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- Title
- Psychophysiology meets computer science: predicting the magnitude of participant physiological response with machine learning.
- Creator
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Parchment, Avonie, Wiegand, Rudolf, Matthews, Gerald, Yan, Xin, Abich, Julian, Greenwood-Ericksen, Adams, University of Central Florida
- Abstract / Description
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The present inquiry uses methods from psychophysiology and machine learning to reduce overall error in classification models. The field of psychophysiology, though rooted in decades of experimentation, has never reached the same level of precision as some aspects of medical inquiry. In fact, while some medical regression models, when determining some way to classify a patient's illness based on certain symptoms, can result in highly significant results with large effect sizes, equal levels...
Show moreThe present inquiry uses methods from psychophysiology and machine learning to reduce overall error in classification models. The field of psychophysiology, though rooted in decades of experimentation, has never reached the same level of precision as some aspects of medical inquiry. In fact, while some medical regression models, when determining some way to classify a patient's illness based on certain symptoms, can result in highly significant results with large effect sizes, equal levels are virtually unheard of in psychophysiology. The present investigation attempts to unravel some part of this mystery and determines some possible reasons for the difficulty in finding similar effect sizes, especially concerning methods that match participant state with physiological response. Of particular focus are two areas: baseline research and experimental data analysis methods. The role of baselining techniques in relation to overall quality of response is the first emphasis and this interest stems from the Law of Initial Value that indicates some relationship between baseline and experimental response. Though this relationship has been continually investigated and found to be lacking for many physiological measures, experimental condition heart rate response has been consistently shown to rely heavily on baseline response. This finding influences the second half of the present inquiry, which deals with the overall analysis of experimental data and the role that traditional statistics could play in the present problem. By comparing logistic regression and support vector models, it is expected that researchers would use the preferred method, based on their goals, to flag potentially highly influential cases that may greatly skew data and make modeling difficult. Additionally, demographic characteristics that could also help identify these influential cases in the future before modeling are shown.
Show less - Date Issued
- 2018
- Identifier
- CFE0007355, ucf:52106
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007355
- Title
- Persistence of Physical Activity Among Veterans.
- Creator
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Davis, Jean, Edwards, Joellen, Loerzel, Victoria, Weiss, Josie, Kehinde, Julius, University of Central Florida
- Abstract / Description
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The global burden of disease is staggering in terms of financial costs and human suffering. The general public is aware that physical activity is healthy, although the fact that physical activity can treat and reverse diseases, reduce the risk of cancers, prevent many chronic diseases, stave off cognitive decline, and contribute to quality longevity is less well known. Healthcare practitioners and policymakers are impeded in efforts to support physical activity due to the lack of knowledge of...
Show moreThe global burden of disease is staggering in terms of financial costs and human suffering. The general public is aware that physical activity is healthy, although the fact that physical activity can treat and reverse diseases, reduce the risk of cancers, prevent many chronic diseases, stave off cognitive decline, and contribute to quality longevity is less well known. Healthcare practitioners and policymakers are impeded in efforts to support physical activity due to the lack of knowledge of factors associated with physical activity persistence. The purpose of this dissertation was to determine these factors and identify which predict persistent physical activity among veterans to inform future programs and policies to support physical activity for health. The theorized influence of physical activity habit is addressed in the initial dissertation manuscript. Habits being more difficult to lapse from than to continue made them suitable for investigation to address the knowledge gap identified when no reports of long-term physical activity habits were found. Veterans provided an ideal population to study long-term physical activity habits with, as research indicates that veterans likely formed physical activity habits through recurrent physical activity required to meet the fitness requirements of active duty service. This led to the research reported in the second manuscript. The research was based on theory, literature review, and input from veterans. The integrated theory of health behavior change informed the predictor variables investigated. The explanatory and predictive cross-sectional study of community-dwelling veterans used the web survey method to answer questions of which factors were associated with sufficient or insufficient physical activity among veterans, and which factors were predictive. Recruitment of veterans occurred through Amazon's Mechanical Turk (MTurk(&)#174;) and linked veterans to the survey on Qualtrics(&)#174;. Findings revealed direct associations of exercise self-regulation, social support for exercise, and some service-related and other demographic factors with sufficient or insufficient physical activity. Qualtrics(&)#174; allowed for the presentation of survey questions in a variety of formats. To determine the best format for survey items, a state of the knowledge review was conducted. This review is presented in the final dissertation manuscript. Implications for future research, health education, clinical practice, and health policy are identified. It is expected that the knowledge gained in this study will inform future Veterans Affairs programs, provider practices, public health initiatives, and health care policies to support physical activity practices for healthy longevity.
Show less - Date Issued
- 2019
- Identifier
- CFE0007886, ucf:52783
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007886
- Title
- Pooling correlation matrices corrected for selection bias: Implications for meta-analysis.
- Creator
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Matthews, Kenneth, Sivo, Stephen, Bai, Haiyan, Hahs-Vaughn, Debbie, Butler, Malcolm, University of Central Florida
- Abstract / Description
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Selection effects systematically attenuate correlations and must be considered when performing meta-analyses. No research domain is immune to selection effects, evident whenever self-selection or attrition take place. In educational research, selection effects are unavoidable in studies of postsecondary admissions, placement testing, or teacher selection. While methods to correct for selection bias are well documented for univariate meta-analyses, they have gone unexamined in multivariate...
