• School Mathematics
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• v.15 no.4
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• pp.723-742
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• 2013

The purpose of this study was to analyze children's proportional reasoning process on an ill-structured "architectural drawing" problem solving and to investigate their level and characteristics of proportional reasoning. As results, they showed various perspective and several level of proportional reasoning such as illogical, additive, multiplicative, and functional approach. Furthermore, they showed their expanded proportional reasoning from the early stage of perception of various types of quantities and their proportional relation in the problem to application stage of their expanded and generalized relation. Students should be encouraged to develop proportional reasoning by experiencing various quantity in ration and proportion situations.

• School Mathematics
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• v.18 no.1
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• pp.43-59
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• 2016

The purpose of this qualitative case study is to investigate differences among two gifted middle school students emerging through the process of algebra word problem solving from the covariational perspective. We collected the data from four middle school students participating in the mentorship program for gifted students of mathematics and found out differences between Junghee and Donghee in solving problems involving varying rates of change. This study focuses on their actions to solve and to generalize the problems situations involving constant and varying rates of change. The results indicate that their covariational reasoning played a significant role in their algebra word problem solving.

• Korean Management Science Review
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• v.33 no.1
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• pp.101-117
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• 2016

In 2000s, incidence of natural disaster is increasing continuously. Therefore, the necessity of research on the effective disaster response is emphasized. Korea is not safe from natural disaster. Natural disasters like torrential downpours, typhoons have occurred more frequently than before. In addition disasters like droughts and MERS has also occurred. Therefore, needs for effective systems and algorithms to respond disaster are increased. This study covers the vehicle routing problem for effective logistics in disaster situations caused by natural disasters. The emergency vehicle route problem has different property from the general vehicle route problem. It has the property of the importance of deadline, the uncertain and dynamic demand information, and the uncertainty in information transfer. In this study, a solution that focused on the importance of deadline. In this study, the heuristic solution using the genetic algorithm are suggested. Finally the simulation experiment which reflects the actual environment are conducted to verify the performance of the solution.

• Journal of Korea Multimedia Society
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• v.22 no.4
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• pp.502-514
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• 2019

Existing user research methods are subject to a variety of research conditions such as the amount and variety of data collected and the expertise of the facilitator of a group research session. In this study, we propose a new user research methodology using an 'Issue-Network' system, which is developed based on the theory and methods of social network analysis. The Issue-Network is designed to define problem spaces from the issues raised by users in a group research session in a form of an interactive network graph. The system helps to break out of ordinary perspectives of looking into problem spaces by enabling an alternative and more creative way to connect issues in the network. In this study, we took a case study of generating the Issue-Network on behalf of the problems raised by users in various driving-related situations. We were able to draw three navigation usage scenarios that cover relatively important problem spaces: safety and being ready for the unexpected, smart navigation and notifications, making use of the spare time. In the future, the Issue-Network system is expected to be used as a tool to identify problems and derive solutions in group research sessions involving a large number of users.

• Journal of The Korean Association For Science Education
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• v.17 no.3
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• pp.313-321
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• 1997

The purpose of this study was to investigate the instructional effect of a four-stage problem solving approach visually emphasizing the molecular level of matter upon students' conceptions and problem solving ability. On the basis of the research results regarding molecular representation in learning chemistry, problem-solving instruction, and the effect of visual materials, the instructional strategy was developed while considering Korean educational situations. The treatment and control groups (2 classes) were selected from a girls' high school in Seoul and taught about stoichiometry, gas, liquid, solid, and solution for 13 weeks. For the treatment group, 52 charts were supplied in order to emphasize the molecular level of matter and/or 4 stage problem solving strategy-understanding, planning, solving, and reviewing. For the control group, traditional instruction was used. Before the instructions, the Group Assessment of Logical Thinking and the Spatial Ability Test were administered, and their scores were used as covariate and blocking variable, respectively. After the instructions, students' conceptions and problem solving ability were measured by the Chemistry Conceptions Test (CCT) and the Chemistry Problem Solving Ability Test (CPSAT), respectively. The results indicated that the CCT scores of the treatment group were significantly higher than those of the control group. The students in the treatment group also exhibited less misconceptions than those in the control group. However, there was not significant difference for the CPSAT scores. No interaction with students' spatial ability was found for both students' conceptions and problem solving ability. Educational implications are discussed.

