Electrical and Electronics Engineering publications abstract of: 10-2017 sorted by title, page: 1

» A Generic Simulation Approach for the Fast and Accurate Estimation of the Outage Probability of Single Hop and Multihop FSO Links Subject to Generalized Pointing Errors
Abstract:
When assessing the performance of the free space optical (FSO) communication systems, the outage probability encountered is generally very small, and thereby the use of nave Monte Carlo simulations becomes prohibitively expensive. To estimate these rare event probabilities, we propose in this paper an importance sampling approach which is based on the exponential twisting technique to offer fast and accurate results. In fact, we consider a variety of turbulence regimes, and we investigate the outage probability of FSO communication systems, under a generalized pointing error model based on the Beckmann distribution, for both single and multihop scenarios. Selected numerical simulations are presented to show the accuracy and the efficiency of our approach compared with naive Monte Carlo.
Autors: Chaouki Ben Issaid;Ki-Hong Park;Mohamed-Slim Alouini;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Oct 2017, volume: 16, issue:10, pages: 6822 - 6837
Publisher: IEEE
 
» A Geometrical View of Scalar Modulation Instability in Optical Fibers
Abstract:
Full models of scalar modulation instability (MI) in optical fibers available in the literature usually involve complex formulations. In this paper, we present a novel approach to the analysis of MI in optical fibers by means of a simple geometrical description in the power versus frequency plane. This formulation allows us to relate the shape of the MI gain to any arbitrary dispersion profile of the medium, thus providing a simple insight. As a result, we derive a straightforward explanation of the nontrivial dependence of the cutoff power on high-order dispersion and explicitly derive the power that maximizes the gain. Our approach puts forth a tool to synthesize a desired MI gain with the potential application to a number of parametric-amplification and supercontinuum-generation devices whose initial-stage dynamics rely upon MI.
Autors: S. M. Hernandez;P. I. Fierens;J. Bonetti;A. D. Sánchez;D. F. Grosz;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 8
Publisher: IEEE
 
» A GPU-Accelerated Approach for Feature Tracking in Time-Varying Imagery Datasets
Abstract:
We propose a novel parallel connected component labeling (CCL) algorithm along with efficient out-of-core data management to detect and track feature regions of large time-varying imagery datasets. Our approach contributes to the big data field with parallel algorithms tailored for GPU architectures. We remove the data dependency between frames and achieve pixel-level parallelism. Due to the large size, the entire dataset cannot fit into cached memory. Frames have to be streamed through the memory hierarchy (disk to CPU main memory and then to GPU memory), partitioned, and processed as batches, where each batch is small enough to fit into the GPU. To reconnect the feature regions that are separated due to data partitioning, we present a novel batch merging algorithm to extract the region connection information across multiple batches in a parallel fashion. The information is organized in a memory-efficient structure and supports fast indexing on the GPU. Our experiment uses a commodity workstation equipped with a single GPU. The results show that our approach can efficiently process a weather dataset composed of terabytes of time-varying radar images. The advantages of our approach are demonstrated by comparing to the performance of an efficient CPU cluster implementation which is being used by the weather scientists.
Autors: Chao Peng;Sandip Sahani;John Rushing;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Oct 2017, volume: 23, issue:10, pages: 2262 - 2274
Publisher: IEEE
 
» A Handbag Zipper Antenna for the Applications of Body-Centric Wireless Communications and Internet of Things
Abstract:
The idea of making use of the metal zipper on the handbag to serve as an off-body antenna is proposed, and the simulations together with measurements have been carried out. The feeding point can be located at the bottom of the zipper, and to be more specific, around one of the teeth. The excitation at certain tooth of the zipper would bring variations in the reflection coefficients as well as the radiation patterns. No matter the zipper is totally closed, quarterly opened, half opened, or is even totally opened, the antenna can operate with acceptable performance, though the common status of the handbag zipper is closed. Thus, it is to some extent reconfigurable, especially for radiation patterns. A fractional bandwidth of 4.92% at 2.44 GHz of the industrial, scientific, and medical band with a gain of about 5 dBi has been achieved. The impact of the human body has been evaluated. It is noticeable but affordable. The measured results indicate reasonable agreements to that of the simulations in both the matching performance and the radiation feature for the zipper antenna, which seems to be a promising candidate for body-centric wireless communications and the Internet of Things.
Autors: Gaosheng Li;Yi Huang;Gui Gao;Xianju Wei;Zhihao Tian;Li-An Bian;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5137 - 5146
Publisher: IEEE
 
» A Handy Dandy Doherty PA: A Linear Doherty Power Amplifier for Mobile Handset Application
Abstract:
As wireless communications progress from second to fourth-generation (4G) systems, the information content drastically increases, requiring high-data-rate transmissions. For efficient use of precious spectrum resources, the modulated signals have wider bandwidths (BWs) and higher peak-toaverage power ratios (PAPRs) than previous generations of systems. Therefore, the power amplifier (PA) operates at a less efficient backoff-power region to achieve the required linearity.
Autors: Yunsung Cho;Daehyun Kang;Kyunghoon Moon;Daechul Jeong;Bumman Kim;
Appeared in: IEEE Microwave Magazine
Publication date: Oct 2017, volume: 18, issue:6, pages: 110 - 124
Publisher: IEEE
 
» A Hidden Markov Model for Seismocardiography
Abstract:
We propose a hidden Markov model approach for processing seismocardiograms. The seismocardiogram morphology is learned using the expectation-maximization algorithm, and the state of the heart at a given time instant is estimated by the Viterbi algorithm. From the obtained Viterbi sequence, it is then straightforward to estimate instantaneous heart rate, heart rate variability measures, and cardiac time intervals (the latter requiring a small number of manual annotations). As is shown in the conducted experimental study, the presented algorithm outperforms the state-of-the-art in seismocardiogram-based heart rate and heart rate variability estimation. Moreover, the isovolumic contraction time and the left ventricular ejection time are estimated with mean absolute errors of about 5 [ms] and , respectively. The proposed algorithm can be applied to any set of inertial sensors; does not require access to any additional sensor modalities; does not make any assumptions on the seismocardiogram morphology; and explicitly models sensor noise and beat-to-beat variations (both in amplitude and temporal scaling) in the seismocardiogram morphology. As such, it is well suited for low-cost implementations using off-the-shelf inertial sensors and targeting, e.g., at-home medical services.
Autors: Johan Wahlström;Isaac Skog;Peter Händel;Farzad Khosrow-khavar;Kouhyar Tavakolian;Phyllis K. Stein;Arye Nehorai;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Oct 2017, volume: 64, issue:10, pages: 2361 - 2372
Publisher: IEEE
 
» A High-Frequency High-Power Test Bench for 11 MW/595 Hz Drives With 1.25 MW Grid Capability
Abstract:
This paper presents a pumpback test bench for high-frequency high-power variable-frequency drives (VFDs) with 11 MW power rating and up to 595 Hz load frequency. A voltage combiner concept is applied to allow a high-frequency output from the two three-level neutral-point-clamped integrated gate-commutated thyristor bridges with minimum switching losses. The accordingly developed pumpback test bench applies a dc power coupling concept combined with a virtual grid concept that can achieve 11 MW test capability with only a 1.25 MW facility transformer. By applying a virtual machine concept, the pumpback test can be conducted without the need of high-frequency machines, while the circulating power losses in the pumpback loop are minimized as well. The virtual grid including the concept tradeoff, filter parameters, and modulation schemes is presented in detail. Moreover, design and installation guidelines for high-frequency components, especially the cables, are presented. The high-frequency high-power VFD and its pumpback test bench are both successfully built and experimentally validated at their rated operation points.
Autors: Jie Shen;Stefan Schröder;Bo Qu;Yingqi Zhang;Fan Zhang;Kunlun Chen;Richard Zhang;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4744 - 4756
Publisher: IEEE
 
» A High-Speed Digital Electrical Capacitance Tomography System Combining Digital Recursive Demodulation and Parallel Capacitance Measurement
Abstract:
Two means can be used to improve the data acquisition rate of the electrical capacitance tomography (ECT) system with a fixed excitation frequency, i.e., improving the capacitance measurement speed or changing the capacitance measurement mode from serial to parallel. This paper presents a newly developed high-speed ECT system by combing digital recursive demodulation and parallel-mode capacitance measurement methods. By using the digital recursive demodulator, the time-cost for one time of capacitance measurement can be one period of the excitation sinusoid or less. By using the parallel-mode capacitance measuring unit, capacitances between the exciting electrode and all other measuring electrodes can be measured simultaneously. The data acquisition rate of the parallel-mode ECT system with a sensor of N electrodes is N-1 times of a traditional serial-mode ECT system with the same excitation frequency. When the excitation frequency is 100 kHz and 0.6 periods of data are used for signal demodulation, the data acquisition rate can reach up to 15 150 frames/s. The developed system together with a heat-resisting circular ECT sensor with 12 electrodes was used to monitor the ignition process of a cylindrical flame generated by a Bunsen burner. Experimental results show that the ECT system can locate the position and capture the dynamic process of the flame with a high temporal resolution.
Autors: Shijie Sun;Zhang Cao;Ang Huang;Lijun Xu;Wuqiang Yang;
Appeared in: IEEE Sensors Journal
Publication date: Oct 2017, volume: 17, issue:20, pages: 6690 - 6698
Publisher: IEEE
 
» A Hybrid EOF Algorithm to Improve MODIS Cyanobacteria Phycocyanin Data Quality in a Highly Turbid Lake: Bloom and Nonbloom Condition
Abstract:
Extensive monitoring of cyanobacterial blooms in lakes and reservoirs can provide important protection for drinking water sources. In most inland waterbodies, phycocyanin (PC) concentrations are the best indicator of cyanobacteria distribution. PC has a characteristic absorption peak near 620 nm; however, reflectance at this wavelength is only available from MEdium Resolution Imaging Spectrometer (MERIS) and Ocean and Land Colour Instrument (OLCI) sensors. MERIS stopped providing data after 2012 and OLCI was only recently launched (February 2016). The Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua is currently the only satellite instrument that can provide well-calibrated top-of-atmosphere radiance data over an extended number of years to the present. In this study, we develop and validate a new approach based on empirical orthogonal function (EOF) to quantify PC concentrations in a turbid inland lake (Lake Chaohu, China). Based on Rayleigh-corrected reflectance data ( ) at 469, 555, 645, and 859 nm, the concentrations of PC were estimated by regression of 87 concurrent MODIS-field measurements for bloom and nonbloom conditions. The validation (N = 93) showed R2 = 0.40 and unbiased RMS = 60.86%. Application of the algorithm from 2000 and 2014 showed spatial distribution patterns and seasonal changes that confirmed in situ and MERIS-based studies of floating algae mats. The spatial information on PC concentrations in Lake Chaohu had a reduced sensitivity to perturbations from thin aerosols and high sediments. This EOF approach allows us for new insights in the long-term dynamics of shallow lakes and reservoirs where having a better understanding of cyanobacterial blooms i- important.
Autors: Min Tao;Hongtao Duan;Zhigang Cao;Steven Arthur Loiselle;Ronghua Ma;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Oct 2017, volume: 10, issue:10, pages: 4430 - 4444
Publisher: IEEE
 
» A Hybrid Formulation of a Frequency-Domain TLM and Integral Equations Field Method
Abstract:
In many applications, heterogeneous structures are separated by some distance in a homogeneous medium. This homogenous space must be entirely meshed when volumic methods are used. This letter presents a hybrid formulation between the frequency-domain transmission line matrix (FDTLM) method and a field integral equation formulation that avoids the meshing of the homogeneous background in which complex objects are located. In addition, it prevents the use of absorbing boundary conditions. To simplify the theoretical development for the 3-D case, the problem of a rectangular waveguide with inductive objects is presented. Although invariance along the waveguide height with the fundamental mode excitation, the problem is treated by 3-D FDTLM nodes for validation. It is found that some computer cost reduction can be achieved as compared with the full meshing approach.
Autors: Meriam Attia;Michel Ney;Taoufik Aguili;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2017, volume: 27, issue:10, pages: 867 - 869
Publisher: IEEE
 
» A Hybrid Inductive-Ultrasonic Link for Wireless Power Transmission to Millimeter-Sized Biomedical Implants
Abstract:
Ultrasound has recently been utilized for efficient wireless power transmission (WPT) to biomedical implants with millimeter (mm) dimensions and below. However, the power transmission efficiency (PTE) of ultrasonic links reduces significantly in mediums with different acoustic impedances. This brief presents a hybrid inductive-ultrasonic WPT link for powering mm-sized implants that utilizes two cascaded co-optimized inductive and ultrasonic links for WPT through bone/air and tissue, respectively. The ultrasonic link is first optimized based on the implant depth () and load () to find the optimal geometries for ultrasonic transducers and operation frequency (). Then, the inductive link is optimized at to drive the transmitter (Tx) transducer. A hybrid link was optimized and measured to transfer power to a receiver (Rx) transducer with the diameter of 1.1 mm, loaded by of 2.5 k and located at cm inside castor oil, as the tissue model. The Tx coil was placed in air and spaced from the Rx coil by 3 cm, resulting in a total powering distance () of 6 cm. At the optimal of 1.1 MHz, the hybrid link achieved a consid- rable measured PTE of 0.16%.
Autors: Miao Meng;Mehdi Kiani;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2017, volume: 64, issue:10, pages: 1137 - 1141
Publisher: IEEE
 
» A Hybrid MPI-OpenMP Strategy to Speedup the Compression of Big Next-Generation Sequencing Datasets
Abstract:
DNA sequencing has moved into the realm of Big Data due to the rapid development of high-throughput, low cost Next-Generation Sequencing (NGS) technologies. Sequential data compression solutions that once were sufficient to efficiently store and distribute this information are now falling behind. In this paper we introduce phyNGSC , a hybrid MPI-OpenMP strategy to speedup the compression of big NGS data by combining the features of both distributed and shared memory architectures. Our algorithm balances work-load among processes and threads, alleviates memory latency by exploiting locality, and accelerates I/O by reducing excessive read/write operations and inter-node message exchange. To make the algorithm scalable, we introduce a novel timestamp-based file structure that allows us to write the compressed data in a distributed and non-deterministic fashion while retaining the capability of reconstructing the dataset with its original order. Our experimental results show that phyNGSC achieved compression times for big NGS datasets that were 45 to 98 percent faster than NGS-specific sequential compressors with throughputs of up to 3 GB/s. Our theoretical analysis and experimental results suggest strong scalability with some datasets yielding super-linear speedups and constant efficiency. We were able to compress 1 terabyte of data in under 8 minutes compared to more than 5 hours taken by NGS-specific compression algorithms running sequentially. Compared to other parallel solutions, phyNGSC achieved up to 6x speedups while maintaining a higher compression ratio. The code for this implementation is available at https://github.com/pcdslab/PHYNGSC.
Autors: Sandino Vargas-Pérez;Fahad Saeed;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Oct 2017, volume: 28, issue:10, pages: 2760 - 2769
Publisher: IEEE
 
