首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   125篇
  免费   2篇
  2019年   2篇
  2018年   1篇
  2017年   1篇
  2016年   5篇
  2015年   2篇
  2014年   4篇
  2013年   48篇
  2011年   1篇
  2010年   2篇
  2009年   1篇
  2008年   3篇
  2005年   1篇
  2004年   1篇
  2001年   1篇
  1998年   3篇
  1997年   1篇
  1996年   3篇
  1995年   2篇
  1993年   1篇
  1992年   4篇
  1990年   1篇
  1986年   3篇
  1985年   3篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   4篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1973年   2篇
  1972年   4篇
  1971年   1篇
  1970年   3篇
  1969年   2篇
  1967年   3篇
  1966年   3篇
排序方式: 共有127条查询结果,搜索用时 15 毫秒
61.
62.
63.

The US Air Force is facing a record shortfall in pilots over the coming decade. Using personnel data on more than 10,000 Air Force pilots, this study examines the factors affecting the retention of pilots and assesses the effectiveness of the pilot bonus programme implemented by the Air Force to reduce attrition. Although surveys indicated sustained deployment rates were the leading cause of job dissatisfaction among Air Force pilots, the results of this study suggest economic factors had the largest impact on retention.  相似文献   
64.
Australia's interest in nuclear weapons in the 1950s and 60s is usually explained in terms of high politics and grand strategy. This proliferation case study explores, in greater detail than hitherto, the important part played by the Royal Australian Air Force (RAAF) in pressing for a nuclear capability. It seeks to understand the reasons behind the RAAF's lobbying, in particular its previous experience with air power, its visceral desire for advanced manned bomber aircraft, and its strong institutional link to the British Royal Air Force. The decision in 1963 to acquire the supersonic US F-111 strike aircraft, instead of rivals including the British TSR.2, is also considered. Once the RAAF's bomber ambitions were satisfied, interest in nuclear weapons was greatly reduced. Finally, some comments are included on the nuclear interests of other air forces in the British Commonwealth.  相似文献   
65.
66.
Optimal control of the production of several products subject to restricted production resources is considered. Linear production, holding and penalty costs are assumed although this is crucial only for production costs. Excess demand results in lost sales. A single point plays an important role in the definition of the optimal policy.  相似文献   
67.
A reliability model for multicomponent multistate systems is presented. This is a generalization of a model previously studied by Hirsch, Meisner, and Boll. In the earlier model, when a failure occurs for which no replacement spare is available, the locations using the same type of part as that having failed are “cannibalized” so as to allocate the shortages to locations where they are least detrimental to system performance. Here, we permit certain restrictions to be imposed upon the cannibalization procedure, and develop effective techniques for relating the probability laws governing the level of system performance to the system structure, cannibalization policy, kit of spare parts, and part reliabilities.  相似文献   
68.
Consider a continuous-time airline overbooking problem that relates to a single-leg flight and a single service class with a stationary fare. Passengers may cancel their reservations at any time and receive a full refund. Therefore fares can be thought of as being paid at flight time. At that time, the airline bumps passengers in excess of flight capacity and pays a penalty for so doing. The wflight-time revenue, that is, fares received less bumping penalties paid, is quasiconcave in the number of reservations at that time. We model the reservations process as a continuous-time terminal-value birth-and-death process. A more general model than is necessary for an airline reservations system is considered, in which the airline controls both the reservation acceptance (birth) and the cancellation (death) rates. In current practice airlines do not control cancellation rates (though other industries do exercise such control, e.g., hotels) and control reservation acceptance rates by declining reservation requests. The more general model might be applied to other targeting applications, such as steering a vehicle through space toward a target location. For the general model a piecewise-constant booking-limit policy is optimal; that is, at all times the airline accepts reservation requests up to a booking limit if the current number of reservations is less than that booking limit, and declines reservation requests otherwise. When the airline is allowed to decline all reservation requests, as is the case in practice, the booking-limit optimal policy defined by using the greatest optimal booking limit at all times is piecewise constant. Moreover, these booking limits fall toward flight time. © 1996 John Wiley & Sons, Inc.  相似文献   
69.
70.
A military cannot hope to improve in wartime if it cannot learn. Ideally, in wartime, formal learning ceases and the application of knowledge begins. But this is optimistic. In 1942, USAAF Eighth Air Force assumed it had the means necessary for victory. In reality, its technique and technology were only potentially – rather than actually – effective. What remained was to create the practice of daylight bombing – to learn. This article (1) recovers a wartime learning process that created new knowledge, (2) tests existing tacit hypotheses in military adaptation research, and (3) offers additional theoretical foundation to explain how knowledge is created in wartime  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号