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V-BLAST BASED LDPC-CODED RELAY COOPERATION

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Transactions of Nanjing University of Aeronautics and Astronautics 2013年第4期30卷 374-382页

作者：唐蕾仰枫帆张顺外范立行 College of Electronics and Information Engineering Nanjing University of Aeronautics and Astronautics

An efficient LDPC-coded multi-relay cooperation architecture is proposed based on virtual vertical Bell Labs layered space-time(V-BLAST)processing for uplink communication,where minimum-mean-square-error(MMSE)and BP-based joint iterative decoding based on the introduced multi-layer Tanner graph are effectively designed to detect and decode the corrupted received sequence at the destination.By introducing V-BLAST transmission to the coded multi-relay cooperation,relays send their streams of symbols simultaneously,which increases the data rate and significantly reduces the transmission delay.The theoretical analysis and numerical results show that the new LDPC coded cooperation scheme outperforms the coded non-cooperation under the same code rate,and it also achieves a good trade-off among the performance,signal delay,and the encoding complexity associated with the number of relays.The performance gain can be credited to the proposed V-BLAST processing architecture and BP-based joint iterative decoding by the introduced multi-layer Tanner graph at a receiver-side.

关键词：航空空气动力学类型直升飞机

Diverse terahertz wavefront manipulations empowered by the spatially interleaved metasurfaces

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Science China(information Sciences) 2023年第3期66卷 230-238页

作者： Jitao LI Zhen YUE Jie LI Chenglong ZHENG Silei WANG Mengyao LI Yating ZHANG Yan ZHANG Jianquan YAO School of Precision Instruments and Opto-electronics Engineering Tianjin University college of Optoelectronic Engineering Chengdu University of Information Technology Department of Physics Capital Normal University

Optical metasurfaces have advanced approaches for manipulating light information in the spatial domain, in which the spatially interleaved metasurfaces demonstrate the ability to manipulate a more complex wavefront of light than metasurfaces without the spatial interleaving. The potential of the spatially interleaved metasurfaces has not been fully exploited. In this paper, we design the spatially interleaved terahertz(THz) metasurfaces based on the ingenious spatial interleaving principles to develop the diverse THz wavefront manipulations. Four functions are performed, including the orbital angular momentum(OAM)superposition of single-frequency vortex beams, the separate vortex focusing of single-frequency dual beams,the different OAM manipulations of bifrequency beams in different planes, and achromatic focusing. The demonstrated functions prove that the spatially interleaved metasurface can manipulate THz wavefront at both single frequency and bifrequency, which traditional metasurfaces cannot. This work paves the way for diverse THz wavefront manipulations.

关键词： terahertz wavefront manipulations metasurfaces spatial interleaving onformation optics

Virtual Machine-Based Task Scheduling Algorithm in a Cloud Computing Environment

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Tsinghua Science and Technology 2016年第6期21卷 660-667页

作者： Zhifeng Zhong Kun Chen Xiaojun Zhai Shuange Zhou college of Computer and information Engineering Hubei University Department of electronics Computing and Mathematics University of Derby

Virtualization technology has been widely used to virtualize single server into multiple servers, which not only creates an operating environment for a virtual machine-based cloud computing platform but also potentially improves its efficiency. Currently, most task scheduling-based algorithms used in cloud computing environments are slow to convergence or easily fall into a local optimum. This paper introduces a Greedy Particle Swarm Optimization（G＆PSO） based algorithm to solve the task scheduling problem. It uses a greedy algorithm to quickly solve the initial particle value of a particle swarm optimization algorithm derived from a virtual machine-based cloud platform. The archived experimental results show that the algorithm exhibits better performance such as a faster convergence rate, stronger local and global search capabilities, and a more balanced workload on each virtual machine. Therefore, the G＆PSO algorithm demonstrates improved virtual machine efficiency and resource utilization compared with the traditional particle swarm optimization algorithm.