» A Hybrid Planar-Doped Potential-Well Barrier Diode for Detector Applications
Abstract:
This paper presents the principle of design and experimental demonstration of a prototype novel planar-doped potential-well barrier (PWB) diode concept that exploits the characteristics of both the PWB and planar-doped barrier (PDB) diodes. The highly doped (Be) sheet charge and potential well are inserted asymmetrically at nearly the same position within an intrinsic region to form a barrier. The hybrid device is designed so that the -doping is used to achieve a desirable minimum barrier height, while the active nature of charge in the potential well is used to enhance the device reverse bias performance. The diode achieved an ideality factor of 1.36 and corresponding voltage responsivity of 10900 V/W at 10 GHz. Diodes of this kind demonstrates promising RF signal detection and can be used in heterodyne applications. An estimated curvature coefficient of 21.2 at a bias of 0.72 V and cut-off frequency of 47.4 GHz were realized. Results of simulation and experiment have shown excellent agreement and an improved asymmetric behavior in the – characteristics in comparison to an equivalent PDB diode.
Autors: Mise Akura;Geoffrey Dunn;Mohamed Missous;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2017, volume: 64, issue:10, pages: 4031 - 4035
Publisher: IEEE
 
» A Jamming-Resistant Channel Hopping Scheme for Cognitive Radio Networks
Abstract:
Jamming attack is one of the major threats in cognitive radio networks (CRNs). In this paper, we propose an anti-jamming channel hopping algorithm, Tri-CH, for CRNs. Tri-CH adopts random jump pattern (i.e., hops randomly over channels) to achieve high security level and reception mode stay pattern (i.e., stays at a channel for receiving packets only) to guarantee bounded time to rendezvous. Tri-CH operates without pre-shared secrets and role pre-assignment. Hence, Tri-CH is applicable to large networks, where nodes join and leave the network frequently, and may play the sender role and the receiver role, simultaneously. According to the theoretical analysis, Tri-CH outperforms in terms of maximum time to rendezvous under jamming attacks.
Autors: Guey-Yun Chang;Szu-Yung Wang;Yuen-Xin Liu;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Oct 2017, volume: 16, issue:10, pages: 6712 - 6725
Publisher: IEEE
 
» A Large-Signal Monolayer Graphene Field-Effect Transistor Compact Model for RF-Circuit Applications
Abstract:
In this paper, we report a physics-based compact model for monolayer graphene field-effect transistors (m-GFETs) based on the 2-D Density of States of monolayer graphene and the drift-diffusion equation. Furthermore, the Ward-Dutton charge partitioning scheme has been incorporated to the model extending its capabilities to AC and transient simulations. The model has been validated through comparison with DC and RF measurements from two different long-channel m-GFET technologies. Moreover, values of parasitic elements included in the model are extracted from measurements on dedicated test structures and verified through electromagnetic simulations (EM). Finally, an EM-SPICE co-simulation has been carried out to assess the applicability of the developed m-GFET model for the design of “balun” circuits.
Autors: Jorge-Daniel Aguirre-Morales;Sébastien Frégonèse;Chhandak Mukherjee;Wei Wei;Henri Happy;Cristell Maneux;Thomas Zimmer;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2017, volume: 64, issue:10, pages: 4302 - 4309
Publisher: IEEE
 
» A Layered Methodology for the Simulation of Extra-Functional Properties in Smart Systems
Abstract:
Smart systems represent a broad class of intelligent, miniaturized devices incorporating functionality like sensing, actuation, and control. In order to support these functions, they must include sophisticated and heterogeneous components, such as sensors and actuators, multiple power sources and storage devices, digital signal processing, and wireless connectivity. The high degree of heterogeneity typical of smart systems has a heavy impact on their design: the challenges are not in fact restricted to their functionality, but are also related to a number of extra-functional properties, including power consumption, temperature, and aging. Current simulation- or model-based design approaches do not target a smart system as a whole, but rather single domains (digital, analog, power devices, etc.) or properties. This paper tries to overcome this limitation by proposing a framework for the concurrent simulation of both functionality and such extra-functional properties. The latter are modeled as different information flows, managed by dedicated “virtual buses” and formalized through the adoption of IP-XACT. SystemC, through the support of physical and continuous time modeling provided by its analog and mixed signal extension, is used to implement both functional and extra-functional models. Experimental results show the efficiency, accuracy and modularity of the proposed approach on an example case study, in which substantial speedups with respect to standard model-based design tools go along with a very high degree of accuracy (< 10−5%). Furthermore, the case study highlights that the proposed framework allows to easily capture at run time the mutual impact of properties, e.g., in case of power and temperature.
Autors: Sara Vinco;Yukai Chen;Franco Fummi;Enrico Macii;Massimo Poncino;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Oct 2017, volume: 36, issue:10, pages: 1702 - 1715
Publisher: IEEE
 
» A Liquid-Level Sensing Technique Based on Differential Detection of Correlation Peaks From Broadband Chaos
Abstract:
A highly sensitive liquid-level sensing technique is proposed and experimentally demonstrated. Two narrowband fiber Bragg gratings (FBGs) with high reflectivity are used to filter out the two light signals from the broadband chaos. Two weak FBGs are served respectively as the liquid-level sensors at two different sensing points. The change of liquid-level will induce the wavelength shift of the weak FBGs, which can be demodulated through calculating the amplitude difference in the logarithm of two cascaded correlation peaks in the cross-correlation spectrum. Adopting the differential calculation of the cascaded correlation peak amplitudes can avoid the complex wavelength detection and enhance the robustness against the power variation of the broadband chaos. Our method can also support the simultaneous multiplexing and locating with high resolution from the time delays of the corresponding correlation peaks. Experimental results show that the liquid level changes linearly with the relative peak amplitude difference in the logarithm and the sensitivity is around 0.019/mm. The sensing resolution of liquid-level can reach at least 3 mm, and the relative resolution is around 0.055. Moreover, the real-time fiber fault monitoring can be achieved with a spatial resolution of around 2.8 cm, which improves the survivability in harsh environment.
Autors: Heng Yi;Li Xia;Jun Xu;Can Yu;Ying Wu;Chen Li;Lin Zu;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 9
Publisher: IEEE
 
» A Load Independent Tapered RF Harvester
Abstract:
This letter proposes a new matching technique that is based on a network of dual line topology with different characteristic impedances. The purpose of this network is to match the Schottky diode’s input impedance in a rectifying circuit with the 50 source impedance. The strength of the proposed technique is based on the fact that it enables a stable efficiency response for different input power levels. It also forces the rectifier to exhibit an almost flat efficiency curve over a wide range of load variations. The proposed circuit is built and measured, where an agreement is attained between simulations and measured results over the IEEE 802.11 b/g bands.
Autors: J. Costantine;A. Eid;M. Abdallah;Y. Tawk;A. H. Ramadan;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2017, volume: 27, issue:10, pages: 933 - 935
Publisher: IEEE
 
» A Local Feature Descriptor Based on Log-Gabor Filters for Keypoint Matching in Multispectral Images
Abstract:
This letter presents a new local feature descriptor for problems related to multispectral images. Most previous approaches are typically based on descriptors designed to work with images uniquely captured in the visible light spectrum. In contrast, this letter proposes a descriptor termed a multispectral feature descriptor (MFD) that is especially developed, such that it can be employed with image data acquired at different frequencies across the electromagnetic spectrum. The performance of the MFD is evaluated by using three data sets composed of images obtained in visible light and infrared spectra, and its performance is compared with those of state-of-the-art algorithms, such as edge-oriented histogram (EOH) and log-Gabor histogram descriptor (LGHD). The experimental results indicate that the computational efficiency of MFD exceeds those of EOH and LGHD, and that the precision and recall values of MFD are statistically comparable to the corresponding values of the forementioned algorithms.
Autors: Cristiano F. G. Nunes;Flávio L. C. Pádua;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Oct 2017, volume: 14, issue:10, pages: 1850 - 1854
Publisher: IEEE
 
» A Low-Complexity Maximum-Likelihood Detector for Differential Media-Based Modulation
Abstract:
Media-based modulation (MBM) uses radio frequency mirrors at the transmit antenna in order to create different channel fade realizations based on their ON/OFF status. These complex fade realizations constitute the channel modulation alphabet. This channel modulation alphabet has to be estimated a priori at the receiver for detection. In this letter, we present a differential MBM (DMBM) scheme which does not require estimation of channel modulation alphabet at the receiver for detection. Consecutive MBM blocks are differentially encoded. We propose a low-complexity maximum-likelihood detection algorithm for DMBM. Simulation results show that the DMBM has only about 2–4 dB performance loss compared with MBM with perfect knowledge of the channel alphabet.
Autors: Y. Naresh;A. Chockalingam;
Appeared in: IEEE Communications Letters
Publication date: Oct 2017, volume: 21, issue:10, pages: 2158 - 2161
Publisher: IEEE
 
» A Low-Complexity Pedestrian Detection Framework for Smart Video Surveillance Systems
Abstract:
Pedestrian detection is a key problem in computer vision and is currently addressed with increasingly complex solutions involving compute-intensive features and classification schemes. In this scope, histogram of oriented gradients (HOG) in conjunction with linear support vector machine (SVM) classifier is considered to be the single most discriminative feature that has been adopted as a stand-alone detector as well as a key instrument in advance systems involving hybrid features and cascaded detectors. In this paper, we propose a pedestrian detection framework that is computationally less expensive as well as more accurate than HOG-linear SVM. The proposed scheme exploits the discriminating power of the locally significant gradients in building orientation histograms without involving complex floating point operations while computing the feature. The integer-only feature allows the use of powerful histogram inter-section kernel SVM classifier in a fast lookup-table-based implementation. Resultantly, the proposed framework achieves at least 3% more accurate detection results than HOG on standard data sets while being 1.8 and 2.6 times faster on conventional desktop PC and embedded ARM platforms, respectively, for a single scale pedestrian detection on VGA resolution video. In addition, hardware implementation on Altera Cyclone IV field-programmable gate array results in more than 40% savings in logic resources compared with its HOG-linear SVM competitor. Hence, the proposed feature and classification setup is shown to be a better candidate as the single most discriminative pedestrian detector than the currently accepted HOG-linear SVM.
Autors: Muhammad Bilal;Asim Khan;Muhammad Umar Karim Khan;Chong-Min Kyung;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Oct 2017, volume: 27, issue:10, pages: 2260 - 2273
Publisher: IEEE
 
» A Low-Cost Time-Correlated Single Photon Counting System for Multiview Time-Domain Diffuse Optical Tomography
Abstract:
Diffuse optical tomography resorting to time-domain measurements (TD-DOT) provides information-rich data that have not yet been fully exploited for image reconstruction, notably to increase imaging spatial resolution. Current TD-DOT scanners suffer from a very low sensitivity owing to their small number of detection channels. This leads to excessively long acquisition times for in vivo imaging. To obtain a higher number of detection channels, thus increasing detection density, a low-cost time-correlated single photon counting (TCSPC) system dedicated to TD-DOT was designed, resorting solely to off-the-shelf electronic components to reduce costs, in distinction to custom application-specific integrated circuit solutions. The system features four input channels, each of them including a leading-edge discriminator for direct interfacing with off-the-shelf photodetector modules and a programmable delay line to compensate for undesired propagation delays, thus also avoiding manual adjustment of cable lengths. The system supports a large number of TCSPC channels using a daisy-chain configuration through an onboard Ethernet switch. It also features a 13.02 ps bin width with a 12.5 ns dynamic range. Results show excellent linearity, with a of 1.7% least significant bit (LSB), peak differential nonlinearity of 5% LSB, and peak integral nonlinearity of 10% LSB and an average accuracy of 19 ps full-width at half-maximum (FWHM) throughout two separate four-channel systems. The system was tested in a TD-DOT acquisition setup, and 37 ps FWHM instrument response functions were obtained using a single-photon avalanche diode (SPAD) detector. Diffuse intrinsic measurements were also acquired and compared with a reference TCSPC system showing similar results.
Autors: Jonathan Bouchard;Arnaud Samson;William Lemaire;Caroline Paulin;Jean-François Pratte;Yves Bérubé-Lauzière;Réjean Fontaine;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Oct 2017, volume: 66, issue:10, pages: 2505 - 2515
Publisher: IEEE
 
» A Low-Noise Area-Efficient Chopped VCO-Based CTDSM for Sensor Applications in 40-nm CMOS
Abstract:
An area-efficient voltage-sensing readout circuit employing chopped voltage-controlled oscillator (VCO)-based continuous-time delta-sigma modulator (CTDSM) is presented in this paper. This VCO-based CTDSM features direct connection to sensors to eliminate pre-amplifier for achieving better hardware efficiency. The VCO is designed as a trans-conductor current-controlled oscillator, which is a fully differential stage cascaded with two CCOs, to provide a high-input impedance to sense the voltage signals from sensors. Analysis shows that the main noise and offset contributor is the stage. This problem is mitigated by employing choppers at critical location within the circuit. The VCO-based CTDSM is implemented in a 40-nm CMOS process. The power consumption is under 1.2-V supply. With a 4-mVp (8-mV input, it achieves 61.85-dB signal-to-noise-and-distortion ratio over a 5-kHz bandwidth and the total harmonic distortion is −70.8 dB. The input-referred noise is 32 nV/Hz. The chip area is only 0.0145 mm.
Autors: Chih-Chan Tu;Yu-Kai Wang;Tsung-Hsien Lin;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2017, volume: 52, issue:10, pages: 2523 - 2532
Publisher: IEEE
 
» A Low-Power 28-nm CMOS FD-SOI Reflection Amplifier for an Active F-Band Reflectarray
Abstract:
A new topology of a low-power F-band reflection amplifier for active reflectarrays is proposed and demonstrated using a CMOS fully depleted silicon-on-insulator 28-nm process. The design enables frequency response and center frequency tuning, as well as phase control of the reflected signal. The chip consumes a core area of only and is incorporated into a printed reflectarray antenna, implementing the first co-polarized active reflectarray. Such implementation enables, for the first time, active reflectarrays with dual polarization ability, which can be used for full-duplex links, as well as polarization diversity applications. Design considerations for a stable reflection amplifier, as well as measurement results of the reflection amplifier and reflectarray, are presented in this paper. Variable stable gain of 5–25 dB at the frequency range of 106–127 GHz was achieved, with noise figure of 10.5–11.7 dB. The total power consumption was 6–20 mW, depending on the chosen frequency response. An active antenna gain of 28 dBi was measured for the reflectarray.
Autors: Naftali Landsberg;Eran Socher;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3910 - 3921
Publisher: IEEE
 
