• Title/Summary/Keyword: spatial regression models

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A Study on the Spatial Distribution Characteristic of Urban Surface Temperature using Remotely Sensed Data and GIS (원격탐사자료와 GIS를 활용한 도시 표면온도의 공간적 분포특성에 관한 연구)

  • Jo, Myung-Hee;Lee, Kwang-Jae;Kim, Woon-Soo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.4 no.1
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    • pp.57-66
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    • 2001
  • This study used four theoretical models, such as two-point linear model, linear regression model, quadratic regression model and cubic regression model which are presented from The Ministry of Science and Technology, for extraction of urban surface temperature from Landsat TM band 6 image. Through correlation and regression analysis between result of four models and AWS(automatic weather station) observation data, this study could verify spatial distribution characteristic of urban surface temperature using GIS spatial analysis method. The result of analysis for surface temperature by landcover showed that the urban and the barren land belonged to the highest surface temperature class. And there was also -0.85 correlation in the result of correlation analysis between surface temperature and NDVI. In this result, the meteorological environmental characteristics wuld be regarded as one of the important factor in urban planning.

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A Comparative Study on the Spatial Statistical Models for the Estimation of Population Distribution

  • Oh, Doo-Ri;Hwang, Chul Sue
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.3
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    • pp.145-153
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    • 2015
  • This study aims to accurately estimate population distribution more specifically than administrative unites using a RK (Regression-Kriging) model. The RK model is the areal interpolation technique that involves linear regression and the Kriging model. In order to estimate a population’s distribution using a sample region, four different models were used, namely; a regression model, RK model, OK (Ordinary Kriging) model and CK (Co-Kriging) model. The results were then compared with each other. Evaluation of the accuracy and validity of evaluation analysis results were the basis RMSE (Root Mean Square Error), MAE (Mean Absolute Error), G statistic and correlation coefficient (ρ). In the sample regions, every statistic value of the RK model showed better results than other models. The results of this comparative study will be useful to estimate a population distribution of the metropolitan areas with high population density

Crime hotspot prediction based on dynamic spatial analysis

  • Hajela, Gaurav;Chawla, Meenu;Rasool, Akhtar
    • ETRI Journal
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    • v.43 no.6
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    • pp.1058-1080
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    • 2021
  • Crime is not a completely random event but rather shows a pattern in space and time. Capturing the dynamic nature of crime patterns is a challenging task. Crime prediction models that rely only on neighborhood influence and demographic features might not be able to capture the dynamics of crime patterns, as demographic data collection does not occur frequently and is static. This work proposes a novel approach for crime count and hotspot prediction to capture the dynamic nature of crime patterns using taxi data along with historical crime and demographic data. The proposed approach predicts crime events in spatial units and classifies each of them into a hotspot category based on the number of crime events. Four models are proposed, which consider different covariates to select a set of independent variables. The experimental results show that the proposed combined subset model (CSM), in which static and dynamic aspects of crime are combined by employing the taxi dataset, is more accurate than the other models presented in this study.

Extraction of Potential Area for Block Stream and Talus Using Spatial Integration Model (공간통합 모델을 적용한 암괴류 및 애추 지형 분포가능지 추출)

  • Lee, Seong-Ho;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.2
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    • pp.1-14
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    • 2019
  • This study analyzed the relativity between block stream and talus distributions by employing a likelihood ratio approach. Possible distribution sites for each debris slope landform were extracted by applying a spatial integration model, in which we combined fuzzy set model, Bayesian predictive model, and logistic regression model. Moreover, to verify model performance, a success rate curve was prepared by cross-validation. The results showed that elevation, slope, curvature, topographic wetness index, geology, soil drainage, and soil depth were closely related to the debris slope landform sites. In addition, all spatial integration models displayed an accuracy of over 90%. The accuracy of the distribution potential area map of the block stream was highest in the logistic regression model (93.79%). Eventually, the accuracy of the distribution potential area map of the talus was also highest in the logistic regression model (97.02%). We expect that the present results will provide essential data and propose methodologies to improve the performance of efficient and systematic micro-landform studies. Moreover, our research will potentially help to enhance field research and topographic resource management.

Improved Estimation of Hourly Surface Ozone Concentrations using Stacking Ensemble-based Spatial Interpolation (스태킹 앙상블 모델을 이용한 시간별 지상 오존 공간내삽 정확도 향상)

  • KIM, Ye-Jin;KANG, Eun-Jin;CHO, Dong-Jin;LEE, Si-Woo;IM, Jung-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.25 no.3
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    • pp.74-99
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    • 2022
  • Surface ozone is produced by photochemical reactions of nitrogen oxides(NOx) and volatile organic compounds(VOCs) emitted from vehicles and industrial sites, adversely affecting vegetation and the human body. In South Korea, ozone is monitored in real-time at stations(i.e., point measurements), but it is difficult to monitor and analyze its continuous spatial distribution. In this study, surface ozone concentrations were interpolated to have a spatial resolution of 1.5km every hour using the stacking ensemble technique, followed by a 5-fold cross-validation. Base models for the stacking ensemble were cokriging, multi-linear regression(MLR), random forest(RF), and support vector regression(SVR), while MLR was used as the meta model, having all base model results as additional input variables. The results showed that the stacking ensemble model yielded the better performance than the individual base models, resulting in an averaged R of 0.76 and RMSE of 0.0065ppm during the study period of 2020. The surface ozone concentration distribution generated by the stacking ensemble model had a wider range with a spatial pattern similar with terrain and urbanization variables, compared to those by the base models. Not only should the proposed model be capable of producing the hourly spatial distribution of ozone, but it should also be highly applicable for calculating the daily maximum 8-hour ozone concentrations.

