• 대한전기학회논문지
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• 제34권1호
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• pp.29-37
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• 1985

During Severe emergencies which result in the case of outage of large generator units, an automatic underfrequency protection scheme can prevent the system frequency from decaying and improve the system stability. This paper presents methods and results of a study on the optimum load shedding scheme which covering as follows. 1) Detail representation of governor model 2) Determination of optimum load shedding amount 3) Selection of action time settings of UFR 4) Comparsson of load shedding programs By this study, the optimum system operating method was recommended for reliable operation of power system.

• 한국항해학회지
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• 제25권3호
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• pp.211-223
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• 2001

Optimum Ship Routing can be defined as \"The selection of an optimum track for a transoceanic crossing by the application of long-range predictions of wind, waves and currents to the knowledge of how the routed vessel reacts to these variables\". This paper treats the methodology how to solve optimum ship routing problem by network modeling and reveals the validity of the network model by some numerical experiments.periments.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.563-564
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• 2006

In silicon wafer manufacturing process, the grinding process has been adopted to improve the flatness of water. The grinding of wafer is usually used by the infeed grinding machine. Grinding conditions are spindle speed, feed speed, rotation speed, grinding stone etc. But grinding condition selection and analysis is so difficult in grinding machine. In the intelligent grinding system based on knowledge many researchers have studied expert system, neural network, fuzzy etc. In this paper we deal grinding condition selection method, Taguchi method and Genetic Analysis.

• Architectural research
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• 제23권4호
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• pp.67-73
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• 2021

An efficient demolition process requires the optimum method selection considering stability, economic feasibility, environment, and workability. In reality the construction cost and period are priority concerns, and safe construction methods are neglected. In addition, the choosing demolition method is often determined subjectively by experienced field engineers. This research paper presents a multi-criteria decision-making method using Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to select the optimum demolition method. Three experienced demolition engineers' opinions were used to develop the TOPSIS model. The case study showed that the preferences of ten attribute measurements for demolition method selection. Authors suggested the most preferable demolition method for the case study project.

• 대한지리학회지
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• 제28권2호
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• pp.137-147
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• 1993

본 연구의 목적은 GIS 기법을 이용하여 지형을 분석함으로써 서울-동두천 간의 추가령곡에서 최적 방어지역을 선정하는 것이다. 연구내용은 지형요소에 의한 보병부대의 최적방어지역 선정, 접근로를 중심으로 한 최적방어지역 선정, 그리고 양자간 차이점의 비교${\cdot}$분석이다. 연구과정은 최적 방어지역의 선정을 위한 고려요소의 검토, GIS를 이용하여 지역을 선정하는 과정 그리고 선정된 최적지역을 분석하는 과정의 세가지로 구성된다. 지형요소를 고려한 보병부대의 최적 방어지역은 도봉산, 수락한, 와방산, 국사봉 등과 같은 험준한 산악지역이며, 접근로를 고려한 최적 방어지역은 국사봉-축석령-불국산을 연결하는 동-서의 지역으로서 공간적 패턴이 특징적으로 나타난다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1523-1524
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• 2013

• 한국지리정보학회지
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• 제4권4호
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• pp.8-20
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• 2001

본 연구는 공공시설의 적지선정을 위해 기존의 방법과는 다른 방법론을 제시하였다. 본 연구의 적지선정모형은 다양한 입지인자를 고려하여 입지인자의 상대적인 중요도에 따라 다단계로 가중치를 부여하여 후보지를 평가하는 방법이다. 여기에 GIS의 도면중첩방법(지도대수)을 적용하여 여러 다양한 입지요인을 만족시키는 후보지를 찾아내는 방법을 제시하였다. GIS를 이용한 적지분석은 간단하면서도 효과적이고, 많은 자료를 시각화할 수 있는 장점이 있다. 이 방법을 사례지구인 대구시 달성군 군청사의 입지선정에 적용하여 후보지를 평가하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4326-4341
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• 2016

In this paper, an adjustable multiple relay selection (MRS) scheme for cooperative communication with amplify-and-forward (AF) relay under frequency selective channels is proposed. In the proposed scheme, the relays are ordered firstly by the steady-state mean square error (MSE), then the relays are sequentially selected out from N relays and the number of cooperating relays is adjusted dynamically according to the steady-state mean square joint error (MSJE). The aim of this work is to dynamically estimate the optimum number N_o of cooperating relays. Optimum means the minimum number of cooperating relays, N_o, achieving the minimum level of steady-state MSJE. Numerical results verify the analyses and show that the scheme can adaptively adjust the number of cooperating relays, and outperform conventional relay selection schemes. Hence, the proposed scheme provides better tradeoff between BER performance and spectral efficiency and to save more energy in cooperative wireless networks.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.153-160
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• 2009

The demand for super tall building construction is increasing worldwide. There has been a constant request for achieving early payback on investment by shortening the construction time. This pertains especially for the case of huge investment projects such as super tall building construction. It is very important to shorten the construction time for the building framework, which requires substantial construction time and cost, and this is directly related to the establishment of an optimum lift plan for construction. When there is a problem in the selection of the lift equipment, it is almost impossible to revise the selection, resulting in a possible failure of the project. Thus, the purpose of this study is to analyze the function and logic for the development of the process for the selection of lift equipment for super tall building projects and further development of making the analyzed process into a system. In line with this research objective, the process of selecting the optimum lift equipment by domestic construction company was investigated and analyzed as well as collecting the actual field data. The actual data were obtained by sensors installed on tower cranes at three construction sites with the help from the construction company.

• Membrane and Water Treatment
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• 제8권2호
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• pp.137-147
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• 2017

A water treatment utility in South Korea operates a large system of pressurized hollow fiber membrane (PHFM) modules. The optimal selection of membrane module for the full scale plant was critical issue and carried out using Risk-based Life Cycle Cost (RbLCC) analysis based on the historical data of operation and maintenance. The RbLCC analysis was used in the process of decision-making for replacing aged modules. The initial purchasing cost and the value at risk during operation were considered together. The failure of modules occurs stochastically depending on the physical deterioration with usage over time. The life span of module was used as a factor for the failure of Poisson's probability model, which was used to obtain the probability of failure during the operation. The RbLCC was calculated by combining the initial cost and the value at risk without its warranty term. Additionally, the properties of membrane were considered to select the optimum product. Results showed that the module's life span in the system was ten years (120 month) with safety factor. The optimum product was selected from six candidates membrane for a full scale water treatment facility. This method could be used to make the optimum and rational decision for the operation of membrane water purification facility.