• Title/Summary/Keyword: Population Cluster Change Analysis

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Effect of Climate Factors on Tree-Ring Growth of Larix leptolepis Distributed in Korea (기후인자가 일본잎갈나무의 연륜생장에 미치는 영향 분석)

  • Lim, Jong Hwan;Sung, Joo Han;Chun, Jung Hwa;Shin, Man Yong
    • Journal of Korean Society of Forest Science
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    • v.105 no.1
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    • pp.122-131
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    • 2016
  • This study was conducted to analyze the effect of climatic variables on tree-ring growth of Larix leptolepis distributed in Korea by dendroclimatological method. For this, annual tree-ring growth data of Larix leptolepis collected by the $5^{th}$ National Forest Inventory were first organized to analyze yearly growth patterns of the species. To explain the relationship between tree-ring growth of Larix leptolepis and climatic variables, monthly temperature and precipitation data from 1950 to 2010 were compared with tree-ring growth data for each county. When tree-ring growth data were analyzed through cluster analysis based on similarity of climatic conditions, six clusters were identified. In addition, index chronology of Larix leptolepis for each cluster was produced through cross-dating and standardization procedures. The adequacy of index chronologies was tested using basic statistics such as mean sensitivity, auto correlation, signal to noise ratio, and expressed population signal of annual tree-ring growth. Response function analysis was finally conducted to reveal the relationship between tree-ring growth and climatic variables for each cluster. The results of this study are expected to provide valuable information necessary for estimating local growth characteristics of Larix leptolepis and for predicting changes in tree growth patterns caused by climate change.

Spatio-temporal Evaluation of Air Temperature-Water Quality Elasticity in Tributary Streams According To Climate Change (기후변화에 따른 지류 하천의 시공간적 기온-수질 탄성도 영향 평가)

  • Park, Jaebeom;Kal, Byungseok;Kim, Seongmin
    • Journal of Wetlands Research
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    • v.23 no.4
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    • pp.296-306
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    • 2021
  • Elasticity is a statistical technique that interprets the changing pattern of another variable according to a change in one variable as a quantitative numerical value and provides more information than correlation analysis and is widely used in climate change research. In this study the elasticity was calculated and sensitivity analysis was performed using air temperature and water quality data of the major tributaries of the Nakdong River. In addition the confidence interval for the elasticity was calculated using the T-Test and the validity of the elasticity was examined. The strength of elasticity shows high strength in the order of summer>fall>spring>winter and the direction shows regional characteristics with both negative and positive elasticity. After performing hierarchical cluster analysis on monthly observation data they were classified into 5 clusters and the characteristics of each cluster were visually analyzed using a parallel coordinate graph. The direction and intensity of the air temperature elasticity show regional characteristics due to the relatively high population density and complex influencing factors such as sewage treatment plants, small-scale livestock houses and agricultural activities. In the case of TP it shows great regional variability according to the circulation of nutrients in the ecosystem caused by algae growth and death according to temperature changes. Since the air temperature elasticity of the major tributaries of the Nakdong River is over weak and is valid at the significance level of 5%, it was analyzed that there is a change in water quality according to the air temperature change.

A Study on the Dwelling Style by Lifestyle of Middle-aged Married Women (중.장년층 기혼여성의 라이프스타일에 따른 주거양식에 관한 연구)

  • Yoon, Chung-Sook;Park, Ji-Min
    • Journal of the Korean housing association
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    • v.21 no.4
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    • pp.81-88
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    • 2010
  • Recently, house demander's needs has diversified in the increasingly by the drastic change in the social environment, changes in family structure and population, the growing interest of living environment. So in the future, housing supply to respond to a variety of housing needs is absolutely necessary to differentiate. The purpose of this study is to analyze the lifestyle types of middle-aged married women with high purchasing power in the current housing market and propose the dwelling style by housing awareness and needs analysis. To collect the data, LOV survey method was used for 528 residents in Seoul and metropolitan area. The data analysis used SPSS PC 14.0 to find the frequency, chi-square, factor analysis, and cluster analysis. The results of analysis are as follows: First, the lifestyle was segmented into four groups such as Conservative goal-achieving lifestyle, Individual self-developing lifestyle, Positive self-trusting lifestyle, Outgoing trend-seeking lifestyle. Second, largely the dwelling style according to lifestyle types was divided into living room-kids room type and living room-kitchen type. Third, there were different preferences on the each type of housing space and the $\alpha$-space by different clusters.

