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Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 02-2017 trié par par titre, page: 0
» "Neural tourniquet" zaps a nerve to stop bleeding [News]
Résumé:
A "neural tourniquet" doesn't sound like a thing that should work. Even its inventors admit it. "It's a real leap of faith: 'I know, we'll stimulate a nerve to control bleeding,'" says Chris Czura, a vice president of the Feinstein Institute for Medical Research, near New York City. "When you say this to surgeons, they look at you funny." But in the Feinstein team's 15 years of research, it has gathered ample evidence for this type of bioelectronic medicine, with studies that show neural stimulation can prevent or stop severe hemorrhages in lab animals. Now the researchers are launching a clinical trial in humans to show the world that their strange idea doesn't just work-it can save lives.
Auteurs: Eliza Strickland;
Apparue dans: IEEE Spectrum
Date publication: 02.-2017, volume: 54, issue:2, pages: 9 - 11
Editeur: IEEE
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» $1times$ - to $2times$ -nm perpendicular MTJ Switching at Sub-3-ns Pulses Below $100~mu$ A for High-Performance Embedded STT-MRAM for Sub-20-nm CMOS
Résumé:
Magnetization switching is confirmed for sub-3-ns pulses below 100~\mu text{A} in perpendicular magnetic tunnel junctions (MTJs) down to 16 nm in diameter. The magnetoresistance ratio exceeded 150%, satisfying requirements for fast read conditions. Using sub-30-nm MTJs, write-error rates of up to an order of −6 (10−6) are demonstrated. Read and write current margins, which are important device designs, are sufficiently large to avoid read disturbances. Moreover, 1\times -to- 2\times -nm MTJs have sufficient data retention for level-2 or level-3 cache requirements. Furthermore, the MTJ resistance remains stable after 1012 write events. To the best of our knowledge, this is the first demonstration of 1\times - to 2\times -nm MTJs supporting cache memory along with read–write current margins, fast read operations, low power consumption, sufficient retention, and high endurance.
Auteurs: Daisuke Saida;Saori Kashiwada;Megumi Yakabe;Tadaomi Daibou;Miyoshi Fukumoto;Shinji Miwa;Yoshishige Suzuki;Keiko Abe;Hiroki Noguchi;Junichi Ito;Shinobu Fujita;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2017, volume: 64, issue:2, pages: 427 - 431
Editeur: IEEE
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» $2times2$ Phased Array Consisting of Square Loop Antennas for High Gain Wide Angle Scanning With Low Grating Lobes
Résumé:
A $2times2$ array antenna comprised of conventional hybrid high impedance surface-based reconfigurable square loop antennas (SLAs) as elements is presented. The SLA element has four conducting arms and each arm is fed at the middle by vertical probes, which is connected to a $50~Omega $ port at the bottom of antenna ground plane. Thus, the SLA element has four feeding ports and it is capable of generating five distinct radiation patterns by using a combination of its feeding ports. Depending upon which of its four ports are excited it can provide four high gain off-boresight tilted beams (8.9 dBi at $theta _{max}= 36^{circ }$ ) in four different quadrants of the space (tilted beam mode). When all the four ports are simultaneously excited with phases of 0°, 0°, 180°, and 180°, it provides an axial beam (6.5 dBi) at boresight (axial beam mode). By combining these two modes the $2 times 2$ array of SLAs can provide a scanning range of −60° to +60° in the elevation plane with high-gain beams (14–11.2 dBi).
Auteurs: Arpan Pal;Amit Mehta;Dariush Mirshekar-Syahkal;Hisamatsu Nakano;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2017, volume: 65, issue:2, pages: 576 - 583
Editeur: IEEE
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» $L_0$ -Regularized Intensity and Gradient Prior for Deblurring Text Images and Beyond
Résumé:
We propose a simple yet effective L_0 -regularized prior based on intensity and gradient for text image deblurring. The proposed image prior is based on distinctive properties of text images, with which we develop an efficient optimization algorithm to generate reliable intermediate results for kernel estimation. The proposed algorithm does not require any heuristic edge selection methods, which are critical to the state-of-the-art edge-based deblurring methods. We discuss the relationship with other edge-based deblurring methods and present how to select salient edges more principally. For the final latent image restoration step, we present an effective method to remove artifacts for better deblurred results. We show the proposed algorithm can be extended to deblur natural images with complex scenes and low illumination, as well as non-uniform deblurring. Experimental results demonstrate that the proposed algorithm performs favorably against the state-of-the-art image deblurring methods.
Auteurs: Jinshan Pan;Zhe Hu;Zhixun Su;Ming-Hsuan Yang;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 02.-2017, volume: 39, issue:2, pages: 342 - 355
Editeur: IEEE
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» $mathsf {pSCAN}$ : Fast and Exact Structural Graph Clustering
Résumé:
We study the problem of structural graph clustering, a fundamental problem in managing and analyzing graph data. Given an undirected unweighted graph, structural graph clustering is to assign vertices to clusters, and to identify the sets of hub vertices and outlier vertices as well, such that vertices in the same cluster are densely connected to each other while vertices in different clusters are loosely connected. In this paper, we develop a new two-step paradigm for scalable structural graph clustering based on our three observations. Then, we present a $mathsf {pSCAN}$ approach, within the paradigm, aiming to reduce the number of structural similarity computations, and propose optimization techniques to speed up checking whether two vertices are structure-similar. $mathsf {pSCAN}$ outputs exactly the same clusters as the existing approaches $mathsf {SCAN}$ and $mathsf {SCANtext{++}}$ , and we prove that $mathsf {pSCAN}$ is worst-case optimal. Moreover, we propose efficient techniques for updating the clusters when the input graph dynamically changes, and we also extend our techniques to other similarity measures, e.g., Jaccard similarity. Performance studies on large real and synthetic graphs demonst- ate the efficiency of our new approach and our dynamic cluster maintenance techniques. Noticeably, for the twitter graph with 1 billion edges, our approach takes 25 minutes while the state-of-the-art approach cannot finish even after 24 hours.
Auteurs: Lijun Chang;Wei Li;Lu Qin;Wenjie Zhang;Shiyu Yang;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 02.-2017, volume: 29, issue:2, pages: 387 - 401
Editeur: IEEE
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» $S$ -Band Relativistic Magnetron Operation With Multichannel Radial Outputs of the Microwave Power
Résumé:
The results of an experimental study of the S-band magnetron operation with a six-vane anode block and multichannel radial outputs for microwave power extraction are presented. The magnetron was driven by a linear induction accelerator (~350 kV, ~2.5 kA, and 150 ns). In the case of three outputs for microwave power extraction and another three outputs connected to waveguides short circuited by movable plungers for adjusting the magnetron resonance, frequency-stable generation of the microwaves radiation with a total power of 570 MW from these three outputs was demonstrated. This power was equal to the power obtained when the same magnetron with one output was operated with high efficiency ( $geq 40$ %). In addition, it was shown that the distribution of the generated microwave power between the three outputs allows wedge insulators to be used in the waveguides vacuum–air interface without electrical breakdown. Finally, microwave radiation, extracted in free space by a cluster of horn antennas connected at the output of the waveguides, was coherently added to each other at the desired distance with a three times larger microwave power density than in the case of 570-MW single output magnetron operation.
Auteurs: Arkady Sayapin;Uri Dai;Yakov E. Krasik;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 02.-2017, volume: 45, issue:2, pages: 229 - 234
Editeur: IEEE
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» –Omic and Electronic Health Record Big Data Analytics for Precision Medicine
Résumé:
Objective: Rapid advances of high-throughput technologies and wide adoption of electronic health records (EHRs) have led to fast accumulation of –omic and EHR data. These voluminous complex data contain abundant information for precision medicine, and big data analytics can extract such knowledge to improve the quality of healthcare. Methods: In this paper, we present –omic and EHR data characteristics, associated challenges, and data analytics including data preprocessing, mining, and modeling. Results: To demonstrate how big data analytics enables precision medicine, we provide two case studies, including identifying disease biomarkers from multi-omic data and incorporating –omic information into EHR. Conclusion: Big data analytics is able to address –omic and EHR data challenges for paradigm shift toward precision medicine. Significance: Big data analytics makes sense of –omic and EHR data to improve healthcare outcome. It has long lasting societal impact.
Auteurs: Po-Yen Wu;Chih-Wen Cheng;Chanchala D. Kaddi;Janani Venugopalan;Ryan Hoffman;May D. Wang;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 02.-2017, volume: 64, issue:2, pages: 263 - 273
Editeur: IEEE
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» (Digitally) Inking in the 21st Century
Résumé:
The ubiquity and mobility of contemporary computing devices has enabled users to consume content, anytime, anywhere. Yet, when we need to create content, touch input is far from perfect. When coupled with touch input, the stylus should enable users to simultaneously ink, manipulate the page, and switch between tools with ease, so why has the stylus yet to achieve universal adoption? Michelle Annett's thesis sought to understand the usability barriers and tensions that have prevented stylus input from gaining traction and reaching widespread adoption. This article in particular explores the limits of human latency perception and evaluates solutions to unintended touch.
Auteurs: Michelle Annett;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 02.-2017, volume: 37, issue:1, pages: 92 - 99
Editeur: IEEE
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» 1/f-Noise in AlGaN/GaN Nanowire Omega-FinFETs
Résumé:
The low-frequency noise (LFN) characteristics of AlGaN/GaN FinFETs with omega-gate and combined two-dimensional electron gas (2DEG) and MOS conduction are investigated. It is found that LFN is dominated by carrier number fluctuations whatever the width of the fin. Charge trapping in narrow devices is one order of magnitude lower than in wide fin device. In narrow devices, the sidewall conduction prevails and the noise mainly stems from the carrier trapping in the sidewall Al2O3 gate dielectric. Instead, in wide fin devices, the top gate AlGaN/GaN HEMT structure dominates and the LFN is mostly governed by the carrier trapping in the GaN layer close to 2DEG channel.
Auteurs: Sindhuri Vodapally;Young In Jang;In Man Kang;In-Tak Cho;Jong-Ho Lee;Youngho Bae;Gérard Ghibaudo;Sorin Cristoloveanu;Ki-Sik Im;Jung-Hee Lee;
Apparue dans: IEEE Electron Device Letters
Date publication: 02.-2017, volume: 38, issue:2, pages: 252 - 254
Editeur: IEEE
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» 18-MHz Silicon Lamé Mode Resonators With Corner and Central Anchor Architectures in a Dual-Wafer SOI Technology
Résumé:
This paper presents Lamé bulk mode square resonators fabricated in a novel silicon-on-insulator technology, MicraGEM-Si. Structures are formed by patterning two wafers with several etched depths and wafer bonding them to create the released movable resonator structures. Two distinct anchoring architectures are studied: one with suspension beams at the nodal corner points, and the other with a central anchoring support. The center support architecture can be suitable for realizing high-performance gyroscopes. Resonators with different support sizes are fabricated and characterized. Fabricated devices were measured to operate at a resonance frequency of ~18 MHz and quality factors as high as ~42 000 in atmospheric pressure, which to the best of our knowledge is the highest reported to date at such an ambient pressure, and ~871 000 in 100-mtorr vacuum, corresponding to a $text{f}cdot text{Q}$ product of $sim 1.6times 10^{13}$ . [2016-0112]
Auteurs: Mohannad Y. Elsayed;Frederic Nabki;
Apparue dans: Journal of Microelectromechanical Systems
Date publication: 02.-2017, volume: 26, issue:1, pages: 67 - 74
Editeur: IEEE
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» 2016 IEEE Education Society Awards, 2016 Frontiers in Education Conference Awards, and Selected IEEE Awards
Résumé:
The IEEE Education Society, the IEEE Computer Society, and the American Society for Engineering Education Educational Research and Methods Division (ASEE ERM) sponsored the 46th Frontiers in Education (FIE) Conference in Erie, PA, USA, held October 12–15, 2016. James Sluss, President of the Society, Russell Meier, President of the ASEE ECE Division, and Elizabeth Eschenbach, Chair, FIE Steering Committee, presented awards sponsored by HP Enterprise, the FIE Conference, the Education Society of IEEE, and the ECE Division of ASEE to the 2016 recipients of these awards.
Auteurs: Edwin C. Jones;Kathleen E. Wage;Sanjit A. Seshia;Susan M. Lord;Michael E. Auer;Lance C. Pérez;Katherine Shu-Min Li;S. L. Krishna Priya;Sasha Nikolic;Francisco J. Arcega;Richard A. Layton;Matthew W. Ohland;Kayode P. Ayodele;Isaac A. Inyang;Lawr
Apparue dans: IEEE Transactions on Education
Date publication: 02.-2017, volume: 60, issue:1, pages: 67 - 77
Editeur: IEEE
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» 2016 IEEE Educational Activities Board Awards
Résumé:
The 2016 IEEE Educational Activities Board (EAB), chaired by IEEE Educational Activities Vice President S. K. Ramesh, upon the recommendation of the EAB Awards and Recognition Committee (ARC) has named the recipients of the 2016 IEEE EAB Awards. EAB Awards recognize and honor individuals and companies for major contributions to engineering and technical education. Awards are given for meritorious activities in accreditation, continuing education, educational innovation, preuniversity education, service to the IEEE EAB, standards education, employee professional development, and informal education systems, as well as related achievements that advance the practice of engineering and engineering education.
Auteurs: Karen A. Panetta;R. Joe Stanley;Salvatore Campione;David L. Soldan;Shi Bu;David Michael Ritter;Matthew W. Ohland;Nafeesa Mazhar;Walter W. Buchanan;Scottie Austin Wilson;Tushar Sharma;Bozenna Pasik-Duncan;Moshe Kam;George A. Bekey;
Apparue dans: IEEE Transactions on Education
Date publication: 02.-2017, volume: 60, issue:1, pages: 78 - 86
Editeur: IEEE
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» 2016 MTT-S Awards [Awards]
Résumé:
Presents the recipients of various MTTS society awards.
Auteurs: Charlie Jackson;
Apparue dans: IEEE Microwave Magazine
Date publication: 02.-2017, volume: 18, issue:1, pages: 114 - 131
Editeur: IEEE
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» 3-D Analytical Modeling of Dual-Material Triple-Gate Silicon-on-Nothing MOSFET
Résumé:
A 3-D analytical model of a new structure, namely, dual-material triple-gate silicon-on-nothing MOSFET is proposed in this paper. 3-D Poisson’s equation with proper boundary conditions was solved to obtain the surface potential variation of the structure considering the popular parabolic potential approximation, and the threshold voltage and electric field were calculated for the model. The proposed model’s immunity to the various short-channel effects, such as threshold voltage roll-off, Drain-Induced Barrier Lowering (DIBL), and subthreshold swing, are also examined, and the impact of the various device parameters on the performance of the device is studied. The 3-D simulated results obtained using ATLAS, a device simulator from Silvaco, validate the analytical results obtained for this structure.
Auteurs: Pritha Banerjee;Subir Kumar Sarkar;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2017, volume: 64, issue:2, pages: 368 - 375
Editeur: IEEE
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» 3-D Displacement Measurement for Structural Health Monitoring Using Low-Frequency Magnetic Fields
Résumé:
Smart structures of the future will require a cost-effective, easily deployable solution for structural health monitoring. High loads on structures cause stresses that may lead to expansion of gaps, which are of utmost importance when it comes to overall structural health, as they absorb excess stress. Existing methods for direct displacement measurement of expansion joints are not ideal, as they operate under line-of-sight assumptions, are sensitive to moisture, or employ moving parts. In addition, the majority of existing sensors for structural health monitoring are uniaxial, and hence are fundamentally unable to measure 3-D displacement. Importantly, none of the existing wireless sensors for structural health monitoring can be embedded in concrete. We propose a system that uses low-frequency magnetic fields to conduct 3-D displacement measurement directly from within concrete, with a median displacement error of 0.5 mm in all directions, with a maximum separation distance of 50 mm between the transmitter and the receiver. The sensors can be attached to the concrete surface after the building is erected, or can be included in the concrete mix at manufacture, to monitor displacement between gaps in expansion joints, perform crack detection in concrete ties for railroads and in pavements, as well as aid position measurement for the assembly of premanufactured concrete blocks. Embedment in concrete allows operation throughout the lifetime of a structure, providing early warning of impending disaster and helping to inform repair operations.
Auteurs: Orfeas Kypris;Andrew Markham;
Apparue dans: IEEE Sensors Journal
Date publication: 02.-2017, volume: 17, issue:4, pages: 1165 - 1174
Editeur: IEEE
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» 3-Gb/s High-Speed True Random Number Generator Using Common-Mode Operating Comparator and Sampling Uncertainty of D Flip-Flop
Résumé:
True random number generators (TRNGs) are important in data encryption for information security applications. In this paper, we propose a TRNG that utilizes a comparator in the common-mode operation and the sampling uncertainty of a D flip-flop (DFF). The comparator output is affected by the input common-mode noise and the noise that is simultaneously self-induced. A slicer generates an unpredictable and asynchronous pulse to the input of the DFF according to the output-referred noise of the comparator. By sampling the random pulse with a 3-GHz external clock, there is a sampling uncertainty, which helps to increase the random quality. As a result, we use the independent two random sources for TRNG. The area of the designed circuit is 1609 $mu text{m}^{mathrm { {2}}}$ . In spite of the small size, the data rate of the proposed TRNG is 3 Gb/s. We verify that the output bit stream passes all of the National Institute of Standards and Technology test suites. We fabricate the TRNG in a 65-nm CMOS process with a 1.2 V supply voltage. The power consumption of the proposed TRNG is 5 mW, and the energy per bit is 1.6 pJ/b.
Auteurs: Sang-Geun Bae;Yongtae Kim;Yunsoo Park;Chulwoo Kim;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 605 - 610
Editeur: IEEE
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» 3D Myocardial Elastography In Vivo
Résumé:
Strain evaluation is of major interest in clinical cardiology as it can quantify the cardiac function. Myocardial elastography, a radio-frequency (RF)-based cross-correlation method, has been developed to evaluate the local strain distribution in the heart in vivo. However, inhomogeneities such as RF ablation lesions or infarction require a three-dimensional approach to be measured accurately. In addition, acquisitions at high volume rate are essential to evaluate the cardiac strain in three dimensions. Conventional focused transmit schemes using 2D matrix arrays, trade off sufficient volume rate for beam density or sector size to image rapid moving structure such as the heart, which lowers accuracy and precision in the strain estimation. In this study, we developed 3D myocardial elastography at high volume rates using diverging wave transmits to evaluate the local axial strain distribution in three dimensions in three open-chest canines before and after radio-frequency ablation. Acquisitions were performed with a 2.5 MHz 2D matrix array fully programmable used to emit 2000 diverging waves at 2000 volumes/s. Incremental displacements and strains enabled the visualization of rapid events during the QRS complex along with the different phases of the cardiac cycle in entire volumes. Cumulative displacement and strain volumes depict high contrast between non-ablated and ablated myocardium at the lesion location, mapping the tissue coagulation. 3D myocardial strain elastography could thus become an important technique to measure the regional strain distribution in three dimensions in humans.
Auteurs: Clement Papadacci;Ethan A. Bunting;Elaine Y. Wan;Pierre Nauleau;Elisa E. Konofagou;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2017, volume: 36, issue:2, pages: 618 - 627
Editeur: IEEE
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» 3D Quasi-Static Ultrasound Elastography With Plane Wave In Vivo
Résumé:
In biological tissue, an increase in elasticity is often a marker of abnormalities. Techniques such as quasi-static ultrasound elastography have been developed to assess the strain distribution in soft tissues in two dimensions using a quasi-static compression. However, as abnormalities can exhibit very heterogeneous shapes, a three dimensional approach would be necessary to accurately measure their volume and remove operator dependency. Acquisition of volumes at high rates is also critical to performing real-time imaging with a simple freehand compression. In this study, we developed for the first time a 3D quasi-static ultrasound elastography method with plane waves that estimates axial strain distribution in vivo in entire volumes at high volume rate. Acquisitions were performed with a 2D matrix array probe of 2.5 MHz frequency and 256 elements. Plane waves were emitted at a volume rate of 100 volumes/s during a continuous motorized and freehand compression. 3D B-mode volumes and 3D cumulative axial strain volumes were successfully estimated in inclusion phantoms and in ex vivo canine liver before and after a high intensity focused ultrasound ablation. We also demonstrated the in vivo feasibility of the method using freehand compression on the calf muscle of a human volunteer and were able to retrieve 3D axial strain volume at a high volume rate depicting the differences in stiffness of the two muscles which compose the calf muscle. 3D ultrasound quasi-static elastography with plane waves could become an important technique for the imaging of the elasticity in human bodies in three dimensions using simple freehand scanning.
Auteurs: Clement Papadacci;Ethan A. Bunting;Elisa E. Konofagou;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2017, volume: 36, issue:2, pages: 357 - 365
Editeur: IEEE
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» 4 New ways to store renewable energy with water [News]
Résumé:
If Elon Musk has his way, in the future we'll all be storing renewable electricity inside big banks of lithium-ion batteries. But let's not forget the energy storage situation today. In the United States, 97 percent of utility-scale storage in 2014 was in pumped-storage hydroelectric plants, according to research by Oak Ridge National Laboratory, in Tennessee.
Auteurs: Andrew Silver;
Apparue dans: IEEE Spectrum
Date publication: 02.-2017, volume: 54, issue:2, pages: 13 - 15
Editeur: IEEE
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» 4H-SiC Trench IGBT With Back-Side n-p-n Collector for Low Turn-OFF Loss
Résumé:
In this paper, an n-p-n collector incorporated in the back side of a 4H-SiC trench IGBT is presented to reduce the turn-off energy loss. A comparative study between the proposed structure and the conventional structure is conducted through ATLAS. The simulation results have demonstrated that the turn-off energy loss is reduced by more than 82.96% with a slight degradation in the on-state voltage drop.
