• 제목/요약/키워드: Population Density

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콩 꼬투리에서 서식하는 세균 및 콩나물 부패균의 밀도 변화 (Population Density Changes of Bacteria Causing Soybean Sprout Rot on Soybean Pods)

  • 이은정;한광섭;심명용;최재을
    • 식물병과 농업
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    • 제5권1호
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    • pp.41-45
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    • 1999
  • Bacterial population densities on soybean pods from Chungnam province ranges 105~106 CFU/$\textrm{cm}^2$, whereas those of bacteria causing sprout rot ranged 0~103 CFU/$\textrm{cm}^2$. Erwinia chrysanthemi, Xanthomonas campestris pv. glycines, Staphylococcus sp., and Micrococcus sp. were identified as pathogenic bacteria causing soybean sprout rot. The population density of X. campestris pv. glycines was higher than those of other bacteria.

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A Comparative Study on the Spatial Statistical Models for the Estimation of Population Distribution

  • Oh, Doo-Ri;Hwang, Chul Sue
    • 한국측량학회지
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    • 제33권3호
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    • pp.145-153
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    • 2015
  • This study aims to accurately estimate population distribution more specifically than administrative unites using a RK (Regression-Kriging) model. The RK model is the areal interpolation technique that involves linear regression and the Kriging model. In order to estimate a population’s distribution using a sample region, four different models were used, namely; a regression model, RK model, OK (Ordinary Kriging) model and CK (Co-Kriging) model. The results were then compared with each other. Evaluation of the accuracy and validity of evaluation analysis results were the basis RMSE (Root Mean Square Error), MAE (Mean Absolute Error), G statistic and correlation coefficient (ρ). In the sample regions, every statistic value of the RK model showed better results than other models. The results of this comparative study will be useful to estimate a population distribution of the metropolitan areas with high population density

개발도상국들의 인구정책에 관한 비교연구 -출산조절정책을 중심으로- (A Comparative Study on Population Policies in Developing Countries)

  • 안계춘
    • 한국인구학
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    • 제9권1호
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    • pp.54-68
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    • 1986
  • This study was designed to make a comparative analysis of fertility control policies in developing countries selected from Asia and Latin America. Considering the size and the density of population, the history of the fertility control policy, and the availability of references, eight countries were chosen among Asian developing countries that have adopted the fertility control as an official policy. All of nine countries in Latin America that have adopted family planning as an official policy were included in this study. An attempt was made to formulate an analytical framework to be used for a comparative analysis of fertility control policies. It can be represented by a continuum which consists of individual approaches and structural approaches to fertility control at both extremes. It represents fairly well the controversies between those who advocate family planning and those who advocate measures beyond family planning, but assumes that the two sides of the controversy form a continuum of approaches to fertility control. Various fertility control policies of each country were placed along this continuum and analyzed. The results of the analysis can be summarized as follows: (a) Those countries that have higher population pressure in terms of either the size of population or the population density tend to adopt fertility control policies earlier in time. (b) Those countries that have higher population pressure in terms of either the size of population or the population density tend to adopt more comprehensive measures along the continuum of fertility control policies. (c) Those countries that adopted more comprehensive measures along the continuum seem to have succeeded in reducing their level of fertility more effectively. (d) Developing countries in Asia tend to adopt more comprehensive measures to control fertility than those in Latin American countries. (e) The reduction of fertility in developing countries seems to be associated with both the fertility control policies and the level of socioeconomic development.

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Responses of weed community and soil biota to cessation of fertilization

