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全局动力学模型用于水声信号分类仿真实验研究
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作者 薛文虎 张明敏 《系统仿真学报》 CAS CSCD 2002年第5期650-652,共3页
水下弱信号的检测和分类是水声信号处理领域中的难题。本文研究了一种使用混沌动力学系统理论中全局动力学模型进行水声信号检测和分类的方法,用仿真数据对所建模型的有效性进行了验证。通过将模型拟合到几种舰船辐射噪声,成功地对其进... 水下弱信号的检测和分类是水声信号处理领域中的难题。本文研究了一种使用混沌动力学系统理论中全局动力学模型进行水声信号检测和分类的方法,用仿真数据对所建模型的有效性进行了验证。通过将模型拟合到几种舰船辐射噪声,成功地对其进行了分类。仿真结果表明,该方法在高噪声背景下(信噪比为0dB时)仍能对信号进行分类,且分类概率可以从模型系数空间的系综统计特性中直接计算得到。 展开更多
关键词 全局动力学模型 水声 信号分类 仿真 实验
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单翼大挠性航天器全局模态动力学建模及试验 被引量:14
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作者 袁秋帆 王超磊 +1 位作者 齐乃明 曹世磊 《宇航学报》 EI CAS CSCD 北大核心 2019年第4期369-377,共9页
针对小中心刚体-单侧大挠性结构构型的航天器,通过定义广义全局模态振型,提出一种全局模态动力学模型。采用统一形式描述整体刚体运动和整体挠性变形,基于哈密顿原理推导了全局模态动力学方程,结合瑞利瑞兹法推导了非约束模态频率和模... 针对小中心刚体-单侧大挠性结构构型的航天器,通过定义广义全局模态振型,提出一种全局模态动力学模型。采用统一形式描述整体刚体运动和整体挠性变形,基于哈密顿原理推导了全局模态动力学方程,结合瑞利瑞兹法推导了非约束模态频率和模态振型的计算方法。通过仿真和试验校验了全局模态动力学模型的准确性。与有限元模型对比,分析了非约束模态频率随着刚柔质量比和惯量比的变化情况,第一阶模态频率的最大误差为0.003 Hz,说明全局模态动力学模型能够比较准确地描述非约束模态频率;理论模型能够比较准确地描述动态响应,端部横向位移的最大误差为2.6%;基于气浮平台构建了试验系统,理论模型、有限元仿真和物理试验结果均比较接近,说明理论模型准确描述了非约束模态频率随刚柔耦合特性变化的规律。 展开更多
关键词 全局模态动力学模型 全局模态振型 非约束模态频率 瑞利瑞兹法
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基于键图的复杂机电系统模块化自动建模及仿真 被引量:1
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作者 王艾伦 仇勇 吴吉平 《株洲工学院学报》 2002年第6期58-61,共4页
将键合图与模块化理论相结合,建立了一个开放式的机电系统模块库,并在此基础上建立了一个典型复杂机电系统——高速轧机的全局耦合动力学模型;模块的物理模型和数学模型统一,因而可方便地自动生成系统的数学模型;模块可拆卸,拼装以适用... 将键合图与模块化理论相结合,建立了一个开放式的机电系统模块库,并在此基础上建立了一个典型复杂机电系统——高速轧机的全局耦合动力学模型;模块的物理模型和数学模型统一,因而可方便地自动生成系统的数学模型;模块可拆卸,拼装以适用于不同类型的轧机。此方法也可用于其他复杂机电系统的动力学建模和分析。 展开更多
关键词 复杂机电系统 仿真 键合图 模块化 自动生成 耦合建模 高速轧机 全局耦合动力学模型
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Hybrid Differential Evolution for Estimation of Kinetic Parameters for Biochemical Systems 被引量:1
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作者 ZHAO Chao XU Qiaoling LIN Siming LI Xuelai 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第2期155-162,共8页
Determination of the optimal model parameters for biochemical systems is a time consuming iterative process. In this study, a novel hybrid differential evolution (DE) algorithm based on the differential evolution te... Determination of the optimal model parameters for biochemical systems is a time consuming iterative process. In this study, a novel hybrid differential evolution (DE) algorithm based on the differential evolution technique and a local search strategy is developed for solving kinetic parameter estimation problems. By combining the merits of DE with Gauss-Newton method, the proposed hybrid approach employs a DE algorithm for identifying promising regions of the solution space followed by use of Gauss-Newton method to determine the optimum in the identified regions. Some well-known benchmark estimation problems are utilized to test the efficiency and the robustness of the proposed algorithm compared to other methods in literature. The comparison indicates that the present hybrid algorithm outperforms other estimation techniques in terms of the global searching ability and the con- vergence speed. Additionally, the estimation of kinetic model parameters for a feed batch fermentor is carried out to test the applicability of the proposed algorithm. The result suggests that the method can be used to estimate suitable values of model oarameters for a comolex mathematical model. 展开更多
