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Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 05-2017 trié par par titre, page: 5
» FabSquare: Fabricating Photopolymer Objects by Mold 3D Printing and UV Curing
Résumé:
The FabSquare system is a personal fabrication method that lets users fabricate objects by molding photopolymers inside a 3D printed mold. The molds are printed with UV-transparent materials that allow for UV curing--the polymerization and solidification of the fluid content. The molds can be repeatedly reused to fabricate identical objects or create new objects with identical geometry, but different components. Because the necessary equipment is easily obtainable and affordable, the FabSquare approach is suitable for ordinary users in nonspecialized labs, allowing them to rapidly fabricate a range of objects. https://extras.computer.org/extra/mcg2017030034s1.mp4https://extras.computer.org/extra/mcg2017030034s2.pdf
Auteurs: Vahid Babaei;Javier Ramos;Yongquan Lu;Guillermo Webster;Wojciech Matusik;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 05.-2017, volume: 38, issue:3, pages: 34 - 42
Editeur: IEEE
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» Family of Enhanced ZCS Single-Stage Single-Phase Isolated AC–DC Converter for High-Power High-Voltage DC Supply
Résumé:
AC–DC power supply is essential equipment which builds the connection between the ac grid and the dc loads. In order to achieve high-power density and high efficiency, a family of enhanced zero-current-switched (ZCS) single-stage single-phase isolated ac–dc converters is proposed for high-power high-voltage dc application. Only one resonant capacitor is required for the proposed converters to realize ZCS operation. On the other hand, the over voltage problem which exists in former developed ZCS ac–dc topologies is eliminated. Thus, lower voltage rating IGBTs can be applied. Higher efficiency is realized. At the same time, these converters inherit the feature such as one-stage power conversion, low conduction loss, good total harmonics distortion performance, etc. A 3 kW prototype is built to verify the proposed converters. A comparison is made to show the efficiency improvement clearly.
Auteurs: Chushan Li;Dewei Xu;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3629 - 3639
Editeur: IEEE
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» Fast and Accurate Computation of the Multilook Interferometric Phase Probability Density Function
Résumé:
This letter reports a method to compute the multilook interferometric phase probability density function (pdf) used in interferometric synthetic aperture radar (InSAR). The method is fast and accurate for at least 10 000 looks and the full range of interferometric correlations. This is accomplished by computing the products of large and small numbers in the underlying hypergeometric series logarithmically and by deriving a single-term recursion relation to accelerate the computation. This letter extends the usable range of inputs to the multilook interferometric phase pdf for radar systems with a large number of looks and the entire practical range of interferometric correlation.
Auteurs: Mark S. Haynes;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 769 - 772
Editeur: IEEE
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» Fast and Efficient Analysis of Radome-Enclosed Antennas in Receiving Mode by an Iterative-Based Hybrid Integral Equation/Modified Surface Integration Method
Résumé:
An iterative-based hybrid method, which combines the volume-surface integral equation (VSIE) and the modified surface integration (MSI) method, is presented to analyze the radome-enclosed antennas in receiving mode. Compared with the previously published hybrid approaches, this method improves computational accuracy by including the effects of shaded wall of the radome and the mutual interactions between antennas and radome during the numerical solution of the VSIE in an iterative manner. By embedding different parts of the antenna-radome structure (ARS) into three distinct oct-trees, the multilevel fast multipole algorithm (MLFMA) is used to accelerate both the VSIE solution and the surface/volume integrations in the MSI stage. The new method obtains more accurate results than its original version within less CPU time, and keeps good accuracy with much less memory usage and computational time when compared with the MLFMA-accelerated full-wave VSIE solution for the entire ARS.
Auteurs: Binbin Wang;Mang He;Jinbo Liu;Chuanfang Zhang;Houjun Sun;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2436 - 2445
Editeur: IEEE
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» Fast Grid Security Assessment With N − k Contingencies
Résumé:
The challenge of grid security assessment with $N- k$ contingencies lies in a huge amount of transmission security constraints and even for the modest values of N and k, the computational complexity would be very high. A new method for fast grid security assessment is presented in this paper for DC grid. The key idea is to construct a small number of representative constraints to equivalently “represent” the huge number of original security constraints. It is proved that applying the representative constraints is sufficient to assess grid security as the original security constraints do. An important feature of the new method is that the representative constraints need to be constructed only once offline. They are only related to the parameters of transmission network and do not change with power injections. Numerical testing is performed for IEEE-RTS 24-bus system, IEEE 118-bus system, and the Polish 2383-bus system. The number of representative constraints to be assessed is only 1.1%, 0.32%, and 0.27% of that of the original constraints, respectively, and the computational time of security assessment is greatly reduced.
Auteurs: Yafei Yang;Xiaohong Guan;Qiaozhu Zhai;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2193 - 2203
Editeur: IEEE
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» Fast Packet Classification Based on Hybrid Cutting
Résumé:
Most existing packet classification algorithms adopt only one cutting strategy. However, the proposed algorithm adopts a hybrid one that combines equi-sized cuttings with pivot-based cuttings, so it can significantly increase cutting efficiency. Therefore, it can have distinct features, such as smaller table size, larger supportable rule set, and higher classification performance compared with the existing competitors.
Auteurs: Jae-Hyeong Wee;Wooguil Pak;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1011 - 1014
Editeur: IEEE
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» Fault-Tolerant Converter With a Modular Structure for HVDC Power Transmitting Applications
Résumé:
For the high-voltage direct-current (HVDC) power transmission system of offshore wind power, dc/dc converters are the potential solution to collect the power generated by off-shore wind farms to HVDC terminals. The converters operate with high-voltage gain, high efficiency, and fault tolerance over a wide range of operating conditions. In this paper, an isolated ultrahigh step-up dc/dc converter with a scalable modular structure is proposed for HVDC offshore wind power collection. A flyback-forward converter is employed as the power cell to form the expandable electrically isolated modular dc/dc converter. The duty ratio and phase-shift angle control are also developed for the proposed converter. Fault-tolerant characteristics of the converter are illustrated through the redundancy operation and fault-ride-through tests. Redundancy operation is designed to maintain high operation efficiency of the converters and fault-ride-through operation improves the converter reliability under harsh operating conditions. Analytical studies are carried out, and a 750-W prototype with three modular cells is built and experimentally tested to verify the performance of the proposed modular dc/dc converter.
Auteurs: Yihua Hu;Guipeng Chen;Yang Liu;Lin Jiang;Peng Li;Stephen J. Finney;Wenping Cao;Huifeng Chen;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2245 - 2256
Editeur: IEEE
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» FBG Thermal Sensing Features for Hot Spot Monitoring in Random Wound Electric Machine Coils
Résumé:
This paper investigates the key design and operational features of embedded fiber Bragg grating (FBG) sensing for thermal hot spot monitoring in random wound coils, such as used in low voltage electrical machines. To this end thermal experiments are performed on test wound coils embedded with FBG sensors to examine the vital application features of embedded sensor design, such as the sensor packaging material choice, in-situ calibration, sensitivity to vibration, and thermal response time. Measurement error rates are examined and quantified in representative practical tests. The reported results enable a much improved understanding of the performance implications of embedded FBG sensor design features and the attainable in-situ hot spot thermal monitoring performance in random wound coils.
Auteurs: Anees Mohammed;Siniša Djurović;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3058 - 3067
Editeur: IEEE
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» FBMC System: An Insight Into Doubly Dispersive Channel Impact
Résumé:
It has been claimed that filter bank multicarrier (FBMC) systems suffer from negligible performance loss caused by moderate dispersive channels in the absence of guard time protection between symbols. However, a theoretical and systematic explanation/analysis for the statement is missing in the literature to date. In this paper, based on one-tap minimum mean square error (MMSE) and zero-forcing (ZF) channel equalizations, the impact of doubly dispersive channel on the performance of FBMC systems is analyzed in terms of mean square error of received symbols. Based on this analytical framework, we prove that the circular convolution property between symbols and the corresponding channel coefficients in the frequency domain holds loosely with a set of inaccuracies. To facilitate analysis, we first model the FBMC system in a vector/matrix form and derive the estimated symbols as a sum of desired signal, noise, intersymbol interference (ISI), intercarrier interference (ICI), interblock interference (IBI), and estimation bias in the MMSE equalizer. Those terms are derived one-by-one and expressed as a function of channel parameters. The numerical results reveal that under harsh channel conditions, e.g., with large Doppler spread or channel delay spread, the FBMC system performance may be severely deteriorated and error floor will occur.
Auteurs: Lei Zhang;Pei Xiao;Adnan Zafar;Atta ul Quddus;Rahim Tafazolli;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3942 - 3956
Editeur: IEEE
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» Feasibility Study of Using Electrically Conductive Concrete for Electromagnetic Shielding Applications as a Substitute for Carbon-Laced Polyurethane Absorbers in Anechoic Chambers
Résumé:
This paper investigates conductive concrete in electromagnetic shielding applications as a viable alternative to carbon-laced polyurethane, which is used as an absorber material in anechoic chambers. To greatly increase concrete’s electromagnetic shielding performance, carbon black, graphite powder, and steel fibers are introduced to its composition. Samples of conductive concrete have been prepared and its shielding effectiveness is evaluated. The test method is based on using power spectrum analysis to characterize the degree of shielding due to the different mechanisms of reflection and absorption. The tested samples are in the shape of anechoic chambers pyramidal cones, to provide gradual impedance gradient. Slabs with flat surface are also built and tested in order to compare the results. Measured data are then compared with published figures for commercial chamber performances. The range of frequency tested is from 1 to 5.5 GHz. The pyramidal conductive concrete samples yield an excellent shielding effectiveness of approximately 65 dB as opposed to the carbon-laced polyurethane performance of 50 dB.
Auteurs: Tuqa Khalid;Lutfi Albasha;Nasser Qaddoumi;Sherif Yehia;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2428 - 2435
Editeur: IEEE
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» Feature Constrained Multi-Task Learning Models for Spatiotemporal Event Forecasting
Résumé:
Spatial event forecasting from social media is potentially extremely useful but suffers from critical challenges, such as the dynamic patterns of features (keywords) and geographic heterogeneity (e.g., spatial correlations, imbalanced samples, and different populations in different locations). Most existing approaches (e.g., LASSO regression, dynamic query expansion, and burst detection) address some, but not all, of these challenges. Here, we propose a novel multi-task learning framework that aims to concurrently address all the challenges involved. Specifically, given a collection of locations (e.g., cities), forecasting models are built for all the locations simultaneously by extracting and utilizing appropriate shared information that effectively increases the sample size for each location, thus improving the forecasting performance. The new model combines both static features derived from a predefined vocabulary by domain experts and dynamic features generated from dynamic query expansion in a multi-task feature learning framework. Different strategies to balance homogeneity and diversity between static and dynamic terms are also investigated. And, efficient algorithms based on Iterative Group Hard Thresholding are developed to achieve efficient and effective model training and prediction. Extensive experimental evaluations on Twitter data from civil unrest and influenza outbreak datasets demonstrate the effectiveness and efficiency of our proposed approach.
Auteurs: Liang Zhao;Qian Sun;Jieping Ye;Feng Chen;Chang-Tien Lu;Naren Ramakrishnan;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 05.-2017, volume: 29, issue:5, pages: 1059 - 1072
Editeur: IEEE
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» Field Demonstration of a Real-Time 100-Gb/s PON Based on 10G-Class Optical Devices
Résumé:
We have demonstrated the first field trial of a real-time 100-Gb/s passive optical network with downstream/upstream data rates of 25/10-Gb/s/λ based on 10G-class optical devices supporting 0–40 km differential reach. We employ a single delay-interferometer (DI) to realize chirp management as well as frequency equalization to combat the chromatic dispersion during the fiber transmission and equalize the frequency response of the bandwidth-limited system. Owing to the periodical characteristic, DI can successfully manage the four downstream wavelengths simultaneously. As for the upstream transmission, a fiber Bragg grating is employed to compensate the dispersion of the four upstream channels. In addition, an optical amplification deployed at the optical line termination (OLT) is used to amplify the downstream optical power and pre-amplify the upstream signal for supporting more users. All the active and passive components except for transceivers are packaged into a single module in the OLT. The system stability is verified within 67-h real-time bit error rate measurement. We obtained a power budget of 33 dB with 0–40 km reach of standard single mode fiber based on non-return-to-zero on-off-keying modulation format for both downstream and upstream.
Auteurs: Honglin Ji;Lilin Yi;Zhengxuan Li;Lei Xue;Xiang Li;Qi Yang;Suyi Wang;Ying Yang;Shaohua Yu;Weisheng Hu;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1914 - 1921
Editeur: IEEE
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» Field Measurement and Analysis of Long-Reach and High-Splitting-Ratio 10G-EPON With Optical Amplifier in Central Office
Résumé:
It is important to economize the infrastructure of the access network and enhance its profitability because it represents the greatest part of network infrastructure cost. As 10G-EPON can be cost-effectively shared among various access services, it is one of the strong candidates to reduce the infrastructure cost of the next-generation access network. To further enhance cost effectiveness, it is useful to improve the acceptable link budget of access systems by using optical amplifiers (OAs), which can increase the splitting ratios and extend the reachable distance of the system. In this paper, we demonstrate an $N$:1 redundant 10G-EPON system with dual-rate central-office-set-type semiconductor optical amplifier (CO-SOA). Our 10G-EPON system reduces OPEX and CAPEX due to its extended reachable distance and elimination of intermediate offices while keeping its system reliability with the $N$ :1 protection system. Moreover, we also develop a method for estimating the total reachable distance of 10G-EPON systems with OAs in order to quantitatively evaluate the effect of extending reachable distance on various combinations of splitting ratio based on the results of actual demonstrations. Analyses of field measurement results clarify that the proposed system has sufficient design flexibility so as to satisfy the subscriber distribution requirements as regards the factors of splitting ratio and reachable distance. The results indicate that the $N$:1 optical subscriber unit protection with CO-SOAs is a promising approach to practical 10G-EPON systems that are cost effective and reliable.
Auteurs: Takuya Tsutsumi;Yoshihito Sakai;Toshihito Fujiwara;Hiroshi Ou;Yasutaka Kimura;Takeshi Sakamoto;Ken-Ichi Suzuki;Manabu Kubota;Akihiro Otaka;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1775 - 1784
Editeur: IEEE
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» Field Simulation Approach for Computing the Commutation Angle Error of EC Motors
Résumé:
Electronically commutated motors produce a mechanical torque by switching the currents in their stator winding system according to the instantaneous rotor position during rotation. The rotor position is determined by Hall sensors capturing the magnetic field of the rotor's permanent magnets. In operation, the Hall sensors are exposed not only to the rotor field, but also to the field of stator windings. This inevitably leads to a certain commutation angle error (CA error) and a reduced motor performance. This paper presents a general 3-D magnetic field simulation approach for computing the CA error and for finding an optimal position of the Hall sensors. The obtained numerical results and their verification by measurements are presented in detail.
Auteurs: Christian Koster;Jens Schulze;Thomas Schmidiger;Raniero Pittini;Jasmin Smajic;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 1942 - 1947
Editeur: IEEE
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» Fin-Array Tunneling Trigger With Tunable Hysteresis on (001) Silicon Substrate
Résumé:
We report the fabrication and characterization of a GaAs fin-array tunneling trigger monolithically integrated on an exact (001) silicon substrate. A Schmitt-trigger-like behavior was observed under double sweep condition by connecting the tunnel diode with an on-chip load resistor. The tunneling trigger circuit was studied using load line analysis. Critical parameters of the circuit were extracted. We found that the circuit hysteresis can be tuned by tailoring of the diode dimensions and load resistor values.
Auteurs: Yu Han;Qiang Li;Kei May Lau;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 556 - 559
Editeur: IEEE
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» Finding Needles in a Haystack: Missing Tag Detection in Large RFID Systems
Résumé:
Radio frequency identification technology has been widely used in missing tag detection to reduce and avoid inventory shrinkage. In this application, promptly finding out the missing event is of paramount importance. However, the existing missing tag detection protocols cannot efficiently handle the presence of a large number of unexpected tags whose IDs are not known to the reader, which shackles the time efficiency. To deal with the problem of detecting missing tags in the presence of unexpected tags, this paper introduces a two-phase Bloom filter-based missing tag detection (BMTD) protocol. The proposed BMTD exploits Bloom filter in sequence to first deactivate the unexpected tags and then test the membership of the expected tags, thus dampening the interference from the unexpected tags and considerably reducing the detection time. Moreover, the theoretical analysis of the protocol parameters is performed to minimize the detection time of the proposed BMTD and achieve the required reliability simultaneously. In addition, we derive a critical threshold on the unexpected tag size for the execution of first phase in BMTD. Extensive experiments are then conducted to evaluate the performance of the proposed BMTD. The results demonstrate that the proposed BMTD significantly outperforms the state-of-the-art solutions.
Auteurs: Jihong Yu;Lin Chen;Rongrong Zhang;Kehao Wang;
Apparue dans: IEEE Transactions on Communications
Date publication: 05.-2017, volume: 65, issue:5, pages: 2036 - 2047
Editeur: IEEE
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» Finite Element Small-Signal Simulation of Electromagnetic Devices Considering Eddy Currents in the Laminations
Résumé:
This paper presents the validation of a small-signal finite-element simulation strategy comparing different simulation approaches. At first, a full 3-D non-linear model in the time domain is presented. Then, the small-signal strategy has been applied to the 3-D model achieving a considerable reduction of computational time. In both 3-D models, the eddy currents in the laminations are fully modeled. Then, in order to avoid 3-D model, a 2-D model has been considered. In this case, eddy currents are included adopting a homogenization technique. In the 2-D case, both non-linear time domain simulations and small-signal strategy have been implemented. The results of the four considered simulation strategies are in very good agreement, proving that the small-signal simulation strategy can be profitably used in order to reduce significantly the computational cost. As an example, this paper considers a two-port mutual inductor as a test model.
Auteurs: Omar Bottesi;Luigi Alberti;Ruth V. Sabariego;Johan Gyselinck;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 8
Editeur: IEEE
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» Finite Model Approximations and Asymptotic Optimality of Quantized Policies in Decentralized Stochastic Control
Résumé:
We consider finite model approximations of a large class of static and dynamic team problems where these models are constructed through uniform quantization of the observation and action spaces of the agents. The strategies obtained from these finite models are shown to approximate the optimal cost with arbitrary precision under mild technical assumptions. In particular, quantized team policies are asymptotically optimal. This result is then applied to Witsenhausen's celebrated counterexample and the Gaussian relay channel problem. For Witsenhausen's counterexample, our approximation approach provides, to our knowledge, the first rigorously established result that one can construct an $varepsilon$-optimal strategy for any $varepsilon > 0$ through a solution of a simpler problem.
Auteurs: Naci Saldi;Serdar Yüksel;Tamás Linder;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2360 - 2373
Editeur: IEEE
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» Finite-Difference Modeling of Broadband Huygens’ Metasurfaces Based on Generalized Sheet Transition Conditions
Résumé:
An explicit time-domain finite-difference technique for modeling zero-thickness Huygens’ metasurfaces based on generalized sheet transition conditions (GSTCs) is proposed and demonstrated using full-wave simulations. The Huygens’ metasurface is modeled using electric and magnetic surface susceptibilities, which are found to follow a double-Lorentz dispersion profile. To solve zero-thickness Huygens’ metasurface problems for general broadband excitations, the double-Lorentz dispersion profile is combined with GSTCs, leading to a set of first-order differential fields equations in time domain. Identifying the exact equivalence between Huygens’ metasurfaces and coupled RLC oscillator circuits, the field equations are then subsequently solved using standard circuit modeling techniques based on a finite-difference formulation. Several examples, including generalized refraction, are shown to illustrate the temporal evolution of scattered fields from the Huygens’ metasurface under plane-wave normal incidence, in both harmonic steady-state and broadband regimes. In particular, due to its inherent time-domain formulation, a significant strength of the methodology is its ability to model time-varying metasurfaces, which is demonstrated with a simple example of a pumped metasurface leading to new frequency generation and wave amplification.
