GENI体系结构的中间件GMC建立开放真实的试验环境

2006年11月1日，GENI的网站上发布了GENI体系结构中间件的阐述文章，该文从GENI体系结构的管理核心——GMC（GENI Management Core）出发。描述GENI系统的体系结构。作者指出，该文并不描述一个特殊的关于链路、节点、子网等的部署，其定义的框架只是简单地统筹了这些组件在逻辑上怎样组成一个紧密联系的设施。GMC的目的是为建立一个开放的、大规模的，真实的试验设施框架。这个试验设施将允许研究人员用试验来回答复杂网络系统的问题，评估另一个体系结构以及评价工程开销。[编者按]     

Higher Education as a System: The English Experience

With particular, although not exclusive, reference to England, this article explores the appropriateness of describing higher education as a system. It has two main purposes: to explore the grounds for labelling English higher education as a system and to argue that, because this is no longer an appropriate label, a different conceptualisation is required. The central argument is that the structure of higher education is formed through the interaction of the state, market and higher education institutions and is, therefore, a shifting political construct. Furthermore, it will be hypothesised that the English (indeed, the British) model of higher education is better described as an increasingly internally differentiated network of sectors rather than as a system.     

Learning more by being taught less: a “time-for-self-study” theory explaining curricular effects on graduation rate and study duration

In this article, an alternative for Tinto’s integration theory of student persistence is proposed and tested. In the proposed theory, time available for individual study is considered a major determinant of both study duration and graduation rate of students in a particular curriculum. In this view, other activities in the curriculum, in particular lectures, constrain self-study time and therefore must have a negative impact on persistence. To test this theory, we collected study duration and graduation rate information of all—almost 14,000 students—enrolling in eight Dutch medical schools between 1989 and 1998. In addition, information was gathered regarding the timetables of each of these curricula in the particular period: lectures hours, hours spent in small-group tutorials, practicals, and time available for self-study. Structural equation modeling was used to study relations among these variables. In line with our predictions, time available for self-study was the only determinant of graduation rate and study duration. Lectures were negatively related to self-study time, negatively related to graduation rate, and positively related to study duration. The results suggest that extensive lecturing may be detrimental in higher education. However, in the curricula employing limited lecturing considerable energy was spent in supporting self-study activities of students and preventing postponement of learning. Given our findings, both activities will likely have large pay offs, in particular in curricula with low graduation rates.     

Remembering William Goffman: Mathematical information science pioneer

This paper reviews the career and legacy of William (Bill) Goffman, who served as a researcher, Professor, Dean and Emeritus at Case Western Reserve University, Cleveland, Ohio, from 1959 to 2000. Goffman pioneered mathematical information science broadly and in several key areas. First, he applied disease epidemiology concepts to model accurately the spread of knowledge and the formation of knowledge systems and their ecologies, including the dynamics of scientific discovery. Second, he proposed significant improvements in information retrieval through the deployment of multi-valued logic, appropriate file ordering, effective and efficient retrieval measures, and simplified retrieval approaches, including early work in citation-based searching. Third, Goffman applied Bradford-like distributions to model effective core research literature collection development and usage. Fourth, he developed original epidemiology models, and was an early contributor in biomedical informatics. His mathematical contributions have stood the test of time and will continue to be applicable indefinitely.     

College students solving chemistry problems: A theoretical model of expertise

A model of expertise in chemistry problem solving was tested on undergraduate science majors enrolled in a chemistry course. The model was based on Anderson's Adaptive Control of Thought‐Rational (ACT‐R) theory. The model shows how conceptualization, self‐efficacy, and strategy interact and contribute to the successful solution of quantitative, well‐defined chemistry problems in the areas of stoichiometry, thermochemistry, and properties of solutions. A statistical path analysis and students' explanations supported the model and indicated that the students' problem conceptualization and chemistry self‐efficacy influenced their strategy use, which, in turn, strongly influenced their problem‐solving success. The implication of these findings for future research and developing students' expertise in chemistry problem solving is that a strategy is advantageous when it is built on a foundation of conceptual knowledge and chemistry self‐efficacy. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 1070–1089, 2009