• Journal of Korean Society for Quality Management
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• v.43 no.3
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• pp.453-466
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• 2015

Purpose: The purpose of this study is to design a systematic method to estimate optimal operation conditions of design variables for an electronic device alignment system. Method: The 2-level factorial design and the central composite design are used in order to plan experiments. Based on the experiment results, a regression model is established to find optimal conditions for the design variables. Results: 3 of 5 design variables are selected as major factors that affect the alignment system significantly. The optimized condition for each variable is estimated by using a sequential experiment plan and a quadratic regression model. Conclusion: The method designed in this study provides an efficient and systematic plan to select the optimized operation condition for the design variables. The method is expected to improve inspection accuracy of the system and reduce the development cost and period.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.215-216
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• 2006

The effect of manufacturing parameters on friction characteristics of motorcycle break system was studied using a disk-on-pad type friction tester. Such parameters conditions have an effect on the frictional factor such as applied load, sliding speed, and number of ventilated disk hole. However, it is difficult to know the mutual relation of these factors. In this study, the friction characteristics using design of experiment containing 3 elements were investigated for an optimal condition for the best motorcycle break system employing Full factorial design. From this study, the result was shown that the applied load in frictional factors was the most important, next to sliding speed, number of ventilated disk hole.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.1
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• pp.31-40
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• 2014

The production of astaxanthin in the microalga Haematococcus pluvialis has been investigated using a sequential methodology based on the application of two types of statistical designs. The employed preliminary experiment was a fractional factorial design $2^6$ in which the factors studied were: excessive irradiance and nitrate starvation, phosphate deficiency, acetate supplementation, salt stress, and elevated temperature. The experimental results indicate that the amount of astaxanthin accumulation in the cells can be enhanced by excessive irradiance and nitrate starvation whereas the other factors tested did not yield any enhancement. In the subsequent experiment, a central composite design was applied with four variables, light intensity, nitrate, phosphate, and acetate, at five levels each. The optimal conditions for the highest astaxanthin production were found to be $1040{\mu}E/(m^2{\cdot}s)$ light intensity, 0.04 g/L nitrate, 0.31 g/L phosphate, 0.05 g/L acetate concentration.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.11
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• pp.1454-1464
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• 2005

The study was based on a three-stage, non-repetitive factorial experiment in which chemical-rotted kenaf fibers were treated separately with hydrogen peroxide concentrations of $0.5\%,\;1\%\;and\;2\%$, with pH solutions of 7, 9 and 11, and treatment times of 30, 60 and 90 minutes. Under optimal conditions, the study was conducted to determine the strength and elongation of kenaf fibers by the addition of chelators, penetrants and surfactants. The hydrogen peroxide concentration, solution pH and treatment time directly affected the strength of kenaf fibers. The hydrogen peroxide concentration, solution pH affected the elongation of kenaf fibers. It was found, however, that the interaction between pH and treatment time, concentration and treatment time, concentration and treatment time and pH affected the strength of kenaf fibers. Also, It was found that the interaction between pH and concentration, concentration and treatment time, concentration and treatment time and pH affected the elongation of kenaf fibers. Under the hydrogen peroxide conditions of $2\%$ concentration, pH 11 and a treatment time of 60 minutes, there were no effects on the strength and elongation of kenaf fibers with the addition of chelator SP, CA.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.10
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• pp.685-691
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• 2015

In this work, to identify effective parameter for performance of piezoelectric jetting dispenser, experimental investigation is carried out based on design of experiment. After preparing jetting dispenser using two stack-type piezoelectric actuators, basic working principle of the jetting dispenser is described. Eight operating conditions are chose as main factors and it is assumed that each factor has two levels. To reduce number of experiments for performance evaluation, the experimental sets are designed based on factional factorial design method. Experimental setup is established and the weight of single dot is measured by using precision scale. The main and interaction effects of factors are analyzed using commercial statistical program and optimal operating condition for small amount and small variation of weight of dispensed single dot are determined.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.131-135
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• 2002

