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Title: Econometric Modeling Analysis of Public Transit Ridership: Application for Orlando Region.
Creator: Rahman, Moshiur, Eluru, Naveen, Abdel-Aty, Mohamed, Yasmin, Shamsunnahar, Uddin, Nizam, University of Central Florida
Abstract / Description: Policy makers are considering several alternatives to counter the negative externalities of personal vehicle dependence. Towards this end, public transit investments are critical in growing urban regions such as Orlando, Florida. Transit system managers and planners mostly rely on statistical models to identify the factors that affect ridership as well as quantifying the magnitude of the impact on the society. These models provide vital feedback to agencies on the benefits of public transit...
Show morePolicy makers are considering several alternatives to counter the negative externalities of personal vehicle dependence. Towards this end, public transit investments are critical in growing urban regions such as Orlando, Florida. Transit system managers and planners mostly rely on statistical models to identify the factors that affect ridership as well as quantifying the magnitude of the impact on the society. These models provide vital feedback to agencies on the benefits of public transit investments which in turn act as lessons to improve the investment process. We contribute to public transit literature by addressing several methodological challenges for transit ridership modeling. Frist, we examine the impact of new transit investments (such as an addition of commuter rail to an urban region) on existing transit infrastructure (such as the traditional bus service already present in the urban region). The process of evaluating the impact of new investments on existing public transit requires a comprehensive analysis of the before and after measures of public transit usage in the region. Second, we accommodate for the presence of common unobserved factors associated with spatial factors by developing a spatial panel model using stop level public transit boarding and alighting data. Third, we contribute to literature on transit ridership by considering daily boarding and alighting data from a recently launched commuter rail system (SunRail). The model system developed will allow us to predict ridership for existing stations in the future as well as potential ridership for future expansion sites. Fourth, we accommodate for potential endogeneity between bus headway and ridership by proposing a simultaneous model system of headway and ridership. Finally, a cost benefit analysis exercise is conducted for examining the impact of Sunrail on the region.
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Date Issued: 2018
Identifier: CFE0007583, ucf:52577
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007583

Title: Federal, State and Local Law Enforcement Agency Interoperability Capabilities and Cyber Vulnerabilities.
Creator: Trapnell, Tyrone, Caulkins, Bruce, Wiegand, Rudolf, Bockelman, Patricia, Canham, Matthew, University of Central Florida
Abstract / Description: The National Data Exchange (N-DEx) System is the central informational hub located at the Federal Bureau of Investigation (FBI). Its purpose is to provide network subscriptions to all Federal, state and local level law enforcement agencies while increasing information collaboration across all domains. The National Data Exchange users must satisfy the Advanced Permission Requirements, confirming the terms of N-DEx information use, and the Verification Requirement (verifying the completeness,...
Show moreThe National Data Exchange (N-DEx) System is the central informational hub located at the Federal Bureau of Investigation (FBI). Its purpose is to provide network subscriptions to all Federal, state and local level law enforcement agencies while increasing information collaboration across all domains. The National Data Exchange users must satisfy the Advanced Permission Requirements, confirming the terms of N-DEx information use, and the Verification Requirement (verifying the completeness, timeliness, accuracy, and relevancy of N-DEx information) through coordination with the record-owning agency (Management, 2018). A network infection model is proposed to simulate the spread impact of various cyber-attacks within Federal, state and local level law enforcement networks that are linked together through the topologies merging with the National Data Exchange (N-DEx) System as the ability to manipulate the live network is limited. The model design methodology is conducted in a manner that creates a level of organization from the state level to the local level of law enforcement agencies allowing for each organizational infection probability to be calculated and entered, thus making the model very specific in nature for determining spread or outbreaks of cyber-attacks among law enforcement agencies at all levels. This research will enable future researchers to further develop a model that is capable of detecting weak points within an information structure when multiple topologies merge, allowing for more secure operations among law enforcement networks.
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Date Issued: 2019
Identifier: CFE0007543, ucf:52621
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007543

Title: Analysis and Simulation for Homogeneous and Heterogeneous SIR Models.
Creator: Wilda, Joseph, Shuai, Zhisheng, Brennan, Joseph, Nevai, A, University of Central Florida
Abstract / Description: In mathematical epidemiology, disease transmission is commonly assumed to behave in accordance with the law of mass action; however, other disease incidence terms also exist in the literature. A homogeneous Susceptible-Infectious-Removed (SIR) model with a generalized incidence term is presented along with analytic and numerical results concerning effects of the generalization on the global disease dynamics. The spatial heterogeneity of the metapopulation with nonrandom directed movement...
Show moreIn mathematical epidemiology, disease transmission is commonly assumed to behave in accordance with the law of mass action; however, other disease incidence terms also exist in the literature. A homogeneous Susceptible-Infectious-Removed (SIR) model with a generalized incidence term is presented along with analytic and numerical results concerning effects of the generalization on the global disease dynamics. The spatial heterogeneity of the metapopulation with nonrandom directed movement between populations is incorporated into a heterogeneous SIR model with nonlinear incidence. The analysis of the combined effects of the spatial heterogeneity and nonlinear incidence on the disease dynamics of our model is presented along with supporting simulations. New global stability results are established for the heterogeneous model utilizing a graph-theoretic approach and Lyapunov functions. Numerical simulations confirm nonlinear incidence gives raise to rich dynamics such as synchronization and phase-lock oscillations.
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Date Issued: 2015
Identifier: CFE0005906, ucf:50872
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005906

