• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.216-226
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• 2022

Background: The amount of smoking in adolescence increases with a younger age of smoking initiation and affects physical health. To establish and evaluate smoking-related policies, it is important to determine actual smoking status. Validation of self-reported questionnaires can identify the accuracy of the questionnaire data reflecting smoking status. Objectives: The purpose of this study was to evaluate the validity of self-reported smoking status and identify factors affecting the accuracy of self-reported smoking in South Korean adolescents. Methods: This study investigated the consistency between cotinine concentrations and self-reported questionnaire data through the analysis of urine samples collected from 922 adolescents aged 13~18 among the participants of Cycle 3 of the Korean National Environmental Health Survey. Smoking status was classified using the cotinine cut-off point of 39.85 ㎍/L in adolescents, and factors affecting the accuracy were analyzed through multiple logistic regression analysis. Results: The smoking rates according to the self-reported questionnaire and cut-off point-based cotinine concentrations among adolescents were 3.1% and 5.1%, respectively. The results found 97.1% consistency between self-reported smokers and smokers according to cotinine concentration. Factors affecting the discrepancy showed a significant relationship, including gender, secondhand smoke, and use of e-cigarettes. Conclusions: The results can be used as basic data to establish a smoking policy for adolescents through continuous monitoring and improvement of questionnaire items of factors affecting the discrepancy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.32-38
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• 1975

In order to clarify the effect of underchannel drainage and culture on the ill-drainage paddy fields, the experiment was carried out at different amounts of fertilizer and planting space under the culvert. It had been found that the effect of underchannel drainage on the ill-drainage paddy field was very efficacious, and planting density was more effective on yield than the amount of fertilizer applied.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.141-146
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• 1982

In the vine training methods, main vine training yield was 36% higher than the non-training. Main vine training date was studied for increasing cone yield in hops. Training was done four different dates from May 14 to May 29 including non-training as a check. Earlier training increased cone yield from 12 to 43% due to more beared branches per plant, longer branch length caused by accelerating the branch growth, and an increased of number of cone per beared branch and total cone number.

• Journal of the Korean Society of Food Culture
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• v.38 no.4
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• pp.270-282
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• 2023

We performed a study to examine the association between diet quality and nonalcoholic fatty liver disease (NAFLD). Our study included 3,586 women aged 40-64 years who participated in the sixth Korea National Health and Nutrition Examination Survey. The study subjects were classified into the NAFLD group (n=816) and the normal group (n=2,770) using the hepatic steatosis index. The anthropometric indices, blood profiles, and dietary intake data of the subjects were obtained. The waist circumference, body mass index, and the serum levels of triglycerides, fasting blood sugar, HbA1c, and systolic and diastolic blood pressures were higher in the NAFLD compared to the normal groups (p<0.001, respectively). The intakes of protein (g/kg body weight, p<0.001), potassium (p<0.001), and vitamin A (p=0.006) were significantly lower in the NAFLD group. It was observed that the higher the total Korean Healthy Eating Index score, the lower the risk of NAFLD. A reverse relationship was shown between the NAFLD risk and the intakes of total fruits, total vegetables, vegetables excluding Kimchi and pickled vegetables, meat, fish, eggs and beans. Therefore, it is recommended that middle-aged women in Korea increase their intakes of fruits, vegetables, and foods high in protein for the proper management of NAFLD.

• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.890-896
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• 2023

This study aims to examine the relationship between serum folic acid levels and metabolic syndrome. The analysis data were downloaded and used for the 7th 3rd (2018) data of the National Health and Nutrition Survey and in this study, 495 men, 706 women, and a total of 1,201 people were finally analyzed. The data analysis used Chi-square and t-test for the difference in serum folic acid according to general characteristics, Pearson correlation for the relationship between sub-factors of metabolic syndrome, and logistic regression analysis for serum folic acid levels and metabolic syndrome indicators. According to the results of this study, there was a significant negative correlation between serum folic acid levels and waist circumference (r=-0.113, p<0.01), triglyceride (r=-0.086, p<0.05), and HDL-cholesterol (r=0.086, p<0.05) showed a significant positive correlation. As a result of regression analysis, in the case of HDL-cholesterol, the group with normal serum folic acid levels was significantly higher than the group with low (p<0.05). Therefore, through this study, it is proposed to develop appropriate eating habits and health education programs to prevent metabolic syndrome.

• Journal of the Korean Society of Radiology
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• v.4 no.4
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• pp.5-10
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• 2010

The $Ca_2SiO_4$ phosphors doped by La with 0.1 wt%, 0.3 wt%, 0.5 wt%, and 1.0 wt% concentration were prepared by sintering at $1000^{\circ}C$ for 90 minutes in N2 atmosphere. The phosphors were ground in powdered form and were grouped in $100{\mu}m$ size, then the samples had been exposed to low energy X-ray and UV light. The TL glow curves were measured by heating the phosphors at $10^{\circ}C/s$ rate. There was no significantly meaningful correlation between the TL intensity and the doping level. The intensities of the TL peak measured from X-ray irradiated samples doped with 0.1 wt% were relatively strong. The activation energy and the frequency factor were 0.434 ~ 0.516 eV and 0.5 ~ 0.56, respectively. The intensities of the TL peak measured from UV irradiated samples doped with 0.3 wt% were relatively strong. The activation energy and frequency factor were 0.415 ~ 0.477 eV and 0.5 ~ 0.53, respectively. The TL process were found to be the 2nd order for both X-ray and UV irradiation. The TL intensity was increased linearly with the increase of the radiation dose. In summary, the $Ca_2SiO_4 phosphors developed in this study showed good TL characteristics at low energy X-ray and UV light. We believe they will be used as TLDs in near future for personal and environmental radiation detection dosimetry.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.21-27
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• 2020