Acetobacter xylinum KJ1 efficiently producing bacterial cellulose(BC) in shaking culture was isolated from a rotten grape. The strain was used to investigate optimum operating conditions for increasing BC production and factorial design model was employed for the optimization. The results of experiments were statistically analyzed by SAS program. Reciprocal effects of each factors(carbon source concentration, shaking speeds(rpm), oxygen pressure, and CSL concentration) and culture condition of BC production were examined by getting regression equation of the dependent variable. Comparisons between experimental results and predicted results about BC concentration were done in total 24 experiments by combination of each factors using SAS program, and the correlation coefficients of BC concentration and BC yield were 0.91 and 0.81, respectively. The agitated cultures were performed in various operation conditions of factors which affected considerably to BC production in jar fermentor. The results showed that BC concentration was 11.67g/ L in 80 hours cultivation under the condition of carbon source concentration shaking speeds(rpm) : oxygen pressure: CSL concentration = 4% : 460rpm : 0.28 : 6%. On the other hand BC yield was 0.42g/g in 80 hours cultivation under the condition of carbon source concentration shaking speeds(rpm) : oxygen pressure: CSL concentration = 4% : 564rpm : 0.21 : 2%. The BC production could be enhanced up to more than 65.3% by factorial design. The result of a verifying experiment under the optimal conditions determined by the factorial design to the BC production showed that the model was appropriate by obtaining BC concentration of 11.02g/L in the optimum condition

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.694-697
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• 2005

The design of experiments are used for optimal design of formed tools to machine automobile bearing rubber seal die, which is classified into the high precision rubber mold. The clearance angle, rake angle and the length cutting edge are considered as the factors. The cutting force is selected to be a characteristic value and compared with the mean tool wear and life by repeated experiments. The design of the experiment is based on the repeated one-way factorial design, which finds the significance of the factors and the best level to predict the tool life by using ANOVA and regression.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.43-44
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• 2005

SU-8 is a epoxy based photoresist designed for MEMS applications, where a thick, chemically and thermally stable image is desired. But SU-8 has proven to be very sensitive to variation in processing variables and hence difficult to use in the fabrication of useful structures. In this paper, negative SU-8 photoresist processed has been characterized in terms of delamination. Based on a full factorial designed experiment. Employing the design of experiment (DOE), a process parameter is established, and analyzing of full factional design is generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

• Journal of Life Science
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• v.33 no.3
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• pp.268-276
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• 2023

This study was conducted to optimize the formulation conditions of the immediate-release layer of carvedilol in the development of a two-layer tablet formulation for carvedilol and ivabradine. Using a 2⁴+3 full-factorial design of experiments, excipients (microcrystalline cellulose, citric acid, and crospovidone) of the carvedilol immediate-release layer (wet granulation part) and process parameters for the tablet compression process (main compression) were optimized, and seven types of each dependent variable (assay, content uniformity, hardness, friability, disintegration, and dissolution [pH 1.2 and 6.8]) were evaluated using design expert software. The analysis of variance results confirmed that the main compression has a significant effect on hardness, friability, and disintegration time and that microcrystalline cellulose has a major effect on friability and dissolution. In addition, it was confirmed that citric acid has a significant effect on friability. Crospovidone affects friability and dissolution. According to the design space from the design of the experiment results, the optimized range is microcrystalline cellulose (~18.0-32.0 mg), citric acid (~0.5-12 mg), and main compression (~615-837 kgf). Consequently, this study confirmed the availability of manufacturing the carvedilol immediate-release layer in which all risk factors evaluated in the initial risk assessment are removed.

• Journal of Life Science
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• v.7 no.4
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• pp.342-346
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• 1997

This experiment was carried out to clarify the effects of gibberellin(GA) aplication and bagging on repeening and quality in 'Delaware' grape berries. Treatments are 4 plots(2X2 factorial experiment); GA, GA+bagging, bagging and control. The clusters were dipped twice in 100 ppm GA with GA treatment : 10 days before and after the full bloom. The results obtained as follows: 1. GA treatment made the seedless grape berry reduced in the fresh weight but it hastened the ripening period about 2 weeks. 2. Total soluble solid(TSS), viscosity and pH value of berry juice increased with maturation. The concentration of TSS and viscosity were higher in GA treatment plot than GA non-treatment. 3. Berry-hardness, titratable acidity and alcohol inslouble solid(AIS) decreased with maturation. Expically berry-hardness and AIS decreased more greatly in GA non-treatment than GA treatment. 4. The concentration of anthocyanin increased with ripening but pectic substance didn't fluctuate nearly. These of anthocyanin and pectin were higher in GA non-treatment plot than GA treatment. 5. By analysis of factorial experiment GA treatment was highly significant with the $^{o}$Brix/Acidity ratio, juice viscosity and AIS, but high negatively, significant with berry-hardness and berry fresh weight. And it was significant with T S S and negatively, titratable acidity. Bagging was significant with $^{o}$Brix/Acidity ratio and AIS content, but negatively, titratable acidity. 6. Qualitative characters were high correlated with the $^{o}$Brix/Acidity ratio in simple correlation but direct effect by the path-coefficient analysis didn't coincide with simple correlation. The direct effect of pH was large and juice viscosity, the next. And that of berry-hardness was negligible but, AIS, small negatively.