• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1A
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• pp.135-146
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• 2008

In this paper, a hybrid damage monitoring scheme for prestressed concrete (PSC) girder bridges by using sequential acceleration and impedance signatures is newly proposed. Damage types of interest include prestress-loss in tendon and flexural stiffness-loss in a concrete girder. The hybrid scheme mainly consists of three sequential phases: damage alarming, damage classification, and damage estimation. In the first phase, the global occurrence of damage is alarmed by monitoring changes in acceleration features. In the second phase, the type of damage is classified into either prestress-loss or flexural stiffness-loss by recognizing patterns of impedance features. In the third phase, the location and the extent of damage are estimated by using two different ways: a mode shape-based damage detection to detect flexural stiffness-loss and a natural frequency-based prestress prediction to identify prestress-loss. The feasibility of the proposed scheme is evaluated on a laboratory-scaled PSC girder model for which hybrid vibration-impedance signatures were measured for several damage scenarios of prestress-loss and flexural stiffness-loss.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.367-373
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• 2008

In the design of horizontally curved plate girder web panels, it is required to evaluate accurately the elastic buckling strength under pure shear. Currently, elastic shear buckling coefficients of curved web panels stiffened by transverse intermediate stiffeners are determined by assuming conservatively that straight web panels without curvature are simply supported at the juncture between the flange and web. However, depending upon the geometry and the properties of the curved plate girder, the elastically restrained support may behave rather closer to a fixed support. The buckling strength of curved girder web is much greater (maximum 38%) than that of a straight girder calculated under the assumption that all four edges are simply supported in Lee and Yoo (1999). In the present study, a series of numerical analyses based on a 3D finite element modeling is carried out to investigate the effects of geometric parameters on both the boundary condition at the juncture and the horizontal curvature of web panel, and the resulting data are quantified in a simple design equation.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.360-360
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• 2022

토양수분과 유출 간 관계를 정량화하는 것은 수문 기작 및 유출 발생 과정의 이해를 위한 중요한 정보를 제공한다. 특히, 유출과정의 특성화는 수문 사상에 따른 불포화대 내 토양수 및 토사 손실 제어와 산사태 및 비점오염원 발생 예측을 위해 필수적이다. 유출과정과 관련된 비선형성과 복잡성을 확인하기 위해 토양수분과 유출 사이의 이력 거동이 조사되었다. 특히, 수문 과정 내 이력 현상 구체화를 위해 정성적인 시각적 분류 및 정량적 평가를 위한 이력 지수들이 개발되었다. 정성적인 시각적 분류는 시간에 따라 시계 및 반시계방향으로 다중 루프 형상을 나누는 방식으로 진행되었고, 정량적 평가의 경우 이력 고리(Hysteretic loop) 내 상승 고리(Rising limb)와 하강 고리(Falling limb)의 차이를 기준으로 한 지수로 이력 현상을 특성화하였다. 이전에 제안된 방법론들은 연구자의 판단이 들어가기 때문에 보편적이지 않고 이력 현상을 개발된 지수에 맞춤에 따라 자료 손실이 나타나는 한계가 존재한다. 자료의 손실 없이 불포화대 내 발생 가능한 대표 이력 현상을 자동으로 추출하기 위해 적합한 비지도 학습기반 기계학습 방법론의 제안이 필요하다. 우리 연구에서는 국내 산지 사면에서 강우 사상 동안 다중 깊이(10, 30, 60cm)로 56개의 토양수분 측정지점에서 확보된 토양수분 시계열 자료와 산지 사면 내 위어를 통해 확보된 유출 시계열 자료를 사용하였다. 먼저, 기존에 분류 방법을 기반으로 계절 및 공간특성에 따라 지배적으로 발생하는 토양수분-유출 간 이력 현상을 특성화하였다. 다음으로, 토양수분-유출 간 이력 패턴을 자료 손실 없이 형상화하여 자동으로 데이터베이스화하는 알고리즘을 개발하였다. 마지막으로, 비지도 학습방법을 이용하여 데이터베이스화된 실제 발현 이력 현상 내 확률분포를 최대한 가깝게 추정하는 은닉층을 반복적인 재구성 학습을 통해 구현함으로써 대표 이력 현상 패턴을 추출하였다.

