全文获取类型
收费全文 | 654篇 |
免费 | 12篇 |
出版年
2021年 | 12篇 |
2019年 | 22篇 |
2018年 | 12篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 130篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2005年 | 9篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1998年 | 11篇 |
1997年 | 19篇 |
1996年 | 10篇 |
1995年 | 8篇 |
1994年 | 15篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 17篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 21篇 |
1986年 | 12篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 10篇 |
1973年 | 14篇 |
1972年 | 8篇 |
1971年 | 7篇 |
1970年 | 8篇 |
1969年 | 9篇 |
1968年 | 6篇 |
1967年 | 7篇 |
排序方式: 共有666条查询结果,搜索用时 0 毫秒
401.
402.
403.
404.
This article presents a flexible days‐on and days‐off scheduling problem and develops an exact branch and price (B&P) algorithm to find solutions. The main objective is to minimize the size of the total workforce required to cover time‐varying demand over a planning horizon that may extend up to 12 weeks. A new aspect of the problem is the general restriction that the number of consecutive days on and the number of consecutive days off must each fall within a predefined range. Moreover, the total assignment of working days in the planning horizon cannot exceed some maximum value. In the B&P framework, the master problem is stated as a set covering‐type problem whose columns are generated iteratively by solving one of three different subproblems. The first is an implicit model, the second is a resource constrained shortest path problem, and the third is a dynamic program. Computational experiments using both real‐word and randomly generated data show that workforce reductions up to 66% are possible with highly flexible days‐on and days‐off patterns. When evaluating the performance of the three subproblems, it was found that each yielded equivalent solutions but the dynamic program proved to be significantly more efficient. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 678–701, 2013 相似文献
405.
Peter M. Sales 《Small Wars & Insurgencies》2013,24(1):93-97
Recent counterinsurgency experiences in Iraq and Afghanistan have demonstrated that the local operating environment often is dominated by indigenous power-holders. As counterinsurgents seek to establish control over the local population, collaboration with these agents has become an essential aspect of contemporary counterinsurgency. Although the practice of constructing collaborative relationships with indigenous power-holders might be perceived as unconventional by today's counterinsurgents, the approach itself goes back to the colonial era in which modern counterinsurgency has its roots. This article explores the dynamics, benefits, and dangers of collaborative relationships with indigenous power-holders by analysing an infamous episode in Dutch colonial history, the case of the collaboration between Dutch colonial authorities and warlord Teuku Uma during the Aceh War (1873–1913). This relationship ended in disaster for the Dutch as Uma departed their side at the moment he had become their pivotal asset in the local political landscape. The article explains that the Dutch succeeded to co-opt Uma, but failed to control him as they lacked the will and means to do so. Furthermore this case study provides an insight in the way the Dutch colonial authorities dealt with the complex process of intelligence-gathering in a fragmented indigenous society. 相似文献
406.
Robert Citino 《战略研究杂志》2013,36(2):324-344
It is common to attribute the operational difficulties faced by post-Napoleonic armies to an increase in defensive firepower. In fact, the immense ‘mass armies’ of the day also suffered from problems of command, control and information that ultimately worked to their undoing. The German achievement in the interwar period went beyond tanks and aircraft. It also involved harnessing the radio to the service of the field army. Radio made it possible to coordinate mobile masses of men and equipment and to process the huge amounts of information they generated. The smooth flow of information was key to the Wehrmacht's revival of decisive battlefield victory in 1939–40. 相似文献
407.
Casualty figures suggest that the US/Allied Counter Improvised Explosive Device (C-IED) policy and the present allocation of national assets, resources, and intellectual capital have not been very successful. A number of explanations for why this has been the case are discussed and critiqued here. 相似文献
408.
409.
A. S. Andreou K. E. Parsopoulos M. N. Vrahatis G. A. Zombanakis 《Defence and Peace Economics》2013,24(4):329-347
The aim of this paper is to indicate the extent to which the arms race against Turkey, in which Greece and Cyprus have been entangled, imposes a defence expenditure burden that is tough for the two allies to bear. To do so we have resorted to evaluating the optimal military expenditure for the two countries, allied in the context of the Integrated Defence Doctrine, which is compatible with the constraints imposed by the resources of their economies. All experiments and scenarios examined lead to the conclusion that the current defence burden of the two allies seems to be driving their economies beyond capacity limits. The fact remains, however, that under the circumstances, a one-sided disarmament policy like the one currently followed by Greece, is a risky choice given that the long-term armament programmes pursued by Turkey, whose role in this arms race has been proven as leading, leave very small room to the Greek and Cypriot sides to reduce their own defence expenditure. 相似文献
410.
W. Robert J. Alexander 《Defence and Peace Economics》2013,24(2):213-221
The issue of guns or butter is one of the most fundamental economic questions, yet there is no consensus on a theoretical framework for examining it. Over the last decade, a version of a simple Keynesian macroeconomic model has been applied a number of times to examining the link between defence spending and economic growth in a range of countries. There are reasons for doubting the soundness of this model as a basis for empirical work. 相似文献