Show moreSelection effects systematically attenuate correlations and must be considered when performing meta-analyses. No research domain is immune to selection effects, evident whenever self-selection or attrition take place. In educational research, selection effects are unavoidable in studies of postsecondary admissions, placement testing, or teacher selection. While methods to correct for selection bias are well documented for univariate meta-analyses, they have gone unexamined in multivariate meta-analyses, which synthesize more than one correlation from each study (i.e., a correlation matrix). Multivariate meta-analyses of correlations provide opportunities to explore complex relationships and correcting for selection effects improves the summary effect estimates. I used Monte Carlo simulations to test two methods of correcting selection effects and evaluate a method for pooling the corrected matrices. First, I examined the performance of Thorndike's corrections (for both explicit and incidental selection) and Lawley's multivariate correction for selection on correlation matrices when explicit selection takes place on a single variable. Simulation conditions included a wide range of selection ratios, samples sizes, and population correlations. The results indicated that univariate and multivariate correction methods perform equivalently. I provide practical guidelines for choosing between the two methods. In a second Monte Carlo simulation, I examined the confidence interval coverage rates of a Robust Variance Estimation (RVE) procedure when it is used to pool correlation matrices corrected for selection effects under a random-effects model. The RVE procedure empirically estimates the standard errors of the corrected correlations and has the advantage of having no distributional assumptions. Simulation conditions included tau-squared ratio, within-study sample size, number of studies, and selection ratio. The results were mixed, with RVE performing well under higher selection ratios and larger unrestricted sample sizes. RVE performed consistently across values of tau-squared. I recommend applications of the results, especially for educational research, and opportunities for future research.
Show less - Date Issued
- 2019
- Identifier
- CFE0007680, ucf:52483
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007680
- Title
- DETECTING BURIED METALLIC WEAPONS IN A CONTROLLED SETTING USING A CONDUCTIVITY METER AND A GROUND-PENETRATING RADAR.
- Creator
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Dionne, Charles, Schultz, John, University of Central Florida
- Abstract / Description
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Searching for buried metallic evidence at crime scenes or at potential disposal sites can be a daunting task for forensic personnel. In particular, it is common to search for a small firearm that was discarded or buried by the perpetrator. When performing forensic searches, it is recommended to first use non-invasive methods such as geophysical instruments to minimize damage to evidence and to the crime scene. Geophysical tools are used to pinpoint small areas of interest across a scene that...
Show moreSearching for buried metallic evidence at crime scenes or at potential disposal sites can be a daunting task for forensic personnel. In particular, it is common to search for a small firearm that was discarded or buried by the perpetrator. When performing forensic searches, it is recommended to first use non-invasive methods such as geophysical instruments to minimize damage to evidence and to the crime scene. Geophysical tools are used to pinpoint small areas of interest across a scene that will be invasively tested later. Prior to this project, there was no published research that tested the utility of the conductivity meter to search for metallic weapons such as firearms and blunt or sharp edged weapons. A sample comprised of 32 metallic weapons was buried in a controlled setting to test the applicability of a conductivity meter for forensic searches. Weapons were tested at multiple depths; once data collection was performed for one depth, the weapons were reburied 5cm deeper until they were no longer detected. Results obtained with conductivity meter were compared to results obtained by the ground-penetrating radar using different depths and transect intervals. The effects of several variables on detection such as weapon size, metallic composition, burial depth, and transect interval were analyzed in order to explore the limitations of each instrument. Results obtained from this controlled research can provide guidelines to help law enforcement in real-world searches.
Show less - Date Issued
- 2009
- Identifier
- CFE0002597, ucf:48264
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002597
- Title
- STUDY OF THE HYDRODYNAMICS OF DROPLET IMPINGEMENT ON A DRY SURFACE USING LATTICE BOLTZMANN METHOD.
- Creator
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Gu, Xin, Kumar, Ranganathan, University of Central Florida
- Abstract / Description
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In this work, a two-phase lattice Boltzmann method (LBM) approach is implemented to investigate the hydrodynamic behavior of a single droplet impingement on a dry surface. LBM is a recently developed powerful technique to compute a wide range of fluid flow problems, especially in applications involving interfacial dynamics and complex geometries. Instead of solving the non-linear Navier-Stokes equations, which are complicated partial differential equations, LBM solves a set of discretized...
Show moreIn this work, a two-phase lattice Boltzmann method (LBM) approach is implemented to investigate the hydrodynamic behavior of a single droplet impingement on a dry surface. LBM is a recently developed powerful technique to compute a wide range of fluid flow problems, especially in applications involving interfacial dynamics and complex geometries. Instead of solving the non-linear Navier-Stokes equations, which are complicated partial differential equations, LBM solves a set of discretized linear equations, which are easy to implement and parallelize. The fundamental idea of LBM is to recover the macroscopic properties of the fluid which obeys Navier-Stokes equations, by using simplified kinetic equations that incorporate the essential physics at the microscopic level. Considering the numerical instability induced by large density difference between two phases during the LBM simulations, the particular LBM scheme used in this study has its benefits when dealing with high density ratios. All the simulations are conducted for density ratio up to 50 in a three-dimensional Cartesian coordinate system, and three important dimensionless numbers, namely Weber number, Reynolds number and Ohnesorge number, are used for this study. To validate this multiphase LBM approach, several benchmark tests are conducted. First, the angular frequency of an oscillating droplet is calculated and compared with the corresponding theoretical value. Errors are found to be within 6.1% for all the cases. Secondly, simulations of binary droplet collisions are conducted in the range of 20 - Date Issued
- 2009
- Identifier
- CFE0002622, ucf:48190
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002622
- Title
- A MULTIPLE CASE STUDY INVESTIGATING THE EFFECTS OF TECHNOLOGY ON STUDENTS' VISUAL AND NONVISUAL THINKING PREFERENCES: COMPARING PAPER-PENCIL AND DYNAMIC SOFTWARE BASED STRATEGIES OF ALGEBRA WORD PROBLEMS.
