.13 to 6.28 GHz under zero bias magnetic field. These features demonstrate that this multiferroic composite is a promising candidate for fabricating E-field-tunable microwave components.
Autors: Shandong Li;Xiaomin Liu;Honglei Du;Qiang Li;Jie Xu;Xia Wang;Hwaider Lin;Nian X. Sun;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Electrical and Methanol Sensing Characteristics of RF Sputtered n-ZnO/p-Si Heterojunction Diodes
Abstract:
This paper reports structural, electrical, and gas sensing characteristics of n-ZnO/p-Si heterojunction diodes fabricated using RF sputtering technique. The microstructural and surface morphological properties have been studied using X-ray diffraction, atomic force microscopy, and scanning electron microscopy, respectively. The electrical properties of the fabricated diodes have been investigated using current-voltage (–) and capacitance-voltage (–) measurements. The estimated values for rectification ratio, ideality factor, and barrier height were found to be ~100, 3.27, and 0.72eV, respectively, at room temperature. The values recorded for carrier concentration and barrier height using – measurement were cm and 0.79 eV, respectively. The value of series resistance using Chueng’s function was found to be 1710 . After detailed structural and electrical characterization, methanol sensing response (3–100 ppm) of n-ZnO/p-Si heterojunction diodes for the temperature range of 27 °C–150 °C have also been investigated. The optimum operating temperature for methanol sensing was found to be considerably low,- i.e., 100 °C. The values of response magnitude, response time and recovery time at 100 °C were estimated as 82%, ~4 and ~7 s, respectively. The cross sensitivity study for the nearest interfering species, such as ethanol, 1-propanol, butanol, butanone, and benzene, has confirmed the high selectivity of n-ZnO/p-Si heterojunction diodes for methanol sensing.
Autors: Shashi Kant Sharma;Basanta Bhowmik;Vipin Pal;Chinnamuthan Periasamy;
Appeared in: IEEE Sensors Journal
Publication date: Nov 2017, volume: 17, issue:22, pages: 7332 - 7339
Publisher: IEEE
 
» Electrical and Structural Characterization of Self-Aligned InGaZnO Thin-film Transistors Fabricated by Excimer Laser Irradiation
Abstract:
We conducted electrical and structural characterization of a self-aligned InGaZnO (IGZO) thin-film transistor (TFT) fabricated by selectively reducing the resistance of the source and drain (S/D) regions by backside excimer laser irradiation. We present the influence of the resistance of the S/D regions on the transfer characteristics and discuss the applicability of our resistance reduction method to the self-aligned oxide TFT fabrication process. In our proposed method, since the low-resistance regions are formed directly by using the gate electrode as a mask, the positions of the S/D regions can be accurately set. We demonstrate this by analyzing the spreading resistance and height profiles for the IGZO film.
Autors: Mitsuru Nakata;Hiroshi Tsuji;Yoshihide Fujisaki;Yoshiki Nakajima;Tatsuya Takei;Toshihiro Yamamoto;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5972 - 5977
Publisher: IEEE
 
» Electrical Balance Duplexer Field Trials in High-Speed Rail Scenarios
Abstract:
Electrical balance duplexers (EBDs) present a potential alternative to the fixed-frequency duplexing filters used for frequency division duplexing in cellular handset radio frequency front ends. However, the transmit-to-receive (Tx–Rx) isolation can be affected by interaction between the antenna and the environment, and therefore, the EBDs balancing impedance must adaptively track time-domain antenna impedance variation. A rail scenario presents a potentially demanding use case for an EBD, as fast moving trains in the vicinity of the antenna may cause dynamically changing reflections, which can be received as self-interference. In this paper, measured dynamic antenna reflection coefficients at 745 and 1900 MHz from train mounted antennas are included in the EBD circuit simulations in order to investigate the resulting variation in Tx–Rx isolation, and determine requirements for balancing impedance adaptation. This paper also presents the results from rail-based field trials of a hardware prototype EBD, which implements real-time antenna impedance tracking. Results show that the rail scenario does result in variation in Tx–Rx isolation, but that rebalancing the EBD at the intervals of 5 ms was sufficient to maintain >50 dB isolation for ~95% of the time.
Autors: Leo Laughlin;Chunqing Zhang;Mark A. Beach;Kevin A. Morris;John L. Haine;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6068 - 6075
Publisher: IEEE
 
