• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.542-547
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• 1998

As the concern for a global energy conservation and environmental protection are increasing, it has been more important thing to correspond with CFC depletion. Alternate refrigerants have merit such as lower global warming effect, but also have demerits such as lower efficiency, miscibility, increasing noise and poor reliability problems. Then we have to develop more efficient, silent and robust compressors to satisfying world-wide demand. In this paper, parametric study on rotary compressor muffler for a room air-conditioner was carried out to investigate the effect of important design variables on noise by using Taguchi robust design method with signal-to-noise(S/N) ratio. Taguchi method seems to be helpful for finding optimum value of design variables for noise level. We also applied neural network to find optimal value of design variables.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.5
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• pp.367-373
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• 2013

In this article, we deal with a design problem for determining the levels of noise factors in the Taguchi method. First, the proposed levels by Taguchi method is reviewed in case of smaller-the-better performance characteristics. We obtain the optimal levels of noise factors minimizing the mean square error of SN(signal to Noise) ratio and compare the optimal levels with the levels proposed by Taguchi method under the first and second order models. Secondly, the concept of V-optimality is applied to determining the levels of noise factors.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.848-852
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• 2001

A new approach to the design of bank note counters is suggested. Modern bank note counters are equipped with several types of sensors for counting and detection of counterfeit bank notes. To achieve higher speed of counting while maintaining the sensing capability, longitudinal feeding scheme is proposed. Several merits of longitudinal feeding are discussed. Taguchi method is used for the optimization of the feeding mechanism.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.29-34
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• 2012

This study describes the selection of optimum machining conditions for a high-hardness resin by using a large 5-axis machine. The experiments were conducted to examine the main factors that affect the surface roughness, such as the spindle speed, axial and radial depths of the cut, and pattern of the cutter path. To analyze the experiment results, the factor with the biggest impact on machining was determined using the smaller-the-better characteristic of the Taguchi method; the effectiveness of the experiment was then confirmed by verifying the selected optimum machining condition.

• Journal of Korean Society for Quality Management
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• v.38 no.3
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• pp.408-412
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• 2010

In this note, we deal with a design problem for determining the levels of noise factors in the Taguchi method. Recently, Ree(2009) proposed a new method to determine the levels of noise factors that is dependent on the distribution of the noise factors. We discuss the original suggestion from Taguchi method, propose a way to compare the two methods and investigate the performance(mean square error) of two proposals by examples.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.37-46
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• 2004

A performance analysis for newly being considered electric rail car office has been made in this study. The major purpose is to examine a proposed design in terms of its capacity and the proposed number of travels (82-84) per day. For this study we first examined the overall system configuration with detailed operational processes of cleaning and inspection. We then developed a simulation model using ARENA and designed input data from 12 selected factors and their interaction effects. A simulation run for each treatment combination of $L_{16}(2^{15})$ orthogonal array was run and 20 batch means were obtained. Through careful analyses of the results obtained, we drew a diversity of suggestions including the best factor level combination. Our confirmation experiments at the optimal level combination further validate the possibility of 82 runs and the consistency in the results.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.66.2-66.2
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• 2010

미니탭(Minitab) 프로그램에 있는 실험계획법(Design of experiment)를 이용하여 박막실리콘 I-layer의 주효과 및 교호작용에 대한 연구를 실시하였다. I-layer의 주요 특성은 증착속도 및 전도도에 대하여 분석을 하였으며, 최종적으로 선택된 증착조건을 사용하여 비정질 실리콘 태양전지를 제조하여 확인 하였다. 실험설계는 2수준 5인자 완전설계요인법을 사용하였다. 분석결과 단막의 증착속도에 영향을 주는 주효과로는 Power와 E/S거리고 나타났으며, Power와 E/S거리, Power와 Pressure에서 큰 교호작용이 일어남을 확인 할 수 있었다. 암전도의 영향을 주는 주효과는 Sub. Temp.를 제외하고는 모두 영향을 주고 있었으며, 상당히 복잡한 교호작용을 이루고 있어 정확한 분석을 할 수는 없었다. 광전도도의 경우도 주효과에서 SiH4 flow rate를 제외하고는 모두 영향을 주고 있었으며, 복잡한 교호작용으로 정확한 분석이 어려웠다. 따라서 P-value를 분석하여 최종 R-제곱값이 증착속도는 97%이상의 높은 값을 얻었으나 전도도의 경우 최대차수 3차항으로 70~80%정도의 낮은 값을 얻었을 수 있었다. 낮은 값을 얻은 이유로는 실험설계시 몇몇 조건이 불안정한 plasma 상태로 인하여 전도도의 측정 편차가 커 분석오차가 높았을 것으로 추정된다. 암전도를 망소특성, 광전도도를 망대특성으로 광민감도 $10^5$으로 최적화 하여 비정질 태양전지를 만들어 평가한 결과 약 9%대의 광변환 효율을 얻을 수 있었으나 만족도 40%대의 낮은 값으로 향후 이와 관련한 더 정밀한 측정 및 분석이 요구된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4729-4735
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• 2014

To protect the environment, the regulation of emissions from off-road engines which are relatively neglected, is being reinforced. This paper deals with the robust design of off-road diesel engines considering the emission characteristics. Measurements of the NOx and PM levels based on the DOE were carried out. The injector hole number, injection timing and EGR rate were selected as the control factors. The orthogonal arrays table $L_9(3^3)$ was made from 2 or 3 levels for each factor and measurements of emissions were accomplished based on the table. The small-the-better SN ratio according to the Taguchi method was evaluated. The ANOVA (analysis of variance) for the SN ratio was conducted. The injection timing on the NOx emissions and the EGR rate on the PM have the largest effect on the low-load operation condition. The confidence levels of the control factors were more than 90%.

• 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.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.264-269
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• 2012

Die slide injection marvelously reduces the cost and time in processing plastic products because they can simplify the conventional process through eliminating additional process. However, this process must resolve some defects like whitening, resin infiltration, blowhole, resin overflow, etc. In this study, the process parameters of the injection molding are optimized by using the finite element method and Taguchi method. The injection molding analysis is simulated by employing the Moldflow insight 2010 code and the 2nd injection is by adopting the Multi-stage injection code. The process parameters are optimized by using the $L_{16}$ orthogonal array and smaller-the-better characteristics of the Taguchi method that was used to produce an airtight container (coolant reservoir tank) from polypropylene (PP) plastic material.rodanwhile, the optimum values are confirmed to be similar in 95% confidence and 5% significance level through analysis of variance (ANOVA). rooreover, new products and old products were compared by mdasuring the dimensional accuracy, resulting in the improvement of dimensional stability more than 5%.