» A Low-Power High-Dynamic-Range Receiver System for In-Probe 3-D Ultrasonic Imaging
Abstract:
In this paper, a dual-mode low-power, high dynamic-range receiver circuit is designed for the interface with a capacitive micromachined ultrasonic transducer. The proposed ultrasound receiver chip enables the development of an in-probe digital beamforming imaging system. The flexibility of having two operation modes offers a high dynamic range with minimum power sacrifice. A prototype of the chip containing one receive channel, with one variable transimpedance amplifier (TIA) and one analog to digital converter (ADC) circuit is implemented. Combining variable gain TIA functionality with ADC gain settings achieves an enhanced overall high dynamic range, while low power dissipation is maintained. The chip is designed and fabricated in a 65 nm standard CMOS process technology. The test chip occupies an area of 76 170 . A total average power range of 60–240  for a sampling frequency of 30 MHz, and a center frequency of 5 MHz is measured. An instantaneous dynamic range of 50.5 dB with an overall dynamic range of 72 dB is obtained from the receiver circuit.
Autors: Hourieh Attarzadeh;Ye Xu;Trond Ytterdal;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Oct 2017, volume: 11, issue:5, pages: 1053 - 1064
Publisher: IEEE
 
» A Low-Power SiGe BiCMOS 190-GHz Receiver With 47-dB Conversion Gain and 11-dB Noise Figure for Ultralarge-Bandwidth Applications
Abstract:
This paper presents a 190-GHz direct-conversion receiver capable of supporting higher order modulation schemes and implemented in a 130-nm SiGe BiCMOS technology. The circuit consists of a low-noise amplifier, an active fundamental mixer, a local-oscillator driver, a variable-gain baseband (BB) amplifier, and a totem-pole output stage. To exploit the advantages of sub-THz frequencies in terms of available bandwidth (BW) at a low dc power consumption, all circuit blocks are concurrently optimized for large BW and high power efficiency. A high and tunable conversion gain as well as a large maximum BB voltage swing is targeted to allow direct operation with state-of-the-art analog-to-digital converters. While consuming only 122 mW of dc power, the fabricated circuit exhibits a record 3-dB RF BW of 35 GHz, a maximum conversion gain of 47 dB with a tuning range of 20 dB, a maximum BB voltage swing of more than 800 , and a minimum double-sideband noise figure of 10.7 dB.
Autors: David Fritsche;Gregor Tretter;Paul Stärke;Corrado Carta;Frank Ellinger;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 4002 - 4013
Publisher: IEEE
 
» A Low-Profile Dual-Polarized Patch Antenna With Stable Radiation Pattern Using Ground-Slot Groups and Metallic Ground Wall
Abstract:
A low-profile dual-polarized patch antenna with stable radiation pattern for use in base stations operating from 1.7 to 2.7 GHz is presented. The antenna consists of a square patch radiator placed at 20 mm ( at the center frequency of 2.2 GHz) above a square ground plane. For bandwidth enhancement, the square patch radiator is dual fed using four probes, each having a U-shape. Two wideband 180° baluns are designed using composite right/left handed transmission lines to generate two signals with same amplitude, but phase shift of 180° for the probes. The radiation pattern is stabilized using four slot groups on the ground plane and a metallic ground wall around the radiating patch. The antenna is studied and designed using computer simulation. Results show that the simulated half-power beamwidths have variations of only 4° and 5° in the elevation (EL) and azimuth (AZ) planes, respectively, across the operating band. Measured results show that the antenna has the impedance bandwidths of 1.68–2.83 GHz and 1.7–2.85 GHz for the two input ports, isolation of more than 38 dB, and cross-polarization of less than −20 dB at the boresight in both the EL and AZ planes. The measured boresight gains are 7.8 ± 0.6 dBi for both two ports, and the radiation efficiencies are 74%–84% and 73%–82% for ports 1 and 2, respectively.
Autors: Qinlong Li;S. W. Cheung;Changfei Zhou;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5061 - 5068
Publisher: IEEE
 
» A Low-Profile Wide-Bandwidth Planar Inverted-F Antenna Under Dual Resonances: Principle and Design Approach
Abstract:
A low-profile planar inverted-F antenna (PIFA) under the operation of TM0,1/2 and TM2,1/2 modes in a single patch resonator for bandwidth enhancement is proposed. Initially, our study demonstrates that all of the even-order modes can effectively be suppressed by employing a rectangular PIFA instead of the conventional microstrip patch antenna. Then, a pair of shorting pins is appropriately loaded underneath the side-shorted radiating patch to investigate the variation of their odd-mode resonant frequencies. The results indicate that the resonant frequency of TM0,1/2 mode () is dramatically increased up while almost maintaining that of TM2,1/2 mode (). After that, the width of the radiating patch is progressively enlarged in order to move the more closely to the . By using this approach, the dual radiative resonant modes can be reallocated in proximity to each other. Additionally, a narrow slot is etched out on the radiating patch so as to counteract the equivalent inductance caused by the shorting pins and probe. As such, a wide-bandwidth with stable radiation pattern is achieved for the PIFA under the operation of these dual-resonant modes. After the extensive analysis is executed, the proposed antenna is fabricated and tested. Simulated and measured results are found in good agreement with each other, demonstrating that its impedance bandwidth is tremendously widened to about 15.3% with appearance of two in-band attenuation poles. In particular, a low-profile property with the height of 0.036 free-space wavelength is achieved.
Autors: Neng-Wu Liu;Lei Zhu;Wai-Wa Choi;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5019 - 5025
Publisher: IEEE
 
» A Lyapunov Function for Switching Command of a DC–DC Power Converter With an LC Input Filter
Abstract:
This paper describes a method to control a dc–dc switching power converter with an LC input filter working under continuous conduction mode. It is known that the interaction between the low-pass filter and the tightly controlled switching converter occurs, and it might lead to an instability operation. The idea of this method relies on the Lyapunov stability criterion. The switching command of this control is defined by the manner of pre-evaluating the stability of the controlled system. All state variables are controlled in the same time. Therefore, the responses of this controlled system are fast while guaranteeing a stable operation. The proposed control is applied to a boost converter to demonstrate the implementation and its performance. The simulation and experimental results validate the proposed control approach.
Autors: Roghayeh Gavagsaz-Ghoachani;Matheepot Phattanasak;Jean-Philippe Martin;Serge Pierfederici;Babak Nahid-Mobarakeh;Pierre Riedinger;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 5041 - 5050
Publisher: IEEE
 
» A Magnetic Plethysmograph Probe for Local Pulse Wave Velocity Measurement
Abstract:
Objective: We present the design and experimental validation of an arterial compliance probe with dual magnetic plethysmograph (MPG) transducers for local pulse wave velocity (PWV) measurement. The MPG transducers (positioned at 23 mm distance apart) utilizes Hall-effect sensors and permanent magnets for arterial blood pulse detection. Methods: The MPG probe was initially validated on an arterial flow phantom using a reference method. Further, 20 normotensive subjects (14 males, age = 24 ± 3.5 years) were studied under two different physical conditions: 1) Physically relaxed condition, 2) Postexercise condition. Local PWV was measured from the left carotid artery using the MPG probe. Brachial blood pressure (BP) was measured to investigate the correlation of BP with local PWV. Results: The proposed MPG arterial compliance probe was capable of detecting high-fidelity blood pulse waveforms. Reliable local pulse transit time estimates were assessed by the developed measurement system. Beat-by-beat local PWV was measured from multiple subjects under different physical conditions. A profound increment was observed in the carotid local PWV for all subjects after exercise (average increment = 0.42 ± 0.22 m/s). Local PWV values and brachial BP parameters were significantly correlated (r ≥ 0.72), except for pulse pressure (r = 0.42). Conclusion: MPG arterial compliance probe for local PWV measurement was validated. Carotid local PWV measurement, its variations due to physical exercise and correlation with BP levels were examined during the in vivo study. Significance: A novel dual MPG probe for local PWV measurement and potential use in cuffless BP measurement.
Autors: Nabeel P M;Jayaraj Joseph;Mohanasankar Sivaprakasam;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Oct 2017, volume: 11, issue:5, pages: 1065 - 1076
Publisher: IEEE
 
» A Magnetically Coupled Communication and Charging Platform for Microsensors
Abstract:
A double layer spiral antenna with side length of was fabricated by a multilayer electroplating process and bonded with an radio frequency identification chip by silver epoxy to form a microsensor chip. A theoretical power transfer model was built to optimize the power transfer efficiency. The resonant frequency of the microsensor was characterized inside a small coupling loop, exhibiting a high degree of agreement with theoretical results. A magnetically coupled communication and charging platform was developed to work with the microsensors. The reader antenna was composed of a coupling loop and a secondary coil with 40-mm diameter wrapped around a polycarbonate tube. To maximize the magnetic field generated inside the secondary coil, a lump circuit model was built and its resonant modes were analyzed. The maximum current inside the secondary coil was achieved at the serial resonant frequency, at which the current followed a sinusoidal distribution along the coil. The magnetic field distribution inside the coil was calculated to analyze the read-out of the reader antenna. The communication and power transfer was demonstrated with the microsensors flowing through the reader antenna by successfully retrieving the sensor ID. [2016-0318]
Autors: Guangwu Duan;Xiaoguang Zhao;Xin Zhang;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Oct 2017, volume: 26, issue:5, pages: 1099 - 1109
Publisher: IEEE
 
» A Mean-Field Game of Evacuation in Multilevel Building
Abstract:
This paper puts forward a simple mean-field game that captures some of the key dynamic features of crowd and pedestrian flows in multilevel building evacuations. It considers both microscopic and macroscopic route choice by strategic agents. To achieve this, we use mean-field differential game with local congestion measure based on the location of the agent in the building. Including the local mean-field term and its evolution along the path causes a sort of dispersion of the flow: the agents will try to avoid high density areas in order to reduce their overall walking costs and queuing costs at the stairs and exits. Each agent state is represented by a center of a box that follows a simple first-order dynamical system in an Euclidean space. Each agent will move to one of the closest exits that is safer and with less congested path. First, we formulate the problem and derive optimality equations using maximum principle and dynamic programming with boundary conditions. Second, well posedness and existence results are provided. Numerics and simulations are carried out to illustrate mean-field equilibria of a safer evacuation process. Finally, the methodology is shown to be flexible enough to include movement noises and stochastic structural component of the building.
Autors: Boualem Djehiche;Alain Tcheukam;Hamidou Tembine;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Oct 2017, volume: 62, issue:10, pages: 5154 - 5169
Publisher: IEEE
 
» A MEMS Condenser Microphone-Based Intracochlear Acoustic Receiver
Abstract:
Goal: Intracochlear sound pressure (ICSP) measurements are limited by the small dimensions of the human inner ear and the requirements imposed by the liquid medium. A robust intracochlear acoustic receiver (ICAR) for repeated use with a simple data acquisition system that provides the required high sensitivity and small dimensions does not yet exist. The work described in this report aims to fill this gap and presents a new microelectromechanical systems (MEMS) condenser microphone (CMIC)-based ICAR concept suitable for ICSP measurements in human temporal bones. Methods: The ICAR head consisted of a passive protective diaphragm (PD) sealing the MEMS CMIC against the liquid medium, enabling insertion into the inner ear. The components of the MEMS CMIC-based ICAR were expressed by a lumped element model (LEM) and compared to the performance of successfully fabricated ICARs. Results: Good agreement was achieved between the LEM and the measurements with different sizes of the PD. The ICSP measurements in a human cadaver temporal bone yielded data in agreement with the literature. Conclusion: Our results confirm that the presented MEMS CMIC-based ICAR is a promising technology for measuring ICSP in human temporal bones in the audible frequency range. Significance: A sensor for evaluation of the biomechanical hearing process by quantification of ICSP is presented. The concept has potential as an acoustic receiver in totally implantable cochlear implants.
Autors: Flurin Pfiffner;Lukas Prochazka;Dominik Péus;Ivo Dobrev;Adrian Dalbert;Jae Hoon Sim;Rahel Kesterke;Joris Walraevens;Francesca Harris;Christof Röösli;Dominik Obrist;Alexander Huber;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Oct 2017, volume: 64, issue:10, pages: 2431 - 2438
Publisher: IEEE
 
» A MEMS Tensile Testing Technique for Measuring True Activation Volume and Effective Stress in Nanocrystalline Ultrathin Microbeams
Abstract:
Signature parameters, such as true activation volume and effective stress, are often characterized to identify the governing plastic deformation mechanisms, including that of nanocrystalline metals. The accurate measurement of these parameters using transient tests was recently questioned for nanocrystalline metals, in which grain-boundary-based mechanisms can concurrently occur with dislocation glide. Here, we demonstrate the use of a microelectromechanical systems (MEMS) device to measure true activation volume and effective stress based on repeated stress relaxation and stress dip experiments, respectively. The technique was demonstrated on 100-nm-thick nanocrystalline Au microbeams. These miniaturized tests open up the possibility of observing the mechanisms directly under a transmission electron microscope, and providing a direct link between these measured parameters and the governing mechanisms. [2016-0306]
Autors: Saurabh Gupta;Olivier N. Pierron;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Oct 2017, volume: 26, issue:5, pages: 1082 - 1092
Publisher: IEEE
 
» A Metacoupler for Converting Propagating Waves to Guided Waves in Wire Waveguides
Abstract:
Propagating electromagnetic waves in free space cannot directly couple to guided waves in waveguides due to momentum mismatch. Here, we propose a method to design a metacoupler that can convert propagating waves into guided waves along wire waveguides in a noninvasive way. The metacoupler is attached to the wire waveguide and imposes an additional wave vector to the scattered waves, thus, filling the momentum gap between the propagating waves and guided waves. Numerical simulations have confirmed the conversion effect in corrugated metal wire and silicon wire waveguides.
Autors: Hongchen Chu;Jie Luo;Yun Lai;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 7
Publisher: IEEE
 
» A Methodology for Designing and Evaluating Cloud Scheduling Strategies in Distributed Videoconferencing Systems
Abstract:
Over the last few years, videoconferencing systems have experienced several changes that enable videoconferencing applications in personal devices to a high number of users. To efficiently attend this high and variable demand, deploying distributed videoconferencing servers in cloud-based infrastructures is highly recommended. However, videoconferencing systems have particular characteristics that impede the application of regular resource scheduling solutions used in other kinds of distributed environments. In this paper, we propose a methodology to design and evaluate scheduling strategies adapted to the necessities of each specific scenario. It involves using a new metric to estimate the resource consumption of each connection and provides a set of coefficients to evaluate the efficiency of the strategy. We test the methodology in a real setup and compare the behavior and performance of three scheduling algorithms. The conclusion is that the proposed methodology allows us to configure decision policies adapted to the requirements and necessities of a range of use cases. Thereby, we achieve a more efficient way of using cloud resources, improving the service performance and saving costs.
Autors: Álvaro Alonso;Ignacio Aguado;Joaquín Salvachúa;Pedro Rodríguez;
Appeared in: IEEE Transactions on Multimedia
Publication date: Oct 2017, volume: 19, issue:10, pages: 2282 - 2292
Publisher: IEEE
 
