• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.551-554
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• 2005

This study uses a characteristic function to explain correlations between the objective function and design variables. Analysis of means and table of orthogonal array were carried out. The change of shape of diaphragm, thickness of diaphragm and voice coil weight based on the table of orthogonal array is made. Therefore this study carried to decide shape of diaphragm, voice coil weight and thickness of diaphragm for minimizing 1st natural frequency and maximizing 2nd natural frequency of diaphragm using design of experiments and characteristic function with constraints. we showed improved design factors that minimized 1st natural frequency and maximized 2nd natural frequency of diaphragm.

• 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.

• Journal of KSNVE
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• v.11 no.2
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• pp.234-240
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• 2001

Recently, the regulations from the government and the concerns of people be raised to the interest in exhaust and intake noise of passenger car as much as other vehicles. In these demands, performance prediction software was developed in this paper. In this study, Robust design was used for improving the noise reduction capacity of intake system with the performance prediction software. On the basis of the existing design, length and radius of each component that was thought to be effective to the performance of intake system was selected. At first, factors are arranged by using Ll8 table of orthogonal array and then optimum value can be obtained by modified Ll6 table of orthogonal array.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.1871-1877
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• 1999

An optimal design method using a response surface method for dynamic characteristics of a washer is presented. The proposed method uses the design of experiment and a computer model is used for the experiment. The value of the cost function is estimated using a computer model for each case of the design variable variation. An orthogonal array is used to obtain best cases to be considered with minimum number of experimentation. Using these experimental values, optimal design is performed using a response surface method. The method used in this paper can be applied to any complicated mechanical systems that can be modelled and analyzed by a computer program. The method is applied to the design of dynamic characteristics of a washer.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.770-775
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• 2001

Steel bar breaking system is a component of a sled test system for automobile crashworthiness. It is a recent idea for the sled test. In a sled test, a crash pulse is given as a input made from a real test. The steel bar breaking system is designed to generate a certain crash pulse. Orthogonal arrays from design of experiments (DOE) are employed. The factors of the array are panel thickness and the number of steel bars, and the levels are candidate values of them. A simulation is utilized for the crash analysis. A commercial system called LS/DYNA3D is adopted. A test system is designed based on the results.

• Journal of Power System Engineering
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• v.6 no.2
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• pp.68-72
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• 2002

Design of experiment was applied to analyze the shrinkage characteristics of the bobbin molded by injection molding. Among lots of design and processing conditions, the thickness of a bobbin and cooling conditions of a mold were considered. The temperature difference between top and bottom parts of the bobbin was considered as the objective to minimize the shrinkage of a bobbin. Optimal thickness of a bobbin was 2.0mm at the part of body and 1.5mm at the part of wing, respectively. Optimal cooling conditions such as cooling time and coolant inlet temperature were 12 second and $12^{\circ}C$, respectively.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.225-229
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• 2000

Burrs formed during face milling operations are very hard to characterize like other machining burrs because there are many parameters which affect the cutting process. Many researchers have tried to predict burr characteristics including burr size and shapes with various experimental conditions such as cutting speed, feed rate, in-plane exit angle, number of inserts, etc., but it still remains as a challenging problem for the complicated combination effects between the parameters. In this paper, Taguchi method, which is a systematic optimization application of design and analysis of experiments, is introduced to acquire optimum cutting parameters for burr minimization. Optimized experimental conditions are provided to show the effectiveness of this approach.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.101-108
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• 2010

Domestic three-way catalyst satisfies exhaust gas conversion efficiency or pressure drop etc. but doesn't satisfy thermal durability. Thermal stress analysis for three-way catalyst was performed based on experimental temperature distribution. Thermal safety of three-way catalyst was estimated by safety factor. Aspect ratio variable had the most significant effect on thermal stress. Thickness variable had the least significant effect on thermal stress. Optimal conditions for premature failure prevention of three-way catalyst were as follows : (1) aspect ratio of three-way catalyst : 0.6:1 (2) 2.84mm thick (3) silicon nitride. The safety of Taguchi-optimized three-way catalyst were 4.7 times higher than that of existent three-way catalyst.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.174-185
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• 2002

The automotive industry faces many competitive challenges including weight and cost reduction to meet need for higher fuel economy. Tailored blanks offer the opportunity to decrease door weight, reduce manufacturing costs, and improve door stiffness. Optimization technology is applied to the inner panel of a door which is made by tailored blanks. The design of tailored blanks door starts from an existing door. At first, the hinge reinforcement and inner reinforcement are removed to use tailored blanks technology. The number of parts and the welding lines are determined from intuitions and the structural analysis results of the existing door. Size optimization is carried out to find thickness while the stiffness constraints are satisfied. The door hinge system is optimized using design of experiment approach. A commercial optimization software MSC/NASTRAN is utilized for the structural analysis and the optimization processes.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.130-140
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• 1999

During crash of a vehicle, most of the kinetic energy of the driver is absorbed by the steering system. The deformation characteristics of the steering system has significant effects on the injury of the driver. A part of the energy is absorbed by the steering wheel and another part by the collapsable steering column. It is believed that strength distribution between the wheel and the column has an important effect on the injury of the driver. A design criterion is suggested for steering wheels for maximum protection of drivers. Tagushi method is used to analyse the effects of design parameters.