• 제목/요약/키워드: population distribution

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확률강우분포의 매개변수 및 불확실성 추정을 위한 베이지안 기법의 비교 (Comparison of Bayesian Methods for Estimating Parameters and Uncertainties of Probability Rainfall Distribution)

  • 서영민;박재호;최윤영
    • 한국환경과학회지
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    • 제28권1호
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    • pp.19-35
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    • 2019
  • This study investigates the performance of four Bayesian methods, Random Walk Metropolis (RWM), Hit-And-Run Metropolis (HARM), Adaptive Mixture Metropolis (AMM), and Population Monte Carlo (PMC), for estimating the parameters and uncertainties of probability rainfall distribution, and the results are compared with those of conventional parameter estimation methods; namely, the Method Of Moment (MOM), Maximum Likelihood Method (MLM), and Probability Weighted Method (PWM). As a result, Bayesian methods yield similar or slightly better results in parameter estimations compared with conventional methods. In particular, PMC can reduce parameter uncertainty greatly compared with RWM, HARM, and AMM methods although the Bayesian methods produce similar results in parameter estimations. Overall, the Bayesian methods produce better accuracy for scale parameters compared with the conventional methods and this characteristic improves the accuracy of probability rainfall. Therefore, Bayesian methods can be effective tools for estimating the parameters and uncertainties of probability rainfall distribution in hydrological practices, flood risk assessment, and decision-making support.

수도권 대학정원정책의 수동권 인구분산교과에 관한 연구 (University Enrollment Policy in the Capital Region and Its Impact on Population Dispersal)

  • 임창호;구자훈;안근원
    • 지역연구
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    • 제9권1호
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    • pp.45-63
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    • 1993
  • University enrollment has long been regarded as one of the major factors inducing population concentration in Seoul and the Capital Region of Korea. Consequently, since early 1980's increases in enrollment and new establishments of extention universities beyond the boundary of Seoul, has been promoted, while university enrollment quota in Seoul has been strictly controlled. The degree of actual population dispersal, however, resulting from such a university enrollment policy has not been empirically tested. This paper aims at: First, identifying the trend of population growth and evolution process of the university enrollment policy in the Capital Region; Second, comparing the degree of influence of university enrollment on population concetration factors; Third, measuring actual effect of the enrollment control on population dispersal out of Seoul and the Capital Region. Major findings are as follows: First, only a week correlation between population and university enrollment growth trends was found; Second, the relative degree of influence on population concentration in the Capital Region, were order, in the order of magnitude, the physical amenity factor, the socio-cultural amenity factor, the employment climate factor and the educational factor. Third, and most improtant, based on the comparison of spatial distribution of graduated high schools and current residence of the selected university students, the gap between the two distributions was revealed and the inter-regional student population movement was estimated. The result shows that in Seoul's case about one-half of and in Kyunggi Province's case about one-fifth of university enrollment size, contributes to population concentration into Seoul. Fourth, as to the universities outside of the Capital Region, little effect in the case of universities located within the commuting distance, and a little effect on population dispersal in the case of universities located beyond commuting distance, were found. In sum, it seems clear that university enrollment policy in the Capital Region, especially in Inchon/Kyunggi Province has not been effective on student population dispersal out of Seoul and the Capital Region. Therefore, it is strongly recommended that university enrollment policy be throughly re-examined from its goal to the implementation means.

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참당귀(Angelica gigas Nakai) 개체군의 환경 특성 분석 (A Study on Environment Characteristics of the Angelica gigas Nakai Population)

  • 추병길;지윤의;문병철;이아영;천진미;윤태숙;김호경
    • 한국환경복원기술학회지
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    • 제12권1호
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    • pp.92-100
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    • 2009
  • This study was carried out to investigate vegetation structure and soil properties of Angelica gigas population distributed in Jeombongsan, Bangtaesan, Odaesan, Gyebangsan and Jirisan. From August 2007 until September 2008, 5m${\times}$5m quadrat was established in native area of Angelica gigas in order to record a dominants and coverage, and soil factors at 20 sites. It was found that the altitude in the distributed areas for Angelica gigas population was 710m or more. Angelica gigas population was classified into Parasencio auriculata var. kamtschatical dominant population, Pseudostellaria palibiniana dominant population, Isodon excisus dominant population and typical dominant population. In the site of study, soil pH, electrical conductivity, soil organic matter, available phosphorous, and exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable natrium concentration and total nitrogen were ranged from 5.1~6.2, 0.1~0.79dS/m, 2.21~22.11%, 9.56~37.97mg/kg, 1.85~23.88cmol+/kg, 0.21~1.18cmol+/kg, 1.07~5.09cmol+/kg, 0.04~0.14cmol+/kg and 0.09~1.04% respectively. The Parasencio auriculata var. kamtschatical dominant population was found in area of high altitude and had high slope degree. But Pseudostellaria palibiniana dominant population was found in area of low altitude and low slope degree. Isodon excisus dominant population was found to have higher soil pH and exchangeable potassium concentration than the other dominant population.

