摘要:

AbstractTwo years of rainfall acidity data for the eastern United States were analyzed. The data consist of rainfall‐event pH measurements from a nine station monitoring network. A spatio‐temporal stochastic model, including deterministic components for seasonal variation and rainfall washout, and stochastic components for spatial, temporal, and measurement variation, was fitted to the data. The fitted autocorrelation structure from this model was used, in the process known as Kriging, to obtain BLUE contour maps of seasonal and rainfall adjusted yearly average pH over the monitoring reg

ISSN:0319-5724    

DOI:10.2307/3314707

出版商:Wiley‐Blackwell    

年代:1983

数据来源: WILEY

ISSN:0319-5724    

DOI:10.2307/3314708

出版商:Wiley‐Blackwell    

年代:1983

数据来源: WILEY

摘要:

AbstractThis paper concerns the modelling and analysis of toxicity data in which the time to some toxic response is recorded and of importance. The paper begins with a review of a variety of dose‐response models, including log‐linear, proportional hazards, multievent, and compartmental models, that have been suggested and used in this context. Models for competing risks are also reviewed and several possible approaches are considered and discussed in the context of dose response experiments. The formulation of a model for competing risks that utilizes cause‐specific hazards gives a natural basis for the modelling and analysis of certain experimental situations in which only partial information is available on the time to response. Such situations arise, for example, when the presence of tumour is not clinically detectable in carcinogenicity trials. Likelihood construction is discussed, and appropriate likelihood contributions are derived. The paper concludes with a discussion of measures of risk which take account of the time dependence of the toxic response under

ISSN:0319-5724    

DOI:10.2307/3314709

出版商:Wiley‐Blackwell    

年代:1983

数据来源: WILEY

ISSN:0319-5724    

DOI:10.2307/3314710

出版商:Wiley‐Blackwell    

年代:1983

数据来源: WILEY

摘要:

AbstractGrowing concern about the health effects of exposure to pollutants and other chemicals in the environment has stimulated new research to detect and quantify environmental hazards. This research has generated many interesting and challenging methodological problems for statisticians. One type of statistical research develops new methods for the design and analysis of individual studies. Because current research of this type is too diverse to summarize in a single article, we discuss current work in two areas of application: the carcinogen bioassay in small rodents and epidemiologic studies of air pollution. To assess the risk of a potentially harmful agent, one must frequently combine evidence from different and often quite dissimilar studies. Hence, this paper also discusses the central role of data synthesis in risk assessment, reviews some of the relevant statistical literature, and considers the role of statisticians in evaluating and combining evidence from diverse sources.

ISSN:0319-5724    

DOI:10.2307/3314711

出版商:Wiley‐Blackwell    

年代:1983

数据来源: WILEY

ISSN:0319-5724    

DOI:10.2307/3314712

出版商:Wiley‐Blackwell    

年代:1983

数据来源: WILEY

摘要:

AbstractThis study analyzes the properties of the linear filters of the X‐11‐ARIMA seasonal adjustment method applied for current seasonal adjustment. It provides the general formula for the combined weights that result from the ARIMA model extrapolation filters with the X‐11 seasonal‐adjustment filters. The three cases studied correspond to the three ARIMA models automatically tested by the X‐11‐ARIMA program, namely, (0, 1, 1)(0, 1, 1), (0, 2, 2)(0, 1, 1), and (2, 1. 2)(0, 1,1). The parameter values chosen reflect different degrees of flexibility of the trend‐cycle and seasonal components. It is shown that the X‐11‐ARIMA linear filters for current seasonal adjustment are very flexible; they change with both the ARIMA extrapolation model and its parameter values, contrary to those of the X‐11 program, which are fixed for a g

ISSN:0319-5724    

DOI:10.2307/3314713

出版商:Wiley‐Blackwell    

年代:1983

数据来源: WILEY