Title: Mechanism of Hip Dysplasia and Identification of the Least Energy Path for its Treatment by using the Principle of Stationary Potential Energy.
Creator: Zwawi, Mohammed abdulwahab m, Moslehy, Faissal, Kassab, Alain, Mansy, Hansen, Divo, Eduardo, University of Central Florida
Abstract / Description: Developmental dysplasia of the hip (DDH) is a common newborn condition where the femoral head is not located in its natural position in the acetabulum (hip socket). Several treatment methods are being implemented worldwide to treat this abnormal condition. One of the most effective methods of treatment is the use of Pavlik Harness, which directs the femoral head toward the natural position inside the acetabulum. This dissertation presents a developed method for identifying the least energy...
Show moreDevelopmental dysplasia of the hip (DDH) is a common newborn condition where the femoral head is not located in its natural position in the acetabulum (hip socket). Several treatment methods are being implemented worldwide to treat this abnormal condition. One of the most effective methods of treatment is the use of Pavlik Harness, which directs the femoral head toward the natural position inside the acetabulum. This dissertation presents a developed method for identifying the least energy path that the femoral head would follow during reduction. This is achieved by utilizing a validated computational biomechanical model that allows the determination of the potential energy, and then implementing the principle of stationary potential energy. The potential energy stems from strain energy stored in the muscles and gravitational potential energy of four rigid-body components of lower limb bones. Five muscles are identified and modeled because of their effect on DDH reduction. Clinical observations indicate that reduction with the Pavlik Harness occurs passively in deep sleep under the combined effects of gravity and the constraints of the Pavlik Harness.A non-linear constitutive equation, describing the passive muscle response, is used in the potential energy computation. Different DDH abnormalities with various flexion, abduction, and hip rotation angles are considered, and least energy paths are identified. Several constraints, such as geometry and harness configuration, are considered to closely simulate real cases of DDH. Results confirm the clinical observations of two different pathways for closed reduction. The path of least energy closely approximated the modified Hoffman-Daimler method. Release of the pectineus muscle favored a more direct pathway over the posterior rim of the acetabulum. The direct path over the posterior rim of the acetabulum requires more energy. This model supports the observation that Grade IV dislocations may require manual reduction by the direct path. However, the indirect path requires less energy and may be an alternative to direct manual reduction of Grade IV infantile hip dislocations. Of great importance, as a result of this work, identifying the minimum energy path that the femoral head would travel would provide a non-surgical tool that effectively aids the surgeon in treating DDH.?
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Date Issued: 2015
Identifier: CFE0006022, ucf:51000
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006022

Title: Modeling Crowd Mobility and Communication in Wireless Networks.
Creator: Solmaz, Gurkan, Turgut, Damla, Bassiouni, Mostafa, Guha, Ratan, Goldiez, Brian, University of Central Florida
Abstract / Description: This dissertation presents contributions to the fields of mobility modeling, wireless sensor networks (WSNs) with mobile sinks, and opportunistic communication in theme parks. The two main directions of our contributions are human mobility models and strategies for the mobile sink positioning and communication in wireless networks.The first direction of the dissertation is related to human mobility modeling. Modeling the movement of human subjects is important to improve the performance of...
Show moreThis dissertation presents contributions to the fields of mobility modeling, wireless sensor networks (WSNs) with mobile sinks, and opportunistic communication in theme parks. The two main directions of our contributions are human mobility models and strategies for the mobile sink positioning and communication in wireless networks.The first direction of the dissertation is related to human mobility modeling. Modeling the movement of human subjects is important to improve the performance of wireless networks with human participants and the validation of such networks through simulations. The movements in areas such as theme parks follow specific patterns that are not taken into consideration by the general purpose mobility models. We develop two types of mobility models of theme park visitors. The first model represents the typical movement of visitors as they are visiting various attractions and landmarks of the park. The second model represents the movement of the visitors as they aim to evacuate the park after a natural or man-made disaster.The second direction focuses on the movement patterns of mobile sinks and their communication in responding to various events and incidents within the theme park. When an event occurs, the system needs to determine which mobile sink will respond to the event and its trajectory. The overall objective is to optimize the event coverage by minimizing the time needed for the chosen mobile sink to reach the incident area. We extend this work by considering the positioning problem of mobile sinks and preservation of the connected topology. We propose a new variant of p-center problem for optimal placement and communication of the mobile sinks. We provide a solution to this problem through collaborative event coverage of the WSNs with mobile sinks. Finally, we develop a network model with opportunistic communication for tracking the evacuation of theme park visitors during disasters. This model involves people with smartphones that store and carry messages. The mobile sinks are responsible for communicating with the smartphones and reaching out to the regions of the emergent events.
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Date Issued: 2015
Identifier: CFE0006005, ucf:51024
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006005

Title: More is not always better: Unpacking the cognitive process underlying introspective psychological measurement.
Creator: Lapalme, Matthew, Wang, Wei, Fritzsche, Barbara, Jentsch, Florian, University of Central Florida
Abstract / Description: For decades, psychometricans have measured non-cognitive constructs with little attention paid to the underlying cognitive processes of response. Previous advancement in psychometrics suggests that traditional cognitive oriented approaches may, in fact, yield construct deficiency and spurious results when applied to non-cognitive measurement. This thesis highlights the importance of specifying an ideal point response process for non-cognitive measurement and empirically demonstrates that an...
Show moreFor decades, psychometricans have measured non-cognitive constructs with little attention paid to the underlying cognitive processes of response. Previous advancement in psychometrics suggests that traditional cognitive oriented approaches may, in fact, yield construct deficiency and spurious results when applied to non-cognitive measurement. This thesis highlights the importance of specifying an ideal point response process for non-cognitive measurement and empirically demonstrates that an ideal point response processes undergirds self-reported personality and attitude measurement. Furthermore, this thesis also advances current understanding on the limitations of ideal point assumptions by exploring the moderating effects of various individual differences in motivation and ability.
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Date Issued: 2015
Identifier: CFE0006223, ucf:51074
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006223

