Electrical and Electronics Engineering publications abstract of: 10-2017 sorted by title, page: 8

» Fast Binary Counters Based on Symmetric Stacking
Abstract:
In this brief, a new binary counter design is proposed. It uses 3-bit stacking circuits, which group all of the “1” bits together, followed by a novel symmetric method to combine pairs of 3-bit stacks into 6-bit stacks. The bit stacks are then converted to binary counts, producing 6:3 counter circuits with no xor gates on the critical path. This avoidance of xor gates results in faster designs with efficient power and area utilization. In VLSI simulations, the proposed counters are 30% faster than existing parallel counters and also consume less power than other higher order counters. Additionally, using the proposed counters in existing counter-based Wallace tree multiplier architectures reduces latency and power consumption for 64 and 128-bit multipliers.
Autors: Christopher Fritz;Adly T. Fam;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Oct 2017, volume: 25, issue:10, pages: 2971 - 2975
Publisher: IEEE
 
» Fast Depth Imaging Denoising With the Temporal Correlation of Photons
Abstract:
This paper proposes a novel method to filter out the false alarm of LiDAR system by using the temporal correlation of target reflected photons. Because of the inevitable noise, which is due to background light and dark counts of the detector, the depth imaging of LiDAR system exists a large estimation error. Our method combines the Poisson statistical model with the different distribution feature of signal and noise in the time axis. Due to selecting a proper threshold, our method can effectively filter out the false alarm of system and use the ToFs of detected signal photons to rebuild the depth image of the scene. The experimental results reveal that by our method it can fast distinguish the distance between two close objects, which is confused due to the high background noise, and acquire the accurate depth image of the scene. Our method need not increase the complexity of the system and is useful in power-limited depth imaging.
Autors: Zhenchao Feng;Weiji He;Jian Fang;Guohua Gu;Qian Chen;Ping Zhang;Yuanjin Chen;Beibei Zhou;Minhua Zhou;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 10
Publisher: IEEE
 
» Fast Detection of Compressively Sensed IR Targets Using Stochastically Trained Least Squares and Compressed Quadratic Correlation Filters
Abstract:
Target detection of potential threats at night can be deployed on a costly infrared focal plane array with high resolution. Due to the compressibility of infrared image patches, the high resolution requirement could be reduced with target detection capability preserved. For this reason, a compressive midwave infrared imager (MWIR) with a low-resolution focal plane array has been developed. As the most probable coefficient indices of the support set of the infrared image patches could be learned from the training data, we develop stochastically trained least squares (STLS) for MWIR image reconstruction. Quadratic correlation filters (QCF) have been shown to be effective for target detection and there are several methods for designing a filter. Using the same measurement matrix as in STLS, we construct a compressed quadratic correlation filter (CQCF) employing filter designs for compressed infrared target detection. We apply CQCF to the U.S. Army Night Vision and Electronic Sensors Directorate dataset. Numerical simulations show that the recognition performance of our algorithm matches that of the standard full reconstruction methods, but at a fraction of the execution time.
Autors: Brian Millikan;Aritra Dutta;Qiyu Sun;Hassan Foroosh;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Oct 2017, volume: 53, issue:5, pages: 2449 - 2461
Publisher: IEEE
 
» Fast ISAR Imaging Based on Enhanced Sparse Representation Model
Abstract:
Traditional sparse representation-(SR) based inverse synthetic aperture radar (ISAR) imaging schemes can achieve significant performance, but they suffer from high costs of memory and computational complexity, because the SR of a 2-D image is converted into that of a 1-D vector. Instead of memory consuming vector operations, we propose a fast ISAR imaging algorithm, where the decomposition and reconstruction of a 2-D scene is implemented using matrix operations directly. Besides the spatial sparsity of a scene, its structural sparsity is presented using the range profile of the scene, where both can be used to enhance sparsity exploitation during image reconstruction. Also, benefitting from the structural sparsity of the range profile, the target energy can be accumulated during the process, which further improves performance. Compared to available SR-based ISAR imaging algorithms, the proposed algorithm reduces both memory costs and computational complexity significantly, which is proven using simulated and real data.
Autors: Guanghui Zhao;Fangfang Shen;Jie Lin;Guangming Shi;Yi Niu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5453 - 5461
Publisher: IEEE
 
» Fast Parallel Path Concatenation for Graph Extraction
Abstract:
Heterogeneous graph is a popular data model to represent the real-world relations with abundant semantics. To analyze heterogeneous graphs, an important step is extracting homogeneous graphs from the heterogeneous graphs, called homogeneous graph extraction. In an extracted homogeneous graph, the relation is defined by a line pattern on the heterogeneous graph and the new attribute values of the relation are calculated by user-defined aggregate functions. The key challenges of the extraction problem are how to efficiently enumerate paths matched by the line pattern and aggregate values for each pair of vertices from the matched paths. To address above two challenges, we propose a parallel graph extraction framework, where we use vertex-centric model to enumerate paths and compute aggregate functions in parallel. The framework compiles the line pattern into a path concatenation plan, which determines the order of concatenating paths and generates the final paths in a divide-and-conquer manner. We introduce a cost model to estimate the cost of a plan and discuss three plan selection strategies, among which the best plan can enumerate paths in iterations, where is the length of a pattern. Furthermore, to improve the performance of evaluating aggregate functions, we classify the aggregate functions into three categories, i.e., distributive aggregation, algebraic aggregation, and holistic aggregation. Since the distributive and algebraic aggregations can be computed from the partial paths, we speed up the aggregation by computing partial aggregate values during the path enumeration.
Autors: Yingxia Shao;Kai Lei;Lei Chen;Zi Huang;Bin Cui;Zhongyi Liu;Yunhai Tong;Jin Xu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Oct 2017, volume: 29, issue:10, pages: 2210 - 2222
Publisher: IEEE
 
