Shoe collar height effect on athletic performance,ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance

Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting. Fifteen university basketball players performed maximum-effort side-step cutting to the left 45° direction or a straight ahead run in response to a random light signal. Seven successful cutting trials were collected for each condition. Athletic performance, ground reaction force, ankle kinematics and kinetics of both legs were analysed using paired t-tests. Results indicated that high-collar shoes resulted in less ankle inversion and external rotation during initial contact for the planting leg. The high-collar shoes also exhibited a smaller ankle range of motion in the sagittal and transverse planes for both legs, respectively. However, no collar effect was found for ankle moments and performance indicators including cutting performance time, ground contact time, propulsion ground reaction forces and impulses. These findings indicated that high-collar shoes altered ankle positioning and restricted ankle joint freedom movements in both legs, while no negative effect was found for athletic cutting performance.     

On co-authorship for author disambiguation

Author name disambiguation deals with clustering the same-name authors into different individuals. To attack the problem, many studies have employed a variety of disambiguation features such as coauthors, titles of papers/publications, topics of articles, emails/affiliations, etc. Among these, co-authorship is the most easily accessible and influential, since inter-person acquaintances represented by co-authorship could discriminate the identities of authors more clearly than other features. This study attempts to explore the net effects of co-authorship on author clustering in bibliographic data. First, to handle the shortage of explicit coauthors listed in known citations, a web-assisted technique of acquiring implicit coauthors of the target author to be disambiguated is proposed. Then, a coauthor disambiguation hypothesis that the identity of an author can be determined by his/her coauthors is examined and confirmed through a variety of author disambiguation experiments.     

A novel actuation method of transporting droplets by using electrical charging of droplet in a dielectric fluid

We evaluate the feasibility of manipulating droplets in two dimensions by exploiting Coulombic forces acting on conductive droplets immersed in a dielectric fluid. When a droplet suspended in an immiscible fluid is located near an electrode under a dc voltage, the droplet can be charged by direct contact, by charge transfer along an electrically conducting path, or by both mechanisms. This process is called electrical charging of droplet (ECOD). This charged droplet may then be transported rapidly by exploiting Coulombic forces. We experimentally demonstrate electrical actuation of a charged droplet by applying voltage sequences. A charged droplet is two dimensionally actuated by following the direction of the electrical field signal. The droplet does not contact the surface of the microfluidic chip when it moves. This characteristic is very advantageous because treatments of the substrate surfaces of microfluidic chip become simpler. In order to test the feasibility of using ECOD in a droplet-based microreactor, electrocoalescence of two oppositely charged droplets is also studied. When two droplets approach each other due to Coulombic attraction, a liquid bridge is formed between them. We postulate that if the applied electric field is weaker than a certain critical level, the two droplets coalesce instantaneously when the charges are exchanged and redistributed through this liquid bridge.     

从“媒介系统依赖”到“传播机体”——“媒介系统依赖论”发展回顾及新概念

祝建华 :本文描述的“传播机体”理论是“媒体依赖”理论在全球化和新媒体时代的继承和发展 ,用于分析媒体、个人、社群乃至社会各层面之互动关系。陈力丹 :鲍尔 -洛基奇是前任《传播学研究》的两主编之一 ,她与德弗勒的合著《大众传播诸论》1 5年前就在中国出版了中译本 ,因而被我国传播学界知悉。她在理论传播学方面与时俱进 ,现在已经将她早年论证的“媒介依赖论” ,以美国洛杉矶不同文化区域的传播生态作为研究对象 ,发展到了现在的“传播机体论”。本期发表的是她发言的理论部分。     

Classifying higher education institutions in Korea: a performance-based approach

The purpose of this study was to classify higher education institutions according to institutional performance rather than predetermined benchmarks. Institutional performance was defined as research performance and classified using Hierarchical Cluster Analysis, a statistical method that classifies objects according to specified classification factors. In the analysis, 47 Korean universities with doctoral programs were classified as research universities (seven universities), research active universities (14 universities), and doctoral universities (26 universities). In the detailed discussions, profiles of each group were analyzed and discussed; and, disciplinary classifications were conducted in engineering, natural science, and social science and humanities. In addition, to validate the classifications, the research performances of these categories were compared with those of U.S. peers. In the comparisons, the research performance of Korean universities was similar to that of U.S. peers. From the analysis, the classification results emerging from the performance-based approach were shown to be equivalent to that of conventional classifications using predetermined benchmarks.

Research agenda for social Q&A

As new venues of information and tools for information access are emerging, people's online information seeking behavior is dramatically evolving. While a majority of well-established and classical models of information seeking and behavior are still valid, there is a growing need to study and explain novel information sources and information seeking behaviors that are unique to these sources. One emerging domain is social question and answer (Q&A). This article develops a research agenda for social Q&A, reviewing recent studies and identifying core issues, questions, and challenges.     

ANALYSIS OF THE LEARNING EXPECTATIONS RELATED TO GRADE 1–8 MEASUREMENT IN SOME COUNTRIES

This study analyzes measurement learning expectations involving area and volume in grades 1–8 across several U.S. states and high-performing TIMSS Asian countries, including Singapore, Taiwan, and Japan. Based on a review of official curriculum documents, results of this study indicate that the mathematics content, grade placement, and cognitive level of learning expectations related to selected measurement topics vary markedly across states and countries. This variability in learning expectations results in striking differences in students’ opportunity to learn.     

Unspoken Stories by North Korean and Korean-American Educators: A Trioethnography on South Korean Education

This paper articulates the challenges of the South Korean education system through a co-constructed narrative, employing duoethnographic methodology. The authors offer critical and contextualized perspectives on their personal and professional observations on the dysfunctional aspects of South Korean education including dehumanization and overachievement. Drawing upon the framework of education for sustainable development, the authors suggest implications for educational reform both at the micro and macro, and practical and conceptual levels. This study is significant in that it considers voices of educators with socio-political backgrounds often marginalized in South Korean society.