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11.
Unlike most of the literature, this paper includes domestic political considerations in which two countries must decide defensive countermeasures against a common terrorist threat. A delegation problem arises as voters strategically choose a policymaker whose preferences differ from their own. As a consequence, countries limit the presumed oversupply of defensive countermeasures. Thus, the inclusion of domestic politics gives a new perspective on counterterrorism. The timing of elections is also shown to make a difference.  相似文献   
12.
In this paper we consider the problem of minimizing the costs of outsourcing warranty repairs when failed items are dynamically routed to one of several service vendors. In our model, the manufacturer incurs a repair cost each time an item needs repair and also incurs a goodwill cost while an item is awaiting and undergoing repair. For a large manufacturer with annual warranty costs in the tens of millions of dollars, even a small relative cost reduction from the use of dynamic (rather than static) allocation may be practically significant. However, due to the size of the state space, the resulting dynamic programming problem is not exactly solvable in practice. Furthermore, standard routing heuristics, such as join‐the‐shortest‐queue, are simply not good enough to identify potential cost savings of any significance. We use two different approaches to develop effective, simply structured index policies for the dynamic allocation problem. The first uses dynamic programming policy improvement while the second deploys Whittle's proposal for restless bandits. The closed form indices concerned are new and the policies sufficiently close to optimal to provide cost savings over static allocation. All results of this paper are demonstrated using a simulation study. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005  相似文献   
13.
A population of items which break down at random times and require repair is studied (the classic “machine repair problem with spares”). It is desired to determine the number of repair channels and spares required over a multiyear planning horizon in which population size and component reliability varies, and a service level constraint is imposed. When an item fails, a spare (if available) is immediately dispatched to replace the failed item. The failed item is removed, transported to the repair depot, repaired, and then placed in the spares pool (which is constrained to be empty not more than 10% of the time) unless there is a backlog of requests for spares, in which case it is dispatched immediately. The first model considered treats removal, transportation, and repair as one service operation. The second model is a series queue which allows for the separate treatment of removal, transportation, and repair. Breakdowns are assumed Poisson and repair times exponential.  相似文献   
14.
Given the nature of global counterinsurgency operations, the demands of military expansion, and the need for cultural, linguistic, and regional expertise, the United States Army should evaluate the establishment of US-led foreign troop units for its evolving force structure. This article proposes the creation of an American foreign legion based upon the recruitment of US-led, ethnically homogeneous tribal force units to meet the grist mill of counterinsurgency operations. This structured approach would be more beneficial than the current reliance on a de facto American Foreign Legion, represented by private military contractors (PMCs), many of them comprised of foreigners. These PMCs carry a number of oversight, accountability, and legal risks not found in a fully integrated, and US-officered foreign legion. The British Brigade of Gurkhas, the South-West African Police Counter-Insurgency Unit (Koevoet), and the Kit Carson Scouts serve as relevant historical examples where foreign troops were used to supplement national manpower resources.  相似文献   
15.
This essay will discuss two of the key pillars of asymmetry: notably Information Operations and terrorism, including the links between the two. While a great deal changed on 11 September 2001, one thing that has not changed in substance is the challenge of protecting the Information Society, notably from cyber-threats. Although the immediate threat to Western societies is from the physical and possibly bio-weapons favoured by Al Qaeda and its associates, it is time now to prepare for future threats to the information society, including cyber-threats.  相似文献   
16.

The paper looks at various scenarios of possible concern for intervening third parties when two factions are engaged in a conflict and act strategically against one another. A standard conflict model is used to determine appropriate intervention strategies in order to lower the overall level of conflict. Choosing a suitable strategy in such a setting, the third party must not only take into account the direct impact of its efforts but also the indirect impacts that result from the strategic interaction among the parties involved.  相似文献   
17.
