DOI: 10.1016/j.atmosenv.2014.04.023
Scopus记录号: 2-s2.0-84899503823
论文题名: Reliability of reflectance measures in passive filters
作者: Saldiva de André C ; D ; , Afonso de André P ; , Rocha F ; M ; , Saldiva P ; H ; N ; , Carvalho de Oliveira R ; , Singer J ; M
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 92 起始页码: 178
结束页码: 181
语种: 英语
英文关键词: Air pollution
; Outliers
; Passive filters
; Random effects
; Reliability
Scopus关键词: Air pollution
; Estimation
; Passive filters
; Random processes
; Reflection
; Statistics
; Correlation coefficient
; Environmental Monitoring
; Optical reflectance
; Outliers
; Ozone concentration
; Random effects
; Reactive chemicals
; Variance components
; Reliability
; ozone
; atmospheric pollution
; calibration
; environmental monitoring
; error analysis
; filter
; ozone
; pollution exposure
; reflectance
; article
; calibration
; environmental exposure
; environmental monitoring
; filter
; human
; measurement
; optical reflectance
; optics
; particulate matter
; priority journal
; reliability
; urban area
; Brazil
; Sao Paulo [Brazil]
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: Measurements of optical reflectance in passive filters impregnated with a reactive chemical solution may be transformed to ozone concentrations via a calibration curve and constitute a low cost alternative for environmental monitoring, mainly to estimate human exposure. Given the possibility of errors caused by exposure bias, it is common to consider sets of m filters exposed during a certain period to estimate the latent reflectance on n different sample occasions at a certain location. Mixed models with sample occasions as random effects are useful to analyze data obtained under such setups. The intra-class correlation coefficient of the mean of the m measurements is an indicator of the reliability of the latent reflectance estimates. Our objective is to determine m in order to obtain a pre-specified reliability of the estimates, taking possible outliers into account. To illustrate the procedure, we consider an experiment conducted at the Laboratory of Experimental Air Pollution, University of São Paulo, Brazil (LPAE/FMUSP), where sets of m=3 filters were exposed during 7 days on n=9 different occasions at a certain location. The results show that the reliability of the latent reflectance estimates for each occasion obtained under homoskedasticity is km=0.74. A residual analysis suggests that the within-occasion variance for two of the occasions should be different from the others. A refined model with two within-occasion variance components was considered, yielding km=0.56 for these occasions and km=0.87 for the remaining ones. To guarantee that all estimates have a reliability of at least 80% we require measurements on m=10 filters on each occasion. © 2014 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/80836
Appears in Collections: 气候变化事实与影响
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作者单位: Institute of Mathematics and Statistics, University of São Paulo, Brazil; School of Medicine, University of São Paulo, Brazil; Federal University of São Paulo, Brazil
Recommended Citation:
Saldiva de André C,D,, Afonso de André P,et al. Reliability of reflectance measures in passive filters[J]. Atmospheric Environment,2014-01-01,92