• 한국농공학회지
• /
• 제29권3호
• /
• pp.125-137
• /
• 1987

The purpose of this paper is to examine some difficulties in water management of agricultural reservoirs in Korea, for there are approximately more than 15,000 reservoirs which are now being utilized for the purpose of irrigation, along with the much amount of expenses and labors to be invested against droughts and floods periodically occurred. Recently, the effective use of water resources in the agricultural reservoirs with a single purpose, is becomming multiple according to the alterable environment of water use. Therefore, the task to allocate agricultural water rationally and economically must be solved for the multiple use of agricultural reservoirs. On the basis of the above statement, this study aims at suggesting the rational method of water management by introducing an optimal technique to allocate the water in an existing agricultural reservoir rationally, for the sake of maximizing the economic effect. To achieve this objective, a reservoir, called "0-Bongje" as a sample of the case study, is selected for an agricultural water development proiect of medium scale. As a model for the optimum allocation of water in the multi-purpose use of reservoirs a linear programming model is developed and analyzed. As a result, findings of the study are as follows : First, a linear programing model is developed for the optimum allocation of water in the multi-purpose use of agricultural reservoirs. By adopting the model in the case of reservoir called "O-Bongje," the optimum solution for such various objects as irrigation area, the amount of domestic water supply, the size of power generation, and the size of reservoir storage, etc., can be obtained. Second, by comparing the net benefits in each object under the changing condition of inflow into the reservoir, the factors which can most affect the yearly total net benefit can be drawn, and they are in the order of the amount of domestic water supply, irrigation area, and power generation. Third, the sensitivity analysis for the decision variable of irrigation which may have a first priority among the objects indicate that the effective method of water management can be rapidly suggested in accordance with a condition under the decreasing area of irrigation. Fourth, in the case of decision making on the water allocation policy in an existing multi-purpose reservoir, the rapid comparison of numerous alternatives can be possible by adopting the linear programming model. Besides, as the resources can be analyed in connection with various activities, it can be concluded that the linear programing model developed in this study is more quantitative than the traditional methods of analysis. Fifth, all the possible constraint equations, in using a linear programming model for adopting a water allocation problem in the agricultural reservoirs, are presented, and the method of analysis is also suggested in this study. Finally, as the linear programming model in this study is found comprehensive, the model can be adopted in any different kind of conditions of agricultural reservoirs for the purpose of analyzing optimum water allocation, if the economic and technical coefficients are known, and the decision variable is changed in accordance with the changing condition of irrigation area.

• 해양환경안전학회지
• /
• 제21권2호
• /
• pp.154-163
• /
• 2015

본 연구에서는 한국 항만과 연안해역 수로측량의 변천과 현황, 기존의 문제점을 살펴보고, 문헌연구와 해양선진국 수로측량 사례분석을 통해 잠정기준을 도출하였다. 그리고 전문가 집단에 대한 설문조사 및 분석을 통해 잠정기준의 우선순위와 상대적 중요도를 분석하였다. 연구의 결과, 주요 항만과 연안해역의 수로측량 우선순위로는 해저지형 변화, 해상교통량, 기존 수로측량 실적, 이해당사자 또는 이용자의 요구, 해양사고, 해양환경 및 생태자원 보존 등으로 나타났다. 이러한 기준의 우선순위에 따른 계량모형을 설정하여 한국 주요 무역항에 대한 수로측량 상대적 순위도 도출하였다. 본 연구가 제시한 정량적이고 과학적인 방법에 의한 수로측량의 필요성과 방향은 앞으로 한국 수로측량의 선진화와 해상교통안전의 확보에 기여할 것으로 기대된다.

• 한국수자원학회논문집
• /
• 제37권3호
• /
• pp.207-217
• /
• 2004

국내의 경우 전국적으로 관거의 신설보다는 기존에 매설되어있는 관거의 노후에 따른 개량에 대한 관심이 증대되고 있으나, 그에 따른 연구는 미비한 실정이다. 국내ㆍ외에서는 유전자 알고리즘을 이용하여 개량시기를 결정하는 연구 예가 있으나, 이러한 연구에서 개량시기를 결정하는 요소들이 매우 단순하여 관거의 노후에 따른 복합적인 의사결정이 이루어지지 않고 있다. 본 연구에서는 관거별 통수능력 및 불명수 발생량을 산정하여 배수분구내 토구별 최적 개량 우선순위를 결정하는 한편, 유전자 알고리즘을 이용하여 최적개량비용을 산정하는 최적개량 의사결정 시스템을 개발하였다.