Auteurs: Yan-Juan Liu;Ying Wang;Yue Hao;Cheng-Hao Yu;Fei Cao;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2017, volume: 64, issue:2, pages: 488 - 493
Editeur: IEEE
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» \Sigma \Delta Effects and Charge Locking in Capacitive MEMS Under Dielectric Charge Control
Résumé:
This work investigates, analytically and experimentally, the effects induced by the use of a first-order sigma-delta ($SigmaDelta$) feedback loop as a control method of dielectric charging for capacitive microelectromechanical systems (MEMS). This technique allows setting of a desired level of net charge in the dielectric of a MEMS device by continuously alternating the polarity of the actuation voltage. This control system displays a number of interesting effects, inherited from $SigmaDelta$ modulation and not usually found in conventional MEMS applications, with the charge-locking phenomenon being the most relevant. The convergence time and the effectiveness of the control method are also investigated and discussed.
Auteurs: Panagiotis Giounanlis;Sergi Gorreta;Manuel Dominguez-Pumar;Joan Pons-Nin;Orla Feely;Elena Blokhina;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 206 - 210
Editeur: IEEE
Document complet vers site de l'éditeur
 
» \Sigma \Delta Effects and Charge Locking in Capacitive MEMS Under Dielectric Charge Control
Résumé:
This work investigates, analytically and experimentally, the effects induced by the use of a first-order sigma-delta ( \Sigma \Delta ) feedback loop as a control method of dielectric charging for capacitive microelectromechanical systems (MEMS). This technique allows setting of a desired level of net charge in the dielectric of a MEMS device by continuously alternating the polarity of the actuation voltage. This control system displays a number of interesting effects, inherited from \Sigma \Delta modulation and not usually found in conventional MEMS applications, with the charge-locking phenomenon being the most relevant. The convergence time and the effectiveness of the control method are also investigated and discussed.
Auteurs: Panagiotis Giounanlis;Sergi Gorreta;Manuel Dominguez-Pumar;Joan Pons-Nin;Orla Feely;Elena Blokhina;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 206 - 210
Editeur: IEEE
Document complet vers site de l'éditeur
 
» \Sigma \Delta Effects and Charge Locking in Capacitive MEMS Under Dielectric Charge Control
Résumé:
This work investigates, analytically and experimentally, the effects induced by the use of a first-order sigma-delta ( \Sigma \Delta ) feedback loop as a control method of dielectric charging for capacitive microelectromechanical systems (MEMS). This technique allows setting of a desired level of net charge in the dielectric of a MEMS device by continuously alternating the polarity of the actuation voltage. This control system displays a number of interesting effects, inherited from \Sigma \Delta modulation and not usually found in conventional MEMS applications, with the charge-locking phenomenon being the most relevant. The convergence time and the effectiveness of the control method are also investigated and discussed.
Auteurs: Panagiotis Giounanlis;Sergi Gorreta;Manuel Dominguez-Pumar;Joan Pons-Nin;Orla Feely;Elena Blokhina;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 206 - 210
Editeur: IEEE
Document complet vers site de l'éditeur
 
» $SigmaDelta$ Effects and Charge Locking in Capacitive MEMS Under Dielectric Charge Control
Résumé:
This work investigates, analytically and experimentally, the effects induced by the use of a first-order sigma-delta ($SigmaDelta$) feedback loop as a control method of dielectric charging for capacitive microelectromechanical systems (MEMS). This technique allows setting of a desired level of net charge in the dielectric of a MEMS device by continuously alternating the polarity of the actuation voltage. This control system displays a number of interesting effects, inherited from $SigmaDelta$ modulation and not usually found in conventional MEMS applications, with the charge-locking phenomenon being the most relevant. The convergence time and the effectiveness of the control method are also investigated and discussed.
Auteurs: Panagiotis Giounanlis;Sergi Gorreta;Manuel Dominguez-Pumar;Joan Pons-Nin;Orla Feely;Elena Blokhina;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 206 - 210
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 0.26-nJ/node, 400-kHz Tx Driving, Filtered Fully Differential Readout IC With Parasitic RC Time Delay Reduction Technique for 65-in $169 times 97$ Capacitive-Type Touch Screen Panel
Résumé:
This paper presents a readout method and circuit for large, capacitive-type touch-screen panels (TSPs). Despite the considerable amount of RC time delay of large-area TSPs, the proposed readout method with a receiver (Rx) input series-capacitor improves the settling speed of signals transferred from the transmitter (Tx) to the Rx, by reducing the RC time delay. Combined with the Rx input series-capacitor, a capacitive-input fully differential filtered charge integrator effectively cancels out the display noise and reduces the self-noise in capacitive-type TSPs. The proposed Rx circuit was implemented using 0.35- $mu text{m}$ CMOS. Using a 65-in metal-mesh TSP with 169 Tx and 97 Rx electrodes mounted on a liquid-crystal display for testing, the proposed readout method achieved 65% reduction of signal settling time within an accuracy of $geq 3tau $ for the longest signal path of the TSP. Using the RC time delay reduction technique, the Tx driving frequency could be boosted by as much as 400 kHz, and the measured signal-to-noise ratio of 43.5 dB was obtained for finger touch at a 120-Hz scan rate, resulting in a figure-of-merit of 0.26 nJ/node, while the overall power consumption was 76 mW.
Auteurs: Sang-Hui Park;Hyun-Sik Kim;Jun-Suk Bang;Gyu-Ha Cho;Gyu-Hyeong Cho;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 528 - 542
Editeur: IEEE
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» A 0.4 $mu text{g}$ Bias Instability and 1.2 $mu text{g}/surd $ Hz Noise Floor MEMS Silicon Oscillating Accelerometer With CMOS Readout Circuit
Résumé:
This paper describes a silicon-on-insulator MEMS oscillating accelerometer with a fully differential CMOS continuous-time oscillation sustaining circuit and a digital frequency measurement circuit. To reduce the amplitude-stiffness-induced frequency variation, the effects of flicker noise in the automatic amplitude control circuit are classified into additive and multiplicative components, which are suppressed by chopper stabilization and tail current source free structures, respectively. A low-power digital frequency measurement circuit employing a time-domain $Sigma Delta $ ADC is integrated on chip. The accelerometer achieves a bias instability of 0.4/2 $mu text{g}$ , a bias stability of 4.13/13.2 $mu text{g}$ , and a noise floor of 1.2/2.6 $mu text{g} / surd $ Hz, as measured from the analog/digital outputs, respectively, with a scale factor of 280 Hz/g and a full scale of ±20 g. The chip is fabricated in 0.35 $mu text{m}$ standard CMOS technology, and consumes 4.37 mW under a 1.5 V supply.
Auteurs: Xi Wang;Jian Zhao;Yang Zhao;Guo Ming Xia;An Ping Qiu;Yan Su;Yong Ping Xu;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 472 - 482
Editeur: IEEE
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» A 0.92-THz SiGe Power Radiator Based on a Nonlinear Theory for Harmonic Generation
Résumé:
We propose a nonlinear device model and a systematic methodology to generate maximum power at any desired harmonic. The proposed power optimization technique is based on the Volterra-Wiener theory of nonlinear systems. By manipulating the device nonlinearity and optimizing the embedding network, optimum conditions for harmonic power generation are provided. Using this theory, a 920–944-GHz frequency quadrupler is designed in a 130-nm SiGe:C process. The circuit achieves the peak output power of −17.3 and −10 dBm of effective isotropic radiated power and consumes 5.7 mW of dc power. To the best of our knowledge, this circuit demonstrates the highest generated power among Si/SiGe-based sources at this frequency range.
Auteurs: Hamidreza Aghasi;Andreia Cathelin;Ehsan Afshari;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 406 - 422
Editeur: IEEE
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» A 1 MHz BW 34.2 fJ/step Continuous Time Delta Sigma Modulator With an Integrated Mixer for Cardiac Ultrasound
Résumé:
Fully digitized 2D ultrasound transducer arrays require one ADC per channel with a beamforming architecture consuming low power. We give design considerations for per-channel digitization and beamforming, and present the design and measurements of a continuous time delta-sigma modulator (CTDSM) for cardiac ultrasound applications. By integrating a mixer into the modulator frontend, the phase and frequency of the input signal can be shifted, thereby enabling both improved conversion efficiency and narrowband beamforming. To minimize the power consumption, we propose an optimization methodology using a simulated annealing framework combined with a C++ simulator solving linear electrical networks. The 3rd order single-bit feedback type modulator, implemented in a 65 nm CMOS process, achieves an SNR/SNDR of 67.8/67.4 dB across 1 MHz bandwidth consuming 131 $mutext{W}$ of power. The achieved figure of merit of 34.2 fJ/step is comparable with state-of-the-art feedforward type multi-bit designs. We further demonstrate the influence to the dynamic range when performing dynamic receive beamforming on recorded delta-sigma modulated bit-stream sequences.
Auteurs: Rune Kaald;Trym Eggen;Trond Ytterdal;
Apparue dans: IEEE Transactions on Biomedical Circuits and Systems
Date publication: 02.-2017, volume: 11, issue:1, pages: 234 - 243
Editeur: IEEE
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» A 1-to-2048 Fully-Integrated Cascaded Digital Frequency Synthesizer for Low Frequency Reference Clocks Using Scrambling TDC
Résumé:
Generation of low jitter, high frequency clock from a low frequency reference clock using classical analog phase-locked loops (PLLs) requires large loop filter capacitor and power hungry oscillator. Digital PLLs can help reduce area but their jitter performance is severely degraded by quantization error. Specifically, their deterministic jitter (DJ), which is proportional to the loop update rate becomes prohibitively large at low reference clock frequencies. We propose a scrambling TDC (STDC) to improve DJ performance and a cascaded architecture with digital multiplying delay locked loop as the first stage and hybrid analog/digital PLL as the second stage to achieve low random jitter in a power efficient manner. Fabricated in a 90 nm CMOS process, the prototype frequency synthesizer consumes 4.76 mW power from a 1.0 V supply and generates 160 MHz and 2.56 GHz output clocks from a 1.25 MHz crystal reference frequency. The long-term absolute jitter of the 160 MHz digital MDLL and 2.56 GHz digital PLL outputs are 2.4 $rm{{ps}_{rms}}$ and 4.18 $rm{{ps}_{rms}}$ , while the peak-to-peak jitter are 22.1 ps and 35.2 ps, respectively. The proposed frequency synthesizer occupies an active die area of 0.16mm2 and achieves power efficiency of 1.86 mW/GHz.
Auteurs: Romesh Kumar Nandwana;Saurabh Saxena;Amr Elshazly;Kartikeya Mayaram;Pavan Kumar Hanumolu;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2017, volume: 64, issue:2, pages: 283 - 295
Editeur: IEEE
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» A 1.2V-to-0.4V 3.2GHz-to-14.3MHz Power-Efficient 3-Port Register File in 65-nm CMOS
Résumé:
This paper presents a 44.2-mW 3.2-GHz 3-port register file (RF) that demonstrates measured operation from 1.2 V down to 0.4 V. The 32-entry $times ,32$ -bit/word 2-read/1-write RF is fabricated in TSMC 65-nm low-power low threshold voltage (low- $text {V}_{mathrm {t}}$ ) CMOS process. A four-transistor read port is presented that permits the design of low-capacitance dynamic local bitlines (LBLs). Switching power in the LBLs and the LBL precharge buffer is thereby reduced. Based on extensive simulation results, the proposed read port is recommended for use in wide-worded RFs, which employ a wide dynamic-OR structure at the LBL stage. The proposed RF outperforms the conventional design in terms of power consumption for frequencies exceeding 3-GHz. The read port exploits intrinsic capacitive coupling to achieve robust operation over a wide voltage range. The architecture of the read port simultaneously enhances robustness of the dynamic bitline by 58.8% as compared to the conventional low- $text {V}_{mathrm {t}}$ bitline.
Auteurs: Khawar Sarfraz;Mansun Chan;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2017, volume: 64, issue:2, pages: 360 - 372
Editeur: IEEE
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» A 100 MHz Hybrid Supply Modulator With Ripple-Current-Based PWM Control
Résumé:
This paper presents a 100 MHz hybrid supply modulator (HSM) with ripple-current-based pulse width modulation (PWM) control. By sensing the ripple current, a ripple current sensor (RCS) is able to overcome the bandwidth limitation of an absolute current sensor. By leveraging the RCS, we propose a large-signal PWM control method for HSMs. This method has an intrinsically fast switching loop, and thus eliminates the need for the feed-forward path used in many previous designs. The possibility of generating high-order harmonics in PWM-controlled HSMs is pointed out for the first time, and design recommendations to avoid them are presented. A very-high-frequency triangular wave generator that is robust to both process-voltage-temperature (PVT) variations and device mismatches is proposed. A proof-of-concept prototype was fabricated in CMOS 130 nm technology. Switching at 100 MHz, this HSM is able to track a 0.8 $V_{mathrm {mathbf {pp}}}$ sinusoidal waveform up to 13 MHz with high fidelity. It achieves a peak efficiency of 88.2% at the maximum output power of 23 dBm. To the best of our knowledge, this is the first PWM-controlled HSM that is able to operate at 100 MHz.
Auteurs: Min Tan;Wing-Hung Ki;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 569 - 578
Editeur: IEEE
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» A 100-mA, 99.11% Current Efficiency, 2-mVpp Ripple Digitally Controlled LDO With Active Ripple Suppression
Résumé:
Digital low-dropout (DLDO) regulators are gaining attention due to their design scalability for distributed multiple voltage domain applications required in state-of-the-art system-on-chips. Due to the discrete nature of the output current and the discrete-time control loop, the steady-state response of the DLDO has inherent output voltage ripple. A hybrid DLDO (HD-LDO) with fast response and stable operation across a wide load range while reducing the output voltage ripple is proposed. In the HD-LDO, a DLDO and a low current analog ripple cancelation amplifier (RCA) work in parallel. The output dc of the RCA is sensed by a 2-bit analog-to-digital converter, and the digitized linear stage current is fed into the DLDO as an error signal. During load transients, a gear-shift controller enables fast transient response using dynamic load estimation. The DLDO suppresses the output dc of the RCA within its current resolution. With this arrangement, a majority of the dc load current is provided by the DLDO and the RCA supplies ripple cancelation current. The HD-LDO is designed and fabricated in a 180-nm CMOS technology, and occupies 0.697 mm2 of the die area. The HD-LDO operates with an input voltage range of 1.43–2.0 V and an output voltage range of 1.0–1.57 V. At 100-mA load current, the HD-LDO achieves a current peak efficiency of 99.11% and a settling time of 15 clock periods with a 0.5-MHz clock for a current switching between 10 and 90 mA. The RCA suppresses fundamental, second, and third harmonics of the switching frequency by 13.7, 13.3, and 14.1 dB, respectively.
Auteurs: Michael Cheah;Debashis Mandal;Bertan Bakkaloglu;Sayfe Kiaei;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 02.-2017, volume: 25, issue:2, pages: 696 - 704
Editeur: IEEE
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» A 1000 frames/s Vision Chip Using Scalable Pixel-Neighborhood-Level Parallel Processing
Résumé:
This paper presents a novel vision chip architecture based on pixel-neighborhood-level parallel processing. In the architecture, an 8-b RISC processing core is embedded in an $8times 8$ array of digital pixel sensors on the same focal plane. These neighborhood processors (NPs) are tiled in a 2-D array to form the final imager resolution. Program execution is carried out in parallel across the array of pixel-neighborhood processing cores, allowing for direct scalability in terms of resolution, without reduction in processing speed or frame rate. To accomplish this, a compact, low-complexity NP architecture along with a general-purpose, 8-b instruction set has been designed and implemented. A prototype vision chip containing an $8 times 10$ array of NPs with a $64 times 80$ resolution has been designed and fabricated in a 0.13- $mu text{m}$ 1P8M CMOS fabrication process. The system is reprogrammable and can perform a wide range of image and video processing tasks. Several example algorithms are implemented and tested on the single-chip vision system to demonstrate the functionality of pixel-neighborhood-level parallelism, including 1000-frames/s object tracking.
Auteurs: Joseph A. Schmitz;Mahir K. Gharzai;Sina Balkır;Michael W. Hoffman;Daniel J. White;Nathan Schemm;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 556 - 568
Editeur: IEEE
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» A 103.12-Gb/s WDM PAM4 VCSEL-Based Transmission With Light Injection and Optoelectronic Feedback Techniques
Résumé:
A 103.12-Gb/s wavelength-division-multiplexing (WDM) four-level pulse amplitude modulation (PAM4) transmission based on 850-nm and 880-nm vertical-cavity surface-emitting lasers (VCSELs) with light injection and optoelectronic feedback techniques is proposed and experimentally demonstrated. Results show that two such 7.5-GHz VCSELs with light injection and optoelectronic feedback techniques are potent for 103.12-Gb/s WDM PAM4 transmissions. To the authors’ knowledge, it is the first one to successfully adopt two VCSEL transmitters with light injection and optoelectronic feedback techniques in a WDM PAM4 transmission. A total transmission rate of 103.12 Gb/s (51.56 Gb/s/λ × 2 λs) is achieved in the proposed WDM PAM4 transmissions. The link performances of the proposed WDM PAM4 transmissions have been evaluated in real time. Good real-time bit error rate performance and three independent clear eye diagrams are obtained at a 180-m OM4 multimode fiber operation. Such a proposed 103.12-Gb/s WDM PAM4 VCSEL-based transmission has great potential for providing efficient bandwidth in short-reach optical communications.
Auteurs: Hai-Han Lu;Chung-Yi Li;Chang-Kai Lu;Chun-Ming Ho;Hwan-Wei Chen;Ming-Te Cheng;Zih-Yi Yang;Sheng-Jhe Huang;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2017, volume: 9, issue:1, pages: 1 - 8
Editeur: IEEE
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» A 12-b ENOB 2.5-MHz BW VCO-Based 0-1 MASH ADC With Direct Digital Background Calibration
Résumé:
This paper presents a scaling friendly mostly digital voltage-controlled-oscillator (VCO)-based 0-1 multistage noise shaping (MASH) analog-to-digital converter. A novel background calibration technique corrects conversion errors due to VCO linear gain drift, residue generating digital-to-analog converter mismatches, and nonlinearity of the VCO voltage-to-frequency conversion. The proposed architecture minimally modifies the basic 0-1 MASH architecture and directly calibrates the main VCOs without relying on replica matching. A redundant first-stage coarse quantizer enables fast error estimation in the digital domain. A 12-b prototype implemented in 180-nm CMOS achieves 12-b ENOB over 2.5 MHz and consumes 4.8 mW from a 1.8 V supply.
Auteurs: Kareem Ragab;Nan Sun;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 433 - 447
Editeur: IEEE
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» A 120-GHz Electrical Interferometer for Contactless Permittivity Measurements With Direct Digital Read-Out
Résumé:
This work describes an electrical interferometer for contactless permittivity measurements working at 120 GHz. It was fabricated in a 130 nm SiGe process featuring an ft and fmax of 240 and 330 GHz. The on-chip system contains a 120 GHz VCO with a tuning range of 7 GHz featuring a divide-by-64 circuit to enable external PLL operation. The subsequent buffer provides 7 dBm of output power at 120 GHz. Additionally, the IC contains high-precision and high-resolution phase shifters based on a slow-wave transmission line approach with digital control for direct readout ability. A 120 GHz LNA with 17 dB gain and a power detector to provide DC output signals were realized on chip. It enables sample emulation capability by phase shift inducement in the measurement as well as a reference transmission line. In terms of phase detection, the system shows a sensitivity of 907.36 MHz/°.
Auteurs: Jan Wessel;Klaus Schmalz;J. Christoph Scheytt;Dietmar Kissinger;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 198 - 200
Editeur: IEEE
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» A 14-Bit 30-MS/s 38-mW SAR ADC Using Noise Filter Gear Shifting
Résumé:
We present a successive approximation register analog-to-digital converter (ADC) that employs a comparator with time-varying noise performance, realized by changing the integration time of a $G_{m}-C$ preamplifier. This approach allows us to relax precision and enhance speed during noncritical decisions, leading to an aggregate speed-up of 22% compared to a conventional design. The ADC operates at 30 MS/s, achieves a peak signal-to-noise and distortion ratio of 77.2 dB, and consumes 38 mW from 1.2 V/2.5 V supplies, corresponding to a Schreier FOM of 163.1 dB (161.6 dB at Nyquist). The proof-of-concept converter is implemented in a 40-nm LP complementary metal-oxide semiconductor process and occupies 0.24 mm2.
Auteurs: Martin Krämer;Erwin Janssen;Kostas Doris;Boris Murmann;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 116 - 120
Editeur: IEEE
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» A 15.5-dBm 160-GHz High-Gain Power Amplifier in SiGe BiCMOS Technology
Résumé:
This letter presents the design of a 160 GHz cascode based differential power amplifier (PA) realized in a 130 nm SiGe BiCMOS technology. It consists of 4 driving stages and an output power stage, providing a peak differential gain of 30 dB and a 3-dB small-signal bandwidth of around 50 GHz. Gain is enhanced by means of inductive positive feedback in the common-base stage. By using optimally sized HBTs in the power stage and operating in the weak avalanche region, high output power is achieved. The designed PA achieves a peak differential $P_{textrm {sat}} $ of 15.5 dBm at 160 GHz and a PAE of 7.2%, which is to-date the highest reported output power for PAs above 150 GHz, in Si-based technologies.
