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

» From Pthreads to Multicore Hardware Systems in LegUp High-Level Synthesis for FPGAs
Abstract:
In the last decade, processor speeds have remained fairly stagnant, and to improve performance further, the industry started to increase the number of processor cores. The use of specialized hardware, such as field-programmable gate arrays (FPGAs), has also been on the rise. The traditional design methodology for FPGAs, however, requires hardware knowledge, which makes the platform inaccessible to software engineers. High-level synthesis (HLS) tools aim to resolve this issue by allowing software design methodologies to be used for FPGAs. However, HLS remains difficult to use for many software engineers, as there are tasks, such as system integration, which is still mostly a manual process. Consequently, creating a multicore hardware system on an FPGA is not feasible for most software engineers. To this end, we provide an HLS framework, which can automatically generate a multicore hardware system from software. We provide support for POSIX threads, which can be compiled to concurrently executing hardware cores that can be used in a processor–accelerator hybrid system, or in a hardware-only system without a processor. With this, we show that we can create multicore FPGA systems that can provide significant benefits in performance and energy-efficiency compared with hardware executing sequentially, and software executing on MIPS/ARM/x86 processors.
Autors: Jongsok Choi;Stephen D. Brown;Jason H. Anderson;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Oct 2017, volume: 25, issue:10, pages: 2867 - 2880
Publisher: IEEE
 
» From the Calibration of a Light-Field Camera to Direct Plenoptic Odometry
Abstract:
This paper presents a complete framework from the calibration of a plenoptic camera toward plenoptic camera based visual odometry. This is achieved by establishing the multiple view geometry for plenoptic cameras. Based on this novel multiple view geometry, a calibration approach is developed. The approach optimizes all intrinsic parameters of the plenoptic camera model, the 3D coordinates of the calibration points, and all camera poses in a single bundle adjustment. Our plenoptic camera based visual odometry algorithm, called direct plenoptic odometry (DPO), is a direct and semi-dense approach, which takes advantage of the full sensor resolution. DPO also relies on our multiple view geometry for plenoptic cameras. Tracking and mapping works directly on the micro images formed by the micro lens array and, therefore, has not to deal with aliasing effects in the spatial domain. The algorithm generates a semi-dense depth map based on correspondences between subsequent light-field frames, while taking differently focused micro images into account. Up to our knowledge, it is the first method that performs tracking and mapping for plenoptic cameras directly on the micro images. DPO outperforms state-of-the-art direct monocular simultaneous localization and mapping (SLAM) algorithms and can compete in accuracy with latest stereo SLAM approaches, while supplying much more detailed point clouds.
Autors: Niclas Zeller;Franz Quint;Uwe Stilla;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Oct 2017, volume: 11, issue:7, pages: 1004 - 1019
Publisher: IEEE
 
» From the editors' desk
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Ed Cherney;Robert Fleming;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Oct 2017, volume: 33, issue:5, pages: 7 - 8
Publisher: IEEE
 
» Fronthaul-Limited Uplink OFDMA in Ultra-Dense CRAN With Hybrid Decoding
Abstract:
In an ultra-dense cloud radio access network (UD-CRAN), a large number of remote radio heads (RRHs), typically employed as simple relay nodes, are distributed in a target area, which could even outnumber their served users. However, one major challenge is that the large amount of information required to be transferred between each RRH and the central processor (CP) for joint signal processing can easily exceed the capacity of the fronthaul links connecting them. This motivates our study in this paper on a new hybrid decoding scheme where in addition to quantizing and forwarding the received signals for joint decoding at the CP, i.e., forward-and-decode (FaD) as in the conventional CRAN, the RRHs can locally decode-and-forward (DaF) the user messages to save the fronthaul capacity. In particular, we consider the uplink transmission in an orthogonal frequency division multiple access (OFDMA)-based UD-CRAN, where the proposed hybrid decoding is performed on each OFDMA sub-channel (SC). We study a joint optimization of the processing mode selections (DaF or FaD), user-SC assignments and the users’ transmit power allocations over all SCs to maximize their weighted-sum-rate subject to the RRHs’ individual fronthaul capacity constraints and the users’ individual power constraints. Although the problem is nonconvex, we propose a Lagrange duality based solution, which can be efficiently computed with good accuracy. Further, we propose a low-complexity greedy algorithm which is shown to achieve close to the optimal performance under practical setups. Simulation results show the promising throughput gains of the proposed designs with hybrid decoding, compared to the existing schemes that perform either DaF or FaD at al- SCs.
Autors: Reuben George Stephen;Rui Zhang;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Oct 2017, volume: 66, issue:10, pages: 9074 - 9084
Publisher: IEEE
 
» FTC and Apple Sue Qualcomm for Cell Phone Standardization Skullduggery, Part 3: Determining SEP Reasonable Royalty
Abstract:
This article, the third in a multipart series, describes and comments on the relief that the courts award in cases involving standard-essential patents (SEPs)—the law that courts have established on how to determine a reasonable royalty—in particular, a royalty on reasonable and nondiscriminatory terms (RAND royalty) for a SEP.
Autors: Richard H. Stern;
Appeared in: IEEE Micro
Publication date: Oct 2017, volume: 37, issue:5, pages: 61 - 69
Publisher: IEEE
 
» Fully Autonomous Driving: Where Technology and Ethics Meet
Abstract:
The prospect of automatized car traffic confronts ethics, law, and politics with novel and far-reaching questions. It cannot be excluded that automatized cars meet with critical situations in which losses of life and limb are inevitable and in which the necessity arises to negotiate between two or more evils. Despite all security measures, a residual risk is unavoidable, which raises questions: How safe is safe enough? How safe is too safe? This contribution argues that it is important to clearly separate between the tasks of technology and ethics as well as between the responsibilities of different stakeholders.
Autors: Dieter Birnbacher;Wolfgang Birnbacher;
Appeared in: IEEE Intelligent Systems
Publication date: Oct 2017, volume: 32, issue:5, pages: 3 - 4
Publisher: IEEE
 
» Fully Convolutional Network With Task Partitioning for Inshore Ship Detection in Optical Remote Sensing Images
Abstract:
Ship detection in optical remote sensing imagery has drawn much attention in recent years, especially with regards to the more challenging inshore ship detection. However, recent work on this subject relies heavily on hand-crafted features that require carefully tuned parameters and on complicated procedures. In this letter, we utilize a fully convolutional network (FCN) to tackle the problem of inshore ship detection and design a ship detection framework that possesses a more simplified procedure and a more robust performance. When tackling the ship detection problem with FCN, there are two major difficulties: 1) the long and thin shape of the ships and their arbitrary direction makes the objects extremely anisotropic and hard to be captured by network features and 2) ships can be closely docked side by side, which makes separating them difficult. Therefore, we implement a task partitioning model in the network, where layers at different depths are assigned different tasks. The deep layer in the network provides detection functionality and the shallow layer supplements with accurate localization. This approach mitigates the tradeoff of FCN between localization accuracy and feature representative ability, which is of importance in the detection of closely docked ships. The experiments demonstrate that this framework, with the advantages of FCN and the task partitioning model, provides robust and reliable inshore ship detection in complex contexts.
Autors: Haoning Lin;Zhenwei Shi;Zhengxia Zou;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Oct 2017, volume: 14, issue:10, pages: 1665 - 1669
Publisher: IEEE
 
» Fully Distributed Demand Response Using the Adaptive Diffusion–Stackelberg Algorithm
Abstract:
In this paper, we consider the demand response problem in smart grid consisting of a retailer and multiple residential consumers, where the retailer determines consumers’ payments based on their power consumption profile. Our aim is to propose a fully distributed algorithm that is able to optimize the aggregate cost, utility, and retailer's profit simultaneously. To this end, we first formulate the consumer-side trend as a constrained convex optimization problem and propose a fully distributed adaptive diffusion algorithm to solve it. In addition, we design a one-leader -follower Stackelberg game to model interactions among the retailer and consumers. The proposed framework is able to continuously track the drifts resulting from the changes in the real-time pricing or the consumer preferences. Moreover, it is scalable and does not require network-wide information or rely on central controller. We provide comprehensive simulation results to show the effectiveness of the proposed framework.
Autors: Milad Latifi;Azam Khalili;Amir Rastegarnia;Saeid Sanei;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2291 - 2301
Publisher: IEEE
 
» Fully Programmable Redundancy Circuits for STT-MRAM
Abstract:
We propose fully programmable redundancy schemes for spin-transfer-torque magnetic random access memories (STT-MRAMs). To store redundancy information, these schemes use magnetic tunnel junctions (MTJs), which are core memory elements of STT-MRAMs. This can greatly simplify the fabrication process of STT-MRAMs. Furthermore, it also allows reprogramming of the redundancy information after packaging or even during normal use by end-users without requiring any special high-voltage setup. We propose two redundancy schemes. First, we propose an address comparator, which uses MTJs and is a direct replacement of a conventional address comparator. Second, we propose a scheme in which the redundancy circuits share the storage cells and read–write peripheral circuits with the normal data array structure.
Autors: Dong-Gi Lee;Sang-Gyu Park;
Appeared in: IEEE Transactions on Magnetics
Publication date: Oct 2017, volume: 53, issue:10, pages: 1 - 6
Publisher: IEEE
 
» Fully Reconfigurable Manifold Multiplexer
Abstract:
In this paper, a fully reconfigurable three channel manifold-coupled output multiplexer is presented. The multiplexer is based on frequency and bandwidth reconfigurable four-pole filters with two transmission zeros. The filters employ nonresonating cavities to achieve tunability of couplings. A novel manifold reconfiguration concept has been developed, allowing frequency and bandwidth tuning for filters connected to the manifold. This is achieved by adding tunable reactive elements along the manifold. These reactive elements allow the phase relationships between the channels to be adapted. This concept has been demonstrated on a three-channel multiplexer operating at ka-band frequencies (in satellite communication ka-band denotes the 17.7–21.2-GHz band for downlink). It allows contiguous as well as noncontiguous frequency plans. The multiplexer band could be tuned to a frequency range of 500 MHz (19.9–20.4 GHz), and the bandwidth for the individual filters could be tuned from 36 to 72 MHz. Even swapping the center frequencies of two filters on the manifold is possible.
Autors: Christian Arnold;Jean Parlebas;Richard Meiser;Thomas Zwick;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3885 - 3891
Publisher: IEEE
 
» Fully Solution Processed Bottom-Gate Organic Field-Effect Transistor With Steep Subthreshold Swing Approaching the Theoretical Limit
Abstract:
This letter realizes both large gate dielectric capacitance and reduced sub-gap density of states at the channel in the same organic field effect transistor (OFET) structure by adopting optimized low-k/high-k bilayer gate dielectric. Subthreshold swing (SS) as small as 64 mV dec can be achieved with a thick (>360 nm) gate dielectric layer. This is the smallest SS value reported so far for all reported low voltage OFETs, and is even comparable with that of 22 nm technology node Si-FETs. The device can thus be switched within a very small voltage swing of 0.8 V, while having an ON/OFF ratio larger than 105. The device also shows excellent operational and storage stabilities.
Autors: Jiaqing Zhao;Wei Tang;Qiaofeng Li;Wenjiang Liu;Xiaojun Guo;
Appeared in: IEEE Electron Device Letters
Publication date: Oct 2017, volume: 38, issue:10, pages: 1465 - 1468
Publisher: IEEE
 
» Functional Graphical Models for Manufacturing Process Modeling
Abstract:
Graphical models are widely used to model the statistical relationships among variables in a system. Existing graphical models can be used to model the relationships among scalar variables, but cannot be directly applied to model a system with functional variables. In this paper, a novel functional graphical model is proposed to model complex systems where functional variables are measured. To cope with the small sample size problem, we further develop a special sparsity penalization approach to robustly learn the graphical model from limited sample size, and develop a difference from the mean penalization for functional variables. Simulation studies and a case study in a plasma spray manufacturing process are used to demonstrate the effectiveness of the proposed method.

Note to Practitioners—Emerging sensing and information technologies have provided unprecedented functional data collection capacity from systems over time. It is important and challenging to model the relationships among these variables. Among many different modeling alternatives, graphical models are powerful tools to characterize the underlying relationships among variables in systems. However, traditional graphical models cannot directly model a system with a mixture of functional and scalar variables. The proposed model aims to address this challenge by proposing a functional graphical model. Based on simulation studies and a case study for a plasma spray manufacturing process, it is shown that the proposed method performs well under various conditions.

