• Journal of Ship and Ocean Technology
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• v.8 no.2
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• pp.41-60
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• 2004

Ship design process requires lots of complicated analyses for determining a large number of design variables. Due to its complexity, the process is divided into several tractable designs or analysis problems. The interdependent relationship requires repetitive works. This paper employs collaborative optimization (CO), one of the multidisciplinary design optimization (MDO) techniques, for treating such complex relationship. CO guarantees disciplinary autonomy while maintaining interdisciplinary compatibility due to its bi-level optimization structure. However, the considerably increased computational time and the slow convergence have been reported as its drawbacks. This paper proposes the use of an approximation model in place of the disciplinary optimization in the system-level optimization. Neural network classification is employed as a classifier to determine whether a design point is feasible or not. Kriging is also combined with the classification to make up for the weakness that the classification cannot estimate the degree of infeasibility. For the purpose of enhancing the accuracy of a predicted optimum and reducing the required number of disciplinary optimizations, an approximation management framework is also employed in the system-level optimization.

• Journal of Ocean Engineering and Technology
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• v.36 no.1
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• pp.41-49
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• 2022

With the advancement of intelligent vehicles and unmanned systems, there is a growing interest in underwater surveys using autonomous marine vehicles (AMVs). This study presents an automated planning strategy for a long-term survey mission using a fleet of AMVs consisting of autonomous surface vehicles and autonomous underwater vehicles. Due to the complex nature of the mission, the actions of the vehicle must be of high-level abstraction, which means that the actions indicate not only motion of the vehicle but also symbols and semantics, such as those corresponding to deploy, charge, and survey. For automated planning, the planning domain definition language (PDDL) was employed to construct a mission planner for realizing a powerful and flexible planning system. Despite being able to handle abstract actions, such high-level planners have difficulty in efficiently optimizing numerical objectives such as obtaining the shortest route given multiple destinations. To alleviate this issue, a widely known technique in operations research was additionally employed, which limited the solution space so that the high-level planner could devise efficient plans. For a comprehensive evaluation of the proposed method, various PDDL-based planners with different parameter settings were implemented, and their performances were compared through simulation. The simulation result shows that the proposed method outperformed the baseline solutions by yielding plans that completed the missions more quickly, thereby demonstrating the efficacy of the proposed methodology.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.1124-1128
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• 2005

In this paper, a plan-coordination architecture is proposed for multi-agent control in the fractal manufacturing system (FrMS). A fractal in FrMS is a set of distributed agents whose goal can be achieved through cooperation, coordination, and negotiation with other agents. Since each agent in the FrMS generates, achieves, and modifies its own plan fragments autonomously during the coordination process with other agents, it is necessary to develop a systematic methodology for the achievement of global plan in the manufacturing system. The heterarchical structure of the FrMS provides a compromised plan-coordination approach, it compromise a centralized plan-generation/execution (which mainly focuses on the maximization of throughput) with a distributed one (which focuses on the autonomy of each module and flexibility of the whole system). Plan-coordinators in lower level fractal independently generate plan fragments according to the global plan of higher level fractal, and plan-coordinators in higher level fractal mediate/coordinate the plan fragments to enhance the global performance of the system. This paper assumes that generation method of the plan fragments and the negotiation policy of the fractal is achieved by a simple process, and we mainly focuses on the information exchanging and distributed decision making process to coordinate the combinations of plan fragments within a limited exchange of information.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.129-139
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• 2020

The objective of this study is twofold: first, to investigate how organizations encourage factors that have an impact on employees' entrepreneurial behavior from employee's perspectives and experiences; and second, to discover how and why employees behave entrepreneurially within the organization. A case study method is considered as an appropriate approach to scrutinize intrapreneurial behavior because it principally concentrates on an investigation into a contemporary organizational phenomenon and context concerning entrepreneurial activities in-depth within its real situation. In data collection, an Asian multinational retail company was selected. Semi-structured interviews were carried out with 24 executive-level employees who had been working in various departments for more than 5 years. Each in-depth interview lasts for a duration of 40 to 60 minutes. The results reveal several understandings into the combination of individual-level and organizational-level factors that promote the intrapreneurial behavior and activities of the established firm in the context of Thailand. In this regard, six factors have been found as the key determinants that make an impact on innovativeness, proactiveness, and risk-taking behaviour of the employees. Those factors are personal preference, organizational stability, management support, compensation, reward system, teamwork, quality of relationship with colleagues, work autonomy and the quality of relationship with the superiors.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.4
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• pp.843-853
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• 2017