Auteurs: Muhammad Furqan;Faisal Ahmed;Bernd Heinemann;Andreas Stelzer;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 177 - 179
Editeur: IEEE
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» A 250- $mutext{W}$ 2.4-GHz Fast-Lock Fractional-N Frequency Generation for Ultralow-Power Applications
Résumé:
This brief presents a fast-lock 2.4-GHz fractional-N phase-locked loop (PLL) for ultralow-power applications. To minimize the power consumed by all the other circuits except for the main oscillator, we propose a master–slave PLL structure in which a low-frequency master PLL is followed by a slave injection-locked oscillator operating at high frequency. A frequency-error compensation circuit is also implemented in the slave oscillator to eliminate possible drift in the free-running frequency. With a fractional-N coarse-lock unit in the master PLL and a fine frequency initialization unit in the slave oscillator, the PLL supports two fast-lock modes: 1) start-up locking from deep-power-down mode and 2) instantaneous relocking from standby mode. The implemented PLL in 65-nm complementary metal-oxide-semiconductor (CMOS) consumes 250 $mutext{W}$ from a 0.8-V supply, demonstrating a power efficiency of 0.102 mW/GHz. The PLL performs the two fast-lock operations with lock times of less than 22 $mutext{s}$ from deep power down and 1 $mutext{s}$ from standby, respectively.
Auteurs: Seunghwan Hong;Shinwoong Kim;Seungnam Choi;Hwasuk Cho;Jaehyeong Hong;Young-Hun Seo;Byungsub Kim;Hong-June Park;Jae-Yoon Sim;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 106 - 110
Editeur: IEEE
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» A 28 nm, 475 mW, and 0.4–1.7 GHz Embedded Transceiver Front-End Enabling High-Speed Data Streaming Within Home Cable Networks
Résumé:
A 28 nm CMOS software-defined transceiver (SDTRX) enabling high-speed data (HSD) streaming, including ultra HD TV, within home cable networks is presented. By making efficient use of available cable bandwidth, the SDTRX dynamically handles up to 1024-QAM OFDM-modulated HSD streams. This paper addresses SDTRX system-level design methodology as the key driver in enabling performance optimization for achieving a wide frequency range of operation at lowest power and area consumption. By employing an optimized architecture constructed on available state-of-the-art 28 nm functional building blocks, the monolithic SDTRX consists of a mixer-based harmonic rejection RX with a digital-to-analog converter-based TX and a smart phase-locked loop system. It operates over 0.4–1.7 GHz frequency range while consuming less than 475 mW in half-duplex mode. Moreover, by developing a simple transmitter (TX) to receiver (RX) loopback circuit, the system is enabled to efficiently calibrate TX output power and to remove the need for a dedicated external pin. This low-cost SDTRX is embedded in various 28 nm CMOS multimedia system-on-chip and is, to the authors’ knowledge, the first reported transceiver front-end to enable true HSD streaming within home cable networks.
Auteurs: S. Spiridon;D. Koh;J. Xiao;M. Brandolini;B. Shen;C.-M. Hsiao;H. Huang;D. Guermandi;S. Bozzola;H. Yan;M. Introini;L. Krishnan;K. Raviprakash;Y. Shin;R. Gomez;J. Chang;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 338 - 345
Editeur: IEEE
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» A 28-GHz Harmonic-Tuned Power Amplifier in 130-nm SiGe BiCMOS
Résumé:
The design methodology and measurement results of a millimeter-wave harmonic-tuned power amplifier (PA) are presented. The PA uses optimum fundamental and second-harmonic terminations to achieve high peak power-added efficiency (PAE). We present a parasitic-aware design technique for the output network realized as a bandpass filter cascaded with or surrounded by a low-pass matching network. This technique demonstrates a method of manipulating the second-harmonic phase of a Chebyshev bandpass filter, while maintaining a suitable impedance match at the fundamental. The technique is applied to a 28-GHz PA in SiGe BiCMOS, which achieves 15.3-dB gain, 18.6-dBm saturated output power, 15.5-dBm output 1-dB compression point, and 35.3% peak PAE. When backed off 6- from 1-dB compression, the PA achieves 11.5% PAE with a third-order intermodulation product of −33.7 dBc.
Auteurs: Anirban Sarkar;Brian A. Floyd;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 522 - 535
Editeur: IEEE
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» A 28-GHz Quadrature Fractional-N Frequency Synthesizer for 5G Transceivers With Less Than 100-fs Jitter Based on Cascaded PLL Architecture
Résumé:
This paper introduces a quadrature fractional-N cascaded frequency synthesizer and its phase noise analysis, optimization, and design for future 5G wireless transceivers. The performance improvement of the cascaded phase-locked loop (PLL) over single-stage PLL in terms of jitter and power consumption is theoretically presented and verified with measured results. The cascaded PLL is implemented using a first-stage fractional-N charge-pump PLL followed by a second-stage quadrature dividerless subsampling PLL. The fractional division in the first-stage PLL is implemented using a high-resolution phase mixer for lower quantization noise. Two prototypes of the single-stage PLL and the cascaded PLL were implemented in the 65-nm bulk CMOS process. The 26–32 GHz quadrature cascaded PLL consumes a total of 26.9 mW from 1-V supply and achieves less than 100-fs integrated jitter with −116.2 and −112.6-dBc/Hz phase noise at 1-MHz offset for the integer-N and the fractional-N modes, respectively. The fractional-N single-stage and cascaded PLLs achieve figure-of-merits of −230.58 and −248.75 dB, respectively.
Auteurs: Waleed El-Halwagy;Amlan Nag;Philip Hisayasu;Farshid Aryanfar;Pedram Mousavi;Masum Hossain;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 396 - 413
Editeur: IEEE
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» A 280-GHz 10-dBm Signal Source Based on InP HBT Technology
Résumé:
A 280-GHz high-power signal source has been developed in this work based on a 250-nm InP heterojunction bipolar transistor (HBT) technology. The fabricated signal source is composed of two in-phase locked common-base cross-coupled oscillators, the output of which is on-chip combined by a pair of rat-race couplers and a Wilkinson power combiner for enhanced output power. The developed signal source exhibits an oscillation frequency of 276.4 GHz and a phase noise of–89 dBc/Hz at 1 MHz offset. The output power of the signal source is measured to be 10 dBm (10 mW), while consuming a dc power of 196 mW (dc-to-RF efficiency of 5.1%).
Auteurs: Jongwon Yun;Jungsoo Kim;Jae-Sung Rieh;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 159 - 161
Editeur: IEEE
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» A 30 $mutext{W}$ Remotely Powered Local Temperature Monitoring Implantable System
Résumé:
An implantable local temperature monitoring system for a laboratory mouse is presented. Magnetic coupling is used to remotely power the passive implant. The temperatures of two local points are monitored by thermistors. A low-power readout circuit is implemented by directly amplifying and resolving the sensor response in the time domain. A free-running oscillator operating at 868 MHz transmits the sensor data to the base station. The average power dissipation of the implant is decreased by time interleaving between the sensor readout and the data communication. The power transfer to the implant is also time interleaved with other operations to avoid interference with data communication. A voltage regulation loop for the implant based on controlling the duration of powering the base station power amplifier is also described. A prototype chip is implemented in 0.18 $mutext{m}$ CMOS. The implant requires average RF power of 29.5 $mutext{W}$ for operation and is capable of measuring two thermistors with accuracy of ±0.05 °C.
Auteurs: Mehrdad A. Ghanad;Michael M. Green;Catherine Dehollain;
Apparue dans: IEEE Transactions on Biomedical Circuits and Systems
Date publication: 02.-2017, volume: 11, issue:1, pages: 54 - 63
Editeur: IEEE
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» A 30-MHz–3-GHz CMOS Array Receiver With Frequency and Spatial Interference Filtering for Adaptive Multi-Antenna Systems
Résumé:
A 30-MHz–3-GHz wideband complementary metal–oxide–semiconductor phased array receiver with interference suppression capability in the frequency and spatial domains is presented. A frequency filtering function is provided by a two-stage harmonic rejection mixer with 16-phase local oscillator (LO) signals that are generated by frequency dividers and phase interpolators. The developed IC suppresses third- to seventh-order harmonic interference by more than 55 dB in a wide range from 30 MHz to 3 GHz. The 16-phase LO signal generator combined with a 2-b baseband phase shifter (PS) also works as a 6-b PS. Equipped with a 6-b amplitude control in addition to the 6-b phase control, the array receiver enables analog null steering that can reduce a spatial interference coming from a specific direction. The multi-chip synchronization needed for the null steering function is realized with pre-set circuits in the frequency dividers. Space propagation measurements made on a four-element array antenna system using the developed ICs indicated that the null steering function reduces spatial interference by 20 dB and reduces the error vector magnitude of a 2-GHz radio frequency, 20-MHz bandwidth, and 64-quadrature amplitude modulation signal from −12.7 to −26.3 dB even when a strong interferer exists.
Auteurs: Naoki Oshima;Masaki Kitsunezuka;Kenta Tsukamoto;Kazuaki Kunihiro;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 362 - 373
Editeur: IEEE
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» A 33fJ/Step SAR Capacitance-to-Digital Converter Using a Chain of Inverter-Based Amplifiers
Résumé:
A 12 – bit energy-efficient capacitive sensor interface circuit that fully relies on capacitance-domain successive approximation (SAR) technique is presented. Analysis shows that for SAR capacitance-to-digital converter (CDC) comparator offset voltage will result in parasitic-dependent conversion errors, which necessitates using an offset cancellation technique. Based on the presented analysis, a SAR CDC that uses a chain of cascode inverter-based amplifiers with near-threshold biasing is proposed to provide robust, energy-efficient, and fast operation. A hybrid coarse-fine capacitive digital-to-analog converter (CapDAC) achieves 11.7 – bit effective resolution, and provides 83% area saving compared to a conventional binary weighted implementation. The prototype fabricated in a $0.18mu m$ CMOS technology is experimentally verified using MEMS capacitive pressure sensor. Experimental results show an energy efficiency figure-of-merit (FoM) of $33fJ/Step$ which outperforms the state-of-the-art. The CDC output is insensitive to analog references; thus, a very low temperature sensitivity of $2.3ppm/ {^{circ }}C$ is achieved without the need for calibration.
Auteurs: Hesham Omran;Abdulaziz Alhoshany;Hamzah Alahmadi;Khaled N. Salama;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2017, volume: 64, issue:2, pages: 310 - 321
Editeur: IEEE
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» A 40-Gb/s SiGe-BiCMOS MZM Driver With 6-V $_{text {p-p}}$ Output and On-Chip Digital Calibration
Résumé:
A wide-swing optical modulator driver is implemented in 0.13- $mu text{m}$ SiGe-BiCMOS using a three-stage distributed amplifier with a digital input line. Measurements demonstrate 6 - $text{V}_{{text {p-p}}}$ differential output, symmetric 6 -ps (min) rise/fall times, 333-fs (rms) additive jitter, and better than 20-dB output return loss (S11) below 58 GHz. Full output swing with adjustable (6–12 ps) rise/fall times is realized after a three-step calibration sequence facilitated by an on-chip energy detector and digital control. The circuit supports 28–48-Gb/s external data sources, or 2 $^{11}-1$ PRBS and 1-0 internal data generators for calibration and characterization respectively. The 3-mm2 driver IC (1.8-mm2 active area) consumes 1.92 W from +5/−2.5-V supplies.
Auteurs: Leonardo Vera;John R. Long;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 460 - 471
Editeur: IEEE
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» A 43-mW MASH 2-2 CT $Sigma Delta$ Modulator Attaining 74.4/75.8/76.8 dB of SNDR/SNR/DR and 50 MHz of BW in 40-nm CMOS
Résumé:
This paper proposes a multistage noise-shaping continuous-time sigma-delta modulator (CT $Sigma Delta text{M}$ ) with on-chip RC time constant calibration circuits, multiple feedforward interstage paths, and a fully integrated noise-cancellation filter (NCF). The core modulator architecture is a cascade of two single-loop second-order CT $Sigma Delta text{M}$ stages, each of which consists of an integrator-based active- RC loop filter, current-steering feedback digital-to-analog converters, and a 4-b flash quantizer. On-chip RC time constant calibration circuits and high-gain multistage operational amplifiers are realized to mitigate quantization noise leakage due to process variation. Multiple feedforward interstage paths are introduced to: 1) synthesize a fourth-order noise transfer function with dc zeros; 2) simplify the design of NCF; and 3) reduce signal swings at the second-stage integrator outputs. Fully integrated in 40-nm CMOS, the prototype chip achieves 74.4 dB of signal-to-noise-and-distortion ratio (SNDR), 75.8 dB of signal-to-noise ratio, and 76.8 dB of dynamic range in 50.3 MHz of bandwidth (BW) at 1 GHz of sampling frequency with 43 mW of power consumption (P) from 1.1/1.15/2.5-V power supplies. It does not require external software calibration and possesses minimal out-of-band signal transfer function peaking. The figure-of-merit (FOM), defined as $text {FOM}=text {SNDR}+10times log _{10}(text {BW}/text {P})$ , is 165.1 dB.
Auteurs: Alexander Edward;Qiyuan Liu;Carlos Briseno-Vidrios;Martin Kinyua;Eric G. Soenen;Aydın Ilker Karşılayan;Jose Silva-Martinez;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 448 - 459
Editeur: IEEE
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» A 46 $mu text{W}$ 13 b 6.4 MS/s SAR ADC With Background Mismatch and Offset Calibration
Résumé:
A 6.4 MS/s 13 b ADC with a low-power background calibration for DAC mismatch and comparator offset errors is presented. Redundancy deals with DAC settling and facilitates calibration. A two-mode comparator and 0.3 fF capacitors reduce power and area. The background calibration can directly detect the sign of the dynamic comparator offset error and the DAC mismatch errors and correct both of them simultaneously in a stepwise feedback loop. The calibration achieves 20 dB spur reduction with little area and power overhead. The chip is implemented in 40 nm CMOS and consumes 46 $mu text{W}$ from a 1 V supply, and achieves 64.1 dB SNDR and a FoM of 5.5 fJ/conversion-step at Nyquist.
Auteurs: Ming Ding;Pieter Harpe;Yao-Hong Liu;Benjamin Busze;Kathleen Philips;Harmke de Groot;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 423 - 432
Editeur: IEEE
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» A 5.28-Gb/s LDPC Decoder With Time-Domain Signal Processing for IEEE 802.15.3c Applications
Résumé:
This paper presents a high-throughput, energy-efficient, and scalable low-density parity-check (LDPC) decoder with time-domain (TD) signal processing. The proposed arbiter-based minimum value finder is able to support practical long codes. The latency for determining the first two minimum values required in the check node unit is significantly reduced through TD processing. A layered ${Q}$ -based decoding architecture together with the associated scheduling is proposed in order to reduce the amount of memory used for check node storage. Multimode operations are supported by leveraging the structure of the base matrices and the proposed scalable minimum finder architecture. As a proof of concept, a TD-based multimode LDPC decoder for high-speed IEEE 802.15.3c is designed and fabricated in a 90-nm CMOS process. The LDPC decoder integrates 495k logic gates in 2.25 mm2 and achieves a throughput of 5.28 Gb/s at 157 MHz from a 1.05 V supply voltage. The power and normalized energy dissipation are 182 mW and 34.47 pJ/b, respectively. The proposed LDPC decoder is more hardware and energy efficient than previous digital counterparts and is able to support long codes for practical applications, which is still infeasible for the state-of-the-art TD-based LDPC decoders.
Auteurs: Mao-Ruei Li;Chia-Hsiang Yang;Yeong-Luh Ueng;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 592 - 604
Editeur: IEEE
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» A 53–117 GHz LNA in 28-nm FDSOI CMOS
Résumé:
This letter presents the design of a wideband millimeter-wave (mm-wave) low-noise amplifier (LNA) in a 28-nm FDSOI CMOS technology. Having a total power consumption of 38.2 mW, the LNA provides gain over 12 dB from 53 to 117 GHz, and has a measured NF of 6 dB from 75 to 105 GHz. To the author’s best knowledge, the presented LNA achieves the lowest NF with widest bandwidth among previously presented wideband CMOS LNAs operating in the W-band.
Auteurs: Denizhan Karaca;Mikko Varonen;Dristy Parveg;Ali Vahdati;Kari A. I. Halonen;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 171 - 173
Editeur: IEEE
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» A 56 Gb/s PAM4 VCSEL-Based LiFi Transmission With Two-Stage Injection-Locked Technique
Résumé:
A 56 Gb/s four-level pulse amplitude modulation (PAM4) light-based WiFi (LiFi) transmission based on a 680-nm/5.4-GHz vertical-cavity surface-emitting laser (VCSEL) with a two-stage injection-locked technique is proposed and demonstrated. Experimentally results show that a 5.4-GHz VCSEL with a two-stage injection-locked technique is effective for 56 Gb/s PAM4 LiFi transmissions. To the authors' knowledge, it is the first one to adopt a 680-nm VCSEL transmitter with two-stage injection-locked technique in a 56 Gb/s PAM4 LiFi transmission. A pair of doublet lenses is employed in the proposed PAM4 VCSEL-based LiFi transmissions to enhance the free-space link. The link performances of the proposed PAM4 LiFi transmissions have been analyzed in real time. Good bit error rate performance and three independent clear eye diagrams are obtained over a 20-m free-space link. Such a proposed 56 Gb/s PAM4 VCSEL-based LiFi transmission with two-stage injection-locked technique has the potential to play a significant role in future wireless infrastructure for providing high transmission rate and long free-space transmission distance effectively.
Auteurs: Hai-Han Lu;Chung-Yi Li;Hwan-Wei Chen;Chun-Ming Ho;Ming-Te Cheng;Zih-Yi Yang;Chang-Kai Lu;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2017, volume: 9, issue:1, pages: 1 - 8
Editeur: IEEE
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» A 6-GS/s 9.5-b Single-Core Pipelined Folding-Interpolating ADC With 7.3 ENOB and 52.7-dBc SFDR in the Second Nyquist Band in 0.25- $mu$ m SiGe-BiCMOS
Résumé:
A pipelined folding-interpolating analog-to-digital converter (ADC) with a distributed quantizer is presented. The mismatch-insensitive analog frontend provides excellent spurious-free dynamic range (SFDR) and signal-to-noise ratio without calibration or digital postprocessing. The algorithm of the digital coder relaxes the requirements on the interface between analog core and digital coder. The single-core ADC achieves an effective resolution of 7.3 b and an SFDR of 52.7 dBc in the second Nyquist band at 6 GS/s with an overall power consumption of 10.2 W.
Auteurs: M. Buck;M. Grözing;R. Bieg;J. Digel;X.-Q. Du;P. Thomas;M. Berroth;M. Epp;J. Rauscher;M. Schlumpp;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 414 - 422
Editeur: IEEE
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» A 71–86-GHz Phased Array Transceiver Using Wideband Injection-Locked Oscillator Phase Shifters
Résumé:
This paper presents the first phased array transceiver operating from 71 to 86 GHz using injection-locked oscillators (ILOs) for phase shifting. A folded-cascode ILO is proposed to extend the locking range of an array of oscillators. Frequency multiplication covers a 10-GHz tuning range with 23-dB power gain. Each ILO path covers more than ±300° and exhibits low amplitude variation with respect to phase shift range (<1 dB) and excellent isolation and amplitude error (<0.5 dB) between array elements. A wideband, bidirectional RF front end delivers 10-dBm maximum output power with more than 20-dB conversion gain over the 3-dB bandwidth in the transmit (TX) mode and a minimum 9.5-dB noise figure with more than 20-dB conversion gain in the receive (RX) mode. Low phase noise is demonstrated in the ILO approach over the phase tuning range with −112 dBc/Hz at 1-MHz offset and phase noise variation for different phase shift states under 2.5 dB, corresponding to less than 2° phase error. Array patterns demonstrate the wide scan range, and dynamic measurements show that the transmitter supports up to 6-Gb/s data rate with 256 QAM. The chip has $3.4times2.1$ mm2 area implementing in the 90-nm BiCMOS technology and consuming 386.4 mW in the TX mode and 286 mW in the RX mode per element.
Auteurs: Najme Ebrahimi;Po-Yi Wu;Mahdi Bagheri;James F. Buckwalter;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 346 - 361
Editeur: IEEE
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» A Bandpass Frequency Selective Surface With a Low Cross-Polarization Based on Cavities With a Hybrid Boundary
Résumé:
A novel low cross-polarization bandpass frequency selective surface (FSS) with low passband ripples and a steep roll-off at both sides of the passband is proposed. Different from available substrate integrated waveguide FSSs in which the boundary of every unit cell is electrically conducting, the proposed FSS unit cell is composed of two specially designed cavities with mixed electrically and magnetically conducting boundaries. These boundaries are formed by an array of shorting vias and complementary slots etched on both the top and bottom metallic patches, respectively. A bandwidth enhancement is achieved by properly merging three individual resonances excited in the two hybrid cavities and the slots within the required frequency range. An FSS centered at 4.58 GHz is fabricated and its near- and far-field performances are measured, with the results in good agreement with the prediction. The characteristics, including a steep roll-off, low passband ripples, a low cross-polarization, and stability at oblique incidence angles, are verified by the measurement.
Auteurs: Li-Li Yang;Xing-Chang Wei;Da Yi;Jian-Ming Jin;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2017, volume: 65, issue:2, pages: 654 - 661
Editeur: IEEE
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» A Bandpass Graphene Frequency Selective Surface With Tunable Polarization Rotation for THz Applications
Résumé:
In order to achieve tunable polarization rotation of the transmitted wave and controllable bandpass response simultaneously, a new graphene frequency selective surface (GFSS) is proposed for terahertz applications. The GFSS is built up by sandwiching a high-resistivity Si-substrate with a graphene patch array and a graphene sheet, both of which are electromagnetically biased. The configuration is analyzed by using an equivalent tensorial surface conductivity and transmission matrices of graphene structures, which is validated by full-wave simulations. The transmission coefficient, axial ratio, and polarization rotation angle of the bandpass GFSS are captured. An observable polarization rotation angle is obtained with a relatively large transmittance, which is superior to the graphene sheet and bandstop patch-type structures. The passband frequency is found to be not sensitive to the incident angle for either TE- or TM-polarized incidence, while it can be shifted from 1.6 to 2.2 THz with the polarization rotation angle varying from 24° to 16° by changing the chemical potential from 0.6 to 1 eV. When the applied magnetic field is set up to 3 T, the maximum rotation angle of polarization reaches up to 30° for TM incidence and 45° for TE incidence while the passband remains around 2 THz.
