• 한국ITS학회 논문지
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• 제9권3호
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• pp.30-40
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• 2010

고속도로 본선 정체의 원인으로 진출램프에서 발생한 대기행렬의 본선 역류가 크게 작용하며, 이에 고속도로 진출램프 대기행렬 발생으로 인한 본선 영향을 적절히 표현하는 연속류 모형과 실제 제어 시 기반이 되는 적용성 연구가 필요하다. 본 연구에서는 고속도로 용량 변화에 따른 공급과 수요 곡선을 탄력적으로 적용하여 진출램프 대기행렬 영향으로 인한 고속도로 본선 교통류를 표현할 수 있는 Supply-Demand 모형의 적용성을 평가하였다. 먼저 Supply-Demand 모형 적용 시 요구되는 입력자료인 구간별 Sending & Receiving function과 진출램프 대기행렬의 본선 영향 등을 고려한 고속도로 본선 용량제약을 처리하는 방안을 제시하였다. 실시간 data를 사용하여 Supply-Demand 모형을 적용하는 일련의 과정을 모형화 한 후, 극심한 상습정체가 발생하는 내부순환로의 홍은진출을 포함하는 구간에 적용, 조정 및 발전시켜 분석하였다. 적용결과, 대기행렬의 본선 영향 범위와 대기행렬 패턴이 실제 교통류와 유사하게 예측되었다. 즉, Supply-Demand 모형이 Sending & Receiving function을 탄력적으로 적용함으로써, 진출램프 대기행렬의 본선 역류 등으로 인한 고속도로 본선의 용량 변화가 적절히 반영되는 것으로 검증되었다.

• 한국산림과학회지
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• 제95권5호
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• pp.539-542
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• 2006

This study confirmed econometrically the causality of forest inventory and roundwood supply using Korean data. In general, forest inventory is included as explanatory variable in roundwood supply function. We checked whether each series is stationary or not before using it in the model, and determined whether the combination of the series is comtegrated. The relationship between forest inventory and roundwood supply was represented by bivariate vector autoregressive model. The causality of forest evidence of the causal relationship between change in forest inventory and change in roundwood supply in Korea. That is, change in forest inventory does not cause change in roundwood supply in Korea. It seems reasonable not to include forest inventory as explanatory variable in roundwood supply function in Korea.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1172-1177
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• 1993

Dynamic characteristics of a hydraulic power supply are studied theoretically and computationally. The transfer function between the supply pressure and the load flow is derived considering relief valve dynamics, accumulator dynamics, and flow line dynamics. Frequency responses and time responses are obtained in many conditions using the transfer function and nonlinear mathematical model respectively.

• 한국전자거래학회지
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• 제7권3호
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• pp.121-137
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• 2002

SCM(Supply Chain Management) have been introduced in many companies for integrated management and improvement of business process. Recently, as internet and e-business concept are spread globally, the SCM concept is expanded from one internal company process to inter-company process, it makes a Global SCM concept. In this paper, we discuss the implementation of the Global SCM concept using e-business infrastructure, and propose SCM portal models. Four types of the SCM portal model are discussed, which are forecasting information sharing model, e-Marketplace-typed model, collaboration model and logistics information sharing model. The major concept of the SCM portal is to share information of supply chain process, it provide merits of scale to company. The result of this paper can be summarized as follows : First, the information sharing is very useful in the Global SCM. Second, the e-business infrastructure, especially e-Marketplace can be usefully used for implementation of SCM portal. Third, the M2M(Market to Market) function of e-Marketplace is a major function for implementing SCM portal.

• 대한안전경영과학회지
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• 제3권1호
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• pp.45-56
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• 2001

In the supply chain, The ATP function doesn't only give customers to confirmation of delivery. It can be used by the core function with ATP rule that can reconcile supplies and demands on the supply chain. Therefore We can acquire the conformation about accuracy on the due date of supplier by using the ATP function of management about real and concurrent access on the supply chain, also can decide the affect about product availability due to forecasting or customer's orders through the ATP. This study analyze the data concerned with ATP and define the necessity on a SCM solution. Under the these environments, after defining the ATP rule that can improve the customer value and data flow related the CRM, we propose the advanced ATP model that proposes the method and classification system that can flexibly aggregate the ATP data with ATP rule on the supply chain.

