Using Prediction to Promote Mathematical Understanding and Reasoning

Research has shown that prediction has the potential to promote the teaching and learning of mathematics because it can be used to enhance students' thinking and reasoning at all grade levels in various topics. This article addresses the effectiveness of using prediction on students' understanding and reasoning of mathematical concepts in a middle school algebra context. In the treatment classroom, prediction questions were utilized at the launch of each algebra lesson, and in the control classroom such questions were not used. Both classrooms were taught by the same teacher and used the same curriculum. After completing each of the linear and exponential units, the two classrooms were compared in terms of their mathematical understanding and reasoning through unit assessments. Overall, the treatment classroom outperformed the control classroom on the unit assessments. This result supports that prediction is a valid construct with respect to enhanced conceptual understanding and mathematical reasoning.     

A Method of Estimating Craft Manpower Requirements at Industry Level

Accurate estimation of future craft manpower requirements is essential to an industry if shortage of manpower on the one hand and unemployment on the other are to be avoided. Such estimation should allow for the fact that there is a range of likely outcomes, should permit modification with the passage of time and should be objective.This article proposes a method, based on studies of the printing industry, of obtaining a probabilistic forecast of future manpower requirements by treating changes in individual technical and economic factors as random variables and combining them in a statistical model. The implications of this are then examined for various policies, using a cost utility model and calculations of the expected value of unemployment resulting from different levels of recruitment.     

上层带扰动参数的二层多目标优化问题的灵敏度分析

借助集值优化问题的灵敏度分析，讨论了下层无扰动，上层带扰动参数的二层多目标最优化问题的灵敏度分析．     

数学期望型水平值逼近全局最小值的方法

郑权在1978年提出的一种积分水平集算法概念性算法.由于水平集一般情况下难以求出,此算法通过Monte-Carlo随机取点来实现.本文提出了数学期望型水平值逼近全局最小值的概念性算法,它利用了相对熵主要思想,通过改变重要样本密度函数,克服了郑权算法水平集不易求得而难以求出水平值的困难.本文还给出了求全局最小值的收敛准则并证明了它的渐进收敛性.     

Mathematical Level Raising Through Collaborative Investigations with the Computer

Investigations with the computer can have different functions in the mathematical learning process, such as to let students explore a subject domain, to guide the process of reinvention, or to give them the opportunity to apply what they have learned. Which function has most effect on mathematical level raising?We investigated that question in the context of developing learning materials for 16-year-old students in the domain of probability theory,consisting of computer simulations based on a gambling game and investigation tasks about these games. We compared the difference in level raising between three versions of the learning materials: investigations with the computer before, during or after the learning of a mathematical concept. It was shown that there was no significant difference in the final mathematical level that students attained in the three conditions (the product). However, there were differences in the level on which students approached the investigation tasks (the process). Furthermore,we found evidence of new categories in the students' answers, lying between the perceptual and conceptual levels, which may give important insight into the process of level raising. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Invisible Wall Project: Reasoning and Problem Solving Processes of Primary and Lower Secondary Students

The Invisible Wall Project analyzes problem-solving processes of children in Grades 3 and 4 and Grades 8 and 9. The central idea of the research is to use sets of tasks that are all unsolvable, which means they have a goal that cannot be reached. The unsolvability, however, is of a kind that can be understood even by younger children. In our case, the tasks are geometrical puzzles that have to be covered with given tiles. To the unprepared problem solver, the unsolvability is like an “invisible wall” against which the solver bounces in his or her attempt to tackle the task. On the basis of 172 transcribed interviews, we analyze the students' reasoning behavior and compare the nature of the problem-solving processes of primary and lower secondary students.     

A Longitudinal Study of Middle and Secondary Level Science Textbook Vocabulary Loads

Middle and secondary science textbooks have long been a primary support for instruction, often leading to heavy emphasis on domain‐specific vocabulary. A longitudinal study was conducted to compare vocabulary loads of science textbooks published since 2010 to results of two previous studies going back to 1983. In each study, textbooks chosen represent convenience samples of commonly used middle and secondary science textbooks. Vocabulary emphasis in science textbooks remains high, and may present a problem for struggling readers and English language learners (ELL). Some vocabulary loads were found to approach or even exceed recommended limits for vocabulary instruction in modern foreign language courses. Also, science vocabulary can present an additional challenge for native English speakers and ELLs since many terms have no common colloquial English or native language equivalents. Recommendations for how to promote effective science vocabulary development are provided. Overall, over three decades there has been little change in heavy emphasis on vocabulary in middle and secondary science textbooks.     

模糊推理中的规则约简

为避免模糊推理中出现复合规则爆炸的情况,研究了方程pΛq→r=(p→r)V(q→r)关于uninorm诱导蕴涵所有解的情况.选用uninorm诱导的R-蕴涵作为上述方程中蕴涵时,证明了没有新的非平凡解出现;选用uninorm诱导的S-蕴涵作为上述方程中蕴涵时,获得了uninorm满足该方程的充要条件.     

Upper and Lower Bounds of the (co)chain Type Level of a Space

We establish an upper bound for the cochain type level of the total space of a pull-back fibration. It explains to us why the numerical invariants for principal bundles over the sphere are less than or equal to two. Moreover computational examples of the levels of path spaces and Borel constructions, including biquotient spaces and Davis-Januszkiewicz spaces, are presented. We also show that the chain type level of the homotopy fibre of a map is greater than the E-category in the sense of Kahl, which is an algebraic approximation of the Lusternik-Schnirelmann category of the map. The inequality fits between the grade and the projective dimension of the cohomology of the homotopy fibre.     

关于数学期望型水平值逼近优化问题总极值的算法

本文研究用数学期望型水平值逼近一类优化问题总极值的算法,证明了算法所构造的数学期望型水平值迭代方程的解的存在唯一性,同时证明了方程的解是原来优化问题的总极值,并对可统一到该算法理论框架下的几种可实现算法进行了简要描述,数值实验结果验证了算法的有效性.     

The Place of Logic in Reasoning

Reasoning is a goal-oriented activity. The logical steps are at best the median part of a full reasoning: before them, a language has to be defined, and a model of the goal in this language has to be developed; after them, their result has to be checked in the real world with respect to the goal. Both the prior and the subsequent steps can be conducted rationally; none of them has a logical counterpart. Furthermore, Logic aims at prescribing what a correct reasoning is. But correct with respect to what? If the answer is: with respect to truth, the next question is whether the truth in everyday life, physics, economy, is the same as the truth that logicians have in mind. Resorting to Logic is justified only if an idealization in terms of true propositions in the logical sense is compatible with the goal. If such an idealization is legitimate, so is the use of classical Logic. If not, there is no authority forbidding to skew Logic in order to better reflect the nature of the reasoning required for the task.     

A Survey of Job Opportunities and Job Requirements and their Effect on the Mathematics Teaching for Early Leavers in Secondary Schools

A questionnaire survey was used to gauge the opinions of mathematics teachers about some history of mathematics material recently developed for use in the classroom. Teachers' opinions of the materials were generally favourable, but a sizeable proportion responded that they would not be prepared to actually use such material in their own teaching.

     

数学软件在数学建模中的应用

本文以 2 0 0 1年全国大学生数学竞赛 A题为例 ,介绍数学软件在数学建模中的应用 ,并通过例子揭示该竞赛题本身在数学表述上是有缺陷的 .