• 전기학회논문지
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• 제58권2호
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• pp.256-263
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• 2009

For the power system to keep in a stable operating state, sufficient ancillary services must be available to respond to credible contingency events and return the power system to a satisfactory operating state in the case of contingencies as well as blackout events within specified predefined limits. The logical and reasonable bases of valuing and pricing the ancillary services are required to reach the common ground among market participants. The total amount of black start service transactions is quite small compared to the total ancillary service transactions as well as energy market transactions. Black start services must be provided as one of the ancillary services in the deregulated electricity market. In order to procure and remunerate black start services, it is necessary to quantify the value of the black start sources within the power system. In this paper, an approach to assess the value of the black start service is presented based on the cost-of-service solution. Financial simulation of the influence on market participants for the proposed approach on the service is carried out. The cost of the black start service is allocated in accordance with the principle of "causer pays", and the cost is shared by the producers and consumers equally that created the requirement for the service. Under the present electricity market, the mechanism to recover the cost is not implemented, a new approach to the ancillary services to provide incentive for the service providers has to be studied in the near future.

• 전기학회논문지
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• 제62권10호
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• pp.1390-1396
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• 2013

The paper estimated the reasonable market price of lead-acid battery energy storage system (BESS) intended for demand management of electricity customers. As time-of-use (TOU) tariffs have extended to a larger number of customers and gaps in the peak and off-peak rates have gradually risen, deployment of BESS has been highly needed. However, immature engineering techniques, lack of field experiences and high initial investment cost have been barriers to opening up ESS markets. This paper assessed electricity cost that BESS operation could save for customers and, based on the possible cost savings, estimated reasonable prices at which BESSs could become a more prospective option for demand management of customers. Battery scheduling was optimized to maximize the electricity cost savings that BESS would possibly achieve under TOU tariffs conditions. Basic economic factors such as payback period and return on investment were calculated to determine reasonable market prices. Actual load data of 12 industrial customers were used for case studies.

• 한국유기농업학회지
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• 제1권
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• pp.19-28
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• 1992

The definitions of organic farming method has rather philosophical meaning than application of agricultural practices. The meaning of organic farming method has certainly basic differences in comparison with the conventional farming methods. The main definitions of organec farming method have certainly to reduce or not to apply any kinds of farm inputs materials by increasing quality of agricultural prod-ucts. However, the quality of produced food by organic farming method should be improved in compari-son with cinvethional farming method. By applying organic method, the qualith of food, envir-onment as well as spiritual attitude of human being should be improved in future. Actually, there are very wide fields of research on organic farming methods such as production tech-niques, soil and water conservation, plant and animal production, marketing and consumers behavior on organic products. In this article the present situation of organic farming methods in the United States of Americal is investigated in cimparison with conventional rice production. The production cost of rice per acre in the United States of America mde 58, 788 Won in 1986, while it was 121, 699 Won in Korea having about 107 percent higher in Korea than tham the U.S.A There is a larger rice farm cost analysis between conventional and organic rice farm in California. The cash cost pre 1 lbs of conventional rice made 4.86 $, while the organic rice was 6.96$ showing about 43.2%higher level of cost in organic products(1 lbs=0.45359kg) At present, there is less econmic advantage of organic rice production in California because of lower yields as well as price levels, Therefore, the total net return over cash cost peracer/yeat was a little lower in organic rice production than conventional rice prouction.

• 농업과학연구
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• 제27권2호
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• pp.158-175
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• 2000

Up to date, the economic feasibility analysis on land consolidation and on-farm development projects were mainly depended upon the direct benefits from market value of project outputs. Therefore the projects were neglected in allocation of the government's financial funds and loans on account of undervaluation of the project benefits including socio-economic and environmental values of the projects. Accordingly the Extended Benefit Cost Analysis Method should be adapted to cover not only the benefits such as non-market values of environmental functions of the projects and but also the economic market values of the project outputs. The main objectives of this study is (1) to provision of the guideline for economic feasibility analysis based on the IBRD and ADB guidelines, (2) to estimate the benefits such as Productivity increase effect, labor saving effect, off-farm income increase effect during off-farm season, saving of O&M cost of farm mechanization, enhance of farmer's public health, increase of environmental public function of paddy fields, effect of food security and establishment of peaceful and uncontroversial rural society by implementing the land consolidation and on-farm development, (3) to introduce the newly adapted analytical method as the extended benefit cost analysis which could make possible the analysis of non-market goods such as the food security value and the environmental public value of paddy fields. To carry out the study, the publication on the guideline for economic analysis of agricultural projects were reviewed and consulted and for the post evaluation of the land consolidation and on-farm development project, field survey in Jeongja area were made for the feasibility study of the project by new method. According to the initial project plan, Jeongja land consolidation and on-farm development project has 96ha of benefit area and the project was started in 1989 and completed in the spring, 1990. The total project costs were amounted to 1,052 million won and the annual project benefits were estimated at 135.4 million in 1989 constant market prices. On the other hand, the newly estimated project benefits as a part of post evaluation of the project were amounted to 602.1 million won including all the benefits from the market and non-market commodities of the project as mentioned above column. The original IRP(Internal rate of return) of the project was estimated at 15.81%. On the other hand, the IRR of the post evaluation of the project was amounted to 16.83%. In case of including the benefit from the environment public function of paddy field, the SRR(Social Rate of Return) was reached to 38.81% and when we added the benefit from food security of the project, the SRR showed very high rate as 46.41%. In conclusion, the project were verified socio-economically feasible and environmentally sustainable considering the above decision making criteria.