In the case of electronic payment, the obligation to use the certificate-based authentication was abolished. As Fin-tech service providers gain autonomy, various authentication methods are provided. SMS, ARS, PIN, Text-passwords, Fingerprints are popular authentication methods in the mobile Fin-tech services. In this study evaluate the usability and security of authentication methods in a unified mobile environment. We evaluate the usability through SUS and interview. Also we evaluate the security level of authentication methods through NIST guideline. At the result of the usability evaluation, Fingerprint authentication method had been determined as the highest usability, also Fingerprint authentication method had been determined as the safest authentication method by obtaining Security Level 4.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.2
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• pp.167-176
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• 2024

Lip-reading is the task of inferring the speaker's utterance from silent video based on learning of lip movements. It is very challenging due to the inherent ambiguities present in the lip movement such as different characters that produce the same lip appearances. Recent advances in deep learning models such as Transformer and Temporal Convolutional Network have led to improve the performance of lip-reading. However, most previous works deal with English lip-reading which has limitations in directly applying to Korean lip-reading, and moreover, there is no a large scale Korean lip-reading dataset. In this paper, we introduce the first large-scale Korean lip-reading dataset with more than 120 k utterances collected from TV broadcasts containing news, documentary and drama. We also present a preprocessing method which uniformly extracts a facial region of interest and propose a transformer-based model based on grapheme unit for sentence-level Korean lip-reading. We demonstrate that our dataset and model are appropriate for Korean lip-reading through statistics of the dataset and experimental results.

• The Journal of the Korean dental association
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• v.54 no.5
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• pp.374-383
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• 2016

The purpose of this study is to analyze the determinants of pay satisfaction of dental employees. The questionnaire used in this study consists of personal characteristics, characteristics of workplace, administration of pay, Pay satisfaction questionnaire (PSQ). PSQ was translated, and backward translation into korean was implemented. A pilot test was conducted with 25 dental employees to complete the questionnaire. Survey was conducted from February to July in 2015, receiving 323 valid responses. Anova or t-test was conducted with categorized characteristics, by calculating pay satisfaction scores. Principal factor analysis which is an exploratory factor analysis was conducted to investigate the consistency of pay satisfaction. Multiple regression analysis was conducted to investigate how much effect the variables have on pay satisfaction. The result of principal factor analysis showed that pay satisfaction consists of 3 factors which are 'paying system', 'pay level', 'benefits'. 'Pay raise' which was one of 4 factors of original PSQ was not the factor of pay satisfaction of dental employees. The result of analysis of characteristics showed that the scores of paying system between dental clinic and dental hospital had significant difference. The result of multiple regression analysis showed tendencies pay satisfaction increases when age and monthly income increases and whole career and the number of unit chairs decreases. Increasing the autonomy of employees and simplification of paying system would improve pay satisfaction efficiently. When age increases, the pay level increases because of the seniority-based pay structure, and this leads to the higher satisfaction. The higher amount of pay leads to higher satisfaction. The expectation over pay increases relatively higher than the increase of pay level and this leads to the less satisfaction. When the number of unit chairs is fewer, the workplace is smaller, so the employees have more autonomy, and this leads to higher satisfaction.

• Journal of Distribution Science
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• v.14 no.6
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• pp.65-73
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• 2016

