• Journal of Nutrition and Health
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• v.55 no.6
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• pp.656-669
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• 2022

Purpose: This study investigates the relationship between sleep duration, sleep quality, time use, and dietary quality of adolescents. Methods: A cross-sectional study was conducted, enrolling 423 high school students (112 male and 311 female students) in Chungnam using a questionnaire comprising general characteristics, sleep status, use of time, and Nutrition Quotient for Korean Adolescents (NQ-A). Results: On weekdays, male students reported getting 6.6 hours of sleep, which was significantly higher than the 5.8 hours reported by female students. The sleep quality score between male and female students was not significantly different on weekdays and weekends. Comparing the students categorized as getting 6 hours of sleep duration on weekdays and 8 hours on weekends, a significantly higher total NQ-A score was obtained for the long sleep duration group of female students on weekdays. In male students who reported increased screen time on weekdays and study time on weekends, there was a greater frequency of short sleep duration. Our data also revealed that the longer the sleep duration higher the NQ-A score. In addition, higher NQ-A scores were determined with shorter screen time and more prolonged exercise time. Conclusion: Our results suggest that intense study time and excessive use of smartphones have a negative effect on sleep in high school students. In addition, poor sleep quality and lack of sleep are likely to affect eating habits and nutritional status. Therefore, there is a need to provide nutritional education to adolescents imparting knowledge that associates desirable sleep habits and the correct use of time.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.86-101
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• 2019

Remote sensing technology has been continuously developed both quantitatively and qualitatively, including platform development, exploration area, and exploration functions. Recently, the use cases and related researches in the agricultural field are increasing. Also, since it is possible to detect and quantify the condition of cropland and establish management plans and policy support for cropland and agricultural environment, it is being studied in various fields such as crop growth abnormality determination and crop estimation based on time series information. The purpose of this study was to analyze the vegetation index for agricultural land reclamation area using a UAV equipped with a multi-spectral sensor. In addition, field surveys were conducted to evaluate the accuracy of vegetation indices calculated from multispectral image data obtained using UAV. The most appropriate vegetation index was derived by evaluating the correlation between vegetation index calculated by field survey and vegetation index calculated from UAV multispectral image, and was used to analyze vegetation index of the entire area.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.123-123
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• 2019

최근 기후변화로 인해 중국, 한국, 일본, 몽골 등을 포함한 동아시아 지역은 태풍, 가뭄, 홍수와 같은 자연재해의 발생 빈도가 증가하고 있는 추세이다. 중국의 경우 2017년 극심한 가뭄으로 1,850만 (ha)의 농작물 피해가 발생하였으며, 몽골 또한 2017년 4월 이후 극심한 가뭄으로 사막화가 급속도로 진행되고 있다. 위성 기반의 강우 자료는 공간과 시간 해상도가 높아짐에 따라 지상관측소 강수량 자료의 대체 수단으로 이용되고 있다. 본 연구에서는 Climate Hazards Groups InfraRed Precipitation with Station (CHIRPS), Precipitation Estimation From Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), Global Precipitation Climatology Centre (GPCC) 강우 위성 자료를 활용하여 기상학적 가뭄지수인 표준강수지수 (Standardized Precipitation Index, SPI)를 산정하였다. 시간 해상도는 월별 영상을 기준으로 2008년부터 2017년까지 지난 10년간의 데이터를 이용하였으며, 각각 격자가 다른 위성영상을 기존 기상관측소와 비교하였다. 피어슨 상관계수 (Pearson Correlation Coefficient, R)를 활용하여 강우 위성 영상과 지상관측소의 상관관계를 분석하고, 평균절대오차 (Mean Absolute Error, MAE), 평균제곱근오차 (Root Mean Square Error, RMSE)를 통해 통계적으로 정확도를 분석하였다. 인공위성 강수량 자료는 미계측 지역이 많은 곳이나 측정이 불가능한 지역에 효율성 측면에서 중요한 이점을 제공할 것으로 판단된다.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.239-253
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• 2005