• Korean Journal of Poultry Science
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• v.16 no.4
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• pp.193-199
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• 1989

This study was conducted to estimate heritabilities and genetic correlations on egg compositions in Korean Native Ogol Fowl. The date analysis were a total of 58,320 eggs in 450 pullets producted from 150 dams and 20 sires of Korean Native Ogol Fowl raised at Chungnam National University from June 18. 1987 to April 6. 1989. The results obtained are summarized as follows： 1. On the egg compositions, the albumen weight at first egg, 300 and 500 days were $24.003\pm$2.499, $28.354\pm$2.755 and $31.863\pm$3.341g； the yolk weight were $10.272\pm$1.536, $16.346\pm$1.321 and $19.212\pm$1.661g： the shell weight were $3.906\pm$0.414, $4.336\pm$0.506 and $4.822\pm$0.515g, respectively. 2. The heritability estimates of egg compositions based on the valiance of sires, dams and combined components were 0.620-0.723, 0.206-0.300 and 0.413-0.511 for albumin weight；0.439-0.737, 0.484-0.544 and 0.492-0.615 for yolk weight：0.172-0.187, 0.412-0.642 and 0.390-0.503 for shell weight, respectively. 1. The genetic and phenotypic correlation coefficients of egg compositions were as follows； The coefficients between albumen weight and yolk weight were 0.089-0.654 and 0.084-0.255；between albumen weight and shell weight were 0.396-0.925 and 0.225-0.544； between yolk weight and shell weight were 0.227-0.357 and 0.098-0.358 respectively.

• Journal of Animal Science and Technology
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• v.50 no.1
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• pp.33-44
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• 2008

The purpose of this study was to estimate the genetic parameters and trend of Landrace and Yorkshire pigs, which were raised on private farms from 1999 to 2005 and tested for their reproductive performance by the Korea Animal Improvement Association. Prior to analysis, records without pedigree or having value with larger than±3×standard deviation for the Total number of born were excluded. The effects of breed and environmental factors were estimated with least square method(Harvey, 1979), and estimation of breeding values and genetic parameters were performed on the data of 1’st litter only with GIBBSF90(Misztal, 2001) which was programmed according to Gibbs Sampling method based on Bayesian Inference by Gianola and Fernando(1986), Jensen(1994) and others. Gibbs sampling was performed 50,000 times for each parameter, and the first 5000 samples were regarded as those in burn-in period and thus, excluded for post hoc analysis. Total number of born and total number of accident were statistically significant(p<0.01) for the breed, farrowing year, farrowing season and parity effects, and the number born alive at birth was statistically significantp<(0.01) for the breed, farrowing year, farrowing season and parity effects. No particular trend was observed in the genetic and phenotypic improvement of the total number of born and number born alive at birth before 2001, when the piglet registration system started, but the tendencies of increasing for the total number of born and number born alive and decreasing for the total number of accident were observed since 2001. Somewhat higher heritability estimates of our study seems to be attributed to the situations that first parity records with poor farrowing performances were used in the analyses and it was impossible to obtain accurate reproductive performance due to the absence of criteria for record keeping at the level of individual farms.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.10-20
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• 1991

This study was conducted to estimate heritabilities and genetic correlations on egg compositions and egg qualities in Korean Native Ogol fowl. The data were gathered from a total of 58,320 eggs in 450 pullets produced from 150 dams and 20 sires of Korean Native Ogol fowl raised at Chungnam National University from June 18, 1987 to April 6, 1989. The results obtained are summarized as follows : 1. The heritability estimates of egg compositions based on the variance of sires, dams and combined components were 0.620 - 0.723, 0206 - 0.300 and 0.413 - 0.511 for albumen weight: 0.439 - 0.737, 0.484 - 0.544 and 0.492 - 0.615 for yolk weight: 0.172 - 0.187, 0.412 - 0.642 and 0.309 - 0.503 for shell weight, respectively. 2. The heritability estimates of egg qualities based on the variance of sires, dams and combined components were 0.202 - 0279, 0.557 - 0.819 and 0.428 - 0.508 for shell thickness : 0.202 - 0.394, 0.119 - 0.678 and 0.256 - 0.440 for albumen height : 0.108 - 0.443, 0237 - 0.698 and 0244 - 0.399 for Haught units, respectively. 3. The genetic and phenotypic correlations of egg compositions were as follows; The coefficients between albumen weight and yolk weight were 0.089 - 0.564 and 0.084 - 0.235; between albumen weight and shell weight were 0.396 - 0.925 and 0225 - 0.544; between yolk weight and shell weight were 0.220 - 0.357 and 0.098 - 0.358, respectively. 4. The genetic and phenotypic correlations of egg qualities as follows; between shell thickness and albumen height were 0.082 - 0.356 and - 0.163 - 0.060; between shell thickness and Haught units were - 0.076 - 0.167 and - 0.185 - 0.010; between albumen height and Haught units were 0.338 - 0.604 and 0.154 - 0285, respectively. 5. The genetic correlations of egg compositions and egg qualities were as follows: between albumen weight and shell thickness, albumen height. Haught units were - 0.380 - - 0.002, 0239 - 0.387, and - 0279 - - 0.127; between yolk weight and shell thickness, albumen height, Haught units were - 0.294 - - 0.133, - 0.049 - 0.133 and - 0.196 - - 0.136; between shell weight and shell thickness, albumen height, Haught units were 0.127 - 0.476, 0.140 - 0273 and 0.038 - 0223, respectively.

