Assessing program impact using latent growth modeling: a primer for the evaluator

Latent growth modeling (LGM) has emerged as a flexible analytic technique for modeling change over time because it can describe developmental processes at both the inter- and intra-individual levels. The LGM method can also provide a means for testing the contribution of other variables in order to explain variability in growth trajectories. This paper didactically illustrates the use of LGM as an analytical tool in program evaluation. Specifically, a hypothetical evaluation of a high school drug prevention program was used to demonstrate: (a) how LGM can be used to assess the longitudinal impact of a prevention program by comparing treatment and control populations with respect to individual differences in initial status and in rate of change; and (b) how predictors of initial status (post-intervention) and growth selected on the basis of a particular program theory can be incorporated in the model to explain program impact. Some advantages and limitations of using LGM in program evaluation are highlighted.     

Practical Maximum Pseudolikelihood for Spatial Point Patterns(with Discussion)

This paper describes a technique for computing approximate maximum pseudolikelihood estimates of the parameters of a spatial point process. The method is an extension of Berman & Turner's (1992) device for maximizing the likelihoods of inhomogeneous spatial Poisson processes. For a very wide class of spatial point process models the likelihood is intractable, while the pseudolikelihood is known explicitly, except for the computation of an integral over the sampling region. Approximation of this integral by a finite sum in a special way yields an approximate pseudolikelihood which is formally equivalent to the (weighted) likelihood of a loglinear model with Poisson responses. This can be maximized using standard statistical software for generalized linear or additive models, provided the conditional intensity of the process takes an 'exponential family' form. Using this approach a wide variety of spatial point process models of Gibbs type can be fitted rapidly, incorporating spatial trends, interaction between points, dependence on spatial covariates, and mark information.     

A survey of statistical methods on remote sensing in russian literature from 1976 to 1985

In this article we review the major areas of remote sensing in the Russian literature for the period 1976 to 1985 that use statistical methods to analyze the observed data. For each of the areas, the problems that have been studied and the statistical techniques that have been used are briefly described     

竹木家具设计原则和造型方法

探讨了竹木家具设计的原则和造型方法,提出了适合新型竹木家具的人体工效学原则、可持续发展原则、人性化设计原则、本地化设计原则和手工艺与现代科技相结合的设计原则,以及借鉴、置换、重构和移植的新型竹木家具造型方法。     

传统统计面对的挑战

针对统计的黑匣子特性,借用Breiman的两种统计文化的平台,分析传统统计面临的挑战和危机,并探索统计领域究竟要向何处发展的问题。研究表明：统计学必须重新回到针对实际问题而与数据打交道,并且创造有关理论的传统上来。只有这样,才能应对不断产生的新问题所带来的挑战。     

基于NURBS方法的转子表面造型技术

采用双三次NURBS方法对某型号转子进行几何造型,对造型过程中出现的曲面延伸、求交和裁剪等问题进行了研究.根据叶片的形状特征,以曲线的几何形式为基础,提出了一种简单实用的曲线曲面延伸方法,实现了切矢量连续的叶片型面的延伸.对于两相交面分别为自由曲面和解析曲面的求交问题,提出了一种简化的跟踪算法,实现了转子叶片型面和圆台面的准确求交和裁剪,从而实现转子精确的几何造型.     

Contemporary American stepparenthood: Integrating cohabiting and nonresident stepparents

Our understanding of contemporary stepfamily life requires incorporating emerging trends in cohabitation and nonresident stepparenting into our `traditional' definition of a stepparent (married adult with resident stepchildren). Using the National Survey of Families and Households, I provide a demographic profile of stepparents that includes cohabiting and nonresident stepparents. Adopting this revised view of stepparenthood alters our knowledge of both the prevalence and composition of stepparent families. The `traditional' definition of a stepparent is shown to describe less thanhalf of all stepparents today. Results also highlight diversity in stepparents' parenting obligations and sociodemographic characteristics. This revised view of stepparenthood has implications for future research on and policy targeted at stepfamilies.     

基于BP人工神经网络的磨料水射流切割深度模型

在已知的磨料水射流切割混凝土实验数据的基础上,应用BP人工神经网络理论,并且借助MATLAB神经网络工具箱,建立磨料水射流切割深度模型.模型中包括的射流参数有射流压力、靶距、磨料粒径、磨料流量、磨料喷嘴直径、磨料喷嘴长度及横移速度.通过模型预测结果与实验结果的比较,表明模型具有一定的精度.     

对素描教学的认识与思考

素描是造型艺术的基础，是基础课的重要组成部分，这个技术训练要有相应科学的教学方法，使技法和理论有机地融合在一起。     

Remedial Policies in Radiologically-Contaminated Forests: Environmental Consequences and Risk Assessment

As a result of the Chernobyl nuclear power plant accident in 1986, large forested areas in Europe were contaminated by radionuclides. Extensive societal pressure has been exerted to decrease the radiation dose to the population and to the environment. Thus, in making abatement and remediation policy decisions not only economic costs, but also human and environmental risk assessment are desired. Forest remediation by organic layer removal, one of the most promising cleanup policies, is considered in this paper. Ecological risk assessment requires evaluation of the radionuclide distribution in forests. The FORESTPATH model^(1,2) is used for predicting the radionuclide fate in forest compartments after deposition as well as for evaluating the application of the remedial policy. Time of intervention and radionuclide deposition profile was predicted as being crucial for the remediation efficiency. Risk assessment conducted for a critical group of forest users in Belarus shows that consumption of forest products (berries and mushrooms) leads to about 0.004% risk of a fatal cancer. Cost-benefit analysis for forest cleanup suggests that complete removal of organic layer is too expensive for application in Belarus.