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- Title
- A MATHEMATICAL STUDY OF TWO RETROVIRUSES, HIV AND HTLV-I.
- Creator
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Baxley, Dana, Mohapatra, Ram, University of Central Florida
- Abstract / Description
-
In this thesis, we examine epidemiological models of two different retroviruses, which infect the human body. The two viruses under study are HIV or the human immunodefiency virus and HTLV-I, which is the human T lymphotropic virus type I. A retrovirus is a virus, which injects its RNA into the host, rather than it's DNA. We will study each of the different mathematical models for each of the viruses separately. Then we use MATLAB-SIMULINK to analyze the models by studying the...
Show moreIn this thesis, we examine epidemiological models of two different retroviruses, which infect the human body. The two viruses under study are HIV or the human immunodefiency virus and HTLV-I, which is the human T lymphotropic virus type I. A retrovirus is a virus, which injects its RNA into the host, rather than it's DNA. We will study each of the different mathematical models for each of the viruses separately. Then we use MATLAB-SIMULINK to analyze the models by studying the reproductive numbers in each case and the disease progression by examining the graphs. In Chapter 1, we mention basic ideas associated with HIV and HTLV-I. In Chapter 2 some of the basic mathematical model of epidemiology is presented. Chapter 3 is devoted to a model describing the intra-host dynamics of HIV. Here, we take into account how HIV infects and replicates in the CD4+ T cells. The model studied in this thesis examines the difference between cells, which are susceptible to the virus, and cells, which are not susceptible. Through the graphs associated with this model, we are able to see how this difference affects disease progression. In Chapter 4, we examine the effect of HTLV-I virus on human body. The HTLV-I virus causes a chronic infection in humans and may eventually lead to other diseases. In particular, the development of Adult T-cell Leukemia or ATL is studied in this thesis. The T-cell dynamics and progression to ATL is described using a mathematical model with coupled differential equations. Using mathematical analysis and SIMULINK, we obtain results on stability, asymptotic stability and the manner of progression of the disease. In Chapter 5 and appendices, we mention our inference and the MATLAB-SIMULINK codes used in this thesis, so that a reader can verify the details of the work carried out in this thesis.
Show less - Date Issued
- 2007
- Identifier
- CFE0001886, ucf:47398
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001886
- Title
- An application of a computerized mathematical model for estimating the quantity and quality of nonpoint sources of pollution from small urban and nonurban watersheds.
- Creator
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Ingraham, Charles John, Wanielista, Martin P., Engineering
- Abstract / Description
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Florida Technological University College of Engineering Thesis; The problem of "Total Water Management" is reviewed; particular emphasis is given to the magnitude and intensity of pollution from nonpoint sources. The relationship between land usage in south Florida and subsequent effects upon receiving water bodies is discussed. Basic factors effecting hydrological and ecological subsystems are illustrated. The U.S. Army Corps of Engineers Urban Storm Water Runoff Mathematical Model, "STORM,"...
Show moreFlorida Technological University College of Engineering Thesis; The problem of "Total Water Management" is reviewed; particular emphasis is given to the magnitude and intensity of pollution from nonpoint sources. The relationship between land usage in south Florida and subsequent effects upon receiving water bodies is discussed. Basic factors effecting hydrological and ecological subsystems are illustrated. The U.S. Army Corps of Engineers Urban Storm Water Runoff Mathematical Model, "STORM," is introduced. Model parameters and methodology are discussed. The mathematical relationships and modeling processes are reviewed and the model is exercised using a "new generation" southeast Florida community (The City of Palm Beach Gardens) as the subject of study. It is concluded that the model can be beneficial in supporting estimates of pollutant loading to receiving waters from nonpoint sources. Iteration with the model, varying control facility cost and capacity, provides a cost effective tool for land and water resource planners. However, due to the particular nature of soils, atmospheric and urban conditions in south Florida, the model should be calibrated with input constants and default values derived to more accurately reflect the southeast Florida environment.
