This research develops a framework to estimate the effective sample size of Global Positioning System (GPS) based panel surveys in urban travel behavior studies for a variety of planning purposes. Recent advances in GPS monitoring technologies have made it possible to implement panel surveys with lengths of weeks, months or even years. The many advantageous features of GPS-based panel surveys make such surveys attractive for travel behavior studies, but the higher cost of such surveys compared to conventional one-day or two-day paper diary surveys requires scrutiny at the sample size planning stage to ensure cost-effectiveness. The sample size analysis in this dissertation focuses on three major aspects in travel behavior studies: 1) to obtain reliable means for key travel behavior variables, 2) to conduct regression analysis on key travel behavior variables against explanatory variables such as demographic characteristics and seasonal factors, and 3) to examine impacts of a policy measure on travel behavior through before-and-after studies. The sample size analyses in this dissertation are based on the GPS data collected in the multi-year Commute Atlanta study. The sample size analysis with regard to obtaining reliable means for key travel behavior variables utilizes Monte Carlo re-sampling techniques to assess the trend of means against various sample size and survey length combinations. The basis for the framework and methods of sample size estimation related to regression analysis and before-and-after studies are derived from various sample size procedures based on the generalized estimating equation (GEE) method. These sample size procedures have been proposed for longitudinal studies in biomedical research. This dissertation adapts these procedures to the design of panel surveys for urban travel behavior studies with the information made available from the Commute Atlanta study. The findings from this research indicate that the required sample sizes should be much larger than the sample sizes in existing GPS-based panel surveys. This research recommends a desired range of sample sizes based on the objectives and survey lengths of urban travel behavior studies.

Transportation funding is critical to maintaining the assets that provide mobility for the movement of Georgia's people and goods. Currently, most of Georgia's transportation revenue is provided by the motor fuel tax. Inflation and recent increases in fuel economy have decreased fuel tax revenue in Georgia and weakened the Georgia Department of Transportation's (GDOT)'s ability to maintain and expand its transportation network. This thesis synthesizes factors from literature that affect motor fuel tax revenue. These include demographic, economic, technological, and environmental forces that influence travel behavior and vehicle fuel economy. A model was then created that incorporated these factors to model GDOT's 2009 fuel tax revenue and then project revenue in 2020 and 2030. The model uses an input/output structure that segments the fleet into personal, freight, and transit categories. User inputs, historical data, and projections are linked via relationships and feedback loops to project travel and fuel tax revenue forward. Because a near-infinite number of scenarios exist, conservative and aggressive scenarios were created for 2020 and 2030 scenarios that output revenue on an absolute, per-mile, and per-capita basis for comparison with more recent revenues. The model outputs predict marginal declines in revenue by 2020 and significant declines by 2030. In response to these declines, the thesis evaluates methods of increasing transportation revenue. These methods include increasing the fuel tax, incorporating a VMT-fee, and widespread tolling measures. After evaluation, a policy recommendation is provided for how to best implement revenue strategies.

The construction industry represents a significant part of the Gross Domestic Product, (GDP) in the UK. It employs around 1.4 million people and has averaged around 7.5% of GDP over recent years. Although the industry is of major importance to the UK economy, it still under achieves. Many projects run over budget and are completed late to schedule and a lot of resource is invested in making good defects, repair and replacement and in litigation (Latham 1994). These shortfalls in the construction industry were investigated by EGAN 1998 in his report, Rethinking Construction. EGAN proposed five key drivers for change, these consisted of committed leadership, focus on the customer, integrating the processes and teams, a quality driven agenda and commitment to people. Targets were set to gauge the improvements to the UK, these include 10% reduction in capital cost and construction time, 20% reduction in defects and accident, 20% increase in productivity and profitability and 10% increase in predictability of project performance. This thesis reviews one of the most important drivers, which is the improvement to integrate construction processes through improved project controls. The aim of the Thesis was to investigate by a literature review, a questionnaire and survey and three audits of client’s processes and work practices how Project Controls was currently operating to deliver Projects on time and within budget. It was then necessary to review (how based on best practice) current Project Control processes and systems could be improved. The improvements are portrayed by the development a series of “road maps” and “tool kits” demonstrating how processes and systems could be improved. This research thesis investigates the status of Project Controls in the UK and develops methodologies to improve controls. The investigation of Project Controls is based on five pieces of work, namely; i) A literature review of current practices; ii) The development of a questionnaire and survey results; iii) Three client reports of work carried out by the author. The five pieces of work were then contextualised to form a commentary of findings and recommendations for improvement. The recommendations were then linked to a methodology for improvements to the key elements of Project Controls. The aims of the thesis were achieved in that many issues of weakness were identified in current Project Control systems and processes and “road maps” were developed identifying in detail how best practice should be adopted. The thesis identifies major weaknesses in control of major projects with examples such a Pharmaceuticals, Building construction and Road construction industries demonstrating minimal understanding of the concepts and benefits of effective control. It could be described as disappointing series of examples of why some of our Industries fail to deliver to cost and schedule. However, the thesis does layout via “road maps” how improvements could be made, this knowledge has in part been shared with some clients in the Pharmaceutical and Road construction. The thesis therefore does demonstrate a contribution to knowledge and some of its recommendations are being implemented in practice. The primary conclusions of the Thesis indicates that with the exception of Oil & Gas companies there are major gaps between what is accepted as best practice and what is happening in Industry with regards to Project Controls. There is a lack of understanding at Project Control engineer and Project Manager Level. There is a need for additional training in particular for Project Managers as their understanding and ability to see the benefits is paramount to driving forward effective planning and control for projects. Also it is necessary that robust Project Control procedures are established in all industries to integrate the cost and planning disciplines to ensure a common approach to best practice is adopted.

