• 대한기계학회논문집A
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• 제21권8호
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• pp.1298-1310
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• 1997

In recent years, grinding techniques for precision machining of brittle materials used in electric, optical and magnetic parts have been improved by using superabrasive wheel and precision grinding machine. The completion of optimum dressing of superabrasive wheel makes possible the effective precision grinding of brittle materials. However, the present dressing system cannot have control of optimum dressing of the superabrasive wheel. In this study, a new system and the grinding mechanism of optimum in-process electrolytic dressing were proposed. This system can carry out optimum in-process dressing of superabrasive wheel, and give very effective control according to unstable current and gap increase. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of brittle materials.

• 한국강구조학회 논문집
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• 제13권4호
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• pp.337-349
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• 2001

교량은 계속적으로 변하는 하중 환경에 의해서 다른 구조물에 비해 비교적 빨리 노후화 되기 때문에 초기비용 이외에도 교량의 유지관리, 교통의 원활한 소통 또는 적체 등에 따른 비용, 교량의 손상에 따른 보수보강 및 교량의 해체 재건설 등 추가적인 비용의 영향이 크므로 공용간 생애주기 비용(LCC)을 설계단계에서부터 체계적이고 합리적으로 고려되어야 한다. 이에 본 연구에서는 강상판교의 설계에 있어서 주형의 휨 전단, 사용성, 피로에 대한 보강기대비용 등을 포함하는 LCC에 근거한 비용함수모형을 이용하여 이를 최적설계에 적용하고 기존의 설계방법과 비교 분석하였다. 적용예제의 결과에 나타난 바와 같이 LCC를 고려한 강상판 교량의 최적설계는 더욱 합리적이고, 경제적이며, 안전한 설계를 유동할 수 있으리라 판단된다.

• 한국시뮬레이션학회논문지
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• 제10권2호
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• pp.1-14
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• 2001

The layout design of component plays an important role in the design and usability of many engineering products. The Engineering artifacts of today are becoming increasingly complicated. The simulated annealing method has been applied effectively to the layout and packing problems of wafer. The main characteristics of simulated annealing method is that an optimum can be obtained from the many local optimums by controlling the temperature and introducing the statistic flickering. The objective of this study is to suggest a method to apply the simulated annealing method to the three dimensional layout design of submergible boat which has multiple constraint conditions and evaluation criteria. We describe an approach to define cost function, constraints and generate layouts using a computer. In this research three dimensional LAYout Design Optimization Program(LAYDOP ver.2) has been developed. The layout result(the total value of evaluation criteria) designed by a human layout expert has been improved by 31.0% using this program.

• 대한기계학회논문집B
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• 제20권1호
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• pp.255-265
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• 1996

Up to the present the study on the performance prediction of HAWT was performed mainly by assuming the axial flow. So in this paper we aimed at the fully non-axial flow of HAWT. For this purpose, we defined the wind turbine pitch angle in addition to the yaw angle to specify the arbitrary wind direction. And we adopted the Glauert method as the basic analysis method then modified this method suitably for our goal. By comparing the computational results obtained by this modified new Glauert method with the experimental results, it was proved that our method was a very efficient method. And on the basis of the reliability of this method we considered the effect of all the design parameters and presented the optimum blade geometry and the optimum operating condition to gain the best performance curve.

• 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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.227-232
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• 1994

Recently, TBM (Tunnel Boring Machince) method for a tunnel construction in domestic is very promisible due to shorten a constrution period. It is very important to increase the efficiency of the shotcrete for the TBM. The major factors influencing the efficienty of shotcrete are materials, mix disign, constrution conditions and skill of nozzle-man. In this paper, first, optimum synthesize conditions for the shotcrete accelerators was explored and early stiffenting mechanisms also studied. Second, TBM method was applied for a real job site using the optimum conditions obtained from a lab scale experiment.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.129-135
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• 2001

The optimum design problems for the design of counterforted wall were formulated and computer programing to solve these problems were developed in this study. Both discrete optimization and continuous optimization method were applied to the design of counterforted wall and the results of these optimization methods were compared each other.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.252-253
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• 2006

This paper presents OC relay coordination to protect distribution system by Adaptive Evolutionary Algorithm(AEA). AEA is a optimization method to overcome the problems of classical optimization. The results show that the proposed method can improve more optimum relay settings than present available methods.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.246-249
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• 2003

무인 표적기에 탑재될 추진 시스템인 프로펠러를 설계하였다. 프로펠러 설계 방법으로 Vortex theory를 적용하였으며 설계 변수에 따른 프로펠러 성능을 해석하였다. 최적 설계 목표는 효율의 최대화이며, 또한 설계된 프로펠러의 성능을 해석하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.312-317
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• 1997

This paper present an optimum design for the rotor-bearing system of a high-speed (80000RPM) ultra-centrifuge supported by ball bearings with nonlinear stiffness characteristics. To obtain the nonlinear bearing stiffnesses, a ball bearing is modelled in five degrees of freedom and is analyzed quasi-statically. The dynamic behaviors of the nonlinear rotor-bearing system are analyed by using a transfer-matrix method iteratively. For optimum design, minimizing the weight of a rotor is used as a cost function and the Augmented Lagrange Multiplier (ALM) method is employed. The result shows that the rotor-bearing system is optimized to obtain 8% weight reduction.