• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.55-61
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• 2011

This study investigate the use of ultraviolet(UV) light with hydrogen peroxide($H_2O_2$) for Methyl Tert Butyl Ether(MTBE) degradation in photolysis reactor. The process in general demands the generation of OH radicals in solution at the presence of UV light. These radicals can then attack the MTBE molecule and it is finally destroyed or converted into a simple harmless compound. The MTBE removal by photolysis were mathematically described as the independent variables such as irradiation intensity, initial concentration of MTBE and $H_2O_2$/MTBE ratio, and these were modeled by the use of response surface methodology(RSM). These experiments were carried out as a Box-Behnken Design(BBD) consisting of 15 experiments. Regression analysis term of Analysis of Variance(ANOVA) shows significantly p-value(p<0.05) and high coefficients for determination values($R^2$=94.60%) that allow satisfactory prediction of second-order regression model. And Canonical analysis yields the stationery point for response, with the estimate ridge of maximum responses and optimal conditions for Y(MTBE removal efficiency, %) are $x_1$=25.75 W of irradiation intensity, $x_2$=7.69 mg/L of MTBE concentration and $x_3$=11.04 of $H_2O_2$/MTBE molecular ratio, respectively. This study clearly shows that RSM is available tool for optimizing the operating conditions to maximize MTBE removal.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.615-624
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• 2014

The purpose of this study is to ascertain the effect of the reputation of ski resorts on multidimensional trust, customer satisfaction and spread by word-of-mouth. To attain this goal, 400 adult male and female subjects using 3 Ski Resorts located in Gangwon-do in Korea in 2013 were selected. For this, convenient sampling was used. The data was processed with the 382 final available samples excluding the 18 inappropriate questionnaires through frequency-, exploratory factor-, reliability-, correlation-, and simple/multiple regression-analyses by using the PASW 18.0. The result is as follows. First, the reputation of the ski resorts was found to have a positive effect regarding the trust of the resorts and their employees. Second, trust in ski resorts and their employees was found to have a positive effect on customer satisfaction. Third, trust in ski resorts and their employees was found to have a positive effect on the spread of word-of-mouth about the resorts. Fourth, customer satisfaction was found to have a positive effect on the diffusion by word-of-mouth.

• Journal of the Korean Data and Information Science Society
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• v.20 no.3
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• pp.541-550
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• 2009

This research attempted to find out any implications for strategies to design and develop the connections between the activities of the brain function and the fields of English learning (dictation, word level, speaking, word memory, listening). Thus, in developing the brain based learning model for the English education, attempts need to be made to help learners to keep the whole brain toward learning. On this point, this study indicated the significant results for the exclusive brain location and the brainwaves on the each English learning field by the quantitative EEG analysis. The results of this study presented the guidelines for the balanced development of the left brain and the right brain to train the specific site of the brain connected to the English learning fields. In addition, whole brain training model is developed by the quantitative EEG data not by the theoretical learning methods focused on the right brain training.

• Fire Science and Engineering
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• v.32 no.5
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• pp.112-121
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• 2018

In the present study, a group of subjects consisting of "Fire Professional Engineers" was selected to examine the effects of life safety awareness and safety behaviors of the subjects on life safety through an analyses of the descriptive statistics, factors, reliability, and correlation; simple regression and three-stage regression analyses on mediation were also carried out based on the hypotheses developed. The results showed that the degree of safety behavior increased by 72.1% in accordance with the increased safety awareness of fire professional engineers; the life safety was also increased by 61.5% and 64.5% by the increases in safety awareness and safety behavior of fire professional engineers, respectively. In addition, the safety behaviors demonstrated a partial mediatory effect in the relationship between safety awareness and life safety. All hypotheses (H1, H2, H3, H4), established for the present study, were accepted based on statistical verifications that justified an amendment of the Acts pertinent to firefighting service focusing on life safety; the data are expected to be exploited to reflect significance of life safety.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.629-633
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• 2008

Purpose : This study was designed to investigate normal domestic values for the diameter of the left main coronary artery (LCA), the left anterior descending coronary artery (LAD) and the right coronary artery (RCA). These data are necessary to define dilatation of coronary arteries in Kawasaki disease cases. Methods : Study subjects were 43 normal healthy children whose ages ranged from 3 months to 6 years. They children visited Konkuk University hospital for echocardiograph examination between March 2005 and November 2007. Measurements of coronary arterial diameters at each branch were done by off-line analyses of recorded images. Simple regression analysis of each the measurements were performed using the body size (body surface area, etc.) as the independent variable. Results : Body surface area was significantly related to the diameters of LCA ($r^2=0.20$, P=0.0038), of LAD ($r^2=0.41$, P<0.0001), and of RCA ($r^2=0.30$, P=0.0002). In the regression model, the estimates of the y-intercept were 1.703, 1.058, and 1.007; the estimates of the regression coefficient were 0.971, 1.175, and 1.177; and the estimates of the standard deviation were 0.315, 0.221, and 0.282 with respect to the three coronary arteries. Conclusion : A the linear regression model of the diameters of three coronary arteries adjusted for body surface area was produced. With these results, the Z-score calculation of the diameter of three coronary arteries, based on normal domestic data, will be possible.

