• Title/Summary/Keyword: Spatial Statistical

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County Level Clustering on Alcohol and HIV Mortality

  • Park, Byeonghwa
    • Communications for Statistical Applications and Methods
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    • v.20 no.1
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    • pp.53-62
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    • 2013
  • This study focuses on spatial/temporal relationship deaths caused by Human Immunodeficiency Virus (HIV) and Alcohol Use Disorder (AUD). Several studies have found links between these two diseases. By looking for clusters in mortality of Alcohol and HIV related deaths this study contributes to the field through the identification of exact spatial/temporal time of high and low occurrence risks based on the observed over the expected number of deaths. This study does not provide political or social interpretations of the data. It merely wants to show where clusters are found.

One-step Least Squares Fitting of Variogram

  • Choi, Hye-Mi
    • Communications for Statistical Applications and Methods
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    • v.12 no.2
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    • pp.539-544
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    • 2005
  • In this paper, we propose the one-step least squares method based on the squared differences to estimate the parameters of the variogram used for spatial data modelling, and discuss its asymptotic efficiency. The proposed method does not require to specify lags of interest and partition lags, so that we can delete the subjectiveness and ambiguity originated from the lag selection in estimating spatial dependence.

Hierarchical Bayesian Analysis of Spatial Data with Application to Disease Mapping

  • Kim, Dal-Ho;Kang, Sang-Gil
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.781-790
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    • 1999
  • In this paper we consider estimation of cancer incidence rates for local areas. The raw estimates usually are based on small sample sizes and hence are usually unreliable. A hierarchical Bayes generalized linear model is used which connects the local areas thereby enabling one to 'borrow strength' Random effects with pairwise difference priors model the spatial structure in the data. The methods are applied to cancer incidence estimation for census tracts in a certain region of the state of New York.

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Statistical Image Processing using Java on the Web

  • Lim, Dong Hoon;Park, Eun Hee
    • Communications for Statistical Applications and Methods
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    • v.9 no.2
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    • pp.355-366
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    • 2002
  • The web is one of the most plentiful sources of images. The web has an immediate need for image processing technology in Java. This paper provides a practical introduction to statistical image processing using Java on the web. The paper describes how images are represented in Java and deals with four image processing operations based on basic statistical methods: point processing, spatial filtering, edge detection and image segmentation.

Statistical Model Analysis of Urban Spatial Structures and Greenhouse Gas (GHG) - Air Pollution (AP) Integrated Emissions in Seoul (서울시 도시공간구조와 온실가스-대기오염 통합 배출량의 통계모형분석)

  • Jung, Jaehyung;Kwon, O-Yul
    • Journal of Environmental Science International
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    • v.24 no.3
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    • pp.303-316
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    • 2015
  • The relationship between urban spatial structures and GHG-AP integrated emissions was investigated by statistically analyzing those from 25 administrative districts of Seoul. Urban spatial structures, of which data were obtained from Seoul statistics yearbook, were classified into five categories of city development, residence, environment, traffic and economy. They were further classified into 10 components of local area, population, number of households, residential area, forest area, park area, registered vehicles, road area, number of businesses and total local taxes. GHG-AP integrated emissions were estimated based on IPCC(intergovernmental panel on climate change) 2006 guidelines, guideline for government greenhouse inventories, EPA AP-42(compilation of air pollutant emission factors) and preliminary studies. The result of statistical analysis indicated that GHG-AP integrated emissions were significantly correlated with urban spatial structures. The correlation analysis results showed that registered vehicles for GHG (r=0.803, p<0.01), forest area for AP (r=0.996, p<0.01), and park area for AP (r=0.889, p<0.01) were highly significant. From the factor analysis, three groups such as city and traffic categories, economy category and environment category were identified to be the governing factors controlling GHG-AP emissions. The multiple regression analysis also represented that the most influencing factors on GHG-AP emissions were categories of traffic and environment. 25 administrative districts of Seoul were clustered into six groups, of which each has similar characteristics of urban spatial structures and GHG-AP integrated emissions.

Detection of Hotspots on Multivariate Spatial Data

  • Moon, Sung-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1181-1190
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    • 2006
  • Statistical analyses for spatial data are important features for various types of fields. Spatial data are taken at specific locations or within specific regions and their relative positions are recorded. Lattice data are synoptic observation covering an entire spatial region, like cancer rates corresponding to each county in a state. Until now, the echelon analysis has been applied only to univariate spatial data. As a result, it is impossible to detect the hotspots on the multivariate spatial data In this paper, we expand the spatial data to time series structure. And then we analyze them on the time space and detect the hotspots. Echelon dendrogram has been made by piling up each multivariate spatial data to bring time spatial data. We perform the structural analysis of temporal spatial data.