Title: Physical Hydrogeological Modeling of Florida's Sinkhole Hazard.
Creator: Perez, Adam, Nam, Boo Hyun, Wang, Dingbao, Chopra, Manoj, Singh, Arvind, An, Jin Woo, University of Central Florida
Abstract / Description: Sinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole...
Show moreSinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole states.The scope of this study is to develop a physical model to simulate sinkholes (referred to as a sinkhole simulator), which can assess the qualitative behavior of the hydrogeological mechanism of Florida's sinkhole formations. Two sinkhole simulators were developed, with the second simulator constructed to overcoming the limitations of the first. The first generation sinkhole simulator incorporated a falling head groundwater system and the sinkhole could only be observed once the ground surface was breached. The second generation sinkhole simulator incorporated a constant head groundwater system which accurately depicts field conditions and the sinkhole was able to be observed during all stages of formation within this model. In both simulators multiple hydrogeological conditions were created and water level transducers were installed at various locations within the soil profile to monitor variations in the groundwater table during the sinkhole process, this was done to investigate the soil-groundwater behavior.Findings from this study include: 1) groundwater recharge is a critical sinkhole triggering factor, 2) the groundwater table cone of depression increases as the raveled zone or void travels up through the overburden due to sinkhole formation, 3) The cover-subsidence sinkhole failure mechanism is similar to the failure mechanism present in Terzaghi's trapdoor experiment and the cover-collapse failure mechanism consists of four district components: failure planes with erosion envelope, arch dropout failure, formation of elliptical void, and slope stability failure, and 4) a strong qualitative relationship between soil strength and type of sinkhole formed (cover-subsidence or cover-collapse) was observed.
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Date Issued: 2017
Identifier: CFE0006637, ucf:51247
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006637

Title: Provider Recommendation of HPV Vaccination: Bridging the Intention-Behavior Gap.
Creator: Landis, Erica, Neuberger, Lindsay, Sandoval, Jennifer, Miller, Ann, University of Central Florida
Abstract / Description: The present study, guided by preproduction formative research principles, employed in-depth interviews and a brief survey with pediatric healthcare providers (N=15) to investigate the consistency between behavioral intention to strongly recommend the HPV vaccine, and implementation of the actual behavior. Specifically, the Integrative Model of Behavioral Prediction (IMBP) was used as a framework to examine the impact of skills and environmental constraints on that behavioral intention...
Show moreThe present study, guided by preproduction formative research principles, employed in-depth interviews and a brief survey with pediatric healthcare providers (N=15) to investigate the consistency between behavioral intention to strongly recommend the HPV vaccine, and implementation of the actual behavior. Specifically, the Integrative Model of Behavioral Prediction (IMBP) was used as a framework to examine the impact of skills and environmental constraints on that behavioral intention-behavioral performance relationship. Results suggest providers intend to strongly recommend the HPV vaccine at a high level, but actually recommend the vaccine with a slightly lesser frequency. A thematic analysis of interview transcripts yielded a list of skills (e.g., tact, cultural competence) and environmental constraints (e.g., a lack of policy or school entry requirement, limited time designated for each patient) that contribute to that consistency gap. Additionally, healthcare providers indicated several preferences on training design (e.g., Continuing Medical Education course, delivered by medical and communication professionals) that could be used to inform future message construction. Suggestions for overcoming the environmental constraints reported by providers are presented, and implications for incorporating the emergent skills and preferences into training as a novel strategy for improving provider communication about the HPV vaccine outlined.
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Date Issued: 2016
Identifier: CFE0006132, ucf:51162
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006132

Title: Academic Blade Geometries for Baseline Comparisons of Forced Vibration Response Predictions.
Creator: Little, James, Kauffman, Jeffrey, Gordon, Ali, Bai, Yuanli, University of Central Florida
Abstract / Description: Predicting the damping associated with underplatform dampers remains a challenge in turbomachineryblade and friction damper design. Turbomachinery blade forced response analysismethods usually rely on nonlinear codes and reduced order models to predict vibration characteristicsof blades. Two academic blade geometries coupled with underplatform dampers are presentedhere for comparison of these model reduction and forced response simulation techniques. The twoblades are representative of free...
Show morePredicting the damping associated with underplatform dampers remains a challenge in turbomachineryblade and friction damper design. Turbomachinery blade forced response analysismethods usually rely on nonlinear codes and reduced order models to predict vibration characteristicsof blades. Two academic blade geometries coupled with underplatform dampers are presentedhere for comparison of these model reduction and forced response simulation techniques. The twoblades are representative of free-standing turbine blades and exhibit qualitatively similar behavioras highly-complex industrial blades. This thesis fully describes the proposed academic bladegeometries and models; it further analyzes and predicts the blades forced response characteristicsusing the same procedure as industry blades. This analysis classifies the results in terms of resonancefrequency, vibration amplitude, and damping over a range of aerodynamic excitation toexamine the vibration behavior of the blade/damper system. Additionally, the analysis investigatesthe effect variations of the contact parameters (friction coefficient, damper / platform roughnessand damper mass) have on the predicted blade vibration characteristics, with sensitivities to each parameter. Finally, an investigation of the number of modes retained in the reduced order modelshows convergence behavior as well as providing additional data for comparison with alternativemodel reduction and forced response prediction methods. The academic blade models are shownto behave qualitatively similar to high fidelity industry blade models when the number of retained modes in a modal analysis are varied and behave qualitatively similar under sensitives to designparameters.
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Date Issued: 2017
Identifier: CFE0006616, ucf:51281
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006616

