國家衛生研究院 NHRI:Item 3990099045/6407
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    Please use this identifier to cite or link to this item: http://ir.nhri.org.tw/handle/3990099045/6407


    Title: Spatiotemporal modeling with temporal-invariant variogram subgroups to estimate fine particulate matter PM2.5 concentrations
    Authors: Chen, CC;Wu, CF;Yu, HL;Chan, CC;Cheng, TJ
    Contributors: Division of Biostatistics and Bioinformatics
    Abstract: Short-term exposure estimation of daily air pollution levels incorporating geographic information system (GIS) into spatiotemporal modeling remains a great challenge for assessing corresponding acute adverse health effects. Due to daily meteorological effects on the dispersion of pollutants, explanatory spatial covariables and their coefficients may not be the same as in classical land-use regression (LUR) modeling for long-term exposure. In this paper, we propose a two-stage spatiotemporal model for daily fine particulate matter (PM 2.5) concentration prediction: first, daily nonlinear temporal trends are estimated through a generalized additive model, and second, GIS covariates are used to predict spatial variation in the temporal trend-removed residuals. To account for spatial dependence on meteorological conditions, the dates of the study period are divided by the sill of the daily empirical variogram into approximately temporal-invariant subgroups. Within each subgroup, daily PM 2.5 estimations are obtained by combining the temporal and spatial parts of the estimations from the two stages. The proposed method is applied to the modeling of spatiotemporal PM 2.5 concentrations observed at 18 ambient air monitoring stations in Taipei metropolitan area during 2006-2008. The results showed that the PM 2.5 concentrations decreased whereas the relative humidity and wind speed increased with the sill subgroups, which may be due to the effects of daily meteorological conditions on the dispersions of the particles. Also, the covariates and their coefficients of the LUR models varied with subgroups and had in general higher adjusted R-squares and smaller root mean square errors in prediction than those of a single overall LUR model.
    Date: 2012-07
    Relation: Atmospheric Environment. 2012 Jul;54:1-8.
    Link to: http://dx.doi.org/10.1016/j.atmosenv.2012.02.015
    JIF/Ranking 2023: http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=NHRI&SrcApp=NHRI_IR&KeyISSN=1352-2310&DestApp=IC2JCR
    Cited Times(WOS): https://www.webofscience.com/wos/woscc/full-record/WOS:000306200600001
    Cited Times(Scopus): http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=84860623725
    Appears in Collections:[Chu-Chih Chen] Periodical Articles

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