• Title/Summary/Keyword: Moran I

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Testing Non-Stationary Relationship between the Proportion of Green Areas in Watersheds and Water Quality using Geographically Weighted Regression Model (공간지리 가중회귀모형(GWR)을 이용한 유역 녹지비율과 하천수질의 비균질적 관계 검증)

  • Lee, Sang-Woo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.6
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    • pp.43-51
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    • 2013
  • This study aims to examine the presence of non-stationary relationship between water quality and land use in watersheds. In investigating the relationships between land use and water quality, most previous studies adopted OLS method which is assumed stationarity. However, this approach is difficult to capture the local variation of the relationships. We used 146 sampling data and land cover data of Korean Ministry of Environment to build conventional regressions and GWR models for BOD, TN and TP. Regression model and GWR models of BOD, TN, TP were compared with $R^2$, AICc and Moran's I. The results of comparisons and descriptive statistics of GWR models strongly indicated the presence of Non-Stationarity between water quality and land use.

Test of the Scale Effect of MAUP in Crime Study: Analyses of Sex Crime Using Nation-Wide Data of Eup-Myon-Dong and Si-Gun-Gu (범죄연구에 있어 가변적 공간단위 문제(MAUP)의 스케일효과 검증 : 전국 읍면동과 시군구를 대상으로 한 성범죄 분석)

  • Cheong, Jinseong;Park, Jongha
    • The Journal of the Korea Contents Association
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    • v.15 no.10
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    • pp.150-159
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    • 2015
  • This study attempted to test the scale effect of MAUP, particularly focusing on the spatial autocorrelation of sex crime, correlations among neighborhood structural variables, and causal mechanism leading to sex crime. Analysis results of nation-wide Eup-Myon-Dong and Si-Gun-Gu data discovered that the spatial autocorrelation, correlations among independent variables, and determinant coefficient of multiple regression of Si-Gun-Gu level were generally bigger and stronger than those of Eup-Myon-Dong, which appeared to be due to the averaging effect. Regarding the causal effect to sex crime, two interesting results were found: First, the ratio of non-apartment residency lowered sex crime at both levels contrary to the hypothesis. Second, the ratio of food and lodging increased sex crime only at Eup-Myon-Dong level. These suggested that future research need to perform more detailed analyses dividing data into subsets such as urban vs. rural and/or economically advantaged vs. disadvantaged areas.

An Analysis of Spatial Characteristics of Environmental-Friendly Certified Farms - Focused on Jeollanam-do - (친환경 인증 농경지의 공간적 특성 분석 - 전라남도를 대상으로 -)

  • Park, Yujin;Gu, Jeong-Yoon;Lee, Sang-Woo;An, Kyungjin;Choi, Jinah;Kim, Sangbum;Park, Se-Rin
    • Journal of Korean Society of Rural Planning
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    • v.29 no.3
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    • pp.79-89
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    • 2023
  • As the demand for environmental-friendly agricultural products continues to rise due to increased concerns regarding food safety and ecosystem conservation, it is becoming important to identify regions and spatial locations where environmental-friendly should be intensively established for production integration. This study aims to analyze the spatial distribution of environmental-friendly certified farms in Jeollanam-do, South Korea. Spatial statistical analysis based on Local Moran's I and Getis-Ord Gi* were used to identify spatial cluster characteristics and landscape indices were utilized to analyze spatial patterns of environmental-friendly certified farms. The results indicated that Haenam-gun, Gangjin-gun, Muan-gun, and Jindo-gun were identified as hotspots, while Muan-gun, Goheung-gun, and Jindo-gun exhibited high connectivity. This suggests that environmental-friendly certified farms in Muan-gun and Jindo-gun were clustered and closely connected to one another. Based on the results of the spatial distribution of environmental-friendly certified farms, areas belonging to the hotspot and with high connectivity should be managed as clustered districts to secure the foundation and system of environmental-friendly certified farms. Areas that belong to cold spots and have low connectivity should be preceded by measures to promote conversion to environmental-friendly agriculture. In addition, it is necessary to make it possible to create a large-scale cluster district through a long-term spatial planning strategy to expand the environmental-friendly certified farms. The findings of this study can provide quantitative data on policies and discussions for developing a model for rural spatial planning.

