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After the Second World War the Admiralty and shipbuilding industry agreed that the largest possible capacity for warship building should be maintained. This proved impossible as the Royal Navy struggled to evoke a strategy in the nuclear era and the price of increasingly complex vessels rose remorselessly. As the shipbuilding industry wilted in the 1960s in the face of international competition a process of natural selection was followed by increasing political intervention in the industry. Nationalisation in the 1970s aimed to preserve capacity and employment, policy aims which were reversed by privatisation in the 1980s and which, ultimately resulted in an oligopoly in the warship building sector.  相似文献   
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We consider the problem of service rate control of a single‐server queueing system with a finite‐state Markov‐modulated Poisson arrival process. We show that the optimal service rate is nondecreasing in the number of customers in the system; higher congestion levels warrant higher service rates. On the contrary, however, we show that the optimal service rate is not necessarily monotone in the current arrival rate. If the modulating process satisfies a stochastic monotonicity property, the monotonicity is recovered. We examine several heuristics and show where heuristics are reasonable substitutes for the optimal control. None of the heuristics perform well in all the regimes and the fluctuation rate of the modulating process plays an important role in deciding the right heuristic. Second, we discuss when the Markov‐modulated Poisson process with service rate control can act as a heuristic itself to approximate the control of a system with a periodic nonhomogeneous Poisson arrival process. Not only is the current model of interest in the control of Internet or mobile networks with bursty traffic, but it is also useful in providing a tractable alternative for the control of service centers with nonstationary arrival rates. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 661–677, 2013  相似文献   
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Though North Korea agreed to partial denuclearization in February 2007, achieving that goal is at best a long way off. A natural gas pipeline linking all of Northeast Asia and promising energy and economic help could help convince the isolated nation to step away from its nuclear programs entirely; it could also provide the nonproliferation and energy security benefits that have eluded the region for so long. These economic benefits could motivate the other nations involved in the six-party talks to deal with North Korea more than if only nuclear reactors were offered.  相似文献   
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Using an economic simulation model, the study finds that the proposed expenditure by the U.S. Department of Energy of billions of dollars to manage the nuclear weapons environmental legacy followed by sharp reductions in expenditures would cause economic spikes and then depressions in three rural regions (Hanford in Washington, INEEL in Idaho, and SRS in South Carolina). The economies of larger and growing metropolitan regions with DOE sites will not be noticeably impacted. Simulations suggest pronounced impacts on income, jobs, and gross regional product in the three dependent rural regions. Policy options are reviewed to address the economic stresses of these rural dependent regions.  相似文献   
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Machine maintenance is modeled in the setting of a single‐server queue. Machine deterioration corresponds to slower service rates and failure. This leads to higher congestion and an increase in customer holding costs. The decision‐maker decides when to perform maintenance, which may be done pre‐emptively; before catastrophic failures. Similar to classic maintenance control models, the information available to the decision‐maker includes the state of the server. Unlike classic models, the information also includes the number of customers in queue. Considered are both a repair model and a replacement model. In the repair model, with random replacement times, fixed costs are assumed to be constant in the server state. In the replacement model, both constant and variable fixed costs are considered. It is shown in general that the optimal maintenance policies have switching curve structure that is monotone in the server state. However, the switching curve policies for the repair model are not always monotone in the number of customers in the queue. Numerical examples and two heuristics are also presented. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007  相似文献   
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Policy research and scholarship on food has rapidly increased in recent decades. The attention to ‘gender' within this work appears to signal important practical and academic efforts to mainstream gendered understandings of food consumption, distribution and production into expansive conceptualisations of human security. This article argues that the gender-related work on food has wide-ranging and often troubling political and theoretical foundations and implications. Often growing out of knowledge regimes for managing social crises and advancing neo-liberal solutions, much gender and food security work provides limited interventions into mainstream gender-blind work on the nexus of power struggles, food resources and globalisation. A careful analysis of knowledge production about gender and food is therefore crucial to understanding how and why feminist food studies often transcends and challenges dominant forms of scholarship and research on food security. This article's critical assessment of what food security studies in South Africa has entailed at the regional level and in global terms also focuses on the methodological and theoretical feminist interventions that can stimulate rigorous conceptual, research and practical attention to what has come to be understood as food sovereignty.  相似文献   
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ALL TOGETHER NOW     
Banning Weapons of Mass Destruction, by Frederick N. Mattis. Praeger Security International, 2009. 129 pages, $39.95.  相似文献   
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In discussing China's January 2007 hit-to-kill intercept of the Chinese weather satellite FengYun-1C, most American analysts sought the “message” for the United States—either by asserting that China's test was a deliberate step toward a comprehensive counterspace capability to offset U.S. conventional military superiority or an attempt to force the United States to the negotiating table on “the prevention of an arms race in outer space.” Chinese officials, after a long silence, eventually claimed the test was an “experiment” that was “not targeted at any country.” We traveled to China several times in 2007 and had a series of conversations with Chinese individuals knowledgeable about the history of this particular antisatellite program and with access to information about the decision-making process prior to and after the final test. These discussions were off the record, not for attribution, given the sensitivity of the subject. They reflected the views of some of the key institutions involved in the test from the State, the Communist Party, the People's Liberation Army, and aerospace experts involved in debris calculations. The information conveyed to us suggests that American commentators tend to place much greater importance on the United States as a driver in China's decision to develop the technology and conduct the test than do the Chinese.  相似文献   
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