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作者：Pilla, Ramani S.; Qu, Annie; Loader, Catherine
作者单位：University System of Ohio; Case Western Reserve University; Oregon State University
摘要：In many biomedical studies, we are interested in comparing treatment effects with an inherent ordering. We propose a quadratic score test (QST) based on a quadratic inference function for detecting an order in treatment effects for correlated data. The quadratic inference function is similar to the negative of a log-likelihood, and it provides test statistics in the spirit of a chi(2)-test for testing nested hypotheses as well as for assessing the goodness of fit of model assumptions. Under th...
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作者：Zhuang, Jiancang
作者单位：Research Organization of Information & Systems (ROIS); Institute of Statistical Mathematics (ISM) - Japan
摘要：The paper gives first-order residual analysis for spatiotemporal point processes that is similar to the residual analysis that has been developed by Baddeley and co-workers for spatial point processes and also proposes principles for second-order residual analysis based on the viewpoint of martingales. Examples are given for both first- and second-order residuals. In particular, residual analysis can be used as a powerful tool in model improvement. Taking a spatiotemporal epidemic-type aftersh...
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作者：Moulines, Eric; Crisan, Dan; Rowlingson, Barry; Chopin, N.; Connor, S. B.; Kendall, W. S.; Kent, John T.; Casella, Bruno; Ball, Frank; Dryden, Ian; Golalizadeh, Mousa; Bingham, N. H.; Clifford, Peter; Genon-Catalot, Valentine; Kalogeropoulos, Konstantinos; Kessler, Mathieu; Klueppelberg, Claudia; Kuensch, Hans R.; Lyons, T. J.; Mamon, Rogemar; Yu, Keming; Moller, Jesper; Pasquali, Sara; Ruggeri, Fabrizio; Pavlopoulos, Harry; Robert, Christian P.; Rousset, Mathias; Doucet, Arnaud; Stramer, Osnat
作者单位：IMT - Institut Mines-Telecom; IMT Atlantique
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作者：Neuhaus, John M.; McCulloch, Charles E.
作者单位：University of California System; University of California San Francisco
摘要：We consider the situation where the random effects in a generalized linear mixed model may be correlated with one of the predictors, which leads to inconsistent estimators. We show that conditional maximum likelihood can eliminate this bias. Conditional likelihood leads naturally to the partitioning of the covariate into between- and within-cluster components and models that include separate terms for these components also eliminate the source of the bias. Another viewpoint that we develop is ...
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作者：Kent, J. T.; Mardia, K. V.; McDonnell, P.
作者单位：University of Leeds
摘要：The complex Bingham distribution was introduced by Kent as a tractable model for landmark-based shape analysis. It forms an exponential family with a sufficient statistic which is quadratic in the data. However, the distribution has too much symmetry to be widely useful. In particular, under high concentration it behaves asymptotically as a normal distribution, but where the covariance matrix is constrained to have complex symmetry. To overcome this limitation and to provide a full range of as...
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作者：Ni, LQ; Cook, RD
作者单位：State University System of Florida; University of Central Florida; University of Minnesota System; University of Minnesota Twin Cities
摘要：Sliced inverse regression is one of the widely used dimension reduction methods. Chiaromonte and co-workers extended this method to regressions with qualitative predictors and developed a method, partial sliced inverse regression, under the assumption that the covariance matrices of the continuous predictors are constant across the levels of the qualitative predictor. We extend partial sliced inverse regression by removing the restrictive homogeneous covariance condition. This extension, which...
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作者：Yuan, M; Lin, Y
作者单位：University System of Georgia; Georgia Institute of Technology; University of Wisconsin System; University of Wisconsin Madison
摘要：We consider the problem of selecting grouped variables (factors) for accurate prediction in regression. Such a problem arises naturally in many practical situations with the multifactor analysis-of-variance problem as the most important and well-known example. Instead of selecting factors by stepwise backward elimination, we focus on the accuracy of estimation and consider extensions of the lasso, the LARS algorithm and the non-negative garrotte for factor selection. The lasso, the LARS algori...
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作者：Gervini, Daniel
作者单位：University of Wisconsin System; University of Wisconsin Milwaukee
摘要：The paper introduces free-knot regression spline estimators for the mean and the variance components of a sample of curves. The asymptotic distribution of the mean estimator is derived, and asymptotic confidence bands are constructed. A comparative simulation study shows that free-knot splines estimate salient features of the functions (such as sharp peaks) more accurately than smoothing splines. This adaptive behaviour is also illustrated by an analysis of weather data.
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作者：Li, Baibing
作者单位：Loughborough University
摘要：The purpose of the paper is to present a new statistical approach to hierarchical cluster analysis with n objects measured on p variables. Motivated by the model of multivariate analysis of variance and the method of maximum likelihood, a clustering problem is formulated as a least squares optimization problem, simultaneously solving for both an n-vector of unknown group membership of objects and a linear clustering function. This formulation is shown to be linked to linear regression analysis...
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作者：Jansen, M
作者单位：Eindhoven University of Technology; KU Leuven
摘要：The paper introduces a framework for non-linear multiscale decompositions of Poisson data that have piecewise smooth intensity curves. The key concept is conditioning on the sum of the observations that are involved in the computation of a given multiscale coefficient. Within this framework, most classical wavelet thresholding schemes for data with additive homoscedastic noise can be used. Any family of wavelet transforms (orthogonal, biorthogonal or second generation) can be incorporated in t...