Auteurs: Tom J. Smy;Shulabh Gupta;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2566 - 2577
Editeur: IEEE
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» Finite-Difference Time-Domain Technique for Gyroelectric Material Structure Simulation Using Recursive Convolutions in Polarization
Résumé:
A gyrotropic material handling method is proposed. Our technique does not require modification of the finite-difference time-domain stepping algorithm, and the gyroelectric phenomenon can be treated as a variation of material polarization. The simulation of electromagnetic wave transmission through a test gyroelectric structure of a magnetized plasma layer is presented and compared with the analytical solution. An open source implementation is presented.
Auteurs: A. V. Friman;A. A. Gorbatsevich;P. P. Sverbil;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2745 - 2747
Editeur: IEEE
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» Finite-Element Modeling of Metasurfaces With Generalized Sheet Transition Conditions
Résumé:
A modeling of metasurfaces in the finite-element method (FEM) based on generalized sheet transition conditions (GSTCs) is presented. The discontinuities in electromagnetic fields across a metasurface as represented by the GSTC are modeled by assigning nodes to both the sides of the metasurface. The FEM-GSTC formulation in both 1-D and 2-D domains is derived and implemented. The method is extended to handle more general bianistroptic metasurfaces. The formulations are validated by several illustrative examples.
Auteurs: Srikumar Sandeep;Jian-Ming Jin;Christophe Caloz;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2413 - 2420
Editeur: IEEE
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» Finite-Length Linear Schemes for Joint Source-Channel Coding Over Gaussian Broadcast Channels With Feedback
Résumé:
In this paper, we study linear encoding for a pair of correlated Gaussian sources transmitted over a two-user Gaussian broadcast channel in the presence of unit-delay noiseless feedback, abbreviated as the GBCF. Each pair of source samples is transmitted using a linear transmission scheme in a finite number of channel uses. We investigate three linear transmission schemes: A scheme based on the Ozarow–Leung (OL) code, a scheme based on the linear quadratic Gaussian (LQG) code of Ardestanizadeh et al., and a novel scheme derived in this paper using a dynamic programming (DP) approach. For the OL and LQG schemes we present lower and upper bounds on the minimal number of channel uses needed to achieve a target mean-square error (MSE) pair. For the LQG scheme in the symmetric setting, we identify the optimal scaling of the sources, which results in a significant improvement of its finite horizon performance, and, in addition, characterize the (exact) minimal number of channel uses required to achieve a target MSE. Finally, for the symmetric setting, we show that for any fixed and finite number of channel uses, the DP scheme achieves an MSE lower than the MSE achieved by either the LQG or the OL schemes.
Auteurs: Yonathan Murin;Yonatan Kaspi;Ron Dabora;Deniz Gündüz;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 2737 - 2772
Editeur: IEEE
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» Finite-Time Fuzzy Sampled-Data Control for Nonlinear Flexible Spacecraft With Stochastic Actuator Failures
Résumé:
This paper deals with the problem of finite-time sampled-data control for nonlinear flexible spacecraft described by Takagi–Sugeno (T–S) fuzzy model with stochastic actuator failures. Different from the existing literatures, T–S fuzzy approach is used to model the nonlinear behaviors of flexible spacecraft for its good approximation performance. A novel and general input model related to Markovian variables is developed to depict the stochastic actuator failures, which is capable of covering various faulty modes. With the aid of stochastic analysis and convex optimization techniques, a novel fault-tolerant fuzzy switching controller is designed to carry out the finite-time attitude stabilization for flexible spacecraft with the existence of stochastic failures and sampled-data inputs, and an optimal $H_infty$ performance level is ensured simultaneously. Finally, a practical example with simulation results are provided to validate the effectiveness of the developed control strategy.
Auteurs: Guanghui Sun;Shidong Xu;Zhan Li;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3851 - 3861
Editeur: IEEE
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» Finite/Fixed-Time Stabilization for Nonlinear Interconnected Systems With Dead-Zone Input
Résumé:
The decentralized control problem is considered for a class of nonlinear time-varying interconnected systems. Each subsystem is with the dead-zone input and unmodeled dynamics. The interconnections are bounded by time-varying nonlinear functions, which relaxes the commonly used linear condition or time-invariant condition. Based on the recursive method, we design a new decentralized finite-time controller such that all the state variables reach zero in finite time. The reaching time is based on the design parameters and initial value of system state. Furthermore, the fixed time stability conditions are given and the constructed controller can guarantee the fixed-time stabilization of the system, in which the reaching time only depends the control design parameters. Finally, simulation results are presented to illustrate the effectiveness of proposed method.
Auteurs: Changchun Hua;Yafeng Li;Xinping Guan;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2554 - 2560
Editeur: IEEE
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» First Principles Optimization of Opto-Electronic Communication Links
Résumé:
We introduce a first principles, end-to-end analysis of opto-electronic communication links which incorporates a thorough model of the receiver circuitry, in addition to the more familiar laser transmitter optimization. In particular, we optimize receiver sensitivity and power by studying their dependence on front-end design as well as follow-on digital sampler requirements. We find that the photo-receiver sensitivity is the most important factor in controlling the overall link power consumption. Our physical model and circuit optimization principles are applied to a heterogenous-integrated photonic+CMOS platform, where we show state-of-the-art performance through this physics-based rapid-design protocol. Incidentally this greatly simplifies the design process. Lastly, we apply this approach to extrapolate future performance trends, platform bottlenecks, and fundamental limits in optical link design while showcasing the potential for sub-1fJ/bit system efficiency at high speeds.
Auteurs: Krishna T. Settaluri;Christopher Lalau-Keraly;Eli Yablonovitch;Vladimir Stojanović;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1270 - 1283
Editeur: IEEE
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» First-Principles Investigation on Interaction of NH3 Gas on a Silicene Nanosheet Molecular Device
Résumé:
Using nonequilibrium Green's function method and density functional theory, electronic properties along with NH 3 adsorption properties on armchair silicene nanosheet device are investigated. The armchair silicene nanosheet is utilized for modeling silicene molecular device. The variation in the peak amplitude is noticed along the conduction band and valence band through the transmission spectrum in silicene molecular device. The density of states spectrum illustrates the variation in the peak maxima owing to transfer of electrons between silicene nanosheet and NH 3 gas molecule. I–V characteristics support the variation in the current upon adsorption of NH3 gas molecule on silicene molecular device. The findings show that silicene molecular device can be utilized for detection of NH3 gas in the mixed gas atmosphere.
Auteurs: Veerappan Nagarajan;Ramanathan Chandiramouli;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 445 - 452
Editeur: IEEE
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» First-Principles-Based Quantum Transport Simulations of Monolayer Indium Selenide FETs in the Ballistic Limit
Résumé:
We investigate the ballistic performance of monolayer indium selenide (InSe) n-type FETs, benchmarking with monolayer WS2, WSe2, and black phosphorus FETs. We utilize first-principles-based quantum transport simulations employing density functional theory and nonequilibrium Green’s function. The transfer characteristics, subthreshold swing, and drain-induced barrier lowering of InSe FETs are assessed and compared with those of the benchmarks. Our comparison of InSe FETs to the benchmark transistors reveals that InSe transistors are competitive in ON-state performance, but the short-channel effects in ultrascaled InSe FETs need to be suppressed. InSe FETs are favorable for high-performance applications rather than low power ones.
Auteurs: Yongsoo Ahn;Mincheol Shin;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2129 - 2134
Editeur: IEEE
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» Fixed Rank Kriging for Cellular Coverage Analysis
Résumé:
Coverage planning and optimization is one of the most crucial tasks for a radio network operator. Efficient coverage optimization requires accurate coverage estimation. This estimation relies on geo-located field measurements that are gathered today during highly expensive drive tests (DT) and will be reported in the near future by users’ mobile devices thanks to the Third-Generation Partnership Project (3GPP) minimization of drive tests (MDT) feature. This feature consists of an automatic reporting of the radio measurements associated with the geographic location of the user's mobile device. Such a solution is still costly in terms of battery consumption and signaling overhead. Therefore, predicting the coverage on a location where no measurements are available remains a key and challenging task. This paper describes a powerful tool that gives an accurate coverage prediction on the whole area of interest: It builds a coverage map by spatially interpolating geo-located measurements using the Kriging technique. This paper focuses on the reduction of the computational complexity of the Kriging algorithm by applying fixed rank Kriging (FRK). The performance evaluation of the FRK algorithm both on simulated measurements and real field measurements shows a good tradeoff between prediction efficiency and computational complexity. In order to go a step further toward the operational application of the proposed algorithm, a multicellular use case is studied. Simulation results show good performance in terms of coverage prediction and detection of the best serving cell.
Auteurs: Hajer Braham;Sana Ben Jemaa;Gersende Fort;Eric Moulines;Berna Sayrac;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4212 - 4222
Editeur: IEEE
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» Flash Light Sintering of Silver Nanoink for Inkjet-Printed Thin-Film Transistor on Flexible Substrate
Résumé:
In this paper, we study flash light sintering of inkjet-printed silver nanoink and show its application in printed and flexible thin film transistors. Flash method, which uses pulsed light to sinter metal nanoparticles, is a very fast and low-temperature sintering method. Hence, it facilitates in quick fabrication of low cost, flexible electronic devices. In the current work, various silver patterns were obtained by inkjet printing of silver nanoink on flexible substrate and then the patterns were sintered by flash method. Several flash sintering parameters were carefully optimized to achieve high electrical conductivity. In next stage, such printed and flash sintered silver patterns were used as source and drain contacts in thin-film transistor. Indium tin oxide coated polyethylene terephthalate sheet was used as substrate as well as bottom gate contact in transistor structure. On the other hand, polystyrene and pentacene were used in gate dielectric and channel layer, respectively. Such printed transistor with channel length of 28 μm and width of 68 μm exhibited field effect mobility of 0.09 cm2V−1s −1 and ON/OFF ratio on the order of 106. Finally, a comparative study was made between transistor performance with printed silver contacts and vacuum deposited silver contacts to ensure printing and sintering steps do not cause any notable degradation to the organic semiconducting layer.
Auteurs: Sudipta Kumar Sarkar;Harshad Gupta;Dipti Gupta;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 375 - 382
Editeur: IEEE
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» Flat Panel Light-Field 3-D Display: Concept, Design, Rendering, and Calibration
Résumé:
Recent autostereoscopic 3-D (A3D) displays suffer from many limitations such as narrow viewing angle, low resolution, and shallow depth effects. As these limitations mainly originate from the insufficiency of pixel resources, it is not easy to obtain a feasible solution that can solve all the limitations simultaneously. In many cases, it will be better to find a good compromising design. Generally, the multiview display and the integral imaging display are the representative designs of A3D. However, as they are too canonical and lack flexibility in design, they tend to be a tradeoff. To address these design issues, we have analyzed the multiview display and the integral image display in a light-field coordinate and developed a 3-D display design framework in a light-field space. The developed framework does not use the “view” concept anymore. Instead, it considers the spatial distribution of rays of the 3-D display and provides more flexible and sophisticated design methods. In this paper, the developed design method is explained using a new pixel value assigning algorithm, called the light-field rendering, and vision-based parameter calibration methods for 3-D displays. We have also analyzed the blur effects caused by the depth and display characteristics. By implementing the proposed method, we have designed a 65-in 96-view display with a 4K panel. The developed prototype has showed almost seamless parallax with a high-resolution comparable to the conventional four to five views displays. This paper will be useful to readers interested in A3D displays, especially in the multiview and the integral imaging displays.
Auteurs: Dongkyung Nam;Jin-Ho Lee;Yang Ho Cho;Young Ju Jeong;Hyoseok Hwang;Du Sik Park;
Apparue dans: Proceedings of the IEEE
Date publication: 05.-2017, volume: 105, issue:5, pages: 876 - 891
Editeur: IEEE
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» Flexibility Is Key in New York: New Tools and Operational Solutions for Managing Distributed Energy Resources
Résumé:
New York State is pioneering a new approach to regulating its electric utility companies that is expected to usher in the distributed energy system of tomorrow. Among the goals of the New York REV (Reforming the Energy Vision) proceeding launched in 2015 are a 40% reduction in greenhouse gas emissions from 1990 levels and a mandate for 50% of the state's electricity to be generated from renewable resources by 2030. In 2014, 25% of New York's electric generation was produced by renewables, of which 80% was from hydropower. In addition to these and other objectives, the New York Public Service Commission has identified the need to establish a distributed system platform provider (DSPP), which will facilitate new markets to accelerate adoption and realize the value of distributed energy resources (DERs). To do this, the incumbent utilities will perform the role of the DSPP and create and operate the distributed system platform (DSP). Building the DSP is a big task, and each of the New York utilities is in the process of deploying it according to their distribution system implementation plans (DSIPs).
Auteurs: Bob Currie;Chad Abbey;Graham Ault;Jeff Ballard;Brian Conroy;Ryan Sims;Chris Williams;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 05.-2017, volume: 15, issue:3, pages: 20 - 29
Editeur: IEEE
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» Flexible and Stretchable Microwave Microelectronic Devices and Circuits
Résumé:
Electronic systems built on flexible plastic films and stretchable rubber sheets have attracted new applications in many emerging fields. Integration of high-speed electronics such as microwave power amplifiers and switches can extend the applications even further with wireless capabilities. As such, flexible and stretchable microwave electronics represent opportunities for future electronics where remote capabilities are desired. Here, we review advances in numerous types of microelectronic devices used for fast, flexible, and stretchable electronic devices, as well as flexible and stretchable passive elements and circuitries. We first introduce the challenges associated with design and fabrication, and the characteristics required for high-frequency operation of the devices on foreign substrates. Second, we review the recent efforts that were made utilizing different types of high-performance semiconductors, which are ideal for high-speed flexible and stretchable electronics, such as silicon, compound semiconductors, and 1-D and 2-D materials. Third, passive electronic components fabricated on such substrates, including inductors, capacitors, and transmission lines, are reviewed. Finally, we discuss the flexible and stretchable microwave electronics at the circuit level and review the recent advances in making numerous types of flexible and stretchable microwave circuits for diverse applications.
Auteurs: Yei Hwan Jung;Huilong Zhang;Sang June Cho;Zhenqiang Ma;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 1881 - 1893
Editeur: IEEE
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» Flexible Capacitive Hydrogel Tactile Sensor With Adjustable Measurement Range Using Liquid Crystal and Carbon Nanotubes Composites
Résumé:
In this paper, we present a $4times4$ capacitive pressure tactile sensor fabricated with new materials, which consists of one dielectric layer and two electrode layers. The dielectric layer is composed of carbon nanotubes dispersed in liquid crystal, which is surrounded by a hydrogel elastomeric membrane. An upper Au parylene film and a lower Au parylene film taped on the kapton tapes are served as the electrode layers. The properties of the devices are well characterized and the capability of adjustable measurement range is successfully realized. Experimental results demonstrate that the capacitance will change with the different driving frequency and voltage accordingly.
Auteurs: Lixin Chen;Jingquan Liu;Xiaolin Wang;Bowen Ji;Xiang Chen;Bin Yang;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 1968 - 1972
Editeur: IEEE
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» Flexible multiband OFDM ultra-wideband services based on optical frequency combs
Résumé:
In the paper, a flexible multiband orthogonal frequency-division multiplexing (OFDM) ultra-wideband service based on optical frequency combs is proposed and experimentally demonstrated for 5G wireless communications. By using optical frequency comb technology, the flexibility and capacity of wavelength-division multiplexing passive optical networks (WDM-PONs) can be improved. Meanwhile, the different sub-bands of multiband OFDM ultra-wideband signals are modulated with different modulation formats to ensure the data rate needs of different users. An adaptively modulated 128-/64-/32-ary-quadratureamplitude- modulation-encoded multiband OFDM ultrawideband signal is generated. In addition, a joint channel estimation method with training sequences and pilot symbols is applied to improve system performance. After 50-km standard single-mode fiber transmission, the experimental results show that the proposed system can provide bandwidth resources for 15 end users with an average access rate of 1.781 Gb∕s per user and a high data rate of 5.343 Gb∕s.
Auteurs: Jing He;Fengting Long;Rui Deng;Jin Shi;Min Dai;Lin Chen;
Apparue dans: IEEE/OSA Journal of Optical Communications and Networking
Date publication: 05.-2017, volume: 9, issue:5, pages: 393 - 400
Editeur: IEEE
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» Flexible network architecture and provisioning strategy for geographically distributed metro data centers
Résumé:
The fifth generation of mobile networks (5G) is expected to introduce new services with strict end-to-end delay requirements. For this reason, service providers and network operators are increasingly relying on geographically distributed metro data centers (DCs) to bring services closer to end-users and reduce delivery time. The metro DCs frequently exchange data for different purposes, such as backup and load balancing. Some of these data transfers require guaranteed low delays. Meanwhile, efficient use of network resources is necessary to limit the cost of the network infrastructure. To address these issues, in this paper, we propose a converged intra- and inter-DC network architecture and a dynamic provisioning strategy that are able to (i) efficiently support different classes of service, (ii) offer fast data transfers among metro DCs, and (iii) enable efficient utilization of network resources. Simulation results show that the proposed network architecture and provisioning strategy achieve at least two times faster average data transfer between DCs and better network resource utilization compared with conventional solutions. We also present a prototype and an extensive set of experimental results, thus proving the implementation feasibility and effectiveness of the proposed approach.
Auteurs: Matteo Fiorani;Payman Samadi;Yiwen Shen;Lena Wosinska;Keren Bergman;
Apparue dans: IEEE/OSA Journal of Optical Communications and Networking
Date publication: 05.-2017, volume: 9, issue:5, pages: 385 - 392
Editeur: IEEE
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» Flexible Optoelectric Neural Interface Integrated Wire-Bonding $mu$ LEDs and Microelectrocorticography for Optogenetics
Résumé:
As an advanced brain–computer interface, the flexible surface electrode array has been used for spatiotemporal localization of neural interactions by recording electrocorticography (ECoG) signals over brain cortical areas. Compared with the electrical stimulation, optogenetics provides a potentially ideal way to stimulate the genetically modified brain tissue by light. In this paper, we developed an optoelectric neural interface combining a micro ECoG ( $mu $ ECoG) recording electrode array and a microlight-emitting diode ( $mu $ LED) array. Three $mu $ LED chips were connected to a flexible polyimide substrate by a unique wire bonding method, and their light-emitting surfaces were downward and in the same plane with the substrate’s lower surface, which allowed blue light directly going through the aligned holes on substrate with barely no loss. In addition, the recording electrodes were modified with electroplated platinum black or activated iridium oxide, and their stability was proved well after repetitive pressures. Mechanical strength and conformality of two $mu $ ECoG arrays with 5 and $10~mu text{m}$ thicknesses were tested. Finally, this bidirectional neural interface was proved to be effective by an acute in vivo experiment performed by attaching two devices with varied thicknesses to the cortical surface of a mouse expressing Channelrhodopsin-2.
Auteurs: Bowen Ji;Minghao Wang;Xiaoyang Kang;Xiaowei Gu;Chengyu Li;Bin Yang;Xiaolin Wang;Jingquan Liu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2008 - 2015
Editeur: IEEE
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» Flexible Organic Amplifiers
Résumé:
Signal processing is fundamental to the modern information society. Sensing and signal processing of various biological signals using human body conformable flexible organic integrated circuits have been actively researched to enable continuous health condition monitoring via wearable devices. To amplify very small electrical biological signals from humans, high performance flexible organic amplifiers are required. In this paper, we briefly review the principles and recent progresses of printable organic amplifiers, including materials, processes, and circuits.