• 조명전기설비학회논문지
• /
• 제23권9호
• /
• pp.31-39
• /
• 2009

본 논문에서는 경제성 평가를 기반으로 하는 배전 설비투자 우선순위를 결정하기 위하여 배전계통 구성, 설비 및 부하정보를 이용하여 배전계통을 모델링 하고, 현 계통의 신뢰도를 개선하기 위한 방향으로 설비투자 대안들을 설계한 다음, 이 대안들을 대상으로 신뢰도 및 경제성을 평가하는 모델을 제시하였다. 이러한 투자대안들의 신뢰도 영향과 경제성을 분석하기 위하여 한전의 주요 배전설비(15종)의 신도율(시변고장율)과 설비투자시 영향을 받는 고객들의 정전비용을 적용하여 경제적 효과를 산출하였으며, 이러한 투자 방법론의 유효성을 검증하기 위하여 한전의 배전사업소 실제 투자안을 대상으로 하여 경제성 평가를 수행한 결과와 비교분석하였다.

• 한국항해학회지
• /
• 제12권2호
• /
• pp.43-55
• /
• 1988

The amount of cargoes and fishery production have increased continuously during the last decade due to the great growth of the Korean economy. These increasements have made our coastal traffic congested, and the future coastal traffic is also expected to increase considerably. The increased traffic can be a cause of large sea pollution as well a s greater sea casualties us as properties and human lives, which could result in a big national loss. In order to prevent the sea casualties and promote the safety of coastal traffic, the Vessel Traffic Management System (VTMS) along the Korean coastal waterway is inevitably introduced. But, the precise evaluation is necessary required prior to the implementation of VTMS because this system necessitates a huge amount of budgets. This paper aims to propose the model of evaluation process, but the evaluation as to the urgency of establishment is not only very complicated and fuzzy but also affected by the subjectivity of human. Therefore, fuzzy integral is adopted as the mathematical model of evaluation in which decision-maker can intervence by making decision considering the calculated membership-function. Four aspects, namely, the frequency of sea-casualities, the traffic volume, the frequency fuzzy day, and the complexity of waterway are selected as the item of evaluation, and the fuzzy measure are applied to the evaluation of 8 candidated regions such as the adjacent area to the port Inchen, Kunsan, Mokpo, Wando, Yosu, Pusan, Pohang, Donghae. As a result of evaluation, the priority as to the candidated regions is obtained, and the following prior execution regions, namely, the adjacent area to the port Pusan, Yosu, Mokpo & Wando are selected by considering the present situation, but, in the long run, the VTMS should be executed in the whole coast of the nation, through the cost-effectiveness analysis.

• 한국빅데이터학회지
• /
• 제5권2호
• /
• pp.155-170
• /
• 2020

본 연구의 목적은 서울시 중학생의 진로성숙도 예측 요인을 찾기 위해 머신러닝 기법(Decision Tree, Random Forest, XGBoost)을 서울교육종단연구 4~6차년도 데이터에 적용하였다. 적용에 따라 도출된 세 가지 머신러닝 모형의 변수 중요도와 각 지표별 성능을 확인하였다. 또한 XGBoostExplainer 패키지를 활용하여 모형을 해석하였으며, 데이터 전처리와 분석 모두 R과 R Studio를 활용하였다. 그 결과 각 모형별로 변수 중요도 순위는 다소 차이가 있으나 '성취목표', '창의성', '자아개념', '부모자녀와의 관계', '회복탄력성'이 높은 순위를 보였다. 또한 XGBoostExplainer를 활용하여 패널별 진로성숙도에 정적·부적 영향을 주는 요인을 탐색하였고, '성취목표'가 진로성숙도 예측 최우선 요인임을 찾을 수 있었다. 본 연구결과를 바탕으로 머신러닝 및 변수선택 방법의 비교연구와 서울교육종단연구 코호트별 비교연구가 수행되어야 함을 제언하였다.

