• 한국경영과학회지
• /
• 제20권2호
• /
• pp.77-93
• /
• 1995

A mathematical model for long-rage water supply planning was formulated as a dynamic plant location problem with network arc capacity expansion, and illustative example was presented. The proposed solution procedure identifies economical construction timings of surface water supply facilities and water conveyence systems and the best water supply operating patterns as well. In this study, we present a heuristic solution procedure using Simulated annealing Method in conjunction with Bertsekas & Tseng's RELAXT-II for the 0-1 integer network problem.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 2007년도 추계학술대회 및 정기총회
• /
• pp.67-89
• /
• 2007

This study addresses manufacturers' ability to influence their supply chain network in order to adapt to their competitive environment. From the perspective of a manufacture, the supply chain comprises a network of suppliers and customers, and is theoretically viewed as a complex adaptive system. This study considers the following questions: (1) How can adaptability of supply chain network be operationally defined? (2) How does adaptability of supply chain network lead to combinative capabilities? (3) What is the influence of adaptability of supply chain network on business performance? Drawing on literature streams in supply chain management, operations strategy, organizational change and learning, and complexity theory, this study develops and tests the constructs and operational measures of adaptability of supply chain network and model the nomological set of relationships among constructs that form the basis of our theory. This study then develops and tests a model describing the outcomes of adaptability of supply chain network and its influence on combinative capability and business performance. Empirical results of this study show that adaptability supply chain network directly and positively affects combinative capability. Further, this study finds that adaptability of supply chain network does not impact business performance directly, but rather is mediated through combinative capability, which provides the requisite variety for firms to survive and thrive in dynamic environments.

• 한국시뮬레이션학회논문지
• /
• 제21권1호
• /
• pp.55-68
• /
• 2012

최근 경제는 제조업에서 서비스업으로 이동하고 있기 때문에 서비스 공급사슬을 이해하는 것이 중요하다. 그러나, 공급사슬과 관련된 기존연구의 대부분은 제조업에 집중하고 있다. 이러한 상황을 극복하기 위해서, 서비스 공급사슬을 조사하고 분석할 필요가 있다. 시뮬레이션은 복잡한 시스템을 분석하고 설계하는데 가장 자주 사용되는 기법 중에 하나이다. 서비스 공급사슬은정교한 설계 단계가 필요한 복잡하고 거대한 시스템이다. 특히, 서비스 공급사슬의 성과를 예측하기 위해서 서비스 공급사슬을 구성하고 있는 구성요소 사이의 동적인 상호작용의 행위를 밀접하게 조사하는 것이 중요하다. 본 연구에서는 첫 번째로 서비스공급사슬의 개념적 모델이 개발된다. 다음으로 개발된 서비스 공급사슬의 개념적 모델에 대한 시뮬레이션 모델을 개발하기위한 새로운 절차를 제시한다. 시뮬레이션 모델링의 절차는 UML 분석과 설계 도구를 이용하며 ARENA 시뮬레이션 언어로 구현된다. 제안된 절차의 두 가지 주요한 특성은 서비스 공급사슬을 설계하는데 체계적인 절차의 정의와 또한 ARENA 시뮬레이션 언어로 개념적 모델의 변환에 대한 규칙을 제공한다. 본 연구의 결과는 서비스 공급사슬의 지식을 개선하는데 이용될 수 있으며, 또한 서비스 공급사슬 시뮬레이션 모델의 개발을 효율적으로 할 수 있도록 지원한다.

• 한국경영과학회지
• /
• 제34권3호
• /
• pp.55-69
• /
• 2009

It is often to apply revenue sharing models in rental industries which consist of a retailer and a wholesaler. This research analyzed the influences to profit of the supply chain if we adopt the revenue sharing model when the demand is uncertain and price sensitive. We found the conditions of the revenue sharing model to maximize the profit of the supply chain, and identified incentive compatible conditions for revenue sharing. It is proved that vertical integration guarantees maximization of profit for the supply chain. Also we found that it is possible to derive Incentive compatible schemes by controlling ranges of revenue sharing ratios.

