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David S. Sorenson 《Defense & Security Analysis》2019,35(1):23-39
Despite multiple base closing rounds, the United States Department of Defense still has excess base capacity, and thus President Trump and high-level Defense Department officials are calling for more base closure through the Base Realignment and Closure (BRAC) process. However, another BRAC may not be the optimal solution, because simple base closure is not an efficient way to reduce surplus base capacity. Thus, Defense Department officials should consider other methods to reduce surplus capacity, including reduction in base size, leasing excess base property, or transferring it to another government agency for a variety of alternative uses. The surplus capacity issue also offers an opportunity to DOD to reassess base utilization, to update base requirements with current and future force structure. While BRAC focuses on American military bases, the process and alternatives also have international applications. 相似文献
224.
The debate over whether there exists a British counter-insurgency tradition of minimum force is one that has been thoroughly discussed. Is there anything left to say? This study suggests there is further insight to be attained if one explicitly evaluates the concept of minimum force in relation to the conduct of the security forces in the years of the Northern Ireland conflict. Through an examination of three key periods in the conflict, it will be shown that while there was invariably an awareness of the need to act with restraint among senior officers at the strategic level, this was often difficult to apply at the tactical level in the heat of confrontation. The argument demonstrates that the British Army, and other instruments of the state, rarely acted in a manner that could be described as ‘minimal’. Instead, it was the broader liberal values of the British state that explains largely the degrees of restraint exhibited by the government and security forces. 相似文献
225.
Michael E. Smith 《Contemporary Security Policy》2016,37(3):446-460
The EU Global Strategy (EUGS) is a broad and ambitious document in terms of its geographic scope and thematic priorities. However, the EU cannot devote equal attention to all aspects of the EUGS; so there is still scope for more clarity regarding the EU’s core strategic aims. This article argues that in addition to fostering internal cohesion, the EU’s strategic priority must involve stabilizing its own neighbourhood. This task has challenged the EU for decades because of an inherent credibility deficit regarding the EU’s own capabilities, yet the EUGS does not diagnose and remedy this problem as effectively as it could have. Therefore much more work will need to be done in terms of reforming EU institutions and developing common capabilities if the EU hopes to achieve its central internal and external security goals as outlined in the EUGS and related policy statements. 相似文献
226.
Typically weapon systems have an inherent systematic error and a random error for each round, centered around its mean point of impact. The systematic error is common to all aimings. Assume such a system for which there is a preassigned amount of ammunition of n rounds to engage a given target simultaneously, and which is capable of administering their fire with individual aiming points (allowing “offsets”). The objective is to determine the best aiming points for the system so as to maximize the probability of hitting the target by at least one of the n rounds. In this paper we focus on the special case where the target is linear (one‐dimensional) and there are no random errors. We prove that as long as the aiming error is symmetrically distributed and possesses one mode at zero, the optimal aiming is independent of the particular error distribution, and we specify the optimal aiming points. Possible extensions are further discussed, as well as civilian applications in manufacturing, radio‐electronics, and detection. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 323–333, 1999 相似文献
227.
We apply the techniques of response surface methodology (RSM) to approximate the objective function of a two‐stage stochastic linear program with recourse. In particular, the objective function is estimated, in the region of optimality, by a quadratic function of the first‐stage decision variables. The resulting response surface can provide valuable modeling insight, such as directions of minimum and maximum sensitivity to changes in the first‐stage variables. Latin hypercube (LH) sampling is applied to reduce the variance of the recourse function point estimates that are used to construct the response surface. Empirical results show the value of the LH method by comparing it with strategies based on independent random numbers, common random numbers, and the Schruben‐Margolin assignment rule. In addition, variance reduction with LH sampling can be guaranteed for an important class of two‐stage problems which includes the classical capacity expansion model. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 753–776, 1999 相似文献
228.
This article considers the dynamic lot-size problem under discounting, allowing speculative motive for holding inventory. A variable rolling-horizon procedure is presented, which, under certain regularity conditions, is guaranteed to generate an infinite-horizon optimal-production plan. We also discuss a fixed rolling-horizon procedure which provides a production plan that achieves an infinite-horizon cost within a user-specified tolerance ϵ of optimality. The fixed-horizon length T* needed in this procedure is given in terms of a closed-form formula that is independent of specific forecasted demands. We also present computational results for problems with a range of cost parameters and demand characteristics. 相似文献
229.
Put-to-light order picking systems invert the basic logic of conventional picker-to-parts systems. Instead of successively visiting the storage positions of the stock keeping units (SKUs) when collecting picking orders, an order picker accompanies successive bins each containing multiple items of a specific SKU along a lane of subsequent orders. Whenever the picker passes an order requiring the current SKU, which is indicated by a light signal, she puts the requested number of items into the bin associated with the order. Such an order picking system is well-suited if the assortment is not overly large and all orders demand similar SKUs, so that it is mainly applied in distribution centers of brick-and-mortar retail chains. This paper evaluates four different setups of put-to-light systems, which, during operations, require the solution of different storage assignment and SKU sequencing problems. We formulate these problems, prove computational complexity, and suggest suited solution algorithms. By applying these algorithms in a comprehensive computational study, we benchmark the impact of the four different setups on picking performance. In this way, warehouse managers receive decision support on how to set up their put-to-light systems. 相似文献
230.
In 1841 Henry Wilkinson in his book Engines of War and William Greener in The Science of Gunnery describe a range of methods then in use for shaping the outside of gun barrels after the barrel forging process, ranging from manual off-hand grinding to the use of precision machines. In the same year G. & J. Rennie published the design of their state-of-the-art lathe that was capable of turning complex and dished barrel forms. This built upon the earlier work of both Henry Nock and John Jones. In the early years of the 19th century both Britain, at Enfield and other locations, and the USA, at Harpers Ferry and Springfield, began to introduce barrel-turning technology. This paper uses measurements taken from a significant number of military barrels made by several makers, and also newly exposed information about Henry Nock and the Enfield Factory of 1815, to understand better the technologies that were applied to military flintlock barrel finishing from the 1780s to the 1840s, and particularly during the major wars of 1793–1815, when high output was paramount. Measurements both of barrel form and out-of-roundness are presented. These allow the interpretation of the techniques being used by different makers at different locations, and raise questions about the purpose and achievement of the complex dished barrel forms found on British military flintlock muskets. This approach also allows us to better describe the earliest factory on the Enfield site, one of the most significant sites in the wider history of UK manufacturing. 相似文献