• ETRI Journal
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• 제23권3호
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• pp.129-137
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• 2001

A random sampling or systematic sampling method is commonly used to assess the accuracy of classification results. In remote sensing, with these sampling methods, much time and tedious work are required to acquire sufficient ground truth data. So, a more effective sampling method that can represent the characteristics of the population is required. In this study, fractal analysis is adopted as an index for reference sampling. The fractal dimensions of the whole study area and the sub-regions are calculated to select sub-regions that have the most similar dimensionality to that of the whole area. Then the whole area's classification accuracy is compared with those of sub-regions, and it is verified that the accuracies of selected sub-regions are similar to that of whole area. A new kind of reference sampling method using the above procedure is proposed. The results show that it is possible to reduce sampling area and sample size, while keeping the same level of accuracy as the existing methods.

• 생명과학회지
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• 제32권4호
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• pp.279-284
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• 2022

본 연구는 일반농가에서 적용 가능한 유전평가시스템을 구축을 위해 경기 지역에서 사육중인 암소 619두를 BLUP (Best Linear Unbiased Prediction)과 GBLUP (Genomic Best Linear Unbiased Prediction)을 사용하여 각 형질(도체중, 등심단면적, 등지방두께, 근내지방도) 별 추정 육종가의 정확도를 비교분석 하였다. GBLUP의 경우 참조집단의 크기를 다르게 그룹을 나누어 분석하였다. 분석결과 GBLUP 참조집단의 크기가 커질수록 각 형질의 육종가의 정확도도 상승하는 것을 확인 하였다. BLUP과 GBLUP 방법을 사용하여 추정한 육종가의 정확도를 비교하면, GBLUP 방법을 사용하여 육종가를 추정하였을 때 도체중, 등심단면적, 등지방두께 근내지방도순으로 각각 0.10, 0.09, 0.09, 0.11 이상 상승한 것을 확인할 수 있었다. 따라서, GBLUP 방법을 암소 평가 및 선발에 적용한다면, 정밀하고 정확한 개체 선발이 가능하고 참조집단의 크기를 더욱 키운다면 보다 정확한 개체 선발을 할 수 있기 때문에 선발의 효율성이 증가할 것으로 사료된다.

• International Journal of Knowledge Content Development & Technology
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• 제14권2호
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• pp.81-97
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• 2024

The study investigated computer literacy skills as a determinant of electronic reference sources utilization among selected secondary school students in Ado-Odo Ota Local Government, Ogun State, Nigeria. Four specific objectives with conforming research questions guided the study. Descriptive survey research design was adopted for the study. The population of the study comprises of SSS3 students of the three selected Community Secondary Schools in Ado Odo Ota. A sample size of 150 was used for the study. The instrument for data collection was a self-developed structured questionnaire. Data collected was analyzed using frequency and percentages. Findings of the study revealed that majority of secondary school students were not aware of the availability of electronic reference sources. It also revealed that the level of their computer literacy skills was below average. Majority of them have never used computer before and the few of them that have used computer before used it in their homes, their friend's homes or in the cyber café. It was found that lack of formal training on the use of electronic reference sources, lack of access to computer, lack of awareness of availability of electronic reference sources, lack of funds for internet subscriptions, over dependency on printed reference sources and lack of motivation to use electronic reference sources were the major hindrances to the use of electronic reference sources among secondary school students. It was recommended that the school librarians and teachers should play a role in creating awareness among secondary school students about the availability of online/ electronic reference sources among others.

• Animal cells and systems
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• 제4권1호
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• pp.39-44
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• 2000

To assess the genetic diversity and population structure of Korean K. borealis, allozyme analysis was performed. The average genetic variability of Korean K. borealis populations was %P=13.2, Ho=0.048, and He=0.045. This value was the lowest in comparison with other Korean amphibian species studied. Also, the value was much lower than that of a reference population from Chinese K. borealis (%P=50, Ho=0.125, He=0.172). Wright's F-statistics showed that Korean K. borealis has distinctly low level of gene flow among regional populations (F$_{ST}$=0.339, Nm=0.487) in comparison with other Korean amphibian species studied. However, the average level of genetic divergence among Korean K. borealis populations was moderate (Nei's D=0.020). Therefore, it appeared that low levels of genetic diversity (He=0.045) and gene flow (Nm=0.487) among regional populations ave probably due to the results of decreasing population size and patchy distribution of this species in Korea.