Show less - Date Issued
- 1975
- Identifier
- CFR0003515, ucf:53006
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0003515
- Title
- Personal Computer Simulation Program for Step Motor Drive Systems.
- Creator
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Koos, William M., Harden, Richard C., Engineering
- Abstract / Description
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University of Central Florida College of Engineering Thesis; A system of equations modeling a class of step motors known as the permanent magnet rotor step motor is presented. The model is implemented on a APPLE personal computer in a version of BASIC. Measurements are then made on an existing motor and input to the program for validation. A special test fixture is utilized to take performance data on the motor to facilitate comparisons with the predictions of the program. The comparisons...
Show moreUniversity of Central Florida College of Engineering Thesis; A system of equations modeling a class of step motors known as the permanent magnet rotor step motor is presented. The model is implemented on a APPLE personal computer in a version of BASIC. Measurements are then made on an existing motor and input to the program for validation. A special test fixture is utilized to take performance data on the motor to facilitate comparisons with the predictions of the program. The comparisons show the model is indeed valid for design of step motor drive systems and emphasize the practical nature of using personal computers and simulations for design
Show less - Date Issued
- 1982
- Identifier
- CFR0008163, ucf:53067
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0008163
- Title
- THE DEVELOPMENT OF A FUZZY MODEL TO QUANTIFY TRAINING ANDEDUCATIONAL FACTORS AND THE RESULTING IMPACT ON STUDENT SUCCESSAND LEARNING.
- Creator
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Butler, Chandre, McCauley-Bell, Pamela, University of Central Florida
- Abstract / Description
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The utilization of fuzzy mathematical modeling for quantification of the quality of training and educational delivery is an innovative application that can result in measurable and repeatable results. This research was designed to apply proven quantification techniques and Industrial Engineering methodologies to a nontraditional environment. The outcomes of this research provide the foundation, initial steps and preliminary validation for the development of a systematic fuzzy theoretical...
Show moreThe utilization of fuzzy mathematical modeling for quantification of the quality of training and educational delivery is an innovative application that can result in measurable and repeatable results. This research was designed to apply proven quantification techniques and Industrial Engineering methodologies to a nontraditional environment. The outcomes of this research provide the foundation, initial steps and preliminary validation for the development of a systematic fuzzy theoretical model to be applied for the quantification of various areas within training and education delivery. The test bed for this methodology is Orange County Public School system, the twelfth largest school district in the nation. The organizational and operational factors of a large school district are highly compatible with Systems Engineering concepts. The debate over education reform has drawn from referenced areas within the Industrial Engineering community including quality, continuous improvement, benchmarking and metrics development, data analysis, and scientific/systemic justification requirements. In spite of these applications, the literature does not reflect a consistent and broad application of these techniques in addressing the evaluation and quantification of educational delivery systems. This research draws on the previously listed areas within Industrial Engineering to apply these techniques to enhance the understanding and promote quantification of the multiple factors acting on the educational delivery system. The importance of addressing these issues is a national concern given the significant changes in the United States educational delivery system. For example, over the past 40 years there has been a more than three-hundred percent increase in per-pupil appropriations yet the academic performance gains have been limited and the quantification and measurement of those gains is even more limited. This body of work willidentify the systems, sub-systems, system factors, and factor degrees of existence necessary to quantify and measure these performance changes. Finally, the research will quantify the inputs and produce a model that provides a numeric value that represents the condition of the system and various subsystems of an educational system.
Show less - Date Issued
- 2005
- Identifier
- CFE0000890, ucf:46640
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000890
- Title
- An analytical model for evaluating database update schemes.
- Creator
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Kinsley, Kathryn C., Hughes, Charles E., Arts and Sciences
- Abstract / Description
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University of Central Florida College of Arts and Sciences Thesis; A methodology is presented for evaluating the performance of database update schemes. The methodology uses the M/Hr/1 queueing model as a basis for this analysis and makes use of the history of how data is used in the database. Parameters have been introduced which can be set based on the characteristics of a specific system. These include update to retrieval ratio, average file size, overhead, block size and the expected...
