• Title/Summary/Keyword: Statistical correlation analysis

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Comparisons of 1-Hour-Averaged Surface Temperatures from High-Resolution Reanalysis Data and Surface Observations (고해상도 재분석자료와 관측소 1시간 평균 지상 온도 비교)

  • Song, Hyunggyu;Youn, Daeok
    • Journal of the Korean earth science society
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    • v.41 no.2
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    • pp.95-110
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    • 2020
  • Comparisons between two different surface temperatures from high-resolution ECMWF ReAnalysis 5 (ERA5) and Automated Synoptic Observing System (ASOS) observations were performed to investigate the reliability of the new reanalysis data over South Korea. As ERA5 has been recently produced and provided to the public, it will be highly used in various research fields. The analysis period in this study is limited to 1999-2018 because regularly recorded hourly data have been provided for 61 ASOS stations since 1999. Topographic characteristics of the 61 ASOS locations are classified as inland, coastal, and mountain based on Digital Elevation Model (DEM) data. The spatial distributions of whole period time-averaged temperatures for ASOS and ERA5 were similar without significant differences in their values. Scatter plots between ASOS and ERA5 for three different periods of yearlong, summer, and winter confirmed the characteristics of seasonal variability, also shown in the time-series of monthly error probability density functions (PDFs). Statistical indices NMB, RMSE, R, and IOA were adopted to quantify the temperature differences, which showed no significant differences in all indices, as R and IOA were all close to 0.99. In particular, the daily mean temperature differences based on 1-hour-averaged temperature had a smaller error than the classical daily mean temperature differences, showing a higher correlation between the two data. To check if the complex topography inside one ERA5 grid cell is related to the temperature differences, the kurtosis and skewness values of 90-m DEM PDFs in a ERA5 grid cell were compared to the one-year period amplitude among those of the power spectrum in the time-series of monthly temperature error PDFs at each station, showing positive correlations. The results account for the topographic effect as one of the largest possible drivers of the difference between ASOS and ERA5.

Analysis of Empirical Multiple Linear Regression Models for the Production of PM2.5 Concentrations (PM2.5농도 산출을 위한 경험적 다중선형 모델 분석)

  • Choo, Gyo-Hwang;Lee, Kyu-Tae;Jeong, Myeong-Jae
    • Journal of the Korean earth science society
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    • v.38 no.4
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    • pp.283-292
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    • 2017
  • In this study, the empirical models were established to estimate the concentrations of surface-level $PM_{2.5}$ over Seoul, Korea from 1 January 2012 to 31 December 2013. We used six different multiple linear regression models with aerosol optical thickness (AOT), ${\AA}ngstr{\ddot{o}}m$ exponents (AE) data from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Terra and Aqua satellites, meteorological data, and planetary boundary layer depth (PBLD) data. The results showed that $M_6$ was the best empirical model and AOT, AE, relative humidity (RH), wind speed, wind direction, PBLD, and air temperature data were used as input data. Statistical analysis showed that the result between the observed $PM_{2.5}$ and the estimated $PM_{2.5}$ concentrations using $M_6$ model were correlations (R=0.62) and root square mean error ($RMSE=10.70{\mu}gm^{-3}$). In addition, our study show that the relation strongly depends on the seasons due to seasonal observation characteristics of AOT, with a relatively better correlation in spring (R=0.66) and autumntime (R=0.75) than summer and wintertime (R was about 0.38 and 0.56). These results were due to cloud contamination of summertime and the influence of snow/ice surface of wintertime, compared with those of other seasons. Therefore, the empirical multiple linear regression model used in this study showed that the AOT data retrieved from the satellite was important a dominant variable and we will need to use additional weather variables to improve the results of $PM_{2.5}$. Also, the result calculated for $PM_{2.5}$ using empirical multi linear regression model will be useful as a method to enable monitoring of atmospheric environment from satellite and ground meteorological data.

