• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.534-537
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• 2000

Recently, A manufacturing formula centered of the customer is one of the most important parts for the company competition. Especially, it is the matters of weight and importance that Make to Order(MTO) and Make to stock(MTS) is considered at the same time for designing manufacturing system based the order effectly. This paper suggests a alternative Available to promise(ATP) and capable to promise(CTP) to confirm the delivery time to customer, how to link mid-long term production plan with short term daily based scheduling, how to relate middle processes of device based industry to mid-long term plan through the example of S company in a manufacturing formula mixed MTO and MTS

• 제어로봇시스템학회논문지
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• 제6권5호
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• pp.426-432
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• 2000

A novel mixed-integer linear programming model for the short-term scheduling of a sequential multipurpose batch plant is addressed. First, a time slot domain to each unit is introduced. By assigning each time slot to a product, we obtain the production sequence that minimizes makespan. For multiple-unit assignment problem where a few parallel units with the same function exist, production paths are defined for the distinction of the same stage with a different unit. As a second issue, the model adapted for sequence dependent changeover is presented. For a time slot of a unit, if a product is assigned to the time slot and a different product is assigned to the adjacent time slot, the changeover time considering this situation is included. The performance of the proposed models are illustrated through two examples.

• 대한전기학회논문지:전력기술부문A
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• 제48권8호
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• pp.917-923
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• 1999

This paper proposes an efficient method of hydro-thermal scheduling in coordination with head variation and hydraulically coupled plants using Evolutionary Programing(EP). Based on the EP technique, the proposed algorithm is capable of determining the global optimal solutions. The constraints such a power balance condition, water available condition and transmission losses are embedded and satisfied throughout the proposed EP approach. The effectiveness of the proposed approach is demonstrated on the test systems and compared to those of other method. The results show that the new approach obtains a more highly optimal solutions than the conventional other methods such as newton-raphson method, Dynamic Programming(DP), LU factorization.

• 에너지공학
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• 제6권1호
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• pp.11-18
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• 1997

본 논문은 에너지 효율이 높은 열병합발전시스템을 대상으로 유전알고리즘을 적용하여 단기운전계획을 수립하였다. 특히 열병합발전시스템의 효율은 약 70%이지만 효율이 일정하지 않을 뿐만 아니라 비선형적인 특징을 가지므로 실제 산업체의 열병합발전소의 데이터를 기초로 하여 적합한 가변효율방정식을 구하였다. 또한 본 논문에서 적용된 유전알고리즘은 계산시간의 감소와 높은 정밀도를 가진 실변수 유전알고리즘으로 시뮬레이션 하였다. 그 결과로 가변효율을 가진 열병합발전시스템의 단기운전계획이 유전알고리즘을 적용하여 적절하게 운전계획이 수립되고 있음을 나타내었으며 각종 보조설비가 유연성 있게 협력하며 필요시마다 효율적으로 운전되고 있음을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.4016-4027
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• 2014

Understanding network latency is important for providing consistent and acceptable levels of services in network-based applications. However, due to the difficulty of estimating applications' network demands and the difficulty of network latency modeling the management of network resources has often been ignored. We expect that, since network latency repeats cycles of congested states, a systematic classification method for network status would be helpful to simplify issues in network resource managements. This paper presents a simple empirical method to classify network status with a real operational network. By observing oscillating behavior of end-to-end latency we determine networks' status in run time. Five typical network statuses are defined based on a long-term stability and a short-term burstiness. By investigating prediction accuracies of several simple numerical models we show the effectiveness of the network status classification. Experimental results show that around 80% reduction in prediction errors depending on network status.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.543-545
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• 1995

The purpose of this paper is to determine the proper reliability criteria used in generation expansion planning of electric utilities. In this paper, we tried to combine long-term generation expansion planning and short-term weekly maintenance scheduling program package. We set two scenarios in which the O&M technology of power plants will be improved or not in the future. We performed LOLP sensitivity analysis for each scenario to determine the optimum reliability criteria in the power system operation aspects.

