Being sloppy about slope: The effect of changing the scale

What is the slope of a(linear) function? Due to the ubiquitous use of mathematical software, this seemingly simple question is shown to lead to some subtle issues that are not usually addressed in the school curriculum. In particular, we present evidence that there exists much confusion regarding the connection between the algebraic and geometric aspects of slope, scale and angle. The confusion arises when some common but undeclared default assumptions, concerning the isomorphism between the algebraic and geometric systems, are undermined. The participants in the study were 11^th-grade students, prospective and in-service secondary mathematics teachers, mathematics educators and mathematicians — a total of 124 people. All participants responded to a simple but non-standard task, concerning the behavior of slope under a non-homogeneous change of scale. Analysis of the responses reveals two main approaches, which we have termed ‘analytic’ and ‘visual’, as well as some combinations of the two.     

高级家用电子产品维修智能化考核系统的研究

提出了一种基于单片机的电子产品维修训练与考核智能化系统方案 ,通过上位机和下位机构成主从结构的监控系统 ,实现对故障检修训练与考核的管理 ,包括随机设置故障、恢复故障及自动评分 .在上位机 ,能及时了解各下位机故障维修及考核的情况 ,实现了监控的实时性和灵活性 ,提高了工作效率及降低成本 .     

如何提高学生学习计算机课的兴趣

中等职业学校计算机基础教育,应更多地侧重于培养学生计算机的应用能力。在实际的教学过程中我们发现,目前计算机教学中存在着许多不尽人意之处。如果还采用陈旧的教学方法和教学内容,学生容易感到枯燥乏味,失去学习的兴趣。因此,改革课程体系和学习模式,提高学生学习计算机课的积极性,是当前需要解决的首要问题。     

For a learnable mathematics in the digital cultures

I begin with some general remarks concerning the co-evolution of representational forms and mathematical meanings. I then discuss the changed roles of mathematics and novel representations that emerge from the ubiquity of computational models, and briefly consider the implications for learning mathematics. I contend that a central component of knowledge required in modern societies involves the development of a meta-epistemological stance – i.e. developing a sense of mechanism for the models that underpin social and professional discourses. I illustrate this point in relation to recent research in which I am investigating the mathematical epistemology of engineering practice. Finally, I map out one implication for the design of future mathematical learning environments with reference to some data from the `Playground Project. This revised version was published online in July 2006 with corrections to the Cover Date.     

一线多机同时上网的实现

分析论述了一线多机的工作原理及技术特点;阐述了“一线多机”应用的具体实现;解决了在中小型局域网中用Wingate代理实现多机同时上网的实际问题.结合未来网络发展趋势,指出了此类代理服务器软件的广阔前景.     

Transputer及当前应用与发展

简要介绍Ｔｒａｎｓｐｕｔｅｒ的结构,功能及发展史,概述了Ｔｒａｎｓｐｕｔｅｒ的当前应用状况,并预测了Ｔｒａｎｓｐｕｔｅｒ的未来发展前景。     

影响微机安全的主要因素及防护措施

温度、湿度、灰尘、静电和病毒等影响微机安全的各种因素 ,如不加以注意 ,极易使微机出现故障 .因此 ,在日常工作中应采取相应的措施 ,加强防护 ,以保证微机的正常运行 .     

The Diffusion of Mobile Internet in Japan

In Japan, the mobile phone has become an increasingly popular medium of accessing the Internet and e-mail, especially among those who may not have affordable access to a computer. The lower startup costs and the easier overall accessibility of mobile phones relative to personal computers suggest that the mobile phone may be a possible alternative for overcoming unequal access to information communication technology in Japan and elsewhere. Using microdata from 2001, we compare and contrast the determinants of mobile versus computer-based Internet in Japan. Our findings show that mobile Internet access, as compared to computer access, is determined less by demographics, socioeconomic status, and technological readiness, suggesting that barriers to Internet access are lower for mobile phones than is the case for computers.     

为课件制作降降温

由于多媒体集文字、声音、图形、图像、动画、视频于一身，静与动相结合，多媒体教学摆脱了一些机械呆板的教学形式，依赖大量的多媒体素材把以往受时间和空间限制的内容搬进了课堂，信息容量大，表现力丰富，操作方便是多媒体教学得天独厚的优势。媒体的炒作、教育行政部门的干预，在我国掀起了一股课件热。由于我国除沿海开放地区外，计算机硬件资源分布还很不平衡，大家一窝蜂地制作课件，会造成一些负面效应，笔者认为应为课件制作降降温。     

Student and Teacher Perspectives in Computer-Mediated Learning Environments in Teacher Education

Rapid advances in technology, particularly with the Internet, have led to the availability of numerous tools to support teaching and learning. This study involved the use of an Internet application, Connecting Communities of Learners (CCL), in courses for prospective teachers. Unlike earlier studies involving the use of the CCL, the context of this study related to full-time graduate students who used the CCL to augment weekly face-to-face instruction. An interpretive study was undertaken to ascertain student and teacher perceptions of the learning environments associated with the use of the CCL. Through the use of the CCL, students were able to be autonomous in regard to their own learning, co-participate with their peers and the instructor, and establish and maintain a community of learners in which participants could interact with others as co-teachers and co-learners. The CCL was perceived as a useful tool for building learning environments in which all participants can contribute written texts as evidence of what is known and as objects from which others can learn. This revised version was published online in July 2006 with corrections to the Cover Date.