» Fast Real-Time Causal Linewise Progressive Hyperspectral Anomaly Detection via Cholesky Decomposition
Abstract:
Real-time processing of anomaly detection has become one of the most important issues in hyperspectral remote sensing. Due to the fact that most widely used hyperspectral imaging spectrometers work in a pushbroom fashion, it is necessary to process the incoming data line in a causal linewise progressive manner with no future data involved. In this study, we proposed several processes to well improve the computational performance of real-time causal linewise progressive anomaly detection (RCLP-AD). At first, Cholesky decomposition along with linear system solving (CDLSS) was used since the background statistical matrix are symmetric positive definite. The computational performance as well as the numerical stabilities is well improved. In order to show the computational advantage of the proposed method, we did a comprehensive comparative analysis regarding the computational complexity of different linewise processing techniques, in terms of the theoretical floating point operations (flops) and the real computer processing time. Moreover, the symmetric property of some intermediate resulting matrices in the process is considered for further computational optimization. Finally, from an onboard detection point of view, we defined the line-varying global background (i.e., an area covered by recently acquired data lines) to improve the detection power. To substantiate the performance of the CDLSS-based RCLP-AD regarding the accuracy and efficiency, two hyperspectral datasets were used in our experiments.
Autors: Lifu Zhang;Bo Peng;Feizhou Zhang;Lizhe Wang;Hongming Zhang;Peng Zhang;Qingxi Tong;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Oct 2017, volume: 10, issue:10, pages: 4614 - 4629
Publisher: IEEE
 
» Fast Rise Time High Current Electron Beam: Emission, Acceleration, and Drift Motion
Abstract:
Fast processes associated with emission, acceleration, and drift motion of a high current, moderately magnetized electron beam (particles energy ~300 keV; current ~3 kA) were studied experimentally when tubular explosive-emission cathode was supplied by subnanosecond rise time voltage pulse. Kinematic effect causes the sharpening of the observed beam front which was proven by particle-in-cell numerical modeling. The angular structure of tubular beam was studied through the current waveform records from collector probe after beam propagation through a radial-slit collimator. Current waveforms had time resolution no worse than 10 ps and provided the analysis of the beam temporal structure after its acceleration as well as in the process of further electrons drift motion in a finite guiding magnetic field.
Autors: Sergei A. Shunailov;Gennady A. Mesyats;Ilya V. Romanchenko;Vladislav V. Rostov;Konstantin A. Sharypov;Valery G. Shpak;Marat R. Ul’maskulov;Michael I. Yalandin;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Oct 2017, volume: 45, issue:10, pages: 2755 - 2761
Publisher: IEEE
 
» Fast Semiconductor Switching Modules for Transformer-Coupled LC Inversion Generators
Abstract:
The recent availability of fast high-power semiconductor switches makes the transformer coupled LC inversion generator (TCLCG) topology a very promising candidate for the realization of reliable, multi-kHz repetition rate pulse generators with an output voltage in the range of 200 kV and more. Usage of 1:1 transformers instead of closing switches in each generator stage reduces the total number of switches inside the TCLCG to only one, independent of the numbers of stages. Thus, problem of synchronization as in Marx-generators or classical LC inversion generators can be omitted. In principle, capacitors are initially charged to the charging voltage, whereas the odd-numbered of each stage are charged with the opposite polarity to the even-numbered capacitors. Fast voltage inversion of the even-numbered capacitors leads to efficient voltage multiplication provided the semiconductor switching module will be sufficiently fast to minimize switching losses. For initial investigations, a special asymmetrically compensated three-stage test TCLCG was designed and set up. Three high-voltage semiconductor switching modules were experimentally tested in detail; two 20-kV high-voltage switching modules consisting of a series arrangement of 15 Si-based insulated gate bipolar transistors or 15 SiC-based MOSFETs, with in each case 1700-V breakdown voltage, and a fast experimental 10-kV thyristor switching module with kilo ampere current carrying capability. The achievable output signal rise time and generator efficiency for different electrical loads (resistive, capacitive, or inductive) are discussed.
Autors: Rainer Bischoff;Volker Brommer;Meik Stoll;Sigo Scharnholz;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Oct 2017, volume: 45, issue:10, pages: 2618 - 2622
Publisher: IEEE
 
» Fast Simulation of Dynamic Ultrasound Images Using the GPU
Abstract:
Simulated ultrasound data is a valuable tool for development and validation of quantitative image analysis methods in echocardiography. Unfortunately, simulation time can become prohibitive for phantoms consisting of a large number of point scatterers. The COLE algorithm by Gao et al. is a fast convolution-based simulator that trades simulation accuracy for improved speed. We present highly efficient parallelized CPU and GPU implementations of the COLE algorithm with an emphasis on dynamic simulations involving moving point scatterers. We argue that it is crucial to minimize the amount of data transfers from the CPU to achieve good performance on the GPU. We achieve this by storing the complete trajectories of the dynamic point scatterers as spline curves in the GPU memory. This leads to good efficiency when simulating sequences consisting of a large number of frames, such as B-mode and tissue Doppler data for a full cardiac cycle. In addition, we propose a phase-based subsample delay technique that efficiently eliminates flickering artifacts seen in B-mode sequences when COLE is used without enough temporal oversampling. To assess the performance, we used a laptop computer and a desktop computer, each equipped with a multicore Intel CPU and an NVIDIA GPU. Running the simulator on a high-end TITAN X GPU, we observed two orders of magnitude speedup compared to the parallel CPU version, three orders of magnitude speedup compared to simulation times reported by Gao et al. in their paper on COLE, and a speedup of 27000 times compared to the multithreaded version of Field II, using numbers reported in a paper by Jensen. We hope that by releasing the simulator as an open-source project we will encourage its use and further development.
Autors: Sigurd Storve;Hans Torp;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Oct 2017, volume: 64, issue:10, pages: 1465 - 1477
Publisher: IEEE
 
