• Computers and Concrete
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• v.31 no.2
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• pp.85-95
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• 2023

Natural pozzolans are used as additives in cement to develop more durable and high-performance concrete. Pozzolanic activity index (PAI) is important for assessing the performance of a pozzolan as a binding material and has an important effect on the compressive strength, permeability, and chemical durability of concrete mixtures. However, the determining of the 28 days (short term) and 90 days (long term) PAI of concrete mixtures is a time-consuming process. In this study, to reduce extensive experimental work, it is aimed to predict the short term and long term PAIs as a function of the chemical compositions of various natural pozzolans. For this purpose, the chemical compositions of various natural pozzolans from Central Anatolia were determined with X-ray fluorescence spectroscopy. The mortar samples were prepared with the natural pozzolans and then, the short term and the long term PAIs were calculated based on compressive strength method. The effect of the natural pozzolans' chemical compositions on the short term and the long term PAIs were evaluated and the PAIs were predicted by using multiple linear regression (MLR) and adaptive neuro-fuzzy inference system (ANFIS) model. The prediction model results show that both reactive SiO₂ and SiO₂+Al₂O₃+Fe₂O₃ contents are the most effective parameters on PAI. According to the performance of prediction models determined with metrics such as root mean squared error (RMSE) and coefficient of correlation (R²), ANFIS models are more feasible than the multiple regression model in predicting the 28 days and 90 days pozzolanic activity. Estimation of PAIs based on the chemical component of natural pozzolana with high-performance prediction models is going to make an important contribution to material engineering applications in terms of selection of favorable natural pozzolana and saving time from tedious test processes.

• Journal of the Korean earth science society
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• v.29 no.6
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• pp.495-505
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• 2008

The main purposes of this study are to: (1) to develop astronomy observation program based on a standardized coefficient decision program; and (2) to apply the developed program to after-school or club activities. As a first step, we analyzed activities related to astronomy in the authorized textbooks that are currently adopted in high schools. based on the analysis, we developed an astronomy observation program according to the standardized coefficient decision program, and the program was applied to students' astronomical observations as part of the club activities. Specifically, this program used a 102 mm refracting telescope and digital camera. we took into account the observation site's environment of the urban areas in which many school were located and then developed a the computer program for observation activities. The results of this study are as follows. First, the current astronomical education in schools was based off of the textbooks. Specifically, it was mostly about analyzing the materials and making simulated experiments. Second, most schools participated in this study were located in urban areas where students had more difficulty in observation than in rural areas. Third, an exemplary method was investigated in order to make an astronomical observation efficiently in urban areas with the existing devices. In addition, the standardized coefficient decision program was developed to standardize the magnitude of stars according to the observed value. Finally, based on the students' observations, we found that there was no difference between the magnitude of a star in urban sites and in rural sites. The current astronomical education in schools lacks an activity of practical experiments, and many schools have not good observational sites because they are located in urban areas. However, use of this program makes it possible to collect significant data after a series of standardized corrections. In conclusion, this program not only helps schools to create an active astronomy observation activity in fields, but also promotes students to be more interested in astronomical observation through a series of field-based activities.

• Korean Journal of Medicinal Crop Science
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• v.17 no.2
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• pp.115-120
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• 2009

To obtain the information on antioxidant activity by harvesting parts and time in Cudrania tricuspidata Bureau, total phenolic contents, flavonoid contents, superoxide dismutase (SOD) like activity and 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activity of methanol extracts from Cudrania tricuspidata were investigated. Total phenolic contents was the highest in leaf [$30.2{\sim}38.8\;mg/g$ dry weight (DW)] and followed by root bark, stem bark, fruit, root except bark and stem except bark. Among harvesting time, total phenolic contents of leaf was the highest as $38.1{\sim}38.8\;mg/g$ DW in May and June, and then decreased to October. Root bark harvested in April and May contained $26.6{\sim}27.8\;mg/g$ DW total phenolic compounds and total phenolic content fell to a very low values at 1.8 mg/g DW in February. Flavonoid contents was very high in leaf and root bark. Especially, root bark harvested in April had the highest of flavonoid contents as 23.2 mg/g DW. As a result of simple linear regression analysis of total phenolic contents on flavonoid contents according to harvesting parts, it showed a high correlation (p < 0.001) with $0.57{\sim}0.97\;R^2$ (coefficient of determination). As $RC_{50}$ value, that was, the concentration of sample required for 50% reduction of DPPH absorbance, was $13.7{\sim}20.5\;{\mu}g/mL$ in leaf so DPPH radical scavenging activity was very high. But SOD like activity of $1,000\;{\mu}g$ extract/mL MeOH was a low value of $0.3{\sim}9.2%$ in all samples.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.546-559
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• 2016

