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Values And Evidence: How Models Make A Difference, Wendy S. Parker, Wendy S. Parker

Philosophy Faculty Publications

We call attention to an underappreciated way in which non-epistemic values influence evidence evaluation in science. Our argument draws upon some well-known features of scientific modeling. We show that, when scientific models stand in for background knowledge in Bayesian and other probabilistic methods for evidence evaluation, conclusions can be influenced by the non-epistemic values that shaped the setting of priorities in model development. Moreover, it is often infeasible to correct for this influence. We further suggest that, while this value influence is not particularly prone to the problem of wishful thinking, it could have problematic non-epistemic consequences in some cases.

Meta-Analysis Of Single-Case Data: A Monte Carlo Investigation Of A Three Level Model, Corina M. Owens

USF Tampa Graduate Theses and Dissertations

Numerous ways to meta-analyze single-case data have been proposed in the literature, however, consensus on the most appropriate method has not been reached. One method that has been proposed involves multilevel modeling. This study used Monte Carlo methods to examine the appropriateness of Van den Noortgate and Onghena's (2008) raw data multilevel modeling approach to the meta-analysis of single-case data. Specifically, the study examined the fixed effects (i.e., the overall average baseline level and the overall average treatment effect) and the variance components (e.g., the between person within study variance in the average baseline level, the between study variance in …

Operational Performance Evaluation Of Four Types Of Exit Ramps On Florida's Freeways, Linjun Lu

USF Tampa Graduate Theses and Dissertations

This research focuses primarily on the analysis of exit ramp performance related to safety and operations. The safety analysis focuses on the impacts of different exit ramp types for freeway diverge areas and different factors contributing to the crashes that occur on the exit ramp sections. The operational analysis is based mainly on simulations by TSIS-CORSIM. Different ramp effects and guidance for selecting optimal exit ramp type are concluded. Issues related to ramp sections and crossroad sections are also demonstrated. Minimum ramp length and minimum distance between ramp terminal and downstream or upstream intersections are calculated. The operational analysis was …

Asymmetric Passive Dynamic Walker Used To Examine Gait Rehabilitation Methods, John Sushko

USF Tampa Graduate Theses and Dissertations

Testing gait rehabilitation devices on humans can be a difficult task, due to the effects of the neurological controls of the human body. This thesis advances the use of a passive dynamic walker (PDW) tuned to have asymmetric gait patterns similar to those with physical impairments to test rehabilitation devices. A passive dynamic walker is a multipendulum system that has a stable gait pattern when walking down a slope without any energy inputs except the forces due to gravity. A PDW model is better suited for testing rehabilitation devices because it has been shown to resemble human gait and separates …

Analyses Of Variable Refrigerant Flow And Exergy In Air Conditioning Systems, Rashid Ali Alshatti

USF Tampa Graduate Theses and Dissertations

This thesis consists of two research problems in the air conditioning (A/C) area. For the first problem, the aim is to model and simulate a variable refrigerant flow (VRF) air conditioning system. The coefficient of performance (COP) for refrigeration or heat pump system is one of the critical parameters for designing an air conditioning system. The modeling of the system components for a VRF cycle under different cooling conditions using R-134a and R-22 as refrigerants was carried out. Calculations were performed by varying different parameters such as condenser and evaporator temperatures, and refrigerant type. The R-134a refrigerant shows a better …

Modeling And Analysis Of Cooperative Search Systems, Carlos A. Portilla

USF Tampa Graduate Theses and Dissertations

The analysis of performance gains arising from cueing in cooperative search

systems with autonomous vehicles has been studied using Continuous Time Markov

Chains; where the search time distributions are assumed to follow the exponential

distributions. This work proposes the use of Petri Nets to model and analyze these

systems. The Petri Net model considers two types of autonomous vehicles: a search-only

vehicle and n search-engage vehicles. Specific performance metrics are defined to

measure system’s performance. Through simulation, it is shown that the search time with

stationary targets and cues that provide exact target location follows a triangular

distribution. A methodology …

Improving The Energy Efficiency Of Ieee 802.3az Eee And Periodically Paused Switched Ethernet, Mehrgan Mostowfi

USF Tampa Graduate Theses and Dissertations

It is estimated that networked devices consumed about 150 TWh of electricity in 2006 in the

U.S. which has cost around $15 billion and contributed about 225 billion lbs of CO

2

to

greenhouse gas emissions. About 13.5% of this energy is consumed by network equipment such

as switches and routers.

This thesis addresses the energy consumption of Ethernet, and designs and evaluates

improvements on existing methods to reduce the energy consumption of Ethernet links and

switches.

