• Journal of Korea Water Resources Association
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• v.55 no.6
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• pp.405-419
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• 2022

Flood frequency analysis commonly used to design the hydraulic structures to minimize flood damage includes uncertainty. Therefore, the most appropriate design flood within a uncertainty should be selected in the final stage of a hydraulic structure, but related studies were rarely carried out. The total expected cost function introduced into the flood frequency analysis is a new approach for determining the optimal design flood. This procedure has been used as UNCODE (UNcertainty COmpliant DEsign), but the application has not yet been introduced in South Korea. This study introduced the mathematical procedure of UNCODE and calculated the optimal design flood using the annual maximum inflow of hydroelectric dams located in the Bukhan River system and results were compared with that of the existing flood frequency. The parameter uncertainty was considered in the total expected cost function using the Gumbel and the GEV distribution, and the Metropolis-Hastings algorithm was used to sample the parameters. In this study, cost function and damage function were assumed to be a first-order linear function. It was found that the medians of the optimal design flood for 4 Hydroelectric dams, 2 probability distributions, and 2 return periods were calculated to be somewhat larger than the design flood by the existing flood frequency analysis. In the future, it is needed to develop the practical approximated procedure to UNCODE.

• The Science & Technology
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• v.29 no.2 s.321
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• pp.78-82
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• 1996

'별들의 전쟁'을 위해 개발한 최첨단기술을 이용하여 육지에서 멀리 떨어진 바다 밑에서 싼 비용으로 석유를 캐는 새로운 채유방법이 개발되었는가 하면 신기술을 도입하여 석유확인 매장량보다 더 많이 묻혀 있다고 알려진 오일샌드에서 싼 비용으로 석유를 생산하는 길이 열려 세계 석유자원계의 큰 관심을 모으고 있다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.29-38
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• 2018

This study aims to propose a method for the estimation of operational delay cost using transportation card data in bus accidents. Average operational delay time from bus accidents was surveyed among 12 bus companies through an interview method. Then, the operational delay cost was estimated using actual traffic accident data and transportation card data. Results showed that average loss time per bus accident was found to be 45 minutes. In addition, total occupancy of 659 was estimated for the accidents investigated using transportation card data, resulting a total loss time of 494.25 hours. An estimated operational delay cost was 186.9 thousand won per accident, which was 6.37% of social agency cost. The magnitude of this number implied that operational delay cost may have a significant impact on traffic accident cost if included.

• Journal of the military operations research society of Korea
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• v.36 no.2
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• pp.107-124
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• 2010

In order to estimate the life cycle expense of the weapon system acquisition from the first demand planning phase until the last disuse phase, we apply the reliable expense analysis method to the current situation in Korea by using the sensitivity analysis. We estimate the total cost of the weapon system acquisition by focusing on the most important variables such as exchange rate, and hence by strengthening the function of the existing expense analysis method, which is used to be simply recognized as a tool of cost reduction. Therefore, this study could make a contribution to the literature in this area, in terms of deriving the most cost-efficient method of acquisition by comparing the various estimated costs that result from the different alternatives of the weapon system acquisition.

• Proceedings of the Korea Association of Information Systems Conference
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• 1997.10a
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• pp.379-388
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• 1997

새로운 소프트웨어를 개발할 때에 이미 개발되어진 소프트웨어를 재사용 함으로써 얻을 수 있는 장점은 많다. 그 중에서 이미 검증된 소프트웨어를 사용함으로써, 오류가 감 소됨에 따라 고품질의 소프트웨어를 생산할 수 있고, 소프트웨어의 개발비용을 생산성을 향 상시킬 수 있다. 본 논문에서는 소프트웨어를 재사용 함으로써 소프트웨어 개발 시에 사용 되는 비용과 생산성을 상대 비교해서, 소프트웨어 개발에 소요되는 비용과 생산성의 관계를 나타내는 새로운 모형과 예를 제시하고 있다. 또한 소프트웨어 재사용시에 개발기관과 총인 월에 대한 생산성을 COCOMO 모형을 사용해 규명하고 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.419-421
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• 2011

물류에 있어서 공 컨테이너로 인한 물류비용 증가에 대해서 기존에 다양한 관심과 연구가 있었다. 하지만 기존 연구에서는 공컨테이너의 재배치나 예측에 관한 연구는 많았지만 선박회사의 공컨테이너 운영의 관리운영에 대한 부분은 부족한 면이 있었던 것이 사실이다. 따라서, 본 연구에서는 컨테이너가 총 운항비용의 20%를 상위하는 현재의 상황에서 공 컨테이너의 효율적인 이용이 비용절감에 중요한 부분임을 감안하여 목포 신항만을 이용하는 해운회사들의 효율적인 공컨테이너 운영 관리에 대하여 연구하였다.

