一类非完整系统的输出反馈控制问题研究

针对一类具有虚拟控制方向和非线性不确定项的非完整系统,研究了其输出反馈控制器的设计问题。采用状态转换技术和反推方法,设计了只依赖于输出值的输出反馈控制器。同时为了处理初值为零的情况,提出了基于第一个子系统输出值的切换控制策略,通过仿真算例说明了控制器的有效性。     

基于遗传算法的MIL-STD-188-220c标准最佳转发树的构造

针对MIL-STD-188-220C标准的路由协议多目的地址最佳转发树问题,提出一种基于遗传算法的优化算法,仿真结果表明,该算法具有收敛快,寻路成功率高的优点。     

Revenue maximization in two-station tandem queueing systems

We study optimal pricing for tandem queueing systems with finite buffers. The service provider dynamically quotes prices to incoming price sensitive customers to maximize the long-run average revenue. We present a Markov decision process model for the optimization problem. For systems with two stations, general-sized buffers, and two or more prices, we describe the structure of the optimal dynamic pricing policy and develop tailored policy iteration algorithms to find an optimal pricing policy. For systems with two stations but no intermediate buffer, we characterize conditions under which quoting either a high or a low price to all customers is optimal and provide an easy-to-implement algorithm to solve the problem. Numerical experiments are conducted to compare the developed algorithms with the regular policy iteration algorithm. The work also discusses possible extensions of the obtained results to both three-station systems and two-station systems with price and congestion sensitive customers using numerical analysis.     

Planning gamma accelerated degradation tests with two accelerating variables

Gamma accelerated degradation tests (ADT) are widely used to assess timely lifetime information of highly reliable products with degradation paths that follow a gamma process. In the existing literature, there is interest in addressing the problem of deciding how to conduct an efficient, ADT that includes determinations of higher stress‐testing levels and their corresponding sample‐size allocations. The existing results mainly focused on the case of a single accelerating variable. However, this may not be practical when the quality characteristics of the product have slow degradation rates. To overcome this difficulty, we propose an analytical approach to address this decision‐making problem using the case of two accelerating variables. Specifically, based on the criterion of minimizing the asymptotic variance of the estimated q quantile of lifetime distribution of the product, we analytically show that the optimal stress levels and sample‐size allocations can be simultaneously obtained via a general equivalence theorem. In addition, we use a practical example to illustrate the proposed procedure.     

舰船腐蚀电场建模及补偿最优解验证

基于等效偶极子法,从补偿偶极子长度、角度、大小三方面给出了任意角度的补偿偶极子场解析式,再利用电荷矢量叠加原理,建立了"腐蚀偶极子+补偿偶极子"电场模型。仿真以单轴桨船为例,先验证"腐蚀偶极子+补偿偶极子"电场模型的正确性,再进行补偿偶极子对舰船电场的影响验证,从而得出补偿最优解。模拟实验结果表明,补偿阳极在工程允许条件下距离补偿系统接船端最远处,且补偿系统平行于水平面和船体时补偿效果最优;在补偿最优条件下,理论上是可以抵消原舰船腐蚀电场的。     

Dynamic routing of prioritized warranty repairs

Recent years have seen a strong trend toward outsourcing warranty repair services to outside vendors. In this article we consider the problem of dynamically routing warranty repairs to service vendors when warranties have priority levels. Each time an item under warranty fails, it is sent to one of the vendors for repair. Items covered by higher priority warranty receive higher priority in repair service. The manufacturer pays a fixed fee per repair and incurs a linear holding cost while an item is undergoing or waiting for repair. The objective is to minimize the manufacturer's long‐run average cost. Because of the complexity of the problem, it is very unlikely that there exist tractable ways to find the optimal routing strategies. Therefore, we propose five heuristic routing procedures that are applicable to real‐life problems. We evaluate the heuristics using simulation. The simulation results show that the index‐based “generalized join the shortest queue” policy, which applies a single policy improvement step to an initial state‐independent policy, performs the best among all five heuristics. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

基于灰色决策原理的导弹核武器最佳配置模型

核武器是国家军事战略的基石,其配置的合理性直接影响核力量作战运用的成效.分析了影响导弹核武器配置的因素,将导弹核武器划分为平时和战时两种状态,构建了导弹核武器最佳配置的灰色规划模型计算结果验证了模型的正确性.研究表明:基于灰色规划原理构建的最佳配置模型在解的稳定性、模型的适应性上要优于同类线性规划模型.核武器最佳配置问题一直是核作战运用研究的重要内容.研究成果可为导弹武器的订购、存贮、阵地配置及作战运用提供理论决策依据.     

The rise and fall of counterproliferation policy

The US government initiated a Defense Counterproliferation Initiative to address the concern that, in the post-Cold War years, the proliferation of nuclear, biological, and chemical weapons would be widespread and create a significant challenge to the US military’s combat operations. In particular, non-nuclear states might use chemical or biological warfare agents against US forces with the belief that nuclear weapons would not be used against them in retaliation. Following the events of September 11, 2001, defense strategy and policy shifted to a wider view of the threat of adversarial use of “weapons of mass destruction” (WMD) and the term “counterproliferation” was replaced by “combating” or “countering WMD.” Over time, the Defense Department increasingly moved away from counterproliferation principles with the detrimental effect of losing capabilities that US forces still need for contemporary adversaries. This shift has been aggravated by other US government agencies’ use of “counterproliferation” in lieu of what would have been termed “nonproliferation” activities in the 1990s. The loss of clarity within the US government on these terms has led to the inability to focus the “whole of government” on this significant national security challenge. To alleviate this challenge, the US government needs a top-down initiative to refocus policy on the distinctly different aspects of WMD with respect to military combat operations, combating terrorism, and homeland security.     

The poverty of power in military power: how collective power could benefit strategic studies

Strategic studies deals intimately with the topic of power. Most scholars in the discipline work with a concept of power as an adversarial zero-sum competition. This is natural and necessary. However, other conceptions of power developed within political science and sociology could enrich strategic studies. Approaching two typical, traditional tasks of strategy – alliance building and war-fighting – this article demonstrates the heuristic mileage of theories of collective power. In particular, we can shed new light on the post-Cold War transformation of NATO as well as state-building as a strategy in counter-insurgencies with new ideas of power. Broadening the palette of theories of power is thus valuable if strategic studies is to prosper as an independent field of study.     

Hybrid warfare through the lens of strategic theory

Hybrid warfare is the latest of the terms/concepts that have been used within the defence community in the last three decades to label contemporary warfare. It has been officially adopted in the core strategic documents of NATO, EU and national governments and has already inspired many articles, policy papers and books; however, this paper is unique in the sense that it analysis the hybrid warfare concept through the lens of strategic theory. It is argued that hybrid warfare does not merit the adoption as a doctrinal concept. Strategic theory instead, which lies at the nexus of all dimensions of warfare, provides a better viewpoint to approach contemporary warfare. It concludes that efforts should be directed towards exploring warfare under the light of eternal principles instead of proving the emergence of new types of warfare.