• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.6
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• pp.347-353
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• 2003

In models of imperfect competition of deregulated electricity markets, the key task is to find the Nash equilibrium(NE). The approaches for finding the NE have had two major bottlenecks: computation of mixed strategy equilibrium and treatment of multi-player games. This paper proposes a payoff matrix approach that resolves these bottlenecks. The proposed method can efficiently find a mixed strategy equilibrium in a multi-player game. The formulation of the m condition for a three-player game is introduced and a basic computation scheme of solving nonlinear equalities and checking inequalities is proposed. In order to relieve the inevitable burden of searching the subspace of payoffs, several techniques are adopted in this paper. Two example application problems arising from electricity markets and involving a Cournot and a Bertrand model, respectively, are investigated for verifying the proposed method.

• Journal of the Korea Safety Management & Science
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• v.7 no.1
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• pp.179-198
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• 2005

The purpose of this study is to propose a strategic approach to improve firms competitive advantages by selecting main business body and business sector at the same time. In this study the strategy of an efficient business model for joint logistics is suggested by means of searching for a joint program. The methods applied to this study were literature survey, questionnaire and internet information as well as case studies on advanced domestics and foreign logistics enterprises. The research scope of this study has focused on the joint logistics of SMEs being in the DVD(Digital Video Disk) industry sector. The results of this study are shown as follows ; first, in short terms, main business operating body has, second, in long terms, logistics operating enterprise has a direct effect on the joint logistics operation strategy of the DVD(Digital Video Disk) industry in Korea. The conclusion of this study shows that this method as a model of consequence to increase the joint logistics implementation successfully.

• Journal of Information Processing Systems
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• v.16 no.1
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• pp.210-223
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• 2020

Since constrained optimization algorithms are easy to fall into local optimum and their ability of searching are weak, an improved symbiotic organisms search algorithm with mixed strategy based on adaptive ε constrained (ε_SOSMS) is proposed in this paper. Firstly, an adaptive ε constrained method is presented to balance the relationship between the constrained violation degrees and fitness. Secondly, the evolutionary strategies of symbiotic organisms search algorithm are improved as follows. Selecting different best individuals according to the proportion of feasible individuals and infeasible individuals to make evolutionary strategy more suitable for solving constrained optimization problems, and the individual comparison criteria is replaced with population selection strategy, which can better enhance the diversity of population. Finally, numerical experiments on 13 benchmark functions show that not only is ε_SOSMS able to converge to the global optimal solution, but also it has better robustness.

• Journal of Korean Library and Information Science Society
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• v.31 no.2
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• pp.279-302
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• 2000

This study is to develop a new automatic system for the Korean thesaurus browser by which we can automatically control all the processes of searching queries such as, representation, generation, extension and construction of searching strategy and feedback searching. The system in this study is programmed by Delphi 4.0(PASCAL) and consists of database system, automatic indexing, clustering technique, establishing and expressing thesaurus, and automatic information retrieval technique. The results proved by this system are as follows: 1)By using the new automatic thesaurus browser developed by the new algorithm, we can perform information retrieval, automatic indexing, clustering technique, establishing and expressing thesaurus, information retrieval technique, and retrieval feedback. Thus it turns out that even the beginner user can easily access special terms about the field of a specific subject. 2) The thesaurus browser in this paper has such merits as the easiness of establishing, the convenience of using, and the good results of information retrieval in terms of the rate of speed, degree, and regeneration. Thus, it t m out very pragmatic.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.98-105
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• 2011

Reduced complexity codebook searching for Quantized Equal Gain Transmission(QEGT) is proposed over MIMO-OFDM systems. QEGT codebook is divided into M groups of Q index members. Each group has a representative index. At the 1st stage only the representative indices are searched then the best index is selected. At the 2nd stage the optimum index is determined only among the group of the selected representative index. This strategy reduces the overall index search algorithm comparing to the conventional methods. Monte-Carlo simulation shows that the searching complexity is reduced, but the link-level performance is still almost the same as the conventional methods when the number of transmission antennas are 3 to 7.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.889-898
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• 2013

