• Journal of Korea Water Resources Association
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• v.44 no.3
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• pp.209-220
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• 2011

Input uncertainty is one of the major sources of uncertainty in hydrologic modeling. In this paper, first, three alternate rainfall inputs generated by different interpolation schemes were used to see the impact on a distributed watershed model. Later, the residuals of precipitation interpolations were tested as a source of ensemble streamflow generation in two river basins in the U.S. Using the Monte Carlo parameter search, the relationship between input and parameter uncertainty was also categorized to see sensitivity of the parameters to input differences. This analysis is useful not only to find the parameters that need more attention but also to transfer parameters calibrated for station measurement to the simulation using different inputs such as downscaled data from weather generator outputs. Input ensembles that preserves local statistical characteristics are used to generate streamflow ensembles hindcast, and showed that the ensemble sets are capturing the observed steamflow properly. This procedure is especially important to consider input uncertainties in the simulation of streamflow forecast.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.149-158
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• 1998

The aim of this paper is to propose the technique of the two dimensional geodetic coordinates conversion between WGS84 and Bessel spheroids by the two-dimensional affine transformation modeling based on the UTM plane coordinates without the local geoid model which is essential to three dimensional coordinates conversion. Area of approximately $25\times{11}$ square km in the city of Inchon was selected as the test area. The transformation parameters were determined using the eleven triangulation control points in test area. And then, those paraneters were applied to the fifteen cadastral control points which selected as checking points for precision checking of transformation parameters. The average and standard deviations of the absolute values of the conversion residuals of checking points in latitude/longitude and N/E(UTM) and/or x/y(TM) are $\pm0.006"$$\pm0.013"$ and $\pm{17cm/}\pm{30cm}$ respectively. Also, coefficients for 7-parameters, 3-parameters and UTM model transformation computed according as sizes of transformed area, and then the transformed characteristics of checking points according to transformation methods analyzed synthetically.hetically.

• Journal of the Korean Geographical Society
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• v.45 no.6
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• pp.806-819
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• 2010

Population data has been essential and fundamental in spatial analysis and commonly aggregated into political boundaries. A conventional method for population distribution estimation was a regression model with land use data, but the estimation process has limitation because of spatial autocorrelation of the population data. This study aimed to improve the accuracy of population distribution estimation by adopting a Regression-Kriging method, namely RK Model, which combines a regression model with Kriging for the residuals. RK Model was applied to a part of Seoul metropolitan area to estimate population distribution based on the residential zones. Comparative results of regression model and RK model using RMSE, MAE, and G statistics revealed that RK model could substantially improve the accuracy of population distribution. It is expected that RK model could be adopted actively for further population distribution estimation.

• Journal of The Korean Astronomical Society
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• v.39 no.2
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• pp.41-50
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• 2006

We present the results of new multi-color CCD photometry for the contact binary XZ Leo, together with reasonable explanations for the period and light variations. Six new times of minimum light have been determined. A period study with all available timings confirms Qian's (2001) finding that the O-C residuals have varied secularly according to $dP/dt\;=\;+8.20{\times}10^{-8}\;d\;yr^{-l}$. This trend could be interpreted as a conservative mass transfer from the less massive cool secondary to the more massive hot primary in the system with a mass flow rate of about $5.37{\times}10^{-8}\;M_{\odot}\;yr^{-l}$. By simultaneous analysis of our light curves and the previously published radial-velocity data, a consistent set of light and velocity parameters for XZ Leo is obtained. The small differences between the observed and theoretical light curves are modelled by a blue third light and by a hot spot near the neck of the primary component. Our period study does not support the tertiary light but the hot region which may be formed by gas streams from the cool secondary. The solution indicates that XZ Leo is a deep contact binary with the values of q=0.343, $i=78^{\circ}.8$, ${\Delta}(T_1-T_2)=126\;K$, and f=33.6 %, differing much from those of Niarchos et al. (1994). Absolute parameters of XZ Leo are determined as follows: $M_1=1.84\;M_{\odot},\;M_2=0.63\;M_{\odot},\;R_1=1.75\;R_{\odot},\;R_2=1.10\;R_{\odot},\;L_1=7.19\;L_{\odot},\;and\;L_2=2.66\;L_{\odot}$.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1217-1223
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• 2020

Objective: Eggshells with a uniform color and intensity are important for egg production because many consumers assess the quality of an egg according to the shell color. In the present study, we evaluated the influence of dominant effects on the variations in eggshell color after 32 weeks in a crossbred population. Methods: This study was conducted using 7,878 eggshell records from 2,626 hens. Heritability was estimated using a univariate animal model, which included inbreeding coefficients as a fixed effect and animal additive genetic, dominant genetic, and residuals as random effects. Genetic correlations were obtained using a bivariate animal model. The optimal diagnostic criteria identified in this study were: L^🟉 value (lightness) using a dominance model, and a^🟉 (redness), and b^🟉 (yellowness) value using an additive model. Results: The estimated heritabilities were 0.65 for shell lightness, 0.42 for redness, and 0.60 for yellowness. The dominance heritability was 0.23 for lightness. The estimated genetic correlations were 0.61 between lightness and redness, -0.84 between lightness and yellowness, and -0.39 between redness and yellowness. Conclusion: These results indicate that dominant genetic effects could help to explain the phenotypic variance in eggshell color, especially based on data from blue-shelled chickens. Considering the dominant genetic variation identified for shell color, this variation should be employed to produce blue eggs for commercial purposes using a planned mating system.

