The main limitations in performing uncertainty analysis of CFD models using conventional methods are associated with cost and effort. For these reasons, there is a need for the development and implementation of efficient stochastic CFD tools for performing uncertainty analysis. One of the main contributions of this research is the development and implementation of Intrusive and Non-Intrusive methods using polynomial chaos for uncertainty representation and propagation. In addition, a methodology was developed to address and quantify turbulence model uncertainty. In this methodology, a complex perturbation is applied to the incoming turbulence and closure coefficients of a turbulence model to obtain the sensitivity derivatives, which are used in concert with the polynomial chaos method for uncertainty propagation of the turbulence model outputs. / Ph. D.

Estimates of the number of U.S. deaths each year resulting from medical errors range from 44,000 (Institute of Medicine, 1999) to 195,000 (HealthGrades, 2004). Additionally, instances of medical harm are estimated to occur at a rate of approximately 15 million per year in the U.S., or about 40,000 per day (Institute for Healthcare Improvement, 2007). Although several organizational behavior management (OBM) intervention techniques have been used to improve particular behaviors related to patient safety, there remains a lack of patient-safety-focused behavioral interventions among healthcare workers. OBM interventions are often applied to needs already identified within an organization, and the means by which these needs are determined vary across applications. The current research addresses gaps in the literature by applying a broad needs-assessment methodology to identify patient-safety intervention targets in a hospital and then translating OBM intervention techniques to identify and improve the prevention potential of responses to reported medical errors. A content analysis of 17 months of descriptions of follow-up actions to error reports for nine types of the most-frequently-occurring errors was conducted. Follow-up actions were coded according to a taxonomy of behavioral intervention components, with accompanying prevention scores based on criteria developed by Geller et al. (1990). Two error types were selected for intervention; based on the highest frequency of reporting and lowest average follow-up prevention score. Over a three-month intervention period, managers were instructed to respond to these two error types with active communication, group feedback, and positive reinforcement strategies. Results indicate improved prevention potential as a consequence of improved corrective action for targeted errors. Future implications for identifying and classifying responses to medical error are discussed. / Ph. D.

Asynchronous Transfer Mode (ATM) protocol was designed to support real-time traffic steams over high quality links like fiber optics where the transmission error is extremely low. ATM performs poorly in an error-prone environment such as wireless communications. The purpose of this research is to investigate error control schemes in wireless ATM (W-ATM) to support real-time service, such that the physical layer error conditions are handled in lower layers under ATM transport layer. Automatic Repeat reQuest schemes (ARQ) and Forward Error Correction (FEC) have been widely used for reliable data transmissions. However, the current existing ARQ schemes can potentially introduce unbounded delay in high error rate environments like W-ATM network due to the lack of delay control mechanism. As a result, they are not appropriate for real-time data communications in which there are strict packet delay requirements. In this dissertation, we explored the issues related to W-ATM area. Adaptation of FEC, specifically Reed-Solomon code, to channel error conditions in W-ATM is investigated. The quality-of-service (QoS)-aware error control algorithm is originated and its performance is evaluated. The algorithm is further simplified to make it more suitable for practical applications. The requirements of ARQ applicability for real-time communication environment like W-ATM is extensively analyzed. An ARQ scheme, called D-bit protocol, is developed to satisfy the real-time requirements. The scheme supports reliable packet discarding while allowing retransmissions without compromising user-level QoS for real-time stream applications. Simulations show the effectiveness and liveness of the protocol. / Ph. D.

