• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.138-144
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• 2023

In this study, the effect of electrochemical treatment in mitigating alkali leaching into an aquatic environment was investigated. To modify the surface of cement paste, 1000 mA/m² of the direct current was passed through anodic graphite to the external mesh for 4 weeks. Then, the cement paste specimen was exposed to still water in air-tight condition to prevent natural healing of alkali leaching in the water. For 100 days of monitoring in water, the pH value was marginally increased at the electrochemical treatment, while control specimen ranked to the even higher pH accounting for 13.2 in the pH. Moreover, after the pH monitoring, the pH profile for the paste specimen indicated that the electrochemical treatment was effective in securing the higher alkalinity of cement matrix. The water obtained from alkali leaching process, was used to ecological test for Daphnia magna. It was evident that the electrochemical treatment had minimal adverse effect on ecological impact, while control specimen mostly immobilized the standard Daphnia magna.

• Journal of Advanced Technology Convergence
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• v.2 no.2
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• pp.49-55
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• 2023

As interest in "beauty" increases due to the improvement of a high cultural level, job stress and emotional labor caused by nail workers working are gradually increasing, and it is judged that it should be solved in the beauty industry. This study investigated the effect of working stress and emotional labor on turnover intention of nail workers, and the survey tool was a questionnaire for 250 nail industry workers in Daejeon and Chungcheong. The SPSS 21.0 statistical program was used to analyze the collected data, and the research results showed that job stress and emotional labor of nail workers had a statistically significant correlation with turnover intention, indicating that there was a correlation between general job stress and emotional labor. Therefore, it is considered very important for research in this field to analyze the impact of job stress and emotional labor on turnover of nail industry workers and to provide basic data necessary for the development of this field, job satisfaction improvement, and work stress response. In order to establish the nail field as a part of the growing beauty industry, it is expected that there will be better research results if the turnover rate is reduced and compared and analyzed to improve job satisfaction through analysis of the causes of job stress and emotional labor of nail industry workers.

• 한국체육학회지인문사회과학편
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• v.55 no.1
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• pp.457-467
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• 2016

Understanding professional baseball fans' expenditure is expected to provide fundamental marketing information that help increase each team's marketing profits and values and produce a better economic impact on its community. In this regard, this study employed a survey method with a total of 372 residents located in Changwon. A questionnaire included factors such as demographics, consumption patterns and perceived socio-psychic effect(PSE), all of which were derived from literature review. A binary logistic regression was modeled with a dichotomous dependent variable, expenditure(30,000 won more or less). The following were input in the model as the independent variables in order to see the relationships; gender, marriage, education, occupation, income, location, age, leisure type, distance, companion, transportation, interest, and PSE. The results of the logistic regression analysis are as follows. Overall, the model was statistically significant, χ²(21, N=372)=59.159, p=.000. Cox and Snell R² was reported as .147 and .200 respectively. So, the model accounted for between 14.7% and 20.0% of the variation in expenditure. Among the independent variables, income, location, companion, and PSE were found to be the significant factors to expenditure. For income, subjects with 2 million won less of income, compared to those with 4 million won more, were .38 times less likely to pay the money of 30,000 won more. For location, subjects in Masan, compared to those in Jinhae, were 3.49 times more likely to pay 30,000 won more. Subjects in Changwon, compared to those in Jinhae, were 3.05 times more likely to pay 30,000 won more. For companion, people visiting the stadium alone, compared to those with friends/colleague, were .36 times less likely to pay 30,000 won more. For PSE, the odds of 30,000 won more paid increased by 1.37 times with one-unit increase in PSE.

• 한국체육학회지인문사회과학편
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• v.54 no.4
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• pp.329-345
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• 2015

Our study examines the relationship between coach turnover and professional sport team performance using the evidences of Korean professional soccer teams. We collected panel dataset of 304 team-year observations and 96 coaches from Korean professional soccer league during the period of 1983-2013. Among them, our final sample is comprised of 226 observations and 81 coaches manifested for fixed-effect generalized least square (GLS) regression analysis. Drawing on sport management literatures and organizational learning theory, we argue that it takes time for a new head coach to take charge of the team in which the new leader who secure more time to interact with organization members is better able to remodel and improve team performance. Our empirical findings reveal that off-season coach turnover has a positive impact while turnover during the season has its negative influences on team performance. In addition, we find that subsequent team performance in association of off-season coach turnover is comparably better than that of on-season succession. The results show that coach succession rendered from inside the professional soccer team mediates the relationship between coach turnover and team performance. Our findings imply that coach turnover in professional sport teams is a significant factor affecting team performance.

