• Title/Summary/Keyword: 다구치방법

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A Study on the Prediction Technique of Impact Dispersion Area for Flight Safety Analysis (비행안전분석을 위한 낙하분산영역 예측 기법에 대한 연구)

  • Choi, Kyu-Sung;Sim, Hyung-Seok;Ko, Jeong-Hwan;Chung, Eui-Seung
    • Aerospace Engineering and Technology
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    • v.13 no.2
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    • pp.177-184
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    • 2014
  • Flight safety analyses concerned with Launch Vehicle are performed to measure the risk to the people, ship and aircraft using impact point and impact dispersion area of debris generated by on-trajectory failures and malfunction turns. Predictions of impact point and impact dispersion area are essential for launch vehicle's flight safety analysis. Usually, impact dispersion area can be estimated in using Monte-Carlo simulation. However, Monte-Carlo method requires more several hundreds of iterative calculations which requires quite some time to produce impact dispersion area. Herein, we check the possibility of applying JU(Julier Uhlmann) transformation and Taguchi method instead of Monte-Carlo method and we propose a best method in terms of compuational time to produce impact dispersion area by comparing the results of the three methods.

Statistical approach to obtain the process optimization of texturing for mono crystalline silicon solar cell: using robust design (단결정 실리콘 태양전지의 통계적 접근 방법을 이용한 texturing 공정 최적화)

  • Kim, Bumho;Kim, Hoechang;Nam, Donghun;Cho, Younghyun
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.47.2-47.2
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    • 2010
  • For reducing outer reflection in mono-crystalline silicon solar cell, wet texturing process has been adapted for long period of time. Nowadays mixed solution with potassium hydroxide and isopropyl alcohol is used in silicon surface texturing by most manufacturers. In the process of silicon texturing, etch rate is very critical for effective texturing. Several parameters influence the result of texturing. Most of all, temperature, process time and concentration of potassium hydroxide can be classified as important factors. In this paper, temperature, process time and concentration of potassium hydroxide were set as major parameters and 3-level test matrix was created by using robust design for the optimized condition. The process optimization in terms of lowest reflection and stable etch rate can be traced by using robust design method.

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Numerical Analysis of Mold Deformation Including Plastic Melt Flow During Injection Molding (플라스틱 유동을 고려한 사출성형 충전공정 중 금형의 변형 해석)

  • Jung, Joon Tae;Lee, Bong-Kee
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.7
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    • pp.719-725
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    • 2014
  • In the present study, a numerical analysis of an injection molding process was conducted for predicting the mold deformation considering non-Newtonian flow, heat transfer, and structural behavior. The accurate prediction of mold deformation during the filling stage is important to successfully design and manufacture a precision injection mold. While the local mold deformation can be caused by various factors, a pressure induced by the polymer melt is considered to be one of the most significant ones. In this regard, the numerical simulation considering both the melt filling and the mold deformation was carried out. A mold core for a 2D axisymmetric center-gated disk was used for the demonstration of the present study. The flow behavior inside the mold cavity and temperature distribution were analyzed along with the core displacement. Also, a Taguchi method was employed to investigate the influence of the relevant parameters including flow velocity, mold core temperature, and melt temperature.

Performance measures for correlated multiple characteristics in parameter design (다특성치 파라미터 설계의 평가척도에 관한 연구)

  • 김욱일;강창욱
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1994.04a
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    • pp.367-369
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    • 1994
  • 지금까지 다구치 방법에서는 다특성치 문제에 있어서 특성치들 간의 관계를 무시하고 특성치들은 서로 독립이라는 가정 하에, 각 특성치에 대한 최적공 정조건을 찾아 다특성치로 확장시키는 방법이 사용되었다. 그러나 현실적으 로 많은 다특성치 문제에서 특성치들 간의 상관관계가 존재한다. 따라서 본 연구에서는 특성치들 간의 상관관계를 고려한 새로운 평가척도를 제시하고 자 한다. 본 연구에서는 각 특성치와 특성치들 간의 상관관계에 가중치를 부 여하는 방법을 사용하였다. 다특성치 손실함수를 단일 특성치 종류의 조합에 따라 여섯개의 모형으로 구분하였고, 각 모형의 다특성치 손실함수는 특성치 자체에 의해 야기되는 손실과 특성치들간의 관계에 의해 야기되는 손실로 나누었다. 또한 새로운 평가척도로는 다특성치 손실함수의 각 항에 의해 야 기되는 기대손실의 합인 다특성치의 기대손실을 선택하였다. 본 연구의 타당 성에 대해서는 기존의 데이터를 이용. 분석하여 기존 논문과 비교하였다.