Geometric trimming of surfaces results in a new mathematical description of the matching surface. This matching surface is required to closely resemble the remaining portion of the original surface. Typically, the approximation error in such cases is measured with a view to minimize it. The data associated with the error between two matching surfaces is large and needs to be filtered into meaningful information.This research looks at suitable norms for achieving this data reduction or abstraction with a view to provide quantitative feedback about the approximation error. Also, the differences between geometric shapes are easily discerned by the human eye but are difficult to characterize or describe. Error visualization tools have been developed to provide effective visual inputs that the designer can interpret into meaningful information. / Master of Science

Error theorists about race face a challenge from the occurrence of diseases and other health ailments that, appear, to be tracked by groups that are carved out by racial terms. If race does indeed allow us to make useful medical distinctions, then it would seem foolish or even a form of medical injustice to deny its reality. This paper provides a response to the stated challenge. First, by primarily using the work of Anthony Appiah, I will describe the error theorist position and its arguments for the non-reality of race. From here, I demonstrate the extent to which medical professionals grant the race is a scientifically arbitrary term and give arguments for accepting race as an alternative that may even be more medically useful. Finally, I advance an eliminativist argument to further motivate the notion that race, if it is truly not necessary, should be eliminated from use. / Master of Arts / Error theorists about race face a challenge from the occurrence of diseases and other health ailments that, appear, to be tracked by groups that are carved out by racial terms. If race does indeed allow us to make useful medical distinctions, then it would seem foolish or even a form of medical injustice to deny its reality. This paper provides a response to the stated challenge. First, by primarily using the work of Anthony Appiah, I will describe the error theorist position and its arguments for the non-reality of race. From here, I demonstrate the extent to which medical professionals grant the race is a scientifically arbitrary term and give arguments for accepting race as an alternative that may even be more medically useful. Finally, I advance an eliminativist argument to further motivate the notion that race, if it is truly not necessary, should be eliminated from use.

This thesis is primarily an attempt to reconstruct the debate between Josiah Royce and Ralph Barton Perry concerning the viability of both the realist and idealist positions. Secondarily, I will show that this debate is a crucial part of an adequate understanding of the changes that took place in American philosophy in the early part of twentieth century. Royce's arguments against the neorealist position of Perry (and others) centered on both the nature of error, and the nature of independence. Perry' response to these arguments was an elaborate effort to demonstrate a coherent and consistent neorealist system which avoided the problems that Royce claimed must beset any such system. I will not attempt to assign the label of "winner" to either participant, however, I will show that the degree of incommensurability involved in the debate played an important role in the shift in American philosophy at the time. / Master of Arts

Cocaine use has contributed to 5 million individuals falling into the cycle of addiction. Prior research in cocaine dependence mainly focused on rewards. Losses also play a critical role in cocaine dependence as dependent individuals fail to avoid social, health, and economic losses even when they acknowledge them. However, dependent individuals are extremely adept at escaping negative states like withdrawal. To further understand whether cocaine use may contribute to dysfunctions in aversive learning, this paper uses fMRI and an aversive learning task to examine cocaine dependent individuals abstinent from cocaine use (C-) and using as usual (C+). Specifically of interest is the neural signal representing actual loss compared to the expected loss, better known as prediction error (δ), which individuals use to update future expectations. When abstinent (C-), dependent individuals exhibited higher positive prediction error (δ+) signal in their striatum than when they were using as usual. Furthermore, their striatal δ+ signal enhancements from drug abstinence were predicted by higher positive learning rate (α+) enhancements. However, no relationships were found between drug abstinence enhancements to negative learning rates (α±-) and negative prediction error (δ-) striatal signals. Abstinent (C-) individuals' striatal δ+ signal was predicted by longer drug use history, signifying possible relief learning adaptations with time. Lastly, craving measures, especially the desire to use cocaine and positive effects of cocaine, also positively correlated with C- individuals' striatal δ+ signal. This suggests possible relief learning adaptations in response to higher craving and withdrawal symptoms. Taken together, enhanced striatal δ+ signal when abstinent and adaptations in relief learning provide evidence in supporting dependent individuals' lack of aversive learning ability while using as usual and enhanced relief learning ability for the purpose of avoiding negative situations such as withdrawal, suggesting a neurocomputational mechanism that pushes the dependent individual to maintains dependence. / Master of Science

