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Quantitative Verification of Knowledge Precondition for Open System

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Chinese Journal of Electronics 2016年第2期25卷 227-233页

作者： XU weifeng LIU Shufen WANG Xiaoyan College of Computer Science and Technology Jilin University

A quantitative verification method is proposed to quantitatively verify knowledge precondition of actions and plans. Probability epistemic game structure(PEGS) is proposed to model knowledge preconditions in open systems, an extension of concurrent game structure with probabilistic transition. We introduce a probability operator P-λinto Alternating temporal epistemic logic(ATEL) and define a Probability alternating-time temporal epistemic logic(PATEL) for quantitatively model checking the properties of PEGS. We designed an algorithm to compute the probability aiming at model checking verification problems of PATEL based on DTMC and *** convert a portion of the PATEL verification problems into PATL problems by defining the knowledge formulas Ka φ, EA sφ and CA sφ as atomic propositions. We study a train controller using PRISM-games to demonstrate the applicability of above quantitative verification method.

关键词： Quantitative verification Knowledge precondition Alternating-time temporal logic(ATL) Open system

Influence of Test Temperature on the Tensile Properties along the Thickness in a Friction Stir Welded Aluminum Alloy

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Journal of Materials Science & Technology 2015年第9期31卷 953-961页

作者： weifeng Xu Jinhe Liu Daolun Chen State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University Department of Mechanical and Industrial Engineering Ryerson University

The aim of this study was to evaluate microstructures and the influence of test temperature on the tensile properties, strain hardening behavior and fracture characteristics of friction stir welded （FSWed） 2219- T62 aluminum alloy thick plate joints. A fine and equiaxed recrystallized grain structure had no significant change in grains at the top of weld nugget zone （WNZ） at a rotational rate of 500 r/min compared with 300 r/min, but the grains and second-phase particles at the middle of WNZ exhibited obvious coarsen- ing. The yield strength, ultimate tensile strength and joint efficiency were observed to decrease with increasing test temperatures. However, the elongation presented a contrast trend. Compared with the middle and bottom slices, the top slice （216 and 342 MPa） had a higher strength and a lower elongation （8.5%） at different test temperatures. Hardening capacity and strain hardening exponent of bottom slices were higher than those of the top and middle slices. Both of them at room temperature （RT） were bigger than those at higher temperature （HT） and lower temperature （LT）. The FSWed joints basically failed in the border area between the thermo-mechanical affected zone （TMAZ） and heat-affected zone （HAZ） of the top slice, and in the HAZ of the middle or bottom slices, while the fracture surfaces exhibited dimple fracture characteristics at different test temperatures.

关键词： Friction stir weldingAluminum alloyMicrostructureTensile propertiesStrain hardeningTest temperature

A Survey of Macroscopic Brain Network Visualization Technology

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Chinese Journal of Electronics 2018年第5期27卷 889-899页

作者： CHEN weifeng SHI Lei CHEN Wei School of Information Zhejiang University of Finance & Economics State Key Lab of Computer Science Institute of SoftwareChinese Academy of Sciences State Key Lab of CAD&CG Zhejiang University

Brain science, as an important branch of Neuroscience, is a discipline that studies the structure and function of brain nervous system of human and other mammals. With the invention of new technologies such as brain imaging, light microscopes and brain electromagnetics,brain science is gradually unraveling the mysteries of human emotion, intelligence and behavior. In this wave, data visualization punctuates the landmark advances in brain science since its beginning. This survey reviews the recent literature on brain network visualization(aka connectome)from the fields of both connectomics and visualization. In particular, we focus on the macroscopic-level brain network visualization techniques, that reveal the structural and functional connectivity of the whole brain, in comparison to microsopic-level neuronal connectivities. We also discuss the interactive visualization tools currently available for viewing the brain networks. Finally, we conclude with a number of ongoing challenges in macroscopic brain network visualization.