Energy Efficient Ethernet (EEE) is an emerging IEEE 802.3 standard which allows Ethernet

links to sleep when idle. In this thesis, a performance …

Improving Ad-Hoc Team Performance Using Video Games, Jeff David Craighead

USF Tampa Graduate Theses and Dissertations

This dissertation examined the effects of distributed, multiplayer training video games on the performance of distributed teams of robot operators. Two hypotheses were tested, the first hypothesis stated that online, game-based team training will improve the performance of an ad-hoc team versus an ad-hoc team formed of individually trained teammates. The second hypothesis stated that the fractal dimension of a robot's path can be used as an indicator of its operator's skill. Forty-one volunteers participated in an experiment in which they played a distributed, online training game which showed them the basics of operating an Inuktun Extreme VGTV for a …

2-D Finite Element Modeling For Nanoindentation And Fracture Stress Analysis, Chi Chen

USF Tampa Graduate Theses and Dissertations

In Chapter 1, a brief introduction of nanoindentation and finite element method is presented. General procedures have been developed based on FEM modeling of nanoindentation data to obtain the mechanical properties of thin films. Selected FEM models are illustrated in detail.

In Chapter 2, nanoindentation test is simulated using finite element method based on contact mechanics approach. The relationship between load and indentation depth is obtained. The numerical results show good agreement with experimental data. It is shown that FEM is an effective tool for simulation of nanoindentation tests of metallic films. However, limitations caused by simplification of models and …

Modeling Upper Body Kinematics While Using A Transradial Prosthesis, Derek J. Lura

USF Tampa Graduate Theses and Dissertations

The prostheses used by the majority of persons with upper limb amputations today offer a limited range of motion. Relative to anatomical joints transradial (below the elbow) prosthesis users lose at least two of the three degrees of freedom provided by the wrist and forearm. Some myoeletric prostheses currently allow for forearm pronation and supination (rotation about an axis parallel to the forearm) and the operation of a powered prosthetic hand. Body-powered prostheses, incorporating hooks and other cable driven terminal devices, have even fewer active degrees of freedom. In order to perform activities of daily living, an amputee must use …

The Model-Based Systematic Development Of Logis Online Graphing Instructional Simulator, Darrel R. Davis

USF Tampa Graduate Theses and Dissertations

This Developmental Research study described the development of an interactive online graphing instructional application and the impact of the Analysis Design Development Implementation Evaluation (ADDIE) model on the development process. An optimal learning environment was produced by combining Programmed Instruction and Adaptive Instruction principles with a graphing simulator that implemented guided contingent practice. The development process entailed the creation and validation of three instruments measuring knowledge, skills, and attitudes, which were components of the instruction.

The research questions were focused on the influence of the ADDIE model on the development process and the value of the LOGIS instructional application. The …

Gate Level Dynamic Energy Estimation In Asynchronous Circuits Using Petri Nets, Ryan Mabry

USF Tampa Graduate Theses and Dissertations

This thesis introduces a new methodology for energy estimation in asynchronous circuits. Unlike existing probabilistic methods, this is the first simulative work for energy estimation in all types of asynchronous circuits.

The new simulative methodology is based on Petri net modeling. A real delay model is incorporated to capture both gate delays and interconnect delays. The switching activity at each gate is captured to measure the average dynamic energy consumed per request/acknowledge handshaking pair. The new type of Petri net is called Hierarchical Colored Asynchronous Hardware Petri net (HCAHPN). The HCAHPN is able to capture the temporal and spatial correlations …

Multi-Criteria Decision Making In Outpatient Scheduling, Jana Iezzi

USF Tampa Graduate Theses and Dissertations

Hospital ambulatory patients are seen in outpatient departments (OPDs) located in the hospital. 83.3 million visits were made to these departments in 2002. Many sources of patient waiting time exist including: poor coordination of information, inefficient scheduling, inaccurate time estimation and others. Well-designed and executed patient scheduling has the potential to remedy some of these problems. To properly schedule patients, variability in demand must be addressed. Patients may cancel appointments, arrive late and arrive without appointments. We address this problem based on a Multi-attribute Decision Making (MADM) approach. Decision models are developed using the Simple Additive Weighting (SAW) method to …

Study Of Laplace And Related Probability Distributions And Their Applications, Gokarna Raj Aryal

USF Tampa Graduate Theses and Dissertations

The aim of the present study is to investigate a probability distribution that can be derived from the laplace probability distribution and can be used to model various real world problems. In the last few decades, there has been a growing interest in the construction of flexible parametric classes of probability distributions. Various forms of the skewed and kurtotic distributions have appeared in the literature for data analysis and modeling. In particular, various forms of the skew laplace distribution have been introduced and applied in several areas including medical science, environmental science, communications, economics, engineering and finance, among others. In …

System Optimization For Micron And Sub-Micron Particle Identification Using Spectroscopy-Based Techniques, Eduardo Zurek

USF Tampa Graduate Theses and Dissertations

This dissertation describes an approach and a model for the analysis of critical parameters related to the optical and electronic components of spectroscopy systems. The model described herein enables a systematic study of the impact of these parameters on the total performance of the system; therefore, it is a tool for the design and optimization of spectrometers.