» Fast Startup of LC VCOs Using Circuit Asymmetries
Abstract:
An LC VCO whose design includes deliberate circuit mismatches is presented. It is shown that such mismatches can reduce the oscillation start-up time due to a common-mode disturbance simultaneous with the turn-on of the tail current. The use of this technique is applied to a low-power transmitter for an ultra-wideband wireless communication system using the on–off keying modulation scheme. Measurements using a 0.18- CMOS technology with a 4.2-GHz carrier frequency demonstrate the technique.
Autors: Joshua H. Kim;Ali Tazarv;Michael M. Green;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2017, volume: 64, issue:10, pages: 1172 - 1176
Publisher: IEEE
 
» Fast-Lipschitz Power Control and User-Frequency Assignment in Full-Duplex Cellular Networks
Abstract:
In cellular networks, the three-node full-duplex transmission mode has the potential to increase spectral efficiency without requiring full-duplex capability of users. Consequently, three-node full-duplex in cellular networks must deal with self-interference and user-to-user interference, which can be managed by power control and user-frequency assignment techniques. This paper investigates the problem of maximizing the sum spectral efficiency by jointly determining the transmit powers in a distributed fashion, and assigning users to frequency channels. The problem is formulated as a mixed-integer nonlinear problem, which is shown to be non-deterministic polynomial-time hard. We investigate a close-to-optimal solution approach by dividing the joint problem into a power control problem and an assignment problem. The power control problem is solved by Fast-Lipschitz optimization, while a greedy solution with guaranteed performance is developed for the assignment problem. Numerical results indicate that compared with the half-duplex mode, both spectral and energy efficiencies of the system are increased by the proposed algorithm. Moreover, results show that the power control and assignment solutions have important, but opposite roles in scenarios with low or high self-interference cancellation. When the self-interference cancellation is high, user-frequency assignment is more important than power control, while power control is essential at low self-interference cancellation.
Autors: José Mairton B. da Silva;Gábor Fodor;Carlo Fischione;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Oct 2017, volume: 16, issue:10, pages: 6672 - 6687
Publisher: IEEE
 
» Fault Detection Over Frequency Region: Generalized Spectral Factorization Approach
Abstract:
We present results on fault detection in presence of disturbances of descriptor systems over a frequency region. Instead of the methodology of the generalized KYP lemma, used in the literature, we use the methodology of generalized spectral factorization. Illustrative examples are given.
Autors: Jovan D. Stefanovski;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Oct 2017, volume: 62, issue:10, pages: 5296 - 5301
Publisher: IEEE
 
» Fault Diagnosis of Space-Borne Fiber-Optic Gyros Based on Random Walk Coefficient Prediction and In-Orbit Calculation
Abstract:
A novel fault diagnosis method for the space-borne interferometric fiber-optic gyroscope (IFOG) is presented in this paper. The noise source of the fiber-optic gyroscope is analyzed first. Then, the prediction model of the random walk coefficient (RWC) is established based on the radiation-induced attenuation effect on optical fiber, and the estimation model of RWC is developed by using the detected signal acquired by the photo-detector. In addition, an improved iterative method to calculate the RWC with the output data of the IFOG in orbit is proposed. The three RWC values mentioned above are compared to determine the operational state of the gyroscope. And an in-situ fault diagnosis strategy for the IFOG is proposed finally. Based on the ground simulation and fault injection, the feasibility of the strategy is proved.
Autors: Jing Jin;Ting Zhang;Kun Ma;Haoshi Zhang;Fei Teng;Shaobo Zhang;
Appeared in: IEEE Sensors Journal
Publication date: Oct 2017, volume: 17, issue:20, pages: 6637 - 6645
Publisher: IEEE
 
» Fault Tolerance Capability and Semiconductor’s Hold-Off Voltage of Solid-State Bipolar Marx Modulators
Abstract:
Two solid-state bipolar Marx modulators are analyzed and compared regarding hold-off semiconductor voltages and open-fault tolerance capability. Normal and abnormal operating conditions are considered, such as switch synchronization mismatches, failures, and open faults. Ten-stage laboratory prototypes of two bipolar Marx modulators have been assembled using 1200-V insulated gate bipolar transistors and matching diodes, to operate at 500-V dc input voltage. Outputs are 4-kV bipolar pulses, 1% duty ratio, into resistive loads, and 1-kHz frequency. Lack of synchronization and open-fault tests confirm that only topologies with redundant switches can operate without semiconductors being subjected to double hold-off voltages while presenting current paths to clear faults.
Autors: Hiren Canacsinh;J. Fernando Silva;L. M. Redondo;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Oct 2017, volume: 45, issue:10, pages: 2661 - 2666
Publisher: IEEE
 
» Feast or Famine [From the Editor's Desk]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Alfy Riddle;
Appeared in: IEEE Microwave Magazine
Publication date: Oct 2017, volume: 18, issue:6, pages: 6 - 22
Publisher: IEEE
 
» Feature-Fused SAR Target Discrimination Using Multiple Convolutional Neural Networks
Abstract:
Target discrimination has been one of the hottest issues in the interpretation of synthetic aperture radar (SAR) images. However, the presence of speckle noise and the absence of robust features make SAR discrimination difficult to deal with. Recently, convolutional neural network has obtained state-of-the-art results in pattern recognition. In this letter, we propose a target discrimination framework that jointly uses intensity and edge information of SAR images. This framework contains three parts, namely, feature extraction block, feature fusion block, and final classification block. In addition, a novel feature fusion method that can preserve the spatial relationship of different features is introduced. Experimental results on the miniSAR data demonstrate the effectiveness of our method.
Autors: Ning Wang;Yinghua Wang;Hongwei Liu;Qunsheng Zuo;Jinglu He;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Oct 2017, volume: 14, issue:10, pages: 1695 - 1699
Publisher: IEEE
 
