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1.
一种新的昆虫神经网络预测预报方法   总被引:6,自引:0,他引:6  
昆虫预测预报是植物保护中的一个困难问题.本文首先从系统的观点出发,分析了影响昆虫种群密度的主要因素;在研究传统时间序列模型共性的基础上,给出了广义时间序列模型;提出了一种新的昆虫预测模式—神经网络预测预报方法;用此方法对棉田害虫烟蓟马进行了预报,数值结果表明这是一种很好的预测预报方法,预测精度较其它方法都有很大提高.  相似文献   

2.
图的度序列   总被引:8,自引:0,他引:8  
李炯生 《数学进展》1994,23(3):193-204
图的度序列是图论研究中一个重要的课题.至今已发表了400余篇文章.本文概述这一课题的某些进展,其中包括了可图序列的判准、蕴含P可图序列和强迫P可图序列的一些主要结论,同时列出了一些有待进一步研究的问题.  相似文献   

3.
王学军  胡舒合 《应用数学》2007,20(3):541-547
设{xn,n≥1}是鞅差序列,Sn=∑i=1^n Xi,Xi∈L^p,i≥1,文章研究了混合序列和M-Z序列部分和Sn的大偏差,并得到了和鞅差序列类似的结果.  相似文献   

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固定资产投资系统的稳定性分析及最优控制问题   总被引:6,自引:0,他引:6  
给出带有时滞的一类固定资产模型,此模型为含有非局部和时滞边界条件的分布参数系统。通过Lyapunov函数,对系统的稳定性进行了分析,给出系统稳定的充分条件,然后,讨论了积累率的最优控制问题。根据Banach空间的一些理论,证明了其最优解的存在唯一性。  相似文献   

5.
一类非平稳时间序列的周期性   总被引:1,自引:0,他引:1  
本文研究了一类非平稳时间序列的稳定性及周期性,得到了它为周期相关序列的充分必要条件,推广了文献[3]的结论.  相似文献   

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本文根据Kalman滤波与时间序列分析的理论,对非线性随机系统,导出了状与参数同时进行估计的递推算法,确定了它们的统计性质。为减少估计误差,用两层估计方法改进了估计精度。这个结果在SISO系统中得到了证实。  相似文献   

7.
基于1978~2014年中国教育发展水平、就业人数与实际资本存量的数据,应用动力学原理建立模型,讨论了模型均衡解的稳定性,同时分析了该经济系统受到外部扰动时的动力学行为.研究结果表明,外部扰动产生的系统混沌效应会影响经济系统的正常运行,从而管理者有必要对经济系统提出有效的应对策略.因此,基于动力学原理,本文为时间序列动力学特征的微观刻画提供了一个视角.  相似文献   

8.
经济系统是一个复杂巨系统,具有复杂的层次结构.近年来,系统科学理论的发展为研究经济系统提供了新的思路和方法,已有了很大进展.劳动力是资产发展系统中的一个重要参数,对具有劳动力增长的非线性资产发展方程中劳动力的最优控制问题进行了研究.利用Banach空间理论,对极小化序列中的弱收敛序列,构造一强收敛极小化序列,得到了其最优解的存在性和唯一性,结果推广和改进了最近文献的一些主要结果.这个问题的研究对于促进我国经济高速、稳定持续增长具有重要的理论意义和现实指导价值.  相似文献   

9.
研究了由两个运行部件和一个储备部件并且具有常规故障和临界人为错误的随机模型,故障系统的修复时间是任意分布的.先把系统方程的解转化为Volterra 积分方程的形式,证明了系统方程中正解的存在唯一性,再以泛数指标泛函作为衡量系统可控性的标准,研究该系统的最优控制问题.  相似文献   

10.
研究了刮板沉降箱式除尘可修复系统稳态解的最优控制问题.通过利用范数指标泛函作为控制变量的标准,并采用极小化序列的方法,得到了系统最优控制元.  相似文献   

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Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

13.
We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.  相似文献   

14.
It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.  相似文献   

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正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with  相似文献   

17.
正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.  相似文献   

18.
A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].  相似文献   

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