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41.
Estimating the performance of an automatic target recognition (ATR) system in terms of its probability of successfully identifying a target involves extensive image collection and processing, which can be very time‐consuming and expensive. Therefore, we investigate the Wald sequential test for the difference in two proportions as a sample size‐reducing alternative to ranking and selection procedures and confidence intervals. An analysis of the test parameters leads to a practical methodology for implementing the Wald test for fairly comparing two systems, based on specific experimental goals. The test is also extended with the modified, sequentially rejective Bonferroni procedure for the multiple pairwise comparison of more than two systems. Two sampling schemes for different experimental goals are also discussed. The test methodology is applied to actual data to compare different configurations of a specific ATR system, with the results demonstrating that the modified Wald sequential procedure is a useful alternative to comparing proportions with confidence intervals, particularly when data are expensive. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 357–371, 1999  相似文献   
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Police investigations of terrorist incidents are rarely straightforward. This paper reports the findings of research that looked at low-level paramilitary attacks in Northern Ireland which have taken place during the ceasefire era. Of 500 incidents studied, 28 were followed by the arrest of suspects. The study examines what factors were important for linking later arrests with other features of the incident. These results are discussed in terms of the wider implications for the successful investigation of paramilitary offences and in terms of the specific implications for investigative policing within Northern Ireland.  相似文献   
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This paper has been presented with the Best Paper Award. It will appear in print in Volume 52, No. 1, February 2005.  相似文献   
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Person-borne improvised explosive devices (PBIEDs) are often used in terrorist attacks in Western countries. This study aims to predict the trajectories of PBIED fragments and the subsequent safety risks for people exposed to this hazard. An explosive field test with a typical PBIED composed of a plastic explosive charge and steel nut enhancements was performed to record initial fragment behaviour, including positions, velocity, and trajectory angles. These data were used to predict the full trajectory of PBIED fragments using a probabilistic analysis. In the probabilistic analyses a probability of fatality or serious injury was computed. Based on the results presented, many practical conclusions can be drawn, for instance, regarding safe evacuation distances if a person were exposed to a suspected PBIED.  相似文献   
46.
Cyber operations are relatively a new phenomenon of the last two decades.During that period,they have increased in number,complexity,and agility,while their design and development have been processes well kept under secrecy.As a consequence,limited data(sets)regarding these incidents are available.Although various academic and practitioner public communities addressed some of the key points and dilemmas that surround cyber operations(such as attack,target identification and selection,and collateral damage),still methodologies and models are needed in order to plan,execute,and assess them in a responsibly and legally compliant way.Based on these facts,it is the aim of this article to propose a model that i))estimates and classifies the effects of cyber operations,and ii)assesses proportionality in order to support targeting decisions in cyber operations.In order to do that,a multi-layered fuzzy model was designed and implemented by analysing real and virtual realistic cyber operations combined with interviews and focus groups with technical-military experts.The proposed model was evaluated on two cyber operations use cases in a focus group with four technical-military experts.Both the design and the results of the evaluation are revealed in this article.  相似文献   
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This paper investigates the effect of alliance membership on the defense burdens of major powers in the 19th and 20th centuries. We hypothesize that the reactions of states to alliance membership will be different in the pre‐nuclear and nuclear eras. Possession of nuclear weapons by allies makes the security provided by the alliance more akin to a collective good than is the case in the pre‐nuclear era. States join alliances for two reasons: security and autonomy. The effects of each of these concerns are identified. We include in our model such alliance‐level factors as the power equivalence of the allies and the number of states in the alliance. We also look at state‐level variables such as power position within the alliance. We conclude that the nuclear period generally operates as the free‐rider principle would posit, while models based on “complementarity of effort” are more applicable in the earlier period.  相似文献   
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ABSTRACT

The Kingdom of Lesotho spends around five per cent of its annual budget – some 700 million Maloti ($US52.6 million) in 2017 – on the Lesotho Defence Force (LDF). Lesotho’s geographical position means that the LDF has no meaningful role regarding its primary function of defending the country from external aggression and it hardly engages in its secondary functions. In addition, the LDF has a long history of interference with democratic processes and engaging in human rights abuse. The financial resources currently allocated to the LDF could do far more for security, widely defined, if they were allocated to a number of other government expenditure categories.  相似文献   
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