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作者：Chan, Yao-ban; Hall, Peter
作者单位：University of Melbourne
摘要：In this paper we develop a nonparametric approach to clustering very high-dimensional data, designed particularly for problems where the mixture nature of a population is expressed through multimodality of its density. Therefore, a technique based implicitly on mode testing can be particularly effective. In principle, several alternative approaches could be used to assess the extent of multimodality, but in the present problem the excess mass method has important advantages. We show that the r...
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作者：Krivobokova, Tatyana; Kneib, Thomas; Claeskens, Gerda
作者单位：University of Gottingen; University of Gottingen; Carl von Ossietzky Universitat Oldenburg; KU Leuven; KU Leuven
摘要：In this article we construct simultaneous confidence bands for a smooth curve using penalized spline estimators. We consider three types of estimation methods: (a) as a standard (fixed effect) nonparametric model, (b) using the mixed-model framework with the spline coefficients as random effects, and (c) a full Bayesian approach. The volume-of-tube formula is applied for the first two methods and compared with Bayesian simultaneous confidence bands from a frequentist perspective. We show that ...
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作者：Smith, Michael; Min, Aleksey; Almeida, Carlos; Czado, Claudia
作者单位：University of Melbourne; Technical University of Munich
摘要：Copulas have proven to be very successful tools for the flexible modeling of cross-sectional dependence. In this paper we express the dependence structure of continuous-valued time series data using a sequence of bivariate copulas. This corresponds to a type of decomposition recently called a vine in the graphical models literature, where each copula is entitled a pair-copula. We propose a Bayesian approach for the estimation of this dependence structure for longitudinal data. Bayesian selecti...
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作者：Spirling, Arthur; Quinn, Kevin
作者单位：Harvard University; University of California System; University of California Berkeley
摘要：Legislative voting records are an important source of information about legislator preferences, intraparty cohesiveness, and the divisiveness of various policy issues. Standard methods of analyzing a legislative voting record tend to have serious drawbacks when applied to legislatures, such as the United Kingdom House of Commons, that feature highly disciplined parties, strategic voting, and large amounts of missing data. We present a method (based on a Dirichlet process mixture model) for ana...
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作者：Liang, Kun; Nettleton, Dan
作者单位：Iowa State University
摘要：Gene category testing problems involve testing hundreds of null hypotheses that correspond to nodes in a directed acyclic graph. The logical relationships among the nodes in the graph imply that only some configurations of true and false null hypotheses are possible and that a test for a given node should depend on data from neighboring nodes. We developed a method based on a hidden Markov model that takes the whole graph into account and provides coherent decisions in this structured multiple...
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作者：Bilder, Christopher R.; Tebbs, Joshua M.; Chen, Peng
作者单位：University of Nebraska System; University of Nebraska Lincoln; University of South Carolina System; University of South Carolina Columbia
摘要：In situations where individuals are screened for an infectious disease or other binary characteristic and where resources for testing are limited, group testing can offer substantial benefits. Group testing, where subjects are tested in groups (pools) initially, has been successfully applied to problems in blood bank screening, public health, drug discovery, genetics, and many other areas. In these applications, often the goal is to identify each individual as positive or negative using initia...
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作者：Rodriguez, Abel; Dunson, David B.; Gelfand, Alan E.
作者单位：University of California System; University of California Santa Cruz; Duke University
摘要：We develop a model for stochastic processes with random marginal distributions. Our model relies on a stick-breaking construction for the marginal distribution of the process, and introduces dependence across locations by using a latent Gaussian copula model as the mechanism for selecting the atoms. The resulting latent stick-breaking process (LaSBP) induces a random partition of the index space, with points closer in space having a higher probability of being in the same cluster. We develop a...
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作者：Prentice, Ross L.
作者单位：Fred Hutchinson Cancer Center; University of Washington; University of Washington Seattle
摘要：This article reviews the status of statistical methods for chronic disease prevention research, with emphasis on the reliability of findings and on future methodological needs and opportunities. Observational studies, especially cohort studies, play a major role in disease prevention research, but depend on adequate confounding control methods for a useful interpretation. Stratification and regression methods that are commonly used to control confounding are described, and comparative findings...
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作者：Chen, Kani; Guo, Shaojun; Lin, Yuanyuan; Ying, Zhiliang
作者单位：Hong Kong University of Science & Technology; Columbia University; Chinese Academy of Sciences; Academy of Mathematics & System Sciences, CAS
摘要：Multiplicative regression model or accelerated failure time model, which becomes linear regression model after logarithmic transformation, is useful in analyzing data with positive responses, such as stock prices or life times, that are particularly common in economic/financial or biomedical studies. Least squares or least absolute deviation are among the most widely used criterions in statistical estimation for linear regression model. However, in many practical applications, especially in tr...
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作者：Huang, Li-Shan; Davidson, Philip W.
作者单位：University of Rochester
摘要：Fish consumption during pregnancy exposes the fetus to both the neurotoxicant methylmercury and nutrients known to be beneficial for brain development. When nutrient status is not measured, maternal methylmercury levels may be a partial biomarker for both toxic and nutrient exposures. It is therefore necessary to employ a flexible model-such as the partial linear model-that will allow for possible nonlinear trends of methylmercury. To enhance interpretations of fitting a partial linear model, ...
