• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.92-99
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• 2024

To minimize the cumulative radiation dose, various path-finding approaches for single agent have been proposed. However, for emergence situations such as nuclear power plant accident, these methods cannot be effectively utilized for evacuating a large number of workers because no multi-agent method is valid to conduct the mission. In this study, a novel algorithm for solving the multi-agent path-finding problem is proposed using the conflict-based search approach and the objective function redefined in terms of the cumulative radiation dose. The proposed method can find multi paths that all agents arrive at the destinations with reducing the overall radiation dose. To verify the proposed method, three problems were defined. In the single-agent problem, the objective function proposed in this study reduces the cumulative dose by 82% compared with that of the shortest distance algorithm in experiment environment of this study. It was also verified in the two multi-agent problems that multi paths with minimized the overall radiation dose, in which all agents can reach the destination without collision, can be found. The method proposed in this study will contribute to establishing evacuation plans for improving the safety of workers in radiation-related facilities.

• Journal of The Korean Association For Science Education
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• v.16 no.2
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• pp.154-163
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• 1996

In Korea, previous survey in science education mainly dealt with Quantitative variables. Qualitative ethnographic observation can bring deeper understanding of the context of school lesson and it's feature. The purpose of this study was to develop qualitative understanding about the learning experiences provided in middle school and students' responses to them through observation and interview and to investigate it from a constructivist perspective. Six lessons of the 9th grade were observed and recorded on the video tape. The topics of the lessons were potential energy, kinetic energy and conservation of mechanical energy. We had also unstructured interview with the teacher and three groups of students. The teacher's deductive explanation starting from scientific definition and quantitative problem solving using formula were the main features of the classroom lectures. The video - watching lesson was taking the role of a break rather than being seen as a useful tool for science learning and teaching by both students and the teacher. The teacher's perception about the lab experiment was not supported by the responses from the students. The teacher and students preferred problem-book to textbook for their teaching and learning. From a constructivist's perspective, however the teacher seemed to have intention of introducing daily life context, he couldn't unfold it to main context of the lessons. Students were so accustomed to passive learning that they did not express directly their complaint about their learning and did not participate in planing and controling their learning. The teacher and the students believed the scientific knowledge came from an exact experiment. There was a cooperation to seek right answer rather than a social process of making sense of knowledge. In conclusion, the observed science lessons of a middle school showed typical cross section of teacher - centered, passive learning environment, which is far from constructivist perspective.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.156-170
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• 2006

Determining the best visibility positions on terrain surface has been one of the frequently used analytical issues in GIS visibility analysis and the search for a solution has been carried out effectively using spatial search techniques. However, the spatial search process provides operational and methodological challenges for finding computational algorithms suitable for solving the best visibility site problem. For this problem, current GIS visibility analysis has not been successful due to limited algorithmic structure and operational performance. To meet these challenges, this paper suggests four algorithms explored robust search techniques: an extensive iterative search technique; a conventional solution based on the Tornqvist algorithm; genetic algorithm; and simulated annealing technique. The solution performance of these algorithms is compared on a set of visibility location problems and the experiment results demonstrate the useful feasibility. Finally, this paper presents the potential applicability of the new spatial search techniques for GIS visibility analysis by which the new search algorithms are of particular useful for tackling extensive visibility optimization problems as the next GIS analysis tool.

• KIPS Transactions on Software and Data Engineering
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• v.1 no.2
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• pp.91-102
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• 2012

Computer aided language learning has become popular. But the level of automation of constructing a Korean learning assistant system is not so high because a practical language learning system needs large scale knowledge resources, which is very hard to acquire. In this paper, we propose a Korean learning assistant system that utilizes easily obtainable knowledge resources like a corpus, web documents and a lexicon. Our system has three modules - problem solving, pronunciation marker and writing assistant. Automatic problem generator uses a corpus and a lexicon to make problems with one correct answer and three distracters, then verifies their suitability by utilizing frequency information from web documents. We analyze pronunciation rules for a pronunciation marker and recommend appropriate words and sentences in real-time by using data extracted from a corpus. In experiment, we evaluate 400 automatically generated problems, which show 89.9% problem suitability and 64.9% example suitability.

• Journal of The Korean Association For Science Education
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• v.33 no.7
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• pp.1471-1485
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• 2013

The purpose of this study was to develop a HAM (Heuristic Attention Model) by analyzing the difference between eye movements according to the science achievement of elementary school students on discrimination task. Science achievement was graded by the results of the Korea national achievement test conducted in 2012 for a random sampling of classes. As an assessment tool to check discrimination task, two discrimination measure problems from TSPS (Test of Science Process Skill, developed in 1994) which were suitable for an eye tracking system were adopted. The subjects of this study were 20 students from the sixth grade who agreed to participate in the research. SMI was used to collect EMD (eye movement data). Experiment 3.2 and BeGaze 3.2 programs were used to plan experiments and analyze EMD. As a result, eye movements of participants in discrimination tasks varied greatly in counts and duration of fixation, first fixation duration, and dwell time, according to students' science achievement and difficulty of the problems. By the analysis of EMD, strategies of the students' problem-solving could be found. During problem solving, subjects' eye movements were affected by visual attention; bottom-up attention, top-down attention and convert attention, and aflunter attention. In conclusion, HAM was developed, and it is believed to help in the development of a science learning program for underachievers.