• 한국체육학회지인문사회과학편
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• v.57 no.4
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• pp.375-386
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• 2018

Due to the rapid increase of the elderly population in Korea, there is a growing interest in 'Healthy Aging.' In this trend, it is important to identify the relationship between their lifestyle factors and quality of life. The purpose of this study was to identify the association of physical activity level, sedentary behavior and health-related quality of life (HRQoL) among Korean older adults. A total of 4,589 older adults at the Sixth and Seventh National Health and Nutrition Examination Survey was analyzed. The results showed that better HRQoL was observed among physically active older female, which was more evident among physically active female with central obesity while no such relationship was observed among older male. On the other hand, higher sedentary time was associated with lower HRQoL in both male and female subjects. Our analyses indicated that central obesity was closely related with HRQoL regardless of their physical activity levels in female subjects. Further analyses investigating association between sub-dimension of HRQoL and sub-domain of physical activity showed that higher transport physical activity was associated with better anxiety/depression score and higher sedentary time was associated with poorer score on mobility, usual activities among male and mobility, self-care, usual activity and anxiety/depression among female. Our finding suggests that physical activity level, sedentary behavior and central obesity associated with HRQoL.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1593-1603
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• 2023

In deterministic and Monte Carlo transport codes, b-delayed emission is included using a group structure where all of the precursors are grouped together in 6 groups or families, but given the increase in computational power, nowadays there is no reason to keep this structure. Furthermore, there have been recent efforts to compile and evaluate all the available b-delayed neutron emission data and to measure new and improved data on individual precursors. In order to be able to perform a transient Monte Carlo simulation, data from individual precursors needs to be implemented in a transport code. This work is the first step towards the development of a tool to explore the effect of individual precursors in a fissile system. In concrete, individual precursor data is included by expanding the capabilities of the open source Monte Carlo code OpenMC. In the modified code - named Time Dependent OpenMC or OpenMC(TD)- time dependency related to β-delayed neutron emission was handled by using forced decay of precursors and combing of the particle population. The data for continuous energy neutron cross-sections was taken from JEFF-3.1.1 library. Regarding the data needed to include the individual precursors, cumulative yields were taken from JEFF-3.1.1 and delayed neutron emission probabilities and delayed neutron spectra were taken from ENDF-B/VIII.0. OpenMC(TD) was tested in a monoenergetic system, an energy dependent unmoderated system where the precursors were taken individually or in a group structure, and in a light-water moderated energy dependent system, using 6-groups, 50 and 40 individual precursors. Neutron flux as a function of time was obtained for each of the systems studied. These results show the potential of OpenMC(TD) as a tool to study the impact of individual precursor data on fissile systems, thus motivating further research to simulate more complex fissile systems.

• Journal of Korean Medicine for Obesity Research
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• v.23 no.1
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• pp.1-9
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• 2023

Objectives: Noni fruit juice (NFJ) is liquor extracted from Morinda citrifolia (noni) fruit and has been used as an herbal remedy in many countries. However, the NFJ's anti-adipogenic and anti-inflammatory effects on adipocytes are poorly understood. The purpose of this study was to explore the commercially standardized NFJ effects on lipid accumulation throughout 3T3-L1 preadipocytes differentiation and interleukin-1β (IL-1β)-mediated inducible nitric oxide synthase (iNOS) expression in 3T3-L1 preadipocytes. Methods: Cellular lipid accumulation and triglyceride (TG) content in differentiating 3T3-L1 preadipocytes were assessed subsequently via the Oil Red O staining and AdipoRed assay. MTS assay was used to examine NFJ cytotoxicity in (differentiating) 3T3-L1 preadipocytes. Immunoblotting and reverse transcriptase polymerase chain reaction analysis were used to measure the expression levels of target protein and mRNA in (differentiating) 3T3-L1 preadipocytes, respectively. Results: NFJ treatment at 150 μL/mL led to a substantial reduction of fat accumulation and TG content during 3T3-L1 adipogenesis with no discernable impact on the cell viability. Of note, while NFJ treatment (150 μL/mL) largely inhibited the CCAAT/enhancer-binding protein-α (C/EBP-α) and peroxisome proliferator-activated receptor-β (PPAR-β) protein expressions, it did not influence PPAR-γ in differentiating 3T3-L1 preadipocytes. Of interest, treatment with IL-1β at 20 ng/mL for 4 hours elicited in firm induction of iNOS mRNA expression in 3T3-L1 preadipocytes. However, NFJ treatment at 100 or 200 μL/mL greatly attenuated the IL-1β-induced iNOS mRNA expression in 3T3-L1 preadipocytes. Conclusions: NFJ has anti-adipogenic and anti-inflammatory effects on (differentiating) 3T3-L1 preadipocytes which are in part intervened via control of the expression of C/EBP-α, PPAR-β, and iNOS.

