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   382篇
  免费   6篇
  388篇
  2021年   10篇
  2019年   7篇
  2018年   4篇
  2017年   3篇
  2016年   7篇
  2014年   6篇
  2013年   59篇
  2012年   3篇
  2011年   2篇
  2009年   5篇
  2007年   12篇
  2005年   2篇
  2004年   3篇
  2003年   7篇
  2002年   6篇
  2001年   2篇
  2000年   3篇
  1999年   3篇
  1998年   7篇
  1997年   8篇
  1996年   9篇
  1995年   3篇
  1994年   6篇
  1993年   10篇
  1992年   7篇
  1991年   9篇
  1990年   10篇
  1989年   18篇
  1988年   14篇
  1987年   8篇
  1986年   13篇
  1985年   7篇
  1984年   5篇
  1983年   3篇
  1982年   10篇
  1981年   6篇
  1980年   7篇
  1979年   9篇
  1978年   8篇
  1977年   5篇
  1976年   5篇
  1975年   4篇
  1974年   8篇
  1973年   5篇
  1972年   3篇
  1971年   7篇
  1970年   6篇
  1969年   5篇
  1967年   6篇
  1948年   4篇
排序方式: 共有388条查询结果,搜索用时 15 毫秒
211.
212.
213.
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   
214.
Why did the United States, a country notorious for supporting coups and military dictatorships in Latin America during the Cold War, seek to depoliticize security forces in the Caribbean basin during the early twentieth century? Drawing from primary sources, I argue that this emphasis on military non-partisanship abroad stemmed from Progressive Era reforms popular at home. These reforms, which stressed bureaucratic efficiency via nonpartisan expertise, had become institutionalized within the US military and State Department and then channelled into the imperial administration of Nicaragua and the Dominican Republic. The State Department and Marine Corps attempted to replace local partisan armies with the kind of professional, nonpartisan armed forces that the US's own military had come to exemplify. That these civil-military reform efforts ultimately backfired should serve as a reminder of the difficulties inherent in using military interventions to transform coercive apparatuses and their societies.  相似文献   
215.
Many mathematical models have been formulated to describe combat between two weapon systems. However, until recently duel models did not explicitly represent target detection within a duel, leading to the necessity for the development of new model for each tactical situation. An earlier article by two of the authors described a duel between weapons with constant firing times and explicit modeling of detection. This article enhances the study of this form of duel between weapons by introducing a variable parameter for firing times. This enhancement removes the discontinuities evident during parametric analysis of the earlier model and hence provides a more coherent model of this combat situation. © 1993 John Wiley & Sons, Inc.  相似文献   
216.
After first formulating the problem of the Marine Environmental Protection program of the Coast Guard as a multiple-objective linear program, we investigate the applicability and limitations of goal programming. We point out how the preemptive goal-programming approach is incompatible with utility preferences. Then we observe the tendency of optimal solutions for standard linear goal programs to occur at extreme points. We also note problems of more general approaches, such as dealing with additively separable approximations to preferences.  相似文献   
217.
Does the United Nations naming and shaming of specific violations of human rights decrease government repression? In this article, we argue that international shaming of specific human rights violations can weaken the target government, bringing new challenges and making the government cessation of repression less feasible. When international naming and shaming campaigns target specific repressive tactics, they increase the costs of some – but not all – means of repression. Using original data on naming and shaming by the United Nations Human Rights Council (HRC), we show that the shaming of one physical integrity violation is jointly associated with decreases in that violation and increases in other violations of human rights.  相似文献   
218.
A linear programming model for analyzing the strategic deployment mix of airlift and sealift forces and prepositioning to accomplish the composite requirements of a set of possible contingencies is described in this paper. It solves for the least-cost mix of deployment means capable of meeting any one of a spectrum of contingencies, or meeting simultaneous contingencies. The model was developed by RAC as part of the U.S. Army's study program and has been used in analyses of deployment systems conducted in support of the U.S. Army, the Joint Chiefs of Staff and the Office of the Secretary of Defense. Results of analyses have influenced the preparation of long-range plans as well as the formulation of the FY67 Department of Defense budget. The paper gives the background and assumptions of the model, describes the model by means of a simple hypothetical example followed by a selected subset of a complete version, and discusses how the model is used.  相似文献   
219.
Given herein is an easily implemented method for obtaining, from complete or censored data, approximate tolerance intervals associated with the upper tail of a Weibull distribution. These approximate intervals are based on point estimators that make essentially most efficient use of sample data. They agree extremely well with exact intervals (obtained by Monte Carlo simulation procedures) for sample sizes of about 10 or larger when specified survival proportions are sufficiently small. Ranges over which the error in the approximation is within 2 percent are determined. The motivation for investigation of the methodology for obtaining the approximate tolerance intervals was provided by the new formulation of Lanchester Combat Theory by Grubbs and Shuford [3], which suggests a Weibull assumption for time-to-incapacitation of key targets. With the procedures investigated herein, one can use (censored) data from battle simulations to obtain confidence intervals on battle times associated with given low survivor proportions of key targets belonging to either specified side in a future battle. It is also possible to calculate confidence intervals on a survival proportion of key targets corresponding to a given battle duration time.  相似文献   
220.
The absence of formal diplomatic relations between India and Israel from India's hesitant recognition of Israel in 1950 and the establishment of full relations in January 1992, was the result of a complex interplay between two sets of tensions. The first involved the Arab–Israeli dispute, and India's sympathies with a post-colonial Arab world and with the Non-Aligned Movement; the second involved accommodating Muslim opinion within India. Normalization has proceeded more strongly as the growth of Hindu nationalism has weakened Muslim leverage on Indian foreign policy.  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