• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.286-295
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• 2022

In this study, the concentration distribution of indoor radon in Daejeon Metropolitan City was investigated and the reduction efficiency was evaluated by applying the radon reduction methods. Based on the results of the National Institute of Environmental Research, indoor radon measurements were conducted on 24 selected houses, and the average value of District A was 261 Bq/m3, far exceeding the standard, and even in the same house, indoor radon concentration was affected by measurement point and time. In the case of eight houses that applied the soil venting method to reduce radon, the indoorradon level was significantly lowerthan the standard value, and the average reduction efficiency was also around 55%, indicating a good reduction effect. In addition, the average reduction efficiency was around 90% in the two houses that carried out the shielding method, showing the very excellent effect of the indoorradon reduction. Even if the same reduction method is applied when reducing radon, the reduction efficiency may vary depending on various factors such as the structure of the building, the frequency of ventilation, and the season, so it is necessary to accurately evaluate the effectiveness of the reduction method in the future. Based on this, it is necessary to establish indoor radon management measures in Daejeon Metropolitan City to reduce human harm caused by radon exposure.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.435-442
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• 2022

In this study, the density of KS L 5110 was compared with that of gas pycnometer and electronic densimeter for efficient density management of cement, blast furnace slag powder and fly ash. Correlation and usability according to the test method were reviewed, and based on the results of the experiment, the availability of alternative test methods was analyzed. As a result of the density test according to test methods, the density of cement, blast furnace slag powder and fly ash tended to decrease in the order of gas pycnometer, KS L 5110 and electronic densimeter. Because the volume range of the sample to be evaluated is different depending on test methods. The coefficient of determination R² was in the range of 0.71 to 0.93, and the correlation according to test methods showed a relatively good correlation. If correction is applied through correlation, it is analyzed that alternative test methods can be used. As a result of the usability review considering the test procedure, measurement time and coefficient of variation, the gas pycnometer had the simplest test procedure and good reliability. In addition, it is expected that the reproducibility between the testers is relatively high because the skill is not greatly required.

• The Korea Journal of Herbology
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• v.29 no.2
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• pp.15-21
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• 2014

Objectives : The purpose of this study was to investigate inhibitory effects of steamed Polygonatum odoratum extract (POE) on differentiation and adipogenesis in 3T3-L1 adipocytes. Methods : Polygonatum odoratum (P. odoratum) extract was extracted with ethyl acetate. Total phenolic and flavonoid contents in POE were measured for antioxidant activity. The spectrophotometric method was used to determine the DPPH and ABTS radical scavenging activity and ferric-reducing antioxidant potential (FRAP). MTT assay was examined for cell toxicity, oil red O staining was performed for intracelluar adipogenesis in differentiated 3T3-L1 adipocytes. Western blot analysis for measurement of CCAAT/enhancer-binding protein ${\alpha}$ ($C/EBP{\alpha}$), peroxisome proliferator-activated receptor${\gamma}$ ($PPAR{\gamma}$) and AMP-activated protein kinase (AMPK) expressions were performed. Results : The results revealed that POE has antioxidant activities. Contents of total polyphenolics and flavonoids were $50.83{\pm}1.52$ GAE mg/100g dry weight of POE and $17.05{\pm}2.47$ RE mg/100g dry weight of POE, respectively. DPPH radical scavenging activity, and FRAP in 10 mg/ml concentration were $92.1{\pm}0.6%$, $244.8{\pm}9.0{\mu}M$ Fe(II) and ABTS inhibition in 5 mg/ml concentration was $84.8{\pm}4.1%$. Treatment of POE in adipocytes inhibited the differentiation and adipogenesis of 3T3-L1 adipocytes compared to those of vehicle control. Additionally, protein expressions of $C/EBP{\alpha}$ and $PPAR{\gamma}$, major transcription factor for the adipogenic genes, were significantly decreased compared to those of vehicle control (p<0.05). Futhermore, phosphorylation of AMPK was increased in 3T3-L1 adipocytes treated with POE compared to that of vehicle control (p<0.05). Conclusions : we demonstrate that steamed P. odoratum extract (POE) has potentiating antioxidant activities, inhibits differentiation and lipid accumulation and also induces energy expenditure in adipocytes, which may contribute to antiobesity property.

