• Journal of the military operations research society of Korea
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• v.29 no.2
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• pp.61-80
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• 2003

A fire sequencing problem is considered. Fire sequencing problem is a kind of scheduling problem that seeks to minimize the overall time span under a result of weapon­target allocation problem. The assigned weapons should impact a target simultaneously and a weapon cannot transfer the firing against another target before all planned rounds are consumed. The computational complexity of the fire sequencing problem is strongly NP­complete even if the number of weapons is two, so it is difficult to get the optimal solution in a reasonable time by the mathematical programming approach. Therefore, a genetic algorithm is adopted as a solution method, in which the representation of the solution, crossover and mutation strategies are applied on a specific condition. Computational results using randomly generated data are presented. We compared the solutions given by CPLEX and the genetic algorithm. Above $7(weapon){\times}15(target)$ size problems, CPLEX could not solve the problem even if we take enough time to solve the problem since the required memory size increases dramatically as the number of nodes expands. On the other hand, genetic algorithm approach solves all experimental problems very quickly and gives good solution quality.

• International Journal of Contents
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• v.8 no.2
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• pp.23-27
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• 2012

The successful use of digital textbooks (DTs) in schools requires the development of various teaching and learning methods that are appropriate for DTs. However, recent DT studies have focused mainly on the implementation of DT features and formats. The objective of this study was to investigate a problem-based learning instructional model appropriate to DTs and to present the experimental results using the problem-based DT to demonstrate its educational effectiveness. Two learning-achievements tests were conducted to analyze the learning experience and effectiveness of the problem-based DT after it had been used in a high school for a certain period. The experimental results indicated that the students who used the DT, especially lower-level students, exhibited improved problem-solving ability and demonstrated a better practical understanding of the subject than students who used printed textbooks.

• Journal of Families and Better Life
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• v.30 no.6
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• pp.1-11
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• 2012

We investigated the effects of maternal parenting behavior and social supports on children's problem behaviors. The participants are 148 elementary school children and their teachers from one elementary school in Seoul. The data were analyzed by using descriptive statistics, correlation analysis, t-test, and multiple regression. The major findings are summarized as follows: (1) there were differences in maternal parenting behavior(warmth), teacher support, and internal problem behaviors according to children's gender; (2) mothers's parenting behavior(warmth) and teachers' support explained children's overt problem behaviors; and (3) mothers' parenting behaviors(supervision) and friends' support explained children's internal problem behaviors. In conclusion, there were differences between the subscale of maternal parenting behavior and social supports influencing overt problem behaviors and internal problem behaviors.

• The Mathematical Education
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• v.51 no.2
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• pp.95-114
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• 2012

This study examines the use of ill-structured problem to help the 4th graders' problem solving and reasoning. It appears that children with good understanding of problem situation tend to accept the situation as itself rather than just as texts and produce various results with extraction of meaningful variables from situation. In addition, children with better understanding of problem situation show AR (algorithmic reasoning) and CR (creative reasoning) while children with poor understanding of problem situation show just AR (algorithmic reasoning) on their reasoning type.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.381-384
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• 2002

The free surface flow problem has been one of the most interesting and challenging topic in the area of the naval ship hydrodynamics and ocean engineering field. The problem has been treated mainly in the scope of the potential theory and its governing equation is well known Laplace equation. But in general, the exact solution to the problem is very difficult to obtain because of the nonlinearlity of the free surface boundary condition. Thus the linearized free surface problem has been treated often in the past. But as the computational power increases, there is a growing trend to solve the fully nonlinear free surface problem numerically. In the present study, a time-dependent finite element method is developed to solve the problem. The initial-boundary problem is formulated and replaced by an equivalent variational formulation. Specifically, the computations are made for a highly nonlinear flow phenomena behind a transom stern ship and a vertical strut piercing the free surface.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1792-1802
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• 1996

The analysis of prepositional phrases in English-to Korean machine translation has problem on the PP-attachment resolution, semantic analysis, and acquisition of information. This paper presents an analysis system for prepositional phrases, which solves the problem. The analysis system consists of the PP-attachment resolution hybrid system, semantic analysis system, and semantic feature generator that automatically generates input information. It provides objectiveness in analyzing prepositional phrases with the automatic generation of semantic features. The semantic analysis system enables to generate natural Korean expressions through selection semantic roles of prepositional phrases. The PP-attachment resolution hybrid system has the merit of the rule-based and neural network-based method.

• Journal of Engineering Education Research
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• v.10 no.3
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• pp.93-108
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• 2007

The purpose of this study is to investigate characteristics which are related with effective solution of technological problems. For this, an effective problem solver and an ineffective problem solver have been compared in terms of the problem solving activity with a population of students who are enrolled in College of Engineering, C University in Daejeon. As a result, this paper can be concluded as follows: An effective problem solver differs from an ineffective problem solver in terms of time consumed during problem solution modeling a problem solution identifying a problem cause and frequency and time consumed during evaluating a result.

• The Mathematical Education
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• v.55 no.1
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• pp.73-89
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• 2016

The purpose of this study was to analyze middle school students' problem posing types and strategies. we analyzed problems posed by 120 middle school students during mathematics class focused on problem posing activities in various aspects. Students' posed problems were classified into five types: not a problem(NP), non-math(NM), impossible(IM), insufficient(IN), sufficient(SU) and each of the posed problems. Students used three kinds of problem posing strategies such as goal manipulation(GM), assumption manipulation(AM), and condition manipulation(CM), and in posing one problem, one or more than two strategies were used. According to the prior studies, problem posing can contributes to the development of students' problem solving ability, creativity, mathematical aptitude, and a broader understanding of mathematical concepts. However, we found that some students had difficulties in posing problems or limited understandings of that. We hope the results of the study contribute to encouraging problem posing activities in mathematics instruction.

• Journal of Families and Better Life
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• v.29 no.4
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• pp.161-174
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• 2011

The purpose of this study was to investigate the structural relationships among different variables related to school adjustment. 601 elementary school students residing in Pohang-City in Korea completed questionnaires about school adjustment, internal problem behavior, external problem behavior, family adaptability and family cohesion. A variance-covariance matrix of this sample was analyzed using AMOS 19.0, and the maximum likelihood minimization function. The goodness of fit was evaluated via SRMR, RMSEA with a 90% confidence interval, CFI, and TLI. The results were as follows: First, family adaptability, family cohesion, internal problem behavior and external problem behavior were all found to have a significant direct effect how the children adjusted to their school. Second, family adaptability, and family cohesion had a direct effect on internal problem behavior. Third, family cohesion had a direct effect on external problem behavior, but family adaptability had a substantial indirect effect on the children's external problem behavior that was mediated by their internal problem behavior. Fourth, internal problem behavior had a direct effect on external problem behavior.

• Convergence Security Journal
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• v.4 no.3
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• pp.9-18
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• 2004

This paper is to analyze security and technical problem of NEIS and suggest an improving methods about the effective system. Therefore questionnaire was performed in the five items with security as well as technical problem of NEIS to primary and secondary school teachers. The result of questionnaire analysis on each item is that they think of NEIS as the essential system for the age of information, despite problems such as the invasion of human right and security as well as reveal of personal data.