• Communications of Mathematical Education
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• v.24 no.2
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• pp.475-502
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• 2010

In this paper, the ability to use mathematical representations in solving math problem was analyzed according to student assessment levels using 113 first-year high school students, and the characteristics of their representation usage according to student assessment levels were also examined. For this purpose, problems were presented that could be solved using various mathematical representations, and the students were asked to solve them using a maximum of three different methods. Also, based on the comparative analysis results of a paper evaluation, six students were selected and interviewed, and the reasons for their representation usage differences were analyzed according to their student assessment levels. The results of the analysis show that over 50% of high ranking students used two or more representations in all questions to solve problems, but with middle ranking students, there were deviations depending on the difficulty of the questions. Low ranking students failed to use representation in diverse ways when solving problems. As for characteristics of symbol usage, high ranking students preferred using formulas and used mathematical representations efficiently while solving problems. In contrast, middle and low ranking students mostly used tables or pictures. Even when using the same representations, high ranking students' representations were expressed in a more structurally refined manner than those by middle and low ranking students.

• Journal of Science Education
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• v.41 no.1
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• pp.60-79
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• 2017

The purpose of this study was to develop a program for the history of science and technology in order for the technical high school students to understand the nature of science (NOS). The program was composed of the six topics based on the textbooks such as convergence science and physics I, and was taught to 290 10th graders at a technical high school located in the metropolitan area. The questionnaire about NOS was asked the students before and after the instruction, so as to investigate the effect of the program on improving their understandings of NOS. The analysis followed t-test and ANOVA using SPSS 23.0 for Windows program. The questionnaire based on the conceptual framework of the four themes of the NOS (Lee, 2014). The research findings were as follows. First, the program was effective in improving their understanding of NOS since the t-test result was significant statistically for the overall domains of NOS (p<.01). Second, there was no significant gender differences in the understanding of NOS among technical high school students (p<.05), neither did their majors (p<.05). Third, all domains in NOS were statistically correlated (p<.01), and in a particular, each domain was consistently correlated with the aspect of the nature of the interactions among science, technology, and society. Hence, the further studies should be conducted to examine how the history of science and technology effects the understanding of the NOS and how the domains in NOS affected each other.

• Journal of Science Education
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• v.41 no.1
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• pp.80-97
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• 2017

The purpose of this study was to develop understanding-oriented materials based on backward course design model and analyze their effects on 'biology and environment' unit of elementary school science. Backward Design starts from a specification of learning outcomes and decisions on methodology and syllabus are developed from the learning outcomes. This method has a strength maintaining consistency between educational contents-evaluation-learning activities and also promoting student's authentic understanding. The 78 students 6th graders participated in this experiments. Data was collected using project activities, the science academic emotion scale and academic achievement. The collected data was analyzed by t-test and ANCOVA analysis using the SPSS 23 statistical program. The following major conclusions were drawn on the basis of data analysis. First, the experimental group showed a relatively accurate understanding of the contents of science but they could not produce creative output in two project activities. Second, the interaction effect of the instruction based on backward curriculum design and science academic emotion was not significant statistically. Third, the experimental group showed a significant improvement in the academic achievement of 'biology and environment' unit.

• Journal of Educational Research in Mathematics
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• v.22 no.2
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• pp.179-202
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• 2012

To implement effective technology-based education, we need knowledge for functional aspects of technology as well as design and procedural aspects of curriculums. Also, we need positive teaching efficacy. In this regard, we investigate the effects on teachers' TPACK and technology teaching efficacy on mathematics after make the teachers design and teach technology-based classes according to the ASSURE model which is suitable in designing technology-based educations. First, we let the teachers design and teach two unit hour classes. The first class had been done with the teachers learned functional aspects of technologybased educations, and the second one with them designed based on the steps in the ASSURE model. To analyze the effects of ASSURE model, we have performed a case-study for one teacher who had taken part in our college class. As a result, we conclude that the teacher's experiences in designing classes based on the ASSURE model help improve the teacher's TPACK and technology teaching efficacy on mathematics in a positive way.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.1
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• pp.277-298
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• 2018