This study was conducted to analyze the relationship between sleep quality, stress response, physical activity and sleep hygiene in shift work nurses and identify factors influencing sleep quality. The participants were 168 shift nurses from university hospitals and general hospitals located in C city, Gyeongnam. Data were collected from March 25 to 31, 2016. The study instrument use to the Pittsburgh Sleep Quality Index, Stress Response Inventory, Korean version of the International Physical Activity Questionnaire Short Form and Sleep Hygiene Scale. Date were analyzed by frequency, t-test, ANOVA, Pearson's correlation and hierarchical multiple regression using SPSS/win18.0. The sleep quality index was 7.35 (range 0-21), stress response was 2.20 (range 1-5), physical activity was 3986MET-min/week, and sleep hygiene was 2.73 (range 1-6 points). There were significant differences in sleep quality according to shift work experience, health status and circadian rhythm type. Factors influencing sleep quality included shift work experience, sleep hygiene, stress response and physical activity, which together explained 40% of the total variance of sleep quality. Therefore, it is recommended that sleep hygiene education be implemented as a strategy to reduce stress response, and that shift work nurses engage in a moderate level of physical activity to improve their sleep quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.110-115
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• 2012

Various unripe peach (Prunus persica L. Batsch) seeds, which were picked on late May, were subjected to 80% methanol extracts to investigate the antioxidant activities, whitening effects, and anti-wrinkle activities. The yield of 6 cultivars (Takinosawa Gold, Kawanakawase Hakuto, Madoka, Yumefuji, Nagasawa Hakuho, and Hong Bak) from unripe peaches were the highest on Yumefuji, followed by Madoka, Kawanakawase Hakuto, Takinosawa Gold, Hong Bak, and Nagasawa Hakuho (6.16%, 6.08%, 5.65%, 5.25%, 5.23%, and 5.20%). The content of the total polyphenol of seed extracts ranged from 18.33 to 27.08 mg/g. The antioxidant in vitro assays including the DPPH and ABTS radical scavenging activities were the highest with Hong Bak and Kawanakawase Hakuto. The tyrosinase inhibition activity greatly affected the Takinosawa Gold and Kawanakawase Hakuto. Compared to the elastase inhibition activity of 6 cultivars, Madoka was higher than others, while the lowest was Hong Bak. The significant correlation coefficient values were determined (more than p=0.05) between the yield, total polyphenol content, antioxidant activities, tyrosinase inhibition, and elastase inhibition activities. The results suggested that the total polyphenol content has a high positive value on the DPPH, ABTS radical scavenging activity, and tyrosinase inhibition activity. Also, the tyrosinase inhibition activity and elastase inhibition activity showed a significant correlation (r=+0.594). The ABTS inhibition activity and tyrosinase inhibition activity that is the most suitable character represented significant positive correlation (r=+0.846). This data suggested that the methanol extracts from these unripe peaches could be potential candidates for natural cosmetics.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.207-213
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• 1999

To examine individual variation in drug metabolism catalyzed by flavin-containing monooxygenase (FMO), 179 Korean volunteers' urinary molar concentration ratio of theobromine (TB) and caffeine (CA) was determined. Their urine was collected for 1 hr (between 4 and 5 hrs) after they drank a cup of coffee containing 115 mg CA and analyzed by an HPLC system. The lowest TB/CA ratio obtained was 0.40, the highest ratio was 15.17 (38-fold difference), and the median ratio for all subjects was 1.87. The mean was 2.66 with 2.36 S.D.. In 134 nonsmokers, the mean ratio was $2.35{\pm}1.93,$ that of 51 males was $2.30{\pm}2.26$ and 83 females was $2.37{\pm}1.85,$ respectively. There was no significant gender difference in the obtained TB/CA ratio (Mann-Whitney test; p=0.518). There were no smokers among the 83 female volunteers. In the remaining 96 male subjects, the ratio obtained in 51 nonsmokers was $2.30{\pm}2.06$ and that of 45 smokers was $3.62{\pm}3.19.$ This indicated that the TB/CA ratio was increased significantly in smokers (p=0.007). However, when the TB/CA ratios (FMO activity) obtained in all 179 Korean volunteers are compared with the urinary concentration ratios of paraxanthine (PX) plus 1,7-dimethylurate (17U) to CA (CYP1A2 activity), there was a weak but significant correlation (Pearson's correlation coefficient test; $r^2=0.28,$ p＜0.0001). This indicates that, although the urinary TB/CA ratio mostly represents FMO activity, minor contribution by CYP1A2 activity cannot be ignored. In conclusion, the FMO activity measured by taking the urinary TB/CA ratio from normal healthy Korean volunteers shows marked individual variations without significant gender differences and the increased TB/CA ratio observed in cigarette smokers may have been caused by the increased CYP1A2 activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2023-2028
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• 2014

The main purpose of this study is to explore the factors related to the performance of industry-university cooperation and determine methods for improving activation of industry-university cooperation. The data was collected by questionnaire survey mailed to the participating researcher and university professors which executed the university-industry cooperation projects. We determined cronbach Alpha Coefficient, pearson's correlation coefficient and multiple regression analysis. According to multiple regression analysis, reflect of mutual needs and local industry construction have statistically significant relationships with general satisfaction of university. Knowledge and working ability of industry-university cooperation, activeness of industry-university cooperation activity, Local economy scale and local industry construction have statistically significant relationships with general satisfaction of industry. In relation continuity, activeness of industry-university cooperation activity and information exchange have statistically significant relationships with relation continuity of university. Knowledge and working ability of industry-university cooperation and activeness of industry-university cooperation activity have statistically significant relationships with relation continuity of industry. In outcome utilization, knowledge and working ability of industry-university cooperation, research establishment and apparatus have statistically significant relationships with outcome utlization of university. In conclusion, capability factors, cooperative factors, political factors and external environment factors affected industry-universiry cooperation. Knowledge and working ability of industry-university cooperation will be able to upgrade on general satisfaction, relation continuity and outcome utilization.