» Electrical Impedance Myography for Evaluating Paretic Muscle Changes After Stroke
Abstract:
Electrical impedance myography (EIM) was used to assess the paretic muscle intrinsic electrical properties post stroke. Twenty-seven subjects with chronic hemiparesis participated in this study. Muscle impedance was measured by applying high-frequency, low-intensity alternating current to biceps brachii muscles. Major EIM parameters, resistance (), reactance (), phase angle (), and electrical anisotropy ratios (AR) of the three parameters, were examined at 50 kHz. Statistical analysis demonstrated significant reduction of reactance, phase angle, AR of resistance, and AR of reactance in the paretic muscle compared with the contralateral side (Paretic X: , contralateral X: , and p < 0.001; Paretic : , contralateral : 14.5 ± 0.82°, and p < 0.001; Paretic AR of R: 0.969 ± 0.013, contralateral AR of R: 1.008 ± 0.011, and p < 0.02; and Paretic AR of X: 0.981 ± 0.066, contralateral AR of X: 1.114 ± 0.041, and p < 0.02). Correlation analysis, however, did not show any significant relationship between EIM parameters and clinical assessments. Findings of this paper indicate- significant changes in the muscular intrinsic electrical properties after stroke, possibly related to structural modifications induced by loss of muscle fibers or fat infiltration as well as changes in the quality of cell membranes post stroke.
Autors: Xiaoyan Li;Le Li;Henry Shin;Sheng Li;Ping Zhou;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 2113 - 2121
Publisher: IEEE
 
» Electrical Impedance Tomography: Tissue Properties to Image Measures
Abstract:
Electrical impedance tomography (EIT) uses electrical stimulation and measurement at the body surface to image the electrical properties of internal tissues. It has the advantage of noninvasiveness and high temporal resolution but suffers from poor spatial resolution and sensitivity to electrode movement and contact quality. EIT can be useful to applications, where there are conductive contrasts between tissues, fluids, or gasses, such as imaging of cancerous or ischemic tissue or functional monitoring of breathing, blood flow, gastric motility, and neural activity. The past decade has seen clinical application and commercial activity using EIT for ventilation monitoring. Interpretation of EIT-based measures is complex, and this review paper focuses on describing the image interpretation “pathway.” We review this pathway, from Tissue Electrical Properties, EIT Electrodes & Hardware, Sensitivity, Image Reconstruction, Image Processing to EIT Measures. The relationship is discussed between the clinically relevant parameters and the reconstructed properties. An overview is given of areas of EIT application and of our perspectives for research and development.
Autors: Andy Adler;Alistair Boyle;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2494 - 2504
Publisher: IEEE
 
» Electrical Properties Tomography Based on $B_{{1}}$ Maps in MRI: Principles, Applications, and Challenges
Abstract:
Objective: The purpose is to provide a comprehensive review of the electrical properties tomography (EPT) technique, which was introduced to image the electrical properties (EPs) of tissue noninvasively by exploiting the measured field data of MRI. Methods: We reviewed the principle of EPT, reconstruction methods, biomedical applications such as tumor imaging, and existing challenges. As a key application of EPT, the estimation of specific absorption rate (SAR) due to MRI was discussed in the background of elevated risk of tissue heating at high field. Results and Conclusion: Since the originally proposed local, homogeneous Helmholtz equation-based reconstruction algorithm, advanced EPT algorithms have emerged to address the challenges of EPT, including reconstruction error near tissue boundaries, noise sensitivity, inaccurate phase estimation, and elimination of the unmeasurable component, along with demonstrations of in vivo experiments. EPT techniques have been applied to investigate EPs of both healthy and pathological tissues in vivo and factors contributing to various EP value, including sodium, water content, etc. More studies are anticipated to consolidate the current findings. EPT-based subject-specific SAR estimation has led to in vivo demonstration of its feasibility and prediction of temperature increase of phantom during MRI scans merely using measured data. Significance: EPT has the advantage of high resolution and practical feasibility in a clinical setup for imaging the biomedically interesting EPs of tiss- e in the radiofrequency range. EPT-based SAR estimation is another promising topic for predicting tissue heating of individual subjects during a specific MRI scan.
Autors: Jiaen Liu;Yicun Wang;Ulrich Katscher;Bin He;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2515 - 2530
Publisher: IEEE
 
