• Transactions of Materials Processing
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• v.13 no.5
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• pp.409-414
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• 2004

TRIP steel has got attention in automobile industry because of its high strength and high formability. However, the information on deformation behavior of TRIP steel, including bending and springback, is not enough until now. In this research, the V-die bending experiment and analysis have been done to obtain the information of springback of TRIP steel. And a new numerical method, where elastic modulus is varied with the change of the strain, was suggested. Tensile test for TRIP steel was done to get tensile properties as well as strain dependency of elastic modulus of the material. Strain-dependency of elastic modulus was used the numerical analysis of V-die bending and unbending process to predict springback amount. The results were compared with experiment, showing reasonable agreement. Through the analysis of V-die bending as well as draw bending of TRIP steel, the proposed scheme with variable elastic modulus was proven to well predict the deformation behavior of TRIP steel during bending and springback.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.119-130
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• 2023

Among the various elements of probabilistic safety assessment (PSA), human failure events (HFEs) and their dependencies are major contributors to the quantification of risk of a nuclear power plant. Currently, the dependency among HFEs is reflected using a post-processing method in PSA, wherein several drawbacks, such as limited propagation of minimal cutsets through the fault tree and improper truncation of minimal cutsets exist. In this paper, we propose a method to model the HFE dependency directly in a fault tree using the if-then-else logic. The proposed method proved to be equivalent to the conventional post-processing method while addressing the drawbacks of the latter. We also developed a software tool to facilitate the implementation of the proposed method considering the need for modeling the dependency between multiple HFEs. We applied the proposed method to a specific case to demonstrate the drawbacks of the conventional post-processing method and the advantages of the proposed method. When applied appropriately under specific conditions, the direct fault-tree modeling of HFE dependency enhances the accuracy of the risk quantification and facilitates the analysis of minimal cutsets.

• Journal of Korean Clinical Nursing Research
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• v.28 no.2
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• pp.198-209
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• 2022

Purpose: The purpose of the study was to shorten the KPCS-1 (Korean Patient Classification System-1) for predicting nursing care need level and to explore whether the patients can be clustered by their acuity and dependency. Methods: The participants were inpatients in two surgical wards and two internal medicine wards at a teritory hospital during 14 days investigations. The KPCS-1 was evaluated once a day for all inpatients and 2,082 cases of data from a total of 411 patients were analyzed. Results: The items were reducted from 50 items to 26 items by partial least squares analysis and expert review. Through factor analysis, it was confirmed that hygiene, diet, elimination, and exercise were categorized as dependence factors. Patients were clustered with low acuity/low dependency (average score: 7.68±2.81/1.05±1.33), high acuity/low dependency (average score: 17.20±4.15/1.94±2.40), medium acuity/high dependency (average score: 13.56±5.30/9.66±2.64) through cluster analysis. The total score of the three groups for their nursing care needs was 8.73±3.36, 19.14±5.74, and 23.24±6.31 in order, and the results showed a statistically significant difference (F=1712.12, p<.001). Conclusion: The shortening of the KPCS-1 and the new criteria for categorizing patients according to acuity and dependence will increase clinical utility and be useful for manpower assignment criteria in detail.

• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.1
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• pp.51-64
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• 1988

A new approach to the logical design of 4NF database shceme, which can be easily automated, is proposed. The main features of the approach are : introduction of a single attribute right hand side, extension of the concept of independent relations, semantic analysis, and adaoption of dependency matrix. The underlying viewpoints of functional relationships of the approach are different from Fagin's in that we distinguish functional and multivalued dependency in terms of cardinality. An algorithm for automatic generation of fourth normal form is presented and implemented.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.431-433
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• 2012

스파스 분석(Sparse analysis)은 프로그램의 데이터 의존관계(Data dependency)에 따라 필요한 정보를 필요한 부위와 시점으로 바로 보냄으로써 분석을 수행한다. 이 데이터 의존관계의 성질을 이용하면 프로그램 분석을 효율적으로 병렬화 할 수 있는 여지가 생긴다. 이 논문에서는 데이터 의존 관계를 이용하여 스파스 분석을 병렬화 하는 방법을 제시한다. 9개 오픈소스를 통해 실험해본 결과, 프로그램에 따라 6~37%, 평균적으로는 24% 가량 속도가 향상되었다.