Analysis of Spatio-Temporal Patterns of Nighttime Light Brightness of Seoul Metropolitan Area using VIIRS-DNB Data (VIIRS-DNB 데이터를 이용한 수도권 야간 빛 강도의 시·공간 패턴 분석)

  • Zhu, Lei;Cho, Daeheon;Lee, Soyoung
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.2
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    • pp.19-37
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    • 2017
  • Visible Infrared Imaging Radiometer Suite Day-Night Band (VIIRS-DNB) data provides a much higher capability for observing and quantifying nighttime light (NTL) brightness in comparison with Defense Meteorological Satellite-Operational Linescan System (DMSP-OLS) data. In South Korea, there is little research on the detection of NTL brightness change using VIIRS-DNB data. This study analyzed the spatial distribution and change of NTL brightness between 2013 and 2016 using VIIRS-DNB data, and detected its spatial relation with possible influencing factors using regression models. The intra-year seasonality of NTL brightness in 2016 was also studied by analyzing the deviation and change clusters, as well as the influencing factors. Results are as follows: 1) The higher value of NTL brightness in 2013 and 2016 is concentrated in Seoul and its surrounding cities, which positively correlated with population density and residential areas, economic land use, and other factors; 2) There is a decreasing trend of NTL brightness from 2013 to 2016, which is obvious in Seoul, with the change of population density and area of industrial buildings as the main influencing factors; 3) Areas in Seoul, and some surrounding areas have high deviation of the intra-year NTL brightness, and 71% of the total areas have their highest NTL brightness in January, February, October, November and December; and 4) Change of NTL brightness between summer and winter demonstrated a significantly positive relation with snow cover area change, and a slightly and significantly negative relation with albedo change.

Temporal variation of wintering bird population and environmental factors in Donglim reservoir (동림저수지에서 월동조류 개체군의 시계열적 변화와 환경 요인)

  • Park, Jongchul;Kim, Woo-Yuel
    • Journal of Wetlands Research
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    • v.19 no.2
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    • pp.223-229
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    • 2017
  • This study analyzed the relationship between environmental factors and the temporal changes of the bird populations during the every January from 1999 to 2016 (18 years) in Donglim reservoir. 'Winter Waterbird Census of Korea' data by National Institute of Biological Resources were used for the bird population data, and principal component analysis and cluster analysis were used to analyze the changes of annual population. The average temperature of January and the average storage rate of the reservoir were used as environmental factors. According to the results of the study, the population changes in the study area can be explained by the increase and decrease of two water bird groups and a mountain bird group. The average temperature of the years when the population of water bird groups increased was more than $1.4^{\circ}C$ in comparison with the year when mountain birds increased. On the other hand, the influence of the water content was not clear. The visiting of Baikal Teal affected by temperature was a factor affecting the other group of water bird and a mountain bird group. The results of this study suggest that the temperature change affects the global spatial distribution of birds and the migration of large population species such as Baikal Teal affects species composition and populations of birds at local scale. Therefore, understanding of environmental changes at large scale and spatial distribution of species and flock contributes to understand the temporal variation of the bird population at regional or local scales.

Analysing the Relationship Between Tree-Ring Growth of Quercus acutissima and Climatic Variables by Dendroclimatological Method (연륜기후학적 방법에 의한 상수리나무의 연륜생장과 기후인자와의 관계분석)

  • Moon, Na Hyun;Sung, Joo Han;Lim, Jong Hwan;Park, Ko Eun;Shin, Man Yong
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.2
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    • pp.93-101
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    • 2015
  • This study was conducted to analyze the relationship between tree-ring growth of Quercus acutissima and climatic variables by dendroclimatological method. Annual tree-ring growth data of Quercus acutissima collected by the $5^{th}$ National Forest Inventory (NFI5) were organized to analyze the spatial distribution of the species growth pattern. To explain the relationship between tree-ring growth of Quercus acutissima and climatic variables, monthly temperature and precipitation data from 1950 to 2010 were compared with tree-ring growth data for each county. When tree-ring growth data were analyzed through cluster analysis based on similarity of climatic conditions, four clusters were identified. In addition, index chronology of Quercus acutissima for each cluster was produced through cross-dating and standardization procedures. The adequacy of index chronologies was tested using basic statistics such as mean sensitivity, auto correlation, signal to noise ratio, and expressed population signal of annual tree-ring growth. Response function analysis was conducted to reveal the relationship between tree-ring growth and climatic variables for each cluster. The results of this study are expected to provide valuable information necessary for estimating local growth characteristics of Quercus acutissima and for predicting changes in tree growth patterns caused by climate change.