Auteurs: Huabin Sun;Yong Xu;Yong-Young Noh;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 1944 - 1954
Editeur: IEEE
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» Flicker Noise Performance on Thick and Thin Oxide FinFETs
Résumé:
1/f noise was characterized on Fin Field-Effect Transistors (FinFETs) to compare noise performance of CORE and IO devices of a technology node. Thin FinFETs (CORE devices with Equivalent Oxide Thickness (EOT) <1.5 nm and channel length L < 28 nm) were compared to thick FinFETs (IO devices with EOT > 3 nm and long channel L > 100 nm). At low gate bias condition [( $mathsf {V_{g}} -mathsf{V_{{{{th}}}}} le 0.15$ V), after normalization with respect to device area and EOT], noise level of thin FinFETs shows almost tenfold larger than that of thick FinFETs. Moreover, it is found that the discrepancy of noise measured at linear and saturation condition is more significant for FinFETs with shorter channel length. The bias-dependent noise was well fitted by unified model. The extracted defects concentration of thin FinFETs is ~10 times larger than that of thick FinFETs. Finally, flicker noise spectra measured after bias temperature instability stress were compared to that of before stress, the trap concentrations were calculated, and found that defects primarily presents in the metal/high-k interface and have more impact on noise performance if EOT is decreased.
Auteurs: Yi Ming Ding;Durgamadhab Durga Misra;Purushothaman Srinivasan;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2321 - 2325
Editeur: IEEE
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» Floating Gate Nonvolatile Memory Using Individually Cladded Monodispersed Quantum Dots
Résumé:
This paper presents nonvolatile memory characteristics of a quantum dot gate floating gate nonvolatile memory (QDNVM) that employs SiOx-cladded silicon quantum dots as discrete charge storage nodes of the floating gate. The cladding of Si quantum dots and control of their size are shown to result in a faster access and improved retention time. The floating gate is formed by site-specific self-assembly of SiOx-Si quantum dots on the tunnel oxide layer over the p-region between source and drain of an n-channel field-effect transistor (FET). Experimental data on fabricated long channel devices show threshold voltage shift as a function of duration and magnitude of the electrical stress applied during the “Write” operation. Current–voltage characteristics ( $I_{mathrm {D}}$ $V_{mathrm {D}}$ and $I_{D}$ $V_{G})$ are presented before and after stress. The electrical characteristics are explained using a quantum dot gate FET model which includes the threshold voltage shift ( $Delta text{V}_{mathrm { {TH}}})$ as a function of charge on the floating gate quantum dots due to applied electrical stress.
Auteurs: Ravi Shankar R. Velampati;El-Sayed Hasaneen;E. K. Heller;Faquir C. Jain;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 05.-2017, volume: 25, issue:5, pages: 1774 - 1781
Editeur: IEEE
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» Flow Characteristics of a Two-Stage EHD Gas Pump in a Circular Pipe
Résumé:
Flow characteristics of a two-stage electrohydrodynamic (EHD) gas pump in a circular tube have been experimentally investigated for two different sizes (61.8 and 127.8 mm in diameter). Each stage uses eight emitting electrodes flush mounted on the tube wall. Two electrode configurations, aligned and offset, with fixed spacing between electrodes have been considered in this study. The main objective of the study is to verify whether or not a two-stage EHD pump can sustain or even increase the volume flow rate produced by a single-stage pump over a greater tube length. To this end, electrodes at both stages are charged at the same voltages in positive polarity from 18 to 22 kV. Velocities are measured at three cross sections along the tube length and then integrated to obtain the volume flow rate. The velocity profile and volume flow rate delivered by the single top stage of the pump are compared with those produced by the two stages combined to give additional insight to the problem. The results obtained have important implications for practical applications of EHD gas pump.
Auteurs: Yilma T. Birhane;Sheam-Chyun Lin;Feng C. Lai;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2461 - 2470
Editeur: IEEE
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» Fluorescence Diffusion in the Presence of Optically Clear Tissues in a Mouse Head Model
Résumé:
Diffuse Optical Tomography commonly neglects or assumes as insignificant the presence of optically clear regions in biological tissues, estimating their contribution as a small perturbation to light transport. The inaccuracy introduced by this practice is examined in detail in the context of a complete, based on realistic geometry, virtual fluorescence Diffuse Optical Tomography experiment where a mouse head is imaged in the presence of cerebral spinal fluid. Despite the small thickness of such layer, we point out that an error is introduced when neglecting it from the model with possibly reduction in the accuracy of the reconstruction and localization of the fluorescence distribution within the brain. The results obtained in the extensive study presented here suggest that fluorescence diffuse neuroimaging studies can be improved in terms of quantitative and qualitative reconstruction by accurately taking into account optically transparent regions especially in the cases where the reconstruction is aided by the prior knowledge of the structural geometry of the specimen. Thus, this has only recently become an affordable choice, thanks to novel computation paradigms that allow to run Monte Carlo photon propagation on a simple graphic card, hence speeding up the process a thousand folds compared to CPU-based solutions.
Auteurs: Daniele Ancora;Athanasios Zacharopoulos;Jorge Ripoll;Giannis Zacharakis;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 05.-2017, volume: 36, issue:5, pages: 1086 - 1093
Editeur: IEEE
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» Foreword
Résumé:
“Flexible electronics” has been thriving in the scholarly world as a buzz phrase for nearly two decades. A flourishing industry focusing on such physically bendable electronics is also growing rapidly. Specially, two major consumer electronics giants, Samsung and LG, have announced the arrival of organic light-emitting diode-based displays. Still, the focus is dominated by innovation in materials—more specifically, organic molecules, 1-D nanowires and nanotubes, and, more recently, 2-D atomic-scale materials like graphene and dichalcogenide materials. The focus of research on flexible electronics is presently geared toward materials and proof-of-concept-level exciting applications. Materials research is focusing on energy harvesting and energy storage, and applications are mostly concentrated on sensing-based advanced health care technology (wearable and implantable electronics). Although they are all compelling visions, still advances in pragmatic fully integrated systems are rare. As we know, a fully integrated autonomous system for in vivo or in vitro applications requires a variety of electronics: power supply, power management circuitry, interface circuit components, high-performance microprocessor or small-scale data-processing unit, and active and passive communication components. Therefore, the main objective of this dedicated issue is to engage the Electron Devices Community in a serious discussion, with their scholarly contributions specifically focused on solving major challenges in the general area of flexible electronics.
Auteurs: Yong-Young Noh;Xiaojun Guo;Muhammad Mustafa Hussain;Zhenqiang Jack Ma;Deji Akinwande;Mario Caironi;Thomas D. Anthopoulos;Tse Nga Tina Ng;Ryoichi Ishihara;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 1878 - 1880
Editeur: IEEE
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» Formation Mechanism of Silicon Nanowires Using Chemical/Electrochemical Process
Résumé:
In this work, Si nanostructure arrays are fabricated using a low-cost chemical/electrochemical etching method. The technique consists of two consecutive chemical and electrochemical etching steps. A mask-less and nonlithographical technique of anisotropic wet etching of silicon samples in hydroxide solutions was used to generate pyramid shape seeding points. The subsequent fabrication stages consist of electrochemically etching to generate nanowires. The growth mechanism of the nanowires was investigated experimentally in order to find out the effects of various fabrication parameters on the physical properties of the nanowires like their structures, shapes, sizes, aspect ratio, and morphologies. Modeling and simulation of the nanowires growth are performed using multiphysics software tool, COMSOL, in order to explain and confirm the experimental results.
Auteurs: Parsoua Abedini Sohi;Mojtaba Kahrizi;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 507 - 513
Editeur: IEEE
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» FPGA-Based System for In-Line Measurement of Velocity Profiles of Fluids in Industrial Pipe Flow
Résumé:
The rheology of a fluid flowing in an industrial process pipe can be calculated by combining the pressure drop and the velocity profile that the fluid develops across the tube diameter. The profile is obtained noninvasively through an ultrasound Doppler investigation. Unfortunately, at present, no system capable of real-time velocity profile assessment is available for in-line industrial rheological measurements, and tests are operated by manually moving fluid specimens to specialized laboratories. In this work, we present an embedded system capable of in-line and real-time measurement of velocity profile and pressure drop, which enables the automatic rheological characterization of non-Newtonian fluids in process pipes. The system includes all the electronics for the ultrasound front-end, as well as the digital devices for the real-time calculation of the velocity profile. The proposed system is highly programmable, low-noise, and specifically targeted for industrial use. It is shown capable of producing, for example, 512-point velocity profiles at 45 Hz rate. An application is presented where a sludge fluid, flowing at 600 L/min in a 48 mm diameter high-grade stainless steel pipe, is characterized in real-time with a ±5% accuracy.
Auteurs: Stefano Ricci;Valentino Meacci;Beat Birkhofer;Johan Wiklund;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3997 - 4005
Editeur: IEEE
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» Fractional Hilbert Transform Sampling Method and Its Filter Bank Reconstruction
Résumé:
In this paper, conventional Hilbert transform sampling method is generalized to fractional Hilbert transform sampling method. First, a frequency-domain analysis method is applied to derive the fractional Hilbert transform sampling theorem of a band-limited signal. Then, an analog filter bank method is presented to recover the original continuous-time signal from the discrete-time sampled signals. Because the analog filter bank is not easy to be implemented, a digital filter bank method is proposed to solve the reconstruction problem. Next, a sparse design of digital reconstruction filters is studied to reduce the arithmetic implementation complexity using sparse FIR filter design techniques. Finally, several numerical examples are illustrated to show the effectiveness of the proposed fractional Hilbert transform sampling method and its filter bank reconstruction.
Auteurs: Chien-Cheng Tseng;Su-Ling Lee;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1214 - 1224
Editeur: IEEE
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» Freeform Compliant CMOS Electronic Systems for Internet of Everything Applications
Résumé:
The state-of-the-art electronics technology has been an integral part of modern advances. The prevalent rise of the mobile device and computational technology in the age of information technology offers exciting applications that are attributed to sophisticated, enormously reliable, and most mature CMOS-based electronics. We are accustomed to high performance, cost-effective, multifunctional, and energy-efficient scaled electronics. However, they are rigid, bulky, and brittle. The convolution of flexibility and stretchability in electronics for emerging Internet of Everything application can unleash smart application horizon in unexplored areas, such as robotics, healthcare, smart cities, transport, and entertainment systems. While flexible and stretchable device themes are being remarkably chased, the realization of the fully compliant electronic system is unaddressed. Integration of data processing, storage, communication, and energy management devices complements a compliant system. Here, a comprehensive review is presented on necessity and design criteria for freeform (physically flexible and stretchable) compliant high-performance CMOS electronic systems.
Auteurs: Sohail F. Shaikh;Mohamed T. Ghoneim;Galo A. Torres Sevilla;Joanna M. Nassar;Aftab M. Hussain;Muhammad M. Hussain;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 1894 - 1905
Editeur: IEEE
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» Frequency Dependence of Magnetic Dissipation in Microwave Garnet Films
Résumé:
A frequency dependence of the magnetic dissipation parameter (half-linewidth) $Delta {H}$ for films of yttrium–iron garnet (YIG) was experimentally investigated in the interval of microwave frequencies 1.7–26 GHz. The $Delta {H}$ value did not change over a frequency range of 2.2–26 GHz. The effect of conducting screens placed near a YIG film on the $Delta {H}$ value was also studied experimentally. For a screened film, the value of $Delta {H}$ exceeds $Delta {H}$ for an unscreened film when the distance between the film and the metal screen was less than 40– $70~mu text{m}$ .
Auteurs: Boris A. Kalinikos;Nikolai G. Kovshikov;Pavel A. Kolodin;Ivan P. Panchurin;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 2
Editeur: IEEE
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» Frequency Selective Surface Structure Miniaturization Using Interconnected Array Elements on Orthogonal Layers
Résumé:
Traditionally, the element of a frequency selective surface (FSS) is rotationally symmetrical and the element arrays in a multilayer FSS are aligned with each other. A new approach to miniaturize the size of the FSS array element is proposed in this paper by interconnecting the array elements only in one direction in a two-layer FSS structure. One layer acts as an enhanced inductor while the other layer provides capacitance. The interconnection between the adjacent array elements changes the equivalent circuit and produces a strong cross-layer capacitance, which lowers the resonant frequency significantly. The dimensions of the miniaturized FSS element are much smaller than the wavelength at the resonant frequency (periodicity $ll lambda )$ . The element can also have a low profile since the cross-layer capacitance is stronger with a thinner substrate. The sensitivity to the incident angle of the proposed structure is comparable with traditional ones. A theoretical equivalent circuit model is developed to characterize the structure, based on the analysis of the geometrical configuration of the FSS structure and the electric field distribution on it. The theory was verified by the experimental results.
Auteurs: Muaad Naser Hussein;Jiafeng Zhou;Yi Huang;Muayad Kod;Abed Pour Sohrab;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2376 - 2385
Editeur: IEEE
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» Frequency-Dependent Directive Radiation of Monopole-Dielectric Resonator Antenna Using a Conformal Frequency Selective Surface
Résumé:
Development of a conformal frequency selective surface (FSS) for radiation diversity of hybrid monopole-dielectric resonator antenna has been demonstrated in this paper. In the proposed method, a planar FSS screen with meandered unit cell is designed to be reflective at 5 GHz followed by its mapping on a cylindrical surface of flexible dielectric material. The proposed conformal reflector when kept at a specific distance from the radiating element improves the bandwidth of the antenna from 26.8% to 53.67% in 4–6 GHz band. A significant enhancement of 5–6 dBi in gain is also achieved over this band. Gain of the antenna with reflector is maintained around 9.5 dBi with a variation of ±1.5 dB. On the other hand, omni-directional radiation of the antenna is maintained at an upper band of 7–9 GHz. Simulations have been performed using ANSYS High Frequency Structure Simulator (HFSS). Experimental measurements of the fabricated prototype have been provided. The proposed design is useful to achieve pattern diversity in multiband antenna system.
Auteurs: Ayan Chatterjee;Susanta Kumar Parui;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2233 - 2239
Editeur: IEEE
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» Frequency-Domain Transient Imaging
Résumé:
A transient image is the optical impulse response of a scene, which also visualizes the propagation of light during an ultra-short time interval. In contrast to the previous transient imaging which samples in the time domain using an ultra-fast imaging system, this paper proposes transient imaging in the frequency domain using a multi-frequency time-of-flight (ToF) camera. Our analysis reveals the Fourier relationship between transient images and the measurements of a multi-frequency ToF camera, and identifies the causes of the systematic error-non-sinusoidal and frequency-varying waveforms and limited frequency range of the modulation signal. Based on the analysis we propose a novel framework of frequency-domain transient imaging. By removing the systematic error and exploiting the harmonic components inside the measurements, we achieves high quality reconstruction results. Moreover, our technique significantly reduces the computational cost of ToF camera based transient image reconstruction, especially reduces the memory usage, such that it is feasible for the reconstruction of transient images at extremely small time steps. The effectiveness of frequency-domain transient imaging is tested on synthetic data, real data from the web, and real data acquired by our prototype camera.
Auteurs: Jingyu Lin;Yebin Liu;Jinli Suo;Qionghai Dai;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 05.-2017, volume: 39, issue:5, pages: 937 - 950
Editeur: IEEE
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» Frequency-Hopping Pulse Position Modulation Ultrawideband Receiver
Résumé:
Pulse position modulation (PPM) has been used in the radio-frequency (RF) domain to achieve both low-dissipation requirements and provide precision ranging. In ultrawideband (UWB) architectures, it underpins an asynchronous receiver, multiple access environments, and interference-resistant transmission. When combined with frequency hopping (FH), it allows for an additional level of immunity to jamming and low probability of intercept. Realization of a FH-PPM transceiver poses a practical challenge, particularly in the UWB RF range. With UWB pulses reaching the multi-gigahertz range, FH adds to the effective bandwidth at which the receiver must be operated, exceeding the performance of a modern quantizer and digital demodulation backplane. This study describes a new photonics-assisted FH-PPM receiver architecture that rests on mutually coherent frequency combs. The performance of the new receiver was characterized by receiving and decoding an 80–Mb/s rate FH-PPM UWB signal.
Auteurs: Daniel J. Esman;Vahid Ataie;Bill P.-P. Kuo;Nikola Alic;Stojan Radic;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1894 - 1899
Editeur: IEEE
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» Friction Compensation Based on Time-Delay Control and Internal Model Control for a Gimbal System in Magnetically Suspended CMG
Résumé:
Nonlinear friction torque is an important factor affecting the angular velocity precision of a gimbal system in double gimbal magnetically suspended control moment gyro. To effectively eliminate the influence of friction torque and implement high precision control of the gimbal system, a method that combines time delay control (TDC) with two-degree-of-freedom (2-DOF) internal model control (IMC) is proposed. First, nonlinear friction torque of the gimbal system is estimated via time-delay estimation. Second, to independently adjust the tracking performance and disturbance rejection performance, and to enhance the robustness of TDC, 2-DOF IMC is introduced. Simulation and experimental results indicate that the proposed control method not only improves the compensation performance of the gimbal system with nonlinear friction torque, but also enhances the robustness and realizes the high precision control of the gimbal servo system.
Auteurs: Peiling Cui;Dachuan Zhang;Shan Yang;Haitao Li;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3798 - 3807
Editeur: IEEE
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» From Available Synchrophasor Data to Short-Circuit Fault Identity: Formulation and Feasibility Analysis
Résumé:
This paper proposes a novel formulation for determining the short-circuit fault identity, that is the fault type, faulted line, and exact fault distance on it, by using available synchrophasor data. A simple and yet quite effective procedure is developed to model the fault area as a stand-alone sub-system. Thanks to phasor measurement units (PMUs), the proposed technique does not require the operating point and model of the portions being replaced. This greatly alleviates the complexity and technical problems involved in modeling the entire power system, as enforced by existing wide-area methods. A couple of effective theorems in Circuit Theory are exploited in a way as to make the prefault bus impedance matrix applicable in the postfault condition. The obtained fault equations are readily solved by the least-squares method to provide a closed-form solution for the fault distance. Two necessary and sufficient conditions are introduced to assess the fault location feasibility by any given set of PMUs. High accuracy is achieved since the calculations merely involve sound equations remaining after removing erroneous measurements of instrument transformers. The proposed method is successfully validated by more than 10 000 simulation cases conducted on the New England 39-bus and 118-bus test systems.
Auteurs: Sadegh Azizi;Majid Sanaye-Pasand;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2062 - 2071
Editeur: IEEE
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» From Higher Education to Open Education: Challenges in the Transformation of an Online Traditional Course
Résumé:
Open education has revolutionized the educational environment. Massive open online courses have become the main showcase for open educational resources, but the competition to establish a position in this movement has led to the rapid publication of many courses of arguable quality. This paper presents and analyzes the process of creating a small private online course that meets the requirements to be offered as a massive course. The starting point was an online higher education course that had previously been published as OpenCourseWare. In this paper, data were examined from 112 students enrolled in four different academic years, during which changes were progressively incorporated to transform the traditional course to an open course. The results show an improvement in students’ perceptions of resources and assessments and in their overall satisfaction. New assessment tools were developed and validated, without affecting the academic results. The process had positive effects on the instructional design of the final course, but some risks were identified when the course was adapted as a massive course. The final course provides useful input for future developments and a more effective student-focused methodology.
Auteurs: José Luis Martín Núñez;Edmundo Tovar Caro;José Ramón Hilera González;
Apparue dans: IEEE Transactions on Education
Date publication: 05.-2017, volume: 60, issue:2, pages: 134 - 142
Editeur: IEEE
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» From Random Matrix Theory to Coding Theory: Volume of a Metric Ball in Unitary Group
Résumé:
Volume estimates of metric balls in manifolds find diverse applications in information and coding theory. In this paper, new results for the volume of a metric ball in unitary group are derived via tools from random matrix theory. The first result is an integral representation of the exact volume, which involves a Toeplitz determinant of Bessel functions. A simple but accurate limiting volume formula is then obtained by invoking Szegő’s strong limit theorem for large Toeplitz matrices. The derived asymptotic volume formula enables analytical evaluation of some coding-theoretic bounds of unitary codes. In particular, the Gilbert–Varshamov lower bound and the Hamming upper bound on the cardinality as well as the resulting bounds on code rate and minimum distance are derived. Moreover, bounds on the scaling law of code rate are found. Finally, a closed-form bound on the diversity sum relevant to unitary space-time codes is obtained, which was only computed numerically in the literature.
Auteurs: Lu Wei;Renaud-Alexandre Pitaval;Jukka Corander;Olav Tirkkonen;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 2814 - 2821
Editeur: IEEE
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» From the editors' desk
Résumé:
Presents the introductory editorial for this issue of the publication.