Show moreUniversity of Central Florida College of Arts and Sciences Thesis; A methodology is presented for evaluating the performance of database update schemes. The methodology uses the M/Hr/1 queueing model as a basis for this analysis and makes use of the history of how data is used in the database. Parameters have been introduced which can be set based on the characteristics of a specific system. These include update to retrieval ratio, average file size, overhead, block size and the expected number of items in the database. The analysis is specifically directed toward the support of derived data within the relational model. Three support methods are analyzed. These are first examined in a central database system. The analysis is then extended in order to measure performance in a distributed system. Because concurrency is a major problem in a distributive system, the support of derived data is analyzed with respect to three distributive concurrency control techniques -- master/slave, distributed and synchronized. In addition to its use as a performance predictor, the development of the methodology serves to demonstrate how queueing theory may be used to investigate other related database problems. This is an important benefit due to this lack of fundamental results in the area of using queueing theory to analyze database performance.
Show less - Date Issued
- 1983
- Identifier
- CFR0011600, ucf:53041
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011600
- Title
- A Multiple Case Study Exploring the Relationship Between Engagement in Model-Eliciting Activities and Pre-Service Secondary Mathematics Teachers' Mathematical Knowledge for Teaching Algebra.
- Creator
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Abassian, Aline, Safi, Farshid, Dixon, Juli, Andreasen, Janet, Bush, Sarah, Bostic, Jonathan, University of Central Florida
- Abstract / Description
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The goal of this research study was to explore the nature of the relationship between engagement in model-eliciting activities (MEAs) and pre-service secondary mathematics teachers' (PSMTs') mathematical knowledge for teaching (MKT) algebra. The data collection took place in an undergraduate mathematics education content course for secondary mathematics education majors. In this multiple case study, PSMTs were given a Learning Mathematics for Teaching (LMT) pre-assessment designed to measure...
Show moreThe goal of this research study was to explore the nature of the relationship between engagement in model-eliciting activities (MEAs) and pre-service secondary mathematics teachers' (PSMTs') mathematical knowledge for teaching (MKT) algebra. The data collection took place in an undergraduate mathematics education content course for secondary mathematics education majors. In this multiple case study, PSMTs were given a Learning Mathematics for Teaching (LMT) pre-assessment designed to measure their MKT algebra, and based on those results, three participants were selected with varying levels of knowledge. This was done to ensure varied cases were represented in order to be able to examine and describe multiple perspectives. The three examined cases were Oriana, a PSMT with high MKT, Bianca, a PSMT with medium MKT, and Helaine, a PSMT with low MKT. Over the course of five weeks, the three PSMTs were recorded exploring three MEAs, participated in two interviews, and submitted written reflections. The extensive amount of data collected in this study allowed the researcher to deeply explore the PSMTs' MKT algebra in relation to the given MEAs, with a focus on three specific constructs(-)bridging, trimming, and decompressing(-) based on the Knowledge of Algebra for Teaching (KAT) framework. The results of this study suggest that engaging in MEAs could elicit PSMTs' MKT algebra, and in some cases such tasks were beneficial to their trimming, bridging, and decompressing abilities. Exploring MEAs immersed the PSMTs in generating descriptions, explanations, and constructions, that helped reveal how they interpreted mathematical situations that they encountered. The tasks served as useful tools for PSMTs to have deep discussions and productive discourse on various algebra topics, and make many different mathematical connections in the process.
Show less - Date Issued
- 2018
- Identifier
- CFE0007143, ucf:52305
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007143
- Title
- AN IMPROVED THERMOREGULATORY MODEL FOR COOLING GARMENT APPLICATIONS WITH TRANSIENT METABOLIC RATES.
