• 한국국방경영분석학회지
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• 제23권1호
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• pp.138-150
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• 1997

The life-cycle of the K-1 tank has been 10 years simply applying that of the U.S. M-1 tank. Therefore, this paper is focused on determination of an economic life-cycle for the K-1 tanks. The current operation cost is adjusted by interest rate and the depreciation cost is applied in this study for more reliable estimation of the life-cycle cost. The Equivalent Annual Method is utilized and then various regression techniques are applied for deriving an effective economic life-cycle. The economic life-cycle of the K-1 tank results in 13 years in this study. considering 95% confidence interval, the life cycle of the K-1 tank is between 10.5 years and 15.5 years.

• 한국수자원학회논문집
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• 제35권2호
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• pp.187-194
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• 2002

하천유역 면적강우량 산정의 정확도를 개선하기 위하여 기존 강우관측자료의 통계적 특성을 이용한 강우관측망의 최적설계방법을 연구하였다. 최적설계를 위한 목적함수는 면적강우량의 추정오차 및 지점강우량 관측비용의 항으로 구성하고, 그 값이 최소인 관측망은 선정하였다. 통계f7파의 추정방법으로는 통계적 분산 산정방법인 크리깅 모형을 채택하였다. 비용은 강우관측소의 설치비와 연간운영 비론 적용하고, 오차항과 비용항의 통합에는 등치매개변수를 이용하였다. 연구된 최적설계방법을 댐 신설로 강우관측소 증설이 필요한 용담댐 유역에 적용하여, 대상유역의 최적 강우관측망을 제안하였다.

• 한국국방경영분석학회지
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• 제16권2호
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• pp.1-13
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• 1990

The life of an equipment depends upon its operating characteristics and physical environment factors. This paper presents the economic life length of 2 1/2 ton truck considering the operation terrains. For this specific research, the operation terrains are categorized into seacoast area, mountain area and plain area. To compute the life length, the method of equivalent annual cost is employed. The sample vehicles from each corresponding area are randomly selected from those vehicles whose ages exceed 9 years. This research finds the following results : (1) The life length operated at seacoast area is 9.75 years, (2) The life length operated at mountain area is 11.25 years, (3) The life length operated at plain area is 14 years. This research argues that the key factor such as characteristics of operating enviroment for allocation of operating and maintaining cost should be considered.

• 산업공학
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• 제12권3호
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• pp.414-423
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• 1999

A nuclear power plant requires a huge amount of initial investment and long construction lead time. As we expect that there may exist a relationship between investment and construction lead time, a number of researchers have reported that nearly a half of investments is incurred due to time factors such as the time value of money and inflation or escalation rates. Therefore, we investigated in this paper a relationship between the initial investment and the construction lead time of a nuclear power plant construction, and proposed a method for a trade-off analysis between the annual equivalent worth and the investment alternatives to reduce the construction lead time. Finally, we presented a real case to numerically explain the steps of the method presented in this paper.

• 한국조리학회지
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• 제11권3호
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• pp.121-137
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• 2005

Today's rapid industrialization and population concentration in cities lead to a vast economic growth, and consequently, people's increased desire of spending demands abundant and diverse food. As a result in Korea, annual food waste is 4.1 million tons (24.6% of household waste) and daily food waste amount to 11,397 tons which is equivalent to 1,400 loads of 8-ton truck. It is best to recycle toed waste as manure, forage, and fuel than reclamation but separate collection of food waste is very difficult by reason of water content. So only a little portion of food waste from large-scaled restaurants and cafeterias that handle food waste relatively well. requirement for recycling food wastes into forage and manure needless to say, reduction activity is best way. Therefore, large-scaled restaurants and cafeterias need to seek plans to minimize food resource waste thus reducing the cost and waste processing cost by implementing appropriate reduction program.

• 한국방사선학회논문지
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• 제17권1호
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• pp.79-90
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• 2023

본 논문은 원자력발전소(원전) 사고에 의한 조기사망의 사회적 비용을 추정하기 위해 조건부가치측정법(Contingent Valuation Method, CVM)을 이용하여 통계적 생명가치(Value of a Statistical Life, VSL)를 추정한다. VSL 추정치는 약 35억 5천만 원이다. 이에 세계 원전 역사상 발생한 모든 사고 사망자수 약 181만 명을 곱하여 추정한 사회적 비용은 1,952조 원으로서 한국의 2022년 실질 GDP에 비견되는 수준이다. 연평균 조기사망자수와 사회적 비용은 각각 26,000명과 28조 원이다. 1987~2021년간 세계 화력발전소의 사고와 대기오염물질 배출로 인해 발생한 조기사망의 사회적 비용 추정치는 26,919조 원인데, 이는 미국의 2021년 GDP 규모에 상당하는 규모로서 9조 원을 기록한 원전의 약 3,000배에 달한다. 2021년 한 해만 보더라도, 화력발전소의 사회적 비용은 1,075조 원에 달하지만, 원전은 2,920억 원에 불과하다. 한국의 경우, 2050 탄소중립 정책의 영향으로 재생에너지 발전 비중이 증가할 것이므로, 화력발전 대비 원자력발전 비중을 증가시키는 에너지믹스를 제안한다. 본 논문은 또한 효율적인 에너지 정책을 담보하기 위해 CVM을 이용한 VSL 추정 연구를 지속적으로 축적할 필요가 있음을 강조한다.

