회전목마 : 해외위업선에서의 혼승문제에 관하여

이득환 한국해사문제연구소 1988 (月刊)海洋韓國 Vol.181 No.-

임의회귀 검정일 모형을 이용한 홀스타인 젖소의 1산차 산유형질 및 체세포지수에 대한 유전모수

이득환,조주현,한광진 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.5

The objective of this study was to estimate genetic parameters for test-day milk production and somatic cell score using field data collected by dairy herd improvements program in Korea. Random regression animal models were applied to estimate genetic variances for milk production and somatic cell score. Heritabilities for milk yields, fat percentage, protein percentage, solid-not-fat percentage, and somatic cell score from test day records of 5,796 first lactation Holstein cows were estimated by REML algorithm in single trait random regression test-day animal models. For these analyses, Legendre polynomial covariate function was applied to model the fixed effect of age-season, the additive genetic effect and the permanent environment effect as random. Homogeneous residual variance was assumed to be equal throughout lactation. Heritabilities as a function of time were calculated from curve parameters from univariate analyses. Heritability estimates for milk yields were in range of 0.13 to 0.29 throughout first lactation. Heritability estimates for fat percentage, protein percentage and solid-not-fat percentage were withing 0.09 to 0.11, 0.12 to 0.19 and 0.17 to 0.23, respectively. For somatic cell score, heritabilities were within 0.02 to 0.04. Heritabilities for milk productions and somatic cell score were fluctuated by days in milk with comparing 305d milk production.

결측기록을 포함한 홀스타인종 젖소에 대한 다형질 개체모형에서 이중사슬 깁스샘플링 방법을 이용한 비유형질에 대한 유전모수 추정

이득환,한광진 한국동물자원과학회 2001 한국축산학회지 Vol.43 No.1

24,889 lactation productions with missing traits which were collected 19,807 cows from 1997 to Apr. 2000 for progeny test of dairy cattle in Korea by Dairy Cattle Improvement Center were used to estimate genetic parameters for milk production. A Gibbs sampling vs Bayesian inference was used in order to sample from marginal posterior distribution of (co)variance components and coupling chains as a kind of multiple sequences of chains were used to determine convergence to the stationary distribution. Using Gibbs sampling, genetic parameters could be estimated with more than 300,000 equations. The coupling chains with different random number seeds could not find convergence point. But using starting values as a good prior information for (co)variance components should be helpful to converge at fast. Genetic parameter estimates for lifetime lactation productions with repeatability model were a little bit lower than or similar to estimates which were used for national evaluation in US even though those of first lactation were as low as not reliable. Mean estimates of heritability in repeatability model were 0.28, 0.26, 0.24, and 0.25 for milk, fat, protein, and SNF, respectively. Mean estimates of genetic correlations in the same model were 0.51, 0.86. 0.73 for milk vs fat, milk vs protein, and fat vs protein, respectively. The fractions for permanent environmental variation of total variation at all lactation traits in this study were as low as about 10 % and means of repeatability were 0.38 for milk yields and 0.35 for fat, protein and SNF yields, respectively. When considering the small fractions of these variations, we presume that low correlation between lactation productions according to parity and multiple trait models would be recommended rather than a repeatability model.

한우의 경제형질들과 관련한 유단백 유전자와 성장호르몬 유전자의 효과

이득환,황규춘,한재용,전광주,이학교,조병욱 한국축산학회 1998 한국축산학회지 Vol.40 No.2

Milk protein genes and growth hormone gene have been targeted as modulator genes in growth and carcass traits. With the objectives to detect some correlation or genotypic effect of three known functional genes on economic performance, 19 sires and their 139 progenies of Hanwoo population were genotyped for κ-casein, β-lactoglobulin and growth hormone(GH) loci by polymerase chain reaction(PCR)-restriction fragment length polymorphism(RFLP) analysis. The growth traits, such as Body Weight and Average Daily Gain, and carcass traits of this population were analysed for possible association with three genetic loci. The frequency of B allele for κ-casein was 0.37 in Hanwoo and 0.23 for β-lactoglobulin. Among the analysed loci, κ-casein gene was found most significantly associated with the growth traits of economic importance. However, the ,β-lactoglobulin and GH did not show significant effects in Hanwoo. For carcass traits, effects of κ-casein were significant in EMA. Therefore, genotyping the candidate animals for κ-casein in Hanwoo can be of great benefit in selection programs.

1987 년의 회고와 1988 년 계획 : 국제경쟁역을 유지하는 길만이 우리의 살길

이득환 한국해사문제연구소 1988 (月刊)海洋韓國 Vol.172 No.-

범주형 자료를 포함한 다형질 임계개체 모형에서 유전능력 추정 알고리즘

이득환 한국동물자원과학회 2004 한국축산학회지 Vol.46 No.2

Algorithms for estimating breeding values on several categorical data by using latent variables with threshold conception were developed and showed. Thresholds on each categorical trait were estimated by Newton's method via gradients and Hessian matrix. This algorithm was developed by way of expansion of bivariate analysis provided by Quaas(2001). Breeding values on latent variables of categorical traits and observation on linear traits were estimated by preconditioned conjugate gradient(PCG) method, which was known having a property of fast convergence. Example was shown by simulated data with two linear traits and a categorical trait with four categories(CE=calving ease) and a dichotomous trait(SB=Still Birth) in threshold animal mixed model(TAMM). Breeding value estimates in TAMM were compared to those in linear animal mixed model (LAMM). As results, correlation estimates of breeding values to parameters were 0.91~0.92 on CE and 0.87~0.89 on SB in TAMM and 0.72~0.84 on CE and 0.59~0.70 on SB in LAMM. As conclusion, PCG method for estimating breeding values on several categorical traits with linear traits were feasible in TAMM.

