• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.522-527
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• 2005

Rail network authority have to do the safety ensuring activities including the maintenance of railway facility, integrated performance verification between the facilities and related rolling stock and safety inspections, etc. When constructing the new lines or revising the conventional lines, full system commissioning should be done before the revenue service with railway operator. To develop the optimal full system commissioning model, the status of domestic and foreign railway facility and railway accidents are analysed and the problems of the safety management are derived. As one of countermeasures for the problems, the procedures and criteria for the full system commissioning are developed.

• 수산경영론집
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• 제44권1호
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• pp.81-90
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• 2013

This study is aimed to analyze economic effectiveness of the sea cucumber seed releasing program in Gyeongsangbuk-do region. Based on the surveyed data, the production value of released sea cucumber and the seed releasing program cost are estimated and compared to determine the economic validity of the sea cucumber seed releasing program. Results show that the B/C ratio, as an indicator of economic evaluation, is 2.0, indicating that the sea cucumber seed releasing program in Gyeongsangbuk-do region would be economically feasible under the current production and market conditions. Sensitivity analyses of main variables indicate that the economic effectiveness can be increased when the recapture rate would be increased and the seed price of sea cucumber would be decreased.

• 아태비즈니스연구
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• 제1권1호
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• pp.41-60
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• 2010

After over a decade of sluggish economic growth accompanied by massive fiscal stimulus in the 1990s, it remains an open question whether and how Japanese firms have restructured their operations, and whether these efforts have borne any fruit. Using a randomly selected sample of 300 firms from the Tokyo Stock Exchange, we collect all restructuring announcement in the FY 2000-2001 (April 2000-March 2002) period. Our results are striking in that while we find that firms engaging in restructuring of various sorts display improved earnings in the period following the restructuring announcement, shareholders do not appear to benefit at the time of the restructuring announcements.

• 산업경영시스템학회지
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• 제32권4호
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• pp.63-71
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• 2009

The traditional portfolio optimization problem is to find an investment plan for securities with reasonable trade-off between the rate of return and the risk. The seminal work in this field is the mean-variance model by Markowitz, which is a quadratic programming problem. Since it is now computationally practical to solve the model, a number of alternative models to overcome this complexity have been proposed. In this paper, among the alternatives, we focus on the Mean Absolute Deviation (MAD) model. More specifically, we developed an algorithm to obtain an optimal portfolio from the MAD model. We showed mathematically that the algorithm can solve the problem to optimality. We tested it using the real data from the Korean Stock Market. The results coincide with our expectation that the method can solve a variety of problems in a reasonable computational time.

• 한국철도학회논문집
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• 제10권1호
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• pp.34-38
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• 2007

Rail network authority have to do the safety ensuring activities including the maintenance of railway facilities, integrated performance verification between the facilities and related lolling stock and safety inspections, etc. When constructing the new lines or upgrading the conventional lines, full system commissioning should be done before the revenue service with railway operator. To develop the optimal full system commissioning model, the status of domestic and foreign railway facilities and railway accidents are analysed and the problems of the safety management are derived. As one of countermeasures for the problems, the procedures and criteria for the full system commissioning are developed.

• Journal of Information Technology Applications and Management
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• 제9권4호
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• pp.151-164
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• 2002

This paper predicts how mobile Internet portal services will go ahead and what contents will be needed at the portal site. Mobile Internet interface needs to be concise and compressed because of the size of terminals Thus mobile internal service wants integrated portal service We study the service strategy for mobile internet portal Service according to the product life cycle Many Korean people who have used 'wired and fixed' Internet services and mobile phones want the mobile Internet portal to provide many attractive functions and high quality of service Thus we consider the current Korean mobile Internet service as the maturity phase of its life cycle The maturity phase needs the strategy of diversifying and focusing on, thus we recommend the hub portal model for Korean mobile Internet service, In this paper, we survey contents of mobile Internet portal service as a case study. With the result of the analysis, we present the promising contents as follows: video conference service, financial service, stock trading service, traffic information service, location map service, emergency rescue service, and so on.

• Industrial Engineering and Management Systems
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• 제7권1호
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• pp.44-50
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• 2008

Focusing on the exponential smoothing method equivalent to (1, 1) order ARMA model equation, a new method of estimating smoothing constant using exponential smoothing method is proposed. This study goes beyond the usual method of arbitrarily selecting a smoothing constant. First, an estimation of the ARMA model parameter was made and then, the smoothing constants. The empirical example shows that the theoretical solution satisfies minimum variance of forecasting error. The new method was also applied to the stock market price of electrical machinery industry (6 major companies in Japan) and forecasting was accomplished. Comparing the results of the two methods, the new method appears to be better than the ARIMA model. The result of the new method is apparently good in 4 company data and is nearly the same in 2 company data. The example provided shows that the new method is much simpler to handle than ARIMA model. Therefore, the proposed method would be better in these general cases. The effectiveness of this method should be examined in various cases.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.1258-1261
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• 2015

재고관리 시스템이란 기업 활동에서 상품의 구입, 보유, 판매, 발송 등의 여러 원활한 활동을 하기 위해 상품의 흐름을 종합적으로 관리하는 시스템이다. 현재 많은 중소기업에서 바코드를 이용한 재고관리 시스템을 사용하고 있다. 바코드를 이용한 재고관리 시스템은 바코드의 인식거리가 50cm, 인식 속도가 대략 4초 정도 된다. 이러한 성능 때문에 입고 와 출고 부분에서 수작업으로 진행되어 많은 인력 소모가 되고 있다. 따라서 본 논문에서는 바코드에 비해 인식 거리, 인식 속도가 월등히 좋은 RFID 시스템을 이용하여 입고와 출고를 하고, 불필요한 인력 소모를 감소하여 효율적인 재고관리가 이루어지도록 연구하고자 한다.

• 산업경영시스템학회지
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• 제23권54호
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• pp.37-44
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• 2000

This study is focused on confirmation of the usefulness of EVA through the empiritical test of it which is used in practical business as the new performance measures of the VBM(value based management). The results of test are as followed : We could confirm the possibility that the EVA per share could be used as the useful performance measure as it shows the positive relation with the stock prices. The explanatory power showed especially higher than any other cases if the EPS shows positive and the EVA per share shows positive. When we interpret this study, we must keep in mind that the magnitude of the EVA is very different from by organs of publication in our country. Accordingly, the study to confirm the usefulness of EVA must be basically limited. Therefore, to get the useful result through the study related with the EVA, the publication of the trustful EVA must be proceeded by unified standard.

• International Journal of Railway
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• 제3권1호
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• pp.34-37
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• 2010

In recent, the railway system consists of subsystems as rolling stock and infrastructures as signaling, telecommunication, power supply, overhead contact and platform screen door, etc. Furthermore, each subsystem has complicated interface so as not to understand these relationship. Consequently, to operate the railway system continuously with required safety and availability, the failure data should be corrected and analyzed systematically during operation. To achieve this object effectively, this paper presents the method which is evaluating the operational risk quantitatively using failure data, and selecting the critical equipment. Following this analysis, the improvement plan is established and applied to reduce the operational risk on system or equipment. From this study, the critical equipments of system could be determined and prioritized by risk analysis. Also, the effective maintenance to prevent critical failure could be implanted by this suggested methodology.