• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1212-1221
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• 1993

The shape optimization procedure applying finite element method was carried out for the specific purpose of analysis of a tractor chassis frame. Minimization of the mass as an objective function is executed under multiple constrained conditions of nodal displacements and stresses. The optimization process executions were succeeded in converging into single optimum solution. Although mass reduction and stress alleviation were attained by 40% and 26 to 24% respectively , the geometry of the shape is so complicated for fabrication that the refinement of the geometry is of necessity.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.565-568
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• 1996

In this paper, a solution method is proposed to calculate the optimum solution to discrete optimal H$_{.inf}$ control problem for feedback of linear time-invariant system states and disturbance variable. From the results of this study, condition of existence and uniqueness of its solution is that transfer matrix of controlled variable to input variable is left invertible and has no invariant zeros on the unit circle of the z-domain as well as extra geometric conditions given in this paper. Through a numerical example, the noniterative solution method proposed in this paper is illustrated.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권1호
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• pp.19-30
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• 2002

This paper addresses characteristics of compressible flow dynamics inside a pipe with an accumulator and an inlet orifice. It also presents a simple but stable numerical method associated with the accumulator-orifice calculation. In particular, a focus is given to developing a method of finding an optimum design of the accumulator-orifice system (i.e., the accumulator size and the throttle resistance) that gives the most effective dissipation of the water-hammering problem. It is found that there exists indeed an optimum set of parameter values for the most effective dissipation of the wave energy.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.231-236
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• 1996

Recently to develope an automobile with better properties, much researches and investments are executed in many countries. In this paper, the weight of an engine block intend to minimize without changing the natural frequency. The weight minimization of an engine block is started from much less initial thickness than original thickness of the model and performed by using the sensitive analysis method and the optimum structural modification method. It can be considered that the weight minimization is completed through this process, because the optimum structural modification method includes the constraint of minimum changing quantity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.301-306
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• 1996

A torsional damper is generally used to reduce the torsional vibration which occurs at a crankshaft of a multi-cylinder high speed diesel engine. Vibration amplitude should be estimate by the appropriate simulation model to determine the optimum specifications of damper. In this paper a new method which was based on the random tabu search method(RTSM) would be introduced for the viscous damper design to optimize the damping performance. The result was ascertained by comparing with conventional rubber damper.

• 대한조선학회논문집
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• 제31권4호
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• pp.147-156
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• 1994

선체의 구조설계는 최적화 방법을 이용하여 상당히 오래 전부터 최적 구조설계 방법을 사용해 오고 있었으나, 대부분의 경우, 설계변수(設計變數)를 연속적인 실수(實數)로 가정하여 최적해를 구하거나, 아니면 실수(實數)와 정수(整數)가 혼합된 문제에 대해서는 뚜렷한 해결 방안을 제시하지 못하고 있는 실정이다. 특히 최적해의 국부(局部) 최적성 내지는 이산적(離散的) 변수 특성이 있는 최적설계 문제에 대해서는 몇개의 초기치를 사용하여 얻어진 최적해를 상호 비교하여 주어진 문제의 전체적(全體的) 최적해를 구하고자 하였다. 많은 경우 이러한 방법은 확실한 대안이 되지 못하고 본질적인 문제점은 미해결로서 남아 있어 왔다. 그래서 본 연구에서는 생물의 진화 법칙을 모사한 유전적(遺傳的) 알고리즘을 이용하여 선체 구조물의 최적설계시 고려해야 하는 보강재의 갯수를 정수(整數)로 취급하는 문제라든지 판 두께와 같이 이산적(離散的) 특성을 갖는 설계변수 문제 등(等)이 최적설계에 미치는 영향을 검토하여 보다 일반적인 최적화 방법으로서 유전적(遺傳的) 알고리즘의 유용성을 확인하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.25-30
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• 1997

In recent years, grinding techniques for precision machining of astainless steel used in shaft, screw parts and clear value have been improved by using superabrasive wheel and precision grinding machine. The completion of optimum dressing of superabrasive wheel makes possible the effective percision grinding of stainless steel. However, the present dressing system cannot have control of optimum dressing of the superabrabive 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. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of stainless steel(SUS304).

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1995년도 추계학술대회논문집
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• pp.87-90
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• 1995

Biomechanical can physchological approaches have provided the optimum stair dimensions but physiological approach has never been used in assessing the common method of assessing the optimum stair dimension. Therefore, this study was conducted to investigate the validity of the physiological measure of heart rate in assessing the optimum stair dimensions. Sixteen subjects were asked to walk up three different stairs with their normal walking speed. The results showed that the physiological approach with the heart rate difference was found to be valid in assessing the optimum stair dimension. The optimum stair dimension from this study (riser length for 185 mm and tread length for 310 mm) was chosen because it was similar to optimum dimension by the psychological approach (Irvine et al., 1990).

• 한국항행학회논문지
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• 제12권5호
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• pp.412-419
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• 2008

유전자 알고리즘은 효과적으로 최적의 해를 구하는 기법이나 진화연상산자의 선정에 따라 조기에 국부 최적해에 고착되어 전역 최적해로의 탐색을 어렵게 하는 문제점을 가지고 있다. 본 논문에서는 국부 최적해로 수렴하게 되는 원인을 분석하고, 국부 최적해에서 벗어나 전역 최적해로의 천이가 가능하도록 하는 방법을 제안하였다. 본 논문에서 사용한 방법은 평균 해밍거리에 따라 진화연산자를 가변시키는 방법으로서 국부 최적해에 고착되지 않도록 유전자에 다양성을 부여하여 지속적으로 모집단의 진화 특성을 유지하는 방법이다. 제안된 방법은 시뮬레이션을 통하여 효용성을 입증하였다.

• 한국생산제조학회지
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• 제7권5호
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• pp.29-37
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• 1998

In recent years, grinding techniques for precision machining of stainless steel used in shaft, screw parts and clear value have been improved by using the superabrasive wheel and precision grinding machine. The completion of optimum dressing of superabrasive wheel makes possible the effective precision grinding of stainless steel. 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 dressing of superabrasive wheel. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of stainless steel (STS304)