Title: A Case Study of the Percieved Effectiveness of the Two-Semester, Job-Embedded Internship.
Creator: Osmond, Stephanie, Taylor, Rosemarye, Baldwin, Lee, Kennedy, Mary, Zugelder, Bryan, University of Central Florida
Abstract / Description: The purpose of the study was to examine the perceived effectiveness of the two-semester, job-embedded internship for the development of effective Science, Technology, Engineering, and Mathematics (STEM) teachers. Students who were enrolled in the Resident Teacher Professional Preparation Program (RTP3) were able to earn a Master's in the Art of Teaching (MAT), which included a two-semester, job-embedded internship. This study was designed to analyze the perceived effectiveness of the two...
Show moreThe purpose of the study was to examine the perceived effectiveness of the two-semester, job-embedded internship for the development of effective Science, Technology, Engineering, and Mathematics (STEM) teachers. Students who were enrolled in the Resident Teacher Professional Preparation Program (RTP3) were able to earn a Master's in the Art of Teaching (MAT), which included a two-semester, job-embedded internship. This study was designed to analyze the perceived effectiveness of the two-semester, job-embedded internship model at one urban high school from not only the resident teachers', but also designees and stakeholders of the RTP3. Resident teachers participated in the two-semester, job-embedded internship with the support of school site based mentors, school district and school site coaches, and university intern coordinators. The resident teachers participated in all aspect of the teaching process, and were evaluated using the school site evaluation instrument. As part of their internship, the resident teachers were evaluated using the Internship Assessment Summary Sheet. The resident teachers were also asked to participate in Lesson Study. Data were gathered through both qualitative and quantitative sources. To collect qualitative data, interviews were conducted with the resident teachers, school site designees, school district designees and university designees. Each respondent was asked 10 questions developed by the researcher and vetted by experts in the field. The questions were designed to gather perceptions of effectiveness in preparation of the resident teachers, as well as strengths and weaknesses of the model. Recommendations for future use of the two-semester, job-embedded internship model were also gathered. Quantitative data were collected and analyzed using the Internship Assessment Summary Sheet to assess the perception of the intern coordinators.The findings were that the two-semester, job-embedded internship was overall perceived as an effective model in preparing STEM teachers. The model allowed resident teachers to be engaged in the teaching process from the beginning of the school year. The support that was given throughout the internship was beneficial in helping resident teachers with teaching practice. It was recommended that using frequent and actionable feedback should be continued. The one weakness of the model was the need for more pedagogical preparation, especially in the area of classroom management.
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Date Issued: 2015
Identifier: CFE0005860, ucf:50935
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005860

Title: Understanding the Capabilities and Limitations of Advanced Interactive M(&)S: A Cricothyroidotomy Simulation Case Study.
Creator: Campbell-Wynn, Lillian, Proctor, Michael, Kincaid, John, Crumpton-Young, Lesia, Liu, Alan, Burgess, Deborah, University of Central Florida
Abstract / Description: Simulation for surgical education and training is increasingly perceived as a valuable contribution to traditional teaching methods providing a structured learning experience. Surgical simulations allow surgeons to practice tactics, techniques and procedures numerous times without the cost, limitations and ethical problems of using cadaver-based models. The goal of this research is to advance the use of modeling and simulation in support of emergency medical training. This research explores...
Show moreSimulation for surgical education and training is increasingly perceived as a valuable contribution to traditional teaching methods providing a structured learning experience. Surgical simulations allow surgeons to practice tactics, techniques and procedures numerous times without the cost, limitations and ethical problems of using cadaver-based models. The goal of this research is to advance the use of modeling and simulation in support of emergency medical training. This research explores questions identified through a case study of two different modeling and simulation techniques (-) virtual reality and mannequins - in the support of combat emergency medical education and training. To reduce the scope to a manageable dissertation, the research focuses on CricSim as representative form of virtual reality simulation and HapMed as a form of mannequin simulation both with haptic-enabled capabilities. To further narrow the scope, the research focuses on training of a medical technique common to both simulation systems, which for this research was the cricothyroidotomy airway management technique. The U.S. Army expressed interest in training of combat medics in the cricothyroidotomy airway management technique and offered to support experimentation with both facilities and trained combat medics as the sample population. An experiment supporting this research took place at Fort Indiantown Gap, a National Guard Training Center located in Annville, Lebanon County, Pennsylvania and is the home of the Medical Battalion Training Site. An advanced airway management course is augmented with combat medics receiving training and evaluation on performing the cricothyroidotomy procedure using CricSim and HapMed with system experts provided by each respective developer. The NASA Task Load survey is used to collect participants' assessment of workload in terms of Mental Demand, Physical Demand, Temporal Demand, Level of Effort, Performance and Level of Frustration based on four primary tasks of the cricothyroidotomy. Additionally, the Technology Acceptance Model survey is used to provide insight into participant's assessment of usability. Professional trainers also provide their assessment of the virtual simulators suitability in support of the combat medics in performing their tasks based on their standards. The results of the participants' assessment of each virtual simulator take the form of a comparison study. To improve the advancement of medical simulation in the training of cricothyroidotomy procedure, a summary of findings, generalized conclusions, lessons learned and recommendations for future research are illuminated. The dissertation team is comprised of medical experts within the U.S. Air Force Education and Training Command, U.S. Army Research and Medical Command, and the Uniformed Services University of the Health Sciences as well as simulation subject matter experts from the University of Central Florida.
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Date Issued: 2013
Identifier: CFE0005142, ucf:50705
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005142

