• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.3
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• pp.77-86
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• 2018

Recently, Korean construction industry is moving from quantitative growth to qualitative growth. Among the changes in the construction industry, the competency of the project manager who represents the construction project as well as the construction company has been referred to as a factor that effects qualitative growth. This research utilized previous research analysis and expert interview in order to extract essential competency factors of a construction project manager. DEMATEL method was utilized to analyze the quantitative and objective causal relationship between the competency factors. The causal relationship of the competency factors were visualized through Digraph (directed graph) and competency areas of the project manager that requires strengthening were also suggested. Analysis result showed that the important competency categories of a project manager were Internal & External Communication, Project Management Body of Knowledge, and Inspirational Leadership. The analysis results of this research can be utilized in developing competency enhancement method for future project managers and as a basic data in developing an education program.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.1275-1286
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• 2021

The purpose of this study is to employ the theory of consumption value and consumers' innovative personality characteristics to explain the adoption of new personal electronics devices in Vietnamese market. This study adapts a quantitative survey-based approach to test hypotheses about relationship between consumption value, product specific innovativeness and new product adoption. The study uses a quantitative data set of 915 consumers who owned one mobile electronic device at least in Ho Chi Minh city, one of the biggest cities of Vietnam. The data was collected through personal interview and convenient sampling method. The conceptual model was tested using PLS structural equation model. The findings of this study suggest that both consumption value and product specific innovativeness influence the adoption of new electronic products. The results also reveal that product specific innovativeness mediates the relationship between consumption value and new product adoption. The study further identified that consumption value was taken as a second-order multidimensions construct with five components, namely functional value, epistemic value, economic value, social value and emotional value. As a result, the research suggests some implications to enhance marketers' capabilities to develop strategies for launching new hi-tech products in an emerging market as Vietnam.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.348-355
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• 2023

Epifluorescence microscopy with image analysis was evaluated as a biofilm quantification method (i.e., quantification of surface area colonized by biofilms), in comparison with crystal violet (CV) staining. We performed different experiments to generate multispecies biofilms with natural and artificial bacterial assemblages. First, four species were inoculated daily in 16 different sequences to form biofilms (surface colonization, 0.1%-56.6%). Second, a 9-species assemblage was allowed to form biofilms under 10 acylase treatment episodes (33.8%-55.6%). The two methods comparably measured the quantitative variation in biofilms, exhibiting a strong positive relationship (R² ≥ 0.7). Moreover, the two methods exhibited similar levels of variation coefficients. Finally, six synthetic and two natural consortia were allowed to form biofilms for 14 days, and their temporal dynamics were monitored. The two methods were comparable in quantifying four biofilms colonizing ≥18.7% (R² ≥ 0.64), but not for the other biofilms colonizing ≤ 3.7% (R² ≤ 0.25). In addition, the two methods exhibited comparable coefficients of variation in the four biofilms. Microscopy and CV staining comparably measured the quantitative variation of biofilms, exhibiting a strongly positive relationship, although microscopy cannot appropriately quantify the biofilms below the threshold colonization. Microscopy with image analysis is a promising approach for easily and rapidly estimating absolute quantity of multispecies biofilms.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.345-362
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• 2017

The primary purpose of this study was to determine the risk of various disease outcomes due to exposure to cyanobacteria toxin (microcystin-LR) through drinking water in a Korean watershed. In order to determine the risk in a more quantitative way, the risk assessment framework developed by the National Research Council (NRC) of the United States (US) - hazard identification, dose-response relationship, exposure assessment, and risk characterization - was used in this study. For dose-response relationships, a computer software (BenchMark Dose Software (BMDS)) developed by the US Environmental Protection Agency (EPA) was used to fit the data from previous studies showing the relationship between the concentration of microcystin-LR and various disease outcomes into various dose-response models. For exposure assessment, the concentrations of microcystin-LR in the source water and finished water in a Korean watershed obtained from a recent study conducted by the Ministry of Environment of Korea were used. Finally, the risk of various disease outcomes due to exposure to cyanobacteria toxin (microcystin-LR) through drinking water was characterized by Monte-Carlo simulation using Crystall Ball program (Oracle Inc.) for adults and children. The results of this study suggest that the risk of disease due to microcystin-LR toxin through drinking water is very low and it appears that current water treatment practice should be able to protect the public from the harmful effects of cyanobacteria toxin (microcystin-LR) through drinking water.

• Toxicological Research
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• v.32 no.4
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• pp.337-343
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• 2016

We determined the toxicity of mixtures of ethyl acetate (EA), isopropyl alcohol (IPA), methyl ethyl ketone (MEK), toluene (TOL) and xylene (XYL) with half-maximal effective concentration ($EC_{50}$) values obtained using human hepatocytes cells. According to these data, quantitative property-activity relationships (QPAR) models were successfully proposed to predict the toxicity of mixtures by multiple linear regressions (MLR). The leave-one-out cross validation method was used to find the best subsets of descriptors in the learning methods. Significant differences in physico-chemical properties such as boiling point (BP), specific gravity (SG), Reid vapor pressure (rVP) and flash point (FP) were observed between the single substances and the mixtures. The $EC_{50}$ of the mixture of EA and IPA was significantly lower than that of contained TOL and XYL. The mixture toxicity was related to the mixing ratio of MEK, TOL and XYL (MLR equation $EC_{50}=3.3081-2.5018{\times}TOL-3.2595{\times}XYL-12.6596{\times}MEK{\times}XYL$), as well as to BP, SG, VP and FP (MLR equation $EC_{50}=1.3424+6.2250{\times}FP-7.1198{\times}SG{\times}FP-0.03013{\times}rVP{\times}FP$). These results suggest that QPAR-based models could accurately predict the toxicity of polar and nonpolar mixtures used in rotogravure printing industries.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.325-332
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• 2010

