The interface of computer science and statistics

Current scientific, technical, and management progress is characterized by the generation of a tremendous amount of data for analysis. This, in turn, poses a significant challenge: to effectively and efficiently extract meaningful information from the large volume of data. Two relatively young professions, computer science and statistics, are intimately linked in any response to the challenge. They have consequently become indispensable to scientific, technical, and management progress, occupying a position at its very heart Computer science and statistics have each been separately documented by many books as well as numerous papers. However, the interface of computer science and statistics, the area of their interaction, has been documented only in part. This paper begins characterization of the entire interface by providing a structure and an historical background for it A structure for the interface is introduced initially, followed by an historical background for the interface presented in two parts. First to be summarized is the evolution of the interface from an interweaving of the mechanical prerequisites to the computer and mathematical prerequisities to computer science and of the foundations for probability and statistics. Development of statistics prior to 1900 then is reviewed.     

GSPN的分析方法及其应用

随着计算机和信息技术的发展,广义随机Petri网(G SPN)作为一种图形化的建模工具,不仅可以对系统进行形式化的描述和快速原型开发,而且由于其具有坚实的数学理论基础,可以对系统进行正确性验证和性能评价,因此在系统的设计过程中,得到了广泛的应用。基于结构分析方法、可达图分析和数值分析方法讨论分析了G SPN,并给出了具体的算例,最后讨论了G SPN的应用领域。     

概述数学教师教学必备软件及软件平台

本文阐述一个数学教师教学所用到的软件及软件平台,主要有:1)平台类:数学软件平台、课件开发平台、素材创作平台、编程语言平台、Internet操作平台;2)软件类:试卷排版软件、试卷批改软件、组卷评测软件、成绩统计软件及排课软件。     

An inventory problem with obsolescence

A stochastic single product convex cost inventory problem is considered in which there is a probability, π_j, that the product will become obsolete in the future period j. In an interesting paper, Barankin and Denny essentially formulate the model, but do not describe some of its interesting and relevant ramifications. This paper is written not only to bring out some of these ramifications, but also to describe some computational results using this model. The computational results show that if obsolescence is a distinct possibility in the near future, it is quite important that the probabilities of obsolescence be incorporated into the model before computing the optimal policies.     

Total optimality of incrementally optimal allocations

This paper considers the problem of finding optimal solutions to a class of separable constrained extremal problems involving nonlinear functionals. The results are proved for rather general situations, but they may be easily stated for the case of search for a stationary object whose a priori location distribution is given by a density function on R, a subset of Euclidean n-space. The functional to be optimized in this case is the probability of detection and the constraint is on the amount of effort to be used Suppose that a search of the above type is conducted in such a manner as to produce the maximum increase in probability of detection for each increment of effort added to the search. Then under very weak assumptions, it is proven that this search will produce an optimal allocation of the total effort involved. Under some additional assumptions, it is shown that any amount of search effort may be allocated in an optimal fashion.     

舰船辐射噪声对声纳作用距离影响的不确定性研究

为了研究目标舰船辐射噪声对声纳作用距离产生的影响,用蒙特卡洛方法对目标航速进行模拟。通过经验公式得出舰船的辐射噪声级并进行统计分析,得出舰船辐射噪声的概率分布直方图,由此可以导出被动声纳作用距离的概率分布直方图。相对于传统的声纳作用距离预报结果,该方法给出的作用距离预报结果是一个满足某一分布的随机变量,而非一个确定的值,为作用距离的预报提供了概率的依据,为艇指挥员的决策提供了定量信息。同时,通过计算得出舰船航速的均方差与声纳作用距离的均方差基本成线性递增关系。     

A heuristic procedure for allocating tasks in fault-tolerant distributed computer systems

One way of achieving the increased levels of system reliability and availability demanded by critical computer-based control systems is through the use of fault-tolerant distributed computer systems. This article addresses the problem of allocating a set of m tasks among a set of n processors in a manner that will satisfy various task assignment, system capacity, and task scheduling constraints while balancing the workload across processors. We discuss problem background, problem formulation, and a known heuristic procedure for the problem. A new solution-improving heuristic procedure is introduced, and computational experience with the heuristics is presented. With only a modest increase in the amount of computational effort, the new procedure is demonstrated to improve dramatically solution quality as well as obtain near-optimal solutions to the test problems.     

D-S证据理论应用中的一种验证方法

D-S证据理论是一种比概率论确定性弱的不确定性理论,它能将"不知道"和"不确定"两个认知学上的主要概念区别开来,在多传感器数据融合中具有广泛的应用前景.D-S证据理论在实际应用中却存在一个困难,当目标的个数较多时,需要计算的项数太多,容易造成漏项,引起计算错误.提出了一种确定计算项数的算法,作为验证计算结果的必要条件,并通过图解的方法找出需要计算的项.     

