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为评估炸药在封闭容器内爆炸产生的振动效应对周围环境的影响,对封闭式爆炸容器小药量TNT炸药爆炸产生的爆炸振动效应进行了爆源邻近实地监测和测试。结果表明:小药量炸药爆炸引起的爆炸振动效应对距爆源100 m以外的普通砖结构民用住宅产生的速度强度远低于其临界峰值速度,不会对其结构产生明显影响。 相似文献
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The purpose of this paper is to investigate the problem of constructing an appointment template for scheduling patients at a specific type of multidisciplinary outpatient clinic called an integrated practice unit (IPU). The focus is on developing and solving a stochastic optimization model for a back pain IPU in the face of random arrivals, an uncertain patient mix, and variable service times. The deterministic version of the problem is modeled as a mixed integer program with the objective of minimizing a weighted combination of clinic closing time (duration) and total patient waiting time (length of stay). A two‐stage stochastic program is then derived to account for the randomness and the sequential nature of the decisions. Although it was not possible to solve the two‐stage problem for even a limited number of scenarios, the wait‐and‐see (WS) problem was sufficiently tractable to provide a lower bound on the stochastic solution. The introduction of valid inequalities, limiting indices, and the use of special ordered sets helped to speed up the computations. A greedy heuristic was also developed to obtain solutions much more quickly. Out of practical considerations, it was necessary to develop appointment templates with time slots at fixed intervals, which are not available from the WS solution. The first to be derived was the expected value (EV) template that is used to find the expected value of the EV solution (EEV). This solution provides an upper bound on the objective function value of the two‐stage stochastic program. The average gap between the EEV and WS solutions was 18%. Results from extensive computational testing are presented for the EV template and for our adaptation of three other templates found in the literature. Depending on the relative importance of the two objective function metrics, the results demonstrate the trade‐off that exists between them. For the templates investigated, the “closing time” ranged from an average of 235 to 275 minutes for a 300‐minute session, while the corresponding “total patient time in clinic” ranged from 80 to 71 minutes. 相似文献
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Simon Anglim 《Small Wars & Insurgencies》2013,24(4):588-608
The period from December 1940 through to the spring of 1941 saw the British Army win a series of rapid and decisive victories over Italian and Vichy French forces in North and East Africa and the Middle East. A key feature of these operations was the extensive British use of fast-moving all-arms mobile formations utilising superior speed and mobility to out-manoeuvre considerably larger Italian formations. A number of reasons have been given for the British Army adopting this mode of warfare, but the paper contends that the best explanation is that they were an organic evolution from methods used by the British Army in ‘small wars’ throughout the early twentieth century, use of mobile ‘frontier columns’ at the operational and tactical level of war being described and recommended by Callwell himself and visible with the Army in practice in operations in India and the Middle East in particular. The inter-war period saw the combination of this model of warfare with post-First World War military technology, notably tanks, close air support and coordination by wireless. Colonial operations in this period also saw some utilisation of what would later be identified as ‘Special Forces’ – also used extensively in the Desert War – the most obvious example being Captain Orde Wingate's Special Night Squads in Palestine in 1938. 相似文献
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Transnational terrorism data are difficult to forecast because they contain an unknown number of structural breaks of unknown functional form. The rise of religious fundamentalism, the demise of the Soviet Union, and the rise of al Qaeda have changed the nature of transnational terrorism. ‘Old School’ forecasting methods simply smooth or difference the data. ‘New School’ methods use estimated break dates to control for regime shifts when forecasting. We compare the various forecasting methods using a Monte Carlo study with data containing different types of breaks. The study's results are used to forecast various types of transnational terrorist incidents. 相似文献
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全面分析了轻武器在未来战争中的地位和作用 ,总结了轻武器现装备的主要特点 ,归纳了近二十年来在轻武器装备领域的主要技术成果 ,提出了轻武器未来发展趋势。 相似文献
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针对装甲装备关键部件维修性验证中出现的小子样问题,提出了基于Bayes理论的小子样维修性验证,重点针对对数正态分布下维修性指标验证的验后似然比验证方法进行了深入研究。通过对装甲装备某关键部件的试验数据的实例分析,验证了该方法在减少样本容量及试验费用方面的有效性和合理性。 相似文献
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针对装备软件成本估算时面临的历史数据少的小样本难题,提出把机器学习理论运用到装备软件成本估算研究领域,构建了基于相关向量机的小样本装备软件成本估算模型,采用COCOMO模型数据库中的数据对所构建模型进行训练和验证。为进一步验证所构建模型的合理性,在机器学习领域分别运用支持向量机模型和神经网络模型对相同数据进行估算,实验结果证明了基于相关向量机估算模型在小样本装备软件成本估算时比其他两种模型更精确。 相似文献