- Creator
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Westin, Johan, Kapat, Jayanta, University of Central Florida
- Abstract / Description
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Current state-of-the-art thermoregulatory models do not predict body temperatures with the accuracies that are required for the development of automatic cooling control in liquid cooling garment (LCG) systems. Automatic cooling control would be beneficial in a variety of space, aviation, military, and industrial environments for optimizing cooling efficiency, for making LCGs as portable and practical as possible, for alleviating the individual from manual cooling control, and for improving...
Show moreCurrent state-of-the-art thermoregulatory models do not predict body temperatures with the accuracies that are required for the development of automatic cooling control in liquid cooling garment (LCG) systems. Automatic cooling control would be beneficial in a variety of space, aviation, military, and industrial environments for optimizing cooling efficiency, for making LCGs as portable and practical as possible, for alleviating the individual from manual cooling control, and for improving thermal comfort and cognitive performance. In this study, we adopt the Fiala thermoregulatory model, which has previously demonstrated state-of-the-art predictive abilities in air environments, for use in LCG environments. We validate the numerical formulation with analytical solutions to the bioheat equation, and find our model to be accurate and stable with a variety of different grid configurations. We then compare the thermoregulatory model's tissue temperature predictions with experimental data where individuals, equipped with an LCG, exercise according to a 700 W rectangular type activity schedule. The root mean square (RMS) deviation between the model response and the mean experimental group response is 0.16°C for the rectal temperature and 0.70°C for the mean skin temperature, which is within state-of-the-art variations. However, with a mean absolute body heat storage error (e_BHS_mean) of 9.7 W·h, the model fails to satisfy the ±6.5 W·h accuracy that is required for the automatic LCG cooling control development. In order to improve model predictions, we modify the blood flow dynamics of the thermoregulatory model. Instead of using step responses to changing requirements, we introduce exponential responses to the muscle blood flow and the vasoconstriction command. We find that such modifications have an insignificant effect on temperature predictions. However, a new vasoconstriction dependency, i.e. the rate of change of hypothalamus temperature weighted by the hypothalamus error signal (DThy·dThy/dt), proves to be an important signal that governs the thermoregulatory response during conditions of simultaneously increasing core and decreasing skin temperatures, which is a common scenario in LCG environments. With the new DThy·dThy/dt dependency in the vasoconstriction command, the e_BHS_mean for the exercise period is reduced by 59% (from 12.9 W·h to 5.2 W·h). Even though the new e_BHS_mean of 5.8 W·h for the total activity schedule is within the target accuracy of ±6.5 W·h, e_BHS fails to stay within the target accuracy during the entire activity schedule. With additional improvements to the central blood pool formulation, the LCG boundary condition, and the agreement between model set-points and actual experimental initial conditions, it seems possible to achieve the strict accuracy that is needed for automatic cooling control development.
Show less - Date Issued
- 2008
- Identifier
- CFE0002460, ucf:47707
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002460
- Title
- MATHEMATICAL MODELING OF SMALLPOX WITHOPTIMAL INTERVENTION POLICY.
- Creator
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LAWOT, NIWAS, ROLLINS, DAVID, University of Central Florida
- Abstract / Description
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In this work, two differential equation models for smallpox are numerically solved to find the optimal intervention policy. In each model we look for the range of values of the parameters that give rise to the worst case scenarios. Since the scale of an epidemic is determined by the number of people infected, and eventually dead, as a result of infection, we attempt to quantify the scale of the epidemic and recommend the optimum intervention policy. In the first case study, we mimic a densely...
