• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.200-211
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• 2009

A mathematical modeling program called Soil and Water Assessment Tool (SWAT) developed by USDA was applied to Kyongan stream watershed. It was run under BASINS (Better Assessment Science for Integrating point and Non-point Sources) program, and the model was calibrated and validated using KTMDL monitoring data of 2004${\sim}$2008. The model efficiency of flow ranged from very good to fair in comparison between simulated and observed data and it was good in the water quality parameters like flow range. The model reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The results of pollutant loads estimation as yearly (2004${\sim}$2008), pollutant loadings from 2006 were higher than rest of year caused by high precipitation and flow. Average non-point source (NPS) pollution rates were 30.4%, 45.3%, 28.1% for SS, TN and TP respectably. The NPS pollutant loading for SS, TN and TP during the monsoon rainy season (June to September) was about 61.8${\sim}$88.7% of total NPS pollutant loading, and flow volume was also in a similar range. SS concentration depended on precipitation and pollution loading patterns, but TN and TP concentration was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. SWAT based on BASINS was applied to the Kyongan stream watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and non-point sources in watershed scale.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.77-89
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• 2004

The spatial and temporal variations of aerosol optical depth (AOD) over Northeast Asia regions have special importance in the aerosol research for estimation of aerosol radiative forcing parameters and climate change. Aerosol optical and physical properties (AOD and ${\AA}$ngstrom parameter) have been investigated by using Moderate Resolution Imaging Spectroradiometer (MODIS) and Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) to estimate aerosol characteristics over the study region during 2001. Additionally, aerosol characteristics over the Korean peninsular during Aerosol Characteristic Experiment in Asia (ACE-Asia) Intensive Observation Period (IOP) have been investigated by using satellite observations. The results showed that the daily-observed aerosol data indicate seasonal variations with relatively higher aerosol loading in the spring and very low during the winter. The typical Asian dust case showed higher AOD (>0.7) with lower Angstrom exponent (<0.5) and higher AI (>0.5) that is mainly due to the composition of coarse particles in the springtime. Mean AOD for 2001 at 4 different places showed 0.65$\pm$0.37 at Beijing, 0.31$\pm$0.19 at Gosan, 0.54$\pm$0.26 at Seoul, and 0.38$\pm$0.19 at Kwangju, respectively. An interesting result was found in the present study that polluted aerosol events with small size dominated-aerosol loading around the Korean peninsular are sometimes observed. The origin of these polluted aerosols was thought to East China. Aerosol distribution from satellite images and trajectory results shows the proof of aerosol transport. Therefore, aerosol monitoring using satellite data is very useful.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.189-196
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• 2018

BACKGROUND: Water quality management of river requires quantification of pollutant loads and implementation of measures through monitoring study, but it requires labour and costs. Therefore, many researchers are performing nonpoint source pollution analysis using computer models. However, calibration of model parameters needs observed data. Nitrogen concentration in rainfall is one of the factors to be considered when estimating the pollutant loads through application of the nonpoint source pollution model, but the default value provided by the model is used when there are no observed data. Therefore, this study aims to provide the representative nitrogen concentration of the rainfall for the administrative district ensuring rational modeling and reliable results. METHODS AND RESULTS: In this study, rainfall monitoring data from June 2015 to December 2017 were used to determine the nitrogen concentration in rainfall for each administrative district. Range of the $NO_3{^-}$ and $NH_4{^+}$ concentrations were 0.41~6.05 mg/L, 0.39~2.27 mg/L, respectively, and T-N concentration was 0.80~7.71 mg/L. Furthermore, the national average of T-N concentration in this study was $2.84{\pm}1.42mg/L$, which was similar to the national average of T-N 3.03 mg/L presented by the Ministry of Environment in 2015. Therefore, the nitrogen concentrations suggested in this study can be considered to be resonable values. CONCLUSION: The nitrogen concentrations estimated in this study showed regional differences. Therefore, when estimating the pollutant loads through application of the nonpoint source pollution model, resonable parameter estimation of nitrogen concentration in rainfall is possible by reflecting the regional characteristics.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.577-584
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• 2011