Autors: Hongyue Sun;Shuai Huang;Ran Jin;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Oct 2017, volume: 14, issue:4, pages: 1612 - 1621
Publisher: IEEE
 
» Fundamental Limits of Non-Coherent Interference Alignment via Matroid Theory
Abstract:
We consider the problem of non-coherent interference alignment, in which the goal is to align the signals of multiple interfering transmitters at a single receiver where the transmitters are not aware of the channel state information. We cast this problem as a problem of determining rank loss conditions for a column concatenation of full-rank matrices, such that each row of the composing matrices is scaled by a random coefficient. We determine necessary and sufficient conditions for the design of each matrix, such that the random ensemble will almost surely lose rank by a certain amount. The result is proved by converting the problem to determining rank loss conditions for the union of some specific matroids, and then using tools from matroid and graph theories to derive the necessary and sufficient conditions. As an application, we discuss how this result can be applied to the problem of topological interference management, and characterize the linear symmetric degrees of freedom for a class of network topologies.
Autors: Navid Naderializadeh;Aly El Gamal;A. Salman Avestimehr;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6573 - 6586
Publisher: IEEE
 
» Further Results on Extended Delivery Time for Secondary Packet Transmission
Abstract:
Cognitive radio transceiver can opportunistically access the underutilized spectrum resource of primary systems for new wireless services. With interweave cognitive implementation, secondary transmission may be interrupted by primary transmission. To facilitate the packet delay analysis of such secondary transmission, we study the extended delivery time of secondary packet transmission. In particular, we derive the exact distribution function of extended delivery time of a fixed-size secondary packet with non-work-preserving strategy, where interrupted packets must be repeated. We also analyze the effect of imperfect periodic sensing, i.e., the secondary user periodically senses the spectrum for availability, with a chance of missing an available channel on a certain sensing attempt. These results complement previous work on work-preserving strategy with perfect sensing. Selected numerical and simulation results are presented for verifying the mathematical formulation.
Autors: Muneer Usman;Hong-Chuan Yang;Mohamed-Slim Alouini;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Oct 2017, volume: 16, issue:10, pages: 6451 - 6459
Publisher: IEEE
 
» Fusing Complete Monotonic Decision Trees
Abstract:
Monotonic classification is a kind of classification task in which a monotonicity constraint exist between features and class, i.e., if sample has a higher value in each feature than sample , it should be assigned to a class with a higher level than the level of 's class. Several methods have been proposed, but they have some limits such as with limited kind of data or limited classification accuracy. In our former work, the classification accuracy on monotonic classification has been improved by fusing monotonic decision trees, but it always has a complex classification model. This work aims to find a monotonic classifier to process both nominal and numeric data by fusing complete monotonic decision trees. Through finding the completed feature subsets based on discernibility matrix on ordinal dataset, a set of monotonic decision trees can be obtained directly and automatically, on which the rank is still preserved. Fewer decision trees are needed, which will serve as base classifiers to construct a decision forest fused complete monotonic decision trees. The experiment results on 10 datasets demonstrate that the proposed method can reduce the number of base classifiers effectively and then simplify classification model, and obtain good classification performance simultaneously.
Autors: Hang Xu;Wenjian Wang;Yuhua Qian;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Oct 2017, volume: 29, issue:10, pages: 2223 - 2235
Publisher: IEEE
 
» Fusion of Visible Light Indoor Positioning and Inertial Navigation Based on Particle Filter
Abstract:
With the increasing demand for indoor positioning-based services, indoor positioning methods based on Bluetooth, Wi-Fi, ultra wide band (UWB), inertial navigation, and visual light communications (VLC) have been proposed. Considering the limitations of accuracy, cost and complexity, we propose a fusion positioning scheme integrating VLC positioning and inertial navigation base on particle filter. The experimental results demonstrated that the performance degradation caused by the multipath effect and light obstruction in VLC-based positioning and the cumulative error associated with inertial navigation are solved in the proposed fusion system. The accuracy of the fusion positioning system is in centimeters, which is two to four times better as compared to the VLC-based positioning or inertial navigation alone. Furthermore, the fusion positioning system has the advantages of high accuracy, energy saving, low cost, and easy to install, making it a promising candidate for future indoor positioning applications.
Autors: Zhitian Li;Aiying Yang;Huichao Lv;Lihui Feng;Wenzhan Song;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 13
Publisher: IEEE
 
» Future trends in security for Instrumentation and Measurement [Trends in Future I&M]
Abstract:
In the past several issues of I&M Magazine, I have introduced to you people who explained how their lives are influenced by instrumentation and measurement. I am still preparing some articles that are meant to show you how various fields of activity are influenced by this topic.
Autors: Irina Florea;
Appeared in: IEEE Instrumentation & Measurement Magazine
Publication date: Oct 2017, volume: 20, issue:5, pages: 21 - 22
Publisher: IEEE
 
» Fuzzy Color Spaces: A Conceptual Approach to Color Vision
Abstract:
In this paper, we introduce formal definitions of the concepts of fuzzy color and fuzzy color space. First, we formalize the notion of fuzzy color for representing the correspondence between computational representation of colors and perceptual color categories identified by a color name. Second, we propose a methodology for learning fuzzy colors based on the paradigm of conceptual spaces, where prototypes are used for each category to be learnt. Since the conceptual space approach yields crisp categorizations, we introduce a novel methodology for defining fuzzy boundaries of color categories on the basis of a Voronoi tessellation of a color space. Finally, we also formalize the notion of fuzzy color space as the collection of fuzzy colors corresponding to the color categories employed in a certain context/application and/or for a specific user. Different typologies of fuzzy color spaces are proposed in order to be consistent with the nature of the categories we want to model. Our approach is illustrated by defining fuzzy color spaces using RGB with the Euclidean distance. Examples based on the well-known ISCC-NBS color naming system are presented, as well as others based on collections of color names and prototypes provided by users. The proposal is evaluated and compared with the most used approaches for color modeling. Additionally, a website located at http://www.jfcssoftware.com including all experimentation data, software implementing our models, and additional materials is available to researchers in color modeling.
Autors: Jesus Chamorro-Martínez;Jose Manuel Soto-Hidalgo;Pedro Manuel Martínez-Jiménez;Daniel Sánchez;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2017, volume: 25, issue:5, pages: 1264 - 1280
Publisher: IEEE
 
» Fuzzy Fault Detection Filter Design for T–S Fuzzy Systems in the Finite-Frequency Domain
Abstract:
This paper deals with the fault detection filter design for a nonlinear discrete-time system in the Takagi–Sugeno fuzzy form with faults and unknown inputs. Both unknown input and fault frequencies are assumed to be known and to reside in low-/middle-/high-frequency ranges. A filter is proposed in the finite-frequency domain to reduce the conservatism generated by those designed in the entire-frequency domain. In order to guarantee the best robustness to disturbances and sensitivity to faults, the developed filter combines the / performances. The asymptotic stability of the filtering error dynamics is ensured by using a fuzzy Lyapunov function and a linear matrix inequality approach. Finally, two examples are presented to validate the proposed new design techniques.
Autors: Ali Chibani;Mohammed Chadli;Peng Shi;Naceur Benhadj Braiek;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2017, volume: 25, issue:5, pages: 1051 - 1061
Publisher: IEEE
 
» Fuzzy Scheduled Optimal Control of Integrated Vehicle Braking and Steering Systems
Abstract:
The safe hard braking of a turned vehicle requires short stopping distance while maintaining the vehicle in the path. To achieve the first aim, a wheel slip controller is designed to calculate the maximum braking force of each wheel according to the tire/road conditions. For the second aim, a new optimal multivariable controller for integrated active front steering and direct yaw moment control is analytically developed to control the vehicle directional stability directly. Since the required stabilizing external yaw moment has to be produced by reducing the maximum achievable braking forces of one side wheels, it leads to increase the stopping distance and should be kept as low as possible. In an effective way to manage the integrated control inputs, a fuzzy logic is defined to determine the weight factor of each control input in the integrated optimal control law. This logic is defined using the stability index obtained by the phase plane analysis of nonlinear vehicle model. Therefore, the proposed controller can be tuned automatically for different driving conditions. The simulation results carried out using a validated vehicle model demonstrate that the integrated control system has a better performance compared with stand-alone braking and steering systems to attain the desired purposes.
Autors: Mehdi Mirzaei;Hossein Mirzaeinejad;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Oct 2017, volume: 22, issue:5, pages: 2369 - 2379
Publisher: IEEE
 
» Fuzzy Wavelet Polynomial Neural Networks: Analysis and Design
Abstract:
In this study, we propose a concept of fuzzy wavelet polynomial neural networks (FWPNNs) based on concepts and constructs of polynomial neural networks and fuzzy wavelet neurons (FWNs). These networks exhibit a rule-based architecture while each rule in the FWN consists of the premise part and consequence part. The premise part is realized by using C-means clustering method, while the consequence part is realized by means of wavelet functions whose parameters are estimated with the aid of the least square method. In some sense, the FWPNN can be regarded as a generalized fuzzy wavelet neural network (FWNN). Unlike Gaussian membership functions that are commonly utilized to implement the premise part of the rules in typical FWNNs, C-means method is employed here to overcome a possible curse of dimensionality. Polynomial neural networks (PNNs) are used to express the nonlinearity of a complex system. Furthermore, the particle swarm optimization is used to optimize the design parameters of the proposed network. Based on the PNNs and FWNNs, the proposed FWPNNs take advantages of these two neural networks: it exhibits the abilities to describe high-order nonlinear relations between input and output variables and it is beneficial to describe models impacted by uncertainty. The proposed FWPNNs are applied for time-series prediction and regression problems (e.g., control of dynamic plants). Several well-known modeling benchmarks including regression and time series are considered to evaluate the performance of the proposed FWPNNs. A comparative analysis shows that the proposed FWPNNs result in better performance when comparing with some previous models reported in the literature.
Autors: Wei Huang;Sung-Kwun Oh;Witold Pedrycz;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2017, volume: 25, issue:5, pages: 1329 - 1341
Publisher: IEEE
 
» Fuzzy-Based Clustering-Task Scheduling for Lifetime Enhancement in Wireless Sensor Networks
Abstract:
Clustering is one of the effective approaches for prolonging the lifetime of a wireless sensor network and increasing its scalability. In current clustering protocols, load balancing is achieved by rotating the costly role of the cluster head among the sensors. To achieve this, the network operation is divided into fixed time durations called rounds. Network nodes are clustered for one round and are reclustered for the next round, i.e., round-based policy. Using this policy, loads of nodes are somewhat balanced. However, the imposed overhead from consecutive reclusterings wastes the energy resource of network nodes. Although many attempts have been made to introduce energy-efficient clustering protocols, the reclustering overhead still remains a serious drawback of these protocols. To mitigate this problem, this paper proposes a fuzzy-based hyper round policy (FHRP) to efficiently and flexibly schedule the clustering-task. In FHRP, instead of every round, clustering is performed at the beginning of every Hyper Round (HR), which is composed of many rounds. During the network lifetime, the length of an HR is not fixed and is computed using a fuzzy inference system. The node’s residual energy and its distance from the sink are used as the inputs of this fuzzy system and the HR length is its output. Thus, the nodes’ situation is taken into account for determining the reclustering time. Simulation results reveal the effectiveness of FHRP in reducing the clustering energy overhead, lengthening the network lifetime, and conserving the network nodes’ energy.
Autors: Peyman Neamatollahi;Mahmoud Naghibzadeh;Saeid Abrishami;
Appeared in: IEEE Sensors Journal
Publication date: Oct 2017, volume: 17, issue:20, pages: 6837 - 6844
Publisher: IEEE
 
» Gait Phase Estimation Based on Noncontact Capacitive Sensing and Adaptive Oscillators
Abstract:
This paper presents a novel strategy aiming to acquire an accurate and walking-speed-adaptive estimation of the gait phase through noncontact capacitive sensing and adaptive oscillators (AOs). The capacitive sensing system is designed with two sensing cuffs that can measure the leg muscle shape changes during walking. The system can be dressed above the clothes and free human skin from contacting to electrodes. In order to track the capacitance signals, the gait phase estimator is designed based on the AO dynamic system due to its ability of synchronizing with quasi-periodic signals. After the implementation of the whole system, we first evaluated the offline estimation performance by experiments with 12 healthy subjects walking on a treadmill with changing speeds. The strategy achieved an accurate and consistent gait phase estimation with only one channel of capacitance signal. The average root-mean-square errors in one stride were 0.19 rad (3.0% of one gait cycle) for constant walking speeds and 0.31 rad (4.9% of one gait cycle) for speed transitions even after the subjects rewore the sensing cuffs. We then validated our strategy in a real-time gait phase estimation task with three subjects walking with changing speeds. Our study indicates that the strategy based on capacitive sensing and AOs is a promising alternative for the control of exoskeleton/orthosis.
Autors: Enhao Zheng;Silvia Manca;Tingfang Yan;Andrea Parri;Nicola Vitiello;Qining Wang;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Oct 2017, volume: 64, issue:10, pages: 2419 - 2430
Publisher: IEEE
 