This study aims to demonstrate the importance of information literacy instructions by showing effects of information literacy skills on critical thinking dispositions among high school students. We collected 761 survey responses from high school students and conducted multiple regression analysis to examine the relationships between the two variables. The findings show that (1) students' information search skills affect their pursuit of truth, openness, inquiring mind, and objectivity, (2) the information analytic skills influence the levels of pursuit of truth, openness, and objectivity, (3) the information presentation and delivery skills affect the levels of inquiring mind, organization, and self-trust, and, (4) the information evaluation skills influence the levels of pursuit of truth, openness, inquiring mind, organization, objectivity, and self-trust. However, students' synthesis and application skills of students did not affect their critical thinking dispositions. To sum up, we observed the influence of information literacy skills on critical thinking dispositions. The results of this study provide foundations for maintaining and developing information literacy instructions in school libraries.

• 대한공업교육학회지
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• v.31 no.1
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• pp.63-85
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• 2006

This study was performed to deduce the constituents of competence for the practical duty in technical high school's heat treatment and tensile test practice. In order to accomplish this purpose 1) the constituents of competence for the practical duty were deduced through the job analysis and the skill hierarchy analysis of heat treatment and tensile test, 2) the deduced constituents of competence for the practical skill performance were correspond to the Mager's five performance type, that is, discrimination (knowing when to do it, knowing when it's done), problem solving (how to decide what to do it), recall (knowing what to do, knowing why to do it), manipulation (how to do it) and speech (how to say it). The results of this study will be helped to the selection of learning objective, learning content, instruction and evaluation method.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.1-11
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• 2012

As the process technology scales down, multi-core processors cause serious problems such as increased interconnection delay, high power consumption and thermal problems. To solve the problems in 2D multi-core processors, researchers have focused on the 3D multi-core processor architecture. Compared to the 2D multi-core processor, the 3D multi-core processor decreases interconnection delay by reducing wire length significantly, since each core on different layers is connected using vertical through-silicon via(TSV). However, the power density in the 3D multi-core processor is increased dramatically compared to that in the 2D multi-core processor, because multiple cores are stacked vertically. Unfortunately, increased power density causes thermal problems, resulting in high cooling cost, negative impact on the reliability. Therefore, temperature should be considered together with performance in designing 3D multi-core processors. In this work, we analyze the temperature of the cache in quad-core processors varying cache organization. Then, we propose the low-temperature cache organization to overcome the thermal problems. Our evaluation shows that peak temperature of the instruction cache is lower than threshold. The peak temperature of the data cache is higher than threshold when the cache is composed of many ways. According to the results, our proposed cache organization not only efficiently reduces the peak temperature but also reduces the performance degradation for 3D quad-core processors.

• Restorative Dentistry and Endodontics
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• v.35 no.5
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• pp.321-334
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• 2010

Objectives: The purpose of this study is to evaluate bonding efficacy by means of measuring the effect of remained solvent on Degree of conversion(DC) and ${\mu}TBS$ and FE-SEM examination. Materials and Methods: Two 2-step total etching adhesives and two single-step self etching adhesives were used in this study. First, volume weight loss of 4 dentin adhesives were measured using weighting machine in process of time in normal conditions and calculate degree of evaporation (DE). Reaction/reference intensity ratio were measured using micro-Raman spectroscopy and calculate DC according to DE. Then 2 experimental groups were prepared according to air-drying methods (under, over) and control group was prepared to manufacturer's instruction. Total 12 groups were evaluated by means of micro tensile bond strength and FE-SEM examination. Results: Degree of evaporation (DE) was increased as time elapsed but different features were observed according to the kind of solvents. Acetone based adhesive showed higher DE than ethanol and butanol based adhesive. Degree of conversion (DC) was increased according to DE except for $S^3$ bond. In ${\mu}TBS$ evaluation, bond strength was increased by additional air-drying. Large gaps and droplets were observed in acetone based adhesives by FE-SEM pictures. Conclusions: Additional air-drying is recommended for single-step self etching adhesive but careful consideration is required for 2-step total etching adhesive because of oxygen inhibition layer. Evaporation method is carefully chose and applied according to the solvent type.