关键词 parameter estimation kinetic model hybrid differential evolution Gauss-Newton feed batch fermentor
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路面不平度对遥控武器站伺服性能的影响分析
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作者 谢馨 张连超 +2 位作者 郑杰基 李宝宇 范大鹏 《中国科学:技术科学》 EI CSCD 北大核心 2024年第6期1137-1148,共12页
随着车载遥控武器站遂行作战任务的不断增加,对遥控武器站行进间射击精度提出了越来越高的要求,而车辆在行进过程中由不平整路面引入的基座扰动,会给武器火线稳定精度带来极大的影响.针对路面不平度扰动对遥控武器站稳定性能影响机理不... 随着车载遥控武器站遂行作战任务的不断增加,对遥控武器站行进间射击精度提出了越来越高的要求,而车辆在行进过程中由不平整路面引入的基座扰动,会给武器火线稳定精度带来极大的影响.针对路面不平度扰动对遥控武器站稳定性能影响机理不明的问题,本文在分析遥控武器站系统组成、工作原理及关键技术指标基础上,建立了包含驱动、传动、控制以及路面不平度随机扰动的遥控武器站系统机电耦合全局动力学模型,分析不同路面等级、不同车速下路面不平度扰动对系统稳定精度的影响,搭建路面不平度随机扰动模拟测试平台,验证理论分析和数值仿真的有效性.仿真和实验结果表明,当车速为18 km/h时,在稳定平台作用下,稳定误差几乎不随路面等级的变化而变化.当车速为36和72 km/h时,随着路面等级提高至E级以上时,系统稳定误差呈近似指数增长,且速度越高,稳定精度恶化得越严重. 展开更多
关键词 遥控武器站 路面不平度 机电耦合全局动力学模型 稳定精度
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THE ASYMPTOTIC BEHAVIOR OF GLOBAL SMOOTH SOLUTIONS TO THE MACROSCOPIC MODELS FOR SEMICONDUCTORS 被引量:4
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作者 HSIAOLING: WANGSHU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2001年第2期195-210,共16页
The authors study the asymptotic behavior of the smooth solutions to the Cauchy problems for two macroscopic models (hydrodynamic and drift-diffusion models) for semiconductors and the related relaxation limit problem... The authors study the asymptotic behavior of the smooth solutions to the Cauchy problems for two macroscopic models (hydrodynamic and drift-diffusion models) for semiconductors and the related relaxation limit problem. First, it is proved that the solutions to these two systems converge to the unique stationary solution time asymptotically without the smallness assump- tion on doping profile. Then, very sharp estimates on the smooth solutions, independent of the relaxation time, are obtained and used to establish the zero relaxation limit. 展开更多
关键词 Hydrodynamic model SEMICONDUCTORS Asymptotic behavior Global smooth solution Zero relaxation limit
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GLOBAL DYNAMICS OF A DELAYED HIV-1 INFECTION MODEL WITH ABSORPTION AND SATURATION INFECTION 被引量:2
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作者 RUI XU 《International Journal of Biomathematics》 2012年第3期191-203,共13页
In this paper, an HIV-1 infection model with absorption, saturation infection and an intracellular delay accounting for the time between viral entry into a target cell and the production of new virus particles is inve... In this paper, an HIV-1 infection model with absorption, saturation infection and an intracellular delay accounting for the time between viral entry into a target cell and the production of new virus particles is investigated. By analyzing the characteristic equations, the local stability of an infection-free equilibrium and a chronic-infection equilibrium of the model is established. By using suitable Lyapunov functionals and LaSalle's invariance principle, it is proved that if the basic reproduction ratio is less than unity, the infection-free equilibrium is globally asymptotically stable; and if the basic reproduction ratio is greater than unity, sufficient condition is derived for the global stability of the chronic-infection equilibrium. 展开更多
关键词 HIV-1 infection ABSORPTION intracellular delay global stability LaSalle's invariance principle.