The Analysis of Risk Factors and Significance of Tumor Necrosis Factor(TNE)-$\alpha$ in Henoch-$Sch\ddot{o}nlein$ Nephritis (Henoch-$Sch\ddot{o}nlein$ 자반증 환아에서 신침범에 대한 위험인자 분석 및 tumor necrosis factor-$\alpha$의 의의)

  • Song Young-Jun;Ha Tae-Sun
    • Childhood Kidney Diseases
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    • v.4 no.1
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    • pp.40-47
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    • 2000
  • Purpose: Renal involvement is the most important prognostic factor of HSP. Therefore, the pathogenesis and prognostic factors in renal involvement have been studied by many researchers. The aim of this study was to evaluate the clinical risk factors and the role of TNF-$\alpha$ in renal involvement of HS purpura. Methods: The subjects of this study were 12 patients of HS purpura, 7 patients of HS nephritis, and 5 age-matched controls. We have analysed the rist factors for renal involvement in clinical symptoms and collected the sera and urines of all subjects in acute and convalescent stage. The concentration of TNF-$\alpha$ in the collected sera and urines were measured by sandwich ELISA and compared with that of age-matched controls. Results: Statistical analysis showed that persistent purpura increased the risk of developing renal involvement (P=0.0018). and serum TNF-$\alpha$ levels in the acute stage of patients with renal involvement($11.45{\pm}7.01$ pg/ml) were significantly higher than those of without renal involvement($6.32{\pm}1.31$pg/m1) and of age-matched controls($5.99{\pm}1.34$pg/m1)(P=0.012, 0.027, respectively). However, urine TNF-$\alpha$ levels have no correlation with renal involvement. On investigation of serum TNF-$\alpha$ levels in acute stage of HS purpura, persistent purpura had a significantly higher increase(P=0.038). Conclusion: Serum concentration of TNF-$\alpha$ is a risk factor and has a predictable value along with clinical risk factors, such as, persistent purpura for renal involvement in HS purpura. Also, the effectiveness of the specific treatment fur antagonizing TNF-$\alpha$ in HS nephritis may need further study.

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Development of nutrition quotient for Korean preschoolers (NQ-P): Item selection and validation of factor structure (취학전아동 대상 영양지수 개발 : 평가항목 선정과 구성 타당도 검증)

  • Lee, Jung-Sug;Kang, Myung-Hee;Kwak, Tong-Kyung;Chung, Hae Rang;Kwon, Sehyug;Kim, Hye-Young;Hwang, Ji-Yun;Choi, Young-Sun
    • Journal of Nutrition and Health
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    • v.49 no.5
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    • pp.378-394
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    • 2016
  • Purpose: Screening of preschool-age children for nutrition programs to improve dietary intake and behaviors requires cost-effective and easily administered validated assessment tools. The purpose of this study was to develop a parent/caregiver-administered instrument for measuring diet quality and behaviors of preschoolers as a nutrition quotient for preschoolers (NQ-P). Methods: Development of NQ-P was carried out in three steps: item generation, item reduction, and validation. The 24-h dietary record was selected as the gold standard reference tool. The 38 items of the NQ-P checklist were derived from a systematic literature review, expert in-depth interviews, statistical analysis of the fifth Korean National Health and Nutrition Examination Survey data, and national nutrition policies and recommendations. Self-administered questionnaires were delivered to parents who recorded 24-h dietary intakes of 100 responders aged 3~5 yr. Pearson's correlation was used to measure the level of agreement between questionnaires. Item reduction was performed, and 20 items were selected based on survey results, expert reviews, and priorities of national nutrition policy and recommendations. The 412 nationwide subjects sampled through daycare centers completed the 20-item checklist questionnaire. The construct validity of the NQ-P was assessed using confirmatory factor analysis, LISREL. Results: After analyses of exploratory factors, NQ-P items identified three dimensions of diet (balance, moderation, and environment). The three-factor structure accounted for 49.28% of the total variance. Standardized path coefficients were used as weights of the items. The NQ-P and three-factor scores of the subjects were calculated by the obtained weights of the questionnaire items. Conclusion: A food behavior checklist for preschoolers' NQ would be a useful and suitable instrument for evaluating nutrition adequacy and dietary quality of Korean preschoolers.