Auteurs: Xiang Li;Lin Lin;Lin-Sheng Wu;Wen-Yan Yin;Jun-Fa Mao;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2017, volume: 65, issue:2, pages: 662 - 672
Editeur: IEEE
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» A Better Balun? Done The Design of a 4:1 Wideband Balun Using a Parallel-Connected Transmission-Line Balun
Résumé:
This article presents a 4:1 wide-band balun that won the student design competition for wide-band baluns held during the 2016 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS2016) in San Francisco, California. For this contest, sponsored by Technical Committee MTT-17, participants were required to implement and evaluate their own baluns, with the winning entry achieving the widest bandwidth while satisfying the conditions of the competition rules during measurements at IMS2016. Some of the conditions were revised for this year's competition compared with previous competitions as follows.
Auteurs: Hansik Oh;Wooseok Lee;Hwiseob Lee;Hyungmo Koo;Sungjae Oh;Keum Choel Hwang;Kang-Yoon Lee;Cheon-seok Park;Youngoo Yang;
Apparue dans: IEEE Microwave Magazine
Date publication: 02.-2017, volume: 18, issue:1, pages: 85 - 90
Editeur: IEEE
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» A Biomechanical Modeling Guided CBCT Estimation Technique
Résumé:
Two-dimensional-to-three-dimensional (2D-3D) deformation has emerged as a new technique to estimate cone-beam computed tomography (CBCT) images. The technique is based on deforming a prior high-quality 3D CT/CBCT image to form a new CBCT image, guided by limited-view 2D projections. The accuracy of this intensity-based technique, however, is often limited in low-contrast image regions with subtle intensity differences. The solved deformation vector fields (DVFs) can also be biomechanically unrealistic. To address these problems, we have developed a biomechanical modeling guided CBCT estimation technique (Bio-CBCT-est) by combining 2D-3D deformation with finite element analysis (FEA)-based biomechanical modeling of anatomical structures. Specifically, Bio-CBCT-est first extracts the 2D-3D deformation-generated displacement vectors at the high-contrast anatomical structure boundaries. The extracted surface deformation fields are subsequently used as the boundary conditions to drive structure-based FEA to correct and fine-tune the overall deformation fields, especially those at low-contrast regions within the structure. The resulting FEA-corrected deformation fields are then fed back into 2D-3D deformation to form an iterative loop, combining the benefits of intensity-based deformation and biomechanical modeling for CBCT estimation. Using eleven lung cancer patient cases, the accuracy of the Bio-CBCT-est technique has been compared to that of the 2D-3D deformation technique and the traditional CBCT reconstruction techniques. The accuracy was evaluated in the image domain, and also in the DVF domain through clinician-tracked lung landmarks.
Auteurs: You Zhang;Joubin Nasehi Tehrani;Jing Wang;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2017, volume: 36, issue:2, pages: 641 - 652
Editeur: IEEE
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» A Brief Message From the New Editor-In-Chief
Résumé:
Auteurs: J. E. Fowler;
Apparue dans: IEEE Signal Processing Letters
Date publication: 02.-2017, volume: 24, issue:2, pages: 135 - 135
Editeur: IEEE
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» A Capacitor Voltage Balancing Strategy With Minimized AC Circulating Current for the DC–DC Modular Multilevel Converter
Résumé:
The dc-dc modular multilevel converter (MMC), which has originated from the ac-dc MMC circuit topology, is an attractive converter topology for interconnection of medium-/high-voltage dc grids. Proper operation of the dc-dc MMC necessitates injection of an ac circulating current to maintain its submodule (SM) capacitor voltages balanced. The ac circulating current, however, needs to be minimized for efficiency improvement. In addition, a unique type of imbalance amongst the SM capacitor voltages that is caused by dc power flow needs to be mitigated. This paper proposes a closed-loop control strategy for the dc-dc MMC to simultaneously regulate the dc-link currents, maintain the SM capacitor voltages balanced, and minimize the ac circulating current. Performance and effectiveness of the proposed control strategy are evaluated based on simulation studies in the MATLAB Simulink and experimentally verified on a laboratory prototype.
Auteurs: Heng Yang;Maryam Saeedifard;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 02.-2017, volume: 64, issue:2, pages: 956 - 965
Editeur: IEEE
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» A Closer Look at ROADM Contention
Résumé:
ROADMs provide the wavelength-switching capability in the optical layer of most transport networks. As the need for greater network configurability grows, ROADMs continue to evolve to provide greater flexibility. More specifically, ROADMs that provide colorless, directionless, gridless, and contentionless operation are on the roadmap of many equipment vendors and service providers. The first three of these properties are easy to define. ROADM contention, however, can take on many forms, which has led to some misconceptions regarding the contentionless property. We examine ROADM contention in more detail in order to provide greater clarity regarding contentionless ROADMs.
Auteurs: Jane M. Simmons;
Apparue dans: IEEE Communications Magazine
Date publication: 02.-2017, volume: 55, issue:2, pages: 160 - 166
Editeur: IEEE
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» A Coalition Formation Game for Remote Radio Head Cooperation in Cloud Radio Access Network
Résumé:
With the increasing demand of spectrum and emergence of mobile devices, a cloud radio access network (C-RAN) is a promising technology to improve network capacity and coverage. The key concept of the C-RAN is to separate the radio function unit in remote radio heads (RRHs) from the digital function unit in baseband units (BBUs). This separation facilitates efficient spectrum and infrastructure sharing in the C-RAN. This paper considers the cooperative interference management among RRHs in the C-RAN. The RRHs can form coalitions to mitigate intra-interference and jointly serve their subscribers. To characterize RRH performance under the coalition, this paper develops two signal-to-interference-plus-noise-ratio (SINR)-based downlink throughput models of RRH, where one adopts tools from stochastic geometry to capture the interference from vehicular users (VUs) belonging to noncooperative RRHs, and another ignores the VU interference. In this paper, a coalition formation game is formulated to model the situation in which RRHs of C-RAN can make an individual decision to cooperatively serve their VUs if the throughput of the RRH can be improved. To obtain the solution of the proposed game, we develop a distributed coalition formation algorithm and analyze the stability of the coalition structure using a Markov chain model. Simulation results show that, as compared with the noncoalition and grand coalition, our distributed coalition formation can improve the C-RAN throughput by at least 20% and 80%, respectively. Furthermore, according to extensive simulation, we can define the conditions needed for RRHs to form a coalition and obtain higher throughput.
Auteurs: Shun-Cheng Zhan;Dusit Niyato;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 02.-2017, volume: 66, issue:2, pages: 1723 - 1738
Editeur: IEEE
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» A Compact 12-Way Slotted Waveguide Power Combiner for Ka-Band Applications
Résumé:
A power divider/combiner based on a double sided slotted waveguide geometry suitable for Ka-band applications is proposed. This structure allows up to 50% reduction of the total device length compared to previous designs of this type without compromising manufacturing complexity or combining efficiency. Efficient design guidelines based on an equivalent circuit technique are provided and the performance is demonstrated by means of a 12-way divider/combiner prototype operating in the range 29-31 GHz. Numerical simulations show that back to back insertion loss of 1.19 dB can be achieved, corresponding to a combining efficiency of 87%. The design is validated by means of manufacturing and testing an experimental prototype with measured back-to-back insertion loss of 1.83 dB with a 3 dB bandwidth of 20.8%, corresponding to a combining efficiency of 81%.
Auteurs: José Antonio García Pérez;Savvas Kosmopoulos;George Goussetis;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 135 - 137
Editeur: IEEE
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» A Compact 128-Element Schottky Diode Grid Frequency Doubler Generating 0.25 W of Output Power at 183 GHz
Résumé:
This paper presents a compact varactor grid frequency doubler encapsulated in a waveguide environment, thus providing single mode (H10) waveguide connection at both input and output. Schottky diodes are used as varactors in this 128-element grid frequency doubler. By packaging the grid and its embedding network together with a stepped waveguide taper on the output, a module measuring 9 mm $times $ 19 mm by 19 mm is created. A peak output power of 0.25 W is produced at 183 GHz with 1.32 W of input power and a corresponding conversion efficiency of 19%. The peak conversion efficiency is 23% at 183 GHz with 666 mW of input power.
Auteurs: Robin Dahlbäck;Vladimir Drakinskiy;Josip Vukusic;Jan Stake;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 162 - 164
Editeur: IEEE
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» A Compact Broadband Riblet-Type Three-Way Power Divider in Rectangular Waveguide
Résumé:
A compact broadband three-way power divider based on a Riblet type coupler is proposed and designed in W-band. Coupling occurs among three adjacent waveguides through narrow walls. Two cylindrical posts located in the coupling region, help to achieve efficient coupling within shorter length and also to reduce reflections. The tapering of the input central waveguide improves the return loss of the power divider. The proposed power divider is validated with experimental measurements and measured power division ratio is −5.2 dB ± 0.25 dB. The return loss and isolation between the output ports is better than 20 dB over 88.75-97.5 GHz frequency range. The amplitude imbalance between the output ports is less than ± 0.4 dB. The fractional bandwidth for the power divider is 9.47% and the coupling length is $1.7lambda _{mathrm {mathbf {g}}}$ . The simulated and measured results are in close agreement.
Auteurs: G. Arun Kumar;Bijit Biswas;D. R. Poddar;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 141 - 143
Editeur: IEEE
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» A Compact Reconfigurable Coupler with Tunable Coupling Coefficients and Frequencies
Résumé:
A compact microstrip coupler with tunable frequencies and coupling coefficients is presented. The calculation equations for capacitances under two different reconfigurable situations are derived. The design procedures are also given upon different requirements. To demonstrate the design strategies, a prototype with center frequency of 2 GHz is fabricated and measured. The measured results show a tunable frequency range from 1 to 3 GHz with 3 dB coupling, and a tunable coupling coefficient range from 0.86 dB to 9.5 dB at center frequency.
Auteurs: Tianyu Zhang;Wenquan Che;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 129 - 131
Editeur: IEEE
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» A Compact Two-Wavelength Time-Domain NIRS System Based on SiPM and Pulsed Diode Lasers
Résumé:
This paper presents a complete, compact, and low power consumption instrument designed for time-domain near-infrared spectroscopy. It employs two custom-designed pulsed diode lasers (operating at 830 and 670 nm, with average optical power higher than 2 mW at 40 MHz repetition frequency), a single-photon detection module (based on a 1 mm2 active area silicon photomultiplier), and a custom time-to-digital converter with 10 ps time resolution. The system experimental characterization shows an instrument response function narrower than 300 ps (full-width at half maximum), with measurement stability better than ±1% over several hours of operation. The instrument, which is housed into a compact aluminum case (size 200 × 160 × 50 mm3), is specifically tailored for portability and ease of operation, hence fostering the diffusion of time-domain diffuse optics techniques. Thanks to a total power consumption lower than 10 W, this system is suitable for battery operation, thus enabling on-field measurements.
Auteurs: Mauro Buttafava;Edoardo Martinenghi;Davide Tamborini;Davide Contini;Alberto Dalla Mora;Marco Renna;Alessandro Torricelli;Antonio Pifferi;Franco Zappa;Alberto Tosi;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2017, volume: 9, issue:1, pages: 1 - 14
Editeur: IEEE
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» A Comprehensive Digital Protection Scheme for Low-Voltage Microgrids with Inverter-Based and Conventional Distributed Generations
Résumé:
Microgrid (MG) protection is one of the main challenges in proliferation of microgrids. Due to limited fault current feeding of inverter-based distributed generations (DGs), in islanded operation of MG, protection problems become more complicated; and, therefore, conventional protection strategies cannot be applied. Hence, new protection methods that are applicable in islanded and grid-connected modes of operation are necessary. In this paper, a comprehensive digital-relay based protection is introduced for the protection of MGs. The proposed method includes protection of lines, distributed generations, and the point of common coupling. The structure and graphical schematic of the proposed digital relays are also presented. The proposed method is independent of the MG operation mode and benefits from single-phase tripping. In this method, due to fault isolation from both sides of a line, downstream loads and DGs can operate after fault clearance. To demonstrate the effectiveness of the proposed protection method, numerous simulations are carried out on an MG test system in the PSCAD/EMTDC environment.
Auteurs: Seyed Fariborz Zarei;M. Parniani;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2017, volume: 32, issue:1, pages: 441 - 452
Editeur: IEEE
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» A Comprehensive Evaluation of Microwave Emissivity and Brightness Temperature Sensitivities to Soil Parameters Using Qualitative and Quantitative Sensitivity Analyses
Résumé:
Passive microwave remote sensing has experienced significant success for soil moisture (SM) inversion. However, quantifying the uncertainties caused by soil parameter sensitivities has not attracted sufficient attention. Although local sensitivity analysis (SA) has been used to describe parameter sensitivity in the past, it fails to quantify parameter sensitivities, especially interactions, for nonlinear microwave emission models. This paper presents a comprehensive evaluation that combines physically based emission models and various global SA algorithms to evaluate parameter sensitivity. All the algorithms exhibit highly consistent sensitivity measures, which means a reliable SA result is obtained. The results indicate that the sums of the main sensitivity indices of SM and surface roughness parameters—root-mean-square height (RMSH) and correlation length—are greater than 0.92 and 0.95 for emissivity and brightness temperature (TB), respectively. Furthermore, we find that: 1) the parameter probability distributions have little effect on the sensitivity measures; 2) the SM sensitivity decreases and the RMSH sensitivity increases as the frequency increases and the incidence angle decreases; and 3) the SM is more sensitive on V-polarized than on H-polarized emissivity and TB, while the RMSH is much more sensitive on the polarization index. The presented global SA quantitatively explains the optimal frequency, incidence angle, and polarization for SM inversion and extends the parameter SA for microwave emission models to a more general framework, as well as provides an implication for bare soil emission modeling and SM inversion.
Auteurs: Chunfeng Ma;Xin Li;Jing Wang;Chen Wang;Qingyun Duan;Weizhen Wang;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2017, volume: 55, issue:2, pages: 1025 - 1038
Editeur: IEEE
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» A Comprehensive Numerical Model of Steady-State Negative Corona for Coaxial Cylindrical Electrode in Atmosphere Air
Résumé:
Corona numerical model to predict the distributions of space charge and electric field is an important aspect in coaxial cylindrical electrode. Compared with the existing steady-state negative corona models, electron diffusion, space charge recombination, photoionization, and secondary electron emission mechanism are simultaneously considered in a comprehensive negative corona model. The 1-D hydrodynamic equations are calculated by the fourth-order Runge–Kutta method and the central finite difference method. The effects of these four terms in the conversation equations are analyzed quantitatively. In addition, the influence of corona current and conductor radius on the distribution of space charge and electric field and voltage–current characteristics has been discussed. The results from the comprehensive model show that under the high corona current, the comprehensive scheme is superior to the simplified model and the ion flow model in the accuracy.
Auteurs: Yong Yi;Liming Wang;Zhengying Chen;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 02.-2017, volume: 45, issue:2, pages: 200 - 207
Editeur: IEEE
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» A Comprehensive Study of Reverse Current Degradation Mechanisms in Au/Ni/n-GaN Schottky Diodes
Résumé:
In this paper, we perform a comprehensive study on the reverse current degradation mechanisms in Au/Ni/n-GaN Schottky diodes based on an in-depth understanding on the defect-related current transport mechanisms. Instead of traditional Poole–Frenkel (PF) emission model, an extended bulk-limited PF transport process, including the compensation effect, is adopted to explain the variation of the PF current slope as a function of the stress time, which majorly takes place inside the depletion region near the neutral semiconductor side. Based on the electrostatic analysis, we develop a shallow donor-like defects model to address the current degradation kinetics, which states that the energetic electrons produced by Fowler–Nordheim tunneling can induce significant Joule heating effect during the subsequent drift move of field, and give rise to the formation of the donor-like defects, and in turn enhance the surface electrical field to cause a significant increase of the tunneling component, in good agreement with the emission microscope observations.
Auteurs: Jian Ren;Wenjie Mou;Linna Zhao;Dawei Yan;Zhiguo Yu;Guofeng Yang;Shaoqing Xiao;Xiaofeng Gu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2017, volume: 64, issue:2, pages: 407 - 411
Editeur: IEEE
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» A Comprehensive Study on Cross-View Gait Based Human Identification with Deep CNNs
Résumé:
This paper studies an approach to gait based human identification via similarity learning by deep convolutional neural networks (CNNs). With a pretty small group of labeled multi-view human walking videos, we can train deep networks to recognize the most discriminative changes of gait patterns which suggest the change of human identity. To the best of our knowledge, this is the first work based on deep CNNs for gait recognition in the literature. Here, we provide an extensive empirical evaluation in terms of various scenarios, namely, cross-view and cross-walking-condition, with different preprocessing approaches and network architectures. The method is first evaluated on the challenging CASIA-B dataset in terms of cross-view gait recognition. Experimental results show that it outperforms the previous state-of-the-art methods by a significant margin. In particular, our method shows advantages when the cross-view angle is large, i.e., no less than 36 degree. And the average recognition rate can reach 94 percent, much better than the previous best result (less than 65 percent). The method is further evaluated on the OU-ISIR gait dataset to test its generalization ability to larger data. OU-ISIR is currently the largest dataset available in the literature for gait recognition, with 4,007 subjects. On this dataset, the average accuracy of our method under identical view conditions is above 98 percent, and the one for cross-view scenarios is above 91 percent. Finally, the method also performs the best on the USF gait dataset, whose gait sequences are imaged in a real outdoor scene. These results show great potential of this method for practical applications.
Auteurs: Zifeng Wu;Yongzhen Huang;Liang Wang;Xiaogang Wang;Tieniu Tan;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 02.-2017, volume: 39, issue:2, pages: 209 - 226
Editeur: IEEE
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» A Computer-Aided Diagnosis System With EEG Based on the P3b Wave During an Auditory Odd-Ball Task in Schizophrenia
Résumé:
Objective: To design a Computer-aided diagnosis (CAD) system using an optimized methodology over the P3b wave in order to objectively and accurately discriminate between healthy controls (HC) and schizophrenic subjects (SZ). Methods: We train, test, analyze, and compare various machine learning classification approaches optimized in terms of the correct classification rate (CCR), the degenerated Youden's index (DYI) and the area under the receiver operating curve (AUC). CAD system comprises five stages: electroencephalography (EEG) preprocessing, feature extraction, seven electrode groupings, discriminant feature selection, and binary classification. Results: With two optimal combinations of electrode grouping, filtering, feature selection algorithm, and classification machine, we get either a mean CCR = 93.42%, specificity = 0.9673, sensitivity = 0.8727, DYI = 0.9188, and AUC = 0.9567 (total-15 Hz-J5-MLP), or a mean CCR = 92.23%, specificity = 0.9499, sensitivity = 0.8838, DYI = 0.9162, and AUC = 0.9807 (right hemisphere-35 Hz-J5-SVM), which to our knowledge are higher than those available to date. Conclusions: We have verified that a more restrictive low-pass filtering achieves higher CCR as compared to others at higher frequencies in the P3b wave. In addition, results validate previous hypothesis about the importance of the parietal-temporal region, associated with memory processing, allowing us to identify powerful {feature,electrode} pairs in the diagnosis of schizophrenia, achieving higher CCR and AUC in classification of both right and left Hemispheres, and parietal-temporal EEG signals, like, for instance, the {PSE, P4} pair (J5 and mutual information feature selection). Significance: Diagnosis of schizophrenia is made thoroughly by psychiatrists but as any human-based decision th- t has a subjective component. This CAD system provides the human expert with an objective complimentary measure to help him in diagnosing schizophrenia.
Auteurs: Lorenzo Santos-Mayo;Luis M. San-José-Revuelta;Juan Ignacio Arribas;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 02.-2017, volume: 64, issue:2, pages: 395 - 407
Editeur: IEEE
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» A Consensus-Based Algorithm for Truck Platooning
Résumé:
The platooning of trucks can be considered to be a potential approach to mitigate some of the negative effects that trucking can have on traffic streams. This paper proposes a cooperative distributed approach for forming/modifying platoons of trucks based on consensus algorithms. In this approach, trucks exchange information about their current status in real time, and the platoon is formed in consecutive iterations. This distributed consensus-based algorithm is compared with a centralized optimization-based algorithm for truck platooning, in which the trucks move with a set of predetermined speeds for a definite amount of time to form a platoon. The two approaches are tested and compared using various scenarios generated based on real data collected on a highway in Basel, Switzerland. Based on the results, the consensus-based algorithm proved to be a more general scheme that is able to form platoons even in cases with large initial separation of trucks. This algorithm is able to handle complex situations using its capability to form partial platoons.
Auteurs: Mahnam Saeednia;Monica Menendez;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 02.-2017, volume: 18, issue:2, pages: 404 - 415
Editeur: IEEE
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» A Context-Driven Extractive Framework for Generating Realistic Image Descriptions
Résumé:
Automatic image annotation methods are extremely beneficial for image search, retrieval, and organization systems. The lack of strict correlation between semantic concepts and visual features, referred to as the semantic gap, is a huge challenge for annotation systems. In this paper, we propose an image annotation model that incorporates contextual cues collected from sources both intrinsic and extrinsic to images, to bridge the semantic gap. The main focus of this paper is a large real-world data set of news images that we collected. Unlike standard image annotation benchmark data sets, our data set does not require human annotators to generate artificial ground truth descriptions after data collection, since our images already include contextually meaningful and real-world captions written by journalists. We thoroughly study the nature of image descriptions in this real-world data set. News image captions describe both visual contents and the contexts of images. Auxiliary information sources are also available with such images in the form of news article and metadata (e.g., keywords and categories). The proposed framework extracts contextual-cues from available sources of different data modalities and transforms them into a common representation space, i.e., the probability space. Predicted annotations are later transformed into sentence-like captions through an extractive framework applied over news articles. Our context-driven framework outperforms the state of the art on the collected data set of approximately 20 000 items, as well as on a previously available smaller news images data set.