• Journal of the Korean Society of School Health
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• v.8 no.1
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• pp.143-154
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• 1995

Korea has been recently reducing the quality of life as well as rising medical cost because of the increase of chronic diseases. But we can prevent those chronic diseases through the improvement of environment or life style. We evaluated the educational effectiveness of chronic diseases(hypertention, diabetes, cancer, stroke and other chronic diseases) designed to increase the knowledge, attitude and practice of chronic diseases among university students. Between August 1994 and November 1994, we implemented chronic diseases prevention instruction in intervention students; unmatched control students were selected in same university. We conducted pre- and post-intervention surveys both intervention and control students with self-reported questionnaires(50 items). We assigned score(0-4 points) to items and conducted a analysis of covariance(ANCOVA) with sex, grade and economic status as the covariate, using the SAS PC computer statistical package. And we culculated odds ratio with safety scores between intervention and control students. The results of this study were followed. 1. In demographic characteristics of subjects both pre- and post intervention, we found no significant differences in intervention and control students at religion, father's education, mother's education, mother's occupation and type of residence(p>0.05), but we found significant differences at sex(p<0.001), grade(p<0.001) and economic status(p<0.05). 2. The sex, grade and economic status-adjusted mean prevention knowledge scores for diabetes and stroke increased from the pre- to post-survey in the intervention students(p<0.001), but control students did not increased(p>0.05). As odds ratios in knowledge were below 1, the knowledge of intervention students were higher than control students. 3. The attitudes for general adult health increased from the pre- to post-survey in the intervention students(p<0.05), but control students did not increased(p>0.05). As odds ratios in attitudes were approximately 1, we can not say effectiveness in intervention students 4. The pratices for cancer and stroke increased from the pre- to post-survey in both the intervention and control students(p<0.001). Also odds ratio of hypertention was 0.91, and that of stroke was 1.14. 5. Health related behaviors did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). But odds ratio of drinking was 0.76 and that of body weight was 1.21. 6. Health status did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). As odds ratio of health status was 1.09, prevention education was not effect in intervention students We would like to recommend as follows; 1. University students must learn about prevention of chronic diseases. Because the knowledge of invetervention students was higher than that of control students. 2. The prevention education of chronic diseases should be taught from primary school. 3. Adult health education for university students must be practiced continuously. Education period(l5 weeks) in this study was not complete. 4. The evaluation of chronic diseases was conducted real measurement(such as BP check) as well as self reported-survey. 5. Educational materials(video tape, pamphlet) related the prevention of chronic diseases should be developed at national level. And we must easely use those materials. 6. The prevention education of chronic diseases should be made through mass media as well as school education.

• Journal of Internet Computing and Services
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• v.16 no.5
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• pp.99-105
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• 2015

Currently robots are widely used in schools for educational purpose. With wide spread of robot-based education, it is known that major advantage of robot-based education is to enhance creativity and logical thinking of students. Although robots can be very useful tools for assisting students' study activities, there have not been lots of teaching-learning models for robot-based education.In this paper, a teaching-learning model is presented for robot-based education. The proposed model is designed based on constructivism. The proposed model consists of 6 stages: preparation, design, assembling, demonstration run, evaluation, and application & extension. The proposed model has the following characteristics. First, the proposed model is designed to enhance creativity and logical thinking ability of learners. Learners are supposed to be involved in self-directed activities and required to provide results based on their own ideas. Teachers are supposed to mediate students only if necessary. Second, learners are encouraged to participate in activity via diverse interaction. The interaction in this model includes learner-to-learner interaction, learner-to-teacher interaction, and learner-to-expert interaction. The proposed model encourages learners to solve the problem with cooperating each other. Also, teachers are supposed to guide students if necessary and observe and monitor behavior of students all the time. Third, motivation is provided in the beginning stage of the instruction. Fourth, in the proposed model, both study results and study process are equally important. In the model, study process is reviewed at the final stage.