• Title/Summary/Keyword: Spatial autocorrelation

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GEO-LINEAMENT CHARACTERIZATION USING WAVELET APPROACH: A CASE STUDY IN THE UISEUNG CALDERA REGION

  • Kim, Mi-Kyung;Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.243-246
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    • 2006
  • Wavelet approach is regarded as a useful methodology for geo-environment analysis with respect to spatial objects with periodicity and spatial pattern, compared to autocorrelation analysis, Fourier analysis, variogram analysis and so on. However, there are a few case studies for geo-lineament characterization with the actual geo-based information such as remotely sensed imagery and DEM. In this study, wavelet approach in the Uiseung caldera region are carried out to delineate characterization for geolineament spatial pattern. There are high possibilities of the development of radial lineaments from the centre of round crater due to the eruption of a volcano and the subsidence of a crater. We have grasped the directionality of the whole linear structures of the caldera via rose diagram, and then performed wavelet analysis on the profiles of orthogonal directions for main directions of the lineaments. The result of this study is likely to be used as a fundamental data in order to grasp the outline of caldera structure prior to the close estimation

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Genetic Diversity and Spatial Structure of Symplocarpus renifolius on Mt. Cheonma, Korea

  • Jeong, Ji-Hee;Park, Yu-Jin;Kim, Zin-Suh
    • Korean Journal of Plant Resources
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    • v.20 no.6
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    • pp.530-539
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    • 2007
  • Genetic variation and structure of 9 subpopulations of Symplocarpus renifolius Schott ex Tzvelev on Mt. Cheonma, in Korea, were determined via starch-gel electrophoresis. The genetic diversity at 10 loci for 8 isozymes ($P_{99}=66%,\;A=2.26,\;H_o=0.212,\;H_e=0.230$) was found to be considerably higher than that seen in other long-lived perennial plants. On the whole, the genotype frequencies were in accordance with Hardy-Weinberg expectations. Approximately 5%($\theta=0.049$) of the total variability was among subpopulations. The high levels of observed genetic diversity in S. renifolius were attributed to a universal outcrossing system and other specific factors like differences in age classes and widely scattered individuals around the main distribution. Heterozygosity was highest at a mid-range of elevation($450m{\sim}600m$). The lowest heterozygosity at lower elevation was attributed to the possible origin of seeds transported by water from upstream regions during the monsoon season. Spatial structure in a subpopulation evidenced a strong autocorrelation between closer individuals within $3{\sim}4m$ of distance. This was assumed to be attributable to the restricted seed dispersal characteristics of S. renifolius. In accordance with the findings generated in this study, some implications regarding the conservation of S. renifolius at the Mt. Cheonma were also presented.

Analysis of Functional Autocorrelation and Development of Functional Econometric Model through Urban Interactions - Focusing on Economic Growth of Small and Medium Sized Cities - (도시 상호작용에 따른 기능적 자기상관분석 및 기능계량경제모형 개발 - 중소도시의 경제성장을 중심으로 -)

  • Kim, Dohyeong;Woo, Myungje
    • Journal of Korea Planning Association
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    • v.54 no.3
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    • pp.63-74
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    • 2019
  • Korean government has implemented policies to strengthen the competitiveness of small and medium sized cities. However, since it is often difficult to enhance the competitiveness through individual projects, many local governments in metropolitan areas are working together to pursue local growth. On the other hand, small and medium sized cities that are not included in metropolitan areas due to their spatial limitations have difficulties in implementing effective growth policies. Given this background, the purpose of this study is to identify the functional correlation based on urban interactions and develop functional econometric model for the economic growth of small and medium sized cities. This study uses spatial econometrics models and functional weight matrix to identify the effects of functional networks on small and medium sized cities. The results show the effect of functional networks on the growth of small and medium sized cities and provide policy implications for regional spatial planning that addresses effective management of small and medium sized cities.

