离散随机系统的一类综合控制

研究离散线性随机系统在方差约束下的综合控制设计问题,即设计期望的静态输出反馈控制器,使闭环极点位于单位圆内的一个环形区域内。同时,每个稳态状态方差都满足给定的上界约束,从而使闭环系统具有良好的稳定特性和动态性能。本文利用修正的代数Ｌｙａｐｕｎｏｖ方程,推导出控制器存在的充分条件和解集刻划,并提供了说明性的数值算例。文中所得结果具有形式简洁、易于工程实现的特点     

改进的二进制粒子群算法的传感器优化配置

传感器组合优化问题是设备状态检测系统设计的重要问题.在研究传感器与故障有向图的基础上,提出了传感器优化配置模型;根据传感器组合优化自身特点,从位改变率、惯性权重两个方面对BPSO算法进行了参数分析.结合免疫算法的“亲和度”思想以及非线性惯性权重递减公式,提出了改进的二进制粒子群算法.案例显示,改进的二进制PSO算法提高了算法在整个解空间的搜索能力,加快了收敛速度,能够很好地用于解决传感器优化问题.     

A robust sensor covering and communication problem

We consider the problem of placing sensors across some area of interest. The sensors must be placed so that they cover a fixed set of targets in the region, and should be deployed in a manner that allows sensors to communicate with one another. In particular, there exists a measure of communication effectiveness for each sensor pair, which is determined by a concave function of distance between the sensors. Complicating the sensor location problem are uncertainties related to sensor placement, for example, as caused by drifting due to air or water currents to which the sensors may be subjected. Our problem thus seeks to maximize a metric regarding intrasensor communication effectiveness, subject to the condition that all targets must be covered by some sensor, where sensor drift occurs according to a robust (worst‐case) mechanism. We formulate an approximation approach and develop a cutting‐plane algorithm to solve this problem, comparing the effectiveness of two different classes of inequalities. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 582–594, 2015     

ANALYSING DEFENCE DEPENDENCY: THE IMPACT OF THE ROYAL NAVY ON A SUB‐REGIONAL ECONOMY

This paper provides a methodology for estimating the economic impact of defence spending at a sub‐regional level. It does so by calculating the income and employment generated by Britain’s Royal Navy and associated defence activities in the City of Portsmouth and its surrounding area, during the financial year 2003–2004. In an era of military consolidation, the paper offers an insight into the multifaceted impact of defence‐related expenditure. Hence, it presents a generic framework that could prove useful to other researchers when seeking to measure the sub‐regional impact of naval, airforce and army facilities in other national contexts.     

SWAZILAND

The election of Sheik Sharif Sheik Ahmed as the transitional president of Somalia was the climax of the United Nations (UN)-led Djibouti peace process. The election, it was hoped, would herald the beginning of the reconstitution of the Somalian state. Unfortunately, nearly three years after the event, that has still not happened. The government of Sheik Sharif has faced a number of challenges which are yet to be resolved. In the end, the Djibouti peace process has not guaranteed a stable and functional national government in Somalia.     

How should the peace and security performance of SADC be evaluated?

This article responds to the reviews by Gwinyayi Dzinesa and Elling Tjønneland of Community of insecurity: SADC's struggle for peace and security in southern Africa. It does this by exploring the methodological and analytical challenges in evaluating SADC's peace and security endeavours. It emphasises the need to present explicitly the criteria for assessment, to concentrate on the actual performance of the organisation rather than on its declarations and structures, and to make assessments and predictions on the basis of historical trends and sound analysis.     

THE MIDDLE EAST WMD-FREE ZONE CONFERENCE

This article reviews the origins and evolution of the Middle East weapons of mass destruction-free zone (WMDFZ) concept and the proposal for a 2012 conference on the subject, and explores new challenges and opportunities for regional arms control in the current regional environment. It suggests that new models may be necessary to revitalize regional arms control efforts. The establishment of a broad regional security forum could include, but should not be limited to, curtailing weapons of mass destruction through the zone approach. Even if the 2012 conference fails to materialize, or is limited to a one-time event, the proposal for such a conference has provided an important opportunity to rethink future options for a regional arms control and security process.     

Special Section: Nuclear Stability In South Asia

The question of nuclear stability in South Asia is a subject of both academic and policy significance. It is the only region in the world that has three, contiguous nuclear-armed states: India, the People's Republic of China, and Pakistan. It is also freighted with unresolved border disputes. To compound matters, all three states are now modernizing their nuclear forces and have expressed scant interest in any form of regional arms control. These issues and developments constitute the basis of this special section, which explores the problems and prospects of nuclear crisis stability in the region.     

构筑中国新地缘安全战略的理论准备与思考

目前,中国面临的地缘安全挑战已经达到了一个危险的临界点,而对当前挑战的应对却没有表现出整体的成熟。显然,没有适应新形势的完整的地缘安全理论是造成出现不成熟的应对危机举措的重要原因。因此,从理论上突破传统中国地缘安全战略的影响,构筑新的完整的地缘安全理论,是一项紧迫而必须完成的任务。