关键词： Brain network Connectomics Visualization

Dynamic Multi-Task Allocation Method for Passenger Diffusion in Mobile Crowd Sensing

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Chinese Journal of Electronics 2021年第5期30卷 940-946页

作者： JIANG Weijin lyu Sijian College of Computer and Information Engineering Hunan University of Technology and Business

This paper aims to solve the problem of low efficiency, high cost and instability in opportunistic network transmission in the process of mobile group intelligence perception task allocation. Two multi-task dynamic distribution methods based on Lowest cost Participant selection algorithm(LC-PSA) based on user incentive cost and Least number Participant selection algorithm(LN-PSA) based on number of users are proposed respectively. Through these two algorithms,the goal of minimizing the number of people and moving distance required for the task and reducing the system's incentive cost is achieved. Simulation experiments show that compared with similar algorithms, the number of participants in the task distribution scheme selected by the LN-PSA algorithm is reduced by 24.0%, and the system resource consumption is lower, which can provide stable services for the system when users are insufficient in emergencies. Compared with the traditional greedy heuristics algorithm, the LC-PSA algorithm reduces the total system cost by 37.74% and has better overall performance in the comparison experiment.

关键词： mobile group intelligence perception task allocation system resource consumption Lowest cost Participant selection algorithm multitask dynamic distribution methods dynamic multitask allocation method optimisation LN-PSA algorithm passenger diffusion number Participant selection algorithm user incentive cost LC-PSA algorithm instability greedy algorithms opportunistic network transmission traditional greedy heuristics algorithm mobile computing moving distance task distribution scheme mobile crowd sensing resource allocation total system cost

A New Method for Diagnosing the Temperature Profile in an Axisymmetric Plasma

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Chinese Physics Letters 1995年第3期12卷 171-174页

作者： WANG weifeng XU Xueji Institute for Electric Light Sources Fudan UniversityShanghai 200433

A relative spectroscopic method employing two spectral lines is developed to determine the radial temperature profile in an axisymmetric plasma *** method is independent of the well-known Abel-inversion and of gas pressure if optically-thin lines are used,and also has no restriction on the presumption of the temperature profile such as the Bartels'approximation,i.e.,the *** high efficiency of the technique is tested by its application to a dielectric barrier gas *** discharge configuration is an enclosed cylindrical and annular gap filled with Hg-Ar mixture.

关键词： discharge. cylindrical filled

On-Chip Reconfigurable Microwave Photonic Processor

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Chinese Journal of Electronics 2023年第2期32卷 334-342页

作者： ZHANG weifeng WANG Bin Radar Research Lab School of Information and Electronics Beijing Institute of Technology Key Laboratory of Electronic and Information Technology in Satellite Navigation (Beijing Institute of Technology) Ministry of Education Beijing Institute of Technology Chongqing Innovation Center Chongqing Key Laboratory of Novel Civilian Radar

Microwave photonic processors leverage the modern photonics technique to process the microwave signal in the optical domain, featuring high speed and broad bandwidth. Based on discrete optical and microwave components, different microwave photonic processors are reported. Due to the limitation of the optoelectronic components, most of the realized processors are designed to serve a specific demand. With the booming development of photonic integrated circuits(PICs), new possibilities are opened for the implementation of integrated microwave photonic processors. By using the highprecision planar fabrication process, on-chip microwave photonic processors are enabled to have unprecedently full reconfigurability to perform multiple processing *** overview regarding our recent work on reconfigurable microwave photonic processors is presented with an emphasis on silicon photonics integrated solutions.

关键词： Microwave integrated circuits Program processors Optical device fabrication Optical resonators Microwave theory and techniques Microwave circuits System-on-chip

PID Control of Planar Nonlinear Uncertain Systems in the Presence of Actuator Saturation

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IEEE/CAA Journal of Automatica Sinica 2022年第1期9卷 90-98页

作者： Xujun lyu Zongli Lin College of Engineering Huazhong Agricultural UniversityWuhan 430070China Charles L.Brown Department of Electrical and Computer Engineering University of VirginiaP.O.Box 400743CharlottesvilleVA 22904-4743 USA