Auteurs: Amara Tariq;Hassan Foroosh;
Apparue dans: IEEE Transactions on Image Processing
Date publication: 02.-2017, volume: 26, issue:2, pages: 619 - 632
Editeur: IEEE
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» A Continuity-Based Series Solution for Electromagnetic Scattering by Arbitrary Shaped Multilayer Cylinders: TM Case
Résumé:
A fast and simple method for direct electromagnetic scattering problems related to multilayer cylindrical objects having arbitrary shaped dielectric or conducting layers is presented. First, the field in each layer is represented as a series of Bessel and Hankel functions with unknown coefficients. Then, the continuity of the field, along with its radial derivative, is imposed and two equations for several unknowns are obtained for each boundary. By taking the inner products of these equations with complex exponential functions and using the orthogonality property, the equations are augmented to form a linear system for relatively small number of unknown coefficients that can easily be solved. Once these coefficients are determined, one can compute the field value anywhere including the inner regions of the multilayer structure. It has been numerically shown that, for multilayer objects having homogeneous layers and piecewise smooth boundaries, the proposed method is a significantly simple and fast alternative to general purpose numerical techniques.
Auteurs: Birol Aslanyürek;Tolga Ulaş Gürbüz;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2017, volume: 65, issue:2, pages: 812 - 819
Editeur: IEEE
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» A Cooperative Framework for Fireworks Algorithm
Résumé:
This paper presents a cooperative framework for fireworks algorithm (CoFFWA). A detailed analysis of existing fireworks algorithm (FWA) and its recently developed variants has revealed that ( $i$ ) the current selection strategy has the drawback that the contribution of the firework with the best fitness (denoted as core firework) overwhelms the contributions of all other fireworks (non-core fireworks) in the explosion operator, ($ii$ ) the Gaussian mutation operator is not as effective as it is designed to be. To overcome these limitations, the CoFFWA is proposed, which significantly improves the exploitation capability by using an independent selection method and also increases the exploration capability by incorporating a crowdness-avoiding cooperative strategy among the fireworks. Experimental results on the CEC2013 benchmark functions indicate that CoFFWA outperforms the state-of-the-art FWA variants, artificial bee colony, differential evolution, and the standard particle swarm optimization SPSO2007/SPSO2011 in terms of convergence performance.
Auteurs: Shaoqiu Zheng;Junzhi Li;Andreas Janecek;Ying Tan;
Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Date publication: 02.-2017, volume: 14, issue:1, pages: 27 - 41
Editeur: IEEE
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» A Coupled-Line Balanced-to-Single-Ended Out-of-Phase Power Divider With Enhanced Bandwidth
Résumé:
In this paper, a coupled-line balanced-to-single-ended out-of-phase power divider is proposed. Configured by three quarter-wavelength coupled lines, the proposed power divider is compact and able to enhance the bandwidth of differential-mode power dividing, isolation, common-mode suppression, and phase difference between the output ports. Furthermore, enhancing the bandwidth for common-mode suppression using additional quarter-wavelength open stubs is discussed. Analytical solution of the parameters for specified bandwidth can be achieved using odd- and even-mode analysis. Analytical and practical bandwidth limitation has been analyzed, and it is shown that the bandwidths can be controlled by the odd- and even-mode impedance of the coupled lines. For demonstration, a prototype of size 15 mm $times95$ mm ( $0.15~lambda _{g} times 0.95~lambda _{g}$ ) achieves an operating bandwidth ( $vert S_{ddAA}vert < -20$ dB) of 30% with the minimum insertion loss of 0.1 dB.
Auteurs: Jin Shi;Jianpeng Lu;Kai Xu;Jian-Xin Chen;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 459 - 466
Editeur: IEEE
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» A Critical Survey of Deconvolution Methods for Separating Cell Types in Complex Tissues
Résumé:
Identifying properties and concentrations of components from an observed mixture, known as deconvolution, is a fundamental problem in signal processing. It has diverse applications in fields ranging from hyperspectral imaging to noise cancellation in audio recordings. This paper focuses on in-silico deconvolution of signals associated with complex tissues into their constitutive cell-type-specific components and a quantitative characterization of the cell types. Deconvolving mixed tissues/cell types is useful in the removal of contaminants (e.g., surrounding cells) from tumor biopsies, as well as in monitoring changes in the cell population in response to treatment or infection. In these contexts, the observed signal from the mixture of cell types is assumed to be a convolution, using a linear instantaneous (LI) mixing process, of the expression levels of genes in constitutive cell types. The goal is to use known signals corresponding to individual cell types and a model of the mixing process to cast the deconvolution problem as a suitable optimization problem. In this paper, we present a survey and in-depth analysis of models, methods, and assumptions underlying deconvolution techniques. We investigate the choice of the different loss functions for evaluating estimation error, constraints on solutions, preprocessing and data filtering, feature selection, and regularization to enhance the quality of solutions and the impact of these choices on the performance of commonly used regression-based methods for deconvolution. We assess different combinations of these factors and use detailed statistical measures to evaluate their effectiveness. Some of these combinations have been proposed in the literature, whereas others represent novel algorithmic choices for deconvolution. We identify shortcomings of current methods and avenues for further investigation. For many of the identified shortcomings, such as normalization issues and data filtering, we provi- e new solutions. We summarize our findings in a prescriptive step-by-step process, which can be applied to a wide range of deconvolution problems.
Auteurs: Shahin Mohammadi;Neta Zuckerman;Andrea Goldsmith;Ananth Grama;
Apparue dans: Proceedings of the IEEE
Date publication: 02.-2017, volume: 105, issue:2, pages: 340 - 366
Editeur: IEEE
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» A Cross-Layer Approach to Reducing Packet Delay in Polling-Based Multiuser Systems
Résumé:
We consider a system where users are polled for transmission by a central server, and the link layer of each user employs automatic repeat request (ARQ) to ensure error-free delivery of packets. We present a cross-layer approach for reducing average packet delay (queuing delay plus service time). It is known that forward error correction (FEC) schemes can potentially lower the average packet delay by reducing the packet error probability (PEP) and, hence, the number of retransmissions. However, more precise results in the literature are few and far between. In this paper, we first establish that relative to an uncoded system, it is sufficient to reduce the average service time (AST) using FEC to achieve lower average packet delay. We then study and quantify the reduction in AST that can be achieved using the best possible FEC codes. The specific findings and contributions from our work are as follows: 1) We provide several bounds on the reduction in AST using the best possible FEC codes; 2) we give a sufficient condition when no FEC scheme can reduce the AST; 3) for Gaussian channels, we find that a relatively high PEP $(sim!!text{10}^{-2})$, which is obtained using as high a coding rate as possible, typically results in sufficiently small AST; 4) the performance of optimum maximum-likelihood decoding can be approached by a lower complexity bounded distance decoder; and 5) average packet delay can be further reduced in certain cases by opportunistically combining and encoding several packets jointly.
Auteurs: Anshoo Tandon;Mehul Motani;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 02.-2017, volume: 66, issue:2, pages: 1506 - 1518
Editeur: IEEE
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» A Cross-Layer Bandwidth Allocation Scheme for HTTP-Based Video Streaming in LTE Cellular Networks
Résumé:
This letter investigates the benefits of flexible resource allocation when performing HTTP-based adaptive streaming (HAS) across cellular systems such as long-term evolution (LTE). To guarantee video fluidity in the presence of fluctuations of the instantaneous video source rate and channel capacity, we consider an HAS-based proxy video manager and resource controller located at the cellular base station. Based on the channel quality observed by mobile clients, the manager allocates the wireless bandwidth to mobile clients for transmitting the video streams. We propose a cross-layer bandwidth allocation scheme that takes into account the channel quality as well as the video quality requirements and encoding rate fluctuations of the HAS video stream and minimizes the transmission delays experienced by users. This cross-layer bandwidth allocation achieves the optimum in terms of HAS streams delays and it outperforms different bandwidth allocations procedures and state-of-the-art LTE schedulers.
Auteurs: Stefania Colonnese;Francesca Cuomo;Tommaso Melodia;Izhak Rubin;
Apparue dans: IEEE Communications Letters
Date publication: 02.-2017, volume: 21, issue:2, pages: 386 - 389
Editeur: IEEE
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» A Data-Driven Fuzzy Information Granulation Approach for Freight Volume Forecasting
Résumé:
The performance of the logistic system is one of the most important aspects in regional economy, and the freight volume is the biggest part of the logistic system. In this paper, an information granulation method is introduced to represent the freight volume in a fuzzy manner. After the characteristic features have been extracted from the raw time-series data and represented as information granules, the granules are modeled with the support vector machine (SVM). In consideration of both algorithm efficiency and prediction accuracy, an efficient version of SVM called least square (LS) SVM is employed and integrated with a parameter optimization algorithm, the particle swarm optimization. Simulation results on a real dataset illustrate the performance of the proposed method, and comparison studies are carried out with LS and partial LS-based methods.
Auteurs: Shen Yin;Yuchen Jiang;Yang Tian;Okyay Kaynak;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 02.-2017, volume: 64, issue:2, pages: 1447 - 1456
Editeur: IEEE
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» A Decision-Support System for Sustainable Water Distribution System Planning
Résumé:
An interactive decision-support system (DSS) can help experts prepare water resource management plans for decision makers and stakeholders. The design of the proposed prototype incorporates visualization techniques such as circle views, grid layout, small multiple maps, and node simplification to improve the data readability of water distribution systems. A case study with three urban water management and sanitary engineering experts revealed that the proposed DSS is satisfactory, efficient, and effective.
Auteurs: Alina Freund;Nazli Yonca Aydin;Dirk Zeckzer;Hans Hagen;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 02.-2017, volume: 37, issue:1, pages: 44 - 55
Editeur: IEEE
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» A Deep Collaborative Computing Based SAR Raw Data Simulation on Multiple CPU/GPU Platform
Résumé:
The outstanding computing ability of a graphics processing unit (GPU) brings new vitality to the typical computing intensive issue, so does the synthetic aperture radar (SAR) raw data simulation, which is a fundamental problem in SAR system design and imaging research. However, the computing power of a CPU was underestimated, and the tunings for a CPU-based method were missing in the previous works. Meanwhile, the collaborative computing of multiple CPUs/GPUs was not exploited thoroughly. In this paper, we propose a deep multiple CPU/GPU collaborative computing framework for time-domain SAR raw data simulation, which not only introduces the advanced vector extension (AVX) method to improve the computing efficiency of a multicore single instruction multiple data CPU, but also achieves a satisfactory speedup in the CPU/GPU collaborative simulation by fine-grained task partitioning and scheduling. In addition, an irregular reduction based SAR coherent accumulation approach is proposed to eliminate the memory access conflict, which is the most difficult issue in the GPU-based raw data simulation. Experimental results show that the multicore vector extension method greatly improves the computing power of a CPU-based method through about 70\times speedup, thereby outperforming the single GPU simulation. Correspondingly, compared with the baseline sequential CPU approach, the multiple CPU/GPU collaborative simulation achieves up to 250\times speedup. Furthermore, the irregular reduction based atomic-free optimization boosts the performance of the single GPU method by 20% acceleration. These results prove that the deep multiple CPU/GPU collaborative method is promising, especially for the case of huge volume raw data simulation with a wide swath and high r- solution.
Auteurs: Fan Zhang;Chen Hu;Wei Li;Wei Hu;Pengbo Wang;Heng-Chao Li;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 02.-2017, volume: 10, issue:2, pages: 387 - 399
Editeur: IEEE
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» A Deep Learning Model for Robust Wafer Fault Monitoring With Sensor Measurement Noise
Résumé:
Standard fault detection and classification (FDC) models detect wafer faults by extracting features useful for fault detection from time-indexed measurements of the equipment recorded by in situ sensors (sensor signals) and feeding the extracted information into a classifier. However, the preprocessing-and-classification approach often results in the loss of information in the sensor signals that is important for detecting wafer faults. Furthermore, the sensor signals usually contain noise induced by mechanical and electrical disturbances. In this paper, we propose the use of a stacked denoising autoencoder (SdA), which is a deep learning algorithm, to establish an FDC model for simultaneous feature extraction and classification. The SdA model can identify global and invariant features in the sensor signals for fault monitoring and is robust against measurement noise. Through experiments using wafer samples collected from a work-site photolithography tool, we confirmed that as the sensor measurement noise severity increased, the SdA’s classification accuracy could be as much as 14% higher than those of the twelve models considered for comparison, each of which employed one of three feature extractors and one of four classifiers.
Auteurs: Hoyeop Lee;Youngju Kim;Chang Ouk Kim;
Apparue dans: IEEE Transactions on Semiconductor Manufacturing
Date publication: 02.-2017, volume: 30, issue:1, pages: 23 - 31
Editeur: IEEE
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» A Demodulation-Based Technique for Robust Estimation of Single-Phase Grid Voltage Fundamental Parameters
Résumé:
This paper proposes a robust technique for the single-phase grid voltage fundamental amplitude, frequency, and phase angle estimation under distorted grid conditions. It is based on a demodulation method tuned at a fixed frequency. It does not have stability issue due to an open-loop structure, does not require real-time evaluation of trigonometric and inverse trigonometric functions, and also avoids the use of look-up table. It can provide accurate estimation of the single-phase grid voltage fundamental parameters under dc offset and harmonics. When compared with a frequency adaptive demodulation technique, the proposed one is less affected by dc offset, can provide faster frequency estimation, and also avoids interdependent loop, trigonometric, and inverse trigonometric functions operation. Simulation and experimental results are presented to verify the performance of the proposed technique.
Auteurs: Md. Shamim Reza;Vassilios G. Agelidis;
Apparue dans: IEEE Transactions on Industrial Informatics
Date publication: 02.-2017, volume: 13, issue:1, pages: 166 - 175
Editeur: IEEE
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» A Design Methodology of Class-E/F3 Power Amplifier Considering Linear External and Nonlinear Drain–Source Capacitance
Résumé:
A single-ended Class-E/Fn power amplifier (PA) with linear external and nonlinear drain-to-source (intrinsic) capacitances is designed and analyzed to achieve optimum operation. The effects of nonlinear intrinsic and linear external capacitance at high and low frequencies increase, respectively. The different specifications of the Class-E/F3 PA are shown versus the external and intrinsic capacitances. A Class-E/F3 amplifier at 4-MHz frequency, based on the theoretical results, is analyzed, simulated, and fabricated. The efficiency, power gain, and output power versus the input power are presented as well. The measured results are close to the analytical derivations at optimum conditions of zero-voltage switching and zero-voltage-derivative switching.
Auteurs: Akram Sheikhi;Mohsen Hayati;Andrei Grebennikov;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 548 - 554
Editeur: IEEE
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» A Deterministic and Self-Consistent Solver for the Coupled Carrier-Phonon System in SiGe HBTs
Résumé:
A stationary deterministic solver based on a spherical harmonics expansion of the Boltzmann transport equations for electrons, holes, and phonons is presented to study self-heating in ultrascaled bipolar transistors. With the electrothermal device simulator, a state-of-the-art toward-terahertz SiGe heterojunction bipolar transistor is analyzed and the simulation results are verified against experimental data. To investigate nonequilibrium effects for the carrier-phonon system, the impact of hot longitudinal optical phonons on steady-state carrier transport is discussed. Furthermore, the self-consistent and deterministic solution of the coupled set of equations allows to extract the junction temperature by making use of a method based on the simulated DC characteristics. The resultant junction temperature is compared with the value obtained from the temperature profile within the nanoscale device. Good agreement is obtained for the average temperature in the base–emitter junction verifying the analytical approach used to extract the thermal resistance of the device by experiments.
Auteurs: Hamed Kamrani;Dominic Jabs;Vincenzo d’Alessandro;Niccòl Rinaldi;Klaus Aufinger;Christoph Jungemann;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 02.-2017, volume: 64, issue:2, pages: 361 - 367
Editeur: IEEE
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» A Diaphragm Type Fiber Bragg Grating Vibration Sensor Based on Transverse Property of Optical Fiber With Temperature Compensation
Résumé:
This paper has presented a novel diaphragm-type fiber Bragg grating (FBG) vibration sensor with a small mass and an excellent sensitivity through the use of the transverse property of a tightly suspended optical fiber with two fixed ends. Two suspended optical fibers that were embedded with an FBG element each, have been arranged symmetrically along the both sides of the diaphragm in a parallel manner, and their middle points were connected with the two surfaces of the mass by rigid thin rods to sense vibration. The theoretical model of the presented sensor has been derived, and its sensing characteristics have been analyzed by numerical simulation to determine the physical parameters. Experiments have been conducted to show that its sensitivity is 31.25 pm/g within a working bandwidth range of 10~150 Hz. The linearity and relative sensitivity errors are 2.21% and ±10%, respectively. The experimental resonant frequency of 300 Hz is consistent with the theoretical value, which has verified the effectiveness of the proposed theoretical model. The temperature response of this sensor has decreased to 1.32 pm/°C in the range of 30~90°C after implementing the temperature compensation. Compared with the existing diaphragm-enabled FBG vibration sensors, the proposed sensor enables to support the easy implementation of distributed measurement, and the small mass allows for detection on mass-sensitive structures.
Auteurs: Tianliang Li;Chaoyang Shi;Yuegang Tan;Ruiya Li;Zude Zhou;Hongliang Ren;
Apparue dans: IEEE Sensors Journal
Date publication: 02.-2017, volume: 17, issue:4, pages: 1021 - 1029
Editeur: IEEE
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» A Dissipative Systems Theory for FDTD With Application to Stability Analysis and Subgridding
Résumé:
A connection between the finite-difference time-domain (FDTD) method and the theory of dissipative systems is established. The FDTD equations for a rectangular region are interpreted as a dynamical system having the magnetic field on the boundary as input and the electric field on the boundary as output. Suitable expressions for the energy stored in the region and the energy absorbed from the boundaries are introduced, and used to show that the FDTD system is dissipative under a generalized Courant-Friedrichs–Lewy condition. Based on the concept of dissipation, a powerful theoretical framework to investigate the stability of FDTD-like methods is devised. The new method makes FDTD stability proofs simpler, more intuitive, and modular. Stability conditions can indeed be given on the individual components (e.g., boundary conditions, meshes, and embedded models) instead of the whole coupled setup. As an example of application, we derive a new subgridding scheme with support for material traverse, arbitrary grid refinement, and guaranteed stability. The method is easy to implement and has a straightforward stability proof. Numerical results confirm its stability, low reflections, and ability to handle material traverse.
Auteurs: Fadime Bekmambetova;Xinyue Zhang;Piero Triverio;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 02.-2017, volume: 65, issue:2, pages: 751 - 762
Editeur: IEEE
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» A Distributed Coverage Adjustment Algorithm for Femtocell Networks
Résumé:
In two-tier femtocell networks, adjusting the transmission power values of femtocell base stations (BSs) such that indoor users receive high signal quality while limiting leakage to outdoor users is an important problem. This paper proposes a novel distributed and self-optimized power adjustment algorithm for two-tier femtocell networks, in which a BS adjusts the transmission power based on the signal quality of neighboring BSs. Achieving fairness among users with minimal information exchange is desired. There are no predefined target parameters used to adjust transmission power, contrary to existing approaches in the literature. The convergence properties of the algorithm under fixed and time-varying communication infrastructures are investigated. The performance is further verified by simulations and comparisons with other algorithms for the coverage problem.
Auteurs: Kamil Senel;Mehmet Akar;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 02.-2017, volume: 66, issue:2, pages: 1739 - 1747
Editeur: IEEE
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» A Distributed FMCW Radar System Based on Fiber-Optic Links for Small Drone Detection
Résumé:
This paper discusses a distributed frequency modulation continuous wave radar system. This K-band radar system has high sensitivity, linearity, and flatness to detect low-radar cross section targets and measure their range and velocity. To reduce the leakage between a transmitter and a receiver, the system uses not RF cables but fiber-optic links that have low distortion characteristics and low propagation loss. The transmitter and the receiver are each mounted on a designed fixture to reduce the ground reflections. In addition, they are located on different platforms to reduce the leakage signal flowing directly from the transmitter to the receiver. Measurements in terms of the range and the velocity of a small drone have been carried out to evaluate the proposed distributed radar system. The results show that we can clearly detect the small drone within a 500 m range, which demonstrates the high sensitivity of the system and high isolation between the transmitter and the receiver.
Auteurs: Dong-Hun Shin;Dae-Hwan Jung;Dong-Chan Kim;Jong-Wook Ham;Seong-Ook Park;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 02.-2017, volume: 66, issue:2, pages: 340 - 347
Editeur: IEEE
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» A Distributed RF Transmitter Using One-Way Wireless Clock Transfer
Résumé:
A coherent distributed two-element radio-frequency (RF) transmitter implemented with wireless clock transfer is presented in this letter. This work represents the first demonstration, to the authors’ knowledge, of a distributed RF transmitter using one-way wireless clock transfer, where the slave node need not provide any information to the master node. Two 1-GHz transmitters were implemented and coherent gain above 90% of ideal signal summation was achieved with a probability of 0.97. Experimental results show near-ideal 6-dB gain from the two-transmitter system at a distance of 85 m.
