• 한국경영과학회지
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• 제31권2호
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• pp.129-140
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• 2006

Quantity Flexibility contract coordinates individually motivated supplier and buyer to the systemwide optimal outcome by effectively allocating the costs of market demand uncertainty. The main feature of the contract is to couple the buyer's commitment to purchase no less than a certain percentage below the forecast with the supplier's guarantee to deliver up to a certain percentage above. In this paper we refine the previous models by adding some realistic features including the upper and lower limits of the purchase. We also incorporate purchase and canceling costs in a cost function to reflect the real world contracting process more accurately. To obtain the solution of the model, we derive a condition for extreme points using the Leibniz's rule and construct an algorithm for finding the optimal solution of the model. Several examples illustrating the algorithm show that the approach is valid and efficient.

• 전자공학회논문지A
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• 제33A권3호
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• pp.55-64
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• 1996

In this paper, we analyze packaging data of th eprinted board assemblies (PBAs) of an ATM switching system (the first network test bed) by statistical methods and discuss the relation between devices packaging area of a PBA and power consumption by a regression nalysis method. As a result, we evaluate the maximum power consumption of the PBA. And, this paper presents a forecasting mehtod of the packagable maximum power consumption per a PBA when TTL devices are replaced by ASIC or FPGA ones in a PBA. And, we forecast the possibility of packaging ATM switch circuit packs in the near future form a statistical viewpoint. These evaluation and forecasting results can reduce much development cost and time because trial nd error will not be made using these useful data when phase II ATM switching system will be realized in the near future.

• 한국시뮬레이션학회논문지
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• 제7권2호
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• pp.33-43
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• 1998

To evaluate the server performance and forecast capacity requirements, we carry out simulation of Multimedia-on-demand(MOD) server. In multimedia service environment, especially for on-demand service, one of the key problems is capacity planning, which requires ensuring that adequate computer resources will be available to meet the future workload demands in a cost-effective manner. In this paper, we design and implement a simulation model for MOD server with failures of components (e.g., processors, disks and networks). By acquisition of utilization and queue length parameters, we can estimate desirable capacity of server components with various arrival rates of customers and failure rates of components. For a given failure probability, we also compute packet delay probability and reliability of the server. It is possible to derive some important design information of the MOD server by using the above parameters.

• 대한안전경영과학회지
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• 제12권3호
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• pp.183-188
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• 2010

The recent market trend of demand and supply of domestic paper industry expected confusion in near future due to massive imports of low cost product because of suddenly emerging of China's mass productive equipment and capacity. Related domestic industry is deploying joint co-coperative partnership and logistic service, joint operations of transportation and distribution center and innovation activity for customer satisfaction. This paper tries to present a solution through analysis of related paper industry a case study.

• 디지털산업정보학회논문지
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• 제4권3호
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• pp.115-126
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• 2008

This thesis is the research for methods to forecast of dynamic changes at retail stores in the ubiquitous era, and, through adopting RFID based technology, to minimize cost of operation of stores and bringing up better customer service. The core methods had been researched and studied are to build future-oriented stores by providing store system with better customer's convenience based on referring to case studies of future-oriented stores and efficient inventory management method enabling more profitable store, and adopting Smart Carts, Smart Shelf and e-POP and environment sensors as a method in order to provide more improved customer service.

• 산업공학
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• 제11권2호
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• pp.13-24
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• 1998

A distribution system is composed of multiple levels from a producer to customers, and it's objective is to supply customers with goods timely with a prescribed level of quality at a minimum cost. For the installation and operation of multi-echelon distribution system, DRP(Distribution Resource Planning) is widely used. However, because of the characteristic difference of material flow dynamic of each distribution center, it is almost impossible to get the optimal distribution scheduling. In this paper, an improved DRP method to schedule multi-echelon distribution network is proposed so that the lot-size and order point is dynamically obtained to meet the change of demand rate and timing. The experiment is done with various demand pattern, forecast errors of demand and lead times of central distribution center. The proposed method is compared with traditional statistical approach.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.169-170
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• 2009

국제물류에서 화물 표준화 단위인 컨테이너 물동량이 점점 증가함에 따라 컨테이너 공급부족 현상이 지속되어 컨테이너의 매매가 및 리스료도 높은 상승세를 기록하고 있다. 이러한 부분에서 컨테이너의 관리는 점점 중요시 되고 있는 실전이다. 그러나 대륙별 공컨테이너의 수급불균형은 점점 증가하고 있는 추세여서 예측이나 모형수립이 어려워 리스에 대한 의존율이 높아짐으로써 비용의 증가에 커다란 영향을 미치고 있다.

• 상하수도학회지
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• 제23권2호
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• pp.241-249
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• 2009

It is well known that the trend of water demand in large-size water supply systems has been suddenly changed, and many expansions of water supply facilities become unnecessary. To be cost-effective, thus, politicians as well as many professionals lay stress on the adaptive management of water supply facilities. Failure in adapting to the new trend of demand is sure to be the most critical reason of unnecessary expansions. Hence, we try to develop the model and modeling procedure that do not depend on the old data of demand, and provide engineers with the fast learning process. To forecast water demand of Seoul, the Bayesian parameter estimation was applied, which is a representative method for statistical pattern recognition. It results that we can get a useful time-series model after observing water demand during 6 years, although trend of water demand were suddenly changed.

• Current Research on Agriculture and Life Sciences
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• 제32권4호
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• pp.215-223
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• 2014

This study examines the contribution level of greenhouse gas(GHG) emission reduction and installation costs of renewable energy facilities. The GHG emission forecasts and industrial structures in the 16 regions of Korea are then analyzed to identify the proper supply of renewable energy sources for each region. The results show that water power is the most effective and efficient renewable energy source to reduce GHG emissions, followed by sunlight, wind power, geothermal heat, and solar heat, respectively. The 16 regions are then categorized into 4 groups based on their GHG emission forecast and industrial structure: high emission and manufacturing group, low emission and manufacturing group, low emission and service group, and high emission and service group. The proper supply of renewable energy sources for each group is then determined based on the contribution level and cost efficiency of GHG emission reduction.

• 한국건설관리학회논문집
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• 제7권6호
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• pp.185-192
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• 2006

공공임대주택의 경과연수가 증가함에 따라 시설물의 노후화로 인한 유지관리비용이 급격히 증가하고 있다. 이에 효과적으로 대처하기 위해서는 우선 비용에 대한 정확한 예측을 하고 필요한 재원을 확보하는 일이 무엇보다도 중요하다 따라서 시설물 유지관리비에 영향을 미치는 요인들을 분석하고, 이를 고려한 비용 예측방법의 개발이 필요하다. 공공임대주택 운영관리비의 약 60%를 국가에서 지원하고 있는 미국의 경우는 수년간의 실적데이터를 바탕으로 운영관리비를 효과적으로 예측할 수 있는 방법을 개발하여, 공공임대주택이 적정한 수준에서 잘 운영될 수 있도록 하고 있다. 그러나 아직까지 국내에서는 공공임대주택을 대상으로 운영관리비 영향요인이나 예측 툴에 관한 연구 실적은 매우 미흡한 실정이다. 본 논문은 최근 5년간 공공임대주택에 실제 지출된 운영관리비를 바탕으로, 시설물 유지관리비용에 미치는 영향요인과 요인별 영향력 등을 밝혀냄으로써, 향후 객관적이고 정확한 비용예측 도구를 개발하는데 일조 하고자 한다.