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Responses of Annual Variability of Vegetation NPP to Climate Variables Using Satellite Techniques in Gadarif State, Sudan
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作者 Anwar Mohamedelhassan Bo Zhang +1 位作者 Abdelrahim E. Jahelnabi Eman M. Elhassan 《Journal of Geographic Information System》 2024年第2期136-147,共12页
Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into... Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into photosynthesis. It is very sensible for factors affecting on vegetation variability such as climate, soils, plant characteristics and human activities. So, it can be used as an indicator of actual and potential trend of vegetation. In this study we used the actual NPP which was derived from MODIS to assess the response of NPP to climate variables in Gadarif State, from 2000 to 2010. The correlations between NPP and climate variables (temperature and precipitation) are calculated using Pearson’s Correlation Coefficient and ordinary least squares regression. The main results show the following 1) the correlation Coefficient between NPP and mean annual temperature is Somewhat negative for Feshaga, Rahd, Gadarif and Galabat areas and weakly negative in Faw area;2) the correlation Coefficient between NPP and annual total precipitation is weakly negative in Faw, Rahd and Galabat areas and somewhat negative in Galabat and Rahd areas. This study demonstrated that the correlation analysis between NPP and climate variables (precipitation and temperature) gives reliably result of NPP responses to climate variables that is clearly in a very large scale of study area. 展开更多
关键词 Climate variables MODIS NPP Climate Change Correlation Coefficient Gadarif state Remote Sensing GIS Applications
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3D finite element simulation of microstructure evolution in blade forging of Ti-6Al-4V alloy based on the internal state variable models 被引量:4
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作者 Jiao Luo Bin Wu Miao-quan Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第2期122-130,共9页
The physically-based internal state variable (ISV) models were used to describe the changes of dislocation density, grain size, and flow stress in the high temperature deformation of titanium alloys in this study. T... The physically-based internal state variable (ISV) models were used to describe the changes of dislocation density, grain size, and flow stress in the high temperature deformation of titanium alloys in this study. The constants of the present models could be identified based on experimental results, which were conducted at deformation temperatures ranging from 1093 K to 1303 K, height reductions ranging from 20% to 60%, and the strain rates of 0.001, 0.01, 0.1, 1.0, and 10.0 s-1. The physically-based internal state variable models were implemented into the commercial finite element (FE) code. Then, a three-dimensional (3D) FE simulation system coupling of deformation, heat transfer, and microstructure evolution was developed for the blade forging of Ti-6Al-4V alloy. FE analysis was carried out to simulate the microstructure evolution in the blade forging of Ti-6Al-4V alloy. Finally, the blade forging tests of Ti-6Al-4V alloy were performed to validate the results of FE simulation. According to the tensile tests, it is seen that the mechanical properties, such as tensile strength and elongation, satisfy the application requirements well. The maximum and minimum differences between the calculated and experimental grain size of primary α phase are 11.71% and 4.23%, respectively. Thus, the industrial trials show a good agreement with FE simulation of blade forging. 展开更多
关键词 titanium alloys FORGING microstructure evolution internal state variables mechanical properties
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Estimation Method of State-of-Charge For Lithium-ion Battery Used in Hybrid Electric Vehicles Based on Variable Structure Extended Kalman Filter 被引量:18
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作者 SUN Yong MA Zilin +2 位作者 TANG Gongyou CHEN Zheng ZHANG Nong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期717-726,共10页
Since the main power source of hybrid electric vehicle(HEV) is supplied by the power battery,the predicted performance of power battery,especially the state-of-charge(SOC) estimation has attracted great attention ... Since the main power source of hybrid electric vehicle(HEV) is supplied by the power battery,the predicted performance of power battery,especially the state-of-charge(SOC) estimation has attracted great attention in the area of HEV.However,the value of SOC estimation could not be greatly precise so that the running performance of HEV is greatly affected.A variable structure extended kalman filter(VSEKF)-based estimation method,which could be used to analyze the SOC of lithium-ion battery in the fixed driving condition,is presented.First,the general lower-order battery equivalent circuit model(GLM),which includes column accumulation model,open circuit voltage model and the SOC output model,is established,and the off-line and online model parameters are calculated with hybrid pulse power characteristics(HPPC) test data.Next,a VSEKF estimation method of SOC,which integrates the ampere-hour(Ah) integration method and the extended Kalman filter(EKF) method,is executed with different adaptive weighting coefficients,which are determined according to the different values of open-circuit voltage obtained in the corresponding charging or discharging processes.According to the experimental analysis,the faster convergence speed and more accurate simulating results could be obtained using the VSEKF method in the running performance of HEV.The error rate of SOC estimation with the VSEKF method is focused in the range of 5% to 10% comparing with the range of 20% to 30% using the EKF method and the Ah integration method.In Summary,the accuracy of the SOC estimation in the lithium-ion battery cell and the pack of lithium-ion battery system,which is obtained utilizing the VSEKF method has been significantly improved comparing with the Ah integration method and the EKF method.The VSEKF method utilizing in the SOC estimation in the lithium-ion pack of HEV can be widely used in practical driving conditions. 展开更多