Auteurs: Robert L. Schmid;Thomas M. Comberiate;Jason E. Hodkin;Jeffrey A. Nanzer;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 195 - 197
Editeur: IEEE
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» A Dual-Clock VLSI Design of H.265 Sample Adaptive Offset Estimation for 8k Ultra-HD TV Encoding
Résumé:
Sample adaptive offset (SAO) is a newly introduced in-loop filtering component in H.265/High Efficiency Video Coding (HEVC). While SAO contributes to a notable coding efficiency improvement, the estimation of SAO parameters dominates the complexity of in-loop filtering in HEVC encoding. This paper presents an efficient VLSI design for SAO estimation. Our design features a dual-clock architecture that processes statistics collection (SC) and parameter decision (PD), the two main functional blocks of SAO estimation, at high- and low-speed clocks, respectively. Such a strategy reduces the overall area by 56% by addressing the heterogeneous data flows of SC and PD. To further improve the area and power efficiency, algorithm-architecture co-optimizations are applied, including a coarse range selection (CRS) and an accumulator bit width reduction (ABR). CRS shrinks the range of fine processed bands for the band offset estimation. ABR further reduces the area by narrowing the accumulators of SC. They together achieve another 25% area reduction. The proposed VLSI design is capable of processing 8k at 120-frames/s encoding. It occupies 51k logic gates, only one-third of the circuit area of the state-of-the-art implementations.
Auteurs: Jianbin Zhou;Dajiang Zhou;Shihao Wang;Shuping Zhang;Takeshi Yoshimura;Satoshi Goto;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 02.-2017, volume: 25, issue:2, pages: 714 - 724
Editeur: IEEE
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» A Dual-Input Central Capacitor DC/DC Converter for Distributed Photovoltaic Architectures
Résumé:
This paper proposes a dual-input central capacitor dc/dc converter for distributed photovoltaic (PV) power harnessing, which can be used to boost dual input sources with minimized semiconductor voltage/current stress and converter rating. Also the proposed circuit could realize the independent maximum power point tracking capability for two input PV sources. This paper analyzes the operational principle of the proposed dual-input central capacitor dc/dc converter under both continuous conduction mode and discontinuous conduction mode and presents a comparative study between dual-input central capacitor converter and its counterparts. Besides, an adaptive control method considering PV power difference, operational safety and efficiency is elaborated. Finally, the proposed converter along with its adaptive control method was verified through matlab simulation and a laboratory prototype.
Auteurs: Mengxing Chen;Feng Gao;Ruisheng Li;Xianwei Li;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2017, volume: 53, issue:1, pages: 305 - 318
Editeur: IEEE
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» A Dual-Path 4-Phase Nonuniform Wideband Receiver With Digital MMSE Harmonic Rejection Equalizer
Résumé:
This paper presents a dual-path nonuniform blocker tolerant wideband receiver that employs digital harmonic rejection to suppress local oscillator (LO) harmonic interferers. The proposed receiver performs harmonic rejection of any LO harmonic including seventh and ninth using only four uniformly spaced clocks each with 25% duty cycle. An adaptive minimum mean-squared error (MMSE) harmonic rejection equalizer is developed that minimizes the desired signal distortion in the mean-squared error sense in the presence of harmonic interferers and the correlated noise between the two paths. The chip prototype is fabricated in 130 nm CMOS process and achieved harmonic rejection ratio (HRR) >75 dB for LO harmonic interferers up to the measured 11th harmonic. The 3.1 dB noise figure (NF) at 1 GHz frequency, 14.5 dBm out-of-band third-order intermodulation intercept point (OBIIP3) at 80 MHz offset from 1 GHz and higher than 10 dB return loss in the frequency range of 100–1450 MHz is measured for the proposed receiver.
Auteurs: Esmail Babakrpur;Won Namgoong;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 02.-2017, volume: 65, issue:2, pages: 386 - 395
Editeur: IEEE
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» A Fast and Accurate Hardware String Matching Module with Bloom Filters
Résumé:
Many fields of computing such as Deep Packet Inspection (DPI) employ string matching modules (SMM) that search for a given set of positive strings in their input. An SMM is expected to produce correct outcomes while scanning the input data at high rates. Furthermore the string sets that are searched for are usually large and their sizes increase steadily. Bloom Filters (BFs) are hashing data structures which are fast but their false positive results require further processing. That is, their speed can be exploited for Standard Bloom Filter SMMs (SBFs) as long as the positive probability is low. Multiple BFs in parallel can further increase the throughput. In this paper, we propose the Double Bloom Filter SMM (DBF) which achieves a higher throughput than the SBF and maintains a high throughput even for large positive probabilities. The second Bloom Filter of DBF stores a small enough subset of the positive strings such that its false positive probability is approximately zero. We develop an analytical model of the DBF and show that the throughput advantage of DBF over SBF becomes more prominent if the positive probability and the fraction of matches in the second Bloom Filter increase. Accordingly, we propose a heuristic algorithm that stores the strings that are more frequently matched in the second Bloom Filter according to localities identified in the input. Our numerical results are obtained using realistic values from an FPGA implementation and are validated by SystemC simulations.
Auteurs: Salih Zengin;Ece Güran Schmidt;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 02.-2017, volume: 28, issue:2, pages: 305 - 317
Editeur: IEEE
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» A Fast and Compact Charger for an Li-Ion Battery Using Successive Built-In Resistance Detection
Résumé:
In this brief, a successive built-in resistance (BIR) detection, which operates in the constant average current mode, is proposed to achieve fast charging of a lithium-ion (Li-ion) battery by accurately compensating for the voltage across the BIR. In addition, a low-dropout regulator-based structure is adopted to implement a compact-sized battery charger without using any extra external components. The proposed battery charger is fabricated using a 0.13- $mutext{m}$ BCD process technology with 6-V high-voltage CMOS devices, and its measurement result shows that the overall charging time is reduced by 0.5 h with a 750-mAh Li-ion battery.
Auteurs: Kyunghoon Chung;Seong-Kwan Hong;Oh-Kyong Kwon;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 161 - 165
Editeur: IEEE
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» A Fast Local Bus Current-Based Primary Relaying Algorithm for HVDC Grids
Résumé:
This paper proposes a fast, selective, reliable, and local bus primary relaying algorithm for high-voltage direct current (HVDC) grids. The proposed relaying algorithm only uses measurements obtained from current sensors to detect faults and identify their locations. This algorithm is local and requires only communication at the bus level rather than the system level. Furthermore, the algorithm is not sensitive to the system configuration and operating point and can be employed during line or converter outages with limited retuning and adjustments. The proposed algorithm is applied to a four-terminal HVDC grid. Study results show that the proposed algorithm 1) detects faults on both transmission lines and DC buses; 2) identifies the faulted bus or transmission line; 3) requires insignificant computation capacity; 4) distinguishes between faults and other system transients to prevent erroneous circuit-breaker trips; and 5) is not sensitive to measurement noise.
Auteurs: Sahar Pirooz Azad;Dirk Van Hertem;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2017, volume: 32, issue:1, pages: 193 - 202
Editeur: IEEE
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» A Fast, Robust, and Incremental Model for Learning High-Level Concepts From Human Motions by Imitation
Résumé:
Social robots are becoming a companion in everyday life. To be well accepted by humans, they should efficiently understand meanings of their partners’ motions and body language and respond accordingly. Learning concepts by imitation brings them this ability in a user-friendly way. This paper presents a fast and robust model for incremental learning of concepts by imitation (ILoCI). In ILoCI, observed multimodal spatiotemporal demonstrations are incrementally abstracted and generalized based on their perceptual and functional similarities during the imitation. Perceptually similar demonstrations are abstracted by a dynamic model of the mirror neuron system. The functional similarities of demonstrations are also learned through a limited number of interactions with the teacher. Incremental relearning of acquired concepts together through memory rehearsal enables the learner to gradually extract and utilize the common structural relations among demonstrations to expedite the learning process especially at the initial stages. Performance of ILoCI is assessed using a standard benchmark dataset and a human–robot interaction task in which a humanoid robot learns to abstract teacher's hand motions during imitation. Its performance is also evaluated on occluded observations that are probable in real environments. The results show efficiency of ILoCI in concept acquisition, recognition, prediction, and generation in addition to its robustness to occlusions and high variability in observations.
Auteurs: Mina Alibeigi;Majid Nili Ahmadabadi;Babak Nadjar Araabi;
Apparue dans: IEEE Transactions on Robotics
Date publication: 02.-2017, volume: 33, issue:1, pages: 153 - 168
Editeur: IEEE
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» A Finger Vein Image-Based Personal Identification System With Self-Adaptive Illuminance Control
Résumé:
As a biometric trait, finger vein pattern-based technology is highly effective for personal identification with high security. In this paper, we presented the design of a personal identification system based on near infrared (NIR) finger vein image. In this paper, we introduced an observation model of finger vein imaging, upon which a self-adaptive illuminance control algorithm is proposed and integrated into image acquisition hardware. According to the distribution of pixel intensity of the acquired image, the proposed algorithm could automatically adjust the illuminance distribution of lighting: increase the illuminance of lighting, under which the thicker part of finger body is presented and decrease the illuminance of lighting, under which the thinner part of finger body is presented. With this adaptation, the whole finger body could be illuminated appropriately according to its thickness distribution, and the overexposure and underexposure are avoided effectively. An NIR finger vein image database containing 2040 images is established and published in this paper. In the image preprocessing stage, Gabor filters are used to enhance captured raw finger vein images. In our experiment, the identification performance of our system is evaluated using the recognition rate and the margin distribution. A sparse representation-based algorithm is used to calculate the recognition rate and provide data for margin analysis. The results prove the effectiveness of the proposed illuminance control algorithm and the whole system in finger vein-based personal identification.
Auteurs: Liukui Chen;Jing Wang;Shiyu Yang;Haibo He;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 02.-2017, volume: 66, issue:2, pages: 294 - 304
Editeur: IEEE
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» A Flexible Geometric Mean Decomposition Processor for MIMO Communication Systems
Résumé:
This paper presents a geometric-mean-decomposition (GMD) processor for multiple-input multiple-output (MIMO) communication systems. The proposed GMD processor has a flexible architecture that supports channel matrices of arbitrary dimensions. A complex-valued bi-diagonalization is proposed at the preprocessing stage, which substantially reduces the overall hardware complexity. The proposed GMD processor naturally supports an economic channel state information (CSI) feedback mechanism, rendering it highly suitable for frequency-division-duplexing (FDD) systems. To illustrate the performance of the proposed architecture, we demonstrate an efficient implementation supporting 2 to 8 spatial streams in a 90-nm CMOS technology. The latency constraint of 16 $mutext{s}$ specified in the 802.11ac standard is adopted for this hardware realization. The chip integrates 437.7 K gates in 1.830 $times$ 1.829 $text{mm}^{2}$ and dissipates 125.5 mW at 66.67 MHz from a 1 V supply. Compared with the existing GMD implementations, this work supports GMD for matrices of larger dimensions with comparable silicon area, despite the added spatial information feedback capability.
Auteurs: Yu-Cheng Tsai;Chiao-En Chen;Chia-Hsiang Yang;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2017, volume: 64, issue:2, pages: 446 - 456
Editeur: IEEE
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» A Framework of Mixed Sparse Representations for Remote Sensing Images
Résumé:
In this paper, a new framework of mixed sparse representations (MSRs) is proposed for solving ill-conditioned problems with remote sensing images. In general, it is very difficult to find a common sparse representation for remote sensing images because of complicated ground features. Here we regard a remote sensing image as a combination of subimage of smooth, edges, and point-like components, respectively. Since each domain transformation method is capable of representing only a particular kind of ground object or texture, a group of domain transformations are used to sparsely represent each subimage. To demonstrate the effect of the framework of MSR for remote sensing images, MSR is regarded as a prior for maximum a posteriori when solving ill-conditioned problems such as classification and super resolution (SR), respectively. The experimental results show that not only the new framework of MSR can improve classification accuracy but also it can construct a much better high-resolution image than other common SR methods. The proposed framework MSR is a competitive candidate for solving other remote sensing images-related ill-conditioned problems.
Auteurs: Feng Li;Lei Xin;Yi Guo;Junbin Gao;Xiuping Jia;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2017, volume: 55, issue:2, pages: 1210 - 1221
Editeur: IEEE
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» A Frequency-tunable Two-tone RF Signal Generator by Polarization Multiplexed Optoelectronic Oscillator
Résumé:
A two-tone radio frequency (RF) signal generator realized by a polarization multiplexed optoelectronic oscillator (OEO) is proposed and demonstrated. The OEO employs a dual-polarization modulator and can simultaneously generate two frequency tones through OEO oscillations in two orthogonal polarizations of the same optical carrier. Frequencies of the two tones can be tuned independently by adjusting the electrical filters. Advantage of the proposed system is that, the optical interference between two-tone oscillations is effectively suppressed by polarization isolation and the multi-frequency intermodulation in a single modulator is avoided, which leads to the generation of a high quality two-tone RF signal. In the experiment, a two-tone signal at 9.95GHz and 10.66 GHz is generated with a phase noise (@10kHz) of −105.06 dBc/Hz and −104.43 dBc/Hz, respectively. The frequency tunability of the two-tone signal generator is also demonstrated in a range from 4 GHz to 12 GHz.
Auteurs: Bindong Gao;Fangzheng Zhang;Pei Zhou;Shilong Pan;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 192 - 194
Editeur: IEEE
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» A Fresh Look for IEEE Industry Applications Magazine [From the Editor's Desk]
Résumé:
Presents the introductory editorial for this issue of the publication.
Auteurs: Lanny Floyd;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 02.-2017, volume: 23, issue:1, pages: 3 - 3
Editeur: IEEE
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» A Full Soft-Switching ZVZCS Flyback Converter Using an Active Auxiliary Cell
Résumé:
In this paper, a new soft switching flyback dc-dc converter with a simple zero-voltage and zero-current switching (ZVZCS) cell is proposed. The auxiliary resonant cell consists of one switch, one diode, one inductor, and two capacitors. It provides ZVZCS not only for the main switch but also for the auxiliary switch at both turn-on and turn-off times. In addition, all the auxiliary diodes and body diodes of the switches operate under full ZVZCS except the output diode which turns off only with zero current switching. This soft switching technique makes the proposed converter have less switching losses which leads the converter to operate in higher frequencies and efficiency. Another outstanding feature of the proposed converter is using the auxiliary resonant cell out of the main power path to have lower voltage stress on the switches. In this paper, pulse width modulation (PWM) is employed to control the main switch. A detailed mode analysis of the proposed converter operation is presented along with design procedure. Finally, the accuracy performance of the converter is verified through a 60 W experimental prototype results.
Auteurs: Hadi Tarzamni;Ebrahim Babaei;Amirreza Zarrin Gharehkoushan;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 02.-2017, volume: 64, issue:2, pages: 1123 - 1129
Editeur: IEEE
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» A Fully Integrated Discrete-Time Superheterodyne Receiver
Résumé:
The zero/low intermediate frequency (IF) receiver (RX) architecture has enabled full CMOS integration. As the technology scales and wireless standards become ever more challenging, the issues related to time-varying dc offsets, the second-order nonlinearity, and flicker noise become more critical. In this paper, we propose a new architecture of a superheterodyne RX that attempts to avoid such issues. By exploiting discrete-time (DT) operation and using only switches, capacitors, and inverter-based gm-stages as building blocks, the architecture becomes amenable to further scaling. Full integration is achieved by employing a cascade of four complex-valued passive switched-cap-based bandpass filters sampled at 4\times of the local oscillator rate that perform IF image rejection. Channel selection is achieved through an equivalent of the seventh-order filtering. A new twofold noise-canceling low-noise transconductance amplifier is proposed. Frequency domain analysis of the RX is presented by the proposed DT model. The RX is wideband and covers 0.4–2.9 GHz with a noise figure of 2.9–4 dB. It is implemented in 65-nm CMOS and consumes 48–79 mW.
Auteurs: Massoud Tohidian;Iman Madadi;Robert Bogdan Staszewski;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 02.-2017, volume: 25, issue:2, pages: 635 - 647
Editeur: IEEE
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» A Game Theoretic Framework for Device Association in Heterogeneous Cellular Networks With H2H/IoT Co-Existence
Résumé:
In this letter, a device association algorithm is proposed to consider the diverse association requirements for human-to-human devices (H2HDs) and Internet of Things devices (IoTDs) coexisted in heterogeneous cellular network. The association strategy was developed to jointly maximize downlink (DL) sum rate and minimize total uplink (UL) transmit power for H2HDs while maximizing UL energy efficiency for IoTDs. The association problem is formulated as a cooperative Nash bargaining game. We first develop a two-player bargaining algorithm for two base stations to bargain their associated devices. Then, based on this algorithm and the Hungarian method, a multi-player bargaining algorithm is developed. Simulation results show that the proposed algorithm outperforms the comparable schemes, especially in terms of DL rate distribution for H2HDs, device side energy efficiency for IoTDs, as well as fairness performance among devices.
Auteurs: M. K. Elhattab;Mahmoud M. Elmesalawy;I. I. Ibrahim;
Apparue dans: IEEE Communications Letters
Date publication: 02.-2017, volume: 21, issue:2, pages: 362 - 365
Editeur: IEEE
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» A Gene Selection Method for Microarray Data Based on Binary PSO Encoding Gene-to-Class Sensitivity Information
Résumé:
Traditional gene selection methods for microarray data mainly considered the features’ relevance by evaluating their utility for achieving accurate predication or exploiting data variance and distribution, and the selected genes were usually poorly explicable. To improve the interpretability of the selected genes as well as prediction accuracy, an improved gene selection method based on binary particle swarm optimization (BPSO) and prior information is proposed in this paper. In the proposed method, BPSO encoding gene-to-class sensitivity (GCS) information is used to perform gene selection. The gene-to-class sensitivity information, extracted from the samples by extreme learning machine (ELM), is encoded into the selection process in four aspects: initializing particles, updating the particles, modifying maximum velocity, and adopting mutation operation adaptively. Constrained by the gene-to-class sensitivity information, the new method can select functional gene subsets which are significantly sensitive to the samples’ classes. With the few discriminative genes selected by the proposed method, ELM, K-nearest neighbor and support vector machine classifiers achieve much high prediction accuracy on five public microarray data, which in turn verifies the efficiency and effectiveness of the proposed gene selection method.
Auteurs: Fei Han;Chun Yang;Ya-Qi Wu;Jian-Sheng Zhu;Qing-Hua Ling;Yu-Qing Song;De-Shuang Huang;
Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Date publication: 02.-2017, volume: 14, issue:1, pages: 85 - 96
Editeur: IEEE
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» A General Framework for Asynchronous Communication
Résumé:
We study a problem of sequential frame detection in an asynchronous framework, where a single frame of length $N$ slots is transmitted uniformly in a large interval of known size $A$ slots. In this setup, we seek to characterize the scaling needed of $N$ and the channel (input) parameters for asynchronous optimal frame synchronization. We note that the framework permits a natural trade-off between $N$ and $alpha $ , where $alpha $ is the synchronization threshold of the channel (usually parameterized by the channel input). We present a general framework that permits this trade-off and then characterize the scaling needed of both $N$ and $alpha $ as a function of the asynchronism period $A$ . Finally, we apply our results to the AWGN channel as an illustration.
Auteurs: R. M. Sundaram;Devendra Jalihal;Venkatesh Ramaiyan;
Apparue dans: IEEE Communications Letters
Date publication: 02.-2017, volume: 21, issue:2, pages: 266 - 269
Editeur: IEEE
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» A General Theory of Phase Noise in Transconductor-Based Harmonic Oscillators
Résumé:
We present a rigorous phase noise analysis of a generic harmonic oscillator where the active core can be modeled as a transconductor. Phase noise equations are derived without any specific assumption on the nature of the resonator in the oscillator; furthermore, we provide closed-form $1/f^{2}$ phase noise equations when the resonator consists of an arbitrary number of cascaded LC tanks, each tuned at a different harmonic of the oscillation frequency. We also show that the phase noise caused by transconductor white noise is always proportional to the phase noise caused by resonator losses, and that no flicker noise from the transconductor is up-converted into phase noise in an oscillator with an odd-symmetric voltage waveform. The phase noise for a number of different oscillators/resonators has been simulated, always obtaining an exceedingly good agreement between theoretical predictions and numerical results.
Auteurs: Federico Pepe;Pietro Andreani;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2017, volume: 64, issue:2, pages: 432 - 445
Editeur: IEEE
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» A Generative Approach to Chinese Shanshui Painting
Résumé:
The Shan Shui in the World project recreated Manhattan, New York, in the style of traditional Chinese shanshui paintings by using a generative algorithm to transform its buildings into mountains. This project revisits the ideas implicit in Chinese literati paintings of shan shui: the relationship between urban life and people's yearning for nature and between social responsibility and spiritual purity. Shan Shui in the World was made possible by the growing ubiquitousness of data and the development of data visualization techniques, especially generative art.
Auteurs: Weili Shi;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 02.-2017, volume: 37, issue:1, pages: 15 - 19
Editeur: IEEE
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» A Generic Electrothermal Li-ion Battery Model for Rapid Evaluation of Cell Temperature Temporal Evolution
Résumé:
This paper presents a generic electrothermal model for Li-ion battery. The model is developed with the objective to simplify the parameter identification procedure, while representing adequately the thermal effects on the battery performance. Most of the well-accepted electrothermal Li-ion battery models require in-depth and proprietary battery data or dedicated test environments for parameter identification. The dedicated test bench usually involves expensive thermal test chambers, calorimeters, and temperatures sensors, and challenges associated with their installations. This makes the electrical and thermal simulation of Li-ion batteries difficult to achieve. This paper proposes a generic electrothermal model with a simpler parameter identification process. The parameters identification process is solely based on datasheet discharge curves and simple experiments at room temperature. The model is validated experimentally using a 12 V 40 Ah LiFePO4 battery module. The performance of the model is tested with constant current discharges, constant current-constant voltage charges, as well as with a Simplified Federal Urban Driving Schedule dynamic driving cycle, at different operating temperatures. As expected, the simulation results show an error within ±1% and ±1.3% compared to experimental results, for both steady and dynamic states, respectively.
