• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.295-300
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• 1998

Recently graphical modelling is being studied as a useful process analysis tool for exploratory causal analysis. Graphical modelling is a presentation method that uses graphs to describe statistical models of the structures of multivariate data. This paper describes an application of this graphical modeling with two cases from the automotive parts industry. One case is the unbalance problem of the pulley, an automotive generator part. There is multivariate data of the product from each of the processes which are connected in the series. By means of exploratory causal analysis between the variables using graphical modeling, the key processes which causes the variation of the final characteristics and their mechanism of the causal relationship have become clear. Another case is, also, the unbalanced problem of automotive starter parts which consists of many parts and is manufactured by complex machinery and assembling process. By means of the similar technique, the key processes are obtained easily and the results are reasonable from technical knowledge.

• Journal of The Korean Association For Science Education
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• v.15 no.4
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• pp.429-436
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• 1995

The purpose of this study is to identify students' alternative frameworks about tide concept, to investigate some characters of them and students' understanding types with increasing grade in secondary school earth science course. The objective questionnaire method was used, and the subjects of this study are 528 students selected randomly in secondary school. The results are as follow. 1) Thirteen alternative frameworks about tide concept, related to the phase change of the moon and the motion of the earth are identified. 2) The alternative frameworks needed mechanical and causal reasoning have the trend reinforced or sophisticated with increasing the grade. And alternative frameworks needed phenomenal and mechanical, phenomenal and causal reasoning are changed little but ones needed phenomenal, variative and basic reasoning change scientifically. The rates of the alternative frameworks needed definitional, empirical, phenomenal reasoning decrease at the learning grade of that concept but increase after that grade. 3) Middle school students have the definitional, phenomenal, empirical and qualitative understanding types but high school students have the causal, analytic, quantitative and mechanical ones on tide concept.

• Journal of Korean Society for Quality Management
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• v.38 no.3
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• pp.378-390
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• 2010

From the perspective of employees working for public service agencies, we analyzed the causal relationship between service quality, relationship quality, design quality, customer satisfaction, and trust in public services. We conduct statistical analyses on the quality attributes we derived from a critical incident technique(CIT) analysis and build a measurement model, which has a second-order hierarchical structure. Survey data was collected from social work, childcare, and healthcare services. Using a structural equation modeling method, we identify a causal model and simultaneously estimate factor loadings and path coefficients. We find that all the quality dimensions are antecedents to satisfaction and then satisfaction precedes trust. The results show that service quality and design quality mediate in parallel the effect of relationship quality on satisfaction and both relationship and design qualities have stronger effects on satisfaction rather than service quality.

• Korean System Dynamics Review
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• v.1 no.2
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• pp.33-60
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• 2000

This study aims to conceptually identify the circular causal-relationship which is structured between downsizing and technological innovation in organization. First, through the literature review concerning downsizing and (technological) innovations, we have outlined the conceptual building blocks and research boundaries in this field. Second, we used system thinking method to accomplish our research purpose. The research findings are as follows. First, the promotion of financial resources by downsizing have trade-off relations that have negative of effects in short terms, but positive effects in long time. Second, workforce reduction by downsizing usually has negative influence on employees. Third, capital reduction by downsizing generates not only the climates of cost-cut but also the fact that although the climates may increase economic performance in short terms, it may interrupt technological innovations in long terms. In conclusion, this theses suggests that the relationship of downsizing and technological innovations have complex causal and feedback structures. Therefore, the results of this thesis propose that the argument or practices of downsizing with partial emphasis is very dangerous. Finally some limitations are also discussed.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2472-2479
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• 2008

There exist several ways to analyse the accident causal analysis. Selection of a method and procedure depends on the characteristics of the system being analysed. Moreover, the selection should take into account of how the accidents causes are classified, since analysis model should make use of the classified causes to identify factors contributing to the risk of accidents. For railway case, a relational analysis as well as statistical estimation of significant hazard frequencies is applied to identify the dominant causes of accidents. This paper introduces outline of the causal analysis system, which is a significant part of the railway accident information and analysis system.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.1
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• pp.1-7
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• 2014

