• Title/Summary/Keyword: percentile value

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Development of Method to Define Influence Area using Travel Time on the Feasibility Study (도로사업 예비 타당성조사에서 통행시간을 이용한 영향권 설정기법의 개발)

  • Kim, Kang-Soo;Oh, Dong-Kyu;Chung, Sung-Bong
    • Journal of Korean Society of Transportation
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    • v.23 no.8 s.86
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    • pp.139-145
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    • 2005
  • `Influence Area` means the area that the traffic flow pattern of which is changed remarkably after the construction of highway facilities. The Influence area would be a significant criteria for demand forecasting and economic analysis. However existing methods for defining influence area such as O/D method, traffic volume variation method and rate of traffic volume variation method have no standard criteria. In this paper, some problems which existing methods have are analyzed and a new method travel time method - is introduced. Influence area can be induced as the area where the vehicles reach from starting traffic zone to ending zone to which 95 percentile vehicles want to travel. In addition, the value of standard criteria for defining influence ayes are induced via this method.

Analysis of Utilization and Perception of Special Weather Reports for Climate Change Adaptation: Focus on Dryness Advisory and Warning (기후변화적응을 위한 기상특보 인지도 및 활용도 분석: 건조특보를 중심으로)

  • Choi, Su-Jin;Kim, Eun-Byul;Jung, Woo-Sik;Kim, Baek-Jo;Park, Jong-Kil
    • Journal of Environmental Science International
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    • v.23 no.6
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    • pp.1121-1130
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    • 2014
  • This study aims to find the perception and utilization of the citizen about the dryness watch warning (DWW) among special weather reports. For this we have made up a descriptive questionnaire including the perception, utilization of special weather reports. Using the SPSS 17.0 program, descriptive statistics, t-test, ANOVA and Scheffe test were used to analyze the collected data. The results are as follows; The perception of DWW is measured by 4 point Likert scale and the average is $15.97{\pm}3.70$ (percentile=57.0). This value shows that the awareness level is not that high and according to the occupation, college students show the lowest awareness and housewives show the highest awareness. According to the age, the teens and twenties show the lowest awareness and fifties and sixties show the highest awareness. Although the perception of the teens and college students are rather poor, there were many positive answers that it is necessary to establish the advanced disaster prevention plan according to the questionnaire about the utilization of DWW. Therefore, if we come up with an effective plan to improve the perception than we can expect a large-effect in terms of fire and forest fire prevention. The perception of DWW can be improved by providing weather information and weather related education program on TV or internet which have the high level of preference. Also, it is necessary to provide online and offline program of advertising education and disaster management education through the weather forecast bureau which is the host organization of delivering weather information.

Characteristic of PM10 Distribution Related to Precise Local Wind Patterns in Busan Metropolitan Area (상세 국지 기류 분포를 고려한 부산 지역 내 미세 먼지 분포 특성)

  • Hong, Seon-Hwa;Lee, Soon-Hwan
    • Journal of Environmental Science International
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    • v.26 no.12
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    • pp.1375-1387
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    • 2017
  • In order to investigate the $PM_{10}$ concentration trend and its characteristics over five different sub area in Busan from 2013 to 2015, data analysis with considering air flow distribution according to its topography was carried out using statistical methodology. The annual mean concentrations of $PM_{10}$ in Busan tend to decrease from $49.6{\mu}g/m^3$ in 2013 to $46.9{\mu}g/m^3$ in 2015. The monthly mean concentrations value of $PM_{10}$ were high during spring season, from March to May, and low during summer and fall due to frequent rain events. The concentration of $PM_{10}$ was the highest in five different sub-area in Busan. High concentration episodes over 90 percentile of daily $PM_{10}$ concentration were strongly associated with mean daily wind speed, and often occurred when the westerly wind or southwesterly wind were dominant. Regardless of wind direction, the highest correlation of $PM_{10}$ concentrations was observed between eastern and southern regions, which were geographically close to each other, and the lowest in the western and eastern regions blocked by mountains. Wind flow along the complex terrain in Busan is also one of the predominant factors to understand the temporal variation of $PM_{10}$ concentrations.

Meal skipping relates to food choice, understanding of nutrition labeling, and prevalence of obesity in Korean fifth grade children