Show moreIn this work, two differential equation models for smallpox are numerically solved to find the optimal intervention policy. In each model we look for the range of values of the parameters that give rise to the worst case scenarios. Since the scale of an epidemic is determined by the number of people infected, and eventually dead, as a result of infection, we attempt to quantify the scale of the epidemic and recommend the optimum intervention policy. In the first case study, we mimic a densely populated city with comparatively big tourist population, and heavily used mass transportation system. A mathematical model for the transmission of smallpox is formulated, and numerically solved. In the second case study, we incorporate five different stages of infection: (1) susceptible (2) infected but asymptomatic, non infectious, and vaccine-sensitive; (3) infected but asymptomatic, noninfectious, and vaccine-in-sensitive; (4) infected but asymptomatic, and infectious; and (5) symptomatic and isolated. Exponential probability distribution is used for modeling this case. We compare outcomes of mass vaccination and trace vaccination on the final size of the epidemic.
Show less - Date Issued
- 2006
- Identifier
- CFE0001193, ucf:46848
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001193
- Title
- A Mathematical Model for Determining the Thermal Distribution Resulting from Discharge of a Heated Effluent.
- Creator
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Epstein, Alan H., Nimmo, Bruce, Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; A mathematical model is presented for the problem of determining the two-dimensional temperature distribution resulting from the discharge of a heated effluent into a shallow, quiescent receptacle. The physical model ofr the problem is the two-dimensional jet augmented by an imposed condition of viscous drag due to bottom friction effects. By virtue of the assumption that the physical properties of the effluent are independent of...
Show moreFlorida Technological University College of Engineering Thesis; A mathematical model is presented for the problem of determining the two-dimensional temperature distribution resulting from the discharge of a heated effluent into a shallow, quiescent receptacle. The physical model ofr the problem is the two-dimensional jet augmented by an imposed condition of viscous drag due to bottom friction effects. By virtue of the assumption that the physical properties of the effluent are independent of temperature over the operational temperature range of the plume, the analysis separates the total problem into a flow problem and a temperature problem. Solution of the temperature distribution is accomplished both analytically and numerically. Analytically, the temperature distribution is found through sequential integral solution of the equations defining the mathematical model, under the physical assumptions of a Gaussian flow distribution and the following relationship between the velocity and temperature distributions: [formula] where the subscript (max) denotes conditions along the jet centerline. Numerically, the equations defining the mathematical model are solved by a finite differencing technique implemented with the aid of an I.B.M. 360 digital computer. Comparison of the predictions of the model with the classical two-dimensional momentum jet indicate that the model is a reasonable approximation of the real physical problem. In addition, there is seen to be a critical dependence of the flow in the plume on the depth of the receptacle.
Show less - Date Issued
- 1972
- Identifier
- CFR0012146, ucf:53131
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0012146
- Title
- A Military Training System Perspective and Model for Training Program Management.
- Creator
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Boudreaux, Alvin J., Clapp, Donald E., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; A perspective of the Naval Education and Training System (NETS) is developed and utilized as a framework on which a simulation model of general training system activities is constructed. The simulation model, which is based on functional activities, emphasizes the interdependent consequences of decisions and actions created through management planning, analysis, and control of training programs. A simulation experiment was...
Show moreFlorida Technological University College of Engineering Thesis; A perspective of the Naval Education and Training System (NETS) is developed and utilized as a framework on which a simulation model of general training system activities is constructed. The simulation model, which is based on functional activities, emphasizes the interdependent consequences of decisions and actions created through management planning, analysis, and control of training programs. A simulation experiment was conducted using a test situation description (scenario) to reflect the impact of management decisions and actions on the resulting allocation of resources and timeliness of training program activities. Conclusions are drawn regarding the utility and implications of the system dynamics model as a management tool with which to improve training. Recommendations are made regarding future experimentation and analysis which is required for sufficient development of a useful management tool.
Show less - Date Issued
- 1974
- Identifier
- CFR0003500, ucf:53016
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0003500
- Title
- Feasability analysis of ramp control systems, a simulation approach.
- Creator
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Popkin, Henry Allen, Klee, Harold, Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; The ever increasing traffic congestion being experienced on urban freeways has caused attention to be focused on methods for improving traffic operations on these facilities. The reduction or elimination of freeway congestion can be handled in two basic ways: 1) by increasing the freeway's capacity defined as the number of vehicles per unit time that can pass a given point in one lane of the freeway multiplied by the number of...