• Fire Science and Engineering
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• v.24 no.6
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• pp.133-138
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• 2010

This study is aimed to investigate the relationship between job-related stressor, problem solving style and psychological distress and the effects of job-related stress and problem solving style on psychological distress of firefighters. The Job-related Stress Scale, Problem Solving Style Questionnaire, and the Symptom Checklist-Revised (SCL-90-R) were administered to 148 firefighters working in Seoul and Gyounggi. Correlation analysis revealed that job-related stress, problem-solving styles such as helplessness and problem-solving control correlated positively with psychological distress and that problem-solving confidence and approaching style correlated negatively with it. Multiple regression analysis showed that job-related negative cognition and emotion, helplessness and approaching style accounted for 43% of the variance in the psychological distress. Among problem-solving styles, helplessness had the highest predictive power for psychological distress. Self-reported helplessness is an important determinant of firefighters' reactions to problematic situations encountered in their job.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.4
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• pp.37-45
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• 2022

In this paper, a multi agent-multi task assignment problem, which is a representative problem of combinatorial optimization, is presented. The objective of the problem is to determine the coordinated agent-task assignment that maximizes the sum of the achievement rates of each task. The achievement rate is represented as a concave down increasing function according to the number of agents assigned to the task. The problem is expressed as an NP-hard problem with a non-linear objective function. In this paper, to solve the assignment problem, we propose a hybrid cross-entropy algorithm as an effective and efficient solution methodology. In fact, the general cross-entropy algorithm might have drawbacks (e.g., slow update of parameters and premature convergence) according to problem situations. Compared to the general cross-entropy algorithm, the proposed method is designed to be less likely to have the two drawbacks. We show that the performances of the proposed methods are better than those of the general cross-entropy algorithm through numerical experiments.

• Journal of Convergence for Information Technology
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• v.9 no.2
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• pp.49-54
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• 2019

University education emphasizes the development of convergent as well as computational thinking, many universities provide software education to improve their problem-solving ability. In this study, we use Python programming based on problem-solving learning, and analyze the correlation between problem-solving learning satisfaction and academic achievement. A questionnaire survey was conducted among 143 students, we tried to analyze the relationship of problem-solving learning with actual academic performance using correlation and multiple regression analysis. The results indicate a relationship between satisfaction and academic achievement, and that it affects students' academic achievement. The ability to identify various problem situations and solve problems using computational thinking will become increasingly important, it is desirable that the universities provide software education based on problem-solving learning.

• Education of Primary School Mathematics
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• v.25 no.4
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• pp.297-312
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• 2022

Word problems can lead learners to more meaningfully learn mathematics by providing learners with various problem-solving experiences and guiding them to apply mathematical knowledge to the context. This study attempted to provide implications for the textbook writing and teaching and learning process by examining the word problem of elementary mathematics textbooks from the perspective of practical context. The word problem of elementary mathematics textbooks was examined, and elementary mathematics textbooks in the United States and Finland were referenced to find specific alternatives. As a result, when setting an unnatural context or subject to the word problem in elementary mathematics textbooks, artificial numbers were inserted or verbal expressions and illustrations were presented unclearly. In this case, it may be difficult for learners to recognize the context of the word problem as separate from real life or to solve the problem by understanding the content required by the word problem. In the future, it is necessary to organize various types of word problems in practical contexts, such as setting up situations in consideration of learners in textbooks, actively using illustrations and diagrams, and organizing verbal expressions and illustrations more clearly.

• Journal of Elementary Mathematics Education in Korea
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• v.16 no.3
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• pp.427-450
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• 2012

Using representations is essential for students to organize their thinking, to solve problems and to communicate each other. Students express information or situations suggested by problems easily and organize and infer them systematically using representations. Also, teachers are able to comprehend students' levels of understanding and thinking process better through them, and influence their representations. This study was conducted to understand mathematical representations of students uprightly and to seek implications for proper teaching of representations, by analyzing representations of students in mathematical problem solving process and the transformation process of representation via interactions.