» Electrical–Thermal Characterization of Through Packaging Vias in Glass Interposer
Abstract:
Low-cost thin glass is developed as a promising material to advanced interposers for high density electrical interconnection in 2.5-D and three-dimensional (3-D) integration. In this paper, the electrical–thermal performance of through glass vias is investigated. The distributed transmission lines model for tapered through glass vias (T-TGVs) in signal-ground-signal type differential structure is first established and validated against the 3-D full-wave electromagnetic simulator. The model is applicable to TGVs made of carbon nanotubes(CNTs) by incorporating CNT quantum and kinetic effects. Using the proposed model, the impact of various parameters on the electrical characteristics of the differential T-TGVs is investigated. It is observed that the inductive element of conductor loss plays a significant role on the electrical performance, which makes the CNT-TGV interconnects show unique electrical characterization that totally different from its through silicon vias (TSVs) counterpart. For example, the signal loss of TGV interconnects in different-mode signaling is even lower than that in common-mode and increasing via pitch increases signal loss. Furthermore, the thermal performance of 2.5-D integration with TGVs is investigated with COMSOL multiphysics. It is shown that TGV is a primary path for heat dissipation and increasing TGV distribution density can significantly lower the peak temperature of 2.5-D integration. Because of high thermal conductivity of CNTs, glass interposer with CNT-TGVs can achieve better thermal performance in comparison to its Cu counterpart.
Autors: Libo Qian;Yinshui Xia;Ge Shi;Jiang Wang;Yidie Ye;Shimin Du;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 901 - 908
Publisher: IEEE
 
» Electrically “Long” Dipoles in a Collocated/Orthogonal Triad—for Direction Finding and Polarization Estimation
Abstract:
In dipole-antenna array signal-processing algorithm development, research has focused on “short dipoles” whose physical length () is under (1/10) of a wavelength . Such electrically “short” dipoles have very small input impedances, rendering such “short” dipoles to be inefficient radiators. Practical dipoles, with an electrical length of , have notably larger input impedance, hence making them better radiators. Of such practical dipoles, this paper investigates their use for azimuth-polar direction finding and for polarization estimation. This paper will first present the measurement model (i.e., array manifold) of a triad of such practical dipoles, collocated in space and orthogonally oriented. This paper will then develop the corresponding closed-form algorithms to estimate the bivariate azimuth–elevation direction-of-arrival or the bivariate polarization. Such closed-form algorithms previously have been unavailable in the existing literature for such a triad of electrically “long” dipoles of pragmatic radiation efficiency.
Autors: Kainam Thomas Wong;Yang Song;Caleb J. Fulton;Salman Khan;Wai-Yip Tam;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6057 - 6067
Publisher: IEEE
 
» Electricity Markets and Renewables: A Survey of Potential Design Changes and Their Consequences
Abstract:
The design of wholesale electricity markets is complex. Unlike other commodities, electricity cannot be stored in a warehouse. Electricity generation must occur simultaneously with consumption, whereby electricity delivery is based on laws of physics. Under the structure of regulated electricity rates, consumers are generally not directly exposed to the instantaneous cost of the delivered electricity. Countries around the world have successfully managed these complexities by restructuring the electricity sector with markets that allow wholesale electricity suppliers to compete in providing energy, reliability services, financial services, and sometimes capacity. Still, wholesale electricity market restructuring has certainly been a moving target.
Autors: Erik Ela;Congcong Wang;Sai Moorty;Kenneth Ragsdale;Jon O'Sullivan;Mark Rothleder;Ben Hobbs;
Appeared in: IEEE Power and Energy Magazine
Publication date: Nov 2017, volume: 15, issue:6, pages: 70 - 82
Publisher: IEEE
 
