• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.86-91
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• 2016

End milling is an important and common machining operation because of its versatility and capability to produce various profiles and curved surfaces. This paper presents an experimental study of the cutting force variations in the end milling of SM25C with HSS(high speed steel) and carbide tool. This paper involves a study of the Taguchi design application to optimize cutting force in a end milling operation. The Taguchi design is an efficient and effective experimental method in which a response variable can be optimized, given various control and noise factors, using fewer resources than a factorial design. This study included feed rate, spindle speed and depth of cut as control factors, and the noise factors were different cutting tool in the same specification. An orthogonal array of $L_9(3^3)$ of ANOVA analyses were carried out to identify the significant factors affecting cutting force, and the optimal cutting combination was determined by seeking the best cutting force and signal-to-noise ratio. Finally, confirmation tests verified that the Taguchi design was successful in optimizing end milling parameters for cutting force.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1362-1365
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• 2003

On this study. we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized buckling strength of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result optimization achievement repeatedly using statistical orthogonal array of experimental design.

• International Journal of Quality Innovation
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• v.5 no.2
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• pp.1-16
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• 2004

Credit scoring is widely used to make credit decisions, to reduce the cost of credit analysis and enable faster decisions. However, traditional credit scoring models do not account for the influence of noises. This study proposes a robust credit scoring system based on Mahalanobis-Taguchi System (MTS). The MTS, primary proposed by Taguchi, is a diagnostic and forecasting method using multivariate data. The proposed approach's effectiveness is demonstrated by using real case data from a large Taiwanese bank. The results reveal that the robust credit scoring system can be successfully implemented using MTS technique.

• Journal of Korean Society for Quality Management
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• v.24 no.1
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• pp.96-109
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• 1996

In this paper, we consider the quality problem of black oxide process in casting for which Taguchi method is used. We explain simply the Taguchi method and existing problems in Black Oxide process. We analyze the problem by the quality improvement procedure proposed by Taguchi. The design factors and noises using cause-effect diagram are found, the experiment is made using orthogonal array. After ANOVA, the critical factors are determined and the optimal process condition is designed. After parameter design, we derive the tolerance levels. As a result of changing the levels of process parameters, the variance of quality characteristic was decreased by quarter and the average value was also decreased by half. We estimated the predictable profit of the improvement.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.92-97
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• 2012

Injection mold is a manufacturing process used to produce parts of complicated shape at a low cost. Many factors affect the quality of injection molded part during injection molding process. A study on the optimization of injection mold is progressed by using a simulation software like Moldflow. Filling, packing and cooling phases of injection molding processes are analyzed according to the mold design considering the shrinkage of molded part, the degree of filling rate and the wearing of a mold. Taguchi method is applied to analyze the significance of processing parameter and the dynamic characteristics according to the variation of processing parameters. From the results, the mold temperature and packing pressure influenced the shrinkage of injection molded part.

• Journal of Microbiology
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• v.43 no.1
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• pp.38-43
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• 2005

Lactic acid production parameter optimization using Lactobacillus amylovorus NRRL B-4542 was performed using the design of experiments (DOE) available in the form of an orthogonal array and a software for automatic design and analysis of the experiments, both based on Taguchi protocol. Optimal levels of physical parameters and key media components namely temperature, pH, inoculum size, moisture, yeast extract, $MgSO_4{\cdot}7H_20$, Tween 80, and corn steep liquor (CSL) were determined. Among the physical parameters, temperature contributed higher influence, and among media components, yeast extract, $MgSO_4{\cdot}7H_20$, and Tween 80 played important roles in the conversion of starch to lactic acid. The expected yield of lactic acid under these optimal conditions was 95.80% and the actual yield at optimum conditions was 93.50%.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.36-44
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• 2000

In this paper drill shape and cutting conditions for environmentally conscious dry drilling of A319 Al-alloy are studied by experimental method. The experiment is planned with Taguchi's method that is based on the orthogonal array of design factors. The result is summarized as follows (1) Drill geometry optimization can increase the number of holes in dry drilling and also large helix angle and large point angle are desirable in dry drilling. (2) It is found that cutting conditions that is cutting speed and feed rate are closely related to the drill geometry(3) For dry drilling of Al-alloys drill shape and cutting conditions are selected and tested by experimental method. But it is found that the perfect dry drilling is difficult because of the machining characteristics of Al-alloys and so new machining method such as minimal lubricant application is required.

• 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.

• 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.

• 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.