汉晋时期的数字化标榜与取士制度

汉晋时期,名士相互之间兴起一种数字化标榜之风。此风由东汉时开始,最先表现在"郡国之书",随着世家大族及其文化的形成,又渐渐朝谱牒或家谱的方向转移。在九品中正制度关于人才选拔方面的弊端逐渐明显化之后,乡党清议和"郡国之书"失去了择士的现实功能,名士间依然盛行此风,但往往更多地称述于"志好"相同或"同志"间的士人集团。     

Simulation for the complex Bingham distribution

The complex Bingham distribution is relevant for the shape analysis of landmark data in two dimensions. In this paper it is shown that the problem of simulating from this distribution reduces to simulation from a truncated multivariate exponential distribution. Several simulation methods are described and their efficiencies are compared.     

Perfect simulation for correlated Poisson random variables conditioned to be positive

In this paper we present a perfect simulation method for obtaining perfect samples from collections of correlated Poisson random variables conditioned to be positive. We show how to use this method to produce a perfect sample from a Boolean model conditioned to cover a set of points: in W.S. Kendall and E. Thönnes (Pattern Recognition 32(9): 1569–1586, 1999), this special case was treated in a more complicated way. The method is applied to several simple examples where exact calculations can be made, so as to check correctness of the program using ²-tests, and some small-scale experiments are carried out to explore the behaviour of the conditioned Boolean model.     

The Statistics of Simulating Chaos

When simulating a dynamical system, the computation is actually of a spatially discretized system, because finite machine arithmetic replaces continuum state space. For chaotic dynamical systems, the discretized simulations often have collapsing effects, to a fixed point or to short cycles. Statistical properties of these phenomena can be modelled with random mappings with an absorbing centre. The model gives results which are very much in line with computational experiments. The effects are discussed with special reference to the family of mappings f (x)=1-|1-2x|,x [0,1],1,<,,<,. Computer experiments show close agreement with predictions of the model.     

利用智能主体分析"时尚"的涌现

时尚作为一种社会现象,是由个别人物的倡导和示范,先在少数人中流行,然后迅速蔓延到社会.多数人出于新奇与从众心理而仿效.对于它的研究有助于人们把握这种社会现象的产生与蔓延过程,深入认识和控制它的发展.由于它的复杂多样性,当前还缺乏对它的定量分析与研究.论文利用基于智能主体的仿真方法,分析了时尚的涌现过程.文中建立了两种模型,用于确定公众能否接受某种时尚的临界值.一种模型基于公众能获取全部信息,另一种则基于个人只能获取邻近信息.     

网络环境下数字化产品适用的营销模型研究

互联网和电子商务的广泛应用与开展,为数字产品营销提供了巨大的市场空间.同时,数字产品独特的交易过程也使其营销过程不同与传统产品.本文探讨三种经典的营销模型4P、4C和4S应用到数字产品的营销时的适用性.在已有研究总结出的四条命题基础上,通过三种渠道收集了45个数字产品营销工具作为样本,采用分类方法将三种经典的营销模型作为分类框架,对样本进行分类比较研究,验证了提出的五条假设并发现了三条有意义的结论:其一,数字产品的可试性和其需要的营销工具数量显著相关;其二,三种营销模型对不同种类的数字产品存在适用性的差异;其三,在网络营销环境中,数字产品常用的传输模式(下载和交互)与其适宜的分销方式(网上商店和独立网站)之间存在因果关系.     

Kolmogorov-Smirnov Type Test-Statistics For The Gamma,Erlang-2 And The Inverse Gaussian Distributions When The Parameters Are Unknown.

Critical values are presented for the Kolmogorov-Smirnov type test statistics for the following three cases: (i) the gamma distribution when both the scale and the shape parameters are not known, (ii) the scale parameter of the gamma distribution is not known and (iii) the inverse Gaussian distribution when both the parameters are unknown. This study was motivated by the necessity to fit the gamma, the Erlang-2 and the inverse Gaussian distributions to the interpurchase times of individuals for coffee in marketing research.     

An Empirical Likelihood Ratio Test for Normality

The empirical likelihood ratio (ELR) test for the problem of testing for normality is derived in this article. The sampling properties of the ELR test and four other commonly used tests are provided and analyzed using the Monte Carlo simulation technique. The power comparisons against a wide range of alternative distributions show that the ELR test is the most powerful of these tests in certain situations.     

实验仿真软件的开发研究

在研究《自动控制原理》课题特点和 CAI教育理论的基础上 ,以微型计算机平台介绍了《控制原理虚拟实验室》仿真软件开发的步骤及方法 ,论述了实验仿真软件开发研究的指导思想 ,实验仿真软件要求 ,以及如何发挥计算机网络优势     

动静叶相互干涉的三维非定常流场数值模拟

将双时间步法应用于叶栅级的全三维黏性非定常数值求解，讨论了分区算法中内边界条件的给定问题，本算法可保证分区边界上具有与内点相同的精度，具有很好的数值稳定性，且通量基本守恒，将该方法应用于具有弯曲导叶的涡轮级的计算可得到典型的非定常流谱，揭示了动静叶之间的相互干涉对叶片气动性能的影响，数值计算结果表明本文给出的算法是合理有效的。