» Electromagnetic Analysis of a Synchronous Reluctance Motor With Single-Tooth Windings
Abstract:
This paper explores some of the key electromagnetic design aspects of a synchronous reluctance motor that is equipped with single-tooth windings (i.e., fractional slot concentrated windings). The analyzed machine, a 6-slot 4-pole motor, utilizes a segmented stator core structure for ease of coil winding, pre-assembly, and facilitation of high slot fill factors (~60%). The impact on the motors torque producing capability and its power factor of these inter-segment air gaps between the stator segments is investigated through 2-D finite element analysis (FEA) studies where it is shown that they have a low impact. From previous studies, torque ripple is a known issue with this particular slot–pole combination of synchronous reluctance motor, and the use of two different commercially available semi-magnetic slot wedges is investigated as a method to improve torque quality. An analytical analysis of continuous rotor skewing is also investigated as an attempt to reduce the torque ripple. Finally, it is shown that through a combination of 2-D and 3-D FEA studies in conjunction with experimentally derived results on a prototype machine that axial fringing effects cannot be ignored when predicting the q-axis reactance in such machines. A comparison of measured orthogonal axis flux linkages/reactances with 3-D FEA studies is presented for the first time.
Autors: C. M. Donaghy-Spargo;B. C. Mecrow;J. D. Widmer;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 7
Publisher: IEEE
 
» Electromagnetic Design and Analysis of a Novel Transmission System Supporting Multi-Path Power Flows for Electric Vehicles
Abstract:
This paper proposes a novel transmission system supporting multi-path power flows for electric vehicles (EVs). It mainly consists of a coaxial magnetic gear (CMG), a lock, a clutch, and two electric machines (EMs). The key feature of the CMG is that its modulating ring can rotate freely. One of the EMs is integrated with the CMG, which constitutes an integrated magnetic gear permanent magnet machine. And the other is connected to the inner rotor of the CMG through a clutch and a shaft with a lock. By toggling the clutch, controlling the states of the lock and the two EMs, the proposed transmission system can achieve flexible power splits. It is very interesting that one of the EM can play the role of a flywheel storage device when necessary, which is capable of buffering the energy from regenerative braking, so as to protect the battery. In this paper, the configuration of the transmission system is illustrated; its operating principle is elaborated. Then, the electromagnetic design is conducted to meet the demands arising from EVs. Finally, the electromagnetic performances are analyzed by using finite-element method, which verifies the rationality of the electromagnetic design.
Autors: Yujun Shi;Linni Jian;Jin Wei;Zhengxing Deng;Zhijian Ling;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 7
Publisher: IEEE
 
» Electromagnetic Scattering From Individual Crumpled Graphene Flakes: A Characteristic Modes Approach
Abstract:
Graphene flakes (GFs) in real composites are rarely perfectly flat, and often exhibit complicated crumpled shapes. Therefore, the goal of this paper was to quantify the electromagnetic scattering characteristics of individual crumpled GFs with shapes resembling those found in real composites. The extinction cross sections of tens of GFs, with different sizes and various levels of crumpleness, were calculated using multiple independent solvers. The results show that resonances in the extinction cross section spectrum decrease in amplitude as the GFs become more crumpled. Moreover, some crumpled GFs exhibited a broader resonance than that of perfectly flat GFs. To explain these results, we used a characteristic mode analysis to decompose the graphene surface currents into a set of fundamental currents or modes. For perfectly flat square GFs, the vertical and horizontal modes were found to overlap and resonate at the same frequencies. However, as the GFs became more crumpled, the horizontal/vertical symmetry broke down causing the corresponding modes to separate and resonate at different frequencies leading to an overall broader bandwidth. These results attest to the importance of modeling the exact shape of GFs to accurately characterize their electromagnetic response.
Autors: Kalyan C. Durbhakula;Ahmed M. Hassan;Fernando Vargas-Lara;Deb Chatterjee;Md. Gaffar;Jack F. Douglas;Edward J. Garboczi;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6035 - 6047
Publisher: IEEE
 
