• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.835-843
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• 2010

The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different components of the medium. Corn flour, peptone, and $KH_2PO_4$ were important factors significantly affecting hydroxyl radical scavenging activity. These selected variables were subsequently optimized using path of steepest ascent (descent), a central composite design, and response surface analysis. The optimal medium composition was (% w/v): corn flour 5.30, peptone 0.32, $KH_2PO_4$ 0.26, $MgSO_4$ 0.02, and $CaCl_2$ 0.01. Under the optimal condition, the hydroxyl radical scavenging rate (49.4%) was much higher than that using either basal fermentation medium (10.2%) and single variable optimization of fermentation medium (35.5%). The main monosaccharides components of the RSM optimized polysaccharides are rhamnose, arabinose, xylose, mannose, glucose, and galactose with molar proportion at 1.45%, 3.63%, 2.17%, 15.94%, 50.00%, and 26.81%.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.111-121
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• 2007

The experimental design and response surface methodologies haven been applied to the investigation of the chemical coagulation of livestock wastewater. The chemical coagulation reactions were mathematically described as a function of parameters raping mixing (rpm) of chemical coagulation ($X_1$), slow mixing (rpm) of chemical coagulation ($X_2$), $FeCl_3 $ concentration (mg/L) ($X_3$) and pH ($X_4$) being modeled by use of the central composite design. Empirical models were developed to describe relationship between the experimental variables and response. Statistical analysis indicates that three factors ($X_1$: raping mixing (rpm), $X_2$: slow mixing (rpm), $X_3$: $FeCl_3 $ concentration (mg/L) on the linear term (main effect), slow mixing (rpm) (${X_2}^2$) on the non-linear term (quadratic), and two factors ($X_1-X_3$, $X_2-X_3$) on the non-linear term (cross-product) had significant effects, respectively. The estimated ridge of maximum responses and optimal conditions for CODcr using canonical analysis was 87.44% ($X_1$: 229 rpm, $X_2$: 51 rpm, $X_3$: 877 mg/L, $X_4$: 4.3). To confirm this optimum condition, three additional experiments were performed and the mean CODcr removal (%) and concentration (mg/L) with a standard deviation of $87{\pm}1.2%$ ($576{\pm}34ppm$) were obtained.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.11 s.158
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• pp.1598-1607
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• 2006

The purpose of this study was to analyze the proportion of gathered skirts using a three-dimensional measurement system. And in this experiment, we have attempted to accumulate three-dimensional data of wearing model and find out adequate methods for analyzing shape of clothes. The experimental design consists of two factorial designs. We established three different kinds of fabrics, ratio of gathers. The measurement tool for three-dimensional model was whole body 3D scanner(Exima-WBS2H). Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. As the results show, there were different effect of gather and proportion of shapes among the measurements of width, thickness and areas made by different lines of vision in cross-sectional silhouette. And there were difference shapes of section area at each part of gathered skirts between vertical-outline silhouette and vortical-plane silhouette made by gathering conditions. And also the cross-sectional silhouettes and vertical silhouettes were related to shape of clothes.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.185-193
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• 2020

This purpose of this study was to investigate the effects of 16-week long-term walking exercise on the feeling, mood state, and life stress of college students. Participations in this study were 50 college students, and 24 Walking Group and 26 Control Group were random sampled to experiment the psychological effect of exercise walking. The experimental design was designed by factorial design by 2×3 repeated measurements. Data collection was conducted for 0week, 8week, 16week of feeling, mood state and life stress of college students. As a result, WG showed a positive increase in feeling status compared to CG. Negative mood state such as tension, anger, depression, fatigue, and confusion have been greatly reduced, vigor has increased, and stress on college student life such as friends, study, economy, future, and values has decreased statistically. The results of this study can be used as a way of coping with the stress of college students to improve their study motivation and quality of life.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.695-703
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• 2008

A locally isolated thermophile, Geobacillus sp. SAB-40, producing thermostable extracellular amylase constitutively and an induced intracellular ${\beta}$-galactosidase was characterized and identified based on 16S rRNA sequencing. A phylogenetic analysis then revealed its closeness to Geobacillus stearothermophilus. To evaluate the effect of the culture conditions on the coproduction of both enzymes by G stearothermophilus SAB-40, a Plackett-Burman fractional factorial design was applied to determine the impact of twenty variables. Among the tested variables, $CaCI_2$, the incubation time, $MgSO_4{\cdot}7H_2O$, and tryptone were found to be the most significant for encouraging amylase production. Lactose was found to promote ${\beta}$-galactosidase production, whereas starch had a significantly negative effect on lactase production. Based on a statistical analysis, a preoptimized medium attained the maximum production of amylase and ${\beta}$-galactosidase at 23.29 U/ml/ min and 12,958 U/mg biomass, respectively, which was 3-and 2-fold higher than the yield of amylase and lactase obtained with the basal medium, respectively.

