二维浅水流动的离散涡方法

根据二维浅水流动中旋涡既可产生于流动边界层，也可在主流场中自生自灭的特点，建立起Eulerian-Lagrangian框架下的二维浅水流动离散涡方法；利用该方法数值仿真了高雷诺数下的二维浅水方柱绕流，得到了流动的速度场、涡谱，计算结果中明显可见流动分离、旋涡以及旋涡随时间的发展演化，即模拟出流动所具有的非定常不稳定等非线性特征。     

网络负载生成器的研究与设计

介绍了产生模拟负载时面临的问题,给出了网络负载生成器的设计方法,分析了三种事件驱动方式select、poll和epoll实现的负载生成器性能。通过比较得出结论,即采用epoll方式实现的负载生成器在3种方式中具有更好的性能。     

基于高速DG的伪随机序列及其产生研究

针对专用伪随机序列发生器的不足,对基于高速数据发生器的伪随机序列及其产生作了较深入的研究。阐述了伪随机序列的几种码制和产生方式,提出了基于高速数据发生器的伪随机序列设计的一般原则和方法,并给出了典型伪随机序列在高速数据发生器中的设计实现和实验结果。     

煤气发生炉气化过程分析与提高煤气品质的技术措施

对煤炭气化过程进行理论分析,阐明了反应温度对煤炭气化过程热效率的影响.根据煤气发生炉的气化特性指标,探讨了影响煤气发生炉气化品质的因素,从煤炭性质、煤炭粒度及饱和温度等方面得出了提高煤气品质的技术措施.     

Long-range correlation analysis of the Wichmann-Hill random number generator

The distribution of points (r _n,r _n+s), n = 0, 1, 2,...whose coordinates are terms at distance s of the pseudorandom sequence generated by the Wichmann and Hill method is studied. It is known that for many congruential generators critical values of the distance s exist such that these points, far from being uniformly distributed, are concentrated on very few lines. An algorithm is described for computing the critical distances within the Wichmann-Hill sequence and the results obtained are compared with those of other linear congruential generators.     

A modal method for generating binomial variables

The paper considers the problem of generating binomial random variables when the parameters n and p may vary from call to call (as in the generation of multinomial random variables), A new algorithm, based on sequentially searching alternately down and up from the modal probability, is introduced. This is easy to program and requires no special library facilities It is suitable for microcomputers as well as mainframes Some sample timings are given for a FORTRAN 7 7 implementation     

The political position generator—A new instrument for measuring political ties in China

This paper proposes a novel instrument – the political position generator - for measuring individuals’ political ties, or personal, affective connections to state officials and other political actors. It adopts and adapts the more general position generator framework in social capital research to capture three key dimensions of political ties – upper reachability, network diversity, and tie strength. The measure is validated with data from a representative survey of the Chinese population and three scales representing the three political ties dimensions are created. In correlational and multivariate regression analyses, we find initial evidence of the instrument’s criterion-related (discriminant and concurrent) validity.     

A statistical analysis of the screening measure of multiple recursive random number generators of orders one and two

This paper presents the results of a comprehensive empirical analysis of the screening measure of multiple recursive generators (MRGs) of orders one and two. Two kinds of screening measures are distinguished: spectral test and lattice test. With regard to these screening measures, two exhaustive searches of the twenty best MRGs of orders one and two are conducted. Some empirical comparisons reveal that the screening procedure with maximum spectral value criterion is preferred in terms of efficiency and thus, is a good way of obtaining ideal MRGs of higher orders. Several extensively tested second-order MRGs are also presented and are therefore recommended.     

Social mobility and social capital in contemporary Britain

This paper seeks to contribute to social capital research by linking measures of formal and informal forms of social capital to social mobility trajectories and assessing their impact on social trust. Drawing on data from a recent national survey – Cultural Capital and Social Exclusion (2003/2004 ) – we analyse formal civic engagement and informal social connections. The latter data are obtained using, for the first time in a study in Britain, Lin's (2001 ) 'Position Generator' approach as a means to identify the volume, range and position of individuals' informal social contacts. The pattern of contacts suggests that access to social ties is strongly conditioned by mobility trajectory. We also show that civic engagement in formal associations is especially high among second-generation members of the service class. It is also shown that both class trajectory and possession of two types of social capital have significant impacts on trust. Among the social groups disadvantaged in terms of bridging social ties are not only those in lower classes but also women and members of minority ethnic groups.