• Journal of KIISE:Information Networking
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• v.32 no.4
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• pp.515-524
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• 2005

As the number of the mobile nodes (MNs) increases in the networks, the signaling traffic generated by mobility management for MNs will increase explosively, and such a phenomenon will probably affect overall network performance. In this paper, we propose a novel analytical approach using a continuous-time Markov chain model and hierarchical network model for the analysis on the signaling load of representative IPv6 mobility support Protocols such as Mobile IPv6 (MIPv6) and Hierarchical Mobile IPv6 (HMIPv6). According to these analytical modeling, this paper derives the various signaling costs, which are generated by an MN during its average domain residence time when MIPv6 and HMIPv6 are deployed under the same network architecture, respectively. In addition, based on these derived costs, we investigate the effects of various mobility/traffic-related parameters on the signaling costs generated by an MN under MIPv6 and HMIPv6. The analytical results show that as the average moving speed of an MN gets higher and the binding lifetime is set . to the larger value, and as its average packet arrival rate gets lower, the total signaling cost generated during its average domain residence time under HMIPv6 will get relatively lower than that under MIPv6, and that under the reverse conditions, the total signaling cost under MIPv6 will get relatively lower than that under HMIPv6.

• The Journal of the Convergence on Culture Technology
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• v.3 no.2
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• pp.21-30
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• 2017

This study investigated the total annual direct cost of cerebrovascular disease patients. For this study, 265 respondents who answered that they used more than one emergency, inpatient, and outpatient services for cerebrovascular disease during the year of 2012 among Korean medical panel investigators in 2012 were included. In general, patients with cerebrovascular disease responded to cerebrovascular disease among Korean medical panel respondents in 2012. Percentage of respondents using inpatient and outpatient services. Total direct cost was calculated. According to the results of the study, the per capita annual medical expenditure per person is about 561,934 won, 669,557 won for men and 448,696 won for women. In the case of health insurance subscribers, the per capita self burden due to cerebrovascular disease averaged 634,459 won and the medical benefit recipients 160,236 won. The average total direct cost of 265 people with cerebrovascular disease is about 162,165,690, 193,223,955 won for men and 129,486,685 for women. The total direct cost per person due to cerebrovascular disease was 183,095,125 won and the medical benefit recipient was 46,241,705 won. According to household income, the highest rate of 672,268 won in the third income group of the household income, and 108,970,650 won in the fifth income group, the lowest total direct cost of the patients with cerebrovascular disease.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.129-143
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• 2015

Increasing concerns on climate change and energy security accelerated policies to reduce green-house gas emission, especially from the transportation sector. Electric vehicle (EV) has been on the spotlight to deal with such environmental issue and V2G (Vehicle-to-Grid) technology began to draw attentions as an alternative to reduce ownership costs while contributing to an efficient and decentralized power grid. This study conducts a scenario analysis on total cost of ownership of EV under V2G scheme and compare with non-V2G EV and Internal Combustion Engine (ICE) vehicle. As result, V2G service is expected to provide an annual average profit of $210 to EV users willing to reverse flow its residual power in the battery. The profit from V2G service leaves a margin of $4,530 over operational lifetime, compared with $2,420 cost of charge for non-V2G EV. In summary, total cost of ownership of V2G-capable EV was 6.2% less than non-V2G EV and 10.2% higher than ICE vehicle. The results confirm a comparative economic advantage of operating EV under V2G scheme. Increased number of EVs with V2G service has shown to provide positive effects to power industry for valley filling in load distribution, thus, favorably increasing the overall economic feasibility.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.57-60
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• 2000

본 논문은 전송되는 멀티캐스트 트래픽에 의해 아크별로 발생하는 전송비용의 합을 최소화하는 멀티캐스트 경로 설정 알고리즘을 제시한다. 비용함수는 콘벡스 형태이고 멀티캐스팅이 요구되는 트래픽은 분할 전송이 가능하다고 가정한다. 가정에 의해 분할되는 트래픽은 여러 개의 다른 멀티캐스트 트리경로 상으로 전송이 가능하며 총 전송비용도 줄일 수 있다. 트래픽의 분할전송이 가능하여도 만일 비용함수가 선형이면 이는 Steiner 문제가 된다. 본 연구는 단일 멀티캐스트 트래픽 수요형태만을 고려한 본 연구자들의 수행연구［1］에 대한 계속연구로서 복수개의 멀티캐스트 트래픽 수요형태를 고려한다. 또한 본 연구의 결과에서 얻는 많은 멀티캐스트 트리 경로들 중 전송비용을 최소화하도록 하면서 제한된 k개의 트리 경로들을 선택하는 휴리스틱 방법을 소개한다. 본 연구는 ATM 망의 멀티캐스트 트래픽을 위한 가상경로 설계 또는 인터넷 환경의 다양한 멀티캐스트 트래픽을 위한 경로설정 등에 적용될 수 있다. 임의의 적용 망에 대한 결과를 포함한다.