• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.98-104
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• 2018

Macroscopic accident analyses have been conducted to incorporate transportation safety into long-term transportation planning. In macro-level accident prediction model, exposure variable(e.g. a settled population) have been used as fundamental explanatory variable under the concept that each trip will be subjected to a probable risk of accident. However, a settled population may be embedded error by exclusion of active population concept. The objective of this research study is to develop macro-level accident prediction model using floating population variable(concept of including a settled population and active population) collected from mobile phone data. The concept of accident prediction models is introduced utilizing exposure variable as explanatory variable in a generalized linear regression with assumption of a negative binomial error structure. The goodness of fit of model using floating population variable is compared with that of the each models using population and the number of household variables. Also, log transformation models are additionally developed to improve the goodness of fit. The results show that the log transformation model using floating population variable is useful for capturing the relationships between accident and exposure variable and generally perform better than the models using other existing exposure variables. The developed model using floating population variable can be used to guide transportation safety policy decision makers to allocate resources more efficiently for the regions(or zones) with higher risk and improve urban transportation safety in transportation planning step.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.365-372
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• 2018

The Wintering Waterbird Census of Korea was started in 1999 and monitors 200 major migratory sites in South Korea. Waterfowl counts have been undertaken for more than 20 years since; however, a limited number of studies have analyzed the temporal patterns of waterfowl population. In this study, we analyzed population size changes of wintering whooper swan (Cygnus cygnus) at 112 monitoring sites from 2001 to 2018. The average number of whooper swans was $4,296{\pm}42.66$ and there was a trend for an increase in population size across the survey period. We found that the population in the Nakdong River Estuary, one of the major wintering sites over 18 years (26.22% of the national population), had rapidly decreased (-0.77% per year). Conversely, the whooper swan population in the Junam Reservoir and Sihwa Lake increased (+1.64%, +0.54% per year, respectively). Estuaries showed the highest dominance of whooper swans among the five different habitat types, accounting for 32.13% of the population. Reservoir/lakes had 30.60% of the total population and reclaimed lakes(18.24%), river (13.11%), and coast (5.93%) followed. The annual distribution of the whooper swan population in South Korea has been affected by various habitat conditions resulting from human activities and urbanization. To better understand the complex factors that can cause rapid changes in wintering waterfowl populations, it is necessary to integrate the data from the bird census program with environmental conditions to conduct in-depth pattern analyses over longer time periods.

• Journal of Preventive Medicine and Public Health
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• v.38 no.2
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• pp.147-153
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• 2005

Objectives: Studies on the geographical differences in mortality tend to use a census population, rather than a registration population, as the denominator of mortality rates in South Korea. However, an administratively determined registration population would be the logical denominator, as the geographical areas for death certificates (numerator) have been determined by the administratively registered residence of the deceased, rather than the actual residence at the time of death. The purpose of this study was to examine the differences in the total number of a district population, and the associated district-specific mortality indicators, when two different measures as a population denominator (census and registration) were used. Methods: Population denominators were obtained from census and registration population data, and the numbers of deaths (numerators) were calculated from raw death certificate data. Sex- and 5-year age-specific numbers for the populations and deaths were used to compute sex- and age-standardized mortality rates (by direct standardization methods) and standardized mortality ratios (by indirect standardization methods). Bland-Altman tests were used to compare district populations and district-specific mortality indicators according to the two different population denominators. Results : In 1995, 9 of 232 (3.9%) districts were not included in the 95% confidence interval (CI) of the population differences. A total of 8 (3.4%) among 234 districts had large differences between their census and registration populations in 2000, which exceeded the 95% CI of the population differences. Most districts (13 of 17) exceeding the 95% CI were rural. The results of the sex- and age-standardized mortality rates showed 15 (6.5%) and 16 (6.8%) districts in 1995 and 2000, respectively, were not included in the 95% CI of the differences in their rates. In addition, the differences in the standardized mortality ratios using the two different population denominators were significantly greater among 14 districts in 1995 and 11 districts in 2002 than the 95% CI. Geographical variations in the mortality indicators, using a registration population, were greater than when using a census population. Conclusion: The use of census population denominators may provide biased geographical mortality indicators. The geographical mortality rates when using registration population denominators are logical, but do not necessarily represent the exact mortality rate of a certain district. The removal of districts with large differences between their census and registration populations or associated mortality indicators should be considered to monitor geographical mortality rates in South Korea.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.363-374
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• 2007

