• 제목/요약/키워드: moran i

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An Analysis on the Spatial Pattern of Local Safety Level Index Using Spatial Autocorrelation - Focused on Basic Local Governments, Korea (공간적 자기상관을 활용한 지역안전지수의 공간패턴 분석 - 기초지방자치단체를 중심으로)

  • Yi, Mi Sook;Yeo, Kwan Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • 제39권1호
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    • pp.29-40
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    • 2021
  • Risk factors that threaten public safety such as crime, fire, and traffic accidents have spatial characteristics. Since each region has different dangerous environments, it is necessary to analyze the spatial pattern of risk factors for each sector such as traffic accident, fire, crime, and living safety. The purpose of this study is to analyze the spatial distribution pattern of local safety level index, which act as an index that rates the safety level of each sector (traffic accident, fire, crime, living safety, suicide, and infectious disease) for basic local governments across the nation. The following analysis tools were used to analyze the spatial autocorrelation of local safety level index : Global Moran's I, Local Moran's I, and Getis-Ord's G⁎i. The result of the analysis shows that the distribution of safety level on traffic accidents, fire, and suicide tends to be more clustered spatially compared to the safety level on crime, living safety, and infectious disease. As a result of analyzing significant spatial correlations between different regions, it was found that the Seoul metropolitan areas are relatively safe compared to other cities based on the integrated index of local safety. In addition, hot spot analysis using statistical values from Getis-Ord's G⁎i derived three hot spots(Samchuck, Cheongsong-gun, and Gimje) in which safety-vulnerable areas are clustered and 15 cold spots which are clusters of areas with high safety levels. These research findings can be used as basic data when the government is making policies to improve the safety level by identifying the spatial distribution and the spatial pattern in areas with vulnerable safety levels.

Three Species Associations with Spatial Autocorrelation Analysis in Community (군락내 공간적 분석에 의한 세 종간 상관관계)

  • 허만규;허홍욱;김창호
    • The Korean Journal of Ecology
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    • 제23권1호
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    • pp.17-23
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    • 2000
  • The spatial distribution of allelic frequencies was studied in the natural population of three species (Ligustrum obtusiflolium, Alnus japonica, and Pinus densflora). The distributional patterns of the crown-cover centers were compared between two populations in forests. L. obtusifolium and p. densiflora showed a significantly positive spatial autocorrelation as measured by Moran's I. In P densiflora, the genetic similarity was shown by individuals within up to a scale of 18 m distance and this is partly due to combination of pollen dispersal and long distance seed dispersal by wind or men. In L. obtusifolium, population structure in the distribution of allelic frequencies is related to mating systems and is consisted of a scale of 12.5 m intervals. No spatial structuring of allele frequencies was found for polymorphic enzyme loci within a natural population of Alnus japonica. The results also in- dicate that positive associations between L. obtusifolium and P densiflora can occur when both select the same habitat or have the same environmental requirements.

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An Analysis on the Change Factors and the Spatial Pattern of the Housing Market Structure (주택시장의 구조변화요인과 공간적 패턴 분석)

  • Kim, Jung Hee
    • Journal of Korean Society for Geospatial Information Science
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    • 제23권1호
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    • pp.39-45
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    • 2015
  • The housing market is transformed by a variety of socio-economic characteristics, also appeared differently according to regional characteristics. This study aims to draw out the change factors influencing on the housing market structure and to analyze the drawn factors' distribution pattern by area. For this purpose, First, targeting 251 areas in the units of city, county and districts nationwide, this study drew out demographic, socio-economic variables influencing on the housing market structure for 5 years ranging 2005 to 2010. For that, the factor analysis was conducted. Second, this study grasped the change factors of the housing market structure's spatial patterns using the kriging method, a spatial statistical method. Third, this study used the Moran I, one of spatial autocorrelation analysis methods in order to grasp whether the factors had statistically significant concentration or dispersion or showed a random distribution pattern.