Spatial Association of Population Concentration in Seoul Metropolitan Area (서울대도시권 인구집중의 공간적 연관성 연구)

  • Park, Jane;Chang, Hoon;Kim, Jy So
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3D
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    • pp.391-397
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    • 2008
  • This paper analyzes the spatial patterns of population distribution in Seoul Metropolitan Area in terms of spatial association using spatial statistics and spatial exploratory technique. Our empirical analysis based on global index shows that, in Seoul Metropolitan Area, the population had been distributed with strong positive spatial association over the period of 1980-2005. It implies that the population of each region is affected by the population distribution of adjacent regions. In addition, the analysis using local index was conducted for detecting the local patterns of spatial association, and the result shows that the clusters of population had been moved in the direction of West(Incheon and Bucheon) and South(Anyang and Seongnam) of Seoul where a large scale of lands or towns were developed over the period. These results will be the preliminary data for establishing management and development plans of Seoul Metropolitan Area.

An Empirical Study on the Spatial Effect of Distribution Patterns between Small Business and Social-environmental factors (소상공인 점포의 분포와 환경요인의 공간적 영향관계에 관한 실증연구)

  • YOO, Mu-Sang;CHOI, Don-Jeong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.1
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    • pp.1-18
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    • 2019
  • This research measured and visualized the spatial dependency and the spatial heterogeneity of the small business in Cheonan-si, Asan-si with $100m{\times}100m$ grids based on global and local spatial autocorrelation. First, we confirmed positive spatial autocorrelation of small business in the research area using Moran's I Index, which is ESDA(Exploratory Spatial Data Analysis). And then, through Getis-Ord $GI{\ast}$, one kind of LISA(Local Indicators of Spatial Association), local patterns of spatial autocorrelation were visualized. These verified that Spatial Regression Model is valid for the location factor analysis on small business commercial buildings. Next, GWR(Geographically Weighted Regression) was used to analyze the spatial relations between the distribution of small business, hourly mobile traffic-based floating population, land use attributes index, residence, commercial building, road networks, and the node of traffic networks. Final six variables were applied and the accessibility to bus stops, afternoon time floating population, and evening time floating population were excluded due to multicollinearity. By this, we demonstrated that GWR is statistically improved compared to OLS. We visualized the spatial influence of the individual variables using the regression coefficients and local coefficients of determinant of the six variables. This research applied the measured population information in a practical way. Reflecting the dynamic information of the urban people using the commercial area. It is different from other studies that performed commercial analysis. Finally, this research has a differentiated advantage over the existing commercial area analysis in that it employed hourly changing commercial service population data and it applied spatial statistical models to micro spatial units. This research proposed new framework for the commercial analysis area analysis.

Analysis of Spatial Characteristics of Vacant House in Consideration of the Modifiable Areal Unit Problem (MAUP) - Focused on the Old Downtowns of Busan Metropolitan City - (공간단위 수정가능성 문제(MAUP)를 고려한 빈집 발생지역의 특성 분석 - 부산광역시 원도심 일대를 대상으로 -)

  • SEOL, Yu-Jeong;KIM, Ji-Yun;KIM, Ho-Yong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.25 no.1
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    • pp.120-132
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    • 2022
  • Recently, the rapid increase in vacant houses in urban areas has caused various problems such as worsening urban landscape, causing safety accidents, crime accidents, and hygiene problems. According to the Statistics Korea Future Population Estimation results, the growth rate of Korean population and households is expected to continue to decrease, which is likely to lead to an increase in the occurrence of vacant houses. If the problem caused by the occurrence of vacant houses is neglected, it causes not only a physical decline such as a deterioration of the residential environment but also a social and economic decline. In order to solve this problem, it is necessary to grasp the spatial distribution characteristics of vacant houses at the local level considering the existence of regional characteristics and spatial influence. Therefore, in this study, in order to measure global spatial autocorrelation, the analysis was conducted centering on the old downtown area of Busan, where there are many vacant houses through Moran's I and Geographically Weighted Regression(GWR). In addition, the distribution of vacant houses in different spatial units in Eup_Myeon_Dong and Census was analyzed to evaluate the possibility of Modifiable Areal Unit Problem(MAUP), which differ in the results of spatial analysis as the spatial analysis units change. As a result of the analysis, the occurrence of vacant houses by Eup_Myeon_Dong in the old downtown area of Busan had spatial heterogeneity, and the spatial analysis results of vacant houses were different as the spatial analysis units were different. Accordingly, in order to understand the exact distribution characteristics of vacant house occurrence, spatial dimensions using the GWR model should be considered, and it is suggested that consideration of the MAUP is necessary.

