• Industrial Engineering and Management Systems
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• v.13 no.4
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• pp.421-431
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• 2014

The market basket data in the form of a binary user-item matrix or a binary item-user matrix can be modelled as a binary classification problem. The binary logistic regression approach tackles the binary classification problem, where principal components are predictor variables. If users or items are sparse in the training data, the binary classification problem can be considered as a cold-start problem. The binary logistic regression approach may not function appropriately if the principal components are inefficient for the cold-start problem. Assuming that the market basket data can also be considered as a special regression problem whose response is either 0 or 1, we propose three supervised learning approaches: random forest regression, random forest classification, and elastic net to tackle the cold-start problem, comparing the performance in a variety of experimental settings. The experimental results show that the proposed supervised learning approaches outperform the conventional approaches.

• Korean Journal of Human Ecology
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• v.15 no.4
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• pp.541-549
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• 2006

The purpose of this study is to clarify that parents' values and beliefs in bringing up their children deeply relate to their children's problem behaviors, The subjects are 267 preschoolers attending kindergarten in Daegue area, Statistical techniques are Two Way ANOVA, Scheffe' test, Pearson's Correlation and Regression, The results of this study are as follows: (1) Problem behaviors of preschoolers are significantly related to parents' values, Preschoolers whose parents have a higher level of values have a lower level of problem behaviors. (2) Problem behaviors of preschoolers are significantly related to parents' beliefs, Preschoolers whose parents have a higher level of beliefs have a higher level of problem behaviors. (3) The Multiple Regression analysis shows that parents' parenting values and beliefs are crucially predictive of preschoolers' problem behaviors. Especially, parents' parenting beliefs is more relevant to preschoolers' problem behaviors than parents' parenting values is.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.118-126
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• 2009

This research investigates the problem of minimizing setup costs in resequencing jobs having first-in, first-out(FIFO) constraints at conveyorized production or assembly systems. Sequence changing at conveyor junctions in these systems is limited due to FIFO restriction. We first define the general problem of resequencing jobs to workstations satisfying precedence relationships between jobs(Generalized Sequential Ordering Problem, GSOP). Then we limit our scope to FIFO precedence relationships which is the conveyor selection problem at a diverging junction(Diverging Sequential Ordering Problem, DSOP), modeling it as a 0-1 integer program. With the capacity constraint removed, we show that the problem can be modeled as an assignment problem. In addition, we proposed and evaluated the heuristic algorithm for the case where the capacity constraint cannot be removed. Finally, we discuss the case study which motivated this research and numerical results.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.592-595
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• 1999

In this paper, we propose a unified method to solve the various robust filtering problem for a class of uncertain discrete time systems. Generally, to solve the robust filtering problem, we must convert the convex optimization problem with uncertainty blocks to the uncertainty free convex optimization problem. To do this, we derive the robust matrix inequality problem. This technique involves using constant scaling parameter which can be optimized by solving a linear matrix inequality problem. Therefore, the robust matrix inequality problem does not conservative. The robust filter can be designed by using this robust matrix inequality problem and by considering its solvability conditions.

• Korean Journal of Child Studies
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• v.28 no.5
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• pp.143-159
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• 2007

This study examined the relation between the quality of constructive play and convergent and divergent problem solving. The subjects were 48 five-year-old children. Unit blocks were used to test the quality level of constructive play; a 40 piece puzzle and pattern blocks were used to test convergent problem solving; the pattern blocks also were used to test divergent problem solving. Children's block play was videotaped and pictures were taken of constructions made by children. Data were analyzed by correlation and stepwise multiple regression. Results showed statistically significant correlations between the quality of constructive play and convergent and divergent problem solving. Among the sub variables of constructive play, social play patterns affected convergent problem solving; diversity affected divergent problem solving.

• Korean Management Science Review
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• v.26 no.1
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• pp.171-182
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• 2009

We consider the inventory replenishment problem and the vehicle routing problem simultaneously in the vending machine operation. This problem is known as the inventory routing problem. We design a memory cell in the clonal selection algorithm. The memory cell store the best solution of previous solved problem and use an initial solution for next problem. In general, the other clonal selection algorithm used memory cell for reserving the best solution in current problem. Experiments are performed for testing efficiency of the memory cell in demand uncertainty. Experiment result shows that the solution quality of our algorithm is similar to general clonal selection algorithm and the calculations time is reduced by 20% when the demand uncertainty is less than 30%.

• Journal of Families and Better Life
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• v.14 no.3
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• pp.237-248
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• 1996

This study regarded the marital problem solving as the process of ego states marital problem perception and marital problem solving behaviors and was to verify that the match of husband and wife in that process differed in marital adjustment, The subjects of the study were 225 married couples for 1-10 years. The results of the study were summarized as following: 1) Husband/wife's marital adjustments differed in a accordance with marital problem solving behavior matches between husband and wife. 2) Marital problems solving behaviors were the most effected by marital problem perception and were indirectly effected by ego states. Particularly marital problem solving behaviors was the more effec ted by perception of husband than of wife.

• Journal of the military operations research society of Korea
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• v.26 no.2
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• pp.120-130
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• 2000

The purpose of this study is to present a method for determining the k most vital arcs in shortest path problem using an evolutionary algorithm. The problem of finding the k most vital arcs in shortest path problem is to find a set of k arcs whose simultaneous removal from the network causes the greatest increase in the total length of shortest path. Generally, the problem determining the k most vital arcs in shortest path problem has known as NP-hard. Therefore, in order to deal with the problem of real world the heuristic algorithm is needed. In this study we propose to the method of finding the k most vital arcs in shortest path problem using an evolutionary algorithm which known as the most efficient algorithm among heuristics. The method presented in this study is developed using the library of the evolutionary algorithm framework and then the performance of algorithm is analyzed through the computer experiment.

• Journal of Navigation and Port Research
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• v.29 no.2
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• pp.141-146
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• 2005

For a long time, genetic algorithms have been recognized as a new method to solve difficult and complex problems and the performance of genetic algorithms depends on genetic operators, especially crossover operator. Various problems like the traveling salesman problem, the transportation problem or the job shop problem, in logistics engineering can be modeled as a sequencing problem This paper proposes modified genetic crossover operators to be used at various sequencing problems and uses the traveling salesman problem to be applied to a real world problem like the delivery problem and the vehicle routing problem as a benchmark problem Because the proposed operators use parental information as well as network information, they could show better efficiency in performance and computation time than conventional operators.

• Journal of Korean Academy of Nursing Administration
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• v.12 no.2
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• pp.287-294
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• 2006

Purpose: The purpose of this study was to identify the change of critical thinking disposition and problem solving process in students who experienced problem-based learning. Method: This research design was one group pre-post test design. Twenty-five nursing students who participated in ‘'Nursing Process' course with two PBL packages for a semester in 2004 were the subjects of this study. The data were analyzed by repeated measures of ANOVA, and content analysis. Result: The problem defining in problem solving process was improved significantly, but there was no significant difference in the critical thinking disposition. Conclusion: The results of this study suggest that PBL has a positive effect on nursing students' problem solving process, But for a more significant effect on a continuous base for critical thinking of nursing students, faculties should use web based and simulation-based education for self directed learning along with clinical situation-based scenarios.