• Korean Journal of Agricultural Science
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• v.17 no.2
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• pp.87-94
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• 1990

This study was conducted to estimate the genetic and phenotypic correlations between economic traits and egg compositions, egg qualities in Korean Native Ogol fowl. The data analysis were the records of 450 pullets produced 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 between 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 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 and -0.477~-0.313 ; between egg weight and albumen weight, yolk weight, shell weight were 0.825~0.939, 0.382~0.564 and 0.374~0.937, respectively. 2. The genetic correlation coefficients between economic traits and egg qualities were as follows : between body weight and egg shape index, shell thickness, albumen height, Haugh units were 0.215~0.337, 0.248~0.650, 0.161~0.624 and 0.157~0.499 ; between number of egg production and egg shape index, shell thickness, albumen height, Haugh units were -0.384~-0207, -0.557~-0.306, -0.555~-0.198 and -0.582~-0.974 ; 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 and -0.207~0.020, respectively.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.4
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• pp.1-13
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• 2010

This research was conducted to understand the characteristics and traits of Baekje's palace backyard by studying and analyzing the usage, shape, size, material, and place of origin of the odd-shaped stones found at the remains of Baekje's palace in Waggung-ri, Iksan. The results of the research are as following. The odd-shaped stones found at the Baekje palace backyard were used for two purposes. Some of the stones were used as heaping stones(疊石) for the stone waterfall in the backyard while others were used as ornamental stones(置石) to exhibit the uniqueness and beauty of the stone themselves. The stones used for the waterfall had various shapes and materials and were arranged to symbolize the beauty of natural scenery. On the other hand, the ornamental stones were used to exhibit their beauty of forms. Among the twenty six ornamental stones, four were large, four were mid-sized, and eighteen were small. The twenty four heaping stones used for the waterfall were all categorized as small. All of the stones were not too big, easily coming into sight of human beings. The heaping stones were mostly limestones, and some of them were metamorphic rocks such as marble, quartz, green rock, slaty rock, and phyllite. Almost all of the odd-shaped stones used for Baekje's palace backyard have beautiful patterns and specific forms that resemble natural scenes or animals such as a turtle, terrapin, pig, bear, or elephant. Some of the ornamental stones apparently went through carving to emphasize the unique shapes. Considering the usage and characteristic of the odd-shaped stones, one of the most characteristic feature of the Wanggung-ri palace backyard can be said to be 'the garden of odd-shaped stones'. Meanwhile, according to references, interviews, questionings, and on-the-spot surveys on the people who quarried the stones, the stones found at the remains of the Wanggung-ri palace came mostly from Mt. Cheonho in Hosan-ri, Yeosan-myeon, Iksna, and Mt. Shidae in Dosoon-ri, Wanggung-myeon.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.83-89
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• 2010

The objective of this study was to investigate the effect of the environmental and genetic factors on the carcass traits of Korean cattle. We have used the data of 22,954 Korean cattle slaughtered from 2005 to 2009 in Gyeongnam region and estimated the genetic parameters of 36,868 cattle including the pedigree individuals by means of EM-REML analytical method. In summary, the heritability of the carcass weight, eye muscle area, backfat thickness and marbling score was 0.39, 0.30, 0.33 and 0.62, respectively. The carcass weight and the eye muscle area showed high correlation between them with the genetic correlation of 0.86 and the phenotypic correlation of 0.72. The high heritability of marbling score is assumed to be the result of focusing the breed improvement on the quality of the meat. Through this study, it is considered that the Korean cattle in Gyeongnam region are improving, which will thus contribute to the increase of the farmer's income. Additional study on the economic trait must be carried out to obtain clearer results that will lead to further improvement of Korean cattle.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.173-182
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• 2016

This study was aimed to identify the phenotypic relationships between calving interval and lactation curve parameters in Korean Holstein cow. The data of 36,505 lactation records was obtained from the Dairy Herd Improvement program run by Dairy Cattle Improvemnet Center of National Agricultural Federation of Korea. All lactation records were collectied from the multiparous cows calving between 2011 to 2013. The estimated lactation curves were drawn using Wood model based on actual milk yield records, and NLIN Procedure of SAS program (ver. 9.2). General linear multivariate models for calving interval, 305-d milk yield, lactation parameters(A, b, c), persistency, peak day, and peak yield included fixed effects of calving year-season (spring, summer, fall and winter) and parity(2, 3 and 4). For calving interval, 305-d milk yield, lactation parameters(A, b, c), persistency, peak day and peak yield, all two fixed effect(calving year-season, parity) were significant(p<0.05). The estimated lactation functions using Wood model for 2, 3, and 4 parity were yt=24.66t0.175e-0.00302t, yt=24.69t0.192e-0.00334t, and yt=24.22t0.200e-0.00341t, respectively. Phenotypic correlation (partial residual correlation) between calving interval and 305-d milk yield, A, b, c, persistency, peak day, and peak yield were 0.093, -0.014, 0.028, -0.046, 0.099, 0.085, and 0.052, respectively. To conclude, if calving interval increase then ascent to peak, persistency, peak day and peak yield are increase, and descent after peak is decrease. So, total 305-d milk yield is increase.