• 한국수소및신에너지학회논문집
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• 제33권3호
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• pp.247-254
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• 2022

Slush hydrogen containing liquid and solid hydrogen is expected to achieve zero boil-off by suppressing boil-off gas because heat of fusion for solid absorbe the heat ingress from atmosphere. In this paper, quantitative analysis on storage cost considering specific energy consumption between 1,000 m³ class liquid hydrogen storage system with re-liquefaction and slush hydrogen storage system during equivalent zero boil off period. Even though approximately 50% of total storage capacity should be converted into solid phase during the initial cargo bunkering, total energy consumption to convert into slush hydrogen is relatively 25% less than re-liquefaction energy for boil off hydrogen during zero boil off period. That's because energy consumption of slush phase change take up only 1.8% of liquefaction energy. moreover, annual revenue requirement including CAPEX, OPEX and electric cost for slush hydrogen storage could be more reduced approximately 32.5% than those of liquid hydrogen storage and specific energy storage cost ($/kg-H₂) could also be lowered by about 41.7% compared with liquid hydrogen storage.

• 한국기후변화학회지
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• 제7권3호
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• pp.217-229
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• 2016

Increased evidences reveal that the global climate change adversely affect on the environment. Smart grid system is one of the ways to reduce greenhouse gas emissions in the electricity generation sector. Since 2013, Korea Electric Power Corporation (KEPCO) has installed smart grid station in KEPCO office buildings. The goal of this paper is two folds. One is to quantify the reduction in greenhouse gas emissions through smart grid stations installed in KEPCO office buildings as a part of pilot project. Among components of smart grid stations, this research focused on the photovoltaic power system (PV) and energy storage system (ESS). The other is to estimate the reduction in greenhouse gas emissions when PV is applied on individual houses. Results show that greenhouse gas emissions reduce 5.8~11.3% of the emissions generated through the electricity usage after PV is applied in KEPCO office buildings. The greenhouse gas emissions reduction from ESS is not apparent. When PV of 200~500 W is installed in individual houses, annual greenhouse gas emission reduction in 2016 is expected to be approximately $2.2{\sim}5.4million\;tCO_2-eq$, equivalent to 6~15% of greenhouse gas emissions through the electricity usage in the house hold sector. The saving of annual electricity cost in the individual house through PV of 200 W and 500 W is expected to be 47~179 thous and KRW and 123~451 thousand KRW, respectively. Results analyzed in this study show the environmental effect of the smart grid station. In addition, the results can be further used as guidance in implementing similar projects.

• The Korean journal of internal medicine
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• 제33권6호
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• pp.1160-1168
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• 2018

Background/Aims: The Republic of Korea is a country where the hemodialysis population is growing rapidly. It is believed that the numbers of treatments related to vascular access-related complications are also increasing. This study investigated the current status of treatment and medical expenses for vascular access in Korean patients on hemodialysis. Methods: This was a descriptive observational study. We inspected the insurance claims of patients with chronic kidney disease who underwent hemodialysis between January 2008 and December 2016. We calculated descriptive statistics of the frequencies and medical expenses of procedures for vascular access. Results: The national medical expenses for access-related treatment were 7.12 billion KRW (equivalent to 6.36 million USD) in 2008, and these expenses increased to 42.12 billion KRW (equivalent to 37.67 million USD) in 2016. The population of hemodialysis patients, the annual frequency of access-related procedures, and the total medical cost for access-related procedures increased by 1.6-, 2.6-, and 5.9-fold, respectively, over the past 9 years. The frequency and costs of access care increased as the number of patients on hemodialysis increased. The increase in vascular access-related costs has largely been driven by increased numbers of percutaneous angioplasty. Conclusions: The increasing proportion of medical costs for percutaneous angioplasty represents a challenge in the management of end-stage renal disease in Korea. It is essential to identify the clinical and physiological aspects as well as anatomical abnormalities before planning angioplasty. A timely surgical correction could be a viable option to control the rapid growth of access-related medical expenses.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.482-486
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• 2005

Total forest growing stock and growing stock per ha in Korea are $470\times10^6m^3\;and\;73m^3$, respectively. Those figures mean that forest growing stock was increased 4.7 times more during last 30 years. The annual production of forest biomass comes from forest tending executed by Korea Forest Service was estimated about $1.07\times10^6m^3$ M/T, which was equivalent to $0.45\%$ of total imported crude oil of Korea at 2002. The production is expected to increase and reach up to $1.9\times10^6 M/T$ till 2008. The analysis of economic feasibility showed that the production cost of wood chip(134,786Won/T) was about 30,389 Won/T higher than heat value of wood chip, 104,397 Won/T estimated from that of kerosene. For the promotion of forest bioenergy utilization, more efforts need to be given for the education and public relations to induce publicity a willingness-to-pay for the environment friendly fuels under the good understanding for the use of bioenergy. In addition, we need to provide a community-based biomass utilization program by region to allocate the role of each participant and to increase the profitability of bioenergy.