• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.49-55
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• 1996

Water parsley(Oenanthe javanica(Blume) DC) was raised with varying population density(S) in the laboratory aquarium unit to determine the growth equation. The population density was measure after 7 days. The resultant growth curve was well fit to the equation 1/S = A+B (1/S0) with a high correlation coefficient ($R^2$ = 0.999). The maximum specific absorption rate was $9.011 \times 10^{-5}$ kg $NO_x-N/kg$ water parsley$\cdot$day and $1.31 \times 10^{-5}$ kg $PO_4-P/kg$ water parsley$\cdot$day when the average population density was $2.62 kg/m^2$. The relationship between population density and nutrient absorption rate, the absorption rate of $NO_x-N$ was 5.04~5.24 mg/l$\cdot$day when the population density was $7.51~10.0 $mg/m^2\cdot day$ and the absorption rate of $PO_4-P$ was 0.56~0.78 mg/l$\cdot$day when the population density was 5.02~10.0 $kg/m^2\cdot day$. Taking into account the nutrient absorption rate and growth rate, the population density between $7.0 kg/m^2\cdot day$ and $8.0 kg/m^2 \cdot day$ was selected. The removal rate of nutrient was investigated after 7 days culture. Removal rate of $NO_x-N$ was 95.6~99.95% with initial concentration of 35 mg $NO_x-N/l$, and the removal rate of $PO_4-P$ was also high, indicating 80.24~98.9% with initial concentration of 5.95 mg $PO_x-P/l$.

• Korean Journal of Plant Resources
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• v.12 no.2
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• pp.152-160
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• 1999

Bacterial population density on soybean leaves was $10^2~10^5CFU/cm^2$. Bacterial population density was increased by progress of plant growth stage. Population density of soybean sprout rotting bacteria on soybean leaves was $0~10^3CFU/cm^2$. Population density of soybean sprouts rotting bacteria was related to cultivating area, but not related to plant growth stage. Cultivar and population density of soybean sprout rotting bacteria were less corelated, and varied by plant growth stages and plant parts. Erwina cypripedii, E. carotovora subsp. carotovora, Xanthomonas campestris pv. glycines, Staphylococcus sp., and Micrococcus sp. were identified as pathogenic bacteria causing soybean sprout rot. In generally population density of E. cypripedii, E. carotovora subsp. carotovora, Micrococcus sp., and X. campestris pv. glycines were high.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1232-1246
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• 2021

Recently, the cattle genome sequence has been completed, followed by developing a commercial single nucleotide polymorphism (SNP) chip panel in the animal genome industry. In order to increase statistical power for detecting quantitative trait locus (QTL), a number of animals should be genotyped. However, a high-density chip for many animals would be increasing the genotyping cost. Therefore, statistical inference of genotype imputation (low-density chip to high-density) will be useful in the animal industry. The purpose of this study is to investigate the effect of the reference population size and marker density on the imputation accuracy and to suggest the appropriate number of reference population sets for the imputation in Hanwoo cattle. A total of 3,821 Hanwoo cattle were divided into reference and validation populations. The reference sets consisted of 50k (38,916) marker data and different population sizes (500, 1,000, 1,500, 2,000, and 3,600). The validation sets consisted of four validation sets (Total 889) and the different marker density (5k [5,000], 10k [10,000], and 15k [15,000]). The accuracy of imputation was calculated by direct comparison of the true genotype and the imputed genotype. In conclusion, when the lowest marker density (5k) was used in the validation set, according to the reference population size, the imputation accuracy was 0.793 to 0.929. On the other hand, when the highest marker density (15k), according to the reference population size, the imputation accuracy was 0.904 to 0.967. Moreover, the reference population size should be more than 1,000 to obtain at least 88% imputation accuracy in Hanwoo cattle.

• Journal of the Korean Geographical Society
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• v.38
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• pp.61-74
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• 1988

Changing patterns of population densities in urban centers are different between Western countries and non-Western countries. Although Seoul is located in a non-Western country, the result of this study shows that its pattern of population density falls into the category of Western cities. Through the examination of three population density gradient models, it is clear that no model can precisely explain the population distribution of Seoul over time. Some of the models partly indicate the actual population distrisbution. The Clark model is appropriate to denote population distribution in the center of Seoul at an early stage in development. The Sherratt model cannot adequately explain the population distribution of Seoul.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.929-934
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• 2000

Optimum stand density of alfalfa (Medicago sativa L.) varies with locations and climates. Stand density is one of the factors that determines herbage yield, forage quality and persistence of alfalfa. As establishment costs increase, the question arises whether present population densities are optimum for obtaining maximum herbage yield and forage quality. The objectives of this study were: 1) to determine the optimum plant density for highest herbage yield and forage quality for the dehydrated alfalfa industry under Edmontons climatic conditions in Alberta, Canada; 2) to compare herbage yield and forage quality of the cultivars 'Algonquin' and 'Vernal' grown at a range of stand densities. Alfalfa seedlings of both cultivars were either transplanted at spacings of 6, 10, 15 and 25 cm or direct seeded at the 4.5 cm plant spacings, providing population densities of 494, 278, 100, 45 and $16plants/m^2$. The experimental design was a randomized complete block with a split-plot arrangement having three replicates; the main plots consisted of two alfalfa cultivars Algonquin and Vernal, and the sub-plots were the five population densities. The cultivar Vernal had significantly higher annual yield than did the cultivar Algonquin. There was no significant effect of plant density on herbage yield. There was no difference in crude protein (CP) between the two cultivars. At the first cut, there was a significant quadratic effect of plant density on CP content and the greatest CP occurred at the 100 plants/m2 density. Crude protein was not affected by plant density at the second cut. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) were not affected by plant density. The cultivar Algonquin usually had a lower ADF and NDF than cultivar Vernal. In conclusion, high population densities ($278plants/m^2$ or more) of alfalfa did not improve herbage yield and forage quality compared with low plant population densities ($100plants/m^2$ or less) of alfalfa.