• Journal of Distribution Science
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• v.18 no.11
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• pp.31-39
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• 2020

Purpose: This study attempts to explain why online luxury shopping malls have implemented a difficult registration process and membership fees. These features weaken online shopping convenience, one of the major reasons why people shop online instead of offline. Therefore, this study scrutinizes the effects of membership features on trust, focusing on the moderating effects of registration difficulty and membership fees. Research design, data and methodology: A survey method with a total of 296 survey data was used. A 2 × 2 × 2 factorial design was employed. The three independent variables are price discount rate (20% vs. 70%), registration difficulty (low vs. high), and membership fees (yes vs. no). Results: The results reveal that a price discount rate has a negative effect on trust, whereas membership fees and registration difficulty moderate its negative effect on trust. Conclusions: A high price discount rate lowers trust for online luxury shopping malls. Meanwhile, registration difficulty and membership fees can be used to prevent consumers from losing trust caused by the high price discount rate. Therefore, registration difficulty and membership fees are signals implying that not everyone can use these private online shopping malls, which provide low prices for luxury items.

• Journal of Mechanical Science and Technology
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• v.18 no.10
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• pp.1829-1836
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• 2004

This study presents the performance optimization of hypervelocity launcher system by using the experimentall data. During the optimization, the RSM (Response Surface Method) is adopted to find the operating parameters that could maximize the projectile speed. To construct a reliable response surface model, 3 full factorial method is used with the selected design variables, such as piston mass and 2 driver fill pressure. Nine test data could successfully construct the reasonable response surface, which used to yield the optimal operational conditions of the system using the genetic algorithm. The optimization results are confirmed by the experimental test with a good accuracy. Thus, the optimization can improve the performance of the facility.

• Journal of Magnetics
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• v.15 no.3
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• pp.132-137
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• 2010

Plasma etching of $SiO_2$ contact holes was statistically analyzed by a fractional factorial experimental design. The analysis revealed the dependence of the etch rate and DC self-bias voltage on the input factors of the magnetically enhanced reactive ion etching reactor, including gas pressure, magnetic field, and the gas flow rates of $CHF_3$, $CF_4$, and Ar. Empirical models of the DC self-bias voltage and etch rate were obtained. The DC self-bias voltage was found to be determined mainly by the operating pressure and the magnetic field, and the etch rate was related mainly to the pressure and the flow rates of Ar and $CHF_3$.

• Human Ecology Research
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• v.52 no.4
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• pp.429-441
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• 2014

The use of smartphones has grown rapidly over a short period of time, particularly for commuting news search, smart banking, and social networking services, and has had a significant impact on the pattern of contemporary life. Further, a wide range of applications are downloaded on to smartphones. This has also led a considerable number of complaints regarding these applications. In this study, we focus on the levels of dissatisfaction that users experience with smartphone applications and their effects on consumer complaint behavior along with the moderating effects of the complaint handling process and attribution. The aim of this study is to verify whether the following hypothesis--2 (low/high dissatisfaction level of smartphone applications)${\times}2$ (poor/excellent complaint handling process)${\times}2$ (internal/external consumer attribution)--is in accordance with the betweengroup design to build a factorial design experiment. The results of this study are as follows. First, the consumer's tendency to complain significantly influenced their dissatisfaction level. Second, consumer complaint behavior is modulated by the complaint handling process. Third, the external-attribution tendency of consumers was found to lead to more dissatisfaction than the tendency for internal attribution.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.4 s.44
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• pp.371-377
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• 1992

The purposes of the study were 1) to extend the cognitive categorization theory in an attempt to explain the of garment category, fashionability, and wearer's body types on impression formation, and 2) to find out structures of wearer's impressional dimension and wearer's professional image. The research included a quasi-experiment and survey. The experimental design was a $2^{3}$full factorial design of 3 independent variables. The experimental materials developed for the study were a set of stimuli and a response scale. The stimuli consisted of 8 drawings made by 3 independent variables (garment category, fashion level, wearer's body type). Result were as follows: 1) Garment category, fashionability and wearer's body type had significant effects on impression of the 5 factors-evaluation, potency, appearance, sociability and good-bad, with exception of wearer's body type which was nonsignificant to the potency factor. 2) Garment category was most effective on the evaluation and the potency. However wearer's body type was most effect on the appearance factor and fashionability variable was most effective on the good-bad factor. It was conclued that the results supported the cognitive categorization theory on impression formation and a cognitive categorization hypothesis of clothes.