Auteurs: Ed Cherney;Robert Fleming;
Apparue dans: IEEE Electrical Insulation Magazine
Date publication: 05.-2017, volume: 33, issue:3, pages: 6 - 7
Editeur: IEEE
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» Full Wave Analysis of Plasma Loaded Coaxial Gyrotron Cavity With Triangular Corrugations on the Insert
Résumé:
The presence of plasma inside the gyrotron interaction structure alters the mode field. The presence of a magnetic field changes the plasma to an anisotropic media. Field analysis of a plasma loaded coaxial gyrotron cavity with triangular corrugations on the insert is undertaken using full wave approach. Modes inside a plasma loaded interaction structure have all six nonzero field components and hence are hybrid modes. Plasma modes (space charge modes), cyclotron modes, and waveguide EH and HE modes are the three families of modes that can exist in plasma loaded waveguide. Inside the gyrotron interaction structure, the cyclotron mode and the desired mode (HE) couple and this coupling leads to change in the eigenvalue of the modes. In this paper, a full wave approach has been used to analyze the dispersion relation and calculate eigenvalue of the desired HE mode.
Auteurs: Sukwinder Singh;M. V. Kartikeyan;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2369 - 2375
Editeur: IEEE
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» Full-Duplex Device-to-Device-Aided Cooperative Nonorthogonal Multiple Access
Résumé:
This paper presents a full-duplex device-to-device (D2D)-aided cooperative nonorthogonal multiple access (NOMA) scheme to improve the outage performance of the NOMA-weak user in a NOMA user pair, where the NOMA-weak user is helped by the NOMA-strong user with the capability of full-duplex D2D communications. The expressions for the outage probability are derived to characterize the performance of the proposed scheme. The results show that the proposed cooperative NOMA scheme can achieve superior outage performance compared to the conventional NOMA and orthogonal multiple access (OMA). In order to further improve the outage performance, an adaptive multiple access (AMA) scheme is also studied, which dynamically switches between the proposed cooperative NOMA, conventional NOMA, and OMA schemes, according to the level of residual self-interference and the quality of links. The results show that the AMA scheme outperforms the above multiple access schemes in terms of outage performance.
Auteurs: Zhengquan Zhang;Zheng Ma;Ming Xiao;Zhiguo Ding;Pingzhi Fan;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4467 - 4471
Editeur: IEEE
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» Full-Duplex MIMO in Cellular Networks: System-Level Performance
Résumé:
This paper characterizes, through a stochastic geometry analysis, the increase in spectral efficiency that full-duplex transmission brings about in wireless networks. While, on isolated links, full-duplex promises a doubling of the spectral efficiency, in the context of a network this is weighted down by the corresponding rise in interference, and our characterization captures the balance of these effects. The analysis encompasses both the forward link (FL) and the reverse link (RL) with single-user and multiuser transmissions. And, as a complement to the analysis, Monte-Carlo simulations on a Vodafone LTE field test network are also presented. In the FL, the rise in interference is found to have minor impact and a doubling in spectral efficiency can indeed be approached, especially in microcellular networks. In the RL, however, a major difficulty arises in the form of exceedingly strong interference among base stations. This renders full-duplex transmission all but unfeasible in macrocellular networks (unless major countermeasures could be implemented) and undesirable in dense microcellular networks. Only in microcells with sufficient spacing among base stations does RL full-duplex pay off. Thus, full-duplex is seen not to blend easily with densification.
Auteurs: Ratheesh K. Mungara;Ilaria Thibault;Angel Lozano;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3124 - 3137
Editeur: IEEE
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» Full-Duplex Regenerative Relaying and Energy-Efficiency Optimization Over Generalized Asymmetric Fading Channels
Résumé:
This paper is devoted to the end-to-end performance analysis, optimal power allocation (OPA), and energy-efficiency (EE) optimization of decode-and-forward (DF)-based full-duplex relaying (FDR) and half-duplex relaying (HDR) systems. Unlike existing analyses and works that assume simplified transmission over symmetric fading channels, we consider the more realistic case of asymmetric multipath fading and shadowing conditions. To this end, exact and asymptotic analytic expressions are first derived for the end-to-end outage probabilities (OPs) of the considered DF-FDR set ups. Based on these expressions, we then formulate the OPA and EE optimization problems under given end-to-end target OP and maximum total transmit power constraints. It is shown that OP in FDR systems is highly dependent upon the different fading parameters and that OPA provides substantial performance gains, particularly, when the relay self-interference (SI) level is strong. Finally, the FDR is shown to be more energy-efficient than its HDR counterpart, as energy savings beyond 50% are feasible even for moderate values of the SI levels, especially at larger link distances, under given total transmit power constraints and OP requirements.
Auteurs: Paschalis C. Sofotasios;Mulugeta K. Fikadu;Sami Muhaidat;Qimei Cui;George K. Karagiannidis;Mikko Valkama;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3232 - 3251
Editeur: IEEE
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» Full-Parallax Holographic Light-Field 3-D Displays and Interactive 3-D Touch
Résumé:
A light-field 3-D display (LFD) reproduces light rays or wavefront as if there are real objects, and a perfect 3-D display that satisfies all the depth cues in human vision becomes possible. By reproducing both horizontal and vertical parallaxes, i.e., full-parallax, an LFD reconstructs a real or virtual image in 3-D space. A rich 3-D experience can be provided to viewers, and moreover, multiple viewers can share the same reproduced 3-D image. A technology called holographic stereogram (HS) is the integration of ray-based and wavefront-based methods, and has been applied to LFD. Hardcopy HS has already been commercialized. The technology of HS is helpful also for an interactive LFD; a full-parallax LFD using a projector and a holographic screen that modulates the directions of light rays is based on the principle of HS. In this case, accurate registration between the projected image and the holographic screen is necessary, and it is achieved by projecting some test patterns and capturing them with a calibration camera. As a full-parallax LFD can reproduce real images in midair between the screen and viewers, it is possible to realize interactive 3-D touch interface. If a user touches the 3-D real image floating in the air, the reproduced light is scattered by the user’s fingertip. The scattered light is detected by a color image sensor placed behind the holographic screen, and can be employed to detect the user’s touch. In this system, the reproduced 3-D images and the 3-D touch detection are associated with each other, and thus, we do not have to worry about the complicated registration between them. The identification of the user’s interaction is simple, because the color information of the 3-D image can be used for this purpose. Some experimental results of the 3-D touch-sensing display are introduced, and possible applications of this technology are discussed as well.
Auteurs: Masahiro Yamaguchi;
Apparue dans: Proceedings of the IEEE
Date publication: 05.-2017, volume: 105, issue:5, pages: 947 - 959
Editeur: IEEE
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» Full-Sphere Angle of Arrival Detection using CMRCLEAN
Résumé:
Extraneous signals propagating into the quiet zone (QZ) of an antenna measurement chamber pose a large contribution to the error of measurements therein. From the angle of arrival (AoA) of these extraneous signals, the locations of the reflective points, from which these signals originate, can be determined. If the location of a reflection point is known, it can be treated, and thus the level of the extraneous signal can be reduced or even completely mitigated. The combining mode rotation with CLEAN (CMRCLEAN) algorithm has shown that it is capable of detecting the AoA of closely spaced reflective sources, even in the presence of a strong signal such as the main beam illuminating the QZ. In this communication, the CMRCLEAN algorithm is further improved to allow a better discrimination of signals and their amplitude. Furthermore, this communication will show the ability of the improved algorithm to detect reflections from opposing directions, such as those originating from the back wall, which is opposite to the much stronger range illumination.
Auteurs: Marc Dirix;Dirk Heberling;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2769 - 2772
Editeur: IEEE
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» Fundamental Analysis on Data Dissemination in Mobile Opportunistic Networks With Lévy Mobility
Résumé:
Mobile opportunistic networks take advantage of contact opportunities due to the mobility of individual nodes for distributing data. Studying the inherent traits of data dissemination in mobile opportunistic networks can reveal their potential to support emerging applications, such as emergency services and mobile commerce. In this paper, we employ the Lévy mobility model to characterize the movement pattern of nodes. Because the Lévy mobility closely mimics human walking patterns, the analysis model that we adopt is realistic. Our analyses consider small- and large-scale perspectives. In the small-scale case, we investigate the distribution of the minimum time needed by the data to spread to a given region. In the large-scale case, we examine the probability bounds of the earliest time at which the data arrives in a region that is sufficiently far away. We also derive the rate at which such a probability tends to zero as the distance to the region increases to infinity. The results of extensive numerical simulations validate our analysis.
Auteurs: Shengling Wang;Xia Wang;Xiuzhen Cheng;Jianhui Huang;Rongfang Bie;Feng Zhao;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4173 - 4187
Editeur: IEEE
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» Fundamental Limits of Cache-Aided Interference Management
Résumé:
We consider a system, comprising a library of $N$ files (e.g., movies) and a wireless network with a $K_{T}$ transmitters, each equipped with a local cache of size of $M_{T}$ files and a $K_{R}$ receivers, each equipped with a local cache of size of $M_{R}$ files. Each receiver will ask for one of the $N$ files in the library, which needs to be delivered. The objective is to design the cache placement (without prior knowledge of receivers’ future requests) and the communication scheme to maximize the throughput of the delivery. In this setting, we show that the sum degrees-of-freedom (sum-DoF) of $min left {{frac {K_{T} M_{T}+K_{R} M_{R}}{N},K_{R}}right }$ is achievable, and this is within a factor of 2 of the optimum, under uncoded prefetching and one-shot linear delivery schemes. This result shows that (i) the one-shot sum-DoF scales linearly with the aggregate cache size in the network (i.e., the cumulative memory available at all nodes), (ii) the transmitters’ caches and receivers’ caches contribute equally in the one-shot sum-DoF, and (iii) caching can offer a throughput gain that scales linearly with the size of the network. To prove the result, we propose an achievable scheme that exploits the redundancy of the content at transmitter’s caches to cooperatively zero-force some outgoing interference, and availability of the unint- nded content at the receiver’s caches to cancel (subtract) some of the incoming interference. We develop a particular pattern for cache placement that maximizes the overall gains of cache-aided transmit and receive interference cancellations. For the converse, we present an integer optimization problem which minimizes the number of communication blocks needed to deliver any set of requested files to the receivers. We then provide a lower bound on the value of this optimization problem, hence leading to an upper bound on the linear one-shot sum-DoF of the network, which is within a factor of 2 of the achievable sum-DoF.
Auteurs: Navid Naderializadeh;Mohammad Ali Maddah-Ali;Amir Salman Avestimehr;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 3092 - 3107
Editeur: IEEE
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» Fundamental Limits of Cache-Aided Wireless BC: Interplay of Coded-Caching and CSIT Feedback
Résumé:
Building on the recent coded-caching breakthrough by Maddah-Ali and Niesen, the work here considers the $K$ -user cache-aided wireless multi-antenna symmetric broadcast channel with random fading and imperfect feedback, and analyzes the throughput performance as a function of feedback statistics and cache size. In this setting, this paper identifies the optimal cache-aided degrees-of-freedom (DoF) within a factor of 4, by identifying near-optimal schemes that exploit a new synergy between coded caching and delayed CSIT, as well as by exploiting the unexplored interplay between caching and feedback-quality. The DoF expressions reveal an initial gain due to current CSIT, and an additional gain due to coded caching, which is exponential in the sense that any linear decrease in the required DoF performance, allows for an exponential reduction in the required cache size. In the end, this paper reveals three new aspects of caching: a synergy between memory and delayed feedback, a tradeoff between memory and current CSIT, and a powerful ability to provide cache-aided feedback savings.
Auteurs: Jingjing Zhang;Petros Elia;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 3142 - 3160
Editeur: IEEE
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» Fundamental Limits of Photonic RF Phase-Shift Amplification by RF Interferometry
Résumé:
The fundamental limits posed by classical noise on Photonic RF Phase amplification by RF Interferometry (PARFI) are modeled theoretically and verified experimentally. With 320-MHz modulated light and a phase-shift amplification of 3000, we demonstrate a phase-shift resolution of $1.6 cdot {10^{ - 4}}^{circ}$ and 200-nm distance resolution. Based on these results, we postulate that single-nanometer distance resolution can be achieved with PARFI.
Auteurs: Moshe Ben Ayun;Seva Rosenberg;Daniel Gotliv;Shmuel Sternklar;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1906 - 1913
Editeur: IEEE
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» Fundamentals of Modeling Finite Wireless Networks Using Binomial Point Process
Résumé:
Modeling the locations of nodes as a uniform binomial point process, we present a generic mathematical framework to characterize the performance of an arbitrarily located reference receiver in a finite wireless network. Different from most of the prior works where the serving transmitter (TX) is located at the fixed distance from the reference receiver, we consider two general TX-selection policies: 1) uniform TX-selection: the serving node is chosen uniformly at random from amongst all transmitting nodes and 2) $k$ -closest TX-selection: the serving node is the $k$ th closest node (out of all transmitting nodes) to the reference receiver. The key intermediate step in our analysis is the derivation of a new set of distance distributions that lead not only to the tractable analysis of coverage probability but also enable the analysis of wide range of classical and currently trending problems in wireless networks. Using this new set of distance distributions, we further investigate the diversity loss due to $mathtt {SIR}$ correlation in a finite network. We then obtain the optimal number of links that can be simultaneously activated to maximize network spectral efficiency. Finally, we evaluate optimal caching probability to maximize the total hit probability in cache-enabled finite networks.
Auteurs: Mehrnaz Afshang;Harpreet S. Dhillon;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3355 - 3370
Editeur: IEEE
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» Future Automotive Architecture and the Impact of IT Trends
Résumé:
The transfer of IT and consumer-electronics technologies to the automotive domain will provide major opportunities. However, both these technologies and the automotive industry will require much adaptation.
Auteurs: Matthias Traub;Alexander Maier;Kai L. Barbehön;
Apparue dans: IEEE Software
Date publication: 05.-2017, volume: 34, issue:3, pages: 27 - 32
Editeur: IEEE
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» Fuzzy Load Modeling of Plug-in Electric Vehicles for Optimal Storage and DG Planning in Active Distribution Network
Résumé:
Plug-in electric vehicle (PEV) charge challenges can be addressed by including their effects on the planning of distribution network components. The planning problem becomes more combinatorial when the uncertainty of PEVs is considered as well. In this paper, storage and distributed generation (DG) planning is considered as an option to deal with the problems arising from PEV uncertainty. The optimal location, capacity, and power rating of the stationary batteries, as well as the location and capacity of dispatchable DGs, are determined to minimize the cost objective function under technical constraints. Short-term scheduling and long-term planning, as optimization problems, are solved using Tabu Search and simulated annealing algorithms, respectively. Simulation results show that when connecting PEVs to the distribution network, both of the stationary battery and DG units are needed from technical and economic points of view. Moreover, the optimal penetration of stationary storage units increases if the uncertainty of PEVs is considered.
Auteurs: Ali Ahmadian;Mahdi Sedghi;Masoud Aliakbar-Golkar;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3622 - 3631
Editeur: IEEE
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» GaN Nanowire Schottky Barrier Diodes
Résumé:
A new concept of vertical gallium nitride (GaN) Schottky barrier diode based on nanowire (NW) structures and the principle of dielectric REduced SURface Field (RESURF) is proposed in this paper. High-threading dislocation density in GaN epitaxy grown on foreign substrates has hindered the development and commercialization of vertical GaN power devices. The proposed NW structure, previously explored for LEDs offers an opportunity to reduce defect density and fabricate low cost vertical GaN power devices on silicon (Si) substrates. In this paper, we investigate the static characteristics of high-voltage GaN NW Schottky diodes using 3-D TCAD device simulation. The NW architecture theoretically achieves blocking voltages upward of 700 V with very low specific on-resistance. Two different methods of device fabrication are discussed. Preliminary experimental results are reported on device samples fabricated using one of the proposed methods. The fabricated Schottky diodes exhibit a breakdown voltage of around 100 V and no signs of current collapse. Although more work is needed to further explore the nano-GaN concept, the preliminary results indicate that superior tradeoff between the breakdown voltage and specific on-resistance can be achieved, all on a vertical architecture and a foreign substrate. The proposed NW approach has the potential to deliver low cost reliable GaN power devices, circumventing the limitations of today’s high electron mobility transistors (HEMTs) technology and vertical GaN on GaN devices.
Auteurs: Gourab Sabui;Vitaly Z. Zubialevich;Mary White;Pietro Pampili;Peter J. Parbrook;Mathew McLaren;Miryam Arredondo-Arechavala;Z. John Shen;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2283 - 2290
Editeur: IEEE
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» Gas Spectroscopy System for Breath Analysis at mm-wave/THz Using SiGe BiCMOS Circuits
Résumé:
The unique fingerprint spectra of volatile organic compounds for breath analysis and toxic industrial chemicals make an mm-wave (mmW)/THz gas sensor very specific and sensitive. This paper reviews and updates results of our recent work on sensor systems for gas spectroscopy based on integrated transmitter (TX) and receiver (RX), which are developed and fabricated in IHP’s $0.13~mu text{m}$ SiGe BiCMOS technology. In this paper, we present an mmW/THz spectroscopic system including a folded gas absorption cell of 1.9 m length between the TX and RX modules. We discuss the results and specifications of our sensor system based on integrated TX and RX. We demonstrate TXs and RXs with integrated antennas for spectroscopy at 238–252 GHz and 494–500 GHz using integer- $N$ phase-locked loops (PLLs). We present a compact system by using fractional- ${N}$ PLLs allowing frequency ramps for the TX and RX, and for TX with superimposed frequency shift keying or reference frequency modulation. In another configuration, the voltage controlled oscillators of the TX and RX local oscillator are tuned directly without PLLs by applying external voltages. Further developments of our system are aimed at realizing an even wider frequency span by switching between frequency bands, and to use a more compact gas absorption cell.
Auteurs: Klaus Schmalz;Nick Rothbart;Philipp F.-X. Neumaier;Johannes Borngräber;Heinz-Wilhelm Hübers;Dietmar Kissinger;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1807 - 1818
Editeur: IEEE
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» Gas-Liquid Two-Phase Flow Measurement Using Coriolis Flowmeters Incorporating Artificial Neural Network, Support Vector Machine, and Genetic Programming Algorithms
Résumé:
Coriolis flowmeters are well established for the mass flow measurement of single-phase flow with high accuracy. In recent years, attempts have been made to apply Coriolis flowmeters to measure two-phase flow. This paper presents data driven models that are incorporated into Coriolis flowmeters to measure both the liquid mass flowrate and the gas volume fraction of a two-phase flow mixture. Experimental work was conducted on a purpose-built two-phase flow test rig on both horizontal and vertical pipelines for a liquid mass flowrate ranging from 700 to 14500 kg/h and a gas volume fraction between 0% and 30%. Artificial neural network (ANN), support vector machine (SVM), and genetic programming (GP) models are established through training with the experimental data. The performance of backpropagation-ANN (BP-ANN), radial basis function-ANN (RBF-ANN), SVM, and GP models is assessed and compared. Experimental results suggest that the SVM models are superior to the BP-ANN, RBF-ANN, and GP models for two-phase flow measurement in terms of robustness and accuracy. For liquid mass flowrate measurement with the SVM models, 93.49% of the experimental data yield a relative error less than ±1% on the horizontal pipeline, while 96.17% of the results are within ±1% on the vertical installation. The SVM models predict the gas volume fraction with a relative error less than ±10% for 93.10% and 94.25% of the test conditions on the horizontal and vertical installations, respectively.
Auteurs: Lijuan Wang;Jinyu Liu;Yong Yan;Xue Wang;Tao Wang;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 852 - 868
Editeur: IEEE
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» Gaussian Multiple Access via Compute-and-Forward
Résumé:
Lattice codes used under the compute-and-forward paradigm suggest an alternative strategy for the standard Gaussian multiple-access channel (MAC): the receiver successively decodes the integer linear combinations of the messages until it can invert and recover all messages. In this paper, a multiple-access technique called compute-forward multiple access (CFMA) is proposed and analyzed. For the two-user MAC, it is shown that without time-sharing, the entire capacity region can be attained using CFMA with a single-user decoder as soon as the signal-to-noise ratios are above $1+sqrt {2}$ . A partial analysis is given for more than two users. Finally, the strategy is extended to the so-called dirty MAC, where two interfering signals are known non-causally to the two transmitters in a distributed fashion. Our scheme extends the previously known results and gives new achievable rate regions.