The shortest-path searching algorithm must not only find a global solution to the destination, but also solve a turn penalty problem (TPP) in an urban road transportation network (URTN). Although the Dijkstra algorithm (DA) as a representative node-based algorithm secures a global solution to the shortest path search (SPS) in the URTN by visiting all the possible paths to the destination, the DA does not solve the TPP and the slow execution speed problem (SEP) because it must search for the temporary minimum cost node. Potts and Oliver solved the TPP by modifying the visiting unit from a node to the link type of a tree-building algorithm like the DA. The Multi Tree Building Algorithm (MTBA), classified as a representative Link Based Algorithm (LBA), does not extricate the SEP because the MTBA must search many of the origin and destination links as well as the candidate links in order to find the SPS. In this paper, we propose a new Link-Based Single Tree Building Algorithm in order to reduce the SEP of the MTBA by applying the breaking rule to the LBA and also prove its usefulness by comparing the proposed with other algorithms such as the node-based DA and the link-based MTBA for the error rates and execution speeds.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.2
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• pp.180-187
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• 2018

Corrugated bulkhead has been adopted for cargo tank bulkheads of commercial vessels such as bulk carriers, product oil carriers and chemical tankers. It is considered that corrugated bulkhead is a preferred structural solution, compared to the flat stiffened bulkhead, due to several advantages such as lower mass, easier maintenance and smaller corrosion problems. Many researches to find the optimum shape of corrugated bulkhead have been mostly carried out for bulk carriers. Compared to corrugated bulkheads of bulk carriers, ones of chemical tankers are more complicated since they are composed of transverse and longitudinal bulkheads, and they are made of higher priced materials. The purpose of this study is the development of minimum weight design method for corrugated bulkhead of chemical tankers. Evolution strategy is applied as an optimization technique. It has been verified from many researches that evolution strategy searches global optimum point prominently by using multi-individual searching technique. Multi-individual searching methods need excessive time if they connect to 3-D finite element model for repetitive structural analyses. In order to resolve this issue, 2-D beam element connected to deck and lower stool is substituted for a corrugated structure in this study. To verify the reliability of the structural responses by idealized 2-D beam model, they have been compared with ones by 3-D finite element model. In this study, optimum design for corrugated bulkhead of 30 K chemical tanker has been carried out, and the results by developed optimum design program have been compared with design data of existing ship. It is found out that optimum design is about 9% lighter than one of existing ship.

• Management & Information Systems Review
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• v.18
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• pp.41-67
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• 2006

Value Creation issue for customers is emerging from the college education. Most colleges are facing to cope with over-supplied education facility problems against reducing population to apply to enter universities/colleges. The best way to overcome those problems might be to implement the Customer Satisfaction Management Strategy as if they were private firms for making profit. The main purpose in this study is to provide guidelines for CS strategy with a private college. It is focused on designing research plans and searching CS index. The process of this study is as follows; - Introduced the value creation strategy for customers with private colleges. - Proposed the CS management which is very important for enhancing competitive power - Evaluate various models to measure service quality and CSI for college service. - Provided some guidelines to research design of CS according to 6 customer categories. - Proposed some methodologies to apply a service quality measurement model. - Suggested a revised model from SERVPERF to adapt with college customers satisfaction. The result from this study showed that Customer Satisfaction Management would be the most important strategy to cope with confronting difficulties for private college and the revised model from SERVPERF would be an alternative solution. Further study is essential to assure the suggested model is valuable for private colleges because empirical test has not completed yet.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.720-723
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• 1997

This paper presents a cooperative control method for multiple robots. This method is based on local sensors. The proposed method integrates all information obtained by local perception through a set of sensors and generates commands without logical conflicts in designing control logic. To control multiple robots effectively, a global control strategy is proposed. These methods are constructed by using AND/OR logic and transition firing sequences in Petri nets. To evaluate these methods, the object-searching task is introduced. This task is to search an object like a box by two robots and consists of two sub-tasks, i.e., a wall tracking task and a robot tracking task. Simulation results for the object-searching task and the wall tracking task are presented to show the effectiveness of the method.

• Culinary science and hospitality research
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• v.23 no.6
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• pp.57-69
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• 2017

In this quantitative research, it was enhanced to understand the impact of intrinsic motivation on creative process engagement by examining the significant role of psychological safety on intrinsic motivation. These relationships were examined by targeting the employees working full-time for five star deluxe hotels. Total number of 230 responses had been collected out of 250 cases requested and he number of 213 cases was used for the final analysis. The data were analyzed using structural equation modeling with SPSS 19.0 and AMOS 7 software program. The results suggested that psychological safety is significantly associated with intrinsic motivation. Furthermore, the hotel employees' problem identification, information searching & coding, and idea generation are affected by intrinsic motivation. That is, intrinsic motivation plays a significant role for each sub-factors of creative process engagement in the hotel industry. The theoretical and practical implications of these findings are established and related suggestion for formulating marketing strategy is well discussed.