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Global dynamics of a nonlocal population model with age structure in a bounded domain:A non-monotone case
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作者 YUAN YueDing GUO ZhiMing 《Science China Mathematics》 SCIE CSCD 2015年第10期2145-2166,共22页
We study the global dynamics of a nonlocal population model with age structure in a bounded domain. We mainly concern with the case where the birth rate decreases as the mature population size become large. The analys... We study the global dynamics of a nonlocal population model with age structure in a bounded domain. We mainly concern with the case where the birth rate decreases as the mature population size become large. The analysis is rather subtle and it is inadequate to apply the powerful theory of monotone dynamical systems. By using the method of super-sub solutions, combined with the careful analysis of the kernel function in the nonlocal term, we prove nonexistence, existence and uniqueness of positive steady states of the model.Moreover, due to the mature individuals do not diffuse, the solution semiflow to the model is not compact. To overcome the difficulty of non-compactness in describing the global asymptotic stability of the unique positive steady state, we first establish an appropriate comparison principle. With the help of the comparison principle,we can employ the theory of dissipative systems to obtain the global asymptotic stability of the unique positive steady state. The main results are illustrated with the nonlocal Nicholson's blowflies equation and the nonlocal Mackey-Glass equation. 展开更多
关键词 nonlocal and delay model existence and uniqueness of positive steady states global asymptotic stability bounded domain
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Global dynamics for a live-virus-blood model with distributed time delay 被引量:1
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作者 Ding-Yu Zou Shi-Fei Wang Xue-Zhi Li 《International Journal of Biomathematics》 2017年第5期143-158,共16页
In this paper, the global properties of a mathematical modeling of hepatitis C virus (HCV) with distributed time delays is studied. Lyapunov functionals are constructed to establish the global asymptotic stability o... In this paper, the global properties of a mathematical modeling of hepatitis C virus (HCV) with distributed time delays is studied. Lyapunov functionals are constructed to establish the global asymptotic stability of the uninfected and infected steady states. It is shown that if the basic reproduction number R0 is less than unity, then the uninfected steady state is globally asymptotically stable. If the basic reproduction number R0 is larger than unity, then the infected steady state is globally asymptotically stable. 展开更多
关键词 Hepatitis C virus distributed time delays live-virus-blood system global asymptotic stability Lyapunov functional.
