ISSN:0319-5724    

DOI:10.1002/cjs.5550160101

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractAlthough the ecologic effects of acid rain have been widely reported, relatively little is known about the effects of acidic air pollution on human health. Some epidemiologic and animal studies suggest, however, that acidity is an important determinant of the respiratory health effects of aerosols. This paper reviews some of that evidence and discusses its implications for the design and analysis of epidemiologic studies. We contrast two types of exposure patterns: peak exposures associated with air pollution episodes, and chronic exposures resulting from persistently high levels of air pollutants. Recent work on the analysis of repeated categorical outcome variables provides new methods for the analysis of episode studies. Studies of long‐term exposure require comparisons among population groups, and these comparisons can be subject to the design effects characteristic of multistage sample surveys. We examine the implications of these design effects for epidemiologic studies. Finally, the paper discusses the measurement errors induced by the use of outdoor measurements to quantify personal exposure to air pollutants. Recent work on methods for errors‐in‐variables problems may aid in assessing the effects of such errors on conventional analyses of air‐pollution

ISSN:0319-5724    

DOI:10.2307/3315060

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractSix years of rainfall‐event pH measurements from the nine‐station MAP3S/PCN monitoring network in the eastern United States were analyzed. The initial objective was an attempted validation of the model developed by Eynon and Switzer (1983,Canad. J. Statist.11, 11–24) on this independent data set. Because some features of the structure presumed in the model are not evident in this data set, the underlying structure of the data was then explored in some detail. Both aspects of the investigation confirmed that the identification of an appropriate statistical model for such data is a difficult undertaking; anticipated structure may not be evident, and the data corresponding to specific stations or years may exhibit anomalous beh

ISSN:0319-5724    

DOI:10.2307/3315061

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractA scavenging‐type model is propsed for the analysis of hourly data of nitrate or other pollutants in precipitation. The model would, in principle, allow for the separate estimation of the cloud‐water pollutant contribution and the air‐column contribution. In turn, these may be interpreted as regional and local contributions. As an illustration, the model was fitted to data from four precipitation events. Estimation of the model parameters was done on an event‐specific basis except for pooling of the scavenging rate pa

ISSN:0319-5724    

DOI:10.2307/3315062

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractWe investigate ordinary least‐squares and Bayesian methods for constructing interval estimates for historical lake pH's inferred from diatom sediments. The Bayesian method explicitly models several forms of variability, including the sampling and classification variability of the diatom records, estimation variability, and measurement error in observed pH's. The two methods produce similar interval estimates, but the Bayesian model allows design recommendations to be mad

ISSN:0319-5724    

DOI:10.2307/3315063

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractThis report is about the analysis of stochastic processes of the formR = S + N, whereSis a “smooth” functional andNis noise. The proposed methods derive from the assumption that the observedR‐values and unobserved values ofR, the assumed inferential objectives of the analysis, are linearly related through Taylor series expansions of observed about unobserved values. The expansion errors and all otherprioriunspecified quantities have a joint multivariate normal distribution which expresses the prior uncertainty about their values. The results include interpolators, predictors, and derivative estimates, with credibility‐interval estimates automatically generated in each case. An analysis of an acid‐rain wet‐deposition time series is included to indicate the efficacy of the proposed method. It was this problem which led to the methodological developments reported in

ISSN:0319-5724    

DOI:10.2307/3315064

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractTests of homogeneity of normal means with the alternative restricted by an ordering on the means are considered. The simply ordered case, μ1≤ μ2≤ ··· ≤ μk, and the simple tree ordering, μ1≤ μj, for;j= 2, 3,…,k, are emphasized. A modification of the likelihood‐ratio test is proposed which is asymptotically equivalent to it but is more robust to violations of the hypothesized orderings. The new test has power at the points satisfying the hypothesized ordering which is similar to that of the likelihood‐ratio test provided the degrees of freedom are not too small. The modified test is shown to be un

ISSN:0319-5724    

DOI:10.2307/3315065

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractA new necessary and sufficient condition is derived for the equality between the ordinary least‐squares estimator and the best linear unbiased estimator of the expectation vector in linear models with certain specific design matrices. This condition is then applied to special cases involving one‐way and two‐way classification m

ISSN:0319-5724    

DOI:10.2307/3315067

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY

摘要:

AbstractLightning data collected over three dry seasons from the detection system operated by the British Columbia Ministry of Forests were analyzed to estimate the distribution of lightning signal strength and component detection efficiencies. The analysis was based on more than 165,000 lightning‐strike records, where component detectors served both as lightning finders and as data collectors for evaluating the performance of other component detectors in the network. In spite of the unusual feature of this application involving a system evaluating itself, much was revealed to identify weaknesses and suggest improvements. A postanalysis system‐modification update is inclu

ISSN:0319-5724    

DOI:10.2307/3315069

出版商:Wiley‐Blackwell    

年代:1988

数据来源: WILEY