全文获取类型
收费全文 | 197篇 |
免费 | 9篇 |
出版年
2021年 | 1篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 69篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有206条查询结果,搜索用时 15 毫秒
141.
This article aims to review some of the key lessons learnt by the Royal Ulster Constabulary's (RUC) Special Branch in the 37 years of the troubles in Northern Ireland. Above all counter-terrorism is an intelligence led operation and Special Branch are the key agency for this in all UK police forces, who have now benefited enormously from the expertise that the RUC's Special Branch built up over the years and have passed on to their colleagues throughout the UK. Intelligence is more often than not a human role and relies on human agencies, which was the case in Northern Ireland. The bulk of intelligence gathering was carried out at quite low levels although the sifting and analysing of it became a more specialist skill. Electronic intelligence and computerised systems were often quite low down in the order of priorities and uses, which tends to confound popular impressions. Agents, informers and good old fashioned ‘coppers’ who knew their patch were much more important both in terms of gathering information and in terms of undermining the terrorists morale from within and it was these factors that fundamentally defeated the IRA in Northern Ireland. 相似文献
142.
Michael Brzoska 《Defence and Peace Economics》2013,24(1):67-80
Available sources value transfers of weapons irrespective of whether they are paid for and how. Data from the U.S. indicates that the shares of arms given for free or on credit are high. If other arms exporters, all military aid and all credits used for military purposes are considered, which is done here on the basis of rough estimates and an opportunity cost model, the true cash costs of weapons in the year of the actual transfer are small. On the other hand, the financial burden of earlier arms imports via debt service has grown over time. It most probably exceeded the true cash cost of imports of arms in the late 1980s. Large differences between arms transfer data and the actual true costs of arms transfers means that analysis of the economic effects of arms imports without considering these financial aspects makes little sense. 相似文献
143.
Bruce G. Linster Richard L. Fullerton Michael Mckee Stephen Slate 《Defence and Peace Economics》2013,24(4):285-302
This paper experimentally tests a number of hypotheses that follow from models of international competition that are based on Tullock style rent‐seeking models. Specifically, we designed and performed experiments to see how variations in the degree of publicness in the prize as well as changes in the values assigned to the prize affect alliances in terms of individual nation contributions, total contributions, burden sharing, and the likelihood of winning the prize. While there was substantial variation in individual behavior, the results of the experiments generally conform to the theoretical predictions of the rent‐seeking model of international competition and alliances. 相似文献
144.
Michael D. Gordin 《The Nonproliferation Review》2013,20(2):375-380
Five Myths about Nuclear Weapons, by Ward Wilson. Houghton Mifflin Harcourt, 2013. 188 pages, $22. 相似文献
145.
146.
Tactical learning is critical to battlefield success, especially in a counterinsurgency. This article tests the existing model of military adaption against a ‘most-likely’ case: the British Army’s counterinsurgency in the Southern Cameroons (1960–61). Despite meeting all preconditions thought to enable adaptation – decentralization, leadership turnover, supportive leadership, poor organizational memory, feedback loops, and a clear threat – the British still failed to adapt. Archival evidence suggests politicians subverted bottom-up adaptation, because winning came at too high a price in terms of Britain’s broader strategic imperatives. Our finding identifies an important gap in the extant adaptation literature: it ignores politics. 相似文献
147.
This article is concerned with the determination of pricing strategies for a firm that in each period of a finite horizon receives replenishment quantities of a single product which it sells in two markets, for example, a long‐distance market and an on‐site market. The key difference between the two markets is that the long‐distance market provides for a one period delay in demand fulfillment. In contrast, on‐site orders must be filled immediately as the customer is at the physical on‐site location. We model the demands in consecutive periods as independent random variables and their distributions depend on the item's price in accordance with two general stochastic demand functions: additive or multiplicative. The firm uses a single pool of inventory to fulfill demands from both markets. We investigate properties of the structure of the dynamic pricing strategy that maximizes the total expected discounted profit over the finite time horizon, under fixed or controlled replenishment conditions. Further, we provide conditions under which one market may be the preferred outlet to sale over the other. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 531–549, 2015 相似文献
148.
We consider a parallel‐machine scheduling problem with jobs that require setups. The duration of a setup does not depend only on the job just completed but on a number of preceding jobs. These setup times are referred to as history‐dependent. Such a scheduling problem is often encountered in the food processing industry as well as in other process industries. In our model, we consider two types of setup times—a regular setup time and a major setup time that becomes necessary after several “hard‐to‐clean” jobs have been processed on the same machine. We consider multiple objectives, including facility utilization, flexibility, number of major setups, and tardiness. We solve several special cases assuming predetermined job sequences and propose strongly polynomial time algorithms to determine the optimal timing of the major setups for given job sequences. We also extend our analysis to develop pseudopolynomial time algorithms for cases with additional objectives, including the total weighted completion time, the total weighted tardiness, and the weighted number of tardy jobs. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012 相似文献
149.
Michael J. Armstrong 《海军后勤学研究》2007,54(1):66-77
This article considers two related questions of tactics in the context of the salvo model for naval missile combat. For a given set of targets, how many missiles should be fired to produce an effective attack? For a given available salvo size, how many enemy targets should be fired at? In the deterministic version of the model I derive a simple optimality relationship between the number of missiles to fire and the number of targets to engage. In the stochastic model I employ the expected loss inflicted and the probability of enemy elimination as the main performance measures and use these to derive salvo sizes that are in some sense “optimal.” I find that the offensive firepower needed for an effective attack depends not only on a target's total strength but also on the relative balance between its active defensive power and passive staying power. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献
150.
We develop a heuristic procedure for partitioning graphs into clusters of nodes such that each cluster of nodes induces a connected subgraph with the objective of minimizing the differences within clusters as measured by the total differences between all pairs of nodes of a cluster. We apply our procedure to determine optimal delivery zones for community sections of a major newspaper while including a number of operational constraints. Our results demonstrate a 18–56% improvement in the total differences within the zones designed over the usual intuitive heuristics. Given the magnitude of the revenue generated by larger local newspapers through zoning, our method demonstrates how better zoning can significantly enhance the value of segmentation. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005. 相似文献