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Assessment of Power Quality Based on D-S Evidence Theory

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International Journal of Automation and computing 2014年第6期11卷 635-643页

作者： chun-xia dou Ting Gui Ye-Fei Bi Jin-Zhao Yang xiao-Gang Li Institute of Electrical Engineering Yanshan University

Technological advancement of measurement systems has enhanced the accuracy of power quality assessment by using a combination of measured information. This paper proposes a novel approach for estimating power quality based on information fusion technique of Dempster-Shafer(D-S) evidence theory. First, in order to accurately extract transient features regarding power quality indexes, wavelet packet transform and lifting wavelet transform are proposed to detect various disturbance signals measurement. By using many kinds of transformed transient indexes and steady state indexes, a novel reliability distribution function is constructed,and synthesized assessment index of power quality is drafted based on information fusion technique of D-S evidence theory. Finally,the simulation results prove that D-S evidence theory is a more effective means for evaluating the power quality.

关键词： Power quality Dempster-Shafer (D-S) evidence theory information fusion technique wavelet packet transform lifting wavelet transform

Optimal Control for Switched Systems with Impulsive Effects

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Optimal Control for Switched Systems with Impulsive Effects

Finiteness Conditions and Relative Singularity Categories

第三十一届中国控制会议

作者： Bin Liu~(1 2) Dongnan Liu~1 chun-xia dou~3 1.College of Sciences Hunan University of Technology Zhuzhou 412008 China. 2.Research School of Engineering The Australian National University ACT 0200 Australia. 3.Institute of Electrical Engineering Yanshan University Qinhuangdao 066004 China.

＜正＞In this paper,we studies the optimal control problem for controlled switched systems with impulsive effects. By establishing the dynamic programming principle for this kind of system,we derive the necessary conditions for optimality of an associated hybrid performance ***,we provide the sufficient conditions for optimality. Specializing the obtained results to the case of linear controlled switched systems with impulsive effects,we derive the corresponding sufficient ***,one example is given to illustrate the results.

关键词： Switched systems hybrid performance functional optimal control impulse.

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Acta Mathematica Sinica,English Series 2022年第8期38卷 1436-1446页

作者： chun xia ZHANG School of Mathematical Sciences Chongqing Normal UniversityChongqing 401331P.R.China

We introduce the n-pure projective(resp.,injective)dimension of complexes in n-pure derived categories,and give some criteria for computing these dimensions in terms of the n-pure projective(resp.,injective)resolutions(resp.,coresolutions)and n-pure derived *** a consequence,we get some equivalent characterizations for the finiteness of n-pure global dimension of ***,we study Verdier quotient of bounded n-pure derived category modulo the bounded homotopy category of n-pure projective modules,which is called an n-pure singularity category since it can reflect the finiteness of n-pure global dimension of rings.

关键词： n-pure projective dimension n-pure injective dimension n-pure global dimension n-pure derived category n-pure singularity category

Predictive control for mechanical system with backlash based on hybrid model

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1301-1308页

作者： dou Lihua Dong Lingxun Chen Jie xia Yuanqing Dept. of Information Science and Technology Beijing Inst. of Technology Beijing 100081 P. R. China

The mechanical system with backlash is distinguished between a＂backlash mode＂and a＂contact mode＂.The inherent switching between the two operating modes makes the system a prime example of hybrid *** eliminating the bad effect of backlash, a piecewise affine（PWA） model of the mechanical servo system with backlash is *** optimal control of constrained PWA system is obtained by taking advantage of model predictive control（MPC） method, and the explicit solution of MPC in a look-up table form is figured out by combining the dynamic programming and multi-parametric quadratic programming, thereby establishing an explicit hybrid model predictive ***, a piecewise quadratic（PWQ） function for guaranteeing the stability of closed-loop control is found by formulating the search of PWQ function as a semi-definite programming *** the tracking experiments, it is demonstrated that the explicit hybrid model predictive controller has a good traction control effect on the mechanical system with *** error meets the demands of real ***, compared to the direct on-line computation, the computation burden is reduced by the explicit solution, thereby being suitable for real-time control of system with short sampling time.

关键词： predictive controller hybrid model hybrid control backlash mode.

Mobility Prediction Based Tracking of Moving Objects in Wireless Sensor Networks

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Chinese Journal of Electronics 2023年第4期32卷 793-805页

作者： TANG Chao xia Yinqiu dou Lihua School of Automation Beijing Institute of Technology Beijing Institute of Technology Chongqing Innovation Center

This paper investigates the multi-sensor fused localization of moving targets in a wireless sensor network. Each ultra-wide band(UWB) sensor is assigned a stability weight according to its survival time prediction. The measurement accuracy of each sensor into the constraints of the weight distribution based on the interactive multi-model method, a double weight distribution algorithm that considers measurement accuracy and stability is proposed. Based on the double weight algorithm,the measurement information of each UWB sensor, the inertial measurement unit(IMU)-based state vector and the UWB-based state vector by federated Kalman filter are integrated to realize the correction of the IMU. Finally, several numerical simulations are performed to show that the proposed algorithm can effectively suppress the measurement dropout when tracking moving targets in a wireless sensor network, and it can also automatically adjust the weight of each sensor based on the measurement error covariance to improve the tracking accuracy.

