• 한국공작기계학회논문집
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• 제14권1호
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• pp.58-65
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• 2005

A planetary gear trains has characteristics in compactness, power transformation ability and constant meshing. Usability is increased in applications of auto transmission and industrial gearbox. Study on optimum design of planetary gear train has been progressed on miniaturization of weight, miniaturization of planetary gear train and improvement of high strength. There are demands of study f3r the planetary gear train required long life estimation. In this work being considered life, strength, interference, contact ratio and aspect ratio, the optimum design algorithm is proposed to reduce the volume of planetary gear train with transferring the same amount of power. In the design of algerian for planetary gear train, the determination of teeth number is separated to achieve simplicity and the simulated annealing method as a global optimal technique is used far optimal design method.

• 한국공간구조학회논문집
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• 제24권3호
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• pp.35-42
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• 2024

Recent advances in computer technology have made it possible to solve numerous challenges but require faster hardware development. However, the size of the classical computer has reached its physical limit, and researchers' interest in quantum computers is growing, and it is being used in various engineering fields. However, research using quantum computing in structural engineering is very insufficient. Therefore, in this paper, the characteristics of qubits, the minimum unit of quantum information processing, were grafted with the crow search algorithm to propose QCSA (quantum crow search algorithm) and compare the convergence performance according to parameter changes. In addition, by performing the optimal design of the example truss structure, it was confirmed that quantum computing can be used in the architectural field.

• 통합자연과학논문집
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• 제13권3호
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• pp.92-96
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• 2020

Taguchi's robust parameter design is an approach to reduce the performance variation of quality characteristics in products and processes. In robust design, the signal-to-noise ratio (SN ratio) was used to find the optimum condition to minimize the variation of quality characteristics as much as possible and bring the average of quality characteristics closer to the target value. In this paper, we propose a simultaneous optimization method based on a linear model of the SN ratio as a method to find the optimal condition of the control factor in case of multi-characteristics. In addition, the proposed method and the existing method were compared and studied by taking actual cases.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.638-642
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• 2003

This paper presents a parameter design of an Electrorheological(ER) panel for noise reduction using Taguchi method. Taguchi method is a robust design method that determines control parameters in the presence of noise effect. Host structure thickness, spacer thickness, base oil viscosity and the weight ratio of ER particles are chosen for the control factors. A test setup in an SAE J1400 facility is used to analyze the sound transmission loss. The sensitivity of each factor with signal-to-noise(S/N) ratio and analysis of variance are investigated. The analysis results show that the weight ratio of ER particle and base oil viscosity of the ER fluid mostly affects the noise reduction in the presence of electric field. Based on the Taguchi method, an optimal configuration was designed and comparison is made with experimental result fer the verification.

• 대한안전경영과학회지
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• 제9권2호
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• pp.215-233
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• 2007

Even though the ad hoc Shewhart methods remain controversial due to various mathematical flaws, there is little disagreement among researchers and practitioners when a set of process data has a skewness distribution. In the context and language of process control, the error related to the process data shows that time to signal increases when a control parameter shifts to a skewness direction. In real-world industrial settings, however, quality practitioners often need to consider a skewness distribution. To address this situation, we developed an enhanced design method to utilize advantages of the traditional attribute control chart and to overcome its associated shortcomings. The proposed design method minimizes bias, i.e., an average time to signal for the shift of process from the target value (ATS) curve, as well as it applies a variable sampling interval (VSI) method to an attribute control chart for detecting a process shift efficiently. The results of the factorial experiment obtained by various parameter circumstances show that the VSI c control chart using nearly unbiased ATS design provides the smallest decreasing rate in ATS among other charts for all experimental cases.