• 정보처리학회논문지D
• /
• 제16D권5호
• /
• pp.767-790
• /
• 2009

임베디드 시스템을 위한 릴리스 플랜 수립은 제품 개발 초기 요구사항 분석 단계에서 요구사항의 우선순위 결정을 통해 달성되므로 우선순위 결정은 매우 중요하다. 이때, 우선순위 활동에서는 요구사항간 의존관계와 제품 개발에 관여하는 관점들을 고려해야 한다. 특히 임베디드 시스템에서 하드웨어와 소프트웨어의 특징에 기반한 아키텍처 스타일에 따른 요구사항간 상충관계는 반드시 반영해야 한다. 그러나, 기존 연구에는 하드웨어 및 소프트웨어로 구성된 시스템에 대한 요구사항을 고려하는 우선순위 선정 프로세스가 체계적이지 못하다. 따라서, 본 논문에서는 임베디드 시스템을 위한 요구사항간 의존관계, 관점에 기반한 요구사항 우선순위의 모델과 프로세스를 제안한다. 이를 위해 아키텍처 스타일에 따른 우선순위 요소 또는 요구사항간 상충관계를 분석하고, 임베디드 시스템 제품 개발에 관여하는 관점들을 식별하여 요구사항 우선순위를 정립한다. 그리고 제안된 방법을 핸드폰 개발 사례의 요구사항 우선순위에 적용하여 신뢰성을 보인다. 본 논문의 기법을 적용하여 임베디드 시스템의 특성에 부합하도록 요구사항을 좀 더 명확하게 최적화하여 우선순위화함으로써 제품 릴리스에 대한 위험성을 최소화할 수 있다.

• 전기학회논문지P
• /
• 제63권3호
• /
• pp.163-168
• /
• 2014

In this paper, when photovoltaic systems are connected to distribution system, most effective capacity and location of PV system are studied considering customer interruption costs of power distribution system. The reliability model of PV system considering the duration of sunshine, the model of time-varying load and Roy Billinton test system (bus2 model) are used. To simulate the effects of PV system, various cases are selected; (1) base case which is no connection of PV system to power distribution system when faults are occurred, (2) 3MW case which is 3[MW] connection of PV system (3) 4[MW] case, and (4) 20[MW] case which is 20[MW] connection of PV system to the bus of power distribution system. The capacity limit of connected PV system is settled to 14[MW] for all cases except case 4. The reliability and customer interruption costs for residential, general, industrial, and educational customer is evaluated.

• 기술혁신연구
• /
• 제6권2호
• /
• pp.159-177
• /
• 1998

Although each company is trying to develop an economic analysis model with its own particular style or format, the appropriate method is not yet developed because there are many problems to be solved such as uncertainity of outcomes and intangible benefits of technology. The purpose of tris paper therefore is to suggest an economic analysis methodology, which reflects the complexity and the risk of R&D investment, through a case study on the development of a superconductor fault current limiter. A self-developed Monte Carlo simulation program utilized as a main tool in this paper was very useful for risk analysis of R&D investment which could not be solved in the previous DCF(Discounted Cash Flow) model. We also introduce learning effect to consider the intangible benefits such as Know-How obtained from R&D execution. The expected value and its probability distribution for R&D investment can be obtained by combining the Monte Carlo method with the decision tree approach. This result is helpful in judging the priority and the resource-allocation of R&D projects. It is however necessary to develop more precise model for quantifying the technology stock and the simulation program using the continuous probability distribution in expected values to improve the reliability of economic analysis on R&D projects.

• 대한안전경영과학회지
• /
• 제19권3호
• /
• pp.137-150
• /
• 2017

Logistic enterprises want to be competitive enterprises in fierce logistic market and worry about the securement of discriminative competitiveness for it. The standards for the judgement of logistic industry's maintenance of competitiveness are not only economic feasibility of logistic costs but also the satisfaction of users because well-established service system for variety and enhancement of logistic needs. Some of the quality attributes sufficiently satisfy expectation of customers, but not guarantee high-quality satisfaction. Therefore, it's difficult to grasp quality attributes with the existing approach of perceived service quality. Quality attribute model suggested by Kano is widely used as the concept is accurate, there is high possibility to be used at the stage of product/service planning, and it can be easily applied. Kano model has a limitation that quality attributes are classified with mode and the differences between strong property of the quality attribute and week property in quality attributes were ignored. Therefore, Timko calculated customer satisfaction coefficient with the result of Kano's survey and effects of customer satisfaction and unsatisfaction through relations between satisfaction coefficient and unsatisfaction coefficient. The purposes of this study are to use ASC, the average of satisfaction coefficient and unsatisfaction, as the satisfaction of quality characteristics, decide the importance of quality characteristics with TOPSIS, a representative multi-standard decision-making method, and calculate strategy improvement propriety of logistic service quality.