• Industrial Engineering and Management Systems
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• 제4권1호
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• pp.47-53
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• 2005

The efficiency of fabrication (fab) operation is one of the key factors in order for a semiconductor manufacturing company to stay competitive. Optimization of manpower and forecasting manpower needs in a modern fab is an essential part of the future strategic planing and a very important to the operational efficiency. As the semiconductor manufacturing technology has entered the 8-inch wafer era, the complexity of fab operation increases with the increase of wafer size. The wafer handling method has evolved from manual mode in 6-inch wafer fab to semi-automated or fully automated factory in 8-inch and 12-inch wafer fab. The distribution of manpower requirement in each specialty varied as the trend of fab operation goes for downsizing manpower with automation and outsourcing maintenance work. This paper is to study the specialty distribution of manpower from the requirement in a typical 6-inch, 8-inch to 12-inch wafer fab. The human resource planning in today’s fab operation shall consider many factors, which include the stability of technical talents. This empirical study mainly focuses on the human resource planning, the manpower distribution of specialty structure and the forecast model of internal demand/supply in current semiconductor manufacturing company. Considering the market fluctuation with the demand of varied products and the advance in process technology, the study is to design a headcount forecast model based on current manpower planning for direct labour (DL) and indirect labour (IDL) in Taiwan’s fab. The model can be used to forecast the future manpower requirement on each specialty for the strategic planning of human resource to serve the development of the industry.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.797-799
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• 1997

This paper presents an operation and planning model of integrated energy systems which consist of small scale cogeneration systems, thermal accumulator, ice storage and electrical energy storage systems. In the proposed planning model, an optimization of total cost which contains investment, operation, thermal shortage and salvage costs has carried out with the maximum principle based on the lifetime of each system component and unit price per capacity. From this model, optimal investment capacity per annum can be determined during the studied periods using the marginal costs according to the operation characteristics of each system component.

• 대한전기학회논문지
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• 제38권9호
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• pp.724-732
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• 1989

The structure of engine and its interaction are investigated and the construction of mathematical model for the performance evaluation is presented and then simulated. The total system is classified as air-fuel inlet element, intake manifold, combustion, and engine dynamics and their control function are schematically evaluated. Because of the model structure with general engine function and computer simulation of the chosen engine, physical characteristics of the corresponding engine and the engine data of normal operation state are used. According to the study, it is possible to predict the mixture rate by by the difference in the mass of fuel and air into cylinder and to evaluate and trace dynamic characteristic of operation state under various operating condition. The model characteristic under the transient operating condition makes it possible to effectively evaluate the operation of actual engine through the result of simulation.

• 한국수자원학회논문집
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• 제40권2호
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• pp.101-112
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• 2007

본 연구에서는 댐군을 연계운영할 경우 발생하는 효과를 이수측면에서 평가할 수 있는 방법을 개발하여 한강수계 댐군 운영 실적의 평가에 적용하였다. 개발된 평가방법에서는 용수공급과 유황개선 부분에서 연계운영의 효과를 평가하기 위하여 평가지점에서 필요수량에 대한 충족률과 유황안정도를 평가지표로 사용하였다 발전 부분에서 연계운영의 효과는 댐군에 의해 생산된 총발전량을 평가지표로 사용하였다. 실제 운영실적은 공칭공급량을 공급하는 단독운영과 최적화 모형에 의한 평가지표들과 비교하여 평가되었다. 한강수계의 2001년부터 2004년까지의 실제 연계운영 실적을 단독운영과 최적화 모형의 결과와 각 연도별로 비교해 보면, 용수공급 측면에서 필요수량 충족률은 단독운영은 $94.36{\sim}99.68%$, 실제운영은 $97.16{\sim}99.90%$, 최적화 모형은 4개년 모두 100.0 %를 나타냈다. 댐 운영 방법별로 하상계수와 유황계수를 사용하여 유황안정도를 평가해 보면, 유황이 단독운영 보다 실제운영과 최적화 모형이 더 안정적인 결과를 나타냈다. 실제 총발전량을 다른 운영방법의 결과와 비교해 보면, 최적화 모형은 실제 총발전량 보다 $-3.47{\sim}6.54%$ 증가된 결과를 나타냈으며, 단독운영은 실제 총발전량 보다 $12.68{\sim}38.94%$ 감소된 결과를 나타냈다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.639-643
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• 2007

Tidal regime change with general hydrolic condition change is examined, according to Garolim Tidal Power Plant (TPP) operation. Numerical model has been developed for the Yellow and East China Seas region, in order to consider the tidal regime change by the TPP operation. The changes of tidal elevation and tidal current inside the Garolim bay are also investigated in details, along with examining the change of the tidal flat area with operation. The field measurement for the tide and current have been carried out for the validation of the numerical model and for understanding the state of current system in the present state.

