• 한국방재학회 논문집
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• 제8권6호
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• pp.15-20
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• 2008

상수관망의 수리해석 방법은 demand-driven analysis와 pressure-driven analysis로 구분할 수 있으며, 급작스런 용수수요증가, 관거파괴 등과 같이 비정상운영상태인 용수공급시스템의 수리모의에 demand-driven analysis를 사용할 경우 비현실적인 결과를 줄 수 있다. 특히 현재 국내에서는 비상상황에 대한 비상급수계획 수립 시에 demand-driven analysis를 사용하고 있으나, pressure-driven analysis의 적용을 통한 비상급수계획의 적정성 평가가 수행되어야 할 것이다. 본 연구에서는 pressure-driven analysis를 위해 최근 개발된 WaterGEMS모형을 이용하여 2007년 수도정비 사업을 계획한 J시의 비상급수계획의 적정성을 평가하였다. 적용 결과 소블럭의 용수공급 안정성 향상을 위한 방안 제시가 가능하였으며, 수립된 비상급수계획이 적합한 것으로 판단되었다.

• 산업경영시스템학회지
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• 제40권4호
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• pp.29-37
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• 2017

This papers focuses on remanufacturing processes in a closed loop supply chain. The remanufacturing processes is considered as one of the effective strategies for enterprises' sustainability. For this reason, a lot of companies have attempted to apply remanufacturing related methods to their manufacturing processes. While many research studies focused on the return rate for remanufacturing parts as a control parameter, the relationship with demand certainties has been studied less comparatively. This paper considers a closed loop supply chain environment with remanufacturing processes, where highly fluctuating demands are embedded. While other research studies capture uncertainties using probability theories, highly fluctuating demands are modeled using a fuzzy logic based ambiguity based modeling framework. The previous studies on the remanufacturing have been limited in solving the actual supply chain management situation and issues by analyzing the various situations and variables constituting the supply chain model in a linear relationship. In order to overcome these limitations, this papers considers that the relationship between price and demand is nonlinear. In order to interpret the relationship between demand and price, a new price elasticity of demand is modeled using a fuzzy based nonlinear function and analyzed. This papers contributes to setup and to provide an effective price strategy reflecting highly demand uncertainties in the closed loop supply chain management with remanufacturing processes. Also, this papers present various procedures and analytical methods for constructing accurate parameter and membership functions that deal with extended uncertainty through fuzzy logic system based modeling rather than existing probability distribution based uncertainty modeling.

• 수산경영론집
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• 제39권1호
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• pp.17-42
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• 2008

This study tried to build a structure model for the Korean flatfish aquaculture market by a system dynamics approach. A pool of several factors to influence the market structure was built. In addition, several reasonable factors related to the flatfish aquaculture market were selected to construct the causal loop diagram (CLD). Then the related stock/flow diagrams of the causal loop diagrams were constructed. This study had been forecasting a production price and supply, demand, and consumption volume for the flatfish market by a monthly basis, and then made some validation to the forecasting. Finally, four governmental policies such as import, storage, reduction of input, and demand control were tentatively evaluated by the created model. As a result, the facts that the demand control policy is most effective, and import and storage policies are moderately effective were found.

• 한국산림과학회지
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• 제97권4호
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• pp.458-466
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• 2008

본 연구는 장기 밤수급 예측과 국내외 시장여건 변화가 국내 밤시장에 미치는 영향을 분석하기 위하여 수행되었다. 이를 위해 본 연구에서는 생밤시장과 깐밤시장을 상호 수직적으로 연결하는 부분균형모델을 개발하였다. 개발된 모델의 내생변수에 대한 예측능력을 측정하기 위하여 1990년부터 2003년까지 사후예측을 실시하였다. 전반적으로 신규재배면적 및 폐기면적을 제외하고는 모든 내생변수들에 대한 모델의 예측오차가 낮았다. 수급예측 결과 국내 생밤생산량은 2005년에 76,447톤에서 2020년에는 76,286톤으로 약간 감소할 것으로 예측되었으며, 일본으로 수출되는 깐밤의 양은 지속적으로 감소할 것으로 예측되었다.

• 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.

• 디지털융복합연구
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• 제11권12호
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• pp.1-10
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• 2013

부가통신서비스산업은 통신서비스 산업과 국가 경제 발전에 중요성이 증대되고 있다. 따라서 본 연구는 산업연관분석을 이용하여 2000년, 2005년 2009년 세 개년도 동안 부가통신서비스 산업의 역할에 대해 조사하였다. 분석을 위해 수요유도모형에 따른 생산유발효과, 부가가치유발효과 그리고 취업유발효과, 공급유도모형과 레온티에프 가격 모형에 따른 공급지장효과, 물가파급효과 그리고 전후방연쇄효과에 대해 알아보았다. 분석 결과 생산유발효과는 2000년 0.5253원, 2009년 1.31314원, 부가가치유발효과는 0.25112원에서 0.5337원으로 취업유발효과는 0.09749명에서 0.21025명으로 성장하였고, 공급지장효과는 1.29003원에서 2.12048원, 레온티에프 가격모형에 의한 물가파급효과는 0.0022%에서 0.00258%로 상승하였다. 마지막으로 산업연쇄효과에 따르면 최종 수요적 원시산업형의 특징을 가지는 것으로 나타났다.

• 한국국방경영분석학회지
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• 제11권1호
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• pp.1-7
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• 1985

A computer-aided simulation model for inventory control was developed using Apple II Plus micro-computer. The model forecasts quarterly demands with Single Exponential Smoothing method and simulates Supply Demand Review and Inventory Level Settings for each items. The simulation is based on the assumption that the demand occurrences have their own probability distributions.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2007년도 춘계학술대회
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• pp.349-357
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• 2007

We consider supply chain which consist of one manufacturer, one distributor and N retailers for a single product. This paper determines inventory replenishment period of supply chain using houristic method and propose order policy through re-coordination of inventory replenishment. Also, We develops inventory management model to calculate total cost of supply chain under assumptions of constant demand. The computational results show that the proposed inventory replenishment period and inventory management model is efficient.

• 디지털융복합연구
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• 제5권1호
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• pp.47-53
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• 2007

We consider supply chain which consist of one manufacturer, one distributor and N retailers for a single product. This paper determines inventory replenishment period of supply chain using heuristic method and propose order policy through re-coordination of inventory replenishment. Also, We develops inventory management model to calculate total cost of supply chain under assumptions of constant demand. The computational results show that the proposed inventory replenishment period and inventory management model is efficient.

• 산업경영시스템학회지
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• 제24권65호
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• pp.11-22
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• 2001

Recently, many studies on the supply chain management have been published due to increasing attention placed on the design and performance analysis of the supply chain as a whole. Using the Beer distribution game introduced in Sterman[1995], we develop a simple order-up-to-R inventory model to minimize sum of the inventory holding cost and shortage cost under probabilistic demand. We show that performance of the model is robust through extensive simulation experiment. Applying the model to serially connected supply chain, we observe that, if the unit shortage cost is relatively high, R value computed independently is an optimal solution.