» Electromagnetic Torque Performance Analysis of a Parallel Hybrid Excitation Machine With Axial Paralleling of Permanent Magnet Part and Variable Reluctance Part
Abstract:
In this paper, the electromagnetic torque (EM) performance analysis of a parallel hybrid excitation machine (PHEM) is investigated. It is composed of a permanent magnet (PM) part and variable reluctance part. The flux paths of the two parts are independent and the armature windings are connected in series. PHEM is an axial parallel coupling of two different types of brushless machine. The mechanisms of EM torque for the two parts are quite different and many problems of torque coupling still remain unsolved. A 2-D EM-circuit coupling simulation model is built to analyze the torque characteristics and coupling relationships. The simulation results indicate that the PM part plays a main role in the output torque of PHEM. The large inductance ripple of variable reluctance part would cause large torque ripple in PHEM. The target machine is experimentally tested to verify the output torque characteristics. Furthermore, the torque-angle characteristics are studied with different field current and it shows that the best load angle could be around 110° to get maximum output torque and relatively smaller torque ripple.
Autors: Zhou Miao;Zhuoran Zhang;Weiwei Geng;Ye Liu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Electromagnetic–Mechanical Design of Synchronous Reluctance Rotors With Fine Features
Abstract:
This paper explores the tradeoff between the electromagnetic and mechanical performances with regard to the design of a synchronous reluctance machine rotor with fine features in the lamination profile—the analyzed machine consists of four rotor poles and its stator is equipped with single tooth coils. The change in the electromagnetic characteristics of the - and -axis reactances is explored for variation in radial and tangential rib widths and the impact of increased rib width on the saliency ratio of the machine. It is shown that the increased radial and tangential rib widths impair electromagnetic performance, with the tangential rib having the most pronounced effect on performance in this rotor design. The mechanical performance of the design is also explored in a similar manner, where it is shown that the high stress concentration in the rotor radial and tangential ribs limits the maximum speed of the machine in the field weakening region. The radial rib is found to have the dominant impact on supporting the flux guides. It is shown that the prototyped machine can achieve good electromagnetic performance while maintaining mechanical integrity up to a 25% overspeed of 10 000 r/min with features as small as 0.3 mm. Additionally, the challenges associated with manufacturing, selecting a higher rotor pole number, and the possibility of mechanical failure are also discussed in the context of electromagnetic–mechanical design of such rotors, with important avenues of further research suggested.
Autors: Christopher M Donaghy-Spargo;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 8
Publisher: IEEE
 
» Electron Cyclotron Resonance Gain in the Presence of Collisions
Abstract:
A cyclotron resonance maser source using low-effective-mass conduction electrons in graphene, if successful, would allow for generation of far infrared (FIR) and terahertz (THz) radiation without requiring magnetic fields running into the tens of tesla. In order to investigate this possibility, we consider a situation in which electrons are effectively injected via pumping from the valence band to the conduction band using an IR laser source, subsequently gyrate in a magnetic field applied perpendicular to the plane of the graphene, and give rise to gain for an FIR/THz wave crossing the plane of the graphene. The treatment is classical, and includes on equal footing the electron interaction with the radiation field and the decay in electron energy due to collisional processes. Gain is found even though there is no inversion of the energy distribution function. Gain can occur for electron damping times as short as hundreds of femtoseconds.
Autors: Nightvid Cole;Thomas M. Antonsen;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Nov 2017, volume: 45, issue:11, pages: 2945 - 2954
Publisher: IEEE
 
» Electronic–Photonic Co-Optimization of High-Speed Silicon Photonic Transmitters
Abstract:
System-level driven electronic–photonic codesign is the key to improving the bandwidth density and energy efficiency for high-speed silicon photonic links. In many data-communication scenarios, optical link power is dominated by its transmitter side including the laser source. In this paper, we propose a comprehensive co-optimization framework for high-speed silicon photonic transmitters utilizing compact models and a detailed optical simulation framework. Given technology and link constraints, microring and Mach–Zehnder transmitter designs are optimized and compared based on a unified optical phase shifter model. NRZ and PAM4 modulation schemes are analyzed and compared for microring-based transmitters at 50 Gb/s. Multistage and traveling wave Mach–Zehnder transmitters are optimized and discussed as well. The results show that, for a 50 Gb/s NRZ optical link, an optimized microring transmitter could save more than 60% of the total laser and driver power compared to an optimized Mach–Zehnder transmitter under equivalent photonic technology constraints. For a given datarate and receiver sensitivity, design tradeoffs of silicon photonic processes, devices, and architecture choices are discussed in depth. In addition, this paper introduces a new Simulink toolbox for transient optical simulation. Combined with the proposed optimization engine, it provides an electrooptical co-optimization approach toward truly energy-efficient high-speed silicon photonic links.
Autors: Sen Lin;Sajjad Moazeni;Krishna T. Settaluri;Vladimir Stojanović;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4766 - 4780
Publisher: IEEE
 