关键词： cloud computing virtual machine G＆PSO algorithm

Tribo-corrosion mechanisms and electromechanical behaviours for metal implants materials of CoCrMo,Ti6Al4V and Ti15Mo alloys

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Biosurface and Biotribology 2022年第1期8卷 44-51页

作者： Hongxiang Wang Jingjing Zheng Xiaolei Sun Yong Luo Jiangsu Vocational College of Electronics and Information Huai'anChina School of Materials Science and Physics China University of Mining&TechnologyXuzhouChina

Corrosion and wear play significant roles in the aseptic loosening of artificial hip joints for the long-term service.In this present study,tribo-corrosion tests were carried out through a reciprocating ball-on-plate system to evaluate the corrosion and wear prop-erties of CoCrMo,Ti6Al4V and Ti15Mo alloys in a simulated body fluid(SBF)solution.It was found that the tribo-corrosion behaviours of CoCrMo/Al_(2)O_(3)and Ti15Mo/Al_(2)O_(3)systems had significant wear-corrosion synergistic interaction,and wear-induced corro-sion was dominant.For Ti6Al4V/Al_(2)O_(3)systems,their wear mechanism under SBF lubrication was a combination of abrasive,adhesive and fatigue wear.While the wear mechanism of the Ti15Mo/Al_(2)O_(3)system under synergistic interaction was a combination of abrasive and adhesive wear.Finally,it was suggested that the Ti15Mo alloy would be the better alternative for metal implant applications compared with the CoCrMo alloy for the consideration of both wear and potential poisonous ions such as Co(III)and Cr(VI).

关键词： artificial joints biomaterials wear mechanisms

A Novel PID Neural Network Controller based on Memristor

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A Novel PID Neural Network Controller based on Memristor

A survey of decision making in adversarial games

第36届中国控制会议

作者： GENG Yangyang DUAN Shukai DONG Zhekang WANG Lidan College of Electronics and Information Engineering Southwest University college of Electrical Engineering Zhejiang University

ISBN: (纸本)9781538629185

In this paper,an effective optimize method based on adaptive PID neural network controller is presented.Chaotic Particle Swarm Optimization（CPSO） is introduced to initialize the parameters of neural network for improving the convergent speed and preventing weights trapping into local optima.In order to realize the hardware platform of PID neural network controller and facilitate weight update algorithm,the nanoscale memristor is utilized to analog electronic synapse.Meanwhile,the stability of closed-loop system is further proved by Lyapunov theory.Based on several comparative experiments on automatic voltage regulation system,the final results illustrate that the proposed controller can obtain better precision in a shorter time.

关键词： Memristor adaptive PID neural network Chaotic Particle Swarm Optimization algorithm automatic voltage regulation system

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Science China(information Sciences) 2024年第4期67卷 85-112页

作者： Xiuxian LI Min MENG Yiguang HONG Jie CHEN College of Electronics and Information Engineering Tongji University Shanghai Research Institute for Intelligent Autonomous Systems

In many practical applications, such as poker, chess, drug interdiction, cybersecurity, and national defense, players often have adversarial stances, i.e., the selfish actions of each player inevitably or intentionally inflict loss or wreak havoc on other players. Therefore, adversarial games are important in realworld applications. However, only special adversarial games, such as Bayesian games, are reviewed in the literature. In this respect, this study aims to provide a systematic survey of three main game models widely employed in adversarial games, i.e., zero-sum normal-form and extensive-form games, Stackelberg(security) games, and zero-sum differential games, from an array of perspectives, including basic knowledge of game models,(approximate) equilibrium concepts, problem classifications, research frontiers,(approximate) optimal strategy-seeking techniques, prevailing algorithms, and practical applications. Finally, promising future research directions are also discussed for relevant adversarial games.

