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Fuzzy Modeling of Non-Uniformly Sampling Nonlinear Systems Based on Clustering Method and Convergence Analysis

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Journal of Systems Science & Complexity 2021年第2期34卷 502-519页

作者： WANG Hongwei XIE lirong School of Electrical Engineering Xinjiang UniversityUrumqi 830047China School of Control Science and Control Engineering Dalian University of TechnologyDalian 116024China

The studying motivation of this paper is that there exist many modeling issues of nonuniformly sampling nonlinear systems in industrial *** on multi-model modeling principle,the corresponding model of non-uniformly sampling nonlinear systems is described by the nonlinear weighted combination of some linear models at local working *** modeling based on multimodel scheme is a common method to describe the dynamic process of non-linear *** this paper,the fuzzy modeling method of non-uniformly sampling nonlinear systems is *** premise structure of the fuzzy model is confirmed by GK fuzzy clustering,and the conclusion parameters of the fuzzy model are estimated by the recursive least squared *** convergence perfromance of the proposed identification algorithm is given by using lemmas and martingale ***,the simulation example is given to demonstrate the effectiveness of the proposed method.

关键词： Convergence analysis fuzzy modeling nonlinear systems non-uniformly sampling systems

N-SVRG:Stochastic Variance Reduction Gradient with Noise Reduction Ability for Small Batch Samples

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Computer Modeling in Engineering & Sciences 2022年第4期131卷 493-512页

作者： Haijie Pan lirong Zheng School of Information Science and Engineering Fudan UniversityShanghai200433China

The machine learning model converges slowly and has unstable training since large variance by random using a sample estimate gradient in *** this end,we propose a noise reduction method for Stochastic Variance Reduction gradient(SVRG),called N-SVRG,which uses small batches samples instead of all samples for the average gradient calculation,while performing an incremental update of the average *** each round of iteration,a small batch of samples is randomly selected for the average gradient calculation,while the average gradient is updated by rounding of the past model gradients during internal *** suitably reducing the batch size B,the memory storage as well as the number of iterations can be *** experiments are compared with the state-of-the-art Mini-Batch SGD,AdaGrad,RMSProp,SVRG and SCSG,and it is demonstrated that N-SVRG outperforms SVRG and SASG,and is on par with ***,by exploring the relationship between the small values of different parameters n.B and k and the effectiveness of the algorithm,we prove that ourN-SVRG algorithm has some stability and can achieve sufficient accuracy even in the case of small batch *** advantages and disadvantages of various methods are experimentally compared,and the stability of N-SVRG is explored by parameter settings.

关键词： Machine learning SGD SVRG memory storage

Modeling and parameter identification of linear time-varying systems based on adaptive chirplet transform under random excitation

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Chinese Journal of Aeronautics 2021年第4期34卷 56-66页

作者： Jie ZHANG Zhiyu SHI lirong LI State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Shanghai Aircraft Customer Service Co. Ltd.Shanghai 200241China

In this paper,a time–frequency algorithm based on adaptive chirplet transform for parameter modeling and identification of Linear Time-Varying(LTV)systems under random excitation is *** is assumed that the solution of responses of LTV structures is expressed as the sum of multicomponent Linear Frequency Modulated(LFM)signals in a *** the measured acceleration response is used to perform the adaptive chirplet transform,in which an integral algorithm is employed to reconstruct the velocity and displacement *** vibration differential equation with time-varying coefficients is transformed into a simple linear ***,for systems under random excitation,the input–output relation based on correlation function is also derived to estimate the parameters including physicals parameters and instantaneous modal *** full procedure of the method is presented and validated by using simulated *** results show that the presented method is accurate and robust for various LTV systems under random excitation.

关键词： Acceleration response Chirplet transform LTV systems Random excitation System parameter identification

Cold standby repairable system with working vacations and vacation interruption

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Journal of Systems Engineering and Electronics 2015年第5期26卷 1127-1134页

作者： Baoliang Liu lirong Cui Yanqing Wen College of Mathematics and Computer Science Shanxi Datong University School of Management and Economics Beijing Institute of Technology

This paper studies a cold standby repairable system with working vacations and vacation interruption. The repairman’s multiple vacations policy, the working vacations policy and the vacation interruption are considered simultaneously. The lifetime of components follows a phase-type(PH) distribution. The repair time in the regular repair period and the working vacation period follow other two PH distributions at different rates. For this system, the vector-valued Markov process governing the system is constructed. We obtain several important performance measures for the system in transient and stationary regimes applying matrixanalytic methods. Finally, a numerical example is given to illustrate the results obtained.