Although the physics of the optical and electronic components in spectroscopy systems are known and well established, the systemic approach to the understanding of their interactions is recent and it is an area of active research. The results from this study are at …

Statistical Models In Environmental And Life Sciences, Lakshminarayan Rajaram

USF Tampa Graduate Theses and Dissertations

The dissertation focuses on developing statistical models in environmental and life sciences. The Generalized Extreme Value distribution is used to model annual monthly maximum rainfall data from 44 locations in Florida. Time dependence of the rainfall data is incorporated into the model by assuming the location parameter to be a function of time, both linear and quadratic. Estimates and confidence intervals are obtained for return levels of return periods of 10, 20, 50, and 100 years. Locations are grouped into statistical profiles based on their similarities in return level graphs for all locations, and locations within each climatic zone. A …

Does Agreeableness Help A Team Perform A Problem Solving Task?, Frederick R. B Stilson

USF Tampa Graduate Theses and Dissertations

The relationship between mean team Agreeableness and team performance has not been shown definitively. The present study was performed looking at archival data from a study that assessed team performance from 62 two person teams using the DDD and involving two types of training and two types of information probes during the computer task. In addition, each of the participants took a personality test based on the IPIP with an emphasis on Agreeableness and its 6 facets. Using HLM analysis, it was determined that Agreeableness does not have a significant effect on team performance for a problem solving tasks (delta …

Opportunistic Maintenance Policy Of A Multi-Unit System Under Transient State, Sulabh Jain

USF Tampa Graduate Theses and Dissertations

Most modern systems are equipped with very complex, expensive, and high technology components whose maintenance costs have become an increasingly large portion of the total operating cost of these systems. Thus, the efficacy of the maintenance policy for these and related systems has become a major concern to both manufacturing and design engineers. Different kinds of maintenance strategies have been proposed to solve the problem. While some of these have proven effective, there is yet no definitive approach that has been found that support the maintainability requirements of transient systems or systems that exhibit transient behavior. Transient behavior is the …

Performance Evaluation Of Multi-Product Kanban-Like Control Systems, Sachin S. Deokar

USF Tampa Graduate Theses and Dissertations

Over the years, much attention has been given to the analysis of the pull type ordering system to reduce in-process inventory and to improve product quality. Kanban Control Systems are widely used to control the release of parts in multi-stage manufacturing systems operating under a pull mechanism. Considerable research has been done to study the individual manufacturing systems for multi stage and single product. However, not much research has been done to compare different pull control policies for multi product manufacturing systems.

Most of the research done in multi-product system assumes that a kanban card is dedicated to a part …

Modeling Alternate Strategies For Airline Revenue Management, Kapil Joshi

USF Tampa Graduate Theses and Dissertations

Ever since the deregulation of the airline industry in 1978, fierce competition has made every airline try and gain a competitive edge in the market. In order to accomplish this, airlines are turning to advanced optimization techniques such as revenue management. Revenue management is a way for airlines to maximize capacity and profitability by managing supply and demand through price management.

Over the last few years research in the field of revenue management has steadily progressed from seat inventory control techniques such as single leg seat inventory and network inventory control to ticket pricing techniques. Ticket pricing techniques involve setting …

Real Delay Graphical Probabilistic Switching Model For Vlsi Circuits, Vivekanandan Srinivasan

USF Tampa Graduate Theses and Dissertations

Power optimization is a crucial issue at all levels of abstractions in VLSI Design. Power estimation has to be performed repeatedly to explore the design space throughout the design process at all levels. Dynamic Power Dissipation due to Switching Activity has been one of the major concerns in Power Estimation. While many Simulation and Statistical Simulation based methods exist to estimate Switching Activity, these methods are input pattern sensitive, hence would require a large input vector set to accurately estimate Power. Probabilistic estimation of switching activity under Zero-Delay conditions, seriously undermines the accuracy of the estimation process, since it fails …

Development Of Assessment Tasks To Measure The Driving Capabilities Of Persons With Disabilities, Ashwin Upadhyay

USF Tampa Graduate Theses and Dissertations

The need to lead an independent and fuller life is as much a right of a person with physical disability as any other human being. Driving capabilities of a person with a disability have been assessed and evaluated using qualitative techniques. However, certain inadequacies that arise using qualitative measures can be avoided if the assessment is based on quantitative techniques.

