• The KIPS Transactions:PartD
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• v.19D no.3
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• pp.221-228
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• 2012

This paper proposes a new forging work-in-process control system that guarantees independency of a specific device and provides cost-effectiveness. Until now, much research has been studied on improving the process productivity through efficient work-in-process or inventory controls. Especially, incorporating various IT technologies such as barcode, RFID, and image recognition has been done. However, those approaches cause many problems due to the characteristics of the forging work-in-process control environment. To overcome the limitations of the existing approaches, this paper proposes a novel forging work-in-process control system. The proposed system in this paper identifies and precisely manages positions of objects by using GPS information of smart mobile devices. Therefore, identification tags as well as specific devices for reading the tags do not been required. It resolves the problems of the previous approaches and enhances the productivity of the overall forging work-in-process control process.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.479-482
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• 2011

This paper proposes a design of a ship backbone network-based on the survival and efficiency of the ship network. Currently IEC operates the standard ship network, a standard specification "IEC 61162-410 maintains the operation of the network. IEC 61162-410 offers a high stability of the ship network by using terminal equipment. But current studies are incomplete because it has been assumed that the ship's network will operate at double its current capacity. This paper analyzes the double ship backbone topology for an organization and then will summarise the minimum costs required to implement the ship backbone topology using an ILP. Also, we present an effective traffic assignment technique that uses an ILP, metaheuristic, heuristic algorism-based underlying the ship backbone network. The results by experimenting the design of the network confirmed a greter efficiency, stability and cost-effectiveness of the ship network.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.605-616
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• 2014

The purpose of this study is to analyze transport efficiency of each of the 17 urban railway lines being operated by national public agencies using Data Envelopment Analysis (DEA) and to seek strategies for improving efficiency of the urban railway system. The study identified the economies of scale derived from these values of efficiency and examined the effects on cost for free ride loss and profit of transport by the fare system as the external factor. At the time, Transport profits are estimated by two production factors such as the number of vehicles and service frequency derived from multiple regression. Finally, the measures to improve the efficiency were presented in terms of profitability in the national urban railway line by applying the values of efficiency derived from DEA to multidimensional scaling (MDS).

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.447-450
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• 2010

IT 기술의 혁신과 저변 확대로 모든 조직들이 정보시스템 구축을 통해 업무의 성과창출 및 생산성 제고 등의 효과를 거두고 있으며, 이에 정보시스템의 규모는 점점 방대해지고 투자비용은 지속적으로 증대하고 있다. 상대적으로 정보시스템에 대한 유지 관리 부문의 비용도 급증하고 효율성 측면에서도 문제가 되고 있는 실정이다. 이에 본 연구는 특정기관의 정보시스템 유지 관리 부문 중에서도 특히 아웃소싱에 대한 문제점과 비효율성을 진단하고 개선점을 도출하여 효율화 방안을 제시하였다.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.527-534
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• 2012

In order to achieve sustainable growth and gain competitive advantages business performance should be monitored regularly by a company. In the port industry container terminal operators are facing growing competition. A large scale of new container terminals are constructed and the number of new container terminal operators are increasing. Container shipping lines are gaining bargaining power against terminal operators in terms of negotiating terminal usage. The competitive environments result in reduced cargo handling charges and poor financial performance of container terminal operators. It becomes very important to examine how efficiently container terminal operators are operating their terminals and how to improve their performance. This paper investigates the measurement efficiency for container terminal operators in Korea using Data envelopment analysis(DEA) of DEA-CCR and DEA-BCC Model. This paper finds out which container terminal operators are inefficient and how to improve their management efficiency.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.111-114
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• 2021

기업은 IT 를 일종의 자산으로 판단하여 IT 센터를 직접 구축하고 온프레미스 형태의 시스템을 운영했다. 그러나 경영 환경의 변화가 빨라지면서 IT 부문의 비용 효율성에 대한 압박도 커지고 있다. 클라우드 컴퓨팅을 도입하면 IT 자원을 효율적으로 활용하고 사용한 만큼 비용을 지불할 수 있어 IT 자원의 효율화가 가능하다. 하지만 무작정 클라우드로 옮기는 방식으로 인해 시스템 복잡성이 오히려 증가하고, 관리포인트 증가로 시스템 안전성을 해치는 상황이 벌어지고 있는 것도 현실이다. 신규 서비스 제공 시 기존 시스템 안전성을 해치지 않으면서 IT 자원의 효율적인 활용도 고려하는 방안으로 서비스 단위별 클라우드 컴퓨팅 도입을 검토하였다. 이 방법은 클라우드의 우수한 시스템을 사용하며, 실시간 오케스트레이션이 가능하고, 보안도 우수하다고 볼 수 있다. 기존 인프라를 유지하면서 클라우드 컴퓨팅을 구현한 하이브리드 방식으로 시스템 구축 결과 중단 없는 시스템 운영이 가능하였으며, 보안도 보다 강화된 결과를 얻었다. 향후 시스템 구축 시 온프레미스의 경우 서비스 단위로 클라우드 서버를 병행 운영한다면 운영효율성 뿐 아니라 기능성까지 만족시킬 수 있을 것으로 기대한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.935-944
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• 2023

