Graduation date: 2004

The semi-parametric approach to the analysis of proportional hazards survival data is relatively new, having been initiated in 1972 by Sir David Cox, who restricted its use to hypothesis tests and confidence intervals for fixed effects in a regression setting. Practitioners have begun to diversify applications of this model, constructing residuals, modeling the baseline hazard, estimating median failure time, and analyzing experiments with random effects and repeated measures. The main purpose of this thesis is to show that working with an incompletely specified loglikelihood is more fruitful than working with Cox's original partial loglikelihood, in these applications. In Chapter 2, we show that the deviance residuals arising naturally from the partial loglikelihood have difficulties detecting outliers. We demonstrate that a smoothed, nonparametric baseline hazard partially solves this problem. In Chapter 3, we derive new deviance residuals that are useful for identifying the shape of the baseline hazard. When these new residuals are plotted in temporal order, patterns in the residuals mirror patterns in the baseline hazard. In Chapter 4, we demonstrate how to analyze survival data having a split-plot design structure. Using a BLUP estimation algorithm, we produce hypothesis tests for fixed effects, and estimation procedures for the fixed effects and random effects. / Graduation date: 1999

Quantitative habitat models of wildlife-habitat relationships are developed to formalize our current understanding about an ecological system. A habitat association model is one of these models that is useful for answering questions about how the habitat is occupied, how much growth habitat is required by the animal, or how the animal selects its food and habitat. Radio telemetry is adopted as a technique for studying home range and habitat use. The major objective of a radio telemetry study is to collect behavioral or demographic data in order to be able to estimate population parameters for home range and habitat selection. A radio telemetry study is a kind of multinomial experiment. The Logistic Regression Model is often used for estimating the relationship between animal activities and the habitat characteristics of the location used (animal preference). However, this model is not a good model for the telemetry data. Under this model, the slope parameter estimate becomes lower and farther from the true value as the Average Habitat Quality (AHQ) increases, with Diversity fixed. The Multinomial Model is better suited to telemetry data. Using the Logistic Regression Model, a habitat association study can be conducted in conjunction with adaptive cluster sampling. In terms of the variance of the regression parameter estimate, adaptive cluster sampling is better than simple random sampling. Adaptive sampling plans are also satisfied for habitat association analysis with imperfect detectability. / Graduation date: 1995

Graduation date: 1994

Objectives: This Study wanted to analysis the characteristics of the elder adult who had hospitalized with pneumonia. We also evaluated the factors that will affect the unexpected readmission in elderly pneumonia patients. Methods: This is a retrospective cohort study design. The study data was collected 341 pneumonia patients who have hospitalized in a general teaching hospital in Kaohsiung city from year 2009 to 2010. The study population was divided into two groups, the sample size of the old group (age >= 65yrs), and the young group (age < 65yrs) was 173 and 168, respectively. The methods of stepwise multiple logistic regressions were needed to evaluate the association between aging and different days of unplanned readmission in adult pneumonia patients. Results: All the 341 adult pneumonia patients, we found 613 male and 926 female. The demography characteristic of the study subjects, the means of age was 61.9yrs (s.d. = 19.3yrs), and BMI was 23.4 kg/m2 (s.d. = 4.5 kg/m2). The percentage of ICD-9-CM that code 486 was 95.6%. Most patients were community-acquired pneumonia (98.8%), hospitalized from emergency room (85.3%), and admission in general wards (92.7%). The unplanned readmission within 14/30 days, 60 days, and 90days were 9.1%, 11.7%, and 15.0%, respectively. The significant factors that were associated with readmission within 14 days include age, Hb, hospitalized days, hypertension, and other disease. When we used the multiple logistic regression analysis to adjust the other variables, only age still significant with readmission within 14 days (the crude OR of the old group was 4.561, adjusted OR was 2.714, 95% CI of OR from 1.002 to 7.353). In the stepwise multiple logistic regression models, the variable that was associated with readmission with 14 or 30 days were age (>= 65yrs, OR = 3.025), WBC (>=10750 mm3, OR=2.917), and Hb (>=12.4 g/dL, OR=0.390). We remain the elderly subjects to evaluate the factor that will influence readmission states. In all the stepwise logistic regression models, we found the experience with used endotracheal tube in the hospitalized period were the significant increases the readmission rate within 14 or 30 days, 60 days, and 90 days. Conclusion: In our study shows that the situations of unexpected readmission in pneumonia patients were strong association with aging. We suggest that the indicator of medical quality should be adjusted before we comparison the readmission rate in the different institute. The major factors that will be associated to affect the readmission states were endotracheal tube used (significant with 14 or 30 days readmission rate), CRP level (significant with 60 days and 90 days readmission rate), and Hb level (significant with 60 days and 90 days readmission rate).

Thesis (M.A.)--University of Notre Dame, 2009. / Thesis directed by Scott E. Maxwell for the Department of Psychology. "December 2009." Includes bibliographical references (leaves 70-72).

Thesis (M.Sc.)--Memorial University of Newfoundland, 2001. / Bibliography: leaves 59-62.

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 100-104). Also available in print.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Samuel E. Buttrey. Includes bibliographical references (p. 73-74). Also available online.

Thesis (M.S. in Space Systems Operations)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Eric Christiansen, Rudy Panholzer, Dan Bursch. Includes bibliographical references (p. 75-76). Also available online.