The purpose of this study was to explore the subject of timescale estimating for rule-based systems. A model for estimating the timescale necessary to build rule-based systems was built and then tested in a controlled environment.

The purpose of this study is to determine which of three forecasting methods provides the most accurate short-term forecasts, in terms of absolute and mean absolute percentage error, for a unique set of data. The study applies three forecasting techniques--the Box-Jenkins or ARIMA method, cycle regression analysis, and multiple regression analysis--to quarterly sales tax revenue data. The final results show that, with varying success, each model identifies the direction of change in the future, but does not closely identify the period to period fluctuations. Indeed, each model overestimated revenues for every period forecasted. Cycle regression analysis, with a mean absolute percentage error of 7.21, is the most accurate model. Multiple regression analysis has the smallest absolute percentage error of 3.13.

<p>A significant hurdle for analyzing big data is the lack of effective technology and statistical inference methods. A popular approach for analyzing data with large sample is subsampling. Many subsampling probabilities have been introduced in literature (Ma, \emph{et al.}, 2015) for linear model. In this dissertation, we focus on generalized estimating equations (GEE) with big data and derive the asymptotic normality for the estimator without resampling and estimator with resampling. We also give the asymptotic representation of the bias of estimator without resampling and estimator with resampling. we show that bias becomes significant when the data is of high-dimensional. We also present a novel subsampling method called A-optimal which is derived by minimizing the trace of some dispersion matrices (Peng and Tan, 2018). We derive the asymptotic normality of the estimator based on A-optimal subsampling methods. We conduct extensive simulations on large sample data with high dimension to evaluate the performance of our proposed methods using MSE as a criterion. High dimensional data are further investigated and we show through simulations that minimizing the asymptotic variance does not imply minimizing the MSE as bias not negligible. We apply our proposed subsampling method to analyze a real data set, gas sensor data which has more than four millions data points. In both simulations and real data analysis, our A-optimal method outperform the traditional uniform subsampling method.</p>

"This project utilized generalized estimating equations and general linear modeling to model learning curves for sonographer performance in emergency ultrasonography. Performance was measured in two ways: image quality (interpretable vs. possible hindrance in interpretation) and agreement of findings between the sonographer and an expert reviewing sonographer. Records from 109 sonographers were split into two data sets-- training (n=50) and testing (n=59)--to conduct exploratory analysis and fit the final models for analysis, respectively. We determined that the number of scans of a particular exam type required for a sonographer to obtain quality images on that exam type with a predicted probability of 0.9 is highly dependent upon the person conducting the review, the indication of the scan (educational or medical), and the outcome of the scan (whether there is a pathology positive finding). Constructing family-wise 95% confidence intervals for each exam type demonstrated a large amount of variation for the number of scans required both between exam types and within exam types. It was determined that a sonographer's experience with a particular exam type is not a significant predictor of future agreement on that exam type and thus no estimates were made based on the agreement learning curves. In addition, we concluded based on a type III analysis that when already considering exam type related experience, the consideration of experience on other exam types does not significantly impact the learning curve for quality. However, the learning curve for agreement is significantly impacted by the additional consideration of experience on other exam types."

Modelos de customer scoring são utilizados para mensurar o risco de crédito de clientes de instituições financeiras. Neste trabalho, são apresentadas três estratégias que podem ser utilizadas para o desenvolvimento desses modelos. São discutidas as vantagens de cada uma dessas estratégias, bem como os modelos e a teoria estatística associada a elas. Algumas medidas de performance usualmente utilizadas na comparação de modelos de risco de crédito são descritas. Modelos para cada uma das estratégias são ajustados utilizando-se dados reais obtidos de uma instituição financeira. A performance das estratégias para esse conjunto de dados é comparada a partir de medidas usualmente utilizadas na avaliação de modelos de risco de crédito. Uma simulação também é desenvolvida com o propósito de comparar o desempenho das estratégias em condições controladas. / Customer scoring models are used to measure the credit risk of financial institution´s customers. In this work, we present three strategies that can be used to develop these models. We discuss the advantages of each of the strategies, as well as the models and statistical theory related with them. We fit models for each of these strategies using real data of a financial institution. We compare the strategies´s performance through some measures that are usually used to validate credit risk models. We still develop a simulation to study the strategies under controlled conditions.

