A stochastic model to predict radio interference caused by corona on high voltage transmission systems

A stochastic model to predict radio interference fields caused by corona discharges on high voltage transmission lines has been developed. This model is based on corona discharges distributed randomly in time and space;A stochastic model for the corona current induced by corona discharges on power lines is proposed. Based on the proposed corona current model, a rigorous analysis is presented to evaluate the radio interference field caused by corona discharges on the single conductor using the stochastic method. The analysis developed for a single conductor is applied to the three phase transmission line;Most random parameters generated by the stochastic RI analysis are shown to be determined from the existing RI data

ANTERIOR CRUCIATE LIGAMENT INJURY RISK FACTORS DIFFERENCES BETWEEN FEMALE DANCERS AND FEMALE SOCCER PLAYERS DURING SINGLE-LEGGED AND DOUBLE LEGGED LANDING TASKS

The purpose of this study was to compare ACL injury risk factors between female dancers and female soccer players during single-legged drop landing and double legged drop landing vertical jump tasks. Fifteen elite female soccer players and 45 professional female dancers (15 ballet, 15 modern, and 15 Korean dancers) were recruited to participate in this study. Two-way repeated measure of ANOVAs (participant groups & landing tasks, 4x2) were used. Female dancers landed with a significantly lower trunk flexion, trunk external rotation, knee external rotation, and knee valgus moment than those of female soccer players. Also, single-legged drop landing task demonstrated a higher trunk external rotation and knee valgus moment than those of double legged drop landing vertical jump task

Guided instruction with Logo programming and the development of cognitive monitoring strategies among college students

As our society changes and becomes more complex, and as new knowledge and technology emerge, the need for teaching students to be independent thinkers and problem solvers increases more rapidly than ever before. Responding to the ever increasing societal demands, educators have sought for proper learning tools and methodologies to improve students\u27 higher-order thinking and problem solving skills. In particular, cognitive monitoring has been a primary concern of educators and cognitive psychologists. Cognitive monitoring has been regarded as one of the most important strategies in efficient thinking and problem solving. Logo programming has been considered a powerful tool to help students develop higher order thinking, an awareness of their thinking processes, and problem solving skills. Unfortunately, little evidence has been collected for the development of cognitive monitoring and problem solving through Logo programming;This research examined the effects of guided instruction with Logo programming on the development of cognitive monitoring strategies among college students. Guided instruction in this study involved three pedagogical elements. First, Logo programming was selected as a particular learning tool to teach cognitive monitoring strategies. Second, an explicit instructional model of cognitive monitoring processes was included in the process of solving Logo problems: decomposing, planning, executing, identifying errors, and debugging. Third, teacher mediated practice of cognitive monitoring activities was facilitated in a Logo programming environment as well as outside of the programming domain;The results of this study demonstrated positive effects of guided instruction with Logo programming on both near transfer and far transfer of cognitive monitoring strategies. The result also indicated that guided instruction contributed most significantly to the development of Logo error identification and debugging skills

Monnaie et cycles

Ce texte offre un survol des principaux modèles du cycle économique qui ont été développés depuis le début des années 1980 en mettant un accent particulier sur l’incorporation de la monnaie dans le modèle néoclassique de croissance. Il défend le point de vue que la monnaie ne contribue substantiellement aux fluctuations agrégées qu’en incorporant des rigidités nominales au modèle.This is a survey of the main business cycle models that have been developed since the early '80s. It emphasizes the incorporation of money in the neoclassical growth model. It argues that money contributes substantially to aggregate fluctuations only if nominal rigidities are introduced in the model

Intercultural competence for future leaders of educational technology and its evaluation

Demands of globalization today continue to increase pressure for the education of global citizens who preserve the variety and vitality of life. Our transatlantic project has been developing a shared community of graduate students and faculty experts in educational technology across six universities. Evidence of the development of intercultural competence was analyzed from artifacts, self-report, interviews, and surveys. The findings showed that students gained intercultural competence in professional and personal spheres, with openness and flexibility that include acceptance, adaptability, and multiple perspectives. Applications of educational technology served as a bridge to introduce new cultures, knowledge and people to students.Demands of globalization today continue to increase pressure for the education of global citizens who preserve the variety and vitality of life. Our transatlantic project has been developing a shared community of graduate students and faculty experts in educational technology across six universities. Evidence of the development of intercultural competence was analyzed from artifacts, self-report, interviews, and surveys. The findings showed that students gained intercultural competence in professional and personal spheres, with openness and flexibility that include acceptance, adaptability, and multiple perspectives. Applications of educational technology served as a bridge to introduce new cultures, knowledge and people to students

Intercultural competence for future leaders of educational technology and its evaluation

