宏观因素影响下的系统中元件重要性研究

为研究复杂系统在工作环境中其组成元件对系统安全运行的重要性,将汪培庄先生的因素空间理论与笔者提出的空间事故树理论相结合,构造了一套元件重要性研究方法.构建系统T={U,C,D},将元件作为研究对象集合U,系统工作的宏观环境作为因素集C,元件重要性排序集作为D.对宏观环境中的工作时间a1和温度a_2进行划分形成不同的状态区域S_q,计算在S_q中元件xj的失效权重γ(AS_q(x_j))和在S_q中系统T的失效权重δ(AS_q(T))),从而得到x_j在S状态下的等效失效权重Z(AS_q(x_j)),研究状态S_q下的原件重要性排序D_η,及元件x_j失效性对a_1及a_2的敏感性.使用一个实际的电气系统维修情况统计资料,使用上述方法进行了研究,结果表明:不同工作环境下元件对系统的重要程度是不同的.元件对温度和使用时间是敏感的,并得到了在10³0°且5030°且50⁷5d环境下工作系统可靠性是最高的结论.在给定工作环境下,重要性大的元件多储备,重要性小的元件少储备,以满足系统维修需要,并指导实际工程.     

From the main equation to the Klein-Gordon equation

The purpose of this paper is to bring out some connections between the work of Isaacs and physics. The first five sections are devoted to classical dynamics. The theories of Hamilton and Jacobi are revisited via the geometrical approach to optimal control and de Broglie's ideas. The other sections contain a stochastic-type generalization, leading to the Klein-Gordon equation of relativistic wave mechanics.     

3E系统协调发展的PLSPM-GIA测度模型及其应用研究

在总结协调发展水平测算时应该注意的一些问题的基础上,提出建立PLSPM-GIA模型对3E系统协调发展水平进行估算。首先设计3E系统综合发展指标体系,运用PLS路径模型对中国1996-2014年的各系统的综合发展水平进行了计算,然后利用灰色关联模型度量了系统协调度,最后综合考虑系统的发展水平和协调水平,得出系统的协调发展水平。研究表明:①PLSPM-GIA模型能够弥补现有方法的缺陷,而且适用于系统协调发展水平的测度;②从发展水平来看,由高到低依次为经济子系统、能源子系统和环境子系统;③从系统的协调度来看,2005年之前能源经济子系统和能源环境子系统的协调度先上升后缓慢下降,由于受到经济环境子系统协调度缓慢下降的影响,3E系统协调度呈缓慢下降态势,2005年以后3E系统及其子系统的协调度下降趋势明显;④从协调发展水平来看,目前除经济环境子系统外,3E系统和其他子系统均处于轻度失调状态。     

On the classification of the coadjoint orbits of the Sobolev Bott-Virasoro group

The purpose of this paper is to give the classification of the Bott-Virasoro coadjoint orbits, with nonzero central charge, in the functional analytic setting of smooth Hilbert manifolds. The central object of the paper is thus the completion of the Bott-Virasoro group with respect to a Sobolev topology, giving rise to a smooth Hilbert manifold and topological group, called the Sobolev Bott-Virasoro group. As a consequence of this approach, analytic and geometric properties of the coadjoint orbits are studied.     

我国环境污染、对外贸易和工业发展的关系探究

使用Eviews6.0软件分析1983年至2011年的统计数据,研究环境污染、对外贸易和工业发展之间的关系.首先,使用熵值法构造环境污染综合评价指数.然后,使用Grange检验确定三个变量之间的因果关系,使用VAR模型求解三者之间的量化关系,研究了脉冲响应分析和方差分解.结果表明:对外贸易会影响工业发展,对外贸易的变动冲击在前期会促进工业发展,随着年数的增加,其作用逐渐减少;对外贸易对环境的冲击表现为先增加然后平稳的减少;工业发展对环境污染的冲击最大出现在第二期,最后,采用分位数回归研究变量关系在不同分位点的变化规律,结果表明:对外贸易在各个分位点上都是高度显著的促进工业发展;对外贸易仅在高分位点上是显著的带来环境污染.     

On the facets of the secondary polytope

The secondary polytope of a point configuration A is a polytope whose face poset is isomorphic to the poset of all regular subdivisions of A. While the vertices of the secondary polytope - corresponding to the triangulations of A - are very well studied, there is not much known about the facets of the secondary polytope.The splits of a polytope, subdivisions with exactly two maximal faces, are the simplest examples of such facets and the first that were systematically investigated. The present paper can be seen as a continuation of these studies and as a starting point of an examination of the subdivisions corresponding to the facets of the secondary polytope in general. As a special case, the notion of k-split is introduced as a possibility to classify polytopes in accordance to the complexity of the facets of their secondary polytopes. An application to matroid subdivisions of hypersimplices and tropical geometry is given.     

用常微分方程模型分析预防和隔离措施对SARS发病率的影响

通过建立常微分方程模型 ,分析了预防和隔离措施对 SARS发病率的影响 ,并把计算结果与实际统计数据进行了比较 ,结果表明 ,及时高效的预防和隔离措施能够有效地控制 SARS的传播 .     

Investigation of the nonuniform distribution of the elastic and strength characteristics over the cross section of the diaphysis of the human tibia

The elastic, deformation, and strength properties of six different zones of the cross section of the diaphysis of the human tibia have been experimentally investigated. It is shown that when the compact bone tissue is stressed in tension all these properties differ significantly from zone to zone. The greatest values of the initial modulus of elasticity and the tensile strength correspond to the frontal-outer zones of the bone. The nonlinear stress-strain curves are analytically approximated. The secant and tangent moduli are shown to depend on the stress intensity.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 5, pp. 940–946, September–October, 1971.     