Auteurs: Souleman Njoya Motapon;Alexandre Lupien-Bedard;Louis-A. Dessaint;Handy Fortin-Blanchette;Kamal Al-Haddad;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 02.-2017, volume: 64, issue:2, pages: 998 - 1008
Editeur: IEEE
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» A Generic Waveform Abnormality Detection Method for Utility Equipment Condition Monitoring
Résumé:
In recent years, power quality (PQ) disturbance data are increasingly applied to extract useful information about the condition of power systems, such as monitoring incipient equipment failures. A prerequisite for such applications is the ability for a PQ monitor to detect abnormal waveforms. In response to this need, a generic method for waveform abnormality detection is proposed in this paper. The proposed method has two unique features. First, abnormalities are detected by comparing the statistical distributions of waveform variations with and without disturbances. Kullback-Leibler divergence (KLD) is used to assess the difference of the distributions. An abnormality exists if the KLD is larger than a threshold. Second, current waveforms are used for detection since they are more sensitive to equipment conditions. The difficulty to set a proper threshold due to large variations of current values is overcome through the adoption of KLD as the distance measure and a systematic threshold selection scheme. The scheme maximizes the detection probability for a given false alarm probability. Field-measured data and simulated data are applied to verify the effectiveness of the method.
Auteurs: Benzhe Li;Yindi Jing;Wilsun Xu;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2017, volume: 32, issue:1, pages: 162 - 171
Editeur: IEEE
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» A Global Approach to Fast Video Stabilization
Résumé:
This paper presents a novel formulation of video stabilization by directly solving for optimal image warps toward stabilized sequence. With the estimated shaky motion via long or short feature trajectories, our approach encodes another two steps, motion compensation and image warping, into a single global optimization process, rather than operating as two individual steps. This process is done only with positions of embedded mesh vertices as common variables. Spatial and temporal coherence is therein reformulated with similarity-invariant representation of motion trajectories and intra- (and inter-) frame consistency of similar transformations with respect to mesh vertices. Such a one-shot formulation converts video stabilization into a quadratic energy minimization problem defined for image warps, and thus can be efficiently resolved by using a robust solver for sparse linear systems. Experimental results demonstrate the flexibility and efficiency of our approach in producing visually plausible stabilization effects on a variety of videos.
Auteurs: Lei Zhang;Qian-Kun Xu;Hua Huang;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 02.-2017, volume: 27, issue:2, pages: 225 - 235
Editeur: IEEE
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» A Graph-Theoretical Approach for Motif Discovery in Protein Sequences
Résumé:
Motif recognition is a challenging problem in bioinformatics due to the diversity of protein motifs. Many existing algorithms identify motifs of a given length, thus being either not applicable or not efficient when searching simultaneously for motifs of various lengths. Searching for gapped motifs, although very important, is a highly time-consuming task due to the combinatorial explosion of possible combinations implied by the consideration of long gaps. We introduce a new graph theoretical approach to identify motifs of various lengths, both with and without gaps. We compare our approach with two widely used methods: MEME and GLAM2 analyzing both the quality of the results and the required computational time. Our method provides results of a slightly higher level of quality than MEME but at a much faster rate, i.e., one eighth of MEME's query time. By using similarity indexing, we drop the query times down to an average of approximately one sixth of the ones required by GLAM2, while achieving a slightly higher level of quality of the results. More precisely, for sequence collections smaller than 50,000 bytes GLAM2 is 13 times slower, while being at least as fast as our method on larger ones. The source code of our C++ implementation is freely available in GitHub: https://github.com/hirvolt1/debruijn-motif.
Auteurs: Elena Czeizler;Tommi Hirvola;Kalle Karhu;
Apparue dans: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Date publication: 02.-2017, volume: 14, issue:1, pages: 121 - 130
Editeur: IEEE
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» A Group-Ordered Fast Iterative Method for Eikonal Equations
Résumé:
In the past decade, many numerical algorithms for the Eikonal equation have been proposed. Recently, the research of Eikonal equation solver has focused more on developing efficient parallel algorithms in order to leverage the computing power of parallel systems, such as multi-core CPUs and GPUs (Graphics Processing Units). In this paper, we introduce an efficient parallel algorithm that extends Jeong et al.’s FIM (Fast Iterative Method, [1] ), originally developed for the GPU, for multi-core shared memory systems. First, we propose a parallel implementation of FIM using a lock-free local queue approach and provide an in-depth analysis of the parallel performance of the method. Second, we propose a new parallel algorithm, Group-Ordered Fast Iterative Method (GO-FIM), that exploits causality of grid blocks to reduce redundant computations, which was the main drawback of the original FIM. In addition, the proposed GO-FIM method employs clustering of blocks based on the updating order where each cluster can be updated in parallel using multi-core parallel architectures. We discuss the performance of GO-FIM and compare with the state-of-the-art parallel Eikonal equation solvers.
Auteurs: Sumin Hong;Won-Ki Jeong;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 02.-2017, volume: 28, issue:2, pages: 318 - 331
Editeur: IEEE
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» A Hierarchical Intelligent Methodology for Spatiotemporal Control of Wafer Temperature in Rapid Thermal Processing
Résumé:
Rapid thermal processing (RTP) is very important for semiconductor manufacturing. The RTP is actually a spatially distributed dynamical system (SDDS) with multiple control sources. Due to its highly nonlinear and spatiotemporal dynamics, it would be difficult to maintain the temperature uniformity inside the RTP. In this paper, a hierarchical intelligent methodology is proposed for the spatiotemporal control of RTP. The control scheme consists of three different levels. At the lower level, the decomposition strategy is taken to divide the SDDS into several relatively simple subsystems; each of them is handled by one control source. At the mid-level, 3-D fuzzy logic controllers (3-D-FLCs) are designed, which have inherent capability to process spatiotemporal dynamics, to maintain the temperature uniformity of each subsystem. At the upper level, a local coordination strategy will be designed to adjust 3-D-FLCs to overcome interactions between the adjacent subsystems. The proposed scheme is applied to the temperature uniformity control of a rapid thermal chemical vapor deposition system, and better temperature uniformity can be achieved.
Auteurs: Xian-Xia Zhang;Han-Xiong Li;Bing Wang;Shiwei Ma;
Apparue dans: IEEE Transactions on Semiconductor Manufacturing
Date publication: 02.-2017, volume: 30, issue:1, pages: 52 - 59
Editeur: IEEE
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» A High-Gain mm-Wave Amplifier Design: An Analytical Approach to Power Gain Boosting
Résumé:
In this paper, a general embedding is proposed to boost the power gain of any device to the maximum achievable gain ( $G_{max }$ ), which is defined as the maximum theoretical gain of the device. Using a gain-plane based analysis, two linear-lossless-reciprocal embeddings are used to perform a movement from the coordinate of the transistor to the coordinate that corresponds to $G_{max }$ . The proposed embedding is applied to a 10 $mu text{m}$ common-source NMOS transistor, and the theoretical and simulation results are presented and compared. The properties of the embedded transistor are inspected, and the few issues in implementation are investigated and addressed. Finally, using the proposed general embedding, an amplifier is implemented in a 65 nm CMOS process with a measured power gain of 9.2 dB at 260 GHz, which is the highest frequency reported in any silicon-based amplifier.
Auteurs: Hadi Bameri;Omeed Momeni;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 357 - 370
Editeur: IEEE
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» A High-Speed Inkjet-Printed Microelectromechanical Relay With a Mechanically Enhanced Double-Clamped Channel-Beam
Résumé:
We report a high-speed inkjet-printed three-terminal microelectromechanical (MEM) relay with a double-clamped beam that exploits the enhanced stiffness of the double-clamped structure to improve electrical performance. To minimize mechanical delay and pull-in voltage, the contact gap between the channel-beam and drain, and the stiffness of the beam and shape of the drain was carefully designed and optimized through a 3-D finite element simulation. The double-clamped beam prevents stiction-related failure between the channel-beam and drain despite the contact gap being only 370 nm for a $> 500~mu text{m}$ long beam. The resulting printed relay delivers a turn-ON delay of $8~mu text{s}$ at a gate voltage of 10 V, a pull-in voltage of only 7.2 V, immeasurable off-leakage, excellent subthreshold swing, and a small hysteresis window of 2 V without any bending or collapsing of the beam. The device also shows reliable operation over $10^{5}$ cycles while maintaining a high ON/OFF ratio of $10^{8}$ , and extremely low ON-state resistance of 3.7 $Omega $ . [2016-0180]
Auteurs: Seungjun Chung;Muhammed Ahosan Ul Karim;Hyuk-Jun Kwon;William Scheideler;Vivek Subramanian;
Apparue dans: Journal of Microelectromechanical Systems
Date publication: 02.-2017, volume: 26, issue:1, pages: 95 - 101
Editeur: IEEE
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» A High-Speed Large-Range Tip-Tilt-Piston Micromirror Array
Résumé:
This paper introduces the design of a high fill-factor (>99%) micromirror array that consists of 1 mm $^{2}$ hexagonal mirrors, which are expected to each independently achieve continuous, closed-loop control of three degrees of freedom (DOFs)—tip, tilt, and piston—over large ranges (> ±10° rotation and $>pm 30mu text{m}$ translation) at high speeds (~45 kHz for a 1° amplitude of rotational oscillation). The flexure topology of this array is designed using the freedom, actuation, and constraint topologies synthesis approach, which utilizes geometric shapes to help designers rapidly consider every flexure topology that best achieves a desired set of DOFs driven by decoupled actuators. The geometry of this array’s comb-drive actuators is optimized in conjunction with the geometry of the system’s flexures using a novel approach. The analytical models underlying this approach are verified using finite-element analysis and validated using experimental data. The capabilities of this new mirror array will enable, or significantly improve, the performance of a variety of high-impact optical technologies such as advanced optical switches, spatial-light modulators, displays, and laser steering or scanning devices. [2016-0222]
Auteurs: Jonathan B. Hopkins;Robert M. Panas;Yuanping Song;Carolyn D. White;
Apparue dans: Journal of Microelectromechanical Systems
Date publication: 02.-2017, volume: 26, issue:1, pages: 196 - 205
Editeur: IEEE
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» A Highly Compact 2.4-GHz Passive 6-bit Phase Shifter With Ambidextrous Quadrant Selector
Résumé:
An extremely compact architecture for a passive 6-bit digital phase shifter is presented. The phase shifter has a range of 360° with 5.6° resolution at 2.4 GHz. The architecture is composed of an ambidextrous quadrant selector in series with a digital fine-tuned phase shifter that makes use of high-ratio symmetrical digitally variable capacitors loading a lumped element transmission line. The phase shifter achieves a 50 $Omega$ match in all 64 states. The circuit occupies approximately 0.47 mm2 on die, and the entire test chip measured 0.84 mm2, including bond pads and ESD structures. The 1-dB compression point was +23 dBm. The chip was fabricated in a commercial 0.13- $mutext{m}$ silicon-on-insulator CMOS process.
Auteurs: Mackenzie Cook;John W. M. Rogers;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 02.-2017, volume: 64, issue:2, pages: 131 - 135
Editeur: IEEE
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» A Joint Compression Scheme of Video Feature Descriptors and Visual Content
Résumé:
High-efficiency compression of visual feature descriptors has recently emerged as an active topic due to the rapidly increasing demand in mobile visual retrieval over bandwidth-limited networks. However, transmitting only those feature descriptors may largely restrict its application scale due to the lack of necessary visual content. To facilitate the wide spread of feature descriptors, a hybrid framework of jointly compressing the feature descriptors and visual content is highly desirable. In this paper, such a content-plus-feature coding scheme is investigated, aiming to shape the next generation of video compression system toward visual retrieval, where the high-efficiency coding of both feature descriptors and visual content can be achieved by exploiting the interactions between each other. On the one hand, visual feature descriptors can achieve compact and efficient representation by taking advantages of the structure and motion information in the compressed video stream. To optimize the retrieval performance, a novel rate-accuracy optimization technique is proposed to accurately estimate the retrieval performance degradation in feature coding. On the other hand, the already compressed feature data can be utilized to further improve the video coding efficiency by applying feature matching-based affine motion compensation. Extensive simulations have shown that the proposed joint compression framework can offer significant bitrate reduction in representing both feature descriptors and video frames, while simultaneously maintaining the state-of-the-art visual retrieval performance.
Auteurs: Xiang Zhang;Siwei Ma;Shiqi Wang;Xinfeng Zhang;Huifang Sun;Wen Gao;
Apparue dans: IEEE Transactions on Image Processing
Date publication: 02.-2017, volume: 26, issue:2, pages: 633 - 647
Editeur: IEEE
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» A Joint Deep Boltzmann Machine (jDBM) Model for Person Identification Using Mobile Phone Data
Résumé:
We propose an audio–visual person identification approach based on a joint deep Boltzmann machine (jDBM) model. The proposed jDBM model is trained in three steps: 1) learning the unimodal DBM models corresponding to the speech and facial image modalities, 2) learning the shared layer parameters using a joint restricted Boltzmann machine (jRBM) model, and 3) the fine-tuning of the jDBM model after the initialization with the parameters of the unimodal DBMs and the shared layer. The activation probabilities of the units of the shared layer are used as the joint features and a logistic regression classifier is used for the combined speech and facial image recognition. We show that by learning the shared layer parameters using a jRBM, a higher accuracy can be achieved compared to the greedy layer-wise initialization. The performance of our proposed model is also compared with a state-of-the art support vector machine (SVM), deep belief network (DBN), and the deep auto-encoder (DAE) models. In addition, our experimental results show that the joint representations obtained from the proposed jDBM model are robust to noise and missing information. Experiments were carried out on the challenging MOBIO database, which includes audio–visual data captured using mobile phones.
Auteurs: Mohammad Rafiqul Alam;Mohammed Bennamoun;Roberto Togneri;Ferdous Sohel;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 02.-2017, volume: 19, issue:2, pages: 317 - 326
Editeur: IEEE
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» A License to Build (Software)
Résumé:
Despite working in a global job market, software engineers must surmount local problems. The web extra at https://youtu.be/X3Lh_SGDNHY is an audio recording of author David Alan Grier reading his new Global Code column, in which he discusses how professional competencies and ethics can be ensured locally while remaining on par with global standards.
Auteurs: David Alan Grier;
Apparue dans: Computer
Date publication: 02.-2017, volume: 50, issue:2, pages: 104 - 104
Editeur: IEEE
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» A Logic Circuit Design for Perfecting Memristor-Based Material Implication
Résumé:
Memristor-based material implication (M-IMP) logic is popular with logic operations, which provides a possibility that memory is operated directly. However, there is a small limitation that memristor is not able to reach the lowest resistance in M-IMP. In this brief, the M-IMP limitation and its influence are analyzed briefly. In addition, a circuit structure that performs a stateful logic operation on memristor memory based on a nanocrossbar is proposed, which can perfect the M-IMP limitation and eliminate the influence. Moreover, we simulate the proposed circuit design and the simulation results verify the correctness of the analysis.
Auteurs: Qiao Chen;Xiaoping Wang;Haibo Wan;Ran Yang;
Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Date publication: 02.-2017, volume: 36, issue:2, pages: 279 - 284
Editeur: IEEE
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» A Look at What's New: Reviewing the Second Edition of API 547
Résumé:
This article will review many of the changes in the second edition of the American Petroleum Institute (API) 547 specification, General-Purpose Form-Wound Squirrel Cage Induction Motors-185 kW (250 hp) Through 2,240 kW (3,000 hp) [1]. The first edition of this standard [2] was released in 2005 to provide a set of requirements for general-purpose motors based on the key criteria of API Standard 541, fourth edition, applicable to 375-kW (500-hp) and larger motors [3]. The scope of API 547 is limited to a range of motor sizes and configurations that fit a majority of general-purpose severe duty applications that are common in petrochemical applications. API 541 has recently been updated to its fifth edition [4], and the second edition of API 547 has followed suit with revisions to the scope and criteria, various clarifications, data sheet changes, and an expanded data sheet guide.
Auteurs: Tim Rahill;Barry Wood;Mark Chisholm;Joel Ocmand;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 02.-2017, volume: 23, issue:1, pages: 70 - 80
Editeur: IEEE
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» A Low Bandwidth DFB Laser-Based Interrogator for Terahertz-Range Fiber Bragg Grating Sensors
Résumé:
This letter reports an all-electronic, low bandwidth swept frequency laser used to interrogate terahertz-range fiber Bragg gratings (THz FBGs) for distributed strain sensing applications. A distributed feedback laser with current injection modulation was employed as the swept frequency laser source. Using the resulting narrow bandwidth (~110 GHz) laser frequency sweep, high accuracy distributed strain measurements were achieved. In order to experimentally investigate this concept, a strain test was conducted using the THz FBGs. During the test, the laser sweeping time was limited to less than 2 ms. Highly linear results were found (R2 = 0.996), with an observed sensitivity of −0.142 GHz/ $mu varepsilon $ and the standard deviation of $1.167~mu varepsilon $ . A multiplexing test was also conducted, and no cross-talk found between sensor elements. These results demonstrate that this interrogation system holds substantial potential as a method of rapid distributed optical fiber frequency-domain sensing.
Auteurs: Zhen Chen;Gerald Hefferman;Tao Wei;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 02.-2017, volume: 29, issue:4, pages: 365 - 368
Editeur: IEEE
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» A Low-Complexity Graph-Based LMMSE Receiver for MIMO ISI Channels With $M$ -QAM Modulation
Résumé:
In this paper, we propose a low complexity graph-based linear minimum mean-square-error (LMMSE) equalizer in order to remove inter-symbol and inter-stream interference in a multiple input multiple output (MIMO) communication. The proposed state space representation inflicted on the graph provides linearly increasing computational complexity with block length. In addition, owing to the Gaussian assumption used in the presented cycle-free factor graph, the complexity of the suggested equalizer structure is not affected by the size of the signaling space. In addition, we introduce an efficient way of computing extrinsic bit log-likelihood ratio values for the LMMSE estimation compatible with higher order alphabets, which is shown to perform better than the other methods in the literature. Overall, we provide an efficient receiver structure reaching high data rates in frequency selective MIMO systems, whose performance is shown to be very close to a genie-aided matched filter bound through extensive simulations.
Auteurs: Pinar Sen;Ali Özgür Yılmaz;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 02.-2017, volume: 16, issue:2, pages: 1185 - 1195
Editeur: IEEE
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» A Low-Order Model for Offshore Floating Vertical Axis Wind Turbine Aerodynamics
Résumé:
Vertical-axis wind turbines (VAWTs) are an attractive economical solution for a deep offshore floating application with their inherent desirable design characteristics. A low-order model is described in this paper that can be utilized for the aerodynamic modeling of these turbines. The cascade model is employed and has been coupled with a dynamic stall model to account for unsteady aerodynamic effects. To provide enhanced numerical efficiency and stability, an iterative time-advancement scheme with an adaptive under-relaxation has been integrated into the developed model. The model's predictive accuracy has been assessed against applicable experimental data in simulating a VAWT's aerodynamics at high Reynolds numbers. A quantitative comparative study shows that the model produced an average normalized root mean square error of 0.106 and 0.288 for the VAWT's normal and tangential force coefficients, respectively. It has been established also that the model's computational requirement is reasonably low and suitable for the industrial design of offshore floating VAWTs.
Auteurs: Brian Hand;Andrew Cashman;Ger Kelly;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2017, volume: 53, issue:1, pages: 512 - 520
Editeur: IEEE
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» A Lyapunov Redesign of Coordination Algorithms for Cyber-Physical Systems
Résumé:
We present an approach for the coordination of a network of agents in a cyber-physical environment. The agents's dynamics are nonlinear, of arbitrary dimensions and possibly heterogeneous. The objective is to design resource-aware distributed control strategies to ensure a coordination task. In particular, we aim at ensuring the convergence of the differences between the agents' output variables to a prescribed compact set, hence covering rendez-vous and formation control as specific scenarios. We develop event-based sampling strategies for that purpose. Three scenarios are studied. We first focus on event-triggered control, in which case the agents continuously measure the relative distances with their neighbours and only update their control input at some time instants. This set-up is relevant to limit changes in control signals and therefore to reduce the resources usage of the actuators. A triggering rule is defined for each edge using an auxiliary variable, whose dynamics only depends on the local variables. We then explain how to derive time-triggered and self-triggered distributed controllers. These control strategies collect measurements and update the control inputs only at some discrete time instants, which save communication and computation resources. The existence of a uniform minimum amount of times between any two edge events is guaranteed in all cases, thus ruling out Zeno phenomenon. The analysis is carried out within the framework of hybrid systems and an invariance principle is used to conclude about coordination.
Auteurs: Claudio De Persis;Romain Postoyan;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 02.-2017, volume: 62, issue:2, pages: 808 - 823
Editeur: IEEE
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» A Machine-Learning-Driven Sky Model
Résumé:
Sky illumination is responsible for much of the lighting in a virtual environment. A machine-learning-based approach can compactly represent sky illumination from both existing analytic sky models and from captured environment maps. The proposed approach can approximate the captured lighting at a significantly reduced memory cost and enable smooth transitions of sky lighting to be created from a small set of environment maps captured at discrete times of day. The author's results demonstrate accuracy close to the ground truth for both analytical and capture-based methods. The approach has a low runtime overhead, so it can be used as a generic approach for both offline and real-time applications.