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A MULTI-GROUP SVEIR EPIDEMIC MODEL WITH DISTRIBUTED DELAY AND VACCINATION 被引量:2
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作者 JINLIANG WANG YASUHIRO TAKEUCHI SHENGQIANG LIU 《International Journal of Biomathematics》 2012年第3期1-18,共18页
In this paper, based on a class of multi-group epidemic models of SEIR type with bilinear incidences, we introduce a vaccination compartment, leading to multi-group SVEIR model. We establish that the global dynamics a... In this paper, based on a class of multi-group epidemic models of SEIR type with bilinear incidences, we introduce a vaccination compartment, leading to multi-group SVEIR model. We establish that the global dynamics are completely determined by the basic reproduction number R0V which is defined by the spectral radius of the next generation matrix. Our proofs of global stability of the equilibria utilize a graph-theoretical approach to the method of Lyapunov functionals. Mathematical results suggest that vaccination is helpful for disease control by decreasing the basic reproduction number. However, there is a necessary condition for successful elimination of disease. If the time for the vaccines to obtain immunity or the possibility for them to be infected before acquiring immunity is neglected in each group, this condition will be satisfied and the disease can always be eradicated by suitable vaccination strategies. This may lead to over evaluation for the effect of vaccination. 展开更多
关键词 Multi-group SVEIR model vaccination strategy global stability Lyapunovfunctionals graph theory.
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GLOBAL DYNAMICS OF A CHOLERA MODEL WITH TIME DELAY 被引量:1
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作者 YUJIE WANG JUNJIE WEI 《International Journal of Biomathematics》 2013年第1期143-160,共18页
The global dynamics of a cholera model with delay is considered. We determine a basic reproduction number R0 which is chosen based on the relative ODE model, and establish that the global dynamics are determined by th... The global dynamics of a cholera model with delay is considered. We determine a basic reproduction number R0 which is chosen based on the relative ODE model, and establish that the global dynamics are determined by the threshold value R0. If R0 〈 1, then the infection-free equilibrium is global asymptotically stable, that is, the cholera dies out; If R0 〉 1, then the unique endemic equilibrium is global asymptotically stable, which means that the infection persists. The results obtained show that the delay does not lead to periodic oscillations. Finally, some numerical simulations support our theoretical results. 展开更多
关键词 Cholera model DELAY Lyapunov functional global stability.
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Global dynamics and optimal control of an influenza model with vaccination, media coverage and treatment
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作者 Lianwen Wang Zhijun Liu +1 位作者 Dashun Xu Xinan Zhang 《International Journal of Biomathematics》 2017年第5期159-183,共25页
In this work, in order to identify the most effective measure and combinations of several measures to control influenza spread, we propose an SVEIAR influenza model with imperfect vaccination, media coverage and antiv... In this work, in order to identify the most effective measure and combinations of several measures to control influenza spread, we propose an SVEIAR influenza model with imperfect vaccination, media coverage and antiviral treatment. The global dynamics of the model is explored. Sensitivity analysis of the basic reproduction number and the endemic equilibrium is conducted to evaluate the effectiveness of influenza control measures. Purthermore, an optimal control problem incorporating the three measures is formulated to design optimal control strategies for influenza. The cost-effectiveness analysis reveals that combining the three measures is the most cost-effective among the strategies considered. Numerical simulations show that media propaganda can play a dominant role in curbing influenza transmission. 展开更多
关键词 SVEIAR influenza model optimal control media coverage VACCINATION antiviral treatment.
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Dynamics of SVEIS epidemic model with distinct incidence
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作者 N. Nyamoradi M. Javidi B. Ahmad 《International Journal of Biomathematics》 2015年第6期99-117,共19页
In this paper, we study the global dynamics of a SVEIS epidemic model with distinct incidence for exposed and infectives. The model is analyzed for stability and bifurcation behavior. To account for the realistic phen... In this paper, we study the global dynamics of a SVEIS epidemic model with distinct incidence for exposed and infectives. The model is analyzed for stability and bifurcation behavior. To account for the realistic phenomenon of non-homogeneous mixing, the effect of diffusion on different population subclasses is considered. The diffusive model is analyzed using matrix stability theory and conditions for Turing bifurcation are derived. Numerical simulations support our analytical results on the dynamic behavior of tile model. 展开更多
关键词 SVEIS epidemic model DIFFUSION Turing bifurcation stability basic repro-duction number numerical simulation.
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