关于寿命试验

本文讨论了关于寿命试验的一些问题,全文共分四个部分．第一部分分析了截断情况下寿命估计的困难;第二部分考虑对定时寿命试验方法进行修改,以获取分布尾部的信息;第三部分研究在随机截断下基于Ｋａｐｌａｎ－Ｍｅｉｅｒ估计的非参数寿命均值估计;第四部分讨论了第二类截断下定数ｒ的选择问题．     

统计深度函数及其应用

次序统计量在一维统计数据分析中起着很重要的作用．多年来,人们一直在商维数据处理和分析中寻找“次序统计量”,却没有得到很满意的结果．由于缺少自然而有效的高维数据排序方法,因而象一维“中位数”的概念很难推广到高维．统计深度函数则提供了高维数据排序的一种工具,其主要思想是提供了一种从高维数据中心(最深点)向外的排序方法．不仅如此,统计深度函数已经在探索性高维数据分析,统计判决等方面带给我们一种全新的前景,并在工业、工程、生物医学等诸多领域得到很好的应用．本文介绍了统计深度函数概念及其应用,讨论了位置深度函数的标准,介绍了几种常用的统计深度函数．给出了由深度函数特别是由投影深度函数所诱导的位置和散布阵估计,介绍了它们的诸多优良性质,如极限分布,稳健性和有效性．由于在大多数场合下,高崩溃点的估计不是较有效的估计,而由统计深度函数所诱导的估计具有多元仿射不变性,并能提供理想的稳健性与有效性之间的平衡,本文还讨论了基于深度的统计检验和置信区域,介绍了统计深度函数的其他应用,如多元回归、带有变量误差模型、质量控制等,以及实际计算问题．指出了统计深度函数领域有关进一步的工作和研究方向．     

关于《数据库原理》教学中数据仓库构建步骤的探讨

本作根据3年多的《数据库原理》的教学经验，在数据仓库知识的构建部分提出了六步构建方案，通过教学实验，学生容易理解，反响较好，下面就如何构建来进行展开。它的六个构建步骤分别是：概念模型设计，技术准备工作，逻辑模型设计，物理模型设计，数据仓库生成和数据仓库的运行与维护。并重点针对运行与维护在实际使用过程中考虑不周而导致的某些问题，通过仔细分析，提出了部分见解。     

期末评价测试题（一）

说明：本试卷分闭卷和开卷两部分．闭卷又分为第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分．全卷满分120分，其中闭卷满分100分，开卷满分20分．     

循环差分-微分模上双变元维数多项式的Gr?bner基算法北大核心CSCD

Gr?bner基算法是在计算机辅助设计和机器人学、信息安全等领域广泛应用的重要工具.文章在周梦和Winkler(2008)给出的差分-微分模上Gr?bner基算法和差分-微分维数多项式算法基础上,进一步研究了分别差分部分和微分部分的双变元维数多项式算法.在循环差分-微分模情形,构造和证明了利用差分-微分模上Gr?bner基计算双变元维数多项式的算法.     

数学程序性技能刍议

多年来我国数学教学对“双基”十分重视，2001年7月教育部制订《全日制义务教育数学课程标准》(实验稿)在四部分总体目标中的第一部分，对知识与技能部分阐述如下：     

问题

问：题162普通高中数学课程标准关于课程的基本理念的第7条是：强调本质，注意适度形式化，指出在数学教学中，要强调对数学本质的认识．“标准”的第四部分教学建议中也提出了进一步理解数学的本质的要求．     

随机分形

本文概括了随机分形的主要结果，综述了随机分形的最新进展和目前的动态，提出了一些末解决的问题，全文共分为三部分：（１）由随机过程和随机场（如Ｌｅｖｙ过程，Ｇａｕｓｓ场，自相似过程等）产生的各种随机分形集（如象集、水平集、Ｋ重点集等）的Ｈａｕｓｄｏｒｆｆ维数、测度和ｐａｃｋｉｎｇ维数、测试；（２）随机Ｃａｎｔｏｒ型集和统计自相似集的维数和测试；（３）分形集（如Ｓｐｉｅｒｐｉｎｓｋｉ ｇａｓｋｅｔ，ｎｅ     

998年普通高等学校招生全国统一考试数学(理工农医类)

本试卷分第Ⅰ卷（选择题）和第Ⅱ卷（非选择题）两部分．共１５０分．考试时间１２０分钟．第Ⅰ卷（选择题共６５分）一、选择题：本大题共１５小题；第（１）—（１０）题每小题４分，第（１１）—（１５）题每小题５分，共６５分．在每小题给出的四个选项中，只有一项是...     

1998年普通高等学校招生全国统一考试数学(文史类)

本试卷分第Ⅰ卷（选择题）和第Ⅱ卷（非选择题）两部分．共１５０分．考试时间１２０分钟．第Ⅰ卷（选择题共６５分）一、选择题：本大题共１５小题；第（１）—（１０）题每小题４分，第（１１）—（１５）题每小题５分，共６５分．在每小题给出的四个选项中，只有一项是...     

Necessary conditions for the optimality of the automaton part of a logical-dynamical system

A dynamical system controlled by an automaton with memory is considered. The continuous part of the system is described by differential equations, and the automaton part, by recurrence inclusions. The instants of time at which the state of the automaton part is changed are not known in advance and are determined during the optimization process. Moreover, modes with multiple switchings of the automaton part at a given instant of time are admitted. Necessary conditions for the optimality of a program control are obtained. The application of the optimality conditions is illustrated by examples.     