The Performance of the National Authorization System of Private Qualification (강건설계방법을 활용한 창의적 문제해결 실습과정)

  • Kim, Tai-Oun
    • Journal of Engineering Education Research
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    • v.11 no.1
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    • pp.64-75
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    • 2008
  • A new product development and product realization process (PRP) is a circulating and feedback process by generating ideas through creative problem solving process. The early stages of PRP correspond to conceptual design and product development, in which a large portion of product life cycle cost can be saved. The optimal design method for this stage is a robust design suggested by Taguchi. Quality must be 'engineered in' since it can not be 'inspected out.' A robust design is an engineering methodology to improve the quality of a product by minimizing the efforts of variations without eliminating the causes. The objective of this study is to propose a scheme and a case study of robust design for exploring design parameters, and introduce a creative problem solving process. Major research subjects include a creative problem solving process, robust design procedure and their implementation. For the experiment of Taguchi method, a toy catapult is adopted. For the creativity development, a short project is assigned to devise a similar tool with the toy catapult. A reference model is suggested to compare and evaluate their ideas.

Effect of Design Factors on the Performance of Stratified Thermal Storage Tank (성층축열조의 성능에 대한 설계인자의 영향)

  • Chung Jae Dong;Park Joohyuk;Cho Sung-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.11
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    • pp.1077-1083
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    • 2004
  • This study is to systematically analyze the effect of various kinds of design factors on the performance of stratified thermal storage tank. Taguchi method, known as a very reasonable tool in the parametric study, is employed in the present work. Three dimensional unsteady numerical experiment is conducted for 4 design parameters of stratified thermal storage tank: inlet Reynolds number, Froude number, diffuser size d with 3 levels (Re=400, 800, 1200, Fr=0.5, 1.0, 2.0 and d=150 mm, 200mm, 300 mm) and diffuser shape with 2 levels. Orthogonal array $L_{18}(2{\times}3^7)$ is adopted for the analysis of variance. The result gives quantitative estimation of the various design parameters affecting the performance and helps to select the main factors for the optimum design of stratified thermal storage tank. Reynolds number is found to be the most dominant parameter and the diffuser shape plays significant role on the performance of stratified thermal storage tank. Based on this finding, the prior questions on the contribution of the diffuser shape proposed by the authors become clear. The optimum condition for the performance is a set of d=300mm, Re=800, and radial regulated plate diffuser. Conformation test shows the repeatability in the analysis and $1.3\%$ difference between the estimated thermocline thickness and that of numerical result.

Optimizing the Injection Molding Process for Cooling Filter Using Computer Simulation and Taguchi Methods (컴퓨터 시뮬레이션과 다구치 방법을 이용한 냉각 필터 사출성형 공정의 최적화)

  • Lee, Seung-Hoon;Min, Byeong-Hyeon;Kim, Byeong-Gon
    • IE interfaces
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    • v.15 no.3
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    • pp.263-269
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    • 2002
  • The injection molding process is a one of the most efficient techniques for manufacturing plastic parts of complex shape at low cost. In injection molding, molten plastic material is injected into the mold and cooled. Selection of molding conditions greatly affects the quality of molded parts. In this case study, we attempted to optimize the injection molding condition for a cooling filter using Taguchi experimental design methodology. The injection molding experiments were carried out using the Moldflow simulation software.

Determination of Optimum Micro Drilling Conditions Using Experimental Design Methods (실험계획법에 의한 마이크로 드릴링 공정의 최적 절삭조건 결정)

  • 김동우;조명우;이응숙;서태일
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.993-998
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    • 2002
  • watches, air bearings and printed circuit hoards (PCB). However, it is not easy to determine optimum cutting conditions since the micro drilling process is very sensitive to various disturbances. Also, undesirable characteristics to optimize the micro drilling are small signal-to-noise ratios, drill wandering motions and high aspect ratios. Thus, in this study, experimental design methods are applied to determine optimum cutting conditions. Suing the methods, three cutting parameters, fred, step and curving speed are optimized to minimize thrust forces. Obtained conditions are verified through required experimental works. As the results, it is shown that the experimental methods can be applied to micro drilling processes to determine Optimum Cutting Conditions.

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Empirical Design Method for the Damping Force Characteristics of Shock Absorbers (쇽압쇼바 감쇠력 특성의 실험적 설계법 연구)

  • Baek, W.K.;Kim, C.M.
    • Journal of Power System Engineering
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    • v.15 no.4
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    • pp.11-18
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    • 2011
  • A Shock absorber is one of the most important components in vehicle suspension systems. In general, many repeated analyses are required for the design of a shock absorber to satisfy the suspension characteristics of a specific automobile, like fluid flow analysis and mechanical analysis. The purpose of this study is to develop a fast design tool for shock absorber designers. One of the efficient solutions for this can be an empirical design method considering phenomenological effects from the shock absorber design variables. In order to extract the shock absorber's experimental characteristics, we used Taguchi method. This method showed that which design variables have major effects for the shock absorber's damping characteristics. This empirical design method also showed the direction of the design changes to satisfy the designer's intension.