» Feedback Stabilized Optical Fabry–Pérot Interferometer Based on Twin-Core Fiber for Multidimension Microdisplacement Sensing
Abstract:
A novel optical Fabry–Pérot interferometer (FPI) is proposed and experimentally demonstrated for multidimension microdisplacement sensing (MMS). The sensor structure consists of a section of twin-core fiber with a length of 2.4 cm and a section of feedback fiber (FBF) fabricated by normal single-mode fiber. The end faces of two fibers can be formed as the reflection cavity (RC) of the FPI. Mounting the sensor on translation stages, and moving the FBF in different directions to change the RC, the changing mode interference of the reflected beam can be measured. A maximum microdisplacement sensitivity of 0.954 nm/μm with a higher resolution 0.052 μm was achieved. Due to the advantages of the MMS and simple configuration, the sensor is significantly beneficial to practical application.
Autors: Chuanbiao Zhang;Tigang Ning;Jingjing Zheng;Jing Li;Heng Lin;Xuekai Gao;Li Pei;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 9
Publisher: IEEE
 
» Feedback-Based Online Network Coding
Abstract:
Current approaches to the practical implementation of network coding are batch-based, and often do not use feedback, except possibly to signal completion of a file download. In this paper, the various benefits of using feedback in a network coded system are studied. It is shown that network coding can be performed in a completely online manner, without the need for batches or generations, and that such online operation does not affect the throughput. Although these ideas are presented in a single-hop packet erasure broadcast setting, they naturally extend to more general lossy networks, which employ network coding in the presence of feedback. The impact of feedback on sender-side queue size and receiver-side decoding delay is studied in an asymptotic sense as the traffic load approaches capacity. Different notions of decoding delay are considered, including an order-sensitive notion, which assumes that packets are useful only when delivered in order. Strategies for adaptive coding based on feedback are presented. Our scheme achieves throughput optimality and asymptotically optimal sender queue size and is conjectured to achieve asymptotically optimal in-order delivery delay for any number of receivers. This paper may be viewed as a natural extension of Automatic Repeat reQuest to coded networks.
Autors: Jay Kumar Sundararajan;Devavrat Shah;Muriel Médard;Parastoo Sadeghi;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6628 - 6649
Publisher: IEEE
 
» Fekete Points, Formation Control, and the Balancing Problem
Abstract:
We study formation control problems. Our approach is to let a group of systems maximize their pairwise distances while bringing them all to a given submanifold, determining the shape of the formation. The algorithm we propose allows us to initialize the positions of the individual systems in the ambient space of the given submanifold but brings them to the desired formation asymptotically in a stable fashion. Our control inherently consists of a distributed component, maximizing the pairwise distances, and a decentralized component, asymptotically stabilizing the submanifold. We establish a graph-theoretical interpretation of the equilibria that our control enforces and extends our approach to systems living on the special Euclidean group. Throughout this paper, we illustrate our approach on different examples.
Autors: Jan Maximilian Montenbruck;Daniel Zelazo;Frank Allgöwer;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Oct 2017, volume: 62, issue:10, pages: 5069 - 5081
Publisher: IEEE
 
» Fermi Level Depinning in Ti/GeO2/n-Ge via the Interfacial Reaction Between Ti and GeO2
Abstract:
A new method of forming an ohmic contact without an increase in parasitic resistance is proposed in the Ti/GeO2/Ge substrate. Fermi-level depinning in Ti/GeO2/n–Ge contacts is possible with the formation of an interfacial TiOx layer in the contacts via an interfacial reaction. Unlike the intentional deposition of a metal oxide on a Ge substrate, this method provides easy process integration to lessen Fermi-level pinning in n-type Ge substrates.
Autors: Yujin Seo;Tae In Lee;Hyun Jun Ahn;Jungmin Moon;Wan Sik Hwang;Hyun-Yong Yu;Byung Jin Cho;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2017, volume: 64, issue:10, pages: 4242 - 4245
Publisher: IEEE
 
» Fiber Optic Magnetic Field Sensor Based on Magnetic Nanoparticle Assembly in Microcapillary Ring Resonator
Abstract:
A magnetic field sensor based on the magnetic-field-induced nanoparticle assembly effect in microcapillary whispering gallery mode (WGM) ring resonator is proposed and experimentally demonstrated. The chemical characteristics of nanoparticles and the silica microcapillary are used to link up the surface density of the resonator and the magnetic field intensity. The magnetic field variation changes the surface density of nanoparticles adsorbed on the sensor surface and respond to the WGM transmission spectra shift. Because of the powerful surface sensing capability of WGM, the maximum sensing sensitivity reaches 57.59 nm/mT and the detection limit reaches 1.39 × 10 –4, respectively. The magnetic field response characteristic of the sensor is studied as well. This provides the potential to fiber-based magnetic field sensing applications.
Autors: Zhe Yu;Junfeng Jiang;Xuezhi Zhang;Kun Liu;Shuang Wang;Wenjie Chen;Tiegen Liu;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 9
Publisher: IEEE
 
» File Updates Under Random/Arbitrary Insertions and Deletions
Abstract:
The problem of one-way file synchronization, henceforth called “file updates”, is studied in this paper. Specifically, a client edits a file, where the edits are modeled by insertions and deletions (InDels). An old copy of the file is stored remotely at a data-centre, and is also available to the client. We consider the problem of throughput- and computationally-efficient communication from the client to the data-centre, to enable the data-centre to update its old copy to the newly edited file. Two models for the source files and edit patterns are studied: the random pre-edit sequence left-to-right random InDel (RPES-LtRRID) process, and the arbitrary pre-edit sequence arbitrary InDel (APES-AID) process. In both models, we consider the regime, in which the number of insertions and deletions is a small (but constant) fraction of the length of the original file. For both models, information-theoretic lower bounds on the best possible compression rates that enable file updates are derived (up to first order terms). Conversely, a simple compression algorithm using dynamic programming (DP) and entropy coding (EC), henceforth called DP-EC algorithm, achieves rates that are within constant additive gap (which diminishes as the alphabet size increases) to information-theoretic lower bounds for both models. For the RPES-LtRRID model, a dynamic-programming-run-length-compression (DP-RLC) algorithm is proposed, which achieves a compression rate matching the information-theoretic lower bound up to first order terms. Therefore, when the insertion and deletion probabilities are small (such that first order terms dominate), the achievable rate by DP-RLC is nearly optimal for the RPES-LtRRID model.
Autors: Qiwen Wang;Sidharth Jaggi;Muriel Médard;Viveck R. Cadambe;Moshe Schwartz;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6487 - 6513
Publisher: IEEE
 