Genetic Diversity and Spatial Genetic Structure of Berchemia racemosa var. magna in Anmyeon Island (안면도 먹넌출 집단의 유전다양성과 공간적 유전구조)

  • Song, Jeong-Ho;Lim, Hyo-In;Jang, Kyeong-Hwan;Hong, Kyung-Nak;Han, Jingyu
    • Horticultural Science & Technology
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    • v.32 no.1
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    • pp.84-90
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    • 2014
  • Berchemia racemosa var. magna is only found in Anmyeon Island of South Korea. Genetic diversity and the spatial genetic structure of B. racemosa var. magna in Anmyeon Island were studied by I-SSR marker system. Fifty I-SSR amplicons were produced from 8 selected primers. We used 13 polymorphic markers to analyze the genetic structure. Distribution of 39 individuals in the study plot($90m{\times}70m$) showed aggregate pattern (aggregation index = 0.706). Total 21 genets were observed from 39 individuals through I-SSR genotyping. Proportion of distinguishable genotype (G/N), genotype diversity (D) and genotype evenness (E) were 53.8%, 0.966 and 0.946, respectively. In spite of the small number and the narrow distribution, Shannon's diversity index (I = 0.598) was relatively high as compared with those of the other plant species. For ex situ genetic conservation of B. racemosa var. magna, the sampling strategy based on spatial autocorrelation using Tanimoto distance is efficient at choosing the conserved individuals with a 6 meter interval between individual trees.

Analysis of Roadkill Hotspot According to the Spatial Clustering Methods (공간 군집지역 탐색방법에 따른 로드킬 다발구간 분석)

  • Song, Euigeun;Seo, Hyunjin;Kim, Kyungmin;Woo, Donggul;Park, Taejin;Choi, Taeyoung
    • Journal of Environmental Impact Assessment
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    • v.28 no.6
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    • pp.580-591
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    • 2019
  • This study analyzed roadkill hotspots in Yeongju, Mungyeong-si Andong-si and Cheongsong-gun to compare the method of searching the area of the spatial cluster for selecting the roadkill hotspots. The local spatial autocorrelation index Getis-Ord Gi* statistics were calculated by different units of analysis, drawing hotspot areas of 9% from 300 m and 14% from 1 km on the basis of the total road area. The rating of Z-score in the 1km hotspot area showed the highest Z-score in the 28th National Road section on the border between Yecheon-gun and Yeongj-si. The kernel density method performed general kernel density estimation and network kernel density estimation analysis, both of which made it easier to visualize roadkill hotspots than district unit analysis, but there were limitations that it was difficult to determine statistically significant priority. As a result, local hotspot areas were found to be different according to the cluster analysis method, and areas that are in common need of reduction measures were found to be the hotspot of 28th National Road through Yeongju-si and Yecheon-gun. It is deemed that the results of this study can be used as basic data when identifying roadkill hotspots and establishing measures to reduce roadkill.

Analysis of Spatial Characteristics of Vacant Houses using Geographic Weighted Regression Model - Focus on Busan Metropolitan City - (지리가중회귀모델을 적용한 빈집 발생의 공간적 특성 분석 - 부산광역시를 대상으로 -)

  • KIM, Ji-Yun;KIM, Ho-Yong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.1
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    • pp.68-79
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    • 2021
  • The recent occurrence of vacant houses in urban areas is a remarkable social problem. One of the physical declines, the occurrence of vacant houses, accelerates various social and economic declines, such as a decline in population and a slump in the commercial district. Vacant houses have regional characteristics and spatial influence, and it is necessary to approach them locally in order to grasp the exact status of vacant houses. Therefore, in this study, the effect of urban decline on the occurrence of vacant homes was examined by region using global Moran's I and Geographic Weighted Regression(GWR) model. As a result of the analysis, there were spatial autocorrelation and heterogeneity in the occurrence of vacant houses in each eup·myeon·dong, Busan metropolitan city. In addition, there is a difference in the influence of each variable of urban decline on the occurrence of vacant houses, and even the same variable of urban decline has different effects on the occurrence of vacant houses in different regions. Therefore, it is expected that a more efficient vacant home management plan can be presented if the GWR model is used to analyze the coefficient values differentiated by region and categorize the occurrence of vacant houses.