  • Eo, Jin-U
    • Journal of Ecology and Environment
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    • 제33권4호
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    • pp.317-323
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    • 2010
  • Nutrient availability is a critical component of agroecosystems, and is relevant to both above- and below- ground interactions. The principal objective of this study was to determine how the cessation of fertilization affects the communities of weeds and soil organisms in a corn/wheat field. Changes in dominant weed species, substrate-induced respiration, and the population density of nematodes and microarthropods were evaluated. Microbial substrate-induced respiration (SIR) and the population density of microarthropods decreased following the cessation of fertilization and were partly correlated with the aboveground weed biomass. The cessation of organic fertilizer application but continuing application of inorganic fertilizer reduced the population density of nematodes. In response to the cessation of fertilization, weed communities were dominated by species with little dependency on fertilization. Amaranthus retroflexus was identified as the most dominant species in the corn field; however, it was replaced by Digitaria ciliaris after the cessation of fertilization. In the wheat field, the cessation of fertilization led to a rapid reduction in the biomass of most weeds, except for Vicia angustifolia, supposedly as the result of symbiotic nitrogen fixation. Additionally, the fact that weed biomass was partially correlated with SIR or the population density of microarthropods may reflect a mutual feedback between soil organisms and weeds. The results indicate that the cessation of fertilization alters communities of weeds and soil organisms through changes in weed biomass and interactions with symbiotic microorganisms.

남산과 광릉의 토양 미소절지동물에 관한 연구 (Soil Microarthropods Fauna at the Namsan and Kwangreung)

  • 박홍현;정철의;이준호;이범영
    • 한국토양동물학회지
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    • 제1권1호
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    • pp.37-47
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    • 1996
  • This research was carried out to investigate soil mictoarthropods fauna in Namsan and Kwangreung which were considered to receive different degreeds of environmental pressures. In basic environmental data, Namsan where under rather accelerated acidification by air contamination and acidic rain showed low pH, tardy decomposition and turnover rate. Population density of soil microarthropods was high in Kwangreung 17,169.8/\ulcorner\ulcorner(coniferous forests), 17,892.6/$\textrm{m}^2$(deciduous forests) than in Namsan, 12,143.8/$\textrm{m}^2$ (coniferous forests), 14,216$\textrm{m}^2$(deciduous forests). Biomass of soil microarthropods was 2,020.219mg/$\textrm{m}^2$ at coniferous forests and 4,270.172mg/$\textrm{m}^2$ at deciduous forests in Namsan, and 3,287.326mg/$\textrm{m}^2$ at coniferous forests and 4326.1mg/$\textrm{m}^2$ at deciduous forests in Kwangreung. Population density constantly showed high in spring, and seasonal fluctuations were correlated with seasonal precipitation. As far as vertical distribution is concerned, population density was concentrated in litter layer as 70% while 30% are in soil layer and also decreased with increasing depth.

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저개발 국가의 정보화 수준에 관한 분석과 원조정책 상 시사점 (An Empirical Study on Variations in ICT Development Level and ODA Policies)

  • 장종문;성태응;배국진;윤충한
    • 기술혁신학회지
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    • 제15권2호
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    • pp.323-344
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    • 2012
  • 본고에서는 정보격차문제가 일련의 정책적 처방과 함께 단기간에도 개선될 수 있다는 가정을 기초로 정보인프라가 정보화수준에 미치는 영향을 실증적으로 검증하는데 초점을 두었다. 특히 인프라투자의 비용과 편익의 크기를 결정짓는 인구밀도라는 대리변수를 사용하여 규범적으로 정보격차문제에서 가장 이슈가 되는 지역이자 전반적인 정보인프라 구축 정도가 낮아 통계적으로 그 영향을 정확하게 측정하기 어려운 아프리카지역의 정보격차 결정요인을 실증분석하였다. 아프리카 각국의 패널데이터를 사용한 실증분석결과는 인구밀도가 높을수록 높은 정보화 수준을 보인다는 기본가정과 통계적으로 부합하는 결과를 보여주었다. 다시 말해 아프리카지역의 정보격차는 정보인프라투자의 편익에 의존하여 나타나고 있으며, 이는 소득수준이 낮은 지역에서 정보인프라의 부족이 정보격차의 결정요인으로 작용하고 있음을 시사한다. 결론적으로 인구밀도는 ICT분야의 대 아프리카 경제협력과 ODA정책의 효율성을 높이기 위해 필요한 투자대상 혹은 수원국 선정에 중요한 환경요인으로 고려될 필요가 있다.