The purpose of this study is to investigate the ecosystem structure underlying the development of artificial intelligence technology and related industries. In addition, the research on the AI business ecosystem based on AI technology and the ways to activate them was discussed. Ecosystems play a role in organically connecting producers, consumers, and decomposers. In the AI ecosystem, we classified the AI service producers, producers of AI services using the produced services, and data and related infrastructure services that are the basis of AI services. Stakeholders in the AI business ecosystem are the government and various private organizations that have a direct or indirect influence on AI service production, consumption, and operation. In Korea, in particular, the government plays a role as the most influential stakeholders. For example, the company contributes to the increase of producers, which are related to human resource development, and plays a catalyst role in the increase of services produced by R & D funding. In this study, the policy for revitalizing the AI business ecosystem includes (1) securing the environment for increasing producers, (2) spreading AI awareness among consumers, (3) securing data exchange and supply infrastructure, and (4) supporting services and related laws. Secure the system. This study is meaningful in that it contributes to and contributes to the construction of domestic AI-based environment and related research.

• International Journal of Highway Engineering
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• v.4 no.4 s.14
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• pp.13-21
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• 2002

This study examines the importance of conditioning temperature and period before measuring fundamental properties of asphalt mixture. Marshall specimens were made and cured in the air for one day and conditioned by submerging at $60^{\circ}C$ water for 30 min before loading. It was observed that if the specimen was cured in a lower (or higher) than normal lab temperature ($25^{\circ}C$) before submerging, the measured values were not consistent. Indirect tensile strength (ITS) was also measured on the specimens cured at different temperatures. Although there is no regulation specifying how long the specimen should be conditioned before testing, it is recommended that the conditioning time be for the specimen to be at $25^{\circ}C$. Test must be conducted for the specimen cured well before conditioning for desired test. If curing temperature was lower or higher than normal, and mixture was not properly cured, then test results would not be reliable. This study showed how long the specimen should be submerged at $60^{\circ}C$ for Marshall test and conditioned at $25^{\circ}C$ for ITS test for the specimens cured in different temperature.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.865-875
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• 2022

Field measurements and numerical simulations using EFDC model were performed to quantify the changes of water circulation near Gusipo coast located in the Yellow Sea of Korea to estimate the impact of the construction of the coastal structures (jetty, groin, Gusipo port and bridge). The model predicted tide and tidal currents agreed reasonably well with the measurements. The maximum currents during spring tide near the Gusipo Beach (GB) have the range of 20~40 cm/sec whereas those off the GB range from 60 to 80 cm/sec. The typical patterns of tidal current show parallel with the local isobath. Tidal currents flow northeastward during the flood tide whereas the currents during the ebb tide flow southwestward. The current speeds at shielded waters after the construction of coastal structures strongly decreased as compared with those before the construction. The tidal volume due to the construction of coastal structures was estimated using the depth averaged velocity for 24 hours of spring tide. Tidal volume after construction of coastal structures was compared with initial state (before construction). Tidal volume at present state (after construction of jetty, groin, Gusipo port and bridge) decreased by 28.4% as compared with that of the initial state. The volume after construction of jetty and groin decreased by 21.3%, and the volume after construction of Gusipo port and bridge decreased by 9.8%.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.624-629
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• 2012

To capture and recover carbon dioxide ($CO_2$), we impregnated honeycomb made of ceramic paper with $K_2CO_3$ and its absorption characteristics of $CO_2$ were investigated. The absorption amount of $CO_2$ on the honeycomb absorbent impregnated with $K_2CO_3$ was 13.8 wt% at a constant temperature ($70^{\circ}C$) and relative humidity (66%) condition. Because the absorption amount of $CO_2$ achieved almost the same loading ratio of $K_2CO_3$ (17.6 wt%), the absorption reaction of $CO_2$ by $K_2CO_3$ on the honeycomb absorbent seems to be going smoothly. In addition, $CO_2$ absorption breakthrough characteristics of the honeycomb absorbent were analyzed at the temperature range of $50{\sim}80^{\circ}C$, and the water vapor was fed to an absorption column before the feeding of $CO_2$ or simultaneously with $CO_2$. As a result, the absorption capacity of $CO_2$ was more enhanced using the water vapor supplying before $CO_2$ than that of simultaneous supplying. It was confirmed by temperature programmed desorption analysis that the $KHCO_3$ produced by the absorption reaction of $K_2CO_3$ and $CO_2$ is regenerated by the desorption of $CO_2$ at a temperature of about $128^{\circ}C$.