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21.
刘普寅 《国防科技大学学报》1990,12(3):25-31
本文讨论一个凸集C 的支撑函数的几个有用性质,并把这些性质应用于对函数次微分的研究,得到有关函数次微分的几个有趣结果。 相似文献
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兰马群 《国防科技大学学报》1989,11(2):79-83
布朗运动能够概括一大类物理现象,因此一直受到人们的重视。近年来,计算机模拟和实验的结果都表明,布朗运动具有“记忆”效应。本文试图对布朗运动“记忆”效应构造一个模型。在稳定情况下计算结果表明,微粒位移涨落的二次矩仍与时间间隔t成正比,“记忆”效应表现为流体的粘滞性加大。 相似文献
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本文采用相空间有限元方法求解了柱形临界多群中子输运问题。其中对于方程中的坐标变量用分片连续线性多项式作为试探函数,对于方程中的角度变量用分片连续双线性多项式作为试探函数。整个求解空间区域和角度区域分别采用三角形和矩形单元划分,然后利用迦辽金方法得到一个以网格点处角通量为未知数的线性联立代数方程组,方程组中的系数矩阵的存储采用了压缩存储技术。最后用高斯消元法解此有限元方程组,表明相空间有限元方法计算收敛性较好、计算精度高。 相似文献
24.
Israel David 《海军后勤学研究》2001,48(4):259-269
This work highlights the problem in military operations of setting safety limits for friendly forces, neutral forces, or civilians, to avoid sustaining unnecessary casualties both in wartime and in training. We present and investigate an analytic model which both enables the quantitative understanding of the inherent problems, and which furnishes a reasonably flexible tool in the hands of the analyst. Characteristic numerical results are displayed and analyzed: They show in particular that prevailing crude approximations are inadequate. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 259–269, 2001 相似文献
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针对单元网格发生变形重构中新旧网格之间的数据插值问题,提出一种基于格点格式有限体积法的流场数据传递方法。利用非结构动网格技术,将旧网格单元移动到新网格单元,同时时间推进求解流场控制方程,获得移动后旧网格单元物理量,并将其赋给新网格单元,以此来实现两套网格间的信息传递。计算结果表明,该方法在信息传递过程中没有引入插值误差,理论上流场求解方法的精度就是信息传递精度,验证结果表明其显著优于二阶插值精度。 相似文献
26.
Konul Bayramoglu Kavlak 《海军后勤学研究》2017,64(1):19-28
In this article, the reliability and the mean residual life (MRL) functions of a system with active redundancies at the component and system levels are investigated. In active redundancy at the component level, the original and redundant components are working together and lifetime of the system is determined by the maximum of lifetime of the original components and their spares. In the active redundancy at the system level, the system has a spare, and the original and redundant systems work together. The lifetime of such a system is then the maximum of lifetimes of the system and its spare. The lifetimes of the original component and the spare are assumed to be dependent random variables. © 2017 Wiley Periodicals, Inc. Naval Research Logistics, 64: 19–28, 2017 相似文献
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W. Robert J. Alexander 《Defence and Peace Economics》2013,24(1):13-25
The sectoral production function model of Feder (1983) has been widely used to examine the link between defence spending and economic growth. In this paper, the model, for which too much has been claimed in some past work, is examined, and the case is made for using growth in real non‐defence output rather than growth in real aggregate output (inclusive of military spending) as the dependent variable. Attention is restricted to a small group of OECD countries for which reliable labour force and capital stock (as well as defence) data are obtainable. With non‐defence output as the dependent variable and using only high quality data, no evidence in favour of the underconsumptionist (as opposed to the defence as a burden) position is found. 相似文献
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AbstractIn spite of government counter-terrorism expenditure and efforts, the incidence of terrorism in Nigeria appears to be rising. This paper examines the growth and fiscal consequences of terrorism in Nigeria by estimating the terrorism–macroeconomy relation using different measures of terror incidence. The results show that terrorism has an economically and statistically significant negative impact on growth; although this impact is considerably small and short-lived, manifesting only after a lag of about three years. Specifically, the cost of terrorism to Nigeria, in terms of lost GDP per annum, is estimated at 0.82%. Moreover, there is evidence that terrorism leads to the reallocation of economic activity away from private investment spending to government spending; that is, terrorism crowds out investment at a higher rate than its potential to crowd in government spending. Lastly, terrorism alters the composition of government expenditure – with the defence component of government expenditure rising vis-a-vis other expenditure items. The results are robust to allowing for dynamic interactions between terrorism and macroeconomic aggregates. 相似文献
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张娟 《中国人民武装警察部队学院学报》2011,(6):53-54
近年来,随着市场经济的不断发展,个体、私营经济因其投资少、成本低、规模小、工艺简单而逐渐成为政府鼓励和支持的经济类型,但它所带来的"三合一"建筑因形式的变化产生新的消防安全隐患,已经成为当前群死群伤恶性火灾的"重灾区"。就"三合一"建筑存在的新的消防安全问题及整治难点为内容进行分析,并提出几点对策。 相似文献