• ALGAE
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• v.24 no.1
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• pp.31-38
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• 2009

The brown algae padina concrescens is widely distributed in the northwestern Pacific Mexico. We described the population of P. concrescens based on population parameters such as cover, density and size structure and reproduc-tion at two levels tide at the intertidal area in the southwestern Baja. California Peninsula. Monthly visits from January to December 2003 were done. Both cover and density were measured in situ by quadrants method. Samples were collected to obtain size structure and percentage of reproductive fronds. Our results show there is sparial vari-ation in the population structure more than temporal. Thus, cover and density peak were at different months ineach tide level studied, the lower tide level shows the high values in cover as well as density. The frond develop-ment was observed in height/width ratio this relation was consistent only in the low tidal zone. Size class distribu-tion has consistently small size plants in both tide levels.Reproduction was seasonal in the tide channel but in both tide levels all the reproductive plants were tetrasporophyte. Our results suggest that this population is pseudopere-nial and it strongly as a consequence of the intense competition in the intertidal zone.

• Animal cells and systems
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• v.7 no.2
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• pp.127-132
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• 2003

Effects of genotype, settlement density and irradiane on the growth, mortality and population structure of Fucus serratus germlings were examined in the laboratory. The growth of F. serratus germlings was influenced by genotype of parent plants, which is likely to occur by microclimatic differentiation of substrata. The growth of germlings were greater at lower densities than higher densities indicating that intraspecific competition between germlings occurred within three weeks. Also, the growth of F. serratus germlings was better at $120\mumol\;m^-2/s^-1$ than at $60\mumol\;m^-2/s^-1$. However, mortality of germlings was determined by settlement density rather than irradiance. In population structure, skewness was increased at low irradiance and high density indicating that population structure could be changed by intraspecific competition. Thus, it is concluded that genotypic differentiation of F. serratus germlings occurred in a microgeographic scale, and the experimental density and irradiance level affected the growth of germlings.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.273-276
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• 2008

As the rapid and various changing of social aspects, the structures are getting bigger, higher and more complex. The importance of evacuation is on the rise as increased using frequency of multiplex sale facility and it's high population density. According to the result of a survey with 4 domestic wholesales mart's population density, the average and maximum was 0.41(人/$m^2$) and 0.46(人/$m^2$). considering evacuation dangerousness, the maximum value will be suitable for computation of evacuation capacity and this will be submitted as a basic data for computation of evacuation capacity.

• Journal of the Korean Chemical Society
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• v.14 no.1
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• pp.5-12
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• 1970

River water and industrial waste water in Seoul were studied by means of chemical oxygen demand(COD) as an indicator for water pollution, from August 1967 to July 1968. Rivers flowing through residential and industrial areas are badly contaminated and COD of water in Han River increases as it progresses to downstream. Seasonal variation of COD showed that higher value of COD was observed in spring and lower in autumn. It is clear that the seasonal variation of COD is influenced by the precipitation. Close relationship was found between COD and population density. The lowest COD curve obtained by plotting COD values against population density and show that the curve slopes upward. The discontinuation of the curve was shown at the population density of 14,000/km$^2$; an increase in COD was acute over the population density of 14,000/km$^2$.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.173-187
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• 2023

In an era of population decline, depopulated regions facing challenges in attracting inbound population migration must enhance urban vitality through the attraction of living populations. This study focuses on Busan, a city experiencing population decline, comparing the spatiotemporal distribution characteristics of registered residents and living populations in various administrative districts (Eup-Myeon-Dong) using mobile communication big data. Administrative districts are typified based on population change patterns, and regional characteristics are analyzed using indicators related to urban decline and vitality. Spatiotemporal distribution analysis reveals generally similar density patterns between registered residents and living populations; however, a distinctive feature is observed in the city center areas where the density of registered residents is low, while the density of living populations is high. Divergent trends in spatial patterns of change between registered residents and living populations show clusters of registered population decline in low-density areas and clusters of living population decline in high-density areas. Areas adjacent to declining living populations exhibit large clusters of population changes, indicating a spillover effect from high-density to neighboring areas. Typification results reveal that, even in areas with a decline in registered residents, there is active population influx due to commuting or visiting. These areas sustain an increase in the number of businesses, confirming the presence of industrial and economic growth. However, approximately 47% of administrative districts in Busan are experiencing a decline in both registered residents and living populations, indicating ongoing regional decline. Urgent measures are needed for enhancing urban vitality. The study emphasizes the necessity of utilizing living population data as an urban planning indicator, considering the increasing limit distance of urban activities and growing interregional interaction due to advancements in transportation and communication.