The probability of the existence of a feasible flow in a stochastic transportation network

Stochastic transportation networks arise in various real world applications, for which the probability of the existence of a feasible flow is regarded as an important performance measure. Although the necessary and sufficient condition for the existence of a feasible flow represented by an exponential number of inequalities is a well‐known result in the literature, the computation of the probability of all such inequalities being satisfied jointly is a daunting challenge. The state‐of‐the‐art approach of Prékopa and Boros, Operat Res 39 (1991) 119–129 approximates this probability by giving its lower and upper bounds using a two‐part procedure. The first part eliminates all redundant inequalities and the second gives the lower and upper bounds of the probability by solving two well‐defined linear programs with the inputs obtained from the first part. Unfortunately, the first part may still leave many non‐redundant inequalities. In this case, it would be very time consuming to compute the inputs for the second part even for small‐sized networks. In this paper, we first present a model that can be used to eliminate all redundant inequalities and give the corresponding computational results for the same numerical examples used in Prékopa and Boros, Operat Res 39 (1991) 119–129. We also show how to improve the lower and upper bounds of the probability using the multitree and hypermultitree, respectively. Furthermore, we propose an exact solution approach based on the state space decomposition to compute the probability. We derive a feasible state from a state space and then decompose the space into several disjoint subspaces iteratively. The probability is equal to the sum of the probabilities in these subspaces. We use the 8‐node and 15‐node network examples in Prékopa and Boros, Operat Res 39 (1991) 119–129 and the Sioux‐Falls network with 24 nodes to show that the space decomposition algorithm can obtain the exact probability of these classical examples efficiently. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 479–491, 2016     

杜威和桑代克教育科学观之争

杜威和桑代克的教育科学观存在着严重的分歧。回顾杜威和桑代克教育科学观的内容、个人实践与影响,可以发现,两位教育思想巨人的教育科学观争论主要集中在三个方面:第一,在对于实验学校的态度上,杜威认为实验学校是教育科学研究的重要组成部分,而桑代克则认为教育测量与统计才是教育科学的中心,实验学校是可有可无的一部分。这一事实反映了二人对于教育科学本质的不同认识,杜威认为教育科学乃是服务于教育实践的规范科学,而桑代克则认为教育科学是进行教育理论生产的实证科学;第二,在教育研究中对于民主理念的理解上,杜威反对一切形式化的等级结构,而桑代克则认为教育研究中的等级结构是教育学科制度化的必要手段;第三,在教育研究的范式选择上,杜威希望将教育学打造成一门标准的学术科系,一种体现自由学科精神的“复数教育学”。而桑代克则是实证主义研究取向的代表。他主张由大学专业学院中真正的科学家来主导教育知识的生产,并由这些职业科学家建立一种“单数教育学”。     

The construction of an optimal distribution of search effort

Suppòse one object is hidden in the k-th of n boxes with probability p(k). We know the probability q(t, k) of detecting the object if it is hidden in box k and we expend effort t searching box k. Our aim is to minimize the expected search effort of a successful search. Previously this problem has been solved only under the assumption that the functions q(·, k) are concave. We prove, without concavity assumptions, the existence of an optimal distribution of search effort and give a procedure for its construction.     

攻击大目标子母弹射击概率的分析与估算

射击概率是子母弹武器效能分析的重要参数,本文以攻击大（线）目标子母弹为对象,提出一种计算命中概率的简便的近似法,计算结果表明该方法计算量小,计算精度工程上可接受;本文还引出了子母弹封锁概率的概念,并作了初步分析。本文结果对子母弹武器论证与设计使用将提供有益的参考。     

Multichannel queueing systems with heterogeneous classes of arrivals

In an integrated telecommunications network, voice and data traffic compete for the same transmission facilities. Assuming Poisson arrivals and exponential service with different rates, analytic expressions are obtained for measures of performance such as blocking probability and average delay under the following operating rule: class 1 traffic behaves as a loss system while class 2 traffic is buffered when all channels are busy. In view of the inordinate amount of computational effort needed when the number of channels is large, simple approximations have been suggested.     

Inspection policies and processes for deteriorating systems subject to catastrophic failure

Deteriorating reliability systems that are subject to catastrophic failure are analyzed in order to propose and evaluate some deterministic and stochastic inspection models. The underlying deterioration process is assumed to be an increasing Markov renewal process where the true state of the system can not be determined by simple observations. Instead, some tests can be done in order to detect if the system has positive deterioration or not. The results of the tests, however, are not perfect so that the probability of true and false detections depend on the unobserved state of the system. The system is inspected either deterministically at prespecified points in time, or stochastically at random points in time. Both types of models are considered to present explicit computational expressions for various performance measures like the expected number of inspections with different results and the probability of detection. Some practical applications of the results are also included.     

