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251.
In this article, we focus on relatively new maintenance and operational scheduling challenges that are faced by the United States Air Force concerning low‐observable (LO) or stealth aircraft. The LO capabilities of an aircraft degrade stochastically as it flies, making it difficult to make maintenance scheduling decisions. Maintainers can address these damages, but must decide, which aircraft should be put into maintenance, and for how long. Using data obtained from an active duty Air Force F‐22 wing and interviews with Air Force maintainers and program specialists, we model this problem as a generalization of the well‐known restless multiarmed bandit superprocess. Specifically, we use an extension of the traditional model to allow for actions that require varying lengths of time, and generate two separate index policies from a single model; one for maintenance actions and one for the flying action. These index policies allow maintenance schedulers to intuitively, quickly, and effectively rank a fleet of aircraft based on each aircraft's LO status and decide, which aircraft should enter into LO maintenance and for how long, and which aircraft should be used to satisfy daily sortie requirements. Finally, we present extensive data‐driven, detailed simulation results, where we compare the performance of the index policies against policies currently used by the Air Force, as well as some other possible more naive heuristics. The results indicate that the index policies significantly outperform existing policies in terms of fully mission capable (FMC) rates. In particular, the experiments highlight the importance of coordinated maintenance and flying decisions. © 2015 Wiley Periodicals, Inc. 62:60–80, 2015  相似文献   
252.
Job shop scheduling with a bank of machines in parallel is important from both theoretical and practical points of view. Herein we focus on the scheduling problem of minimizing the makespan in a flexible two-center job shop. The first center consists of one machine and the second has k parallel machines. An easy-to-perform approximate algorithm for minimizing the makespan with one-unit-time operations in the first center and k-unit-time operations in the second center is proposed. The algorithm has the absolute worst-case error bound of k − 1 , and thus for k = 1 it is optimal. Importantly, it runs in linear time and its error bound is independent of the number of jobs to be processed. Moreover, the algorithm can be modified to give an optimal schedule for k = 2 .  相似文献   
253.
This study examines the failures of the William J. Clinton and Barack Obama administrations to secure ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). It applies an integrated analytical framework for assessing treaty ratification that builds upon previous research in order to understand why the Clinton administration failed to achieve CTBT ratification in 1999 and why the Obama administration has so far failed to advance the treaty in the Senate. The study concludes that CTBT ratification, despite Obama administration pledges of support, remains highly unlikely. Finally, the study analyzes the common domestic political factors present in both cases and suggests areas for further research.  相似文献   
254.
This article investigates the little-known plans formulated by Harold Wilson's Labour government to deploy Polaris submarines in the Indo-Pacific region. The scheme was first proposed in 1965 as a response to several problems faced by British policy-makers, including China's acquisition of a nuclear capability, Britain's wish to maintain a meaningful position ‘East of Suez’ at reduced cost, and German pressure for equal treatment within NATO on nuclear matters. Despite extensive high-level discussion, the plans were finally abandoned in mid-1968, as Labour moved more decisively to forsake the world role.  相似文献   
255.
The Volkssturm (People's Storm or Home Guard) was formed by the Nazi Party in late 1944 as Allied forces closed in on the Reich from the east and west. The political ambitions of Martin Bormann, Hitler's secretary and the head of the Nazi Party Chancellery, were the driving force for this new national organisation. Lacking resources, the Volkssturm's military value was negligible even in eastern Germany where battalions occasionally fought with great tenacity against the Red Army. However, its foundations, character and nature were indicative of the process through which Party power had reached its zenith on the eve of the Third Reich's collapse.  相似文献   
256.
This article examines the implications of the proliferation of cyberwarfare capabilities for the character and frequency of war. Consideration of strategic logic, perceptions, and bargaining dynamics finds that the size of the effect of the proliferation of cyberwarfare capabilities on the frequency of war will probably be relatively small. This effect will not be constant across all situations; in some cases the advent of cyberwarfare capabilities may decrease the likelihood of war. On the other hand, the use of computer network attack as a brute force weapon will probably become increasingly frequent.  相似文献   
257.
Irrespective our views on the rationality of our opponent's continuing to conduct operations against us, unless utterly extirpated, he retains a vote on when and how conflict will end. This is because war is about power — compelling another actor to do something he would not otherwise do, or to cease doing something he would otherwise prefer to do. In planning for conflict termination we should account for the peculiarities of opponents who may decide not to quit when we have beat them fair and square. We do not desire that they cease conventional fighting, but that they cease fighting altogether.  相似文献   
258.
India tends to be deeply apprehensive of threats from China, while China appears comparatively unconcerned about threats from India, and finds it difficult to understand why India might perceive China as a threat. Two explanations of this asymmetry are (1) a deliberate and systematic understatement of Chinese concerns about India, resulting from the mobilization function of China's public media, and (2) the greater effectiveness of China's application of power over the past 50 years.  相似文献   
259.
This article analyzes the main factors that contributed to the failure of the US intelligence community to alert against Soviet intentions and the intervention in the Egyptian–Israeli War of Attrition in 1969–70. Based on fresh archival sources, this research describes the US intelligence conception concerning the USSR; explains the crystallization of the intelligence estimate on the probability of Soviet intervention in 1970; deals with the intelligence data that were acquired but eventually ignored; and concludes with several plausible explanations for the intelligence blunder.  相似文献   
260.
In 1999 India and Pakistan engaged in a limited war in the Himalayan peaks of Kashmir. Pakistani irregulars occupied territory in the Indian-held district of Kargil. A campaign that lasted 74 days and cost each side more than 1,000 casualties concluded with India in control of the commanding heights around Kargil. The conflict exposed flaws in the Indian armed forces as well as enduring truths of combat in the high mountains. Political constraints combined with the unforgiving environment and a determined enemy to diminish India's military advantage. Transition from counterinsurgency to high-intensity combat in the Himalayas proved to be a daunting task. Early failure was only overcome through innovation and adaptation to the environment. Specialised forces, unconventional techniques and the focused application of overwhelming firepower ultimately secured victory.  相似文献   
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