• 제목/요약/키워드: Population estimates

검색결과 393건 처리시간 0.027초

Genetic Similarity and Variation in the Cultivated and Wild Carassius carassius Estimated with Random Amplified Polymorphic DNAs

  • Yoon, Jong-Man;Kim, Tae-Sun
    • 한국발생생물학회:학술대회논문집
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    • 한국발생생물학회 2001년도 후기 제12차 학술대회 논문집
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    • pp.34-35
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    • 2001
  • RAPD analysis based on numerous markers have been used to investigate patterns of genetic differentiation ann and within two cultured and wild populations represented by the species crucian carp(Carassius carassius). From RAPD analysis using five primers, a total of 442 polymorphic bands were obtained in two populations and 273 were found to be specific to a wild population. According to RAPD-based estimates, average number of polymorphic bands in wild population was approximately 1.5 times as diverse as that in cultured. The average level of bandsharing values was $0.40 \pm 0.05$ in wild population, but was $0.69 \pm 0.08$ in cultured population, With reference to bandsharing values and banding patterns, wild population was considerably more diverse than cultured population. Knowledge of the genetic diversity of crucian carp should help in formulating more effective strategies for managing this aquacultural fish species.

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Variance estimation for distribution rate in stratified cluster sampling with missing values

  • Heo, Sunyeong
    • Journal of the Korean Data and Information Science Society
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    • 제28권2호
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    • pp.443-449
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    • 2017
  • Estimation of population proportion like the distribution rate of LED TV and the prevalence of a disease are often estimated based on survey sample data. Population proportion is generally considered as a special form of population mean. In complex sampling like stratified multistage sampling with unequal probability sampling, the denominator of mean may be random variable and it is estimated like ratio estimator. In this research, we examined the estimation of distribution rate based on stratified multistage sampling, and determined some numerical outcomes using stratified random sample data with about 25% of missing observations. In the data used for this research, the survey weight was determined by deterministic way. So, the weights are not random variable, and the population distribution rate and its variance estimator can be estimated like population mean estimation. When the weights are not random variable, if one estimates the variance of proportion estimator using ratio method, then the variances may be inflated. Therefore, in estimating variance for population proportion, we need to examine the structure of data and survey design before making any decision for estimation methods.

벡터기반 대시매트릭 기법을 이용한 소지역 장수인구 추정 및 분포패턴에 관한 연구 (A Study on Estimates to Longevity Population of Small Area and Distribution Patterns using Vector based Dasymetric Mapping Method)

  • 최돈정;김영섭;서용철
    • 한국측량학회지
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    • 제29권5호
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    • pp.479-485
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    • 2011
  • GIS기법을 이용하여 공간데이터간의 융합을 통한 지역적 장수인구의 분포와 영향요인을 밝혀내는 연구사례가 증가하고 있다. 일반적으로 이러한 연구들은 분석의 공간단위로써 센서스 행정구역을 채택한다. 그러나 센서스 구역 안에서도 공간적 특징의 다양성이 존재하기 때문에 장수현상을 충분히 설명한다고 할 수 없다. 따라서 장수라는 현상을 현실적으로 반영하는 공간단위에 대한 연구가 필요하다. 대시매트릭 기법은 다양한 공간정보를 이용하여 센서스 행정경계 보다 현실적인 공간단위의 재구성이 가능하게 해준다. 또한 이를 응용하여 소지역의 통계량 추정이 가능하다. 본 연구에서는 벡터기반 건물 데이터를 기반으로 대시매트릭 매핑기법을 응용하여 소지역 노인인구 수를 통계적으로 유의한 수준 안에서 재구성 하였다. 또한 클러스터 분석을 통해 센서스 행정경계안에 존재하는 국지적인 공간 영향관계의 변이를 확인 하였다. 본 연구를 통해 국지적 수준의 장수연구에 대한 필요성과 대시매트릭 기법의 응용이 유효한 방법론임을 제시하였다고 판단된다.

