• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.25-28
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• 2003

The $\ulcorner$CIDEAR$\lrcorner$ model proceeds the following six steps : $\ulcorner$Decision Theory ＆ Evaluation Model$\lrcorner$, $\ulcorner$AR Decision ＆ Evaluation Model$\lrcorner$, $\ulcorner$Resource ＆ Performance Analysis Model$\lrcorner$, $\ulcorner$Cross Impact Assumption Model$\lrcorner$, $\ulcorner$Priority Oder Decision Model$\lrcorner$, and $\ulcorner$Efficiency Cause Analysis Model$\lrcorner$ - In this study, twenty-one R＆D projects of a leading company in electronic industry are selected to examine the usefulness of the constructed $\ulcorner$CIDEAR$\lrcorner$ model. Simulation method, Excel, Lindo(Linear Interactive and Discrete Optimizer) and Team EC are used in this case study.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.21-24
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• 2001

This study is concerned with the development of efficient p-median approach to nondegenerate cell formation(CF) in group technology(GT) manufacturing. Unlike most of existing CF methodologies allowing degenerate cells or families that contains no parts or machines, this study attempts to find cell configuration where each machine cell contains at least two or more machines processing at least two or more parts so as to fully utilize the similarity in designing and processing parts. Nondegenerate CF seeks to minimize both the exceptional elements outside the diagonal block and the voids within the diagonal block. To find nondegenerate cells, a two-phase p-median methodology is proposed. In phase 1, the classical p-median model is implemented to find initial cells. In phase 2, bottleneck machines and parts are reassigned until no further degenerate cells and families are found. Test results on moderately medium-sized CF problems show the substantial efficiency of the proposed approach.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.1-14
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• 2009

This study empirically tests post-M&A performance through competitiveness variables based on extensive firm-based panel data over the past 26 years in the world steel industry. Different measures of profitability, productivity, efficiency, market share, and growth rate which are considered as critical factors of competitiveness are used in the analysis. In particular, this paper tries to separate M&A samples into two cases; horizontal integration (between steel makers) and vertical integration (between steel makers and iron ore suppliers/steel consuming firms). Merged firms show significant improvement in competitiveness relative to other individual firms in the steel industry.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.09a
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• pp.99-107
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• 1995

The Phase-type(PH) distribution, defined as a distribution of the time until the absorption in a finite continuous-time Markov chain state with one absorbing state, has been widely used for various stochastic modelling. But great computational burdens often make us hesitate to apply PH methods. In this paper, we propose a seemingly efficient approximation method for phase type distributions. We first describe methods to bound the first passage time distribution in continuous-time Markov chains. Next, we adapt these bounding methods to approximate phase-tupe distributions. Numerical computation results are given to verify their efficiency.

• Journal of the military operations research society of Korea
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• v.35 no.1
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• pp.95-103
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• 2009

HLA is the IEEE 1516 standard for the interoperation among heterogeneous simulations and RTI is a technology which provides a lower infrastructure service to interoperation. In this paper, we propose a Object-Oriented federate model architecture to enhance code reusability. It improves an efficiency of the system development process, and results in development time reduction and cost saving. It also is verified its practical effect through acting HLA certification on an software developed proposed architecture.

• Journal of the Korean Operations Research and Management Science Society
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• v.14 no.2
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• pp.161-161
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• 1989

This research examines the importance of IT training/education, present situation and possible suggestion for the successful training/education. The research method adopts a comparative analytical approach based on questionnaire survey responses from three work groups - managers, employees, and union representatives - drawn from five sample Korean banks. The evidence indicates that all three groups agree that IT improves banking efficiency and reduces job repetitiveness, but their job satisfaction level with IT-based work is surprisingly very low. The main reasons are mainly lack of training/education and poor user manuals. Also the research shows that most respondents would like to get further training/education to more adequately fit them for their jobs. Those from banks which invested in continuing training/education revealed more positive work attitudes and higher job satisfaction.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.1
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• pp.27-41
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• 2005

This paper considers identical parallel machine scheduling problem. Each job has a processing time. due date. weight and family type. If a different type of job is followed by prior job. a family setup is incurred. A two phased heuristic is presented for minimizing the sum of weighted tardiness. In the first phase. using roiling horizon technique. group each job into same family and schedule each family. In the second phase. assign each job to machines using schedule obtained in the first phase. Extensive computational experiments and comparisons among other algorithms are carried out to show the efficiency of the proposed algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.1
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• pp.1-16
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• 1994

In this paper, we try to raise the efficiency of PCB production by improving automated inserting process. This process is composed of part inserting sequence and feeder allocation problem. Until now, this problem is formulated by Traveling Salesman Problem (TSP) or Rural Postman Problem. They concerted more on parts(chips) inserting. But in this paper, we concentrate on Feeder. We formulate 0-1 Integer program (MP2) easier than TSP. This program can be solved by using LP Package (i. e. LINDO, GAMS etc). We propose Heuristic algorithm ISFA which guarantees a local optimum and often gives solution. We give some examples to prove ISFA algorithm.

• International Journal of Fluid Machinery and Systems
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• v.6 no.2
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• pp.49-55
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• 2013

Water lubricated guide bearing was newly released and has been applied to actual hydro turbines with vertical shaft. As a result, they can have not only high bearing performance but environmental advantages in meeting the demand for reducing river pollution by oil leakage from oil lubricated guide bearing. The PTFE composite guide bearing was tested by experimental equipment operated under conditions similar to those of actual hydro turbines. Circumferential and axial tilting bearing segments help to improve the bearing performance and efficiency due to low friction loss in the bearing system. Furthermore, bearing cooling systems could be eliminated and maintenance periods could be extended, thus the initial investment and operating costs of the hydroelectric power plant are reduced.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.211-214
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• 2003

Recently mobile SFA(Sales Force Automation) system makes rapidly progress specially in industries like insurance, manufacture, and distribution. However, there are some problems that information about products and trades is not promptly shared among sales agents or customers, since the current mobile SFA system has simply extended the existing systems for sales management. In order to improve these weaknesses, we introduce LBS(Location Based Service) and mobile P2P(Peer to Peer) service into the existing systems, then design and implement the enhanced system (or mobile SFA using them. Through this improvement, our system makes it possible for customers or sales agents to quickly share various information and increases the efficiency of sales activity by facilitating the competition and cooperation among sales agents and reducing time-cost.