Expansion of Private Tutoring Market for Adults according to Labor Market Changes and the Geographical Characteristics (노동시장의 구조 변화에 따른 성인 대상 사교육 시장의 성장과 공간적 함의)

  • Park, Sohyun;Lee, Keumsook
    • Journal of the Economic Geographical Society of Korea
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    • v.17 no.2
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    • pp.402-419
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    • 2014
  • This study attempts to investigate the spatial characteristics of private tutoring markets for adults which have been expanded rapidly with labor market changes in Korea. In particular, For the purpose, we examine thoroughly various indies of labor markets and private tutoring markets for adults in Korea in first and then analyze the spatial characteristics. We classify private tutoring institutes for adults into two categories by job-statuses and education levels, and analyze the spatial distribution patterns of the attendants of the classes. In order to understand the spatial characteristic of their distributions, we distinguish whether there exist the spatial autocorrelation or not by applying Moran's I values for each categories in first. We also examine the spatial cluster patterns by Hot spots analysis utilizing $G^*$ statistics. Multiple linear regression models are developed for each category to explain the relationships between the spatial distributions of private tutoring institutes and geographical variables.

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Spatial Distribution Characteristics of Financial Industries and the Relationships with Socio-economic Variables: The case of the Seoul Metropolitan Area (금융산업의 분포특성 및 사회.경제적 변수와의 관계 분석: 수도권 지역을 사례로)

  • Moon, Eun Jin;Lee, Keumsook
    • Journal of the Economic Geographical Society of Korea
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    • v.16 no.3
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    • pp.512-527
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    • 2013
  • This study examines the spatial distribution characteristics of financial industry which has been a necessary service for contemporary urban life. In particular, we analyze the spatial distribution patterns of money lending business which is considered with informal financial services as well as the spatial distribution patterns of banks which are representative of the institutional financial services. For the purpose, their density distribution patterns are explored by Kernel density analysis for both financial services in first. Moran's I coefficients are estimated for these two financial services to clarify the distintion in their geographical concentration patterns. The results of spatial autocorrelation analysis show stark differences between the center city and outskirts of the Seoul metropolitan area. Multivariate regression models are developed to explain the relationships between the spatial distributions of financial services and geographical variables. Finally, we discuss financial exclusion problem in the Metropolitan Seoul based on these spatial distribution characteristics.

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A Study on the Method of Freight Generation Estimation according to Company Size in Seoul Metropolitan Area (수도권의 사업체 규모에 따른 화물발생 예측 방법론 연구)

  • Park Sang-Chul;Choi Chang-Ho
    • Journal of Navigation and Port Research
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    • v.29 no.5 s.101
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    • pp.431-437
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    • 2005
  • In korea, Freight generation models developed in korea were estimated by spatial unit method which predict freight flow by traffic zone. But it is difficult to predict freight generation using these models, because there are the difference of the totality method of sampling data on freight volume and the variability of the variables by these models on each case study, This study developed new estimation model to predict freight flow which is generated from each company using the characteristics of each company such as the freight outbound & inbound volume, the number of employee, sales, gross area, land area. This model is simpler than the that of spatial unit and can apply to the other region. The subjects of study were companies in metropolitan area and types of model were exponential regression models. The adequate explanatory variable in the models were sales. this study have a uniqueness apply micro research method to estimate freight generation not use spatial unit method but use flow unit method by each company unit.

Spatial Analysis of the Urban Heat Island Using a 3-D City Model (3차원 도시모형을 이용한 도시열섬의 공간분석)

  • Chun, Bum-Seok;Guldmann, Jean-Michel
    • Spatial Information Research
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    • v.20 no.4
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    • pp.1-16
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    • 2012
  • There is no doubt that the urban heat island (UHI) is a mounting problem in built-up environments, due to energy retention by the surface materials of dense buildings, leading to increased temperatures, air pollution, and energy consumption. To investigate the UHI, three-dimensional (3-D) information is necessary to analyze complex sites, including dense building clusters. In this research, 3-D building geometry information is combined with two-dimensional (2-D) urban surface information to examine the relationship between urban characteristics and temperature. In addition, this research introduces spatial regression models to account for the spatial spillover effects of urban temperatures, and includes the following steps: (a) estimating urban temperatures, (b) developing a 3-D city model, (c) generating urban parameters, and (d) conducting statistical analyses using both Ordinary Least-Squares (OLS) and Spatial Regression Models. The results demonstrate that 3-D urban characteristics greatly affect temperatures and that neighborhood effects are critical in explaining temperature variations. Finally, the implications of the results are discussed, providing guidelines for policies to reduce the UHI.

Spatial Diffusion Patterns of the Organic Farms in Korea and the Geographical Characteristics (한국 친환경농업의 공간적 확산 양상과 그 지리적 함의)

  • Hyun, Ki-Soon;Lee, Keum-Sook
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.3
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    • pp.377-393
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    • 2011
  • This study aims to indicate the spatial characteristics of the changes in the Korean farm land. In particular, we analyze the spatial diffusion patterns of organic farms increasing rapidly with the growth in the agricultural product markets as well as the demand for safe food and sustainable growth. For the purpose, we examine the changes in the distribution patterns of organic farms between year 2000 and 2005. We analyze the agglomeration pattern by Location Quotient (LQ) and Local indicator of spatial association (LISA). Organic farms have been spread out from the outscuirts of Seoul, the capital city, to the traditional agriculture spetilized area in the southern parts of the nation. In order to analyze the relationships between organic farm distribution and the geographical variables affecting the organic farming, we develop multivariate regression models. Our findings indicate that organic farming is related with the number of agriculture-based business and information technique adaptation as well as the level of education and farmers age.

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