• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.1
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• pp.31-38
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• 2005

This paper is focused on the research of environmental and human factors for a design of PMVbased air conditioning system in the ship. In the results from environmental factor research, it is possible to dissatisfy thermally in the wheel house and communication room of 25 ton and engine room of 100 ton. The clothing and activity in the ship is modified using inland indoor characteristics. Thermal resistance of clothing may be more sensitive to PMV(predicted mean vote) than metabolic rate because of large deviation among maritime polices. The distribution of human factor is right long-tailed than standard normal distribution.

• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.119-130
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• 2017

In many literatures on VaR and CTE for multivariate distribution, these are estimated by using transformed univariate distribution with a specific ratio of many kinds of portfolios. Even though there are lots of works to define quantiles for multivariate distributions, there does not exist a quantile uniquely. Hence, it is not easy to define the VaR and CTE. In this paper, we propose the weighted CTE vectors corresponding to various ratio combinations of many kinds of portfolios by extending the researches on the alternative VaR and integrated multivariate CTE based on multivariate quantiles. We extend relation equations about univariate CTEs to multivariate CTE vectors and discuss their characteristics. The proposed weighted CTEs are explored with some data from multivariate normal distribution and illustrative examples.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.6 s.46
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• pp.21-30
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• 2005

In this study, a seismic design methodology for friction dampers based on the story shear force distribution of an elastic building structure is proposed. First, using two normalization methods for the slip-load of a friction damper, numerical analyses of various single-degree-of-freedom systems are peformed. From those analyses, the effect of the slip-load and the brace stiffness was investigated and the optimal silliness ratio of the brace versus original structure was found. Second, from the numerical analysis for five multi-story building structures with different natural frequency and the number of story, reasonable decision method for the total number of installation floor, location of installation and distribution of the slip-loads are drawn. In addition, an empirical equation on the optimal number of installation floor is proposed. Finally, the superiority of the proposed method compared to the existing design method is verified from the numerical analysis using real earthquake data.

• Journal of Korea Water Resources Association
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• v.41 no.6
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• pp.605-617
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• 2008

This study developed a flood index which evaluates runoff characteristics. Runoff characteristics expressed in a hydrograph were reflected in the flood index in the form of characteristic factors such as a rising curve gradient, a peak discharge, a flood response time, and a flood discharge volume prior to peak. This study applied the standardization method to estimate the relative severity of the characteristic factors by transforming the distribution of characteristic factors into the standard normal distribution. The flood index developed in this study is a comprehensive flood index (CFI) which makes up for the weak points of a flash flood index (FFI) in determining relative severities. The CFI was applied to Han River basin and Selma River basin, and was compared with the FFI based on the correlation analysis and the regression analysis. The CFI could comprehensively evaluate flood runoff characteristics because the CFI is not dominated by a specific characteristic factor, and the CFI could explain more efficiently the relationship between rainfall and runoff than the FFI.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.331-334
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• 2010

This paper proposes a new design of a video-base fire detection system using texture and color spatial distribution information. The video sequences used are taken in different days with different lighting conditions having different backgrounds. The time complexity of most previous vision-based fire detection techniques are very high due to lengthy programing. To overcome the problems of lengthy codes and time complexity, in this algorithm, at first we normalize the video image frames by size and color information. Then the spatial distribution of the color information is used to extract the candidate regions, later using visual texture of the fire, we detect the fire regions. The experimental results show an real-time fire detection over thousands of image frames, and have higher detection rate when compared to the conventional fire detection techniques.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.211-222
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• 2020

This study tried to find out whether there is a change over time in the functional classification of forests in relation to human demand for forests. The level in which the concept of ecosystem services has been considered in national forest management plans was also examined. A total of 98 current and previous national forest management plans were available for this study. The composition ratios of the six functions of forests in both the current and previous national forest management plans were surveyed. We used a parametric t-test when the mean values of two (current and previous) groups were normally distributed and used nonparametric Wilcoxon code rank test when the assumption of normality was not met. Timber production forests were shown to follow a normal distribution, while five others, including water regeneration forests, disaster prevention forests, natural environment conservation forests, recreation forests, and living environment conservation forests were not shown to follow a normal distribution. Timber production forests and natural environment forests showed significant changes in the proportion of forest area between previous and current forest management plans. The concept of 'ecosystem services' began to actively appear in the 6th Basic Forest Plan, which started in 2018. However, the level of frequency of the ecosystem services mentioned varied by Regional Forest Services.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.93-100
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• 2003

In this technical information, the long-term measurement data at Gosan between 1992 and 2001 are analyzed with various statistical methods. First. it was confirmed that the basic assumption of t-test is important to classify data correctly. Second, it was founded that the difference of the number of data per month can affect the averaged concentration. Third, by using a non-parametric statistical method long term trend of aerosol composition free from seasonal effects is obtained.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.968-976
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• 2004

In the paper, deformation characteristics of fiber-mixed-soils, mixed polypropylene staple fibers of 0.3% fiber content with sands of various gradation, and their effectiveness of reinforcement were evaluated. A series of Resonant Column tests were performed with specimens prepared with varying Uniformity Coefficient and constant Curvature Coefficient. Maximum shear moduli 01 fiber-mixed-soils were increased by up to 30% and modulus reduction was also restrained in nonlinear range. Normalized shear modulus reduction curves of fiber-mixed-soils shift close to the upper limit of Seed curd Idriss's curves and are located within narrower band than those of unmixed soils, which proves the effectiveness on stiffness increment by reinforcing soils with fibers.

• The Korean Journal of Applied Statistics
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• v.23 no.3
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• pp.471-485
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• 2010

VaR is used extensively as a tool for risk management by financial institutions. For convenience, the normal distribution is usually assumed for the measurement of VaR, but recently the method using extreme value theory is attracted for more accurate VaR estimation. So far, GEV and GPD models are used for probability models of EVT for the VaR estimation. In this paper, the PP model is suggested for improved VaR estimation as compared to the traditonal EV models such as GEV and GPD models. In view of the stochastic process, the PP model is regarded as a generalized model which include GEV and GPD models. In the empirical analysis, the PP model is shown to be superior to GEV and GPD models for the performance of VaR estimation.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.145-154
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• 2003

In this study, the variation in excess pore pressure during dissipation is estimated by using successive cavity expansion theory and finite difference technique based on axisymmetric uncoupled linear consolidation theory with separate consideration of magnitude and initial distribution $\Delta{u}_{oct}$induced by changes of octahedral normal stress, and $\Delta{u}_{shear}$ induced by changes of octahedral shear stress. The coefficient of consolidation is also estimated by trial and error procedure until the predicted dissipation curve matches the measured curve at a typical degree of dissipation. The proposed method is applied to the results of miniature piezocone tests at Louisiana State University calibration chamber system. Based on the results of interpretation and the comparison with experimental measurements and those from other solutions, the prediction dissipation curves show a good match with those measured during dissipation tests and the values of coefficient of consolidation estimated by proposed method are more close to the range of laboratory measurements than those of other theories.