Serum concentrations of Hanwoo steers and bulls as possible indicators of beef quality were analyzed to estimate their correlations with carcass traits. Blood samples were taken 2 months and right before shipping to abattoir and at the time of slaughter. And phenotypic correlation coefficients between serum concentrations and carcass traits were estimated. Beef yield index of steers was positively correlated with serum concentrations of total Protein (0.23), albumin (0.26), and calcium (0.31). But it was negatively co..elated with BUN (-0.30). Loin eye area was positively correlated with BUN (0.17) or with globulin (0.16). Back fat thickness was positively correlated with BUN (0.42) and inorganic phosphorus (0.20) being negatively correlated with total protein (-0.23), albumin (-0.33) and calcium (-0.33). Marbling score in the scale of 1 (scarcely marbled) through 9 (extremely marbled) was positively correlated with BUN (0.28) and negatively with IGF-I and calcium concentrations. Phenotype correlation coefficient of loin eye area with total protein concentration in the serum taken from steers right before shipment was estimated to be -0.16 and that with BUN was estimated to be -0.15. Serum concentrations of IGF, glucose, creatinine and on organic phosphorus from steers measured right before shipment were negatively correlated with respective correlation coefficient estimates as -0.21, -0.21, -0.19 and -0.18. Marbling score was negatively co..elated with serum creatinine (-0.16) measured at that time. Beef yield index of steers was positively correlated (0.31) with age adjusted calcium concentration in the serum taken at the time of slaughter. Correlation between body weight and BUN at slaughter was 0.17 At slaughter, loin eye area was negatively correlated with albumin (-0.19) and back fat thickness was also negatively correlated with age adjusted calcium concentration (-0.38). Marbling was negatively correlated with age adjusted calcium concentration(-0.17). Serum concentrations of testosterone, calcium and inorganic phosphorus taken in 2 months before slaughter were negatively but highly correlated with yield index(0.71, 0.67 and -0.71), respectively. Body weight at slaughter was positively was negatively correlated (0.67) with calcium level while dressing percentage was negatively (-0.69) correlated with serum glucose concentration, 2 months prior to slaughter. Correlation coefficients between back fat thickness and cortisol, between back fat thickness and inorganic phosphate were both positive (0.29 and 0.69). Marbling score was negatively correlated with creatinine (-0.81) and positively with BUN (0.87). Body weight loss during shipping was positively correlated with albumin and inorganic phosphate (0.77, 0.83). Yield index of bulls was positively correlated with serum testosterone concentration (0.66). Dressing percentage was positively and highly correlated with globulin (0.73). Back fat thickness of bulls, however, was negatively correlated with testosterone (-0.60). Loin eye area of bull carcasses was positively correlated with testosterone (0.40). Mar-blaine was negatively co..elated with creatinine (-0.55). Yield index of bulls and age adjusted HDLC concentration at slaughter was negatively correlated (-0.71). Dressing percentage of bulls was positively and highly correlated with globulin concentration (0.70). Back fat thickness was also positively correlated with HDLC (0.69) in the serum taken at slaughter. Correlation coefficients between carcass weight and triglyceride, between loin eye are and testosterone and between marbling score and creatinine or glucose were 0.51, -0.91 and -0.58, respectively.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.150-157
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• 2014

The aim of this study was to suggest a convenient method of monitoring the gingival state through plaque detection. Quantitative Light-Induced Fluorescence-Digital (QLF-D), which can assess mature plaque, can be used to assess the oral hygiene status of individuals and to establish an adequate intervention plans for them. The subjects of the study participated in the clinical training at Department of Dental Hygiene, N University. The subjects completed questionnaires on general characteristics and oral hygiene methods. Then, photographs of maxillary and mandibular anterior teeth of the subjects were taken using the QLF-D. After the oral examinations, gingival state was recorded according to the $L{\ddot{o}}e$ & Silness's Gingival Index (GI). In addition, a plaque control record was calculated in percentage using disclosing agent. The analysis of the relation between the plaque control record and the QLF-D scores showed positive correlation (r=0.638, p<0.001), and the analysis of the relation between the QLF-D scores and the gingival bleeding index scores also showed positive correlation (r=0.562, p<0.001). Besides, the study classified the participants into healthy gingiva group and the gingivitis group according to the classification criteria of GI, and when the difference of QLF-D scores between the groups was analyzed, the QLF-D scores were statistically significantly higher (t=-2.785, p=0.007) in the gingivitis group ($1.71{\pm}1.545$) than the healthy gingiva group ($0.74{\pm}1.290$). When the differences in mean values of the QLF-D scores were analyzed against and the gingival bleeding index scores, the QLF-D scores of 0 and 1 belonged to the category of normal gingival state while the QLF-D scores of 2, 3 and 4 belonged to the category of gingivitis state. Therefore, it is deemed that the red fluorescence detected by the QLF-D from the mature supragingival plaque can be used for monitoring the state of gingivitis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.668-678
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• 2017

In this study, the hydrological and meteorological drought index with precipitation as a major factor were calculated, and various analyses of hydrological drought were conducted. The Modified Surface Water Supply Index (MSWSI) was applied to the hydrological drought index and Standardize Precipitation Index (SPI) was used to estimate the meteorological drought index. The target area for the estimation is the dam area among MSWSI categories. The 4001 basin with 43 years data from 1975 to 2017 was analyzed for the drought occurrence status and time series plotted with the monthly SPI and MSWSI. For the dam watershed based on the precipitation that has the role of a water supply in the hydrological cycle, correlation analysis of precipitation, dam inflow, and stream flow was performed by the monthly and moving average (2~9 months), and the correlation between meteorological and hydrological index by monthly and moving average (3, 6 months) was then calculated. The result of multifaced analysis of the hydrological drought index and meteorological drought index is believed to be useful in developing water policy.