Title: A Human-Centric Approach to Data Fusion in Post-Disaster Managment: The Development of a Fuzzy Set Theory Based Model.
Creator: Banisakher, Mubarak, McCauley, Pamular, Geiger, Christopher, Lee, Gene, Shi, Fuqian, Zou, Changchun, University of Central Florida
Abstract / Description: It is critical to provide an efficient and accurate information system in the post-disaster phase for individuals' in order to access and obtain the necessary resources in a timely manner; but current map based post-disaster management systems provide all emergency resource lists without filtering them which usually leads to high levels of energy consumed in calculation. Also an effective post-disaster management system (PDMS) will result in distribution of all emergency resources such as,...
Show moreIt is critical to provide an efficient and accurate information system in the post-disaster phase for individuals' in order to access and obtain the necessary resources in a timely manner; but current map based post-disaster management systems provide all emergency resource lists without filtering them which usually leads to high levels of energy consumed in calculation. Also an effective post-disaster management system (PDMS) will result in distribution of all emergency resources such as, hospital, storage and transportation much more reasonably and be more beneficial to the individuals in the post disaster period. In this Dissertation, firstly, semi-supervised learning (SSL) based graph systems was constructed for PDMS. A Graph-based PDMS' resource map was converted to a directed graph that presented by adjacent matrix and then the decision information will be conducted from the PDMS by two ways, one is clustering operation, and another is graph-based semi-supervised optimization process. In this study, PDMS was applied for emergency resource distribution in post-disaster (responses phase), a path optimization algorithm based ant colony optimization (ACO) was used for minimizing the cost in post-disaster, simulation results show the effectiveness of the proposed methodology. This analysis was done by comparing it with clustering based algorithms under improvement ACO of tour improvement algorithm (TIA) and Min-Max Ant System (MMAS) and the results also show that the SSL based graph will be more effective for calculating the optimization path in PDMS. This research improved the map by combining the disaster map with the initial GIS based map which located the target area considering the influence of disaster. First, all initial map and disaster map will be under Gaussian transformation while we acquired the histogram of all map pictures. And then all pictures will be under discrete wavelet transform (DWT), a Gaussian fusion algorithm was applied in the DWT pictures. Second, inverse DWT (iDWT) was applied to generate a new map for a post-disaster management system. Finally, simulation works were proposed and the results showed the effectiveness of the proposed method by comparing it to other fusion algorithms, such as mean-mean fusion and max-UD fusion through the evaluation indices including entropy, spatial frequency (SF) and image quality index (IQI). Fuzzy set model were proposed to improve the presentation capacity of nodes in this GIS based PDMS.
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Date Issued: 2014
Identifier: CFE0005128, ucf:50702
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005128

Title: A Generic Framework For Multi-Method Modeling and Simulation of Complex Systems Using Discrete Event, System Dynamics and Agent Based Approaches.
Creator: Mykoniatis, Konstantinos, Karwowski, Waldemar, Kincaid, John, Xanthopoulos, Petros, Akbas, Ilhan, University of Central Florida
Abstract / Description: Decisions about Modeling and Simulation (M(&)S) of Complex Systems (CS) need to be evaluated prior to implementation. Discrete Event (DE), System Dynamics (SD), and Agent Based (AB) are three different M(&)S approaches widely applied to enhance decision-making of complex systems. However, single type M(&)S approaches can face serious challenges in representing the overall multidimensional nature of CS and may result in the design of oversimplified models excluding important factors....
Show moreDecisions about Modeling and Simulation (M(&)S) of Complex Systems (CS) need to be evaluated prior to implementation. Discrete Event (DE), System Dynamics (SD), and Agent Based (AB) are three different M(&)S approaches widely applied to enhance decision-making of complex systems. However, single type M(&)S approaches can face serious challenges in representing the overall multidimensional nature of CS and may result in the design of oversimplified models excluding important factors. Conceptual frameworks are necessary to offer useful guidance for combining and/or integrating different M(&)S approaches. Although several hybrid M(&)S frameworks have been described and are currently deployed, there is limited guidance on when, why and how to combine, and/or integrate DE, SD, and AB approaches. The existing hybrid frameworks focus more on how to deal with specific problems rather than to provide a generic way of applicability to various problem situations.The main aim of this research is to develop a generic framework for Multi-Method Modeling and Simulation of CS, which provides a practical guideline to integrated deployment or combination of DE, SD, and AB M(&)S methods. The key contributions of this dissertation include: (1) a meta-analysis literature review that identifies criteria and generic types of interaction relationships that are served as a basis for the development of a multi-method modeling and simulation framework; (2) a methodology and a framework that guide the user through the development of multi-method simulation models to solve CS problems; (3) an algorithm that recommends appropriate M(&)S method(s) based on the user selected criteria for user defined objective(s); (4) the implementation and evaluation of multi method simulation models based on the framework's recommendation in diverse domains; and (5) the comparison of multi-method simulation models created by following the multi-method modeling and simulation framework.It is anticipated that this research will inspire and motivate students, researchers, practitioners and decision makers engaged in M(&)S to become aware of the benefits of the cross-fertilization of the three key M(&)S methods.
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Date Issued: 2015
Identifier: CFE0005980, ucf:50762
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005980

