广义Liénard方程Poincaré分岔极限环的唯一性和不存在性

讨论了一类广义Linard方程x¨+f1(x)x.2+εf2(x)x.+g(x)=0的Poincar分岔极限环的唯一性和不存在性。将不对Abel积分进行分项,而是利用一阶Mel′nikov函数直接从整体上进行分析讨论,得出了若干判别准则和充分条件。     

Whose Hearts and Whose Minds? The Curious Case of Global Counter-Insurgency

Traditionally regarded as a secondary activity in military thinking and practice, the notion of counter-insurgency (COIN) has undergone a remarkable renaissance. This analysis traces the origins of this renaissance to two distinctive schools: a neo-classical school and a global insurgency school. The global insurgency school critiques neo-classical thought and presents itself as a more sophisticated appreciation of current security problems. An examination of the evolution of these two schools of counter-insurgency reveals how the interplay between them ultimately leaves us with a confused and contradictory understanding of the phenomenon of insurgency and the policies and strategies necessary to combat it.     

PUBLIC SAFETY AND THE MORAL DILEMMA IN THE DEFENSE AGAINST TERROR

The economic theory of defense has traditionally described public safety as achieved through investments that deter adversaries. Deterrence is, however, ineffective and pre‐emptive defense is required when a population of intended victims confronts supreme‐value suicide terror. A moral dilemma then arises, since pre‐emption may impose collective punishment, while in the absence of pre‐emption the population of intended victims is exposed to acts of terror. We consider how a population of intended terror victims confronts the moral dilemma, and compare the threatened population's response with the public‐safety recommendations of external judges who are not personally affected by the threat of terror.     

Ridge regression analysis of the defence‐growth tradeoff in the United States

An examination of past analyses suggests that today's sailors may be less responsive to compensation changes than previous generations. Such a change could make recruiting and retaining high‐quality sailors more difficult. However, variation in researchers' decisions over time may simply have created the appearance of such a change. Our results suggest there is little variation in the pay elasticity over time. In contrast, the different reduced‐form models we use to measure this relationship can explain most of the variation in the literature. Therefore, the evidence suggests that while sailors may have changed over time, their response to compensation has not.     

Heuristic scheduling of resource-constrained projects with cash flows

Resource-constrained project scheduling with cash flows occurs in many settings, ranging from research and development to commercial and residential construction. Although efforts have been made to develop efficient optimal procedures to maximize the net present value of cash flows for resource-constrained projects, the inherent intractability of the problem has led to the development of a variety of heuristic methods to aid in the development of near-optimal schedules for large projects. This research focuses on the use of insights gained from the solution of a relaxed optimization model in developing heuristic procedures to schedule projects with multiple constrained resources. It is shown that a heuristic procedure with embedded priority rules that uses information from the revised solution of a relaxed optimization model increases project net present value. The heuristic procedure and nine different embedded priority rules are tested in a variety of project environments that account for different network structures, levels of resource constrainedness, and cash-flow parameters. Extensive testing with problems ranging in size from 21 to 1000 activities shows that the new heuristic procedures dominate heuristics using information from the critical path method (CPM), and in most cases outperform heuristics from previous research. The best performing heuristic rules classify activities into priority and secondary queues according to whether they lead to immediate progress payments, thus front loading the project schedule. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 365–381, 1997     

Decommissioning and paramilitary strategy in Northern Ireland: A problem compared

This study examines the problems of paramilitary decommissioning in Northern Ireland. It analyses why decommissioning has become so contentious in the Northern Ireland peace process. Decommissioning, though, is not a unique or intrinsically insurmountable problem. This is demonstrated by highlighting the issue in international context. Three examples of decommissioning in conflict resolution processes are assessed: the Lebanon, El Salvador and Mozambique. These varied examples do supply some limited lessons for Northern Ireland. This study argues that the explanation for the intractability of decommissioning in Northern Ireland resides, to a greater extent, in the tactical and strategic reasoning of the main paramilitary groupings in Northern Ireland. The factors that condition their thinking, however, can be found in the nature of the peace process itself which provides the paramilitiaries with every incentive to retain possession of their weapons.     

SPEED BUMP ON THE ROAD TO GLOBAL ZERO

The prospect of the United States continuing to reduce the size of its nuclear arsenal to “very low numbers” has raised questions in Japan and South Korea, where US extended deterrence guarantees are premised on the “nuclear umbrella.” In both countries, however, concerns focus less on numerical arsenal size than on the sufficiency of specific nuclear and non-nuclear capabilities to meet evolving threats and on the degree of broader US commitment to these alliances. This article assesses developments in US-Japan and US-South Korea relationships in response to the Obama administration's nuclear disarmament policies, focusing on how the evolutionary course of those relationships may in turn condition prospects for sustaining this US nuclear policy direction. The analysis finds that the challenges of deterrence credibility and allied reassurance are difficult and long-term, but also that US nuclear arsenal size is secondary to broader political, strategic, and military factors in meeting these challenges. The evaluation concludes that strong alliance relationships and strategic stability in East Asia can be maintained while the size of the US nuclear arsenal continues to decline, but also that deterioration of these relationships could imperil core US nuclear policy and nonproliferation objectives.     

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.