• 수산경영론집
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• 제47권4호
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• pp.1-13
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• 2016

Fish mortality is the most important success factor in aquaculture management. To analyze the effect of mortality considering biological and economic condition is a important problem in land-based aquaculture. This study is aimed to analyze the effect of mortality for duration of cultivation in land-based aquaculture. This study builds the mathematical model that finds the value of decision variable to minimize cost that sums up the water pool usage cost, sorting cost, fingerling cost and feeding cost under critical standing corp constraint. The proposed mathematical model involves many aspects, both biological and economical: (1) number of fingerlings (2) timing and number of batch splitting event, based on (3) fish growth rate, (4) mortality, and (5) several farming expense. Numerical simulation model presented here in. The objective of numerical simulation is to provide for decision makers to analyse and comprehend the proposed model. When extensive biological and cost data become available, the proposed model can be widely applied to yield more accurate results.

• 자원ㆍ환경경제연구
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• 제23권4호
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• pp.617-641
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• 2014

2001년에 개설된 우리나라 전력도매시장은 변동비 반영(CBP) 시장으로 발전기들의 비용절감 유인을 통해 전력생산 비용 최소화를 추구하고 있다. 국내 발전사들은 발전비용 절감을 위한 다양한 노력을 기울여 왔고, 발전연료 구매비용의 인하, 고효율 발전기 도입, 수요지에 인접한 발전소 건설 등이 그 결과로 나타나고 있다. 최근 전력시장 제도개선의 일환으로 계통한계가격(SMP)에서 무부하비용 등을 제외하는 방식에 대한 논의가 제기되고 있다. 본 연구에서는 SMP에서 무부하비용 등을 제외한 후 손실발전기를 별도로 보상하는 방안이 발전사의 비용절감 유인에 미치는 영향을 분석하였다. 그 결과 가격결정 구간에 위치한 LNG복합 발전기들의 비용절감 유인이 위축될 가능성이 높은 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.43-45
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• 2006

Because Cost Based Pool(CBP) has any locational signals for electricity price, there are any locational incentives for construction of new power plant high efficient. in case of Korean electricity power market, this incentives are very important to reduce loss and congestion. This Paper represent the effect of MLF(Marginal Loss Factor) as locational price signal in short period. we investigate mathematically loss reduced effect of MLF and prove to reduce transmission loss using 3bus test system.

• 자원ㆍ환경경제연구
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• 제20권3호
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• pp.567-593
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• 2011

2005년 5개 발전사업자는 변동비 반영시장에 기존의 연료비 외에 연료사용 전후에 관련된 부대비용도 포함시킬 것을 건의하였다. 발전량과의 OLS 분석을 통해 관련을 검토한 결과 이 같은 변동비 희망항목이 발전량과 통계적으로 유의한 관계를 갖고 있다는 일반적인 성향을 발견할 수 없어서 변동비로 인정할만한 종합적인 근거는 취약하였다. 변동비 희망항목 중 몇몇 항목이 특정 발전설비에 대해 OLS 분석에서 통계적 유의성을 갖는 등 변동비가 될 수 있는 가능성을 보이고 있다. 그러나 비용산정의 시차, 재고관리와 이에 따른 회계처리 방법 등의 문제로 인하여 발전량과 유의적인 통계적 관계를 보이지 못할 수 있다. 따라서 변동비 희망항목에 대해서는 통일된 기준을 세우고 자료를 표준화하는 작업이 선행되어야 할 것으로 판단된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.550-552
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• 2001

The vertically integrated power industry was divided into six generation companies and one market operator, where electricity trading was launched at power exchange. In this environment, the profits of each generation companies are guaranteed according to utilization of their own generation equipments. Especially, the electricity demand shows seasonal and weekly regular pattern, which the some capacity should be provided into ancillary service based on the past demand forecasting error and operating results of electricity market. Namely, if generation cost function is applied to SMP and BLMP as announced the previous day, the available generation capacity of the following day could be optimally distributed, and therefore contract capacity of ancillary service applied to CBP(Cost Based Pool) and TWBP(Two-Way Bidding Pool) is determined. Consequently, it is Possible to use the retained equipments optimally. This paper represents on efficient bidding strategies for generation equipments through the calculation of the contract and the application of each generator cost function based on the past demand forecasting error and market operating data.

