• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1369-1377
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• 2020

Objective: The main objectives of the present study were to assess the genetic diversity, population structure and to appraise the efficiency of ongoing selective breeding program in the closed nucleus herd of Nellore sheep through pedigree analysis. Methods: Information utilized in the study was collected from the pedigree records of Livestock Research Station, Palamaner during the period from 1989 to 2016. Genealogical parameters like generation interval, pedigree completeness, inbreeding level, average relatedness among the animals and genetic conservation index were estimated based on gene origin probabilities. Lambs born during 2012 and 2016 were considered as reference population. Two animal models either with the use of F_i or ΔF_i as linear co-variables were evaluated to know the effects of inbreeding on the growth traits of Nellore sheep. Results: Average generation interval and realized effective population size for the reference cohort were estimated as 3.38±0.10 and 91.56±1.58, respectively and the average inbreeding coefficient for reference population was 3.32%. Similarly, the effective number of founders, ancestors and founder genome equivalent of the reference population were observed as 47, 37, and 22.48, respectively. Fifty per cent of the genetic variability was explained by 14 influential ancestors in the reference cohort. The ratio f_e/f_a obtained in the study was 1.21, which is an indicator of bottlenecks in the population. The number of equivalent generations obtained in the study was 4.23 and this estimate suggested the fair depth of the pedigree. Conclusion: Study suggested that the population had decent levels of genetic diversity and a non-significant influence of inbreeding coefficient on growth traits of Nellore lambs. However, small portion of genetic diversity was lost due to a disproportionate contribution of founders and bottlenecks. Hence, breeding strategies which improve the genetic gain, widens the selection process and with optimum levels of inbreeding are recommended for the herd.

• Animal Bioscience
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• v.35 no.4
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• pp.511-516
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• 2022

Objective: A genomic region associated with a particular phenotype is called quantitative trait loci (QTL). To detect the optimal F₂ population size associated with QTLs in native chicken, we performed a simulation study on F₂ population derived from crosses between two different breeds. Methods: A total of 15 males and 150 females were randomly selected from the last generation of each F₁ population which was composed of different breed to create two different F₂ populations. The progenies produced from these selected individuals were simulated for six more generations. Their marker genotypes were simulated with a density of 50K at three different heritability levels for the traits such as 0.1, 0.3, and 0.5. Our study compared 100, 500, 1,000 reference population (RP) groups to each other with three different heritability levels. And a total of 35 QTLs were used, and their locations were randomly created. Results: With a RP size of 100, no QTL was detected to satisfy Bonferroni value at three different heritability levels. In a RP size of 500, two QTLs were detected when the heritability was 0.5. With a RP size of 1,000, 0.1 heritability was detected only one QTL, and 0.5 heritability detected five QTLs. To sum up, RP size and heritability play a key role in detecting QTLs in a QTL study. The larger RP size and greater heritability value, the higher the probability of detection of QTLs. Conclusion: Our study suggests that the use of a large RP and heritability can improve QTL detection in an F₂ chicken population.

• Journal of Agricultural Extension & Community Development
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• v.17 no.4
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• pp.773-797
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• 2010

Recent years, being advanced the phenomena of fewness and aging rapidly in rural areas, rural community has been collapsed fastly. This study is aimed for two intentions: the one is identification of the actual conditions of rural diminishing in population, and the other is having a view of real picture of it in future. The major result of this study is summarized as follows. First, as a result of the rural area's shrinking for a long time advanced, the rural community has grown to under the minimum autogenesis level. Futher more this study have a look out in ten years later that rural community will diminish in population to 42% size compared with now, and the number of elder than 80 years old occupy a half of total population in a standard case. Such a consequence of this study implies no doubt that the rural development policy must lay a stress to cope with a serious situation of rural scantiness. And policy conversion calls for having a new understanding of this situation first.

• The Korean Journal of Applied Statistics
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• v.33 no.3
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• pp.347-355
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• 2020

An Isolation-with-Migration (IM) model is used to estimate extant population sizes, the splitting time of populations split away from their common ancestral populations, and migration rates between the extant populations. An evolutionary model such as IM models is estimated by analyzing DNA sequences sampled from the extant populations in the model. When a true model includes an unsampled 'ghost' population without data, the unsampled population is often ignored from the evolutionary model to infer. In this paper, we conduct a simulation study to investigate the effect of an unsampled population on the estimation of the size of the sampled population. When there exists an unsampled population that shares migrations with the sampled population, the size estimation of the sampled population was biased. However, the size estimation was improved if an evolutionary model, including the unsampled population, was estimated.