Auteurs: Jingge Zhu;Michael Gastpar;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 2678 - 2695
Editeur: IEEE
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» General Stochastic Convergence Theorem and Stochastic Adaptive Output-Feedback Controller
Résumé:
This paper is devoted to the analysis methods/tools to stochastic convergence and stochastic adaptive output-feedback control. As the first contribution, a general stochastic convergence theorem is proposed for stochastic nonlinear systems. The theorem doesn't necessarily involve a positive-definite function of the system states with negative-semidefinite infinitesimal, essentially different from stochastic LaSalle's theorem (see e.g., [1]), and hence can provide more opportunities to achieve stochastic convergence. Moreover, as a direct extension of the convergence theorem, a general version of stochastic Barb ă lat's lemma is obtained, which requires the concerned stochastic process to be almost surely integrable, rather than absolutely integrable in the sense of expectation, unlike in [2]. As the second contribution, supported by the general stochastic convergence theorem, an adaptive output-feedback control strategy is established for the global stabilization of a class of stochastic nonlinear systems with severe parametric uncertainties coupled to unmeasurable states. Its feasibility analysis takes substantial effort, and is largely based on the general stochastic convergence theorem. Particularly, for the resulting closed-loop system, certain stochastic boundedness and integrability are shown by the celebrated nonnegative semimartingale convergence theorem, and furthermore, the desired stochastic convergence is achieved via the general stochastic convergence theorem.
Auteurs: Fengzhong Li;Yungang Liu;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2334 - 2349
Editeur: IEEE
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» General-Purpose Clocked Gate Driver IC With Programmable 63-Level Drivability to Optimize Overshoot and Energy Loss in Switching by a Simulated Annealing Algorithm
Résumé:
A general-purpose clocked gate driver integrated circuit (IC) to generate an arbitrary gate waveform is proposed to provide a universal platform for fine-grained gate waveform optimization handling various power transistors. The fabricated IC with a 0.18 μm Bipolar-CMOS-DMOS process has 63 P-type MOS (PMOS) and 63 N-type MOS (NMOS) driver transistors on a chip whose activation patterns are controlled by 6-bit digital signals and 40 ns time step control. In the 500 V switching measurements with a manual gate waveform optimization, the proposed gate driver reduces the IC overshoot by 25% and 41%, and the energy loss by 38% and 55% for Si-insulated-gate bipolar transistor and SiC-MOSFET, respectively, which demonstrate the feasibility of driving various power devices with the same driver. An automatic optimization by simulated annealing algorithm is introduced to fully utilize the benefit of the gate driver, and the further reduction of IC overshoot by 26% and the energy loss by 18% are achieved over the manual optimization.
Auteurs: Koutarou Miyazaki;Seiya Abe;Masanori Tsukuda;Ichiro Omura;Keiji Wada;Makoto Takamiya;Takayasu Sakurai;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2350 - 2357
Editeur: IEEE
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» Generalized Coprime Planar Array Geometry for 2-D DOA Estimation
Résumé:
In this letter, we propose a generalized coprime planar array (GCPA) geometry for 2-D direction of arrival (DOA) estimation, where two rectangular uniform planar subarrays are used. The proposed geometry allows a more flexible array layout and extends the array aperture to achieve a great performance improvement. We verify that GCPA can obtain a higher degree of freedom (DOF) than square coprime planar array and we derive the principle for array layout of GCPA to obtain the maximum DOF. The superiority of GCPA are revealed by numerical simulations with the classical DOA methods.
Auteurs: Wang Zheng;Xiaofei Zhang;Hui Zhai;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1075 - 1078
Editeur: IEEE
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» Generalized Line Loss Relaxation in Polar Voltage Coordinates
Résumé:
It is common for power system behavior to be expressed in terms of polar voltage coordinates. When applied in optimization settings, loss formulations in polar voltage coordinates typically assume that voltage magnitudes are fixed. In reality, voltage magnitudes vary and may have an appreciable effect on losses. This paper proposes a systematic approach to incorporating the effects of voltage magnitude changes into a linear relaxation of the losses on a transmission line. This approach affords greater accuracy when describing losses around a base voltage condition as compared to previous linear and piecewise linear methods. It also better captures the true behavior of losses at conditions away from the flat voltage profile.
Auteurs: Jonathon A. Martin;Ian A. Hiskens;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1980 - 1989
Editeur: IEEE
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» Generalized Primitive Stamps for Nonlinear Circuit-Field Coupling in the Transient Case
Résumé:
The simultaneous solution of circuit and field equations is often required in the analysis of magnetic devices. Although schemes for the solution of this coupled problem have been proposed, the existing formulations are usually tied to specific time discretization or nonlinear iteration expressions and therefore lack generality. In this paper, a highly systematized approach is proposed for strong circuit-field coupling in a transient finite element context, by identifying primitive stamps for field elements, circuit elements, and circuit-field couplings. The filamentary and solid conductors of the field model are the key elements for systematic interconnection using generalized stamps and modified nodal analysis. As a result, the coupling equations are treated just as any other circuit element, simplifying the implementation and providing a unified framework for circuit-field analysis. Both circuit and field stamps are independent of the time discretization and nonlinear solving procedure. With the proposed scheme, the finite element equations can be linked to circuits of arbitrary topology. The theory is developed for the axisymmetric and Cartesian 2-D cases and several examples are then solved to show the effectiveness of our new approach. Solutions are compared with those produced by well-known and validated commercial software packages which implement different, proprietary, and/or undisclosed circuit-field coupling methods.
Auteurs: Enrique Melgoza-Vazquez;Rafael Escarela-Perez;Jose L. Guardado;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 9
Editeur: IEEE
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» Generalized Small Signal Modeling of Coupled-Inductor-Based High-Gain High-Efficiency DC–DC Converters
Résumé:
Usually, the high-gain high-efficiency dc–dc converters consist of many passive components, which increases the order of the system. As the order increases, system modeling and control become more complex. Thus, there is a need for the simplification of the small signal modeling process of such converters. This paper presents a generalized small signal model and equivalent circuit for an $n$ th-order coupled-inductor-based high-voltage gain converters (CIHVGC) that can be conveniently used for the control design. The state variable representation of a generalized coupled inductor with p windings is included. A simplified step by step procedure to obtain small signal model using visual inspection is presented. Analysis is included and verified using simulations and experiments for the output voltage regulation of high-voltage gain converters. The usefulness and versatility of the proposed model is verified with three examples of high gain converters belonging to the CIHVGC family. All the analytical, simulation, and experimental details of this paper are presented.
Auteurs: Moumita Das;Vivek Agarwal;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2257 - 2270
Editeur: IEEE
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» Generalized Stability Control for Open-Loop Operation of Motor Drives
Résumé:
This paper proposes a general approach to designing a stability control for open-loop operation that can be used for either induction motor, permanent magnet synchronous motor, or any other motor drives. A speed or frequency set point is adjusted by a frequency compensation value to provide the stability control to mitigate hunting or motor stoppage. The proposed method can be utilized in either conventional motor drives or motor drives with an output filter and a transformer used for oil pump applications.
Auteurs: Jingbo Liu;Thomas A. Nondahl;Peter B. Schmidt;Semyon Royak;Timothy M. Rowan;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2517 - 2525
Editeur: IEEE
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» Generating Ambiguous Figure-Ground Images
Résumé:
Ambiguous figure-ground images, mostly represented as binary images, are fascinating as they present viewers a visual phenomena of perceiving multiple interpretations from a single image. In one possible interpretation, the white region is seen as a foreground figure while the black region is treated as shapeless background. Such perception can reverse instantly at any moment. In this paper, we investigate the theory behind this ambiguous perception and present an automatic algorithm to generate such images. We model the problem as a binary image composition using two object contours and approach it through a three-stage pipeline. The algorithm first performs a partial shape matching to find a good partial contour matching between objects. This matching is based on a content-aware shape matching metric, which captures features of ambiguous figure-ground images. Then we combine matched contours into a compound contour using an adaptive contour deformation, followed by computing an optimal cropping window and image binarization for the compound contour that maximize the completeness of object contours in the final composition. We have tested our system using a wide range of input objects and generated a large number of convincing examples with or without user guidance. The efficiency of our system and quality of results are verified through an extensive experimental study.
Auteurs: Ying-Miao Kuo;Hung-Kuo Chu;Ming-Te Chi;Ruen-Rone Lee;Tong-Yee Lee;
Apparue dans: IEEE Transactions on Visualization and Computer Graphics
Date publication: 05.-2017, volume: 23, issue:5, pages: 1534 - 1545
Editeur: IEEE
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» Generation of Duplicated Off-Line Signature Images for Verification Systems
Résumé:
Biometric researchers have historically seen signature duplication as a procedure relevant to improving the performance of automatic signature verifiers. Different approaches have been proposed to duplicate dynamic signatures based on the heuristic affine transformation, nonlinear distortion and the kinematic model of the motor system. The literature on static signature duplication is limited and as far as we know based on heuristic affine transforms and does not seem to consider the recent advances in human behavior modeling of neuroscience. This paper tries to fill this gap by proposing a cognitive inspired algorithm to duplicate off-line signatures. The algorithm is based on a set of nonlinear and linear transformations which simulate the human spatial cognitive map and motor system intra-personal variability during the signing process. The duplicator is evaluated by increasing artificially a training sequence and verifying that the performance of four state-of-the-art off-line signature classifiers using two publicly databases have been improved on average as if we had collected three more real signatures.
Auteurs: Moises Diaz;Miguel A. Ferrer;George S. Eskander;Robert Sabourin;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 05.-2017, volume: 39, issue:5, pages: 951 - 964
Editeur: IEEE
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» Geometric Calibration of an Aerial Multihead Camera System for Direct Georeferencing Applications
Résumé:
An aerial multihead camera consists of a photogrammetric system composed of multiple cameras, which are mounted together in a main structure. By combining the images acquired simultaneously from each camera, a single synthetic image with much larger coverage can be generated. Such systems are usually integrated with a position and orientation system (POS) to perform direct georeferencing (DG) or integrated sensor orientation (ISO). However, to obtain mapping products with high accuracy through a DG procedure, it is essential the implementation of the system geometric calibration. Usually, the aerial multihead camera manufacturers perform the geometric calibration using laboratory methods and only the camera interior orientation parameters (IOPs) and their relative orientation parameters (ROPs) are determined to generate the synthetic image (process known as “platform calibration”). The mounting parameters (lever arms and boresight misalignment angles) relating the synthetic image and GNSS/INS reference systems are usually defined using nominal installation values. The objective of this paper is to present an in-flight calibration methodology for multihead camera systems and its assessment for DG applications. The introduced methodology involves three steps: 1) determination of the cameras’ IOPs and their ROPs; 2) synthetic image generation; and 3) refinement of the IOPs of the synthetic image and the mounting parameters determination between the synthetic image and GNSS/INS reference systems using different methods. The results of the experiments shown the viability of the proposed methodology for DG applications involving photogrammetric procedures for large-scale mapping requirements.
Auteurs: Leonardo E. Filho;Edson A. Mitishita;Ana Paula B. Kersting;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 1926 - 1937
Editeur: IEEE
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» Geometrically Modified Einzel Lenses, From the Conventional Cylindrical Einzel Lens to Cubic and Continuous Einzel Lens
Résumé:
New geometrical counterparts to the conventional Einzel lens, cubic, and the continuous body electrostatic (CBE) lenses are introduced and their performances are investigated in terms of different aberrations and input beam properties. Design curves for the continuous body electrostatic lens are presented. Relative sensitivity is proposed as a figure of merit, based on which the focusing characteristics of the two new lenses are compared with that of a conventional Einzel, and a quadrupole lenses of the same size, as well. Moreover, performance and characteristics of the lenses are compared in terms of their corresponding sensitivities to the applied voltage and the incidence beam nonidealities. Electric field distributions of the lenses are studied, and different aberrations are discussed. It is shown that considering chromatic nonparaxial beams, the CBE lens outperforms the conventional Einzel lens in terms of the sensitivity and the absolute value of the lens demagnification.
Auteurs: Arash Riazi;Navid Yasrebi;Hossein Monjezi;Bizhan Rashidian;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 05.-2017, volume: 45, issue:5, pages: 828 - 835
Editeur: IEEE
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» Global Communications Newsletter
Résumé:
Presents key events and topics in the global communications industry.
Auteurs: Stefano Bregni;Octavia A. Dobre;Maytee Zambrano N.;Magnus Jonsson;Jacek Rak;Dimitri Papadimitriou;Arun Somani;Leo Hwa Chiang;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 19 - 22
Editeur: IEEE
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» Global EDF Schedulability Analysis for Parallel Tasks on Multi-Core Platforms
Résumé:
With the widespread adoption of multi-core architectures, it is becoming more important to develop software in ways that takes advantage of such parallel architectures. This particularly entails a shift in programming paradigms towards fine-grained, thread-parallel computing. Many parallel programming models have been introduced for targeting such intra-task thread-level parallelism. However, most successful results on traditional multi-core real-time scheduling are focused on sequential programming models. For example, thread-level parallelism is not properly captured into the concept of interference, which is key to many schedulability analysis techniques. Thereby, most interference-based analysis techniques are not directly applicable to parallel programming models. Motivated by this, we extend the notion of interference to capture thread-level parallelism more accurately. We then leverage the proposed notion of parallelism-aware interference to derive efficient EDF schedulability tests that are directly applicable to parallel task models, including DAG models, on multi-core platforms, without knowing an optimal schedule. Our evaluation results indicate that the proposed analysis significantly advances the state-of-the-art in global EDF schedulability analysis for parallel tasks. In particular, we identify that our proposed schedulability tests are adaptive to different degrees of thread-level parallelism and scalable to the number of processors, resulting in substantial improvement of schedulability for parallel tasks on multi-core platforms.
Auteurs: Hoon Sung Chwa;Jinkyu Lee;Jiyeon Lee;Kiew-My Phan;Arvind Easwaran;Insik Shin;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 05.-2017, volume: 28, issue:5, pages: 1331 - 1345
Editeur: IEEE
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» Global Parametric Polynomial Approximation of Static Voltage Stability Region Boundaries
Résumé:
A novel method for globally approximating the static voltage stability region boundaries (SVSRBs) of power systems is proposed by applying parametric polynomial approximation to the criterion equation which defines the SVSRB. Known as the Galerkin method, the implicit function portraying the SVSRB is described as a linear combination of basis polynomial functions, and the coefficients of the basis functions are obtained by projecting the SVSRB criterion onto each basis function. The approximation guarantees high precision globally in the whole domain of the parameter of interest rather than only in the neighborhood of a point, and the error can be controlled by the degree of polynomial basis functions. In the meantime, analytical expression of the left or right eigenvector of the system's Jacobian matrix corresponding to the zero eigenvalue is obtained in the form of polynomial, which provides valuable information for online voltage stability control or monitoring. Case studies in a 10-bus test system and IEEE 118-bus test system verifies the validity, accuracy, and flexibility of the proposed method.
Auteurs: Yiwei Qiu;Hao Wu;Yongzhi Zhou;Yonghua Song;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2362 - 2371
Editeur: IEEE
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» Gold-Hyperdoped Black Silicon With High IR Absorption by Femtosecond Laser Irradiation
Résumé:
Gold (Au)-doped-textured silicon (Si) material with a thermostable absorption below bandgap (>50%) is obtained by femtosecond laser irradiation. Although the concentration of Au impurity (1019 cm−3 ) in textured Si is at least four orders of magnitude greater than the solid solubility of Au in crystalline Si, the sheet carrier density (approximately 1010 cm−2) in Au-doped Si is very low due to a self-compensation effect of Au impurity in Si material. The infrared absorption of Au-doped Si is related to laser-induced-structural defects and sub-band absorption of deep energy levels of Au in Si, which is determined by temperature-dependent Hall Effect measurement. Besides supersaturated doping of Au, a gold silicide phase is formed at textured Si surface.
Auteurs: Xin-Yue Yu;Ji-Hong Zhao;Chun-Hao Li;Qi-Dai Chen;Hong-Bo Sun;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 502 - 506
Editeur: IEEE
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» GPU-Accelerated Simulation of Small Delay Faults
Résumé:
Delay fault simulation is an essential task during test pattern generation and reliability assessment of electronic circuits. With the high sensitivity of current nano-scale designs toward even smallest delay deviations, the simulation of small gate delay faults has become extremely important. Since these faults have a subtle impact on the timing behavior, traditional fault simulation approaches based on abstract timing models are not sufficient. Furthermore, the detection of these faults is compromised by the ubiquitous variations in the manufacturing processes, which causes the actual fault coverage to vary from circuit instance to circuit instance, and makes the use of timing accurate methods mandatory. However, the application of timing accurate techniques quickly becomes infeasible for larger designs due to excessive computational requirements. In this paper, we present a method for fast and waveform-accurate simulation of small delay faults on graphics processing units with exceptional computational performance. By exploiting multiple dimensions of parallelism from gates, faults, waveforms, and circuit instances, the proposed approach allows for timing-accurate and exhaustive small delay fault simulation under process variation for designs with millions of gates.
Auteurs: Eric Schneider;Michael A. Kochte;Stefan Holst;Xiaoqing Wen;Hans-Joachim Wunderlich;
Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Date publication: 05.-2017, volume: 36, issue:5, pages: 829 - 841
Editeur: IEEE
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» Grades of IEEE Membership [The Way Ahead]
Résumé:
Presents information on the different grades of IEEE membership.
Auteurs: J. Patrick Donohoe;
Apparue dans: IEEE Potentials
Date publication: 05.-2017, volume: 36, issue:3, pages: 4 - 4
Editeur: IEEE
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» Graphical Representation of the Power Transfer Efficiency of Lumped-Element Circuits Based on Hyperbolic Geometry
Résumé:
By adding a passive element to a power source, an inevitable power attenuation caused by the dissipative loss occurs. It is important for some applications to reduce this undesirable attenuation. A representative example of one of these kinds of applications is impedance matching, for which we transform the source's impedance to a different preferable one with passive elements, and the attenuation is to be as low as possible. To give a visible way to design better circuits in such situations, we propose a graphical representation to understand the attenuation from the viewpoint of hyperbolic geometry. We reveal that the attenuation in logarithmic scale (typically decibels or nepers) is proportionate to the hyperbolic length of the path representing the movement of the reflection coefficient, and the constant of proportionality is determined by the unloaded Q-factor of the connected elements. Exploiting the result, we can find preferable topologies by using the Smith chart with an intuition. In addition to this graphical representation, we also reveal the lower bound of the attenuation in terms of the hyperbolic distance between the two reflection coefficients that we want to match. A new usage of the Smith chart to estimate the loss and its lower bound is given in this brief.
Auteurs: Kyohei Yamada;Takashi Ohira;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 485 - 489
Editeur: IEEE
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» Gravity-Capillary Wave Spectral Modulation by Gravity Waves
Résumé:
In order to more fully understand the specific hydrodynamic relationship between young wind-generated gravity-capillary waves and longer gravity waves, a laboratory experiment was devised to observe changes in short wave spectral behavior over the phase of a long wave. This paper endeavors to expand on the body of laboratory wave modulation data and extend the investigation in support of the radar remote sensing of ocean surface waves. Measurements were made in the University of Miami's surge-structure-atmosphere interaction facility in the air-sea interaction saltwater tank wind-wave tank, with 10 m referenced wind speeds ranging between 5 and 23 m/s and paddle-generated wave steepnesses “ak” varying between 0.05 <; ak <; 0.3. A polarimetric camera was used to capture high sampling frequency maps of wave slope, yielding spatiotemporal information about short wind-wave behavior [provided as temporal variations in the wavenumber spectrum, where k ≈ 15(100-1000) rad/m]. The simultaneous and colocated long wave phase was measured via a side-looking camera. Hydrodynamic modulation transfer function (MTF) phases are found to be in general agreement with established values (between 2 and 10 radians) at the given wind speeds. The positive phase of the modulation places it immediately downwind of the long wave crest, with MTF magnitudes strongest for high wavenumbers at the lowest wind speeds. The results are also presented to show the modulation of gravity-capillary and pure capillary waves as variations in mean square slope over the long wave phase, with peak roughness enhancement found to move upwind of the long wave crest with increasing wind forcing.