» Gamesman Problems [Gamesman Problems]
Abstract:
Various puzzles, games, humorous definitions, or mathematical that should engage the interest of readers.
Autors: Athanasios Kakarountas;
Appeared in: IEEE Potentials
Publication date: Oct 2017, volume: 36, issue:5, pages: 48 - 48
Publisher: IEEE
 
» Gamesman Solutions [Gamesman Solutions]
Abstract:
Various puzzles, games, humorous definitions, or mathematical that should engage the interest of readers.
Autors: Athanasios Kakarountas;
Appeared in: IEEE Potentials
Publication date: Oct 2017, volume: 36, issue:5, pages: 5 - 5
Publisher: IEEE
 
» Gamifying Video Object Segmentation
Abstract:
Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.
Autors: Concetto Spampinato;Simone Palazzo;Daniela Giordano;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Oct 2017, volume: 39, issue:10, pages: 1942 - 1958
Publisher: IEEE
 
» GaN HEMT DC $I$ – $V$ Device Model for Accurate RF Rectifier Simulation
Abstract:
Recently, various high-efficiency RF rectifiers have been proposed. In this letter, to improve the simulation accuracy of RF active rectifier circuits, a new device model for GaN HEMTs is proposed that improves the reproducibility of – characteristics in the third-quadrant region (both drain voltage and drain current are negative). Based on measured characteristic data of an actual GaN HEMT, the device parameters for this model have been decided, and the advantage of the new device model has been confirmed.
Autors: Tsukasa Yasui;Ryo Ishikawa;Kazuhiko Honjo;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2017, volume: 27, issue:10, pages: 930 - 932
Publisher: IEEE
 
» GaN-Based Generic Bifunction LED for Potential Duplex Free-Space VLCs
Abstract:
A generic bifunction GaN light-emitting diode (LED) structure, which has a 300 nm n+ -ZnO epitaxial layer grown on a standard GaN LED epistack and a mesa size of , exhibits a peak responsivity of 450 mA/W to purple lights (380–400 nm) under zero bias and a narrow bandpass of around 60 nm. The corresponding product of quantum efficiency and gain is estimated as 140%. The purple light (380–400 nm) to blue light (>460 nm) rejection ratio can reach two orders of magnitude. The generic bifunction LED does not sacrifice its optical and modulation performances as a light transmitter. The optical power reaches 100 mW with a peak wavelength around 447 nm. A new proposition for duplex free-space visible light communications is depicted.
Autors: Lilin Liu;Xiangying Zhang;Zhenkun Sun;Bing Yan;Dongdong Teng;Gang Wang;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 11
Publisher: IEEE
 
» Gaussian Fitness Functions for Optimizing Analog CMOS Integrated Circuits
Abstract:
Analog CMOS integrated circuits (ICs) designs depend typically on designer knowledge and experience, as such problems are multivariate and multiobjective, presenting many combinations of input variables to be investigated in order to meet the required specifications. Nowadays, the a posteriori approach is widely used to perform the optimization processes of analog CMOS ICs using evolutionary algorithms. However, these techniques are not totally able to explore potential solutions in specific regions of the Pareto front. Designers then have difficulty in choosing the best solution capable of achieving all desired specifications simultaneously among all the ones found. In this context, the a priori approach using fitness functions has become an important alternative method to overcome these issues of the a posteriori methodology. This paper aims to compare different fitness function profiles used in the a priori optimization processes to boost the effectiveness of the search processes in relation to robustness, accuracy, and yield in analog CMOS ICs designs. We show that the Gaussian profile, proposed here, applied to the lower limit, center value, and upper limit fitness functions is able to improve all the a priori optimization evolutionary techniques investigated, including the genetic, imperialist competitive, and shuffled frog leaping algorithms.
Autors: Rodrigo Alves de Lima Moreto;Carlos Eduardo Thomaz;Salvador Pinillos Gimenez;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Oct 2017, volume: 36, issue:10, pages: 1620 - 1632
Publisher: IEEE
 
» Gaussian Process Autoregression for Simultaneous Proportional Multi-Modal Prosthetic Control With Natural Hand Kinematics
Abstract:
Matching the dexterity, versatility, and robustness of the human hand is still an unachieved goal in bionics, robotics, and neural engineering. A major limitation for hand prosthetics lies in the challenges of reliably decoding user intention from muscle signals when controlling complex robotic hands. Most of the commercially available prosthetic hands use muscle-related signals to decode a finite number of predefined motions and some offer proportional control of open/close movements of the whole hand. Here, in contrast, we aim to offer users flexible control of individual joints of their artificial hand. We propose a novel framework for decoding neural information that enables a user to independently control 11 joints of the hand in a continuous manner—much like we control our natural hands. Toward this end, we instructed six able-bodied subjects to perform everyday object manipulation tasks combining both dynamic, free movements (e.g., grasping) and isometric force tasks (e.g., squeezing). We recorded the electromyographic and mechanomyographic activities of five extrinsic muscles of the hand in the forearm, while simultaneously monitoring 11 joints of hand and fingers using a sensorized data glove that tracked the joints of the hand. Instead of learning just a direct mapping from current muscle activity to intended hand movement, we formulated a novel autoregressive approach that combines the context of previous hand movements with instantaneous muscle activity to predict future hand movements. Specifically, we evaluated a linear vector autoregressive moving average model with exogenous inputs and a novel Gaussian process () autoregressive framework to learn the continuous mapping from hand joint dynamics and muscle activity to decode intended hand movement. Our approa- h achieves high levels of performance (RMSE of 8°/s and ). Crucially, we use a small set of sensors that allows us to control a larger set of independently actuated degrees of freedom of a hand. This novel undersensored control is enabled through the combination of nonlinear autoregressive continuous mapping between muscle activity and joint angles. The system evaluates the muscle signals in the context of previous natural hand movements. This enables us to resolve ambiguities in situations, where muscle signals alone cannot determine the correct action as we evaluate the muscle signals in their context of natural hand movements. autoregression is a particularly powerful approach which makes not only a prediction based on the context but also represents the associated uncertainty of its predictions, thus enabling the novel notion of risk-based control in neuroprosthetics. Our results suggest that autoregressive approaches with exogenous inputs lend themselves for natural, intuitive, and continuous control in neurotechnology, with the particular focus on prosthetic restoration of natural limb function, where high dexterity is required for complex movements.
Autors: Michele Xiloyannis;Constantinos Gavriel;Andreas A. C. Thomik;A. Aldo Faisal;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Oct 2017, volume: 25, issue:10, pages: 1785 - 1801
Publisher: IEEE
 
» General Lyapunov Functions for Consensus of Nonlinear Multiagent Systems
Abstract:
In this brief, we investigate the consensus problem of nonlinear multiagent systems by means of general Lyapunov functions. That is, by constructing general Lyapunov functions, such as polynomial Lyapunov functions beyond quadratic forms, a sufficient condition is established for achieving global consensus. Compared with the existing consensus criteria deduced by quadratic Lyapunov functions, our consensus criterion is less conservative and can be applicable for more systems. In particular, for polynomial systems and even certain classes of nonpolynomial systems, our consensus criterion can be formulated based on polynomial Lyapunov functions, which can be calculated by using the sum-of-squares (SOS) programming tools such as SOSTOOLS. Finally, two simulation examples are given to illustrate the effectiveness of our proposed theoretical results.
Autors: Quanyi Liang;Zhikun She;Lei Wang;Housheng Su;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2017, volume: 64, issue:10, pages: 1232 - 1236
Publisher: IEEE
 
» General Power Equation of Switched Reluctance Machines and Power Density Comparison
Abstract:
Switched reluctance machines (SRMs) are becoming increasingly attractive due to their inherent advantages, such as robust and rare-earth-permanent magnet-free topology, as well as excellent fault-tolerance and temperature management. However, the accurate and efficient analyses of SRMs are always challenging since they operate with variable reluctance and pulsating excitation, suffering severe nonlinear characteristics. This paper first introduces a general power equation of SRMs, which can be a powerful tool in the investigation of SRMs. Then, the proposed power equation is validated by finite element (FE) results and experimental results with different excitations. Afterwards, the calculated results with various conditions including different stator inner diameters and different stator outer diameters are compared with the FE-predicted results. Finally, the comparison between SRMs and several conventional machines is carried out to evaluate the power density of SRMs.
Autors: Wei Hua;Guishu Zhao;Hao Hua;Ming Cheng;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4298 - 4307
Publisher: IEEE
 
» Generalized Analytical Expression for Natural Frequencies of a Single Isolated Air-Core Inhomogeneous Transformer Winding
Abstract:
Given a completely inhomogeneous, fully-coupled, N-section ladder network in which elements of each section are distinct from the others, there exists no closed-form solution which connects the ladder network elements to its natural frequencies. Instead of the present practice of comparing individual natural frequencies, finding such a generalized solution would not only permit quantification of deviations between two frequency responses (FRA) but also provides a generic platform for its interpretation. Presently, interpretation of FRA is mostly empirical and difficult to generalize. Although pioneering contributions by Bewley et al., Abetti and Maginniss, Heller and Veverka, and many others, were made towards developing analytical solutions, they were essentially suitable for a homogeneous winding. For any formulation to become suitable for FRA interpretation (corresponding to a pre and postdamage condition), it must obviously be applicable to an inhomogeneous winding structure. Pursuing this motivation, this paper presents complete details of derivation of analytical expressions that aims to correlate natural frequencies (and their deviations as well) of the ladder network to its basic inductances and capacitances. For this, both short-circuit and open-circuit natural frequencies are examined. Finally, the analytical solution is extended from the discrete-domain to the continuous-domain (transformer winding). Recently, authors have shown practical usefulness of this derived formula for localization and severity assessment of radial/axial displacements in an actual single-isolated continuousdisk transformer winding.
Autors: Pritam Mukherjee;L. Satish;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Oct 2017, volume: 32, issue:5, pages: 2313 - 2319
Publisher: IEEE
 
» Generalized Blind Detection of OOK Modulation for Free-Space Optical Communication
Abstract:
For optimal detection of ONOFF keying symbols in free-space optical (FSO) communication, the receiver requires the instantaneous channel fading coefficient. In this letter, to increase the bandwidth efficiency of the FSO channel, we propose a blind data detection method, i.e., without requiring transmission of any training symbols. The proposed blind detection is a two-step method that performs block-by-block detection. Simulation results show that the proposed receiver can achieve a significantly lower bit-error-rate performance compared with the existing blind methods in the context of FSO communications. In addition, the proposed blind method has a simple structure, which makes it particularly suitable for fast FSO communications.
Autors: Mohammad Taghi Dabiri;Seyed Mohammad Sajad Sadough;
Appeared in: IEEE Communications Letters
Publication date: Oct 2017, volume: 21, issue:10, pages: 2170 - 2173
Publisher: IEEE
 
» Generalized Debye Sources-Based EFIE Solver on Subdivision Surfaces
Abstract:
The electric field integral equation is a well-known workhorse for obtaining fields scattered by a perfect electric conducting object. As a result, the nuances and challenges of solving this equation have been examined for a while. Two recent papers motivate the effort presented in this paper. Unlike traditional work that uses equivalent currents defined on surfaces, recent research proposes a technique that results in well-conditioned systems by employing generalized Debye sources (GDS) as unknowns. In a complementary effort, some of us developed a method that exploits the same representation for both the geometry (subdivision surface representations) and functions defined on the geometry, also known as isogeometric analysis (IGA). The challenge in generalizing GDS method to a discretized geometry is the complexity of the intermediate operators. However, thanks to our earlier work on subdivision surfaces, the additional smoothness of geometric representation permits discretizing these intermediate operations. In this paper, we employ both ideas to present a well-conditioned GDS-electric field integral equation. Here, the intermediate surface Laplacian is well discretized by using subdivision basis. Likewise, using subdivision basis to represent the sources results in an efficient and accurate IGA framework. Numerous results are presented to demonstrate the efficacy of the approach.
Autors: Xin Fu;Jie Li;Li Jun Jiang;Balasubramaniam Shanker;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5376 - 5386
Publisher: IEEE
 
» Generalized Degrees of Freedom of the Symmetric $K$ User Interference Channel Under Finite Precision CSIT
Abstract:
The generalized degrees of freedom (GDoF) characterization of the symmetric user interference channel is obtained under finite precision channel state information at the transmitters (CSIT). The symmetric setting is where each cross channel is capable of carrying DoF, while each direct channel is capable of carrying 1 DoF. Remarkably, under finite precision CSIT the symmetric user interference channel loses all the GDoF benefits of interference alignment. The GDoF per user diminish with the number of users everywhere except in the very strong (optimal for every receiver to decode all messages) and very weak (optimal to treat all interference as noise) interference regimes. The result stands in sharp contrast to prior work on the symmetric setting under perfect CSIT, where the GDoF per user remain undiminished due to interference alignment. The result also stands in contrast to prior work on a subclass of asymmetric settings under finite precision CSIT, i.e., the topological interference management problem, where interference alignment plays a crucial role and provides substantial GDoF benefits.
Autors: Arash Gholami Davoodi;Syed Ali Jafar;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6561 - 6572
Publisher: IEEE
 