• Geomechanics and Engineering
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• 제14권1호
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• pp.91-98
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• 2018

Length of a vehicle is an important variation to generate different variants of an automotive platform. This parameter is usually adjusted by embedding dimensional flexibility into different components of the Body in White (BIW) including the floor pan. Due to future uncertainties, it is not necessarily possible to define certain values of wheelbase for the future products of a platform. This work is performed to add flexibility into the design process of a length-variable floor pan. By means of this analysis, the cost and time consuming process of optimization is not necessary to be performed for designing the different variants of a product family. Stiffness and mass of the floor pan are two important functional requirements of this component which directly affect the occupant comfort, dynamic characteristics, fuel economy and environmental protection of the vehicle. A combination of Genetic algorithm, GMDH-type of artificial neural networks and TOPSIS methods is used to optimally design the floor pan associated with arbitrary length of the variant in the defined system range. The correlation between the optimal results shows that for a constant mass of the floor pan, the first natural frequency decreases by increasing the length of this component.

• 한국항공우주학회지
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• 제48권6호
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• pp.411-418
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• 2020

본 논문에서는 복합재 팬 블레이드의 구조적 성능에 대한 근사 및 최적설계 기법을 제안하였다. 그리고 이들을 활용하여 복합재 팬 블레이드의 질량 및 형상의 변화 없이 강성을 최대화하기 위한 적층 패턴의 최적설계를 수행하였다. 이 때 설계 변수 및 설계 영역을 축소하기 위하여 적층 파라미터를 도입하였고, 적층 파라미터의 특성을 활용하여 높은 적합도를 갖는 반응표면 근사모델을 생성하였다. 또한 효율적인 최적해 탐색을 위해 도함수 기반 방법과 유전자 알고리즘을 결합한 2단계 최적화 방법을 적용하였으며, 다양한 요구조건들을 고려한 다목적 최적설계를 수행하였다. 마지막으로는 초기 모델과 최적설계 모델의 유한요소해석 결과를 비교하여 적층 파라미터 기반의 근사 및 최적설계 기법을 검증하였다.

• 전자공학회논문지D
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• 제34D권10호
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• pp.68-76
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• 1997

In this paper, design parameters of rapid thermal processing(RTP) to minimize the wafer temperature uniformity errors are proposed. Lamp ring positions and the wafer height are important parameters for wafer temperature uniformity in RTP. We propose the method to seek lamp ring positions and the wafer gheight for optimal temperature uniformity. The proposed method is applied to seek optimal lamp ring positions and the wafer feight of 8 inch wafer. To seek the optimal lamp ring positions and the wafer height, we vary lamp ring positions and the wafer height and then formulate the wafer temperature uniformity problem to the linear programming problem. Finally, it is shown that the wafer temperature uniformity in RTP designed by optimal problem. Finally, it is hsown that the wafer temperature uniformity is RTP designed by optimal parameters is improved to comparing with RTP designed by the other method.

• 한국유체기계학회 논문집
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• 제15권3호
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• pp.32-38
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• 2012

This paper is aimed to propose the design database(DB) of the inline micro-turbine for 5kW class. CFD analysis is performed to investigate the effect of a turbine on each parameter. This study showed that RadhaKrishna's data is different from the 5kW class in the low-head and the micro-turbine. Therefore, new DB for the design of inline micro-turbine for 5kW class could be needed. This study configured new design DB for the design of inline micro-turbine for 5kW class. The DB of this study showed that the optimal hub ratio(Dp/DR), the optimal body ratio(Db/DR) and the optimal range of body length ratio(Lh/DR) is 50%, 1.1 and 2.3 to 2.9, respectively.

• 상하수도학회지
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• 제12권1호
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• pp.70-80
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• 1998

Many algorithms to find a minimum cost design of water distribution network (WDN) have been developed during the last decades. Most of them have tried to optimize cost only while satisfying other constraining conditions. For this, a certain degree of simplification is required in their calculation process which inevitably limits the real application of the algorithms, especially, to large networks. In this paper, an optimum design method using the Genetic Algorithms (GA) is developed which is designed to increase the applicability, especially for the real world large WDN. The increased to applicability is due to the inherent characteristics of GA consisting of selection, reproduction, crossover and mutation. Just for illustration, the GA method is applied to find an optimal solution of the New York City water supply tunnel. For the calculation, the parameter of population size and generation number is fixed to 100 and the probability of crossover is 0.7, the probability of mutation is 0.01. The yielded optimal design is found to be superior to the least cost design obtained from the Linear Program method by $4.276 million.