This paper investigates PID control design for a class of planar nonlinear uncertain systems in the presence of actuator *** on the bounds on the growth rates of the nonlinear uncertain function in the system model,the system is placed in a linear differential *** vertex system of the linear differential inclusion is a linear system subject to actuator *** placing the saturated PID control into a convex hull formed by the PID controller and an auxiliary linear feedback law,we establish conditions under which an ellipsoid is contractively invariant and hence is an estimate of the domain of attraction of the equilibrium point of the closed-loop *** equilibrium point corresponds to the desired set point for the system ***,the location of the equilibrium point and the size of the domain of attraction determine,respectively,the set point that the output can achieve and the range of initial conditions from which this set point can be *** on these conditions,the feasible set points can be determined and the design of the PID control law that stabilizes the nonlinear uncertain system at a feasible set point with a large domain of attraction can then be formulated and solved as a constrained optimization problem with constraints in the form of linear matrix inequalities(LMIs).Application of the proposed design to a magnetic suspension system illustrates the design process and the performance of the resulting PID control law.

关键词： Actuator saturation domain of attraction nonlinear systems PID control uncertainties

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爆炸作用下建筑结构高效毁伤评估方法

爆炸与冲击 2025年第1期45卷 015101-1-015101-18页

作者：吕晋贤吴昊卢永刚陈德同济大学土木工程学院上海200092 中国工程物理研究院总体工程研究所四川绵阳621999

为综合评估战后建筑结构的毁伤等级，针对爆炸作用下典型地面建筑，即含填充墙钢筋混凝土（reinforced concrete，RC）框架结构，提出了损伤破坏和倒塌的高精度数值仿真分析方法，并通过RC结构爆炸试验、倒塌事故和砌体墙爆炸试验进行... 详细信息

为综合评估战后建筑结构的毁伤等级，针对爆炸作用下典型地面建筑，即含填充墙钢筋混凝土（reinforced concrete，RC）框架结构，提出了损伤破坏和倒塌的高精度数值仿真分析方法，并通过RC结构爆炸试验、倒塌事故和砌体墙爆炸试验进行了充分验证;开展了典型3层原型RC框架结构在不同爆炸当量（25~200 kg TNT）下的内爆炸数值仿真，定量分析了爆炸冲击波在建筑结构内部的传播、结构损伤破坏和墙体飞散等。爆炸作用下建筑结构的高效毁伤评估流程为：结合镜像爆源和非线性叠加原理确定内爆炸荷载，基于等效单自由度方法评估梁、板、柱及墙体构件的毁伤等级，引入构件重要性系数加权确定房间毁伤等级，考虑房间功能及位置重要性评估整体结构的毁伤等级。高精度数值仿真分析与毁伤评估方法计算的典型RC框架结构的整体毁伤等级一致，即在25、100和200 kg TNT爆炸下RC结构分别呈现轻度、中度和重度毁伤，毁伤评估方法可缩短99%以上的计算耗时，兼具可靠性与时效性。

关键词：爆炸荷载建筑结构毁伤评估方法损伤破坏

Preparation and Photochromic Properties of Hybrid Thin Films Based on Heteropolyoxometallate and Polyacrylamide

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Journal of Materials Science & Technology 2002年第6期18卷 558-560页

作者： weifeng JiannianYAO 等 DepartmentofChemistry JilinUniversityChangchun130023China InstituteofChemistryandCenterforMolecularScience ChineseAceademyofSciencesBeijing100080China

A series of photochromic hybrid films were prepared through entrapping Dawson type tungsten heteropolyoxomet-allates (P2W18C626-) and molybdenum heteropolyoxometallate (P2Mo18O626-) into polyacrylamide matrix. FTIR results showed that the Dawson geometry of heteropolyoxometallates is still preserved inside the composites and strong coulombic interaction is built between heteropolyoxometallates and polyacrylamide via hydrogen bonding. Irradiated with ultraviolet light, the transparent films change from colorless to blue and show reversible photochromism. The bleaching process occurs when the films are in contact with air or O2 in the dark. The molybdenum heteropolyoxometallate hybrid film has higher photochromic efficiency and slower bleaching reaction than tungsten heteropolyoxometallate hybrid film. ESR results indicated that polyacrylamide is a hydrogen donor and the photoreduced process is in accordance with the radical mechanism.

关键词： Thin film Heteropolyoxometallate Polyacrylamide Photochromism