» Generalized Determination of Device Noise Parameters
Abstract:
This paper presents a rigorous analysis to determine the noise parameters of linear noisy microwave networks with any number of ports. The analysis expands a well-established approach for the determination of the noise parameters of a linear two-port network to any linear -port networks and enhances the understanding of its measurement procedure as a particular case of this analysis. A thorough discussion of the results of this analysis identifies constraints and highlights practical requirements for a successful noise characterization setup of any -port networks. The analysis is then applied to the measurement of four-port networks. The determination of passive network’s noise parameters allows the experimental validation of the theory, while the determination of an active four-port network’s noise parameters is of particular interest, because its differential noise figure can be determined directly from its noise parameters without the use of external baluns.
Autors: Luciano Boglione;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 4014 - 4025
Publisher: IEEE
 
» Generalized Dual-Band Unequal Filtering Power Divider With Independently Controllable Bandwidth
Abstract:
In this paper, a novel design method of generalized dual-band unequal filtering power divider (DUFPD) is proposed. Using this method, the power divider (PD) could be designed to realize the dual-band filtering response with arbitrary power division, arbitrary frequency ratio, arbitrary real terminated impedances, independently controllable bandwidth, and excellent isolation. To satisfy these characteristics, a proper dual-band filtering structure is selected to replace the conventional quarter-wave length transmission line in the PD. In addition, a single resistor structure is utilized to obtain effective isolation between the output ports. Furthermore, the complete design procedures and analytical equations of the proposed generalized DUFPD are presented based on the circuit and transmission line theories. To demonstrate the validity of the proposed design method, a DUFPD with different real terminated impedances is designed, fabricated, and measured. We show that there is a good agreement between the simulated and measured results.
Autors: Yongle Wu;Zheng Zhuang;Guangyou Yan;Yuanan Liu;Zabih Ghassemlooy;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3838 - 3848
Publisher: IEEE
 
» Generalized Orthopair Fuzzy Sets
Abstract:
We note that orthopair fuzzy subsets are such that that their membership grades are pairs of values, from the unit interval, one indicating the degree of support for membership in the fuzzy set and the other support against membership. We discuss two examples, Atanassov's classic intuitionistic sets and a second kind of intuitionistic set called Pythagorean. We note that for classic intuitionistic sets the sum of the support for and against is bounded by one, while for the second kind, Pythagorean, the sum of the squares of the support for and against is bounded by one. Here we introduce a general class of these sets called q-rung orthopair fuzzy sets in which the sum of the th power of the support for and the th power of the support against is bonded by one. We note that as q increases the space of acceptable orthopairs increases and thus gives the user more freedom in expressing their belief about membership grade. We investigate various set operations as well as aggregation operations involving these types of sets.
Autors: Ronald R. Yager;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2017, volume: 25, issue:5, pages: 1222 - 1230
Publisher: IEEE
 
» Generalized Plateaued Functions and Admissible (Plateaued) Functions
Abstract:
Plateaued functions are very important crypto- graphic functions due to their various desirable cryptographic characteristics. We point out that plateaued functions are more general than bent functions (that is, functions with maximum nonlinearity). Some Boolean plateaued functions have large nonlinearity, which provides protection against fast correlation attacks when they are used as combiners or filters in stream ciphers, and contributes, when they are the component functions of the substitution boxes in block ciphers, to protection against linear cryptanalysis. P-ary plateaued functions have attracted recently some attention in the literature, and many activities on generalized -ary functions have been carried out. This paper increases our knowledge on plateaued functions in the general context of generalized -ary functions. We first introduce two new versions of plateaued functions, which we shall call generalized plateaued functions and admissible plateaued functions. The generalized plateaued functions extend the standard notion of plateaued -ary functions to those whose outputs are in the ring . Next, we study the generalized plateaued functions and use admissible plateaued functions to characterize the generalized plateaued functions by means of their components. Finally, we provide for the first time two constructions of generalized plateaued functions. In particular, we generalize a known secondary construction of binary generalized bent functions and derive constructions of binary generalized plateaued functions with different amplitudes.
Autors: Sihem Mesnager;Chunming Tang;Yanfeng Qi;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6139 - 6148
Publisher: IEEE
 
» Generating Optimized Code for Parallelism Exploitation to an Unconventional Architecture
Abstract:
Along the years, the complexity of processors has increased and with it the demand grows for generating optimized code for them. Therefore, changes in the program, keeping the semantics of the original code and presenting a better performance, known as optimizations are required. The use of non-conventional architectures may be an option for increased performance, as the IPNoSys processor. This processor presents a computer model driven packages which is reflected in its programming model. The objective of this paper is develop the code optimization step in IPNoSys compiler, considering features not explored it, as the parallelism, and even improving your generated code. The optimization modulo offers three levels of optimization. In order to obtain the results a comparison of execution time and memory required of codes generated in the three levels of optimization was performed. The great level optimization reduced at least triple the execution time comparing to no optimized code. Also it was possible reduced the size code by the half in other optimization level.
Autors: Juliene Vieira do Couto;Silvio Roberto Fernandes de Araujo;
Appeared in: IEEE Latin America Transactions
Publication date: Oct 2017, volume: 15, issue:10, pages: 1967 - 1976
Publisher: IEEE
 
» Generation of Colored Noise Patterns With Gaussian Jitter Distribution
Abstract:
Bit rates of high-speed serial links (USB, SATA, PCI-express, etc.) have reached the multigigabits per second, and continue to increase. The transmitted jitter at a given bit error rate is one of the key parameters used to describe the performances of a serializer/deserializer. Generating white- and colored-noise synthetic jitter patterns would allow to better analyze the effect of jitter in a system for design verification and to achieve the desired figure of merit. To our knowledge, there is no other method proposed in the literature to generate colored-noise patterns with the Gaussian distribution. This paper then presents for the first time a novel method for generating the Gaussian distribution synthetic jitter patterns from colored-noise profiles.
Autors: Klodjan Bidaj;Jean-Baptiste Begueret;Jerome Deroo;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Oct 2017, volume: 66, issue:10, pages: 2576 - 2584
Publisher: IEEE
 
» Generation of Orthogonally Polarized Mode-Locked Lasers at Wavelength of 1342 nm
Abstract:
A mode-locked laser with orthogonal polarization at the wavelength of 1342 nm is experimentally achieved by using the natural birefringence of the Nd:YVO4 crystal. A total output power of 2.64 W could be obtained at an incident power of 14.4 W and the pulse durations are measured to be 15.1 and 16.9 ps with pulse repetition rates of 6.0 and 6.45 GHz for the laser output along the π- and σ-polarization, respectively. The mode-locked output is further found to exhibit a complex temporal trace with beat frequencies originated from the different central frequencies and pulse repetition rates.
Autors: Hsing-Chih Liang;Feng-Lan Chang;Tai-Wei Wu;Cheng-Lin Sung;Yung-Fu Chen;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 8
Publisher: IEEE
 
» Generic Construction of Bent Functions and Bent Idempotents With Any Possible Algebraic Degrees
Abstract:
As a class of optimal combinatorial objects, bent functions have important applications in cryptography, sequence design, and coding theory. Bent idempotents are a subclass of bent functions and of great interest, since they can be stored in less space and allow faster computation of the Walsh-Hadamard transform. The objective of this paper is to present a generic construction of bent functions from known ones. It includes the previous constructions of bent functions by Mesnager and Xu et al. as special cases, and produces new bent functions, which cannot be produced by earlier ones. In particular, it also generates infinite families of bent idempotents over of any algebraic degree between 2 and . This together with a recent construction by Su and Tang gives a positive answer to an open problem on bent idempotents proposed by Carlet. In addition, an infinite family of anti-self-dual bent functions is obtained in which the sum of any three distinct functions is again an anti-self-dual bent function in this family. This solves an open problem recently proposed by Mesnager.
Autors: Chunming Tang;Zhengchun Zhou;Yanfeng Qi;Xiaosong Zhang;Cuiling Fan;Tor Helleseth;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6149 - 6157
Publisher: IEEE
 
» Genetic Algorithm-Based Current Optimization for Torque Ripple Reduction of Interior PMSMs
Abstract:
This paper investigates the torque ripple modeling and minimization for interior permanent magnet synchronous machines (PMSMs). At first, a novel torque ripple model is proposed in which the torque ripples resulted from the spatial harmonics of permanent magnet flux linkage, time harmonics of stator currents and the cogging torque are included. Based on the torque ripple model, a genetic algorithm (GA)-based harmonic current optimization approach is proposed for torque ripple minimization. In this approach, GA is applied to optimize both the magnitude and phase angle of the stator harmonic currents to minimize the peak-to-peak torque ripple, minimize the sum of squares of the harmonic currents, and maximize the average torque component produced by the injected harmonic currents. The results demonstrate that the magnitude of the harmonic current can be significantly reduced by optimizing the phase angles of these harmonic currents. This leads to further suppression of the torque ripple when compared with that of a case where phase angles are not considered in the optimization. Also, an increase of the average torque is achieved when the optimum harmonic currents are injected. The proposed model and approach are evaluated through both numerical and experimental investigations on a laboratory interior PMSM.
Autors: Chunyan Lai;Guodong Feng;K. Lakshmi Varaha Iyer;Kaushik Mukherjee;Narayan C. Kar;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4493 - 4503
Publisher: IEEE
 
» Geodetic Imaging of Time-Dependent Three-Component Surface Deformation: Application to Tidal-Timescale Ice Flow of Rutford Ice Stream, West Antarctica
Abstract:
We present a method for inferring time-dependent three-component surface deformation fields given a set of geodetic images of displacements collected from multiple viewing geometries. Displacements are parameterized in time with a dictionary of displacement functions. The algorithm extends an earlier single-component (i.e., single line of sight) framework for time-series analysis to three spatial dimensions using combinations of multitemporal, multigeometry interferometic synthetic aperture radar (InSAR) and/or pixel offset (PO) maps. We demonstrate this method with a set of 101 pairs of azimuth and range PO maps generated for a portion of the Rutford Ice Stream, West Antarctica, derived from data collected by the COSMO-SkyMed satellite constellation. We compare our results with previously published InSAR mean velocity fields and selected GPS time series and show that our resulting three-component surface displacements resolve both secular motion and tidal variability.
Autors: Pietro Milillo;Brent Minchew;Mark Simons;Piyush Agram;Bryan Riel;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Oct 2017, volume: 55, issue:10, pages: 5515 - 5524
Publisher: IEEE
 
» Geometry Analysis and Optimization of PM-Assisted Reluctance Motors
Abstract:
This paper deals with a detailed geometry analysis of the rotor structure for both synchronous reluctance and permanent magnet (PM)-assisted reluctance motor in order to suggest an automatic procedure to design the rotor structure. The shape of flux barriers is selected to achieve both high -axis inductance and low -axis inductance to obtain high output torque and high power factor. Methods to properly design the geometry of the ends of each barrier and PMs are adopted. In order to draw a rotor with proper shape, different modifications are discussed. All details are described to allow any reader to adopt the same procedures. After that, such a procedure is used to rapidly analyze the impact of some geometry changes on the machine performance to give a design guideline. The analyzing process starts from a reluctance motor considering the number of barriers, insulation ratio, split ratio, and slots per pole per phase. Then, the PMs are inset into flux barriers and the effect of PM width on torque, power factor, and flux weakening capability is investigated. At last, the demagnetization limit under overload operations is analyzed.
Autors: Yawei Wang;Giacomo Bacco;Nicola Bianchi;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4338 - 4347
Publisher: IEEE
 
» Geometry of Line Start Synchronous Motors Suitable for Various Pole Combinations
Abstract:
Line start synchronous motors (LSSM) have been recently introduced in the motor market to meet new efficiency class requirements. They exhibit high efficiency and power factor compared with induction motors. On the other hand, the difficult design, manufacture, and high cost due to the presence of permanent magnets limit their widespread use in the market. Another key factor that limits the LSSM diffusion is the need of having a wide variety of different laminations of different sizes, increasing the number of pieces to be stored, the number of mold geometries, etc. This paper investigates the opportunity to use a proper geometry of LSSM that allows the same stator and rotor laminations to be used for a different number of poles. From the manufacturing point of view, the adoption of a unique rotor lamination is extremely advantageous. It is shown that satisfactory performance can be achieved rearranging the stator winding according to the number of poles. Experimental measurements are carried out on an LSSM prototype in which the same lamination is used for 2-pole and 4-pole machines.
Autors: Damiano Mingardi;Nicola Bianchi;Michele Dai Prè;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4360 - 4367
Publisher: IEEE
 