武器装备论证及AHP层次分析法的应用

论证是装备研发过程中首要的、不可或缺的过程,涉及到不同层次、不同领域、不同学科的知识（自然科学、社会科学、工程技术等）,要处理定性的和定量的不同类型的信息和数据。如何把这些知识综合集成起来,解决决策和组织管理问题,需要有科学的方法来支持。本文试以AHP层次分析法解决实际问题一例,见诸论证方法之一斑,为涉及装备论证的科研、管理、决策人员自觉运用科学论证方法起到一点积极作用。     

军事欺骗战法分析的数学方法-应用

针对军事欺骗战法定量分析困难的问题,采用基于贝叶斯统计推断和博弈均衡分析的数学方法,在理论上为解决此难题提供了一种可行的方法。该方法首先定义基本概率矩阵,然后根据贝叶斯原理为交战双方构造用于统计推断的主观概率矩阵,并在由两个主观概率矩阵元素构成的偏序链与实施军事欺骗机会之间建立对应关系,再将此关系推广到基本概率矩阵,即是否存在实施军事欺骗的机会将由基本概率矩阵元素构成的偏序链决定。对理论成果的初步应用表明：通过分析由战场情报信息构成的基本概率矩阵的偏序链,可以科学地运用军事欺骗和反军事欺骗战法。     

Vulnerability assessment to projectiles: Approach definition and application to helicopter platforms

Survivability is defined as the capability of a platform to avoid or withstand a man-made hostile environment. Military aircraft in particular, but also other kinds of platforms subjected to external, impacting threats, are commonly designed according to increasing survivability requirements. The concept of survivability was first formalized by R. Ball in 1985 in its seminal work on combat aircraft survivability. On the basis of the theory presented in his work, many computer programs have been developed which implement the modelling techniques and computations required by vulnerability assessments. However, a clear and general view of the operative computational procedures is still lacking. Moreover, to date only a limited number of applications to helicopter platforms have been investigated in the survivability field, even though these platforms experience numerous flight conditions exposing the system to different types of threats. In this context, this work aims at establishing a multi-purpose general framework for the vulnerability assessment of different types of platforms subjected to external threats, with a focus on helicopters. The in-house software specifically developed for this application is here described in detail and employed to present a case study on a representative military helicopter.     

The asymptotic sufficiency of sparse order statistics in tests of fit with nuisance parameters

In an earlier paper, it was shown that for the problem of testing that a sample comes from a completely specified distribution, a relatively small number of order statistics is asymptotically sufficient, and for all asymptotic probability calculations the joint distribution of these order statistics can be assumed to be normal. In the present paper, these results are extended to certain cases where the problem is to test the hypothesis that a sample comes from a distribution which is a member of a specified parametric family of distributions, with the parameters unspecified.     

Performance and properties of Q‐Statistic monitoring schemes

In this article, we study the Shewhart chart of Q statistics proposed for the detection of process mean shifts in start‐up processes and short runs. Exact expressions for the run‐length distribution of this chart are derived and evaluated using an efficient computational procedure. The procedure can be considerably faster than using direct simulation. We extend our work to analyze the practice of requiring multiple signals from the chart before responding, a practice sometimes followed with Shewhart charts. The results show that waiting to receive multiple signals severely reduces the probability of quickly detecting shifts in certain cases, and therefore may be considered a risky practice. Operational guidelines for practitioners implementing the chart are discussed. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009     

FACILITATING NUCLEAR DISARMAMENT: Verified Declarations of Fissile Material Stocks and Production

Unprecedented interest in seeking progress toward nuclear disarmament exists today; even some nuclear weapon states are looking for new ways to strengthen this process. National declarations of fissile material holdings—highly enriched uranium and plutonium—could play an important role in supporting this effort, facilitating not only transparency but also the irreversibility of the process. This article discusses what kind of content such declarations could have in order to be meaningful and effective, the sequence of data on fissile material holdings that states might release, and some of the challenges to be expected in reconstructing historic fissile material production; it also summarizes current attitudes of weapon states toward making such declarations. Initial declarations can be valuable as confidence-building measures, but better and more background data are necessary if declarations are to serve as the groundwork for deeper cuts in the nuclear arsenals. A robust verification approach would ultimately require inspectors to have access to fissile material production and storage sites. The methods and tools of nuclear forensic analysis—in this context also dubbed nuclear archaeology—would be a key element of this process. This article discusses the capabilities and limitations of potential approaches to verifying declarations of historic production of plutonium and highly enriched uranium; it also identifies and discusses opportunities for further research and development.