» Finding Measurement Configurations for Accurate Robot Calibration: Validation With a Cable-Driven Robot
Abstract:
It is well known that, by properly selecting the measurement configurations in robot calibrations, the observability index of unknown parameters can be maximized, leading to high calibration accuracy. For this purpose, many configuration-search methods were proposed. However, the established methods were mainly based on derivative-free or metaheuristic techniques, whose computational costs were high. Moreover, the robustness of observability index and convergences of configuration searches were not investigated. In this paper, by extending a recent result in matrix perturbation theory to robot kinematics, we establish the closed-form mapping from configuration perturbations to singular-value variations. Based on this mapping, an efficient configuration-search method is proposed, the robustness of the observability index under bounded configuration perturbations is analyzed, and the convergence of configuration searches is studied. The proposed methods were validated by simulations on serial and parallel robots. With roughly estimated initial parameters, self-calibration experiments on a redundant cable-driven parallel robot were performed. The effectiveness of the proposed methods is demonstrated by the experiment results.
Autors: Hongbo Wang;Tianqi Gao;Jun Kinugawa;Kazuhiro Kosuge;
Appeared in: IEEE Transactions on Robotics
Publication date: Oct 2017, volume: 33, issue:5, pages: 1156 - 1169
Publisher: IEEE
 
» Fixed-Time Connectivity-Preserving Distributed Average Tracking for Multiagent Systems
Abstract:
This brief studies the fixed-time average tracking problem for multiagent systems under communication constraints, in which each agent has a limited sensing range. A distributed nonlinear control protocol is proposed to make a team of agents track the average of multiple time-varying reference signals with bounded derivatives. Furthermore, the initial interaction patterns can be preserved under the designed protocol and the average tracking can be achieved within fixed time, where the bound of settling time is independent of the initial conditions. Thus, the fixed convergence time can be flexibly adjusted. Finally, some numerical examples are provided to illustrate the performance and effectiveness of the theoretical results.
Autors: Huifen Hong;Wenwu Yu;Xinghuo Yu;Guanghui Wen;Ahmed Alsaedi;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2017, volume: 64, issue:10, pages: 1192 - 1196
Publisher: IEEE
 
» Flexibility Needed: Challenges for Future Energy Storage Systems [Guest Editorial]
Abstract:
The articles in this special section focus on the technologies that will support future energy storage systems. In modern power systems, we are transitioning to an increasing penetration of massive low-cost wind and solar generation, which will require indispensable system flexibility for balancing requirements to maintain system performance. The existing actors have limited technical capabilities to provide the needed flexibility, and new alternatives are required. The flexibility providers are diverse and being assessed extensively, with a clear sense of urgency.
Autors: Hugh Rudnick;Luiz Barroso;
Appeared in: IEEE Power and Energy Magazine
Publication date: Oct 2017, volume: 15, issue:5, pages: 12 - 19
Publisher: IEEE
 
» Flexible and Fine-Grained Attribute-Based Data Storage in Cloud Computing
Abstract:
With the development of cloud computing, outsourcing data to cloud server attracts lots of attentions. To guarantee the security and achieve flexibly fine-grained file access control, attribute based encryption (ABE) was proposed and used in cloud storage system. However, user revocation is the primary issue in ABE schemes. In this article, we provide a ciphertext-policy attribute based encryption (CP-ABE) scheme with efficient user revocation for cloud storage system. The issue of user revocation can be solved efficiently by introducing the concept of user group. When any user leaves, the group manager will update users’ private keys except for those who have been revoked. Additionally, CP-ABE scheme has heavy computation cost, as it grows linearly with the complexity for the access structure. To reduce the computation cost, we outsource high computation load to cloud service providers without leaking file content and secret keys. Notably, our scheme can withstand collusion attack performed by revoked users cooperating with existing users. We prove the security of our scheme under the divisible computation Diffie-Hellman assumption. The result of our experiment shows computation cost for local devices is relatively low and can be constant. Our scheme is suitable for resource constrained devices.
Autors: Jiguo Li;Wei Yao;Yichen Zhang;Huiling Qian;Jinguang Han;
Appeared in: IEEE Transactions on Services Computing
Publication date: Oct 2017, volume: 10, issue:5, pages: 785 - 796
Publisher: IEEE
 
» Flexible Efficient Top-Emitting Organic Light-Emitting Devices on a Silk Substrate
Abstract:
A flexible efficient top-emitting organic light-emitting device (TOLED) on an off-the-shelf silk substrate has been demonstrated by planarizing the silk substrate with photopolymer NOA63. The flexibility of the bare silk substrates was retained in the planarized silk substrates due to ductile characteristics of cured NOA63. The planarized silk substrate has shown superiority on surface morphology, which is beneficial to the performances of OLEDs. Their maximum luminance and current efficiency are 45545 and 37.7 cd/A, respectively. Moreover, our devices show not only high luminance and efficiency but also high flexibility and mechanical robustness. Emission of operating devices is uniform and free of defects under a very small bending radius and the luminance and efficiency do not deteriorate obviously after repeated bending. TOLEDs on silk substrate are a potential alternative to wearable displays.
Autors: Yue-Feng Liu;Ming-Hui An;Yan-Gang Bi;Da Yin;Jing Feng;Hong-Bo Sun;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 6
Publisher: IEEE
 