» Geotagging Text Content With Language Models and Feature Mining
Abstract:
The large-scale availability of user-generated content in social media platforms has recently opened up new possibilities for studying and understanding the geospatial aspects of real-world phenomena and events. Yet, the large majority of user-generated content lacks proper geographic information (in the form of latitude and longitude coordinates). As a result, the problem of multimedia geotagging, i.e., extracting location information from user-generated text items when this is not explicitly available, has attracted increasing research interest. Here, we present a highly accurate geotagging approach for estimating the locations alluded by text annotations based on refined language models that are learned from massive corpora of social media annotations. We further explore the impact of different feature selection and weighting techniques on the performance of the approach. In terms of evaluation, we employ a large benchmark collection from the MediaEval Placing Task over several years. We demonstrate the consistently superior geotagging accuracy and low median distance error of the proposed approach using various data sets and comparing it against a number of state-of-the-art systems.
Autors: Giorgos Kordopatis-Zilos;Symeon Papadopoulos;Ioannis Kompatsiaris;
Appeared in: Proceedings of the IEEE
Publication date: Oct 2017, volume: 105, issue:10, pages: 1971 - 1986
Publisher: IEEE
 
» GeSn Nanobeam Light-Emitting Diode as a GHz-Modulated Light Source
Abstract:
Designs and theoretical analysis are presented for a room temperature resonant-cavity-enhanced GeSn LED whose emission peaks at the 2 m wavelength. The Ge/GeSn/Ge PIN hetero-diode of length 1 m is embedded in a rib-type Ge-on-Si nanobeam having either 24 or 36 air holes. The maximum LED modulation bandwidth is proportional to the Purcell factor and is inversely proportional to the GeSn bulk spontaneous emission lifetime. For an emission linewidth of 200 nm and of 10 ns, an of 1.6 GHz is predicted.
Autors: Ricky Gibson;Joshua Hendrickson;Richard A. Soref;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 11
Publisher: IEEE
 
» Global Communications Newsletter
Abstract:
Presents key events and topics in the global communications industry.
Autors: Aduwati Sali;Fazirulhisyam Hashim;Chee Yen Leow;Nur Idora Abdul Razak;Hafizal Mohamad;Sarah Abou-Chakra;Cesar Vargas-Rosales;Rafaela Villalpando-Hernandez;
Appeared in: IEEE Communications Magazine
Publication date: Oct 2017, volume: 55, issue:10, pages: 7 - 9
Publisher: IEEE
 
» Global Time-Delay Estimation in Ultrasound Elastography
Abstract:
A critical step in quasi-static ultrasound elastography is the estimation of time delay between two frames of radio-frequency (RF) data that are obtained while the tissue is undergoing deformation. This paper presents a novel technique for time-delay estimation (TDE) of all samples of RF data simultaneously, thereby exploiting all the information in RF data for TDE. A nonlinear cost function that incorporates similarity of RF data intensity and prior information of displacement continuity is formulated. Optimization of this function involves searching for TDE of all samples of the RF data, rendering the optimization intractable with conventional techniques given that the number of variables can be approximately one million. Therefore, the optimization problem is converted to a sparse linear system of equations, and is solved in real time using a computationally efficient optimization technique. We call our method GLobal Ultrasound Elastography (GLUE), and compare it to dynamic programming analytic minimization (DPAM) and normalized cross correlation (NCC) techniques. Our simulation results show that the contrast-to-noise ratio (CNR) values of the axial strain maps are 4.94 for NCC, 14.62 for DPAM, and 26.31 for GLUE. Our results on experimental data from tissue mimicking phantoms show that the CNR values of the axial strain maps are 1.07 for NCC, 16.01 for DPAM, and 18.21 for GLUE. Finally, our results on in vivo data show that the CNR values of the axial strain maps are 3.56 for DPAM and 13.20 for GLUE.
Autors: Hoda Sadat Hashemi;Hassan Rivaz;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Oct 2017, volume: 64, issue:10, pages: 1625 - 1636
Publisher: IEEE
 
» GNSS Multireceiver Vector Tracking
Abstract:
Accurate, reliable, and robust global positioning system (GPS) localization is desirable for many navigation applications. Unfortunately, it is challenging for a single GPS receiver to always provide accurate positioning solutions. In urban environments, intermittent signal availability leads to degraded GPS signal tracking and position estimation of the single GPS receiver. In addition, equipment malfunction of the single GPS receiver results in inaccurate navigation solutions. This paper presents a deeply coupled multireceiver vector tracking (MRVT) architecture that improves the reliability and robustness of GPS signal tracking and position estimation. MRVT jointly tracks GPS signals received by multiple GPS receivers, mitigating GPS signal tracking disruptions, improving the reliability of GPS localization in periods of intermittent signal availability. In addition, the MRVT receiver is more robust to equipment malfunctions than the single GPS receiver. We implemented an MRVT receiver using commercial radio frequency front ends and our PyGNSS software. We experimentally validated the reliability of our MRVT receiver in periods of intermittent GPS availability experienced in downtown San Francisco. Our MRVT receiver exhibited consistent GPS signal tracking and position estimation as compared to vector tracking. In addition, we experimentally validated the robustness of our MRVT receiver to the failure of a single GPS receiver.
Autors: Yuting Ng;Grace Xingxin Gao;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Oct 2017, volume: 53, issue:5, pages: 2583 - 2593
Publisher: IEEE
 
» Govern by blockchain dubai wants one platform to rule them all, while Illinois will try anything
Abstract:
Governments everywhere would like to cut red tape, reduce bureaucracy, and speed the delivery of services. But constituents are still often frustrated by mounds of paperwork and the snail-like pace of official business. Could a blockchain help? Just as blockchains have shaken up the financial industry and changed our perception of money, some government agencies now believe the technology could rejuvenate the public sector. Proponents argue that its immutability will protect records from fraudsters, its transparency will keep employees accountable, and its ability to automatically process new entries can make agencies more efficient. Such promises have persuaded city, state, and federal governments to launch the first batch of public-sector blockchain experiments. Two of the most enthusiastic early adopters have been the U.S. state of Illinois and the city of Dubai in the United Arab Emirates. And intriguingly enough, the two have adopted very different strategies for mixing blockchains into government.
Autors: Amy Nordrum;
Appeared in: IEEE Spectrum
Publication date: Oct 2017, volume: 54, issue:10, pages: 54 - 55
Publisher: IEEE
 
» Granular Encoders and Decoders: A Study in Processing Information Granules
Abstract:
Information granules are generic building blocks supporting the processing realized in granular computing and facilitating communication with the environment. In this paper, we are concerned with a fundamental problem of encoding–decoding of information granules. The essence of the problem is outlined as follows: given a finite collection of granular data X1, X2,…,XN (sets, fuzzy sets, etc.), construct an optimal codebook composed of information granules A 1, A2, …, Ac, where typically c << N, so that any Xk represented in terms of A i's and then decoded (reconstructed) with the help of this codebook leads to the lowest decoding error. A fundamental result is established, which states that in the proposed encoders and decoders, when encoding–decoding error is present, the information granule coming as a result of decoding is of a higher type than the original information granules (say, if Xk is information granule of type-1, then its decoded version becomes information granule of type-2). It would be beneficial to note that as the encoding–decoding process is not lossless (in general, with an exception of a few special cases), the lossy nature of the method is emphasized by the emergence of information granules of higher type (in comparison with the original data being processed). For instance, when realizing encoding–decoding of numeric data (viz., information granules of type-0), the losses occur and they are quantified in terms of intervals, fuzzy sets, probabilities, rough sets, etc., where, in fact, the result becomes- an information granule of type-1. In light of the nature of the constructed result when Xk is an interval or a fuzzy set, an optimized performance index engages a distance between the bounds of the interval-valued membership function. We develop decoding and encoding mechanisms by engaging the theory of possibility and fuzzy relational calculus and show that the decoded information granule is either a granular interval or interval-valued fuzzy set. The optimization mechanism is realized with the aid of the particle swarm optimization (PSO). A series of experiments are reported with intent to illustrate the details of the encoding–decoding mechanisms and show that the PSO algorithm can efficiently optimize the granular codebook.
Autors: Xiubin Zhu;Witold Pedrycz;Zhiwu Li;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2017, volume: 25, issue:5, pages: 1115 - 1126
Publisher: IEEE
 
» Granular Fuzzy Rule-Based Models: A Study in a Comprehensive Evaluation and Construction of Fuzzy Models
Abstract:
Fuzzy models are regarded as numeric constructs and as such are optimized and evaluated at the numeric level. In this study, we depart from this commonly accepted position and propose a granular evaluation of fuzzy models and present an augmentation of fuzzy models by forming information granules around numeric values of the parameters and constructions of the models. The concepts and algorithms of granular fuzzy models are discussed in the setting of Takagi–Sugeno rule-based architectures. We show how different protocols of forming and allocating information granules lead to the improvement of the granular performance of the models. Different from the standard numeric performance measure of fuzzy models coming in the form of the root mean squared error index, two performance measures are introduced that are pertinent to granular constructs, namely coverage and specificity. Furthermore, we propose a global indicator implied by these two measures, called an area under the curve, being computed for the characteristics of the granular model expressed in the coverage-specificity coordinates. A series of experimental studies is reported, which offers a comprehensive overview of the introduced performance measure criteria as well as the underlying realization of the granular fuzzy models.
Autors: Xingchen Hu;Witold Pedrycz;Xianmin Wang;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2017, volume: 25, issue:5, pages: 1342 - 1355
Publisher: IEEE
 
» Graph Regularized and Locality-Constrained Coding for Robust Visual Tracking
Abstract:
Visual tracking is complicated due to factors, such as occlusion, background clutter, abrupt target motion, and illumination variations, among others. In recent years, subspace representation and sparse coding techniques have demonstrated significant improvements in tracking. However, performance gain in tracking has been at the expense of losing locality and similarity attributes among the instances to be encoded. In this paper, a graph regularized and locality-constrained coding (GRLC) technique that encapsulates local manifold structure of the data in order to preserve locality and similarity information among instances is proposed. The GRLC methodology incorporates a similarity-preserving term within the objective function of the locality-constrained linear coding model, thereby overcoming some of the inherent instability issues common to such coding methods. In the proposed GRLC scheme, a graph Laplacian regularizer is chosen as a smoothing operator to learn both the representation dictionary and the coefficients by preserving the local structure of the data. This graph Laplacian smoothing operator ensures that the representations vary smoothly along the geodesics of the data manifold. Thus, by deriving the objective function of the GRLC method, a discriminative dictionary of instances can be iteratively obtained and the corresponding coefficients for each candidate can be computed using this learned dictionary. Finally, an effective observation likelihood function based on reconstruction error and a simple dictionary update scheme for visual target tracking are also proposed. Experimental results on the CVPR2013 visual tracker benchmark have demonstrated a favorable performance of the proposed technique both in terms of accuracy and robustness.
Autors: Tao Zhou;Harish Bhaskar;Fanghui Liu;Jie Yang;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Oct 2017, volume: 27, issue:10, pages: 2153 - 2164
Publisher: IEEE
 
» Graphene Electrodes as Barrier-Free Contacts for Carbon Nanotube Field-Effect Transistors
Abstract:
This work evaluates the performance of carbon nanotube field-effect transistors (CNTFETs) using few layer graphene as the contact electrode material. We present the experimental results of the barrier height at carbon nanotube–graphene junction using temperature dependent – measurements. The estimated barrier height in our devices for both holes and electrons is close to zero indicating the ohmic contact of graphene for both p-type and n-type CNTFETs thus demonstrating the suitability of graphene as electrode material for CMOS-type circuits based on CNTFETs. Furthermore, we observe that there is no correlation between the barrier height and thickness of graphene.
Autors: P. R. Yasasvi Gangavarapu;Punith C. Lokesh;K. N. Bhat;A. K. Naik;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2017, volume: 64, issue:10, pages: 4335 - 4339
Publisher: IEEE
 
» Graphene Oxide Doped SU-8 Waveguide and Its Application as Saturable Absorber
Abstract:
Graphene oxide (GO)-doped SU-8 waveguides have been fabricated and characterized. The GO-doped SU-8 can be processed using standard photolithography parameters. The optical characteristics of the developed waveguides are determined using fibre-butt coupling and cut-back method. Propagation loss of 1.9 dB/cm and a coupling loss of 4 dB per point measured at 1550 nm wavelength are obtained. Q-switched laser operation is achieved by inserting a 3 mm GO-doped SU-8 waveguide into a ring fibre laser configuration, making it a potential candidate as integrated saturable absorber for on-chip polymer waveguide applications.
Autors: Khairul Zafri Mustafa;Wu Yi Chong;Mohd Haniff Ibrahim;Yuen Kiat Yap;Fauzan Ahmad;Choon Kong Lai;Nur Afiqah Mohd Ariffin;Harith Ahmad;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 7
Publisher: IEEE
 
