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291.
A new piece of equipment has been purchased in a lot of size m. Some of the items can be used in destructive testing before the item is put into use. Testing uncovers faults which can be removed from the remaining pieces of equipment in the lot. If t < m pieces of equipment are tested, then those that remain, m1 = m − t, have reduced fault incidence and are more reliable than initially, but m1 may be too small to be useful, or than is desirable. In this paper models are studied to address this question: given the lot size m, how to optimize by choice of t the effectiveness of the pieces of equipment remaining after the test. The models used are simplistic and illustrative; they can be straightforwardly improved. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 623–637, 1997 相似文献
292.
293.
This paper considers the scheduling problem to minimize total tardiness given multiple machines, ready times, sequence dependent setups, machine downtime and scarce tools. We develop a genetic algorithm based on random keys representation, elitist reproduction, Bernoulli crossover and immigration type mutation. Convergence of the algorithm is proved. We present computational results on data sets from the auto industry. To demonstrate robustness of the approach, problems from the literature of different structure are solved by essentially the same algorithm. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 199–211, 1999 相似文献
294.
THOMAS A. MARKS 《Small Wars & Insurgencies》2013,24(2):197-220
Building upon a far-reaching reform movement carried out during the administration of Andres Pastrana (1998–2002), the Colombian military emerged in the Alvaro Uribe first term (2002–06) as a powerful, flexible organization capable of implementing a national strategy for successful counterinsurgency. Sweeping organizational change was accompanied by advances in operational art and tactics, as well as the promotion of new leadership tested in combat. A growing maturity in civil–military relations enabled national advances in democratic politics, economic progress and state integration, the latter to a degree unprecedented in Colombian history. 相似文献
295.
Michael A. Innes 《Small Wars & Insurgencies》2013,24(2):241-251
Numerous writers have acknowledged the importance of radio communications and hate propaganda in the Liberian civil war (1990–1997), but none have explored the subject in depth. A wide variety of related issues have been neglected, including military efforts to seize control of broadcast facilities, the deliberate manipulation of public information and perceptions, and the implications of both for wartime atrocities and post-war justice. In the following essay, I identify and discuss six general strands of thought on guerrilla radio broadcasting and communications in wartime Liberia. The first looks to the relationship between mass media and the state in the pre-civil war era. The second covers the cooption of the wartime free press. Three further themes – Charles Taylor's cultivation of personal power, the relevance of broadcasting for rebel command and control capabilities, and Taylor's media dominance during the 1997 Presidential campaign – demonstrate the strategic and public roles of radio communications and broadcasting. Finally, I look to written survivor memoirs for elite responses to wartime media monopolies, guerrilla propaganda, and psychological warfare. I conclude with some notes on indicators for future research, and their implications for historical and contemporary issues in Liberia. 相似文献
296.
Stephen A. Emerson 《Small Wars & Insurgencies》2013,24(4):669-687
This article provides an in-depth examination and analysis of the 2006–2009 Tuareg rebellion in Mali and Niger. It identifies the underlying reasons behind the rebellion, explores contrasting counter-insurgency (COIN) strategies employed by the two governments, and presents some lessons learned. While both COIN approaches ultimately produced similar peace settlements, the article argues that the Malian strategy of reconciliation combined with the selective use of force was far more effective than the Nigerien iron fist approach at limiting the size and scope of the insurgency and producing a more sustainable peace. It concludes by looking at the role of external actors, particularly the United States, and how the failure to internationalize the conflict was actually more beneficial to the local COIN effort, as well as to the longer strategic interests of the United States in the region. 相似文献
297.
A fundamental contradiction has been built into America's intervention in Afghanistan since the first days of the war in 2001. On the one hand, US policymakers have viewed the promotion of liberal democracy, economic development, and strong centralized state institutions as essential to achieve victory over the long term. On the other hand, however, the US has relied on local warlords to win its battles against the Taliban from the first days of the intervention. The Obama administration's tortured policy review reflects the intractable dilemmas involved in trying to build a modern democratic state while relying on local warlords as crucial allies in the war against the Taliban. 相似文献
298.
We consider the problem of service rate control of a single‐server queueing system with a finite‐state Markov‐modulated Poisson arrival process. We show that the optimal service rate is nondecreasing in the number of customers in the system; higher congestion levels warrant higher service rates. On the contrary, however, we show that the optimal service rate is not necessarily monotone in the current arrival rate. If the modulating process satisfies a stochastic monotonicity property, the monotonicity is recovered. We examine several heuristics and show where heuristics are reasonable substitutes for the optimal control. None of the heuristics perform well in all the regimes and the fluctuation rate of the modulating process plays an important role in deciding the right heuristic. Second, we discuss when the Markov‐modulated Poisson process with service rate control can act as a heuristic itself to approximate the control of a system with a periodic nonhomogeneous Poisson arrival process. Not only is the current model of interest in the control of Internet or mobile networks with bursty traffic, but it is also useful in providing a tractable alternative for the control of service centers with nonstationary arrival rates. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 661–677, 2013 相似文献
299.
Accelerated life testing (ALT) using multiple stresses is commonly used in practice to resemble the operating stresses at normal operating conditions and obtain failure observations in a much shorter time. However, to date, there is little research into the theory of planning ALT for reliability estimation with multiple stresses. ALT with multiple stresses can result in a large number of stress‐level combinations which presents a challenge for implementation. In this article, we propose an approach for the design of ALT plans with multiple stresses and formulate multistress test plans based on different objectives and practical constraints. We develop a simulated annealing algorithm to efficiently determine the testing plan parameters. We demonstrate the proposed method with examples based on an actual test conducted using three stress types. The obtained optimal test plans are compared with those based on fractional factorial design. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 468–478, 2013 相似文献
300.
AbstractIn 2011 a wave of revolutionary movements, the so-called Arab Spring, spread in the Middle East and North Africa. Libya was one of the most affected countries, ending Gaddafi’s dictatorship after an international intervention and a civil war. This paper assesses the effects that this revolution had on Libyan economy. The analysis is made by means of the synthetic control method. Our estimates for the 2011–2014 period show (i) a cumulative loss in the growth rate of per capita real GDP of 64.15%; (ii) a cumulative loss in per capita real GDP of 56,548 dollars; and (iii) a cumulative loss in the aggregate real GDP of 350.5 billion dollars. 相似文献