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Extracting grouping structure or identifying homogenous subgroups of predictors in regression is crucial for high-dimensional data analysis. A low-dimensional structure in particular-grouping, when captured in a regression model, enables to enhance predictive performance and to facilitate a model's interpretability Grouping pursuit extracts homogenous(More)
Polar orbiting satellites remotely sense the earth and its atmosphere, producing data sets that give daily global coverage. For any given day, the data are many and spatially irregular. Our goal in this article is to predict values that are spatially regular at diierent resolutions; such values are often used as input to general circulation models (GCMs)(More)
Recently, a class of multiscale tree-structured models was introduced in terms of scale-recursive dynamics deened on trees. The main advantage of these models is their association with a fast, recursive, Kalman-lter prediction algorithm. In this article, we propose a more general class of multiscale graphical models over acyclic directed graphs, for use in(More)
Nonparametric hypothesis testing for a spatial signal can involve a large numberofhypotheses. For instance, two satellite images of the same scene, taken before and after an event, could be used to test a hypothesis that the event h a s no environmental impact. This is equivalent to testing that the mean diierence of \after;before" is zero at each of the(More)
In this article, we propose a regression method for simultaneous supervised clustering and feature selection over a given undirected graph, where homogeneous groups or clusters are estimated as well as informative predictors, with each predictor corresponding to one node in the graph and a connecting path indicating a priori possible grouping among the(More)
Ambient particles may cause pulmonary inflammation with ensuing morbidity. Particle-induced production of proinflammatory cytokines in vitro has been used as an indicator of particle toxicity. To identify particle components that were related to particle toxicity, Andersen dichotomous impactors were used to collect ambient fine (PM(2.5)) and coarse(More)