关键词 state of charge estimation hybrid electric vehicle general lower-order model variable structure EKF
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Arbitrated quantum signature scheme with continuous-variable squeezed vacuum states 被引量:2
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作者 冯艳艳 施荣华 郭迎 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期239-248,共10页
We propose an arbitrated quantum signature (AQS) scheme with continuous variable (CV) squeezed vacuum states, which requires three parties, i.e., the signer Alice, the verifier Bob and the arbitrator Charlie trust... We propose an arbitrated quantum signature (AQS) scheme with continuous variable (CV) squeezed vacuum states, which requires three parties, i.e., the signer Alice, the verifier Bob and the arbitrator Charlie trusted by Alice and Bob, and three phases consisting of the initial phase, the signature phase and the verification phase. We evaluate and compare the original state and the teleported state by using the fidelity and the beam splitter (BS) strategy. The security is ensured by the CV-based quantum key distribution (CV-QKD) and quantum teleportation of squeezed states. Security analyses show that the generated signature can be neither disavowed by the signer and the receiver nor counterfeited by anyone with the shared keys. Furthermore, the scheme can also detect other manners of potential attack although they may be successful. Also, the integrality and authenticity of the transmitted messages can be guaranteed. Compared to the signature scheme of CV-based coherent states, our scheme has better encoding efficiency and performance. It is a potential high-speed quantum signature scheme with high repetition rate and detection efficiency which can be achieved by using the standard off-the-shelf components when compared to the discrete-variable (DV) quantum signature scheme. 展开更多
关键词 arbitrated quantum signature squeezed vacuum state continuous variable quantum teleportation
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Quantum computation and error correction based on continuous variable cluster states 被引量:3
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作者 郝树宏 邓晓玮 +3 位作者 刘阳 苏晓龙 谢常德 彭堃墀 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第6期18-27,共10页
Measurement-based quantum computation with continuous variables,which realizes computation by performing measurement and feedforward of measurement results on a large scale Gaussian cluster state,provides a feasible w... Measurement-based quantum computation with continuous variables,which realizes computation by performing measurement and feedforward of measurement results on a large scale Gaussian cluster state,provides a feasible way to implement quantum computation.Quantum error correction is an essential procedure to protect quantum information in quantum computation and quantum communication.In this review,we briefly introduce the progress of measurement-based quantum computation and quantum error correction with continuous variables based on Gaussian cluster states.We also discuss the challenges in the fault-tolerant measurement-based quantum computation with continuous variables. 展开更多
关键词 quantum computation quantum error correction continuous variables cluster state
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Modeling of microstructure evolution of AZ80 magnesium alloy during hot working process using a unified internal state variable method 被引量:4
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作者 Zexing Su Chaoyang Sun +2 位作者 Mingjia Wang Lingyun Qian Xintong Li 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第1期299-313,共15页
In this paper, a unified internal state variable(ISV) model for predicting microstructure evolution during hot working process of AZ80 magnesium alloy was developed. A novel aspect of the proposed model is that the in... In this paper, a unified internal state variable(ISV) model for predicting microstructure evolution during hot working process of AZ80 magnesium alloy was developed. A novel aspect of the proposed model is that the interactive effects of material hardening, recovery and dynamic recrystallization(DRX) on the characteristic deformation behavior were considered by incorporating the evolution laws of viscoplastic flow, dislocation activities, DRX nucleation and boundary migration in a coupled manner. The model parameters were calibrated based on the experimental data analysis and genetic algorithm(GA) based objective optimization. The predicted flow stress, DRX fraction and average grain size match well with experimental results. The proposed model was embedded in the finite element(FE) software DEFORM-3 D via user defined subroutine to simulate the hot compression and equal channel angular extrusion(ECAE) processes. The heterogeneous microstructure distributions at different deformation zones and the dislocation density evolution with competitive deformation mechanisms were captured.This study can provide a theoretical solution for the hot working problems of magnesium alloy. 展开更多