Auteurs: Nathan J. M. Laxague;Milan Curcic;Jan-Victor Björkqvist;Brian K. Haus;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2477 - 2485
Editeur: IEEE
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» Green Communications and Computing Networks
Résumé:
The articles in this special section focus on green communications and computing networks.
Auteurs: Jinsong Wu;John Thompson;Honggang Zhang;RangaRao Venkatesha Prasad;Song Guo;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 160 - 161
Editeur: IEEE
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» Ground Moving Target Indication for High-Resolution Wide-Swath Synthetic Aperture Radar Systems
Résumé:
This letter presents a new scheme for ground moving target indication in high-resolution wide-swath (HRWS)-synthetic aperture radar (SAR) systems. The asymmetry of the Doppler spectra is measured to extract the range bins with moving targets. To improve the computational efficiency, only the extracted range bins are used to restore the unambiguous Doppler spectra. The two-look processing technique is then applied to generate two looks and moving targets are indicated by comparing the difference between the two looks. In this detection scheme, the configuration of the conventional HRWS-SAR system remains unchanged and no additional receiving channels are needed. The experimental results show the effectiveness of this detection scheme.
Auteurs: Hongchao Zheng;Junfeng Wang;Xingzhao Liu;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 749 - 753
Editeur: IEEE
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» Ground-Based Cloud Detection Using Graph Model Built Upon Superpixels
Résumé:
Cloud detection plays an important role in climate models, climate predictions, and meteorological services. Although researchers have given increasing efforts on cloud detection, the performance is still unsatisfactory due to the diverse nature of clouds. Considering the fact that one source of information (color or texture) is not enough to segment cloud from clear sky, in this letter, we propose a novel ground-based cloud detection method using graph model (GM) built upon superpixels to integrate multiple sources of information. First, we use the superpixel segmentation to divide the image into a series of subregions according to the color similarity and spatial continuity. Next, adjacent superpixels are merged according to their similarity of extracted features. Finally, we build a GM on the merged superpixels by considering each superpixel as a node and adding edges between neighboring ones. The unary cost is set according to the classification score of Random Forests, while pairwise cost reflects the penalties for color and texture discontinuity between neighboring components. The final segmentation could be acquired by minimizing the cost function. Moreover, the algorithm is computationally efficient as we use the superpixels rather than raw pixels as computation units. Experimental results demonstrate the effectiveness and efficiency of the proposed method for cloud detection.
Auteurs: Cunzhao Shi;Yu Wang;Chunheng Wang;Baihua Xiao;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 719 - 723
Editeur: IEEE
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» Guest Editor's Introduction to the Special Section on the ACM Symposium on Interactive 3D Graphics and Games (I3D)
Résumé:
Auteurs: Kartic Subr;Li-Yi Wei;
Apparue dans: IEEE Transactions on Visualization and Computer Graphics
Date publication: 05.-2017, volume: 23, issue:5, pages: 1427 - 1427
Editeur: IEEE
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» Guest Editorial Special Issue on Nanoelectronic Devices and Circuits for Next Generation Sensing and Information Processing
Résumé:
The articles in this special issue focus on novel device technology and circuit designs to implement smart, efficient, reliable and secure sensing, control, and computing paradigm.
Auteurs: S. P. MOHANTY;X. LI;H. LI;Y. CAO;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 383 - 386
Editeur: IEEE
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» Guest Editorial Special Section on the 2016 IEEE Latin American Symposium on Circuits and Systems (LASCAS 2016)
Résumé:
Welcome to this Special Section, a collection of selected papers presented at the 2016 IEEE Latin American Symposium on Circuits and Systems (LASCAS 2016), held in Florianópolis, Brazil, from February 28 to March 2, 2016. Over 250 delegates attended the conference, where 100 papers were presented, selected from 203 papers submitted across 20 tracks.
Auteurs: Pedro M. Julián;Lisandro Lovisolo;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1017 - 1018
Editeur: IEEE
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» Guest Editorial: Special Section on Nano Devices, Circuits and Systems
Résumé:
The papers in this special section focus on nanotechnology which includes nanoelectronics, optoelectronics, and nanomaterials. Since the Nanotechnology is now widely deployed in sensors, optoelectronic, biology, medicine, and material science, we are trying to enhance the research at the nanoscale, to share knowledge, expertise, techniques, and tools on nanotechnology. The purpose of these papers are to indicate the increasing demands for device, circuits and systems Designs in which the devices are analyzed in low power, high power and high frequency applications. Consequently these analysis are linked with analog and digital circuits.
Auteurs: V. R. Rao;C. K. Sarkar;D. Nirmal;M. Kumar;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 367 - 367
Editeur: IEEE
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» Guided Wave Tomography of Pipe Bends
Résumé:
Detection and monitoring of corrosion and erosion damage in pipe bends are open challenges due to the curvature of the elbow, the complex morphology of these defects, and their unpredictable location. Combining model-based inversion with guided ultrasonic waves propagating along the elbow and inside its walls offers the possibility of mapping wall-thickness losses over the entire bend and from a few permanently installed transducers under the realm of guided wave tomography (GWT). This paper provides the experimental demonstration of GWT of pipe bends based on a novel curved ray tomography algorithm and an optimal transducer configuration consisting of two ring arrays mounted at the ends of the elbow and a line of transducers fixed to the outer side of the elbow (extrados). Using realistic, localized corrosion defects, it is shown that detection of both the presence and progression of damage can be achieved with 100% sensitivity regardless of damage position around the bend. Importantly, this is possible for defects as shallow as 0.50% of wall thickness (WT) and for maximum depth increments of just 0.25% WT. However, due to the highly irregular profile of corrosion defects, GWT generally underestimates maximum depth relative to the values obtained from 3-D laser scans of the same defects, leading in many cases to errors between 3% WT and 8% WT.
Auteurs: Alex J. Brath;Francesco Simonetti;Peter B. Nagy;Geir Instanes;
Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Date publication: 05.-2017, volume: 64, issue:5, pages: 847 - 858
Editeur: IEEE
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» Handoff Performance Improvements in an Integrated Train-Ground Communication System Based on Wireless Network Virtualization
Résumé:
In existing urban rail transit systems, the train-ground communication system for different subsystems is deployed independently. Investing and constructing the communication infrastructures repeatedly not only wastes substantial social resources, but it also is difficult to maintain all these infrastructures. In this paper, we propose an integrated train-ground communication system based on wireless network virtualization for urban rail transit systems. In order to improve the communication-based train control (CBTC) subsystem performance during handoff, we propose a novel handoff scheme to support handoff between virtual networks. The application-layer quality-of-service (QoS) parameters of the CBTC, passenger information system, and closed circuit television subsystems are used as the performance measures in the handoff design. We then formulate the QoS optimization problem in the proposed integrated train-ground communication system as an approximate dynamic programming (ADP) problem. The extensive simulation results show that the proposed integrated train-ground communication system QoS can be improved substantially with our ADP-based optimization model.
Auteurs: Li Zhu;Fei Richard Yu;Tao Tang;Bin Ning;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 05.-2017, volume: 18, issue:5, pages: 1165 - 1178
Editeur: IEEE
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» Hands-On Education about Standardization: Is That What Industry Expects?
Résumé:
Technical standards support compatibility and interoperability among numerous entities existing in the telecommunications market. However, the university curricula rarely include standards analysis and rarely encourage students to create solutions that are based on the standards. This fact poses a hindrance in the adoption of new technologies due to the fact that recent graduates as young professionals will most certainly have difficulties in using new standards they may get in touch with on their first job. In our approach, we acknowledge the need for students to work with standards before they graduate. Research activities, connected with industrial projects in which application of new standardized technologies is in focus, are combined with student projects, enabling students to get their own hands-on experience in analyzing and applying telecommunications standards. As the result, students gain valuable experience for their future careers, an academic setting is used as a safe environment for testing and possibly even enhancing new standards, and the industry attains deeper knowledge about standards and technologies that could be used in their real-world deployments.
Auteurs: Damjan Katusic;Pavle Skocir;Mario Kusek;Gordan Jezic;Carlo Ratti;Iva Bojic;
Apparue dans: IEEE Communications Magazine
Date publication: 05.-2017, volume: 55, issue:5, pages: 133 - 144
Editeur: IEEE
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» Hardness of Firewall Analysis
Résumé:
We identify 13 problems whose solutions can significantly enhance our ability to design and analyze firewalls and other packet classifiers. These problems include the firewall equivalence problem, the firewall redundancy problem, the firewall verification problem, and the firewall completeness problem. The main result of this paper is to prove that every one of these problems is NP-hard. Our proof of this result is interesting in the following way. Only one of the 13 problems, the so called slice probing problem, is shown to be NP-hard by a reduction from the well-known 3-SAT problem. Then, the remaining 12 problems are shown to be NP-hard by reductions from the slice probing problem. This proof suggests that the slice probing problem plays an important role in the design and analysis of firewalls. The negative results of this paper suggest that firewalls designers may need to rely on SAT solvers to solve instances of these 13 problems or may be content with probabilistic solutions of these problems. On the positive side, we show that each of the 13 firewall analysis problems presented in this paper is polynomially reducible to the slice probing problem. Thus any algorithm, that can effectively solve the slice probing problem, can also be employed to effectively solve any of these 13 problems.
Auteurs: Ehab S. Elmallah;Mohamed G. Gouda;
Apparue dans: IEEE Transactions on Dependable and Secure Computing
Date publication: 05.-2017, volume: 14, issue:3, pages: 339 - 349
Editeur: IEEE
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» Hardware Architecture Based on Parallel Tiled QRD Algorithm for Future MIMO Systems
Résumé:
QR decomposition (QRD) has been a vital component in the transceiver processor of future multiple-input multiple-output (MIMO) systems, in which antenna configuration will be more and more flexible. Therefore, the QRD hardware architecture in the future MIMO systems should be more flexible to meet various antenna configurations. Unfortunately, the existing QRD hardware architectures mainly focus on the matrix of one or several fixed sizes. This paper presents a new triangular systolic array QRD hardware architecture based on parallel tiled QRD algorithm to decompose an $ {8}times {8}$ real matrix. The designed hardware architecture is flexible and can be used in various MIMO systems, in which the number of antennas is smaller than 4. This paper also proposes a modified algorithm for the bottleneck operations of parallel tiled QRD algorithm to reduce the hardware overhead. To further reduce the hardware overhead, the Newton–Raphson algorithm is adopted in the proposed algorithm. The implementation results show that the normalized processing latency performance and the normalized processing efficiency performance of the designed QRD hardware architecture both are better than most of the existing QRD hardware architectures. To the best of our knowledge, the hardware architecture presented in this paper achieves the superior normalized QRD rate performance to the existing QRD hardware architectures.
Auteurs: Cang Liu;Chuan Tang;Zuocheng Xing;Luechao Yuan;Yang Zhang;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 05.-2017, volume: 25, issue:5, pages: 1714 - 1724
Editeur: IEEE
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» Hardware Implementation Overhead of Switchable Matching Networks
Résumé:
Nowadays, more and more RF systems include switchable matching networks to decrease the impact of the environment-dependent antenna impedance on the RF front end performance. This paper reviews the theoretical lower limit on the required number of matching states to match VSWR ranges and then presents an analysis of hardware implementations to actually implement a suitable switchable matching network. A number of matching network topologies are analyzed: PI networks, loaded transmission lines, branch line coupler based circuits, single circulators and cascaded circulators. In our investigation only narrow-band applications are targeted. For the various circuit implementations the required number of matching states for each hardware implementation is compared to the theoretical minimum number of states required for the same matching in order to benchmark their hardware implementation overhead. It appears that a matching network using cascaded circulators is the closest to the theoretical optimum for networks with a relatively low number of states: this type of matching network was implemented and analyzed in more detail.
Auteurs: Ettore Lorenzo Firrao;Anne-Johan Annema;Frank E. van Vliet;Bram Nauta;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1152 - 1163
Editeur: IEEE
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» Hardware/Software Approach to Designing Low-Power RNS-Enhanced Arithmetic Units
Résumé:
In this paper, we propose a new approach to use a residue number system (RNS) to design an arithmetic unit to parallelize execution of addition and multiplication. The chosen RNS is defined by a moduli set composed of one larger even modulus ${2^{k}}$ and all remaining moduli of the type ${2^{n}-1}$ , selected to fit into the word size of a typical general-purpose processor, e.g., 32 or 64 b. The RNS operations are implemented in hardware, except for the reverse conversion, which is implemented in software, allowing not only to save hardware area but also offering the ease of run-time changing of the dynamic range, which in turn can result in reducing both power consumption and execution time. Simulation experiments were performed on synthesized seven-operation arithmetic units with varying dynamic range for three applications: constant-coefficient filtering, matrix multiplication, and large Montgomery multiplication. The results show that thanks to smaller modular multipliers, RNS arithmetic units have smaller both area and delay, and, consequently, they allow to achieve up to over 20% energy saving for a constant-coefficient filter application, up to over 28% for the matrix multiplication, and up to 27% for Montgomery multiplication, compared with executions using a positional arithmetic unit.
Auteurs: Piotr Patronik;Stanisław J. Piestrak;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1031 - 1039
Editeur: IEEE
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» Harmonics and Interharmonics Analysis of Electrical Arc Furnaces Based on Spectral Model Optimization With High-Resolution Windowing
Résumé:
In this paper, a spectral model optimization based method for the analysis of harmonics and interharmonics produced by electric arc furnace (EAF) installations is presented. Detecting the changes occurring in the frequency spectrum of the EAF voltages fast and accurately has crucial importance to eliminate the undesired effects of harmonics and interharmonics using advanced technology compensation systems such as active power filters, synchronous static compensators, energy storage systems, etc. The aim of the research work presented here is to reduce the spectral leakage effects experienced by Fourier analysis based methods by estimating the spectral model parameters using nonlinear least squares. The Fourier spectrum of the signal is used as a priori information; however, the proposed model does not suffer from the spectral leakage problems encountered by the Fourier analysis based methods in case of fundamental frequency variation, which frequently occurs in the existence of EAF plants in an electrical system. Moreover, the proposed model permits frequency detection at a much higher resolution than the Fourier analysis based methods. The proposed method has been tested on both synthetic and field data and it has been shown that it is able to detect frequency components and the corresponding amplitudes and phases of harmonics and interharmonics with high accuracy for EAF plants.
Auteurs: Yunus Emre Vatankulu;Zekeriya Şentürk;Ozgul Salor;
Apparue dans: IEEE Transactions on Industry Applications
Date publication: 05.-2017, volume: 53, issue:3, pages: 2587 - 2595
Editeur: IEEE
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» Harnessing Encrypted Data in Cloud for Secure and Efficient Mobile Image Sharing
Résumé:
Nowadays, large volumes of multimedia data are outsourced to the cloud to better serve mobile applications. Along with this trend, highly correlated datasets can occur commonly, where the rich information buried in correlated data is useful for many cloud data generation/dissemination services. In light of this, we propose to enable a secure and efficient cloud-assisted image sharing architecture for mobile devices, by leveraging outsourced encrypted image datasets with privacy assurance. Different from traditional image sharing, we aim to provide a mobile-friendly design that saves the transmission cost for mobile clients, by directly utilizing outsourced correlated images to reproduce the image of interest inside the cloud for immediate dissemination. First, we propose a secure and efficient index design that allows the mobile client to securely find from encrypted image datasets the candidate selection pertaining to the image of interest for sharing. We then design two specialized encryption mechanisms that support secure image reproduction from encrypted candidate selection. We formally analyze the security strength of the design. Our experiments explicitly show that both the bandwidth and energy consumptions at the mobile client can be saved, while achieving all service requirements and security guarantees.
Auteurs: Helei Cui;Xingliang Yuan;Cong Wang;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 05.-2017, volume: 16, issue:5, pages: 1315 - 1329
Editeur: IEEE
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» Has Intel created a universal memory technology? [News]
Résumé:
Today's computers shuttle data around a byzantine system of several different kinds of short- and long-term memory. No wonder, then, that engineers have long dreamed of one memory technology to rule them all, a universal memory that would simplify computing and streamline the path of data.
Auteurs: Katherine Bourzac;
Apparue dans: IEEE Spectrum
Date publication: 05.-2017, volume: 54, issue:5, pages: 9 - 10
Editeur: IEEE
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» Hazelnut Oil Classification by NMR Techniques
Résumé:
Nuclear magnetic resonance (NMR) has been widely used in chemical analysis and medical diagnosis. In recent years, thanks to the development of the NMR instrumentation and the software for data analysis, it is becoming a useful tool for quality control in the food industry. In this field, several applications have been developed related to the compositional and structural analysis, authentication, packaging, and on-line monitoring. This paper highlights the capability of NMR to discern between the oil extracted from healthy and unhealthy hazelnuts, as a preliminary step toward the automatic detection of the hidden defects in full hazelnuts. Different processing techniques are analyzed on the CPMG response in order to set up the final measurement system.
Auteurs: Domenico Di Caro;Consolatina Liguori;Antonio Pietrosanto;Paolo Sommella;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 928 - 934
Editeur: IEEE
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» Heterogeneous Networked Cooperative Scheduling With Anarchic Particle Swarm Optimization
Résumé:
This paper proposes a mathematical model and new solving algorithm for scheduling of a distributed production network with heterogeneous parallel factories distributed in the different geographical places. In this problem, two subproblems must be solved, i.e., 1) assigning jobs to appropriate factory and 2) scheduling jobs on parallel machines in each factory. We also assume that after initial assignment, for better balancing in machines’ loading in the different factories, each job can be shifted among factories. After modeling the problem as mixed integer linear programming, with proposing a new method for solution representation, we propose a novel solving algorithm namely anarchic particle swarm optimization to minimize makespan of jobs. This algorithm is inspired by an anarchic society whose members behave anarchically to improve their situations. By such anarchic particles, the algorithm can prevent falling in local optimum traps. The obtained results of mixed integer linear programming solved by CPLEX are compared with the proposed algorithm, a genetic algorithm and a noncooperative local scheduling for small-sized instances. At the end, the effectiveness of anarchic particle swarm optimization, standard particle swarm optimization, and genetic algorithm are examined on the test problems which contained up to 500 jobs.
Auteurs: Javad Behnamian;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 05.-2017, volume: 64, issue:2, pages: 166 - 178
Editeur: IEEE
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» Hierarchical MK Splines: Algorithm and Applications to Data Fitting
Résumé:
In the era of big data, it is very important to study large-scale data fitting methods. In order to ensure the calculation speed and accuracy, we propose a new kind of hierarchical many-knot splines (hereinafter called “hierarchical MK splines,” generally abbreviated as HMK splines) in this paper. The HMK splines method produces a sequence of MK spline functions. These MK spline functions are constructed into one ideal interpolation function by the MK spline refinement. In the case of regular sampling data, HMK splines can achieve the purpose of accurate approximation for the given data points without solving systems of equations. Further, in order to deal with the issues of scattered data fitting, the use of least-squares method will lead to the necessary of solving a linear system of equations. Since the ill-conditioned systems of equations often lead to unacceptable deviation of calculation results, one tries to avoid it as much as possible. The HMK splines algorithm can meet this requirement; it can avoid the intolerable deviation caused by solving systems of equations. Experimental results show that large-scale scattered data fitting can be easily achieved by the HMK splines algorithm and the reconstruction of nonuniform samples has a high accuracy.
