• Journal of the Korean Society of Safety
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• v.11 no.1
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• pp.16-26
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• 1996

In a series of original papers, [1-17] efficient methods and algorithms have been presented, for the exact solution of many reliability problems represented by binary networks. A starting point of these methods was the concept of domination, firstly introduced in ,elation with reliability problems in [2]. It's application to directed networks resulted in the development of a topological formula for the classical problem of the two terminal reliability. This result was extended later to the all-terminal and the k-terminal reliability problems. All papers mentioned above use a path oriented representation for the network topology. In practical applications, however, it is common and often advantageous to work with cut sets. This article considers the Domination theory for reliability problem of a network. Some topological formula are derived and the power and the application of this formula are shown through the alternative proof of topological formula of A. Satyanarayana [2].

• Journal of KIISE:Databases
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• v.29 no.2
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• pp.138-147
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• 2002

The concept of the critical path in the workflow is important because it can be utilized In many issues in workflow systems, e.g., workflow resource management and workflow time management. However, the critical path in the contest of the workflow has not been much addressed in the past. This is because control flows in the workflow, generally including sequence, parallel, alternative, iteration and so on, are much more complex than those in the ordinary graph or network. In this paper we first describe our workflow model that has considerable work(low control constructs. They would provide the sufficient expressive power for modeling the growing complexities of today's most business processes. Then, we propose a method to systematically determine the critical path in a workflow schema built by the workflow control constructs described in our workflow model.

• Journal of the Korean Society of Visualization
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• v.19 no.2
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• pp.56-62
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• 2021

Solid oxide fuel cells (SOFCs) is the high efficiency fuel cell operating at high temperatures ranging from 700-1000℃. Design of the flow paths of the fuel and air in SOFCs is important to improve cell performance and prevent cell degradation. However, the uneven distribution of current density in the traditional type having one inlet and outlet causes cell degradation. In this regard, the parallel flow path with two inlet and outlets was designed and compared to the traditional type based on computational fluid dynamics (CFD) simulation. To check the cell performance, hydrogen distribution, velocity distribution and current density distribution were monitored. The results validated that the parallel designs with two inlets and outlets have a higher cell performance compared to the traditional design with one inlet and outlet due to a larger reaction area. In case of uniform-type paths, more uniform current density distribution was observed with less cross-sectional variation in flow paths. In case of contracted and expanded inflow paths, significant improvement of performance and uniform current density was not observed compared to uniform parallel path. Considering SOFC cell with uniform current density can prevent cell degradation, more suitable design of SOFC cell with less cross-sectional variation in the flow path should be developed. This work can be helpful to understand the role of flow distribution in the SOFC performance.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.9
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• pp.363-370
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• 2022

Grasping a target object among clutter objects without collision requires machine intelligence. Machine intelligence includes environment recognition, target & obstacle recognition, collision-free path planning, and object grasping intelligence of robot hands. In this work, we implement such system in simulation and hardware to grasp a target object without collision. We use a RGB-D image sensor to recognize the environment and objects. Various path-finding algorithms been implemented and tested to find collision-free paths. Finally for an anthropomorphic robot hand, object grasping intelligence is learned through deep reinforcement learning. In our simulation environment, grasping a target out of five clutter objects, showed an average success rate of 78.8%and a collision rate of 34% without path planning. Whereas our system combined with path planning showed an average success rate of 94% and an average collision rate of 20%. In our hardware environment grasping a target out of three clutter objects showed an average success rate of 30% and a collision rate of 97% without path planning whereas our system combined with path planning showed an average success rate of 90% and an average collision rate of 23%. Our results show that grasping a target object in clutter is feasible with vision intelligence, path planning, and deep RL.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.206-217
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• 2017

The purpose of this study was to explore the causal relationships between turnover intention and its influencing factors among married female nurses. The participants included 148 married nurses at 5 general hospitals in J city. Data were collected by using self-reported questionnaires and were analyzed by using SPSS and AMOS software. The overall fitness of the modified path model to the data was good ($x^2/df=0.002$, GFI = 1.00, AGFI = 1.00, RMSEA = 0.00, NFI = 1.00, CFI = 1.00, TLI = 1.09). Job stress, social support, work-family conflict, and burnout explained 32.0% of the variance in turnover intention of the participants. In particular, work-family conflict had a complete mediating effect between job stress and burnout. In addition, work-family conflict had partial mediating effects between social support and burnout as well as between social support and turnover intention. Social support had direct and indirect effects on work-family conflict, burnout, and turnover intention. In conclusion, strategies for decreasing married nurses' burnout and turnover intention should focus on reducing work-family conflict and increasing social support.

• Korean Journal of Culture and Social Issue
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• v.21 no.3
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• pp.395-417
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• 2015

The first aim of this study was to explore the roles of personality variables on work motivation and job satisfaction. The second purpose was to setup a path model, in which the personality variables would impact on work motivation and job satisfaction. The third purpose of the current study was to examine medation effects of work motivation between personality variables and job satisfaction. In total, 280 older employees who worked in the various fields participated at this study. The reuslts of hierachial regression analysis found that agreeableness, conscientiousness, and interanl locus of control positively predicted on work motivation. The results indicated that openness to experience and neuroticism negatively influenced on work motivation. Also, we found that agreeableness, conscientiousness, and self-esteem positively predicted on job satisfaction. The resutls of path analysis showed that work motvation mediated the relationship between agreeableness, conscientiousness, and interanl locus of control and job satisfaction, respectively. Finally, implicaions of the results, limitations of this study, and directions of future research were discussed.

