概率方法在一些数学问题中的巧妙应用

20世纪以来,由机会游戏起源的概率论飞速发展,并广泛应用于各个工程技术学科和社会学科。概率论也发展成为一门与实际紧密相连的理论严谨的数学科学。其内容丰富,结论深刻,趣味性浓厚,有自己独特的概念和方法,已成为数学一个有特色的分支。     

集合竞价金融实验中的投资者预期与泡沫

介绍一个集合竞价出清机制下的金融实验,利用实验数据对实验者价格预期的形成进行深入研究,发现实验者价格预期依赖于市场最新信息,并对信息进行简单线性加工;动量策略是一种典型的价格预期策略;实验者的价格预期有显著的一致性;市场泡沫与实验者预期有非常密切的联系。     

集成系统的关键事件路径分析方法

通过研究概率事件结构图的事件路径,提出了集成系统的关键事件路径分析方法．根据集成系统体系结构描述提取的规则,构造着色Petri网模型对应的概率事件结构图,并给出其循环事件路径、顺序事件路径和关键事件路径的定义．然后利用着色Petri网模型的仿真统计结果,采用灵敏度分析方法找出其关键事件路径．该方法强化了逻辑结构特性,可靠实用,是离散事件系统结构化分析的基础．最后以一个建模实例详细阐述了该方法的应用,结果适用可信．     

Effect of Student Characteristics on Teachers' Predictions of Student Success

Abstract

To determine teachers' perceptions of the likelihood of students' academic and social success in general education settings, 384 teachers responded to 1 of 32 possible case studies describing a student, in which gender, reading achievement, social behavior, and attentiveness were manipulated experimentally. Results showed that, in some instances, teachers used irrelevant information in their predictions (e.g., social behavior influenced academic predictions, reading achievement influenced social predictions). Furthermore, teachers demonstrated gender bias in some instances and appeared to make negative predictions when an ambiguous label explained students' reading problems. The author discusses implications for the inclusion of students with special needs in general education classes.     

GM概率加密密码系统的实现

本文简要论述了GM概率加密密码系统的基本原理及其实现步骤，并深入讨论了它的理论基础。     

On Event Spaces and Probabilistic Models in Information Retrieval

A basic notion of probability theory is the event space, on which the probability measure is defined. A probabilistic model needs an event space. However, some classes of events (which we may want to model probabilistically) exhibit structure which does not fit well into the traditional event space notion. A simple one-to-many example is discussed at length. The information retrieval case, involving queries, documents and relevance, is analysed. The event space issue makes for some difficulty in comparing different probabilistic models in IR.Revised version of a paper presented at the MF/IR Workshop, SIGIR 2002, Tampere, Finland, under the title On Bayesian models and event spaces in information retrieval.     

"夜晚的黑暗工具"--论《麦克白》中的女巫及其预言

《麦克白》是莎士比亚四大悲剧的最后一部,剧中主人公麦克白从一位王亲贵族和著名大将走上了犯罪的道路,除了他自身的野心和权势欲望之外,女巫及其预言的诱惑也起了一定的作用.如夸大女巫及其预言对麦克白所产生的影响和认为女巫们的预言代表了麦克白内心的罪恶愿望都是与剧情格格不入的.     

How do high school students solve probability problems? A mixed methods study on probabilistic reasoning

When studying a complex research phenomenon, a mixed methods design allows to answer a broader set of research questions and to tap into different aspects of this phenomenon, compared to a monomethod design. This paper reports on how a sequential equal status design (QUAN → QUAL) was used to examine students’ reasoning processes when solving probability problems. A select clustered sampling resulted in the inclusion of 168 high school students in a first, quantitative phase, in which a questionnaire was used to assess how they solved probability problems. This questionnaire included probability items that were based on the outcome orientation, the representativeness misconception, and the equiprobability bias. In a second, qualitative phase, 18 students who were purposefully sampled from the first research phase were interviewed in order to conduct an in-depth study of their probabilistic reasoning processes. In this paper, we illustrate and discuss how several mixed methods research purposes were realized throughout our study: development, expansion, and initiation.     

Prenatal prediction of child abuse and neglect: A prospective study

Five hundred eighty-seven women in a combined Maternity-Infant, Children and Youth project were interviewed at between 3 and 6 months of gestation by a skilled masters degree social worker (M.S.W.) using a Family Stress Checklist developed at the University of Colorado Health Sciences Center. Only 7% of the women were scored as “high risk” for serious parenting problems. Neither single status nor teenage status increased the risk significantly. A review of charts of 100 of the children whose mothers had been considered “at risk” was conducted 2 to 2.5 years later, and compared with 100 charts on children whose mothers had been considered at “no risk,” giving the following results: Twenty-five children had experienced failure to thrive, neglect or abuse. Twenty of these were from the original high risk mothers, giving an incidence of neglect/abuse in that group of 52%. The no risk control group of 100 mothers showed a 2% incidence of abuse/neglect; a low risk group showed a 4% incidence of abuse/neglect; and a mid-score group had an abuse/neglect rate of 5%. The scale proved a remarkably accurate predictor, with a sensitivity (percent correct negatives) of 89%. The authors suggest use of such scales prenatally or even before conception as a step toward the development of true preventive measures.