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171.
172.
分析了RGB-D传感器的标定模型及标定方法,利用标定棋盘和Matlab工具箱对RGB-D传感器进行了标定。采用摄像机标定方法计算了彩色摄像机和深度摄像机的初始化参数,根据标定棋盘和标定板的共面关系计算了相对位姿的初始估计值,并采用非线性最小化方法对标定参数进行了优化。实验结果表明:标定后的彩色图像和深度图像的重投影误差较小,深度测量不确定性标准差比标定前约减小了1/2,有效地提高了RGB-D传感器的测量精度。 相似文献
173.
The Replenishment at Sea Planner (RASP) is saving the U.S. Navy millions of dollars a year by reducing fuel consumption of its Combat Logistics Force (CLF). CLF shuttle supply ships deploy from ports to rendezvous with underway U.S. combatants and those of coalition partners. The overwhelming commodity transferred is fuel, ship‐to‐ship by hoses, while other important packaged goods and spare parts are high‐lined, or helicoptered between ships. The U.S. Navy is organized in large areas of responsibility called numbered fleets, and within each of these a scheduler must promulgate a daily forecast of CLF shuttle operations. The operational planning horizon extends out several weeks, or as far into the future as we can forecast demand. We solve RASP with integer linear optimization and a purpose‐built heuristic. RASP plans Replenishment‐at‐Sea (RAS) events with 4‐hour (Navy watch) time fidelity. For five years, RASP has served two purposes: (1) it helps schedulers generate a daily schedule and animates it using Google Earth, and (2) it automates reports command‐to‐ship messages that are essential to keep this complex logistics system operating. 相似文献
174.
Kenneth L. Lasoen 《战略研究杂志》2017,40(7):927-962
The terrorist attacks in France and Belgium of 2015–2016 that occurred while these countries were in a heightened state of alert raise questions about indications and warning methodology as well as effectiveness of the blanket-protection deployment of security services assisted even by the military. Response and perhaps even more anticipation may require strategic rethinking in light of the predatory attacks that target the most vulnerable spots of the public space. This study looks at threat analysis in Belgium as conducted through her intelligence fusion centre Coordination Unit for Threat Analysis (CUTA)?????? since its inception in 2006. With a special focus on what is known, at the time of writing, about the terrorist attacks in Paris and Brussels, this study hopes to put into context how the system (mal)functions and will also consider the preventive measures that respond to the threat, and the international aspects which have implications far beyond Belgian borders. Therefore, a case is made for not just a Belgian homeland security framework, but one that fits into an EU-wide security concept. 相似文献
175.
South Korea is threatened by its troubled relationship with North Korea. North Korea possesses a large cache of missiles as well as chemical and biological weapons, and the future potential to mount nuclear weapons on its missiles. The United States is also challenged because of its defense commitments to Seoul. As a countermeasure, the United States and South Korea decided to deploy Terminal High Altitude Area Defense (THAAD) missile defenses in South Korea. However, China has objected. Chinese scholars believe the THAAD radar would be able to track Chinese inter-continental ballistic missiles, thereby weakening their deterrent. A technical analysis does not support this assertion. However, it is vital for South Korea, given its proximity and economic interdependence, to reassure China. South Korea should highlight that THAAD will be deployed by the United States Forces Korea and is not a commitment by Seoul to become part of U.S.-led missile defenses in the Asia-Pacific. 相似文献
176.
以某矿车为研究对象,建立了整车6自由度模型,通过在频域内路面功率谱对车轮激振,模拟矿车驾驶室的振动。并改变驾驶室前、后悬置的刚度以及阻尼比,3变量同时作用,根据平顺性评价指标,对前、后悬置刚度进行了合理匹配,为驾驶室悬置刚度值选取提供了依据。 相似文献
177.
针对典型舰船的系统组成,进行了全舰任务成功性指标的示例计算,给出了总体指标的层次化表达方式。以舰船任务过程和典型任务剖面为依据,分析了任务可靠性和任务成功性之间的区别与联系,建立了舰船总体任务成功性指标的多阶段整体模型,并对航渡、待机、交战、撤离、返航阶段分别进行了仿真和解析建模。在建模与计算的基础上,通过敏感性分析计算了任务阶段持续时间的单位降低率等指标,为舰船任务成功性问题及其相关研究,提供了一个系统性的分析框架和方法。 相似文献
178.
Peter Fabricius 《African Security Review》2014,23(4):412-421
When United States (US) President Barack Obama announced in 2013 that he would host the first United States-Africa leaders' summit the next year, he was greeted with considerable scepticism. Many critics thought he was just playing catch-up with other countries and organisations which had been holding Africa summits for years, especially China. But, whatever the motives, the event itself proved to be a substantial success, probably re-setting US relations with Africa for many years to come. 相似文献
179.
180.
Peter Sandholt Jensen 《Defence and Peace Economics》2013,24(5):359-372
We re‐examine the Miguel et al. (2004) study of the impact of growth on civil war, using growth in rainfall as an instrument. Miguel et al. (2004) – in our view, erroneously – include countries participating in civil wars in other states. Restricting the conflict data to states with conflict on their own territory reduces the estimated impact of economic growth on civil war. We show how spatial correlations in rainfall growth and participation in civil conflicts induce a stronger apparent relationship in the mis‐classified data. 相似文献