• Korean Management Science Review
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• v.13 no.1
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• pp.97-109
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• 1996

Genetic Algorithms have been successfully applied to various problems (for example, engineering design problems with a mix of continuous, integer and discrete design variables) that could not have been readily solved with traditional computational techniques. But, several problems for which conventional Genetic Algorithms are ill defined are premature convergence of solution and application of exterior penalty function. Therefore, we developed an Improved Genetic Algorithms (IGAs) to solve above two problems. As a case study, IGAs is applied to several nonlinear optimization problems and it is proved that this algorithm is very useful and efficient in comparison with traditional methods and conventional Genetic Algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.171-180
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• 1992

This paper proposes a solution approach to linear problems with many constraints of variable upper bound (VUB) type. This type of constraints are commonly found in various scheduling type problems for which tighter bounds are essential to achieve an efficiency in enumeration. An analytical framework based on factorization is adopted to devise a solution approach to the problem and extend it for more generalized VUB problem (GVUB). This research shows why the VUB type constraints are amenable to the factorization and gives a unified approach to generalized upper bound(GUB) problems, VUB problems and GVUB problems. Implementation issues are also included.

• Journal of the Korean Mathematical Society
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• v.34 no.1
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• pp.247-255
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• 1997

In this paper, we are concerned with the existence of positive solutions for the boundary value problems of the form; $$(1) u"(t) + q(t)g(u(t)) = 0, 0 < t < 1 $$ $$ u(0) = 0 = u(1), $$ where q is singular at 0 and /or 1.or 1.

• Journal of applied mathematics & informatics
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• v.23 no.1_2
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• pp.183-191
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• 2007

In this paper, we introduce and study a new class of equilibrium problems, known as regularized mixed quasi equilibrium problems. We use the auxiliary principle technique to suggest and analyze some iterative schemes for regularized equilibrium problems. We prove that the convergence of these iterative methods requires either pseudomonotonicity or partially relaxed strongly monotonicity. Our proofs of convergence are very simple. As special cases, we obtain earlier results for solving equilibrium problems and variational inequalities involving the convex sets.

• Journal of the military operations research society of Korea
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• v.12 no.2
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• pp.37-55
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• 1986

Vehicle fleet planning problem is generic name given to a whole class of practical decision making problems which find the vehicle routes and schedules to accomplish the reqired service to customers using vehicles. In this paper the various problems are classified into the three groups according to their characteristics: (1) vehicle routing problems, (2) vehicle scheduling problems, and (3) vehicle routing and scheduling problems. The State of the art of each group is described and the future research directions are presented.

• Korean Journal of Child Studies
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• v.22 no.3
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• pp.91-106
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• 2001

This study examined relationships between peer variables and externalizing behavior problems of 290 4th and 5th grade children in elementary school. The children completed the Friendship Quality Scale and the peer nomination questionnaire. Parents and teachers rated behavior problems of children using the Connors' Rating Scale. Results indicated that rejected children had more behavior problems than popular, average, or neglected children. Socio-emotional supports from a close friend and satisfaction with the friend were negatively related to behavior problems. Behavior problems were mainly predicted by low peer acceptance, and behavior problems of rejected children were negatively and strongly related to socio-emotional supports of a close friend. In conclusion, peer rejection was a risk factor and a friend's support was a protective factor for externalizing behavior problems in 4th and 5th graders.

• Korean Journal of Childcare and Education
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• v.14 no.1
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• pp.109-128
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• 2018

Objective: This study examined the relationships among mothers' marital satisfaction, parenting behavior, and preschoolers' sleep problems. Methods: Three hundred mothers of preschoolers completed questionnaires on three research variables. Data were analyzed by correlation analyses and regression analyses. Results: First, mothers' marital satisfaction was negatively related to preschoolers' sleep problems. Second, mothers' marital satisfaction was positively associated with warmth and reasoning, while mothers' marital satisfaction was negatively associated with intrusiveness, coercion, and neglect. Third, mothers' warmth and reasoning were negatively linked to preschoolers' sleep problems, but mothers' coercion was positively linked to preschoolers' sleep problems. Lastly, mothers' warmth partially mediated the relationship between mothers' marital satisfaction and preschoolers' sleep problems. Conclusion/Implications: This study confirmed that mothers' marital satisfaction and parenting behavior had an influence on preschoolers' sleep problems. These findings highlight the importance of the family context for preschoolers' healthy sleeping habits.

• Journal of the Korean Home Economics Association
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• v.39 no.4
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• pp.79-89
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• 2001

This study investigated institutionalized children's behavior problems depending on their family networks. Subjects were 250 institutionalized children in 15 child-welfare facilities in Seoul(132 preschooler, 55 first and 63 second grade children; 144 boys and 106 girls). Data were analyzed with t-test, ANOVA, and Duncan test. Measures of behavior problems included internalizing (anxiety, immaturity, withdrawal, physical symptom) and externalizing behavior problems (hyperactivity, aggression). Results showed that institutionalized children having parents were higher in internalizing problems than children not having parents, while children living with siblings in the facilities were lower in externalizing problems than children living without siblings. Furthermore, institutionalized children having parents and living without siblings were higher in both internalizing and externalizing problems than children not having parents and living with siblings.

• Journal of Families and Better Life
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• v.26 no.5
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• pp.51-60
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• 2008

This study examined the influence of attachment to parents, parents' monitoring, and deviant peers on trajectories of internalizing and externalizing problems in adolescence. Participants were 2528(1251 male and 1277 female) adolescent from the 2004(age:16 of latent growth curve modeling indicated that (1) Individual differences of internalizing and externalizing problems' nitial levels and changes were significant. (2) Attachment to parents influenced both initial levels and changes of internalizing problems. (3) Attachment to parents and parents' monitoring influenced initial levels of externalizing problems, and deviant peers influenced both initial levels and changes of externalizing problems.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.284-288
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• 2005

Internet-based distance learning is proliferated, but justifying its educational effectiveness is challenging. Investigation into the problems is important and fundamental for the study on the educational effectiveness. In this study, problems of Internet-based distance learning are structured by four categories as environmental problems, student problems, course design problems and operational problems. Based on a survey of distance education participants, problems are analysed. Also, analysis from the point of demographic differences such as sex, job existence and age is performed.