高超音速化学平衡流粘性激波层数值计算

本文给出了层流化学平衡粘性激波层方程对于细长解析体的数值解。这些求解结果是通过空间步进方法得到的,并且与参考文献里的计算结果作了比较,以估价该方法的精确度。结果表明,这种控制方程完全耦合求解的方法能够给出相当精确和稳定的结果,这些结果与参考文献的计算结果相当吻合。     

Civil wars and economic growth: A regional comparison

The paper examines the impact of civil wars on income per-capita growth at home and in neighbors for four regional groupings of countries: Africa, Asia, Latin America, and a pooled Asian and Latin American sample. Both macroeconomic and civil-war influences on growth differ by region. With the use of a distance measure, we demonstrate that the spatial reach from the negative consequences of a civil war are region and time period specific. Generally, there was less dispersion in Africa than in Asia and Latin America. Moreover, Africa demonstrates a greater ability to recover from the adverse effects of civil wars than the other regions tested.     

Defence budgets in the post-Cold War era: a spatial econometrics approach

This paper examines the determinants of national defence budgets in the post-Cold War era employing a spatial econometric framework. Using data for 124 countries over a 16-year time period, I examine spatial relationships in defence spending to investigate how countries account for the military spending of other countries when setting their budgets. Using specially developed weighting matrices, the regression results indicate that defence budgets are positively spatially correlated. These results provide support for the use of ‘external’ factors when examining defence budgets over this time period. The importance of a country’s spatial location when setting its budget is further examined through the identification of regions of high and low defence spending.     

RAIN,GROWTH, AND CIVIL WAR: THE IMPORTANCE OF LOCATION

We re‐examine the Miguel et al. (2004 Miguel, E., Satyanath, S. and Sergenti, E. 2004. Economic shocks and civil conflict: an instrumental variables approach. Journal of Political Economy, 112(4): 725–753. [Crossref], [Web of Science ®] , [Google Scholar]) study of the impact of growth on civil war, using growth in rainfall as an instrument. Miguel et al. (2004 Miguel, E., Satyanath, S. and Sergenti, E. 2004. Economic shocks and civil conflict: an instrumental variables approach. Journal of Political Economy, 112(4): 725–753. [Crossref], [Web of Science ®] , [Google Scholar]) – 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.     

基于R-树索引的Map-Reduce空间连接聚集操作

空间连接聚集是一种常用并且非常耗时的空间数据库操作,特别是在面对大规模空间数据集时,单机运行环境难以满足其对时空开销的需求,如何设计高效的面向云计算环境中的分布式空间连接聚集算法越来越受到人们关注。Map-Reduce作为云计算的核心模式受限于其扁平化的串行扫描操作模型,常被用来加速非索引的空间连接操作,现有工作尚无将Map-Reduce和R-树索引结合来处理空间连接聚集。因此,提出了基于R-树索引的Map-Reduce空间连接聚集算法(RSJA-MR)来更高效地返回连接聚集结果。提出一种分布式R-树索引结构以支持大规模空间数据的索引,RSJA-MR算法利用分布式R-树生成任务集,任务集的执行满足无依赖并行计算模式,很容易在Map-Reduce框架中进行表达。文中提出一种实时缓存策略以支持索引并发访问。实验结果表明:相比非索引的Map-Reduce连接聚集算法,在空间交叠连接聚集查询上,时间性能最少提升8%,在空间包含连接聚集查询上,时间性能最少提升近35%。     

基于插件技术的人工免疫智能空间优化平台研究

采用人工智能方法求解空间优化问题已成为当前地理学研究领域的热点之一。研究目的在于通过设计一个开放的、可扩展的人工免疫空间优化模型框架,开发基于插件技术的优化工具软件,丰富空间优化决策支持的方法和技术体系。研究从空间优化问题的基本特点和计算需求出发,定义了面向空间优化问题求解的克隆选择优化模型框架。在此基础上,采用"插件-宿主平台"结构设计了人工免疫智能空间优化平台的总体架构,定义免疫算子插件与空间优化问题应用插件开发机制。实验结果表明,平台的架构和功能设计充分考虑了计算平台的开放性和扩展性,通过平台标准接口的功能扩展可实现对不同类型空间优化问题的求解。空间优化问题研究者或政府决策部门无需关系人工免疫优化方法的具体内涵即可基于本平台完成其具体空间优化决策支持任务。     

舰载机甲板布列调运优化方法研究

通过分析美军现代航空母舰的布列调运方式和发展趋势,发现舰载机的甲板作业调度、停放布列和移动调运是影响舰载机布列调运优化和提高舰载机出动能力的重要方面。针对这些方面的主要特点,采用动态调度方法、空间布局仿真和路径规划方法进行研究能更好地得到布列调运优化效果。据此基本思想,着重从美军航母甲板管理方式、空间布局、路径规划以及甲板作业调度几个方面阐述舰载机布列调运的研究现状,最后对舰载机布列调运优化未来的研究方向进行了展望。     

Military expenditures,economic growth and spatial spillovers

The relationship between economic growth and military expenditure has been the subject of a large literature in defence economics. This study analyses the influence of military expenditures on economic growth in a global perspective for the time period 2000–2010 taking spatial dimension into account. The augmented Solow model is employed to investigate the defence-growth nexus using the cross-sectional data relating to 128 countries. Following a traditional regression analysis, spatial variations in the relationships are examined utilizing different spatial econometric specifications estimated by maximum likelihood. The regressions are compared with each other via likelihood ratio tests, and the spatial Durbin model is found to be the most appropriate one suggesting that the typical least-squares model is misspecified. Empirical evidence indicates that military expenditure has a positive effect on economic growth with a significant spatial dependence for the time period under consideration.     

A case study of redundant defence workers

In this article, the influence of conflict on the economies of neighbouring countries is discussed. The results from previous papers show a strong negative effect for an entire area around a country suffering from conflict, but this paper reaches a different conclusion, by using more recent data and adjusting the methodology previously employed. Additionally, a new type of contiguity matrix is constructed and used in the actual analysis. The final analysis consists of a large number of regressions and concludes that conflict actually has two opposing effects. First, like conflict countries themselves, directly contiguous countries actually suffer from the negative effects of proximate conflict. Secondly, however, there is also a positive spillover of conflict, which affects non‐contiguous countries and this effect is larger for countries that are closer to the conflict country. The results from the paper predominantly hold for the most violent kind of conflict.     

Budgetary savings from conscription and burden sharing in NATO

We study the spatial and temporal determinants of terrorism risk in Israel, using a geocoded database of Israeli terrorist attacks from 1949 to 2004. In selecting targets, terrorists seem to respond rationally to costs and benefits: they are more likely to hit targets more accessible from their own homebases and international borders, closer to symbolic centers of government administration, and in more heavily Jewish areas. We also examine the waiting time between attacks experienced by localities. Long periods without an attack signal lower risk for most localities, but higher risk for important areas such as regional or national capitals.