• 전기학회논문지
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• 제57권1호
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• pp.20-24
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• 2008

A bid-based pool(BBP) model is representative of energy market structure in a number of restructured electricity markets. Supply function equilibrium(SFE) models of interaction better match what is explicitly required in the bid formats of typical BBP markets. Many of the results in the SFE literature involve restrictive parametrization of the bid cost functions. In the SFE models, two parameters, intercept and slope, are available for strategic bidding. This paper addresses the realistic competition format that players can choose both parameters arbitrarily. In a fixed demand function, equilibrium conditions for generation company's profit maximization have a degree of freedom, which induces multi-equilibrium. So it is hard to choose a convergent equilibrium. However, consideration of stochastic demand function makes the equilibrium conditions independent each other based on the amount of variance of stochastic demand function. This variance provides the bidding players with incentives to change the slope parameter from an equilibrium for a fixed demand function until the slope parameter equilibrium.

• 산업공학
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• 제17권4호
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• pp.472-481
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• 2004

In this paper, we propose a linear programming model of supply planning process for the supply chain collaboration strategy of a company. The amount of its supplying quantity relies on outsourcing suppliers heavily. Conversely, the revenues of those suppliers are highly dependent on the supplying quota from the supply network planning of the company. In order to keep the supply stable through collaboration, the company builds such a policy to guarantee the fairness on revenue between the supplies. For this, the supply network plan should keep the capacity utilization ratio even for all the suppliers. But the production capacities are different and the distribution of molds is disproportional through suppliers, so the supply network plan is not easily established with simple arithmetic processes. Therefore, we developed the linear programming model with those target function and constraints minimizing the costs for holding inventory and penalty of delayed delivery, simultaneously guaranteeing the even capacity utilization through suppliers. The proposed model has been applied to real case and the evaluation for the planning result from the model would be followed in order to make sure that our model guarantee on extracting the supply network plan subordinated to the policy. Also we mention about further studies for improvement of the model.

• 한국산림과학회지
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• 제103권3호
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• pp.462-472
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• 2014

이 연구는 목제품의 수급모형을 개발하고, 제품별로 중장기적인 수요와 공급을 전망하는 데 목적이 있다. 목제품 시장 수급모형은 주요 제품인 제재목, 합판, 파티클보드, 섬유판, 펄프 등으로 한정하였다. 각각의 제품에 대해 공급함수, 수입수요함수, 수요함수 등을 추정하여 부분균형 모형을 구축하였다. 주어진 외생변수를 이용하여 2050년까지 전망한 결과 제재목, 합판, 섬유판 등의 국내공급 및 수입은 감소할 것으로 예상된다. 이는 환경보호와 자원의 무기화 등으로 인해 국내외 원목가격이 인상될 것이라고 예상하였기 때문이다. 반면 폐재를 재활용하는 파티클보드와 목재칩을 원료로 이용하는 펄프의 경우 전체적인 공급은 늘어날 것으로 전망된다.

• 상하수도학회지
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• 제30권1호
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• pp.59-67
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• 2016

Owing to time and cost constraints, new methods that would make it possible to evaluate the safety of the water supply pipeline in a less time- and cost-consuming manner are urgently needed. In response to this exigency, the present study developed a new statistical model to assess the safety of the water supply pipeline using the quantification theory type II. In this research, the safety of the water supply pipeline was defined as 'a possibility of the pipeline failure'. Quantification analysis was conducted on the qualitative data, such as pipe material, coating, and buried condition. The results of analyses demonstrate that the hit ratio of the quantification function amounted to 77.8% of hit ratio, which was a fair value. In addition, all variables that were included in the quantification function were logically valid and demonstrated statistically significant. According to the results derived from the application of the safety evaluation model, the coefficient of determination ($R^2$) between K-region's water supply pipeline safety and the safety inspection amounted to 0.80. Therefore, these findings provide meaningful insight for the measured values in real applications of the model. The results of the present study can also be meaningfully used in further research on safety evaluation of pipelines, establishing of renewal prioritization, as well as asset management planning of the water supply infrastructure.

• 설비공학논문집
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• 제11권6호
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• pp.758-765
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• 1999

The estimation of reasonable amount of domestic cold water and hot water supplies in apartment houses is very important for the economical design of domestic cold water and hot water supply system which include pumps, boilers, heat exchangers, and various water reservoirs. To suggest the model of predicting reasonable amount of domestic cold water and hot water supplies, residents and actual domestic cold water and hot water consumption have been investigated for 740 apartment houses in Seoul and Bun-Dang, Kyunggi-Do. The model is suggested as a function of exclusive area of the apartment house and results of the model show generally good agreement with published data.