Selection of Entomopathogenic Fungus Isaria javanica FT333 for Dual Control of Thrips and Anthracnose (총채벌레 및 고추탄저병의 동시 방제를 위한 곤충병원성 곰팡이 Isaria javanica FT333 선발)

  • Lee, Moran;Jeong, Hyeju;Kim, Jaeyoon;Kim, Dayeon;Ahn, Seung Ho;Lee, SangYeob;Han, Ji Hee
    • The Korean Journal of Mycology
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    • v.46 no.4
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    • pp.479-490
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    • 2018
  • Red pepper is seriously damaged by thrips (Thrips palmi) and anthracnose caused by Colletotrichum acutatum throughout its development. Because of biotic constraints, producers often depend on chemicals that are expensive and have adverse effects on the environment, operator, and beneficial insects. In addition, resistance is developed because of the repeated use of chemicals. In recent decades, the use of microorganisms in crop protection has become a credible alternative because it is eco-friendly. In this study, we aimed to select isolates with insecticidal and fungicidal activities against the pathogens that cause anthracnose and thrips. We treated T. palmi adults and juveniles with 13 strains of entomopathogenic fungi (isolated from the soil by using the insect-bait method), and 6 strains showed excellent insecticidal activity (70-100%) 5 days after the treatment. The selected isolates were cultured with C. acutatum to screen for the strain with excellent anti-fungal activities, among which an isolate FT333 showed more than 95% control efficacy against C. acutatum in vitro. The isolate was identified as Isaria javanica through its morphological characteristics and phylogenetic analysis of the ITS and ${\beta}-tubulin$ nucleotide sequences. The Isaria javanica FT333 isolate could be used effectively for dual bio-control of thrips and anthracnose during red pepper cultivation.

A Spatial Statistical Method for Exploring Hotspots of House Price Volatility (부동산 가격변동 한스팟 탐색을 위한 공간통계기법)

  • Sohn, Hak-Gi;Park, Key-Ho
    • Journal of the Korean Geographical Society
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    • v.43 no.3
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    • pp.392-411
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    • 2008
  • The purpose of this paper is to develop a method for exploring hotspot patterns of house price volatility where there is a high fluctuation in price and homogeneity of direction of price volatility. These patterns are formed when the majority of householders in an area show an adaptive tendency in their decision making. This paper suggests a method that consists of two analytical parts. The first part uses spatial scan statistics to detect spatial clusters of houses with a positive range of price volatility. The second part utilizes local Moran's I to evaluate the homogeneity of direction of price volatility within each cluster. The method is applied to the areas of Gangnam-Gu, Seocho-Gu, and Songpa-Gu in Seoul from August to November of 2003; the Participatory Government of Korea designated these areas and this period as the most speculative. The results of the analysis show that the area around Gaepo-Dong was as a hotspot before the Government's anti-speculative 10.29 policy in 2003; the house prices in the same area stabilized in October, 2003 and the area was identified as a coldspot in December, 2003. This case study shows that the suggested method enables exploration of hotspot of house price volatility at micro spatial scales which had not been detected by visual analysis.

An Analysis on the Spatial Spillover Patterns of Aging Population in Rural Areas (공간자기상관을 활용한 농촌지역 인구 고령화의 공간적 확산 분석)

  • Yeo, Chang-Hwan;Seo, Yun-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.3
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    • pp.39-53
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    • 2014
  • The Korean population is aging rapidly and a disproportionate share of older people(aged 65 and older) lives in rural areas. The rural population is aging more rapidly than the population in urban area. However, the majority of studies on aging population focuses on an urban area rather than a rural area. Rural areas have been alienated from the priority of the national policy. For these reasons, this study is to show the level of population aging and to analyze the spatial spillover patterns of aging population in rural areas for the establishment of localized policy on population aging. The main findings of this study can be summarized as follows. First, the level of population aging varies in different localities such as socio-economic and locational characteristics. Secondly, there are distinct differences between hot spot region(clustering of high aging index) and cold spot region(clustering of low aging index) in spatio-temporal spillover patterns. This study intends to suggest an useful information to establish the area-specific policy on aging population through the results of analysis.

Estimation of the Natural Damage Disaster Considering the Spatial Autocorrelation and Urban Characteristics (공간적 자기상관성과 도시특성 요소를 고려한 자연재해 피해 분석)

  • Seo, Man Whoon;Lee, Jae Song;Choi, Yeol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.4
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    • pp.723-733
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    • 2016
  • This study aims to analyze the effects of urban characteristics on the amount of damage caused by natural disasters. It is focused on the areas of a municipal level in Korea. Also, it takes into account the spatial autocorrelation of the damage caused by natural disasters. Moran's I statistics was estimated to examine the spatial autocorrelation in the damage from the study area. Subsequent to evaluating the suitability for spatial regression models and the OLS regression model, the spatial lag model was employed as an empirical analysis for the study. It showed that the increase in residential area leads to the decrease in the amount of natural disaster damage. On the other hand, the increase in green area and river basin is associated with the increase in the damage. As a result of empirical analysis, appropriate policy establishment and implementation about the damage-adding factors is needed in order to reduce the amount of damage in the future.