» Graphene Surface Plasmons With Dielectric Metasurfaces
Abstract:
An approach to capture light efficiently into graphene surface plasmons by patterning the sinusoidal dielectric metasurfaces above and below the graphene sheet is proposed. The presence of plasmonic resonance is demonstrated by means of an analytical model based on the transformation optics through the extraction of effective graphene conductivity, which is further revealed via a numerical study of the optical spectra as a function of grating parameters at the subwavelength scale. Besides, the resonant position is found to be sensitive to the dielectric contacted with graphene. These findings can deepen our understanding of plasmon resonances and pave the way to the design of graphene plasmonic devices like refractive index sensors.
Autors: Sheng-Xuan Xia;Xiang Zhai;Yu Huang;Jian-Qiang Liu;Ling-Ling Wang;Shuang-Chun Wen;
Appeared in: Journal of Lightwave Technology
Publication date: Oct 2017, volume: 35, issue:20, pages: 4553 - 4558
Publisher: IEEE
 
» Grasp Mode and Compliance Control of an Underactuated Origami Gripper Using Adjustable Stiffness Joints
Abstract:
Every robotic gripper requires an equilibrated solution towards the grasp adaptability, precision, and load-bearing capacity. A versatile soft robotic gripper requires adjustable grasp mode for objects with different sizes and shapes, and adjustable compliance for switching between soft mode for small loads and delicate objects and stiff mode for larger loads and heavier objects. In this paper, we present the design of a tendon-driven robotic origami, robogami, gripper that provides self-adaptability and inherent softness through its redundant and underactuated degrees of freedom (DoF). Robogami is a planar and foldable robotic platform that is scalable and customizable thanks to its unique layer-by-layer manufacturing process. The nominally two-dimensional fabrication process allows embedding different functional layers with a high fidelity. In particular, a polymer layer with adjustable stiffness enables the independent control of the stiffness for each joint. Using this feature, we can control the input energy distribution between different joints and hence the motion of the robogami. Here, we model the behavior of a single finger, and demonstrate the compliance control of the end effector along different directions in simulations and experiments. We also validate the gripper's task versatility in soft and stiff modes by assigning model-based joints stiffness for performing different grasp modes.
Autors: Amir Firouzeh;Jamie Paik;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Oct 2017, volume: 22, issue:5, pages: 2165 - 2173
Publisher: IEEE
 
» Gray Box Modeling of Power Transformer Windings for Transient Studies
Abstract:
For the fast transient study of power transformers, several types of models are available that can be categorized into three groups: white box models, black box models, and gray box models. The identification of their parameters and their usages make the models different. Since white and black box models cannot cover certain cases, such as the failure analysis of a transformer with unknown geometrical data, a new type of model has recently become important for industry and academic researchers. This model, called the gray box model, is intensely analyzed in the current paper, both theoretically and experimentally. The gray box model conceptually lies between the black and white box models. The outcomes of this work have been verified using a suitable test object. The parameter identification of the model is performed by artificial methods. Some useful new ideas, including applying the Weibull Distribution function in inductance estimation and employing an exponential function for the series resistance of windings, are developed in this paper. The number of unknown parameters to be identified in the gray box model is reduced by applying these ideas, which makes the model more simple and feasible.
Autors: Reza Aghmasheh;Vahid Rashtchi;Ebrahim Rahimpour;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Oct 2017, volume: 32, issue:5, pages: 2350 - 2359
Publisher: IEEE
 
» Grid Interfaced Distributed Generation System With Modified Current Control Loop Using Adaptive Synchronization Technique
Abstract:
This paper presents real-time implementation of a grid interfaced distributed generation (DG) system with modified current control loop using three phase amplitude adaptive notch filter (AANF) based synchronization tool. A grid current feedback based modified -current control technique for interfacing inverter is developed in order to achieve constant loading on the grid, transient-free operation, and power factor improvement close to unity power factor (UPF) of the utility grid during sudden load variations. This technique does not require separate calculation of reference reactive component and harmonics component of currents hence reduces control circuit complexity. In addition, it requires only three voltage and three current sensors. Three phase AANF is developed and is used for online extraction of utility voltage phase angle to generate synchronized reference current signals for interfacing inverter. AANF is used because of its adjustable accuracy and amplitude adaptability even under unbalanced voltage sag and swell, frequency variation, and distorted grid conditions. Fast and accurate behavior of three phase AANF improves the dynamic response of entire DG system control performance for sudden load variations. The dynamic behavior of the proposed grid interfaced DG system is experimentally evaluated in maintaining constant loading on grid, transient-free operation, and power factor improvement close to UPF operation of the utility grid, by compensating total reactive power and harmonic current demanded by variable linear as well as nonlinear load.
Autors: Amardeep B. Shitole;Hiralal M. Suryawanshi;Girish G. Talapur;Shelas Sathyan;Makarand S. Ballal;Vijay B. Borghate;Manoj R. Ramteke;Madhuri A. Chaudhari;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2634 - 2644
Publisher: IEEE
 
» Grid-Level Application of Electrical Energy Storage: Example Use Cases in the United States and China
Abstract:
Electrical energy storage (EES) systems are expected to play an increasing role in helping the United States and China-the world's largest economies with the two largest power systems-meet the challenges of integrating more variable renewable resources and enhancing the reliability of power systems by improving the operating capabilities of the electric grid. EES systems are becoming integral components of a resilient and efficient grid through a diverse set of applications that include energy management, load shifting, frequency regulation, grid stabilization, and voltage support.
Autors: Yingchen Zhang;Vahan Gevorgian;Caixia Wang;Xuejiao Lei;Ella Chou;Rui Yang;Qionghui Li;Liping Jiang;
Appeared in: IEEE Power and Energy Magazine
Publication date: Oct 2017, volume: 15, issue:5, pages: 51 - 58
Publisher: IEEE
 
» Gridless 1-b DOA Estimation Exploiting SVM Approach
Abstract:
We investigate the problem of direction of arrival (DOA) estimation with 1-b measurements in massive MIMO systems, as 1-b quantization offers low cost and low complexity in the implementation. We first establish the connection between 1-b DOA estimation and linear classification based on the sparsity of the incident signals. Then, we present an iterative refinement procedure based on Taylor expansion to obtain DOA estimation off the grid. This refinement procedure can be easily extended to other 1-b DOA estimation algorithms with minor changes. Finally, simulations are conducted for validation and the results illustrate the high performance of the proposed algorithm in spite of the extreme 1-b quantization.
Autors: Yulong Gao;Deshun Hu;Yanping Chen;Yongkui Ma;
Appeared in: IEEE Communications Letters
Publication date: Oct 2017, volume: 21, issue:10, pages: 2210 - 2213
Publisher: IEEE
 
» Group Structure Preserving Pedestrian Tracking in a Multicamera Video Network
Abstract:
Pedestrian tracking in video has been a popular research topic with many practical applications. In order to improve tracking performance, many ideas have been proposed, among which the use of geometric information is one of the most popular directions in recent research. In this paper, we propose a novel multicamera pedestrian tracking framework, which incorporates the structural information of pedestrian groups in the crowd. In this framework, first, a new cross-camera model is proposed, which enables the fusion of the confidence information from all camera views. Second, the group structures on the ground plane provide extra constraints between pedestrians. Third, the structured support vector machine is adopted to update the cross-camera model for each pedestrian according to the most recent tracked location. The experiments and detailed analysis are conducted on challenging data. The results demonstrate that the improvement in tracking performance is significant when a group structure is integrated.
Autors: Zhixing Jin;Le An;Bir Bhanu;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Oct 2017, volume: 27, issue:10, pages: 2165 - 2176
Publisher: IEEE
 
» Grouping and Cooperating Among Access Points in User-Centric Ultra-Dense Networks With Non-Orthogonal Multiple Access
Abstract:
A user-centric ultra-dense network (UUDN) is proposed as one of the promising solutions to provide very high area throughput density and flexible access service for users in the fifth-generation systems. On the one hand, network densification provides opportunities to cooperate among a large number of access points (APs) for serving a given user. On the other hand, the limited radio resources cause the serious competition among numerous APs and may degrade the network performance. Therefore, to support large number of connections and break through the restriction of limited frequency resource, non-orthogonal multiple access (NOMA), which supports multiple signals to transmit on the same frequency resource, is introduced into the UUDN. However, NOMA with network densification arises a series of challenges. And the method to group APs efficiently on the same frequency to support for a given user is a critical problem. Thus, in this paper, we propose a user-centric access framework for providing efficient access service and the flexible resource management in NOMA-based UUDN. Under the proposed framework, we then investigate the access scheme that organizes multiple APs into respective AP group (APG) cooperatively to provide access service for each user, aiming at maximizing the system energy efficiency. First, considering the users’ requirement and network environment, a grouping evaluation model is set up to organize APG efficiently. Then, we formulate the resource allocation problem of APG as a mix-integer non-linear programming problem, which is hard to tackle. For tractability purpose, we transform this problem and propose low-complexity algorithms based on matching and differ of convex programming theories to obtain a feasible solution. Extensive simulation results are presented to demonstrate the significant performance improvement compared with the existing schemes.
Autors: Yiming Liu;Xi Li;F. Richard Yu;Hong Ji;Heli Zhang;Victor C. M. Leung;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Oct 2017, volume: 35, issue:10, pages: 2295 - 2311
Publisher: IEEE
 
» Grouping-Based TSV Test Architecture for Resistive Open and Bridge Defects in 3-D-ICs
Abstract:
After the 3-D stacking, 3-D-ICs based on through-silicon-vias (TSVs) must be inspected for any TSV defects such as resistive open or bridge defects. In some research studies, several effective testing techniques have been developed such as parallel or serial test architectures, which measure the voltage across a single TSV with a comparator. However, in the current test architectures, hardware overhead and test time are proportional to the number of TSVs. In this paper, we propose a new unified test architecture for screening of TSV defects in 3-D-ICs. Depending on the number of assembled TSVs, the proposed grouping-based test architecture can effectively reduce the cumulative test time and hardware overhead without compromising the test quality.
Autors: Young-woo Lee;Hyeonchan Lim;Sungho Kang;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Oct 2017, volume: 36, issue:10, pages: 1759 - 1763
Publisher: IEEE
 
» Growth Goals, Travel Grants, Chapter Awards, and Chapter Events [Chapter News]
Abstract:
Presents information on various APS Society chapters.
Autors: Ajay K. Poddar;
Appeared in: IEEE Antennas and Propagation Magazine
Publication date: Oct 2017, volume: 59, issue:5, pages: 10 - 17
Publisher: IEEE
 
» Guest Editor's Introduction: Selected Papers from ACM-BCB 2014
Abstract:
Autors: Ümit V. Çatalyürek;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Oct 2017, volume: 14, issue:5, pages: 1000 - 1001
Publisher: IEEE
 
» Guest Editorial
Abstract:
This Transactions on Microwave Theory and Techniques’ Mini-Special Issue includes ten papers from the 2017 IEEE Radio and Wireless Week (RWW 2017) held in Phoenix, AZ, USA, January 15–18, 2017. The Radio and Wireless Week consists of five related conferences that focus on the intersection between wireless communication theory, systems, circuits, and device technologies: the Radio and Wireless Symposium, the Topical Conference on Power Amplifiers for Wireless and Radio Applications, the Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, the Topical Conference on Wireless Sensors and Sensor Networks, and the Topical Workshop on The Internet of Space. Radio and Wireless Week is thus a multidisciplinary event bringing together innovations that are happening across the broad wireless spectrum. A total of 214 papers were submitted to the RWW 2017 Technical Program Committee, of which 168 papers were accepted for presentation and publication online on the IEEE Xplore website. Together with the technical sessions, four workshops, one special talk on the Internet of Things powered by wireless, a plenary session on 5G hardware and system solutions, a panel session on linearization of power amplifiers for 5G, and a demo track session to show the latest innovative wireless experimental achievements were successfully held.
Autors: Andrei Grebennikov;Nils Pohl;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3559 - 3560
Publisher: IEEE
 