关键词： adversarial games zero-sum games Stackelberg games differential games Nash equilibrium correlated equilibrium regret

Focal evolution induced by combination of nonspiral and spiral phase plates

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Chinese Optics Letters 2007年第5期5卷 257-259页

作者：高秀敏王健 electronics and information college Hangzhou Dianzi University

Focusing properties of Gaussian beam induced by nonspiral and spiral phase plates are investigated nu-merically. The nonspiral phase plate introduces phase singularity to the incident beam, and the spiral one adjusts the radial phase distribution. Intensity distributions in geometrical focal plane show that the parameters of phase plates can alter the intensity distributions considerably. And local dark focal spots may be obtained, the focal spot may evolve into a circle, a two-peak spot, or a curve line, which indicates that the combination of nonspiral and spiral phase plates can be used to form novel focal spots.

关键词： phase optical devices apodization APODIZATION focusing performance Optical Devices Spiral incident beam Phase plates Gaussian beams Phase

Generalized unscented Kalman filtering based radial basis function neural network for the prediction of ground radioactivity time series with missing data

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Chinese Physics B 2011年第6期20卷 546-551页

作者：伍雪冬王耀南刘维亭朱志宇 School of electronics and information Jiangsu University of Science and Technology college of Electrical and information Engineering Hunan University

On the assumption that random interruptions in the observation process are modeled by a sequence of independent Bernoulli random variables, we firstly generalize two kinds of nonlinear filtering methods with random interruption failures in the observation based on the extended Kalman filtering （EKF） and the unscented Kalman filtering （UKF）, which were shortened as GEKF and CUKF in this paper, respectively. Then the nonlinear filtering model is established by using the radial basis function neural network （RBFNN） prototypes and the network weights as state equation and the output of RBFNN to present the observation equation. Finally, we take the filtering problem under missing observed data as a special case of nonlinear filtering with random intermittent failures by setting each missing data to be zero without needing to pre-estimate the missing data, and use the GEKF-based RBFNN and the GUKF-based RBFNN to predict the ground radioactivity time series with missing data. Experimental results demonstrate that the prediction results of GUKF-based RBFNN accord well with the real ground radioactivity time series while the prediction results of GEKF-based RBFNN are divergent.

关键词： prediction of time series with missing data random interruption failures in the observation neural network approximation

High resolution inverse synthetic aperture radar imaging of three-axis-stabilized space target by exploiting orbital and sparse priors

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Chinese Physics B 2017年第10期26卷 459-471页

作者：马俊涛高梅国郭宝锋董健熊娣冯祺 School of information and electronics Beijing Institute of Technology Department of Electronic and Optical Engineering Ordnance Engineering college

The development of inverse synthetic aperture radar （ISAR） imaging techniques is of notable significance for moni- toring, tracking and identifying space targets in orbit. Usually, a well-focused ISAR image of a space target can be obtained in a deliberately selected imaging segment in which the target moves with only uniform planar rotation. However, in some imaging segments, the nonlinear range migration through resolution cells （MTRCs） and time-varying Doppler caused by the three-dimensional rotation of the target would degrade the ISAR imaging performance, and it is troublesome to realize accurate motion compensation with conventional methods. Especially in the case of low signal-to-noise ratio （SNR）, the estimation of motion parameters is more difficult. In this paper, a novel algorithm for high-resolution ISAR imaging of a space target by using its precise ephemeris and orbital motion model is proposed. The innovative contributions are as follows. 1） The change of a scatterer projection position is described with the spatial-variant angles of imaging plane calculated based on the orbital motion model of the three-axis-stabilized space target. 2） A correction method of MTRC in slant- and cross-range dimensions for arbitrarily imaging segment is proposed. 3） Coarse compensation for translational motion using the precise ephemeris and the fine compensation for residual phase errors by using sparsity-driven autofo- cus method are introduced to achieve a high-resolution ISAR image. Simulation results confirm the effectiveness of the proposed method.

关键词： space target ISAR imaging MTRC correction sparsity