• Journal of Conservation Science
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• v.37 no.6
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• pp.626-637
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• 2021

The tomb complex of the royal family from the period of the Ungjin Baekje Kingdom (475 to 538 AD) in Gongju, Korea, contains the tomb of King Muryeong and other royal tombs. After the excavation of the tomb of King Muryeong in 1971, these tombs were opened up to the public, without the establishment of systems for their safety, conservation and management. The tombs have consequently experienced rapid environmental changes and suffered various damages. In this study, specific vulnerable parts inside the tombs were selected for deviation analysis using 3D scanning, and 3D image models were constructed on this basis. Progressive displacement was identified in tomb No. 5, and basic data for future investigations was acquired from tomb No. 6 and the tomb of King Muryeong. In the deviation analysis for the southern plastered wall of tomb No. 5, the damage was not found to exceed the ranges of ±18 mm and ±2 mm. However, the lintel stone was found to be sagging by 0.32 mm on average, and the distance between the walls to have increased by 0.36 mm on average. Direct water seepage occurring in tomb No. 5 is considered to be increasing the damage within the tomb, such as the dropping and sagging of the lintel. The 3D image models constructed in this study will play an important role as baseline data for future research, and can be used to discuss a secure conservation scheme for the tombs through cross-validation with precise measurement monitoring.

• Journal of Industrial Convergence
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• v.20 no.8
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• pp.1-13
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• 2022

Although the number of venture start-ups has increased significantly, it is difficult to judge the success or failure based on short-term performance alone. The survival of a company cannot be guaranteed if it does not show sustainable growth prospects. As a growth factor for venture companies, the level of technology commercialization capability and competitive strategies are considered important. Recently, the emergence of innovative business models is creating new opportunities and driving the growth of numerous venture start-ups. This study tried to investigate the mediating effect of business model innovation in the relationship between technology commercialization capability, competitive strategy and the growth prospects of venture companies. For this, empirical analysis was conducted using the original data of the Research on the Precision Status of Venture Firms 2021. As a result, production, manufacturing, marketing capability, cost leadership and product differentiation had a positive(+) effect on growth prospects. The mediating effect of business model innovation between all factors except for manufacturing capacity and growth prospects was verified. This study expanded the scope of research by shedding new light on the factors influencing the long-term growth prospects of venture companies and revealing business model innovation as a new mediating variable. In future research, it is necessary to develop an objective measurement tool and to identify differences according to industrial characteristics.

• Journal of dental hygiene science
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• v.22 no.4
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• pp.222-232
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• 2022

Background: Self-leadership, an action strategy that can maximize individual capabilities, can affect the organizational commitment of dental hygienists and ultimately improve the quality of medical services. This study aims to demonstrate the need for self-leadership and organizational commitment for dental hygienists and develop measures to improve the quality of medical services. Methods: An online survey of dental hygienists working at dental hospitals and clinics in Seoul and Gyeonggi province, Republic of Korea was conducted from March 28 to May 1, 2022. A total of 341 questionnaires were returned and analyzed. The measurement tools were modified and supplemented based on the theories and models developed by Manz for self-leadership, Mowday for organizational commitment, and Cronin and Taylor for medical services. Descriptive statistics, independent t-tests, ANOVA, simple regression, and multiple regression analyses were performed using SPSS 25.0. Results: In leadership education, self-leadership is based on participation experience, the number of participants, and when and where it is received. Organizational commitment comes from participation experience, and the quality of medical services has been found to affect participation experience and location. Self-leadership had an effect on the quality of medical services (β=0.497, t=10.551, p<0.001; β=0.599, t=13.783, p<0.001; β=0.353, t=7.601, p<0.001) and organizational commitment was found to have a mediating effect. Conclusion: Dental hygienists' self-leadership has a positive effect on the quality of medical services through the formation of appropriate interrelationships within the organization. Therefore, self-leadership programs should be developed, participated in, and promoted to improve the self-leadership of dental hygienists. Moreover, hospitals should improve their environment to provide and improve self-leadership education.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.149-155
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• 2022