북한의 도시화와 인구분포 : 남한과의 비교 (Urbanization and Population Distribution in North Korea : A Comparison to South Korea)

  • 김두섭
    • 한국인구학
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    • 제18권2호
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    • pp.70-97
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    • 1995
  • 이 논문은 지난 반세기동안 북한에서 이루어진 도시화의 추세와 그 특징을 분석하기 위한 것이다. 이를 위해 우선 분단 이후 행정구역변천의 주요 내용을 개괄하였고, 지역별 인구분포를 살펴보았다. 그리고 도시인구의 변화추세와 도시체계의 특징을 경제발전정책과 관련하여 파악하고자 노력하였다. 북한에서는 6.25 전쟁 종료 이후 중공업 위주의 발전정책에 때라 1960년대 말까지 빠른 속도로 도시화가 진행되었으나, 1970년대 초부터 폐쇄적인 경제발전전략이 한계를 드러내면서 도시화의 속도는 현격하게 떨어졌다. 북한의 도시화 과정에 있어서 두드러진 특징은 새로운 도시의 육성전략에 따라 내륙지역의 도시들이 급속히 성장하였고, 중소도시의 인구규모가 꾸준히 증가햐였다는 것이다. 아울러 평양을 비롯한 대도시에서도 도시경계의 확장과 더불어 인구증가가 이루어졌다. 북한의 주요 도시들은 인구규모는 작으나, 외곽에 농업지역을 포함하고 있기 때문에 그 면적은 남한의 대도시들보다 훨씬 더 넓다. 또한 평양이 지니는 사회주의적 종주도시의 성격과 위성도시들의 두드러진 성장도 특징으로 지적될 수 있다. 마지막으로, 이 연구에서는 북한의 이동인구규모와 그 특징, 그리고 통일후에 예상되는 인구이동에 관한 논의도 이루어졌다.

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취약계층을 고려한 미세먼지 쉼터 입지 효율성 평가 (Evaluation of the Location Efficiency of Fine Dust Shelters Considering Vulnerable Population in Seoul)

  • 임재권;이혜경
    • 한국BIM학회 논문집
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    • 제12권4호
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    • pp.104-115
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    • 2022
  • Fine Dust in Korea has been classified as a social disaster since 2019 due to continuous increase in concentration of Particulate Matter 10(PM 10) and PM 2.5. The fine dust issue has negative physical and mental impacts, especially on vulnerable population including children and the elderly. Seoul metropolitan government have installed fine dust shelters since 2019. However, there is a lack of research that evaluates spatiotemporal distribution of these facilities. Therefore, the first aim of this study is to find the relationship between PM levels and dust scattering construction sites, or air pollutant emission sites through in depth spatial analyses. The second purpose is to analyze the spatial distribution of PM shelters in Seoul, and to evaluate the location efficiency of them. Kernel density, krigging, and network analyses were conducted, and floating population was considered instead of census data for this research. The reults of network analysis based on the road system showed that Yangcheon-gu, Songpa-gu, Seongbuk-gu, and Dobong-gu were found to need additional fine dust shelters. Also, the results from analyzing the floating population that includes children and the elderly showed that Songpa-gu, Seodaemun-gu, Gangdong-gu, Seocho-gu, and Dongdaemun-gu need more placements of find dust shelters. The results of this study are expected to provide implications for urban planners to enhance find dust shelter placement in urban areas, and vulnerable population issues would be considered in many ways.