Synthesis of the Optimal Control of Linear Logical-Dynamical Systems Under Instant Multiple Switchings of the Automaton Part

We consider a dynamic system controlled by an automaton with memory. The continuous part of the system is described by linear differential equations and the logical (automaton) part is described by linear recurrence equations. The moments of the state change of the automaton part are not known in advance and they are determined in the process of optimization. Modes with instant multiple switchings of the automaton part are admitted. Based on sufficient optimality conditions, we develop a technique for the synthesis of a feedback control. The application of the technique is demonstrated in an example.     

Abstract nonlinear prediction and operator martingales

In the first part of this paper, nonlinear prediction theory of vector valued random variables in Orlicz spaces is presented. The spaces need not be reflexive and the results of this part are essentially best possible for these spaces. The second part considers operator valued martingales in the strong operator topology and various convergence theorems are proved for them. Again the results are optimal for the Orlicz space situation. These are specialized to the scalar case showing that the well-known martingale convergence theorem can be obtained from the well-known Andersen-Jessen theorem. A few applications are also given. The same ideas and methods of computation unify the otherwise almost independent parts.     

Qualocation methods for elliptic boundary integral equations

Summary. The qualocation methods developed in this paper, with spline trial and test spaces, are suitable for classes of boundary integral equations with convolutional principal part, on smooth closed curves in the plane. Some of the methods are suitable for all strongly elliptic equations; that is, for equations in which the even symbol part of the operator dominates. Other methods are suitable when the odd part dominates. Received December 27, 1996 / Revised version received April 14, 1997     

On Summation Formulas Due to Plana, Lindelöf and Abel, and Related Gauss-Christoffel Rules, III

This is the last part of a work that has been divided into three parts. It contains Sections 4 and 5. Part I and Part II were published in BIT, vol. 37. Some amendments to the earlier parts are given in an appendix of this part.The reader is referred to Part I for the abstract, the contents and the references of the whole work. A short list of references for this part is found at the end of this part. A few new references of interest for the earlier parts are included.     

Borel summability of divergent solutions for singular first-order partial differential equations with variable coefficients. Part I

This article part I and the forthcoming part II are concerned with the study of the Borel summability of divergent power series solutions for singular first-order linear partial differential equations of nilpotent type. Under one restriction on equations, we can divide them into two classes. In this part I, we deal with the one class and obtain the conditions under which divergent solutions are Borel summable. (The other class will be studied in part II.) In order to assure the Borel summability of divergent solutions, global analytic continuation properties for coefficients are required despite of the fact that the domain of the Borel sum is local.     

Sufficient conditions for Stackelberg and Nash strategies with memory

Sufficiency conditions for Stackelberg strategies for a class of deterministic differential games are derived when the players have recall of the previous trajectory. Sufficient conditions for Nash strategies when the players have recall of the trajectory are also derived. The state equation is linear, and the cost functional is quadratic. The admissible strategies are restricted to be affine in the information available.This work was supported in part by the Joint Services Electronics Program under Contract No. N00014-79-C-0424, in part by the National Science Foundation under Grant No. ECS-79-19396, and in part by Department of Energy under Contract No. EX-76-C-01-2088.     

Group technology in production management: The short horizon planning level

We consider a set of parts divided into subsets called part types, determined in such a way that the parts belonging to the same part type are manufactured using the same sequence of tasks (i.e. the same working process). We are looking for a partition of the set of part types into subsets called part families, and for a partition of the set of tasks into subsets called production subsystems defined as follows: (1) the number of part families and the number of production subsystems are equal, (2) one (one only one) production subsystem corresponds to each part family, (3) one (and only one) part family corresponds to each production subsystem, (4) the previous partitions minimize the number of tasks performed in a production subsystem different from that which corresponds to the part family containing the part involved. We give a fast algorithm which leads to a good solution depending on the initial set of part families. We also propose an algorithm to find a ‘good’ initial set of part families.     

Problems of stability with respect to part of the variables

The Lyapunov-Malkin theorem on stability and (simultaneously) exponential asymptotic stability with respect to part of the variables in the linear approximation in critical cases (in Lyapunov's sense) has served as a point of departure for various previous results. These results are strengthened by relaxing all additional assumptions (other than continuity) regarding the coefficients of the linear part of the non-linear system under consideration. The result is extended to the problem of polystability with respect to part of the variables. In addition, a method for narrowing down the admissible domain of variation of “uncontrollable” variables is worked out as applied to problems of asymptotic stability with respect to part of the variables. Examples are considered.     

Tests of ignoring and eliminating in nonsymmetric correspondence analysis

Nonsymmetric correspondence analysis (NSCA) aims to examine predictive relationships between rows and columns of a contingency table. The predictor categories of such tables are often accompanied by some auxiliary information. Constrained NSCA (CNSCA) incorporates such information as linear constraints on the predictor categories. However, imposing constraints also means that part of the predictive relationship is left unaccounted for by the constraints. A method of NSCA is proposed for analyzing the residual part along with the part accounted for by the constraints. The CATANOVA test may be invoked to test the significance of each part. The two tests parallel the distinction between tests of ignoring and eliminating, and help gain some insight into what is known as Simpson’s paradox in the analysis of contingency tables. Two examples are given to illustrate the distinction.