» A Microwave Photonics Fiber Loop Ring-Down System
Abstract:
A microwave photonics fiber loop ring-down system is demonstrated in this paper. In comparison with the traditional time domain fiber loop ring-down setup, the demonstrated system is based on pure frequency domain measurement from a microwave-photonic configuration. The system consists of a direct-modulation laser with its modulation frequency scanned by a vector network analyzer. The amplitude and phase spectra of the demonstrated fiber loop ring-down system are then recorded, followed by a complex Fourier transform to acquire the ring-down curve in the time domain. The loss of the fiber loop can then be evaluated based on the calculated ring-down curve. The system delivers high signal-to-noise ratio, and averaging is not required compared with the traditional time domain measurement. The system is also insensitive to the sources of environmental noise. The measurement principle, experimental setup, and the mathematical model of the system are discussed in this paper. A proof-of-concept macrobending loss test is demonstrated.
Autors: Yiyang Zhuang;Yang Du;Chen Zhu;Mohammed Farhan Ahmed;Yizheng Chen;Rex E. Gerald;Jie Huang;
Appeared in: IEEE Sensors Journal
Publication date: Oct 2017, volume: 17, issue:20, pages: 6565 - 6570
Publisher: IEEE
 
» A Miniature Ultrawideband Electric Field Probe Based on Coax-Thru-Hole via Array for Near-Field Measurement
Abstract:
In this paper, a miniature electric field probe with an ultrawideband of 9 kHz–20 GHz is proposed, fabricated, and tested. The electric field probe is fabricated on a four-layer printed circuit board using high-performance and low-loss Rogers material ( and tan). Coax-thru-hole via array is used to control the signal via impedance to achieve impedance match over the whole working band, reducing the harmful influence on the probe’s characteristic. The ground vias, called via fence, are utilized to suppress the resonance caused by the parallel-plate mode of conductor-backed coplanar waveguide (CB-CPW), expanding the working frequency band. Experimental result shows rather smooth in operation band, demonstrating the working frequency band is up to 9 kHz–20 GHz. The electric field probe has a 2–3 mm spatial resolution, which has a good ability to locate the interference source.
Autors: Zhaowen Yan;Jianwei Wang;Wei Zhang;Yansheng Wang;Jun Fan;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Oct 2017, volume: 66, issue:10, pages: 2762 - 2770
Publisher: IEEE
 
» A Miniaturized Dual-Band FSS With Controllable Frequency Resonances
Abstract:
A novel dual-band miniaturized frequency-selective surface (FSS) is proposed in this letter. The proposed FSS is composed of cross dipole aperture element combined with meandered monopole aperture element. The single layer FSS provides two pass-bands centered at 5.13 and 8.85 GHz with bandwidth of 1.27 and 1.33 GHz, respectively. The two pass-band frequencies of the designed FSS can be controlled independently by simply changing structure parameters of the unit cell. In addition, the dual-band FSS designed using the miniaturized element exhibits excellent resonance stability for different polarizations and incident angles. A prototype of the proposed FSS is fabricated and measured. A good agreement between the simulation and the measured results is obtained, which demonstrates the stable performance of the FSS.
Autors: Xian-Jun Sheng;Jing-Jing Fan;Ning Liu;Chun-Bo Zhang;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2017, volume: 27, issue:10, pages: 915 - 917
Publisher: IEEE
 
» A Minimized 2-D Left-Handed Material Spiral Unit Cell With Rotation Symmetry for Midrange Wireless Power Transfer
Abstract:
This letter presents a technique for designing left-handed material (LHM) unit cell, and a minimized 2-D low-loss LHM square spiral unit cell () with rotation symmetry is developed in the frequency band 13.56–14 MHz. Two LHM slabs with unit cell array are added to the transmission and receiving antennas, respectively, and the power transfer efficiency has increased greatly.
Autors: Hui-Fen Huang;Ting Li;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2017, volume: 27, issue:10, pages: 882 - 884
Publisher: IEEE
 
» A Mobility Model for Random Discrete Dopants and Application to the Current Drivability of DRAM Cell
Abstract:
A new impurity mobility model suitable for the TCAD simulation of the random discrete dopant (RDD) has been proposed. The proposed model has been applied to the DRAM cell transistor of the 20-nm technology generation. The RDD effect in the drain region of the cell transistor alone gives relative standard variation in the driving current of ~3%.
Autors: Hoin Yu;Daewon Kim;Sungman Rhee;Seongwook Choi;Young June Park;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2017, volume: 64, issue:10, pages: 4246 - 4251
Publisher: IEEE
 
» A Model for Designing Ultralow Noise Single- and Dual-Loop 10-GHz Optoelectronic Oscillators
Abstract:
A complete model describing both single- and dual-loop optoelectronic oscillators (OEO) is introduced. It is compared to several experimental configurations, with excellent agreement in all cases. The physical insight into noise coupling mechanisms brought by the model further allows us for the design of ultralow noise OEO. Phase noise performances at 10 GHz with a single 1 km delay line and with a dual 1 km/100 m delay lines are reported. An optimized dual loop configuration exhibits low phase noise floor at high offset frequency (–160 dBc/Hz at 100 kHz) and low spur levels (–145 dBc/Hz), here again in close agreement with our model.
Autors: Oriane Lelièvre;Vincent Crozatier;Perrine Berger;Ghaya Baili;Olivier Llopis;Daniel Dolfi;Pascale Nouchi;Fabienne Goldfarb;Fabien Bretenaker;Loïc Morvan;Grégoire Pillet;
Appeared in: Journal of Lightwave Technology
Publication date: Oct 2017, volume: 35, issue:20, pages: 4366 - 4374
Publisher: IEEE
 
» A Model-Based Predictive Direct Power Control for Traction Line-Side Converter in High-Speed Railway
Abstract:
With the rapid development of China high-speed railway, the low frequency oscillation (LFO) of electrical quantities appears more often recently and leads to some severe problems of train operation. To improve the traction line-side converter control and suppress the phenomenon economically and effectively, a model-based predictive direct power control (MPDPC) approach is proposed in this paper. The approach adopts a discrete-time model of traction line-side converter in d–q reference frame to predict the future values of the input active and reactive power. The optimal switching state is selected by minimizing a cost function of power to evaluate the power errors at the next sampling time. Through the theoretical analysis and simulations, the performance of MPDPC is compared with traditional transient direct current control (TDCC) that is widely adopted in China Railway High-Speed 3 electric-multiple-unit. The real-time online simulations based on Real-Time Laboratory (RT-LAB) are also realized to further validate the results. Moreover, two vehicle-grid cascade simulation systems are constructed, and the LFO suppressing capability of MPDPC and TDCC is compared. Finally, the steady-state characteristic, dynamic characteristic, and LFO suppressing capability of MPDPC are demonstrated through the analysis of key performance indexes.
Autors: Zhigang Liu;Chuan Xiang;Yaqi Wang;Yicheng Liao;Guinan Zhang;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4934 - 4943
Publisher: IEEE
 
» A Modified T-Structured Three-Level Inverter Configuration Optimized With Respect to PWM Strategy Used for Common-Mode Voltage Elimination
Abstract:
This paper presents an optimized topology for a three-level inverter with complete elimination of common-mode voltage (CMV). The proposed multilevel inverter (MLI) configuration is realized by modifying a T-structure inverter. The proposed configuration is an optimized solution with respect to the pulse-width modulation strategy used for CMV elimination. The given three-level inverter structure uses only 16 power semiconductor switches, which is much lower than the existing configurations. A reduced number of power semiconductor devices results in a diminished number of driver circuits, less installation space, and low cost. Further, due to the complete elimination of CMV, the proposed MLI is free from issues such as electromagnetic interference and leakage current with a reduction in filter requirement. The presented topology is also compared with other existing topologies to prove its advantage. It is an optimized solution with respect to the dc bus voltage requirement and the total voltage rating of the devices or the components used in the system. Simulation and experimental results are presented to confirm the capability of the proposed MLI.
Autors: Arpan Hota;Sachin Jain;Vivek Agarwal;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4779 - 4787
Publisher: IEEE
 
» A Multigigabit per Second Integrated Multiple-Input Multiple-Output VLC Demonstrator
Abstract:
In this paper, we report the performance of an imaging multiple-input multiple-output (MIMO) visible light communication (VLC) system. The VLC transmitter consists of a two-dimensional (2-D), individually addressable Gallium Nitride micro light-emitting diode (μLED) array. The receiver uses a 2-D avalanche photodiode array fabricated using complementary metal oxide semiconductor (CMOS). Using integrated CMOS-based LED drivers, a data rate greater than 1 Gb/s was obtained at a link distance of 1 m with the system field of view of 3.45° using four channels. At a reduced link distance of 0.5 m, a data rate of 7.48 Gb/s was obtained using a nine channel MIMO system. This demonstrates the feasibility of compact MIMO systems that offer substantial data rates.
Autors: Sujan Rajbhandari;Aravind V. N. Jalajakumari;Hyunchae Chun;Grahame Faulkner;Katherine Cameron;Robert Henderson;Dobroslav Tsonev;Harald Haas;Enyuan Xie;Jonathan J. D. McKendry;Johannes Herrnsdorf;Ricardo Ferreira;Erdan Gu;Martin D. Dawson;Dominic O&#x
Appeared in: Journal of Lightwave Technology
Publication date: Oct 2017, volume: 35, issue:20, pages: 4358 - 4365
Publisher: IEEE
 
» A Multilevel Artificial Neural Network Nonlinear Equalizer for Millimeter-Wave Mobile Fronthaul Systems
Abstract:
We propose and validate a complex-valued multilevel artificial neural network nonlinear equalizer (ANN-NLE) for single-carrier 16QAM and 64QAM signals transmissions in the 60-GHz radio-over-fiber (RoF) transmission system. First, we analyze the nonlinearities in the fiber-wireless channels. Then, we introduce the principles of the multilevel ANN-NLE proposed for the millimeter-wave RoF systems. From the analysis of nonlinearities in a single-carrier optical transmission channel, it is essential to design a complex-valued ANN-NLE to mitigate the cross-modulation (XM) effects between the in-phase (I) and quadrature-phase (Q) components. Finally, we report on single-carrier signaling at 16QAM and 64QAM on 60 GHz, demonstrating the ability of the proposed ANN-NLE approach to minimize the nonlinear compression in an RoF system. As an added benefit, the complex-valued ANN-NLE has a great tolerance to phase rotations. The convergence time, activation function, step size, and number of taps are discussed in Section IV.
Autors: Siming Liu;Mu Xu;Jing Wang;Feng Lu;Weiheng Zhang;Huiping Tian;Gee-Kung Chang;
Appeared in: Journal of Lightwave Technology
Publication date: Oct 2017, volume: 35, issue:20, pages: 4406 - 4417
Publisher: IEEE
 
» A Multilevel Inverter Structure Based on a Combination of Switched-Capacitors and DC Sources
Abstract:
This paper presents a switched-capacitor multilevel inverter (SCMLI) combined with multiple asymmetric dc sources. The main advantage of proposed inverter with similar cascaded MLIs is reducing the number of isolated dc sources and replacing them with capacitors. A self-balanced asymmetrical charging pattern is introduced in order to boost the voltage and create more voltage levels. Number of circuit components such as active switches, diodes, capacitors, drivers, and dc sources reduces in proposed structure. This multistage hybrid MLI increases the total voltage of used dc sources by multiple charging of the capacitors stage by stage. A bipolar output voltage can be inherently achieved in this structure without using single phase H-bridge inverter that was used in traditional SCMLIs to generate negative voltage levels. This eliminates requirements of high-voltage rating elements to achieve negative voltage levels. A 55-level step-up output voltage (27 positive levels, a zero level, and 27 negative levels) are achieved by a three-stage system that uses only three asymmetrical dc sources (with amplitude of 1 Vin, 2 V in, and 3 Vin) and seven capacitors (self-balanced as multiples of 1 Vin). MATLAB/SIMULINK simulation results and experimental tests are given to validate the performance of proposed circuit.
Autors: Amir Taghvaie;Jafar Adabi;Mohammad Rezanejad;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2162 - 2171
Publisher: IEEE
 
» A Necessary and Sufficient Condition for Having Independent TE and TM Modes in an Anisotropic Waveguide
Abstract:
In a metallic waveguide filled with a lossless anisotropic medium, do independent transverse electric (TE) and transverse magnetic (TM) modes exist? If so, under what conditions? This is a fundamental problem in the electromagnetic waveguide theory, but so far no definitive answers have been published in existing references. This paper proposes a sufficient and necessary condition for this theoretic electromagnetic waveguide problem based on both classic waveguide theory in electromagnetics and basic knowledge in mathematics. Moreover, we prove that for the independent TE modes, the propagation constants obtained from both the longitudinal scalar magnetic field simulation and the transverse vector electric field simulation are the same, and for the independent TM modes, the propagation constants obtained from both the longitudinal scalar electric field simulation and the transverse vector magnetic field simulation are the same. Finally, we validate the correctness of this sufficient and necessary condition by several numerical experiments based on the finite-element method. Therefore, this is a new theoretical result in the electromagnetic waveguide theory, and is expected to be valuable for the design of waveguides filled with anisotropic media.
Autors: Wei Jiang;Jie Liu;Tian Xia;Na Liu;Qing Huo Liu;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3660 - 3670
Publisher: IEEE
 
» A Neuromorphic Chip Optimized for Deep Learning and CMOS Technology With Time-Domain Analog and Digital Mixed-Signal Processing
Abstract:
Demand for highly energy-efficient coprocessor for the inference computation of deep neural networks is increasing. We propose the time-domain neural network (TDNN), which employs time-domain analog and digital mixed-signal processing (TDAMS) that uses delay time as the analog signal. TDNN not only exploits energy-efficient analog computing, but also enables fully spatially unrolled architecture by the hardware-efficient feature of TDAMS. The proposed fully spatially unrolled architecture reduces energy-hungry data moving for weight and activations, thus contributing to significant improvement of energy efficiency. We also propose useful training techniques that mitigate the non-ideal effect of analog circuits, which enables to simplify the circuits and leads to maximizing the energy efficiency. The proof-of-concept chip shows unprecedentedly high energy efficiency of 48.2 TSop/s/W.
Autors: Daisuke Miyashita;Shouhei Kousai;Tomoya Suzuki;Jun Deguchi;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2017, volume: 52, issue:10, pages: 2679 - 2689
Publisher: IEEE
 
» A New Approach to Solve the Constrained OWA Aggregation Problem
Abstract:
Constrained ordered weighted averaging (OWA) aggregation attempts to optimize the OWA aggregation problem with multiple constraints. It is inherently nonlinear, and Yager presented a novel method to transform the nonlinear problem to a mixed integer linear problem. Later, a simple algorithm for exact computation of optimal solutions to a single constrained OWA aggregation problem was presented. In this paper, we deal with the same problem, but in completely different ways in a sense that it is linearized by utilizing the reordering property of the OWA operators. We attempt to solve the linear programming problem via the extreme points in lieu of using a linear programming package for the purpose of deriving an explicit formula for the optimal solution. Furthermore, we consider its dual problem that leads to an equivalent optimal solution. Finally, the proposed method is extended to the OWA optimization problem with multiple constraints including the attitudinal character as well as a range of incomplete arguments.
Autors: Byeong Seok Ahn;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2017, volume: 25, issue:5, pages: 1231 - 1238
Publisher: IEEE
 