Auteurs: Zhanchuan Cai;Ting Lan;Caimu Zheng;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 05.-2017, volume: 19, issue:5, pages: 921 - 934
Editeur: IEEE
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» High Performance Ge pMOSFETs With HfO2/Hf-Cap/GeOx Gate Stack and Suitable Post Metal Annealing Treatments
Résumé:
An equivalent oxide thickness of ~0.53 nm, gate leakage current density of $sim 10^{-4}text{A}$ /cm2 at V FB + 1 V, ION/ IOFF ratio of $10^{text {4}}$ , subthreshold swing of 136 mV/dec, and peak hole mobility of 375 cm2/V-s at N $_{text {inv}} = 1.6 times 10^{12}$ cm−2 in Ge p-type metal–oxide–semiconductor-field-effect transistors (pMOSFETs) are achieved by HfO2/Hf-cap/GeOx gate stack with suitable post-metal-annealing (PMA) treatments. Such a high mobility in Ge pMOSFETs can be attributed to an ultrathin GeOx layer at the surface of Ge substrate. Ge+ and Ge+2 in GeOx layer are re-oxidized to higher oxidation state by gettered oxygen, which is captured by Hf-cap from GeOx and HfO2 during PMA. The minimized contents of Ge+1 and Ge+2 in GeOx are crucial to achieve excellent electrical characteristics.
Auteurs: Shih-Han Yi;Kuei-Shu Chang-Liao;Tzung-Yu Wu;Chia-Wei Hsu;Jiayi Huang;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 544 - 547
Editeur: IEEE
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» High Quality Factor Coaxial Cable Fabry-Perot Resonator for Sensing Applications
Résumé:
This paper describes a novel coaxial cable Fabry–Perot resonator for sensing applications. The sensor is fabricated by creating two highly reflective mirrors in a coaxial cable. The device physics was discussed. The temperature response of the sensor was tested. The temperature measurement is achieved by monitoring the frequency shift of the reflection and transmission spectra as the temperature is increased linearly in steps of 5 °C from 35 °C to 80 °C. This sensor exhibited high temperature sensitivity and measurement resolution. The high quality factor of this sensor leads to high measurement resolution. Highest $Q$ factor of 133 was recorded. It has been derived that the $Q$ factor decreases as the frequency increases.
Auteurs: Mohammed Farhan Ahmed;Ting Xue;Bin Wu;Jie Huang;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3052 - 3057
Editeur: IEEE
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» High Resolution Digital Imager Based on Time Multiplexing Algorithm
Résumé:
In this paper, a new high-resolution digital imager based on a time multiplexing scheme is proposed. The imager produces a 256-grayscale image through capturing 256 successive frames that each belongs to a specific luminance range. Each pixel includes a 1-b analog-to-digital converter (ADC) and a single bit static memory to improve the fill factor. The in-pixel ADC is designed as a compact and fast converter to achieve a high-resolution and video-rate image sensor. The proposed sensor is designed and implemented in a standard 180-nm CMOS technology. The imager achieves an overall dynamic range of over 140 dB at video rate imaging. The pixel pitch is $18.3~mu text{m}$ and the fill factor is about 48%. The circuit operates at a supply voltage as low as 800 mV. At this supply voltage and at video rate imaging, its power consumption is about 4.33 nW. The proposed imager can directly perform some pre-processing algorithms, such as image segmentation and binarization. Additionally, the proposed method transfers the memory and process units of the pixels to the external of the sensor array so it provides a suitable structure for designing high-resolution, wide dynamic range, and fast general-purpose image sensors.
Auteurs: Kourosh Hassanli;Sayed Masoud Sayedi;J. Jacob Wikner;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2831 - 2840
Editeur: IEEE
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» High Responsivity Fire Detectors Based on PbS Colloidal Quantum Dot Photoconductors
Résumé:
In this letter, we report on high responsivity fire detectors based on PbS colloidal quantum dots photoconductors. The devices operate in the near infrared and are equipped with a visible light silicon filter for wavelength selectivity. Devices are fabricated by a simple, low cost, and silicon compatible process based on drop casting of a ligand exchanged solution of PbS nanoparticles. The photodetectors exhibit responsivity as high as 20 A/W at 1-V bias. We exploit the combination of their high responsivity and spectral response for the development of a novel fire detector able to detect a small flame at a distance exceeding 15 m in ambient illumination.
Auteurs: Andrea De Iacovo;Carlo Venettacci;Lorenzo Colace;Leonardo Scopa;Sabrina Foglia;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 703 - 706
Editeur: IEEE
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» High Speed Band-Limited 850-nm VCSEL Link Based on Time-Domain Interference Elimination
Résumé:
Short-distance optical interconnection among servers in data centers has attracted the attentions of a multitude of researchers. The method to make the optical link with high transmission capacity and low cost becomes increasingly crucial. Considering these requirements, we propose a new equalization method for time-domain interference elimination in this letter, employed in a band-limited 850-nm vertical cavity surface-emitting laser (VCSEL) link. The method is named simplified maximum likelihood sequence estimation (MLSE), which reduces about 87.8% computational complexity in digital signal processing compared with the conventional MLSE. Based on the proposed simplified-MLSE and combined with the feed-forward equalizer (FFE), a 60-Gb/s non-return-to-zero (NRZ)-modulated VCSEL link could transmit via 56-m OM4 multimode fiber (MMF), and the bit error rate (BER) is still lower than the 7% hard-decision forward error correction (FEC) threshold. The 3-dB bandwidth of the employed 850-nm VCSEL in this transmission system is only 18 GHz, fulfilling the principle of cost-efficient optical interconnects and showing the enormous potential of our proposal in data centers.
Auteurs: Zhongwei Tan;Chuanchuan Yang;Yixiao Zhu;Zhaopeng Xu;Kaiheng Zou;Fan Zhang;Ziyu Wang;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 751 - 754
Editeur: IEEE
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» High Speed Electro-Absorption Modulator for Long Range Retroreflective Free Space Optics
Résumé:
In this letter, we present the design and implementation of a pixelated electro-absorption modulator-based modulating retroreflector (MRR) for high-speed optical wireless communications. The modulator is based on a multiple quantum well structure embedded in an asymmetric Fabry–Perot cavity. This MRR was used in an outdoor link, operating at 150 Mb/s with a bit error rate (BER) of $1.22times 10^{-6}$ at a range of 200 m. The system was also tested in laboratory-controlled conditions achieving a data rate of 200 Mb/s with a BER of $2times 10^{-4}$ . To the best of our knowledge, this is the fastest retroreflective free-space optics demonstration in both the indoor and outdoor environments.
Auteurs: C. Quintana;Q. Wang;D. Jakonis;X. Piao;G. Erry;D. Platt;Y. Thueux;A. Gomez;G. Faulkner;H. Chun;M. Salter;D. O’Brien;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 707 - 710
Editeur: IEEE
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» High Step-Up DC–DC Converter With Minimum Output Voltage Ripple
Résumé:
In this paper, a new structure for high step-up dc–dc converters is proposed. In the proposed structure, it is possible to extend the topology by increasing the number of active–passive inductor cells. High voltage gain with lower duty cycle, low-current and -voltage stresses on switches, small inductors, and small size of filter are the main advantages of the proposed structure. The proposed converter is analyzed in different operating modes. In order to design the components’ values of the proposed converter, the equations of output voltage ripple are calculated in each operating mode and a design procedure is proposed based on the aforementioned equations. Moreover, the losses and efficiency of the converter are calculated. In order to validate the correctness of calculations and analyses, the experimental results are given.
Auteurs: Hamed Mashinchi Maheri;Ebrahim Babaei;Mehran Sabahi;Seyed Hossein Hosseini;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3568 - 3575
Editeur: IEEE
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» High Voltage Diodes in Diamond Using (100)- and (111)- Substrates
Résumé:
We present a comparative study of PIN structures in diamond on type IIa (100)- and type IIb (111)- oriented bulk diamond substrates. An 8.5- $mu text{m}$ thick i-layer demonstrated a blocking voltage>1kV for the (100)-oriented diamond sample without any mesa isolation, passivation, or edge termination structures. PIN diodes with a 530nm thick drift region, on the (111)- sample, demonstrated a blocking voltage of 207V at a current level of 1A/cm2 with a corresponding blocking electric field of 3.9MV/cm. A deep ultraviolet light emission was observed only in (111)-diodes under forward bias, confirming well-behaved p-n junction characteristics in (111) as compared to (100).
Auteurs: Maitreya Dutta;Franz A. M. Koeck;Wenwen Li;Robert J. Nemanich;Srabanti Chowdhury;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 600 - 603
Editeur: IEEE
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» High Voltage Stress Induced in Transparent Polycrystalline Diamond Field-Effect Transistor and Enhanced Endurance Using Thick Al2O3 Passivation Layer
Résumé:
A transparent polycrystalline diamond field-effect transistor (FET) was fabricated and measured in room temperature measurements, which reveals comparatively high maximum current density and high breakdown voltage of more than 1000 V. A harsh stress environment is proposed for simple and time-effective reliability stress measurement of the FET using a method of 50 continuous cycles of 500-V voltage stress. A 400-nm-thick Al2O3 counter-destructive passivation layer was implemented on the FET for the stress measurements. Devices with wide gate–drain length ( ${L}_text {GD}$ ) retain their FET characteristics after the harsh stress measurements by only 50% reductions maximum current density.
Auteurs: Mohd Syamsul;Yuya Kitabayashi;Takuya Kudo;Daisuke Matsumura;Hiroshi Kawarada;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 607 - 610
Editeur: IEEE
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» High-Breakdown, High- $f_{mathrm{ max}}$ Multiport Stacked-Transistor Topologies for the ${W}$ -Band Power Amplifiers
Résumé:
Effect of silicon technology limitations, including transistor nonidealities, layout parasitics, and low-quality factor on-chip passive components on millimeter wave stacked switching power amplifiers operating at the ${W}$ -band frequencies (75–110 GHz), is presented in this paper. To mitigate the performance degradation in output power and PAE arising from such causes, high-breakdown voltage, high- $f_{mathrm{ max}}$ multiport stacked-transistor topologies are proposed for realizing power amplifiers with high output power and high efficiency at 75–110 GHz. A 90-nm silicon germanium (SiGe) BiCMOS process is used to propose active structures comprising of two and three stacked transistors with integrated layout parasitics that achieve $f_{mathrm{ max}}$ and breakdown voltage of 295 GHz and 8 V and 260 GHz and 11 V, respectively. Functionality of such multiport transistor topologies is demonstrated in proof-of-concept implementations, including a five-stage two-stacked switching power amplifier (PA) that achieves peak output power and PAE of 22 dBm and 19% at 85 GHz, and a six-stage three-stacked PA that achieves peak output power and PAE of 23.3 dBm and 17% at 83 GHz, respectively. For comparison with conventional switching PA designs using native transistor footprints, a five-stage ${W}$ -band nonstacked Class-E amplifiers is also fabricated in the same 90-nm SiGe BiCMOS process with output power and PAE of 19.5 dBm and 16% at 88 GHz. The superior performance of output power and PAE in designs using the multiport transistor topologies highlights the benefit of the proposed approach.
Auteurs: Kunal Datta;Hossein Hashemi;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 05.-2017, volume: 52, issue:5, pages: 1305 - 1319
Editeur: IEEE
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» High-Density Reconfigurable Devices With Programmable Bottom-Gate Array
Résumé:
A novel poly-Si reconfigurable device with a programmable bottom-gate (BG) array is demonstrated for the first time. The BG has non-volatile memory functionality. This device is very efficient in terms of device size and functionality. By changing the bias or program/erase state of the BGs, a device can be transformed to a certain device type among ${n}$ -/ ${p}$ -MOSFETs, and ${n}$ - ${p}$ and ${p}$ - $ {n}$ diodes. The threshold voltage ( $ {V}_{mathsf {th}}$ ) and contact resistance ( ${R}_{mathsf {c}}$ ) of MOSFETs can be controlled independently by the BGs. The subthreshold swings for ${n}$ -/ ${p}$ -MOSFETs are 200 and 230 mV/decade, respectively. The $ {I}_{ mathrm{scriptscriptstyle ON}}/ {I}_{ mathrm{scriptscriptstyle OFF}}$ s of the ${n}$ -/ ${p}$ -MOSFETs measured from a single reconfigurable device are more than $10^{6}$ , which are comparable to those of conventional poly-Si devices.
Auteurs: Jun-Mo Park;Jong-Ho Bae;Jai-Ho Eum;Sung Hun Jin;Byung-Gook Park;Jong-Ho Lee;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 564 - 567
Editeur: IEEE
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» High-Gain and Wide-Bandwidth Filtering Planar Antenna Array-Based Solely on Resonators
Résumé:
This paper presents a new approach for the design of high-gain and wide-bandwidth planar antenna arrays. It is based on the coupling matrix theory which allows the design of the arrays using all-resonator structures. The parameters of the matrix offer the flexibility of achieving a controllable bandwidth. They also introduce a frequency filtering functionality into the arrays which can remove the need to place a bandpass filter after the arrays at the very front end of a communication system. The new approach has been applied to using novel topologies to form two wideband $4 times 4$ planar antenna arrays utilizing rectangular waveguide cavity resonators operated at X-band frequencies. The first topology is seventh order and based on 39 resonators configured in two waveguide-layers; that is one layer for the feed resonators and one layer for the radiating resonators. The second topology is fourth order based on 25 resonators configured only in a single waveguide-layer. Fabrication and measurements have been performed, showing very good agreement with the simulations.
Auteurs: Rashad H. Mahmud;Michael J. Lancaster;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2367 - 2375
Editeur: IEEE
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» High-Linearity AlGaN/GaN FinFETs for Microwave Power Applications
Résumé:
In this letter, we have proposed a novel AlGaN/GaN FinFET featuring T-shaped gate and extremely linearity of transconductance characteristics ( $text{G}_{mathrm {m}})$ . The formation of AlGaN/GaN nano-fins only in the gate opening region is enabled by a developed fabrication process, which is simple and well compatible with the conventional one. When normalized to effective channel width, the fabricated FinFET delivers a 1.45 times higher current density and a 1.66 times higher output power density as high as 11.3 W/mm at 8 GHz compared with the planar HEMTs, along with clearly improved linearity characteristics thanks to a flatter $text{G}_{mathrm {m}}$ response afforded by much lower source access resistance. To the best of our knowledge, this is the first demonstration of superior power performance of high-linearity GaN FinFETs, indicating significant advantages of tri-gate configuration over planar HEMTs for microwave power applications.
Auteurs: Kai Zhang;Yuechan Kong;Guangrun Zhu;Jianjun Zhou;Xinxin Yu;Cen Kong;Zhonghui Li;Tangsheng Chen;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 615 - 618
Editeur: IEEE
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» High-Performance Black Phosphorus MOSFETs Using Crystal Orientation Control and Contact Engineering
Résumé:
We report high performance, orientation-controlled, and locally back-gated black phosphorus (BP) n-MOSFETs and p-MOSFETs with titanium and permalloy contacts, respectively. Devices with channel length ranging from 0.3 to $0.7~mu text{m}$ are analyzed. Armchair-oriented BP p-MOSFETs (n-MOSFETs) display 3.5 times (1.5 times) higher maximum current compared with zigzag devices. Saturated transconductance values up to 4.8 times (1.6 times) higher for BP p-MOSFETs (n-MOSFETs) oriented along the armchair direction compared with the zigzag direction are observed. Using this orientation control and contact engineering, n-MOSFETs with transconductance of $110~mu text{S}/mu text{m}$ and p-MOSFETs with contact resistance as low as 0.31 $text{k}Omega cdot mu text{m}$ are demonstrated.
Auteurs: Nazila Haratipour;Seon Namgung;Roberto Grassi;Tony Low;Sang-Hyun Oh;Steven J. Koester;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 685 - 688
Editeur: IEEE
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» High-Performance Ternary Adder Using CNTFET
Résumé:
Ternary logic is a promising alternative to the conventional binary logic in VLSI design as it provides the advantages of reduced interconnects, higher operating speeds, and smaller chip area. This paper presents a pair of circuits for implementing a ternary half adder using carbon nanotube field-effect transistors. The proposed designs combine both futuristic ternary and conventional binary logic design approach. One of the proposed circuits for ternary to binary decoder simplifies further circuit implementation and provides excellent delay and power advantages in data path circuit such as adder. These circuits have been extensively simulated using HSPICE to obtain power, delay, and power delay product. The circuit performances are compared with alternative designs reported in recent literature. One of the proposed ternary adders has been demonstrated power, power delay product improvement up to 63% and 66% respectively, with lesser transistor count. So, the use of these half adders in complex arithmetic circuits will be advantageous.
Auteurs: Subhendu Kumar Sahoo;Gangishetty Akhilesh;Rasmita Sahoo;Manasi Muglikar;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 05.-2017, volume: 16, issue:3, pages: 368 - 374
Editeur: IEEE
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» High-Performance Uniaxial Tensile Strained n-Channel JL SOI FETs and Triangular JL Bulk FinFETs for Nanoscaled Applications
Résumé:
In this paper, one proposed an effective method to enhance current drivability of junctionless FETs (JL-FETs) by utilizing uniaxial tensile strain effects. The strained layers were deposited on JL-FETs on silicon-on-insulator (SOI) and bulk Si wafers, respectively. Strained JL SOI FETs show an extremely low subthreshold swing (S.S.) of 65 mV/decade with $I_{ mathrm{scriptscriptstyle ON}}/I_{ mathrm{scriptscriptstyle OFF}} >10^{9}$ ; strained JL bulk FinFETs show an S.S. of 75 mV/decade with $I_{ mathrm{scriptscriptstyle ON}}/I_{ mathrm{scriptscriptstyle OFF}}>10^{7}$ . For strained JL bulk FinFETs, a triangular fin shape could suppress leakage current effectively. Regardless of substrates, JL FETs showed excellent performance owing to uniaxial tensile strain technology. Analysis of leakage current in strained JL FETs included effects on Gate-induced drain leakage trap-assisted tunneling effects were discussed by ${I}_{D}$ ${V}_{G}$ curves under various temperatures and activation energy. Compared with JL SOI gate-all-around structures, JL bulk FinFET possesses higher ${I}_{D}$ and offer the promise of higher integration flexibility for Si CMOS compatible process for the future applications.
Auteurs: Po-Jung Sung;Ta-Chun Cho;Fu-Ju Hou;Fu-Kuo Hsueh;Sheng-Ti Chung;Yao-Jen Lee;Michael I. Current;Tien-Sheng Chao;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2054 - 2060
Editeur: IEEE
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» High-Power Photodiode-Integrated-Connected Array Antenna
Résumé:
We present a novel optical feeding technique to achieve efficient excitation of an ultrawideband-connected array (CA) antenna. The passive fiber optic feed allows for preservation of the theoretical bandwidth and low profile of elementary connected dipole elements. In order to improve effective radiated power, high-power charge compensated modified unitravelling carrier photodiodes are integrated into an antenna array for the first time. Circuit and full-wave simulations, which include all required antenna and feed components, are conducted for the optimization of the array's performance. A 9 × 12 element CA is populated with a 1-D array of four photodiode-integrated active elements to demonstrate the concept. The optically fed array is confirmed experimentally to have a 3-dB bandwidth of approximately 7–17 GHz, in good agreement with simulations.
Auteurs: Matthew R. Konkol;Dylan D. Ross;Shouyuan Shi;Charles E. Harrity;Andrew A. Wright;Christopher A. Schuetz;Dennis W. Prather;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 2010 - 2016
Editeur: IEEE
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» High-Power Terahertz Wave Generation by Optical Rectification of a Gaussian Laser Pulse Propagating in Magnetoplasma
Résumé:
This paper presents an investigation of terahertz (THz) wave generation by optical rectification of a Gaussian laser pulse propagating in plasma having periodic density perturbation in the presence of an externally applied static magnetic field in the axial direction. The nonuniform intensity of laser pulse leads to the generation of quasi-static ponderomotive force. The electrons acquire nonlinear oscillatory velocity under the influence of the force. This velocity, on coupling with the density perturbation, induces a nonlinear current density in the radial direction. This nonlinear current density drives a wave, the frequency of which depends on the pulse duration of the laser. The frequency falls in the THz range if the pulse duration of the laser is chosen thoughtfully. For the resonant excitation of the radiation, phase matching is required, which is provided by the periodic density perturbation. Axially applied external magnetic field can be utilized as a controlling parameter to enhance the nonlinear coupling and the yield of the generated wave. The effect of the axial magnetic field on the generated THz intensity is investigated. Variations in THz radiation intensity as functions of the density ripple amplitude and background plasma density have also been studied.