- Creator
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Coskun, Sirin, Dixon, Juli, University of Central Florida
- Abstract / Description
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In this multiple-case study, I developed cases describing three students' (Mary, Ryan and David) solution methods for algebra word problems and investigated the effect of technology on their solution methods by making inferences about their preferences for visual or nonvisual solutions. Furthermore, I examined the students' solution methods when presented with virtual physical representations of the situations described in the problems and attempted to explain the effect of those...
Show moreIn this multiple-case study, I developed cases describing three students' (Mary, Ryan and David) solution methods for algebra word problems and investigated the effect of technology on their solution methods by making inferences about their preferences for visual or nonvisual solutions. Furthermore, I examined the students' solution methods when presented with virtual physical representations of the situations described in the problems and attempted to explain the effect of those representations on students' thinking preferences. In this study, the use of technology referred to the use of the dynamic software program Geogebra. Suwarsono's (1982) Mathematical Processing Instrument (MPI) was administered to determine their preferences for visual and nonvisual thinking. During the interviews, students were presented with paper-and-pencil-based tasks (PBTs), Geogebra-based tasks (GBTs) and Geogebra-based tasks with virtual physical representations (GBT-VPRs). Each category included 10 algebra word problems, with similar problems across categories. (i.e., PBT 9, GBT 9 and GBT-VPR 9 were similar). By investigating students' methods of solution and their use of representations in solving those tasks, I compared and contrasted their preferences for visual and nonvisual methods when solving problems with and without technology. The comparison between their solutions of PBTs and GBTs revealed how dynamic software influenced their method of solution. Regardless of students' preferences for visual and nonvisual solutions, with the use of dynamic software students employed more visual methods when presented with GBTs. When visual methods were as accessible and easy to use as nonvisual methods, students preferred to use them, thus demonstrating that they possessed a more complete knowledge of problem-solving with dynamic software than their work on the PBTs. Nowadays, we can construct virtual physical representations of the problems in technology environments that will help students explore the relationships and look for patterns that can be used to solve the problem. Unlike GBTs, GBT-VPRs did not influence students' preferences for visual or nonvisual methods. Students continued to rely on methods that they preferred since their preferences for visual or nonvisual solutions regarding GBT-PRs were similar to their solution preferences for the problems on MPI that was administered to them to determine their preferences for visual or nonvisual methods. Mary, whose MPI score suggested that she preferred to solve mathematics problems using nonvisual methods, solved GBT-VPRs with nonvisual methods. Ryan, whose MPI score suggested that he preferred to solve mathematics problems using visual methods, solved GBT-VPRs with visual methods. David, whose MPI score suggested that he preferred to solve mathematics problems using both visual and nonvisual methods, solved GBT-VPRs with both visual and nonvisual methods.
Show less - Date Issued
- 2011
- Identifier
- CFE0003900, ucf:48733
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003900
- Title
- The Effect of Speech Elicitation Method on Second Language Phonemic Accuracy.
- Creator
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Carrasquel, Nicole, Farina, Marcella, Folse, Keith, Purmensky, Kerry, Clark, M. H., University of Central Florida
- Abstract / Description
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The present study, a One-Group Posttest-Only Repeated-Measures Design, examined the effect of speech elicitation method on second language (L2) phonemic accuracy of high functional load initial phonemes found in frequently occurring nouns in American English. This effect was further analyzed by including the variable of first language (L1) to determine if L1 moderated any effects found. The data consisted of audio recordings of 61 adult English learners (ELs) enrolled in English for Academic...
Show moreThe present study, a One-Group Posttest-Only Repeated-Measures Design, examined the effect of speech elicitation method on second language (L2) phonemic accuracy of high functional load initial phonemes found in frequently occurring nouns in American English. This effect was further analyzed by including the variable of first language (L1) to determine if L1 moderated any effects found. The data consisted of audio recordings of 61 adult English learners (ELs) enrolled in English for Academic Purposes (EAP) courses at a large, public, post-secondary institution in the United States. Phonemic accuracy was judged by two independent raters as either approximating a standard American English (SAE) pronunciation of the intended phoneme or not, thus a dichotomous scale, and scores were assigned to each participant in terms of the three speech elicitation methods of word reading, word repetition, and picture naming.Results from a repeated measures ANOVA test revealed a statistically significant difference in phonemic accuracy (F(1.47, 87.93) = 25.94, p = .000) based on speech elicitation method, while the two-factor mixed design ANOVA test indicated no statistically significant differences for the moderator variable of native language. However, post-hoc analyses revealed that mean scores of picture naming tasks differed significantly from the other two elicitation methods of word reading and word repetition.Moreover, the results of this study should heighten attention to the role that various speech elicitation methods, or input modalities, might play on L2 productive accuracy. Implications for practical application suggest that caution should be used when utilizing pictures to elicit specific vocabulary words(-)even high-frequency words(-)as they might result in erroneous productions or no utterance at all. These methods could inform pronunciation instructors about best teaching practices when pronunciation accuracy is the objective. Finally, the impact of L1 on L2 pronunciation accuracy might not be as important as once thought.
Show less - Date Issued
- 2017
- Identifier
- CFE0006725, ucf:51880
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006725
- Title
- Computational Methods for Comparative Non-coding RNA Analysis: from Secondary Structures to Tertiary Structures.
