An In‐depth Analysis of Achievement Gaps Between Seventh and Eighth Grades in the TIMSS Database

Middle school data from the Third International Mathematics and Science Study (TIMSS) are analyzed in this article to compare achievement difference between seventh and eighth grades. The statistical computing involves a selective subtraction of item scores in more than 40 countries. The research findings indicate that not all TIMSS items have resulted in a higher mean score at the upper grade level. Item features are discussed to characterize part of the released TIMSS instrument that generates a higher average score at the lower grade. This empirical study may help enrich understanding of the TIMSS benchmark among mathematics and science educators.     

关于不同班级课堂教学评价分数等值排序的数学模型

作为对现有课堂教学评价模型的补充与完善,利用线性标准分的分数转换方法,给出了不同班级教学评价分数等值排序的数学模型,并通过实例说明了该模型的科学性与实用性.     

The Role of Interactions Between Student and Classroom Context in Developing Adaptive Self‐Efficacy in One Sixth‐Grade Mathematics Classroom

Research and theory suggest several instructional practices that could enhance student self‐efficacy. However, little is known about the ways these instructional practices interact with individual students to create opportunities or challenges for developing adaptive self‐efficacy. In this study, we focused on two sources of efficacy, mastery experiences, and social persuasion, and examined how these sources were structured for three students with different levels of mathematics achievement and self‐efficacy within a sixth‐grade mathematics classroom. Analyses within each case showed that each student experienced success and received social persuasion differently. On the other hand, analyses across the cases suggest that not only the amount but also the form (i.e., with and without assistance) of successful experiences and the type of performances (e.g., stating definitions, explaining solution procedures, sharing problem‐solving strategies, and making comments on others' ideas) through which the student experienced mastery may have played important role in developing self‐efficacy. Consistently, the amount and form of teacher feedback was different for each focal student. Examining these differences provide insight into each student's self‐efficacy assessed over the course of the study as well as the kind of support each student needed to develop adaptive self‐efficacy.     

A Math Query Language with an Expanded Set of Wildcards

Math search is a new area of research with many enabling technologies but also many challenges. Some of the enabling technologies include XML, XPath, XQuery, and MathML. Some of the challenges involve enabling search systems to recognize mathematical symbols and structures. Several math search projects have made considerable progress in meeting those challenges. One of the remaining challenges is the creation and implementation of a math query language that enables the general users to express their information needs intuitively yet precisely. This paper will present such a language and detail its features. The new math query language offers an alternative way to describe mathematical expressions that is more consistent and less ambiguous than conventional mathematical notation. In addition, the language goes beyond the Boolean and proximity query syntax found in standard text search systems. It defines a powerful set of wildcards that are deemed important for math search. These wildcards provide for more precise structural search and multi-levels of abstractions. Three new sets of wildcards and their implementation details will also be discussed.      

An Audiotaped Program for Reduction of High School Students' Math Anxiety

This project was designed to develop and test an audiotaped program for the reduction of math anxiety. A tape was developed that uses systematic desensitization as a treatment technique. The taped program contains muscle relaxation exercises and a hierarchy of math-related activities to be visualized while in the relaxed state. Three hundred thirty-six ninth and tenth grade college-bound math students were given two instruments to measure their level of math anxiety as a pretest. Fifty-three measured high and were invited to participate in the treatment; they were given the same instruments as a posttest. Of the twenty who responded, ten completed the treatment and ten did not participate. Those who participated had significant reductions in math anxiety levels. Those who were not treated had math anxiety levels which remained virtually unchanged.     

一种PSO和ANN集成的品位优化模型

利用粒子群算法(PSO)与神经网络(ANN)嵌套的技术(PSO-ANN)模拟矿山这个高度复杂和高度非线性的系统,来优化截止品位及入选品位.其基本思路为:用截止品位与入选品位一起组成进化计算的个体,用自适应神经网络建立收益(适应度函数)与粒子个体的局部联系,然后利用粒子群算法的全局搜索功能找出使适应度函数(收益)最大时的品位组合(截止品位及入选品位).这一嵌套的内层是神经网络,用以计算损失率、金属回收率和成本,外层是进化计算,计算收益值.内层执行局部逼近,外层进行全局搜索,共同实现截止品位与入选品位的优化计算.以大冶铁矿为案例,研究结果表明:现在大冶铁矿截止品位18%,入选品位41-42%的生产方案有待改进,当截止品位为17.8337-17.8367%,入选品位取值为46.4%,2007年1月-2007年11月的精矿量增加139200吨,总净现值增加6.698百万元.     

基于云计算的智慧教室系统设计

云计算在信息时代开启了崭新的一页,目前是计算机领域研究热点,因其强大的计算能力和灵活的服务能力而备受关注.但它在教育领域的应用还处于初级研究阶段,缺少成熟的设计和应用模式.以云计算与物联网技术为基础,提出了一个智慧教室系统的建构模型,并总结了其对传统教育模式的改进.     

The Development of Mathematical Discussions: An Investigation in a Fifth-Grade Classroom

Promoting discussion and argumentation of mathematical ideas among students are aspects of the vision for communication in recent school mathematics reform efforts. Having rich mathematical discussions, however, can present a variety of classroom challenges. Many factors influence classroom discussions and need to be addressed in ways that will assist teachers in creating more inquiry-based mathematics classrooms. The study presented here examined the development of mathematical discussions in a fifth-grade classroom over the course of a school year. Various aspects of the participants' interactions, teacher's pedagogy, and the classroom microculture were investigated. One major result is the evolution of student participation from nonactive listening to active listening and use of others' ideas to develop new conjectures. These changes were paralleled by changes in the teacher's role in the classroom and the nature of her questions, in particular.     

The Development of Mathematical Discussions: An Investigation in a Fifth-Grade Classroom

Promoting discussion and argumentation of mathematical ideas among students are aspects of the vision for communication in recent school mathematics reform efforts. Having rich mathematical discussions, however, can present a variety of classroom challenges. Many factors influence classroom discussions and need to be addressed in ways that will assist teachers in creating more inquiry-based mathematics classrooms. The study presented here examined the development of mathematical discussions in a fifth-grade classroom over the course of a school year. Various aspects of the participants' interactions, teacher's pedagogy, and the classroom microculture were investigated. One major result is the evolution of student participation from nonactive listening to active listening and use of others' ideas to develop new conjectures. These changes were paralleled by changes in the teacher's role in the classroom and the nature of her questions, in particular.     

生产中的数学题解——球面圆弧方程式的推导

根据在某个球形产品的设计中的实际问题 ,本文建立了该问题的数学模型并推导出需求的球面圆弧方程式 .     

基于灰关联系统的我国农村户用沼气影响因素调查分析

沼气是农村新能源的主体,可以减少环境污染、解决农村能源短缺问题.从人口、经济、资源、能源消费结构和市场五个方面,用灰关联方法分析了农村户用沼气发展的推动力,并通过实地调研验证了研究结论.结果表明,影响农村户用沼气的发展的主要因素是农村居民人均年纯收入、电力、煤和大牲口存栏数;收入水平越高,农户越能接受沼气池建设,但也会导致沼气池使用效率下降.建议经济发达地区逐渐取消农村户用沼气,建设大型沼气工程,同时加大贫困地区资金扶持力度,削减经济发达地区户用沼气建设补贴.