• 대한지리학회지
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• 제47권3호
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• pp.359-374
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• 2012

본 논문은 인구센서스 자료를 이용하여 1980년부터 2010년까지의 163개 시군구 지역을 대상으로 한국 인구고령화의 지역적 전개 양상을 분석한 것이다. 이를 위해 고령인구의 일반적인 특징을 기존연구를 중심으로 정리하고, 고령인구의 분포 변화를 시계열적으로 파악하였으며 인구성장률 등과 관련하여 고령인구의 분포를 해석하였다. 1980년부터 5년 단위로 고령인구의 비율에 따라서 한국의 163개 지역들을 고령화사회, 고령사회, 초고령사회로 구분하였다. 지역적 차원에서 시기별로 고령인구의 추이를 고찰하면 1980년부터 고령화사회에 진입하였고, 1995년에 고령사회, 2000년에는 초고령사회에 진입하여 2010년에는 80개의 지역이 초고령사회에 진입하였다. 고령인구의 비율은 도시규모와 인구증가율과 깊은 관계를 보인다. 즉, 도시의 규모가 작을수록 고령인구비율이 높았고, 인구증가폭이 낮을수록 고령인구의 비율은 높은 경향을 나타내었다. 2010년 기준으로 수도권 대도시와 중소도시의 경우 고령화사회에 진입한 도시가 대부분인 반면 농어촌지역의 대부분은 초고령사회에 진입하였다. 지역수준에서 합계출산율과 고령인구는 관련성이 없는 것으로 파악되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.628-635
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• 2018

Objective: To determine the effects of genomic breeding values (GBV) and single nucleotide polymorphisms (SNP) on the total number of piglets born (TNB) in 3 pig breeds (Berkshire, Landrace, and Yorkshire). Methods: After collecting genomic information (Porcine SNP BeadChip) and phenotypic TNB records for each breed, the effects of GBV and SNP were estimated by using single step best linear unbiased prediction (ssBLUP) method. Results: The heritability estimates for TNB in Berkshire, Landrace, and Yorkshire breeds were 0.078, 0.107, and 0.121, respectively. The breeding value estimates for TNB in Berkshire, Landrace, and Yorkshire breeds were in the range of -1.34 to 1.47 heads, -1.79 to 1.87 heads, and -2.60 to 2.94 heads, respectively. Of sows having records for TNB, the reliability of breeding value for individuals with SNP information was higher than that for individuals without SNP information. Distributions of the SNP effects on TNB did not follow gamma distribution. Most SNP effects were near zero. Only a few SNPs had large effects. The numbers of SNPs with absolute value of more than 4 standard deviations in Berkshire, Landrace, and Yorkshire breeds were 11, 8, and 19, respectively. There was no SNP with absolute value of more than 5 standard deviations in Berkshire or Landrace. However, in Yorkshire, four SNPs (ASGA 0089457, ASGA0103374, ALGA0111816, and ALGA0098882) had absolute values of more than 5 standard deviations. Conclusion: There was no common SNP with large effect among breeds. This might be due to the large genetic composition differences and the small size of reference population. For the precise evaluation of genetic performance of individuals using a genomic selection method, it may be necessary to establish the appropriate size of reference population.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.25-36
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• 2015

The complex analysis of the pedigree records of Czech Landrace (CLA), Czech Large White-dam line (CLWd), Czech Large White-sire line (CLWs), Duroc (DC), and Pietrain (PN) was performed to determine trends of genetic diversity (GD), and to find the main sources of the GD loss. The total size of the pedigree was 132,365, 391,151, 32,913, 13,299, and 7,160 animals in CLA, CLWd, CLWs, DC, and PN, respectively. Animals born in the years 2011 through 2013 were assumed as the reference population. The average pedigree completeness index for one generation back was 95.9%, 97.4%, 91.2%, 89.8%, and 94.2% for appropriate breeds. Number of ancestors explaining 100% of gene pool was 186, 373, 125, 157, and 37 in CLA, CLWd, CLWs, DC, and PN, respectively. The relative proportion of inbred animals (58%, 58%, 54%, 47%, and 25%), the average inbreeding (2.7%, 1.4%, 2.5%, 3.6%, and 1.3%) and the average co-ancestry (3.1%, 1.6%, 3.3%, 4.2%, and 3.3%) were found over the past decade in analysed breeds. The expected inbreeding under random mating increased during the last 10 years in CLWs and PN and varied from 1.27% to 3.2%. The effective population size computed on the basis of inbreeding was 76, 74, 50, 35, and 83 in 2012 in CLA, CLWd, CLWs, DC, and PN, respectively. The shortest generation interval (1.45) was observed for CLWd in sire to son selection pathway. The longest generation interval obtained PN (1.95) in sire to daughter pathway. The average relative GD loss within last generation interval was 7.05%, 4.70%, 9.81%, 7.47%, and 10.46%, respectively. The relative proportion of GD loss due to genetic drift on total GD loss was 85.04%, 84.51%, 89.46%, 86.19%, and 83.68% in CLA, CLWd, CLWs, DC, and PN, respectively. All breeds were characterized by a high proportion of inbred animals, but the average inbreeding was low. The most vulnerable breeds to loss of GD are DC and PN. Therefore, a breeding program should be more oriented to prevent the increase of GD loss in these breeds.

