• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.162-165
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• 2004

On this study, we improved diaphgram for micro speaker performance using Taguchi method in discrete design space. The design of diaphgram has an effect on performance of micro speaker such as, thickness of diaphgram, shape of diaphgram, etc. Therefore this study carried to decide shape of diaphgram and thickness of diaphgram for minimizing 2nd natural frequency of diaphgram using Taguchi method. we showed improved design factors that minimized 2nd natural frequency of diaphgram. Also, 2nd natural frequency of diaphgram for micro speaker is reduced up to 37 percent maintaining twist mode shape. From the results of ANOVA, 2nd natural frequency of diaphgram for micro speaker have an effect on position of the outer curved shape and thickness of diaphgram.

• Journal of Intelligence and Information Systems
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• v.5 no.1
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• pp.1-12
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• 1999

강건설계(robust design)는 낮은 비용으로 잡음에 강건한 고품질의 제품이나 공정을 설계하는 체계적이고 효율적인 방법이다. 그러나 강건설계의 과정 중 비표준 직교배열의 사용과 교호인자을 포함한 실험계획은 다소 복잡하고, 전문지식이 필요한 부분으로 비전문가에는 난해한 작업이다. 이를 해결하기 위하여 본 연구에서는 표준직교배열의 변형과 선점도를 이용하여 교호인자를 직교배열의 열에 자동으로 할당하는 전문가시스템 prototype을 개발하였다. 사용자가 수준별 인자수와 교호작용의 유무를 입력하면, 시스템은 적절한 직교배열을 선정하여 필요에 따라 변형하며, 제어인자와 교호작용을 직교배열표에 자동으로 할당하여 출력한다. 개발된 시스템을 사용함으로써 초보자도 직교배열을 쉽게 변형할 수 있으며 다수의 교호인자를 포함한 실험계획을 빠르게 할 수 있다. 본 연구에서 이용된 지식은 문헌에서 추출하였으며, 추론 전략으로는 규칙기반추론(rule-based reasoning)을 이용하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.10
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• pp.773-784
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• 2002

This paper proposes an optimal design to improve the performance of the intake system by reducing the noise. We adapt the Taguchi method and column merging method for the above design. At the first stage of the design, the length and radius of each component of the current intake system are selected as control factors. Then the $L^{18}$ table of orthogonal array is used to get the effective main factors. At the second stage, the $L^{16}$ table of orthogonal array and the column merging method is combined to analyze subdivided significant factors. We know that the robust design with the column merging method provides better design for noise of intake system than the robust design itself.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.71-78
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• 2010

The end shape of tube for automobile power steering system has influence on the ability of performance. In this case study, we attempted to optimize the forming process of a small tube using Taguchi experimental design methodology. A preliminary experiment was conducted and four main control factors were selected. The experiment was set up as an $L_9(3^4)$ orthogonal array, and determined the optimal levels of the four factors through the analysis of the experimental results. As a result, the performance characteristic(close adhesion power) of the product was improved about 36%. In addition, the process capability index $C_{pk}$ is enhanced from 0.94 to 6.85.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.4
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• pp.31-38
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• 2012

In this paper, we selected primary cutting parameters that influence on surface roughness of cut bottom surface in end-milling for SM25C material. Those are overhang, depth of cut, feed rate and spindle speed. And then performed orthogonal array experiment and ANOVA by Taguchi method to determine that improved level combination of cutting parameters for betterment of working efficiency and surface roughness one of quality characteristics. And we verified a advisability of prediction model by verification test about level combination. From the results, main cutting parameter influences on surface roughness is spindle speed and the next is feed rate.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.48-53
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• 2009

Inconel 718 alloy, widely used as material of aircraft engine, has a good mechanical property in high temperature, strong anti-oxidation characteristics in oxidated current over $900^{\circ}C$, and also is not easily digested in the air containing sulfur, therefore, its usage as mechanical component is expanding rapidly. Even though Inconel alloy 718 is difficult to machine, it requires highly precise processing/machining to sustain its component quality of high accuracy. In this paper, general turning operation conditions are tested to select the best cutting process condition by measuring surface roughness through implementing experiments with orthogonal array of cutting speed, feeding speed and cutting depth as processing parameters based on the Taguchi method. Optimal turning operation conditions are extracted from the proposed experimental models.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.158-163
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• 1997

In this paper the tool geometry of the PSS test were optimized in order to assure the reliability of the test. Considering many factors for optimization of the tool geometry, computer-simulation technique using three-dimensional finite element method(FEM) was used. Three design variables -the punch length, punch crown and punch corner radius- are chosen to be optimized according to the Taguchi's experiment technique with the L9 orthogonal array. The optimum condition to ensure the plane strain mode over the overall area of the specimen was clarified. Moreover the simulation results are confirmed by experiment.

• Journal of the Korean Society of Safety
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• v.21 no.1 s.73
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• pp.21-27
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• 2006

In this paper, object of experiment is to study on the effect parameters to obtain optimal surface roughness in face turning. Surface roughness is significantly important to be high quality of parts produced by turning process. For this purpose, the optimization of cutting parameters for face turning operation is investigated applying the Taguchi method. An orthogonal array, signal-to-noise, and the analysis of variance are employed to evaluate effect of cutting parameters for face turning. Also confirmation tests were performed to make a comparison between the results predicted from the mentioned correlations and the theoretical results. Cutting experiment is performed without cutting fluid using coated tungsten carbide insert about workpiece of SM45C. And regression analysis technique has been used to study the effects of the cutting parameters.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.710-715
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• 2004

There are a lot of manholes such as for water supply, sewage, telecommunication cable, traffic sign, electricity supply, and rainwater, etc. Conventional manholes installed on a road are impossible to adjust height, so that they should be entirely excavated to reinstall or repair. This entire excavation of a manhole causes too much time-consuming work, waste of resources, and obstruction of traffic. In this study, in order to solve the above mentioned problems, a cover, outer and inner parts of a manhole are integrated by gear-shaped parts located between outer and inner parts of a manhole. Mechanical design is performed to determine dimension of gear-shaped parts by Taguchi orthogonal array table. Cast molds for a gear-shaped manhole are also manufactured.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.80-85
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• 2006

HSS (high strength steel) is widely applied to reduce the weight but improve the strength in automobiles. This research has been peformed to secure a methodology to accurately predict the springback of HSS for successful tool and process designs in sheet stamping operations. We first peformed U-draw bending test to evaluate the springback characteristic. We then evaluated forming and springback processes using the 1-row model of the finite element method. Based on the peformance measure and parameters selected, extensive analyses of the factor effects on the springback have been made using experimental design concepts. We specifically selected Taguchi's orthogonal array, $L_{18}(2^1{\times}3^7)$, and the optimal level combination of the factors have been drawn from the analysis.