» Guest Editorial - Special Section on Emerging Informatics for Risk Hedging and Decision Making in Smart Grids
Abstract:
The aim of this Special Section is to attract and report the latest advances toward the trend of applying advanced informatics techniques resolving complex problems facing power system operation and planning in the new era of smart grids. Special interests are given to the new methods that can handle various tasks of risk hedging and decision making appeared in eleven system operation and planning, though the scope has been slightly expanded to other topical issues in smart grids as well. The accepted eleven high-quality papers represent how the newadvances and solutions toward resolving complex problems facing power system operation and planning can be brought forward by continuously leveraging emerging techniques in the field of data analytics and informatics. It should be highlighted that with the increased penetration of various emerging technologies such as renewables and electric vehicles (EVs), secure and economic system operation and planning deserve continuous research efforts in producing the most up-to-date methods and solutions dealing with issues of diversified natures and complexities in future power grids. Specifically, the covered topics in this Special Section are topical and broad, concerning mainly power system security analysis and electricity market planning and operation under risks and uncertainties, which are briefly summarized.
Autors: Zhao Xu;Loi Lei Lai;Kit Po Wong;Pierre Pinson;Fangxing Li;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2507 - 2510
Publisher: IEEE
 
» Guest Editorial - Special Section on Systems of Power Converters: Design, Modeling, Control, and Implementation
Abstract:
In this Special Section on Systems of Power Converters: Design, Modeling, Control, and Implementation, we have 11 high-quality papers approved for publication that cover the following three topics. 1) Converter Design and Operation. 2) Subsystem-Level Applications. 3) System-Level Applications. These topics and the corresponding papers are summarized.
Autors: Wenxin Liu;Josep M. Guerrero;Jang-Mok Kim;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2631 - 2633
Publisher: IEEE
 
» Guest Editorial for Special Section on the 11th International Conference on Intelligent Computing (ICIC)
Abstract:
Autors: De-Shuang Huang;Vitoantonio Bevilacqua;M. Michael Gromiha;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Oct 2017, volume: 14, issue:5, pages: 1104 - 1105
Publisher: IEEE
 
» Guest Editorial Introduction to the Special Issue on Internet of Things and Sensors Technologies for Intelligent Transportation Systems
Abstract:
The degree of modernization of transportation is currently an important criterion for urban development. Progress in communication techniques and networking, together with vehicle localization methods, have become the key enablers of innovative transportation systems.
Autors: Reza Malekian;Kui Wu;Kris Steenhaut;Ning Ye;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Oct 2017, volume: 18, issue:10, pages: 2798 - 2801
Publisher: IEEE
 
» Guest Editorial ISCAS 2016 Special Issue
Abstract:
Autors: P. HÄFLIGER;S. CHAKRABARTTY;Z. WANG;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Oct 2017, volume: 11, issue:5, pages: 977 - 978
Publisher: IEEE
 
» Guest Editorial Medical Measurements and Applications: 10 Years of Ideas and Innovation
Abstract:
The interest of industry and academia in medical measurements continues to increase, due to technology advancements that allow new sensors, measurement systems, and methodologies, supporting a wide number of medical applications.
Autors: Luca De Vito;J. Max Cortner;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Oct 2017, volume: 66, issue:10, pages: 2502 - 2504
Publisher: IEEE
 
» Guest Editorial Special Issue for Selected Papers from EAPPC/BEAMS/MEGAGAUSS 2016
Abstract:
The joint conference of the 6th Euro-Asian Pulsed Power Conference (EAPPC 2016), the 21st International Conference on High-Power Particle Beams (BEAMS 2016), and the 15th International Conference on Megagauss Magnetic Field Generation and Related Topics (MEGAGAUSS 2016) was held in Estoril, Portugal, on September 18–22, 2016. It was the first time that researchers from these three areas, although closely related, have come together to share their findings following an integrated scientific program.
Autors: Joshua Leckbee;Fernando Silva;Hong-Je Ryoo;Jianqiang Yuan;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Oct 2017, volume: 45, issue:10, pages: 2610 - 2610
Publisher: IEEE
 
» Guest Editorial Special Section on Emerging Informatics for Risk Hedging and Decision Making in Smart Grids
Abstract:
Autors: Zhao Xu;Loi Lei Lai;Kit Po Wong;Pierre Pinson;Fangxing Li;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2507 - 2510
Publisher: IEEE
 
» Guest Editorial Special Section on Systems of Power Converters: Design, Modeling, Control, and Implementation
Abstract:
Autors: Wenxin Liu;Josep M. Guerrero;Jang-Mok Kim;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2631 - 2633
Publisher: IEEE
 
» Guest Editorial Target and Reverberation Experiment 2013 (TREX13)—Part II
Abstract:
Autors: Brian T. Hefner;Dajung Tang;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Oct 2017, volume: 42, issue:4, pages: 757 - 758
Publisher: IEEE
 
» Guest Editorial: Alternative Computing and Machine Learning for Internet of Things
Abstract:
The impending Internet of Things (IoT) wave is promising to affect every aspect of our daily lives, ranging from smart things to smart buildings, smart cities, and smart environments. A lot of attention has been devoted to the tsunami of data produced by IoT, and the related means of extracting useful actionable information from it, spawning efforts in Big Data processing and machine learning. Yet, all of this does little to address the need for IoT to capture, interpret, and act on this wall of (noisy) information at the right time, at the right place, and in the right form. Conventional computing systems are a poor match to the needs of this emerging massively distributed real-time system. Hence, alternative computing techniques present an attractive alternative, trading off computational resolution for significant gains in quality-of-service energy efficiency and robustness. This observation is based on the conjecture that most applications related to IoT have an inherent error resilience and are evolutionary (that is, learning-based). Alternative computing strategies may be conceived at every level of the design hierarchy, starting from the device level with novel 3-D nonvolatile memory/logic combinations, or at the architectural level by shifting away from the traditional von Neumann architecture to different computing paradigms such as neuromorphic and/or stochastic computation all the way up to the algorithmic and data representation levels.
Autors: Farshad Firouzi;Bahar Farahani;Andrew B. Kahng;Jan M. Rabaey;Natasha Balac;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Oct 2017, volume: 25, issue:10, pages: 2685 - 2687
Publisher: IEEE
 
» Guest Editorial: Special Collection of Papers Arising From UComms16
Abstract:
Autors: John R. Potter;João Alves;Ian F. Akyildiz;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Oct 2017, volume: 42, issue:4, pages: 754 - 756
Publisher: IEEE
 
» Guest Editorial: Video Over Future Networks
Abstract:
Autors: X. Zhu;S. Mao;M. Hassan;H. Hellwagner;
Appeared in: IEEE Transactions on Multimedia
Publication date: Oct 2017, volume: 19, issue:10, pages: 2133 - 2135
Publisher: IEEE
 
» Hamilton Paths With Lasting Separation
Abstract:
We determine the asymptotics of the largest cardinality of a set of Hamilton paths in the complete graph with vertex set under the condition that for any two of the paths in the family there is a subpath of length entirely contained in only one of them and edge-disjoint from the other one.
Autors: Emanuela Fachini;János Körner;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6344 - 6346
Publisher: IEEE
 
» Harbor Water Area Extraction From Pan-Sharpened Remotely Sensed Images Based on the Definition Circle Model
Abstract:
Harbor water area extraction is a key step in nearshore environment pollution surveillance using remote sensing image processing techniques. This letter proposes the definition circle (DC) model of color gradient to describe color fluctuations in harbor water surface areas based on pan-sharpened remote sensing images. The DC model includes two steps: center setting and radius tuning. In the center setting process, labeled training set pixels are selected in the red, green, and blue color space. Then, center setting is completed in the hue, saturation, and intensity color space using the perceptron model. In the radius tuning process, positive and negative sample pixels are used to tune the radius value. After these two steps, the DC model can describe the color gradient of a water surface area and provide accurate harbor water area extraction. A series of experiments shows that the proposed DC model is robust and performs better than other extraction methods based on pan-sharpened remote sensing images.
Autors: Yin Zhuang;Penglin Wang;Yiding Yang;Hao Shi;He Chen;Fukun Bi;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Oct 2017, volume: 14, issue:10, pages: 1690 - 1694
Publisher: IEEE
 
» Hardware Trojan Detection Through Chip-Free Electromagnetic Side-Channel Statistical Analysis
Abstract:
The hardware Trojan (HT) has become a major threat for the integrated circuit (IC) industry and supply chain, and has motivated numerous developments of Trojan detection schemes. Although the side-channel method is the most promising one, nearly all of the side-channel methods require fabricated golden chips, which are very difficult to obtain in reality. In this paper, we propose a novel strategy for HT detection using electromagnetic side-channel-based spectrum modeling and analyzing. We utilize the design data at early stage of the IC lifecycle, and the generated spectrum can serve as the golden reference, and thus we do not need the fabricated golden chips anymore. Another very important feature is that our method is immune to the process variation theoretically. Experimental results on selected Advanced Encryption Standard benchmark circuits on FPGA show that our proposed method can effectively detect Trojans even with very small traces.
Autors: Jiaji He;Yiqiang Zhao;Xiaolong Guo;Yier Jin;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Oct 2017, volume: 25, issue:10, pages: 2939 - 2948
Publisher: IEEE
 
» Head and Media Design for Curvature Reduction in Heat-Assisted Magnetic Recording
Abstract:
Recording curvature in magnetic data-storage technology has long been one of the significant challenges impacting on recording performance. Despite curvature occurrence in the conventional recording techniques such as perpendicular magnetic recording (PMR), heat-assisted magnetic recording (HAMR) is demonstrated to induce much more severe curvature than PMR. HAMR curvature could cause poor bit error rate and limits the maximum areal density capacity. Here we have theoretically predicted and demonstrated various approaches for curvature reduction from the aspect of either altering the near-field transducer head design or recording medium design. Optical and thermal modeling have indicated that by utilizing a crown-shape peg to change the thermal source profile and compensate for thermal expansion and rounding effect, it could potentially improve curvature figure of merit (FOM) and achieve curvature reduction by ~45%. In terms of the recording media design, by altering the heat sink and internal layer media material or geometry, it could also achieve curvature cancellation of ~40% with increased thermal gradient. The combined approach from both HAMR head and media perspectives with balanced recording FOMs, could potentially realize significant curvature reduction to be of similar or better recording curvature level to PMR.
Autors: Zhongyang Li;Weibin Chen;Chris Rea;Martin G. Blaber;Nan Zhou;Hua Zhou;Huaqing Yin;
Appeared in: IEEE Transactions on Magnetics
Publication date: Oct 2017, volume: 53, issue:10, pages: 1 - 4
Publisher: IEEE
 
» Heat Transfer in Filamentary RRAM Devices
Abstract:
We study the heat transport in filamentary resistive random access memory nanosized devices by comparing the accurate results of COMSOL Multiphysics modeling with simplified analytical models for two complementary mechanisms: one neglecting the radial heat transfer from the filament to the insulating host, while the other describing the radial transport through the dielectric in the absence of the filament heat transfer. For the former, we find that the earlier assumed simplification of the electrodes being ideal heat conductors is insufficient; a more adequate approximation is derived where the heat transport is determined by the adjacent proximities of the filament tips in the electrodes. We find that both complementary mechanisms overestimate the maximum temperature yet offering acceptable results. However, the two in parallel provide a better analytical approximation. In addition, we show that the Wiedemann–Franz–Lorenz law helps the analysis when the Lorenz parameter is chosen from the actual data. We present an approximate relation between device SET voltage and SET temperature possessing a high degree of universality and predicting that filament materials with low Lorenz numbers can be good candidates for the future low set voltage devices.
Autors: Dipesh Niraula;Victor G. Karpov;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2017, volume: 64, issue:10, pages: 4106 - 4113
Publisher: IEEE
 
» Hiding the Rumor Source
Abstract:
Anonymous social media platforms, like Secret, Yik Yak, and Whisper, have emerged as important tools for sharing ideas without the fear of judgment. Such anonymous platforms are also important in nations under authoritarian rule, where freedom of expression and the personal safety of message that authors may depend on anonymity. Whether for fear of judgment or retribution, it is sometimes crucial to hide the identities of users who post sensitive messages. In this paper, we consider a global adversary who wishes to identify the author of a message; it observes either a snapshot of the spread of a message at a certain time or sampled timestamp metadata, or both. Recent advances in rumor source detection show that existing messaging protocols are vulnerable against such an adversary. We introduce a novel messaging protocol, which we call adaptive diffusion, and show that under the snapshot adversarial model, adaptive diffusion spreads content fast and achieves perfect obfuscation of the source when the underlying contact network is an infinite regular tree. That is, all users with the message are nearly equally likely to have been the origin of the message. When the contact network is an irregular tree, we characterize the probability of maximum likelihood detection by proving a concentration result over Galton–Watson trees. Experiments on a sampled Facebook network demonstrate that adaptive diffusion effectively hides the location of the source even when the graph is finite, is irregular, and has cycles.
Autors: Giulia Fanti;Peter Kairouz;Sewoong Oh;Kannan Ramchandran;Pramod Viswanath;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6679 - 6713
Publisher: IEEE
 