• Animal Bioscience
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• 제36권3호
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• pp.417-428
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• 2023

Objective: Few studies have genetically monitored chickens over time, and no research has been conducted on ducks. To ensure the sustainable management of key duck breeds, we used microsatellite markers to monitor Brown Tsaiya ducks over time genetically. Methods: The second, fourth, sixth to eighth generations of the Brown Tsaiya duck selected for feeding efficiency and control lines were included in this study to investigate the genetic variations, effective population size, population structure and the differentiation between populations over time with 11 microsatellite markers derived from Brown Tsaiya duck. Results: The results showed there were a slight decrease in the genetic variations and an increase in within-population inbreeding coefficient (F_IS) in both lines, but no consistent increase in F_IS was observed in each line. The effective population size in the second and eighth generations was 27.2 for the selected line and 23.9 for the control line. The change in allele richness showed a downward trend over time, and the selected line was slightly lower than the control line in each generation. The number of private alleles (N_p) in the selected line were higher than in the control line. Moderate differentiation was observed between the second and eighth generations in the selected line (F_ST = 0.0510) and the control line (F_ST = 0.0606). Overall, differentiation tended to increase with each generation, but genetic variation and structure did not change considerably after six generations in the two lines. Conclusion: This study provides a reference for poultry conservation and helps to implement cross-generation genetic monitoring and breeding plans in other duck breeds or lines to promote sustainable management.

• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1657-1663
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• 2019

Objective: A genome-based best linear unbiased prediction (GBLUP) method was applied to evaluate accuracies of genomic estimated breeding value (GEBV) of carcass and reproductive traits in Berkshire, Duroc and Yorkshire populations in Korean swine breeding farms. Methods: The data comprised a total of 1,870, 696, and 1,723 genotyped pigs belonging to Berkshire, Duroc and Yorkshire breeds, respectively. Reference populations for carcass traits consisted of 888 Berkshire, 466 Duroc, and 1,208 Yorkshire pigs, and those for reproductive traits comprised 210, 154, and 890 dams for the respective breeds. The carcass traits analyzed were backfat thickness (BFT) and carcass weight (CWT), and the reproductive traits were total number born (TNB) and number born alive (NBA). For each trait, GEBV accuracies were evaluated with a GEBV BLUP model and realized GEBVs. Results: The accuracies under the GBLUP model for BFT and CWT ranged from 0.33-0.72 and 0.33-0.63, respectively. For NBA and TNB, the model accuracies ranged 0.32 to 0.54 and 0.39 to 0.56, respectively. The realized accuracy estimates for BFT and CWT ranged 0.30 to 0.46 and 0.09 to 0.27, respectively, and 0.50 to 0.70 and 0.70 to 0.87 for NBA and TNB, respectively. For the carcass traits, the GEBV accuracies under the GBLUP model were higher than the realized GEBV accuracies across the breed populations, while for reproductive traits the realized accuracies were higher than the model based GEBV accuracies. Conclusion: The genomic prediction accuracy increased with reference population size and heritability of the trait. The GEBV accuracies were also influenced by GEBV estimation method, such that careful selection of animals based on the estimated GEBVs is needed. GEBV accuracy will increase with a larger sized reference population, which would be more beneficial for traits with low heritability such as reproductive traits.

• Spatial Information Research
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• 제8권1호
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• pp.171-182
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• 2000

분류기법에 의해 원격탐사 영상으로부터 취득된 면속성 수치 지도는 GIS 의사결정자료로 사용되기 이전에 그 정확성에 관한 신뢰도 검증과정을 거쳐야 한다. 분류 정확도를 평가하기 위해서는 오분류행렬(confusion matrix)을 사용하여 전체 정확도, 사용자 정확도, 제작자 정확도 등을 얻게 되는데, 이때 오분류행렬을 구성하기 위해서는 기준자료(reference data)에 대한 표본추출이 이루어져야한다. 기준자료의 표본을 추출하는 기법간의 비교 및 표본 크기를 줄이고자 하는 연구는 많이 이루어져 왔으나, 추출된 표본들간의 거리를 줄임으로서 정확도 평가 비용을 감소시키고자 하는 연구는 미비한 실정이다. 따라서 본 연구에서는 프랙탈 분석을 통하여 기준자료의 표본을 추출하였으며, 이를 바탕으로 기존의 표본추출의 기법과 정확도 차이 및 비용효과 측면을 비교 분석하였다. 연구 결과 , 프랙탈 분석을 통하여 표본을 추출하는 기법은 그 정확도 추정에 있어 기존의 표본추출 기법과 큰 차이를 보이지 않았으며, 추출된 화소들이 가까운 저리에 군집에 있어 비용효과측면에서 유리함을 확인하였다.