This study conducted a descriptive research to compare the degree of patient safety culture awareness among general hospitals and long-term care hospital nurses. The subjects of this study were 150 nurses who worked for more than 6 months at 2 general hospitals and 4 long-term care hospitals located in 3 cities, the data has collected from October to December 2021. To Measure patient safety culture, the patient safety culture measurement tool developed by Soon Gyo Lee was used. Data were analyzed by 𝑥²-test, ANOVA, and t-test using SPSS 20.0 program. As a result of the study, the variables with high patient safety culture were the nurse's age(F=44.17, p=.000), clinical career(F=62.86, p=.000), and current workplace career(F=26.27, p=.000). Among the subdomains of patient safety culture, leadership(t=2.07, p= .040) and patient safety priorities(t=2.18, p=.031) were found to be higher in long-term care hospital nurses than general hospital nurses. Based on this result, we expected that it can be used as data in developing programs to raise the level of patient safety culture in hospitals and long-term care hospitals.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.51-63
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• 2023

Riverine tree management is crucial in realizing a balance between flood control and ecological preservation, which requires an accurate assessment of the impact of trees on river water elevations. In this study, eight different formulas for evaluating vegetation roughness considering the drag force acting on trees, were reviewed, and the characteristics and applicability of these methods were evaluated from a practical engineering perspective. The study compared the characteristics of vegetation roughness measurement methods for calculated roughness coefficients at different water depths and analyzed factors such as effects of tree canopy width, tree density and diameter, and tree stiffness coefficient, and water level estimation results. A comparison of roughness coefficients at the same water depths revealed that the Kouwen and Fathi-Moghadam formulas and the Fischenich formula yield excessive drag coefficients compared to other formulas. Factors such as channel geometry, tree diameter, and tree density showed varying trends depending on the formula but did not exhibit excessive outliers. Formulas considering the tree stiffness coefficient, such as the Freeman et al.'s formula and the Whittaker et al.'s formula, showed significant variations in drag coefficients depending on the stiffness coefficient. When applied to small- and medium-sized virtual rivers in South Korea using the drag coefficient results from the eight formulas, the results indicated a maximum increase in water level of approximately 0.2 to 0.4 meters. Based on this review, it was concluded that the Baptist et al., Huthoff et al., Cheng, Luhar, and Nepf's formulas, which exhibit similar characteristics and low input data uncertainties, are suitable for practical engineering applications.

• Journal of Environmental Impact Assessment
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• v.32 no.4
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• pp.214-229
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• 2023

This study was aimed to derive the following regional characteristics and implications by reviewing the effects of local communities and overseas cases through agricultural heritage and related systems to prepare rural regeneration measures using agricultural and rural heritage. First, The study was examined to improve the awareness to improve awareness of the value and preservation of heritage through the designation of agricultural heritage. However, it was found that it was necessary to prepare for social problems such as the aging population in the future. Second, most of the residents' perceptions showed a positive perception of the designation of agricultural heritage, but they were somewhat less recognized in terms of economics, so it was found that regeneration measures were needed to compensate for this. Third, as a result of applying the effect measurement model, the preservation and management effect that meets the purpose of the system is high, and the effect varies depending on projects such as local governments and residents' councils. Fourth, as a result of examining rural regeneration measures through overseas cases, it was found that rather than large-scale development, various cultural and natural resources and activation measures were prepared by expanding the scope to surrounding areas. This study was conducted only on agricultural heritage areas, but it is meaningful that agricultural and rural heritage should be reviewed from various perspectives suitable for the current trend, and it is meaningful in that it considers not only local residents' perception but also regional effects and revitalization measures.

• The Journal of shipping and logistics
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• v.27 no.4
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• pp.719-746
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• 2011

This study attempted to analyse the results of investments from each individual ship investment company(SIC) in Korea which is operating under its ship investment company system. We analyzed investment result of ship investment company by means of Market Adjusted Return Method for measurement of abnormal return(AR) and cumulative abnormal return(CAR). Some implications from the results of this study are suggested. First, we find that the initial abnormal return of IPO, 30-day CAR and long-term CAR are not significantly different between A and B shipping fund management company. And then, the initial abnormal return of IPO and long-term CAR are not significantly different between newbuilding and secondhand ship SIC. But the 30-day CAR is significantly different between newbuilding and secondhand vessel SIC. Third, the 30-day CAR and long-term CAR are not significantly different between newbuilding and secondhand vessel SIC. But the 30-day AR is not significantly different between container and non-container ship SIC. Finally, newbuilding ship SCI is more stable than secondhand vessel SIC, and container ship SIC is more stable than non-container ship SIC in 3-month cumulative return over the past two and half years, from February 2008 to July 2011.