• Tuberculosis and Respiratory Diseases
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• v.86 no.2
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• pp.111-119
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• 2023

Background: The objective of this study was to investigate whether alcohol consumption might affect the quality of life (QOL), depressive mood, and metabolic syndrome in patients with obstructive lung disease (OLD). Methods: Data were obtained from the Korean National Health and Nutrition Examination Survey from 2014 and 2016. OLD was defined as spirometry of forced expiratory volume in 1 second/forced vital capacity <0.7 in those aged more than 40 years. QOL was evaluated using the European Quality of Life Questionnaire-5D (EQ-5D) index. Patient Health Questionnaire-9 (PHQ-9) was used to assess the severity of depressive mood. Alcohol consumption was based on a history of alcohol ingestion during the previous month. Results: A total of 984 participants with OLD (695 males, 289 females, age 65.8±9.7 years) were enrolled. The EQ-5D index was significantly higher in alcohol drinkers (n=525) than in non-alcohol drinkers (n=459) (0.94±0.11 vs. 0.91±0.13, p=0.002). PHQ9 scores were considerably lower in alcohol drinkers than in non-alcohol drinkers (2.15±3.57 vs. 2.78±4.13, p=0.013). However, multiple logistic regression analysis showed that alcohol consumption was not associated with EQ-5D index or PHQ-9 score. Body mass index ≥25 kg/m², triglyceride ≥150 mg/dL, high-density lipoprotein <40 mg/dL in men and <50 mg/dL in women, and blood pressure ≥130/85 mm Hg were significantly more common in alcohol drinkers than in non-alcohol drinkers (all p<0.05). Conclusion: Alcohol consumption did not change the QOL or depressive mood of OLD patients. However, metabolic syndrome-related factors were more common in alcohol drinkers than in non-alcohol drinkers.

• Restorative Dentistry and Endodontics
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• v.47 no.1
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• pp.3.1-3.9
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• 2022

Objectives: This study aimed to assess the impact of a glide-path on the shaping ability of 2 single-file instruments and to compare the centering ability, maintenance of original canal curvatures and area of instrumentation in simulated S-shaped root canals. Materials and Methods: Forty simulated S-shaped root canals were used and were prepared with One Curve (group OC), One G and OC (group GOC), Reciproc Blue (group RB) and R-Pilot and RB (group PRB) and scanned before and after instrumentation. The images were analyzed using AutoCAD. After superimposing the samples, 4 levels (D1, D2, D3, and D4) and 2 angles (Δ1 and Δ2) were established to evaluate the centering ability and modification of the canal curvatures. Then, the area of instrumentation (ΔA) was measured. The data were analyzed using 2-way analysis of variance and Tukey's test for multiple comparisons (p < 0.05). Results: Regarding the centering ability in the apical part (D3, D4), the use of the glide-path yielded better results than the single-file groups. Among the groups at D4, OC showed the worst results (p < 0.05). The OC system removed less material (ΔA) than the RB system, and for Δ1, OC yielded a worse result than RB (p < 0.05). Conclusions: The glide-path improved the centering ability in the apical part of the simulated S-shaped canals. The RB system showed a better centering ability in the apical part and major respect of the canal curvatures compared with OC system.

• Korean Journal of Construction Engineering and Management
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• v.24 no.4
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• pp.35-43
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• 2023

This study is aiming to analyze the relevance of rating criteria and these criteria may have effects on policy purpose of 'Construction Skilled Workers' Rank System', that are inflow of new comer, improvement of job performance, and decrease job-change. Closely related systems, electronic card system and prevailing wage system, are considered by assuming three scenarios, although they are not introduced yet. Empirical survey shows that the relevance is above average. The empirical result of regression also predicts that policy target might be mostly satisfied. Policy purpose is regressed on rating criteria, they are career, qualification, education and training, award. Career and award have positive impact on inflow of new comer. All four criteria have significant impacts on improvement of job performance. Award has strong effects on decreasing job-change. Especially, when electronic card system and prevailing wage system are adopted simultaneously with 'Construction Skilled Workers' Rank System', the level of satisfaction of policy purpose would be higher.