• Journal of Information Processing Systems
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• 제15권3호
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• pp.655-669
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• 2019

Supplier evaluation is of great significance in green supply chain management. Influenced by factors such as economic globalization, sustainable development, a holistic index framework is difficult to establish in green supply chain. Furthermore, the initial index values of candidate suppliers are often characterized by uncertainty and incompleteness and the index weight is variable. To solve these problems, an index framework is established after comprehensive consideration of the major factors. Then an adaptive weight D-S theory model is put forward, and a fuzzy-rough-sets-AHP method is proposed to solve the adaptive weight in the index framework. The case study and the comparison with TOPSIS show that the adaptive weight D-S theory model in this paper is feasible and effective.

• 자원ㆍ환경경제연구
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• 제14권3호
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• pp.753-773
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• 2005

시장점유율을 고려한 OPEC와 비OPEC의 게임을 고려한 원유공급 투자모형을 분석한다. 국제유가의 불확실성을 반영하기 위하여 확률투자모형인 실물옵션 모형을 이용한다. 원유공급시설의 확장 및 감축을 위한 조정은 국제유가로 표시되는 분기점으로 나타난다. 국제유가가 확장(감축)분기점을 초과(하회)하면 OPEC는 공급시설을 확장(감축)한다. 최근 국제유가를 활용한 시뮬레이션 분석 결과, 확장분기점은 배스켓 가격 기준으로 높게는 56.93달러/배럴, 낮게는 48.44달러/배럴인 것으로 나타났으며, 감축분기점은 36.52달러/배럴과 36.93달러/배럴 사이에 머무는 것으로 나타났다.

• 한국음향학회지
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• 제43권3호
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• pp.344-350
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• 2024

기준음원은 음향파워 측정에 활용되는 중요한 기준기로, 국제 표준으로 그 사양이 규정되어 있으며, 측정 표준 분야에서 주요 교정 품목으로 분류되고 있다. 이러한 기준음원은 공급 전압에 의하여 그 출력이 영향을 받기 때문에 각국에서 자체적으로 교정 서비스 체계를 확보할 필요가 있다. 본 연구에서는 잔향실 조건에서 기준음원을 교정하는 절차를 수립하고 불확도를 평가하였다. 교정 절차는 기본적으로 음향 파워의 정밀급 측정과정을 적용할 수 있으며, 여기서는 ISO 3741의 잔향실을 활용한 측정 방법을 검토하였다. 이를 위한 측정 시스템을 구성하고 실제 2종의 기준 음원에 대하여 측정을 수행하고 측정 불확도를 산출하였다. 측정 예를 통하여 잔향실 내 음압 분포의 불균일성과 체적 측정 불확도가 전체 불확도에 기여가 큰 것을 확인하였다. 추가적으로 입력 전압에 대한 영향을 실험적으로 검토하여 음향 파워 측정에서 반영할 수 있는 불확도 기여량을 검토하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.2179-2183
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• 2009

As urbanization is progressed, the network for distributing water in a basin become complex due to the spatial expansion and parameter uncertainties of water supply systems. When a long range water supply plan is determined, the total construction and operation cost has to be evaluated with the system components and parameter uncertainties as many as possible. In this paper, the robust optimization approach of Bertsimas and Sim is applied in a hypothetical system to find a solution which remains feasible under the possible parameter uncertainties having the correlation effect between the uncertain coefficients. The system components to supply, treatment, and transport water are included in the developed water supply system and construction and expansion of the system is allowed for a long-range period. In this approach, the tradeoff between system robustness and total cost of the system is evaluated in terms of the degree of conservatism which can be converted to the probability of constraint violation. As a result, the degree of conservatism increases, the total cost is increased due to the installation of large capacity of treatment and transportation systems. The applied robust optimization technique can be used to determine a long-range water supply plan with the consideration of system failure.

• 전기학회논문지
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• 제59권1호
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• pp.26-32
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• 2010

This paper proposes a new effective installed reserve rate in order to evaluate reliability of power system considering renewable generators, which include uncertainty of resource supply. It is called EIRR(effective installed reserve rate) in this paper. It is developed with considering capacity credit based on ELCC by using LOLE reliability criterion. While the conventional installed reserve rate index yields over-evaluation reliability of renewable generators, the proposed EIRR describes actual effective installed reserve rate. However, it is not the probabilistic reliability index as like as LOLE or EENS but another deterministic effective reliability index. The proposed EIRR is able to evaluate the realistic contribution to the reliability level for power system considering wind turbine generators and solar cell generators with high uncertainty in resource supply. The case study in model system as like as Jeju power system size presents a possibility that the proposed EIRR can be used practically as a new deterministic reliability index for generation expansion planning or operational planning in future.

