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   260篇
  免费   3篇
  2020年   5篇
  2019年   5篇
  2018年   6篇
  2017年   12篇
  2016年   6篇
  2015年   4篇
  2014年   5篇
  2013年   78篇
  2011年   3篇
  2010年   3篇
  2009年   3篇
  2008年   2篇
  2007年   2篇
  2006年   2篇
  2005年   5篇
  2004年   2篇
  2003年   2篇
  2002年   2篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1995年   8篇
  1994年   5篇
  1993年   4篇
  1992年   7篇
  1991年   9篇
  1989年   4篇
  1988年   3篇
  1987年   6篇
  1986年   4篇
  1985年   7篇
  1984年   2篇
  1983年   3篇
  1980年   5篇
  1979年   1篇
  1978年   4篇
  1977年   2篇
  1976年   2篇
  1975年   3篇
  1974年   6篇
  1973年   4篇
  1972年   1篇
  1971年   1篇
  1970年   3篇
  1969年   1篇
  1968年   2篇
  1967年   1篇
排序方式: 共有263条查询结果,搜索用时 31 毫秒
131.
132.
133.
The Belfast Agreement of 1998 was hailed at the time as a breakthrough in conflict resolution both in Northern Ireland and as a model for international emulation. In fact it has turned out to be neither; rather it has been a sad exercise in surrendering to terrorism and the cause of increased sectarian segregation and enmity. The core of the problem lies in the 'constructive ambiguity' at the heart of the Agreement - that is, a form of words that all could sign up to because each party could interpret them differently. This may have enabled everyone to sign up, but also implied they were signing up to different things and therefore were not in agreement. Consequently clever word games and spin by politicians and senior civil servants have created an, in some ways, worse situation, largely because real, substantive issues were ducked. This in turn has its roots in postmodernism, whose baleful influence can be seen throughout not only the Agreement but most government policy over the past 20 odd years.  相似文献   
134.
This article examines the role of the Macedonian Question in the 1944 December Uprising (Dekemvriana) in Greece. While the Dekemvriana is commonly portrayed in right–left terminology in the historiography, this article argues that part of the reason for the left’s failure was their inability to manage the Macedonian ethnic component of the struggle, either within their armed forces or in their relationship with Yugoslavia. As such, this article integrates the early phases of the Greek Civil War into the broader literature on minorities in civil conflict, while simultaneously exposing some of the myths about Macedonian involvement that result from its contemporary political ramifications.  相似文献   
135.
136.
This article addresses the inventory placement problem in a serial supply chain facing a stochastic demand for a single planning period. All customer demand is served from stage 1, where the product is stored in its final form. If the demand exceeds the supply at stage 1, then stage 1 is resupplied from stocks held at the upstream stages 2 through N, where the product may be stored in finished form or as raw materials or subassemblies. All stocking decisions are made before the demand occurs. The demand is nonnegative and continuous with a known probability distribution, and the purchasing, holding, shipping, processing, and shortage costs are proportional. There are no fixed costs. All unsatisfied demand is lost. The objective is to select the stock quantities that should be placed different stages so as to maximize the expected profit. Under reasonable cost assumptions, this leads to a convex constrained optimization problem. We characterize the properties of the optimal solution and propose an effective algorithm for its computation. For the case of normal demands, the calculations can be done on a spreadsheet. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48:506–517, 2001  相似文献   
137.
This paper considers the scheduling problem to minimize total tardiness given multiple machines, ready times, sequence dependent setups, machine downtime and scarce tools. We develop a genetic algorithm based on random keys representation, elitist reproduction, Bernoulli crossover and immigration type mutation. Convergence of the algorithm is proved. We present computational results on data sets from the auto industry. To demonstrate robustness of the approach, problems from the literature of different structure are solved by essentially the same algorithm. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 199–211, 1999  相似文献   
138.
Least squares fitting of regression models is a widely used technique. The presence of outliers in the data can have an adverse effect on the method of least squares, resulting in a model that does not adequately fit to the bulk of the data. For this situation, robust regression techniques have been proposed as an improvement to the method of least squares. We propose a robust regression procedure that performs well relative to the current robust methods against a variety of dataset types. Evaluations are performed using datasets without outliers (testing efficiency), with a large percentage of outliers (testing breakdown), and with high leverage outliers (testing bounded influence). The datasets are based on 2-level factorial designs that include axial points to evaluate leverage effects. A Monte Carlo simulation approach is used to evaluate the estimating capability of the proposed procedure relative to several competing methods. We also provide an application to estimating costs for government satellites. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 125–139, 1998  相似文献   
139.
Recent developments in artificial intelligence (AI) suggest that this emerging technology will have a deterministic and potentially transformative influence on military power, strategic competition, and world politics more broadly. After the initial surge of broad speculation in the literature related to AI this article provides some much needed specificity to the debate. It argues that left unchecked the uncertainties and vulnerabilities created by the rapid proliferation and diffusion of AI could become a major potential source of instability and great power strategic rivalry. The article identifies several AI-related innovations and technological developments that will likely have genuine consequences for military applications from a tactical battlefield perspective to the strategic level.  相似文献   
140.
We study stochastic clearing systems with a discrete-time Markovian input process, and an output mechanism that intermittently and instantaneously clears the system partially or completely. The decision to clear the system depends on both quantities and delays of outstanding inputs. Clearing the system incurs a fixed cost, and outstanding inputs are charged a delay penalty, which is a general increasing function of the quantities and delays of individual inputs. By recording the quantities and delays of outstanding inputs in a sequence, we model the clearing system as a tree-structured Markov decision process over both a finite and infinite horizon. We show that the optimal clearing policies, under realistic conditions, are of the on-off type or the threshold type. Based on the characterization of the optimal policies, we develop efficient algorithms to compute parameters of the optimal policies for such complex clearing systems for the first time. We conduct a numerical analysis on the impact of the nonlinear delay penalty cost function, the comparison of the optimal policy and the classical hybrid policy (ie, quantity and age thresholds), and the impact of the state of the input process. Our experiments demonstrate that (a) the classical linear approximation of the cost function can lead to significant performance differences; (b) the classical hybrid policy may perform poorly (as compared to the optimal policies); and (c) the consideration of the state of the input process makes significant improvement in system performance.  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