Optimal production and maintenance policy for imperfect production systems

A joint optimization of the production run length and preventive maintenance (PM) policy is studied for a deteriorating production system where the in‐control period follows a general probability distribution with non‐decreasing failure rate. In the literature, the sufficient conditions for the optimality of the equal‐interval PM schedule is explored to derive an optimal production run length and an optimal number of PM actions. Nevertheless, an exhaustive search may arise. In this study, based on the assumption that the conditions for the optimality of the equal‐interval PM schedule hold, we derive some structural properties for the optimal production/PM policy, which increases the efficiency of the solution procedure. These analyses have implications for the practical application of the production/PM model to be more available in practice. A numerical example of gamma shift distribution with non‐decreasing failure rates is used to illustrate the solution procedure, leading to some insight into the management process. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

Towards a new national security policy for Canada

Canada is now at a crossroads unlike any other period in its history and needs to carefully consider which path to take. With the new Trudeau government comfortably ensconced since the defeat of the Harper government in the fall of 2015, a variety of competing interests have emerged in an attempt to turn Canadian policy back to a more nostalgic period of the 1970s that some see as preferable to the institutional lash-up that existed since the rolling out of the Canada First policy in the 2000s. That nostalgic period is, however, misunderstood both willfully for political purposes but also through a lack of historical context. Firmly rooting future actions in a blunt analysis of national interests is preferable to the alternative.     

Optimal nonmyopic gambling strategy for the generalized Kelly criterion

We consider the optimal wagers to be made by a gambler who starts with a given initial wealth. The gambler faces a sequence of two-outcome games, i.e., “win” vs. “lose,” and wishes to maximize the expected value of his terminal utility. It has been shown by Kelly, Bellman, and others that if the terminal utility is of the form log x, where x is the terminal wealth, then the optimal policy is myopic, i.e., the optimal wager is always to bet a constant fraction of the wealth provided that the probability of winning exceeds the probability of losing. In this paper we provide a critique of the simple logarithmic assumption for the utility of terminal wealth and solve the problem with a more general utility function. We show that in the general case, the optimal policy is not myopic, and we provide analytic expressions for optimal wager decisions in terms of the problem parameters. We also provide conditions under which the optimal policy reduces to the simple myopic case. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 639–654, 1997     

基于规则的动态频谱接入研究

动态频谱接入面临的关键技术之一是对接入时机和方式进行有效地管控,防止由于频谱的接入使用过于灵活造成用频的干扰和混乱。将频谱接入的时间和方式给予规则上的约束和指导,基于规则构建动态频谱管理框架可以有效实现频谱的实时管控。对动态频谱接入的规则及表述方式进行了讨论,分析了基于规则的动态频谱接入过程,最后结合美军XG项目的试验结果分析了基于规则的动态频谱接入的应用前景。     

Ideology,ballots, and alliances: Canadian participation in multinational military operations

The decision to employ force abroad is often a contentious political decision, where partisanship plays a crucial role. Prior to military intervention, political parties usually make their ideologically distinctive preferences clear and seek to implement them once in power. What remains unclear, however, is how ideology affects the decision to use military force. This article contends that alliance and electoral calculations constrain the ability of political parties to implement their ideological preferences with regards to the use of force. It examines a “most likely” case for the partisan theory of military intervention, namely Canada’s refusal to take part in the invasion of Iraq and its decision to commit forces to the war against the Islamic State. It finds that only in combination with alliance and electoral calculations does executive ideology offer valuable insights into Canada’s military support to U.S.-led coalition operations, which contributes to our understanding of allied decision-making.     

一纲多本:存在的问题对策与建议

"一纲多本"教科书政策是当代社会多元文化的价值诉求,同时也是我国基础教育改革的应然选择。然而,"一纲多本"政策在实施过程中却引发了学生学习负担加重;学生学习结果呈现"两极化"趋势;教科书质量不理想;教师专业能力发展出现困惑等四方面的现实问题。文章在分析"一纲多本"引发问题原因的基础上,从课程标准、教科书质量、学生和教师等几个方面对其未来的发展前景进行了展望。     

Countering the Quetta Shura: a viable strategy to US policy in Afghanistan

The US strategy in Afghanistan has fallen short of neutralizing the insurgency that threatens the future stability. The primary insurgency's leadership council, the Quetta Shura, has effectively managed influence through a shadow government and superior tactics in recruiting marginalized tribal leaders, leading to a questionable outcome once Coalition forces withdraw in 2014. This article summarizes the threat posed by the Quetta Shura, coinciding with the deficiencies in the current US policy, and recommends a more viable strategy conducive to the current circumstances, based on historical and cultural precedence. Coalition forces have put a great amount of time, money, and effort into establishing a more stable Afghanistan. The USA needs a more aggressive strategy to counter the aspirations of the insurgency, thereby giving the Afghans the opportunity to further progress in the future. Under the current circumstances and policies, a peaceful transition after the Coalition withdrawal is becoming more unlikely.     

Hoping for the Best,preparing for the worst: China's response to US hegemony

In the post-Cold War strategic environment, Beijing could plausibly have opted for Soviet-style geostrategic competition with Washington, but it has not. Chinese leaders have not thus far, and almost certainly will never, amass thousands of nuclear weapons on hair-trigger alert or deploy significant forces to a network of bases spanning the globe. Nevertheless, the below assessment of China's increasing hard and soft power yields the conclusion that a Chinese challenge to US hegemony cannot be ruled out. The United States must prudently maintain military forces appropriate to facing a potential peer competitor. At the same time, however, Washington must engage in a process of creative diplomacy that simultaneously matches China's soft power and engages seriously with Beijing to create areas of consensus and cooperation.     

浅谈影响文职人员作用发挥的主要问题及对策

全军和武警部队实行文职人员制度以来,有效减少了现役编制员额,广泛吸纳了社会优秀人才,增强了军队人才队伍活力,降低了军队人力资源使用成本,在推动军队建设整体转型中发挥了重要作用。然而,在文职人员制度实行过程中,仍然存在认识不到位、重使用轻管理、重任务轻培养等问题。为此,要进一步完善文职人员管理使用制度,增强文职人员队伍活力,提供施展才华、建功立业的事业平台,增强文职人员集体荣誉感和奉献精神,营造拴心留人的良好氛围,使文职人员成为提高部队战斗力、增强“能打胜仗”本领的生力军。     

Book reviews

The Political Economy of Military Spending in the United States, Alex Mintz (ed), London and New York: Routledge, 1992, pp x, 334; ISBN 0–415–07595–5

Penser La Guerre, Penser L'Economie, Christian Schmidt, (Paris: Odile Jacob, 1991), 350p.

Military Production and Innovation in Spain, Jordi Molas‐Gallart, Chur (CH): Harwood Academic Publishers, 1992, pp. vii, 212; ISBN 3–7186–5280–3