  • Kim, Hye-Young;Lee, Na-Rae;Lee, Jung-Sug;Choi, Young-Sun;Kwak, Tong-Kyung;Chung, Hae-Rang;Kwon, Se-Hyug;Choi, Youn-Ju;Lee, Soon-Kyu;Kang, Myung-Hee
    • Nutrition Research and Practice
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    • v.6 no.4
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    • pp.328-333
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    • 2012
  • This study was performed to investigate the differences in food choice, nutrition labeling perceptions, and prevalence of obesity due to meal skipping in Korean elementary school children. A national survey was performed in 2010 to collect data on food intake frequency, understanding of nutrition labeling, and body mass index from 2,335 fifth grade students in 118 elementary schools selected from 16 metropolitan local governments by stratified cluster sampling. The data were analyzed using the SAS 9.1 and SUDAAN 10.0 packages. Students who consumed three meals for 6-7 days during the past week were classified into the regular meal eating (RM) group (n = 1,476) and those who did not were placed into the meal skipping (MS) group (n = 859). The daily intake frequency of fruits, vegetables, kimchi, and milk was significantly lower in the MS group compared to that in the RM group (P < 0.001), whereas the daily intake frequency of soft drinks and instant noodles (ramyeon) was significantly higher in the MS group than that in the RM group (P < 0.05). The MS group demonstrated a significantly lower degree of understanding with regard to nutrition labeling and high calorie foods containing low nutritional value than that in the RM group. The distribution of obesity based on the percentile criteria using the Korean growth chart was different between the MS and RM groups. The MS group (8.97%) had a higher percentage of obese subjects than that in the RM group (5.38%). In conclusion, meal skipping was related to poor food choice, low perception of nutrition labeling, and a high prevalence of obesity in Korean fifth grade children.

Model Performance Evaluation and Bias Correction Effect Analysis for Forecasting PM2.5 Concentrations (PM2.5 예보를 위한 모델 성능평가와 편차보정 효과 분석)

  • Ghim, Young Sung;Choi, Yongjoo;Kim, Soontae;Bae, Chang Han;Park, Jinsoo;Shin, Hye Jung
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.1
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    • pp.11-18
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    • 2017
  • The performance of a modeling system consisting of WRF model v3.3 and CMAQ model v4.7.1 for forecasting $PM_{2.5}$ concentrations were evaluated during the period May 2012 through December 2014. Twenty-four hour averages of $PM_{2.5}$ and its major components obtained through filter sampling at the Bulgwang intensive measurement station were used for comparison. The mean predicted $PM_{2.5}$ concentration over the entire period was 68% of the mean measured value. Predicted concentrations for major components were underestimated except for $NO_3{^-}$. The model performance for $PM_{2.5}$ generally tended to degrade with increasing the concentration level. However, the mean fractional bias (MFB) for high concentration above the $80^{th}$ percentile fell within the criteria, the level of accuracy acceptable for standard model applications. Among three bias correction methods, the ratio adjustment was generally most effective in improving the performance. Albeit for limited test conditions, this analysis demonstrated that the effects of bias correction were larger when using the data with a larger bias of predicted values from measurement values.

Validity of Self-Reported Height, Weight, and Body Mass Index of the Korea Youth Risk Behavior Web-Based Survey Questionnaire

  • Bae, Ji-Suk;Joung, Hyo-Jee;Kim, Jong-Yeon;Kwon, Kyoung-Nam;Kim, Yoon-Jung;Park, Soon-Woo
    • Journal of Preventive Medicine and Public Health
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    • v.43 no.5
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    • pp.396-402
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    • 2010
  • Objectives: Self-reported anthropometric values, such as height and weight, are used to calculate body mass index (BMI) and assess the prevalence of obesity among adolescents. The aim of this study was to evaluate the validity of selfreported height, weight, and BMI of the Korea Youth Risk Behavior Web-based Survey questionnaire. Methods: A convenience sample of 137 middle school students and 242 high school students completed a selfadministered questionnaire in 2008. Body height and weight were directly measured after self-reported values were obtained from the questionnaire survey. Sensitivity, specificity, and kappa statistics were computed in order to evaluate the validity of the prevalence of obesity (BMI $\geq$ 95th percentile or $\geq$ $25;kg/$m^2$) based on self-reported data. Results: Self-reported weight and BMI tended to be underestimated. Self-reported height tended to be overestimated among middle school females and high school males. Obese adolescents tended to underestimate their weight and BMI and overestimate their height more than non-obese adolescents. The prevalence estimate of obesity based on selfreported data (10.6%) was lower than that based on directly measured data (15.3%). The estimated sensitivity of obesity based on self-reported data was 69.0% and the specificity was 100.0%. The value of kappa was 0.79 (95% confidence interval, 0.70 - 0.88). Conclusions: This study demonstrated that self-reported height and weight may lead to the underestimation of BMI and consequently the prevalence of obesity. These biases should be taken into account when self-reported data are used for monitoring the prevalence and trends of obesity among adolescents nationwide.

A Study on development of Road Design Driver Characteristics based on Physio-Physiological Performance (심리생리적 운전부하를 고려한 도로설계운전자 특성기준 정립연구)

  • Kim, Ju-Yeong;Park, Min-Su;Kim, Jeong-Ryong;Jang, Myeong-Sun
    • Journal of Korean Society of Transportation
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    • v.29 no.5
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    • pp.67-78
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    • 2011
  • This paper analyzes the characteristics of drivers' workload observed from with 30 participant drivers with respect to two physio-physiological parameters. For investigating physio-physiological characteristics of road drivers, bio-signals from brain's occipital lobe between simulation experiment and real driving experiment are collected and analyzed. The major findings from the analysis are summarized as follows: First, the drivers' physio-physiological workload is a good parameter for explaining the workload characteristics of road drivers. Secondly, the two physio-physiological workload parameters selected, i.e., beta value and relative energy parameter, are revealed to be statistically significant. Thirdly, it is also revealed to be statistically significant to select 90 percentile measurements in simulator experiment to explain the road drivers' characteristics. Finally, the maximum workload of road design driver is 31.72 in beta parameter, whereas the minimum workload is 1.296 in relative energy parameter.