빅데이터를 사용한 시스템 트레이딩 : KOSPI200 선물을 대상으로

이득환,김수현,강형구 한국재무학회 2014 한국재무학회 학술대회 Vol.2014 No.05

오늘날 우리는 빅데이터를 통해 보다 광범위하고 대규모적이며 정확한 자료를 단시간에 추출 가 능하게 되었다. 이러한 관점에서 본 연구는 빅데이터에 나타난 투자자별 감성이나 정보가 KOSPI200 선물 지수 수익률에 미치는 영향력을 실증 분석하였다. 특히 빅데이터 관련 변수를 새 롭게 정의하고 VAR, 로지스틱 회귀 분석을 통한 예측력을 검정하였다. 이후 예스트레이더를 사용 한 시스템 트레이딩 전략을 적용함으로써 빅데이터를 사용한 투자 전략이 높은 수익을 가져옴을 증명하였다. 실증 분석 결과 빅데이터는 KOSPI200 선물 지수 수익률을 예측하는 정보를 포함한 다는 것을 알 수 있었다. 이러한 실증 분석 결과를 통해 볼 때 본 연구는 개인 투자자의 감성 분 석에서 한 단계 나아가 빅데이터를 활용하여 전문적인 투자자들의 감성, 정보에 대한 추가적인 검증이 필요하다는 것을 시사한다.

한우의 주요 경제형질에 대한 유전모수 추정 2 . Henderson 방법에 3 에 의한 증체형질들에 대한 유전력 및 유전상관 (遺傳相關)

이득환,오봉국,박영일,신언익,양영훈 ( D . H . Lee,B . K . Ohh,Y . I . Park,O . Y . Shin,Y . H . Yang ) 한국축산학회 1991 한국축산학회지 Vol.33 No.7

Heritabilities and genetic correlations were estimated by Henderson`s method 3 on the basis of the data from 867 heads of Korean native cattle tested at Korea Native Cattle Improvement Center. The traits for estimation of genetic parameters were body weights at birth, weaning, yearling. and 18-month of age, and chest girth at yearling age. The heritability estimates were 0.12±0.08 at birth weight, 0.31±0.17 at weaning weight. 0.11±0.08 at gain after weaning, and 0.19±0.07 at yearling weight. The genetic correlation between birth weight and gain after weaning was negatively estimated(-0.60), but that between gain after weaning and yearling weight was positively estimated(0.66).

한우의 이유시 체중 및 도체형질들에 대한 Bayesian 추론과 Al - REML 간에 유전모수 및 육종가 추정치 비교

이득환 한국동물자원과학회 2001 한국축산학회지 Vol.43 No.3

Heritabilities and Genetic correlations among weaning weight and carcass traits in Korean cattle (Hanwoo) were estimated in multivariate animal model using threshold model with Bayesian inference via Gibbs sampling (TM-GIBBS) and using average information algorithm with restricted maximum likelihood (AI-REML). Those estimates were compared with each other to find out genetic property of each trait according to analytic methodologies. Multivariate animal models were set up with maternal effects for weaning weight and additive genetic effects for all traits in this study and considered age of weaning and age of slaughtering as covariates. Data were 1762 records with missing traits and 3762 animals with pedigree from progeny test program by Agricultural Co-operative Federation and the National Livestock Research Institute in Rural Development Administration in Korea. It was enable to converge to relevant criteria point when average information method for likelihood function of parameters by second derivative and Fisher scoring iteration method was used. Furthermore, all parameter estimates using multivariate threshold model and Gibbs sampling also showed to a consistent property even though estimates were different with each other. Heritability estimates for weaning weight and carcass traits by TM-GIBBS were higher than those by AI-REML in Henderson's MME. In special, heritability estimates of MS were 0.43∼0.65 within 95 confidential interval by TM-GIBBS and 0.351 by AI-REML. Genetic correlations between maternal genetic effects of WWT and direct genetic effects of MS were negatively estimated as -0.33 by TM-GIBBS and AI-REML methods. The correlations of breeding values for marbling score between by TM-GIBBS and by AI-REML were slightly lower as 0.966 in Pearson's correlation and 0.970 in Spearman's rank correlation than those for other traits in this study. This study showed that threshold model of categorical trait and other linear type traits were valid and adaptable to genetic evaluation in Korean cattle.

Holstein 젖소의 선형심사형질과 등급형질에 대한 유전변이 추정

이득환 한국동물자원과학회 2006 한국축산학회지 Vol.48 No.2