• Safety and Health at Work
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• v.14 no.4
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• pp.425-430
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• 2023

Background: It is acknowledged that legislation acts as a motivator for organizational action on psychosocial risks. Our study aims to provide evidence on the relationship between key occupational safety and health (OSH) policy principles and organizational action on work-related stress, and, in turn, with reported employee job demands and resources and their experience of work-related stress. We focus on Italy where specific legislation and practices on work-related stress were introduced in 2008 which are underpinned by these key OSH policy principles. Methods: Secondary analysis of the Italian samples from the employer ESENER-2 and employee 6th EWCS surveys was conducted, using path analysis in structural equation modeling (SEM) linking the two datasets. Results: We found a strong statistically significant relationship between OSH policy principles and organizational action on work-related stress (C.I. = .62-.78 p < .001). The existence of an organizational action plan on work-related stress was found to be significantly associated with more reported job resources (C.I. = .02-.24, p < .05) but these were not found to be significantly associated with less work-related stress. No significant association was found between having an organizational action plan for work-related stress and reported job demands. However, job demands were significantly related to reported work-related stress (C.I. = .27-.47, p < .001). Conclusions: Findings add support to the call for specific legislation on work-related psychosocial risks and highlight how an organizational OSH culture underpinned by key OSH principles, and awareness/competence development on psychosocial risk management can have a positive effect on organizational action. However, further support needs to be provided to organizations around developing primary prevention interventions at the organizational level with the aim of reducing job demands.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.159-166
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• 2004

Custom-tailored products are meant by the products having various sizes and shapes to meet the customer's different tastes or needs. Thus fabrication of custom-tailored products inherently involves inefficiency. To minimize this inefficiency, a new paradigm is proposed in this work. In this paradigm, different parts are grouped together according to their sizes and shapes. Then, representative shape of each group is derived and it will be used as the work-piece from which the parts in the group are machined. Once a new product is ordered, the optimal work-piece is selected through making similarity comparisons of new product and each representative shape. Then an effective NC tool-path is generated to machine only the different portions between the work-piece and the ordered product. The efficient machining conditions are also derived from this shape difference. By machining only the different portions between the work-piece and the ordered product, it saves time. Similarity comparison starts with the determination of the closest pose between two shapes in consideration. The closest pose is derived by comparing the ray distances while one shape is virtually rotated with respect to the other. Shape similarity value and overall similarity value calculated from ray distances are used for grouping. A prototype system based on the proposed methodology has been implemented and applied to the grouping and machining of the shoe lasts of various shapes and sizes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.70-73
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• 2003

Custom-tailored products are meant by the products having various sizes and shapes to meet the customer's different tastes or needs. Thus fabrication of custom-tailored products inherently involves inefficiency. To minimize this inefficiency, a new paradigm is proposed in this work. In this paradigm. different paris are grouped together according to their sizes and shapes. Then, representative shape of each group is derived and it will be used as the work-piece from which the parts in the group are machined. Once a new product is ordered, the optimal work-piece is selected through making similarity comparisons of new product and each representative shape. Then an effective NC tool-path is generated to machine only the different portions between the work-piece and the ordered product. The efficient machining conditions are also derived from this shape difference. By machining only the different portions between the work-piece and the ordered product, it saves time. Similarity comparison starts with the determination of the closest pose between two shapes in consideration. The closest pose is derived by comparing the ray distances while one shape is virtually rotated with respect to the other. Shape similarity value and overall similarity value calculated from ray distances are used for grouping. A prototype system based on the proposed methodology has been implemented and applied to the grouping and machining of the shoe lasts of various shapes and sizes.

• Journal of the Korean Home Economics Association
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• v.37 no.2
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• pp.145-158
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• 1999

The purpose of this study is to investigate the relationship between work-family conflict and job-life satisfaction of married female workers. Two data sets were used in this study. Both data sets were gathered from structured questionnaires and time dairies. The first data set was collected from 370 married female production workers in 1995 and the second set was collected from 143 married female clerical workers in 1996. Job and life satisfaction were measured on 5-point Likert scale where 5= very unsatisfied and 5= very satisfied. The overact means for both groups were 2.97, 3.09 for job and life satisfaction respectively The findings of this study are; 1) Clerical workers have significantely higher job and life satisfaction than production workers. 2) Multivariate analysis reveal that work-family conflict is negatively related to job satisfaction while income is positively related to job satisfaction. 3) In the path analysis model, work-family conflict has a negative direct effect and indirect negative effect mediated through job satisfaction on life satisfaction. Job satisfaction and husband's division of housework have a positive direct effect on life satisfaction. However, total labor time has a negative indirect effect mediated through work-family conflict on life satisfaction and income huts a positive indirect effect mediated through job satisfaction on life satisfaction.