• Journal of The Korean Association For Science Education
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• v.22 no.1
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• pp.110-121
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• 2002

In this study, the verbal interactions occurred during the CASE(Cognitive Acceleration through Science Education) activities in the middle school science class has been analyzed regarding with students cognitive level. The subjects were 24 students of 6 groups in a middle school in Korea. Verbal interactions within group discussions during CASE activities were audio-taped, transcribed, and analyzed. Also, classroom observation and interview with students were carried out. The results showed that the student with higher cognitive level tended to be a group leader. They had strong influences on the group discussions in each step of problem solving. Also, the higher cognitive level students were more active in metacognitive discussion and more often used scientific terms. When their group met difficulties in each stage of problem solving, such as perception of problem and designing experiment, the higher cognitive level students suggested some ideas to help their peers and gave them an explanation of how they worked. Low cognitive level students had difficulties in perception and solving the problem as compared with high cognitive students. It was common during activities for the low cognitive level students to fail to identify variables and to distinguish between dependent variables and independent variables. They failed to hold a number of variables at once. However, the metacognitive questions from their peers or teacher were helpful for them to construct the concept of controlling variables. If there is no student who has a high level of thinking in a group, it was necessary to intervene for teacher. A well judged questions from teacher created the cognitive conflict which causes the students to reconstruct their strategy for problem solving and reinforce the control of variables reasoning pattern. From the above results, it is concluded that students' cognitive levels are much related to the verbal interaction patterns. This suggests that teacher should consider individual student's cognitive level in organizing groups and intervene to facilitate the environment for metacognitive interaction.

• Journal of Korean Home Economics Education Association
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• v.31 no.1
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• pp.151-168
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• 2019

This study aims to verify the effects of the sewing practice class, developed for the cultivation of creativity and personality, the two qualities that the Korean Department of Education tried to emphasize in 2009 national curriculum. We conducted a single-group pretest-posttest experiment with the developed sewing practice class as a treatment. Results are as follows. First, the comparison results of before and after the developed sewing practice class showed that there were meaningful differences in creativity and its subfactors such as divergent thinking skill, problem solving ability, open-mindedness and patience. This is because in-class activities such as coming up with ideas by group discussion, creative activities and problem-solving experiences make the students be aware that they are the hosts of the class. It also affected their abilities of producing creative ideas and solving problems proactively. Second, the developed sewing practice class had an impact on students' personality and its subfactors like responsibility, diligence, consideration, communication skill, and collaborative ability. This practice class is based on personal activities which lead to the completion of the group assignment. This has not only emphasized individual responsibilities, but also highlighted the completion of group work and encouraged the flow of communication and cooperation among students. As a result, we concluded that this practice class helped nourish the participating students' personality.

• Journal of Gifted/Talented Education
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• v.16 no.1
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• pp.43-60
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• 2006

This study mainly intended to investigate the relation between scientific inquiry and several entrance exam results of the gifted in earth science gifted program. The scientific inquiry was tested with their experiment designs. Entrance exams included achievement scores, creativity scores, problem solving, and oral test of high ability students. Student entrance scores were used to judge the level of students' competency in science. Recently students' ability of 'doing science' as measured by their designing experiments has been highly appreciated as a criteria of scientifically gifted students. One of the well known tests was Diet Cola Test developed by Fowler(1990). We used it as a test to figure out students' experiment design ability. We selected 22 gifted students in earth science. We compared their entrance test scores and Diet Cola Test results. Based on the comparison results we proposed several guideline of science education program for high ability students.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.83-91
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• 2011

The purpose of this thesis was to implement effective blended PBL(Problem-Based Learning) systems for information communication ethics education. Online learning and face-to-face classes were systematically combined for achieving the teaching-learning goals. And the main module for online learning run on Moodle, an open source learning management system. To examine educational effectiveness of the proposed systems, an experimental study was conducted through the method to the subject of two class in the second-grade of university located in ${\bigcirc}{\bigcirc}$ city. For experiment 60 students(treatment group=30, control group=30) are participated. And they were assigned to one of ten subgroups, comprising of six students, respectively. The results of this study are follows, First, the education using proposed blended PBL method is more effective in cultivating consciousness of information communication ethics than the education using face-to-face PBL learning method. Second, learners who participated in the proposed blended PBL more experienced various effects of PBL, such as (1) Improvement of problem solving ability, (2) Understanding of cooperative learning than the other learners who participated in the face-to-face PBL.

• Journal of Engineering Education Research
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• v.23 no.3
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• pp.49-58
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• 2020

In the era of the fourth industrial revolution, the world is undergoing rapid social change. The purpose of this study is to predict the expected changes and necessary competencies and desired curriculum and teaching methods in the field of mechanical engineering in the near future. The research method was a Delphi study. It was conducted three times with 20 mechanical engineering experts. The results of the study are as follows: In the field of mechanical engineering, it will be increased the situational awareness by the use of measurement sensors, development of computer applications, flexibility and optimization by user's needs and mechanical equipment, and demand for robots equipped with AI. The mechanical engineer's career perspectives will be positive, but if it is stable, it will be a crisis. Therefore active response is needed. The competencies required in the field of mechanical engineering include collaborative skills, complex problem solving skills, self-directed learning skills, problem finding skills, creativity, communication skills, convergent thinking skills, and system engineering skills. The undergraduate curriculum to achieve above competencies includes four major dynamics, basic science, programming coding education, convergence education, data processing education, and cyber physical system education. Preferred mechanical engineering teaching methods include project-based learning, hands-on education, problem-based learning, team-based collaborative learning, experiment-based education, and software-assisted education. The mechanical engineering community and the government should be concerned about the education for mechanical engineers with the necessary competencies in the era of the 4th Industrial Revolution, which will make global competitiveness in the mechanical engineering fields.