» A New CMTF Evaluation Model for Dynamic Target in Photoelectric Imaging System
Abstract:
To evaluate the reliability of photoelectric imaging system, it is essential to research the influences of the illumination contrast and the modulation transfer functions (MTF) to the system imaging capability. This paper deduces a new illumination contrast model based on the optical geometry structure and the optical reflection characteristics of dynamic target; according to the photoelectric imaging principle, defines the system’s MTF by the form of some imaging links, including the optical characteristics, the CCD detector, and the atmospheric characteristics; establishes a new contrast modulation transfer functions (CMTF) mathematical model based on the analysis of the illumination contrast and MTF; obtains the expression of magnitude to evaluate the effects of some key factors to imaging capability. Through the calculation and analysis, under various conditions, with the increasing of target reflectivity, relative aperture, atmospheric coherence length, and optical transmittance, the system imaging capability shows a general trend of rising; with the increasing of background radiation illumination, target distance, standard deviation, and the system imaging capability shows attenuation trend; the results show that different factors have a great impact on the imaging capability, which proves the suitability of CMTF model for evaluating the performance photoelectric system.
Autors: Hanshan Li;Sangsang Chen;
Appeared in: IEEE Sensors Journal
Publication date: Oct 2017, volume: 17, issue:20, pages: 6571 - 6577
Publisher: IEEE
 
» A New Framework for Quality Assessment of High-Resolution Fingerprint Images
Abstract:
The quality assessment of sets of features extracted from patterns of epidermal ridges on our fingers is a biometric challenge problem with implications on questions concerning security, privacy and identity fraud. In this work, we introduced a new methodology to analyze the quality of high-resolution fingerprint images containing sets of fingerprint pores. Our approach takes into account the spatial interrelationship between the considered features and some basic transformations involving point process and anisotropic analysis. We proposed two new quality index algorithms following spatial and structural classes of analysis. These algorithms have proved to be effective as a performance predictor and as a filter excluding low-quality features in a recognition process. The experiments using error reject curves show that the proposed approaches outperform the state-of-the-art quality assessment algorithm for high-resolution fingerprint recognition, besides defining a new method for reconstructing their friction ridge phases in a very consistent way.
Autors: Raoni F. S. Teixeira;Neucimar J. Leite;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Oct 2017, volume: 39, issue:10, pages: 1905 - 1917
Publisher: IEEE
 
» A New Method for Automatic Sleep Stage Classification
Abstract:
Traditionally, automatic sleep stage classification is quite a challenging task because of the difficulty in translating open-textured standards to mathematical models and the limitations of handcrafted features. In this paper, a new system for automatic sleep stage classification is presented. Compared with existing sleep stage methods, our method can capture the sleep information hidden inside electroencephalography (EEG) signals and automatically extract features from raw data. To translate open sleep stage standards into machine rules recognized by computers, a new model named fast discriminative complex-valued convolutional neural network (FDCCNN) is proposed to extract features from raw EEG data and classify sleep stages. The new model combines complex-valued backpropagation and the Fisher criterion. It can learn discriminative features and overcome the negative effect of imbalance dataset. More importantly, the orthogonal decision boundaries for the real and imaginary parts of a complex-valued convolutional neuron are proven. A speed-up algorithm is proposed to reduce computational workload and yield improvements of over an order of magnitude compared to the normal convolution algorithm. The classification performances of handcrafted features and different convolutional neural networks are compared with that of the FDCCNN. The total accuracy and kappa coefficient of the proposed method are 92% and 0.84, respectively. Experiment results demonstrated that the performance of our system is comparable to those of human experts.
Autors: Junming Zhang;Yan Wu;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Oct 2017, volume: 11, issue:5, pages: 1097 - 1110
Publisher: IEEE
 
» A New Small-Signal Parameter Extraction Technique for Large Gate-Periphery GaN HEMTs
Abstract:
In this letter, we propose a method to extract the small-signal equivalent circuit model for GaN HEMTs using extrinsic-level RF broadband (0.5–50 GHz) Z-parameters. The measured Z-parameters of large gate-periphery GaN devices exhibit certain interesting characteristics, due to their inherently larger intrinsic capacitances and their subsequent interaction with the extrinsic inductances. We exploit these characteristics to simultaneously extract the intrinsic as well as the extrinsic small-signal model components and successfully validate it with measured S-parameter data for a GaN device.
Autors: Sheikh Aamir Ahsan;Ahtisham-ul-Haq Pampori;Sudip Ghosh;Sourabh Khandelwal;Yogesh Singh Chauhan;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2017, volume: 27, issue:10, pages: 918 - 920
Publisher: IEEE
 
» A New Three-Dimensional Sliding Mode Guidance Law Variation With Finite Time Convergence
Abstract:
This paper develops a new three-dimensional (3-D) guidance law which guarantees the interception of manoeuvring targets in a finite time. The new guidance law accepts the concept that nullifying the line-of-sight rate guarantees the interception of the target and its derivation is based on finite time sliding mode guidance. By using a 3-D kinematic equation set constructed in a rotating coordinate system, the proposed guidance law alleviates an issue of general 3-D guidance caused by the cross coupling effect between pitch and yaw planes. In theoretical analysis, finite time convergence of the new guidance law is proved and compared with that of a practical sliding mode guidance law. Characteristics such as energy consumption and convergence boundary layer are also theoretically analyzed. Simulation results demonstrate that the new guidance law effectively intercepts manoeuvring targets in a finite time and analysis results are valid.
Autors: Hyo-Sang Shin;Antonios Tsourdos;Ke-Bo Li;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Oct 2017, volume: 53, issue:5, pages: 2221 - 2232
Publisher: IEEE
 
» A New View of Multi-User Hybrid Massive MIMO: Non-Orthogonal Angle Division Multiple Access
Abstract:
This paper presents a new view of multi-user (MU) hybrid massive multiple-input and multiple-output (MIMO) systems from array signal processing perspective. We first show that the instantaneous channel vectors corresponding to different users are asymptotically orthogonal if the angles of arrival of users are different. We then decompose the channel matrix into an angle domain basis matrix and a gain matrix. The former can be formulated by steering vectors and the latter has the same size as the number of RF chains, which perfectly matches the structure of hybrid precoding. A novel hybrid channel estimation is proposed by separately estimating the angle information and the gain matrix, which could significantly save the training overhead and substantially improve the channel estimation accuracy compared with the conventional beamspace approach. Moreover, with the aid of the angle domain matrix, the MU massive MIMO system can be viewed as a type of non-orthogonal angle division multiple access to simultaneously serve multiple users at the same frequency band. Finally, the performance of the proposed scheme is validated by computer simulation results.
Autors: Hai Lin;Feifei Gao;Shi Jin;Geoffrey Ye Li;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Oct 2017, volume: 35, issue:10, pages: 2268 - 2280
Publisher: IEEE
 
» A New Way for a New Generation [Editorial]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Cristian Quintero;
Appeared in: IEEE Potentials
Publication date: Oct 2017, volume: 36, issue:5, pages: 3 - 3
Publisher: IEEE
 
» A Noise-Power-Area Optimized Biosensing Front End for Wireless Body Sensor Nodes and Medical Implantable Devices
Abstract:
In this paper, we present a noise, power, and area efficient biosensing front-end application specified integrated circuit (ASIC) for the next-generation wireless body sensor nodes and implantable devices. We identify the key design parameter tradeoffs in the biomedical recording systems and carry out a thorough analysis and optimization to maximize them. Based on our analysis and optimization of the front end, we propose a design methodology for the recording channel that is applicable to various biomedical applications. The ASIC is implemented in a 0.18- CMOS process to validate our optimization methodology. The ASIC is reconfigurable to accommodate various biopotentials with the high-pass and low-pass cutoff frequencies being 0.5–300 Hz and 150 Hz–10 kHz, respectively. The low-pass cutoff is provided by an ultralow power - low-pass filter, which also acts as an antialiasing filter for the switching-optimized 10-b successive approximation register (SAR) analog-to-digital converter (ADC). The analog front end (AFE) gain is also programmable from 38 to 72 dB. A comprehensive power management unit provides the power supply, multiple reference voltages, and bias currents to the entire chip. The AFE and ADC dissipate only and 306 nW from the on-chip regulators, respectively. The measured input-referred noise is , resulting in the noise efficiency factor and power efficiency factor equals 2.6 and 9.46, respectively. The active area of the AFE is 0.0228 mm2. We verify the chip - unctionality in a number of in vivo and ex vivo biological experiments.
Autors: Hansraj Bhamra;John Lynch;Matthew Ward;Pedro Irazoqui;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Oct 2017, volume: 25, issue:10, pages: 2917 - 2928
Publisher: IEEE
 
» A Novel Approach to Subpixel Land-Cover Change Detection Based on a Supervised Back-Propagation Neural Network for Remotely Sensed Images With Different Resolutions
Abstract:
Extracting subpixel land-cover change detection (SLCCD) information is important when multitemporal remotely sensed images with different resolutions are available. The general steps are as follows. First, soft classification is applied to a low-resolution (LR) image to generate the proportion of each class. Second, the proportion differences are produced by the use of another high-resolution (HR) image and used as the input of subpixel mapping. Finally, a subpixel sharpened difference map can be generated. However, the prior HR land-cover map is only used to compare with the enhanced map of LR image for change detection, which leads to a nonideal SLCCD result. In this letter, we present a new approach based on a back-propagation neural network (BPNN) with a HR map (BPNN_HRM), in which a supervised model is introduced into SLCCD for the first time. The known information of the HR land-cover map is adequately employed to train the BPNN, whether it predates or postdates the LR image, so that a subpixel change detection map can be effectively generated. In order to evaluate the performance of the proposed algorithm, it was compared with four state-of-the-art methods. The experimental results confirm that the BPNN_HRM method outperforms the other traditional methods in providing a more detailed map for change detection.
Autors: Ke Wu;Yanfei Zhong;Xianmin Wang;Weiwei Sun;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Oct 2017, volume: 14, issue:10, pages: 1750 - 1754
Publisher: IEEE
 
» A Novel Approximation for K Distribution: Closed-Form BER Using DPSK Modulation in Free-Space Optical Communication
Abstract:
A new analytical approximate expression for K distribution is proposed by expanding it in terms of orthogonal associated Laguerre polynomial. The expansion is truncated after first three terms, which yields a fairly close approximation to K distribution. The advantage of the proposed approximation is that the analytical closed form expression for bit error rate can be easily derived. KL measure is used to show the accuracy of the proposed approximation. The proposed approximate probability density function and bit error rate work well within the desired range of the channel parameter , which is and corresponds to the scintillation index value ranging from 2 to 3. We have also demonstrated the utility of our approximation for other quality of service metric such as fade probability.
Autors: Rajeev Kumar Singh; Karmeshu;Santosh Kumar;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 14
Publisher: IEEE
 
» A Novel CH5 Inverter for Single-Phase Transformerless Photovoltaic System Applications
Abstract:
Versatile single-phase voltage source inverters with unipolar voltage pulse and leakage current elimination capability have been extensively investigated for transformerless PV systems in the literature. However, the innovative current source inverters with leakage current elimination capability are not well explored. In this brief, a novel single-phase current source H5 (CH5) inverter is proposed. Only one extra IGBT is needed, but the leakage current can be significantly suppressed with a novel space vector modulation. Finally, the experimental tests are carried out on a single-phase CH5 inverter and the experimental results verify the effectiveness of the proposed topology and space vector modulation.
Autors: Xiaoqiang Guo;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2017, volume: 64, issue:10, pages: 1197 - 1201
Publisher: IEEE
 
» A Novel Fabrication Technique for MEMS Based on Agglomeration of Powder by ALD
Abstract:
This paper describes a novel fabrication technique for microelectromechanical systems (MEMS) based on the agglomeration of micron-sized powder into rigid 3-D porous structures by means of atomic layer deposition (ALD). Since ALD is performed at low temperatures, such structures can be created from a broad variety of materials. It is shown that the compatibility of substrates with embedded porous structures to common back-end-of-line environment can be regained, and post-processed by applying standard processes of MEMS and integrated circuit technology is possible. In such a way, for the first time, nearly any material can be integrated onto silicon substrates in a simple and generic way. Moreover, not only a particular porosity or internal surface can be targeted. The bulk properties of the structure can be tailored as well, which opens up unique prospects for the future of MEMS.
Autors: T. Lisec;T. Reimer;M. Knez;S. Chemnitz;A. V. Schulz-Walsemann;A. Kulkarni;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Oct 2017, volume: 26, issue:5, pages: 1093 - 1098
Publisher: IEEE
 
» A Novel High Bandwidth Current Control Strategy for SiC mosfet Based Active Front-End Rectifiers Under Unbalanced Input Voltage Conditions
Abstract:
SiC mosfet based converters are capable of high switching frequency operation. In this paper, the converter is operated with 50-kHz switching frequency for an active front-end rectifier application. Due to high switching frequency, the grid-side filter size is reduced, and the possibility of a high bandwidth current control loop is utilized in this paper. A current control loop with bandwidth of 5 kHz is designed using a proportional-integral controller in synchronously rotating dq-reference frame. In addition, the performance of the controller is tested under unbalanced input supply conditions. During this condition, new feed-forward signals, which are added to the controller output, are proposed. The gain of the feed-forward signal can be modified to achieve balanced sinusoidal grid currents, constant dc-link voltage, or a controlled negative-sequence input current, which are typical application-depending requirements. A closed-form formula to calculate the gain of the feed-forward signal to achieve the above-mentioned requirements is also proposed in this paper. To verify the proposed method, the simulation and experimental results are presented in this paper.
Autors: Ramkrishan Maheshwari;Ionut Trintis;Lajos Török;Stig Munk-Nielsen;Philip James Douglass;Lorand Bede;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Oct 2017, volume: 64, issue:10, pages: 8310 - 8320
Publisher: IEEE
 
» A Novel Hybrid Five-Level Voltage-Source Converter Based on T-Type Topology for High-Efficiency Applications
Abstract:
A novel hybrid five-level voltage-source converter for high-efficiency applications is investigated in this paper. Compared with traditional multilevel converters, this hybrid multilevel converter generates desired staircase voltage levels with a reduced number of power devices and isolated drivers at higher voltage levels. It has redundant switching state combinations in hybrid multilevel converter, which makes it easy to balance flying capacitor voltages and realize fault-tolerant operation. A voltage-balancing control strategy based on switching state redundancies is presented for the hybrid multilevel converter to generate desired levels and also keep voltage balance of flying capacitors at the same time. The performance of the hybrid multilevel converter under various operating conditions is investigated in MATLAB/Simulink. The effectiveness of the proposed hybrid multilevel converter is validated by experiment results.
Autors: Shuai Xu;Jianzhong Zhang;Xing Hu;Yongjiang Jiang;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4730 - 4743
Publisher: IEEE
 