» Electroplated Co–Pt Thick-Film Magnets Prepared in Citric-Acid-Based Plating Baths
Abstract:
We electroplated Co–Pt thick films in acid plating baths using a citric acid, and evaluated the magnetic properties of the annealed films. The maximum coercivity value depended on the amount of the citric acid in the bath, and the high coercivity of approximately 800 kA/m was obtained around Co content of 43 at% for the bath with 30 g/L of citric acid. The thickness linearly increased with the increasing plating time, and high plating rate of approximately /min was obtained. Consequently, -thick films were realized keeping at high coercivity.
Autors: T. Yanai;R. Hamamura;J. Honda;A. Tomita;H. Yamada;N. Fujita;K. Takashima;M. Nakano;H. Fukunaga;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 3
Publisher: IEEE
 
» Electrothermal Transient Analysis of GaN Power Amplifier With Dynamic Drain Voltage Biasing
Abstract:
AM-AM distortion due to dynamic drain voltage biasing for a power amplifier (PA) has been precisely emulated by an electrothermal transient analysis. A transistor model of a 20-W gallium nitride field-effect transistor (FET) in the PA for the electrothermal simulation is composed of thermal equivalent circuits and the Angelov FET model. Radio frequency performances of the PA were simulated by the transient analysis of amplitude modulation input signals with modulation frequencies from 2.5 to 10 MHz. The simulation results showed that a temperature variation in the PA caused AM-AM hysteresis on the order of MHz, which was consistent with the results obtained from a theoretical analysis of the transient temperature.
Autors: Shigeru Hiura;Ryo Ishikawa;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 1019 - 1021
Publisher: IEEE
 
» Elman Neural Network-Based Identification of Krasnosel’skii–Pokrovskii Model for Magnetic Shape Memory Alloys Actuator
Abstract:
Magnetic shape memory alloys (MSMAs), which are a class of innovative functional materials, are used as the actuators to be applied widely in high-precision positioning. However, the hysteresis nonlinearity in the MSMA seriously affects the precision positioning of the MSMA-based actuator. In this paper, to study the hysteresis nonlinearity in the MSMA, the Krasnosel’skii–Pokrovskii (KP) model is employed to describe the hysteresis nonlinearity in the MSMA-based actuator, and the density function of the KP model is identified by the Elman neural network. The simulations show that the modeling error rate of the KP model using the Elman neural network is 0.81%, which is reduced by 63.5% compared with that of the KP model based on a recursive least-squares method. This result demonstrates that the KP model based on the Elman neural network can accurately describe the hysteresis nonlinearity in the MSMA-based actuator.
Autors: Rui Xu;Miaolei Zhou;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Embedding Learning with Events in Heterogeneous Information Networks
Abstract:
In real-world applications, objects of multiple types are interconnected, forming Heterogeneous Information Networks. In such heterogeneous information networks, we make the key observation that many interactions happen due to some event and the objects in each event form a complete semantic unit. By taking advantage of such a property, we propose a generic framework called HyperEdge- BasedEmbedding (Hebe) to learn object embeddings with events in heterogeneous information networks, where a hyperedge encompasses the objects participating in one event. The Hebe framework models the proximity among objects in each event with two methods: (1) predicting a target object given other participating objects in the event, and (2) predicting if the event can be observed given all the participating objects. Since each hyperedge encapsulates more information of a given event, Hebe is robust to data sparseness and noise. In addition, Hebe is scalable when the data size spirals. Extensive experiments on large-scale real-world datasets show the efficacy and robustness of the proposed framework.
Autors: Huan Gui;Jialu Liu;Fangbo Tao;Meng Jiang;Brandon Norick;Lance Kaplan;Jiawei Han;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Nov 2017, volume: 29, issue:11, pages: 2428 - 2441
Publisher: IEEE
 
