-
作者：Moodie, Erica E. M.; Platt, Robert W.; Kramer, Michael S.
作者单位：McGill University; McGill University; McGill University; McGill University
摘要：To estimate the sequence of actions that optimizes response in a longitudinal setting, it is important to study the actions as part of a set of decision rules rather than in a series of single-action comparisons. We take as our motivating example the estimation of the set of decision rules for the duration of breastfeeding with a view to maximizing infant growth. Breastfeeding has many well-recognized beneficial effects on health and development. However observational evidence has suggested th...
-
作者：Rothman, Adam J.; Levina, Elizaveta; Zhu, Ji
作者单位：University of Michigan System; University of Michigan
摘要：We propose a new class of generalized thresholding operators that combine thresholding with shrinkage, and Study generalized thresholding of the sample covariance matrix in high dimensions. Generalized thresholding of the covariance matrix has good theoretical properties and carries almost no computational burden. We obtain in explicit convergence rate in the operator norm that shows the tradeoff between the sparsity of the true model, dimension, and the sample size, and shows that generalized...
-
作者：Wikle, C. K.; Milliff, R. F.
作者单位：University of Missouri System; University of Missouri Columbia; NorthWest Research Associates
-
作者：Chen, Lisha; Buja, Andreas
作者单位：Yale University; University of Pennsylvania
摘要：In the past decade there has been a resurgence of interest in nonlinear dimension reduction. Among new proposals are Local Linear Embedding, Isomap, and Kernel Principal Components Analysis which all construct global low-dimensional embeddings from local affine or metric information, We introduce a competing method called Local Multidimensional Scaling (LMDS). Like LLE, Isomap, and KPCA, LMDS constructs its global embedding from local information, but it uses instead a combination of MDS and f...
-
作者：Lemos, Ricardo T.; Sanso, Bruno
作者单位：Universidade de Lisboa; Universidade de Lisboa; University of California System; University of California Santa Cruz
摘要：We consider the problem of fitting a statistical model to 30 years of sea Surface temperature records collected over a large portion of the Northern Atlantic. The observations were collected sparsely in space and time with different levels of accuracy. The purpose of the model is to produce an atlas of oceanic properties, including climatological mean fields, estimates of historical trends, and a spatio-temporal reconstruction of the anomalies, i.e., the transient deviations from the climatolo...
-
作者：Liang, Hua; Li, Runze
作者单位：University of Rochester; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park
摘要：This article focuses on variable selection for partially linear models when the covariates are measured with additive errors. We propose two classes of variable selection procedures, penalized least squares and penalized quantile regression, using the nonconvex penalized principle. The first procedure corrects the bias in the loss function caused by the measurement error by applying the so-called correction-for-attenuation approach, whereas the second procedure corrects the bias by using ortho...
-
作者：Smith, Richard L.; Tebaldi, Claudia; Nychka, Doug; Mearns, Linda O.
作者单位：University of North Carolina; University of North Carolina Chapel Hill; National Center Atmospheric Research (NCAR) - USA
摘要：Projections of future climate change caused by increasing greenhouse gases depend critically on numerical climate model, coupling the ocean and atmosphere (global climate models [GCMs]). However, different models differ substantially in their projections, which raises the question of how the different models can best be combined into a probability distribution of future climate change. For this analysis, we have collected both Current and future projected mean temperatures produced by nine cli...
-
作者：Lemos, R. T.; Sanso, B.
作者单位：Universidade de Lisboa; Universidade de Lisboa; University of California System; University of California Santa Cruz
-
作者：Sangalli, Laura M.; Secchi, Piercesare; Vantini, Simone; Veneziani, Alessandro
作者单位：Polytechnic University of Milan; Emory University
摘要：This pilot study is a product of the AneuRisk Project, a scientific program that aims at evaluating the role of vascular geometry and hemodynamics in the pathogenesis of cerebral aneurysms. By means of functional data analyses, we explore the AneuRisk dataset to highlight the relations between the geometric features of the internal carotid artery, expressed by its radius profile and centerline curvature. and the aneurysm location. After introducing a new similarity index for functional data, w...
-
作者：Micheas, Athanasios C.; Wikle, Christopher K.
作者单位：University of Missouri System; University of Missouri Columbia
摘要：A methodology is proposed to efficiently model a random set via a multistage hierarchical Bayesian model. We define a NonOverlapping Random Disk Model (NORDM), which is similar in spirit to the well-known Poisson-Boolean model. This model is formulated in a conditional setting that facilitates Bayesian sampling of important parameters in the model. This framework can accommodate any object, not just those with disk shapes, although the model can be easily extended to include any known compact ...
