• Analytical Science and Technology
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• v.20 no.5
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• pp.370-382
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• 2007

In this study, solid-phase microextraction (SPME) technique using GC/FID was studied as a possible alternative to liquid-liquid extraction for the analysis of EGBE, DGBE, DBM and TGME in water, and an optimization condition of trace analysis of EGBE, DGBE, DBM and TGME using the factorial design was described. Experiments used a fractional factorial design method followed by central composite design allowing optimization of a number of factors as well as statical analysis of results. The response surface analysis showed that the extraction efficiency can be described by a second-order polynomial equation in which the salts concentration, extraction temperature, extraction time and sonication time are the major influences. Using DOE, a new data-dependent method was developed that improved the quantity of confidently analyzed EGBE, DGBE, DBM and TGME in water samples.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.65-70
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• 2007

In this study, we analyzed about that after design form manufacture master pattern in Rapid Prototyping-RP through design program, processes to manufacture prototype using Vacuum Casting. In Rapid Prototyping-RP, there is an en-or by shrinkage of resin and, in Vacuum Casting, there is an error by shrinkage of silicon. To select condition which shrinkage become the minimum of each process, manufactured prototype after using Full Factorial Design of Design of Experiments, We could confirm shrinkage using reverse engineering and that result came into effect ANOVA 2-way. We applied errors of each process to master pattern, and then presented the method to improve flood control precision of prototype of Vacuum Casting.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.6
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• pp.126-133
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• 2008

Linear motors are efficient mechanism that offers high speed and positioning accuracy. By eliminating mechanical transmission mechanisms such as ball screw or rack-pinion, much higher speed and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. For the application of the linear motors to precision machine tools an effective cooling method and thermal optimizing measures are required. This paper presents an investigation into the thermal behavior of linear motors with the objective of deriving the optimum cooling conditions. To reach these goals several experiments were carried out, varying operating and cooling conditions. From the experimental results, this research proposed cooling conditions to improve the thermal characteristics of the linear motors.

• Tribology and Lubricants
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• v.24 no.6
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• pp.308-314
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• 2008

The thermal stress have an effect on the frictional factor such as applied load, sliding speed, sliding distance and number of ventilated disk hole. However, it is difficult to know the mutual relation of these factors on thermal stress of motorcycle break disk. For this, temperature of motorcycle break disk is measured using a disk-on-pad type friction tester with full factorial design containing above 4 elements. and the thermal stress analysis of it was carried out using with ANSYS workbench. From this study, the result was shown that the regression equation which have a trust rate of 95% for thermal stress presumption of motorcycle break disk with frictional factor was composed. It is possible to apply for another automobile parts.

• Tribology and Lubricants
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• v.23 no.4
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• pp.175-179
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• 2007

The effect of manufacturing parameters on friction characteristics of motorcycle break system was studied using a design of experiment. 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.

• 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.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.44-51
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• 2016

The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data ($Adj-R^2=0.944$). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was $530k{\Omega}{\cdot}cm$.

• Korean Journal of Rural Living Science
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• v.4 no.1
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• pp.13-22
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• 1993

증편 제조조건의 표준화 방법설정을 위하여 다섯가지(발효원, 가수량, 발효온도, 발효시간, 팽창제) 발효조건을 완전임의 배치법으로 시험, 유의성 검정을 하였으며, 증편의 팽화도 측정 및 팽화된 증편의 생장(증편의 부푼모양, 스폰지감의 생성여부, 기공의 균일성)에 대한 관능검사를 실시하여 다음과 같은 결론을 얻었다. 1. 팽화도에 영향을 미치는 요인으로는 발효원, 가수량, 발효온도, 발효시간 둥이었으며 Yeast 1% 보다는 탁주 또는 Yeast 2%를 사용하는 것이 그리고 3$0^{\circ}C$ 보다는 4$0^{\circ}C$에서 발효시키는 편이 발효시간의 단축효과가 있는 것 같았다. 2. 증편의 팽화가 가장 잘 이루어질 수 있는 발효조건으로는 발효원으로서 탁주를 사용하며 가수량을 75%로 하여 4$0^{\circ}C$에서 4시간 발효시킨 후 성형하여 제조하는 것이었다. 3. 증편 성장에 대한 기호도에 영향을 미치는 발효조건으로는 가수량, 발효온도, 발효시간, 팽창제 둥이었으며 가수량에 관계없이 팽창제를 첨가하여 제조하는 것이 좋고 가수량이 낮을수록 발효시간을 길게하는 편이 나을듯 하다. 4. 증편 성장에 대한 기호도가 가장 높은 증편 제조조건으로는 발효원을 Yeast 1%를 사용하고 반죽의 팽창을 돕기 위해 베이킹파우더 1%를 첨가하며 4$0^{\circ}C$에서 4시간 발효시킨 후 성형하여 찌는 것이었다.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.53-62
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• 2011

This study discusses the effectiveness of safety management programs resulted from examining crash data collected during the period of implementation of the programs by a commercial transport company. For the analysis, two tye of comparison approaches are adopted: 1) a study comparing before-after of the implementation of a safety program, and 2) a study comparing a traffic accident index for various target groups. Technically, the effect of the safety management program is derived by eliminating both the 'regression to the mean' and the changing trend in the traffic accident index. The results show that safety management programs are effective to prevent traffic accidents, whereas company type appears irrelevant. The results also show that the effectiveness is significantly different depending on the intensity of safety management program and company size. In addition, a reciprocal effect is very likely to existamong the combination of these variables. This indicates that in order to improve the accident reduction effectiveness of such programs, the development and application of safety management programs based on both safety management strength and company size are required.

• 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.