- Creator
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Ge, Ping, Zhang, Shaojie, Guha, Ratan, Stanley, Kenneth, Jha, Sumit, Song, Hojun, University of Central Florida
- Abstract / Description
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Unlike message RNAs (mRNAs) whose information is encoded in the primary sequences, the cellular roles of non-coding RNAs (ncRNAs) originate from the structures. Therefore studying the structural conservation in ncRNAs is important to yield an in-depth understanding of their functionalities. In the past years, many computational methods have been proposed to analyze the common structural patterns in ncRNAs using comparative methods. However, the RNA structural comparison is not a trivial task,...
Show moreUnlike message RNAs (mRNAs) whose information is encoded in the primary sequences, the cellular roles of non-coding RNAs (ncRNAs) originate from the structures. Therefore studying the structural conservation in ncRNAs is important to yield an in-depth understanding of their functionalities. In the past years, many computational methods have been proposed to analyze the common structural patterns in ncRNAs using comparative methods. However, the RNA structural comparison is not a trivial task, and the existing approaches still have numerous issues in efficiency and accuracy. In this dissertation, we will introduce a suite ofnovel computational tools that extend the classic models for ncRNA secondary and tertiary structure comparisons.For RNA secondary structure analysis, we first developed a computational tool, named PhyloRNAalifold, to integrate the phylogenetic information into the consensus structural folding. The underlying idea of this algorithm is that the importance of a co-varying mutation should be determined by its position on the phylogenetic tree. By assigning high scores to the critical covariances, the prediction of RNA secondary structure can be more accurate. Besides structure prediction, we also developed a computational tool, named ProbeAlign, to improvethe efficiency of genome-wide ncRNA screening by using high-throughput RNA structural probing data. It treats the chemical reactivities embedded in the probing information as pairing attributes of the searching targets. This approach can avoid the time-consuming base pair matching in the secondary structure alignment. The application of ProbeAlign to the FragSeq datasets shows its capability of genome-wide ncRNAs analysis.For RNA tertiary structure analysis, we first developed a computational tool, named STAR3D, to find the global conservation in RNA 3D structures. STAR3D aims at finding the consensus of stacks by using 2D topology and 3D geometry together. Then, the loop regions can be ordered and aligned according to their relative positions in the consensus. This stack-guided alignment method adopts the divide-and-conquer strategy into RNA 3D structural alignment, which has improved its efficiency dramatically. Furthermore, we also have clustered all loop regions in non-redundant RNA 3D structures to de novo detect plausible RNA structural motifs. The computational pipeline, named RNAMSC, was extended to handle large-scale PDB datasets, and solid downstream analysis was performed to ensure the clustering results are valid and easily to be applied to further research. The final results contain many interesting variations of known motifs, such as GNAA tetraloop, kink-turn, sarcin-ricin and t-loops. We also discovered novel functional motifs that conserved in a wide range of ncRNAs, including ribosomal RNA, sgRNA, SRP RNA, GlmS riboswitch and twister ribozyme.
Show less - Date Issued
- 2016
- Identifier
- CFE0006104, ucf:51212
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006104
- Title
- Neurophenomenological Methods: Experiences of Earth and Space in Simulation.
- Creator
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Morrow, Patricia, Reinerman, Lauren, Cash, Mason, Janz, Bruce, Gallagher, Shaun, University of Central Florida
- Abstract / Description
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The present study explores the nature and structure of spiritual and aesthetic experiences through the interdisciplinary application of neurophenomenology (NP). This approach merges aspects of psychology, neurophysiology, and phenomenology into a unified methodology. The study is nested within a larger project, Space, Science, and Spirituality, and as such, it carries a common goal to use simulation to evoke spiritual and aesthetic responses similar to those expressed by astronauts and...
Show moreThe present study explores the nature and structure of spiritual and aesthetic experiences through the interdisciplinary application of neurophenomenology (NP). This approach merges aspects of psychology, neurophysiology, and phenomenology into a unified methodology. The study is nested within a larger project, Space, Science, and Spirituality, and as such, it carries a common goal to use simulation to evoke spiritual and aesthetic responses similar to those expressed by astronauts and cosmonauts. Careful analysis of previous work in NP provided methodological (")lessons learned("), which guided the experimental design, execution, and analysis of the present study. The data collected provides support for experience as a phenomenon that can be studied through empirical means. Further, the articulation of spiritual and aesthetic experiences akin to astronaut experiences corresponds to specific neurological and psychological indicators. Among those indicators are differences in EEG measures during simulation time relative to expressions of spiritual experience following the simulation and changes in visual processing across theta, alpha, and beta signals as correlated with self-identification. These findings support an embodied theory of experience that incorporates memory, executive function, perception, and consciousness. In addition to its academic contribution, this research holds implications for commercial space flight, long-term space missions, post-traumatic stress disorder therapies, and the entertainment industry.
Show less - Date Issued
- 2013
- Identifier
- CFE0005035, ucf:50018
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005035
- Title
- On Kernel-base Multi-Task Learning.
- Creator
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Li, Cong, Georgiopoulos, Michael, Anagnostopoulos, Georgios, Tappen, Marshall, Hu, Haiyan, Ni, Liqiang, University of Central Florida
- Abstract / Description
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Multi-Task Learning (MTL) has been an active research area in machine learning for two decades. By training multiple relevant tasks simultaneously with information shared across tasks, it is possible to improve the generalization performance of each task, compared to training each individual task independently. During the past decade, most MTL research has been based on the Regularization-Loss framework due to its flexibility in specifying various types of information sharing strategies, the...
