• Journal of the Korean earth science society
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• v.23 no.2
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• pp.180-187
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• 2002

The aim of this study was to investigate the factors affecting earth science problem-solving performances of elementary school pre-service teachers. The participants of the study were 81 students attending an elementary school teacher education university. The instruments of the study were paper-and-pencil tests, questionnaires, and interviews. The tests mainly measured the participants' problem solving abilities in the motions of the moon and the planets. Correlation and multiple regression techniques were used for data analysis. The results demonstrated that the pre-service teachers' problem solving abilities were low. Problem-solving performances were affected by the procedural knowledge, the participants' perception of the past earth science performance, self-efficacy, and the prerequisite declarative knowledge. Contrary to our expectation, the spatial visualization ability was not found to be related to the problem-solving performances. Implications of the study are drawn, and suggestions are made for further research.

• Journal of the Korean Society of Earth Science Education
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• v.2 no.1
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• pp.55-61
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• 2009

This study was designed to explore problem solving process to earth science area by elementary science gifted children, which compared and analyzed the questionnaires and problem solving to earth science area by gifted Science education center, Seoul National University Of Education, The analyzed results showed difference by gender that in the science study level at the time of entrance to the gifted Science education center, male students was the highest in the middle school as 37.5%, and female students in the elementary 6th grade as 61.5%. And male students were investigated to do more precedent study than female students. Secondly, in the problem solving process of earth science related problems, males made most use of problem solving process area(30.3%), and females symbolizing (27.5%) area. Thirdly, comparison of reasoning technology in problem solving process by gender indicated that both sexes made the most use of analytical reasoning (male 62.0%, female 53.6%) to solve problems.

• Journal of Korean Elementary Science Education
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• v.28 no.3
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• pp.229-244
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• 2009

This study was initiated to investigate sixth graders' gender characteristics in science problem solving process and thus find out the proper learning and teaching strategies for each gender. A total of 14 students, each of seven male and female students, were selected through three tests, including items of science knowledge, science inquiry, and creativity. Students were required to solve 26 items and to think aloud for researchers help understand how they thought in their problem solving process. Males and females showed some similarity and difference in four steps of problem solving process, understanding, planning, solving, and reviewing. We found gender differences in self-confidence of their answer. This study is expected to help develop teachers' differential teaching strategy for male and female students' science problem solving.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.1
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• pp.75-87
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• 2012

The purpose of this study is to find out the effects of internet resource-based problem-based learning on the academic achievement in science and the attitude toward science of elementary school students. One experiment class and one control class of grade 6 students were selected to perform a prior investigation on the academic achievement in science and the attitude toward science, then the experiment class attended 4 weeks of lessons that was applied the internet resource-based problem-based learning, and the control class attended the traditional lessons based on the guidelines of teachers. After conducting lessons, a post investigation was performed for each class and the results were analyzed to produce the following conclusions. First, the internet resource-based problem-based learning could be seen to be effective in improving the students' academic achievements in science. The internet resource-based problem-based learning seemed to make students recognize the lesson details better and grasp well the questions given during lessons from the process of finding solutions among many informations and data on the internet. Second, the internet resource-based problem-based learning had a positive effect on all attitudes' areas toward science of students. It looked like that the internet resource-based problem-based learning taught the students to use the internet resources and gave them a friendly feeling, so the children could actively participate in class and had positive recognition on science. Third, from teacher observation and the result of the student recognition investigation, we could know that the students showed lots of interests in the internet resource-based problem-based learning, and they were able to understand the scientific theories in the process of solving problems that were relevant to real life, and thought science in a positive way.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.12-22
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• 2024

The travelling salesman problem is very famous and very difficult combinatorial optimization problem that has several applications in operations research, computer science and industrial engineering. As the problem is difficult, finding its optimal solution is computationally very difficult. Thus, several researchers have developed heuristic/metaheuristic algorithms for finding heuristic solutions to the problem instances. In this present study, a new hybrid genetic algorithm (HGA) is suggested to find heuristic solution to the problem. In our HGA we used comprehensive sequential constructive crossover, adaptive mutation, 2-opt search and a new local search algorithm along with a replacement method, then executed our HGA on some standard TSPLIB problem instances, and finally, we compared our HGA with simple genetic algorithm and an existing state-of-the-art method. The experimental studies show the effectiveness of our proposed HGA for the problem.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.4
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• pp.131-143
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• 2003

