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41.
This article analyses the disunity among African states in terms of United Nations Security Council (UNSC) reform, and attributes it to the contest between South Africa and Nigeria. These two countries have been locked in a hegemonic contest for continental domination. To this end, the article notes that African unity, not in terms of protocol but on the basis of principles and cooperation, is sacrosanct in order for the African Union to make a significant contribution to the reform of the UNSC. It is asserted that the contest between South Africa and Nigeria has been symbolised by the continental leadership aspirations of the heads of state of both countries, and recommends that it be tamed through forging diplomatic and strategic partnerships between the ruling parties of these two countries. The influence of external actors on the African countries, particularly that of France, is underscored as a contributing factor in stalling the debate on the UNSC reform. It recommends that South Africa use its strategic partnership within the association of Brazil, Russia, India, China and South Africa (BRICS), particularly Russia and China as permanent members of the UNSC, to influence the realisation of the reform debate.  相似文献   
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In September 2011, the Commander of the International Security Assistance Force (ISAF) in Afghanistan directed the Afghan Assessment Group to redesign the way in which ISAF was assessing the status of the war, and to be ‘revolutionary’ in so doing. The resulting assessment paradigm was novel, non-doctrinal, and effectively addressed the unique complexities of the counterinsurgency in Afghanistan and the needs of the ISAF Commander. It had a two-tier structure consisting of both strategic and campaign assessments. The former focused on answering a set of strategic questions in narrative, analytic form to address the strategic environment, while the latter used a set of standards and accompanying narrative responses to gauge accomplishment of campaign tasks. Both tiers captured the current state of the war while maintaining an eye on future challenges and opportunities. The two assessments and their associated processes were designed to stimulate discussions leading directly to decisions by senior leaders on actions they could take, direct, or request. While any assessment paradigm will have advantages and disadvantages, an examination of the pros and cons of this assessment paradigm makes clear that it should be considered a ‘best practice’ in the field of counterinsurgency assessment.  相似文献   
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Measuring nationwide progress of counterinsurgency operations in Afghanistan using violence trends is difficult due to several factors: aggregation of data to the national level may obfuscate disparate local trends; the observed seasonality in violence makes comparisons difficult and may obscure progress; and short-term spikes or troughs – attributable to weather, military operations and tempo, or holiday periods – heavily influence simple averaging schemes. Despite these challenges, proper understanding of violence statistics is critical to estimating the effectiveness of military forces added during a surge or redeployed as part of transition. This article explores methods for analyzing observed violence trends to identify causal factors, to provide a comparable baseline, and to inform assessments at appropriate levels of aggregation. One methodology for seasonal adjustment of violence data is discussed and shown to provide a logical baseline for examining trends. An ordinary least squares regression model is developed and implemented using time-series violence data.  相似文献   
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The bilevel programming problem (BLPP) is a sequence of two optimization problems where the constraint region of the first is determined implicitly by the solution to the second. In this article it is first shown that the linear BLPP is equivalent to maximizing a linear function over a feasible region comprised of connected faces and edges of the original polyhedral constraint set. The solution is shown to occur at a vertex of that set. Next, under assumptions of differentiability, first-order necessary optimality conditions are developed for the more general BLPP, and a potentially equivalent mathematical program is formulated. Finally, the relationship between the solution to this problem and Pareto optimality is discussed and a number of examples given.  相似文献   
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This article considers the empty vehicle redistribution problem in a hub‐and‐spoke transportation system, with random demands and stochastic transportation times. An event‐driven model is formulated, which yields the implicit optimal control policy. Based on the analytical results for two‐depot systems, a dynamic decomposition procedure is presented which produces a near‐optimal policy with linear computational complexity in terms of the number of spokes. The resulting policy has the same asymptotic behavior as that of the optimal policy. It is found that the threshold‐type control policy is not usually optimal in such systems. The results are illustrated through small‐scale numerical examples. Through simulation the robustness of the dynamic decomposition policy is tested using a variety of scenarios: more spokes, more vehicles, different combinations of distribution types for the empty vehicle travel times and loaded vehicle arrivals. This shows that the dynamic decomposition policy is significantly better than a heuristics policy in all scenarios and appears to be robust to the assumptions of the distribution types. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008  相似文献   
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The bilevel programming problem (BLPP) is an example of a two-stage, noncooperative game in which the first player can influence but not control the actions of the second. This article addresses the linear formulation and presents a new algorithm for solving the zero-one case. We begin by converting the leader's objective function into a parameterized constraint, and then attempt to solve the resultant problem. This produces a candidate solution that is used to find a point in the BLPP feasible reagion. Incremental improvements are sought, which ultimately lead to a global optimum. An example is presented to highlight the computations and to demonstrate some basic characteristics of the solution. Computational experience indicates that the algorithm is capable of solving problems with up to 50 variables in a reasonable amount of time.  相似文献   
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