Show moreMulti-Task Learning (MTL) has been an active research area in machine learning for two decades. By training multiple relevant tasks simultaneously with information shared across tasks, it is possible to improve the generalization performance of each task, compared to training each individual task independently. During the past decade, most MTL research has been based on the Regularization-Loss framework due to its flexibility in specifying various types of information sharing strategies, the opportunity it offers to yield a kernel-based methods and its capability in promoting sparse feature representations.However, certain limitations exist in both theoretical and practical aspects of Regularization-Loss-based MTL. Theoretically, previous research on generalization bounds in connection to MTL Hypothesis Space (HS)s, where data of all tasks are pre-processed by a (partially) common operator, has been limited in two aspects: First, all previous works assumed linearity of the operator, therefore completely excluding kernel-based MTL HSs, for which the operator is potentially non-linear. Secondly, all previous works, rather unnecessarily, assumed that all the task weights to be constrained within norm-balls, whose radii are equal. The requirement of equal radii leads to significant inflexibility of the relevant HSs, which may cause the generalization performance of the corresponding MTL models to deteriorate. Practically, various algorithms have been developed for kernel-based MTL models, due to different characteristics of the formulations. Most of these algorithms are a burden to develop and end up being quite sophisticated, so that practitioners may face a hard task in interpreting and implementing them, especially when multiple models are involved. This is even more so, when Multi-Task Multiple Kernel Learning (MT-MKL) models are considered. This research largely resolves the above limitations. Theoretically, a pair of new kernel-based HSs are proposed: one for single-kernel MTL, and another one for MT-MKL. Unlike previous works, we allow each task weight to be constrained within a norm-ball, whose radius is learned during training. By deriving and analyzing the generalization bounds of these two HSs, we show that, indeed, such a flexibility leads to much tighter generalization bounds, which often results to significantly better generalization performance. Based on this observation, a pair of new models is developed, one for each case: single-kernel MTL, and another one for MT-MKL. From a practical perspective, we propose a general MT-MKL framework that covers most of the prominent MT-MKL approaches, including our new MT-MKL formulation. Then, a general purpose algorithm is developed to solve the framework, which can also be employed for training all other models subsumed by this framework. A series of experiments is conducted to assess the merits of the proposed mode when trained by the new algorithm. Certain properties of our HSs and formulations are demonstrated, and the advantage of our model in terms of classification accuracy is shown via these experiments.
Show less - Date Issued
- 2014
- Identifier
- CFE0005517, ucf:50321
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005517
- Title
- Landscaping Perceptions and Behaviors: Socio-ecological Drivers of Nitrogen in the Residential Landscape.
- Creator
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Souto, Leesa, Hinkle, Charles, Canan, Penelope, Noss, Reed, Weishampel, John, Pals, Heili, University of Central Florida
- Abstract / Description
-
Driven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen...
Show moreDriven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen inputs to aquatic systems requires a better understanding of the links between residential landscape management and the potential for fertilizer loss. This dissertation examines the linkages between the human behaviors contributing nitrogen to the suburban landscape and the resulting environmental impacts. Framed in socio-psychological theory and social marketing research, the outcomes of this dissertation contribute much needed information to the growing realm of interdisciplinary science that expands integrative theory, develops mixed methods, utilizes spatial and temporal analyses, and conducts actionable research.
Show less - Date Issued
- 2012
- Identifier
- CFE0004604, ucf:49931
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004604
- Title
- Tails in the Wind: An Exploratory Examination of Media Reports on Nonhuman Animals Throughout Hurricane Maria in Puerto Rico.
- Creator
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Jagoda, Nathan, Huff-Corzine, Lin, Rivera, Fernando, Grauerholz, Liz, University of Central Florida
- Abstract / Description
-
On September 20th, 2017, category four Hurricane Maria rattled Puerto Rico, causing extensive damage throughout the island. While the experiences, injuries, and deaths of humans resulting from Hurricane Maria have received both scholarly consideration and large amounts of attention from media sources, one critical area that has been overlooked by many, particularly academics, are the ways in which various media sources have reported on, described and discussed nonhuman animals impacted by the...
Show moreOn September 20th, 2017, category four Hurricane Maria rattled Puerto Rico, causing extensive damage throughout the island. While the experiences, injuries, and deaths of humans resulting from Hurricane Maria have received both scholarly consideration and large amounts of attention from media sources, one critical area that has been overlooked by many, particularly academics, are the ways in which various media sources have reported on, described and discussed nonhuman animals impacted by the storm. This study aimed to address this gap by analyzing media reports of nonhuman animals throughout the days before, during, and after Hurricane Maria in Puerto Rico. Mixed method content analysis was conducted on fifty-five media reports found to contain discussion of nonhuman animals and Hurricane Maria in Puerto Rico, though a majority of the analyses were qualitative in nature. Analyses resulted in the identification of a variety of themes found to be emergent from the data.Themes explored include nonhuman animal abandonment, insufficient shelters, damaged shelters and lack of resources, collaboration between nonhuman animal welfare organizations, spay/neuter practices, positive descriptions of satos, bringing nonhuman animals to the U.S. mainland, a second chance at life for nonhuman animals, and the hierarchical arrangement of nonhuman animals presented within media reports. Results of the study point towards the need for greater planning and resource allocation in regard to nonhuman animals in Puerto Rico both during times of disaster and everyday life. The spay and neuter infrastructure and the animal shelters on the island are especially in need of resources. Additionally, the results indicate that the media sources examined placed their main focus on dogs and cats impacted by the storm, suggesting that these species of nonhuman animals hold a spot towards the top of the American nonhuman animal hierarchical arrangement.