In this paper, we present a survey about the various graph partition problems including the clustering problem, the k-cut problem, the multiterminal cut problem, the multicut problem, the sparsest cut problem, the network attack problem, the network disconnection problem. We compare those problems focusing on the problem characteristics such as the objective function and the conditions that the partitioned clusters should satisfy. We also introduce the mathematical programming formulations, and the solution approaches developed for the problems.

• Journal of Korean Elementary Science Education
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• v.26 no.1
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• pp.32-40
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• 2007

The scientific creativity problem solving ability of children has been greatly emphasized in recent years, because it has been regarded as an example of highly developed reasoning and thinking skills. This study aimed to identify the relationships between scientific aptitude, creativity, and scientific creative problem solving abilities in children. The subjects were 100 5th graders residing in Seoul and a small city in Choongnam. Data was analyzed by t-test and by correlation using spss program packages. The main results of this study were as follows: first, a significant difference was found in the scientific creative problem solving ability of children by their respective levels of science aptitude. Secondly, the scientific creative problem solving ability of the children by their levels of creativity was found to be insignificant. Thirdly, no significant difference was found between creativity and scientific creative problem solving ability among the children examined; however there was a significant difference found between the science aptitude and scientific-creative problem solving ability and between science aptitude and creativity in the children who participated in this study.

• Journal of Korean Elementary Science Education
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• v.19 no.1
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• pp.71-83
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• 2000

This study examined the influences of science project activities based on multiple intelligences on problem solving behaviors of elementary school children. Specifically, the influences of the project activities on the problem solving skills and propensities of the children were investigated. Forty-four fifth graders were selected for the study. They performed the projects and made their products of it during five months on the units of "Weather" and "Our Body" Criteria for assessment of problem solving abilities were determined. The patterns reflected in products of the project activities were examined, then the observation of the subjects' problem solving behaviors and the interviews were performed based on the criteria. The results were analyzed through both of qualitative and quantitative approaches. In these analyses, the implementation of the science projects was found to contribute to the improvement in all sub-factors of problem solving, specially, skills associated with the propensities of problem identification and of the collection, analysis, and synthesis of data significantly increased

• Research in Mathematical Education
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• v.13 no.2
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• pp.75-90
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• 2009

There are concepts in calculus which are difficult to teach and learn. One of these concepts is integration. However, problem posing has not yet received the attention it deserves from the mathematics education community. There is no systematic study that deals with teaching of calculus concepts by problem posing oriented teaching strategy. In this respect this study investigated the effect of problem posing on students' (prospective teachers') academic success when problem posing oriented approach is used to teach the integral concept in Calculus-II (Mathematics-II) course to first grade prospective teachers who are enrolled to the Primary Science Teaching Program of Education Faculty. The study used intervention-posttest experimental design. Quantitative research techniques were employed to gather, analyze and interpret the data. The sample comprised 79 elementary prospective science teachers. The results indicate that problem posing approach effects academic success in a positive way and at significant level.

• Journal of the Korean Operations Research and Management Science Society
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• v.15 no.1
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• pp.99-115
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• 1990

This paper is concerned with the unit commitment problem in an electric power system with both thermal and pumped-storage hydroelectric units. This is a mixed integer programming problem and the Lagrangean relaxation method is used. We show that the relaxed problem decomposes into two kinds of subproblems : a shortest-path problem for each thermal unit and a minimum cost flow problem for each pumped-storage hydroelectric unit. A method of obtaining an incumbenet solution from the solution of a relaxed problem is presented. The Lagrangean multipliers are updated using both subgradient and incremental cost. The algorithm is applied to a real Korean power generation system and its computational results are reported and compaired with other works.