Title: Response of Streamflow and Sediment Loading in the Apalachicola River, Florida to Climate and Land Use Land Cover Change.
Creator: Hovenga, Paige, Medeiros, Stephen, Wang, Dingbao, Kibler, Kelly, University of Central Florida
Abstract / Description: Located in Florida's panhandle, the Apalachicola River is the southernmost reach of the Apalachicola-Chattahoochee-Flint (ACF) River basin. Streamflow and sediment drains to Apalachicola Bay in the Northern Gulf of Mexico, directly influencing the ecology of the region, in particular seagrass and oyster production. The objective of this study is to evaluate the response of runoff and sediment loading in the Apalachicola River under projected climate change scenarios and land use / land cover ...
Show moreLocated in Florida's panhandle, the Apalachicola River is the southernmost reach of the Apalachicola-Chattahoochee-Flint (ACF) River basin. Streamflow and sediment drains to Apalachicola Bay in the Northern Gulf of Mexico, directly influencing the ecology of the region, in particular seagrass and oyster production. The objective of this study is to evaluate the response of runoff and sediment loading in the Apalachicola River under projected climate change scenarios and land use / land cover (LULC) change. A hydrologic model using the Soil Water Assessment Tool (SWAT) was developed for the Apalachicola region to simulate daily discharge and sediment load under present (circa 2000) and future conditions (circa 2100) to understand how the system responds over seasonal and event time frames to changes in climate, LULC, and coupled climate / LULC. These physically-based models incorporate a digital elevation model (DEM), LULC, soil maps, climate data, and management controls. Long Ashton Research Station-Weather Generator (LARS-WG) was used to create downscaled stochastic temperature and precipitation inputs from three Global Climate Models (GCM), each under Intergovernmental Panel on Climate Change (IPCC) carbon emission scenarios for A1B, A2, and B1. Projected 2100 LULC data provided by the United States Geological Survey (USGS) EROS Center was incorporated for each corresponding IPCC scenario. Results indicate climate change may induce seasonal shifts to both runoff and sediment loading, acting to extend periods of high flow and minimum sediment loadings or altering the time at which these events occur completely. Changes in LULC showed minimal effects on flow while more sediment loading was associated with increased agriculture and urban areas and decreased forested regions. A nonlinear response for both streamflow and sediment loading was observed by coupling climate and LULC change into the hydrologic model, indicating changes in one may exacerbate or dampen the effects of the other. Peak discharge and sediment loading associated with extreme events showed both increases and decreases in the future, with variability dependent on the GCM used. Similar behavior was observed in the total discharge resulting from extreme events and increased total sediment load was frequently predicted for the A2 and A1B scenarios for simulations involving changes in climate only, LULC only, and both climate and LULC. Output from the individual GCMs predicted differing responses of streamflow and sediment loading to changes in climate on both the seasonal and event scale. Additional region-specific research is needed to better optimize the GCM ensemble and eliminate those that provide erroneous output. In addition, future assessment of the downscaling approach to capture extreme events is required. Findings from this study can be used to further understand climate and LULC implications to the Apalachicola Bay and surrounding region as well as similar fluvial estuaries while providing tools to better guide management and mitigation practices.
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Date Issued: 2015
Identifier: CFE0006326, ucf:51543
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006326

Title: A Priori Analysis of Error and Bias in Value-Added Models.
Creator: Lavery, Matthew, Hahs-Vaughn, Debbie, Sivo, Stephen, Bai, Haiyan, Amrein-Beardsley, Audrey, University of Central Florida
Abstract / Description: Over the past 20 years, value-added models (VAMs) have become increasingly popular in educational assessment and accountability policies because of the sophisticated statistical controls these models use to purportedly isolate the effect of a single teacher on the learning gains of his or her students. The present research uses a Monte Carlo simulation study design in order to investigate whether VAMs are able to provide accurate estimates of teacher effectiveness when all assumptions are met...
Show moreOver the past 20 years, value-added models (VAMs) have become increasingly popular in educational assessment and accountability policies because of the sophisticated statistical controls these models use to purportedly isolate the effect of a single teacher on the learning gains of his or her students. The present research uses a Monte Carlo simulation study design in order to investigate whether VAMs are able to provide accurate estimates of teacher effectiveness when all assumptions are met and to determine how robust the models are to endogenous peer effects and nonrandom assignment of students to classroom. The researcher generates three years of simulated achievement data for 18,750 students taught by 125 teachers, and analyzes this data with a linear mixed model similar to the SAS(&)#174; EVAAS(&)#174; Multivariate Response Model (MRM; M1), a basic covariate adjustment model (M2), and variations on these models designed to estimate random classroom effects. Findings indicate that the modified EVAAS may be too computationally onerous to be of practical use, and that modified covariate adjustment models do not perform significantly differently than the basic covariate adjustment model. When all assumptions are met, M1 is more accurate than M2, but both models perform reasonably well, misclassifying fewer than 5% of teachers on average. M1 is more robust to endogenous peer effects than M2, however both models misclassified more teachers than when all assumptions are met. M2 is more robust to nonrandom assignment of students than M1. Assigning teachers a balanced schedule of nonrandom classes with low, medium, and high prior achievement seemed to mitigate the problems that nonrandom assignment caused for M1, but made M2 less accurate. Implications for practice and future research are discussed.
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Date Issued: 2016
Identifier: CFE0006344, ucf:51568
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006344

