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421.
Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts.The liquid-filled compart-ment structure can resist the shaped charge warhead effectively.This paper presents experimental and theoretical investigations of the penetration ability of the residual shaped charge jet emerging from the liquid-filled compartment structure after the penetration process at different impact angles.On the basis of shock wave propagation theory,the influence of the liquid-filled compartment structure on jet sta-bility is analysed.The interferences of the liquid backflow caused by a reflected shock wave and a back plate on jet stability under different impact angles are also examined.In addition,the range of the disturbed velocity segments of the jet at different impact angles and the penetration ability of the re-sidual jet are obtained.A theoretical model is validated against the experimental penetration depths. 相似文献
422.
Sean M. Maloney 《Defense & Security Analysis》2007,23(4):405-417
For the Americans, it's no longer just “boots on the ground”: it's blood on the ground that counts. Joel J. Sokolsky
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423.
We examine the problem of adaptively scheduling perfect observations and preventive replacements for a multi‐state, Markovian deterioration system with silent failures such that total expected discounted cost is minimized. We model this problem as a partially observed Markov decision process and show that the structural properties of the optimal policy hold for certain non‐extreme sample paths. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献
424.
We consider how a merger between two naturally differentiated dealers affects their interactions with a common supplier and identify conditions under which the merger can increase or decrease the combined net worth of the two firms. Among other things, we find that the attractiveness of merging depends upon the extent to which end demand can be stimulated by either an upstream supplier or the dealers. Specifically, the greater the supplier's ability to invest in stimulating end demand, the more likely it is that the naturally differentiated firms will be better off operating independently than merging. On the other hand, if the greatest opportunities for stimulating demand are through the service that is provided by the dealers, then merging their operations will be more attractive. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献
425.
In the aftermath of the tragic events of 11 September 2001, numerous changes have been made to aviation security policy and operations throughout the nation's airports. The allocation and utilization of checked baggage screening devices is a critical component in aviation security systems. This paper formulates problems that model multiple sets of flights originating from multiple stations (e.g., airports, terminals), where the objective is to optimize a baggage screening performance measure subject to a finite amount of resources. These measures include uncovered flight segments (UFS) and uncovered passenger segments (UPS). Three types of multiple station security problems are identified and their computational complexity is established. The problems are illustrated on two examples that use data extracted from the Official Airline Guide. The examples indicate that the problems can provide widely varying solutions based on the type of performance measure used and the restrictions imposed by the security device allocations. Moreover, the examples suggest that the allocations based on the UFS measure also provide reasonable solutions with respect to the UPS measure; however, the reverse may not be the case. This suggests that the UFS measure may provide more robust screening device allocations. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005. 相似文献
426.
Tjallie A. M. Scheltinga Sebastiaan J. H. Rietjens Sirp J. De Boer Celeste P. M. Wilderom 《Low Intensity Conflict & Law Enforcement》2005,13(1):54-69
In peace-support operations, employees of international humanitarian organisations often clash with those of the military. A lack of familiarity with each other's practices and values, embedded in their respective organisational cultures, is often seen as the culprit. This article presents and illustrates a road map to manage such cultural differences between cooperating organisations. We found that the military culture, in our Bosnian case study, was seen to operate as a hierarchical culture (characterised by formalisation, stability, predictability and efficiency). The culture of international humanitarian organisations, on the other hand, was depicted as clan-type (characterised by teamwork, participation and consensus). To facilitate the creation of cultural awareness as well as respect for, and reconciliation of, cultural differences we recommend several concrete actions that could improve civil-military cooperation. 相似文献
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In this article we consider the unweighted m-center problem with rectilinear distance. We preent an O(nm–2 log n) algorithm for the m-center problem where m ≥ 4. 相似文献