• Korean Journal of Computational Design and Engineering
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• v.13 no.6
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• pp.421-428
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• 2008

This article investigates the fabrication of polycaprolactone (PCL) composites filled with different volume fractions (10-30%) of tricalcium phosphate (TCP) by selective laser sintering (SLS) for tissue engineering scaffolds. Optimal processing parameters for each composition were developed by design of experiments (DOE). Specimens for compressive testing for each composition were fabricated and tested. The results showed that the compressive modulus increases as a function of TCP volume fraction. The experimentally measured compressive moduli were compared with moduli predicted by Halpin's theoretical model and were found to be in excellent agreement. This result proved that experimentally determined processing parameters for each composition were well optimized.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.183-190
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• 2014

A multiphase pump was developed in this study. The optimum multiphase pump design was arrived at, and the interactions among the different geometric configurations were explained by applying numerical analysis and the DOE (design of experiments) method. First, we designed the base model to meet the specifications. Then, we defined the design parameters related to the meridional plane and the blade angle. Each design parameter was used for generating experiment sets, and numerical analyses were performed on these sets. Finally, the optimized design was selected based on the results of the DOE analysis. The numerical optimization resulted in the optimum model having higher efficiency than the base model. In addition, performance degradation due to changes in the GVF (gas volume fraction) is discussed.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.51-56
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• 2006

A computer code was developed to simulate both the thermal stresses introduced during the post-filling stage and the in-plane deformation after ejection process by finite element method based on the plane stress theory. The computer simulation was applied to the mold design of a 2 inch light guide plate (LGP) for thin film transistor (TFT)-liquid crystal displays (LCD). With injection molding experiments based on the design of experiments (DOE) technique, the influences of the processing conditions in injection molding on brightness and uniformity of the LGP were investigated, and the optimal processing parameters were selected to increase the brightness and uniformity. The verification experiment showed that the brightness and uniformity of the LGP were increased dramatically under the selected optimal processing conditions.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.9
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• pp.15-24
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• 1998

In this research. we have proposed a new technique to determine .the combination of design parameters for the process design of a hot forged product using artificial neural network(ANN) and statistical design of experiments(DOE). The investigated problem involves the adequate selection of the aspect ratio of billet, the ram velocity and the friction factor as design parameters. An optimal billet satisfying the forming limitation, die filling, load and energy as well as more uniform distribution of effective strain, is determined by applying the ability of artificial neural network and considering the analysis of mean and variation on the functional requirement. This methodology will be helpful in designing and controlling parameters on the shop floor which would yield the best design solution.

• Journal of Korean Society for Quality Management
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• v.34 no.1
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• pp.1-12
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• 2006

This paper presents a six sigma project for improving gate painting quality in a medium-sized automotive part company. The project follows a disciplined process of five macro phases: Define, Measure, Analyze, Improve, and Control. A CTQ(critical to quality) is determined based on COPQ(cost of poor quality) analysis, and a process map is utilized for identifying process input variables. Three KPIV s(key process input variable) are selected; Painting Temperature, Painting Quantity, and Painting Viscosity, and DOE(design of experiments) is utilized for finding the optimal process conditions for three KPIVs. MINITAB software is used for data analyses and DOE. The sigma level of defects rate has improved from 2.93 to 3.66.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.1
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• pp.24-32
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• 2016

The mortality rate of car-pedestrian accidents is quite high, compared to the frequency of accidents. Researches on pedestrian protection are being actively performed worldwide. The A-pillar and lower part of the wind shield cause the most serious damage to the pedestrians. Typical devises to protect the pedestrians are the hood lift system and pedestrian airbag. The design of such devices for an sport utility vehicle is performed based on a design process using design of experiments (DOE). The design results are obtained by an orthogonal array (OA), analysis of mean (ANOM) and analysis of variance (ANOVA). A metamodel is also used in the design process.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.11
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• pp.1207-1213
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• 2012

Typically commercial controllers do not give data of the controller gains. Therefore, it is very hard to determine the optimal controller gain even though the dynamic model is derived. In this case, design of experiment (DOE) methodology can be a powerful tool for gain tuning. In this research, gain tuning process is proposed based on the DOE. Micro parallel mechanism platform with 3 degrees-of-freedom (DOF) is used for the experiments. Controller gains are measured indirectly from the voltages of adjustable resistors. The controller gains of three actuators are optimized by two or three steps, respectively. The correlations of the controller gains are also analyzed. The process and methodology can be adopted in gain tuning of other mechanical systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.8
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• pp.720-725
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• 2007

This study investigated the pressing conditions in the molding of aspheric glass lenses for the mega pixel phone camera module using the DOE method. Tungsten carbide (WC; Japan, Everloy Co., 002K),which contained 0.5 w% cobalt (Co), was used to build the mold. The mold surface was ultra-precision ground and polished, and its form accuracy (PV) was 0.85um in aspheric surface. We selected four factors, pressing temperature, force and time of first step, and force of second step, respectively, as the parameters of the pressing process. in order to reduce the number of experiments, we applied fractional factorial design considering the main effects and two-way interactions. The analysis results indicate that the only two main effects, the pressing temperature and the time of pressing step 1, are available for the form accuracy (PV) of the molded lens. The analysis results indicated that the best combination of the factors for lowering the form accuracy(PV) value of molded lens was to have them at their low levels.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.361-362
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• 2006

This paper presents the robust design of gripper part for a high-speed LCD (Liquid Crystal Display) transfer system. In this paper, the 1st DOE (Design of Experiment) is conducted to find out main-effect factors fur the design of gripper part. Thirty-six experiments are performed using $ANSYS^{(R)}$ and their results are statistically analyzed using $MINITAB^{(R)}$, which shows that the factors, i.e., First-width, Second-width, Rec-width, and thickness of gripper part, are more important than other factors. The main effect plots shows that the maximum deflection and mass of gripper part are minimized by increasing First-width, Second-width, Rec-width and thickness. The 2nd DOE is conducted to obtain RSM (Response Surface Method) equation. The CCD (Central Composite Design) technique with four factors is used. Optimum design is conducted using the RSM equation. Genetic algorithm is used for optimal design. Six sigma robust design is conducted to find out a guideline for control range of design parameter. To obtain six sigma level reliability, the standard deviations of design parameters are shown to be controlled within 5% of average design value.

• Journal of Magnetics
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• v.20 no.2
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• pp.193-200
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• 2015

Direct-acting solenoid valves are used in the automotive industry due to their simple structure and quick response in controlling the flow of fluid. We performed an optimization study of response time in order to improve the dynamic performance of a direct-acting solenoid valve. For the optimal design process, we used the commercial optimization software PIAnO, which provides various tools for efficient optimization including design of experiments (DOE), approximation techniques, and a design optimization algorithm. 35 sampling points of computational experiments are performed to find the optimum values of the design variables. In all cases, ANSYS Maxwell electromagnetic analysis software was used to model the electromagnetic dynamics. An approximate model generated from the electromagnetic analysis was estimated and used for the optimization. The best optimization model was selected using the verified approximation model called the Kriging model, and an optimization algorithm called the progressive quadratic response surface method (PQRSM).