• Journal of Korea Water Resources Association
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• v.32 no.2
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• pp.111-120
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• 1999

The relationship between EI Nino-Southern Oscillation(ENSO) and drought in Korea is investigated using the cross correlation analysis. In this paper, Palmer Drought Severity Index(PDSI) is used as an index of drought and nine ENSO indicators are used. To obtain PDSI for Korea, the PDSI equation is derived using monthly precipitation and temperature in Korea. In addition, ENSO composite percentile analyses for PDSI, precipitation and streamflow in Korea are performed to verify the results of the cross correlation. Results of the cross correlation show that the link between drought in Korea and ENSO is statistically significant with 6% of the variance in PDSI for Korea explained by ENSO. The PDSI is negatively correlated with the equatorial Pacific Sea Surface Temperature and the Sea Level Pressure(SLP) at Darwin leading by about 16 months. However, the relationship of the PDSI with the Southern Oscillation Index and the SLP at Tahiti is positive correlation. The ENSO composite percentile analyses show that drought, precipitation and streamflow in Korea are associated with ENSO during 6 months from December of the ENSO ending year

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.545-551
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• 2022

This study analyzed the correlation between stress measurements calculated through HRV signals and thyroid function test items. 181 healthy adults without disease who visited Clinic K were the subjects of this study. Stress resistance (SR) and stress index (SI) were calculated using the acquired HRV signal, and TSH, Free T4, and T3 were used as thyroid function test items. For the measured values, the relationship between each item was statistically analyzed through Pearson correlation analysis. From the results, it was confirmed that Free T4 and SR had a positive correlation (r=0.18) and a negative correlation with SI (r=-0.16). Through this, it was confirmed that there is a significant relationship between thyroid function and HRV signal.

• Korean Journal of Remote Sensing
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• v.35 no.6_3
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• pp.1285-1298
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• 2019

Drought is one of the factors that can cause wildfires. Drought is related to not only the occurrence of wildfires but also their frequency, extent and severity. In South Korea, most wildfires occur in dry seasons (i.e. spring and autumn), which are highly correlated to drought events. In this study, we examined the relationship between wildfire occurrence and drought factors, and developed satellite-based new drought indices for assessing wildfire risk over South Korea. Drought factors used in this study were high-resolution downscaled soil moisture, Normalized Different Water Index (NDWI), Normalized Multi-band Drought Index (NMDI), Normalized Different Drought Index (NDDI), Temperature Condition Index (TCI), Precipitation Condition Index (PCI) and Vegetation Condition Index (VCI). Drought indices were then proposed through weighted linear combination and one-class support vector machine (One-class SVM) using the drought factors. We found that most drought factors, in particular, soil moisture, NDWI, and PCI were linked well to wildfire occurrence. The validation results using wildfire cases in 2018 showed that all five linear combinations produced consistently good performance (> 88% in occurrence match). In particular, the combination of soil moisture and NDWI, and the combination of soil moisture, NDWI, and precipitation were found to be appropriate for representing wildfire risk.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.392-402
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• 2012

In this study, to analyze the stream health using fish assemblage and make effective management, we conducted fish monitoring in the Hoeya River basin and neighboring streams. A total of 33 species classified into 12 families were collected from 29 sites in 2007. Dominant species was Zacco platypus (Relative abundance, RA: 24.8%), and subdominant species was Rhynchocypris oxycephalus (RA: 16.2%). Eight Korean endemic species and 4 exotic species were identified. Moreover, two species (Opsariichthys uncirostris amurensis and Hemiculter eigenmanni) were translocated from other basin. To evaluate stream health of the study sites, Index of Biological Integrity (IBI) was applied, based on fish assemblages. Overall, IBI values were "C (Fair)" or "D (Poor)" condition, according to the grade except two sites which recorded "B (Good)". The correlation between land use pattern of surrounding watershed and IBI was analyzed to verify impact of development on stream health using fish assemblage. As a result, when percentage of the developmental groups increased, IBI values were decreased (Pearson correlation, r=-0.425, p=0.022). In contrast, increment of percent forest and grass land was positively correlated with IBI (r=0.556, p=0.002). The agricultural group and IBI did not significantly correlate with each other (r=-0.231, p=0.333). In this study, we identified a relationship between land use of surrounding watershed and stream health using fish data (i.e. IBI). These results could be provided useful fundamental information to establish management and restoration plan in the Hoeya River basin and other rivers distributed in Korea.