• 대한안전경영과학회지
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• 제11권1호
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• pp.205-211
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• 2009

In reality, distribution planning for a supply chain is established using a certain probabilistic distribution estimated by forecasting. However, in general, the demands used for an actual distribution planning are of deterministic value, a single value for each of periods. Because of this reason the final result of a planning has to be a single value for each period. Unfortunately, it is very difficult to estimate a single value due to the inherent uncertainty in the probabilistic distribution of customer demand. The issue addressed in this paper is the selection of single demand value among of the distributed demand estimations for a period to be used in the distribution planning. This paper proposes an efficient demand selection scheme for minimizing total inventory costs while satisfying target service level under the various experimental conditions.

• 한국환경과학회지
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• 제15권10호
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• pp.967-973
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• 2006

In this study used tank model and specific discharge to calculate low-flow of mountain basin and supply data that need in water resources plan. Low-flow is calculated byspecific discharge and area ratio method as resulted that calculate storage of low-flow by tank model was construed that showd all similar aspect. In judged to help in water resources plan establishment calculating low-flow using model to supplement uncertainty of observed data in that calculate of low-flow ungaged mountain area. It shows by economical and realistic plan until 12 years after development that run parallel and use economic performance analysis result valley flow and groundwater. But wide area water services and Chungju dam since 12 years onward was expose that is economic.

• 산업경영시스템학회지
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• 제36권3호
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• pp.43-50
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• 2013

In this paper, the single-period inventory problem, what is called newsboy problem, has been revisited with two different conditions, uncertain supply and risk-averseness. Eeckhoudt et al. [5] investigated the effect of risk-averseness of a newsboy on the optimal order quantity in a stochastic demand setting. In contrary to Eeckhoudt et al. [5] this paper investigates the effect of risk-averseness in a stochastic supply setting. The findings from this investigation say that if ${\alpha}^*$ represents the optimal order quantity without risk-averseness then the risk-averse optimal order quantity can be greater than ${\alpha}^*$ and can be less than ${\alpha}^*$ as well.

• 한국경영과학회지
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• 제38권2호
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• pp.43-63
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• 2013

Remanufacturing is a process of recovering end-of-life products into serviceable parts for producing new products. Due to the limited supply of recovery cores to remanufacture, a remanufacturing firm also needs to produce or procure new parts for fulfilling the demand. This paper is targeted for solving the problem of determining the optimal amount of newly produced and remanufacturing parts, which is called production and remanufacturing planning (PRP) problem, under uncertain supply of recovery cores. The new production mitigates the risk of insufficient core supply while it takes more costs than the remanufacturing. The PRP model in this paper also considers disassemble-to-order (DTO) environment, in which multiple kinds of parts are remanufactured from multiple products on order of the parts. Whereas existing studies presents only heuristic solutions for DTO remanufacturing, this paper provides an exact solution for this problem and analytical sensitivity of the involved cost parameters, adopting multi-dimensional newsvendor modeling and stochastic linear programming techniques. The result shows that production and remanufacturing plans for multiple products are mutually dependent, and a change of cost parameters involved in only one part is propagated to all other parts.

• 한국콘텐츠학회논문지
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• 제19권9호
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• pp.460-475
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• 2019

공급망 참여자들 사이의 정보공유가 가져다 주는 명확한 효과에도 불구하고 공급망 파트너 사이에 정보자원을 효과적으로 사용한 사례는 흔치 않다. 이와 같은 현상을 설명하기 위해 본 연구는 조직간 정보시스템 비대칭이라는 새로운 개념을 소개한다. 조직간 정보시스템 비대칭은 조직간 정보시스템을 통한 정보투명성에서 공급망 참여자 사이에 비대칭이 있는 것을 의미한다. 조직간 정보시스템 비대칭이 존재하면 조직간 정보시스템은 조직간 정보비대칭을 해소하지 못하고 오히려 이를 고착화시킴으로써 공급망 전체의 비효율을 유발할 수 있다. 본 연구는 이러한 현상이 실제로 나타나는지를 경험적으로 검증한다. 본 연구에서 사용한 데이터는 3종류의 제조업에 속한 중간부품 제조업자와 그들의 공급자들을 대상으로 수집하였다. 데이터 분석 결과, 조직간 정보시스템 비대칭은 전체적인 공급망 성과를 감소시키는 것으로 나타났다. 또한 조직간 정보시스템 비대칭과 공급망 성과의 관계는 환경불확실성에 의해 조절되는 것으로 발견되었다. 구체적으로 환경불확실성이 높을 때 조직간 정보시스템 비대칭이 공급망 성과에 더 큰 영향을 미치는 것으로 나타났다.

