• Genomics & Informatics
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• 제12권3호
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• pp.114-120
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• 2014

Bone mineral density (BMD) is one of the quantitative traits that are genetically inherited and affected by various factors. Over the past years, genome-wide association studies (GWASs) have searched for many genetic loci that influence BMD. A recent meta-analysis of 17 GWASs for BMD of the femoral neck and lumbar spine is the largest GWAS for BMD to date and offers 64 single-nucleotide polymorphisms (SNPs) in 56 associated loci. We investigated these BMD loci in a Korean population called Korea Association REsource (KARE) to identify their validity in an independent study. The KARE population contains genotypes from 8,842 individuals, and their BMD levels were measured at the distal radius (BMD-RT) and midshaft tibia (BMD-TT). Thirteen genomic loci among 56 loci were significantly associated with BMD variations, and 3 loci were involved in known biological pathways related to BMD. In order to find putative functional variants, nearby SNPs in relation to linkage equilibrium were annotated, and their possible functional effects were predicted. These findings reveal that tens of variants, not a single factor, may contribute to the genetic architecture of BMD; have an important role regardless of ethnic group; and may highlight the importance of a replication study in GWASs to validate genuine loci for BMD variation.

• 상하수도학회지
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• 제19권5호
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• pp.547-556
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• 2005

The objective of this study is to obtain adequate intercepting flow during wet weather conditions in combined sewer system. Two study sites are selected under considering different population density, one is developed area with heavy urbanization. Another is recently developing area. In the analysis of field investigation, SS was most significant in initial flushing effects compared with other factors and showed the result with the order of COD, TP, TN. As compared with event mean concentration(EMC) of runoff, BOD, TN and TP showed high concentrations in wide area with relatively large population density. It is by the reason that much pollution load was discharged to receiving water from urbanized area during wet period. According to results of storm-water modeling, 53% of total COD and 52% of total SS pollution load were discharged to receiving water by overflow than intercepting capacity in middle population density site. Also, in the urbanized area, pollution load was discharged to receiving water by 49% of total COD and 77% of total SS. These results can be applied to setup for pollution load flow(budget) generation, collection, treatment and discharging in order to obtain adequate intercepting flow.

• 대한임상검사과학회지
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• 제44권4호
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• pp.199-204
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• 2012

The purpose of this study is to examine the population density of the mosquito species, and to provide the basic data related to vector mosquitoes to manage the possible epidemic diseases. During a 4-year investigation (2001, 2002, 2004, and 2006), we collected the specimens of the mosquitoes at pier no. 1, 3 and 5 of Busan port with light traps from sunset until the next day morning from April to October each year. Through the research, we collected 5,985 mosquito specimens in total and found 7 mosquito species belonging to 3 genera. A total of 1,575, 1,473, 1,478 and 1,459 mosquito specimens were collected in 2001, 2002, 2004 and 2006, respectively. Among them, 5,568 (93.0%) specimens were Culex pipiens pallens, the West Nile virus infection vector, which showed the highest density among the specimens. The population densities of the other species were: 295(4.9%) Culex tritaeniorhynchus, 94(1.5%) Aedes togoi, 12(0.3%) Aedes albopictus, 10(0.2%) Anopheles sinensis, 4(0.1%) Aedes vexans nipponii, 2(0.1%) Culex inatomii. The monthly abundance of mosquitoes from July through September showed the highest values. Although it was a general mosquito monitoring study, this study could provide a base for securing the statistical data on spreading epidemic diseases by people infected outside Korea.

• 암석학회지
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• 제5권2호
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• pp.161-167
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• 1996

The CSD (crystal size distribution) of diopside crystals in the calc-silicate hornfels of the Hwanggangni Formation intruded by the Cretaceous Daeyasan granite shows the patterns of continuous nucleation and growth. There is correlation between the distance from the intrusion contact and the slopes from the linear part of log(population density) vs. size diagrams. In the log(population density) vs. size diagrams of the samples systematically collected from the intrusion contact, two different groups are recognized; the slopes for the samples near the intrusion contact (horizontal distance from the contact less than 50m) are gentler (1500$cm^{-1}$) than those for the samples away from the intrusion contact (2500$cm^{-1}$, distance from the contact greater than 100 m). These differences may reflect the differences in growth rates and crystallization time, or the differences in diopside-forming reactions. All of the log(population density) vs. size diagrams show depletion of smaller crystals. The observed depletion may be due to Ostwald ripening or the changes in nucleation rates as the reactant phases diminishes. Similar grouping is also possible for the observed degree of depletion of smaller crystals; the depletion decreases with increasing distance from the intrusion contact, suggesting temperature-dependent rates of Ostwald ripening.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권6호
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• pp.45-57
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• 2023

To assess land subsidence estimation and preparedness in the Geum River basin, this study applied GIS techniques and identified six key areas. The Geum River basin has experienced an increase in heavy rainfall since late 2010, and four study areas have shown an increase in groundwater levels. Land subsidence primarily occurred from June to September, with higher rainfall years in 2020 and 2023. Approximately 83.6% of land subsidence in Chungcheongbuk-do province occurred in Cheongju-si, mainly attributed to aging sewage pipes. The regions experiencing population growth have likely led to the construction of underground infrastructures and sewer pipes. Thus, it is considered that various factors, including sewage pipe leaks, precipitation, slope gradient, low drainage density, and groundwater level fluctuations, have contributed to land subsidence. Improving land subsidence estimation involves incorporating additional natural factors and human activities.

