• 제목/요약/키워드: Difference-In-Difference

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Comparison of the Characteristics of Precipitable Water Vapor Measured by Global Positioning System and Microwave Radiometer

  • Sohn, Dong-Hyo;Park, Kwan-Dong;Won, Ji-Hye;Cho, Jung-Ho;Roh, Kyoung-Min
    • Journal of Astronomy and Space Sciences
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    • 제29권1호
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    • pp.1-10
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    • 2012
  • In this study, global positioning system (GPS)-derived precipitable water vapor (PWV) and microwave radiometer (MWR)-measured integrated water vapor (IWV) were compared and their characteristics were analyzed. Comparing those two quantities for two years from August 2009, we found that GPS PWV estimates were larger than MWR IWV. The average difference over the entire test period was 1.1 mm and the standard deviation was 1.2 mm. When the discrepancies between GPS PWV and MWR IWV were analyzed depending on season, the average difference was 0.7 mm and 1.9 mm in the winter and summer months, respectively. Thus, the average difference was about 2.5 times larger in summer than that in winter. However, MWR IWV measurements in the winter months were over-estimated than those in the summer months as the water vapor content got larger. The results of the diurnal analysis showed that MWR IWV was underestimated in the daytime, showing a difference of 0.8 mm. In the early morning hours, MWR IWV has a tendency to be over-estimated, with a difference of 1.3 mm with respect to GPS PWV.

The Effects of Circuit Training and Circuit Training with Whole Body Vibration on Pulmonary Function in Adolescent

  • Jun, Hyun ju;Jeong, Chan Joo;Yang, Hoe Song;Jeong, Ye rim;Jegal, Hyuk;Yoo, Young Dae
    • 국제물리치료학회지
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    • 제6권2호
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    • pp.902-907
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    • 2015
  • The purpose of this study was to parallel circuit training and circuit training with sonic systemic mechanism was to compare the differences in pulmonary function and chest expansion in adult men. This study was performed on 20 subjects. 20 subjects were divided into two groups; Circuit training group(n=10), Circuit training with sonic systemic mechanism(n=10). Both of the group performed the exercise 3 times a week for 5 weeks. The data was analyzed by the Repeated t-test for comparing before, during and after changes of factors in each group and the Independent t-test for comparing the between groups. The result are as follows. Circuit training group was statistically significant difference FVC, FEV1/FVC(p<.05), Circuit training with sonic systemic mechanism group was statistically significant difference PEF, VC in pulmonary function(p<.05). Circuit training group was statistically significant difference FEV1/FVC of between the two group in pulmonary function(p<.05). Circuit training group and circuit training with sonic systemic mechanism group was statistically significant difference in chest expansion(p<0.05) and there was no statistically significant difference of between the two group in chest expansion(p>.05).

차분격자볼츠만법의 압축성 유체모델을 도입한 중력류의 흐름현상에 관한 연구 (Study on Analysis of Gravity Currents by the Finite Difference Boltzmann Method using Two-dimensional Compressible fluid Model)

  • 손유식;김원철;강호근
    • 한국해양공학회지
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    • 제16권5호
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    • pp.15-20
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    • 2002
  • In this research, the finite difference lattice Boltzmann method(FDLBM) is used to analyze gravity currents in the lock exchange configuration that occur in many natural and man-made situations. At a lock those are seen when a gate is suddenly opened, and, in the atmosphere, when the thunderstorm outflows make a cold front. At estuaries in the ocean, the phenomenon is found between fresh water from a river and salt water in the sea. Since such interesting phenomena were recognized, pioneers have challenged to make them clear by conducing both experiments and analysis. Most of them were about the currents of liquid or Boussinesq fluids, which are assumed as incompressible. Otherwise, the difference in density of two fluids is small. The finite difference lattice Boltzmann method has been a powerful tool to simulate the flow of compressible fluids. Also, numerical predictions using FDLBM to clarify the gravity currents of compressible fluids exhibit all features, but typically observed in experimental flows near the gravity current head, including the lobe-and-cleft structure at the leading edge.

