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991.
广义Hénon映射的滑模变结构控制同步   总被引:5,自引:1,他引:4       下载免费PDF全文
尹逊和  任勇  山秀明 《物理学报》2002,51(9):1949-1953
基于可线性化的非线性离散变结构跟踪控制方法实现了广义Hénon映射混沌系统的同步.广义Hénon映射的混沌吸引子比Hénon映射的混沌吸引子要复杂得多,对于保密通信来说,这种复杂性正是所期望的.提出的同步方法允许参数有适当的失配程度,这对工程实现是非常有利的,理论分析和仿真结果证实了该方法的有效性 关键词: 广义Hénon映射 混沌 同步 变结构控制  相似文献   
992.
New derivation results for integrands and multifunctions via the Lipschitzean approximations are obtained. Applications to multivalued differential equations on closed convex sets are presented.  相似文献   
993.
 For the analysis of infrared spectroscopic bands and complex patterns partial cross correlation functions of a sample spectrum with reference spectra are calculated. The chosen ranges of the spectra are based on empirical knowledge of infrared spectrum structure correlations. The normalised maxima of the partial cross correlation functions are interpreted as fuzzy truth values and are combined by fuzzy logical operators. By application of that procedure larger common substructures will be derived from the reference spectra than by a maximum common substructure search based on the complete spectra. Received: 30 October 1996/Revised: 24 February 1997/Accepted: 26 February 1997  相似文献   
994.
An analysis of resonances of scattering from multi-element grating formed by a finite number of resonant elements is presented. It has been shown that gratings with three and more elements on its period can support the π-mode. The π-mode of a grating is characterized by the existence of the regions in the vicinity of the grating and along its period where the electromagnetic field has opposite phases. The existence and excitation of the π-mode in finite gratings with resonant cells formed by several scatterers having open cavities have been studied. The particular case of the grating with cells formed by three identical slotted cylinders has been considered in detail. An application of gratings which support the π-mode in electron-vacuum oscillators of millimeter waves for efficient deceleration of electrons and extracting energy from electron beam is discussed.  相似文献   
995.
§ 0 IntroductionA∞ - algebras were first introduced and applied by Stasheff in [12 ,13].Recently,theyappeared in both mathematics and mathematical physics[1 ,5— 8,1 0 ] .An A∞ - algebra is a Z-graded vector space over a fixed field k with a sequence of graded maps mn∶ A n→ A ofdegree n- 2 (n≥ 1) satisfying certain axioms (see [5 ,6 ,12 ,13]) .In this paper,we focusour attentions on,as we call,the minimal A∞ - algebras,which are usual A∞ - algebrasdefined in [5 ,6 ,12 ,13]with m1 =…  相似文献   
996.
§1 IntroductionWe considerthe following inverse eigenvalue problem offinding an n-by-n matrix A∈S such thatAxi =λixi,i =1,2 ,...,m,where S is a given set of n-by-n matrices,x1 ,...,xm(m≤n) are given n-vectors andλ1 ,...,λmare given constants.Let X=(x1 ,...,xm) ,Λ=(λ1 ,λ2 ,...,λm) ,then the above inverse eigenvalue problemcan be written as followsProblem Given X∈Cn×m,Λ=(λ1 ,...,λm) ,find A∈S such thatAX =XΛ,where S is a given matrix set.We also discuss the so-called opti…  相似文献   
997.
Summary. N-Toluensulfonyl-l-prolin amide was tested as catalyst in the enantioselective Michael addition of carbonyl compounds to (E)-β-nitrostyrene in nine ionic liquids under different reaction conditions. The reaction rates and enantioselectivities were strongly dependent on the ionic liquids. Change of enantioselectivity was observed too and it is attributed to both the cation and the anion of ionic liquid. The best yields (up to 98%) and enantioselectivity (70% ee) of product were obtained in a basic ionic liquid [bmim]BF4 at room temperature.  相似文献   
998.
具有位相型修理的离散时间可修排队系统   总被引:1,自引:0,他引:1  
本文研究了具有一般独立输入,位相型修理的离散时间可修排队系统,假定服务台对顾客的服务时间和服务台寿命服从几何分布,运用矩阵解析方法我们给出系统嵌入在到达时刻的稳态队长分布和等待时间分布,并证明这些分布均为离散位相型分布.我们也得到在广义服务时间内服务台发生故障次数的分布,证明它服从一个修正的几何分布.我们对离散时间可修排队与连续时间可修排队进行了比较,说明这两种排队系统在一些性能指标方面的区别之处.最后我们通过一些数值例子说明在这类系统中顾客的到达过程、服务时间和服务台的故障率之间的关系.  相似文献   
999.
A modified formulation for fringe component of diffraction coefficient is implemented to TD-EEC method. An example of diffraction by perfectly conducting plate is used to illustrate our scheme. Comparing with the FDTD results we observe that the improved expression for fringe component is more accurate than that of Michaeli's formulation. This high frequency time domain technique is available for treating the bistatic scattering problems for millimeter waves.  相似文献   
1000.
I.TntroductionStatisticalandneuralnetworkmcthodsforpatternclassiflcationusesignificantlydifTerentapproachesintrainingaclassificr.Inthestatistica1approach,thcformationofaclassifier1arge1ydependsonthestatisticsofthetrainingpatternsand,insomecases,theassumptionsaboutthedistributionofthepopulation.Theneuralnetworkmethodisnon-parametricandcanbeadaptivcinthetrainingprocessl'l.Becauseofitssimplicityandflexibility,theneuralnetworkhasbecnincreasing1yusedforpatternclassiflcation.Itisnowwe11knownthatan…  相似文献   
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