» A Novel Hybrid Islanding Detection Method for Inverter-Based DGs Using SFS and ROCOF
Abstract:
This paper is aimed at proposing a new hybrid method for the islanding detection of distributed-generation (DG) units. Hybrid method operation is based on the combination of an active and a passive method, for which the optimized Sandia frequency shift (SFS) method is used as the selected active method, and rate of change of frequency relay (ROCOF) is used as the passive method. In order to demonstrate the effectiveness of the proposed technique on islanding detection, several simulation studies based on IEEE 1547 and UL1741 anti-islanding test requirements are carried out. The evaluation of simulation results reveals that the control system, based on the proposed hybrid algorithm, meets the DG islanding protection requirements efficiently. Moreover, it will be demonstrated that the proposed hybrid method is capable of accurately operating under multiple DG units, load switching in the grid-connected mode, as well as different load quality factor conditions.
Autors: Mahdiyeh Khodaparastan;Hesan Vahedi;Farid Khazaeli;Hashem Oraee;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Oct 2017, volume: 32, issue:5, pages: 2162 - 2170
Publisher: IEEE
 
» A Novel Hybrid Kinect-Variety-Based High-Quality Multiview Rendering Scheme for Glass-Free 3D Displays
Abstract:
This paper presents a new hybrid Kinect-variety-based synthesis scheme that renders artifact-free multiple views for autostereoscopic/automultiscopic displays. The proposed approach does not explicitly require dense scene depth information for synthesizing novel views from arbitrary viewpoints. Instead, the integrated framework first constructs a consistent minimal image–space parameterization of the underlying 3D scene. The compact representation of scene structure is formed using only implicit sparse depth information of a few reference scene points extracted from raw RGB depth data. The views from arbitrary positions can be inferred by moving the novel camera in parameterized space by enforcing Euclidean constraints on reference scene images under a full-perspective projection model. Unlike the state-of-the-art depth image-based rendering (DIBR) methods, in which input depth map accuracy is crucial for high-quality output, our proposed algorithm does not depend on precise per-pixel geometry information. Therefore, it simply sidesteps to recover and refine the incomplete or noisy depth estimates with advanced filling or upscaling techniques. Our approach performs fairly well in unconstrained indoor/outdoor environments, where the performance of range sensors or dense depth-based algorithms could be seriously affected due to scene complex geometric conditions. We demonstrate that the proposed hybrid scheme provides guarantees on the completeness, optimality with respect to the inter-view consistency of the algorithm. In the experimental validation, we performed a quantitative evaluation as well as subjective assessment of the scene with complex geometric or surface properties. A comparison with the latest representative DIBR methods is additionally performed to demonstrate the superior performance of the proposed scheme.
Autors: Mansi Sharma;Santanu Chaudhury;Brejesh Lall;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Oct 2017, volume: 27, issue:10, pages: 2098 - 2117
Publisher: IEEE
 
» A Novel Intracranial Pressure Readout Circuit for Passive Wireless LC Sensor
Abstract:
We present a wide frequency range, low cost, wireless intracranial pressure monitoring system, which includes an implantable passive sensor and an external reader. The passive sensor consists of two spiral coils and transduces the pressure change to a resonant frequency shift. The external portable reader reads out the sensor's resonant frequency over a wide frequency range (35 MHz–2.7 GHz). We propose a novel circuit topology, which tracks the system's impedance and phase change at a high frequency with low-cost components. This circuit is very simple and reliable. A prototype has been developed, and measurement results demonstrate that the device achieves a suitable measurement distance (>2 cm), sufficient sample frequency (>6 Hz), fine resolution, and good measurement accuracy for medical practice. Responsivity of this prototype is 0.92 MHz/mmHg and resolution is 0.028 mmHg. COMSOL specific absorption rate simulation proves that this system is safe. Considerations to improve the device performance have been discussed, which include the size of antenna, the power radiation, the Analog-to-digital converter (ADC) choice, and the signal processing algorithm.
Autors: Fa Wang;Xuan Zhang;Mehdi Shokoueinejad;Bermans J. Iskandar;Joshua E. Medow;John G. Webster;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Oct 2017, volume: 11, issue:5, pages: 1123 - 1132
Publisher: IEEE
 
» A Novel Ionospheric Sounding Radar Based on USRP
Abstract:
Ionospheric sounding is a technique that provides real-time data on high-frequency ionospheric-dependent radio propagation. This letter presents a Universal Software Radio Peripheral-based ionospheric sounding radar, which relies on a basic system consisting of a synchronized transmitter and receiver. The radar has the advantages of miniaturization, modularization, low power, and low cost. The three most significant features of the radar system are that it is software-defined and universal platform-based and that it has low transmitting power. This novel software-defined vertical-incidence radar system can probe the ionosphere and obtain real-time plasma parameters according to the simulation. Ionograms that directly express probe results are generated by MATLAB after data processing and simulation. Successful development of such an ionospheric sounding software radar will allow universalization and miniaturization of an ionosonde radar system. This letter introduces the implementation of the novel ionospheric sounding radar.
Autors: Ziyang Zhao;Ming Yao;Xiaohua Deng;Kai Yuan;Huixia Li;Zheng Wang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Oct 2017, volume: 14, issue:10, pages: 1800 - 1804
Publisher: IEEE
 
» A Novel Methodology to Label Urban Remote Sensing Images Based on Location-Based Social Media Photos
Abstract:
With the rapid development of the internet and popularization of intelligent mobile devices, social media is evolving fast and contains rich spatial information, such as geolocated posts, tweets, photos, video, and audio. Those location-based social media data have offered new opportunities for hazards and disaster identification or tracking, recommendations for locations, friends or tags, pay-per-click advertising, etc. Meanwhile, a massive amount of remote sensing (RS) data can be easily acquired in both high temporal and spatial resolution with a multiple satellite system, if RS maps can be provided, to possibly enable the monitoring of our location-based living environments with some devices like charge-coupled device (CCD) cameras but on a much larger scale. To generate the classification maps, usually, labeled RS image pixels should be provided by RS experts to train a classification system. Traditionally, labeled samples are obtained according to ground surveys, image photo interpretation or a combination of the aforementioned strategies. All the strategies should be taken care of by domain experts, in a means which is costly, time consuming, and sometimes of a low quality due to reasons such as photo interpretation based on RS images only. These practices and constraints make it more challenging to classify land-cover RS images using big RS data. In this paper, a new methodology is proposed to classify urban RS images by exploiting the semantics of location-based social media photos (SMPs). To validate the effectiveness of this methodology, an automatic classification system is developed based on RS images as well as SMPs via big data analysis techniques including active learning, crowdsourcing, shallow machine learning, and deep learning. As the labels of RS training data are given by ordinary people with a crowdsourcing technique, the developed system is named Crowd4RS. The quantitative and qualitative experiments confirm the effectiveness of the proposed- Crowd4RS system as well as the proposed methodology for automatically generating RS image maps in terms of classification results based on big RS data made up of multispectral RS images in a high spatial resolution and a large amount of photos from social media sites, such as Flickr and Panoramio.
Autors: Mingmin Chi;Zhongyi Sun;Yiqing Qin;Jinsheng Shen;Jón Atli Benediktsson;
Appeared in: Proceedings of the IEEE
Publication date: Oct 2017, volume: 105, issue:10, pages: 1926 - 1936
Publisher: IEEE
 
» A Novel Model for Direction Finding and Phase Center With Practical Considerations
Abstract:
The data model for direction of arrival (DOA) estimation is revisited and studied with more attention to the practical implementation of the antenna arrays and verified through measurement results. A complete data model for a single-channel direction finding system that includes, for the first time, the effects of the switching mechanism among antennas is presented. In order to combat coupling among antenna elements and the radio frequency switch nonidealities, a comprehensive model is developed, which includes more accurate noise modeling. The effect of the phase center (PC) in DOA estimation is then discussed and an improved data model is presented, which includes the antenna’s PC movement. The Cramer–Rao bound for circular arrays including the newly introduced parameter for the PC is derived. The new model shows significant improvement in the estimation accuracy.
Autors: Evangelos Kornaros;Saman Kabiri;Franco De Flaviis;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5475 - 5491
Publisher: IEEE
 
» A Novel Nanoparticle Mediated Selective Inner Retinal Photocoagulation for Diseases of the Inner Retina
Abstract:
A novel nanoparticle mediated methodology for laser photocoagulation of the inner retina to achieve tissue selective treatment is presented. Methods: Transport of 527, 577, and 810 nm laser, heat deposition, and eventual thermal damage in vitreous, retina, RPE, choroid, and sclera were modeled using Bouguer–Beer–Lambert law of absorption and solved numerically using the finite volume method. Nanoparticles were designed using Mie theory of scattering. Performance of the new photocoagulation strategy using gold nanospheres and gold–silica nanoshells was compared with that of conventional methods without nanoparticles. For experimental validation, vitreous cavity of ex vivo porcine eyes was infused with gold nanospheres. After ~6 h of nanoparticle diffusion, the porcine retina was irradiated with a green laser and imaged simultaneously using a spectral domain optical coherence tomography (Spectralis SD-OCT, Heidelberg Engineering). Results: Our computational model predicted a significant spatial shift in the peak temperature from RPE to the inner retinal region when infused with nanoparticles. Arrhenius thermal damage in the mid-retinal location was achieved in ~14 ms for 527 nm laser thereby reducing the irradiation duration by ~30 ms compared with the treatment without nanoparticles. In ex vivo porcine eyes infused with gold nanospheres, SD-OCT retinal images revealed a lower thermal damage and expansion at RPE due to laser photocoagulation. Conclusion: Nanoparticle infused laser photocoagulation strategy provided a selective inner retinal thermal damage with significant decrease in laser power and laser exposure time. Significance: The proposed treatment strategy shows possibilities for an efficient and highly selective inner retinal laser treatment.
Autors: Rupesh Singh;Srinivas Rajaraman;Madhusudhanan Balasubramanian;
Appeared in: IEEE Transactions on NanoBioscience
Publication date: Oct 2017, volume: 16, issue:7, pages: 542 - 554
Publisher: IEEE
 
» A Novel Radio-Over-Fiber System Based on Carrier Suppressed Frequency Eightfold Millimeter Wave Generation
Abstract:
We propose a novel and simple scheme for photonic frequency eightfold millimeter wave (mm-wave) generation with optical carrier suppression based on only one single-drive Mach–Zehnder modulator (MZM). According to our theoretical analysis and experimental demonstration, by adopting designed direct current bias voltage of MZM and the amplitude voltage of the radio frequency (RF) drive signal, two fourth-order optical subcarriers are generated via a single-drive MZM. Furthermore, the corresponding optical central carrier and undesired sidebands are suppressed simultaneously. Based on our proposed scheme, the generation of 72-GHz optical mm-wave by an RF signal of 9 GHz without any optical filtering is experimentally demonstrated. The radio-over-fiber system with 3.5-Gb/s OOK downstream link based on this generated 72-GHz mm-wave is also experimentally demonstrated. As we know, it is the first time to realize frequency eightfold mm-wave signal generation with simultaneous carrier suppression by using only one single-drive MZM in experiment.
Autors: Huizhong Zhang;Lin Cai;Shuixian Xie;Kaiming Zhang;Xinxing Wu;Ze Dong;
Appeared in: IEEE Photonics Journal
Publication date: Oct 2017, volume: 9, issue:5, pages: 1 - 6
Publisher: IEEE
 
» A Novel Stator Structure for Active Axial Force Improvement in a One-Axis Actively Positioned Single-Drive Bearingless Motor
Abstract:
This paper presents a novel stator structure in an actively positioned bearingless motor with 1-degree of freedom. The single-drive bearingless motor concept has been adapted so that the torque and active axial force are regulated independently by the q- and d-axis currents, respectively, with only one three-phase inverter. The axial z-axis position is actively regulated, but the other axes (i.e., the radial and tilting movements) are passively stabilized. A novel stator structure has been proposed to enhance the active axial force. The stator is designed with soft magnetic composites. Experiments confirmed that the active axial force is enhanced by 50%.
Autors: Hiroya Sugimoto;Itsuki Shimura;Akira Chiba;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4414 - 4421
Publisher: IEEE
 
» A Novel Symmetric Double-Slot Structure for Antipodal Vivaldi Antenna to Lower Cross-Polarization Level
Abstract:
An antipodal Vivaldi antenna (AVA) with novel symmetric two-layer double-slot structure is proposed. When excited with equiamplitude and opposite phase, the two slots will have the sum vector of their E-field vectors parallel to the antenna’s plane, which is uniform to the E-field vector in the slot of a balanced AVA with three-layer structure. Compared with a typical AVA with the same size, the proposed antenna has better impedance characteristics because of the amelioration introduced by the coupling between the two slots, as well as the more symmetric radiation patterns and the remarkably lowered cross-polarization level at the endfire direction. For validating the analysis, an UWB balun based on the double-sided parallel stripline is designed for realizing the excitation, and a sample of the proposed antenna is fabricated. The measured results reveal that the proposed has an operating frequency range from 2.8 to 15 GHz, in which the cross-polarization level is less than −24.8 dB. Besides, the group delay of two face-to-face samples has a variation less than 0.62 ns, which exhibits the ability of the novel structure for transferring pulse signal with high fidelity. The simple two-layer structure, together with the improvement both in impedance and radiation characteristics, makes the proposed antenna much desirable for the UWB applications.
Autors: Ya-Wei Wang;Zhong-Wu Yu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5599 - 5604
Publisher: IEEE
 
» A Novel TD-VIE Based on MOT Scheme for Analysis of Dispersive Objects
Abstract:
A novel time-domain volume integral equation (TD-VIE) is proposed to analyze the transient electromagnetic scattering from inhomogeneous dispersive objects. In this TD-VIE method, the higher order Nyström method is applied in spatial domain. Namely, the curvilinear tetrahedron elements are utilized to discretize dielectric objects and resulting unknowns are volume electric current density. The Lagrange interpolation polynomials are used to represent spatial basis functions. In temporal domain, the marching-on-in-time (MOT) scheme is applied and the shifted Lagrange interpolation functions are used to represent temporal basis functions. Moreover, the point-matching method is applied both in spatial and temporal domain. Compared with the traditional spatial Schaubert–Wilton–Glisson basis based on TD-VIE, this novel TD-VIE method is more efficient. Several numerical examples have demonstrated that the proposed method is accurate, stable, and also more efficient than the traditional TD-VIE.
Autors: Shifei Tao;Jun Cao;Zhenhong Fan;R. S. Chen;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5387 - 5395
Publisher: IEEE
 
