This paper presents a size reduction method for the inverted file, the most suitable indexing structure for an information retrieval system (IRS). We notice that in an inverted file the document identifiers for a given word are usually clustered. While this clustering property can be used in reducing the size of the inverted file, good compression as well as fast decompression must both be available. In this paper, we present a method that can facilitate coding and decoding processes for interpolative coding using recursion elimination and loop unwinding. We call this method the unique-order interpolative coding. It can calculate the lower and upper bounds of every document identifier for a binary code without using a recursive process, hence the decompression time can be greatly reduced. Moreover, it also can exploit document identifier clustering to compress the inverted file efficiently. Compared with the other well-known compression methods, our method provides fast decoding speed and excellent compression. This method can also be used to support a self-indexing strategy. Therefore our research work in this paper provides a feasible way to build a fast and space-economical IRS. 相似文献
Students in undergraduate premedical anatomy courses may experience suboptimal and superficial learning experiences due to large class sizes, passive lecture styles, and difficult-to-master concepts. This study introduces an innovative, hands-on activity for human musculoskeletal system education with the aim of improving students’ level of engagement and knowledge retention. In this study, a collaborative learning intervention using the REFLECT (augmented reality for learning clinical anatomy) system is presented. The system uses the augmented reality magic mirror paradigm to superimpose anatomical visualizations over the user’s body in a large display, creating the impression that she sees the relevant anatomic illustrations inside her own body. The efficacy of this proposed system was evaluated in a large-scale controlled study, using a team-based muscle painting activity among undergraduate premedical students (n = 288) at the Johns Hopkins University. The baseline knowledge and post-intervention knowledge of the students were measured before and after the painting activity according to their assigned groups in the study. The results from knowledge tests and additional collected data demonstrate that the proposed interactive system enhanced learning of the musculoskeletal system with improved knowledge retention (F(10,133) = 3.14, P < 0.001), increased time on task (F(1,275) = 5.70, P < 0.01), and a high level of engagement (F(9,273) = 8.28, P < 0.0001). The proposed REFLECT system will be of benefit as a complementary anatomy learning tool for students. 相似文献
Purpose: A relationship exists between attitudes toward physical education and future physical activity. The purpose of this study was to examine changes in attitude toward physical education as students progressed from upper elementary school (Grade 4) through middle school (Grade 8). Method: Three cohorts of students (Cohort 1, Grades 4–6, n = 96; Cohort 2, Grades 5–7, n = 71; and Cohort 3, Grades 6–8, n = 73) were each followed for 3 years to examine changes in attitudes toward physical education. Results: After an initial increase from Grade 4 to Grade 5, a significant decrease was observed from Grades 5 to 8 in students’ positive attitudes toward physical education, with a faster rate of change for girls than boys. Conclusion: This longitudinal study provides further insights regarding the attitudes of students as they progress from Grade 4 to Grade 8 and expands on previous findings identifying decreasing positive attitudes toward physical education as students age, particularly for girls. The results provide evidence to support targeted interventions. 相似文献
Abstract This article addresses three periods of evangelical Christian education development in the twentieth century. The early part of the century was a time of loss of influence and marginalization within the broader religious education movement. The middle part of the century saw an explosion of parachurch educational ministry efforts to assist the evangelical movement and renewed efforts to develop professional organizations and curricular resources for the church. The last part of the century has seen a growth of influence of evangelical educational writers, publishers, schools, and megachurches on the shape of Christian education today. Current assessment, hopes for the future, and gifts to the broader religious education community are reviewed. 相似文献
One of the major innovations in the recent wave of education reform in Hong Kong is the target‐oriented curriculum. An interesting feature of this new curriculum initiative was its amoebic characteristics – changing shape and focus in its course of development. It was reshaped from an assessment system for accountability purposes to a centrally developed curriculum initiative for improving teaching and learning, and finally to a school‐based curriculum development. In this paper, this course of development and the reasons behind it will be described and analysed. The study suggests that the two‐tier educational policy and implementation system in Hong Kong is a major cause leading to such a phenomenon. If this system were not improved, the possibility of achieving real changes at the school and classroom level would be low. 相似文献
Primary objective: Teacher evaluation is being revamped by policy-makers. The marginalized status of physical education has protected this subject area from reform for many decades, but in our current era of system-wide, data-based decision-making, physical education is no longer immune. Standardized and local testing, together with structured observation measures, are swiftly being mandated in the USA as required elements of teacher evaluation systems in an effort to improve school programs and student achievement. The purpose of this investigation was to document how this reform was initiated and the experiences of teachers, students and administrators, from three high school physical education programs, during initiation of this reform. Documenting how physical education programs respond to such reforms develops our understanding of top-down reform efforts and helps to identify conditions under which such reforms have the intended effect on physical education teachers and student learning in physical education.
Theoretical framework: Fullan’s three phases of school change has been used to analyze and guide school change efforts in several subject areas including physical education. The phases are initiation, implementation and institutionalization. This study is situated primarily within the first phase of school change, the initiation phase.
Methods and procedures: This study took place over a 21-month period in 3 suburban school districts in a northeast metropolitan area of the USA. Interviews with district physical education administrators, high school physical education teachers and students were conducted. Field notes of physical education classes, informal interviews and related artifacts including pre- and post-physical education assessments were collected. To ensure trustworthiness, several steps were taken including member checks, triangulation and peer review. The data were analyzed to find common themes and patterns using the constant comparative method.
Results: Several themes emerged: (1) changes in curriculum and assessment; (2) effect on administrators; (3) stakeholder apathy and (4) department collaboration.
Conclusion: Changes, although minor, did take place in the wake of this top-down teacher reform; however, additional research needs to be completed to determine whether or not these changes are meaningful or long lasting. 相似文献
In this paper, we present results on the measurement and analysis of the sound that is produced by the sharp impact loading of a golf ball by a flat massive object (e.g. the face of a golf club). We discuss: (a) the motivation for such a study; (b) some necessary background information on how golf balls vibrate; (c) the techniques used to acquire and analyse the data; and (d) an analysis of the sound made by dropping balls on a smooth, massive concrete target surface. These results establish a simple method for rapid and non-destructive measurement of the effective high-frequency elastic shear moduli of balls and ball cores. 相似文献