To estimate level of genetic variation and genetic differentiation among populations of 3 populations in Abies koreana and 5 populations in Abies nephrolepis, 5 nSSR markers were analyzed. Except 1 locus where too many alleles were observed excessively, population genetic parameters were recalculated with 4 loci. Mean expected heterozygosities ($H_e$) were 0.292 in A. koreana and 0.220 in A. nephrolepis, respectively. In both species, positive fixation coefficient was estimated (F=0.065 for A. koreana and F=0.095 for A. nephrolepis), which suggests that there is an excess of homozygotes relative to Hardy-Weinberg expectations within populations. Relatively high degree of population differentiation was observed in A. koreana ($F_{ST}=0.063$). compared to that of A. nephrolepis ($F_{ST}=0.039$). From 3-level Hierarchical estimation of F-staticstics, only 4.9% of the genetic variation was allocated between species ($F_{PT}$), which suggested that most of genetic variation was shared between two species. On the basis of results from analysis of genetic relationships among populations, 2 populations of A. koreana (Mt. Halla and Mt. Deogyu) were genetically distinct from the populations of A. nephrolepis but a population of Mt. Jiri was allocated within a group of populations of A. nephrolepis. Populations of both species seemed to have undergone genetic drift due to gradual decrease in population size induced by global warming after the last glacier, which resulted in increase of homozygotes by inbreeding. It could be also postulated that these species might be diverged recently and It is likely that the two species have not fully speciated yet.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.87-105
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• 2009

Nonlinear dynamic deformation characteristics, expressed in terms of normalized shear modulus reduction curve (G/$G_{max}-\log\gamma$, G/$G_{max}$ curve) and damping curve (D-$\log\gamma$), are important input parameters with shear wave velocity profile ($V_s$-profile) in the seismic analysis of (new or existing) fill dam. In this paper, the reasonable and economical methods to evaluate the nonlinear dynamic deformation characteristics for core zone and rockfill zone respectively are presented. For the core zone, 111 G/$G_{max}$ curves and 98 damping curves which meet the requirements of core material were compiled and representative curves and ranges were proposed for the three ranges of confining pressure (0~100 kPa, 100 kPa~200 kPa, more than 200 kPa). The reliability of the proposed curves for the core zone were verified by comparing with the resonant column test results of two kinds of core materials. For the rockfill zone, 135 G/$G_{max}$ curves and 65 damping curves were compiled from the test results of gravelly materials using large scale testing equipments. The representative curves and ranges for G/$G_{max}$ were proposed for the three ranges of confining pressure (0~50 kPa, 50 kPa~100 kPa, more than 100 kPa) and those for damping were proposed independently of confining pressure. The reliability of the proposed curves for the rockfill zone were verified by comparing with the large scale triaxial test results of rockfill materials in the B-dam which is being constructed.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.167-178
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• 2016

This study was conducted to estimate genetic parameters for milk production and linear type traits in Holstein dairy cattle in Korea. The data including milk yields, fat yields, protein yields, fat percent, protein percent, somatic score and 15 linear type traits for 10,218 first parity cows collected by Dairy Cattle Improvement Center, National Agricultural Cooperative, Korea, which were calving from January 2009 to April 2013. Genetic and error (co)variances between two traits selected form 19 traits were estimated using bi-trait pairwise analyses with WOMBAT package. The estimated heritabilities for milk yield(MY), fat yield(FY), protein yield(PY), fat percent(FP), protein percent(PP), somatic cell score(SCS), udder depth(UD), udder texture(UT), median suspensory(MS), fore udder attachment(FUA), front teat placement (FTP), rear attachment height(RAH), rear attachment width(RAW), rear teat placement(RTP), front teat length(FTL), foot angle(FA), heel depth(HD), bone quality(BQ), rear legs side view(RLSV), rear legs rear view(RLRV) and locomotion(LC) were 0.128, 0.144, 0.100, 0.273, 0.333, 0.090, 0.179, 0.066, 0.104, 0.109, 0.127, 0.099, 0.059, 0.069, 0.154, 0.014, 0.010, 0.052, 0.065, 0.175 and 0.031, respectively. Among the genetic correlations, UD, UT, FTP, RAW, FTL, FA and RLSV with MY were -0.334, 0.271, 0.445, 0.544, 0.076, -0.281 and -0.228, respectively, and MS, FTP, RTP, FTL, FA, BQ, RLSV, RLRV and LC with PP were -0.147, -0.182, -0.262, -0.136, 0.355, 0.311, 0.135, 0.233 and 0.143, respectively. Especially, MY had the highest positive genetic correlation with RAW (0.544), while SCS had the highest negative genetic correlation with LC (-0.603). FP had negative genetic correlation with most udder traits, whereas, FP had positive genetic correlation with leg and hoof traits (0.056 - 0.355).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.6
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• pp.146-154
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• 2023