Drumming bioacoustics of woodpeckers in South Korea (한국에 서식하는 딱다구리목 드러밍의 생물음향학적 특성 연구)

  • Ki, Kyong-Seok;Hong, Suk-Hwan;Gim, Ji-Yeun
    • Korean Journal of Environment and Ecology
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    • v.28 no.4
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    • pp.404-410
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    • 2014
  • In this study, we conducted an analysis of the drumming bioacoustics of three woodpeckers typical to South Korea. The targeted species were, from largest to smallest in size, the Black Woodpecker(Dryocopus martius), the Great Spotted Woodpecker(Dendrocopos major) and the Japanese Pygmy Woodpecker(Dendrocopos Kizuki). The drumming sounds of these three species of woodpeckers were recorded and analyzed. Sound recordings were taken in the Guryongsa Valley, Chiaksan National Park and on the campus of Sangji University, Wonju City, South Korea. Drumming recordings were obtained in the following manner. As researchers walked along trails in the investigation areas, when woodpecker drumming sounds were indicated, positive identification of the species was made using binoculars then the recording of the drumming sound was started. The average time per drumming, in seconds, was Black Woodpecker(D. martius) 1.614 seconds, Great Spotted Woodpecker(D. major) 0.683 seconds and Japanese Pygmy woodpecker(D. Kizuki) 0.200 seconds. The average number of strikes for each drumming was Black Woodpecker(D. martius) 31.2 times, Great Spotted Woodpecker(D. major) 14.9 times and Japanese Pygmy Woodpecker(D. Kizuki) 6.7 times. The strike speed, in strikes/sec, for each species was the Black Woodpecker(D. martius)19.3strikes/sec, the Great Spotted Woodpecker(D. major) 21.8strikes/sec and Japanese Pygmy Woodpecker(D. Kizuki)33.3strikes/sec. The frequency of drumming, in Hertz, was Black Woodpecker(D. martius) 776.9Hz, Great Spotted Woodpecker (D. major) 1,213.8Hz and Japanese Pygmy Woodpecker(D. Kizuki) 826.0Hz. In interpreting this data, Analysis of Variance (ANOVA) was used and it was determined that there was a significant statistical difference between species in drumming duration, time and interval of striking. The findings support that the bigger the biomass of the woodpecker, the longer the drumming duration and striking time. However, the smaller the size of the woodpecker, the faster the strike speed. A correlation between body type size and drumming characteristics was clearly identified. As for strike frequency, measured in Hertz, the medium sized Great Spotted Woodpecker's (D. major) frequency was high whereas the Black Woodpecker(D. martius) and Japanese Pygmy Woodpecker's(D. Kizuki) frequency was similar. A clear trend in reference to body size on this measure does not exist.

A Study of Oral Health Impact Profile 14 among the Elderly in Rural Area (일부 농촌노인들의 구강건강영향지수(Oral Health Impact Profile)14 평가)

  • Lee, Ga-Ryoung
    • Journal of dental hygiene science
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    • v.10 no.2
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    • pp.109-116
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    • 2010
  • Objective: The purpose of this study was oral health related quality of life among elderly population in some rural area, Korea. Methods: 546 participants (male 196, female 350) aged more than 65 years (mean $71.4{\pm}4.6\;years$) were surveyed cross-sectionally. All the subjects were examined short-form of Oral Health Impact Profile (OHIP-14) by face to face interview. Categorical responses of strata-adjusted Wilcoxon correlation and Kruskal-Willis test and multiple regression analysis after adjusting for socio-demographic variables were adapted for statistical analysis. Results: 1. As for sub-factors of the quality of living related to oral health, the drop in social ability was 4.61, the drop in mental ability 4.53, the drop in physical ability 3.99, mental inconvenience 3.98, social disadvantages 3.82, physical pains 3.77, and functional division 3.44, on the average. 2. As for the quality of living related to oral health, there were statistically significant differences in functional restrictions by gender, the educational level, and the presence of occupation, in physical pains by gender, the educational level, family members living together. mental inconvenience by gender, the educational level, the presence of occupation. and in the drop in physical ability by gender, the educational level, monthly incomes. There were statistically significant differences in the drop in physical ability by gender, the educational level. in the drop in social ability by the educational level, the presence of occupation, monthly income. and in social inconvenience by age, the presence of occupation, monthly income. 3. There were statistically significant differences in the general quality of living related to oral health by gender, the educational level, the presence of occupation.

