• Journal of the Korean Geographical Society
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• v.48 no.1
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• pp.19-36
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• 2013

This study aimed to investigate the change of humidity by city size in South Korea. Using daily mean relative humidity and water vapor pressure during the period of 1954~2011 for 14 weather stations in South Korea, the change of humidity by city size was analyzed. The change of relative humidity had a continuous decreasing trend for the period of 1954~2011. The decreasing trend in large city was bigger than these of rural one. The seasonal relative humidity was significantly changed in spring and winter. The change of water vapor pressure was rarely changed significance of the results by city size. It was not shown the result to constant trend by city size. There was a negative correlation between relative humidity and mean temperature. And change of relative humidity was correlated with city size. Moreover, there was not correlation between relative humidity and water vapor pressure by city size. The decreasing trend of relative humidity was similar to increasing trend of temperature by urbanization. However, there was not shown significant result of water vapor pressure.

• Ocean and Polar Research
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• v.30 no.4
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• pp.373-378
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• 2008

Long-term tide-gauge data from around the Korean Peninsula were reanalyzed. Both the coastal water and the open sea surrounding the Korean Peninsula appeared to have been influenced by global warming. The long-term change in relative sea levels obtained from tidal stations showed a general rising trend, especially near Jeju Island. It is proposed that global warming may have caused shifting of the path of the Kuroshio branch (Tsushima Warm Current) toward Jeju Island, causing a persistent increase in the water levels along the coast of the island over the last few decades.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.195-196
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• 2019

The temperature and relative humidity in concrete change with the passage of time depending on factors such as compressive strength. They are also different depending upon internal depth of concrete. In this study, we have measured the change of the temperature and relative humidity in the concrete for two years to act as the parameters to evaluate the concrete durability and effective maintenance.

• KIEAE Journal
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• v.12 no.4
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• pp.21-30
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• 2012

This study aims to set up Energy self-sufficiency urban planning system responding climate change by reducing fossil energy consumption and carbon emission, and to suggest effective application method. This study has 3 levels. First, it defines energy self-sufficient city responding climate change theoretically. Second, it set up planning system of Energy Self-sufficient city responding climate change. Third, ANP method was applied to introduce priority of application according to relative importance of planning section. As ANP method has to construct network to show interrelation among elements, 1st questionnaire survey was carried out to figure out interrelation. 2nd questionnaire survey introduced to judge relative importance of planning aspects and sections. In conclusion, this study shows interrelation among planning sections. By considering the relative importance, Energy environment and Energy consumption was derived as important planning aspects, and Architecture, Landuse, and Production of renewable energy was estimated as s important planning elements.

• Journal of Environmental Science International
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• v.16 no.2
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• pp.171-178
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• 2007

It is well known that urban relative humidity has continuous decreasing trend owing to the influence of urbanization. The change of relative humidity is directly influenced by two factors, namely, temperature effect and water vapor effect in various urban effects. In this study, the temperature and tile water vapor effects on the relative humidity change were analyzed by using monthly mean relative humidities for a long period($1961{\sim}2005$) in Daegu and Chupungnung. The major results obtained in this study can be summarized as follows. Firstly, the urban dryness was caused mainly by water vapor effect in summer. But, for the other seasons, the urban dryness is mainly due to the temperature effect. Secondly, the relative humidity in Daegu is on the decrease until now. This phenomenon is similar to another Korean huge cities such as Seoul, Daejeon and Incheon. But, it is different compared with Japanese huge cities such as Tokyo, Osaka and Nagoya, indicating a standstill in relative humidity change after 1980s.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.853-856
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• 2005

A low water/cement ratio leads to autogenous shrinkage of cement paste at an early age. This autogenous shrinkage is related to the change of relative humidity in the pore structure that is formed during the hydration process. The relationship between autogenous shrinkage and relative humidity change are relatively well defined today, but the effects of temperature on autogenous shrinkage, relative humidity, and pore structures have been studied less systematically. This study focused on correlating alterations of these properties of cement paste hydrated at constant temperatures of 20, 40, and $60^{\circ}C$. The test results clearly indicate that increasing curing temperature resulted in increased porosity, particularly for pores between 5 to 50 nm as measured by MIP, and increased autogenous shrinkages, as a consequence of a reduction of relative humidity at early ages.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.259-260
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• 2012

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.576-590
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• 2023

Machine learning is widely used in various academic fields, and recently it has been actively applied in the medical research. In the medical field, machine learning is used in a variety of ways, such as speeding up diagnosis, discovering new biomarkers, or discovering latent traits of a disease. In the respiratory field, a relative regional air volume change (RRAVC) map based on quantitative inspiratory and expiratory computed tomography (CT) imaging can be used as a useful functional imaging biomarker for characterizing regional ventilation. In this study, we seek to predict RRAVC using various regular machine learning models such as extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM), and multi-layer perceptron (MLP). We experimentally show that MLP performs best, followed by XGBoost. We also propose several relative coordinate systems to minimize intersubjective variability. We confirm a significant experimental performance improvement when we apply a subject's relative proportion coordinates over conventional absolute coordinates.

• Journal of Sensor Science and Technology
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• v.21 no.6
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• pp.420-424
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• 2012

We have investigated temperature dependence and long-term change of humidity measurement from 32 relative humidity sensors. The readings of the humidity sensors depended not only the reference humidity, but also temperature of the chamber. Approximately, the temperature dependence of the humidity sensor in average was 0.05 %R.H./$^{\circ}C$ in the temperature range from $5^{\circ}C$ to $55^{\circ}C$. For humidity sensors that have an internal temperature compensation circuit, the resulting temperature dependence was weaker by 20%. It should be also noted that for the humidity sensors used in this work underwent ${\pm}3$ %R.H. change per year for level of confidence of 95%. The users of relative humidity sensors may refer this value as a minimum change when they set the calibration interval of the humidity sensors.

• Korean Journal of Child Studies
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• v.22 no.1
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• pp.97-107
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• 2001

This study argues the nature of the microgenetic method in respect to child development research and explores its merits and limitations. The microgenetic method focuses on observations that span the entire period from the beginning of developmental change to the time it reaches a relatively stable state. This produces a high density of observations relative to the rate of change in the phenomenon. In this way, observed behavior may be used in intensive trial-by-trial analysis. The microgenetic method is superior to other methods in the possibilities for observing developmental changes as they occur, examining various aspects of change, detecting variability in behavior, and flexibility in application regardless of theoretical perspectives. Limitations of this method include reliability problems due to repeated observations, artificiality relative to the natural situation, inconsistency of short-and long-term change, and demands on children's motivation for participation in research.