Purpose - Recently, the management conditions of small independent retailers are getting worse everyday as large-scale marts and franchised convenience stores are increasing. The objective of this research is to find out the antecedents and consequences of cooperation in voluntary chain in order to enhance small independent retailer's competitiveness. Voluntary chains, also called affiliation or symbol groups, or allied group represent a high market shared in some European countries like Italy, France, and Germany. Nevertheless, there are still limitations in this research from academic fields. Drawing from network theory, the author investigates the relationship between antecedent factors in voluntary chain cooperation, such as participation benefits, justice of compensation, and autonomy in voluntary chain, and relationship specific asset. The author also attempts to examine the relationship between the relationship specific asset and cooperation of voluntary chain member shop and cooperation and consequence factors of voluntary chain cooperation, such as efficiency, group cohesiveness, and long-term relationship. Research design, data, and methodology - The author presented conceptual framework integrating the major antecedents and consequences of voluntary chain cooperation. The data were collected from 174 independent small retailers who joined K-voluntary chain. K-voluntary chain consists of small independent retailers. In accordance with their status, each entrepreneur associated with the voluntary group can own one or more outlets and can be a part of the life and the decision-making process of the group. This participation is not based on company turnover or on the number of outlets, but based on a one member, one vote system. To verify the research model and test hypotheses, the author carefully investigated the reliability, content validity, convergent validity, and discriminant validity of the proposed model. The data were analyzed by using SPSS 18.0 and AMOS structural equation modeling program. Results - The results of this study are as follows. First, as antecedent variables, participation benefits and justice of compensation have positive effect on the relationship specific assets of voluntary chain members. Second, voluntary chain members' relationship specific asset also directly related to the level of its cooperation to chain headquarter. Third, cooperation of voluntary chain member shop facilitates efficiency, group cohesiveness, and long-term relationship. Unexpectedly, there are no effect autonomy in voluntary chain to relationship specific asset. Conclusions - This research shows several theoretical and practical implications to both marketing scholars and marketers. In terms of theoretical implications, this study applies to network theory and network theory variables to explain the antecedent and consequence factors of cooperation in voluntary chain. From the point of view from business management, most of all, this study shows the way how to reinforce competitiveness of voluntary chain. Specifically, it is necessary for voluntary chain headquarter to give higher level of participation benefit and justice of compensation to its members. Second, the results also indicate what the consequence factors of cooperation in voluntary chain. In other words, to increase the level of marketing efficiency, group cohesiveness, long-term orientation in retail voluntary chain, and chain headquarter need to facilitate participants' cooperation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.4
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• pp.169-178
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• 2012

The aim of this study is to look into the influential factors on the care-workers-perceived job stress level according as the elderly-perceived satisfaction varies depending on care workers' organizational characteristic & attitudes toward work, and there's necessity of reducing their job stress. Hereupon, this study, targeting the care workers at domiciliary visit care centers in Seoul district, analyzed the influential factors of organizational factors consisting of the sub-factors, such as job autonomy, compensation, education and development, members' interrelationship, etc. on the perception level of job stress. As a result of analysis, it was found that the shorter their working hours, the more their salary, the more guaranteed their job autonomy, and the better their interrelationship is, the care workers at a domiciliary visit care center had a positive perception of job stress. Accordingly, the operators of domiciliary visit care centers are requested to have a lot more concerns for diverse forms of improvements which can not only improve care workers' working conditions, such as daily working hours and a pay level but also promote a sense of fellowship between members; in addition, it is hoped that the operators should improve the organizational environment so that care workers can freely carry out their assigned business with a sense of responsibility rather than relying on control and regulation.

• Journal of Korean Academy of Nursing Administration
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• v.9 no.4
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• pp.529-539
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• 2003

Purpose : The objective of this research is to explore the job satisfaction of clinical nurses by the rank of nurse staffing in order to provide effective management for nurses. Method : The research has been conducted on three hundred twenty nurses working at tertiary eight hospitals which were from 2nd rank of nurse staffing to 5th. rank of nurse staffing in Seoul, from August 1 to September 30 of 2003, through survey. For the experimental tools, used Park-Yoon's job satisfaction for nurses(1992) which was modified Stamp's job satisfaction test(1978). The acquired data were analyzed through SPSS program using descriptive method, $x^2$-test, ANCOVA, and LSD. Results : Overall job satisfaction of nurses showed fairly high level of 3.17; in the order of high score, 3.84 for interaction, 3.00 for autonomy, 2.63 for administration. Analysis based of the rank of nurse staffing showed that hospitals of 2nd rank and 3rd. rank of nurse staffing which were higher ratio of patient vs nurse were more satisfied with nurses' job satisfaction than other nurses who were 4th. rank and 5th. rank of nurse staffing. Conclusion : The result of this study revealed that hospital which was higher the rank of nurse staffing was more influenced of nurses' job satisfaction and especially interaction, administration and autonomy which were sub-category of job satisfaction were different among the ranks of nurse staffing.