» Hierarchical Distributed Scheme for Demand Estimation and Power Reallocation in a Future Power Grid
Abstract:
The classical power allocation/reallocation faces difficult challenges in a future power grid with a great many distributed generators and fast power fluctuations caused by high percentage of renewable energy. To perform power reallocation fast in a future power grid with a large number of participants and disturbances, a hierarchical distributed scheme based on a partition framework is proposed. In the proposed scheme, the power grid is naturally partitioned into a certain number of regions, and the total energy demand in the power grid with disturbances is automatically estimated rather than given in advance. Besides, the centralized local optimizations in regions and the distributed global optimization among regions are coupled to solve the power reallocation problem, in which each region performs as a single agent. Thus, the agents in the proposed scheme are much fewer than the purely distributed ones, hence the communication load is greatly relieved and the reallocation process is significantly simplified. Effectiveness of the proposed scheme is verified by the cases.
Autors: Xiong Hu;Hong Zhou;Zhi-Wei Liu;Xinghuo Yu;Chaojie Li;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2279 - 2290
Publisher: IEEE
 
» Hierarchical Place Recognition for Topological Mapping
Abstract:
In this paper, we propose a novel appearance-based approach for topological mapping based on a hierarchical decomposition of the environment. In our map, images with similar visual properties are grouped together in nodes, which are represented by means of an average global descriptor and an index of binary features based on a bag-of-words online approach. Each image is represented by means of a global descriptor and a set of local features, and this information is used in a two-level loop closure approach, where first global descriptors are employed to obtain the most likely nodes of the map and then binary image features are used to retrieve the most likely images inside these nodes. This hierarchical scheme enables us to reduce the search space when recognizing places, maintaining high accuracy when creating a map. Our approach is validated using several public datasets and compared against several state-of-the-art techniques. The accuracy and the sparsity of the generated maps are also discussed.
Autors: Emilio Garcia-Fidalgo;Alberto Ortiz;
Appeared in: IEEE Transactions on Robotics
Publication date: Oct 2017, volume: 33, issue:5, pages: 1061 - 1074
Publisher: IEEE
 
» High Mechanical Strength Thin HIT Solar Cells With Graphene Back Contact
Abstract:
It is widely known that thinner Si substrate is the main path for lower $/Watt HIT solar cells due to improved charge collection, reduced bulk and total recombination, and fewer raw material consumption (Panasonic, IEEE Journal of Photovoltaics., vol. 4, p. 96, 2014). Nonetheless, thin substrates always lead to low mechanical stability and wafer breaking. In this work, spray coated 50 nm graphene layer is used as the back electrode in Si HIT solar cells to enhance the mechanical stability. With the incorporation of graphene as the back electrode in Si HIT solar cells, remarkable improvements in substrate mechanical strength are achieved. Without the degradation of HIT solar cell efficiency, hardness is increased nearly twofold from 902 to 1747 HV. The Young's modulus is increased from 93.9 to 140.1 GPa while the ultimate tensile strength is increased from 96.71 to 273.68 MPa. Low-cost chemical exfoliation method and low-temperature (150 °C) spray coating method have been employed for the preparation and deposition of thin graphene back electrode, respectively. In addition, unlike the graphene as the substitute for ITO in OLED applications, the graphene strengthened thin silicon substrate technology here imposes no additional constraint on the graphene electrode transparency since it is used as a back electrode. We, thereby, believe that our proposed method is effective for attaining higher efficiency and lower $/Watt thin Si HIT solar cell technology with enhanced mechanical strength.
Autors: Albert S. Lin;Parag Parashar;Chih-Chieh Yang;Wei-Ming Huang;Yi-Wen Huang;Ding-Rung Jian;Ming-Hsuan Kao;Shi-Wei Chen;Chang-Hong Shen;Jia-Min Shieh;Tseung Yuen Tseng;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 9
Publisher: IEEE
 
» High Performance CuO Nanorectangles-Based Room Temperature Flexible NH3 Sensor
Abstract:
Here, we report the fabrication of a flexible room temperature ammonia gas sensor using surfactant-free hydrothermally synthesized copper oxide (CuO) nanorectangles. The structural analysis revealed that the CuO nanorectangles possessed monoclinic structure with an average length and breadth of 950 and 450 nm, respectively. The specific surface area of CuO nanorectangles was determined to be 29 m2/g. The sensor was fabricated on a flexible polyethylene terephthalate substrate by screen printing technique. The room temperature ammonia sensing measurement exhibited significant response down to 5 ppm of ammonia with a quick response time of 90 s and recovered to baseline within 120 s. Maximum response of 0.99 was recorded for 100 ppm of ammonia. The rate constants for adsorption and desorption were estimated for 6.5 to 100 ppm of ammonia from the exponential conductance changes during response and recovery process. The sensor showed appreciable stability and reproducibility of the sensing performance over a period of three months. The fabricated flexible sensor demonstrated its ability to detect a wide range of ammonia concentrations at room temperature irrespective of the mechanical deformations applied. Thus, the fabricated sensor is promising and can be suitably employed for practical applications in environments where efficient gas sensing is vitally important.
Autors: Bhuvaneshwari Sakthivel;Libu Manjakkal;Gopalakrishnan Nammalvar;
Appeared in: IEEE Sensors Journal
Publication date: Oct 2017, volume: 17, issue:20, pages: 6529 - 6536
Publisher: IEEE
 
» High Selectivity Wideband Balanced Filters With Multiple Transmission Zeros
Abstract:
Two novel high selectivity wideband balanced filters based on open/shorted stubs with multiple transmission zeros are proposed in this brief. Two and four transmission zeros near each passband for the differential mode (DM) can be easily achieved for two balanced filters. In addition, the common mode can be suppressed with three and five transmission zeros with an insertion loss greater than 15 dB/20 dB over a wide frequency band. Two prototypes with 3-dB fractional bandwidths of 67.6% and 37.8% for the DM with an insertion loss greater than 15 dB (7.0–12.7 GHz) are designed and fabricated. A good agreement can be observed between the measured results and the theoretical expectations.
Autors: Wenjie Feng;Xin Gao;Wenquan Che;Wanchen Yang;Quan Xue;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2017, volume: 64, issue:10, pages: 1182 - 1186
Publisher: IEEE
 
» High-Accuracy Impedance Detection to Improve Transient Stability in Microgrids
Abstract:
The advancements in dc microgrids and the increase in distributed generation systems have led to a new trend toward the coexistence of multiple power converters from different sources (renewable, storage, etc.) supplying a variety of loads of different natures in a weak network. The loads can behave as passive loads (resistances) or be implemented by tightly regulated power converters, leading to constant power load (CPL) behavior. The CPLs present a characteristic negative incremental resistance that can alter the response of the system, even causing instability. In this work, a novel embedded technique based on a digital lock-in amplifier is proposed that enables the real-time detection of the dynamic impedance present in a power converter. The proposed technique uses a very efficient algorithm, along with standard sensors available in the converter, to measure the magnitude and phase of the dynamic load, and uses this information to improve the performance of the converter. A sample application of the proposed technique in an adaptive control system is described. Although the total output power of the converter is independent of the nature of the load, the converter's dynamic response is not. The interaction of the CPL, passive load, and control loop will determine not only the stability but also the transient response. The proposed instrument allows the incremental load of the converter to be accurately measured while reducing the complexity and sensor requirements, and improving the performance of the controller. Simulations of the proposed technique are presented to illustrate its behavior. Experimental results for different kinds of loads are presented to validate the proposed strategy.
Autors: Francisco Paz;Martin Ordonez;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Oct 2017, volume: 64, issue:10, pages: 8167 - 8176
Publisher: IEEE
 
» High-Brightness Multimode Fiber Lasers for Resonant Pumping
Abstract:
We present multimode fiber lasers for tandem pumping of high power Er-, Tm-, and Yb-doped lasers. These pump sources are based on especially developed multimode Er- and Yb-doped double-clad fibers. Er-doped lasers with record pump conversion efficiency >48% at 1565 nm and more than 41% at 1535 and 1590 nm were realized. Yb-doped fiber laser at 1020 nm with record high 85% pump conversion efficiency was demonstrated. Also, we propose novel design of compact and cost-effective multimode laser scheme. The potential of power scaling of proposed lasers to the 1–10-kW level and their advantages as resonant pump sources are discussed.
Autors: Leonid V. Kotov;Svetlana S. Aleshkina;Maksim M. Khudyakov;Mikhail M. Bubnov;Oleg I. Medvedkov;Denis S. Lipatov;Aleksei N. Guryanov;Mikhail M. Likhachev;
Appeared in: Journal of Lightwave Technology
Publication date: Oct 2017, volume: 35, issue:20, pages: 4540 - 4546
Publisher: IEEE
 
» High-Level Energy Estimation for Submicrometric TSV Arrays
Abstract:
The 3-D integration using through silicon vias (TSVs) is one of the most promising approaches to overcome the interconnect delay problem of current CMOS technologies. Nevertheless, the TSV energy consumption is not negligible due to the high capacitive coupling. This paper presents an abstract and yet accurate model to estimate the pattern-dependent energy consumption in arrays of TSVs; it is the first high-level model including the effects of the voltage-dependent metal–oxide–semiconductor (MOS) capacitances surrounding each TSV and a possible temporal misalignment between the input signals. We propose a regression method to estimate the dynamic size of the coupling capacitances as a function of the bit probabilities. Experimental results for real and synthetic data streams, a submicrometer 9-bit TSV array and a 65-nm technology show that the presented TSV energy model exhibits a maximum error of 5.53%, while the traditional high-level model shows errors of up to 79.77%. Furthermore, the new insights provided by our model reveal a possibility to easily boost the efficiency of existing low-power codes for TSV structures by over 10% without affecting the coding efficiency for the planar metal wires or the encoder complexity.
Autors: Lennart Bamberg;Alberto Garcia-Ortiz;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Oct 2017, volume: 25, issue:10, pages: 2856 - 2866
Publisher: IEEE
 
» High-Order Dual-Band Superconducting Bandpass Filter With Controllable Bandwidths and Multitransmission Zeros
Abstract:
In this paper, a compact dual-mode hairpin ring resonator (HRR) with two controllable resonances is proposed to design high-order dual-band high-temperature superconducting (HTS) bandpass filters. Its noncoupled dual-mode resonant characteristics and the mechanism for inherent transmission zero (TZ) production are studied. Moreover, a general dual-path coupling scheme is introduced for high-order coupling realization and applied to the third-order and eighth-order dual-band filter design. Also, two coupling structures for the adjacent HRRs with different orientations are proposed to excite TZs between the passbands for high selectivity. Besides, dual-parallel input–output feeding structure is adopted to tune the external quality factors of the dual-mode HRR individually so that the two passband are realized easily using high-order structure. For demonstration, an eighth-order dual-band HTS filter both operating at 1.9 and 2.6 GHz for mobile communications application are designed and analyzed. Compared with the third-order one, the selectivity of the eighth-order filter has at least 4.2 times improvement and five TZs are produced for high band-edge selectivity. Finally, the eighth-order dual-band filter is fabricated on MgO substrate with YBCO thin films. Measured results agree well with the simulations and show the excellent performance with 0.12-dB minimum insertion loss and better than −75-dB rejection level up to 5 GHz. In addition, the nonlinear characteristics of the fabricated HTS filter is observed by experiment, which shows the temperature dependence of filter center frequency performance and microwave insertion loss.
Autors: Haiwen Liu;Baoping Ren;Shuangxi Hu;Xuehui Guan;Pin Wen;Jiaming Tang;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3813 - 3823
Publisher: IEEE
 
» High-Performance Compact Diplexers for Ku/K-Band Satellite Applications
Abstract:
In this paper, two novel compact diplexers for satellite applications are presented. The first covers the Ku-band with two closely spaced channels (Ku-transmission band: 10.7–13 GHz and Ku-reception band: 13.75–14.8 GHz). The second is wider than the first (overall bandwidth up to 50%) achieves the suppression of the higher order modes, and covers the Ku/K-band with a reception channel between 17.2 and 18.5 GHz. Both diplexers are composed of two novel bandpass filters, joined together with an E-plane T-junction. The bandpass filters are designed by combining a low-pass filtering function (based on /4-step-shaped band-stop elements separated by very short waveguide sections) and a high-pass filtering structure (based on the waveguide propagation cutoff effect). The novel diplexers show a very compact footprint and very relaxed fabrication tolerances, and are especially attractive for wideband applications. A prototype Ku/K-band diplexer has also been fabricated by milling. Measurements show a very good agreement with simulations, thereby demonstrating the validity and manufacturing robustness of the proposed topology.
Autors: Fernando Teberio;Ivan Arregui;Pablo Soto;Miguel A. G. Laso;Vicente E. Boria;Marco Guglielmi;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3866 - 3876
Publisher: IEEE
 

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