This paper presents a novel method for simultaneously and automatically choosing the nonlinear structures of regressors or discriminant functions, as well as the number of terms to include in a rule-based regression model or pattern classifier. Variables are first partitioned into subsets each of which has a linguistic term (called a causal condition) associated with it; fuzzy sets are used to model the terms. Candidate interconnections (causal combinations) of either a term or its complement are formed, where the connecting word is AND which is modeled using the minimum operation. The data establishes which of the candidate causal combinations survive. A novel theoretical result leads to an exponential speedup in establishing this.

• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.3
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• pp.103-109
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• 1992

This research suggest a causal model to investigate factors and variables which significant effects on user satisfaction with city park recreational facilities in Duryu city park in Taegu, and thereby identifying implications for planning and development of urban parks and open space. For this study the data were gathered by self-adminstered questionnares from 993 households selected by the multi-stage probability sampling method. The analysis of the data consists of two phases. The first involves exploratory factor analysis to draw meaningful factors from the data. Three factors were indentified. The second phase test the causal model of this research employing LISREL methodology. On the base of the analysis results, important implications for planning of city park and open space are recommended.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.617-623
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• 2008

A fine-mapping method exploiting linkage disequilibrium was used to detect quantitative trait loci (QTL) on the X chromosome affecting milk production, body conformation and productivity traits. The pedigree comprised 22 paternal half-sib families of Black-and-White Holstein bulls in the Netherlands in a grand-daughter design for a total of 955 sons. Twenty-five microsatellite markers were genotyped to construct a linkage map on the chromosome X spanning 170 Haldane cM with an average inter-marker distance of 7.1 cM. A covariance matrix including elements about identical-by-descent probabilities between haplotypes regarding QTL allele effects was incorporated into the animal model, and a restricted maximum-likelihood method was applied for the presence of QTL using the LDVCM program. Significance thresholds were obtained by permuting haplotypes to phenotypes and by using a false discovery rate procedure. Seven QTL responsible for conformation types (teat length, rump width, rear leg set, angularity and fore udder attachment), behavior (temperament) and a mixture of production and health (durable prestation) were detected at the suggestive level. Some QTL affecting teat length, rump width, durable prestation and rear leg set had small numbers of haplotype clusters, which may indicate good classification of alleles for causal genes or markers that are tightly associated with the causal mutation. However, higher maker density is required to better refine the QTL position and to better characterize functionally distinct haplotypes which will provide information to find causal genes for the traits.

• The Journal of Information Systems
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• v.16 no.4
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• pp.177-194
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• 2007

This study is intended to identify critical success factors(CSF) of real-time enterprises(RTE) by using a policy leverage method of system dynamics. Since RTE is a new theoretical system that unifies existing theories or concepts in business management and information technology, it is not proper to employee a traditional statistical method. To obtain our research goal, causal maps of system dynamics are employed to abstract and arrange RTE information from previous studies. By using the commonness of policy leverage and critical success factors, CSFs for the RTE are deduced by substituting the leverage points on causal maps with necessary success factors to solve the problems. Since this is a new approach to identify success factors. it has some restrictions. Unlike the statistical methods, this approach explains only the directions of causalities and correlations. For the future research, a simulation tool of system dynamics can be employed to discover how each CSF is correlated to the successful implementation of RTE.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.287-298
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• 2018

This research is intended to understand and make practical suggestions on various aspects of the railroad traffic controllers focusing on railroad control of the railroad safety management system's technical standards. The method of analysis is using the causal loop diagram, which is the soft method of System Dynamics. Content of analysis is about the system. 11.7 of the work of the railroad control system. In addition, we compared and analyzed railroad controllers by four railroad operators, suggesting the importance of railroad control and future practical improvement plans.