• 자원ㆍ환경경제연구
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• 제28권2호
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• pp.177-200
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• 2019

전력수급계획의 근간이 되는 전력수요 전망은 GDP와 기상변수 등 다양한 요인에 의해 영향을 받기 때문에 확률 프로세스로 이해할 수 있다. 이 전망치를 바탕으로 전력설비의 구성 방안이 수립되는데, 실제 의사결정 과정은 주어진 확률분포에 대한 정보가 온전하다고 가정한다는 한계를 가진다. 그러나 현실적으로는 확률분포 자체의 중첩 불확실성이 존재하기 때문에 강건한 최적계획(robust optimization)의 수립이 필요하다. 본 논문은 중첩 불확실성을 포함한 발전설비 조정의 최적의사결정을 연구한다. 구체적으로 원자력의 감축투자 관련 실물옵션 모형을 수립하고 우리나라 전력수급기본계획의 특성을 고려한 중첩 불확실성하에서 원전감축 투자를 분석한다. 분석 결과, 현재의 원전축소 정책은 전력수요 증가율이 낮다는 것을 전제로 한 정책으로서 전력수요 증가에 대응할 수 있는 정책 강건성을 갖추지는 못한다는 것을 보여준다.

• 산경연구논집
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• 제10권1호
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• pp.51-58
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• 2019

Purpose - Manufacturers in uncertain environments need to depend on governance mechanisms to reduce the inherent risk in these environments. However, few studies have examined which governance mechanisms a given manufacturers will develop in uncertain environments for managing the relationships with its vertical partner. This study explores how different governance mechanisms function under uncertain environmental circumstances. We also try to investigate the contextual effect of interfirm benevolence as moderator. Research design, data, and methodology - This research provide the conceptual framework of interfirm benevolence on which this research's propositions are predicted. The theoretical background for environmental uncertainty, governance mechanisms and interfirm benevolence will be discussed. Results - The expected results are as follows. Manufacturers in an uncertain environments rely on different governance mechanisms under conditions of high and low interfirm benevolence. In terms of role of interfirm benevolence, interfirm benevolence provides a better understanding of how governance mechanisms can develop in an uncertain supply markets. Conclusions - This research suggests several theoretical and practical implications between channel partners, particularly, this research offers that interfirm benevolence is a crucial competitive factor under environmental uncertainty situation. In future studies, it is necessary to investigate the effect of each governance mechanism structure on performance in an uncertain environment and various level of interfirm benevolence.

• Asian Journal of Business Environment
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• 제11권4호
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• pp.17-29
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• 2021

Purpose: The aim of this study is to explore the dynamic linkage between conditional stock market volatility and macroeconomic uncertainty of Bangladesh. Research design, data, and methodology: This study uses monthly data covering the time period from January 2005 to December 2018. A comprehensive set of macroeconomic variables, namely industrial production index (IP), consumer price index (CPI), broad money supply (M2), 91-day treasury bill rate (TB), treasury bond yield (GB), exchange rate (EX), inflow of foreign remittance (RT) and stock market index of DSEX are used for analysis. Symmetric and asymmetric univariate GARCH family of models and multivariate VAR model, along with block exogeneity and impulse response functions, are implemented on conditional volatility series to discover the possible interactions and causal relations between macroeconomic forces and stock return. Results: The analysis of the study exhibits time-varying volatility and volatility persistence in all the variables of interest. Moreover, the asymmetric effect is found significant in the stock return and most of the growth series of macroeconomic fundamentals. Results from the multivariate VAR model indicate that only short-term interest rate significantly influence the stock market volatility, while conditional stock return volatility is significant in explaining the volatility of industrial production, inflation, and treasury bill rate. Conclusion: The findings suggest an increasing interdependence between the money market and equity market as well as the macroeconomic fundamentals of Bangladesh.

• Journal of Construction Engineering and Project Management
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• 제4권2호
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• pp.31-40
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• 2014

The management of vehicular supply of "perishable" construction material, such as concrete mixes, faces a series of uncertainties such as weather, daily traffic patterns and accidents. Presented in this paper is a logistics control model for managing a hauling fleet with interrelated processes at both ends and queue capacities. Discrete event simulation is used to model the complex interactions of production units and the randomness of the real world. Two alternative strategies for ready mix concrete delivery, with and without an off-site waiting queue, are studied to compare supply performance. Secondly, the paper discusses the effect of an agent-based GPS tracking system providing real-time travel data that lessens the uncertainty of trucking time. The results show that the combination of GPS information with off-site queuing reduces productivity loss and process wastes of concrete placement as well as the idleness of supply trucks when crew or pump experience an unexpected stoppage.

• Industrial Engineering and Management Systems
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• 제14권3호
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• pp.248-274
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• 2015

This study discusses a contract to promote collection and recycling of used products in a green supply chain (GSC). A collection incentive contract is combined with a reward-penalty contract. The collection incentive contract for used products is made between a retailer and a manufacturer. The reward-penalty contract for recycling used products is made between a manufacturer and an external institution. A retailer pays an incentive for collecting used products from customers and delivers them to a manufacturer with a product order quantity under uncertainty in product demand. A manufacturer remanufactures products using recyclable parts with acceptable quality levels and covers a part of the retailer's incentive from the recycled parts by sharing the reward from an external institution. Product demand information is assumed as (i) the distribution is known (ii) mean and variance are known. Besides, the optimal decisions for product quantity, collection incentive of used products and lower limit of quality level for recyclable parts under decentralized integrated GSCs. The analysis numerically investigates how (1) contract for recycling activity, (ii) product demand information and (iii) quality of recyclable parts affect the optimal operation for each GSC. Supply chain coordination to shift IGSC is discussed by adopting Nash Bargaining solution.