Este trabalho de tese tem como objetivo principal propor uma abordagem alternativa para analisar dados Birnbaum-Saunders (BS) correlacionados com base em equações de estimação. Da classe ótima de funções de estimação proposta por Crowder (1987), derivamos uma classe ótima para a análise de dados correlacionados em que as distribuições marginais são assumidas log-BS e log-BS-t, respectivamente. Derivamos um processo iterativo para estimação dos parâmetros, métodos de diagnóstico, tais como análise de resíduos, distância de Cook e influência local sob três diferentes esquemas de perturbação: ponderação de casos, perturbação da variável resposta e perturbação individual de covariáveis. Estudos de simulação são desenvolvidos para cada modelo para avaliar as propriedades empíricas dos estimadores dos parâmetros de localização, forma e correlação. A abordagem apresentada é discutida em duas aplicações: o primeiro exemplo referente a um banco de dados sobre a produtividade de capital público nos 48 estados norte-americanos contíguos de 1970 a 1986 e o segundo exemplo referente a um estudo realizado na Escola de Educação Física e Esporte da Universidade de São Paulo (USP) durante 2016 em que 70 corredores foram avaliados em corridas em esteiras em três períodos distintos. / The aim of this thesis is to propose an alternative approach to analyze correlated Birnbaum-Saunders (BS) data based on estimating equations. From the optimal estimating functions class proposed by Crowder (1987), we derive an optimal class for the analysis of correlated data in which the marginal distributions are assumed either log-BS or log-BS-t. It is derived an iterative process, diagnostic procedures such as residual analysis, Cooks distance and local influence under three different perturbation schemes: case-weights, response variable perturbation and single-covariate perturbation. Simulation studies to assess the empirical properties of the parameters estimates are performed for each proposed model. The proposed methodology is discussed in two applications: the first one on a data set of public capital productivity of the contiguous 48 USA states, from 1970 to 1986, and the second data set refers to a study conducted in the School of Physical Education and Sport of the University of São Paulo (USP), during 2016, in which 70 runners were evaluated in running machines races in three periods.

Uma suposição muito comum na análise de modelos de regressão é a de respostas independentes. No entanto, quando trabalhamos com dados longitudinais ou agrupados essa suposição pode não fazer sentido. Para resolver esse problema existem diversas metodologias, e talvez a mais conhecida, no contexto não Gaussiano, é a metodologia de Equações de Estimação Generalizadas (EEGs), que possui similaridades com os Modelos Lineares Generalizados (MLGs). Essas similaridades envolvem a classificação do modelo em torno de distribuições da família exponencial e da especificação de uma função de variância. A única diferença é que nessa função também é inserida uma matriz trabalho que inclui a parametrização da estrutura de correlação dentro das unidades experimentais. O principal objetivo desta dissertação é estudar como esses modelos se comportam em uma situação específica, de dados de contagem com sobredispersão. Quando trabalhamos com MLGs esse problema é resolvido através do ajuste de um modelo com resposta binomial negativa (BN), e a ideia é a mesma para os modelos envolvendo EEGs. Essa dissertação visa rever as teorias existentes em EEGs no geral e para o caso específico quando a resposta marginal é BN, e além disso mostrar como essa metodologia se aplica na prática, com três exemplos diferentes de dados correlacionados com respostas de contagem. / An assumption that is common in the analysis of regression models is that of independent responses. However, when working with longitudinal or grouped data this assumption may not have sense. To solve this problem there are several methods, but perhaps the best known, in the non Gaussian context, is the one based on Generalized Estimating Equations (GEE), which has similarities with Generalized Linear Models (GLM). Such similarities involve the classification of the model around the exponential family and the specification of a variance function. The only diference is that in this function is also inserted a working correlation matrix concerning the correlations within the experimental units. The main objective of this dissertation is to study how these models behave in a specific situation, which is the one on count data with overdispersion. When we work with GLM this kind of problem is solved by setting a model with a negative binomial response (NB), and the idea is the same for the GEE methodology. This dissertation aims to review in general the GEE methodology and for the specific case when the responses follow marginal negative binomial distributions. In addition, we show how this methodology is applied in practice, with three examples of correlated data with count responses.