• 수산경영론집
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• 제46권3호
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• pp.129-141
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• 2015

Because land based aquaculture is restricted by high investment per rearing volume and control cost, good management planning is important in Land-based aquaculture system case. In this paper master production planning was made to decide the number of rearing, production schedule and efficient allocation of water resources considering biological and economic condition. The purpose of this article is to build the mathematical decision making model that finds the value of decision variable to maximize profit under the constraints. Stocking and harvesting decisions that are made by master production planning are affected by the price system, feed cost, labour cost, power cost and investment cost. To solve the proposed mathematical model, heuristic search algorithm is proposed. The model Input variables are (1) the fish price (2) the fish growth rate (3) critical standing corp (4) labour cost (5) power cost (6) feed coefficient (7) fixed cost. The model outputs are (1) number of rearing fish (2) sales price (3) efficient allocation of water pool.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.481-484
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• 1996

When logistics system is integrated with production system and marketing system, it takes a very important role of the business management. In general, measurement of logistics cost in logistics system uses the conventional cost assignment method. However the conventional method may result in the incorrect cost because the overhead cost may be incorrectly assigned to the products. Activity-Based Costing(ABC) was proposed as an alternative method which will distribute the overhead cost to each cost obeject more accurately. ABC assigns cost to activities based on the amounts of resources used by resource driver, and assigns cost to cost objects based on the amount of activities driver. This study proposes two heuristic algorithms. The first algorithm selects the best activity driver for each cost object by using correlation analysis. The best activity driver is the one that minimizes the sum of loss cost and measurement cost of activity driver. The second algorithm selects the best number of activities by using correlation analysis. The pair of activities with the highest correlation are combined into one if the saving of measurement cost is no less than the loss due to inaccurate distribution of overhead cost. In order to demonstrate the procedure and validity of the algorithms, Real data of one year from a paper manufacturer are used.

• 수산경영론집
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• 제45권2호
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• pp.85-95
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• 2014

Fish stocking is important element of land-based aquaculture management. To maintain constant stocking rate considering biological and economic condition is a convenient strategy in intensive aquaculture. This study is aimed to analyze the effect of over-stocking(more than aquaculture capacity) for certain periods of time. This study make the mathematical decision making model that finds the value of decision variable to minimize cost that sums up the water pool usage cost and sorting cost under critical standing corp constraint. The proposed mathematical decision making model was applied to 12 sample combination of sorting cost and the number of fish on the Oliver flounder culture farms. If a immature fish can be sold for high price than farming cost, restricted over-stocking resulted in a improvement of economic performance. When extensive comparable biological and market data become available, analysis model can be widely applied to yield more accurate results.

• The Korean Journal of Ecology
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• 제21권5_1호
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• pp.409-418
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• 1998

A molel study was conducted to determine the optimal sample size for the analysis of the aquatic insect community in a stream reach of the Pangtae Creek, Kangwon-do in October 1995 and may 1996. The results showed that the required minimum sample size varied and depended on the purposes of the community analysis. Acoording to the Species: Area Curve method, at least 16 Surber samplings ($30{\times}30cm$) were required in a stream reach in each spring and fall survey. The species diversity index did not vary significantly as the sample size increased. Based on the coefficient of variation analysis, the minimum sample sizes of 10 were required in order to compare seasonal differences of the community in the study area. Considering the static community structure of aquatic insects, including both species numbers and individual numbers of aquatic insects, 11 and 7 samplings were optimal sizes for the fall and spring survey, respectively. We concluded that 12 Surber samplings from 3 riffle-pool sequences (4 samplings at each riffle-pool sequence) would be required in a stream reach (length 1 km) to obtain reliable as well as cost efficient data. Our model showed that the optimal sample size should be determined by interactions between minimum sample size, the degree of data reliability, and cost efficiency.

• 에너지공학
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• 제11권1호
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• pp.59-66
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• 2002

수직 통합된 체제의 전력회사가 6개의 발전회사와 1개의 판매회사로 분리되고 전력거래소를 통한 전력거래가 본격화되면서 발전회사는 자체 소유 발전설비의 공급가능용량을 어떻게 활용하느냐에 따라 영업상 수익의 영향을 받게 된다. 특히, 하루 전 발표되는 한계가격(System Marginal Price, Base Load Marginal Price)에 맞도록 전력생산을 위한 발전 비용함수를 적용한다면 익일의 공급가능용량이 최적 배분됨으로써, 변동비 반영 시장(Cost based Generation Pool)과 입찰가격 반영 발전시장(Price Bidding Generation Pool)에 적용될 계통운영보조서비스의 계약 물량 산출 및 익일 생산비용의 최적화를위한 입찰전략(Bidding Strategies) 수립이 가능해 지므로 보유 설비에 대한 최적이용이 가능하게 된다. 따라서 본 논문에서는 수요예측 오차와 과거 시장운영 실적을 기초로 년 간 유지보수 계획을 수립하고, 계통운영보조서비스에 대한 계약물량 산출과 개개 발전기의 비용함수 산출, 적용을 통한 발전설비의 효율적인 입찰 방안에 대해 논하고자 한다.