On the nature and scope of defence economics

Defence economics uses the tools of economics to study the defence sector and its domestic and international implications. Simple models require careful application in defence economics, since indirect effects may have counterintuitive impacts. For example, while certain arms races can lead to the outbreak of war, others may have the counterintuitive effect of discouraging the outbreak of war owing to mutual deterrence.

The world is now multipolar rather than bipolar, analogous to an oligopoly situation. This multipolar world can be analyzed by a qualitative characteristic function, where the formation of a potential coalition allows study of the shift from conflict to cooperation in international relations. Some new issues to be considered in this framework include accidental nuclear war, potential arms races and conflicts in the third world, and the proliferation of chemical weapons and missiles.     

基于K均值排序方法的频域盲分离算法

针对频域盲分离算法中存在的排序不确定性问题,提出一种基于K-means算法的排序方法。该方法在排序中使用K-means算法对分离子信号进行整体排序,与传统相邻频点排序方法相比,大大提高了盲源分离的鲁棒性。仿真结果表明了该方法的有效性。     

装甲装备器材库存超(欠)储状态分析与程度评价

定义了装甲装备器材库存超(欠)储的概念,提出了维修保障资源点器材储存状态的定性判别和量化方法;考虑数量、时间、空间等影响因素,提出了资源点维修器材超(欠)储程度的评价指标和评价方法,并结合某军区实际数据进行了验证。结果表明:资源点的平均超(欠)储程度反映了保障体系内所有资源点库存偏离正常水平的平均程度,可为确定调剂资源点的优先次序和供应数量提供依据。     

Optimal patrol to uncover threats in time when detection is imperfect

Consider a patrol problem, where a patroller traverses a graph through edges to detect potential attacks at nodes. An attack takes a random amount of time to complete. The patroller takes one time unit to move to and inspect an adjacent node, and will detect an ongoing attack with some probability. If an attack completes before it is detected, a cost is incurred. The attack time distribution, the cost due to a successful attack, and the detection probability all depend on the attack node. The patroller seeks a patrol policy that minimizes the expected cost incurred when, and if, an attack eventually happens. We consider two cases. A random attacker chooses where to attack according to predetermined probabilities, while a strategic attacker chooses where to attack to incur the maximal expected cost. In each case, computing the optimal solution, although possible, quickly becomes intractable for problems of practical sizes. Our main contribution is to develop efficient index policies—based on Lagrangian relaxation methodology, and also on approximate dynamic programming—which typically achieve within 1% of optimality with computation time orders of magnitude less than what is required to compute the optimal policy for problems of practical sizes. © 2014 Wiley Periodicals, Inc. Naval Research Logistics, 61: 557–576, 2014     

Two‐dimensional failure modeling with minimal repair

In this paper, we discuss two‐dimensional failure modeling for a system where degradation is due to age and usage. We extend the concept of minimal repair for the one‐dimensional case to the two‐dimensional case and characterize the failures over a two‐dimensional region under minimal repair. An application of this important result to a manufacturer's servicing costs for a two‐dimensional warranty policy is given and we compare the minimal repair strategy with the strategy of replacement of failure. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

“Flectas non frangas”: revisiting early twenty-first century UK–US defense relations (2000–2005) after five years

Adopting the analytical framework of the established interpretive “schools” of Anglo-American relations, this article offers several reflections on UK–US defense relations as they occurred over the significant years of 2000–2005. During those years, trajectories were established on which UK–US defense relations continue to travel today and outcomes emerged which are still being navigated. This article concludes that the Latin phrase, “Flectas Non Frangas” (essentially translated as: “Bend not Break”), is the most appropriate to adopt to characterize the developments undergone in recent UK–US defense relations. Many historical and strategic lessons with contemporary relevance are drawn.     

基于灰色Verhulst优化模型的电子装备故障预测方法

针对平均故障工作时间数据样本量少的特点,提出利用灰色Verhulst模型预测电子装备故障;又针对灰色Verhulst模型存在预测精度不高的问题,研究了灰色Verhulst模型参数的优化方法。通过实际试验数据对2个模型进行了仿真验证,并基于灰色关联度对2个模型的模拟预测精度进行了比较分析,结果表明：基于灰色Verhulst优化模型适合于电子装备故障预测,并具有较高的拟合预测精度。     

风冷式质子交换膜燃料电池湿度调节特性分析

质子交换膜燃料电池（Proton Exchange Membrane Fuel Cells,PEMFC）的内部环境是影响电堆性能及寿命的重要因素,针对风冷式燃料电池运行特点,在分析燃料电池温、湿度环境控制方式的基础上,研究了反应风速对系统湿度特性的影响,提出了反应风速与温度对湿度进行联合控制的方式,并通过3kW小型燃料电池样机实验,验证了该方法的可行性。