• Journal of Preventive Medicine and Public Health
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• 제29권2호
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• pp.347-357
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• 1996

Although occupational low back pain accounts for $20\sim40%$ of all occupational illness and injury, there are limited numbers of studies regarding the effectiveness of back school program. The objective of this study was to evaluate the economic benefit of back school program for early return to work of occupational low back pain patients in the current occupational injury compensation and management system. The cost-benefit analysis in this study was conducted to evaluate the relative magnitude of benefit to cost. The total cost was estimated by calculating the value of components in back school program according to governmental budget protocol. The back school program was consisted of three major approaches, pain center, work-hardening program and funcional restoration program and each of components had various facilities and experts. The total amount of cost was estimated as 250,866,220 won per year. The most promising type of back school program were quite intensive (a 3 to 5-week stay in a specialized center), therefore, if we adopted the 5-week stay course, 10 courses could be held in a year. Following to the medical act, 20 patients per doctor could participate in a each course, ie, total 200 patients in a year. As a result, we could estimate the cost of 1,254,331 won a patient. We estimated the benefit by using data of a few local labor offices about average medical treatment beneficiary and off-duty beneficiary of 46 occupational low back pain patients in 1994. Ullman and Larsson (1977) mentioned that the group of chronic low back pain patients who participated in back school program needed less time to recover by 48.4% of beneficiary duration. And in the trying to estimate the benefit, we asked 10 rehabilitation board certificate doctors about reduction proportion of treatment cost by introducing back school program. The answered reduction proportions were in the range of $30\sim45%$, average 39%. As a final result, we could see that the introduction of back school program in treatment of chronic occupational low back pain patients could produce the benefit to cost ratio as 3.90 and 6.28. And we could conclude that the introduction of back school program was beneficial to current occupational injury compensation and management system.

• Journal of Preventive Medicine and Public Health
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• 제38권1호
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• pp.9-15
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• 2005

Objectives : To analyze medical expenses by cancer site and survival time among cancer patients in their last year of life. Method : The study subjects were 45,394 people that had died of cancers in 2002, were registered by the Korea Central Cancer Registry and received National Health Insurance benefit in the last year (360 days) of life. Personal identification data, general characteristics, dates of death and cancer incidence, and site of cancer were collected from the National Statistical Office and the Korea Central Cancer Registry, and merged with the data of the individual medical expenses of the Health Insurance Review Agency. Results : Average monthly cost curves were U-shaped with high costs near the time of diagnosis and death, and lower costs in between. Medical expenses in the last year of life were around 30.3, 16.7, 13.0, and 12.1 million won among leukemia, lymphoma, ovarian cancer, and breast cancer patients, respectively. Digestive organ cancers including stomach, esophagus, liver, pancreas, and colorectal cancers had relatively low medical expenses. Medical expenses in the last year of life were inverse U-shaped with high expenses near one year of survival. Average monthly cost in the 12 months before death among the patients who had survived $10{\sim}15$ years were more than two-fold greater than the cost before diagnosis among those who had survived for less than one year. Conclusions : Leukemia was the most expensive cancer. It is possible that once diagnosed as cancer, medical expenses do not return to the level before diagnosis. Further research will be needed to understand the magnitude and change of the medical expenses among cancer patients with long term follow up data.

• 한국정보통신학회논문지
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• 제22권8호
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• pp.1123-1132
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• 2018

본 논문에서는 사물 인터넷과 액세스 코드 배포가 가능한 스마트폰 애플리케이션을 기반으로 하는 공공 자전거 공유 시스템을 설계하고 구현하였다. 스마트폰 사용자는 애플리케이션을 사용해 자전거 대여 신청을 하면 서버에서 암호화된 액세스 코드를 받게 되고, 이 코드는 도킹 스테이션에서 자전거의 잠금을 해제하는 용도로 사용되며 자전거 반환 시에도 동일한 코드가 사용된다. 스테이션의 하드웨어 프로토타입은 라즈베리 파이, 아두이노, 키패드, 모터드라이버와 같은 사물 인터넷 디바이스를 기반으로 하여 구현되었으며, 스마트폰 애플리케이션은 기본적으로 액세스 코드를 이용한 공유 자전거 대여 및 반환 기능과 더불어 사전에 자전거를 예약할 수 있는 부가 기능도 포함하고 있다. 구현한 시스템을 테스트 해 본 결과 3~4초의 매우 적은 지연시간을 보여주고 있어 효율적인 시스템임을 알 수 있다. 본 시스템은 단일 콘트롤 박스에서 다수의 자전거를 관리할 수 있도록 구현할 수 있으며, 사용자 역시 스마트폰 애플리케이션만으로 시스템을 이용할 수 있어 비용 효율적이라 여겨진다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1461-1466
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• 2000