In this paper, we consider the discrete nonlinear delay model which describe the control of a single population of cells. We establish a sufficient condition for oscillation of all positive solutions about the positive equilibrium point and give a sufficient condition for the global attractivity of the equilibrium point. The oscillation condition guarantees the prevalence of the population about the positive steady sate and the global attractivity condition guarantees the nonexistence of dynamical diseases on the population.

• Journal of Animal Science and Technology
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• v.62 no.4
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• pp.438-448
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• 2020

This study was performed to increase the accuracy of genomic estimated breeding value (GEBV) predictions for domestic pigs using single-breed and admixed reference populations (single-breed of Berkshire pigs [BS] with cross breed of Korean native pigs and Landrace pigs [CB]). The principal component analysis (PCA), linkage disequilibrium (LD), and genome-wide association study (GWAS) were performed to analyze the population structure prior to genomic prediction. Reference and test population data sets were randomly sampled 10 times each and precision accuracy was analyzed according to the size of the reference population (100, 200, 300, or 400 animals). For the BS population, prediction accuracy was higher for all economically important traits with larger reference population size. Prediction accuracy was ranged from -0.05 to 0.003, for all traits except carcass weight (CWT), when CB was used as the reference population and BS as the test. The accuracy of CB for backfat thickness (BF) and shear force (SF) using admixed population as reference increased with reference population size, while the results for CWT and muscle pH at 24 hours after slaughter (pH) were equivocal with respect to the relationship between accuracy and reference population size, although overall accuracy was similar to that using the BS as the reference.

• The Korean Journal of Malacology
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• v.24 no.1
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• pp.11-24
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• 2008

GDNA was isolated from the jedo venus clam (Protothaca jedoensis, Lischke) from Boryeong (jedo venus clam from Boryeong JVCB) and Wonsan (jedo venus clam from Wonsan; JVCW) located in the West Sea and the East Sea of Korean Peninsula, respectively and we performed clustering analyses, DNA polymorphisms and the populations genetic variations. In the present study, the seven decamer primer generated the one hundred and eleven major/minor specific bands in JVCB population and ninety four-specific bands in JVCW population. Seven primers generated the unique shared bands to each population of one hundred and seventy-six, on average of 25,1, in JVCB population from Boryeong and three hundred thirty, on average of 47,1, in JVCW population from Wonsan, respectively. The dendrogram obtained by the seven oligonucleotides primers, indicates two genetic clusters. Especially, two Protothaca between the individual WONSAN no. 12 and BORYEONG no. 10 showed the longest genetic distance (0.537) in comparison with other individuals used. Accordingly, RAPD analysis showed that the JVCB was a little more genetically diverse than the JVCW population. This result implies the genetic similarity owing to rearing in the same and/or similar circumstances or inbreeding within the JVCW population. So to speak, JVCB population may have high levels of genomic DNA variability owing to the introduction of the wild individuals from the other sites to sampling sites although it may be the geographically diverse distribution of this species. However, it was confirmed that it did not appear like that really in this study. We feel convinced that RAPD analysis discovered a significant genetic distance between two Protothaca population pairs (P<0.001). The existence of population discrimination and genetic diversity between two Protothaca populations was identified by RAPD analysis.