• Journal of Radiation Protection and Research
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• v.27 no.2
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• pp.101-110
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• 2002

The concentrations and activity ratios of $^{137}Cs,\;^{90}Sr\;^{238}Pu$ and $^{239-240}Pu$ in sediment($0sim}20\;$cm) at 15 coastal stations of Korea were determined. The mean concentrations of $^{137}Cs,\;^{90}Sr\;^{238}Pu$ and $^{239-240}Pu$ are $2.24{\pm0.79\;Bq{\cdot}kg^{-1}-dry,\;0.20{\pm}0.04 Bq{\cdot}kg^{-1}-dry,\;0.009{\pm}0.005\;Bq{\cdot}kg^{-1}-dry}$ and $0.27{\pm}0.17\;Bq{\cdot}kg^{-1}-dry$, respectively. The mean activity ratios of $^{137}Cs,\;^{90}Sr$, $^{239-240}Pu/^{137}Cs$ and $^{238}Pu/^{229-240}Pu$ and atomic ratio of $^{240}Pu/^{239}Pu$ are $11.2{\pm}2.9,\;0.123{\pm}0.053$ and $0.033{\pm}0.017$ and $0.218{\pm}0.036$, respectively. The concentrations and activity ratios in sediment samples are similar to those reported from neighbouring country in the northern hemisphere. The correlation coefficient of $^{137}Cs$ and $^{239-240}Pu$ is 0.80. The correlation coefficient of $^{137}Cs$ and soil organic matter(SOM), and $^{239-240}Pu$ and clay content are 0.69 and 0.67, respectively.

• Korean Journal of Radiology
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• v.25 no.2
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• pp.179-188
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• 2024

Objective: ¹⁷⁷Lutetium [Lu] Ludotadipep is a novel prostate-specific membrane antigen targeting therapeutic agent with an albumin motif added to increase uptake in the tumors. We assessed the biodistribution and dosimetry of [¹⁷⁷Lu]Ludotadipep in patients with metastatic castration-resistant prostate cancer (mCRPC). Materials and Methods: Data from 25 patients (median age, 73 years; range, 60-90) with mCRPC from a phase I study with activity escalation design of single administration of [¹⁷⁷Lu]Ludotadipep (1.85, 2.78, 3.70, 4.63, and 5.55 GBq) were assessed. Activity in the salivary glands, lungs, liver, kidneys, and spleen was estimated from whole-body scan and abdominal SPECT/CT images acquired at 2, 24, 48, 72, and 168 h after administration of [¹⁷⁷Lu]Ludotadipep. Red marrow activity was calculated from blood samples obtained at 3, 10, 30, 60, and 180 min, and at 24, 48, and 72 h after administration. Organand tumor-based absorbed dose calculations were performed using IDAC-Dose 2.1. Results: Absorbed dose coefficient (mean ± standard deviation) of normal organs was 1.17 ± 0.81 Gy/GBq for salivary glands, 0.05 ± 0.02 Gy/GBq for lungs, 0.14 ± 0.06 Gy/GBq for liver, 0.77 ± 0.28 Gy/GBq for kidneys, 0.12 ± 0.06 Gy/GBq for spleen, and 0.07 ± 0.02 Gy/GBq for red marrow. The absorbed dose coefficient of the tumors was 10.43 ± 7.77 Gy/GBq. Conclusion: [¹⁷⁷Lu]Ludotadipep is expected to be safe at the dose of 3.7 GBq times 6 cycles planned for a phase II clinical trial with kidneys and bone marrow being the critical organs, and shows a high tumor absorbed dose.

• Health Policy and Management
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• v.27 no.2
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• pp.177-185
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• 2017

Background: The mental problems of the elderly are at issue as a serious social phenomenon. The purpose of this study is to identify risk factors affecting the mood disorders of the elderly. Methods: The subjects were 1,779,236 aged ${\geq}65$ and participated in health screening. Dependent variable was mood disorders. Independent variables were consisted of community level (regional deprivation index and healthcare resources) and individual level (sex, age, insurance type, disability, smoking, alcohol, physical activity, body mass index, and healthcare utilization). Multilevel logistic regression was performed. Results: At the individual level, women, employed insured, severely disabled people, heavy alcohol drinkers, high-intensity physical activity, body mass index, and patients who had chronic disease and severe disease were significantly associated with mood disorders. As the age has increased, it has let increase of mood disorders. At the community level, as the regional deprivation index has increased by 1, mood disorders has been increased by 1.005 times. The intra-class coefficient was 7.04%. Conclusion: We found individual and community level factors are associated with mood disorders. Systematic approach is essential to reduce mood disorders.