Bayesian inference for a Lanchester type combat model

We undertake inference for a stochastic form of the Lanchester combat model. In particular, given battle data, we assess the type of battle that occurred and whether or not it makes any difference to the number of casualties if an army is attacking or defending. Our approach is Bayesian and we use modern computational techniques to fit the model. We illustrate our method using data from the Ardennes campaign. We compare our results with previous analyses of these data by Bracken and Fricker. Our conclusions are somewhat different to those of Bracken. Where he suggests that a linear law is appropriate, we show that the logarithmic or linear‐logarithmic laws fit better. We note however that the basic Lanchester modeling assumptions do not hold for the Ardennes data. Using Fricker's modified data, we show that although his “super‐logarithmic” law fits best, the linear, linear‐logarithmic, and logarithmic laws cannot be ruled out. We suggest that Bayesian methods can be used to make inference for battles in progress. We point out a number of advantages: Prior information from experts or previous battles can be incorporated; predictions of future casualties are easily made; more complex models can be analysed using stochastic simulation techniques. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 541–558, 2000     

Exploiting self‐canceling demand point aggregation error for some planar rectilinear median location problems

When solving location problems in practice it is quite common to aggregate demand points into centroids. Solving a location problem with aggregated demand data is computationally easier, but the aggregation process introduces error. We develop theory and algorithms for certain types of centroid aggregations for rectilinear 1‐median problems. The objective is to construct an aggregation that minimizes the maximum aggregation error. We focus on row‐column aggregations, and make use of aggregation results for 1‐median problems on the line to do aggregation for 1‐median problems in the plane. The aggregations developed for the 1‐median problem are then used to construct approximate n‐median problems. We test the theory computationally on n‐median problems (n ≥ 1) using both randomly generated, as well as real, data. Every error measure we consider can be well approximated by some power function in the number of aggregate demand points. Each such function exhibits decreasing returns to scale. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 614–637, 2003.     

Damage functions and estimates of fratricide and collateral damage

There are multiple damage functions in the literature to estimate the probability that a single weapon detonation destroys a point target. This paper addresses differences in the tails of four of the more popular damage functions. These four cover the asymptotic tail behaviors of all monotonically decreasing damage functions with well‐behaved hazard functions. The differences in estimates of probability of kill are quite dramatic for large aim‐point offsets. This is particularly important when balancing the number of threats that can be engaged with the chances of fratricide and collateral damage. In general, analysts substituting one damage function for another may badly estimate kill probabilities in offset‐aiming, which could result in poor doctrine. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 306–321, 2003.     

Military Ethics and the Situationist Critique

Many contributors to military ethics from diverse locations and philosophical perspectives maintain that virtues are central to martial theory and practice. Yet several contemporary philosophers and psychologists have recently challenged the empirical adequacy of this perspective. Their challenge is known as the situationist critique, a version of which asserts that: (a) situational features rather than character traits such as virtues cause and explain human behavior, and (b) ethical theories and development programs are empirically inadequate to the extent that they incorporate virtues. In this paper, I assess the merit of this critique and consider some implications of my assessment for military practitioners and theorists.     

ADVANCING THE GOALS OF NPT ARTICLE VI

International technical cooperation on issues relevant to the challenges of nuclear disarmament can demonstrate commitment to obligations under Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons, strengthen the security of fissile materials and weapons, and develop technical approaches to support more ambitious disarmament activities in the future. Including non-nuclear weapon states would ensure that their views are taken into account and would invest them in developing solutions to key challenges. This article discusses three areas for technical cooperation that would build on past activities and that could produce such benefits as improved protection, control, and accounting of nuclear weapons and fissile material; enhanced transparency for nuclear weapon complexes; and mechanisms for international management of sensitive civilian nuclear facilities. International cooperation in each of these areas could provide a technical basis for pursuing possible future disarmament negotiations and substantively demonstrate commitment to Article VI.     

一类平面系统极限环的不存在性

在系统奇点唯一的条件下,研究了一类微分系统不存在极限环的的充分条件,运用和发展了以往的结果.     

MAKING HISTORICAL SURVEYS OF STATES’ NUCLEAR AMBITIONS

In signalling its wish to participate in the Additional Protocol at an early stage, Sweden took several steps at the national level long before it actually ratified the protocol in May 2004. In 1998, the Swedish Nuclear Power Inspectorate (SKI) initiated a project to conduct a historical survey of Swedish nuclear weapons research for the period 1945–72. Sweden thus took an important step for the sake of transparency. SKI worked out a general model of how a nationally based survey could be designed, and gradually other states approached SKI in order to learn more about the methods and goals of the historical surveys. In 2002, a cooperative project was initiated between Sweden and Estonia, Latvia, and Lithuania. Finland joined the cooperative effort, and it thus became a dialogue and project carried out by five neighboring states to make national surveys. This article presents summaries of the national reports from Sweden and the Baltic states.     

基于仿真的竞争失效产品步降加速寿命试验优化设计

针对竞争失效产品加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的竞争失效产品步降加速寿命试验优化设计方法.采用Monte-Carlo对步降加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐进方差估计最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MIE理论进行统计分析,建立了基于仿真的竞争失效产品步降加速寿命试验优化设计模型.最后,通过实例分析表明:该方法具有可行性、有效性.