The use of the dairy male calf for beef production has been found to be economically unprofitable during the past due to high cost of feeds and relatively low beef price. However, due to current shortage of domestic beef supply and rising beef price, this research aimed to assess feeding methods and costs and returns in raising dairy male calves for beef production under changing economic conditions. Two diets were compared: calves on an optimal feeding level were given milk replacer for 44 d and a concentrate (with ad lib. hay) to 150 kg bodyweight that contained 16% crude protein; those given a sub-optimal diet, more appropriate for smallholder farms, received milk replacer for 30 d and 14% CP concentrate. Twelve pairs of dairy male calves (average age 32 days) of Holstein-Friesian high grades were used, each pair having similar influencing factors such as weight, age, and genotype. Each animal was kept in a separate feeding stall until reaching the final weight of 150 kg. The results from this experiment showed that the differences of traits concerning growth performance and feed efficiency of the animals raised under the two feeding regimes were statistically nonsignificant. The optimal group was just slightly better, but the cost of production of the sub-optimal group was 24 percent lower (4,667 vs. 6,144 baht per animal) and the cost difference was highly significant. The results from this investigation showed that beef production from dairy male calves can be economically viable when sub-optimal feeding method is used and market beef price is at current level.

• Korean Chemical Engineering Research
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• 제47권6호
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• pp.781-787
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• 2009

석탄액화(Coal to Liquid, CTL) 공정은 직접액화(Direct Coal Liquefaction, DCL) 공정과 간접액화(Indirect Coal Liquefaction, ICL) 공정으로 대분되며, 각 공정의 경제성을 분석하기 위하여 주요 제품(디젤, 납사) 생산량이 50,000 barrel per day(BPD)의 직 간접석탄액화공정을 선정하고 공정에 적합한 검토기준을 세워 건설비용 및 매출액 등을 산정하였다. 또한 석탄액화공정에 대한 중요 변수들의 가격 변동에 따른 민감도 분석을 실시하였다. 생산량을 기준으로 선정된 원료탄(Illinois #6 유연탄)을 사용하였을 때, 총 투자액은 각각 DCL $3,994,858,000, ICL $4,962,263,000로 나타났다. 경제성 분석결과 내부수익률(internal rate of return, IRR)은 기본조건에서 각각 13.27%(DCL), 12.68%(ICL)로 나타났으며, 두 공정 모두 원료석탄 가격과 생산 제품 판매가에 가장 크게 영향을 받는 것으로 나타났다. 원금상환 기간은 DCL이 6.6년, ICL이 6.8년으로 나타났으며, 민감도 분석 결과 제품가격, 원료석탄가격, 건설비의 변동률 순서로 수익률에 변화를 주는 것으로 나타났다.

• 디지털융복합연구
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• 제11권5호
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• pp.119-133
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• 2013

본 연구의 목적은 독점적 지위로 운영되는 발전회사의 환경효율성 분석을 통하여 미래의 녹색경영, 지속경영에 대한 기관 효율성 향상에 기여하고자 하는 것이다. DEA 분석이 가진 내재적인 부족함을 보완하기 위해 C 발전회사 산하 6개의 기관을 직접 방문하여 담당 전문가로부터 DMU의 환경효율성을 위한 인터뷰 자료도 활용하였다. 투입요소로는 경영효율성에서는 비용과 종업원 수를 환경효율성으로는, CO2, NOx, 용수 사용량이 사용되었다. 산출요소로는 연간 총발전량, 판매수익이 사용되었다. 분석에는 규모수익불변(CRS, Constant Return to scale)투입지향의 DEA모형과 VRS(Various Return to Scale)모형을 이용하였다. CRS 분석에 의하면 0.923, BCC 분석으로는 0.969로 나타났으며 7개의 DMU가 효율적인 것으로 나타났다. 산출요소별 비효율적인 투입요소에서는 NOx가 CO2 보다 낮았다. 이는 전력발전에 있어 NOx는 물론 CO2에 관한 효율성이 개선되어야 한다는 것을 보여주고 있다. 환경비효율성을 줄이기 위해서는 결국 신재생에너지와 연료 전지 등 대체에너지원이 지속적으로 개발되어져야 한다.