Auteurs: Ram K. Singh;Subodh Kumar;Ram P. Sharma;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 05.-2017, volume: 45, issue:5, pages: 786 - 790
Editeur: IEEE
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» High-Q Sensor Based on Symmetrical Split Ring Resonator With Spurlines for Solids Material Detection
Résumé:
This paper presents novel structures of planar microwave sensors for detecting and characterizing the dielectric properties in common solid materials which produce high Q-factors with capability to suppress undesired harmonic spurious. These sensors are based on novel planar symmetrical split ring resonator with spurlines filters by employing the perturbation theory, in which the dielectric properties of the resonator affect the Q-factor and resonance frequency. The proposed sensors achieve narrow resonance with low insertion loss and high-Q and sensitivity which peaked up to 652 at 2.22 GHz operating frequency. By using a specific experimental methodology, practical materials are applied as standards (Roger 5880, Roger 4350, FR4) to validate the sensitivity of the sensors for permitting potentially material characterization and detection. Accordingly, the mathematical equation is derived to extract the materials with unknown properties. The average accuracy percentage of the measured results for all cases of the designed sensors is found within 97%–98% compared with those in the literature for the same tested standard materials. It is believed that these sensors would lead for a promising solution of characterizing material particularly in determining material properties and quality, such as in food industry, bio-sensing medicine applications, and therapeutics goods detections.
Auteurs: Rammah Ali Alahnomi;Zahriladha Zakaria;Eliyana Ruslan;Siti Rosmaniza Ab Rashid;Amyrul Azuan Mohd Bahar;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2766 - 2775
Editeur: IEEE
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» High-Quality and Stable Electron Emission Device With Sub-30-nm Aligned Nanogap Arrays
Résumé:
A high-quality and stable electron device of aligned gold nanogap arrays is demonstrated by using a well-controlled method with electron beam lithography and focused ion beam. Sub-30-nm nanogap arrays could be precisely fabricated with reproducibility. Field emission (FE) properties of the nanogaps are directly measured in the vacuum chamber of scanning electron microscopy with a nanomanipulator. Experimental investigation and calculations are carried out to reveal the transition process from the leakage current to the FE. Importantly, the controllable method could allow us to readily construct varying nanospacings. Besides, we also illustrate the independence of emission current on the vacuum degree over a large range, widening the applied range of the devices. These studies clearly demonstrate that electronic devices with sub-30-nm vacuum channel can be readily achieved by coupling varying nanogaps into nanostructures. It may pave the way for exploring the physics in tunneling transport devices, and therefore enable a new generation of high-performance, high-speed and low-cost electronic devices.
Auteurs: Ji Xu;Qilong Wang;Zhi Tao;Yusheng Zhai;Chen Guangdian;Zhiyang Qi;Xiaobing Zhang;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2364 - 2368
Editeur: IEEE
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» High-Speed Resonant Surface Acoustic Wave Instrumentation Based on Instantaneous Frequency Measurement
Résumé:
Surface acoustic wave (SAW) resonators are used for a broad range of wireless sensing applications, some of them having high demands on the resolution as well as the measurement update rate. This paper presents a new interrogation method for precise and fast frequency determination of passive SAW resonators based on instantaneous frequency measurement by a low-cost six-port interferometer. Using a delay line, the frequency measurement is reduced to a phase measurement that can be instantaneously evaluated by the six-port network. No complex signal processing is necessary providing high update rates and low hardware costs. An in-depth analysis of the system concept and its building blocks is presented, and the advantages as well as the limitations are discussed and compared with the current state of the art. Finally, a demonstrator in the 2.4-GHz frequency band shows the feasibility and the precision of the concept with measurement times of only a few microseconds.
Auteurs: Fabian Lurz;Stefan Lindner;Sarah Linz;Sebastian Mann;Robert Weigel;Alexander Koelpin;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 974 - 984
Editeur: IEEE
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» Higher Order Asymptotic Approximations of Eigenmodes for a Circular Waveguide Terminated by a Perfectly Matched Layer
Résumé:
In this paper, the improved asymptotic solutions of eigenmodes (leaky and Berenger modes) are provided for a circular waveguide terminated by a perfectly matched layer. Furthermore, a systematic asymptotic approach is developed by the inverse power series. Numerical simulations demonstrate that the high-precision asymptotic eigenmodes can be obtained.
Auteurs: Jianxin Zhu;Chaofeng Dong;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1980 - 1987
Editeur: IEEE
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» Higher Order Linear Dynamical Systems for Smoke Detection in Video Surveillance Applications
Résumé:
In this paper, we consider the problem of multi-dimensional dynamic texture analysis, and we introduce a new higher order linear dynamical system (h-LDS) descriptor. The proposed h-LDS descriptor is based on the higher order decomposition of the multidimensional image data and enables the analysis of dynamic textures by using information from various image elements. In addition, we propose a methodology for its application to video-based early warning systems that focus on smoke identification. More specifically, the proposed methodology enables the representation of video subsequences as histograms of h-LDS descriptors produced by the smoke candidate image patches in each subsequence. Finally, to further improve the classification accuracy, we propose the combination of multidimensional dynamic texture analysis with the spatiotemporal modeling of smoke by using a particle swarm optimization approach. The ability of the h-LDS to analyze the dynamic texture information is evaluated through a multivariate comparison against the standard LDS descriptor. The experimental results that use two video datasets have shown the great potential of the proposed smoke detection method.
Auteurs: Kosmas Dimitropoulos;Panagiotis Barmpoutis;Nikos Grammalidis;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 1143 - 1154
Editeur: IEEE
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» Higher Order Modes: A Solution for High Gain, Wide Band Patch Antennas for Different Vehicular Applications
Résumé:
Low-gain and narrow bandwidth problems are associated with patch antennas, and due to their inverse relation with each other, these problems cannot be improved simultaneously. It is well understood that the patch antenna excited at the higher order modes (HOMs) can overcome the problems of low gain and narrow bandwidth, provided that the modes are excited properly. For a given geometry, all the resonant frequencies are related in fixed ratios, providing no flexibility for the designer. Furthermore, high side lobe levels and undesirable radiation patterns are associated with the higher order modes. The excitation of higher order modes in given dimensions of the patch is achieved by surface modification and loading of slots on the patch. Two antennas based on a novel design procedure are discussed in the Ku and Ka bands to validate the proposed facts. The antenna in the Ka band has a peak gain of 8.5 dBi with 15.14% of bandwidth, while the one in the Ku band has a peak gain of 11.84 dBi with 17.6% of bandwidth. The design procedure is particularly important in designing antennas for applications like mobile satellite communication, wideband and multimedia applications, collision avoidance systems in vehicles, etc.
Auteurs: Qasim Umar Khan;Mojeeb Bin Ihsan;Dilaawaiz Fazal;Fahad Mumtaz Malik;Shahzad Amin Sheikh;Muhammad Salman;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 3548 - 3554
Editeur: IEEE
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» Highly Sensitive D-Shaped Photonic Crystal Fiber-Based Plasmonic Biosensor in Visible to Near-IR
Résumé:
A simple D-shaped photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) biosensor is proposed for refractive index sensing in visible to near infrared (IR) region. A thin Titanium di-oxide (TiO2) layer is used as an adhesive layer to strongly attach the plasmonic gold (Au) layer with silica fiber surface. TiO2 also helps to tune the operating sensor wavelength from visible to near IR (550–1770-nm wavelength). Finite-element method has been used to investigate the guiding properties. The proposed sensor shows the maximum wavelength interrogation sensitivity of 46 000 nm/RIU and the average sensitivity of 9,800 nm/RIU in the sensing range of 1.33–1.43. It also shows the maximum amplitude sensitivity of 1,086 RIU $^{-1}$ . Using the wavelength and amplitude interrogation methods, proposed sensor gives the theoretical maximum resolution of 2.2 $times 10^{-6}$ and 9.2 $times 10^{-6}$ RIU, respectively. To the best of our knowledge, it has the highest sensitivity and sensor resolution among the reported PCF SPR sensors. The proposed D-shaped PCF has been fabricated following the standard stack-and-draw method to show the feasibility of the proposed sensor. Due to the promising results over the broad range of analyte RI, it would be an excellent candidate for the detection of biomolecules, organic chemicals, chemical, and other analytes.
Auteurs: Ahmmed A. Rifat;Rajib Ahmed;G. Amouzad Mahdiraji;F. R. Mahamd Adikan;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2776 - 2783
Editeur: IEEE
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» Highly Sensitive Twist Sensor Based on Temperature- and Strain-Independent Fiber Lyot Filter
Résumé:
A novel highly sensitive optical fiber twist sensor based on a Lyot filter is proposed and experimentally demonstrated in this paper. The evolution of the transmission spectra of the Lyot filter with respect to twist, temperature, and strain are investigated, respectively. The amplitude of the resonance dip changes as a sine-like function with the twist angle varying, which agrees well with the theoretical analysis. Based on analyzing the amplitude response of the resonance dip, the sensitivities of the sensor with respect to twist, temperature, and strain are found to be −15.586 dB/rad, 0.003 dB/°C, and −0.001 dB/μϵ, indicating the viability of implementing a temperature- and strain-independent twist sensor based on a Lyot filter.
Auteurs: Bo Huang;Xuewen Shu;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 2026 - 2031
Editeur: IEEE
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» Highly Tunable Triangular Wave UWB Baseband Pulse Generator With Amplitude Stabilization in 40-nm CMOS
Résumé:
This brief introduces a highly configurable ultrawideband triangular wave baseband pulse generator designed in 40-nm complementary metal–oxide–semiconductor technology. The baseband pulse width is adjustable between 660 ps and 3.8 ns. An extra amplitude compensation loop is implemented to prevent amplitude changes when the pulse width varies. The amplitude variations are limited to 13% compared with the maximum amplitude over the entire pulse width range. The amplitude compensation loop allows a pulse amplitude tuning range between 280 and 640 mV, whereas the pulse width only varies 80 ps over this entire range. The pulse generator has a maximum simulated signal-to-noise ratio of 59 dB and a measured maximum power consumption of 6.2 pJ/pulse from a 0.9-V power supply and a 100-MHz pulse repetition frequency.
Auteurs: B. Faes;P. Reynaert;P. Leroux;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 505 - 509
Editeur: IEEE
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» History of Aircraft Wiring Arc-Fault Protection [History]
Résumé:
In both new and aging military and civilian aircraft, all critical power wiring has been typically protected against overheating by using combinations of thermal and magnetic circuit breakers or solid-state power controllers (SSPCs). However, the conventional types of these protective devices do not detect and react to hazardous arcing faults, and it is important that they do so to mitigate the risk of aircraft fires caused by aging, damaged insulation, wire chafing, wire breakage, chemical exposure, maintenance procedures, and contamination. Most aircraft electrical systems operate at 115 Vac, 400 Hz, both single and three phase. In addition to this ac power, they utilize 28 Vdc. Hazardous arcing faults can occur in all these power systems between parallel conductors, to ground, or in series (due to a broken or frayed wire or at a loose connection).
Auteurs: Barry C. Brusso;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 6 - 11
Editeur: IEEE
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» Holographic and Light-Field Imaging as Future 3-D Displays
Résumé:
Light-field imaging and holographic imaging are currently the two mostly investigated 3-D imaging technologies because of their potentials to create the viewing environment conforming to a natural viewing condition. The basic optical geometries for image display in these imaging are not different from that of integral photography. The images in the two type of imaging are a set of different view images. These images are arranged as a 2-D point image array, and each point image is expanded with a certain angle to form a viewing zone. The differences between the two types of imaging are the number of point images in the array and the physical entities forming the images. Holographic imaging has many more point images than light-field imaging, and each image in the array consists of coherent right rays from different positions of an object. In light-field imaging, an array of pixels represents a direction view of the object. Despite these differences, they share the same goal of providing a continuous parallax to viewers and require display panels of almost the same characteristics. It is expected that in the future these two imaging techniques will be integrated into the same flat panel along with the plane image.
Auteurs: Jung-Young Son;Hyoung Lee;Beom-Ryeol Lee;Kwang-Hoon Lee;
Apparue dans: Proceedings of the IEEE
Date publication: 05.-2017, volume: 105, issue:5, pages: 789 - 804
Editeur: IEEE
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» Hot-Electron Electroluminescence Under RF Operation in GaN-HEMTs: A Comparison Among Operational Classes
Résumé:
Electroluminescence microscopy and spectroscopy are used to compare the average hot-electron concentration and temperature under radio frequency (RF) operation class A, class B, and class F modes. From the results obtained, class A results, on average, in the highest hot-electron concentration, while class F is the mode with the lowest concentration due to its “L”-shaped load line. The electron temperature extracted from the electroluminescence spectra is reduced with increasing RF power, reflecting the dominance of electroluminescence from the portion of the load line in the semi-on region. The electroluminescence method is not able to give substantial information on the portion of the load line with high field and low current density which will be responsible for the potentially damaging hottest electrons present in the channel.
Auteurs: Tommaso Brazzini;Michael A. Casbon;Michael J. Uren;Paul J. Tasker;Helmut Jung;Hervé Blanck;Martin Kuball;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2155 - 2160
Editeur: IEEE
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» How Abundance Changes Software Engineering
Résumé:
The abundance of processing power is changing the nature of software engineering. By reducing the cost of failure, abundance changes how developers use computing technologies. Also, abundance changes the developer's role by moving the focus from technology to management. This article also contains an erratum. In "App Store 2.0: From Crowdsourced Information to Actionable Feedback in Mobile Ecosystems" (DOI: 10.1109/MS.2017.46) from the Mar./Apr. 2017 issue, in the fifth line of the second column on p. 83, "see sia" should be "see Figure 2a."
Auteurs: Diomidis Spinellis;
Apparue dans: IEEE Software
Date publication: 05.-2017, volume: 34, issue:3, pages: 4 - 7
Editeur: IEEE
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» How Computer Science Departments and Faculty Can Contribute to the CS for All Initiative
Résumé:
As the role of computer science becomes increasingly central to our way of life, ensuring the successful education of future computer scientists is imperative.
Auteurs: W. Richards Adrion;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 103 - 105
Editeur: IEEE
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» How Do Informal Ties Drive Open Innovation? The Contingency Role of Market Dynamism
Résumé:
Scholars and practitioners have recently shifted their attention from traditional closed internal innovation to open innovation (OI). Building on both the resource-based view and the network perspective, we explore the roles of three types of informal ties (i.e., business, government, and university) in driving inbound and outbound OI, and further examine such effects contingent on market dynamism. Empirical results from our study of 260 Chinese firms show that all three types of informal ties positively affect inbound innovation openness, whereas only business ties facilitate outbound innovation openness. In addition, market dynamism strengthens the relationship between university ties and inbound innovation openness, but weakens the effect of business ties on inbound innovation openness. These findings indicate the salience of informal ties in increasing innovation openness and the contingent role of external market conditions. The findings contribute to the understanding of the drivers of innovation openness, and help clarify the differences between inbound and outbound OI.
Auteurs: Xiaoxuan Zhu;Maggie Chuoyan Dong;Jibao Gu;Wenyu Dou;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 05.-2017, volume: 64, issue:2, pages: 208 - 219
Editeur: IEEE
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» How Much Bandpass Filtering is Required in Massive MIMO Base Stations?
Résumé:
In this paper, we study the impact of aliased out-of-band (OOB) interference signals on the information sum rate of the maximum ratio combining receiver in massive multiple-input multiple-output (MIMO) uplink, with both perfect and imperfect channel estimates, in order to determine the required out-of-band attenuation in radio-frequency (RF) bandpass filters (BPFs). With imperfect channel estimates, our study reveals that as the number of base-station (BS) antennas ( ) increases, the required attenuation at the BPFs increases as with , provided the desired information sum rate (both in the presence and in the absence of aliased OOB interferers) remains fixed. This implies a practical limit on the number of BS antennas due to the increase in BPF design complexity and power consumption with increasing .
Auteurs: Sudarshan Mukherjee;Saif Khan Mohammed;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 05.-2017, volume: 66, issue:5, pages: 4481 - 4486
Editeur: IEEE
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» Hull Structure Monitoring Using Inertial Measurement Units
Résumé:
Hull structure monitoring is needed to provide healthy suggestions for a ship. Inertial Measurement Units (IMUs) are available for this application. By installing IMUs on different points of the ship hull, the angular velocity and acceleration of each point can be measured. Once the hull flexure changes, the movement parameters of those points will be different, and the hull flexure can be estimated through matching these parameters by a Kalman filter. We deduced proper measurement equations of the Kalman filter, which is essential for the flexure estimation, and designed real data and simulation data experiments to verify the equation. Results showed that the hull structure can be effectively monitored by the proposed method.
Auteurs: Xianglu Ma;Shiqiao Qin;Xingshu Wang;Wei Wu;Jiaxing Zheng;Yao Pan;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2676 - 2681
Editeur: IEEE
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» Human Activity Classification With Transmission and Reflection Coefficients of On-Body Antennas Through Deep Convolutional Neural Networks
Résumé:
We propose to classify human activities based on transmission coefficient ( $S_{21}$ ) and reflection coefficient ( $S_{11}$ ) of on-body antennas with deep convolutional neural networks (DCNNs). It is shown that spectrograms of $S_{21}$ and $S_{11}$ exhibit unique time-varying signatures for different body motion activities that can be used for classification purposes. DCNN, a deep learning approach, is applied to spectrograms to learn the necessary features and classification boundaries. It is found that DCNN can achieve classification accuracies of 98.8% using $S_{21}$ and 97.1% using $S_{11}$ . The effects of operating frequency and antenna location on the accuracy have been investigated.
Auteurs: Youngwook Kim;Yang Li;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2764 - 2768
Editeur: IEEE
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» Humans Are Dynamic - Our Tools Should Be Too
Résumé:
Security Operation Centers (SOCs) are being operated by universities, government agencies, and corporations to defend their enterprise networks and identify and thwart malicious behaviors in both networks and hosts. The success of a SOC depends on combining good tools and processes with efficient and effective analysts. During four years of anthropological fieldwork methods to study SOCs, the authors discovered that successful SOC innovations must resolve multiple internal and external conflicts to be effective and efficient. This discovery, guided by activity theory (AT) as a framework for analyzing the fieldwork data, enabled them understand these realities. Their research indicates conflict resolution is a prerequisite for continuous improvement of SOCs in both human and technological aspects. Failure to do so can lead to adverse effects, such as analyst burnout and reduction in overall effectiveness.
Auteurs: Sathya Chandran Sundaramurthy;Michael Wesch;Xinming Ou;John McHugh;S. Raj Rajagopalan;Alexandru G. Bardas;
Apparue dans: IEEE Internet Computing
Date publication: 05.-2017, volume: 21, issue:3, pages: 40 - 46
Editeur: IEEE
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» Hybrid Precoding via Successive Refinement for Millimeter Wave MIMO Communication Systems
Résumé:
We propose a hybrid precoding design for spatial multiplexing in millimeter wave massive multiple-input multiple-output systems. The proposed design relies on the popular orthogonal matching pursuit (OMP) algorithm. The OMP algorithm uses necessary columns of the right/left (for receiver/transmitter) unitary matrix of the channel (obtained via a singular value decomposition) to obtain the initial baseband (digital) precoder using principles of basis pursuit. The resulting baseband precoder is then used to refine the RF (analog) precoder. This iterative refinement improves the quality of hybrid preocders. Quantization of the RF and baseband precoding matrices is also discussed for limited feedback systems, where the high-dimensional RF precoder is quantized using codebooks generated using the $K-$ means clustering algorithm. On the other hand, the low-dimensional baseband precoder is quantized using well-known Grassmannian codebooks. Simulation results show that the proposed scheme performs close to the fully digital precoding scheme.
Auteurs: Jawad Mirza;Bakhtiar Ali;Syed Saud Naqvi;Saqib Saleem;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 991 - 994
Editeur: IEEE
Document complet vers site de l'éditeur
 


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