ASSESSING POPULATION BIOEQUIVALENCE IN A $2{\times}2$ CROSSOVER DESIGN WITH CARRYOVER EFFECT IN A BAYESIAN PERSPECTIVE

  • Oh Hyun-Sook
    • Journal of the Korean Statistical Society
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    • 제35권3호
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    • pp.239-250
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    • 2006
  • A $2{\times}2$ crossover design including carryover effect is considered for assessment of population bioequivalence of two drug formulations in a Bayesian framework. In classical analysis, it is complex to deal with the carryover effect since the estimate of the drug effect is biased in the presence of a carryover effect. The proposed method in this article uses uninformative priors and vague proper priors for objectiveness of priors and the posterior probability distribution of the parameters of interest is derived with given priors. The posterior probabilities of the hypotheses for assessing population bioequivalence are evaluated based on a Markov chain Monte Carlo simulation method. An example with real data set is given for illustration.

토양유기물의 분해속도와 Microbial populaiton의 소장에 관한 연구 (On the Decay Rate of Soil Organic Matter and Changes of Soil Microbial populaiton)

  • 김춘민
    • Journal of Plant Biology
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    • 제10권1_2호
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    • pp.21-30
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    • 1967
  • The aim of present study is to elucidate the relationship between decay rate of soil organic matter, and the change of soil microbial population under the oak and pine forest soils in Kwang-nung plantation stand. The results obtained are as follows: 1) The correlation coefficient between decay rate and the soil bacteria is 0.84 and fungi 0.93. 2) The distribution of soil microbial population is higher in both F horizon of the oak forest soil, and F and H horizon of the pine forest soil. However, the number of soil microorganisms decreases with the depth in each forest soil. 3) The population of soil microbes is related to moisture content, total nitrogen, available phosphorus, and exchangeable calcium, except organic carbon in fungi. 4) The soil organic matter has been mainly decomposed by fungi, and the size of its population are governed by the factors such as moisture content, organic carbon, total nitrogen, available phosphorus, and exchangeable calcium.

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Robustness of Predictive Density and Optimal Treatment Allocation to Non-Normal Prior for The Mean

  • Bansal, Ashok K.;Sinha, Pankaj
    • Journal of the Korean Statistical Society
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    • 제22권2호
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    • pp.235-247
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    • 1993
  • The predictive density function of a potential future observation and its first four moments are obtained in this paper to study the effects of a non-normal prior of the unknown mean of a normal population. The derived predictive density function is modified to study changes in utility curves, used to choose the optimum treatment from a given set of treatments, at a given level of stimulus due to slight deviations from normality of the prior distribution. Numerical illustrations are provided to exhibit some effectsl.

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중국 조선족 주거의 공간구성 형태와 그 지역분포에 관한 연구 (A Study on the Chinese-Korean dwelling spatial structure and its distribution in China)

  • 김종영
    • 한국주거학회논문집
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    • 제7권1호
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    • pp.95-103
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    • 1996
  • The purpose of this research are to analyze the Chinese-Korean dwelling spatial structure and distribution of its area as a part of research for Chinese-Korean dwelling and village in China. The study area for this research was chosen three Chinese provinces located in north east part of China where the population of Chinese-Korean dwelling spatical structures and distribution of their area were found using this research.

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인구특성을 고려한 노출평가: 부산지역 고농도 오존일 사례연구 (Ozone Exposure Assessment by Population Characteristics: A Case Study for High Ozone Days in Busan)

  • 황미경;방진희;오인보;김유근
    • 한국환경보건학회지
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    • 제41권2호
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    • pp.71-81
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    • 2015
  • Objectives: Photochemical ozone pollution is associated with increased mortality risk. This study aims to assess the population exposure to ozone according to population characteristics for high ozone days in the Busan metropolitan region (BMR). Methods: The ozone exposure assessment in this study was performed using the WRF-CMAQ simulated ozone concentrations and the population data in the BMR. The settled and daytime population and their activity were considered to conduct the static and dynamic ozone exposure assessment. Results: Applying a static exposure assessment, in case that high ozone occurred throughout Busan area, the highest exposure levels were evaluated in urban neighborhoods. In case of ozone pollution in outer Busan, because sensitive groups have been relatively higher exposure, this case was also evaluated as part of that should not be overlooked. The dynamic exposure was higher than static exposure because the number of population exposed to ozone of high concentration is increased. This approach is important in a regard consider that daytime population distribution when high ozone occur. Conclusion: This study shows the different population exposure according to various ozone distributions for each episode day. Considering demographic characteristic such as population density and activity should be important to understanding the population exposure assessment when ozone pollution occurs.