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This paper presents a branch‐and‐price algorithm for scheduling n jobs on m nonhomogeneous parallel machines with multiple time windows. An additional feature of the problem is that each job falls into one of ρ priority classes and may require two operations. The objective is to maximize the weighted number of jobs scheduled, where a job in a higher priority class has “infinitely” more weight or value than a job in a lower priority class. The methodology makes use of a greedy randomized adaptive search procedure (GRASP) to find feasible solutions during implicit enumeration and a two‐cycle elimination heuristic when solving the pricing subproblems. Extensive computational results are presented based on data from an application involving the use of communications relay satellites. Many 100‐job instances that were believed to be beyond the capability of exact methods, were solved within minutes. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
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Ebru K. Bish Thin‐Yin Leong Chung‐Lun Li Jonathan W. C. Ng David Simchi‐Levi 《海军后勤学研究》2001,48(5):363-385
We consider a container terminal discharging containers from a ship and locating them in the terminal yard. Each container has a number of potential locations in the yard where it can be stored. Containers are moved from the ship to the yard using a fleet of vehicles, each of which can carry one container at a time. The problem is to assign each container to a yard location and dispatch vehicles to the containers so as to minimize the time it takes to download all the containers from the ship. We show that the problem is NP‐hard and develop a heuristic algorithm based on formulating the problem as an assignment problem. The effectiveness of the heuristic is analyzed from both worst‐case and computational points of view. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 363–385, 2001 相似文献
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Jonathan Colman 《战略研究杂志》2013,36(2):285-307
The article explores the 1950 ‘Ambassador's Agreement’ (named after US Ambassador Lewis Douglas) about establishing long-term US air bases in the UK. During the discussions British representatives expressed resentment of American pressure and were concerned about the expense that developing the bases for American purposes might entail. There were even fears that Washington might use the airfields to launch an atomic bomb attack on the USSR without regard to the views of the UK government. The British consented to providing the bases because they wanted to enmesh the US further in UK and Western European defence. For their part American negotiators had wanted to further US atomic strategy without delay. Although the agreement imposed no restriction on the use of the airfields, some US officials believed that in a crisis the UK government might try to prevent them being used for atomic bombing missions. 相似文献
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Jonathan B. Tucker 《The Nonproliferation Review》2013,20(3):363-384
In 2003, Libyan leader Muammar Qaddafi agreed to eliminate his country's weapons of mass destruction (WMD) programs and long-range Scud missiles under strict verification by U.S. and British experts and international inspectors. This article examines the negotiation and implementation of Libya's WMD rollback, with a primary focus on its chemical weapons program, and draws some lessons for the future. Although the Libyan case was unique in many ways, some aspects have relevance for other countries, including the critical role played by multilateral nonproliferation organizations, the utility of economic sanctions and export controls, the importance of a flexible U.S. disarmament funding mechanism, the value of rotating technical assistance teams in and out of the country that is disarming, and the desirability of remaining politically engaged with a former proliferator after rollback is complete. 相似文献
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Jonathan Ferguson 《Arms and Armour》2017,14(1):49-69
The aim of this article is to settle once and for all the question of the term ‘Brown Bess’, as applied to the British soldier’s musket. The specific origin and meaning of this obviously affectionate nickname has long confounded arms and armour scholars, re-enactors, and collectors alike. As a result, various possible solutions have been offered. The article outlines the historical usage of the name, including earlier written references not widely known in the field. The scope of the term is also addressed, using period sources to demonstrate what ‘Brown Bess’ meant to those who actually used the name historically. The many false etymologies of the name are assessed and found wanting or ‘debunked’ outright. Finally, drawing upon existing research from the field of linguistics, the article details the real meaning behind ‘Brown Bess’ the firearm and places ‘her’ in a wider sociohistorical context. 相似文献