Show less - Date Issued
- 2019
- Identifier
- CFE0007822, ucf:52808
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007822
- Title
- MASS CONSERVATION ANALYSIS FOR THE LOWER ST. JOHNS RIVER USING CONTINUOUS AND DISCONTINUOUS GALERKIN FINITE ELEMENT METHODS.
- Creator
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Thomas, Lillie, Hagen, Scott, University of Central Florida
- Abstract / Description
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This thesis provides a mass conservation analysis of the Lower St. Johns River for the purpose of providing basis for future salinity transport modeling. The analysis provides an assessment of the continuous (CG) and discontinuous (DG) Galerkin finite element methods with respect to their mass conservation properties. The following thesis also presents a rigorous literature review pertaining to salinity transport in the Lower St. Johns River, from which this effort generates the data used to...
Show moreThis thesis provides a mass conservation analysis of the Lower St. Johns River for the purpose of providing basis for future salinity transport modeling. The analysis provides an assessment of the continuous (CG) and discontinuous (DG) Galerkin finite element methods with respect to their mass conservation properties. The following thesis also presents a rigorous literature review pertaining to salinity transport in the Lower St. Johns River, from which this effort generates the data used to initialize and validate numerical simulations. Two research questions are posed and studied in this thesis: can a DG-based modeling approach produce mass conservative numerical solutions; and what are the flow interactions between the river and the marshes within the coastal region of the Lower St. Johns River? Reviewing the available data provides an initial perspective of the ecosystem. For this, salinity data are obtained and assembled for three modeling scenarios. Each scenario, High Extreme, Most Variable, and Low Extreme, is 30 days long (taken from year 1999) and represents a unique salinity regime in the Lower St. Johns River. Time-series of salinity data is collected at four stations in the lower and middle reaches of the Lower St. Johns River, which provides a vantage point for assessing longitudinal variation of salinity. As an aside, precipitation and evaporation data is presented for seven stations along the entire St. Johns River, which provides added insight into salinity transport in the river. A mass conservation analysis is conducted for the Lower St. Johns River. The analysis utilizes a segmentation of the Lower St. Johns River, which divides the domain into sections based on physical characteristics. Mass errors are then calculated for the CG and DG finite element methods to determine mass conservative abilities. Also, the flow interactions (i.e., volume exchange) between the river and marshes are evaluated through the use of tidal prisms. The CG- and DG- finite element methods are then tested in tidal simulation performance, which the results are then compared to observed tides and tidal currents at four stations within the lower portion of the Lower St. Johns River. Since the results show that the DG model outperforms the CG model, the DG model is used in the tidally driven salinity transport simulations. Using four stations within the lower and middle part of the Lower St. Johns River, simulated and observed water levels and salinity concentrations are compared.
Show less - Date Issued
- 2011
- Identifier
- CFE0003736, ucf:48797
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003736
- Title
- Practical Implementations of the Active Set Method for Support Vector Machine Training with Semi-definite Kernels.
- Creator
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Sentelle, Christopher, Georgiopoulos, Michael, Anagnostopoulos, Georgios, Kasparis, Takis, Stanley, Kenneth, Young, Cynthia, University of Central Florida
- Abstract / Description
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The Support Vector Machine (SVM) is a popular binary classification model due to its superior generalization performance, relative ease-of-use, and applicability of kernel methods. SVM training entails solving an associated quadratic programming (QP) that presents significant challenges in terms of speed and memory constraints for very large datasets; therefore, research on numerical optimization techniques tailored to SVM training is vast. Slow training times are especially of concern when...
Show moreThe Support Vector Machine (SVM) is a popular binary classification model due to its superior generalization performance, relative ease-of-use, and applicability of kernel methods. SVM training entails solving an associated quadratic programming (QP) that presents significant challenges in terms of speed and memory constraints for very large datasets; therefore, research on numerical optimization techniques tailored to SVM training is vast. Slow training times are especially of concern when one considers that re-training is often necessary at several values of the model's regularization parameter, C, as well as associated kernel parameters.The active set method is suitable for solving SVM problem and is in general ideal when the Hessian is dense and the solution is sparse-the case for the l1-loss SVM formulation. There has recently been renewed interest in the active set method as a technique for exploring the entire SVM regularization path, which has been shown to solve the SVM solution at all points along the regularization path (all values of C) in not much more time than it takes, on average, to perform training at a single value of C with traditional methods. Unfortunately, the majority of active set implementations used for SVM training require positive definite kernels, and those implementations that do allow semi-definite kernels tend to be complex and can exhibit instability and, worse, lack of convergence. This severely limits applicability since it precludes the use of the linear kernel, can be an issue when duplicate data points exist, and doesn't allow use of low-rank kernel approximations to improve tractability for large datasets. The difficulty, in the case of a semi-definite kernel, arises when a particular active set results in a singular KKT matrix (or the equality-constrained problem formed using the active set is semi-definite). Typically this is handled by explicitly detecting the rank of the KKT matrix. Unfortunately, this adds significant complexity to the implementation; and, if care is not taken, numerical instability, or worse, failure to converge can result. This research shows that the singular KKT system can be avoided altogether with simple modifications to the active set method. The result is a practical, easy to implement active set method that does not need to explicitly detect the rank of the KKT matrix nor modify factorization or solution methods based upon the rank. Methods are given for both conventional SVM training as well as for computing the regularization path that are simple and numerically stable. First, an efficient revised simplex method is efficiently implemented for SVM training (SVM-RSQP) with semi-definite kernels and shown to out-perform competing active set implementations for SVM training in terms of training time as well as shown to perform on-par with state-of-the-art SVM training algorithms such as SMO and SVMLight. Next, a new regularization path-following algorithm for semi-definite kernels (Simple SVMPath) is shown to be orders of magnitude faster, more accurate, and significantly less complex than competing methods and does not require the use of external solvers. Theoretical analysis reveals new insights into the nature of the path-following algorithms. Finally, a method is given for computing the approximate regularization path and approximate kernel path using the warm-start capability of the proposed revised simplex method (SVM-RSQP) and shown to provide significant, orders of magnitude, speed-ups relative to the traditional (")grid search(") where re-training is performed at each parameter value. Surprisingly, it also shown that even when the solution for the entire path is not desired, computing the approximate path can be seen as a speed-up mechanism for obtaining the solution at a single value. New insights are given concerning the limiting behaviors of the regularization and kernel path as well as the use of low-rank kernel approximations.
