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   272篇
  免费   9篇
  2020年   7篇
  2019年   5篇
  2018年   5篇
  2017年   10篇
  2016年   8篇
  2015年   8篇
  2014年   6篇
  2013年   78篇
  2012年   2篇
  2011年   5篇
  2010年   5篇
  2009年   3篇
  2008年   2篇
  2007年   4篇
  2006年   3篇
  2005年   5篇
  2004年   4篇
  2003年   4篇
  2002年   3篇
  2001年   4篇
  2000年   3篇
  1999年   6篇
  1998年   5篇
  1997年   2篇
  1996年   3篇
  1995年   9篇
  1994年   4篇
  1992年   5篇
  1991年   3篇
  1990年   2篇
  1989年   4篇
  1988年   2篇
  1986年   6篇
  1985年   8篇
  1984年   2篇
  1983年   2篇
  1981年   2篇
  1980年   4篇
  1978年   5篇
  1977年   2篇
  1976年   2篇
  1975年   3篇
  1974年   6篇
  1973年   5篇
  1972年   1篇
  1971年   1篇
  1970年   3篇
  1969年   1篇
  1968年   2篇
  1967年   2篇
排序方式: 共有281条查询结果,搜索用时 15 毫秒
71.
Dying to Win is one of the most important works on suicide terrorism. It purports to unravel the strategic, social, and individual logic that gives suicide terrorism its coercive value. The methodology that Pape uses to support his various assertions is problematic for three reasons. First, he defines his key terms in such a way as to artificially set suicide terrorism apart from other forms of political violence. Second, in a number of cases Pape selects data from single sources to support particular assertions when other sources of data, used together, could provide more rigorous and useful insights into the phenomenon of suicide bombing. Finally, Pape codes his data on suicide attacks according to a loose set of criteria which, if recoded, calls into question some of his broader conclusions about the strategic utility of suicide terrorism campaigns.  相似文献   
72.
Entering the twenty-first century, China has demonstrated an assertive foreign policy, not only in employing various types of economic and military leverage but also in conducting the Three Warfares (三战) – psychological warfare, public opinion warfare, and legal warfare. This article attempts to identify the motives and methods of China’s Three Warfares by analyzing its history, logic, and agents. Based on this analysis, the author also presents the position of the Three Warfares in China’s foreign policy and the warfares’ impact on the international security environment involving other major powers and China’s neighbors.  相似文献   
73.
In this article we introduce a 2‐machine flowshop with processing flexibility. Two processing modes are available for each task: namely, processing by the designated processor, and processing simultaneously by both processors. The objective studied is makespan minimization. This production environment is encountered in repetitive manufacturing shops equipped with processors that have the flexibility to execute orders either individually or in coordination. In the latter case, the product designer exploits processing synergies between two processors so as to execute a particular task much faster than a dedicated processor. This type of flowshop environment is also encountered in labor‐intensive assembly lines where products moving downstream can be processed either in the designated assembly stations or by pulling together the work teams of adjacent stations. This scheduling problem requires determining the mode of operation of each task, and the subsequent scheduling that preserves the flowshop constraints. We show that the problem is ordinary NP‐complete and obtain an optimal solution using a dynamic programming algorithm with considerable computational requirements for medium and large problems. Then, we present a number of dynamic programming relaxations and analyze their worst‐case error performance. Finally, we present a polynomial time heuristic with worst‐case error performance comparable to that of the dynamic programming relaxations. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.  相似文献   
74.
75.
76.
77.
We deal with the problem of minimizing makespan on a single batch processing machine. In this problem, each job has both processing time and size (capacity requirement). The batch processing machine can process a number of jobs simultaneously as long as the total size of these jobs being processed does not exceed the machine capacity. The processing time of a batch is just the processing time of the longest job in the batch. An approximation algorithm with worst‐case ratio 3/2 is given for the version where the processing times of large jobs (with sizes greater than 1/2) are not less than those of small jobs (with sizes not greater than 1/2). This result is the best possible unless P = NP. For the general case, we propose an approximation algorithm with worst‐case ratio 7/4. A number of heuristics by Uzosy are also analyzed and compared. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 226–240, 2001  相似文献   
78.
Consider a single‐item, periodic review, infinite‐horizon, undiscounted, inventory model with stochastic demands, proportional holding and shortage costs, and full backlogging. Orders can arrive in every period, and the cost of receiving them is negligible (as in a JIT setting). Every T periods, one audits the current stock level and decides on deliveries for the next T periods, thus incurring a fixed audit cost and—when one schedules deliveries—a fixed order cost. The problem is to find a review period T and an ordering policy that satisfy the average cost criterion. The current article extends an earlier treatment of this problem, which assumed that the fixed order cost is automatically incurred once every T periods. We characterize an optimal ordering policy when T is fixed, prove that an optimal review period T** exists, and develop a global search algorithm for its computation. We also study the behavior of four approximations to T** based on the assumption that the fixed order cost is incurred during every cycle. Analytic results from a companion article (where μ/σ is large) and extensive computational experiments with normal and gamma demand test problems suggest these approximations and associated heuristic policies perform well when μ/σ ≥ 2. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 329–352, 2000  相似文献   
79.
The system under study is a single item, two‐echelon production‐inventory system consisting of a capacitated production facility, a central warehouse, and M regional distribution centers that satisfy stochastic demand. Our objective is to determine a system base‐stock level which minimizes the long run average system cost per period. Central to the approach are (1) an inventory allocation model and associated convex cost function designed to allocate a given amount of system inventory across locations, and (2) a characterization of the amount of available system inventory using the inventory shortfall random variable. An exact model must consider the possibility that inventories may be imbalanced in a given period. By assuming inventory imbalances cannot occur, we develop an approximation model from which we obtain a lower bound on the per period expected cost. Through an extensive simulation study, we analyze the quality of our approximation, which on average performed within 0.50% of the lower bound. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 377–398, 2000  相似文献   
80.
In this paper, we consider a new weapon–target allocation problem with the objective of minimizing the overall firing cost. The problem is formulated as a nonlinear integer programming model. We applied Lagrangian relaxation and a branch‐and‐bound method to the problem after transforming the nonlinear constraints into linear ones. An efficient primal heuristic is developed to find a feasible solution to the problem to facilitate the procedure. In the branch‐and‐bound method, three different branching rules are considered and the performances are evaluated. Computational results using randomly generated data are presented. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 640–653, 1999  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