Auteurs: Pýnar Satýlmýs;Thomas Bashford-Rogers;Alan Chalmers;Kurt Debattista;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 02.-2017, volume: 37, issue:1, pages: 80 - 91
Editeur: IEEE
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» A Message From the New Editor-in-Chief
Résumé:
In recent weeks, when someone learnt that I would be the next Editor-in-Chief (EiC) of the IEEE Transactions on Wireless Communications (TWC), they were often not sure whether to offer their congratulations or their condolences. Indeed, it is a significant responsibility to be the EiC of such a prestigious journal and to follow in the footsteps of my esteemed predecessors. At the same time, it is a great honor to be given the chance to serve our community in this role, and the journal is in such a splendid shape that I am gladly accepting the responsibility. The workload is certainly high but seems manageable, especially thanks to the creation of the Executive Editorial Committee (EEC) by the outgoing EiC Jeff Andrews. The main task of the EEC is to screen incoming papers for scope and quality and assign them to area editors. Taking the EiC out of the daily critical path is a transformative change in the editorial process that allows the EiC to focus more on strategic issues—and to spend several hours per day without having to constantly monitor the flow of incoming papers. I had the opportunity to serve as the inaugural chair of the EEC for 2.5 years, which was a rewarding experience and gave me considerable insight into the journal that I can now draw on as EiC. Also, in the role of EEC Chair, I had the chance to work closely with Jeff and witness firsthand the many improvements he made to the submission process and the journal in general. They include the removal of the requirement to submit both a single-column double-spaced and a double-column single-spaced version of the paper (which I am sure every author appreciates) and a coherent policy on submissions of papers that have partially been published at conferences, plus many others “behind the scenes.” Most of all, however, I am grateful to Jeff for the appointments he made to the editorial board. I am in the enviable position of getting to work with a - antastic group of Editors, Area Editors, and Executive Editorial Committee members, all among the top experts in their fields of specialization.
Auteurs: Martin Haenggi;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 02.-2017, volume: 16, issue:2, pages: 680 - 682
Editeur: IEEE
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» A Metal-Assisted Silicon Slot Waveguide for Highly Sensitive Gas Detection
Résumé:
A metal-assisted silicon slot waveguide for highly sensitive gas detection is proposed. To show the superiority of the proposed structure, the optical confinement factor in the gas region and the sensitivity are theoretically investigated using the 2-D vector finite element method. Numerical results show that the proposed structure can achieve a strong light confinement in the gas region compared with the conventional slot waveguide. The maximal optical confinement factor of 85% is obtained in the proposed structure, which is approximately 2.5 times larger than the conventional slot waveguide. Additionally, the results show that the proposed structure has a large sensitivity compared with the conventional slot waveguide. Finally, a ring resonator based on the proposed structure is analyzed to evaluate the Q factor and to increase the validity of results obtained by 2-D simulation.
Auteurs: Yuhei Ishizaka;Shuntaro Makino;Takeshi Fujisawa;Kunimasa Saitoh;
Apparue dans: IEEE Photonics Journal
Date publication: 02.-2017, volume: 9, issue:1, pages: 1 - 9
Editeur: IEEE
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» A Millimeter-Wave Digital Link for Wireless MRI
Résumé:
A millimeter (mm) wave radio is presented in this work to support wireless MRI data transmission. High path loss and availability of wide bandwidth make mm-waves an ideal candidate for short range, high data rata communication required for wireless MRI. The proposed system uses a custom designed integrated chip (IC) mm-wave radio with 60 GHz as radio frequency carrier. In this work, we assess performance in a 1.5 T MRI field, with the addition of optical links between the console room and magnet. The system uses ON-OFF keying (OOK) modulation for data transmission and supports data rates from 200 Mb/s to 2.5 Gb/s for distances up-to 65 cm. The presence of highly directional, linearly polarized, on-chip dipole antennas on the mm-wave radio along with the time division multiplexing (TDM) circuitry allows multiple wireless links to be created simultaneously with minimal inter-channel interference. This leads to a highly scalable solution for wireless MRI.
Auteurs: Kamal Aggarwal;Kiran R. Joshi;Yashar Rajavi;Mazhareddin Taghivand;John M. Pauly;Ada S. Y. Poon;Greig Scott;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 02.-2017, volume: 36, issue:2, pages: 574 - 583
Editeur: IEEE
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» A Mobility Analytical Framework for Big Mobile Data in Densely Populated Area
Résumé:
Due to the pervasiveness of mobile devices, a vast amount of geolocated data is generated, which allows us to gain deep insight into human behavior. Among other data sources, the analysis of data traffic from mobile Internet enables the study of mobile subscribers' movements over long time periods at large scales, which is paramount to research over a wide range of disciplines, e.g., sociology, transportation, epidemiology, networking, etc. However, to efficiently analyze the massive data traffic from the view of user mobility, several technical challenges have to be tackled before releasing the full potential of such data sources, including data collection, trajectory construction, data noise removing, data storage, and methods for analyzing user mobility. This paper introduces a mobility analytical framework for big mobile data, based on real data traffic collected from second-, third- and fourth-generation networks, which covered nearly 7 million people. To construct a user's history trajectories, we apply different rules to extract users' locations from different data sources and reduce oscillations between the cell towers. The comparison of mobility characteristics between our mobile data and other existing data sources shows the large potential of mobile Internet data traffic to study human mobility. In addition, our experiments discover the changing of city hotspots, the movement patterns during peak hours, and people with similar history trajectories, which uncover the common rules that exist among huge populations in a city.
Auteurs: Yuanyuan Qiao;Yihang Cheng;Jie Yang;Jiajia Liu;Nei Kato;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 02.-2017, volume: 66, issue:2, pages: 1443 - 1455
Editeur: IEEE
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» A Model of Radar Backscatter of Rain-Generated Stalks on the Ocean Surface
Résumé:
In this paper, a model of radar backscattering from rain-generated stalks on the ocean surface in a rain field is proposed. In the model, stalks in the rain field form an array and are considered as finite water cylinders standing out of an infinite water surface. The radar backscattering coefficient from these stalks is derived. Both incoherent and coherent backscattering mechanisms from the stalks are considered. The model shows that the radar backscattering intensity is a function of the average distance between stalks on the water surface, the radar wave frequency, and the incident angle of radar waves. For light/moderate rain (at low rain rates), the radar backscattering intensity increases with increasing rain rate. For heavy rain (at high rain rates), the radar backscattering intensity decreases with increasing rain rate. The maximum radar backscattering intensity occurs at a rain rate that depends on the radar wave frequency and the incident angle of radar waves. The present model is used to explain the radar signatures of a rainfall event simultaneously observed by C-band ENVISAT (European satellite) Advanced Synthetic Aperture Radar (ASAR) and ground-based weather radar in the Northwest Pacific. The relationship between the radar return intensity extracted from the C-band ASAR image and the rain rate obtained from ground-based weather radar is in agreement with the model’s calculation. Also, the air–sea interface in rain fields and its effects on the attenuation of radar backscattering are experimentally studied in the laboratory.
Auteurs: Xinan Liu;Quanan Zheng;Ren Liu;Mark A. Sletten;James H. Duncan;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2017, volume: 55, issue:2, pages: 767 - 776
Editeur: IEEE
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» A MPPT Circuit With 25 $mutext{W}$ Power Consumption and 99.7% Tracking Efficiency for PV Systems
Résumé:
A Maximum Power Point Tracking (MPPT) circuit for a 0.7-W photovoltaic (PV) system is proposed. The circuit employs a modified hill-climbing algorithm based on a 3-points comparison instead of the traditional 2-points comparison. The adopted algorithm simplifies the detection of the Maximum Power Point (MPP) and enables the implementation of a periodic sleep-mode to reduce the overall power consumption without compromising effective tracking of irradiance variations. Moreover, to achieve high MPP tracking efficiency, a low-power linear analog multiplier is implemented to accurately compute the instantaneous power of the PV source from its sensed voltage and current levels. This power-metering function is realized in the analog domain to eliminate the need for data converters and to minimize the MPPT circuit's power consumption. A complete design of the proposed circuit is implemented in 0.18- $mutext{m}$ BiCMOS process in less than 1.55 mm 2 and consumes less than 25 $mutext{W}$ with the digital core running at 500 kHz and a measured peak MPP tracking efficiency of 99.7%.
Auteurs: Ahmed A. Abdelmoaty;Mohammad Al-Shyoukh;Ying-Chih Hsu;Ayman A. Fayed;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 02.-2017, volume: 64, issue:2, pages: 272 - 282
Editeur: IEEE
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» A multi-core CPU and many-core GPU based fast parallel shuffled complex evolution global optimization approach
Résumé:
In the field of hydrological modelling, the global and automatic parameter calibration has been a hot issue for many years. Among automatic parameter optimization algorithms, the shuffled complex evolution developed at the University of Arizona (SCE-UA) is the most successful method for stably and robustly locating the global “best” parameter values. Ever since the invention of the SCE-UA, the profession suddenly has a consistent way to calibrate watershed models. However, the computational efficiency of the SCE-UA significantly deteriorates when coping with big data and complex models. For the purpose of solving the efficiency problem, the recently emerging heterogeneous parallel computing (parallel computing by using the multi-core CPU and many-core GPU) was applied in the parallelization and acceleration of the SCE-UA. The original serial and proposed parallel SCE-UA were compared to test the performance based on the Griewank benchmark function. The comparison results indicated that the parallel SCE-UA converged much faster than the serial version and its optimization accuracy was the same as the serial version. It has a promising application prospect in the field of fast hydrological model parameter optimization.
Auteurs: Guangyuan Kan;Tianjie Lei;Ke Liang;Jiren Li;Liuqian Ding;Xiaoyan He;Haijun Yu;Dawei Zhang;Depeng Zuo;Zhenxin Bao;Mark Amo-Boateng;Youbing Hu;Mengjie Zhang;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 02.-2017, volume: 28, issue:2, pages: 332 - 344
Editeur: IEEE
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» A Multiagent System-Based Protection and Control Scheme for Distribution System With Distributed-Generation Integration
Résumé:
In this paper, a multiagent system-based protection and control scheme is proposed to deal with diverse operation conditions in distribution system due to distributed-generation (DG) integration. Based on cooperation between DG controller and relays, an adaptive protection and control algorithm is designed on converter-based wind turbine DG to limit the influence of infeed fault current. With the consideration of DG control modes, an adaptive relay setting strategy is developed to help protective relays adapt suitable settings to different operation conditions caused by the variations of system topology and DG status. The proposed scheme is tested and validated on a test distribution system in a hardware-in-the-loop real-time testing platform.
Auteurs: Z. Liu;C. Su;H. K. Høidalen;Z. Chen;
Apparue dans: IEEE Transactions on Power Delivery
Date publication: 02.-2017, volume: 32, issue:1, pages: 536 - 545
Editeur: IEEE
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» A Multimodal Robot for Perching and Climbing on Vertical Outdoor Surfaces
Résumé:
Perching can extend the useful mission life of a micro air vehicle. Once perched, climbing allows it to reposition precisely, with low power draw and without regard for weather conditions. We present the Stanford Climbing and Aerial Maneuvering Platform, which is to our knowledge the first robot capable of flying, perching with passive technology on outdoor surfaces, climbing, and taking off again. We present the mechanical design and the new perching, climbing, and takeoff strategies that allow us to perform these tasks on surfaces such as concrete and stucco, without the aid of a motion capture system or off-board computation. We further discuss two new capabilities uniquely available to a hybrid aerial–scansorial robot: the ability to recover gracefully from climbing failures and the ability to increase usable foothold density through the application of aerodynamic forces. We also measure real power consumption for climbing, flying, and monitoring and discuss how future platforms could be improved for longer mission life.
Auteurs: Morgan T. Pope;Christopher W. Kimes;Hao Jiang;Elliot W. Hawkes;Matt A. Estrada;Capella F. Kerst;William R. T. Roderick;Amy K. Han;David L. Christensen;Mark R. Cutkosky;
Apparue dans: IEEE Transactions on Robotics
Date publication: 02.-2017, volume: 33, issue:1, pages: 38 - 48
Editeur: IEEE
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» A Multiphase Switched-Capacitor DC–DC Converter Ring With Fast Transient Response and Small Ripple
Résumé:
A fully integrated step-down switched-capacitor dc–dc converter ring with 123 phases has been designed that could achieve fast dynamic voltage scaling for the microprocessor of wearable devices. The symmetrical multiphase converter ring surrounds its load in the square and supplies power to the on-chip power grid that is easily accessible at any point of the chip edges. The frequency of the $V_{mathrm {DD}}$ -controlled oscillator is adjusted through its supply voltage $V_{mathrm {DD}}$ , which allows the unity-gain frequency to be designed higher than the switching frequency. The converter ring has been fabricated in a low-leakage 65-nm CMOS process. This converter achieves a response time of 3 ns, a reference tracking speed of 2.5 V/ $mu text{s}$ , and a minimum output ripple of 2.2 mV. The peak efficiency is 80% at the power density of 66.6 mW/mm2, and the maximum power density is 180 mW/mm2.
Auteurs: Yan Lu;Junmin Jiang;Wing-Hung Ki;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 02.-2017, volume: 52, issue:2, pages: 579 - 591
Editeur: IEEE
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» A Multitude of RFID Tags: A Broadband Design for Stackable Applications
Résumé:
RFID technology has been a part of our lives for a number years. However, research and development are ongoing to produce novel, improved tags for higher ranges working at lower power as well as to differentiate between tags in logistic applications for conventional chip-based RFIDs. Because of such improvements in already existing infrastructures and close-proximity scenarios, the second ultrahigh-frequency (UHF) RFID student design competition was held in May in San Francisco during the 2016 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS2016).
Auteurs: Patrick Soboll;Volker Wienstroer;Rainer Kronberger;
Apparue dans: IEEE Microwave Magazine
Date publication: 02.-2017, volume: 18, issue:1, pages: 107 - 111
Editeur: IEEE
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» A Natural Interface for Remote Operation of Underwater Robots
Résumé:
Human-machine interfaces play a crucial role in intervention robotic systems operated in hazardous environments, such as deep sea conditions. This article introduces a user interface abstraction layer to enhance reconfigurability. It also describes a VR-based interface that utilizes immersive technologies to reduce user faults and mental fatigue. The goal is to show the user only the most relevant information about the current mission.
Auteurs: Juan C. García;Bruno Patrão;Luís Almeida;Javier Pérez;Paulo Menezes;Jorge Dias;Pedro J. Sanz;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 02.-2017, volume: 37, issue:1, pages: 34 - 43
Editeur: IEEE
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» A Navigation and Control Strategy for Miniature Legged Robots
Résumé:
This paper reports on a model-based control strategy for miniature legged robots tasked with navigation in cluttered environments. Our approach uses a new model for crawling locomotion to derive closed-form expressions of state propagation. The latter enable the development of a feedback control navigation strategy. The strategy consists of a waypoint tracking controller that steers the system along desired paths and an outer control loop that updates the reference path to account for uncertainty. This strategy allows noise-resilient navigation for miniature legged robots and is experimentally validated on an eight-legged robot that navigates in obstacle-cluttered environments.
Auteurs: Konstantinos Karydis;Ioannis Poulakakis;Herbert G. Tanner;
Apparue dans: IEEE Transactions on Robotics
Date publication: 02.-2017, volume: 33, issue:1, pages: 214 - 219
Editeur: IEEE
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» A Network-Based Enhanced Spectral Diversity Approach for TOPS Time-Series Analysis
Résumé:
For multitemporal analysis of synthetic aperture radar (SAR) images acquired with a terrain observation by progressive scan (TOPS) mode, all acquisitions from a given satellite track must be coregistered to a reference coordinate system with accuracies better than 0.001 of a pixel (assuming full SAR resolution) in the azimuth direction. Such a high accuracy can be achieved through geometric coregistration, using precise satellite orbits and a digital elevation model, followed by a refinement step using a time-series analysis of coregistration errors. These errors represent the misregistration between all TOPS acquisitions relative to the reference coordinate system. We develop a workflow to estimate the time series of azimuth misregistration using a network-based enhanced spectral diversity (NESD) approach, in order to reduce the impact of temporal decorrelation on coregistration. Example time series of misregistration inferred for five tracks of Sentinel-1 TOPS acquisitions indicates a maximum relative azimuth misregistration of less than 0.01 of the full azimuth resolution between the TOPS acquisitions in the studied areas. Standard deviation of the estimated misregistration time series for different stacks varies from 1.1e-3 to 2e-3 of the azimuth resolution, equivalent to 1.6-2.8 cm orbital uncertainty in the azimuth direction. These values fall within the 1-sigma orbital uncertainty of the Sentinel-1 orbits and imply that orbital uncertainty is most likely the main source of the constant azimuth misregistration between different TOPS acquisitions. We propagate the uncertainty of individual misregistration estimated with ESD to the misregistration time series estimated with NESD and investigate the different challenges for operationalizing NESD.
Auteurs: Heresh Fattahi;Piyush Agram;Mark Simons;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 02.-2017, volume: 55, issue:2, pages: 777 - 786
Editeur: IEEE
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» A New and Simple Design Approach for Harmonic Suppression in Bandpass Filter
Résumé:
This letter introduces a new and simple approach for designing a harmonic-suppressed bandpass filter (BPF), which is effective for both single-ended and balanced BPFs. According to the planar transmission line theory, there must be a voltage-null point on the quarter-wavelength resonator at the third harmonic. It is chosen as the exciting location of the feeding line so that the harmonic of the designed single-end BPF cannot be excited and then is suppressed successfully, while the passband of the BPF operating at the fundamental resonant frequency ( $f_{0}$ ) of the resonator can be optimized and obtained by tuning other parameters. This technique can be easily transplanted to balanced design, and then the differential-mode (DM) third harmonic of the balanced BPF using the half-wavelength resonator can also be rejected effectively. For demonstration, two design examples, i.e. single-ended and balanced BPFs, are designed and measured. Their simulated and experiment results are presented.
Auteurs: Yun-Li Li;Jian-Xin Chen;Qing-Yuan Lu;Wei Qin;Wenhua Li;Zhi-Hua Bao;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 02.-2017, volume: 27, issue:2, pages: 126 - 128
Editeur: IEEE
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» A New Approach to Reduce the Nonlinear Characteristics of a Stressed Power System by Using the Normal Form Technique in the Control Design of the Excitation System
Résumé:
In this paper, a new approach is presented to reduce the nonlinear characteristics of a stressed power system and improve the transient stability of the system by reducing its second-order modal interaction through retuning some parameters of the generator excitation system. In order to determine the second-order modal interaction of the system, a new index on nonlinearity is developed using the normal form theory. Using the proposed index of nonlinearity, a sensitivity function is formed to indicate the most effective excitation system parameters in the nonlinear behavior of the system. These dominant parameters are tuned to reduce the second-order modal interaction of the system and to reduce the index on nonlinearity. The efficiency of the proposed method is initially validated using a four-machine two-area test system. The IEEE 39-Bus New England test system is then used to investigate the performance of the proposed method for a more realistic system. Simulation results show that a proper tuning of the excitation controller can reduce the second-order modal interaction of the system and can even improve the transient stability margin of the network.
Auteurs: Hadi Lomei;Mohsen Assili;Danny Sutanto;Kashem M. Muttaqi;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 02.-2017, volume: 53, issue:1, pages: 492 - 500
Editeur: IEEE
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» A New Biobjective Probabilistic Risk-Based Wind-Thermal Unit Commitment Using Heuristic Techniques
Résumé:
Large penetration of wind generating units in power systems necessitates a flexible unit commitment tool to handle the intermittent nature of these units as well as demand. Moreover, power system operators face not only the risks of wind power curtailments, but also probable unit outages. Therefore, assessing a tradeoff between operational costs and such risks is very important. In the proposed approach, the probability of the residual demand falling within the up-and-down spinning reserve imposed by n – 1 security criterion is converted into a risk index. A new biobjective probabilistic risk/cost-based unit commitment model is proposed to simultaneously minimize both the operational costs and risk. The novel formulation presented provides a new power redispatch process to satisfy up-and-down ramp rate constraints. A new operational-cycles-based unit commitment algorithm is developed. The approach profits from a new nondominated sorting backtracking search optimization algorithm for extracting the Pareto-optimal set. The proposed approach is shown to provide superior results when applied to two test systems: 1) 10-unit and 2) IEEE 118-bus, 54-unit system.
Auteurs: Farhad Bavafa;Taher Niknam;Rasoul Azizipanah-Abarghooee;Vladimir Terzija;
Apparue dans: IEEE Transactions on Industrial Informatics
Date publication: 02.-2017, volume: 13, issue:1, pages: 115 - 124
Editeur: IEEE
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» A New Building Extraction Postprocessing Framework for High-Spatial-Resolution Remote-Sensing Imagery
Résumé:
In conjunction with the recently developed morphological building index (MBI), the proposed postprocessing framework describes the characteristics of buildings by simultaneously considering the spectral, geometrical, and contextual information, and can be successfully applied to large high–spatial-resolution images. In this way, the proposed framework can alleviate the amount of false alarms to a remarkable extent, which mainly come from the bright soil and vegetation in rural and mountainous areas. Validated on a series of large test images obtained by the widely used commercial satellite sensors, the experiments confirm the promising performance of the proposed framework over various areas, including urban, mountainous, rural, and agricultural areas. Furthermore, the proposed framework increases the quality index by 11% and 9% on average compared to the performance of the original MBI and DMP-SVM, respectively. In addition, the parameter sensitivity is analyzed in detail and appropriate ranges of the parameters are suggested. The proposed building detection framework is designed to be of practical use for building detection from high-resolution imagery.
Auteurs: Xin Huang;Wenliang Yuan;Jiayi Li;Liangpei Zhang;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 02.-2017, volume: 10, issue:2, pages: 654 - 668
Editeur: IEEE
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