In March 2011, President Barack Obama ordered US air and naval forces to commence Operation Odyssey Dawn in Libya to impose a no-fly zone. The decision by the Obama Administration to intervene in a limited and supporting role in Libya is an important development in US foreign policy. Operation Odyssey Dawn presents scholars with a valuable opportunity to analyze and explore how US foreign policy is made and what roles domestic politics and elite perceptions play in decisions to use force. The author argues that neoclassical realism is a useful and compelling theoretic framework with which to analyze Operation Odyssey Dawn. While the Administration intervened in response to perceived external-level threats to US national interests, salient intervening domestic-level variables and elite perceptions shaped and guided the tenor and scope of the operation.  相似文献   
18.
Consider a patrol problem, where a patroller traverses a graph through edges to detect potential attacks at nodes. An attack takes a random amount of time to complete. The patroller takes one time unit to move to and inspect an adjacent node, and will detect an ongoing attack with some probability. If an attack completes before it is detected, a cost is incurred. The attack time distribution, the cost due to a successful attack, and the detection probability all depend on the attack node. The patroller seeks a patrol policy that minimizes the expected cost incurred when, and if, an attack eventually happens. We consider two cases. A random attacker chooses where to attack according to predetermined probabilities, while a strategic attacker chooses where to attack to incur the maximal expected cost. In each case, computing the optimal solution, although possible, quickly becomes intractable for problems of practical sizes. Our main contribution is to develop efficient index policies—based on Lagrangian relaxation methodology, and also on approximate dynamic programming—which typically achieve within 1% of optimality with computation time orders of magnitude less than what is required to compute the optimal policy for problems of practical sizes. © 2014 Wiley Periodicals, Inc. Naval Research Logistics, 61: 557–576, 2014  相似文献   
19.
A single server is faced with a collection of jobs of varying duration and urgency. Each job has a random lifetime during which it is available for nonpreemptive service. Should a job's lifetime expire before its service begins then it is lost from the system unserved. The goal is to schedule the jobs for service to maximize the expected number served to completion. Two heuristics have been proposed in the literature. One (labeled πS) operates a static priority among the job classes and works well in a “no premature job loss” limit, whereas the second (πM) is a myopic heuristic which works well when lifetimes are short. Both can exhibit poor performance for problems at some distance from the regimes for which they were designed. We develop a robustly good heuristic by an approximative approach to the application of a policy improvement step to the asymptotically optimal heuristic πS, in which we use a fluid model to obtain an approximation for the value function of πS. The performance of the proposed heuristic is investigated in an extensive numerical study. © 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010  相似文献   
20.
Following a classic Maoist revolutionary war strategy, with both Guevarian and Giapist elements, the African National Congress (ANC) attempted to overthrow, through revolutionary violence, the apartheid government of South Africa. This struggle, which began in 1961 and was eventually suspended in mid-1990, witnessed the general failure of the ANC strategy: for all intents and purposes – and despite all claims to the contrary – the ANC and its armed wing Umkhonto we Sizwe (‘Spear of the Nation’) failed to overthrow of the South African state by force, the purpose for which it was intended. The strongest indication of this was that the ANC was never able to establish (Phase One of revolutionary war) effective internal underground structures of any duration within South Africa. This much was clear when the ANC was unbanned in 1990, but was recognised long before: in October 1986, the ANC stated that ‘despite all our efforts, we have not come anywhere near the achievement of the objectives we set for ourselves’. The ANC's ‘use’ of the UDF structures inside South Africa, in this sense, was not the same thing as establishing effective internal ANC/MK structures in the way that they intended. The ANC/South African Communist Parry (SACP) also underestimated continuously the ability of the government to react strongly and viciously to the ‘Revolutionary Onslaught’: at least part of the blame for this underestimation lay with the promotion of the armed struggle over all other activities. In eidle, the ANC/SACP were unable to reach back effectively into the country to lead a revolution. In the end, the apartheid regime was defeated not by guerrilla action or by revolutionary overthrow, but through the mass action of millions of South Africans.  相似文献   
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