Title: Anthropogenic Organic Chemical Removal from a Surficial Groundwater and Mass Transfer Modeling in a Nanofiltration Membrane Process.
Creator: Jeffery, Samantha, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, Yestrebsky, Cherie, University of Central Florida
Abstract / Description: This dissertation reports on research related to trace organic compounds (TrOCs) in surficial groundwater supplies and their subsequent removal from nanofiltration (NF) membranes. The research was conducted along coastal South Florida in cooperation with the Town of Jupiter Water Utilities, Jupiter, FL (Town). The focus of the research was to determine the extent of reclaimed water impacts on surficial groundwater supplies and subsequent effects on the Town's NF water treatment plant. Routine...
Show moreThis dissertation reports on research related to trace organic compounds (TrOCs) in surficial groundwater supplies and their subsequent removal from nanofiltration (NF) membranes. The research was conducted along coastal South Florida in cooperation with the Town of Jupiter Water Utilities, Jupiter, FL (Town). The focus of the research was to determine the extent of reclaimed water impacts on surficial groundwater supplies and subsequent effects on the Town's NF water treatment plant. Routine monitoring of fourteen TrOCs in reclaimed water and at the water treatment facility revealed varying degrees of TrOC detection in the environment. Certain TrOCs, including caffeine and DEET, were detected in a majority of the water sampling locations evaluated in this work. However, subsequent dilution with highly-treated reverse osmosis (RO) permeate from alternative supplies resulted in TrOCs below detection limits in potable water at the point-of-entry (POE). Pilot testing was employed to determine the extent of TrOC removal by NF. Prior to evaluating TrOC removal, hydraulic transients within the pilot process were first examined to determine the required length of time the pilot needed to reach steady-state. The transient response of a center-port NF membrane process was evaluated using a step-input dose of a sodium chloride solution. The pilot was configured as a two-stage, split-feed, center-exit, 7:2 pressure vessel array process, where the feed water is fed to both ends of six element pressure vessels, and permeate and concentrate streams are collected after only three membrane elements. The transient response was described as a log-logistic system with a maximum delay time of 285 seconds for an 85% water recovery and 267 gallon per minute feed flowrate.Eleven TrOC pilot unit experiments were conducted with feed concentrations ranging from 0.52 to 4,500 ?g/L. TrOC rejection was well-correlated with compound molecular volume and polarizability, with coefficient of determination (R2) values of 0.94. To enhance this correlation, an extensive literature review was conducted and independent literature sources were correlated with rejection. Literature citations reporting the removal effectiveness of an additional sixty-one TrOCs by loose NF membranes (a total of 95 data points) were found to be well-correlated with molecular volume and polarizability, with R2 values of 0.72 and 0.71, respectively.Of the TrOC's detected during this research, the anthropogenic solute caffeine was selected to be modeled using the homogeneous solution diffusion model (HSDM) and the HSDM with film theory (HSDM-FT). Mass transfer coefficients, K_w (water) K_s (caffeine), and k_b (caffeine back-transport) were determined experimentally, and K_s was also determined using the Sherwood correlation method. Findings indicate that caffeine transport through the NF pilot could be explained using experimentally determined K_s values without incorporating film theory, since the HSDM resulted in a better correlation between predicted and actual caffeine permeate concentrations compared to the HSDM-FT and the HSDM using K_s obtained using Sherwood applications. Predicted versus actual caffeine content was linearly compared, revealing R2 values on the order of 0.99, 0.96, and 0.99 for the HSDM without FT, HSDM-FT, and HSDM using a K_s value obtained using the Sherwood correlation method. However, the use of the HSDM-FT and the Sherwood number resulted in the over-prediction of caffeine concentrations in permeate streams by 27 percent and 104 percent, respectively.
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Date Issued: 2016
Identifier: CFE0006331, ucf:51545
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006331

Title: Agent-Based and System Dynamics Hybrid Modeling and Simulation Approach Using Systems Modeling Language.
Creator: Soyler Akbas, Asli, Karwowski, Waldemar, Geiger, Christopher, Kincaid, John, Mikusinski, Piotr, University of Central Florida
Abstract / Description: Agent-based (AB) and system dynamics (SD) modeling and simulation techniques have been studied and used by various research fields. After the new hybrid modeling field emerged, the combination of these techniques started getting attention in the late 1990's. Applications of using agent-based (AB) and system dynamics (SD) hybrid models for simulating systems have been demonstrated in the literature. However, majority of the work on the domain includes system specific approaches where the...
Show moreAgent-based (AB) and system dynamics (SD) modeling and simulation techniques have been studied and used by various research fields. After the new hybrid modeling field emerged, the combination of these techniques started getting attention in the late 1990's. Applications of using agent-based (AB) and system dynamics (SD) hybrid models for simulating systems have been demonstrated in the literature. However, majority of the work on the domain includes system specific approaches where the models from two techniques are integrated after being independently developed. Existing work on creating an implicit and universal approach is limited to conceptual modeling and structure design. This dissertation proposes an approach for generating AB-SD hybrid models of systems by using Systems Modeling Language (SysML) which can be simulated without exporting to another software platform. Although the approach is demonstrated using IBM's Rational Rhapsody(&)#174; it is applicable to all other SysML platforms. Furthermore, it does not require prior knowledge on agent-based or system dynamics modeling and simulation techniques and limits the use of any programming languages through the use of SysML diagram tools. The iterative modeling approach allows two-step validations, allows establishing a two-way dynamic communication between AB and SD variables and develops independent behavior models that can be reused in representing different systems. The proposed approach is demonstrated using a hypothetical population, movie theater and a real(-)world training management scenarios. In this setting, the work provides methods for independent behavior and system structure modeling. Finally, provides behavior models for probabilistic behavior modeling and time synchronization.
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Date Issued: 2015
Identifier: CFE0006399, ucf:51517
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006399

Title: From pet to pest? The potential global range and food web effects of a generalist carnivore.
Creator: Bevan, Hannah, Jenkins, David, Noss, Reed, Campbell, Todd, University of Central Florida
Abstract / Description: The Nile monitor lizard [Varanus niloticus (Linnaeus, 1766)] is a generalist carnivore, native to Sub-Saharan Africa and the Nile River but now established in North America as a result of the pet trade. Once introduced, they are a potential invasive threat to native wildlife. Here, I create ensemble species distribution models (SDMs) to predict the global distribution of this generalist carnivore given current and future climate conditions. I then quantify the monitor's potential effects on...
Show moreThe Nile monitor lizard [Varanus niloticus (Linnaeus, 1766)] is a generalist carnivore, native to Sub-Saharan Africa and the Nile River but now established in North America as a result of the pet trade. Once introduced, they are a potential invasive threat to native wildlife. Here, I create ensemble species distribution models (SDMs) to predict the global distribution of this generalist carnivore given current and future climate conditions. I then quantify the monitor's potential effects on 85 food webs representing (>)900 different species within the projected regions based on stomach content data. Climate, vegetation, and elevation data are used for 507 georeferenced observation points from the Nile monitor's native range to produce current and future (2070) ensemble SDMs. Explanatory variables are evaluated as ten alternative models organized in three subsets according to model assumptions. The true skill statistic (TSS), sensitivity, and specificity were used to assess model performance, and the best subset was averaged to represent an ensemble model. Food web impacts after the generalist predator's addition are determined by changes in nine metrics of food web structure. The most predictive (TSS scores ?0.87) ensemble SDM was based on the MARS and FDA algorithms using elevation and climate for current and future conditions. This model shows that, if introduced, Nile monitors will likely spread into many regions in the Americas, the Caribbean, Madagascar, Southeast Asia, and Australia. Assuming unabated carbon emissions by 2070, climate change will enhance that potential range. Adding Nile monitors to food webs generally increases overall trophic links, connectance, link density, and fraction of intermediate taxa, with decreases in the fraction of top and basal taxa. These results are consistent with a generalist predator that affects many species and is likely to affect food web stability. The potential Nile monitor range is vast and encompasses multiple biodiversity hotspots. Given many strong food web interactions by this generalist predator, vulnerable regions should actively prohibit/regulate Nile monitors as pets, enforce those restrictions, and promote exotic pet amnesty programs. Southern US states should especially act soon to prevent spread of the Nile monitor to the Neotropics from its current introduced population in Florida and as released pets.
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Date Issued: 2016
Identifier: CFE0006441, ucf:51446
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006441