Most of the previous research on multistage interference cancellation receivers for Code Division Multiple Access (CDMA) systems has relied on the use of simulation techniques for performance evaluation. This thesis formulates a model for an adaptive multistage interference cancellation receiver within a CDMA system to be employed at the cellular radio base station. A closed form expression for the probability of bit error for this adaptive multistage interference cancellation receiver is derived, using a Gaussian approximation for Multiple Access Interference (MAI). The Bit Error Rate (BER) after any stage of interference cancellation can be computed from the signal to noise ratio, number of users and processing gain of the CDMA system. The BER expressions are extended to derive asymptotic limits on the performance of interference cancellation as the number of cancellation stages approaches infinity, demonstrating a fundamental limit on the performance improvement that can be expected from any multistage interference cancellation scheme. Furthermore, the analysis quantifies conditions under which interference cancellation may degrade performance. This thesis also extends a software implementation of the Multistage Rake receiver for a wide range of channel models including Gaussian noise, MAI, multipath propagation and near-far effects. Simulation results demonstrate the robustness of the Multistage Rake receiver to near-far effects and manifold capacity improvement compared to conventional demodulation techniques. / Master of Science

The accurate measurement of total temperature in engine diagnostics is a challenging task which is subject to several sources of error. Conduction error is predominant among these sources since total temperature sensors are embedded into a cooled strut for measurement. This study seeks to understand the effect of conduction error on total temperature probe performance from an analytical and experimental standpoint and to provide an effective calibration procedure. The review of historical low-order models, as well as results from a developed thermal resistance model, indicates that conduction error is driven by dimensionless parameters, including the Biot, Nusselt, and Reynolds Numbers, as well as a non-dimensional temperature characterizing the flow/strut temperature difference. A conduction error calibration procedure for total temperature probes is experimentally tested in this study. Data were acquired for nominal flow total temperatures ranging from 550 °F to 850 °F with the probe Reynolds number varying from 2,000 to 12,000 for varying conduction conditions with axial temperature gradients up to 1150 °F per inch. A physics-based statistical model successfully expressed total temperature probe performance as a function of dimensionless conduction driver and probe Reynolds number. This statistical model serves as a “calibration surface” for a particular total temperature probe. Due to the scaling of the problem, this calibration is experimentally obtained in moderate temperature regimes, then implemented in higher temperature regimes. The calibration yields an overall uncertainty in total temperature measurement to be ±4% of the total temperature for flow conditions typical in engine diagnostics, with extreme uncertainties in input conditions. Conduction error is successfully shown to be independent of any temperature regime and driven by dimensionless parameters. / Master of Science

When faced with Duhemian problems of underdetermination, scientific method suggests neither a circumvention of such difficulties via the uncritical acceptance of background assumptions, nor the employment of epistemically unsatisfying subjectivist models of rational retainment. Instead, scientists are challenged to attack problems of underdetermination 'head-on', through a careful analysis of the severity of the testing procedures responsible for the production and modeling of their anomalous data. Researchers faced with the task of explaining empirical anomalies, employ a number of diverse and clever experimental techniques designed to cut through the Duhemian mists, and account for potential sources of error that might weaken an otherwise warranted inference. In lieu of such progressive experimental procedures, scientists try to identify the actual inferential work that an existing experiment is capable of providing so as to avoid ascribing to its output more discriminative power than it is rightfully due. We argue that the various strategies adopted by researchers involved in the testing of Bell's inequality, are well represented by Mayo's error-statistical notion of scientific evidence. In particular, an acceptance of her stringent demand for the output of severe tests to stand at the basis of rational inference, helps to explain the methodological reactions expressed by scientists in response to the loopholes that plagued the early Bell experiments performed by Alain Aspect et al.. At the same time, we argue as a counterpoint, that these very reactions present a challenge for 'top-down' approaches to Duhem's problem. / Master of Arts