A Study on the Decisive Factors in Personal Health Maintenance Practice of Housewives Living in Younhi Area Apartments (연희지역 아파트주부의 건강관리실천의 결정요인분석에 관한 조사연구)

  • 김인숙
    • Journal of Korean Academy of Nursing
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    • v.8 no.2
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    • pp.89-102
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    • 1978
  • Owing to the development of modern science, prolonging man's life, the sudden increase of population and betterment of the standard of living has increased health needs. In order to fulfill these health needs, more active plans for developing health should be made. Health education is one of the methods at hand that can improve the health behavior of the community and the individual through the contact of individuals with their groups. Proper understanding of the characteristics of the sampled group and participation of individuals within the community for the development of their health plan are needed for efficient health education. This study was attempted for the purpose of presenting some data helpful for pre-paring the fundamentals of a health education plan that can improve personal health maintenance practice of a community through efficient health education by investigating the relationship between the response of subjects to personal health maintenance practice and selected decisive factors in personal health maintenance practice. The subjects for this study were a systematic sample of 120 housewives selected from 600 housewives from B Zone Apt. Younhi-3-Dong in Seoul. Data was collected for 4 days from May 16th to May 19th, 1578 through personal interviews with questionnaires by well trained interviewers. Percentage, t-test and stepwise multiple regression analysis by use of EDPS were employed for statistical analysis. Results of this study can be summarized : 1. General characteristics of subjects Subjects over 20 and below 40 years of age formed 62.5% of the toed and the rest were subjects of 40 years and upward. 76.7% of the subjects have less than 4 children. 51.3% of the subjects had completed at least the senior high school course. 2. The response of subjects to personal health maintenance practice. Ratios of personal health maintenance practice to the maximum score for each category are as follows; 84.1% in the category of population and family planning, which was the highest ratio; 82.4% in the prevention of accidents; 68.0% in control of communicable disease; 67.8% in personal health care and habits of daily life, 64.3% in mental health and 52.5% in control of parasites, which was the lowest. 3. The response of subjects to selected decisive factors. in personal health maintenance practice. The arithmetic mean of the score for each decisive factor was as follows: the mutual relation between family members marked 18.33, which is under 73,3% of the maximum score; the degree of interest in health marked 34.48, 70.0% of the maximum score: the degree of utilization and demand for health care facilities marked 25.79 or 64.5% of the maximum score and health maintenance of the family marked 11.58, 43.6% of the maximum score. 4. The relationship between personal health maintenance practice and general characteristics of subjects. 1) There was a significant difference in the numbers of children. (t = 1.83, d.f. =117, p< 0.1) 2) There was a significant difference in the contact rates with mass-media, (t = 5.02, d.f. = 118, p< 0,05) 5. The multiple correlation between personal health maintenance practice and their selected decisive factors. 1) The factor“the degree of interest in health”could account for personal health maintenance practice in 43.6% of the sample. (R = 0.6602, R²= 0,4359, F = 91.1678, p< 0.001) 2) When the factor,“health maintenance of family”is added to this, it accounts for 51.2% of personal health maintenance practice. (R = 0.7158, R²= 0.5124, F = 61.4653, p< 0.001) 3) When the factor,“mutual relations between family members”is also included, it accounts for 53.7% of personal health maintenance practice. (R = 0.7324, R²= 0.5365, F = 44.7509, p< 0.001) 4) When the factor, “the degree of utilization and demand for health care facilities”is included, it accounts for 55.1% of personal health maintenance practice. (R = 0.7421, R²= 0.5507, F = 35.2430, p< 0.001).

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The study of awareness and practice of infection control on dental practitioners during the prosthodontic treatment (치과 보철물 제작 과정에서 감염 관리에 관한 치과 종사자의 인지도 및 실천도에 대한 연구)

  • Jeon, Han-Sol;Lee, Jin-Han
    • The Journal of Korean Academy of Prosthodontics
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    • v.53 no.3
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    • pp.189-197
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    • 2015
  • Purpose: The aim of this study was to assess the degree of awareness and actual practice of dental practitioners regarding infection control during prosthodontic treatment. Materials and methods: Study participants were composed of dentists, dental hygienists, dental technicians working at dental university hospital, general hospital, dental hospital and dental clinics in Daejeon, Korea (n=126). The questionnaires included the data on general characteristics, education, awareness and practice of infection control procedures during prosthodontic treatment through personal self-administration survey. Awareness and practice were measured by Likert scale ranging from 1 to 5. Statistical analysis was done by one-way ANOVA. Influence of awareness on practice was estimated by regression analysis. Results: 27.7% of the respondents answered that the infection control education regarding prosthodontic treatment is insufficient. The mean value of awareness and practice of infection control during the prosthodontic treatment were $2.72{\pm}0.80$, $1.58{\pm}0.88$, respectively. The mean value of practice who answered that had education curriculum at college was $1.62{\pm}0.9$, and $1.31{\pm}0.49$ who did not. The mean value of awareness who equipped guideline was $3.01{\pm}0.9$, and $2.56{\pm}0.70$ who did not. Conclusion: 1. The respondents who received the infection control education by college curriculum showed higher degree of practice than the respondents who did not. 2. The respondents who have appropriate infection control guidebook in their workplace showed higher degree of awareness than the respondents who did not. 3. There was a correlation between the awareness and practice of infection control during prosthodontic treatment; the degree of awareness becomes higher, so does the degree of practice. 4. During the prosthodontic treatment, the degree of practice was lower than the degree of awareness on infection control.