In this study, the peak wave period T_p and mean wave period T₀₂ and T_{m-1, 0}, which are major parameters for classifying ocean characteristics, were calculated using water surface elevation data observed from the second west coast oceanographic and meteorological observation tower. In addition, the ratio of abnormal data, correlation analysis, and optimal probability density function were estimated. In the case of T_p among the calculated representative periods, the proportion of abnormal data was 5.73% and 0.67% at each point, and T₀₂ was 4.35% and 0.01%. T_{m-1, 0} was found to be 2.82% and 0.03%. Meanwhile, as a result of analyzing the relationship between T₀₂ and T_p, the relationship was calculated to be 0.53 and 0.63 for each point. The relationship between T_{m-1, 0} and T_p was 1.15 and 1.32, respectively, and T₀₂, T_{m-1, 0} was 1.18 and 1.22. As a result of estimating the optimal probability density function of the calculated representative period, T_p followed the 'Log-normal' and 'Normal' distributions at each point, and T₀₂ was 'Gamma', 'Normal' distribution and T_{m-1, 0} showed that 'Log-normal' and 'Normal' distribution were dominant, respectively. It is decided that these results can be used as basic data for wave analysis conducted on the west coast.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.221-234
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• 1983

A study was conducted to devise a method to estimate the edible meat weight in live broilers. White Cornish broiler chicks CC, Single Comb White Leghorn egg strain chicks LL, and two reciprocal cross breeds of these two parent stocks (CL and LC) were employed A total of 240 birds, 60 birds from each breed, were reared and sacrificed at 0, 2, 4, 6, 8 and 10 weeks of ages in order to measure various body parameters. Results obtained from this study were summarized as follows. 1) The average body weight of CC and LL were 1,820g and 668g, respectively, at 8 weeks of age. The feed to gain ratios for CC and LL were 2.24 and 3.28, respectively. 2) The weight percentages of edible meat to body weight were 34.7, 36.8 and 37.5% at 6, 8 and 10 weeks of ages, respectively, for CC. The values for LL were 30.7, 30.5 and 32.3%, respectively, The CL and LC were intermediate in this respect. No significant differences were found among four breeds employed. 3) The CC showed significantly smaller weight percentages than did the other breeds in neck, feather, and inedible viscera. In comparison, the LL showed the smaller weight percentages of leg and abdominal fat to body weight than did the others. No significant difference was found among breeds in terms of the weight percentages of blood to body weight. With regard to edible meat, the CC showed significantly heavier breast and drumstick, and the edible viscera was significantly heavier in LL. There was no consistent trend in neck, wing and back weights. 4) The CC showed significantly larger measurements body shape components than did the other breeds at all time. Moreover, significant difference was found in body shape measurements between CL and LC at 10 weeks of age. 5) All of the measurements of body shape components except breast angle were highly correlated with edible meat weight. Therefore, it appeared to be possible to estimate the edible meat wight of live chickens by the use of these values. 6) The optimum regression equations for the estimation of edible meat weight by body shape measurements at 10 weeks of age were as follows. $$Y_{cc}=-1,475.581 +5.054X_{26}+3.080X_{24}+3.772X_{25}+14.321X_{35}+1.922X_{27}(R^2=0.88)$$ $$Y_{LL}=-347.407+4.549X_{33}+3.003X_{31}(R^2=0.89)$$ $$Y_{CL}=-1,616.793+4.430X_{24}+8.566X_{32}(R^2=0.73)$$ $$Y_{LC}=-603.938+2.142X_{24}+3.039X_{27}+3.289X_{33}(R^2=0.96)$$ Where $X_{24}$=chest girth, $X_{25}$=breast width, $X_{26}$=breast length, $X_{27}$=keel length, $X_{31}$=drumstick girth, $X_{32}$=tibotarsus length, $X_{33}$=shank length, and $X_{35}$=shank diameter. 7) The breed and age factors caused considerable variations in assessing the edible meat weight in live chicken. It seems however that the edible meat weight in live chicken can be estimated fairly accurately with optimum regression equations derived from various body shape measurements.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.197-208
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• 1991