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Analysis of Characteristics of Air Pollution Over Asia with Satellite-derived $NO_2$ and HCHO using Statistical Methods (환경 위성관측자료의 통계분석을 통한 동아시아 대기오염특성 연구)

  • Baek, K.H.;Kim, Jae Hwan
    • Atmosphere
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    • v.20 no.4
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    • pp.495-503
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    • 2010
  • Satellite data have an intrinsic problem due to a number of various physical parameters, which can have a similar effect on measured radiance. Most evaluations of satellite performance have relied on comparisons with limited spatial and temporal resolution of ground-based measurements such as soundings and in-situ measurements. In order to overcome this problem, a new way of satellite data evaluation is suggested with statistical tools such as empirical orthogonal function(EOF), and singular value decomposition(SVD). The EOF analyses with OMI and OMI HCHO over northeast Asia show that the spatial pattern show high correlation with population density. This suggests that human activity is a major source of as well as HCHO over this region. However, this analysis is contradictory to the previous finding with GOME HCHO that biogenic activity is the main driving mechanism(Fu et al., 2007). To verify the source of HCHO over this region, we performed the EOF analyses with vegetation and HCHO distribution. The results showed no coherence in the spatial and temporal pattern between two factors. Rather, the additional SVD analysis between $NO_2$ and HCHO shows consistency in spatial and temporal coherence. This outcome suggests that the anthropogenic emission is the main source of HCHO over the region. We speculate that the previous study appears to be due to low temporal and spatial resolution of GOME measurements or uncertainty in model input data.

Cure rate proportional odds models with spatial frailties for interval-censored data

  • Yiqi, Bao;Cancho, Vicente Garibay;Louzada, Francisco;Suzuki, Adriano Kamimura
    • Communications for Statistical Applications and Methods
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    • v.24 no.6
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    • pp.605-625
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    • 2017
  • This paper presents proportional odds cure models to allow spatial correlations by including spatial frailty in the interval censored data setting. Parametric cure rate models with independent and dependent spatial frailties are proposed and compared. Our approach enables different underlying activation mechanisms that lead to the event of interest; in addition, the number of competing causes which may be responsible for the occurrence of the event of interest follows a Geometric distribution. Markov chain Monte Carlo method is used in a Bayesian framework for inferential purposes. For model comparison some Bayesian criteria were used. An influence diagnostic analysis was conducted to detect possible influential or extreme observations that may cause distortions on the results of the analysis. Finally, the proposed models are applied for the analysis of a real data set on smoking cessation. The results of the application show that the parametric cure model with frailties under the first activation scheme has better findings.

Analysis of Determinants of Migration by Age Groups using General Spatial Model in Korea (공간계량모형을 이용한 연령대별 인구 이동 결정 요인 분석)

  • Han, Yi-Cheol;Lee, Jeong-Jae;Jung, Nam-Su;Park, Mee-Jeong;Suh, Kyo
    • Journal of Korean Society of Rural Planning
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    • v.11 no.3 s.28
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    • pp.59-67
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    • 2005
  • According to diverse studies in population migration, there has been a strong age-dependent population distribution in Korea. It is shown that a particular age-group tends to reside in a particular locale or community and the effect possesses usually statistical significance. We quantitatively address this issue: how certain division of age group resides in different region of the country, and investigate possible cause of this migration pattern for different age groups. In this study, population migration trend at age groups of 20s, 30s, 40s and 50s has been analyzed incorporating a spatial econometrics model that accounts for diverse statistical pitfalls such as spatial autocorrelation and spatial dependency. We found that migration trend for different age group corresponds to regional characteristics differently. The study concludes with some policy implications and suggests a need of further study.

ANALYSIS OF SPATIAL FACTORS AFFECTING DENGUE EPIDEMICS USING GIS IN THAILAND

  • Nakhapakorn Kanchana;Tripatht Nitin;Nualchawee Kaew;Kusanagt Michiro;Pakpien Preeda
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.774-777
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    • 2005
  • Dengue Fever(DF) and Dengue haemorrhagic fever(DHF) has become a major international public health concern. Dengue Fever(DF) and Dengue haemorrhagic Fever (DHF) is also still the major health problem of Thailand, although many campaigns against it have been conducted throughout the country. GIS and Remotely Sensed data are used to evaluate the relationships between socio-spatial, environmental factors/indicators and the incidences of viral diseases. The aim of the study is to identify the spatial risk factors in Dengue and Dengue Haemorrhagic Fever in Sukhothai province, Thailand using statistical, spatial and GIS Modelling. Preliminary results demonstrated that physical factors derived from remotely sensed data could indicate variation in physical risk factors affecting DF and DHF. The present study emphasizes the potential of remotely sensed data and GIS in spatial factors affecting Dengue Risk Zone analysis. The relationship between land cover and the cases of incidence of DF and DHF by information value method revaluated that highest information value is obtained for Built-up area. A negative relationship was observed for the forest area. The relations between climate data and cases of incidence have shown high correlation with rainfall factors in rainy season but poor correlation with temperature and relative humidity. The present study explores the potential of remotely sensed data and GIS in spatial analysis of factors affecting Dengue epidemic, strong spatial analysis tools of GIS. The capabilities of GIS for analyst spatial factors influencing risk zone has made it possible to apply spatial statistical analysis in Disease risk zone.

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