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排序方式: 共有270条查询结果,搜索用时 31 毫秒
251.
针对人脸识别问题提出一种新的监督降维算法。算法首先基于稀疏表示理论,利用同类样本间的稀疏重构来构建图。此方案不仅可以克服传统图构造方法中参数选择的困难,而且能够更好地刻画类内信息。然后,算法采用非参数类间离差来刻画类间信息,非参数类间离差在处理复杂分布数据时相比于参数类间离差更具判别力。最后,算法通过保持类内稀疏重构关系的同时最大化非参数类间离差来求得最优的投影矩阵。在ORL和Extended Yale B公共人脸数据库的实验表明,该算法能够获得较好的识别结果。 相似文献
252.
'Funmi Olonisakin 《African Security Review》2015,24(4):376-389
This article explores the convergence between three pillars of influence – feminist security studies, civil society activism and policy decision-making – and its role in the adoption and implementation of United Nations Security Council Resolution (UNSCR) 1325. It argues that these three pillars, individually and collectively, have made important contributions to the debate and action on the gender and security agenda, but that they remain organically disconnected. Their convergence has the potential to achieve path-breaking results in the sphere of gender and security, whilst their divergence makes transformation unattainable. We show the disconnect in the application of UNSCR 1325 in Africa and argue that this is partly the reason why, despite enormous efforts, the gains realised in terms of gender equality in the peace and security arena have been negligible. 相似文献
253.
Roger Handberg 《Defense & Security Analysis》2015,31(1):44-57
Ballistic missile defense (BMD) politics present an interesting evolution in how the USA, especially Congress, has come to think about BMD both as operational reality and as a symbolic policy. The argument here is that BMD's operational reality is increasingly overshadowed by its symbolic aspects. Such a status arose from rapidly changing international and domestic politics. The end result is a situation in which BMD policy in a sense floats above the question of its actual combat effectiveness. Its primary mission in part is sustaining US capacity to remain a global power and support its allies. 相似文献
254.
This study provides an explanation of terrorism by examining interactions between the terrorist group with a minority as a potential pool of recruits and the government supported by a majority. A hawkish deterrence policy makes it more risky for terrorists to launch attacks, but heightens the anti‐government feeling of the terrorist group. In addition, the payoff for the government depends not only on the payoff loss associated with the level of terrorism, but also on the political payoff from the action itself of adopting a hawk policy due to its politicians’ vested interests. We first show that whether the deterrence policy should be ‘hawk to ‘dove is closely dependent on the relationships among the risk associated with terrorism, the anti‐government feeling of the terrorist group, and the political payoff for the government. This study then introduces transnational support enhancing the capability of a terrorist group to intensify its activity and shows that the emergence of transnational support may cause the government to reform its deterrence policy from ‘dove’ toward ‘hawk,’ with terrorism intensified in the society. 相似文献
255.
Michael W. Chinworth 《Defence and Peace Economics》2013,24(2):369-401
Defense budgets in Japan have been complicated compromises from numerous inputs ‐ including threat perceptions, domestic industrial/technological base development, support for the bilateral security treaty with the United States and internal bureaucratic politics ‐ but with the fall of the former Soviet Union, the clearest justification for higher spending disappeared. Double‐digit defense spending increases that were common in the 1980s have been replaced by annual increases lower than present inflation rates, resulting in negative real growth in the country's defense budget. Domestic economic problems and consistent government pressures for smaller budgets have further slowed annual growth in total spending and have contributed to lower procurement budgets. As a result, the domestic Japanese defense industry is facing far more constrained conditions from the growth years of a decade before. Government policymakers are examining Japan's regional security environment as well as its alliance with the United States to determine the appropriate course for the country to take in the coming years. The formal security treaty with the United States is likely to remain a major element of government positions, but other aspects of the country's overall security posture are open to debate. Perceptions of a reduced threat environment are fueling additional pressures for defense budget cuts. The domestic defense industry seeks means to assure its survival in domestic defense markets in this constrained environment. Expansion into overseas markets to offset declining domestic markets is an option that currently is constrained by policy restrictions on arms exports. Industry is advocating re‐examination of those policies and unlike earlier years, government appears willing to respond positively but cautiously to this lobbying. 相似文献
256.
As a result of allied subsidy and the influence of sunk costs, the marginal cost of the Gulf War to the US was reduced to negligible size. This result is at variance with the Olson‐Zeckhauser thesis that in an alliance “the small exploit the large.” A game theoretic alternative explanation suggests that the relation between allies resembles the game of Chicken, successfully played by the US. The ability to shift the marginal costs of war in the short term raises questions about the possible underestimation of long term effects. 相似文献
257.
Michael Krepon 《The Nonproliferation Review》2013,20(2):457-463
Forecasting Nuclear Proliferation in the 21st Century: The Role of Theory (vol. 1, 312 pages, $24.95) and A Comparative Perspective (vol. 2, 488 pages, $24.95), edited by William C. Potter with Gaukhar Mukhatzhanova. Stanford University Press, 2010. 相似文献
258.
Abdurrahim Sıradağ 《African Security Review》2013,22(3-4):308-325
ABSTRACTTurkey has maintained its strategic relations with Africa at the highest level under recent AK Party governments in the field not only of low politics but also of high politics. For example, it opened its largest overseas military base in Somalia in 2017 and signed military, defense and security pacts with more than 25 African countries. This article traces the deep historical and cultural relations with Africa behind its newly evolving foreign policy identity, arguing that its booming economic power has been a significant driving force in shaping a new security strategy. It examines what the growing security involvement means for both Turkey and Africa in order to contribute to the relevant literature through a holistic approach from both theoretical and conceptual perspectives. 相似文献
259.
Concerns about climate change and energy security have prompted some countries to revive dormant nuclear fission power programs to meet growing energy demands and reduce carbon dioxide emissions. However, this so-called nuclear renaissance based on fission would have major drawbacks in the areas of safety, security, and nonproliferation. Nuclear fusion, however, is portrayed by its proponents as mitigating these drawbacks, and scientists continue to pursue fusion's promise with two large-scale projects: the International Thermonuclear Experimental Reactor (ITER), and the Laser Inertial Fusion Engine (LIFE) reactor. Although supporters often hail fusion as proliferation resistant, the technology could be used to create weapons-usable fissile material. This article explains how fissile material could be created in ITER or LIFE and analyzes other nonproliferation implications of fusion; the authors discuss the various challenges faced by ITER and LIFE. 相似文献
260.
For most firms, especially the small‐ and medium‐sized ones, the operational decisions are affected by their internal capital and ability to obtain external capital. However, the majority of the literature on dynamic inventory control ignores the firm's financial status and financing issues. An important question that arises is: what are the optimal inventory and financing policies for firms with limited internal capital and limited access to external capital? In this article, we study a dynamic inventory control problem where a capital‐constrained firm periodically purchases a product from a supplier and sells it to a market with random demands. In each period, the firm can use its own capital and/or borrow a short‐term loan to purchase the product, with the interest rate being nondecreasing in the loan size. The objective is to maximize the firm's expected terminal wealth at the end of the planning horizon. We show that the optimal inventory policy in each period is an equity‐level‐dependent base‐stock policy, where the equity level is the sum of the firm's capital level and the value of its on‐hand inventory evaluated at the purchasing cost; and the structure of the optimal policy can be characterized by four intervals of the equity level. Our results shed light on the dynamic inventory control for firms with limited capital and short‐term financing capabilities.Copyright © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 184–201, 2014 相似文献