» Flexible Low-Power Organic Complementary Inverter Based on Low- ${k}$ Polymer Dielectric
Abstract:
Organic complementary inverters that have high performance, low-power operation, and flexible compatibility are achieved using a simple and low-cost method to prepare a thin low- polymer dielectric on sputtered C nanoparticles. The operation voltage of the flexible inverter can be as low as 3 V, and the gain is close to 200, which is superior to most reported organic-based inverters. The flexible inverter also exhibits outstanding switching stability in multiple signal processing. The present organic inverters may be of value in portable and wearable electronics.
Autors: Jie Liu;Xu Gao;Jian-Long Xu;Antonio Ruotolo;Sui-Dong Wang;
Appeared in: IEEE Electron Device Letters
Publication date: Oct 2017, volume: 38, issue:10, pages: 1461 - 1464
Publisher: IEEE
 
» Flexible PCC Voltage Unbalance Compensation Strategy for Autonomous Operation of Parallel DFIGs
Abstract:
This paper proposes a flexible compensation strategy for parallel-connected doubly fed induction generators (DFIGs) when connected to an unbalanced weak grid. The proposed strategy has two main advantages, the voltage unbalance factor at the point of common coupling (PCC) can be continuously controlled, thus, the flexible tradeoff between the balanced DFIG output current and the balanced PCC voltage can be achieved, and the negative sequence current required by the compensation can be properly shared among the parallel DFIGs and their grid side converters according to their respective operation conditions without the need of real-time communication. The operation performance and stability of the proposed strategy are analyzed. Simulation and experimental results are carried out to verify the proposed compensation strategy.
Autors: Tao Wang;Heng Nian;Z. Q. Zhu;Hongyang Huang;Xiaoming Huang;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4807 - 4820
Publisher: IEEE
 
» Flexible Tactile Sensor Array Mounted on the Curved Surface: Analytical Modeling and Experimental Validation
Abstract:
This paper presents an analytical model to study the sensing performance of the flexible capacitive tactile sensor array when mounted on a curved surface. To predict the deformation of the sensor unit, a cylindrical coordinate is constructed for the upper Polyethylene Terephthalate (PET) and truncated pyramids dielectric layer. The displacement functions model is developed and solved by using the Ritz method. Then, this model is utilized to investigate the capacitance change of the sensor unit and the model-calculated results are compared with the experiment data. Both model calculated and experiment measured results indicate that the capacitances of the sensor array are increased by about 30% when the sensor is mounted on the curved surface with a radius of curvature of 10 mm. Due to the bending effects of the curved surface, the sensitivities of the sensor array are decreased based on the model calculation and are confirmed by experimental validation. Thus, results demonstrate that the developed analytical model can accurately predict the sensing performance of the tactile sensor array on the curved surface and could be utilized for the real applications. [2016-0235]
Autors: Yancheng Wang;Guanhao Liang;Deqing Mei;Zichen Chen;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Oct 2017, volume: 26, issue:5, pages: 1002 - 1011
Publisher: IEEE
 
» Floating Monopole Antenna on a Tethered Subsurface Sensor at 433 MHz for Ocean Monitoring Applications
Abstract:
Low-cost tethered buoys are important for seawater observation, coastal area monitoring, and pollution sensing. Underwater sensor networks operating at 433 MHz (ISM band) suffer high attenuation due to seawater conductivity. Significant propagation distance cannot be achieved through seawater or along the seabed. This paper reports a novel technique for communication between sensors operating in shallow water. A sensor tethered to the bottom was connected to a floating monopole antenna via an insulated wire transmission line. Experiments and calculations show that the attenuation along the transmission line was 38 dB/m. Surface propagation for buoy-to-base station was approximately 1 dB/m with a communication range of 30 m using a 10-dBm transmitter circuit with receiver sensitivity of 110 dBm. For buoy to buoy the surface propagation was measured as 3.5 dB/m with a communication range of 4 m. Experiments were carried out in calm water conditions. The results demonstrate that significant sensor network coverage of coastal regions is possible.
Autors: Zia M. Loni;Hugo G. Espinosa;David V. Thiel;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Oct 2017, volume: 42, issue:4, pages: 818 - 825
Publisher: IEEE
 
» Flocking of the Cucker-Smale Model on General Digraphs
Abstract:
In the literature, the study of the Cucker-Smale (C-S) flocking model is all restricted to connected undirected graphs or digraphs of some special types, containing only a single root. In this technical note, we establish the flocking behavior of the C-S model on general digraphs, which contain all existing interaction topologies in relation to the C-S model as special cases. In particular, the topology with multiple leaders is included. The flocking results are guaranteed under some conditions on the initial state of the flock only. The critical exponent below which unconditional convergence holds is given, depending only on the interaction topology. It is consistent with the ones obtained under some known special topologies in the literature.
Autors: Jiu-Gang Dong;Li Qiu;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Oct 2017, volume: 62, issue:10, pages: 5234 - 5239
Publisher: IEEE
 
» Fog-Aided Wireless Networks for Content Delivery: Fundamental Latency Tradeoffs
Abstract:
A fog-aided wireless network architecture is studied in which edge nodes (ENs), such as base stations, are connected to a cloud processor via dedicated fronthaul links while also being endowed with caches. Cloud processing enables the centralized implementation of cooperative transmission strategies at the ENs, albeit at the cost of an increased latency due to fronthaul transfer. In contrast, the proactive caching of popular content at the ENs allows for the low-latency delivery of the cached files, but with generally limited opportunities for cooperative transmission among the ENs. The interplay between cloud processing and edge caching is addressed from an information-theoretic viewpoint by investigating the fundamental limits of a high signal-to-noise-ratio metric, termed normalized delivery time (NDT), which captures the worst case coding latency for delivering any requested content to the users. The NDT is defined under the assumptions of either serial or pipelined fronthaul-edge transmission, and is studied as a function of fronthaul and cache capacity constraints. Placement and delivery strategies across both fronthaul and wireless, or edge, segments are proposed with the aim of minimizing the NDT. Information-theoretic lower bounds on the NDT are also derived. Achievability arguments and lower bounds are leveraged to characterize the minimal NDT in a number of important special cases, including systems with no caching capabilities, as well as to prove that the proposed schemes achieve optimality within a constant multiplicative factor of 2 for all values of the problem parameters.
Autors: Avik Sengupta;Ravi Tandon;Osvaldo Simeone;
Appeared in: IEEE Transactions on Information Theory
Publication date: Oct 2017, volume: 63, issue:10, pages: 6650 - 6678
Publisher: IEEE
 