关键词 AZ80 magnesium alloy Internal state variable model Microstructure evolution Dynamic recrystallization Hot working process Finite element simulation
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Analytical criteria for local activity of CNN with five state variables and application to Hyper-chaos synchronization Chua's circuit 被引量:1
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作者 Lequan Min and Xisong DongApplied Science School, University of Science and Technology Beijing, Beijing 100083, China 《Journal of University of Science and Technology Beijing》 CSCD 2002年第4期311-318,共8页
The analytic criteria for the local activity theory in one-port cellularneural network (CNN) with five local state variables are presented. The application to a Hyper-chaossynchronization Chua's circuit (HCSCC) CN... The analytic criteria for the local activity theory in one-port cellularneural network (CNN) with five local state variables are presented. The application to a Hyper-chaossynchronization Chua's circuit (HCSCC) CNN with 1125 variables is studied. The bifurcation diagramsof the HCSCC CNN show that they are slightly different from the smoothed CNN with one or two portsand four state variables calculated earlier. The evolution of the patterns of the state variables ofthe HCSCC CNN is stimulated. Oscillatory patterns, chaotic patterns, convergent or divergentpatterns may emerge if the selected cell parameters are located in the locally active domains butnearby or in the edge of chaos domain. 展开更多
关键词 cellular neural network local activity Hyper-Chaos Synchronization Chua's circuit five state variables CHAOS
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On the Definition of State Variables for an Internal State Variable Constitutive Model Describing Metal Deformation 被引量:1
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作者 Paul S. Follansbee 《Materials Sciences and Applications》 2014年第8期603-609,共7页
The quest for an internal state variable constitutive model describing metal deformation is reviewed. First, analogy is drawn between a deformation model and the Ideal Gas Law. The use of strain as a variable in defor... The quest for an internal state variable constitutive model describing metal deformation is reviewed. First, analogy is drawn between a deformation model and the Ideal Gas Law. The use of strain as a variable in deformation models is discussed, and whether strain serves as an internal state variable is considered. A simple experiment that demonstrated path dependence in copper is described. The importance of defining appropriate internal state variables for a constitutive law relates to the ability to accurately model temperature and strain-rate dependencies in deformation simulations. 展开更多
关键词 Consitutive Modeling INTERNAL state variable Metal DEFORMATION IDEAL Gas LAW PATH DEPENDENCE
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Variable dimensional state space based global path planning for mobile robot 被引量:1
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作者 张浩杰 陈慧岩 +6 位作者 姜岩 龚建伟 熊光明 陈慧岩 姜岩 龚建伟 熊光明 《Journal of Beijing Institute of Technology》 EI CAS 2012年第3期328-335,共8页
A variable dimensional state space(VDSS) has been proposed to improve the re-planning time when the robotic systems operate in large unknown environments.VDSS is constructed by uniforming lattice state space and gri... A variable dimensional state space(VDSS) has been proposed to improve the re-planning time when the robotic systems operate in large unknown environments.VDSS is constructed by uniforming lattice state space and grid state space.In VDSS,the lattice state space is only used to construct search space in the local area which is a small circle area near the robot,and grid state space elsewhere.We have tested VDSS with up to 80 indoor and outdoor maps in simulation and on segbot robot platform.Through the simulation and segbot robot experiments,it shows that exploring on VDSS is significantly faster than exploring on lattice state space by Anytime Dynamic A*(AD*) planner and VDSS is feasible to be used on robotic systems. 展开更多
关键词 variable dimensional state space lattice state space Anytime Dynamic A*(AD*) path planning
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New Bosonic Operator Ordering Identities Gained by the Entangled State Representation and Two-Variable Hermite Polynomials 被引量:3
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作者 FANHong-Yi FANYue 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第3期297-300,共4页
Based on the technique of integration within an ordered product of operators, we derive new bosonicoperators' ordering identities by using entangled state representation and the properties of two-variable Hermite ... Based on the technique of integration within an ordered product of operators, we derive new bosonicoperators' ordering identities by using entangled state representation and the properties of two-variable Hermite poly-nomials H and vice versa. In doing so, some concise normally (antinormally) ordering operator identities, such asa+man =:Hm,n(a+,a):, ana+m = (-i)m+n:Hm,n(ia+,ia): are obtained. 展开更多
关键词 量子光学 算符有序等式 HERMITE多项式
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Implementing Classical Hadamard Transform Algorithm by Continuous Variable Cluster State 被引量:1
