Chuanhai Liu

  1. Parameter Expansion and Efficient Inference.

    Authors: Chuanhai Liu, Andrew Lewandowski, Scott Vander Wiel
    Subjects: Methodology
    Abstract

    This EM review article focuses on parameter expansion, a simple technique
    introduced in the PX-EM algorithm to make EM converge faster while maintaining
    its simplicity and stability. The primary objective concerns the connection
    between parameter expansion and efficient inference. It reviews the statistical
    interpretation of the PX-EM algorithm, in terms of efficient inference via bias
    reduction, and further unfolds the PX-EM mystery by looking at PX-EM from
    different perspectives.

  2. Dempster--Shafer Theory and Statistical Inference with Weak Beliefs.

    Authors: Chuanhai Liu, Ryan Martin, Jianchun Zhang
    Subjects: Methodology
    Abstract

    The Dempster--Shafer (DS) theory is a powerful tool for probabilistic
    reasoning based on a formal calculus for combining evidence. DS theory has been
    widely used in computer science and engineering applications, but has yet to
    reach the statistical mainstream, perhaps because the DS belief functions do
    not satisfy long-run frequency properties. Recently, two of the authors
    proposed an extension of DS, called the weak belief (WB) approach, that can
    incorporate desirable frequency properties into the DS framework by
    systematically enlarging the focal elements.

  3. The Dynamic ECME Algorithm.

    Authors: Chuanhai Liu, Yunxiao He
    Subjects: Computation
    Abstract

    The ECME algorithm has proven to be an effective way of accelerating the EM
    algorithm for many problems. Recognising the limitation of using prefixed
    acceleration subspace in ECME, we propose the new Dynamic ECME (DECME)
    algorithm which allows the acceleration subspace to be chosen dynamically. Our
    investigation of an inefficient special case of DECME, the classical Successive
    Overrelaxation (SOR) method, leads to an efficient, simple, and widely
    applicable DECME implementation, called DECME_v1.

  4. Estimating limits from Poisson counting data using Dempster--Shafer analysis.

    Authors: Paul T. Edlefsen, Chuanhai Liu, Arthur P. Dempster
    Subjects: Applications
    Abstract

    We present a Dempster--Shafer (DS) approach to estimating limits from Poisson
    counting data with nuisance parameters. Dempster--Shafer is a statistical
    framework that generalizes Bayesian statistics. DS calculus augments
    traditional probability by allowing mass to be distributed over power sets of
    the event space. This eliminates the Bayesian dependence on prior distributions
    while allowing the incorporation of prior information when it is available. We
    use the Poisson Dempster--Shafer model (DSM) to derive a posterior DSM for the
    ``Banff upper limits challenge'' three-Poisson model.

Syndicate content