1,125 research outputs found

    Aspects of the analysis of multivariative failure time data

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    Multivariate failure time data arise in various forms including recurrent event data when individuals are followed to observe the sequence of occurrences of a certain type of event; correlated failure time when an individual is followed for the occurrence of two or more types of events for which the individual is simultaneously at risk, or when distinct individuals have dependent event times; or more complicated multistate processes when individuals may move among a number of discrete states over the course of a follow-up study and the states and associated sojourn times are recorded. Here we provide a critical review of statistical models and data analysis methods for the analysis of recurrent event data and correlated failure time data. This review suggests a valuable role for partially marginalized intensity models for the analysis of recurrent event data, and points to the usefulness of marginal hazard rate models and nonparametric estimates of pairwise dependencies for the analysis of correlated failure times. Areas in need of further methodology development are indicated

    PROGRAM & PROCEEDINGS of the 2022 COLLOQUIUM OF THE STONY BROOK UNIVERSITY INTELLECTUAL PROPERTY PARTNERS Female Perspectives on Entrepreneurship and Research How diverse perspectives inspire creativity, drive innovation, and encourage inclusive economic growth

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    Diverse and varied perspectives are not only central to our institutional mission, but are essential to our society, as we hope to create a more inclusive, more sustainable and ultimately brighter world. Diverse perspectives and collaboration between different institutions, fields and industries must become the norm. This is the program and proceeding of Stony Brook University\u27s colloquium on female perspectives on entrepreneurship and research and how diverse perspectives inspire creativity, drive innovation, and encourage inclusive economic growth. This was a much-needed discussion in January 2022 that\u27s important for the development of entrepreneurship and research worldwide. At Stony Brook University, the entire research community believes that creating an equitable and integrated work environment is an essential part of the success of its innovation and culture. So, this proceeding provides a transcript of the meaningful moderated discussion between 6 expert panelists about female entrepreneurship and research

    Mixed Discrete and Continuous Cox Regression Model

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    The Cox (1972) regression model is extended to include discrete and mixed continuous/discrete failure time data by retaining the multiplicative hazard rate form of the absolutely continuous model. Application of martingale arguments to the regression parameter estimating function show the Breslow (1974) estimator to be consistent and asymptotically Gaussian under this model. A computationally convenient estimator of the variance of the score function can be developed, again using martingale arguments. This estimator reduces to the usual hypergeometric form in the special case of testing equality of several survival curves, and it leads more generally to a convenient consistent variance estimator for the regression parameter. A small simulation study is carried out to study the regression parameter estimator and its variance estimator under the discrete Cox model special case and an application to a bladder cancer recurrence dataset is provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46860/1/10985_2004_Article_5119440.pd

    Female Perspectives on Entrepreneurship and Research How diverse perspectives inspire creativity, drive innovation, and encourage inclusive economic growth

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    Diverse and varied perspectives are not only central to our institutional mission, but are essential to our society, as we hope to create a more inclusive, more sustainable and ultimately brighter world. Diverse perspectives and collaboration between different institutions, fields and industries must become the norm. This is the program and proceeding of Stony Brook University\u27s colloquium on female perspectives on entrepreneurship and research and how diverse perspectives inspire creativity, drive innovation, and encourage inclusive economic growth. This was a much-needed discussion in January 2022 that\u27s important for the development of entrepreneurship and research worldwide. At Stony Brook University, the entire research community believes that creating an equitable and integrated work environment is an essential part of the success of its innovation and culture. So, this proceeding provides a transcript of the meaningful moderated discussion between 6 expert panelists about female entrepreneurship and research

    Female Perspectives on Entrepreneurship and Research How diverse perspectives inspire creativity, drive innovation, and encourage inclusive economic growth

    Get PDF
    Diverse and varied perspectives are not only central to our institutional mission, but are essential to our society, as we hope to create a more inclusive, more sustainable and ultimately brighter world. Diverse perspectives and collaboration between different institutions, fields and industries must become the norm. This is the program and proceeding of Stony Brook University\u27s colloquium on female perspectives on entrepreneurship and research and how diverse perspectives inspire creativity, drive innovation, and encourage inclusive economic growth. This was a much-needed discussion in January 2022 that\u27s important for the development of entrepreneurship and research worldwide. At Stony Brook University, the entire research community believes that creating an equitable and integrated work environment is an essential part of the success of its innovation and culture. So, this proceeding provides a transcript of the meaningful moderated discussion between 6 expert panelists about female entrepreneurship and research

    Inconsistency of the MLE for the joint distribution of interval censored survival times and continuous marks

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    This paper considers the nonparametric maximum likelihood estimator (MLE) for the joint distribution function of an interval censored survival time and a continuous mark variable. We provide a new explicit formula for the MLE in this problem. We use this formula and the mark specific cumulative hazard function of Huang and Louis (1998) to obtain the almost sure limit of the MLE. This result leads to necessary and sufficient conditions for consistency of the MLE which imply that the MLE is inconsistent in general. We show that the inconsistency can be repaired by discretizing the marks. Our theoretical results are supported by simulations.Comment: 27 pages, 4 figure

    Superluminal neutrinos in long baseline experiments and SN1987a

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    Precise tests of Lorentz invariance in neutrinos can be performed using long baseline experiments such as MINOS and OPERA or neutrinos from astrophysical sources. The MINOS collaboration reported a measurement of the muonic neutrino velocities that hints to super-luminal propagation, very recently confirmed at 6 sigma by OPERA. We consider a general parametrisation which goes beyond the usual linear or quadratic violation considered in quantum-gravitational models. We also propose a toy model showing why Lorentz violation can be specific to the neutrino sector and give rise to a generic energy behaviour E^alpha, where alpha is not necessarily an integer number. Supernova bounds and the preferred MINOS and OPERA regions show a tension, due to the absence of shape distortion in the neutrino bunch in the far detector of MINOS. The energy independence of the effect has also been pointed out by the OPERA results.Comment: 22 pages, 7 figures; comment on Cherenkov emission added, version matching JHEP published pape

    Limits on Production of Magnetic Monopoles Utilizing Samples from the DO and CDF Detectors at the Tevatron

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    We present 90% confidence level limits on magnetic monopole production at the Fermilab Tevatron from three sets of samples obtained from the D0 and CDF detectors each exposed to a proton-antiproton luminosity of 175pb1\sim175 {pb}^{-1} (experiment E-882). Limits are obtained for the production cross-sections and masses for low-mass accelerator-produced pointlike Dirac monopoles trapped and bound in material surrounding the D0 and CDF collision regions. In the absence of a complete quantum field theory of magnetic charge, we estimate these limits on the basis of a Drell-Yan model. These results (for magnetic charge values of 1, 2, 3, and 6 times the minimum Dirac charge) extend and improve previously published bounds.Comment: 18 pages, 17 figures, REVTeX
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