Mandibular Kinesiograph를 이용한 하악개폐운동형태의 분석 (Analysis of Mandibular Opening and Closing Movement Patterns Using Mandibular Kinesiograph)

  • 기우천;조규정;조광훈
    • Journal of Oral Medicine and Pain
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    • 제9권1호
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    • pp.93-101
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    • 1984
  • The author has studied mandibular opening and closing movement patterns using mandibular kinesiograph in order to make basic data that is necessary to diagnose the mandibular movement function. The 83 normal subjects, who were students of the school of dentistry. Kyunpook National University and Daegu Junior Health College, were selected according to sampling criteria. The results were as follow : In the sagittal plan, crossover pattern had the highest incidence in male (72.7%) and female(76.8%). There was no significant defference of distribution of habitual closing movement patterns between male and female.(p>0.05). There were difference between each patterns.(p<0.01) In the frontal plane, there was no difference of distribution of male's opening and closing movement patterns between habitual and maximum velocity (p<0.05),but difference between each subjects. (p<0.05) In the frontal plane, there was no difference of distribution of habitual opening and closing movement patterns between male and female.(p<0.05) In the frontal plane, the average number of habitual opening and closing pathways cross the midline was greater than that of maximum velocity.(p<0.05) The average of the maximum mandibular movemet velocity of male was greater than female in opening and contact(p<0.01) and there was no difference between male and female in closing.(p>0.05)

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학령기 아동의 스트레스와 대처 및 자살 생각: 대구.경북 지역을 중심으로 (Stress, Coping and Suicidal Ideation among School-aged Children: Focused on Daegu/Gyeongbuk Region)

  • 최혜선;이미경
    • 한국학교보건학회지
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    • 제25권1호
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    • pp.85-94
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    • 2012
  • Purpose: The purpose of this study was to investigate the stress, coping and suicidal ideation among school-aged children and provide evidence for developing a stress management program for them. Methods: Data were collected and analyzed from 308 fifth graders from 6 elementary schools located in Daegu/Gyeongbuk. Results: First, for stress by general characteristics, there were significant differences in economic status, school record, self-rated health and life satisfaction. Also, subcategory stress by gender, there was a significant difference in appearance stress. Second, passive/avoidant coping had a significant difference in gender. Social support seeking coping and passive/avoidant coping were significant differences in economic status. Active coping had a significant difference in school record. Passive/avoidant coping had a significant difference in self-rated health. Aggressive coping, active coping, social support seeking coping and passive/avoidant coping had significant differences in self-rated life satisfaction. Third, stress and coping had significant differences by suicidal ideation. Fourth, stress showed positive correlations with aggressive coping and passive/avoidant coping while revealing negative correlation with active coping. Conclusion: These results from the study suggest difference by gender and need more active and positive coping strategy for suicide prevention.

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Effectiveness of Nutrition Education in Improving Maternal Knowledge and Attitudes towards Complementary Feeding Practices: A cluster-randomized controlled trial in Ondo State, Nigeria

  • Akinrinmade, Remilekun;NJOGU, Eunice;OGADA, Irene Awuor;KESHINRO, Olufunke Oluremi
    • 식품보건융합연구
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    • 제5권4호
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    • pp.1-10
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    • 2019
  • Significant low knowledge and poor attitudes on complementary feeding undermine the practices. This study was a cluster randomized controlled trial in which 284 study participants were assigned into two groups. One intervention group and a control group in a ratio of 1:1. Nutrition education on complementary feeding was carried out among the caregivers in the intervention group but the caregivers in the control group were not educated. To determine complementary feeding knowledge and attitudes, data was collected from caregiver at baseline, midline and at endline using researcher-administered questionnaires. Quantitative data were analyzed using SPSS version 22.0. From the analysis, there was a significant difference in complementary feeding knowledge of the caregivers after the intervention. The baseline difference was -0.06, the midline difference was 3.85 the endline difference was 4.00 and the DID of the baseline and endline was 4.06 which was significant at p=0.001. There was a significant difference in the attitude of the caregivers towards complementary feeding at baseline (-0.14), midline (2.09), endline (3.82) and the DID of baseline and endline was 3.96 which was significant at p=0.001. The intervention improved the caregivers' knowledge on complementary feeding and it improved the attitudes of the caregivers towards adequate complementary feeding.

창원시 학교 건축물의 냉난방부하에 대한 전력 소비량 추정에 관한 연구 (A Study on Prediction of Power Consumption Rate for Heating and Cooling load of School Building in Changwon City)

  • 박효석;최정민;조성우
    • 교육녹색환경연구
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    • 제11권2호
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    • pp.19-27
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    • 2012
  • This study was carried out in order to establish the estimation equation for school power consumption using regression analysis based on collected power consumption for two years of weather data and schools are located in Central Changwon and Masan district in Changwon city. (1) The power consumption estimation equation for Heating and cooling is calculated using power consumption per unit volume, the difference between actual power consumption and results of estimation equations is 4.1%. (2) The power consumption estimation equation for heating load is showed 2.6% difference compared to actual power consumption in Central Changwon and is expressed 2.9% difference compared to that in Masan district. Therefore, the power consumption prediction for each school using the power consumption estimation equation is possible. (3) The power consumption estimation equation for cooling load is showed 8.0% difference compared to actual power consumption in Central Changwon and is expressed 2.9% compared to that in Masan district. As the power consumption estimation equation for cooling load is expressed difference compared to heating load, it needs to investigate influence for cooling load.

