• The Mathematical Education
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• v.43 no.3
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• pp.233-255
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• 2004

Problem solving in math education is of great importance. The interest on problem solving in math education is growing all over the world. Problem solving ability is important throughout the fourth-sixth national curriculum in Korea and this is also necessary in the seventh national curriculum. The writer has implemented a proper model for problem posing and this is also necessary in the seventh national curriculum that emphasizes self-leading for improvement in the classroom. This model has advantages to cultivate a good habit of students who tries to solve the problems with concrete strategies, to take part in the problem solving activity and to change their mathematical attitude.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.3
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• pp.162-170
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• 1996

A numerical study on the Stefan problem occurred in cryosurgery is performed. Crank-Nicholson type finite difference algorithm based on the enthaly method is adapted to solve the phase change problem in this study. As it is a moving boundary problem, special emphasis is put on the estimation of the freezing front location. Two cases selected here are freezings of human tissue by disk type cryoprobe and by hemispherical one. In both cases, the heat flows are considered to be one dimensional. The calculated results using enthalpy method are compared with those using the program TRUMP and with Neumann's solution. These results agree guite well with each other. While it is pretty difficult to get accurate freezing front location by TRUMP due to the so- called "phase change knee" occured during the phase change, the algorithm based on the enthalpy method is proved to be very powerful to cope with this kind of problem.f problem.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.5
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• pp.553-559
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• 1999

The robust control problem of the linear systems with uncertainty is classified as the robust stability problem guaranteeing the stability and the robust performance problem guaranteeing the disired performance. In this paper, we considered the robust performance analysis problem, which find the upper buund of the quadratic performance of the uncertain linear system, and the robust guaranteed performance controller design problem which design a controller guaranteeing the desired quadratic performance. At first, we treated the analysis problem and presented the two results; one is dependent on the performance of the nominal system and another is independent on this. And we treated the design method guaranteeing the desired performance for the uncertain linear systems, Finally, we show the usefulness of our results by numerical examples.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.157-164
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• 2006

This paper addresses the design of container liner shipping service networks by explicitly taking into account empty container repositioning and container fleet size. Two key and interrelated issues of deployments of ships and containers are usually treated separately by most existing studies on shipping network design. In this paper, both issues are considered simultaneously. The problem is formulated as a two-stage problem: the upper-problem being formulated as a Knapsack problem and the lower-problem as a Flow problem. A genetic algorithm based heuristic is developed for the problem. Through a number of numerical experiments that were conducted it was shown that the problem considering empty container repositioning provides a more insightful solution than the one without.

• IE interfaces
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• v.1 no.2
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• pp.45-52
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• 1988

Telecommunication networks include repeaters that serve to monitor the condition of each line within the network, and a center that dispatches repairmen to fix broken repeaters. In such a set-up, however, a problem arises : where is the most effective location for the center? First of all, we consider the network problem in which the nodes are the telephone offices and the arcs are the transmission lines. Here we deal with the center location problem in which the center must be located at a node and calls for service are assumed to occur on the arcs. This thesis proposes to prove that this problem can be transformed into a 1-median problem. Furthermore, the transformed problem will be proven to be equivalent to the center location problem that minimizes the sum of the distances weighted by the degrees of each node.

• Education of Primary School Mathematics
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• v.4 no.1
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• pp.51-61
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• 2000

Mathematical Problem solving has been the focus of a considerable amount of research over past 30 years. But nowadays problem solving is being beginning to be of less interest to mathematics education researchers. Moreover, mathematics teachers have an urgent need to be provided with well-documented informations about "teaching of(expecially, via) problem solving" though following research issues ：ⅰ) the role of the teacher in a problem-centered classroom, ⅱ) what actually takes place in problem-centered classrooms, and iii) groups and whole classes' problem solving rather than individuals. This paper intends to give some informations about practice of teaching mathematical problem solving in elementary school.ry school.

• Journal of the Korea Society of Computer and Information
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• v.24 no.9
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• pp.9-20
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• 2019

In this paper, we study the university timetabling problem, which consists of two subproblems, the university course timetabling problem and the examination timetabling problem. Given a set of classrooms, students, teachers, and lectures, the problem is to assign a number of courses (and examinations) to suitable timeslots and classrooms while satisfying the given set of constraints. We discuss the modeling and solution approaches to construct course and examination timetables for one of the largest Korean university. By using binary integer programming formulations, we describe these two complex real-world problems. Then, we propose a solution method, called NOGOOD, to solve the examination timetabling model. The computation results show that NOGOOD finds the optimal examination schedule for the given instance. Although we consider a specific instance of the university timetabling problem, the methods we use can be applicable to modeling and solving other timetabling problems.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.168-176
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• 2021

This study developed and evaluated a learning model to improve collaborative problem-solving skills for nursing students taking physiology courses. This one-group pretest-posttest design used the jigsaw cooperative learning method on 30 nursing students from one local university. We analyzed the effect of a cooperative problem- solving learning model using SPSS 21.0 to compare changes in the students' collaborative self-efficacy, problem-solving abilities, and team-member exchange. As a result, the participants showed significant increases in collaborative self-efficacy, problem-solving ability, and team-member exchange after experiencing cooperative problem- solving learning model. Therefore, we will help nursing students improve their communication skills by enhancing their collaborative self-efficacy and help them solve problems effectively in conflict situations.

• International Journal of Contents
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• v.17 no.1
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• pp.54-60
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• 2021

The aim of this study was to identify factors influencing problem drinking among the Echo Generation in South Korea and provide basic data for early intervention and mediation of problem drinking among the Echo Generation. This descriptive study performed a secondary analysis of raw data from the 2018 Korean National Health and Nutrition Examination Survey and used responses for problem drinking items from 999 Echo Generation participants born between 1979 and 1992. This study comprehensively investigated sociodemographic and health-related factors influencing problem drinking among the Echo Generation. SPSS WIN program (version 26.0) was used for data analysis. Gender (β=-.32, p<.001), education level (β=.10, p=.002), white-collar workers out of job (β=-.09, p=.041), and depression (β=.11, p<.001) were identified as factors that influenced problem drinking among the Echo Generation. Results of this study suggest that in order to prevent problem drinking among the Echo Generation, there should be user-customized prevention education and intervention programs.

• Educational Technology International
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• v.14 no.2
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• pp.137-166
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• 2013

Problem-based learning (PBL) in engineering education has been implemented in various ways. The wide range of PBL methods sometimes creates difficulties in implementing PBL. The purpose of this study was to identify the major variables that a teacher considers in PBL designs for an engineering course and suggest specific PBL methods according to the PBL design variables. This study was conducted using a review research method involving 21 studies from a range of engineering education fields. The results showed that the major variables that engineering professors need to consider when applying PBL are the authenticity of the PBL problem and the method of providing knowledge or information that the learners must know to solve the given problem. Based on the two variables identified, the following four types of PBL methods for engineering education are suggested: 1) lecture-based problem, 2) guided problem-based learning, 3) problem-based learning and 4) co-op problem-based learning.