Demands of globalization today continue to increase pressure for the education of global citizens who preserve the variety and vitality of life. Our transatlantic project has been developing a shared community of graduate students and faculty experts in educational technology across six universities. Evidence of the development of intercultural competence was analyzed from artifacts, self-report, interviews, and surveys. The findings showed that students gained intercultural competence in professional and personal spheres, with openness and flexibility that include acceptance, adaptability, and multiple perspectives. Applications of educational technology served as a bridge to introduce new cultures, knowledge and people to students.Demands of globalization today continue to increase pressure for the education of global citizens who preserve the variety and vitality of life. Our transatlantic project has been developing a shared community of graduate students and faculty experts in educational technology across six universities. Evidence of the development of intercultural competence was analyzed from artifacts, self-report, interviews, and surveys. The findings showed that students gained intercultural competence in professional and personal spheres, with openness and flexibility that include acceptance, adaptability, and multiple perspectives. Applications of educational technology served as a bridge to introduce new cultures, knowledge and people to students

Nutritional, Bone, and Physical Fitness States of Jockeys in Chronic Repetition of Short-Term Weight Loss

Professional jockeys are required to fit their weight, mainly weight loss, for two game days every weekend during racing season which usually lasts 10 months a year in Korea. The repetitive routine weight loss protocol is performed for 4 to 5 days a week include two game days. This situation would have brought some negative effects on the professional jockeys\u27 overall health and physical condition with the relation of their performance. The purpose of the present study was: 1) to examine the weight loss habits of pro-jockeys, and 2) effects of chronic short-term weight loss on nutritional status, bone health, and physical fitness of them. Pro jockeys (n=43) completed a questionnaire for the assessment of weight loss habits. Pro jockeys (n=10, around 12 years of career) were compared with trainee jockeys (n=10, less than 1 years of career) for their nutritional status, bone health, and physical fitness. The nutritional status was measured by a computerized program (CAN Pro 2.0). Bone mineral density was measured by DEXA (Hologic, QDR-4500W, USA). All participants performed grip strength test, standing on one leg with eyes closed test, and side step test for the assessment of physical fitness. According to the result, more than 80% of pro jockeys underwent a routine weight loss process every week, for around 1 kg, within 2 to 3 days prior to the game days by diet mainly and/or exercise/sauna. Around 70% of them reported severe fatigue during the weight loss period. There were no significant differences in nutritional status between two groups. However, they consume average of 1,100 Kcal a day reflecting 21 to 80% of recommended daily consumption during weight loss periods. In bone health, six trainee jockeys and two pro jockeys were diagnosed as osteopenia. One pro jockey was diagnosed as osteoporosis. No significant difference was found in fitness factors between two groups. In conclusion, chronic exposure to short-term weight loss may result in serious health problems especially on bone health. For the jockeys in Korea, balanced diet program and the related education on weight management are strongly required.

A comparison of the effectiveness of science education in Korea and South Africa : a multilevel analysis of TIMSS 2003 data

Science education becomes more important for future national development globally in high-technology-based society. In reaction to the trend, the International Association for the Evaluation of Educational Achievement (IEA) has conducted achievement tests in science along with mathematics, called TIMSS every four years. In TIMSS 2003, while Korea was a higher-performing country, South Africa was ranked in the lower-performing countries. Korea features homogenous demography, centralized curriculum, and competitive educational zeal while South Africa is characterized by multicultural demography with various languages, and previously segregated schools based on races. The current research, which is a secondary analysis of TIMSS 2003 data, aimed at explaining the differences and similarities by identifying factors most likely to influence science achievement in the two countries. A conceptual research framework was built on the comprehensive literature review which involved mainly school effectiveness research and factors related to science achievement. The conceptual framework consists of multi-levels, viz., student, classroom, school, and context, and three key concepts, namely time on task, opportunity to learn, and quality. Two research questions were formulated to reach the goal of the research and the first question is: To what extent does TIMSS 2003 reflect factors related to effective science education? Data from the student, teacher and school questionnaires were included in conjunction with the achievement data and analysed by means of factor, reliability and correlation analyses. The factors found to influence science achievement in three levels are as follows: at the student level, books at home, attitudes towards science, time on task; at the classroom level, time scheduled for science and teacher interaction; at the school level, school size, community size, and student background. The second research question is: To what extent do the factors derived from the analysis explain the differences in the achievement of Korean and South African students? To answer this question, the current research used multilevel modeling techniques to deconstruct the total variance in achievement into within- and between-classroom/school level. The strongest predictor is attitudes towards science in both countries at the student level. Student background in Korea and safety in school in South Africa is the strongest predictor of science achievement at the classroom/school level. Furthermore, educational resources such as books at home and educational level of father are significant in Korea while language, teacher qualification, physical resources, and educational leadership are significant in South Africa. For Korea, 93% of total variance in science achievement occurred at the student level while only 7% was attributable to the classroom/school level. For South Africa, 41% of the total variance was assigned at the student level and 59% at the class/school level. From this comparative study, it was recommended that development of student-centred teaching practices to address negative attitudes to science in Korea be considered as opposed to basic issues such as improving teachers’ subject knowledge, developing language skills, and fostering a culture of learning to improve science performance in South Africa.Thesis (PhD)--University of Pretoria, 2011.Science, Mathematics and Technology Educationunrestricte