» Foreground Removal Approach for Hole Filling in 3D Video and FVV Synthesis
Abstract:
The depth-image-based rendering is a key technique for 3D video and free viewpoint video synthesis. One of the critical problems in current synthesis methods is that the background (BG) occluded by the foreground objects might be exposed in the new view, and some holes are produced in the synthesized video. However, most of the traditional hole-filling approaches may bring some blurry effect or artifacts in the virtual view. In this paper, a foreground removal approach for hole filling is proposed, in which the foreground objects are removed from both the 2D video and its corresponding depth map, and then a BG video and its depth map are generated before the 3D warping and used to eliminate the holes in the synthesized video. Moreover, a BG extension method is applied in the reference view to prevent the large holes occurring along the border areas in the virtual view. Our analysis and experimental results have indicated that the proposed approach has better performance compared with the other methods in terms of the quality of synthesized video, computational complexity, and running time in multiview synthesis or multiframe synthesis.
Autors: Guibo Luo;Yuesheng Zhu;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Oct 2017, volume: 27, issue:10, pages: 2118 - 2131
Publisher: IEEE
 
» Foreword to the Special Issue on Advances in Ground-Penetrating Radar Research and Applications
Abstract:
Autors: Wallace W. L. Lai;Sébastien Lambot;Jan van der Kruk;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Oct 2017, volume: 10, issue:10, pages: 4271 - 4272
Publisher: IEEE
 
» Fountain-Coded File Spreading Over Mobile Networks
Abstract:
Spreading a large file consisting of many packets over a mobile network is challenging due to the short meeting duration for each transmission. Moreover, two typical causes of inefficient file spreading are duplicate packet reception at the destination nodes and excessive overhead exchanges. We propose to employ fountain codes at the source node to jointly addresses the three issues: 1) each coded packet can be small enough to fit into the meeting duration; 2) duplicate packet reception is significantly reduced since each coded packet is innovative; and 3) overhead is greatly saved by using file-level ACK instead of packet-level ACK. We conduct performance analysis in terms of the source-to-destination file delay and source-to-destination file spreading time in both non-relaying and relaying scenarios. While packet duplication can be eliminated in the former scenario, there is still a non-trivial duplication probability if relaying is allowed. Therefore, we propose a fountain-coded two-hop relaying (FTTR) protocol to further reduce the packet duplication ratio so that the spreading performance does not degrade with network size. The file spreading time and packet duplication ratio of FTTR are derived in closed form and verified through simulations.
Autors: Zhaoyang Zhang;Huazi Zhang;Huaiyu Dai;Xiaoming Chen;Dapeng Oliver Wu;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Oct 2017, volume: 16, issue:10, pages: 6766 - 6778
Publisher: IEEE
 
» FPGA Implementation of a Tone-Based Flight Termination System in a Software-Defined Radio Platform
Abstract:
This paper outlines the design and implementation of a tone-based flight termination system (FTS) in a software-defined radio (SDR) platform. It is completely a novel implementation of an analog FTS in an SDR platform of NI Flex-RIO system. This single platform based design appears as a substitute for the previously used multiple platforms based complex system. Ruggedization and relevance design methods are required for the FTS design. Hence, the blueprint of the FTS is carried out in a field-programmable gate array. It ensures reconfigurable, interoperable operations with precise, reliable, and future upgradable implementation. Efficient optimization methods have been adopted to minimize the use of hardware resources. LabVIEW, a graphical programming language, is used for rapid prototyping. The validation of the system was done both in subsystem level as well as the integrated level at real-time mission scenario.
Autors: Amiya Ranjan Panda;Debahuti Mishra;Hare Krishna Ratha;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2360 - 2368
Publisher: IEEE
 
» FPGA-Based Scalable and Power-Efficient Fluid Simulation using Floating-Point DSP Blocks
Abstract:
High-performance and low-power computation is required for large-scale fluid dynamics simulation. Due to the inefficient architecture and structure of CPUs and GPUs, they now have a difficulty in improving power efficiency for the target application. Although FPGAs become promising alternatives for power-efficient and high-performance computation due to their new architecture having floating-point (FP) DSP blocks, their relatively narrow memory bandwidth requires an appropriate way to fully exploit the advantage. This paper presents an architecture and design for scalable fluid simulation based on data-flow computing with a state-of-the-art FPGA. To exploit available hardware resources including FP DSPs, we introduce spatial and temporal parallelism to further scale the performance by adding more stream processing elements (SPEs) in an array. Performance modeling and prototype implementation allow us to explore the design space for both the existing Altera Arria10 and the upcoming Intel Stratix10 FPGAs. We demonstrate that Arria10 10AX115 FPGA achieves 519 GFlops at 9.67 GFlops/W only with a stream bandwidth of 9.0 GB/s, which is 97.9 percent of the peak performance of 18 implemented SPEs. We also estimate that Stratix10 FPGA can scale up to 6844 GFlops by combining spatial and temporal parallelism adequately.
Autors: Kentaro Sano;Satoru Yamamoto;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Oct 2017, volume: 28, issue:10, pages: 2823 - 2837
Publisher: IEEE
 
» Fractional-N DPLL-Based Low-Power Clocking Architecture for 1–14 Gb/s Multi-Standard Transmitter
Abstract:
A low-power clocking solution is presented based on fractional-N highly digital LC-phase-locked loop (PLL) and sub-sampled ring PLL targeting multi-standard SerDes applications. The shared fractional-N digital LC-PLL covers 7–10 GHz frequency range consuming only 8-mW power and occupying 0.15 mm2 of silicon area with integrated jitter of 264 fs. Frequency resolution of the LC-PLL is 2 MHz. Per lane clock is generated using wide bandwidth ring PLL covering 800 MHz to 4 GHz to support the data rates between 1 and 14 Gb/s. The ring PLL supports dither-less fractional resolution of 250 MHz, corrects I/Q error with split tuning, and achieves less than 400-fs integrated jitter. Transmitter works at 14 Gb/s with power efficiency of 0.80 pJ/bit.
Autors: Masum Hossain;Waleed El-Halwagy;AKM Delwar Hossain; Aurangozeb;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2017, volume: 52, issue:10, pages: 2647 - 2662
Publisher: IEEE
 