» A Novel Thermomagnetic-Actuated Gripper With a Piezoelectric–Pyroelectric Sensing Readout of Gripping States and Forces
Abstract:
In this paper, we reported a thermomagnetic-actuated gripper with a piezoelectric–pyroelectric sensing readout of gripping states and forces. The gripper consists of two CuBe cantilever beams, a Gd sheet, NdFeB hard magnets, a thermoelectric generator (TEG), a piezoelectric–pyroelectric PZT sheet, and a polymer-polymethyl methacrylate base. When TEG cools the Gd sheet lower than its Curie temperature, the magnetic attraction between the Gd sheet and the NdFeB magnets is produced due to the thermomagnetic property of the Gd sheet. Subsequently, the magnetic attractive force deflects two beams until beams contact to each other. Thus, the gripper can grasp a small object. Furthermore, when the gripper is operated to grasp the object, the piezoelectric–pyroelectric PZT sheet of the gripper produces voltage response. Through analyzing the voltage response, the gripping state is detected and subsequently the gripping force is obtained. After gripping, a negative dc current is applied to TEG to heat the Gd sheet higher than Gd’s Curie temperature. Due to this, the magnetic attractive force is reduced and eventually eliminated. Consequently, the beams are separated due to their spring-back force. Thus, the gripper releases the object. The experimental results show that the gripper can be sequentially operated to grasp and release the object. Furthermore, as the current applied to the TEG is increased, the gripping force is increased. The maximum gripping force of the gripper is 0.69 N when a dc current of 0.7 A is applied. Moreover, when comparing conventional magnetic-field-actuated magnetic grippers, our gripper can be individually operated by applied currents, detect the gripping state, and sense the gripping force.
Autors: Chin-Chung Chen;Tien-Kan Chung;Chu-Yi Lin;
Appeared in: IEEE Transactions on Magnetics
Publication date: Oct 2017, volume: 53, issue:10, pages: 1 - 16
Publisher: IEEE
 
» A Novel Trail Detection and Scene Understanding Framework for a Quadrotor UAV With Monocular Vision
Abstract:
Vision-based trail detection and autonomous scene understanding play a key role for unmanned aerial vehicles (UAVs) working in complex outdoor environments such as isolated disaster sites. This paper investigates the problems associated with trail detection and tracking, as well as autonomous scene understanding using a quadrotor UAV. A framework that integrates support vector machine-based trail detection with a trail tracker is proposed to accomplish trail direction estimation and tracking at a low cost of computation and in real time. To accurately perform online parameter estimation, a performance test is designed and implemented to evaluate the accuracy. Moreover, the simple linear iterative clustering superpixel segmentation algorithm is utilized in the proposed system framework to guarantee the scene segmentation accuracy. Visual detection for significant objects or people is implemented by using single shot multibox detector algorithm. A series of experiments are conducted by using a quadrotor platform DJI M100 and experimental results show the validity and practicality of the proposed approach.
Autors: Yisha Liu;Qunxiang Wang;Yan Zhuang;Huosheng Hu;
Appeared in: IEEE Sensors Journal
Publication date: Oct 2017, volume: 17, issue:20, pages: 6778 - 6787
Publisher: IEEE
 
» A Novel Tri-Band Wilkinson Power Divider for Multiband Wireless Applications
Abstract:
This letter presents a novel and simple technique for the design of an arbitrary tri-band Wilkinson power divider. The proposed technique is based on the use of quarter-wave open stubs (QWOS) at the desired operation frequencies, placed at appropriate positions along the divider’s 50- output transmission lines, to create the targeted tri-band response. These stubs present a high impedance at the frequencies of interest, while introducing transmission zeroes between the operation bands. For a compact design, slow-wave structure has been adopted to miniaturize the conventional divider’s arms. To validate the above concept, a power divider—intended to operate in the 1.5-, 1.9-, and 2.35-GHz frequency bands—is designed. The results of the fabricated circuit present low insertion loss of less than 0.45 dB while offering an isolation better than 15 dB in the three bands of operation. Compared to recently published results, the proposed divider exhibits the largest fractional bandwidth at each operation frequency. Furthermore, it can be easily extended to more bands by adding QWOS depending on the required number of bands.
Autors: Basem M. Abdelrahman;Hesham N. Ahmed;A. I. Nashed;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2017, volume: 27, issue:10, pages: 891 - 893
Publisher: IEEE
 
» A Novel Utilization of Image Registration Techniques to Process Mastcam Images in Mars Rover With Applications to Image Fusion, Pixel Clustering, and Anomaly Detection
Abstract:
The Mars Science Laboratory is a robotic rover mission to Mars launched by NASA on November 26, 2011, which successfully landed the Curiosity rover in Gale Crater on August 6, 2012. The Curiosity rover has two mast cameras (Mastcams) that acquire stereo images at a number of different wavelengths. Each camera has nine bands of which six bands are overlapped in the two cameras. These acquired stereo band images at different wavelengths can be fused into a 12-band multispectral image cube, which could be helpful to guide the rover to interesting locations. Since the two Mastcams’ fields of view are three times different from each other, in order to fuse the left- and right-camera band images to form a multispectral image cube, there is a need for a precise image alignment of the stereo images with registration errors at the subpixel level. A two-step image alignment approach with a novel utilization of existing image registration algorithms is introduced in this paper and is applied to a set of Mastcam stereo images. The effect of the two-step alignment approach using more than 100 pairs of Mastcam images, selected from over 500000 images in NASA's Planetary Data System database, clearly demonstrated that the fused images can improve pixel clustering and anomaly detection performance. In particular, registration errors in the subpixel level are observed with the applied alignment approach. Moreover, the pixel clustering and anomaly detection performance have been observed to be better when using fused images.
Autors: Bulent Ayhan;Minh Dao;Chiman Kwan;Hua-Mei Chen;James F. Bell;Richard Kidd;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Oct 2017, volume: 10, issue:10, pages: 4553 - 4564
Publisher: IEEE
 
» A Novel Variable Flux Memory Machine With Series Hybrid Magnets
Abstract:
This paper proposes a novel variable flux memory (VFM) machine, in which the “constant” permanent magnet (CPM) with high coercive force and the “variable” PM (VPM) with low coercive force are alternatively located in the interior-PM rotor. Thus, the VPMs and CPMs are magnetically connected in series, with which the CPMs can assist the VPMs to withstand the unintentional demagnetization caused by armature reaction. Therefore, a high armature current can be applied to the machine. Meanwhile, the reluctance torque is retrieved. Thus, a high torque density can be obtained. Based on two-dimensional finite element analysis, first, the electromagnetic performance of the proposed VFM machine in two extreme magnetization states is evaluated in detail. Then, the demagnetization and remagnetization characteristics are investigated, in which the working points of VPMs are illustrated. Furthermore, the advantages of improved efficiency of the proposed VFM machine are demonstrated. A prototype machine is manufactured and tested to validate the predictions.
Autors: Hao Hua;Z. Q. Zhu;Adam Pride;Rajesh P. Deodhar;Toshinori Sasaki;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2017, volume: 53, issue:5, pages: 4396 - 4405
Publisher: IEEE
 
» A Numerical Approach to Stability of Multiclass Queueing Networks
Abstract:
The multiclass queueing network (McQN) arises as a natural multiclass extension of the traditional (single-class) Jackson network. In a single-class network, subcriticality (i.e., subunitary nominal workload at every station) entails stability, but this is no longer sufficient when jobs/customers of different classes (i.e., with different service requirements and/or routing scheme) visit the same server; therefore, analytical conditions for stability of McQNs are lacking, in general. In this note, we design a numerical (simulation-based) method for determining the stability region of a McQN, in terms of arrival rate(s). Our method exploits certain (stochastic) monotonicity properties enjoyed by the associated Markovian queue-configuration process. Stochastic monotonicity is a quite common feature of queueing models and can be easily established in the single-class framework (Jackson networks); recently, also for a wide class of McQNs, including first-come-first-serve networks, monotonicity properties have been established. Here, we provide a minimal set of conditions, under which the method performs correctly. Eventually, we illustrate the use of our numerical method by presenting a set of numerical experiments, covering both single- and multiclass networks.
Autors: Haralambie Leahu;Michel Mandjes;Ana-Maria Oprescu;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Oct 2017, volume: 62, issue:10, pages: 5478 - 5484
Publisher: IEEE
 
» A Parametric Model Approach for Structural Reconstruction of Scale-Free Networks
Abstract:
We propose a parametric network generation model which we call network reconstruction model (NRM) for structural reconstruction of scale-free real networks with power-law exponent greater than 2 in the tail of its degree distribution. The reconstruction method for a real network is concerned with finding the optimal values of the model parameters by utilizing the power-law exponents of model network and the real network. The method is validated for certain real world networks. The usefulness of NRM in order to solve structural reconstruction problem is demonstrated by comparing its performance with some existing popular network generative models. We show that NRM can generate networks which follow edge-densification and densification power-law when the model parameters satisfy an inequality. Computable expressions of the expected number of triangles and expected diameter are obtained for model networks generated by NRM. Finally, we numerically establish that NRM can generate networks with shrinking diameter and modular structure when specific model parameters are chosen.
Autors: Pradumn Kumar Pandey;Bibhas Adhikari;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Oct 2017, volume: 29, issue:10, pages: 2072 - 2085
Publisher: IEEE
 
» A Participatory Urban Traffic Monitoring System: The Power of Bus Riders
Abstract:
This paper presents a participatory sensing-based urban traffic monitoring system. Different from existing works that heavily rely on intrusive sensing or full cooperation from probe vehicles, our system exploits the power of participatory sensing and crowdsources the traffic sensing tasks to bus riders’ mobile phones. The bus riders are information source providers and, meanwhile, major consumers of the final traffic output. The system takes public buses as dummy probes to detect road traffic conditions, and collects the minimum set of cellular data together with some lightweight sensing hints from the bus riders’ mobile phones. Based on the crowdsourced data from participants, the system recovers the bus travel information and further derives the instant traffic conditions of roads covered by bus routes. The real-world experiments with a prototype implementation demonstrate the feasibility of our system, which achieves accurate and fine-grained traffic estimation with modest sensing and computation overhead at the crowd.
Autors: Zhidan Liu;Shiqi Jiang;Pengfei Zhou;Mo Li;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Oct 2017, volume: 18, issue:10, pages: 2851 - 2864
Publisher: IEEE
 
» A Physical Surface Roughness Model and Its Applications
Abstract:
This paper covers the essential aspects of modeling surface roughness for microwave applications based on underlying physics. After a short summary of the relevant field theoretical fundamentals, surface roughness metrology and commonly used roughness parameters are described. Existing models and their limitations are discussed before the recently proposed Gradient Model is introduced. To this purpose, the modeling approach, the derivation from Maxwell’s equations, model predictions, and their experimental verification are shown. Reasonable choices for effective material parameters reflecting the electromagnetic effects of surface roughness as well as a corresponding surface impedance concept are derived. Both concepts allow for easy application of the Gradient Model with 3-D field solvers or analytical models. The obtained simulation results illustrate roughness impact on loss and phase delay in typical transmission lines. Comparison to measurement results up to 100 GHz shows that the Gradient Model accurately predicts these quantities for rough conductor surfaces. As it is not limited to transmission lines only, it significantly improves the design process for arbitrary microwave applications with 3-D field solvers for this frequency range.
Autors: Gerald Gold;Klaus Helmreich;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2017, volume: 65, issue:10, pages: 3720 - 3732
Publisher: IEEE
 
» A Post-Swirl Maneuvering Propulsor Application to Undersea Vehicles
Abstract:
A method to generate vehicle maneuvering forces from a propulsor alone has been applied to a generic undersea vehicle. Open and ducted post-swirl propulsors were configured with an upstream rotor and downstream stator row. During normal operation, the downstream stator blades are all situated at the same pitch angle and generate a roll moment to counter the torque produced by the rotor. By varying the pitch angles of the stator blade about the circumference, it is possible to generate a mean stator side force that can be used to maneuver the vehicle. In addition, the side force can be increased with increasing thrust producing side forces at very low vehicle velocities enabling low-speed maneuvering capability. The viscous, 3-D Reynolds-averaged Navier–Stokes (RANS) commercial code Fluent was used to predict the vehicle and propulsor component forces as well as the velocity field. Open and ducted geometric configurations were studied and force coefficients computed and compared with currently used control surface forces. Computations predicted that the maneuvering propulsor generated side forces equivalent to those produced by conventional control surfaces with side force coefficients on the order of 0.25 for the open propulsor at the self-propulsion point. This translates to 50% larger forces than can be generated by conventional control surfaces on 21 unmanned undersea vehicles. The ducted configuration produces maximum side force coefficients on the order of 0.15, which is still sufficient for vehicle control. Both configurations produced side forces for the Bollard pull condition indicating low-speed maneuvering capability.
Autors: Stephen A. Huyer;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Oct 2017, volume: 42, issue:4, pages: 770 - 781
Publisher: IEEE
 
» A Power-Packed Issue
Abstract:
Welcome to the power and energy theme issue of IEEE Potentials. The following four articles will address highimpact topics in the world of power systems, written by energy experts from both industry and academia. I hope you enjoy reading them and gain a greater insight into this exciting field.
Autors: Edvina Uzunovic;Juan Carlos Montero Quiros;
Appeared in: IEEE Potentials
Publication date: Oct 2017, volume: 36, issue:5, pages: 6 - 7
Publisher: IEEE
 
» A Preventive Approach for Solving Battery Imbalance Issue by Using a Bidirectional Multiple-Input Ćuk Converter Working in DCVM
Abstract:
State of charge (SoC) imbalance among batteries in a battery energy storage system (BESS) degrades the system performance and may lead to safety issue. A bidirectional multiple-input Ćuk converter for the BESS is proposed to prevent batteries from SoC imbalance issue. Compared to the traditional BESS, the battery balancing and voltage/current regulation subsystems are combined into one. As a result, the overall system complexity is significantly reduced. Moreover, the current flow of each battery is self-adjusted according to its terminal voltage. Therefore, the system does not require sophisticated control algorithm for battery balancing. Moreover, the proposed system has no energy dumping and energy transferring between batteries, which avoids unnecessary energy lose. Due to the nature of multiple-input converter structure, the proposed system can handle certain component failure. The proposed approach of designing the BESS has been investigated through simulation and validated experimentally.
Autors: Jian Qi;Dylan Dah-Chuan Lu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Oct 2017, volume: 64, issue:10, pages: 7780 - 7789
Publisher: IEEE
 