• Industrial Engineering and Management Systems
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• 제13권2호
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• pp.231-249
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• 2014

This paper discusses a green supply chain with a manufacturer and a collection trader, and it proposes an optimal production planning for remanufacturing of parts in used products with quality classification errors made by the collection trader. When a manufacturer accepts an order for parts from a retailer and procures used products from a collection trader, the collection trader might have some quality classification errors due to the lack of equipment or expert knowledge regarding quality classification. After procurement of used products, the manufacturer inspects if there are any classification errors. If errors are detected, the manufacturer reclassifies the misclassified (overestimated) used products at a cost. Accordingly, the manufacturer decides to remanufacture from the higher-quality used products based on a remanufacturing ratio or produce parts from new materials. This paper develops a mathematical model to find how quality classification errors affect the optimal decisions for a lower limit of procurement quality of used products and a remanufacturing ratio under the lower limit and the expected profit of the manufacturer. Numerical analysis investigates how quality of used products, the reclassification cost and the remanufacturing cost of used products affect the optimal production planning and the expected profit of a manufacturer.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.51-58
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• 2011

The energy makes the basic element which improves the quality of life with motive power of industry and life. However, using the fossil fuel resources was restricted through it's abuse and exhaustion, and that cause a global warming resultingly. According to the reason, the world increased the interest that are stability and use of new and renewable energy which is clean energy with environment. Therefore, the property data of new and renewable is needed for developing and supplying the energy. In other words, the data of new and renewable energy becomes the standards for supply and evaluation of new and renewable energy with development of industry and technology. Also, the necessity came to the fore as the reference and standards of new and renewable energy data. Therefore, in this study, we evaluate and collect the solar radiation data as the new and renewable data and process the collected data through the standards for valuation. We evaluate uncertainty with standards which are NREL, WMO, and GUM. Whereby the data becomes reference standards data and gains the credibility. For the reliability data, we correct the measuring instrument with correction period. Using the DQMS and SERI QC, we efficiently manage and evaluate the solar radiation data. As a result, we evaluate uncertainty as 1,120 case about 16 area. we achieve credibility of data from evaluated solar radiation data and provide an accurate information to user. The annual average of horizontal radiation presents between 1,484 and 4,577, then the uncertainty evaluates from 163 to 453. The error of uncertainty presents smaller than the measurement values. So, we judge a credibility of data by expression of reliability quantitatively. In additional, the reference standards data which is possible to approach anywhere will be used for the supporting related industry and policy making.

• 한국전자파학회논문지
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• 제25권2호
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• pp.183-188
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• 2014

본 논문은 F급 무선 전력증폭기의 설계에 있어 바이어스 전압의 불확도가 출력 전력에 미치는 영향을 분석하고, 이를 최소화하는 바이어스 조건을 도출하였다. 이를 위하여 불확도 전파이론을 활용하여 전력증폭기의 출력 전력에 대한 드레인 및 게이트 바이어스 공급 전압의 불확도가 전파되는 영향에 대하여 이론적인 해석 및 측정 민감도에 대해 분석하였으며, 1.9 GHz에서 동작하는 F급 전력증폭기 회로에서의 전력 불확도에 대한 이론적, 실험적 분석 방법을 제시하였다. 더불어, 증폭기의 성능을 유지하면서 출력 불확도를 최소화하기 위한 최적의 바이어스 조건을 도출하였다. 그 결과, 1.17 W 출력 전력에 대한 전원 공급 장치의 전압 불확도는 바이어스 조건에 따라 약 15~65 mW의 영향을 미치는 것으로 파악되었으며, 최적 바이어스 조건으로 측정할 경우 출력 전력은 0.37 dB 감소하는 반면에 출력 불확도는 15 mW 이하로 감소시킬 수 있음을 확인하였다.

• Industrial Engineering and Management Systems
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• 제16권1호
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• pp.44-51
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• 2017

In today's competitive environment, supply chain management is a major concern for a company. Two of the key issues in supply chain management are transportation and inventory management. To achieve significant savings, companies should integrate these two issues instead of treating them separately. In this paper we develop a framework for modeling stochastic programming in a supply chain that is subject to demand uncertainty. With reasonable assumptions, two stochastic programming models are presented, respectively, including a single-period and a multi-period situations. Our assumptions allow us to capture the stochastic nature of the problem and translate it into a deterministic model. And then, based on the genetic algorithm and stochastic simulation, a solution method is developed to solve the model. Finally, the computational results are provided to demonstrate the effectiveness of our model and algorithm.

• Management Science and Financial Engineering
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• 제6권2호
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• pp.1-28
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• 2000

Supply chain management issues faced by a manufacturing company are considered in this paper. The supply chain consists of a manufacturing company and its suppliers. The manufacturer produces multiple products with inputs (e.g., raw materials) from the suppliers, but each product needs a different mix of these inputs. The market demand for the products is uncertain. We develop a mathematical model and algorithm, which can help the manufacturer to solve its procurement decision problem: how much of raw material to order from which supplier. The model incorporates such factors as market demand uncertainty, product's input requirement, supplier's as well as manufacturer's capacity, plus other costs comparable with those in a typical newsboy problem. Numerical examples are presented to see the interacting effects among critical parameters and variables.