Single Laboratory Validation and Uncertainty Estimation of a HPLC Analysis Method for Deoxynivalenol in Noodles (면류에서 HPLC를 이용한 데옥시니발레놀 분석법의 검증과 불확도 산정)

  • Ee, Ok-Hyun;Chang, Hyun-Joo;Kang, Young-Woon;Kim, Mee-Hye;Chun, Hyang-Sook
    • Journal of Food Hygiene and Safety
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    • v.26 no.2
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    • pp.142-149
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    • 2011
  • An isocratic high performance liquid chromatography (HPLC) method for routine analysis of deoxynivalenol in noodles was validated and estimated the measurement uncertainty. Noodles (dried noodle and ramyeon) were analyzed by HPLC-ultraviolet detection using immunoaffinity column for clean-up. The limits of detection (LOD) and quantification (LOQ) were 7.5 ${\mu}g$/kg and 18.8 ${\mu}g$/kg, respectively. The calibration curve showed a good linearity, with correlation coefficients $r^2$ of 0.9999 in the concentration range from 20 to 500 ${\mu}g$/kg. Recoveries and Repeatabilities expressed as coefficients of variation (CV) spiked with 200 and 500 ${\mu}g$/kg were $82{\pm}2.7%$ and $87{\pm}1.3%$% in dried noodle, and $97{\pm}1.6%$ and $91{\pm}12.0%$ in ramyeon, respectively. The uncertainty sources in measurement process were identified as sample weight, final volume, and sample concentration in extraction volume as well as components such as standard stock solution, working standard solution, 5 standard solutions, calibration curve, matrix, and instrument. Deoxynivalenol concentration and expanded uncertainty in two matrixes spiked with 200 ${\mu}g$/kg and 500 ${\mu}g$/kg were estimated to be $163.8{\pm}52.1$ and $435.2{\pm}91.6\;{\mu}g$/kg for dried noodle, and $194.3{\pm}33.0$ and $453.2{\pm}91.1\;{\mu}g$/kg for ramyeon using a coverage factor of two which gives a level of statistical confidence with approximately 95%. The most influential component among uncertainty sources was the recovery of matrix, followed by calibration curve.

A Study on Research of Necessity and Practice of Contents of Clothing and Textiles Education (의생활 교육내용의 필요도와 실천도 조사 연구)

  • 박일록;이은희
    • Journal of Korean Home Economics Education Association
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    • v.15 no.3
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    • pp.89-103
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    • 2003
  • The purpose of this study was to investigate to relation of necessity and practice of contents of clothing and textiles education(classify them into four units, choice and dressing of clothes, textile and management of clothes, design and sewing of clothes, knitting and embroidery). Method of posing a questionnaire is adopted to obtain stochastic data required for pertinent analysis. This is the investigation of which 400 (high school students 204, university students 196) girl students located in Choongnam and Junrabookdo province. In this statistical analysis, SPSS 10.0 for Windows Program was utilized to calculate percentage, mean and standard deviation. Also, these materials were verified by t-test, One-way Anova, Pearson's correlation coefficient. The results of this research were as follows. First, girl students' necessity mean point were higher than practice mean point about the contents of clothing and textiles education. And necessity had a positive relationship with practices of contents of clothing and textiles education. Second, there was a significant difference in necessity and practice of contents of clothing and textiles education according to demographic variables. These results should be provide fundamental information for improving students' critical practice in their real life. Since this study has touched only limited research on the topic of clothing and textiles education, it is essential that further research covering a wider array of themes be done in the future. this study has touched only limited research on the topic of clothing and textiles education, it is essential that further research covering a wider array of themes be done in the future.

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