• Journal of Korea Water Resources Association
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• v.30 no.2
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• pp.155-163
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• 1997

In this study, drought analysis of annual flows of Jindong, Hyunpoong, and Waekwan stations located at Nakdong River Basins was performed based on multivariate stochastic models. The stochastic models used were multivariate autoregressive model (MAR) and multivariate contemporaneous (MCAR) model. MCAR(1) and MAR(1) models were selected to be a appropriate models for these stations based on skewness test of normality, test of uncorrelated residuals, and correlograms of the residual series of each model. The statistics generated by MCAR(1) model and MAR(1) model resembled very closely those computed from historical series. The drought characteristics such as run len호, run sum, and run intensity were fairly well reproduced for the various lengths of generated annual flows based on the MCAR(1) and MAR(1) models. Thus, these drought characteristics may give the important informations in planning mid or long term water supplying systems.

• Journal of the Korean Chemical Society
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• v.45 no.3
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• pp.251-255
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• 2001

The structure of the lithium zinc borate LiZnBO3 has been established by single-crystal X-ray diffraction methods. It crystallizes in the triclinic space group P1(Z=2), with unit-cell parameters - $a=5.0915(9)\AA$, $b=5.059(1)\AA$, $c=6.156(1)\AA$, $V=120.6(1)\AA3$ , $\alpha=65.81(1)^{\circ}$, $\beta=65.56(1)^{\circ}$ and $\gamma=59.77(1)^{\circ}$. The structure was determined from 704 unique reflections and refined to the final residuals R=0.039 and wR=0.056. It is characterized by an association of BO3 triangles and LiO4 and ZnO4 tetrahedra. The Li and Zn atoms are disordered around the average positions between Li1 and Li2 atoms or between Zn1 and Zn2 atoms. The disorder can be described by four half-occupied positions about Li1, Li2, Zn1 and Zn2 atoms.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.414-419
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• 1995

${\beta}-carotene$ was extracted from freeze-dried carrot by supercritical carbon dioxide $(SC-CO_2)$ and mixtures of $CO_2$ doped with ethanol or methanol as a cosolvent at temperatures of 40 to $60^{\circ}C$ and pressures of 138 to 276 bar. Solubility of ${\beta}-carotene$ in $SC-CO_2$ increased with the increase of extraction pressure and the decrease of extraction temperature. The highest solubility observed was $4.90\;{\mu}g/g\;CO_2\;for\;{\alpha}-carotene\;and\;0.604\;{\mu}g/g\;CO_2$ for ${\alpha}-carotene\;at\;40^{\circ}C$ and 276 bar. Addition of ethanol increased the solubility being the largest increase of 82% using a mixture of $CO_2$ and 17.4% ethanol. $SC-CO_2$ extraction can be used to selectively obtain natural carotenoids, free of solvent residuals, which can be used as food additives.

• Geophysics and Geophysical Exploration
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• v.12 no.3
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• pp.233-238
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• 2009

An inversion method regulated by the error in the measurement of the first arrival time was developed, and we conducted a feasibility study by applying the method to a real cross-well seismic data. The inversion is a two-step regulation process; 1) derive the measurement error bound based on the resolution of the velocity image want to derive, and exclude the records whose picking error is larger than the error bound, 2) set the travel time residual to zero if the residual is less than the measurement error. This process prevents the trivial residuals are accumulated and contribute to the velocity-model update. Comparison of two velocity images, one by using all records and another by using the regulate inversion method, shows that the later velocity image exhibits less numerical artefacts, and it also indicates that, according to the Fermat's principle, the latter image is a more feasible velocity model.

• Journal of the Korean earth science society
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• v.30 no.6
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• pp.683-691
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• 2009

Geomagnetic variation around May 2, 2009 when Angdong earthquake broke out was analyzed using the data recorded at the Cheong-yang geomagnetic observatory, KMA. Firstly, we predict the geomagnetic variation by PCA analysis of geomagnetic data, and then compare the predicted value with the observed data to find any significant differences in residuals. Secondly, wavelet semblance technique is applied to compare the time series before and after the earthquake. Some meaningful change is detected in the Z-field. Thirdly, eigen value analysis for the 3 component geomagnetic data is performed. The location of the observatory was too far from the epicenter and the magnitude was too small to find decisive precursory phenomenon. Nevertheless we can detect some significant correlation between the earthquake and the variation of the geomagnetic field. Various signal processing methods applied in this study will give some opportunity to find precursory effects in the future.