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作者 王宇 苏琦 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期19-23,共5页
Measurement-based one-way quantum computation, which uses cluster states as resources, provides an efficient model to perforrn computation. However, few of the continuous variable (CV) quantum algorithms and classic... Measurement-based one-way quantum computation, which uses cluster states as resources, provides an efficient model to perforrn computation. However, few of the continuous variable (CV) quantum algorithms and classical algorithms based on one-way quantum computation were proposed. In this work, we propose a method to implement the classical Hadamard transform algorithm utilizing the CV cluster state. Compared with classical computation, only half operations are required when it is operated in the one-way CV quantum computer. As an example, we present a concrete scheme of four-mode classical Hadamard transform algorithm with a four-partite CV cluster state. This method connects the quantum computer and the classical algorithms, which shows the feasibility of running classical algorithms in a quantum computer efficiently. 展开更多
关键词 Implementing Classical Hadamard Transform Algorithm by Continuous variable Cluster state
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Teleportation of a Kind of Three-Mode Entangled States of Continuous Variables 被引量:1
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作者 FAN Hong-Yi LIANG Xian-Ting 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5X期833-836,共4页
A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement ... A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement is feasible because the bipartite entangled states are complete and the squeezed state has a natural representation in the entangled state basis. The calculation is greatly simplified by using the Schmidt decomposition of the entangled states. 展开更多
关键词 量子纠缠 量子隧道 挤压状态 双向纠缠 Schmidt分解
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Development of process energy intensity formula under different state variables 被引量:3
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作者 陈光 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第6期694-696,共3页
In a production process, the actual energy consumption is greatly affected by the production state. Certain processing operations are classified into six states, including normal production, abnormal production, plann... In a production process, the actual energy consumption is greatly affected by the production state. Certain processing operations are classified into six states, including normal production, abnormal production, planned overhaul, unplanned overhaul, transitional period from unplanned overhaul to normal production (referred for short as unplanned transition) and transitional period from planned overhaul to normal production (referred for short as planned transition). The article takes the analysis of relationship between different states of a certain processing operation and corresponding energy consumptions as a startup point to develop a process energy intensity formula with variables of operating rate, yielding rate and operating frequency, etc. This process energy intensity formula can be used to analyze effectively the pattern of impact exerted by different state variables on energy consumption. 展开更多
关键词 冶金工业 治金机械 加工能量强度 生产状态 产品变量 开工率 收益率
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A numerical study of comparison of two one-state-variable,rate-and state-dependent friction evolution laws 被引量:2
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作者 Jeen-Hwa Wang 《Earthquake Science》 CSCD 2009年第2期197-204,共8页
The two one-state-variable, rate- and state-dependent friction laws, i.e., the slip and slowness laws, are com- pared on the basis of dynamical behavior of a one-degree-of-freedom spring-slider model through numerical... The two one-state-variable, rate- and state-dependent friction laws, i.e., the slip and slowness laws, are com- pared on the basis of dynamical behavior of a one-degree-of-freedom spring-slider model through numerical simulations. Results show that two (normalized) model parameters, i.e., A (the normalized characteristic slip distance) and β-α (the difference in two normalized parameters of friction laws), control the solutions. From given values of △, β, and α, for the slowness laws, the solution exists and the unique non-zero fixed point is stable when △〉(β-α), yet not when △ 〈(β-α). For the slip law, the solution exists for large ranges of model parameters and the number and stability of the non-zero fixed points change from one case to another. Results suggest that the slip law is more appropriate for controlling earthquake dynamics than the slowness law. 展开更多
关键词 one-state-variable rate- and state-dependent friction law direct effect evolution effect characteristic slip displacement
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Application of Bipartite and Tripartite Entangled State Representations in Quantum Teleportation of Continuous Variables 被引量:1
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作者 YUAN Hong-Chun QI Kai-Guo 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2X期269-273,共5页
We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formali... We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formalism,teleporting multi-mode coherent state or squeezed state is also possible. Another is that the tripartite entangled state is used as the quantum channel of controlled teleportation of an arbitrary and unknown continuous variable in the case of three participators. 展开更多