The purpose of this study was to investigate the relationship between three quantitative measures of the pendulum test for spasticity in strokes: The relaxation index, the number of oscillations, and the duration of oscillations. Twenty-six stroke subjects participated in the study. Correlations among these measures of spasticity used Pearson's correlation coefficient. There was a statistically significant positive correlation between the relaxation index and number of oscillations in strokes (r=.881, p<.01). In addition there was significant positive correlation between the relaxation index and duration of oscillations (r=.896, p<.01), and between the number of oscillations and duration of oscillations (r=.938, p<.01). Thus, it is possible to use the number of oscillations and duration of oscillations as quantitative measures of spasticity, rather than the relaxation index, which is more complicated to obtain. According to the result of this study, the use of the simple and objective measurements of the number of oscillations and the duration of oscillations are required clinically in the quantitative measures of spasticity in the future.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.5
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• pp.470-482
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• 2021

Purpose: We investigated the relationship between sonographic measurements of fatty liver and body mass index standard deviation score (BMI-Z score), abdominal wall fat thickness (AWFT), and serum biochemical parameters in childhood obesity. Methods: Anthropometric, laboratory, and ultrasonography data were obtained from 174 children with BMI-Z score >1. After the qualitative grading of hepatosteatosis (grades 0-3), the quantitative liver-kidney echogenicity ratio (LKER) was calculated using a software tool. Groups according to sex, age (AG-I to AG-III), BMI-Z score (BMG-I to BMG-III), and hepatosteatosis degree (HS-I and HS-II) were formed. The differences and distributions of the variables were statistically analyzed and compared among the groups. Results: Serum transaminase and glucose levels showed a positive correlation with LKER, whereas the HDL level showed a negative correlation. BMI-Z score and AWFT showed a positive correlation with fasting insulin level and HOMA-IR value. LKER was significantly higher in girls than in boys (p=0.008). In the AG-I group (age 3-8.9 years), the BMI-Z score was significantly higher, whereas AWFT was significantly lower than in the other age groups (p<0.001). The cutoff point of LKER for predicting grade 2 or higher steatosis (HS-II group) was determined to be 1.83. Cardiovascular disease risk was significantly higher in the HS-II group (p=0.035). Conclusion: As a valuable quantitative measurement tool, LKER can be used for the sonographic screening of fatty liver. AWFT, on the basis of its correlation with fasting insulin level and HOMA-IR value, may be a useful sonographic parameter in the management of childhood obesity.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.449-456
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• 2020

This study examines the relation between the quality of leader-member relationship and operational performance of processing enterprises employees in Vietnam, while job satisfaction and innovation are as a mediator variable. In depth interviews are first conducted with five managers and professional workers in five processing enterprises to determine the latent variables and build the structured questionnaire with observed variables. A quantitative survey with 438 employees and managers from 300 processing enterprises was carried out. The method of exploratory factor analysis (EFA), Cronbach's alpha analysis, and confirmatory factor analysis (CFA) was used to test the reliability, the convergent nature, and the consistency of the concepts. Structural equation modeling (SEM) is used to test the proposed model. The result shows that job satisfaction, innovation and operational performance have positive effects on the quality of leader-member relationship. The relationship between leaders and members had indirect impact on employee's operational performance via their job satisfaction and innovation, which illustrates a mediator role of job satisfaction and innovation for employees' performance. The findings of this study suggest that managers need to focus on developing relationship with employees to improve their satisfaction, innovation and performance.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.275-281
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• 2020

This study aims to explore a new approach of relationship assessment by partially employing attitudinal commitment to measure the influence on perception of cooperation within the Vietnamese rice supply chains, which begins from commercial enterprises up to the retailers in the Vietnamese market. The quantitative research is first built around the measurement instruments for the constructs of relationship quality (RQ) and its dimensions; next, a questionnaire is designed; finally, we deal with sample issues and analyze the data to answer the research questions. The truncated sampling technique and Likert-scale survey is a suitable method for analyzing Vietnamese rice retailers and data collection. The preliminary test was conducted using SPSS Statistics; the main test was, then, carried out to evaluate the proposed model and test the hypotheses. Appropriately, the results point to a significant influence of attitudinal factors on trust and satisfaction. In addition, with the involvement of perceived trust and satisfaction, that combination showed the mediating effect between the attitudinal factors and the relationship quality. The ad-hoc analysis indicated the significant role of the two mediators. To be more specific, the high degree of trust and satisfaction has a positive impact on the formation of the relationship between participants in the sector.

• Journal of Ocean Engineering and Technology
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• v.1 no.1
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• pp.138-143
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• 1987

Friction welding has emerged as a reliable process for high-production commercial applications with significant economic and technical advantages. But nondestructive test in friction weld was not clearly developed. Therefore the experimental verification is necessary in order to understand the characteristcs of the pulse echo effects according to various change in welding conditions. This paper presents an attempt to determine the relationship between the varios welding conditions and the coefficients of reflection using the ultrasonic pulse echo method in dissibilar metals friction weld. The new approach of calculating the coefficients of reflection based on measured amplitudes of the echoes is applied in this paper. These coefficients provides a single quantitative measurement which involves both acoustic energy reflected at the welded interface as well as transmitted across the interface. As a result, it was known that the quantitave relationship between welding conditions and the coefficients of reflection using the ultrasonic pulse echo exists in dissimilar metals friction weld.