In this study, the Inverse-type (: Inverse-Exponential, Inverse-Rayleigh) life distribution, which is known to be suitable for reliability research, was applied to a software development cost model based on finite failure NHPP(: Nonhomogeneous Poisson Process), and then the attributes that determine the model's performance were analyzed. Additionally, to evaluate the efficiency of the model, it was compared with the Goel-Okumoto basic model. The performance of the model was analyzed using failure time data, and MLE (: Maximum Likelihood Estimation) was applied to calculate the parameters. In conclusion, first, as a result of analyzing m(t), which determines the development cost, the Inverse-Exponential model was efficient due to its small error in the true value. Second, as a result of analyzing the release time along with the development cost, the Inverse-Rayleigh model was confirmed to be the best. Third, as a result of comprehensive evaluation of the attributes (m(t), cost, and release time) of the proposed model, the Inverse-Rayleigh model had the best performance. Therefore, if software developers can effectively utilize this research data in the early process, they will be able to proactively explore and analyze attributes that affect cost.

• The Optical Journal
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• s.122
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• pp.14-17
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• 2009

국내 프린팅 시장은 지난해 말부터 이어진 경기 불황 한파로 인해 전년대비 15%이상 수요가 감소할 전망이다. 긴축 경영과 맞물려 기업 고객들은 '출력 비용 절감'을 가장 큰 화두로 삼고 노력 중이다. 이 같은 시장 요구에 의해 '비용 절감'과 '업무 효율성 증진' 등 두 마리 토끼를 동시에 잡을 해결책으로 통합문서출력관리서비스(MPS)가 본격적으로 자리잡을 것으로 기대된다. 또한 전체 출력기기 시장에서 복합기의 비중은 지속적으로 높아져 2008년 복합기 비중 71%에서 2012년 82%까지 늘어날 것으로 전망된다.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.113-122
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• 2008

This study extended Park et al.(2007c), which analyzed the efficiency of a hierarchical transit network, showed the result of a real data, and analyzed its applicability. Operating cost was estimated using a model which was established in this study, and minimum transit demand was derived from the operating cost. The minimum transit demand value is just a sample calculation, thus it varies by many inside and outside factors of the model. Looking at the inside of the model, operating cost and travel speed are major factors, and the possibility of introducing urban subway becomes high when the operating cost of the transit system is low and its travel speed is high. As far as the outside factors are concerned, according to the analysis on the network structure, transit demand, and transit mode share, the minimum transit demand value which was derived in this study will be the maximum value among the possible values. In the feasibility study, the benefit is likely to be overestimated and the cost is likely to be underestimated than those of this study. It could be concluded that the methodology of a feasibility study is appropriate in the field standard. This study analyzed the efficiency of introduction of urban subway using analytical approach, thus has many shortcomings and limitations. However the practical approach, like feasibility study, has some limitations as well. This study could be a basis on establishing an analysis framework that is more accurate and reasonable by comparing analytical approach and practical approach.

• Environmental and Resource Economics Review
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• v.15 no.4
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• pp.673-692
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• 2006

In order to test for the dynamic optimality condition for the use of nonrenewable resource, it is necessary to estimate the shadow value of the resource in situ. In the previous literatures, a time series for in situ price has been derived either as the difference between marginal revenue and marginal cost or by differentiating with respect to the quantity of ore extracted the restricted cost function in which the quantity of ore is quasi-fixed. However, not only inconsistent estimates are likely to be generated due to the nonmalleability of capital, but the estimate of marginal revenue will be affected by market power. Since firms will likely fail to minimize the cost of the reproducible inputs subject to market prices under realistic circumstances where imperfect factor markets, strikes, or government regulations are present, the shadow in situ values obtained by estimating the restricted cost function can be biased. This paper provides a valid methodology for checking the dynamic optimality condition for a nonrenewable resource by using the input distance function. Our methodology has some advantages over previous ones: only data on quantities of inputs and outputs are required; nor is the maintained hypothesis of cost minimization required; adoption of linear programming enables us to circumvent autocorrelated errors problem caused by use of time series or panel data. The dynamic optimality condition for domestic coal mining does not hold for constant discount rates ranging from 2 to 20 percent over the period 1970~1993. The dynamic optimality condition also does not hold for variable rates ranging from fourth to four times the real interest rate.