The above requirement necessitates the need to devise a method and a system which is focused on the right development of the techniques used in assessing and measuring different capabilities (such as range of motion and force input) of the …

Stimulus-Free Rt Level Power Model Using Belief Propagation, Sathishkumar Ponraj

USF Tampa Graduate Theses and Dissertations

Power consumption is one of the major bottlenecks in current and future VLSI design. Early microprocessors, which consumed a few tens of watts, are now replaced by millions of transistors and with the introduction of easy-to-design tools to explore at unbelievable minimum dimensions, increase in chip density is increasing at a alarming rate and necessitates faster power estimation methods. Gate level power estimation techniques are highly accurate methods but when time is the main constraint, power has to be estimated a lot higher in the abstraction level. Estimating power at higher levels also saves valuable time and cost involved in …

Graphical Probabilistic Switching Model: Inference And Characterization For Power Dissipation In Vlsi Circuits, Shiva Shankar Ramani

USF Tampa Graduate Theses and Dissertations

Power dissipation in a VLSI circuit poses a serious challenge in present and future VLSI design. A switching model for the data dependent behavior of the transistors is essential to model dynamic, load-dependent active power and also leakage power in active mode - the two components of power in a VLSI circuit. A probabilistic Bayesian Network based switching model can explicitly model all spatio-temporal dependency relationships in a combinational circuit, resulting in zero-error estimates. However, the space-time requirements of exact estimation schemes, based on this model, increase with circuit complexity [5, 24]. This work explores a non-simulative, importance sampling based, …

Modeling Demand Uncertainty And Processing Time Variability For Multi-Product Chemical Batch Process, Rishi Darira

USF Tampa Graduate Theses and Dissertations

Most of the literature on scheduling of multi-product batch process does not consider the uncertainties in demand and variability in processing times. We develop a simulation based variable production schedule model for a multi-product batch facility assuming zero wait transfer policy and single product campaign. The model incorporates the demand uncertainties and processing time variability. The impact of demand uncertainties is evaluated in terms of total annual cost, which comprises of the backorder and inventory costs per year. The effect of variability in processing time is measured by the annual production time. We also develop a constant production schedule model …

Estimation Of Switching Activity In Sequential Circuits Using Dynamic Bayesian Networks, Karthikeyan Lingasubramanian

USF Tampa Graduate Theses and Dissertations

This thesis presents a novel, non-simulative, probabilistic model for switching activity in sequential circuits, capturing both spatio-temporal correlations at internal nodes and higher order temporal correlations due to feedback. Switching activity, one of the key components in dynamic power dissipation, is dependent on input streams and exhibits spatio-temporal correlation amongst the signals. One can handle dependency modeling of switching activity in a combinational circuit by Bayesian Networks [2] that encapsulates the underlying joint probability distribution function exactly.

We present the underlying switching model of a sequential circuit as the time coupled logic induced directed acyclic graph (TC-LiDAG), that can be …

Adaptive Digital Predistortion Linearizer For Power Amplifiers In Military Uhf Satellite, Jayanti Patel

USF Tampa Graduate Theses and Dissertations

The existing UHF Satellite Communications (SATCOM) transponders used for military applications use efficient, saturated power amplifiers, which provide one earth-coverage antenna beam. The amplifier is dedicated to small frequency band and only handles a few carriers simultaneously.

The communications capacity needed to support future military forces on the move will require satellite payload power amplifiers to support hundreds of channels simultaneously, with the channels spread over the entire military UHF SATCOM band. To meet the capacity requirements and simultaneously meet the out-of-band emission, power amplifiers will have to be highly linear. The high-efficiency, ultra-linear power amplifier architecture proposed to support …

Characterization And Generation Of Streaming Video Traces, John N. Shahbazian

USF Tampa Graduate Theses and Dissertations

This thesis describes two methods collectively called Time Series Generation (TSG) that can be used to generate time series inputs modeling packet loss to test IP-based streaming video software. The TSG methods create packet loss models that recreate the mean, variance, and autocorrelation signatures of an actual trace. The synthetic packet loss traces can have their inherent statistics altered, thus allowing for thorough testing of video software in ways that could not be done on actual networks. The two methods comprising TSG, which are individually called the primary and secondary method, use the principle of iterated uniformity to create a …

Modeling Dynamic Interactions In A Software Development Project, Chetan D. Vajre

USF Tampa Graduate Theses and Dissertations

Software industry is getting very competitive in the wake of recession. In most cases, an organization that quotes a lower price and promises to deliver the product at the earliest walks away with the project. But the factor of quality of the product delivered is also very important because that in turn determines the reputation of an organization, which also plays an important role in getting the next project.

Interactions in a software development are dynamic in nature and involve human factors. Models are built taking into account all possible factors so as to present a realistic picture of the …