On the Effect of Misspecifying the Density Ratio Model

The density ratio model specifies that the log-likelihood ratio of two unknown densities is of known linear form which depends on some finite dimensional parameters. The model can be broadened to allow for m-samples in a quite natural way. Estimation of both parametric and nonparametric part of the model is carried out by the method of empirical likelihood. However the assumed linear form has an impact on the estimation and testing for the parametric part. The goal of this study is to quantify the effect of choosing an incorrect linear form and its impact to inference. The issue of misspecification is addressed by embedding the unknown linear form to some parametric transformation family which yields ultimately to its identification. Simulated examples and data analysis integrate the presentation.     

On the relation between the singular and the weak coupling limits

After having recalled some definitions concerning quantum stochastic processes and, in particular, quantum Brownian motions, a general scheme is introduced which allows a unified approach to the weak coupling and singular coupling limits. The analogies and differences between the two are discussed. The main difference consists of the fact that, in the singular coupling limit, the use of a Hamiltonian unbounded below seems to be unavoidable, while this is not the case for the weak coupling limit.     

About the relaxed cocoercivity and the convergence of the proximal point algorithm

The aim of this paper is to study the convergence of two proximal algorithms via the notion of (α, r)-relaxed cocoercivity without Lipschitzian continuity. We will show that this notion is enough to obtain some interesting convergence theorems without any Lipschitz-continuity assumption. The relaxed cocoercivity case is also investigated.     

On the Convergence of the Cross-Entropy Method

The cross-entropy method is a relatively new method for combinatorial optimization. The idea of this method came from the simulation field and then was successfully applied to different combinatorial optimization problems. The method consists of an iterative stochastic procedure that makes use of the importance sampling technique. In this paper we prove the asymptotical convergence of some modifications of the cross-entropy method.     

考虑废旧品质量的闭环供应链混合回收渠道选择研究

为确定最优的回收渠道,对由单个制造商、零售商和第三方组成的闭环供应链系统进行研究。在该系统中,可能存在制造商和零售商、制造商和第三方、零售商和第三方以及制造商、零售商和第三方同时回收的四种渠道,并根据质量差异对废旧品进行翻新或再制造。在分散决策下建立了四种回收渠道模型。比较发现:站在制造商和系统收益最大化及社会效益角度,三渠道是最佳选择,此时得到的废旧品最多;制造商不进行回收时获利最低,且不利于提高废旧品的获取量。最后,通过算例剖析了废旧品再制造率对四种混合回收渠道下成员及系统利润的影响。结果表明:制造商应尽量将废旧品用于再制造。     

On the computation of the Euler constant γ

The problem of the approximation to the Euler constant γ is considered. Some new formulas for the computation of Euler's constant are suggested. The problem of fast evaluation of γ is discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

On the accuracy of the projection computation of the collision integral

The accuracy of the projection method as applied to the computation of the collision integral is analyzed. It is shown that the method has an error of the second order of smallness with respect to the mesh size. An optimal method for choosing additional nodes that minimizes the computational error is found. The theoretical conclusions and the optimality of the method are confirmed in a series of numerical experiments.     

On the establishment of the Takagi Lectures

The Takagi Lectures are the first series of lectures in mathematics to be crowned with a Japanese mathematician’s name. The author provides some historical background of the Takagi Lectures.     

Analyzing of the effect of the dusty fluid,anisotropy and layered of the wall on the wave propagation

This study considers the propagation of time harmonic waves in, prestressed, anisotropic elastic tubes filled with viscous fluid containing dusty particles. The fluid is assumed to be incompressible and Newtonian. The tube material is considered to be incompressible, anisotropic, and elastic. The tube is subjected to a static inner pressure P_i and an axial stretch λ. Utilizing the theory of “Superposing small deformations on large initial static deformations”, differential equations governing wave propagation inside the tube are obtained in terms of cylindrical coordinates. Analytical solutions for the equations of motion for the dust and the fluid are obtained, and expressed numerically. The dispersion relation is obtained as a function of the stretch, the thickness ratio and the parameters for dusty particles.     

基于数字化校园的校园一卡通平台设计

校园一卡通是“数字化校园”建设重要组成部分和基础工程，为“数字化校园”提供了全面的数据采集网络平台。本文从校园一卡通的功能模块、为其他管理系统提供平台、资金结算和系统安全四个方面论述了校园一卡通平台设计。     

森林救火中消防队员增援人数的确定

消防部门在接到森林火情后,由于无法精确得知森林火场的风速、气温、湿度、火势蔓延程度等相关信息,加之时差现象,致使消防部门派出的救援人数有可能过少,此时就必须进行增援.本文在无风、有风的情况下,建立森林损失费用与救援费用最小的优化模型,确定了最佳增援人数.     

On the determination of the coefficients in the viscoelasticity equations

For the integrodifferential viscoelasticity equations, we study the problem of determining the coefficients of the equations and the kernels occurring in the integral terms of the system of equations. The density of the medium is assumed to be given. We suppose that the inhomogeneity support of the sought functions is included in some compact domain B ₀. We consider a series of inverse problems in which an impulse source is concentrated at the points y of the boundary of B ₀. The point y is the parameter of the problem. The given information about the solution is the trace of the solution to the Cauchy problem with zero initial data. This trace is given on the boundary of B ₀ for all y ∈ ?B ₀ and for a finite time interval. The main result of the article consists in obtaining uniqueness theorems for a solution to the initial inverse problem.