» Fragmentation-Avoiding Spectrum Assignment Strategy Based on Spectrum Partition for Elastic Optical Networks
Abstract:
A fragmentation-avoiding spectrum assignment strategy based on spectrum partition is proposed, which is used to resolve the spectrum fragmentation problem in elastic optical networks. For alleviating spectrum fragmentation, a spectrum partition policy, splitting the whole optical spectrum into several dedicated partitions, is presented. Based on this, a joint first-last-fit spectrum assignment policy is presented to enhance the probability of successful transmission of request and spectrum efficiency, where each partition is first used to transmit requests with the same rate in the first-fit policy; and other partitions are used to search available spectrum resources in the last-fit policy when there are no available spectrum resources in the dedicated partition. Meanwhile, a partition selection formula is designed to minimize the interference of spectrum resources during the last-fit spectrum assignment. Moreover, a reconfiguration mechanism, moving requests that are not transmitted in their dedicated partition to their dedicated partition, is also studied. The simulation results indicate that the proposed algorithm can reduce the bandwidth blocking probability and improve spectrum efficiency.
Autors: Huan-Lin Liu;Lei Lv;Yong Chen;Chengying Wei;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 13
Publisher: IEEE
 
» Free Waves [Editor's Comments]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Mahta Moghaddam;
Appeared in: IEEE Antennas and Propagation Magazine
Publication date: Oct 2017, volume: 59, issue:5, pages: 4 - 4
Publisher: IEEE
 
» Freestanding Micro-Supercapacitor With Interdigital Electrodes for Low-Power Electronic Systems
Abstract:
With the rapid development of miniaturized multi-functional systems, micro-energy-storage devices have drawn increasing attention due to the importance of power supply. In this paper, a novel fabrication for freestanding solid-state micro-supercapacitors (MSCs) has been proposed and developed by combining electrolyte transferring with laser patterning process. Typical freestanding MSC is composed of interdigital carbon nanotube/nanofibers as active material employed by laser patterning process, PVA/H3PO4 as both the solid-state electrolyte and the flexible substrate, and gold layer as the current collector. With the in-planar electrode and electrolyte-substrate layout, the dimension of the MSC could be greatly decreased without excess substrate. Taking advantage of electrospinning nanofibers with large surface area and carbon nanotubes with high conductivity, we optimize the line-width (200 ) of the interdigital finger of the MSC, which exhibits high areal capacitance (15.6 mF/cm2) and excellent cycling stability. With the serial design, the working range of MSC units could be greatly enhanced in wearable devices and low-power electronic systems. Therefore, such flexible MSC is a promising candidate to satisfy the requirements of miniaturized energy systems. [2017-0059]
Autors: Yu Song;Xue-Xian Chen;Jin-Xin Zhang;Xiao-Liang Cheng;Hai-Xia Zhang;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Oct 2017, volume: 26, issue:5, pages: 1055 - 1062
Publisher: IEEE
 
» Frequency Doubling of a Pulsed Wavelength-Agile Erbium-Doped Fiber MOPA for Oxygen A-Band Spectroscopy
Abstract:
We report a pulsed wavelength-agile laser near 765 nm, which was frequency doubled from an erbium-doped fiber amplifier for oxygen A-band spectroscopy. A single frequency distributed feedback laser around 1529.6 nm was employed as the seed. After three stages of amplification, its average power was boosted to 610 mW and was then frequency doubled via a 15-mm-long MgO:PPLN crystal with the highest conversion efficiency of 34%. Thanks to the short crystal length expanding the acceptance bandwidth, a power difference of only 36% for the second harmonic output was achieved within the whole wavelength tuning range benefitting low-noise remote sensing. The measured oxygen transmission spectra using a 0.5-meter-long gas cell with multiple passes were mostly in good agreement with the calculations from HITRAN 2012 database indicating the capability of our laser for oxygen A-band related remote sensing.
Autors: Feng You;Tao Chen;Wei Kong;Hao Liu;Yihua Hu;Rong Shu;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 8
Publisher: IEEE
 
» Frequency Shifts of Spectral Lines Generated by Young's Pinhole Wave Scattering Upon a Quasi-Homogeneous Medium
Abstract:
Frequency shifts of light scattered from either a deterministic or random medium have shown great importance in remote sensing imaging applications, however, such scattering system which combines random scatterer with obstacles has not been specifically discussed so far. To solve this problem, we derive analytical expressions for showing the phenomenon that the Young's pinhole wave scattered from a quasi-homogeneous (QH) medium exhibits the red shift of spectral lines, while the first-order Born approximation is applied to treat the weak scattering between the diffractive wave and the medium. The shifted amount of spectrum is strongly dependent of the scattering angle, correlation length of the medium, and Young's pinhole parameter. Furthermore, we also observe that the red shift of the scattered spectrum converts to the blue shift when the correlation length reaches a certain magnitude. Through numerical simulations, analyses are performed on revealing the effects of Young's pinhole parameter and medium's correlation on the spectral shift and spectral switch of the scattered spectrum.
Autors: Jia Li;Yuechun Shi;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 12
Publisher: IEEE
 
» From Cool Chips to Hot Interconnects
Abstract:
This column briefly introduces the articles and departments in the issue.
Autors: Lieven Eeckhout;
Appeared in: IEEE Micro
Publication date: Oct 2017, volume: 37, issue:5, pages: 4 - 5
Publisher: IEEE
 
» 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 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
 
» 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 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 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
 
» 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
 
» 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 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
 
» 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
 

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