» A Prototype Therapy System for Transcutaneous Application of Boiling Histotripsy
Abstract:
Boiling histotripsy (BH) is a method of focused ultrasound surgery that noninvasively applies millisecond-length pulses with high-amplitude shock fronts to generate liquefied lesions in tissue. Such a technique requires unique outputs compared to a focused ultrasound thermal therapy apparatus, particularly to achieve high in situ pressure levels through intervening tissue. This paper describes the design and characterization of a system capable of producing the necessary pressure to transcutaneously administer BH therapy through clinically relevant overlying tissue paths using pulses with duration up to 10 ms. A high-voltage electronic pulser was constructed to drive a 1-MHz focused ultrasound transducer to produce shock waves with amplitude capable of generating boiling within the pulse duration in tissue. The system output was characterized by numerical modeling with the 3-D Westervelt equation using boundary conditions established by acoustic holography measurements of the source field. Such simulations were found to be in agreement with directly measured focal waveforms. An existing derating method for nonlinear therapeutic fields was used to estimate in situ pressure levels at different tissue depths. The system was tested in ex vivo bovine liver samples to create BH lesions at depths up to 7 cm. Lesions were also created through excised porcine body wall (skin, adipose, and muscle) with 3–5 cm thickness. These results indicate that the system is capable of producing the necessary output for transcutaneous ablation with BH.
Autors: Adam D. Maxwell;Petr V. Yuldashev;Wayne Kreider;Tatiana D. Khokhlova;George R. Schade;Timothy L. Hall;Oleg A. Sapozhnikov;Michael R. Bailey;Vera A. Khokhlova;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Oct 2017, volume: 64, issue:10, pages: 1542 - 1557
Publisher: IEEE
 
» A pyrrhic victory for nuclear power [News]
Abstract:
By late this year or early in 2018, two nuclear reactors could start operating in China-an event that might be a lifesaver for the units' crippled builder and designer, Westinghouse Electric Co., and for the technology they represent. Both Westinghouse and its prized AP1000 reactor design have suffered a series of humbling setbacks this year. The AP1000 is arguably the world's most advanced commercial reactor. It is designed to passively cool itself during an accidental shutdown, theoretically avoiding accidents like those at Ukraine's Chernobyl power plant and Japan's Fukushima Daiichi. And for over a decade, it has been the presumed successor to China's mainstay reactors, which employ a 1970s-era French design.
Autors: Peter Fairley;
Appeared in: IEEE Spectrum
Publication date: Oct 2017, volume: 54, issue:10, pages: 11 - 12
Publisher: IEEE
 
» A Q-Band Low-Profile Dual Circularly Polarized Array Antenna Incorporating Linearly Polarized Substrate Integrated Waveguide-Fed Patch Subarrays
Abstract:
An integrated low-profile dual circularly polarized (dual CP) array antenna operating in the Q-band is proposed in this paper, which is realized by sequentially rotating subarrays comprised linearly polarized (LP) substrate integrated waveguide (SIW)-fed patches. The design methodology and working mechanism of the LP SIW-fed patches is presented first, which is implemented with a two-layer printed circuit board structure where the SIW feeding network is located in the bottom substrate and the patches are on the top substrate. Four subarrays are then arranged according to the requirements of a sequential rotation array for producing CP directive beams. A two-layer SIW feeding network for providing the required amplitude and phase distributions for the four subarrays is designed, which includes two input ports for exciting CP radiation with opposite handedness, respectively. Prototypes of the LP subarray and the integrated dual CP array antenna were fabricated and measured. Good agreement between the simulation and measured results validates the designs. The proposed low-cost and lightweight dual CP antenna owns the advantages of wide useful bandwidth (8.9%), high isolation of more than 19 dB, low profile of less than , and good orthogonal polarization discrimination higher than 25 dB.
Autors: Jun Xu;Wei Hong;Zhi Hao Jiang;Jixin Chen;Hui Zhang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5200 - 5210
Publisher: IEEE
 
» A Q-Slot Monopole for UWB Body-Centric Wireless Communications
Abstract:
This paper presents a novel and simple ultrawideband printed rectangular monopole antenna for body-centric wireless communications. The design is based on etching a Q-slot on a rectangular radiator and is optimized to produce the largest bandwidth in free space and close to the human body. We analyze the design of the proposed antenna and assess its performance in terms of bandwidth, gain, efficiency, and radiation patterns. We also characterize the antenna in the time-domain by calculating its fidelity factor. Our results show that the Q-slot antenna maintains its bandwidth when placed in close contact with the human body, or in contact with breast-mimicking tissue phantoms. The very good agreement between the calculated and measured antenna performances in free space and on body suggests that the antenna is immune to variations in the human tissue and is also robust to fabrication tolerances.
Autors: Bright Yeboah-Akowuah;Panagiotis Kosmas;Yifan Chen;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Oct 2017, volume: 65, issue:10, pages: 5069 - 5075
Publisher: IEEE
 
» A Quasi-Resonant Switched-Capacitor Multilevel Inverter With Self-Voltage Balancing for Single-Phase High-Frequency AC Microgrids
Abstract:
In this paper, a quasi-resonant switched-capacitor (QRSC) multilevel inverter (MLI) is proposed with self-voltage balancing for single-phase high-frequency ac (HFAC) microgrids. It is composed of a QRSC circuit (QRSCC) in the frontend and an H-bridge circuit in the backend. The input voltage is divided averagely by the series-connected capacitors in QRSCC, and any voltage level can be obtained by increasing the capacitor number. The different operational mechanism and the resulting different application make up for the deficiency of the existing switched-capacitor topologies. The capacitors are connected in parallel partially or wholly when discharging to the load, thus the self-voltage balancing is realized without any high-frequency balancing algorithm. In other words, the proposed QRSC MLI is especially adapted for HFAC fields, where fundamental frequency modulation is preferred when considering the switching frequency and the resulting loss. The quasi-resonance technique is utilized to suppress the current spikes that emerge from the instantaneous parallel connection of the series-connected capacitors and the input source, decreasing the capacitance, increasing their lifetimes, and reducing the electromagnetic interference, simultaneously. The circuit analysis, power loss analysis, and comparisons with typical switched-capacitor topologies are presented. To evaluate the superior performances, a nine-level prototype is designed and implemented in both simulation and experiment, whose results confirm the feasibility of the proposed QRSC MLI.
Autors: Jun Zeng;Jialei Wu;Junfeng Liu;Huafang Guo;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Oct 2017, volume: 13, issue:5, pages: 2669 - 2679
Publisher: IEEE
 
» A Randomized Approach to Probabilistic Footprint Estimation of a Space Debris Uncontrolled Reentry
Abstract:
This paper studies the problem of characterizing the region of the airspace that will be occupied by a space debris during an uncontrolled reentry (footprint), with the final goal of supporting the air traffic controllers in their task of guiding aircraft safely from their origin to their destination. Given the various sources of uncertainty affecting the debris dynamics, the reentry process is characterized probabilistically and the problem of determining the footprint is formulated in terms of a chance-constrained optimization program, which is solved via a simulation-based method. When observations of the debris initial position and radar measurements of the aircraft prior to the reentry event are available, nonlinear filtering techniques can be adopted and the posterior probability distribution of the debris position as well as of the wind field affecting the reentry process can be integrated in the chance-constraint formulation so as to obtain an enhanced estimate of the footprint. Simulation results show the efficacy of the approach.
Autors: Alessandro Falsone;Maria Prandini;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Oct 2017, volume: 18, issue:10, pages: 2657 - 2666
Publisher: IEEE
 
» A Resonant ZVZCS DC–DC Converter With Two Uneven Transformers for an MVDC Collection System of Offshore Wind Farms
Abstract:
A resonant zero-voltage and zero-current-switching (ZVZCS) dc-dc converter is proposed in this paper for a medium-voltage dc collection system of offshore wind farms. The resonant converter is composed of two full-bridge cells sharing a bridge leg, two transformers with uneven power ratings and different functions, whose secondary windings are connected in series and a voltage-doubler rectifier. The converter operates in discontinuous current mode and can achieve zero-current switching for four main power switches and rectifier diodes over the whole load range. The two auxiliary switches with small forward current can be turned on with ZVZCS, and turned off with zero-voltage switching. Hence, the switching loss can be reduced and efficiency is improved. The operation principle of the converter is analyzed and design rules of main parameters are presented. The influences of the turn ratios of auxiliary transformer and resonant capacitance on the peak and switching-off currents are discussed in detail. Furthermore, a model is built in PLECS and simulation results are given. A 150-1500 V/2 kW prototype is established and tested to verify the operation principle and design rules.
Autors: Liangcai Shu;Wu Chen;Guangfu Ning;Wu Cao;Jun Mei;Jianfeng Zhao;Chun Liu;Guoqing He;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Oct 2017, volume: 64, issue:10, pages: 7886 - 7895
Publisher: IEEE
 
» A Resource-Limited Hardware Accelerator for Convolutional Neural Networks in Embedded Vision Applications
Abstract:
In this brief, we introduce an architecture for accelerating convolution stages in convolutional neural networks (CNNs) implemented in embedded vision systems. The purpose of the architecture is to exploit the inherent parallelism in CNNs to reduce the required bandwidth, resource usage, and power consumption of highly computationally complex convolution operations as required by real-time embedded applications. We also implement the proposed architecture using fixed-point arithmetic on a ZC706 evaluation board that features a Xilinx Zynq-7000 system on-chip, where the embedded ARM processor with high clocking speed is used as the main controller to increase the flexibility and speed. The proposed architecture runs under a frequency of 150 MHz, which leads to 19.2 Giga multiply accumulation operations per second while consuming less than 10 W in power. This is done using only 391 DSP48 modules, which shows significant utilization improvement compared to the state-of-the-art architectures.
Autors: Shayan Moini;Bijan Alizadeh;Mohammad Emad;Reza Ebrahimpour;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2017, volume: 64, issue:10, pages: 1217 - 1221
Publisher: IEEE
 
» A Review of On-Chip Micro Supercapacitors for Integrated Self-Powering Systems
Abstract:
Miniaturized self-powering systems that integrate both energy harvesters and energy storage units as the power sources are essential to realize maintenance-free wireless sensor networks, implantable medical devices, and active radio frequency identification systems. On-chip micro supercapacitors (MSCs) are promising candidates for energy storage in such systems by providing high power densities, fast charge/discharge rates, and long cycle life. Researchers have been improving the performances, especially energy and power densities, of MSCs in recent years. This paper reviews the fundamental working mechanisms and design considerations of on-chip MSCs with special emphasis on the advantages of 3-D configurations. Typical fabrication methods are summarized, and their effects on the device performance and system integration are analyzed. In particular, the power generation of micro energy harvesters and the power consumption of typical wireless micro systems are surveyed, providing the basic and targeting performance requirements of future MSCs that can be integrated with them. [2017-0069]
Autors: Caiwei Shen;Sixing Xu;Yingxi Xie;Mohan Sanghadasa;Xiaohong Wang;Liwei Lin;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Oct 2017, volume: 26, issue:5, pages: 949 - 965
Publisher: IEEE
 
» A Robust Active Damping Control Strategy for an $LCL$ -Based Grid-Connected DG Unit
Abstract:
The connection of a distributed generation (DG) unit to a weak power system is challenging due to stability issues resulted from dynamic interactions between the DG unit and the grid. An LCL-based DG unit is a particularly challenging case due to the presence of a high resonant peak in its frequency response. This paper proposes a robust control strategy to overcome the stability issues of an LCL-based DG unit connected to a weak grid. The main advantage of the proposed control strategy is that it guarantees stability and satisfactory transient performance against the variations of grid impedance. Moreover, it is able to decouple the d and q channels of the control system, which enables independent regulation of the real and reactive output power of the DG unit. Real-time simulations and experimental tests illustrate the effectiveness of the proposed controller in terms of improved transient performance, robust stability, and satisfactory controller set-point tracking.
Autors: Mahdieh S. Sadabadi;Aboutaleb Haddadi;Houshang Karimi;Alireza Karimi;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Oct 2017, volume: 64, issue:10, pages: 8055 - 8065
Publisher: IEEE
 
» A Robust Detection Method of Control Points for Calibration and Measurement With Defocused Images
Abstract:
This paper presents a detection method of control points for the camera calibration and measurement applications, which is robust to defocus. Our method is based on a ground truth, which we call ridge invariance. That is, the positions of broad-brush lines’ ridge lines are invariant to defocus blur. First, the ridge invariance is deduced in theory. Then, the methods for ridge point’s detection including defocus degree estimation and salience enhancement are deduced. In calibration and measurement experiments, new marks are designed and control points are determined at intersects of the ridge curves. Experiments show that our method can obtain precise calibration and measurement results with images in a large defocus amount range. In the effective defocus amount range, the accuracy of the proposed method almost keeps unchanged to the best values. The proposed method has approximated the same performance as conventional methods at good focus values.
Autors: Wendong Ding;Xilong Liu;De Xu;Dapeng Zhang;Zhengtao Zhang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Oct 2017, volume: 66, issue:10, pages: 2725 - 2735
Publisher: IEEE
 
» A Robust Event-Triggered Approach for Fast Sampled-Data Extremization and Learning
Abstract:
This paper presents a general framework for the analysis and design of a class of model-free, robust, and efficient sampled-data-based algorithms for extremization and learning in continuous-time nonlinear systems that generate response maps with an optimal operational set. In particular, we consider plants described by differential inclusions, interconnected in a sampled-data setting with a robust learning algorithm characterized by a constrained difference inclusion. In contrast to standard sampled-data-based approaches, where the learning dynamics are updated after a fixed sufficiently long sampling time has passed, we design a robust dynamic event-based mechanism that triggers the control action as soon as the rate of change of the output of the plant is sufficiently small. By using this event-based update rule, a significant improvement in the convergence time of the closed-loop system can be achieved. Using the framework of set-valued hybrid dynamical systems, we establish for the closed-loop system the existence of a uniformly asymptotically stable compact set, which, by an appropriate tuning of the control parameters, can be made arbitrarily close to the optimal operational set. Our results generalize existing results for periodic sampled-data extremum seeking, and can be used to solve model-free multivariable smooth/nonsmooth constrained optimization problems, as well as learning problems in game theoretical scenarios.
Autors: Jorge I. Poveda;Andrew R. Teel;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Oct 2017, volume: 62, issue:10, pages: 4949 - 4964
Publisher: IEEE
 
» A Robust Flywheel Energy Storage System Discharge Strategy for Wide Speed Range Operation
Abstract:
Wide speed range operation in discharge mode is essential for ensuring discharge depth and energy storage capacity of a flywheel energy storage system (FESS). However, for a permanent magnet synchronous motor/generator-based FESS, the wide-range speed variation in a short discharge period causes consecutive decreases in ac voltage frequency and amplitude. As a result, operation point shift leads to performance deterioration of the conventional local linearization based dc-link voltage control strategies. This study aims to realize a consistent robust discharge performance within the entire available operation range for FESS. We propose a robust discharge strategy that incorporates the speed variation to the dc-link voltage controller. A speed-dependent extended state observer is designed to realize global linearization and enhance the robustness. A speed adaptive feedback control law is designed to ensure consistent dynamic performance within the entire available operation range. Finally, the discharge strategy is validated at different speeds on a high-speed FESS test bench.
Autors: Xiang Zhang;Jiaqiang Yang;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Oct 2017, volume: 64, issue:10, pages: 7862 - 7873
Publisher: IEEE
 

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