• Management Science and Financial Engineering
• /
• 제10권2호
• /
• pp.29-51
• /
• 2004

In this paper, the cost impact of incorrect assumptions about the demand process in a supply chain in which there are two participants, a retailer and a manufacturer, is considered. When participants in the supply chain do not notice serial correlation in the demand process, they would turn to a simple inventory model based on an i.i.d. demand assumption. A mathematical model that allows us to quantify the cost incurred by each participant in the supply chain, when they implement inventory policies based on correct or incorrect assumptions about the demand process, is developed. This model enables us to identify how much it differs from the optimal costs.

• 전기학회논문지
• /
• 제65권5호
• /
• pp.883-887
• /
• 2016

The power supply system in Korean electrified railway has adopted AT feeding. If a fault occurs in some substation for any reason, the vicinity substation must feed electric power on the outage substation through catenary. So, the feeding distance grows twice of the normal state at extended feeding condition. If substation's feeding distance is longer than normal condition, the catenary impedance and train to supply electric power from the substation. Therefore, the severe voltage drop can occur and power supply shall be not allowed. This paper presents the model of compensator against voltage drop using multi-port network algorithm. Whole traction power supply system can be analyzed with this model. Computer simulation including this model is performed based on real train schedule and increased schedule in case studies.

• 대한산업공학회지
• /
• 제24권4호
• /
• pp.475-483
• /
• 1998

Structural changes in an economy system bring about serious problems in establishing economic policies. The boom of middle-east export, the oil shock, and the recent dollar crisis in Korean economy are such examples. Hence, it is necessary to identify and estimate those structural changes. This study focuses on an output and price and analyzes structural changes in aggregate demand and supply. The aggregate demand and supply structures are described by conventional dynamic simultaneous equations model, where each structural change is represented by dummy variables and estimated by the proposed Bayesian method. By applying this model to Korean output and price, structural changes in the aggregate demand and supply are analyzed.

• KDI Journal of Economic Policy
• /
• 제43권2호
• /
• pp.1-22
• /
• 2021

The effects of social distancing measures on income distributions and aggregate variables are examined with an off-the-shelf heterogeneous-agent incomplete-market model. The model shows that social distancing measures, which limit households' labor supply, can decrease the labor supply of low-income households who hold insufficient assets and need income the most given their borrowing constraints. Social distancing measures can therefore exacerbate income inequality by lowering the incomes of the poor. An equilibrium interest rate can fall when the social distancing shock is expected to be persistent because households save more to prepare for rising consumption volatility given the possibility of binding to the labor supply constraint over time. When the shock is expected to be transitory, in contrast, the interest rate can rise upon the arrival of the shock because constrained households choose to borrow more to smooth consumption given the expectation that the shock will fade away. The model also shows that social distancing shocks, which diminish households' consumption demand, can decrease households' incomes evenly for every income quantile, having a limited impact on income inequality.

• 대한안전경영과학회지
• /
• 제22권4호
• /
• pp.45-52
• /
• 2020

Recently, a multi facility, multi product and multi period industrial problem has been widely investigated in Supply Chain Network(SCN). One of keys issues in the current SCN research area involves minimizing both production and distribution costs. This study deals with finding an optimal solution for minimizing the total cost of production and distribution problems in supply chain network. First, we presented an integrated mathematical model that satisfies the minimum cost in the supply chain. To solve the presented mathematical model, we used a genetic algorithm with an excellent searching ability for complicated solution space. To represent the given model effectively, the matrix based real-number coding schema is used. The difference rate of the objective function value for the termination condition is applied. Computational experimental results show that the real size problems we encountered can be solved within a reasonable time.

• 산업공학
• /
• 제13권3호
• /
• pp.348-357
• /
• 2000

SCM(Supply Chain Management) is a new approach to satisfy customers via an integrated management for the whole business processes of the manufacturing from the raw material procurement to the product or service delivery to customers. Typically the semiconductor industry is the one whose supply chain network is distributed all over the world, and its manufacturing process has the particular characteristics which has to be considered in the modeling of supply chain. In this paper we suggest the push and pull type supply chain models based on the manufacturing characteristics and their mathematical formulation for the semiconductor industry. Push supply chain model pursuits the high throughput and the balance of the WIP flow, and pull supply chain model does to minimize the total cost of order-based manufacturing, distribution and transportation process in order to meet customer's request appropriately.