» Emittance Growth in the DARHT-II Linear Induction Accelerator
Abstract:
The dual-axis radiographic hydrodynamic test (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. Radiographic resolution is determined by the size of the source spot, and beam emittance is the ultimate limitation to spot size. On the DARHT-II LIA, we measure an emittance higher than predicted by theoretical simulations, and even though this accelerator produces submillimeter source spots, we are exploring ways to improve the emittance. Some of the possible causes for the discrepancy have been investigated using particle-in-cell codes. The simulations establish that the most likely source of emittance growth is a mismatch of the beam to the magnetic transport, which can cause beam halo.
Autors: Carl Ekdahl;Carl A. Carlson;Daniel K. Frayer;B. Trent McCuistian;Christopher B. Mostrom;Martin E. Schulze;Carsten H. Thoma;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Nov 2017, volume: 45, issue:11, pages: 2962 - 2973
Publisher: IEEE
 
» Enabling “Protocol Routing”: Revisiting Transport Layer Protocol Design in Internet Communications
Abstract:
It’s time to rethink the way networking stacks are implemented and leveraged for next-generation Internet applications. NeuroStack (nStack) is a nimble, extendable transport protocol framework and runtime that enables application-transparent and dynamic new protocol engagement and adaption.
Autors: Kai Zheng;
Appeared in: IEEE Internet Computing
Publication date: Nov 2017, volume: 21, issue:6, pages: 52 - 57
Publisher: IEEE
 
» End of Second Term as Editor-in-Chief [Editor's Remarks]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Hisao Ishibuchi;
Appeared in: IEEE Computational Intelligence Magazine
Publication date: Nov 2017, volume: 12, issue:4, pages: 3 - 3
Publisher: IEEE
 
» Energization-Status Identification of Three-Phase Three-Core Shielded Distribution Power Cables Based on Non-Destructive Magnetic Field Sensing
Abstract:
Three-phase three-core distribution power cables are widely deployed in power distribution networks and are continually being extended to address the ever-increasing power demand in modern metropolises. Unfortunately, there are high risks for the repair crew to operate on energized distribution power cables, which can cause deadly consequences such as electrocution and explosion. The predominant energization-status identification techniques used today are either destructive or only applicable to un-shielded power cables. Moreover, the background interferences affect the sensing technique reliability. In this paper, we have developed a non-destructive energization-status identification technique to identify energized three-phase three-core distribution power cables by measuring magnetic fields around the cable surface. The analysis shows that the magnetic-field-distribution pattern as a function of azimuth around the cable surface of the energized (current- or voltage-energized) three-phase three-core distribution power cable is distinguishable from the de-energized one. The non-idealities of phase currents and cable geometry were also discussed, and the proposed method still works under these circumstances. The sensing platform for implementing this technique was developed accordingly, consisting of magnetoresistive sensors, a triple-layered magnetic shielding, and a data acquisition system. The technique was demonstrated on a 22-kV three-phase three-core distribution power cable, and the energized status of the cable can be successfully identified. The proposed technique does not damage cable integrity by piercing the cable, or exposing the repair crew to hazardous high-voltage conductors. The platform is easy to operate and it can significantly improve the situational awareness for the repair crew, and enhance the stability of power distribution networks.
Autors: Ke Zhu;Wing Kin Lee;Philip W. T. Pong;
Appeared in: IEEE Sensors Journal
Publication date: Nov 2017, volume: 17, issue:22, pages: 7405 - 7417
Publisher: IEEE
 
» Energy Autonomous Wireless Valve Leakage Monitoring System With Acoustic Emission Sensor
Abstract:
Industrial internet will improve process control and increase efficiency to maximize industrial output. Key enabling technologies include low-power wireless communication, energy harvesting power autonomous devices along with the latest in sensing devices. This paper presents a wireless sensing system developed for the key industrial application of condition monitoring, specifically; valve leakage detection. The system integrates advances in all of the three aforementioned topics. A novel MEMS-based acoustic emission sensor is described to detect valve leakage manifested as vibrations in certain frequency bands. An in-house developed ultra-low power wake up radio technology, which enables the deployment of this sensor, will be presented. Two energy-harvesting systems: thermal harvesting in the sensor node and an industrial current loop harvester for the base station are developed. Integration and piloting of this system is described and evaluation results presented. The system presented offers a repeatable and adaptable sensor system deployed for valve leakage detection in an ATEX industrial environment.
Autors: Colm Mc Caffrey;Teuvo Sillanpää;Henrik Huovila;Joona Nikunen;Sami Hakulinen;Pekka Pursula;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Nov 2017, volume: 64, issue:11, pages: 2884 - 2893
Publisher: IEEE
 