• Korean Journal of Human Ecology
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• v.20 no.1
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• pp.71-90
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• 2011

The aim of this study was to investigate on characteristics of sociological and demographic population, marital conflicts and expectations to family counselors' cultural competence surrounding factors of cultural adaptation among immigrated women. This study conducted a survey of 236 immigrated women in Kyonggi province, Seoul metropolitan cities, Cholla and Chunchung provinces and Incheon. The results of this study are as follows: First, a relatively few marital conflicts were found, as a whole, while they had the high levels of expectation to family counselors' cultural competence. Second, immigrated women can be clustered as three different types: 'multiplicity type', 'undifferentiated type' and 'adaptation type'. Third, sociological and demographic population characteristics which were subdivided and clustered according to cultural adaptation made the significant difference between each population. Population with multiplicity type out of the above-stated three types accounted for the highest conflict rates, while population with 'adaptation' type accounted for the lowest conflict rates. Lastly, expectations to family counselors' cultural competence made the significant difference among each population. Population with multiplicity type showed the highest expectation levels on expectations to family counselors' cultural competence, while population with undifferentiated type showed the lowest levels.

• Korean Journal of Plant Taxonomy
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• v.41 no.3
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• pp.182-193
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• 2011

As a part of the on-going effort to conserve endangered Scrophularia takesimensis Nakai in Korea, its genetic structure and diversity from 3 population, consisted of 14 subpopulations in Ulleung Island were analyzed using RAPD band patterns. Out of 60 primers tested, 33 generated amplified bands with its genome, including 149 polymorphic and 67 monomorphic bands. The highest number (146) was found in northern population, especially, 64 in HY subpopulation; the smallest (40) in eastern population. An examination of its genetic structure with AMOVA revealed that about 60% of all variations could be assigned to among subpopulations within populations. Population differentiation among populations and subpopulations is seriously going now because of habitat fragmentation due to human activities, such as road and small port construction. Although the habitats of S. takesimensis in Ulleung Island, Korea are disappeared at an alarming rate, significant levels of genetic variation still exist at species level, and population level, especially northern population. Therefore, three conservation strategies should be needed urgently; 1) preservation of populations as it stands, 2) establishment of recovery plan to connect population and subpopulations genetically, and 3) long-term monitoring.

• Korean Journal of Remote Sensing
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• v.36 no.1
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• pp.83-92
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• 2020

The purpose of this work was to apply geographical information system (GIS) for geostatistical analyzing by selecting a semi-variogram model to quantify the spatial correlation of the population distribution with residential neighborhoods in the both sides of Mosul city. Two hundred and sixty-eight sample sites in 240 ㎢ are adopted. After determining the population distribution with respect to neighborhoods, data were inserted to ArcGIS10.3 software. Afterward, the datasets was subjected to the semi-variogram model using ordinary kriging interpolation. The results obtained from interpolation method showed that among the various models, Spherical model gives best fit of the data by cross-validation. The kriging prediction map obtained by this study, shows a particular spatial dependence of the population distribution with the neighborhoods. The results obtained from interpolation method also indicates an unbalanced population distribution, as there is no balance between the size of the population neighborhoods and their share of the size of the population, where the results showed that the right side is more densely populated because of the small area of residential homes which occupied by more than one family, as well as the right side is concentrated in economic and social activities.

• Journal of Animal Science and Technology
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• v.62 no.6
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• pp.790-800
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• 2020

The Yeonsan Ogye (YO) chicken is a natural heritage of Korea, characterized by black feathers, skin, bones, eyes, and comb. The purebred of YO population has been reared under the natural mating system with no systematic selection and breeding plan. The purpose of this study was to identify the genetic diversity and find the optimal number of population sub-division using 12 polymorphic microsatellite (MS) markers to construct a pedigree-based breeding plan for the YO population. A total of 509 YO birds were used for this study. Genetic diversity and population structure analysis were conducted based on the MS marker genotype information. The overall average polymorphic information content value and expected heterozygosity of the population were 0.586, and 0.642, respectively. The K-mean cluster analysis based on the genetic distance result confirmed that the current YO population can be divided into three ancestry groups. Individuals in each group were evaluated based on their genetic distance to identify the potential candidates for a future breeding plan. This study concludes that a future breeding plan with known pedigree information of selected founder animals, which holds high genetic diversity, could be the best strategy to ensure the conservation of the Korean YO chicken population.