Genetic Improvement for Yield and Yield Related Traits by Introgressive Hybridization in Sweet Corn

  • Nigussie Mandefro;Saleh Ghizan
    • 한국작물학회지
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    • 제50권2호
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    • pp.91-96
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    • 2005
  • Proper choice of source populations contributes to the ultimate success of selection for genetic improvement. The source population should possess the most desirable alleles at as many loci as possible for intra population improvement. Such desirable alleles can be intensified by introgression of exotic germ plasm into locally adapted ones through hybridization followed by selection. The objectives of this study were to determine the mean performance, genetic variability $({\sigma}^2G)$ and heritability of fresh ear yield and other important traits within two sweet corn source populations, $BC1-10{\times}Syn-II$ and BC2-10. One hundred selfed progenies from each of the two source populations were evaluated in a $10\times10$ lattice design, at the Institute of Bioscience (IBS) Farm, University of Putra Malaysia (UPM) following the recommended cultural practices. Significant differences among selfed progenies within $BC1-10{\times}Syn-II$ were observed for all traits, while differences among selfed progenies within BC2-10 were noted for fresh ear yield, ear length, ear diameter, number of kernels per row, ear height, days to tasseling and days to silking. Progenies developed from $BC1-10{\times}Syn-II$ population had higher estimates of ${\sigma}^2G$ than did progenies from BC2-10 population for number of kernel rows per ear, total soluble solids, plant height, days to tasseling and days to silking, showing that selection to improve these traits would be more effective in selfed progenies of $BC1-10{\times}Syn-II$ than that in BC2-10. On the other hand, progenies developed from BC2-10 population had higher estimates of ${\sigma}^2G$ for ear length, ear diameter and ear height, indicating that progenies from this population would have better genetic gain than $BC1-10{\times}Syn-II$. Comparable estimates of genetic variance were found for fresh ear yield, and number of kernels per row, indicating that genetic improvement of the two source populations is expected to produce similar genetic gains for these two traits. Therefore, selfed progenies developed from both source populations could be used to improve the two populations for various traits and thereby develop superior genotypes for immediate use in the production system.

Association of Marker Loci and QTL from Crosses of Inbred Parental Lines

  • Lee, Gi-Woong
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권6호
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    • pp.772-779
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    • 2005
  • The objectives of this study were to examine problems with using F$_1$ data by simulation, association of marker loci and QTL from crosses of inbred parental lines and to enumerate the preliminary characterization of genetic superiority within inbred parental lines. In this study, the association between markers for QTL used as covariates and estimates of variance components due to effects of lines was investigated through computer simulation. The effects of size of population to develop inbred lines and initial frequencies and magnitudes of effects of QTL were also considered. Results show that estimates of variance components due to line effects are influenced by including marker information as covariates in the model for analysis. Estimates of line variance were increased by adding marker information into the analysis, because negative covariances between effects associated with the markers and the remaining effects associated with other loci existed. However, the fit of the model as indicated by the log likelihood improved by adding more markers as covariates into the analysis. Marker assisted selection will be beneficial when markers explain unexplained genetic difference during selection procedure. Markers can be used to identify QTLs affecting traits, and to select for favorable QTL alleles. To efficiently use genetic markers, location of markers at the genome must be identified. The estimates of variance due to effects of with and without marker information used as covariates in the analysis were investigated. The estimates of line variances were always increased when markers were included as covariates for the model because a negative covariance were existed.

섬강에 서식하는 멸종위기종 꾸구리 Gobiobotia macrocephala(Pisces: Cyprinidae)의 서식개체수 추정 (Population Estimates of the Endangered Species, Gobiobotia macrocephala (Pisces: Cyprinidae) in Seom River, Korea)

  • 고명훈;송호복;최승호;송하윤;강동원;문신주;이상준;방인철
    • 한국어류학회지
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    • 제24권3호
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    • pp.177-182
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    • 2012
  • 섬강에 서식하는 꾸구리의 서식개체수를 추정하기 위하여 2010년 9월부터 10월까지 강원도 원주시 섬강 일대에서 조사를 실시하였다. 꾸구리가 출현한 곳은 14개 지점이었으며, 자갈과 돌이 깔린 하류의 여울부에서 주로 서식하고 있었다. 출현개체수가 가장 많고 서식지가 안정된 두 개 지점에서 표지-재포획법과 방형구(족대조사와 수중관찰)를 이용하여 서식개체수를 추정한 결과 표지-재포획법으로 $8,295{\pm}4,922$개체와 $39,846{\pm}14,232$개체로 각각 추정되었고, 방형구의 족대조사는 9,216개체와 37,873개체로, 수중관찰은 5,593개체와 24,347개체로 추정되었다.