• 한국환경과학회지
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• 제11권6호
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• pp.553-560
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• 2002

The research was performed to compare to the biofilm characteristics and phenol removal efficiency in RBCs(Rotating Biological Contactor) using Rhodococcus sp. EL-GT(single population) and activated sludge(mixed population) as inoculum. Both reactors showed similar tendency on variations of dry weight, thickness and dry density of biofilm. However, the growth of biofilm thickness in 3 and 4 stage of single population reactor has sustained longer than that of the mixed population reactor. Unlike the mixed population reactor, the dry density of biofilm in the single population reactor had a difference between 1, 2 stage and 3, 4 stage. The single population reactor was stably operated without the decrease of phenol removal efficiency in the range of pH 6 ~ 9 and 15mM phenol was completely degraded in these pH ranges. But in case of the mixed population reactor, the phenol degradability was dramatically decreased at over 5mM phenol concentration because of the overgrowth and detachment of its biofilm.

• Ocean Science Journal
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• 제41권3호
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• pp.139-148
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• 2006

The distribution of the taxonomical composition and the density of meiobenthos depending on the sediment type has been studied in bottom sediments of Nha Trang Bay. The maximal population density and the taxonomical diversity were observed in the silted coarse and heterogeneous sand ($1031.4{\pm}419.7\;ind.\;10\;cm^{-2}$), whereas the minimal level of density and diversity ($588.1{\pm}152.5\;ind.\;10cm^{-2}$) was in the coarse and heterogeneous sand with shell debris and corals. The correlation between the median diameter of sediment particles and population density of meiobenthos has been revealed (r=0.82, p<0.05). In bottom sediments of Nha Trang Bay, twenty six taxonomic groups of meiobenthos were observed. Nematodes dominated in all sediment types. Representatives of four orders, twenty eight families and ninety seven genera of marine nematodes were identified. The vertical distribution of meiobenthos in different sediment types was considered. A sediment column (10 cm height) was sectioned by five 2 cm portions. In the last layer (8-10 cm) the most number of meiobenthic groups was found in sandy sediments. In the lower layers of silt sediments, only nematodes were found.

• 한국안전학회지
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• 제32권3호
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• pp.130-135
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• 2017

This study deal with the traffic accident. The purpose of this study is to develop the accident density models reflecting the transportation and socioeconomic characteristics based on 230 zones of Korea. In this study, The models which are tested to be statistically significant are developed through multiple linear regression analysis. The main research results are as follows. First, in the transportation-based model, road length, avenue ratio, number of intersections and tunnels are analyzed to be positive to the model, however, school zone is analyzed to be negative to the model. Second, in the socioeconomic-based model, population density, transportation vulnerable ratio, children and truck ratio are analyzed to be positive to the model. Finally, in the integrated models, road ratio, population density, transportation vulnerable ratio, children ratio, truck ratio and number of companies are analyzed to be positive, however, school zone is analyzed to be negative to the model. This results could be expected to give good implications to accident-reduction policy-making.

• Journal of Forest and Environmental Science
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• 제33권3호
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• pp.239-242
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• 2017

Although camera traps have been widely used to understand the abundance of wildlife in recent decades, the effort has been restricted to small sub-set of wildlife which can mark-and-recapture. The Random Encounter Model shows an alternative approach to estimate the absolute abundance from camera trap detection rate for any animals without the need for individual recognition. Our study aims to examine the feasibility and validity of the Random Encounter Model for the density estimation of endangered leopard cats (Prionailurus bengalensis) in Maekdo riparian park, Busan, South Korea. According to the model, the estimated leopard cat density was $1.76km^{-2}$ (CI 95%, 0.74-3.49), which indicated 2.46 leopard cats in $1.4km^2$ of our study area. This estimate was not statistically different from the previous leopard cat population count ($2.33{\pm}0.58$) in the same area. As follows, our research demonstrated the application and usefulness of the Random Encounter Model in density estimation of unmarked wildlife which helps to manage and protect the target species with a better understanding of their status.

• Asian-Australasian Journal of Animal Sciences
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• 제33권12호
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• pp.1912-1921
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• 2020

Objective: This study assessed genomic prediction accuracies based on different selection methods, evaluation procedures, training population (TP) sizes, heritability (h²) levels, marker densities and pedigree error (PE) rates in a simulated Korean beef cattle population. Methods: A simulation was performed using two different selection methods, phenotypic and estimated breeding value (EBV), with an h² of 0.1, 0.3, or 0.5 and marker densities of 10, 50, or 777K. A total of 275 males and 2,475 females were randomly selected from the last generation to simulate ten recent generations. The simulation of the PE dataset was modified using only the EBV method of selection with a marker density of 50K and a heritability of 0.3. The proportions of errors substituted were 10%, 20%, 30%, and 40%, respectively. Genetic evaluations were performed using genomic best linear unbiased prediction (GBLUP) and single-step GBLUP (ssGBLUP) with different weighted values. The accuracies of the predictions were determined. Results: Compared with phenotypic selection, the results revealed that the prediction accuracies obtained using GBLUP and ssGBLUP increased across heritability levels and TP sizes during EBV selection. However, an increase in the marker density did not yield higher accuracy in either method except when the h² was 0.3 under the EBV selection method. Based on EBV selection with a heritability of 0.1 and a marker density of 10K, GBLUP and ssGBLUP_0.95 prediction accuracy was higher than that obtained by phenotypic selection. The prediction accuracies from ssGBLUP_0.95 outperformed those from the GBLUP method across all scenarios. When errors were introduced into the pedigree dataset, the prediction accuracies were only minimally influenced across all scenarios. Conclusion: Our study suggests that the use of ssGBLUP_0.95, EBV selection, and low marker density could help improve genetic gains in beef cattle.