Show less - Date Issued
- 2014
- Identifier
- CFE0005251, ucf:50600
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005251
- Title
- Semi-Analytical Solutions of Non-linear Differential Equations Arising in Science and Engineering.
- Creator
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Dewasurendra, Mangalagama, Vajravelu, Kuppalapalle, Mohapatra, Ram, Rollins, David, Kumar, Ranganathan, University of Central Florida
- Abstract / Description
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Systems of coupled non-linear differential equations arise in science and engineering are inherently nonlinear and difficult to find exact solutions. However, in the late nineties, Liao introduced Optimal Homotopy Analysis Method (OHAM), and it allows us to construct accurate approximations to the systems of coupled nonlinear differential equations.The drawback of OHAM is, we must first choose the proper auxiliary linear operator and then solve the linear higher-order deformation equation by...
Show moreSystems of coupled non-linear differential equations arise in science and engineering are inherently nonlinear and difficult to find exact solutions. However, in the late nineties, Liao introduced Optimal Homotopy Analysis Method (OHAM), and it allows us to construct accurate approximations to the systems of coupled nonlinear differential equations.The drawback of OHAM is, we must first choose the proper auxiliary linear operator and then solve the linear higher-order deformation equation by spending lots of CPU time. However, in the latest innovation of Liao's " Method of Directly Defining inverse Mapping (MDDiM)" which he introduced to solve a single nonlinear ordinary differential equation has great freedom to define the inverse linear map directly. In this way, one can solve higher order deformation equations quickly, and it is unnecessary to calculate an inverse linear operator.Our primary goal is to extend MDDiM to solve systems of coupled nonlinear ordinary differential equations. In the first chapter, we will introduce MDDiM and briefly discuss the advantages of MDDiM Over OHAM. In the second chapter, we will study a nonlinear coupled system using OHAM. Next three chapters, we will apply MDDiM to coupled non-linear systems arise in mechanical engineering to study fluid flow and heat transfer. In chapter six we will apply this novel method to study coupled non-linear systems in epidemiology to investigate how diseases spread throughout time. In the last chapter, we will discuss our conclusions and will propose some future work. Another main focus is to compare MDDiM with OHAM.
Show less - Date Issued
- 2019
- Identifier
- CFE0007624, ucf:52551
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007624
- Title
- Implementation And Performance Comparisons For The Crisfield And Stiff Arc Length Methods In FEA.
- Creator
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Silvers, Thomas, Gordon, Ali, Nicholson, David, Kassab, Alain, Ilie, Marcel, University of Central Florida
- Abstract / Description
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In Nonlinear Finite Element Analysis (FEA) applied to structures, displacements at which the tangent stiffness matrix KT becomes singular are called critical points, and correspond to instabilities such as buckling or elastoplastic softening (e.g., necking). Prior to the introduction of Arc Length Methods (ALMs), critical points posed severe computational challenges, which was unfortunate since behavior at instabilities is of great interest as a precursor to structural failure. The original...
Show moreIn Nonlinear Finite Element Analysis (FEA) applied to structures, displacements at which the tangent stiffness matrix KT becomes singular are called critical points, and correspond to instabilities such as buckling or elastoplastic softening (e.g., necking). Prior to the introduction of Arc Length Methods (ALMs), critical points posed severe computational challenges, which was unfortunate since behavior at instabilities is of great interest as a precursor to structural failure. The original ALM was shown to be capable in some circumstances of continued computation at critical points, but limited success and unattractive features of the formulation were noted and addressed in extensive subsequent research. The widely used Crisfield Cylindrical and Spherical ALMs may be viewed as representing the 'state-of-the-art'. The more recent Stiff Arc Length method, which is attractive on fundamental grounds, was introduced in 2004, but without implementation, benchmarking or performance assessment. The present thesis addresses (a) implementation and (b) performance comparisons for the Crisfield and Stiff methods, using simple benchmarks formulated to incorporate elastoplastic softening. It is seen that, in contrast to the Crisfield methods, the Stiff ALM consistently continues accurate computation at, near and beyond critical points.
Show less - Date Issued
- 2012
- Identifier
- CFE0004277, ucf:49544
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004277
- Title
- HOPF BIFURCATION ANALYSIS OF CHAOTIC CHEMICAL REACTOR MODEL.