대학생의 성별과 인지적 조절초점에 따른 지연행동과 불안의 차이 (The differences in procrastination and anxiety according to the gender and cognitive regulatory focus of university students)

  • 김보경;유순화
    • 수산해양교육연구
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    • 제27권3호
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    • pp.853-869
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    • 2015
  • The purpose of this study is to examine the difference in procrastination and anxiety as a personality trait according to gender and the cognitive regulatory focus of university students. In this study, we would like to answer the following questions: First, is there any difference in procrastination according to gender and regulatory focus? Second, is there any difference in anxiety according to gender and regulatory focus? The participants of this study comprised of 434 university students(171 male, 263 female), studying at 4 universities in South Korea. To examine whether the relative strength of promotion and prevention focus would differ across gender groups and regulatory focus type(promotion or prevention), we conducted a $2{\times}2$ factorial analysis of variance(ANOVA). The results of this study are as follows. First, there were significant difference in procrastination according to gender and regulatory focus, but there were no interaction effect between gender and regulatory focus. Second, there were significant difference in trait anxiety according to gender and regulatory focus, but there were no interaction effect between gender and regulatory focus. This study found that procrastination and anxiety as personality traits are differ depending on gender and regulatory focus(promotion focus and prevention focus). Suggestions and discussions based on these findings are provided.

종관 기상 분포에 따른 PM2.5 농도의 공간적 차이에 관한 연구 (A Study on Spatial Differences in PM2.5 Concentrations According to Synoptic Meteorological Distribution)

  • 채다은;이순환
    • 한국환경과학회지
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    • 제31권12호
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    • pp.999-1012
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    • 2022
  • To investigate the reason for the spatial difference in PM2.5 (Particulate Matter, < 2.5 ㎛) concentration despite a similar synoptic pattern, a synoptic analysis was performed. The data used for this study were the daily average PM2.5 concentration and meteorological data observed from 2016 to 2020 in Busan and Seoul metropolitan areas. Synoptic pressure patterns associated with high PM2.5 concentration episodes (greater than 35 ㎍/m3) were analyzed using K-means cluster analysis, based on the 900 hPa geopotential height of NCEP (National Centers for Environmental Prediction) FNL (Final analysis) data. The analysis identified three sub-groups related to high concentrations occurring only in Busan and Seoul metropolitan areas. Although the synoptic patterns of high PM2.5 concentration episodes that occur independently in Busan and Seoul metropolitan areas were similar, there was a difference in the intensity of pressure gradient and its direction, which tends to be an important factor determining the movement time of pollutants. The spatial difference in PM2.5 concentration in the Korean Peninsula is due to the difference and direction of the atmospheric pressure gradient that develops from southwest to northeast direction.

무인기 기반 동계 사료작물의 건물수량 예측을 위한 최적 식생지수 선정 (Selection of Optimal Vegetation Indices for Predicting Winter Crop Dry Matter Based on Unmanned Aerial Vehicle)

  • 신재영;이준민;양승학;임경재;이효진
    • 한국초지조사료학회지
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    • 제40권4호
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    • pp.196-202
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    • 2020
  • 본 연구는 동계사료작물의 무인기기반 생육모니터링을 위하여 호밀, 총체보리, IRG를 대상으로 다중분광영상으로 건물수량을 예측하기 위한 최적식생지수를 테스트하였다. 2019년 2월부터 4월까지 나주의 실경작지에서 무인기 다중분광카메라로 분광영상을 수집하여 4종류의 식생지수(Normalized Difference Vegetation Index; NDVI, Green Normalized Difference Vegetation Index; GNDVI, Normalized Green Red Difference Index; NGRDI and Normalized Difference Red Edge Index; NDREI)를 산출하고 지상에서 건물수량을 조사하여 식생지수와 건물수량의 상관관계를 조사하였다. 호밀, 총체보리, IRG에 대하여 건물수량과 NDVI의 상관관계(R2)는 0.91~0.92, GNDVI는 0.92~0.94, NGRDI는 0.71~0.85, NDREI는 0.84~0.91로 GNDVI가 가장 효과적이었다.