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331.
When solving location problems in practice it is quite common to aggregate demand points into centroids. Solving a location problem with aggregated demand data is computationally easier, but the aggregation process introduces error. We develop theory and algorithms for certain types of centroid aggregations for rectilinear 1‐median problems. The objective is to construct an aggregation that minimizes the maximum aggregation error. We focus on row‐column aggregations, and make use of aggregation results for 1‐median problems on the line to do aggregation for 1‐median problems in the plane. The aggregations developed for the 1‐median problem are then used to construct approximate n‐median problems. We test the theory computationally on n‐median problems (n ≥ 1) using both randomly generated, as well as real, data. Every error measure we consider can be well approximated by some power function in the number of aggregate demand points. Each such function exhibits decreasing returns to scale. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 614–637, 2003. 相似文献
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This paper deals with the sequencing problem of minimizing linear delay costs with parallel identical processors. The theoretical properties of this m-machine problem are explored, and the problem of determining an optimum scheduling procedure is examined. Properties of the optimum schedule are given as well as the corresponding reductions in the number of schedules that must be evaluated in the search for an optimum. An experimental comparison of scheduling rules is reported; this indicates that although a class of effective heuristics can be identified, their relative behavior is difficult to characterize. 相似文献
334.
Randall R. Dipert 《Journal of Military Ethics》2013,12(1):34-53
Almost all discussions of cyberwarfare, other cyber-attacks, and cyber-espionage have focused entirely on the Internet as the chief means of damage – the Internet as a ‘vector,’ using a term from the theory of infectious diseases. However there are a variety of means, some of which have already been used, that involve cyber-exploitation using vectors other than the Internet. Malware can be installed in the integrated circuits of computers and servers, but also in any devices attached to them – thumb drives, CDs, printers, scanners, and so on. One can also use various forms of electromagnetic radiation at a distance of meters or more to exfiltrate data or to infiltrate corrupt data. I call this large and diverse family of unwanted interference with the functioning of information processing systems other-than-Internet (OTI) attacks on information systems. Stuxnet, and probably the 2007 Israeli corruption of Syrian air defenses, were OTI attacks. Such OTI techniques are more difficult to develop than creating malware, requiring electronic manufacturing facilities or novel technologies, and are thus accessible only to larger corporations and technologically sophisticated countries. Particularly vulnerable would be countries (like the United States and Europe) whose information processing devices are mainly produced outside of the country. Once exploitations via the Internet become harder to perpetrate, OTI exploitations are certain to grow dramatically, eventually requiring equipment for critical uses to be expensively fabricated in (and transported using) secure facilities; expensive detection measures will have to be instituted. This will create challenges for policy, law, and ethics, as well as greatly increasing the cost of many electronic devices. 相似文献
335.
When rational choice theory is applied to the study of terrorism, it is important that attention be given to the derived principles of constrained utility maximization. Particularly useful is the Slutsky equation, which rigorously analyzes the quantity response in one activity to a price change in another. By directing attention to assumptions and/or information about compensated cross price elasticities, expenditure shares, and income elasticities, the Slutsky equation can provide critical guidance in both theoretical and empirical analysis. 相似文献
336.
MARTIN R RUPIYA 《African Security Review》2013,22(1):83-89
Abstract This paper seeks to critically appraise Africa's position within the United Nations Security Council from the inception of the UN in 1945 until the end of 2010, spanning the entire history of the world body. A few factors make such an appraisal a useful exercise. These include the ongoing debates about the reform of the Council in particular and the UN as a whole, and the growing interest that many African students and observers of and actors in international relations seem to have developed in recent years in the working of the world body. In this appraisal, emphasis will be placed on the origin and rationale behind the establishment of the Security Council as well as the use of the veto power by its permanent members, with a special reference to Africa. 相似文献
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We identify the causal effect of a reduction in military personnel on a number of socioeconomic indicators within the peripheries of military bases. The base realignments and closures in Germany are used as an exogenous source of variation that allows us to identify the effect of a demand shock on household income, output, unemployment, and tax revenue within a specified buffer zone around each base. The analysis covers 298 communities for the period 2003–2007. Consistent with evidence found elsewhere, we find that these base adjustments have only a marginal impact on the local community in which the bases are located. 相似文献
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Jon R Lindsay 《战略研究杂志》2013,36(3):422-453
Two big ideas have shaped recent debate about military doctrine: the Revolution in Military Affairs (RMA) and Counterinsurgency (COIN). These ‘network centric’ and ‘population centric’ worldviews appear contradictory, but this is a false dichotomy. American forces have actively developed RMA concepts in COIN environments during recent wars in Iraq and Afghanistan; the exemplar par excellence is innovation by US Special Operations Command (SOCOM) in doctrine, technology, and organization for counterterrorism. Ironically, SOCOM's reimagining of the RMA managed to both improve the strengths and underscore the weaknesses of the American military's technological prowess. 相似文献