A Study on the Population Structure of Democratic People's Republic of Korea

  • Jeon, Saebom;Kim, Seong Eun;Park, Yousung
    • Communications for Statistical Applications and Methods
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    • 제22권1호
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    • pp.1-10
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    • 2015
  • The re-unification of the two Koreas is seen as a potential solution to the aging problem and low fertility, along with the increase in the old population structure of the Republic of Korea. Population structure is an indicator of national competitiveness or growth, but little is known officially about the populations of Democratic People's Republic of Korea (DPRK). Understanding the population structure of the DPRK is important to prepare for re-unification and estimate the socio-economic costs of national welfare under a re-unified Korea. In this paper, we assess reliability of the two modern national censuses of DPRK and use the limited resources available to reconstruct the intercensal populations between these two censuses. Excess deaths from the 1995 famine are estimated at 489,972 to 574,306 and are close to the estimates of Goodkind et al. (2011) and the reconstructed populations in the of DPRK implies a big difference between two Koreas.

ON THE DIFFUSION OPERATOR IN POPULATION GENETICS

  • Choi, Won
    • Journal of applied mathematics & informatics
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    • 제30권3_4호
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    • pp.677-683
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    • 2012
  • W.Choi([1]) obtains a complete description of ergodic property and several property by making use of the semigroup method. In this note, we shall consider separately the martingale problems for two operators A and B as a detail decomposition of operator L. A key point is that the (K, L, $p$)-martingale problem in population genetics model is related to diffusion processes, so we begin with some a priori estimates and we shall show existence of contraction semigroup {$T_t$} associated with decomposition operator A.

Bayes Prediction for Small Area Estimation

  • Lee, Sang-Eun
    • Communications for Statistical Applications and Methods
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    • 제8권2호
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    • pp.407-416
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    • 2001
  • Sample surveys are usually designed and analyzed to produce estimates for a large area or populations. Therefore, for the small area estimations, sample sizes are often not large enough to give adequate precision. Several small area estimation methods were proposed in recent years concerning with sample sizes. Here, we will compare simple Bayesian approach with Bayesian prediction for small area estimation based on linear regression model. The performance of the proposed method was evaluated through unemployment population data form Economic Active Population(EAP) Survey.

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구역단위 인구자료의 공간적 세분화를 위한 밀도 구분적 표면모델에 대한 평가 (An Evaluation of a Dasymetric Surface Model for Spatial Disaggregation of Zonal Population data)

  • 전병운
    • 한국지역지리학회지
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    • 제12권5호
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    • pp.614-630
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    • 2006
  • 자연 및 기술재해에 빠르고 효과적으로 대응하기 위해서는 그 재해지역 내에 있는 인구수를 정확히 추정할 필요가 있다. 그러나 센서스 구역과 재해지역의 공간적 불일치 문제 때문에, 재해지역 내에 있는 인구수를 정확하게 추정할 때에는 구역단위 인구자료를 공간적으로 세분화할 필요가 있다. 본 논문은 센서스 블럭그룹 내의 인구를 개개의 화소로 세분화하기 위한 밀도 구분적 표면모델을 구현하고, 그 표면기반 공간적 세분화 모델의 성능을 통계적 및 가시적으로 평가한다. 표면기반 공간적 세분화 모델은 밀도 구분적 내삽법과 위성영상으르부터 추출된 토지이용 및 피복자료를 사용하며 지리정보시스템에서 구현되었다. 토지이용 및 피복자료는 밀도 구분적 내삽법에서 인구의 지리적 분포에 관한 추가정보를 제공했고, 토지이용 및 피복자료의 퍼센트에 기반을 둔 경험적 표본추출법과 지역가중법은 각 화소에 대한 밀도 구분적 가중치를 객관적으로 결정하기 위해서 사용되었다. 표면기반 공간적 세분화 모델은 애틀란타 대도시권의 밀도 구분적 인구표면을 만드는데 적용되었다. 그 밀도 구분적 인구표변의 정확도는 센서스 수치와의 비교를 통해서 RMSE와 수정 RMSE를 사용하면서 검증되었다. 또한, 각 센서스 트랙과 블럭그룹별 오차들은 퍼센트 오차지도들에 의해서 가시화 되었다. 분석결과에 따르면, 밀도 구분적 인구표면은 인구수의 정확한 추정치를 제시할 뿐만 아니라, 센서스 블록그룹 내의 인구의 상세한 공간분포를 보여 준다. 또한, 인구표면은 대개 교외 및 산림지역 그리고 도심지역에서 인구를 과소평가하거나 과대평가하는 경향이 있다는 것을 밝혀냈다.

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