关键词 电磁学 电子纠缠 量子论 不变量
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DYNAMIC RESPONSE OF ELASTIC RECTANGULAR PLATES BY SPLINE STATE VARIABLE METHOD
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作者 陈荣毅 沈小璞 沈鹏程 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第6期691-698,共8页
Application of spline element and state space method for analysis of dynamic response of elastic rectangular plates is presented. The spline element method is used for space domain and the state space method in contro... Application of spline element and state space method for analysis of dynamic response of elastic rectangular plates is presented. The spline element method is used for space domain and the state space method in control theory of system is used for time domain. A state variable recursive scheme is developed, then the dynamic response of structure can he calculated directly. Several numerical examples are given. The results which are presented to demonstrate the accuracy and efficiency of the present method are quite satisfactory. 展开更多
关键词 spline element state space method dynamic response recursive scheme spline state variable method
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Calculation of Entanglement Entropy for Continuous-Variable Entangled State Based on General Two-Mode Boson Exponential Quadratic Operator in Fock Space 被引量:1
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作者 DAI Fang-Wen MA Lei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第3期590-594,共5页
<Abstract>We obtain an explicit formula to calculate the entanglement entropy of bipartite entangled state of general two-mode boson exponential quadratic operator with continuous variables in Fock space.The sim... <Abstract>We obtain an explicit formula to calculate the entanglement entropy of bipartite entangled state of general two-mode boson exponential quadratic operator with continuous variables in Fock space.The simplicity and generality of our formula are shown by some examples. 展开更多
关键词 计算方法 连续变量 玻色子 指数
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Entanglement swapping of continuous variable using squeezed vacuum states
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作者 闫伟 张为俊 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第10期2885-2888,共4页
We present a realistic scheme for the entanglement swapping of continuous variable, in which a two-mode squeezed vacuum state serves as a quantum channel. The position sum and momentum difference of two local modes ar... We present a realistic scheme for the entanglement swapping of continuous variable, in which a two-mode squeezed vacuum state serves as a quantum channel. The position sum and momentum difference of two local modes are measured. By taking the input entangled state also as a two-mode squeezed vacuum state, we investigate the average fidelity and the yon Neumann entropy of the output state. The results show that the perfect teleportation can be achieved by increasing the squeezing of the quantum channel and that any nonzero squeezing in both the quantum channel and the input entangled state is sufficient to swap the entanglement. 展开更多
关键词 entanglement swapping continuous variable squeezed vacuum states
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SELECTION OF STATE VARIABLES AND CONSTRUCTION OF STATE EQUATIONS
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作者 胡允祥 《Journal of China Textile University(English Edition)》 EI CAS 1991年第3期65-76,共12页
In modern control engineering and simulations,it is perferable to get the governing equationsby an easier way,so that state equations have been widely used.There are many rules to select statevariables,but the uses of... In modern control engineering and simulations,it is perferable to get the governing equationsby an easier way,so that state equations have been widely used.There are many rules to select statevariables,but the uses of these rules may have different forms of limitations and exceptions,yet afully argumented bond graph can be processed in proper way to select the state variables and toyield the state equations.The state variables are usually related to the energy-storing elements.State equations can easily be derived from bond graph by means of constitutive relations and struc-tural relations. 展开更多
关键词 dynamics state variableS system dynamics bond GRAPH
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Chaos Synchronization of Uncertain Lorenz System via Single State Variable Feedback
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作者 Fengxiang Chen Tong Zhang 《Applied Mathematics》 2013年第11期7-12,共6页
This paper treats the problem of chaos synchronization for uncertain Lorenz system via single state variable information of the master system. By the Lyapunov stability theory and adaptive technique, the derived contr... This paper treats the problem of chaos synchronization for uncertain Lorenz system via single state variable information of the master system. By the Lyapunov stability theory and adaptive technique, the derived controller is featured as follows: 1) only single state variable information of the master system is needed;2) chaos synchronization can also be achieved even if the perturbation is occurred in some parameters of the master chaotic system. Finally, the effectiveness of the proposed controllers is also illustrated by the simulations as well as rigorous mathematical proofs. 展开更多
关键词 UNCERTAIN LORENZ System SINGLE state variable CHAOS SYNCHRONIZATION
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