• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.495-501
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• 2011

The purpose of this study is to improve the roundness of CNC turning so that helps the operator to choose the right turning conditions to produce a product with the given parameters. This paper focuses on determining the optimal levels of machining factors for circular shaft with CNC turning. For this purpose, the optimization of factors is performed based on experimental design method. A design and analysis of experiments are conducted to study the effects of these factors on the roundness by using the SIN ratio, analysis of ANOVA, and F-test. Factors, namely, fixed pressure, wall thickness, depth of cut, and feed rate are optimized with consideration of the roundness. The boring tool used in this study is a tungsten carbide coated. The material of workpiece is Al6061 and the machining method is dry cutting.

• Transactions of Materials Processing
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• v.24 no.2
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• pp.121-129
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• 2015

A net-shape forming of small and complex-shaped metal parts by metal injection molding (MIM) has economic advantages in mass production, especially for STS 316L valve fitting. STS 316L offers excellent corrosion resistance, but it has poor machinability, which is a limitation in using it for a cost-effective production where both forging and machining are employed. Simulation and experimental analysis were performed to develop a MIM STS 316L 90° elbow fitting minimizing trial and error. A Taguchi method was used to determine which input parameter was the most sensitive to possible defects (e.g. sink mark depth) during the injection molding. The final prototype was successfully built. The results indicate that the simulation tool can be used during the design process to minimize trial and error, but the final adjustment of parameters based on field experience is essential.

• Korean Journal of Materials Research
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• v.3 no.5
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• pp.514-520
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• 1993

In this paper the cure cycle of carbon fiber/phenolic resin was investigated by the Taguchi Method in an experimental design. Experiments were systematically performed using $L_{18}(2^1 \times 3_7)$ orthorgonal array table of the experimental design. In the experimental design, eight compression molding parameters (heating rate, pressing temperature, pressing rate, molding pressure, curing temperature, dwell time at curing temperature, cooling rate and degassing) were considered and the effects of the parameters on the flexural strength and the apparent porosity of carbon fiber/phenolic composites were investigated. The analysis of variance for the experimental results indicated that molding pressure and curing temperature are the most significant parmeters in the flexural strength and the apparent porosity of carbon fiber/phenolic resin composites, respectively.

• Tunnel and Underground Space
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• v.22 no.4
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• pp.257-265
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• 2012

In this study, a series of CFD (Computational Fluid Dynamics) simulations carried out to evaluate the optimum design model of the internal flow path of drill bit. The Star-CCM+ code was adopted to simulate the multi-phase discharge flow of rock particles and flushing air during a drilling process. The input parameters for the flow simulation of rock particles and air were obtained from the in-situ drilling test results. After the three design factors were determined, the experimental design method (Taguchi method) was utilized to evaluate the optimum value of each factor.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.20-25
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• 2012

As a kind of distributed energy system, the co-generation system based Diesel engine using after-treatment device was devised for its environmental friendly and economic qualities. It is utilized in that the electric power is produced by the generator connected to the Diesel engine, and waste heat is recovered from both the exhaust gases and the engine itself by the finned tube and shell & tube heat exchangers. An after-treatment device composed ceramic heater and DOC(Diesel Oxidation Catalyst) is installed at the engine outlet in order to completely reignite the unburned fuel from the Diesel engine. In this study, mutual relation of each experimental condition was derived through minimum number of experiment using Taguchi Design and ANOVA recently used in the various fields. It is found that the total efficiency (thermal efficiency plus electric power generation efficiency) of this system reaches maximum 94.4% which is approximately higher than that of the typical diesel engine exhaust heat recovery system.

• Journal of the Korean Institute of Gas
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• v.8 no.4 s.25
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• pp.30-35
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• 2004

In this paper, the metal seal for a pressure vessel has been analyzed using the Daguchi method. This method may efficiently optimize the design parameters for a cantilever sealing device of a pressure vessel in terms of dimensions and angles. The computed results indicate that the optimized design parameters can only be drawn by sixteen experimental numbers of iterations when the Daguchi design technique has been employed. This means that the Daguchi design method is very useful for the optimization design of the curved design of the structure. Based on the computed results by the Daguchi design technique, the dimension and angle of the metal seal structure are given as $d_1=50mm,\;d_2=60mm,\;a_1=20^{\circ},\;a_2=8^{\circ},\;a_3=5^{\circ}$.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.623-631
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• 2022

Using the design of experiment (DOE), factors affecting the particle size of hydrated liquid crystalline vesicles containing a high content of ceramide were analyzed and the mixture composition was optimized. Manufacturing temperature, amount of ethanol, and ultrasonic time were selected as the main variables affecting the droplet size of the vesicles, and the effect of these variables on the droplet size was examined through the signal to noise (S/N) ratios of Taguchi method and ANOVA analysis. In addition, mixture composition experiments of three lipid components constituting the vesicle membrane, hydrogenated phosphatidyl choline (HPC), cholesterol (Chol), and ceramide (Cer), were performed according to the simplex central design matrix of the mixture. Regression analysis was conducted with the experimental data to obtain a model equation, and the optimal mixing composition of the three lipid components to minimize the vesicle droplet size was determined as HPC (0.6), Chol (0.1), and Cer (0.3).

• Transactions of Materials Processing
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• v.19 no.5
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• pp.305-310
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• 2010

Recently industry of motor vehicle is making a gradual progress of automotive electric components. According to this step, wire harness equipped at motor vehicle is also increased. The most important component at the wire harness is electric connector. At the manufacturing process of electric connector, exactly at the crimping process, design variables, such as clamping-height, clamping-width and clamping die shape are critical parameters to assure satisfactory harness shape in clamping process of electric connector. In this study we have performed FEM simulation for clamping process and clarified the effect of design variables on compression rate of wire.

• Journal of Ship and Ocean Technology
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• v.9 no.1
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• pp.64-71
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• 2005

In probabilistic design, the challenge is to estimate the uncertainty propagation, since outputs of subsystems at lower levels could constitute inputs of other systems or at higher levels of the multilevel systems. Three uncertainty propagation estimation techniques are compared in this paper in terms of numerical efficiency and accuracy: root sum square (linearization), distribution-based moment approximation, and Taguchi-based integration. When applied to reliability-based design optimization (RBDO) under uncertainty, it is investigated which type of applications each method is best suitable for. Two nonlinear analytical examples and one vehicle crashworthiness for side-impact simulation example are employed to investigate the unique features of the presented techniques for uncertainty propagation. This study aims at helping potential users to identify appropriate techniques for their applications in the multilevel design.

• Journal of Korean Society for Quality Management
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• v.48 no.3
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• pp.463-479
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• 2020

Purpose: The purpose of this study is to evaluate the performance of heating equipments by implementing the extreme environment in which ships navigating the ice zone are exposed and to study and apply the experimental method to infer the optimized design for each factors. Methods: It is required to verify by analysis and experiment how the environment with low temperature and wind speed implemented through the test facility affects the heating walk-way and The optimum design of the heating walk-way in that extreme environment is derived using the Taguchi technique. Results: The results of this study are as follows; It was found the effect on the condition of each factor and derive optimized conditions that satisfy the performance condition of the heating walk-way in extreme use environment. Conclusion: Ships operating in Polar waters require reliable and durable facilities for all environments during sailing.