• Journal of the Korean Data and Information Science Society
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• v.25 no.5
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• pp.1107-1116
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• 2014

In this paper, we review recent developments in network analysis using the graph theory, and introduce ongoing research area with relevant theoretical results. In specific, we introduce basic notations in graph, and conditional and marginal approach in constructing the adjacency matrix. Also, we introduce the Marcenko-Pastur law, the Tracy-Widom law, the white Wishart distribution, and the spiked distribution. Finally, we mention the relationship between degrees and eigenvalues for the detection of hubs in a network.

• Korean Journal of Human Ecology
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• v.23 no.2
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• pp.163-174
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• 2014

This study aimed to discriminate the groups clustered by mobile phone dependency and use type and to explore the quality of parent child-rearing attitudes and peer relationships predicting the types of groups. The subjects were the 688 fourth-grade students participating in the Korea Child Youth Panel Surveys. The data were analyzed with descriptive statistics, cluster analysis, One-way ANOVA and multinominal logistic regressions. The main results of this study were as follows. Firstly, as the result of cluster analysis inputting the mobile phone dependency and use type, the four clustered groups were produced. Secondly, the quality of parent child-rearing attitudes and peer relationships discriminating the four groups were parents' supervision, over-involvement, love, senses of non-alienation from peers and communicating with them. Therefore, this study suggested the parent education and peer-relationship improving program to form children's good habits of mobile phone use.

• Journal of Korean Biological Nursing Science
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• v.18 no.4
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• pp.213-220
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• 2016

Purpose: The aim of this study was to identify the influence of knowledge, attitude and preventive health behavior of cancer on nicotine dependency in male college students who have a habit of smoking. Methods: In this study, a cross-sectional survey design was adopted for the 254 male college students who smoke in D and S city. The data was analyzed for descriptive statistics, t-test, Pearson's correlation coefficient and multiple regression analysis using the SPSS 20.0 program. Results: Knowledge about lung cancer (${\beta}=-.407$, p<.001), preventive health behaviors about cancer (${\beta}=-.223$, p<.001) and the smoking period ($5years{\leq}$) (${\beta}=.198$, p=.001) were identified as the factors influencing nicotine dependency of the subjects. The model explained 33% of variance in nicotine dependency (F=20.49, p<.001). Conclusion: The results suggest that anti-smoking educators should include the strategies to increase knowledge about lung cancer and preventive health behaviors of cancer, and to reduce the smoking period in their smoking cessation program.

• Journal of Family Resource Management and Policy Review
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• v.16 no.4
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• pp.213-233
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• 2012

This descriptive study about a community center for elderly users identifies factors influencing economic dependency. The objective of this study is to find factors that contribute to increased economic dependency and to provide basic data for preventing conflict between caregivers and elderly dependents. The subjects are 204 elderly persons who are community-center users in SongPa-Gu. Thirteen dongs (administrative areas) were chosen randomly in a cluster sample from among 26 dongs in Soungpagu containing a total of 158 community centers for the elderly. I obtained informed consents for my research from all subjects, and collected data by conducting interviews from June 28th, 2011 to August 7th, 2011. The data was analyzed by descriptive statistics, t-test, one-way ANOVA, Duncan test and multi regression analysis. The mean economic dependency score was 3.23, meaning that subjects with this score are dependent at a level that is "over intermediate". The level of formal education, homeownership, financial assistance from family and the number of families, financial assistance to the family and the number of families, economic life satisfaction, self efficacy and social support.

• Journal of the Korean Home Economics Association
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• v.41 no.1
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• pp.169-185
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• 2003

The present study was to investigate whether Cyberspace addiction groups could be classified into types and examine the relationship with types of Cyberspace addiction and adolescents' psychological environment. The findings were as follows: First, adolescents' Cyberspace addiction was analyzed by factor analysis and classified by four different types, which were named as sensation seeking, life interference, time dependency, and psychological dependency. Second, male students experienced more sensation seeking and life interference tendencies than female students who experienced more psychological dependency tendency than male students. High school students experienced more life interference tendency than middle school students. Third, there was relationship with types of adolescents Cyberspace addiction and psychological environment. Adolescents who addicted Cyberspace with sensation seeking were more likely to avoid conversation with families, and had a tendency of compulsiveness and depression. Adolescents who addicted Cyberspace with life interference had a tendency of compulsiveness and depression, and had a problem of school life and family relationship. Adolescents who addicted Cyberspace with time dependency showed the compulsiveness and avoided conversation with families. Adolescents who addicted Cyberspace with psychological dependency were more likely to have peer relationship and had a tendency of depression. Conclusively, the psycho-social environment such as compulsiveness, depression, family and peer relationship, and school environment was related to types of adolescents' Cyberspace addiction more or less.