Title: Estimating a Freight Mode Choice Model: A Case Study of Commodity Flow Survey 2012.
Creator: Keya, Nowreen, Eluru, Naveen, Abdel-Aty, Mohamed, Radwan, Essam, University of Central Florida
Abstract / Description: This research effort develops a national freight mode choice model employing data from the 2012 Commodity Flow Survey (CFS). While several research efforts have developed mode choice model with multiple modes in the passenger travel context, the literature is sparse in the freight context. The primary reasons being unavailability and/or the high cost associated with the acquisition of mode choice and level of service (LOS) measures (-) such as travel time and travel cost. The first...
Show moreThis research effort develops a national freight mode choice model employing data from the 2012 Commodity Flow Survey (CFS). While several research efforts have developed mode choice model with multiple modes in the passenger travel context, the literature is sparse in the freight context. The primary reasons being unavailability and/or the high cost associated with the acquisition of mode choice and level of service (LOS) measures (-) such as travel time and travel cost. The first contribution of the research effort is to develop travel time and cost measures for various modes reported in the CFS. The study considers five modes: hire truck, private truck, air, parcel service and other modes (rail, ship, pipeline, and other miscellaneous single and multiple modes). The LOS estimation is undertaken for a sample of CFS 2012 data that is partitioned into estimation sample and holdout sample. Subsequently, a mixed multinomial logit model is developed using the estimation sample. The exogenous variables considered in the model include LOS measures, freight characteristics, and transportation network and Origin-Destination variables. The model also accounts for unobserved factors that influence the mode choice process. The estimated mode choice model is validated using the holdout sample. Finally, a policy sensitivity analysis is conducted to illustrate the applicability of the proposed model.
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Date Issued: 2016
Identifier: CFE0006835, ucf:51766
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006835

Title: Network Partitioning in Distributed Agent-Based Models.
Creator: Petkova, Antoniya, Deo, Narsingh, Hughes, Charles, Bassiouni, Mostafa, Shaykhian, Gholam, University of Central Florida
Abstract / Description: Agent-Based Models (ABMs) are an emerging simulation paradigm for modeling complex systems, comprised of autonomous, possibly heterogeneous, interacting agents. The utility of ABMs lies in their ability to represent such complex systems as self-organizing networks of agents. Modeling and understanding the behavior of complex systems usually occurs at large and representative scales, and often obtaining and visualizing of simulation results in real-time is critical.The real-time requirement...
Show moreAgent-Based Models (ABMs) are an emerging simulation paradigm for modeling complex systems, comprised of autonomous, possibly heterogeneous, interacting agents. The utility of ABMs lies in their ability to represent such complex systems as self-organizing networks of agents. Modeling and understanding the behavior of complex systems usually occurs at large and representative scales, and often obtaining and visualizing of simulation results in real-time is critical.The real-time requirement necessitates the use of in-memory computing, as it is dif?cult and challenging to handle the latency and unpredictability of disk accesses. Combining this observation with the scale requirement emphasizes the need to use parallel and distributed computing platforms, such as MPI-enabled CPU clusters. Consequently, the agent population must be "partitioned" across different CPUs in a cluster. Further, the typically high volume of interactions among agents can quickly become a signi?cant bottleneck for real-time or large-scale simulations. The problem is exacerbated if the underlying ABM network is dynamic and the inter-process communication evolves over the course of the simulation. Therefore, it is critical to develop topology-aware partitioning mechanisms to support such large simulations.In this dissertation, we demonstrate that distributed agent-based model simulations bene?t from the use of graph partitioning algorithms that involve a local, neighborhood-based perspective. Such methods do not rely on global accesses to the network and thus are more scalable. In addition, we propose two partitioning schemes that consider the bottom-up individual-centric nature of agent-based modeling. The ?rst technique utilizes label-propagation community detection to partition the dynamic agent network of an ABM. We propose a latency-hiding, seamless integration of community detection in the dynamics of a distributed ABM. To achieve this integration, we exploit the similarity in the process flow patterns of a label-propagation community-detection algorithm and self-organizing ABMs.In the second partitioning scheme, we apply a combination of the Guided Local Search (GLS) and Fast Local Search (FLS) metaheuristics in the context of graph partitioning. The main driving principle of GLS is the dynamic modi?cation of the objective function to escape local optima. The algorithm augments the objective of a local search, thereby transforming the landscape structure and escaping a local optimum. FLS is a local search heuristic algorithm that is aimed at reducing the search space of the main search algorithm. It breaks down the space into sub-neighborhoods such that inactive sub-neighborhoods are removed from the search process. The combination of GLS and FLS allowed us to design a graph partitioning algorithm that is both scalable and sensitive to the inherent modularity of real-world networks.
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Date Issued: 2017
Identifier: CFE0006903, ucf:51706
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006903

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