期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
椎-基底动脉供血不足伴痴呆的随访观察
1
作者 苟婴如 袁强 彭蓉 《华西医学》 CAS 2001年第1期45-46,共2页
目的 :了解椎 -基底动脉供血不足 (VBI)患者与痴呆发生的相关性。方法 :采用神经功能评分与神经心理学检查确诊为VBI发作同时伴有痴呆的患者的治疗前、治疗中、治疗后分别进行各项评分。结论 :随VBI症状改善 ,神经心理学损害亦有改善。... 目的 :了解椎 -基底动脉供血不足 (VBI)患者与痴呆发生的相关性。方法 :采用神经功能评分与神经心理学检查确诊为VBI发作同时伴有痴呆的患者的治疗前、治疗中、治疗后分别进行各项评分。结论 :随VBI症状改善 ,神经心理学损害亦有改善。提示VBI可导致某些智能损害和神经功能缺损与记忆障碍存在直接关系。 展开更多
关键词 椎-基底动脉供血不足 痴呆 连线时间 手指敲击速度 简易智能量表
下载PDF
Genetic programming-based chaotic time series modeling 被引量:1
2
作者 张伟 吴智铭 杨根科 《Journal of Zhejiang University Science》 EI CSCD 2004年第11期1432-1439,共8页
This paper proposes a Genetic Programming-Based Modeling (GPM) algorithm on chaotic time series. GP is used here to search for appropriate model structures in function space, and the Particle Swarm Optimization (PSO) ... This paper proposes a Genetic Programming-Based Modeling (GPM) algorithm on chaotic time series. GP is used here to search for appropriate model structures in function space, and the Particle Swarm Optimization (PSO) algorithm is used for Nonlinear Parameter Estimation (NPE) of dynamic model structures. In addition, GPM integrates the results of Nonlinear Time Series Analysis (NTSA) to adjust the parameters and takes them as the criteria of established models. Experiments showed the effectiveness of such improvements on chaotic time series modeling. 展开更多
关键词 Chaotic time series analysis Genetic programming modeling Nonlinear Parameter Estimation (NPE) Particle Swarm Optimization (PSO) Nonlinear system identification
下载PDF
Approximating the Spectral Abscissa for Switched Linear Systems via Coordinate Transformations 被引量:2
3
作者 LIN Meili SUN Zhendong 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2016年第2期350-366,共17页
In this paper,an approach of square coordinate transformation is proposed to approximate the spectral abscissa for continuous-time switched linear systems.By applying elementary transformations iteratively,a series of... In this paper,an approach of square coordinate transformation is proposed to approximate the spectral abscissa for continuous-time switched linear systems.By applying elementary transformations iteratively,a series of minimums of least μ1 matrix set measures are obtained,which are utilized to approximate the spectral abscissa of the switched system.The approach is developed into tractable numerical algorithms that provide upper bound estimates of the spectral abscissa.Numerical simulations show the effectiveness of the proposed method. 展开更多
关键词 Coordinate transformations matrix set measure spectral abscissa switched linear systems.
原文传递
Simplifying the Nonlinear Continuous Time-Cost Tradeoff Problem
4
作者 SU Zhixiong QI Jianxun WEI Hanying 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2017年第4期901-920,共20页
Equivalent simplification is an effective method for solving large-scale complex problems. In this paper, the authors simplify a classic project scheduling problem, which is the nonlinear continuous time-cost tradeoff... Equivalent simplification is an effective method for solving large-scale complex problems. In this paper, the authors simplify a classic project scheduling problem, which is the nonlinear continuous time-cost tradeoff problem(TCTP). Simplifying TCTP is a simple path problem in a critical path method(CPM) network. The authors transform TCTP into a simple activity float problem and design a complex polynomial algorithm for its solution. First, the authors discover relationships between activity floats and path lengths by studying activity floats from the perspective of path instead of time.Second, the authors perform simplification and improve the efficiency and accuracy of the solution by deleting redundant activities and narrowing the duration intervals of non-redundant activities. Finally,the authors compare our method with current methods. The relationships between activity floats and path lengths provide new approaches for other path and correlative project problems. 展开更多
关键词 Activity floats CPM networks operational research SIMPLIFICATION time-cost tradeoff.
原文传递
On the Stability Analysis of Switched Nonlinear Systems with Time Varying Delay Under Arbitrary Switching 被引量:2
5
作者 KERMANI Marwen SAKLY Anis 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2017年第2期329-346,共18页
This paper addresses the stability problem for a class of switched nonlinear time varying delay systems modeled by delay differential equations. By transforming the system representation under the arrow form and using... This paper addresses the stability problem for a class of switched nonlinear time varying delay systems modeled by delay differential equations. By transforming the system representation under the arrow form and using a new constructed Lyapunov function,the aggregation techniques,the Borne-Gentina practical stability criterion associated with the properties, new delay-independent stability conditions of the considered systems are established. Compared with the existing results in this area, the obtained result is explicit, simple to use and allows us to avoid the problem of searching a common Lyapunov function. Finally, an example is provided, with numerical simulations,to demonstrate the effectiveness of the proposed method. 展开更多
关键词 Arbitrary switching arrow form statepunov function continuous-time switched nonlinearstability.matrix Borne-Gentina criterion common Lya-time varying delay systems global asymptotic
原文传递
CONSENSUS AND r-CONSENSUS PROBLEMS FOR SINGULAR SYSTEMS
6
作者 ZHANG Lequn FENG Jun-e YAO Juan 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2014年第2期252-262,共11页
In this paper, the problem of consensus for continuous time singular systems of multi-agent networks is considered. The definition of r-consensus is introduced for singular systems of multi-agent networks. Firstly, li... In this paper, the problem of consensus for continuous time singular systems of multi-agent networks is considered. The definition of r-consensus is introduced for singular systems of multi-agent networks. Firstly, linear systems with algebraic constraints are considered, and the corresponding results about consensus and average-consensus are derived. Then r-consensus and consensus problems of singular systems are investigated. Sufficient conditions of r-consensus and consensus are obtained,respectively. Finally, an illustrative example is given to show the effectiveness of the proposed method. 展开更多
关键词 Balanced graphs CONSENSUS r-consensus singular systems strong connected graphs.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部