Assessment of Agricultural Drought Using Satellite-based TRMM/GPM Precipitation Images: At the Province of Chungcheongbuk-do (인공위성 기반 TRMM/GPM 강우 이미지를 이용한 농업 가뭄 평가: 충청북도 지역을 중심으로)

  • Lee, Taehwa;Kim, Sangwoo;Jung, Younghun;Shin, Yongchul
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.4
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    • pp.73-82
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    • 2018
  • In this study, we assessed meteorological and agricultural drought based on the SPI(Standardized Precipitation Index), SMP(Soil Moisture Percentile), and SMDI(Soil Moisture Deficit Index) indices using satellite-based TRMM(Tropical Rainfall Measuring Mission)/GPM(Global Precipitation Measurement) images at the province of Chungcheongbuk-do. The long-term(2000-2015) TRMM/GPM precipitation data were used to estimate the SPI values. Then, we estimated the spatially-/temporally-distributed soil moisture values based on the near-surface soil moisture data assimilation scheme using the TRMM/GPM and MODIS(MODerate resolution Imaging Spectroradiometer) images. Overall, the SPI value was significantly affected by the precipitation at the study region, while both the precipitation and land surface condition have influences on the SMP and SMDI values. But the SMP index showed the relatively extreme wet/dry conditions compared to SPI and SMDI, because SMP only calculates the percentage of current wetness condition without considering the impacts of past wetness condition. Considering that different drought indices have their own advantages and disadvantages, the SMDI index could be useful for evaluating agricultural drought and establishing efficient water management plans.

Parents' and Kindergarten Teachers' Evaluation of the Traditional Fairy Tales regarding Distributive Justice (공평성을 다룬 전래동화에 대한 부모와 유아교사의 평가)

  • Kong, In Sook
    • Korean Journal of Childcare and Education
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    • v.3 no.2
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    • pp.1-21
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    • 2007
  • This study aims to obtain the basic data in order to develop the distributive justice reasoning program for preschooler. To fulfill this aim, this study investigated the parents' and kindergarten teachers' preference in the selection of the traditional fairy tale and the extent to which parents' and kindergarten teachers' evaluation of the traditional fairy tales dealing distributive justice are in agreement with each other. The subjects were 240 parents and 78 kindergarten teachers selected from five cities in Korea. The questionnaire with six Korean traditional fairy tales which deal with the sharing problem among the friends and the families was used. The data were analyzed in SPSS Win 10.0 program, by frequency, percentile, mean, standard deviation, ${\chi}^2$ and t-test. As a result, most important factor in selecting the traditional fairy tale was the title and the editing state of the book for the kindergarten teacher, while it was the good fame of the press for the parent. The congruence existed between parents' and kindergarten teachers' evaluation in knowledge, adaptability for modern times, amusement and empathy in the function of the traditional fairy tales regarding distributive justice. Meanwhile parents evaluated the traditional fairy tales are more adaptive for value formation and useful than teachers did.

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The Comparison of Waist Circumference, Waist to Hip Ratio and Body Mass Index in Female College Students (여대생의 허리둘레, 허리둔부 둘레비와 체질량지수 비고)

  • Paek, Kyung-Shin;Chaung, Seung-Kyo
    • Research in Community and Public Health Nursing
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    • v.16 no.4
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    • pp.527-533
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    • 2005
  • Purpose: The purpose of this study was to validate waist circumference (WC) and waist to hip ratio (WHR) corresponding to body mass index (BMI) of $25kg/m^2$ and to survey the prevalence of hypertension according to obesity in female college students. Method: Weight, height, waist and hip circumferences and blood pressure were measured for each of 286 female college students in J City, Chungbuk. Results: The subjects' mean BMI was $21.4kg/m^2$, and the estimated prevalence of obesity was 11.2%. The subjects, the 80th-90th percentile of whom had BMI exceeding $25kg/m^2$, were found to have WC of 75-78.1 cm and WHR of 0.79-0.80, respectively. Of the subjects with obesity($BMI{\geq}25kg/m^2$), 53.1% exhibited abdominal obesity ($WC{\geq}80cm$) and 40.6% had WHR over 0.80. Systolic and diastolic blood pressure were correlated with BMI, WC, and WHR. The prevalence rate of hypertension in subjects with obesity($BMI{\geq}25kg/m^2$) was 25%. Additionally, the prevalence rate of hypertension in subjects with abdominal obesity ($WC{\geq}80cm$) was 39.1%. Conclusions: Our study indicates that WC corresponding to BMI of $25kg/m^2$ in female subjects in their twenties is different from that of adult women. We also found that the prevalence rate of hypertension in subjects with abdominal obesity was high. Therefore. we suggest further studies to determine the cutoff value of WC for evaluating abdominal obesity and to investigate the long-term effects of obesity on women in their twenties.

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