Prediction of Spatial Distribution Trends of Heavy Metals in Abandoned Gangwon Mine Site by Geostatistical Technique (지구통계학적 기법에 의한 강원폐광부지 중금속의 공간적 분포 양상 예측 연구)

  • Kim, Su-Na;Lee, Woo-Kyun;Kim, Jeong-Gyu;Shin, Key-Il;Kwon, Tae-Hyub;Hyun, Seung-Hun;Yang, Jae-E
    • Spatial Information Research
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    • v.20 no.4
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    • pp.17-27
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    • 2012
  • This study was performed to evaluate the spatial distribution of heavy metals using principal component analysis and Ordinary Kriging technique in the Gangwon Mine site. In the soils from the sub soil, the contents of Zn and Ni in the PC1 were gradually dispersed from south to north direction, while the components of Cd and Hg in the PC2 showed an increase significantly from middle-south area in the Gangwon Mine site. According to the cluster analysis, pollutant metals of As and Cu were presented a strong spatial autocorrelation structure in cluster D. The concentration of As was 0.83mg/kg and shown to increase from the south to north direction. The spatial distribution maps of the soil components using geostatistical method might be important in future soil remediation studies and help decision-makers assess the potential health risk affects of the abandoned mining sites.

Estimation of Design Wind Speed for Building Using Spatial Information Analysis (공간정보 분석을 통한 건축물의 설계풍속 산정)

  • Lee, Seong-Yun;Jo, Hyun-Jae;Lee, Hyun-Ki;Choi, Se-Hyu
    • Spatial Information Research
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    • v.23 no.3
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    • pp.79-89
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    • 2015
  • Once the building is higher than certain size, the wind effect plays very important role in structure design. Moreover, this is more important in Korea because dangerous phenomena like typhoons are common. Rational wind resistant design is being magnified considering the global flow and climate changes. This research presented the estimation method of design wind load using spatial information analysis based on 1:5,000 digital map and performed comparative analysis with actual application cases. The wind velocity pressure exposure coefficient and topographic coefficient turned out to be more quantitative and rational when calculated through the proposed method. The time and cost are comparatively low when compared with traditional method which contribute to the economic and rational wind resistant design.

Aanalysis the Structure of Heat Environment in Daegu Using Landsat-8 (Landsat-8을 활용한 대구시 열 환경구조 분석)

  • Kim, Jun Hyun;Choi, Jin Ho
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.4_1
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    • pp.327-333
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    • 2014
  • To improve thermal environments in urban area, the structural characteristic analysis of thermal environments of the certain area should be preceded to analyze and supplement its problems. With Landsat-8, we measured the centrality estimation, the distribution map, and the spatial statistical analysis of Daegu Metropolitan City in January and August, which of data applied in analyzing the structure of thermal environments following to its spatial property. The thermal infrared band of satellite images has been used to analyze the standard normal deviated scores, which extract the centrality, while the cluster map, based upon Local Local Moran's I, has composed for understanding the autocorrelation of local spatial within environment space structure. Understanding the distribution features as well as the pivot center of thermal environments with satellite images provides principle database for updating urban thermal environments' policies and plans; because those are reference materials that should have precedence over for diverse thermal environment policies.

Exploring Spatial Variations and Factors associated with Walking Practice in Korea: An Empirical Study based on Geographically Weighted Regression (지리적 가중회귀모형을 이용한 지역별 걷기실천율의 지역적 변이 및 영향요인 탐색)

  • Kim, Eunjoo;Lee, Yeongseo;Yoon, Ju Young
    • Journal of Korean Academy of Nursing
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    • v.53 no.4
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    • pp.426-438
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    • 2023
  • Purpose: Walking practice is a representative indicator of the level of physical activity of local residents. Although the world health organization addressed reduction in prevalence of insufficient physical activity as a global target, the rate of walking practice in Korea has not improved and there are large regional disparities. Therefore, this study aimed to explore the spatial variations of walking practice and its associated factors in Korea. Methods: A secondary analysis was conducted using Community Health Outcome and Health Determinants Database 1.3 from Korea Centers for Disease Control and Prevention. A total of 229 districts was included in the analysis. We compared the ordinary least squares (OLS) and the geographically weighted regression (GWR) to explore the associated factors of walking practice. MGWR 2.2.1 software was used to explore the spatial distribution of walking practice and modeling the GWR. Results: Walking practice had spatial variations across the country. The results showed that the GWR model had better accommodation of spatial autocorrelation than the OLS model. The GWR results indicated that different predictors of walking practice across regions of Korea. Conclusion: The findings of this study may provide insight to nursing researchers, health professionals, and policy makers in planning health programs to promote walking practices in their respective communities.