This study was conducted to estimated the genetic and phenotypic correlations between economic traits and certain other traits in Korean Native Ogol fowl The data analysis were the record of 450 pullets bred from 150 dams and 20 sires of Korean Native Ogol fowl at Chungnam National University from June 18, 1987 to April 6, 1989. The results obtained are summarized as follows ： 1 The genetic correlation coefficients of the economic traits and body shape components were as follows ： between body weight and shank length, breast width. breast girth, tibia length were 0.210~0.788, 0.231~0.826, 0.610~0.995 and 0.096~0.503 between age at first egg and shank length, breast width, breast girth, tibia length were 0.555~0.626, 0.149~0.270, 0.370~0.445 and 0.014-0.124. between number of egg production and shank length, breast girth, tibia length were -0.446~-0.167, -0.162~-0.320, 0.076~0.336 and 0.203~0.312 ： between egg weight and shank length, breast width, breast girth, tibia length were 0.132~0.498, 0.236~0.410, 0.148~0.775 and -0.019~0.593, respectively. 2. The genetic correlation coefficients of the economic traits and egg components were as follows ： between body weight and albumen weight, yolk weight, shell weight were 0.083~0.591, 0 110~0.541 and 0.336~0.782 between age at the first egg and albumen weight, yolk weight, shell weight were 0.476-0.692, 0.265~0.631 and 0.420~0.519 between number of egg Production and albumen weight, yolk weight, shell weight were -0.578~-0.240, -0.255~-0.060, -0.477~-0.313. between egg weight and albumen weight, yolk weight, shell weight were 0.825~0.939, 0.382~0.564, 0.374~0.337, respectively. 3. The genetic correlation coefficients of the economic traits and egg qualifies were as follows ： between body weight and egg shape index, shell thickness, albumen height, Haugh units were 0.215~0.367, 0.248~0.650, 0.161~0.624, 0.157~0.449. between number of egg production and egg shape index, shell thickness, albumen height, Haugh units were -0.384~-0.207, -0.557~-0.306, -0.555~-0.198, -0.582~-0.074 between egg weight and egg shape index, shell thickness, albumen height, Haugh units were 0.276~0.697, 0.290~0.627, 0.238~0.538, -0.207-0.020, respectively. 4. The genetic correlation coefficients of egg compositions and egg qualities were as follows ： between albumen weight and egg shape index, shell thickness, albumen height and Haugh units were 0.110~0.584, -0.380~-0.002, 0.239~0.887 and -0.195~0.279 ： between yolk weight and egg shape index, shell thickness, albumen height and Haugh units were -0.204~0.160, 0.294~0.133, -0.049~0.133 and -0.196~-0 136 ： between shell weight and egg shape index, shell thickness, albumen height and Haugh units were 0.127~0.503, 0.127~0.476, 0.140~0.273 and -0.172~0.233, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.4
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• pp.343-354
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• 2010

The present study was conducted to examine the fermentation characteristics and effective degradability (ED) in the rumen, and whole tract digestibility of whole crop silage based TMR in comparison with conventional separate feeding of concentrate and roughage. Three ruminally fistulated non-lactating Holstein cattle were used in a 3 $\times$ 3 Latin square design. The cattle were fed 8kg of whole crop barley silage based TMR (BS-TMR) or 8kg (DM basis) of whole crop rye silage based TMR (RS-TMR) twice (08:00 and 18:00) daily in an equal amount. The cattle were also fed concentrate (5.6kg) and rice straw (1.4kg) seperately (DM basis, Control) twice daily in an equal amount. The both silages were included in TMR at 20% level (as fed basis). pH in the rumen fluid was not influenced by the diets but was slightly higher from TMR than from control. No difference was found in ammonia-N concentration between diets. Total VFA concentration was relatively increased in the cattle fed RS-TMR to the other diets up to 6h post feeding. The proportion of acetate was increased in the TMR feeding at right before feeding (0 h, p<0.005) and 9 h (p<0.048) post feeding compared with control. Propionate proportion was increased (p<0.046) in both TMRs while butyrate proportion was increased (p<0.029) at 1h post feeding compared to other diets. Effective degradability (ED) of DM and CP of RS-TMR was relatively increased to other diets, and EDNDF of both TMRs was higher than that of control diet due to the increased parameters b (p<0.039) and c (p<0.006) in TMR treatments. Whole track digestibility of most components in the TMRs was slightly increased compared to that in control diet, and RS-TMR had a tendency to be increased whole track digestibility except for NDF compared to BS-TMR. Based on the results observed from the present study, nutrient availability of whole crop silage based TMR looked slightly better than conventional separate feeding of concentrate and rice straw, mainly due to the improved stabilization of fermentation in the rumen and increased NDF digestibility of whole crop silage in TMR.