• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 춘계 학술발표회 논문집
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• pp.191-196
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• 2005

Knowing the time of the process change could lead to quicker identification of the responsible special cause and less process down time, and it could help to reduce the probability of incorrectly identifying the special cause. In this paper, we propose a MLE of the process change point when control charts with the fixed sampling rate (FSR) scheme or the variable sampling rate (VSR) scheme monitor a process to detect changes in the process mean and/or variance of a normal quality variable.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.143-148
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• 2005

The main purpose of this study is to suggest and evaluate an operational method for assessing the potential impact of climate change on hydrologic components and water resources of regional scale river basins. The method, which uses large scale climate change information provided by a state of the art general circulation model(GCM) comprises a statistical downscaling approach and a spatially distributed hydrological model applied to a river basin located in Korea. First, we construct global climate change scenarios using the YONU GCM control run and transient experiments, then transform the YONU GCM grid-box predictions with coarse resolution of climate change into the site-specific values by statistical downscaling techniques. The values are used to modify the parameters of the stochastic weather generator model for the simulation of the site-specific daily weather time series. The weather series fed into a semi-distributed hydrological model called SLURP to simulate the streamflows associated with other water resources for the condition of $2CO_2$. This approach is applied to the Yongdam dam basin in southern part of Korea. The results show that under the condition of $2CO_2$, about $7.6\% of annual mean streamflow is reduced when it is compared with the observed one. And while Seasonal streamflows in the winter and autumn are increased, a streamflow in the summer is decreased. However, the seasonality of the simulated series is similar to the observed pattern and the analysis of the duration cure shows the mean of averaged low flow is increased while the averaged wet and normal flow are decreased for the climate change.

• 한국기후변화학회지
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• 제6권2호
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• pp.133-142
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• 2015

The purpose of this study was to compare the results of climate change prospect and vulnerability assessment and the awareness of those by public officials and citizens at Yeongwol county, Gangwon province where experiencing the most climate change vulnerability. Data of 12 meteorological categories such as mean temperature at Yeongwol weather station from 1995 to 2013 were analyzed. Climate change vulnerability was assessed with 29 sub-categories in 6 categories (health, emergency/disaster, agriculture, forestry, water management, ecosystem) of National Institute of Environment Research's LCCGIS (2013). The awareness of climate change and its vulnerability was surveyed with 154 citizens and 130 officials at Yeoungwol county. The climate change prospect and its vulnerability was similar to the actual climate change effect. However, the awareness of climate change was different between some officials and citizens. The results of this study would be base data for the Yeoungwol county's future climate change adaptation poicy making.

• 지질공학
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• 제18권3호
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• pp.263-276
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• 2008

지하수 저류 변화량 산정은 수리지질의 다양한 분야에서 활용되고 있으며, 갈수록 정확한 지하수 저류 변화량 산정이 요구되고 있다. 본 연구에서는 물수지분석법과 수리지질분석을 이용하여 울산광역시 언양지역의 지하수 저류 변화량을 산정하였다. 산정된 지하수 저류 변화량은 연평균 240mm(연평균 강수량의 18.7%)이다. SCS-CN법으로 산정한 직접유출량은 연평균 강수량의 10.6%인 137mm이다. Thornthwaite방법으로 산정한 증발산량은 연평균 강수량의 60.5%인 776mm이다. 토양의 수리적 특성과 암석의 수리전도도 사이에는 연관성이 나타나지 않는다. 이는 지표부근의 토양의 수리적 특성과 천부의 지하 지층의 수리적 특성이 서로 다름을 지시하는 것이다. 지하수 저류 변화량과 수리특성인자들 간의 중다선형 회귀분석 결과, 강수량과 증발산량에 의해서 지하수 저류 변화량이 설명되는 중다선형 회귀식이 도출되었다.

• 대한간호학회지
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• 제30권2호
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• pp.354-365
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• 2000