Spatial Distribution Pattern of the Populations of Camellia japonica in Busan (부산 사하구 동백나무 집단의 공간적 분포 양상)

  • Kang, Man Ki;Huh, Man Kyu
    • Journal of Life Science
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    • 제24권8호
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    • pp.813-819
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    • 2014
  • The spatial distribution of geographical distances at five natural populations of Camellia japonica in Busan, Korea was studied. The four plots (Mollundae, Gadeok-do, Du-do, and Jwiseum) of C. japonica were uniformly distributed in the forest community and only one plot (Amnam-dong) was aggregately distributed in the forest community. Morisita index is related to the patchiness index showed that the plot $20m{\times}50m$ had an overly steep slope when the area was larger than $20m{\times}20m$, which indicated that the degree of aggregation increased significantly with increasing quadrat sizes, while the patchiness indices did not change from the plot $5m{\times}10m$ to $10m{\times}10m$. The spatial structure was quantified by Moran's I, a coefficient of spatial autocorrelation. Ten of the significant values (76.9%) were positive, indicating similarity among individuals in the first 4 distance classes (80 m), i.e., pairs of individuals with dissimilarity characteristics can separate by more than 100 m.

Analysis on Spatial Pattern Changes of Aging Phenomenon and Relation between Aging Population and Regional Characteristics (고령화 현상의 공간적 패턴 변화와 지역특성과의 관계 분석)

  • Lee, Jimin
    • Journal of Korean Society of Rural Planning
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    • 제22권4호
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    • pp.139-146
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    • 2016
  • Aging phenomenon is an important issue in Korea national policy. This aging phenomenon depends on the social and environmental characteristics of regions. Also aging phenomenon and regional characteristics have spatial dependency. The purpose of this study is to discover the spatial changes in aging population rate and to find local factors of regional aging phenomenon considering spatial autocorrelation. For spatial analysis of ageing phenomenon, local Moran's I and Geographically Weighted Regression (GWR) were applied. As the results, the most significant changes of aging phenomenon appeared between 2000 and 2005, and most of hot-spot regions (aged regions) were distributed in Jullanam-do and Jullabuk-do. The results of GWR (R-square: 0.681) shows that total fertility rate, the number of doctor per 1,000 people and forest area rate have positive relation with aging population rate, but the number of private academy per 1,000 people has negative relation.

Consideration of human disturbance to enhance avian species richness in urban ecosystem (도시생태계 내 조류 종풍부도 증진을 위한 인간영향 및 교란가능성의 반영)

  • Kim, Yoon-Jung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • 제24권5호
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    • pp.25-34
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    • 2021
  • Increase in avian species richness is one of the important issues of urban biodiversity policies, since it can promote diverse ecosystem services such as seed dispersal, education, and pollination. However, though human disturbance can significantly affect avian species richness, there are limited studies on the way to reflect the dynamics of floating population. Therefore, this study analyzed the spatial relationship between avian species richness, floating population, and vegetation cover using telecommunications information to identify the areas that requiring targeted monitoring and restoration action. Bivariate Local Moran's I was applied to identify LISA cluster map that showing representative biotopes, which reflect significant spatial relationship between species richness and population distribution. Edge density and distribution of ndvi were identified for evaluating relative adequacy of selected biotopes to strengthen the robust biodiversity network. This study offers insight to consider human disturbance in spatial context using innovative big data to increase the effectiveness of urban biodiversity measures.

A descriptive spatial analysis of bovine tuberculosis disease risk in 2015 in Gangwon-do, Republic of Korea

  • Kim, Eu-Tteum;Pak, Son-Il
    • Journal of Preventive Veterinary Medicine
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    • 제41권2호
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    • pp.79-83
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    • 2017
  • In this study, we used a choropleth map to explore the spatial variation of the risk of cattle herds being bovine tuberculosis (BTB) positive in Gangwon-do in 2015. The map shows that the risk of being BTB-positive was lower in provinces located in the middle of Gangwon-do (Wonju, Youngwol, Peongchang, and Kangneung) than in other provinces. In addition, one province located in the north (Goseong) had a low risk of BTB. The estimate for the intercept of the spatial lag model was 0.66, and the spatial autocorrelation coefficient (lambda) was 0.20 (Table 1). The Moran's I was 0.33 with p-value of 0.02. In 2015, provinces located in the North West (Hwacheon) and East (Donghae) of Gangwon-do had a higher BTB risk. We identified some specific provinces at low BTB-positive risk, information that may prove useful for control of BTB in the study area.