• East Asian Journal of Business Economics (EAJBE)
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• v.2 no.4
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• pp.1-8
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• 2014

This study examines the relationship between population growth and carbon dioxide emissions in the context of Africa perspective. Population growth and carbon dioxide emissions helped identify the key driving forces of environmental impacts by including other predictors in all the different income levels of all sampled countries in Africa. To explore the role of population growth in the emissions of carbon dioxide, this research employed a panel data set of 52 Africa countries from 1960 to 2012 using fixed effects, random effects and GLS/FGLS estimators to estimate the modified STIRPAT model. The results found that a 1% increase in population growth suggests an increase in carbon dioxide emission loads by about 0.33%, 1.08%, 0.57% and 2.32% on the average, controlling for all other anthropogenic driving forces, for LICA, LMICA, UICA and HICA respectively. There is a significant relationship between population growth and carbon dioxide emissions in all the national income levels in Africa.

• Korea journal of population studies
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• v.17 no.1
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• pp.73-86
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• 1994

In order for handicapped people to maintain better humane life, it is necessary to get statistics of them in developing appropriate national policy. However, it is very difficult to obtain baseline statistics on regular or occasional basis. It's reason is mainly attributed to attitudes of their family's tendency to conceal any existence of such memeber in the household. As a result, the statis-tics on the handicapped population is very inaccurate and under satisfaction. We must produce such statistics periodically in time and with accuracy. Thus, this study porposes five methods which, we believe, can produce reliable statistics of thehandcapped population : 1) vitalization through enforcement of handicapped information into the registration system, 2) inclusion in population census of items related to handicapped information, 3) improvement of the physically handicapped population survey scheme, 4) utilization of hospital patients' records for development of the statistics, and 5) an estimation through the labor force survey.

• Korean Management Science Review
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• v.26 no.1
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• pp.197-208
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• 2009

In this paper, we study stochastic maximal covering location problem considering floating population. Traditional maximal covering location problem assumed that number of populations at demand point is already known and fixed. In this manner, someone who try to solve real world maximal covering location problem must consider administrative population as a population at demand point. But, after observing floating population, appliance of population in steady-state is more reasonable. In this paper, we suggest revised numerical model of maximal covering location problem. We suggest heuristic methodology to solve large scale problem by using genetic algorithm.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.456-460
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• 2005

The purpose of this study is to develop a estimation model of migration with only population data using the cohort-survival model which has been used for forecasting future population. The fluctuation of population can be bisected to the natural change which can be occurred by birth and death and the social change which means migration. The factors of the social change are usually very important for establishing rural policies. However, researches using migration data has limitations because the usage of them are restricted. For verifying a estimation model of migration, comparing estimated population in 2000 year and migration quantity between 1996 and 2000 of 25 gu with real values, using population data and death ratio from 1995 to 2000 of the 25 gu in Seoul. Result shows a reliable data that R-square of forecating population model is 0.9755 and migration is 0.9180. So these model are worth to estimate a population and migration quantity to restricted migration data.

• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.127-135
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• 2014

The purpose of this study is to show the relation of the change between spacial structure and social conditions of rural area. The spacial structure change of Asan city was analyzed using Space Syntax, and multiple regression analysis (dependent variables: connectivity, global integration, local integration / independent variables: population, household, farm population, farm population of 65years old and over, farm household, part-time farm households, cultivated land) was accomplished. As th result, that the increase of connectivity is related to the increase of population and farm population of 65years old and over and the decrease of farm population, and the increase of local integration is related to the increase of farm population of 65years old and over was showed. However, that global integration is not related to change of social conditions was proved.

• Journal of the Korean Statistical Society
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• v.10
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• pp.145-157
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• 1981

Regional relocation of population in Korea is required strongly from natural and environmental sides for substantial growth of economy and the rigorous revival national economy against especially internationalization. This paper aimed for analysed the population distribution by regional and special characteristics of the inter-migration and showed the direction of population policy through the model building. Relocation methods of population by region has been examined through the process from the approach method by Haurin's production function to the approach by the utility function. The examination of the development model is done efficiently, how utility these approach models are depends on that scientific and composite plan for population problems against forced policy should be taken precedence.