全文获取类型
收费全文 | 563篇 |
免费 | 14篇 |
出版年
2019年 | 12篇 |
2017年 | 17篇 |
2016年 | 10篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 109篇 |
2012年 | 5篇 |
2011年 | 5篇 |
2010年 | 8篇 |
2009年 | 11篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 11篇 |
2003年 | 5篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 12篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 15篇 |
1993年 | 14篇 |
1992年 | 8篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 14篇 |
1987年 | 15篇 |
1986年 | 16篇 |
1985年 | 12篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 12篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1973年 | 7篇 |
1972年 | 9篇 |
1971年 | 4篇 |
1970年 | 9篇 |
1969年 | 6篇 |
1968年 | 4篇 |
1967年 | 6篇 |
排序方式: 共有577条查询结果,搜索用时 15 毫秒
161.
The problem of determining the sample sizes in various strata when several characteristics are under study is formulated as a nonlinear multistage decision problem. Dynamic programming is used to obtain an integer solution to the problem. © 1997 John Wiley & Sons, Inc. 相似文献
162.
Robbie J. Totten 《Defense & Security Analysis》2015,31(3):199-212
What are relationships between epidemics, national security, and US immigration policy? This question is important because it sheds light on transnational or nontraditional security areas, American immigration policy, and a pressing issue for US leaders who have recently faced epidemics such as the West Africa Ebola outbreak that began in 2013. This article answers it and lays ground in the area by reviewing epidemics in world history, using International Relations and Security Studies works to specify dangers of contagions for states, and identifying three general immigration measures that American leaders have utilized from the seventeenth century to the present day to protect against contagions, which are (1) policies restricting entrance of foreigners thought to carry specified diseases, (2) the isolation or quarantining of immigrants with contagious disease, and (3) delegating the President with authority to stop immigration in the event of an epidemic abroad. This study has implications for research and contemporary US immigration policy. 相似文献
163.
Stephen J. Cimbala 《Defense & Security Analysis》2017,33(3):193-208
Nuclear deterrence and cyber war seem almost antithetical in their respective intellectual pedigrees. Nuclear weapons are unique in their ability to create mass destruction in a short time. Information or “cyber” weapons, at least for the most part, aim at sowing confusion or mass disruption instead of widespread physical destruction. Nevertheless, there are some intersections between cyber and nuclear matters, and these have the potential to become troublesome for the future of nuclear deterrence. For example, cyber attacks might complicate the management of a nuclear crisis. As well, information attacks on command-control and communications systems might lead to a mistaken nuclear launch based on false warnings, to erroneous interpretations of data or to panic on account of feared information blackout. It is not inconceivable that future nuclear strike planning will include a preliminary wave of cyber strikes or at least a more protracted “preparation of the battlefield” by roaming through enemy networks to plant malware or map vulnerabilities. 相似文献
164.
This article examines challenges in international nuclear safeguards pertaining to the timely detection of highly enriched uranium production at large-scale gas centrifuge enrichment plants. To establish where present gas centrifuge enrichment plant safeguards measures and approaches could be strengthened, we have created a discrete time model for simulating hypothetical misuse scenarios, both through transient phases and at steady-state. We find that timely detection of misuse at modern large-scale facilities presents a challenge for international safeguards. A toolbox of unattended measurement systems, along with remote monitoring, however, could be used to improve detection timeliness, enabling the initiation of follow-up activities, potentially on a rapid time scale. These measures, which would need very low false alarm rates, should be implemented in a graded approach, depending on the characteristics of each enrichment plant and an analysis of plausible acquisition paths for the State in which it is situated. Some of these technologies could provide significant benefit to plant operators. 相似文献
165.
Brenda J. Lutz 《Small Wars & Insurgencies》2014,25(5-6):1039-1054
John Brown is usually not considered to have been a terrorist, and even recent analyses of his activities consider him to be a guerrilla fighter or insurgent in his activities in Kansas. Brown, however, meets the criteria of a terrorist more than a guerrilla fighter when his activities in the Kansas Territory are considered. His raid on Harpers Ferry, however, is more in line with guerrilla operations or insurgent activities. 相似文献
166.
167.
Constructing a strict total order for alternatives characterized by multiple criteria: An extension 下载免费PDF全文
Akram Dehnokhalaji Pekka J. Korhonen Murat Köksalan Nasim Nasrabadi Diclehan Tezcaner Öztürk Jyrki Wallenius 《海军后勤学研究》2014,61(2):155-163
The problem of finding a strict total order for a finite set of multiple criteria alternatives is considered. Our research extends previous work by us, which considered finding a partial order for a finite set of alternatives. We merge the preference information extracted from the preference cones and corresponding polyhedral sets, with the information derived from pairwise comparisons of two alternatives, yielding a preference matrix. This preference matrix is used as input to an integer programming model to obtain a strict total order that provides a transitive ranking for the set of alternatives. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 155–163, 2014 相似文献
168.
In most western countries, there is a strong incentive for defence department budget-holders to expend all of the funds they are authorized to spend in a fiscal year. In this paper, we question whether this emphasis makes sense. We develop a model of a defence department’s operating expenditure assuming a fixed level of funding for a year and uncertain costs. The results of the model suggest that the incentive for departmental managers to expend all authorized funds is inefficient. We explore the implications of the model for the Department of National Defence (DND) in Canada in light of the recent criticism of DND lapsed funding by the Auditor-General of Canada. 相似文献
169.
This paper provides a political economy analysis of the evolution of unmanned aerial vehicles (UAV), or ‘drones’ in the USA. Focus is placed on the interplay between the polity and private economic influences, and their impact on the trajectory of political, economic, and military outcomes. We identify the initial formation of the drone industry, trace how the initial relationships between the military and the private sector expanded over time, and discuss present relationships. Understanding the historical evolution of UAV technology, as well as the major players in the industry today, is important for ongoing policy debates regarding the use of drones both domestically and internationally. 相似文献
170.