Open Access. Powered by Scholars. Published by Universities.®

Statistics and Probability Commons™

Open Access. Powered by Scholars. Published by Universities.®

2006

Discipline
Institution
Keyword
Publication
Publication Type

Articles 241 - 244 of 244

Full-Text Articles in Statistics and Probability

A Normal-Mixture Model With Random-Effects For Rr-Interval Data, Jessica Mckinney Ketchum Jan 2006

A Normal-Mixture Model With Random-Effects For Rr-Interval Data, Jessica Mckinney Ketchum

Theses and Dissertations

In many applications of random-effects models to longitudinal data, such as heart rate variability (HRV) data, a normal-mixture distribution seems to be more appropriate than the normal distribution assumption. While the random-effects methodology is well developed for several distributions in the exponential family, the case of the normal-mixture has not been dealt with adequately in the literature. The models and the estimation methods that have been proposed in the past assume the conditional model (fixing the random-effects) to be normal and allow a mixture distribution for the random effects (Xu and Hedeker, 2001, Xu, 1995). The methods proposed in this …


Meta-Analysis Of Open Vs Closed Surgery Of Mandibular Condyle Fractures, Marcy Lauren Nussbaum Jan 2006

Meta-Analysis Of Open Vs Closed Surgery Of Mandibular Condyle Fractures, Marcy Lauren Nussbaum

Theses and Dissertations

A review of the literature reveals a difference of opinion regarding whether open or closed reduction of condylar fractures produces the best results. It would be beneficial to critically analyze past studies that have directly compared the two methods in an attempt to answer this question. A Medline search for articles using the key words 'mandibular condyle fractures' and 'mandibular condyle fractures surgery' was performed. The articles chosen for the meta-analysis contained data on at least one of the following: postoperative maximum mouth opening, lateral excursion, protrusion, deviation on opening, asymmetry, and joint pain or muscle pain. Several common statistical …


Design And Analysis Methods For Cluster Randomized Trials With Pair-Matching On Baseline Outcome: Reduction Of Treatment Effect Variance, Misook Park Jan 2006

Design And Analysis Methods For Cluster Randomized Trials With Pair-Matching On Baseline Outcome: Reduction Of Treatment Effect Variance, Misook Park

Theses and Dissertations

Cluster randomized trials (CRT) are comparative studies designed to evaluate interventions where the unit of analysis and randomization is the cluster but the unit of observation is individuals within clusters. Typically such designs involve a limited number of clusters and thus the variation between clusters is left uncontrolled. Experimental designs and analysis strategies that minimize this variance are required. In this work we focus on the CRT with pre-post intervention measures. By incorporating the baseline measure into the analysis, we can effectively reduce the variance of the treatment effect. Well known methods such as adjustment for baseline as a covariate …


Methods For The Estimation Of Missing Values In Time Series, David S. Fung Jan 2006

Methods For The Estimation Of Missing Values In Time Series, David S. Fung

Theses: Doctorates and Masters

Time Series is a sequential set of data measured over time. Examples of time series arise in a variety of areas, ranging from engineering to economics. The analysis of time series data constitutes an important area of statistics. Since, the data are records taken through time, missing observations in time series data are very common. This occurs because an observation may not be made at a particular time owing to faulty equipment, lost records, or a mistake, which cannot be rectified until later. When one or more observations are missing it may be necessary to estimate the model and also …