» Energy Detection With Random Arrival and Departure of Primary Signals: New Detector and Performance Analysis
Abstract:
By taking into account the random arrival and departure of primary signals, spectrum sensing is formulated to a hypothesis testing problem with null hypothesis : primary signals are absent or present but departing within a sensing interval (secondary users are allowed to access the spectrum), and alternative hypothesis : primary signals are present and not departing within a sensing interval (secondary users are not allowed to access the spectrum). The above-mentioned binary hypothesis testing involves two mutually exclusive random variables (i.e., the departure and arrival time instants of primary signals). To tackle these random variables, we develop an average log-LRT (aveLLR) based energy detector (ED) by using the Bayesian criterion. The theoretical performance of the aveLLR-based ED is analyzed and numerical simulations are provided to demonstrate its superior performance. It is interesting that when the ratio of the length of sensing intervals to the holding time of channel states is small, the proposed aveLLR-based ED is approximately reduced to the conventional ED (C-ED). It was commonly believed that high primary user traffic would degrade the performance of C-ED severely, as C-ED does not consider the random arrival and departure of primary signals. However, we reveal that the ratio plays a key role, and when the ratio is small, the impact of the primary user traffic on the C-ED is marginal.
Autors: Ming Jin;Qinghua Guo;Youming Li;Jiangtao Xi;Yanguang Yu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10092 - 10101
Publisher: IEEE
 
» Energy Efficiency and Spectrum Efficiency Tradeoff in the D2D-Enabled HetNet
Abstract:
We investigate the tradeoff between energy efficiency (EE) and spectrum efficiency (SE) in the heterogeneous network composed of a macro base station (BS), several pico BSs, and device-to-device (D2D) communication pairs during the uplink transmission. A utility function of the tradeoff between EE and SE is defined first. Then, we formulate the tradeoff utility maximization problem as a joint channel allocation and power control problem for cellular and D2D users. The original problem is transformed into a more tractable subtractive form, and we further decompose the problem into several subproblems that can be solved separately. Numerical results confirm the effectiveness of the proposed scheme and offer valuable insights. Compared with EE, SE is much less sensitive to the variation of the tradeoff factor, which indicates that our proposed scheme can achieve high EE while guaranteeing a fairly large value of SE with a properly chosen EE–SE tradeoff factor.
Autors: Hui Gao;Min Wang;Tiejun Lv;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10583 - 10587
Publisher: IEEE
 
» Energy Efficiency Evaluation of Multi-Tier Cellular Uplink Transmission Under Maximum Power Constraint
Abstract:
This paper evaluates the energy efficiency of uplink transmission in heterogeneous cellular networks (HetNets), where fractional power control (FPC) is applied at user equipments (UEs) subject to a maximum transmit power constraint. We first consider an arbitrary deterministic HetNet and characterize the properties of energy efficiency for UEs in different path loss regimes, or different access regions. By introducing the notion of transfer path loss, we reveal that, for UE whose path loss is below the transfer path loss, its energy efficiency highly depends on the value of power control coefficient adopted by FPC. In contrast, for UE with path loss above the transfer path loss, the uplink energy efficiency asymptotically decreases inversely with path loss, independent of the adopted power control coefficient. Based on these properties, we characterize the optimal power control coefficients for maximizing the energy efficiency of FPC in different access regions. Next, we extend the analysis to stochastic HetNets where UEs and BSs are distributed as independent Poisson point processes, and investigate the distribution of transmit power for uplink UEs. Moreover, the probability of truncation outage due to constrained maximal transmit power, as well as the average energy efficiency of UEs are analytically derived as functions of the BS and UE densities, power control coefficient, and receiver threshold. Simulation results validate the analytical results, show the consistency between deterministic and stochastic analyses, and suggest suitable power control coefficient for achieving energy efficient uplink transmission by FPC in HetNets.
Autors: Jing Zhang;Lin Xiang;Derrick Wing Kwan Ng;Minho Jo;Min Chen;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7092 - 7107
Publisher: IEEE
 

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