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Investigation on performance of all optical buffer with large dynamical delay time based on cascaded double loop optical buffers

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Chinese Physics B 2010年第9期19卷 420-427页

作者：王拥军吴重庆忻向军余贶琭张晓磊 School of electronic Engineering Beijing University of Posts and Telecommunications key laboratory of Information Photonics and Optical Communications of Education Ministry Institute of Optical Information Beijing Jiaotong UniversityKey Laboratory of Education Ministry on Luminescence and Optical Information Technology

Optical buffers are critical for optical signal processing in future optical packet-switched networks. In this paper, a theoretical study as well as an experimental demonstration on a new optical buffer with large dynamical delay time is carried out based on cascaded double loop optical buffers （I：）LOBs）. It is found that pulse distortion can be restrained by a negative optical control mode when the optical packet is in the loop. Noise analysis indicates that it is feasible to realise a large variable delay range by cascaded DLOBs. These conclusions are validated by the experiment system with 4-stage cascaded DLOBs. Both the theoretical simulations and the experimental results indicate that a large delay range of 1-9999 times the basic delay unit and a fine granularity of 25 ns can be achieved by the cascaded DLOBs. The performance of the cascaded DLOBs is suitable for the all optical networks.

关键词： all optical packets switching optical buffer with large delay range signals impairment noise analysis of semiconductor optical amplifier

Adaptive multiscale convolutional neural network model for chemical process fault diagnosis

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Chinese Journal of Chemical Engineering 2022年第10期50卷 398-411页

作者： Ruoshi Qin Jinsong Zhao State key laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China beijing key laboratory of Industrial Big Data system and Application Tsinghua UniversityBeijing 100084China

Intelligent fault recognition techniques are essential to ensure the long-term reliability of *** to the variations in material,equipment and environment,the process variables monitored by sensors contain diverse data characteristics at different time scales or in multiple operating *** much progress in statistical learning and deep learning for fault recognition,most models are constrained by abundant diagnostic expertise,inefficient multiscale feature extraction and unruly multimode *** overcome the above issues,a novel fault diagnosis model called adaptive multiscale convolutional neural network(AMCNN)is developed in this paper.A new multiscale convolutional learning structure is designed to automatically mine multiple-scale features from time-series data,embedding the adaptive attention module to adjust the selection of relevant fault pattern *** triplet loss optimization is adopted to increase the discrimination capability of the model under the multimode *** benchmarks CSTR simulation and Tennessee Eastman process are utilized to verify and illustrate the feasibility and efficiency of the proposed *** with other common models,AMCNN shows its outstanding fault diagnosis performance and great generalization ability.

关键词： Neural networks Multiscale Adaptive attentionmodule Triplet lossoptimization Fault diagnosis Chemical processes

Image processing based three-dimensional model reconstruction for cross-platform numerical simulation

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China Foundry 2023年第2期20卷 139-147页

作者： Yu-cheng Sun Yu-hang Huang Na Li Xiao Han Ai-long Jiang Jin-wu Kang Ji-wu Wang Hai-liang Yu State key laboratory of Engine reliability Weichai Power Co.Ltd.Weifang 261061ShandongChina School of Mechanical Engineering Central South UniversityChangsha 41000China School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China key laboratory for Advanced Materials Processing technology School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Numerical simulation is the most powerful computational and analysis tool for a large variety of engineering and physical *** a complex problem relating to multi-field,multi-process and multi-scale,different computing tools have to be developed so as to solve particular fields at different scales and for different ***,the integration of different types of software is ***,it is difficult to perform the transfer of the meshes and simulated results among software packages because of the lack of shared data formats or encrypted data *** image processing based method for three-dimensional model reconstruction for numerical simulation was proposed,which presents a solution to the integration problem by a series of slice or projection images obtained by the post-processing modules of the numerical simulation *** means of mapping image pixels to meshes of either finite difference or finite element models,the geometry contour can be extracted to export the stereolithography *** values of results,represented by color,can be deduced and assigned to the *** the models with data can be directly or indirectly integrated into other software as a continued or new numerical *** three-dimensional reconstruction method has been validated in numerical simulation of castings and case studies were provided in this study.

