排序方式: 共有118条查询结果,搜索用时 15 毫秒
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在不确定性条件下,同时考虑到多维输出之间的相关关系和单输出的均值,构建由多输出数学期望列阵和协方差矩阵组成的多输出模型确认局部混合矩指标和全局混合矩指标。其中局部混合矩指标包括绝对指标(LA-3M)和相对指标(LR-3M),它们适合单点位置的多输出局部模型确认;全局混合矩指标也包括绝对指标(GA-3M)和相对指标(GR-3M),它们适合多点位置的多输出全局模型确认。通过数字算例和工程算例,所提指标可行有效,能够方便地度量计算模型和物理实验之间的差异程度。 相似文献
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由于复杂的空中目标机动,其三维方向的机动强度是不一致的,传统IMM算法存在模型匹配不准确的问题,提出一种机动目标IMM三维并行滤波的跟踪算法。算法以CV和修正的CS模型为子集,在3个坐标轴上分别根据目标机动的分量实际更新其模型概率,并行IMM滤波方法,尽量确保模型的适配性,提高滤波精度。仿真结果表明,该算法比传统IMM方法跟踪精度更高,对空中机动目标跟踪适应性更强。 相似文献
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This article proposes an approximation for the blocking probability in a many‐server loss model with a non‐Poisson time‐varying arrival process and flexible staffing (number of servers) and shows that it can be used to set staffing levels to stabilize the time‐varying blocking probability at a target level. Because the blocking probabilities necessarily change dramatically after each staffing change, we randomize the time of each staffing change about the planned time. We apply simulation to show that (i) the blocking probabilities cannot be stabilized without some form of randomization, (ii) the new staffing algorithm with randomiation can stabilize blocking probabilities at target levels and (iii) the required staffing can be quite different when the Poisson assumption is dropped. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 177–202, 2017 相似文献
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针对径向基插值代理模型样本点预测误差为零时无法获得误差函数进行序列再采样优化的问题,将样本点分布约束引入序列再采样过程,利用潜在最优解加速收敛性,提出一种适用于径向基插值代理模型序列优化的再采样策略,该策略兼顾仿真模型的输出响应特性与样本点的空间分布特性。仿真结果表明,使用该在采样策略后,算法寻优效率和精度均优于传统基于代理模型的优化方法,在对最优解进行有效预测的同时,能显著减少原始模型计算次数。 相似文献
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This study examines the effects of home-state unemployment rates on attrition behavior of Navy enlistees for successive career windows during the first term of service: the first 6?months, the second 6?months, the second year, and the third year of service. The results indicate that attrition is negatively associated with changes in the local unemployment rate during the first three career windows covering two years of service. However, after two years of service, the estimated effect of the unemployment rate becomes insignificant for most groups of sailors. This is likely because sailors with the poorest job matches are sorted out early in the first term of service. 相似文献
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This paper employs both linear and non‐linear models to investigate the relationship between national defense spending and economic growth for Taiwan and China. Using data from 1953–2000 on defense spending, GDP, import, export and capital, we find that China's defense spending leads that of Taiwan. There exists the phenomenon of an arms race between both countries when official Chinese data are used. On the one hand, feedback relations prevail between economic growth and defense spending growth in Taiwan. On the other hand, China's national defense is found to lead economic growth. 相似文献
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分析了密码算法加密过程的功耗泄露模型,给出了差分功耗分析的基本原理,针对ARIA分组密码中查找S盒的功耗泄漏进行了差分功耗分析,并进行仿真实验。实验结果表明:ARIA密码中S盒查表操作功耗消耗易遭受差分功耗攻击,对800个随机明文的功耗曲线进行实验分析,可获取ARIA加密前4轮轮密钥,结合密钥扩展算法即可获取128位的主密钥。 相似文献
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结合未来陆军机动作战实际,研究了集中射击指挥条件下,防空兵群动态防空抗击效率的评估方法。提出了目标可射击概率应依据火力单位射程选用不同模型评估的观点,探讨了火力单位转移、导弹(弹药)储备和群指挥所状态等因素对群抗击效率的影响及其评估模型。在此基础上,指出了所建模型的适用范围和需要进一步解决的问题。 相似文献