关键词： reliability phase-type(PH) distribution multiple vacations working vacations vacation interruption rate of occurrence of failure

LINDEMANN COEFFICIENT OF THE TWO-DIMENSIONAL COLLINS MODEL SYSTEM HAVING LENNARDJONES POTENTIAL

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Chinese Physics Letters 1990年第6期7卷 280-283页

作者： CHEN lirong CHEN Qinghu Department of Physics Anhui Normal UniversityWuhu241000

We introduced the Lennard-Jones potential into the two-dimensional Collins model *** additional potential energy has been derived for two-dimensional *** to the classical statistics,the Lindemann coefficient δ_(c) of this system is calculated along the melting *** calculated results shows that the value ofδc approximates to 0.08,which is in agreement with one of the rare gas solids in the order of magnitude.

关键词： solids potential rare

Reliability modelling based on dependent two-stage virtual age processes

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Journal of Systems Engineering and Electronics 2021年第3期32卷 711-721页

作者： QIU Qingan CUI lirong School of Management and Economics Beijing Institute of TechnologyBeijing 100081China

This paper proposes reliability and maintenance models for systems suffering random shocks arriving according to a non-homogeneous Poisson *** system degradation process include two stages:from the installation of a new system to an initial point of a defect(normal stage),and then from that point to failure(defective stage),following the delay time *** employing the virtual age method,the impact of external shocks on the system degradation process is characterized by random virtual age increment in the two stages,resulting in the corresponding two-stage virtual age *** operating in the defective state,the system becomes more susceptible to fatigue and suffers from a greater aging *** is carried out either on failure or on the detection of a defective state at periodic or opportunistic *** paper evaluates system reliability performance and investigates the optimal opportunistic maintenance policy.A case study on a cooling system is given to verify the obtained results.

关键词： reliability evaluation delay-time model virtual age process opportunistic maintenance

Markov repairable systems with stochastic regimes switching

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Journal of Systems Engineering and Electronics 2011年第5期22卷 773-779页

作者： Liying Wang lirong Cui Mingli Yu School of Management and Economics Beijing Institute of Technology B eijing 100081 E R. China Department of Mathematics and Physics Shijiazhuang Tiedao University Shijiazhuang 050043 E R. China

Compared with the classical Markov repairable system, the Markov repairable system with stochastic regimes switching introduced in the paper provides a more realistic description of the practical system. The system can be used to model the dynamics of a repairable system whose performance regimes switch according to the external conditions. For example, to satisfy the demand variation that is typical for the power and communication systems and reduce the cost, these systems usually adjust their operating regimes. The transition rate matrices under distinct operating regimes are assumed to be different and the sojourn times in distinct regimes are governed by a finite state Markov chain. By using the theory of Markov process, Ion channel theory, and Laplace transforms, the up time of the system are studied. A numerical example is given to illustrate the obtained results. The effect of sojourn times in distinct regimes on the availability and the up time are also discussed in the numerical example.

关键词： Markov repairable system up time stochastic regimes switching system Markov process.

Genetic Resources,Breeding Programs in China,and Gene Mining of Peach:A Review

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Horticultural Plant Journal 2020年第4期6卷 205-215页

作者： Yong Li lirong Wang Zhengzhou Fruit Research Institute Chinese Academy of Agricultural SciencesZhengzhou450009China

Research on peach genetic resources and breeding has achieved remarkable progress in recent decades,especially in *** this review,we first described the geographic distribution,ecology,phenotypes,and genetic diversity of peach landraces and wild relatives in *** also discussed the ***,breeding programs of peaches in China are summarized,including breeding history,breeding targets,breeding institutes,elite breeding materials,breeding solutions,and domestically bred representative ***,we reviewed the genes or loci that have been mined using both linkage mapping and genome wide association study(GWAS)as well as the evolutionary genetics and domestication history of the ***,we gave our perspectives and suggestions for future breeding in terms of breeding material selection and breeding technology innovation.

关键词： peach genetic resources landrace wild relatives breeding gene mining GWAS

Convergence analysis of a least squared algorithm of linear switched identification

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Journal of Control and Decision 2020年第4期7卷 379-396页

作者： Hongwei Wang lirong Xie School of Control Science and Engineering Dalian University of TechnologyDalianPeople’s Republic of China School of Electrical Engineering Xinjiang UniversityUrumqiPeople’s Republic of China

A novel identification algorithm is proposed to deal with the modelling issues of linear switched systems under the switching modes being *** main contributions of this paper embody the following aspects:(1)for simplifying the identification problems,the label functions are proposed to replace the switching states of the modes;(2)The recursive least square algorithm is used to identify the system parameters,and the convergence performance of the proposed algorithm is *** using convergence analysis,the parameter estimation error can converge to zero point when the input signals satisfy persistent excited conditions and the total time of mode mismatch is ***,the effectiveness of the proposed method is verified by a simulation example.

关键词： Linear switched systems label functions mode matching convergence analysis