关键词： cross-platform numerical simulation 3D model reconstruction image processing slice

Application Prospect of Fission-Powered Spacecraft in Solar system Exploration Missions

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Space(Science & technology) 2021年第1期2021卷 309-323页

作者： Y.Xia J.Li R.Zhai J.Wang B.Lin Q.Zhou beijing Institute of Spacecraft Environment Engineering BeijingChina Science and technology on reliability and Environmental Engineering laboratory BeijingChina Institute of Nuclear and New Energy technology of Tsinghua University The Key Laboratory of Advanced Reactor Engineering and SafetyMinistry of EducationBeijingChina

Fission power is a promising technology,and it has been proposed for several future space *** is being considered for highpower missions whose goal is to explore the solar system and even *** fission power has made great progress when NASA’s 1 kWe Kilowatt Reactor Using Stirling technology(KRUSTY)prototype completed a full power scale nuclear test in *** success stimulated a new round of research competition among the major space *** article reviews the development of the Kilopower reactor and the KRUSTY system *** summarizes the current missions that fission reactors are being considered as a power and/or propulsion *** projects include visiting Jupiter and Saturn systems,Chiron,and Kuiper belt object;Neptune exploration missions;and lunar and Mars surface base *** studies suggest that the Fission Electric Propulsion(FEP)/Fission Power system(FPS)is better than the Radioisotope Electric Propulsion(REP)/Radioisotope Power system(RPS)in the aspect of cost for missions with a power level that reaches~1 kWe,and when the power levels reaches~8 kWe,it has the advantage of lower *** a mission that travels further than~Saturn,REP with plutonium may not be cost acceptable,leaving FEP the only *** missions prefer the use of FPS because it satisfies the power level of 10’s kWe,and FPS vastly widens the choice of possible landing *** to the current situation,we are expecting a flagship-level fission-powered space exploration mission in the next 1-2 decades.

关键词： satis Saturn isotope

Description of the Cover Picture

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Journal of Harbin Institute of technology(New Series) 2018年第2期25卷 85-96页

作者： Jianfeng Yang Chuangmian Huang Yuanhang Wang Kai Li The Fifth electronic Institute of Ministry of Industry and Information technology Guangzhou 510610China Guangdong Province Research Center of electronic Information Products reliability and Environment Engineering technology Guangzhou 510610China Guangdong Provincial key laboratory of electronic Information Products reliability technology Guangzhou 510610China Guangzhou Province key laboratory of electronic Information Products reliability and Environment Engineering technology Guangzhou 510610China

Vibration isolation system(VIS)is usually applied to improve the pointing capability and resolution of a space optical payload.A novel vibration isolator is *** equivalent stiffness model of the isolator is derived by analyzing its static characteristics.A VIS based on the bipod configuration is *** dynamic model is derived and verified using the finite element method and *** this isolator contains viscoelastic material’which makes the frequency responsive analysis more difficult’an efficiency analysis approach based on the complex stiffness of viscoelastic material is proposed to calculate the transmissibility of the ***’a prototype of the vibration isolator is manufactured and experimental studies are carried *** experimental results show that the analytical results are in good correspondence with the experimental data and the isolator can effectively attenuate the vibrations for the optical ***：isolator;viscoelastic material；space optical

关键词： isolator viscoelastic material space optical payload

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Adaptive Control of Discrete-time Nonlinear systems Using ITF-ORVFL

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IEEE/CAA Journal of Automatica Sinica 2022年第3期9卷 556-563页

作者： Xiaofei Zhang Hongbin Ma Wenchao Zuo Man Luo School of Automation Beijing Institute of TechnologyBeijing 100081 School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China School of Automation Beijing Institute of Technologyand also with the State Key Laboratory of Intelligent Control and Decision of Complex Systems(Beijing Institute of Technology)Beijing 100081China School of Automation Beijing Institute of TechnologyBeijing 100081and he is with Beijing Institute of Electronic System EngineeringBeijing 100854China School of Automation Beijing Institute of TechnologyBeijing 100081and she is with Ant GroupBeijing 310013China

Random vector functional ink(RVFL)networks belong to a class of single hidden layer neural networks in which some parameters are randomly *** network structure in which contains the direct links between inputs and outputs is unique,and stability analysis and real-time performance are two difficulties of the control systems based on neural *** this paper,combining the advantages of RVFL and the ideas of online sequential extreme learning machine(OS-ELM)and initial-training-free online extreme learning machine(ITFOELM),a novel online learning algorithm which is named as initial-training-free online random vector functional link algo rithm(ITF-ORVFL)is investigated for training *** link vector of RVFL network can be analytically determined based on sequentially arriving data by ITF-ORVFL with a high learning speed,and the stability for nonlinear systems based on this learning algorithm is *** experiment results indicate that the proposed ITF-ORVFL is effective in coping with nonparametric uncertainty.