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서부 호주 밀 재배지역의 흰개미(Drepanotermes tamminensis (Hill)) 서식 밀도 조사 (Quantification of Population of an Australian Termite, Drepanotermes tamminensis(Hill), within a Western Australian Wheatbelt)

  • 박현철
    • 한국토양동물학회지
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    • 제9권1_2호
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    • pp.16-23
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    • 2004
  • 본 연구는 서부 호주의 Durokkopin 자연 보호 구역에 서식하고 있는 흰개미의 개미집과 서식밀도를 조사하기 위해 수행되었다. 조사결과 Woodland에서의 흰개미 집의 분포와 서식밀도가 Shrubland보다 월등히 높았으며, 일부 흰개미집의 경우 조사기간인 14개월 동안 크기가 감소한 것으로 조사되었으나, 일반적으로 조사기간 중 흰개미 집의 크기 변화는 거의 없었으며, 계급별 구성비율 또한 거의 변화가 없는 것으로 조사되었다. 그러나, 흰개미 개체수는 개미집이 작을수록 증가율이 높은 것으로 조사되었다. 본 연구결과를 토대로 종합해 보면, 두 조사지역 중 Wooldland가 Shurubland보다 공시 흰개미인 Drepanotermes tomminensis (Hill)에 보다 나은 서식처를 제공하는 것으로 사료된다.

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쌀바구미 개체군(딱정벌레목: 바구미과)의 행렬모형의 일반화와 그의 적용 가능성 (A Generalization of the Matrix Model of Rice Weevil Population (Coeloptera: Curculionidae) and its Applicability)

  • 윤태중;류문일;조혜원
    • 한국응용곤충학회지
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    • 제36권3호
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    • pp.215-223
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    • 1997
  • 온일도(Degree day)를 시간단위로한 쌀바구미의 행렬모형을 작성하였다. 기본행렬모형에서 측정된 계차증가율은 2.155/100DD였으며, 성충밀도는 지수함수적으로 증가하였다. 종내경쟁을 도입한 행렬모형에서 성충밀도는 수렴진동의 형태를 보였으며 69.300일도경에서 530으로 안정되었다. 주어진 실험조건에서 실험개체군의 밀도변동 모형에서 예측되는 것과 유사하였다. 그러나 초기최고밀도와 밀도변동추이에서 양자간에 차이를 보였다. 이는 주로 실험 개체군의 경우 자원의 일정성이 유지되지 않았던 데에서 유기된 결과로 생각된다.

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인구학적 요인 및 응급의료시스템 요인에 따른 119구급 서비스 이송 분석 연구 (Analysis of 119 emergency medical service patient transfer according to demographic and emergency medical system factors)

  • 김민희;문준동
    • 한국응급구조학회지
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    • 제28권1호
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    • pp.63-76
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    • 2024
  • Purpose: To analyze trends related to demography and EMS and to provide supporting data for the appropriate deployment of EMS providers. Methods: In this cross-sectional study, data on patients transported by 119 EMS, demographics, and EMS factors were collected using the Korean Statistical Information Service (KOSIS) and the National Fire Agency annual report from 2017 to 2021. Results: During the study period, the total number of patients and those with severe disorders transported via 119 EMS showed an increasing trend. The total fertility rate and population during the same period tended to decrease, and the population density and number of households increased; however, there was a disparity between regions. The main demographic factors affecting the number of patients transported were population density and total fertility rate, while the main EMS factors were the number of ambulances and provision of emergency medical information services(hospital guidance, pharmacy information, and first aid guidance). Conclusion: From the perspective of EMS providers' force deployment, it is necessary to consider population density, population, number of households, total fertility rate, and number of emergency medical institutions and to strengthen the role of diverting the use of 119 EMS by minor patients by providing emergency medical information.

Bayesian estimation for finite population proportions in multinomial data

  • Kwak, Sang-Gyu;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • 제23권3호
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    • pp.587-593
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    • 2012
  • We study Bayesian estimates for finite population proportions in multinomial problems. To do this, we consider a three-stage hierarchical Bayesian model. For prior, we use Dirichlet density to model each cell probability in each cluster. Our method does not require complicated computation such as Metropolis-Hastings algorithm to draw samples from each density of parameters. We draw samples using Gibbs sampler with grid method. We apply this algorithm to a couple of simulation data under three scenarios and we estimate the finite population proportions using two kinds of approaches We compare results with the point estimates of finite population proportions and their standard deviations. Finally, we check the consistency of computation using differen samples drawn from distinct iterates.