• 산업경영시스템학회지
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• 제34권3호
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• pp.97-105
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• 2011

Previous researches have focused on the efficiency of project execution and the satisfaction of internal customers In view of the fact that a project is successful if any defects are not found in the short-term performance test of the project final outcome. To execute a project that both internal customer and external customer are satisfied in terms of longer-term benefit perspective, the project claim costs (PCC) which may occur for the warranty period of the project final outcome should be considered. We propose a model included PCC to the linear programming between time and cost to expedite a project and perform the validity test by applying the model to an example project. This model and related procedure will contribute to overall project activities' cost reduction by taking preventive actions for PCC.

• 제어로봇시스템학회논문지
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• 제12권12호
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• pp.1163-1168
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• 2006

Manufacturing technology for the production of high value-added fine chemical products is emphasized and getting more attention as the diversified interests of customers and the demand of high quality products are getting bigger and bigger everyday. Thus, the development of advanced batch processes, which is the preferred and most appropriate way of producing these types of products, and the related technologies are becoming more important. Therefore, high-precision batch distillation is one of the important elements in the successful manufacturing of fine chemicals, and the importance of the process operation strategy with quality assurance cannot be overemphasized. Accordingly, proposing a process structure explanation and operation strategy of such processes including batch processes and batch distillation would be of great value. We investigate optimal operation strategy and production planning of multi-purpose plants consisting of batch processes and batch distillation for the manufacturing of fine chemical products. For the short-term scheduling of a sequential multi-purpose batch plant consisting of batch distillation under MPC and UIS policy, we proposed a MILP model based on a priori time slot allocation. Also, we consider that the waste product of being produced on batch distillation is recycled to the batch distillation unit for the saving of raw materials. The developed methodology will be especially useful for the design and optimal operations of multi-purpose and multiproduct plants that is suitable for fine chemical production.

• 전기학회논문지
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• 제60권4호
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• pp.717-725
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• 2011

In the power system with an electric storage system that can increase utilization rate of the source of such new renewable energy, this paper introduces the approach on the daily unit commitment scheduling that determines simultaneously optimum operational condition and output of thermal generators and electric storage device. The unit commitment is one of the most important issues in economic operation and security of short-term operational plan of the power system. It is to determine on/off status of generator to minimize operational cost during the given period. The committed generator should satisfy various operational limitation such as estimated demand by system, spinning reserve condition within minimum operational cost. In order to determine on/off or charge/discharge/idle condition and output level of units and electric storage system, the MILP(Mixed Integer Linear Programming) is suggested. The proposed approach is the mixed method between LP(Linear Programming) and IP(integer programming) which seeks the value of real number and integer that maximize or minimize function objective within given condition. The daily unit commitment problem with the electric storage system is applied to MILP algorithm through linearization and formulation process. The proposed approach is applied to the test system.

• 한국콘텐츠학회논문지
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• 제18권6호
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• pp.564-573
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• 2018

최근 들어 기업의 외부 환경은 글로벌 경쟁, 원가 절감과 이윤 확보에 대한 압박 및 신기술의 급격한 발전 등에 의해 매우 급속하게 변화하고 있다. 특히, 고객 요구 사항의 빈번한 변화는 제조 기업에게 심각한 도전이 되고 있다. 이러한 도전에 대응하기 위해서는, 고객 서비스 향상과 운영 효율성 제고를 위해 여러 관리 기능 중에서 생산계획 기능이 우선적으로 정립되어야 한다. 생산계획은 전체 공급망 관리 중에서 생산 프로세스에서의 단기적 의사결정을 다루며, 그 역할은 고객 주문과 제한된 자원 사이에서 균형을 찾는 것이다. 본 논문의 목적은 공급망 관리 관점에서 생산계획의 기능성과 시스템 아키텍처를 분석하고, 이를 기반으로 생산계획 솔루션들 간의 비교를 가능케 하기 위한 분류 프레임워크를 제시하는 것이다.