关键词： Adaptive control initial-training-free online learning algorithm random vector functional link networks

Two-dimensional extreme distribution for estimating mechanism reliability under large variance

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Advances in Manufacturing 2020年第3期8卷 369-379页

作者： Zhi-Hua Wang Zhong-Lai Wang Shui Yu School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu611731People’s Republic of China Center for system reliability and Safety University of Electronic Science and Technology of ChinaChengdu611731People’s Republic of China

The effective estimation of the operational reliability of mechanism is a significant challenge in engineering practices,especially when the variance of uncertain factors becomes *** this challenge,a novel mechanism reliability method via a two-dimensional extreme distribution is investigated in the *** time-variant reliability problem for the mechanism is first transformed to the time-invariant system reliability problem by constructing the two-dimensional extreme *** joint probability density functions(JPDFs),including random expansion points and extreme motion errors,are then obtained by combining the kernel density estimation(KDE)method and the copula ***,a multidimensional integration is performed to calculate the system time-invariant *** cases are investigated to demonstrate the effectiveness of the presented method.

关键词： Time-variant reliability Great variance Two-dimensional Extreme distribution Kernel density estimation(KDE) Multidimensional Integration

Dual smoothing ionospheric gradient monitoring algorithm for dual-frequency BDS GBAS

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Chinese Journal of Aeronautics 2020年第12期33卷 3395-3404页

作者： Zhipeng WANG Yu YIN Dan SONG Kun FANG Qiang LI Xiao LI National key laboratory of CNS/ATM School of Electronic and Information EngineeringBeihang UniversityBeijing 100083China beijing Hualong Tong Science and technology Co LtdBeijing 100084China

In this study,a Dual Smoothing Ionospheric Gradient Monitor Algorithm(DSIGMA)was developed for Code-Carrier Divergence(CCD)faults of dual-frequency Ground-Based Augmentation systems(GBAS)based on the Bei Dou Navigation Satellite system(BDS).Divergence-Free(DF)combinations of the signals were used to form test statistics for a dualfrequency ***,the single-frequency DSIGMA was reviewed,which supports the GBAS approach service type D(GAST-D)for protection against the effect of large ionospheric *** single-frequency DSIGMA was used to create a novel input scheme for the dual-frequency DSIGMA by introducing DF *** steady states of the test statistics were also *** monitors were characterized using BDS measurement data,whereby standard deviations of 0.0432 and 0.0639 m for the proposed two test statistics were used to calculate the monitor *** extensive simulation was designed to assess the monitor performance by comparing the Probability of Missed Detection(PMD)according to the differential error with the range domain PMD limits under different fault *** results showed that the proposed algorithm has a higher integrity performance than the single-frequency *** minimum detectable divergence with the same missed probability is less than 50%that of GAST-D.

关键词： Approach Augmentation Integrity Ionosphere-monitoring Satellite navigation Smoothing algorithms Steady state Threshold

Compressed Sensing of Wireless Sensor Networks Data with Missed Measurements

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Chinese Journal of electronics 2015年第2期24卷 388-392页

作者： WANG Kai LIU Yulin WAN Qun JING Xiaojun Chongqing Communication Institute China electronic system Engineering Company University of electronic Science and technology of China beijing University of Posts and Telecommunications

In Wireless sensor networks(WSNs),missed measurements may be caused by the sensor malfunction and interruption of communication between sensor nodes. The feasibility of exact recovery of WSNs data with missed measurements is analyzed in the framework of compressed sensing. A new incomplete measurement model was developed and the data reconstruction algorithm was proposed. The required number of the missing measurements and the sparsity condition of network data are found for exact compressed sensing of WSNs *** derivation shows that a WSNs data of length N with no more than M/(log(N/M) + 1) nonzero coefficients can be exactly recovered with M Gaussian measurements,provided that fraction of the missed measurements is less than a quarter of the Restricted isometry property(RIP)constant squared. Simulation results validate the theoretical results.

关键词： Wireless sensor networks Compressed sensing Missed measurements Data reconstruction