- Creator
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Mandragona, Daniel, Choudhury, Roy, University of Central Florida
- Abstract / Description
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Bifurcations in Huang's chaotic chemical reactor system leading from simple dynamics into chaotic regimes are considered. Following the linear stability analysis, the periodic orbit resulting from a Hopf bifurcation of any of the six fixed points is constructed analytically by the method of multiple scales across successively slower time scales, and its stability is then determined by the resulting final secularity condition. Furthermore, we run numerical simulations of our chemical reactor...
Show moreBifurcations in Huang's chaotic chemical reactor system leading from simple dynamics into chaotic regimes are considered. Following the linear stability analysis, the periodic orbit resulting from a Hopf bifurcation of any of the six fixed points is constructed analytically by the method of multiple scales across successively slower time scales, and its stability is then determined by the resulting final secularity condition. Furthermore, we run numerical simulations of our chemical reactor at a particular fixed point of interest, alongside a set of parameter values that forces our system to undergo Hopf bifurcation. These numerical simulations then verify our analysis of the normal form.
Show less - Date Issued
- 2018
- Identifier
- CFH2000342, ucf:45831
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000342
- Title
- EXPLORING TEACHING METHODS CORRESPONDING WITH THE THEORY OF BASIC HUMAN VALUES IN LATE CHILDHOOD AND EARLY ADOLESCENCE CLASSROOMS.
- Creator
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Daly, Nicole, Roberts, Sherron-Killingsworth, University of Central Florida
- Abstract / Description
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Recent research that indicates ten universal values are shared across cultures has developed into the Schwartz Value Systems Theory. This theory describes the ten basic human values that derive from different motivational forces such as social superiority, an inner desire in novelty, and loyalty to one's group. The values and corresponding motivational forces guide an individual's decisions. After the Schwartz Value Systems Theory had been developed, two surveys have been created in order to...
Show moreRecent research that indicates ten universal values are shared across cultures has developed into the Schwartz Value Systems Theory. This theory describes the ten basic human values that derive from different motivational forces such as social superiority, an inner desire in novelty, and loyalty to one's group. The values and corresponding motivational forces guide an individual's decisions. After the Schwartz Value Systems Theory had been developed, two surveys have been created in order to assess an individual's value hierarchy. While both of these surveys accurately measure an adult's values, further research has indicated children possess individual values similarly to adults. As a result, the Picture Based Values Survey for Children was created in order to consider children's values. The results from the children who took the Picture Based Values Survey For Children revealed that those children as a group acquired the same value hierarchy as adults. Since motivational forces determine an individual's values, it would seem predictable that values might have an effect on a student's level of motivation to succeed in the classroom. When a student's motivational goals are met in the classroom, then they will become engaged in the lesson by aligning students' values to the teaching methods incorporated in the lesson. This thesis therefore integrates prior research on children's value development, the effects these values have on society and the classroom, and ways to exhibit values through discourse and teaching methods. Further, this seeks to apply this research in late childhood and early adolescence classrooms by examining the effects that may result from teachers exhibiting each of the ten universal values through their teaching methods through publicly shared videos.
Show less - Date Issued
- 2017
- Identifier
- CFH2000267, ucf:45995
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000267
- Title
- A GROUNDED THEORY STUDY OF THE IMPACT OF FLORIDA SCHOOL REPORT CARDS ON HIGH SCHOOL ENGLISH LANGUAGE ARTS TEACHERS' SELF-EFFICACY AND PERCEPTIONS OF STUDENT WRITING.
- Creator
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Briand, Casey S, Olan, Elsie L., University of Central Florida
- Abstract / Description
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This study sought to uncover how the annual Florida School Report Card influences secondary English Language Arts (ELA) teachers' self-efficacy and perceptions of student writing. The study's findings suggested that ELA teachers' self-efficacy may be indirectly influenced by the School Report Card. The participants in this study suggested that they do not feel totally capable of applying the information learned from the School Report Card to their own classrooms. The teachers who participated...
Show moreThis study sought to uncover how the annual Florida School Report Card influences secondary English Language Arts (ELA) teachers' self-efficacy and perceptions of student writing. The study's findings suggested that ELA teachers' self-efficacy may be indirectly influenced by the School Report Card. The participants in this study suggested that they do not feel totally capable of applying the information learned from the School Report Card to their own classrooms. The teachers who participated in the study also reported that they have low outcome expectations when interacting with the School Report Card. They do not believe that their actions can influence the School Report Card, and suggested that they see the school grade as a moving target with changing rules they may not be able to keep up with. The School Report Card was not suggested to directly impact the participants' perceptions of student writing. Instead, the data suggested that a variety of internal and external factors influence the way teachers perceive their students' writing quality. Finally, most of the participants suggested that they view the school grade as an unfair measure of achievement, and a tool that does not take into account the quality of the learning in the school and represents the school poorly. Cultural Historical Activity Theory (CHAT) was used to situate these findings and gain a better understanding of how the School Report Card functions as a tool for teachers and administrators.
Show less - Date Issued
- 2016
- Identifier
- CFH2000108, ucf:46040
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000108
- Title
- SMOOTHING PARAMETER SELECTION IN NONPARAMETRIC FUNCTIONAL ESTIMATION.
- Creator
-
Amezziane, Mohamed, Ahmad, Ibrahim, University of Central Florida
- Abstract / Description
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This study intends to build up new techniques for how to obtain completely data-driven choices of the smoothing parameter in functional estimation, within the confines of minimal assumptions. The focus of the study will be within the framework of the estimation of the distribution function, the density function and their multivariable extensions along with some of their functionals such as the location and the integrated squared derivatives.
- Date Issued
- 2004
- Identifier
- CFE0000307, ucf:46314
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000307