A Study on Scale Effects of the MAUP According to the Degree of Spatial Autocorrelation - Focused on LBSNS Data - (공간적 자기상관성의 정도에 따른 MAUP에서의 스케일 효과 연구 - LBSNS 데이터를 중심으로 -)

  • Lee, Young Min;Kwon, Pil;Yu, Ki Yun;Huh, Yong
    • Journal of Korean Society for Geospatial Information Science
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    • 제24권1호
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    • pp.25-33
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    • 2016
  • In order to visualize point based Location-Based Social Network Services(LBSNS) data on multi-scaled tile map effectively, it is necessary to apply tile-based clustering method. Then determinating reasonable numbers and size of tiles is required. However, there is no such criteria and the numbers and size of tiles are modified based on data type and the purpose of analysis. In other words, researchers' subjectivity is always involved in this type of study. This is when Modifiable Areal Unit Problem(MAUP) occurs, that affects the results of analysis. Among LBSNS, geotagged Twitter data were chosen to find the influence of MAUP in scale effects perspective. For this purpose, the degree of spatial autocorrelation using spatial error model was altered, and change of distributions was analyzed using Morna's I. As a result, positive spatial autocorrelation showed in the original data and the spatial autocorrelation was decreased as the value of spatial autoregressive coefficient was increasing. Therefore, the intensity of the spatial autocorrelation of Twitter data was adjusted to five levels, and for each level, nine different size of grid was created. For each level and different grid sizes, Moran's I was calculated. It was found that the spatial autocorrelation was increased when the aggregation level was being increased and decreased in a certainpoint. Another tendency was found that the scale effect of MAUP was decreased when the spatial autocorrelation was high.

Analysis of Pattern Change of Real Transaction Price of Apartment in Seoul (서울시 아파트 실거래가의 변화패턴 분석)

  • Kim, Jung Hee
    • Journal of Korean Society for Geospatial Information Science
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    • 제22권1호
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    • pp.63-70
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    • 2014
  • This study is to analyze impact of geography and timing on the real transactions prices of apartment complexes in Seoul using data provided by the Ministry of Land, Infrastructure and Transport. The average real transactions and location data of apartment complex was combined into the GIS data. First, the pattern of apartment real transaction price change by period and by area was analyzed by kriging, the one of the spatial interpolation technique. Second, to analyze the pattern of apartment market price change by administrative district(administrative 'Dong' unit), the average of market price per unit area was calculated and converted to Moran I value, which was used to analyze the clustering level of the real transaction price. Through the analysis, spatial-temporal distribution pattern can be found and the type of change can be forecasted. Therefore, this study can be referred as of the base data research for the housing or local policies. Also, the regional unbalanced apartment price can be presented by analyzing the vertical pattern of the change in the time series and the horizontal pattern of the change based on GIS.

Study on Selection of Optimized Segmentation Parameters and Analysis of Classification Accuracy for Object-oriented Classification (객체 기반 영상 분류에서 최적 가중치 선정과 정확도 분석 연구)

  • Lee, Jung-Bin;Eo, Yang-Dam;Heo, Joon
    • Korean Journal of Remote Sensing
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    • 제23권6호
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    • pp.521-528
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    • 2007
  • The overall objective of this research was to investigate various combination of segmentation parameters and to improve classification accuracy of object-oriented classification. This research presents a method for evaluation of segmentation parameters by calculating Moran's I and Intrasegment Variance. This research used Landsat-7/ETM image of $11{\times}14$ Km developed area in Ansung, Korea. Segmented images are generated by 75 combinations of parameter. Selecting 7 combinations of high, middle and low grade expected classification accuracy was based on calculated Moran's I and Intrasegment Variance. Selected segmentation images are classified 4 classes and analyzed classification accuracy according to method of objected-oriented classification. The research result proved that classification accuracy is related to segmentation parameters. The case of high grade of expected classification accuracy showed more than 85% overall accuracy. On the other hand, low ado showed around 50% overall accuracy.