How to calculate the practical significance of citation impact differences? An empirical example from evaluative institutional bibliometrics using adjusted predictions and marginal effects

Evaluative bibliometrics is concerned with comparing research units by using statistical procedures. According to Williams (2012) an empirical study should be concerned with the substantive and practical significance of the findings as well as the sign and statistical significance of effects. In this study we will explain what adjusted predictions and marginal effects are and how useful they are for institutional evaluative bibliometrics. As an illustration, we will calculate a regression model using publications (and citation data) produced by four universities in German-speaking countries from 1980 to 2010. We will show how these predictions and effects can be estimated and plotted, and how this makes it far easier to get a practical feel for the substantive meaning of results in evaluative bibliometric studies. An added benefit of this approach is that it makes it far easier to explain results obtained via sophisticated statistical techniques to a broader and sometimes non-technical audience. We will focus particularly on Average Adjusted Predictions (AAPs), Average Marginal Effects (AMEs), Adjusted Predictions at Representative Values (APRVs) and Marginal Effects at Representative Values (MERVs).     

A Probabilistic Model for Evaluation of Volleyball Scoring Systems

Abstract

A probabilistic model for the game of volleyball is developed to evaluate alternative scoring systems. This Markov chain model is then recursively solved, to determine the distribution of the number of serves per game and the probability that a given team wins. These results are then used to evaluate the effects on the game of volleyball of a proposed change in the scoring system.     

基于主动式边界基元模型的多类目标识别方法

针对形状特征,提出了一种基于主动式边界基元模型的多类目标自动识别方法. 该方法以主动式边界基元为基础构建字典,可准确描述各类目标的形状结构, 不受尺度、旋转等变化的影响;然后,综合分析上下文信息进行概率学习,采用级联框架和Bootstrap动态采样训练最优边界分类器,实现目标的类别识别和位置定位,并可获取精确形状. 实验结果表明,该方法能有效提取多种类型和复杂结构的目标,具有较强的实用价值.     

汉字概率检索理论及其实现

因特网上信息检索的新问题需要新理论来解决,概率检索理论是其中选择之一。本文在基于英文的概率检索理论基础上,提出了改进的基于汉字的概率检索理论,在实现中又以直接排序代替了先计算后排序的思路,使得所开发软件达到实用程度。     

Query Expansion with Long-Span Collocates

The paper presents two novel approaches to query expansion with long-span collocates—words, significantly co-occurring in topic-size windows with query terms. In the first approach—global collocation analysis—collocates of query terms are extracted from the entire collection, in the second—local collocation analysis—from a subset of retrieved documents. The significance of association between collocates was estimated using modified Mutual Information and Z score. The techniques were tested using the Okapi IR system. The effect of different parameters on performance was evaluated: window size, number of expansion terms, measures of collocation significance and types of expansion terms. We present performance results of these techniques and provide comparison with related approaches.     

预言的句法结构

借助某些科学的、神学的或者哲学的理论,我们可以对自然事件和人类的未来做出预言,一个好的、诚实的预言必须对未来事件的时间和状态做出明确的承诺。人类对于世界的解释经历了神话的、自然主义的和非决定论的三种传统,每一种知识论的传统都影响到预言的可能性。根据非决定论的传统,由于预言所借助的理论知识的归纳特征,任何对于未来状态的断言都只是一种猜测;另一方面,无论自然界还是人类社会都存在大量的不确定性因素,这导致我们实际上无法对未来事件做出精确的预言。人类身处一个不确定的世界中,对于安全性和确定性的渴望似乎是我们这个物种无法摆脱的迷梦。     

概率极限状态设计法在确定地基承载力中的应用

传统的安全系数法确定地基承载力存在许多缺陷。本文对安全系数法存在的问题进行了详细的分析。介绍了概率极限状态设计法在确定地基承载力中的应用，可供工程实践之参考。     

分布估计算法的模型分析与研究

分布估计算法是在遗传算法基础上发展起来的一类新型进化优化算法.分布估计算法采用概率图模型表示基因变量之间的连锁关系,以构建优良解集的概率分布模型和采样分布模型来实现迭代优化.详细分析分布估计算法的基本原理,对采用不同概率图模型的分布估计算法进行总结和分析,并针对分布估计算法领域的研究现状,提出仍需解决的主要问题.     

The Role of Teachers and Schooling Experiences in Learners’ Adult Life Quality: A Senegalese Case Study

School attended, Qur’anic education attendance, fathers’ occupation, and some aspects of teachers’ classroom actions make a difference for the adult life of the former learners. This paper presents findings from a longitudinal study of the career and life situations of Senegalese individuals who were of school age in the beginning of the 1980s. Data was collected on teacher ratings and predictions of school success as well as absenteeism during the academic year 1980/1981. In a follow up study in 1999/2000 the individuals were 25-32 years old and they were interviewed and tested on a simple life-skills test.     

基于物种敏感度分布的概率生态风险评价的Matlab实现

分析了基于物种敏感度分布（SSD）的概率生态风险评价的数学原理，并在此基础上首次给出了概率生态风险评价的Matlab函数"PERA"，该函数只需要污染物的生物毒性数据和环境监测数据作为输入变量即可获得SSD曲线、HC5值、联合概率曲线（JPC）以及JPC与坐标轴所围面积表示的发生有害生物效应的总体风险概率（ORP值）等指标，可用于污染物环境基准的推导和污染物生态风险评价。