• Sleep Medicine and Psychophysiology
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• v.21 no.1
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• pp.21-28
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• 2014

Objective: Few studies have evaluated the personality characteristics of patients with obstructive sleep apnea (OSA) and simple snoring. We investigated the personality characteristics of OSA and simple snoring patients and compared differences in personality between the two groups using the Eysenck Personality Questionnaire (EPQ). Materials and Methods: Two hundred and thirty-seven patients who were suspected to have OSA or simple snoring participated in this study. A self-questionnaire which included the EPQ was administered to all participants. All subjects underwent polysomnography in a sleep laboratory and those with an apnea-hypopnea index (AHI) ${\geq}5$ were included in the OSA group, while those with an AHI <5 were included in the simple snoring group. Results: OSA patients had significantly lower scores for Psychoticism (F=4.563, p=0.034) than simple snorers. There were no significant differences in Extraversion (F=3.029, p=0.083), Lie (F=0.398, p=0.529), or Neuroticism (F=3.367, p=0.068) scores between the two groups. In the correlation analysis of the OSA group, AHI was positively correlated with Extraversion score (r= 0.16, p=0.029) and negatively correlated with Lie score (B=-0.31, p<0.001). Using multiple stepwise linear regression analysis with the four EPQ parameter scores as dependent variables, Lie score was associated with older age (B=0.14, p<0.001) and lower AHI (B=-0.05, p<0.001), Psychoticism score was associated with higher Pittsburgh Sleep Quality Index (PSQI ; B=0.14, p<0.001), Neuroticism score was associated with higher PSQI (B=0.34, p=0.001) and female sex (B=3.15, p=0.003), and Extraversion score was associated with younger age (B=-0.08, p=0.020) and higher body mass index (B=0.26, p=0.023). Conclusion: This study suggests that patients with OSA are significantly less prone to psychotic personality characteristics than those with simple snoring. Among OSA patients, higher AHI was correlated with low falsehood and high extraversion tendencies.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.658-665
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• 2019

In the era of the rapid development of a tremendous number of new technologies and products, the emotional communication between products and users has become an important research topic. However, the user's emotional measurement methods have not been widely used in the field of product design. Besides, as an important space that can improve people's life quality and urban entertainment at the emotional level, seaside space also creates an atmosphere of frequent emotional communication among tourists, landscape and environmental facilities. To deduce the applicability and advantages and disadvantages of the experiential emotional measurement method in product design, this paper took the seaside seat users of Haeundae as the object and carried out the Self-report of the experiential emotional measurement method. Specifically, the experiment of Self-report was divided into two stages: prior survey and subsequent main investigation. Then the hypothesis was verified by using Bivariate Regression and Multiple Regression through SPSS. Furthermore, through the experiment of the Self-report, the applicability and advantages and disadvantages of experiential emotional measurement method in product design were derived. In the future, based on the applicability, advantages and disadvantages of the experiential emotional measurement method derived in this study, it is expected to become the fundamental and reliable data for the development of emotional measurement methods that can be suitable for product design.

• Culinary science and hospitality research
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• v.21 no.5
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• pp.14-24
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• 2015

Fast food restaurants are one of the fastest growing industries in the world. Even though it is an emerging field, there are few studies about the relationship of fast food customer satisfaction about brand value and behavior intention. The current study examined which factor concerning brand value affects to customer satisfaction in fast food restaurants and investigated how customer satisfaction affects the behavior intention. The subjects of this study are current undergraduate students in Busan, South Korea. A self-administrated questionnaire survey was distributed to 528 students who have been to fast-food restaurants in Busan, Korea and 493 questionnaires were used for data analysis. Research findings indicated that food quality, brand image, brand awareness, and brand association through multiple linear regression were significant factors for customer satisfaction. In addition, the result of a simple linear regression showed that customer satisfaction was positively related to behavior intention. This study can provide valuable information and offer specific ways for fast food managers to increase customer satisfaction and behavior intention.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.9
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• pp.351-360
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• 2018

The LWR (Locally Weighted Regression) model, which is traditionally a lazy learning model, is designed to obtain the solution of the prediction according to the input variable, the query point, and it is a kind of the regression equation in the short interval obtained as a result of the learning that gives a higher weight value closer to the query point. We study on an incremental ensemble learning approach for LWR, a form of lazy learning and memory-based learning. The proposed incremental ensemble learning method of LWR is to sequentially generate and integrate LWR models over time using a genetic algorithm to obtain a solution of a specific query point. The weaknesses of existing LWR models are that multiple LWR models can be generated based on the indicator function and data sample selection, and the quality of the predictions can also vary depending on this model. However, no research has been conducted to solve the problem of selection or combination of multiple LWR models. In this study, after generating the initial LWR model according to the indicator function and the sample data set, we iterate evolution learning process to obtain the proper indicator function and assess the LWR models applied to the other sample data sets to overcome the data set bias. We adopt Eager learning method to generate and store LWR model gradually when data is generated for all sections. In order to obtain a prediction solution at a specific point in time, an LWR model is generated based on newly generated data within a predetermined interval and then combined with existing LWR models in a section using a genetic algorithm. The proposed method shows better results than the method of selecting multiple LWR models using the simple average method. The results of this study are compared with the predicted results using multiple regression analysis by applying the real data such as the amount of traffic per hour in a specific area and hourly sales of a resting place of the highway, etc.

• Journal of Distribution Research
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• v.11 no.4
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• pp.1-29
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• 2006

This study focuses on finding out the determinants of relational quality between the supplier and the retailer in the Chinese cosmetics market. A total of 72 questionnaires were collected by surveying beauty shops which mainly do business with the foreign cosmetics suppliers in Shanghai area. The findings support the premise that a retailer's trust in a supplier is positively related to the retailer's commitment. Supplier's ability, guanxi and cultural sensitivity have positive impacts on trust. Formalization and cultural sensitivity affect commitment positively. But the formalization is not significantly related to the retailer's trust. The guanxi is not found to be significantly related to the retailer's commitment yet. Finally, the authors discuss some theoretical contributions, managerial implications. And then, they present limitations of this study and the future research directions.