Update on polycystic ovary syndrome

  • Kim, Jin Ju
    • Clinical and Experimental Reproductive Medicine
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    • v.48 no.3
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    • pp.194-197
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    • 2021
  • Polycystic ovary syndrome (PCOS) is a common disorder in reproductive-age women. In 2018, an international evidence-based guideline announced recommendations spanning a wide range of issues on the assessment and management of PCOS. From the 166 recommendations, the present study reviews those that are of particular clinical relevance for daily practice and introduces other relevant studies that have been published since the global guideline. The 2018 guideline increased the antral follicle count cutoff for the diagnosis of PCOS from 12 to 20 when using a high-frequency probe. Hirsutism was defined as having a score of ≥4-6 based on a lower percentile of 85%-90% or cluster analysis, which was lower than the traditionally used 95th percentile-based cutoff. The diagnosis of PCOS in adolescents is challenging, and irregular menstruation was defined carefully according to years from menarche. The use of ultrasonography for the diagnosis of PCOS was restricted to those 8 years after menarche. As medication for non-fertility indications, combined oral contraceptives are the first-line drug. Metformin, in addition to lifestyle modifications, should be considered for adult patients with a body mass index ≥25 kg/m2 for the management of weight and metabolic outcomes. An aromatase inhibitor is the recommended first-line medication for ovulation induction, a subsequent individual patient data meta-analysis also reported the same conclusion. Whether the new global guideline will be fully adopted by many specialists and change clinical practice is open to question. Further studies are needed to better understand and manage PCOS patients well.

Spatial Structure and Historical Change of Cemeteries in Seattle, USA (시애틀 공동묘지의 공간적 구조와 역사적 변화 양상)

  • Kim, Chung Ho
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.3
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    • pp.36-45
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    • 2018
  • Cemeteries in the United States are frequently observed near residential areas in cities even though they are spaces for the dead. However, it has not been fully studied when and how cemeteries were formed in the process of urbanization. Thus, this research aimed to investigate the spatial structure and historical change of cemeteries in Seattle due to urbanization, focusing on the contextual relationship between cemeteries and the surroundings according to two time periods: the early formation period of cemeteries in Seattle and the current period. For this, a mixed method was taken in this paper that combined historical analysis based on old references and historic maps with cluster analysis using GIS. In conclusion, the research found that early cemeteries of Seattle in downtown areas were introduced as by-products of urban formation, but the cemeteries in the suburbs were established ahead of urban growth and neighborhood development. In addition, Seattle's cemeteries not only showed a similar locational pattern to Seattle's shopping centers, but also were positively associated with population distribution given the Hot Spot Analysis. In other words, Seattle's cemeteries were originally located in rural areas, but later came to be located in urban areas, sustaining the landscape of American rural cemeteries.

Genetic diversity and geographic differentiation in the endangered Primula farinosa subsp. modesta, a subalpine endemic to Korea (한반도 아고산대 특산·희귀식물 설앵초의 유전적 다양성과 지리적 분화)

  • Chung, Jae-Min;Son, Sung-Won;Kim, Sang-Yong;Park, Gwang-Woo;Kim, Sung-Shik
    • Korean Journal of Plant Taxonomy
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    • v.43 no.3
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    • pp.236-243
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    • 2013
  • Many plant species in subalpine regions are under threat of extinction as a result of climate change. In this study, the genetic diversity and geographic differentiation of three regions and six populations of Primula farinosa subsp. modesta (Bisset & Moore) Pax in Korea were assessed using the ISSR (Inter Simple Sequence Repeat) marker. The average genetic diversity (P = 60.62, SI = 0.299, h = 0.190) was relatively lower than that of other long-lived perennials, even though it is a self-incompatible species. AMOVA analysis showed that 50% of the total genetic diversity was partitioned among regions and Bayesian cluster analysis showed some remarkable geographic trends that were structured into 2 or 3 regions, suggesting limited gene flow among regions. Considering the population fragmentation, low level genetic diversity, and high genetic differentiation, it is essential to establish in situ and ex situ conservation strategies for P. farinosa subsp. modesta.

A Study on the Distributive Equity of Neighborhood Urban Park in Seoul Viewed from Green Welfare (녹색복지 관점에서 서울시 생활권 도시공원의 분배적 형평성 분석)

  • Kim, Yong-Gook
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.3
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    • pp.76-89
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    • 2014
  • The functions of urban park including health related benefit and climate adaptation and mitigation are expanding. However, in-depth research and discourse on the equitable distribution of expanded park function has been limited so far. Following research suggests Green Welfare concept to reflect distributive equity and multifunctionality in the process of urban park policy development and execution. This study developed park welfare indices to analyze disparities of neighborhood urban park(NUP) distribution viewed from green welfare by literature review. The findings analyzed through the Correlation Analysis and Cluster Analysis by SPSS 18.0. The results of the study are as follows. First, green welfare is defined as "to receive equitable benefits and participate in the delivery process of green services which are promoting health and securing safety from climate change risks for every citizen by life cycle regardless of socioeconomic status". Second, NUP per person in Seoul indicate meaningful differences by socioeconomic and environmental status of Seoul administrative districts. Park welfare indices correlated to NUP per person were shown population density(negative), percentage of individuals $aged{\geq}65$(positive), percentage of self-reliance of local finance(positive), flood and air pollution vulnerability by climate change(negative). Third, the cluster analysis identifies three significant clusters that indicate differences of park welfare level. Thus, it was found that NUP in Seoul from a green welfare perspective was provided disproportionately. Future urban park policy in Seoul was required equitable distribution of multifunctionality of park beyond quantitative expansion, and priority consideration should be given to park service consumer.