• 전기학회논문지
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• 제62권5호
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• pp.596-603
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• 2013

The increase of distributed power generation is closely related to interest in microgird including renuable energy sources such as photovoltaic (PV) systems and fuel cell. By the growing interest of microgrid all over the world, many studies on microgrid operation are being carried out. Especially operation technique which is core technology of microgrid is to supply heat and electricity energy simultaneously. Optimal microgrid scheduling can be established by considering CHP (Combined Heat and Power) generation because it produce both heat and electricity energy and its total efficiency is high. For this reason, CHP generation in microgrid is being spotlighted. In the near future, wide application of microgrid is also anticipated. This paper proposes a mathematical model for optimal operation of microgrid considering both heat and power. To validate the proposed model, the case study is performed and its results are analyzed.

• 산업경영시스템학회지
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• 제23권58호
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• pp.17-27
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• 2000

In FMS where tool movement policy is adopted, a mathematical model has been developed which determines the selection of a tool type for each operation and tool loading-part assignment simultaneouly. The objective is to minimize the total cost of operation including machining time cost, tool cost, tool replacement and loading time cost, and tool change time cost. Due to the complexity of the problem, an approximate solution procedure has been developed utilizing the special structure of the model. Tool selection was determined first to allocate one tool type to each operation considering more than one tool type alternatives for each operation. Tool loading-part assignment was determined to minimize tile total number of tool changes due to part mix based on the tool selection.

• 신재생에너지
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• 제3권2호
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• pp.3-10
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• 2007

Tidal regime change with general hydrolic condition change is examined, according to Garolim Tidal Power Plant (TPP) operation. Numerical model has been developed for the Yellow and East China Seas region, in order to consider the tidal regime change by the TPP operation. The changes of tidal elevation and tidal current inside the Garolim bay are also investigated in details, along with examining the change of the tidal flat area with operation. The field measurement for the tide and current have been carried out for the validation of the numerical model and for understanding the state of current system in the present state.

• 한국컴퓨터정보학회논문지
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• 제4권4호
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• pp.94-100
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• 1999

본 논문은 흡필드 모델의 실수연산을 고속으로 수행할 수 있는 디지털 신경회로망의 구현에 관한 연구이다. 흡필드 모델［1］-［8］의 연산과정은 행렬-벡터의 연산으로 기술 할 수 있으며, 이 연산과정은 순환, 반복적으로 이루어지므로 어레이프로세서 구조로 설계하기에 적합하다. 또한, Look-up-Table(연산표)에 의하여 비선형 함수를 출력함으로써, 고속의 실수 연산을 수행할 수 있도록 설계하였다. 본 논문에서 제안한 방법은 현재 개발된 VLSI기술로 실현 가능하기 때문에 실제 신경회로망의 응용분야에 이용될 수 있을 것으로 기대된다.

• 설비공학논문집
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• 제11권3호
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• pp.339-348
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• 1999

A computer model was developed in order to predict the temperature distribution and the performance of the vertical tube-in-tube ground coil heat exchanger. This model has been validated by experimental results conducted by ORNL. The heat exchanger performance with the variation of the length is calculated and compared. As results, the heat exchanger performance is proportional to the length but the performance per unit length decreases. The minimum performance of 70m - PVC heat exchanger during cyclic operation for a week is obtained 20,054kJ/h for cooling operation and 13,915kJ/h for heating operation. And minimum temperature difference is $4.64^{\circ}C$ for cooling operation and $2.64^{\circ}C$ for heating operation. In each case, it is noted that the temperature difference between the pipe and the far-field occurs within 0.8m from the heat exchanger.