关键词： Weight measurement Wireless communication Wireless sensor networks Measurement errors Target tracking Heuristic algorithms Measurement uncertainty

Inertial gravity waves observed by a Doppler wind LiDAR and their possible sources

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Earth and Planetary Physics 2020年第5期4卷 461-471页

作者： xiangHui Xue DongSong Sun HaiYun xia xianKang dou Chinese Academy of Sciences Key Laboratory of Geospace Environment University of Science and Technology of ChinaHefei 230026China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China Anhui Mengcheng Geophysics National Observation and Research Station University of Science and Technology of China Hefei 230026China Synergetic Innovation Center of Quantum Information&Quantum Physics University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for the Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

In this paper,we use wind observations by a Doppler wind LiDAR near Delingha(37.4°N,97.4°E),Qinghai,Northwestern China to study the characteristics of inertial gravity waves in the *** focus on 10–12 December 2013,a particularly interesting case *** of the time,the inertial gravity waves extracted from the LiDAR measurements were stationary with vertical wavelengths of about 9–11 km and horizontal wavelengths of about 800–1000 ***,for parts of the observational period in this case study,a hodograph analysis indicates that different inertial gravity wave propagation features were present at lower and upper *** the middle and upper stratosphere(~30–50 km),the waves propagated downward,especially during a period of stronger winds,and to the northwest–*** the lower stratosphere and upper troposphere(~10–20 km),however,waves with upward propagation and northeast–southwest orientation were *** taking into account reanalysis data and satellite observations,we have confirmed the presence of different wave patterns in the lower and upper stratosphere during this part of the observational *** combined data sets suggest that the different wave patterns at lower and upper height levels are likely to have been associated with the presence of lower and upper stratospheric jet streams.

关键词： gravity waves lidar wind observations

System portfolio selection based on GRA method under hesitant fuzzy environment

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Journal of Systems Engineering and Electronics 2022年第1期33卷 120-133页

作者： LI Zhuoqian dou Yajie xia Boyuan YANG Kewei LI Mengjun College of Systems Engineering National University of Defense TechnologyChangsha 410073China

The hesitant fuzzy set(HFS) is an important tool to deal with uncertain and vague *** equipment system portfolio selection, the index attribute of the equipment system may not be expressed by precise data;it is usually described by qualitative information and expressed as multiple possible *** propose a method of equipment system portfolio selection under hesitant fuzzy *** hesitant fuzzy element(HFE) is used to describe the index and attribute values of the equipment *** hesitation degree of HFEs measures the uncertainty of the criterion data of the equipment *** hesitant fuzzy grey relational analysis(GRA) method is used to evaluate the score of the equipment system, and the improved HFE distance measure is used to fully consider the influence of hesitation degree on the grey correlation *** on the score and hesitation degree of the equipment system,two portfolio selection models of the equipment system and an equipment system portfolio selection case is given to illustrate the application process and effectiveness of the method.

关键词： system portfolio selection hesitant fuzzy set(HFS) grey relational analysis(GRA) score-hesitation tradeoff portfolio model

Research on Cognitive Cooperation in Multi-Agent Systems

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Wuhan University Journal of Natural Sciences 2006年第1期11卷 278-282页

作者： SUN Juan dou Wan-chun State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210093 JiangsuChina Department of Computer Science and Technology Nanjing University Nanjing 210093Jiangsu China

The accomplishment of a complex problem usually involves cooperation between participators with different knowledge background concerned. This paper identifies interdependency between different sub problems （through problem decomposition） as the major factor that influences cooperative relations in multi-Agent systems, based on which we propose an efficient means to measure cooperation coefficient （degree） between different Agents. Then cognitive cooperation between Agents is analyzed which aims at collecting the wisdom of the cognitive community for a systematic solution to the overall problem.

关键词： multi-Agent systems cognitive cooperation knowledge flow

Fog removal and enhancement method for UAV aerial images based on dark channel prior

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Journal of Control and Decision 2023年第2期10卷 188-197页

作者： Fei xia Hu Song Haoxiang dou Information Operation Inspection Center State Grid Jiangsu Information&Telecommunication CompanyNanjingPeople’s Republic of China

The existing UAV aerial image de-fog methods have low image contrast after de-fog,the difference between light and dark image is not obvious,leading to poor de-fog ***,an aerial image de-fog enhancement method based on dark channel a priori is *** image variance and absolute gradient mean are combined to get the weight coefficients,and the edge pixels are smoothed by using the multiple decomposition *** image intensity is calculated and the noise is reduced.A convolution neural network is introduced to calculate the atmospheric transmittance in *** on this,dark channel prior algorithm is used to enhance the light and shade difference of aerial photography image and realise the de-fog enhancement of aerial photography *** verify the performance of the proposed method,simulation experiments are designed which were compared with the existing methods results in better fog-removing effect,higher contrast and shorter time.

关键词： Dark channel prior unmanned aerial vehicle(UAV) aerial image fog enhancement halo artefact image denoising