改进灰色预测在油田多目标规划决策中的应用

建立了S油田勘探、开发、炼化、机械、公用工程等多个部门和全局的非线性多级目标优化规划模型,应用关联分析、改进灰色预测、回归分析求取规划模型的约束方程并线性化;编制了相应的计算软件,使之快速预测和优化油田各部门“九五”各年的投资和产值;并将优化结果与油田过去或计划值加以对比,给油田规划决策带来一定的参考。     

Estimating household structure in ancient China by using historical data: a latent class analysis of partially missing patterns

Summary.  Social data often contain missing information. The problem is inevitably severe when analysing historical data. Conventionally, researchers analyse complete records only. Listwise deletion not only reduces the effective sample size but also may result in biased estimation, depending on the missingness mechanism. We analyse household types by using population registers from ancient China (618–907 AD) by comparing a simple classification, a latent class model of the complete data and a latent class model of the complete and partially missing data assuming four types of ignorable and non-ignorable missingness mechanisms. The findings show that either a frequency classification or a latent class analysis using the complete records only yielded biased estimates and incorrect conclusions in the presence of partially missing data of a non-ignorable mechanism. Although simply assuming ignorable or non-ignorable missing data produced consistently similarly higher estimates of the proportion of complex households, a specification of the relationship between the latent variable and the degree of missingness by a row effect uniform association model helped to capture the missingness mechanism better and improved the model fit.     

Bayesian networks for imputation

Summary.  Bayesian networks are particularly useful for dealing with high dimensional statistical problems. They allow a reduction in the complexity of the phenomenon under study by representing joint relationships between a set of variables through conditional relationships between subsets of these variables. Following Thibaudeau and Winkler we use Bayesian networks for imputing missing values. This method is introduced to deal with the problem of the consistency of imputed values: preservation of statistical relationships between variables ( statistical consistency ) and preservation of logical constraints in data ( logical consistency ). We perform some experiments on a subset of anonymous individual records from the 1991 UK population census.     

Estimator Choice and Fisher's Paradox: A Monte Carlo Study

This paper argues that Fisher's paradox can be explained away in terms of estimator choice. We analyse by means of Monte Carlo experiments the small sample properties of a large set of estimators (including virtually all available single-equation estimators), and compute the critical values based on the empirical distributions of the t-statistics, for a variety of Data Generation Processes (DGPs), allowing for structural breaks, ARCH effects etc. We show that precisely the estimators most commonly used in the literature, namely OLS, Dynamic OLS (DOLS) and non-prewhitened FMLS, have the worst performance in small samples, and produce rejections of the Fisher hypothesis. If one employs the estimators with the most desirable properties (i.e., the smallest downward bias and the minimum shift in the distribution of the associated t-statistics), or if one uses the empirical critical values, the evidence based on US data is strongly supportive of the Fisher relation, consistently with many theoretical models.     

具体应用中的矛盾分析法之种种

矛盾分析法在科学认识中的具体应用,可作多侧面的展开,形成多方面的更为具体的科学方法。这些具体科学方法可概括为,矛盾的定性分析法、矛盾的定位分析法、矛盾的定点分析法、矛盾的定量分析法、矛盾的定势分析法、矛盾的历史过程分析法、矛盾的逻辑过程分析法、矛盾的系统分析法、矛盾的对立面互补分析法等等.它们均体现哲学方法与具体科学方法的一致性。     

A study of simulated annealing and a revised cascade algorithm for image reconstruction

We describe an image reconstruction problem and the computational difficulties arising in determining the maximum a posteriori (MAP) estimate. Two algorithms for tackling the problem, iterated conditional modes (ICM) and simulated annealing, are usually applied pixel by pixel. The performance of this strategy can be poor, particularly for heavily degraded images, and as a potential improvement Jubb and Jennison (1991) suggest the cascade algorithm in which ICM is initially applied to coarser images formed by blocking squares of pixels. In this paper we attempt to resolve certain criticisms of cascade and present a version of the algorithm extended in definition and implementation. As an illustration we apply our new method to a synthetic aperture radar (SAR) image. We also carry out a study of simulated annealing, with and without cascade, applied to a more tractable minimization problem from which we gain insight into the properties of cascade algorithms.     

光纤扭转对循环延迟线偏振控制系统特性影响的研究

借助模式耦合理论和矩阵光学的知识,对引入光纤扭转机构后的延迟线偏振控制系统的偏振转换特性进行了分析,推导出了描述该系统偏振特性的琼斯矩阵,得到了光纤扭转对系统偏振特性影响的理论模型。     

分析Chiral分层媒质特性的一般方法(英文)

提出了一套系统方法用于求解任意导体片位于界面的Chiral分层媒质的谐振频率,衰减因子和电磁场分布。文中的分析是在Fourier变换域的并矢格林函数和矩阵分析的基础上来进行的,给出的公式的最大价值在于它提供了求解Chiral分层媒质问题的方法论。     

Doing Gender unto the Other: Fiction as a Mode of Studying Gender Discrimination in Organizations

Although ‘doing gender’ has been recently defined as an accomplishment, an element of social practice, this understanding of the concept needs to be extended to coercive action such as subtle workplace discrimination. Even though great effort has been invested in revealing the dynamic of such social practices, the researcher's task is not easy for a variety of reasons. This type of study is difficult to conduct by following traditional research design and many alternative approaches have been tried. This article presents the possibility of using fiction as one possible and relatively unexploited venue of research.     

提高我国科技成果向生产力转化的能力

运用技术经济理论,对我国科技成果转化存在障碍的原因即科技成果转化资金匮乏、企业技术市场参与度低、对技术的需求拉力不足、进口技术减少了对我国自身科技成果市场需求的空间等进行分析,并对提高我国科技成果向生产力转化的能力提出了对策建议。