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   308篇
  免费   15篇
  2021年   5篇
  2020年   4篇
  2019年   9篇
  2017年   6篇
  2016年   8篇
  2015年   8篇
  2013年   54篇
  2011年   5篇
  2009年   3篇
  2008年   3篇
  2007年   8篇
  2006年   3篇
  2005年   4篇
  2004年   5篇
  2003年   4篇
  2002年   7篇
  2001年   3篇
  1999年   11篇
  1998年   4篇
  1997年   2篇
  1996年   5篇
  1995年   4篇
  1994年   6篇
  1993年   7篇
  1992年   8篇
  1991年   12篇
  1990年   5篇
  1989年   5篇
  1988年   8篇
  1987年   7篇
  1986年   6篇
  1985年   3篇
  1984年   4篇
  1982年   4篇
  1981年   5篇
  1980年   4篇
  1979年   4篇
  1978年   7篇
  1977年   3篇
  1976年   2篇
  1975年   3篇
  1974年   6篇
  1973年   6篇
  1972年   2篇
  1971年   10篇
  1970年   2篇
  1969年   3篇
  1968年   4篇
  1967年   5篇
  1966年   7篇
排序方式: 共有323条查询结果,搜索用时 15 毫秒
21.
Some U.S. military leaders have asserted that the United States, Japan, Australia, and India and the Republic of Korea are developing multilateral defense cooperation to deter aggression and uphold norms much like North Atlantic Treaty Organization (NATO) has in Europe. Frequent military exercises and China’s threats to freedom of navigation (FoN) and North Korea’s nuclear missiles comprise the motive force for such cooperation. However, cooperation thus far has been trilateral and minimal, given divergent national interests and dispersed geopolitical locations. Cooperation among Japan, Republic of Korea (ROK), and the United States is increasing given the threat, but ROK’s public opinion is divided about Japan. Australia, Japan, and India have increased cooperation with the United States but are reluctant to conduct FoN operations with the United States to challenge China’s expansionism in the South China Sea. If China becomes more aggressive and blocks FoN or seizes territory, development toward an Asian NATO is possible.  相似文献   
22.
This article synthesizes three elements of power and balancing in the South China Sea (SCS): analytical perspectives on China's behaviour and intentions, the American rebalance to Asia and the dispositions of American allies and partners. Based on extensive interviews and theoretical analysis, it concludes that ‘soft balancing’ backed by American military power provides the optimum chance for resolving the growing dispute. Short to medium-term weakness of Malaysia, Philippines and Vietnam, as well as Japan, means the United States must provide much of the military power while working to build their forces. The most promising alternative is multilateral diplomacy through the Association of Southeast Asian Nations’ Regional Forum, a vehicle for negotiating a Code of Conduct and implementation of the UN Convention on the Law of the Sea. If China remains motivated mainly by defense of realist interests, the costs imposed against expansion will eventually cause recalculation of Beijing's strategy, and soft balancing by the United States and its partners has a chance of working. The constructivist perspective, stressing self-conceptualization of Chinese strategic culture, supports Chinese confidence that patience will eventually bring dominance. If China tries offensively to change the status quo, soft balancing is less likely to influence Beijing. President Xi Jin Ping appears to be offensively asserting power, seeking regional dominance before he is due to step down in 2023. This supports the finding of enhanced risks of unintended escalation in the SCS and the East China Sea.  相似文献   
23.
We consider the problem of sequencing n jobs on a single machine, with each job having a processing time and a common due date. The common due date is assumed to be so large that all jobs can complete by the due date. It is known that there is an O(n log n)‐time algorithm for finding a schedule with minimum total earliness and tardiness. In this article, we consider finding a schedule with dual criteria. The primary goal is to minimize the total earliness and tardiness. The secondary goals are to minimize: (1) the maximum earliness and tardiness; (2) the sum of the maximum of the squares of earliness and tardiness; (3) the sum of the squares of earliness and tardiness. For the first two criteria, we show that the problems are NP‐hard and we give a fully polynomial time approximation scheme for both of them. For the last two criteria, we show that the ratio of the worst schedule versus the best schedule is no more than . © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 422–431, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10020  相似文献   
24.
In this article, we consider the concurrent open shop scheduling problem to minimize the total weighted completion time. When the number of machines is arbitrary, the problem has been shown to be inapproximable within a factor of 4/3 ‐ ε for any ε > 0 if the unique games conjecture is true in the literature. We propose a polynomial time approximation scheme for the problem under the restriction that the number of machines is fixed. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011  相似文献   
25.
In this article, we discuss the optimal allocation problem in a multiple stress levels life‐testing experiment when an extreme value regression model is used for statistical analysis. We derive the maximum likelihood estimators, the Fisher information, and the asymptotic variance–covariance matrix of the maximum likelihood estimators. Three optimality criteria are defined and the optimal allocation of units for two‐ and k‐stress level situations are determined. We demonstrate the efficiency of the optimal allocation of units in a multiple stress levels life‐testing experiment by using real experimental situations discussed earlier by McCool and Nelson and Meeker. Monte Carlo simulations are used to show that the optimality results hold for small sample sizes as well. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007  相似文献   
26.
27.
We consider the problem of scheduling a set of n jobs on a single batch machine, where several jobs can be processed simultaneously. Each job j has a processing time pj and a size sj. All jobs are available for processing at time 0. The batch machine has a capacity D. Several jobs can be batched together and processed simultaneously, provided that the total size of the jobs in the batch does not exceed D. The processing time of a batch is the largest processing time among all jobs in the batch. There is a single vehicle available for delivery of the finished products to the customer, and the vehicle has capacity K. We assume that K = rD, where and r is an integer. The travel time of the vehicle is T; that is, T is the time from the manufacturer to the customer. Our goal is to find a schedule of the jobs and a delivery plan so that the service span is minimized, where the service span is the time that the last job is delivered to the customer. We show that if the jobs have identical sizes, then we can find a schedule and delivery plan in time such that the service span is minimum. If the jobs have identical processing times, then we can find a schedule and delivery plan in time such that the service span is asymptotically at most 11/9 times the optimal service span. When the jobs have arbitrary processing times and arbitrary sizes, then we can find a schedule and delivery plan in time such that the service span is asymptotically at most twice the optimal service span. We also derive upper bounds of the absolute worst‐case ratios in both cases. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 470–482, 2015  相似文献   
28.
29.
30.
This paper presents a model for choosing a minimum-cost mix of strategic defenses to assure that specified production capacities for several economic sectors survive after a nuclear attack. The defender selects a mix of strategic defenses for each of several geographic regions. The attacker chooses an allocation of attacking weapons to geographic regions, within specified weapon inventories. The attack is optimized against any economic sector. This formulation allows the defense planner the capability to assess the results of the optimal defense structure for a “worst case” attack. The model is a mathematical program with nonlinear programming problems in the constraints; an example of its application is given and is solved using recently developed optimization techniques.  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