Purpose: This study was performed to identify the factors that change exercise behave. This study will also classify and identify the characteristics of excercise stages to which the elderly belong Also, to identify the processes of change which influence on the changes in exercise performed by the elderly. Methods: Convenient samples of 198 subjects over the age 60 in Seoul Korea(mean age=70) were selected from elderly communities and were all mentally conpetant older adults. The data were collected from April 1,1999 to May 30, 1999. The research instruments were measured the change in exercise (Marcus et al., 1992b), such as Stage of Change measure(Marcus et al,1992a). The data were analyzed by SAS Program. Results: 1. According to the measure of change without missing data, 191 subjects were distributed each stage of change for exercise: 50 subjects (26.1%), 7 subjects (3.6%), 52 subjects (27.2%), 4 subjects (2%), and 78 (40.8%) belonged to the precontemplation stage, the contemplation stage, the preparation stage, the action stage and the maintenace stage. 2. According to the factor analysis, 6 factors of change were identified as appropriate processes of change and were named by the researchers. The names were; 'Supportive helping relationship', 'Self cognitive determination', 'Environmental reinforcement', Consciousness raising', Reinforcement of negative condition and 'Conversion of negative condition'. 3. According to the stage of change, there were significant mean differences in the 'Supportive helping relationship(F=22.04, p=.0001)', 'Self cognitive determination (F=50.87, p=.0001)', 'Reinforcement of negative condition(F=7.84,p=.0006)'. 4. Through the discriminant analysis, it was found that Self cognitive determination is the most influential variable as one of the processes of change which can discrimiate the three stages of change (precontemplation, preparation, and maintenance). Also the next significant variable was Reinforcement of negative condition. Conclusion: The process of the dey change is one of concepts of The transtheoretical model known as strategies and the techniques people use as they go through the different stages of change. Even though this study is cross- sectional not longitudinal study, the finding of this study gives useful information for exercise intervention, by using this strategy of exercise for elderly in different stages of change in exercise.

• 한국환경과학회지
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• 제4권5호
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• pp.1-1
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• 1995

An attempt was made to study the subdivision of Korea by the annual amount and the annual change pattern of monthly precipitation days(that is one of the important elements of the precipitation characteristics), using the mean values for the years 1961-1990 at the 68 stations. The amplitudes of annual change were normalized and using these values, the principal component analysis was applied to determine the annual change patterns. The results show that they are expressed by the combinations of the three change patterns in almost whole regions of Korea. As a result,the annual change pattern of precipitation days in Korea is classified into 8 types from A to e,in detail, 36 types from A0 to e$\circled2$.And regional division of precipitation days in Korea is divided into 13 regions from I a to IIIC,into detail, 41 regions from I no to IIICl.

• 한국환경과학회지
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• 제4권5호
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• pp.387-402
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• 1995

An attempt was made to study the subdivision of Korea by the annual amount and the annual change pattern of monthly precipitation days(that is one of the important elements of the precipitation characteristics), using the mean values for the years 1961-1990 at the 68 stations. The amplitudes of annual change were normalized and using these values, the principal component analysis was applied to determine the annual change patterns. The results show that they are expressed by the combinations of the three change patterns in almost whole regions of Korea. As a result, the annual change pattern of precipitation days in Korea is classified into 8 types from A to e, in detail, 36 types from A0 to e$\circled2$.And regional division of precipitation days in Korea is divided into 13 regions from I a to IIIC, into detail, 41 regions from I no to IIICl.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.179-187
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• 2022

The project performances can be measured in terms of meeting the project schedule, budget, and conformance to functional and technical specifications. Numerous studies have been conducted to examine the causes and effects of change orders for both vertical and horizontal construction, respectively. However, these studies mainly focus on a single project type, so this paper examines the impact of change order for cost growth and schedule overruns using four different building types to close the gap in the change order research area. A total of 211 building projects are collected from four building types: healthcare, residential, office, and education. Statistical analyses using ANOVA tests and linear regression models are used to examine the created metric $CO/day on the cost and schedule impacts. The results found that mean $CO/day values were not statistically different among building types, and that the sum of change orders is a statistically significant predictor of $CO/day. The results will help project stakeholders mitigate the negative change orders effects can be a challenge for project managers and researchers alike.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.75-81
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• 2001

This paper presents the atomization characteristics of single hole injector in the direct injection type diesel engine. The spray characteristics of fuel injector such as the droplet size and velocity were measured by phase Doppler particle analyzer. In this paper, the atomization characteristics of fuel spray are investigated for the experimental analysis of the measuring data by the results of mean diameter and mean velocity of droplet. The effect of fuel injection pressure on the droplet size shows that the higher injection pressure results in the decrease of mean droplet diameter in the fuel spray. The minimum size of fuel spray droplet appears on the location of 40mm axial distance from nozzle exit of diesel injector. Based on the experimental results, the correlation between the droplet diameter and mean velocity of the diesel spray due to the change of axial and radial distance from the nozzle tip were investigated.

• 한국전산유체공학회지
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• 제15권4호
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• pp.32-39
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• 2010

In this study, we consider Taylor-Couette flow with the outer cylinder at rest and the inner one oscillating with a mean angular velocity. Varying the mean angular velocity, amplitude and frequency of the oscillation, we investigate the characteristics of modulated Taylor vortices. At a constant mean angular velocity, Taylor vortices intensify as the amplitude increases and frequency decreases. The axial wavenumber is calculated by spectral analysis. When the frequency varies, the axial wavenumber does not change at a constant mean angular velocity and amplitude. But, the axial wavenumber increases, as the mean angular velocity increases.