Show moreFlorida Technological University College of Engineering Thesis; The ever increasing traffic congestion being experienced on urban freeways has caused attention to be focused on methods for improving traffic operations on these facilities. The reduction or elimination of freeway congestion can be handled in two basic ways: 1) by increasing the freeway's capacity defined as the number of vehicles per unit time that can pass a given point in one lane of the freeway multiplied by the number of lanes on the freeway, or 2) by decreasing the traffic loads imposed on these freeways. Monumental costs and adverse public relations are involved in the construction of either new freeways or additional lanes in urban areas to increase freeway capacity. Due to these factors, the move in recent years has been toward decreasing traffic loads to accomplish the goals of reduction or elimination of freeway congestion. In an effort to combat the freeway congestion, traffic researchers have devoted much time and effort to the theoretical and practical aspects of systems in which controlled access is utilized to prevent or reduce congestion caused by traffic demands in excess of freeway operational capacity. Such systems perform the function of 'freeway surveillance and control'. An important aspect of these systems is the control mechanism used for the regulation of the ramp traffic to the freeway. This topic of ramp metering is the subject of this report.
Show less - Date Issued
- 1975
- Identifier
- CFR0003522, ucf:52998
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0003522
- Title
- ANALYSIS AND OPTIMIZATION OF A SOLAR THERMAL COLLECTOR WITH INTEGRATED STORAGE.
- Creator
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Bonadies, Monica, Kapat, Jay, University of Central Florida
- Abstract / Description
-
Solar energy, a topic popular in the United States during the oil embargo of the 1970ÂÂ's, has become a relevant topic once more with the current focus on reducing greenhouse emissions. Solar thermal energy in particular has become popular as it uses existing steam turbine technology to produce electricity, with the benefit of using solar energy to produce steam rather than coal or nuclear heat sources. Solar thermal can also be used at lower temperatures to heat water...
Show moreSolar energy, a topic popular in the United States during the oil embargo of the 1970ÂÂ's, has become a relevant topic once more with the current focus on reducing greenhouse emissions. Solar thermal energy in particular has become popular as it uses existing steam turbine technology to produce electricity, with the benefit of using solar energy to produce steam rather than coal or nuclear heat sources. Solar thermal can also be used at lower temperatures to heat water for pools or for residential use. While this energy source has its benefits, it has the problem of being opportunistic – the energy must be used as it is captured. With the integration of storage, a solar thermal system becomes more viable for use. In this work, a low temperature (50-70o C) thermal storage unit with a solar thermal collector is experimentally run then studied using both analytical and numerical methods. With these methods, suggestions for future developments of the storage unit are made. The prototype collector and storage combination tested worked best during the winter months, when there was low humidity. Furthermore, the heat exchanger design within the storage unit was found to work well for charging (heating) the unit, but not for discharging the storage to heat water. The best modeling method for the storage unit was the use of FLUENT, which would allow for the suggested changes to the prototype to be simulated before the next prototype was constructed.
Show less - Date Issued
- 2010
- Identifier
- CFE0003260, ucf:48548
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003260
- Title
- MATHEMATICAL MODELS OF MOSQUITO POPULATIONS.
- Creator
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Reed, Hanna, Shuai, Zhisheng, University of Central Florida
- Abstract / Description
-
The intent of this thesis is to develop ordinary differential equation models to better understand the mosquito population. We first develop a framework model, where we determine the condition under which a natural mosquito population can persist in the environment. Wolbachia is a bacterium which limits the replication of viruses inside the mosquito which it infects. As a result, infecting a mosquito population with Wolbachia can decrease the transmission of viral mosquito-borne diseases,...
Show moreThe intent of this thesis is to develop ordinary differential equation models to better understand the mosquito population. We first develop a framework model, where we determine the condition under which a natural mosquito population can persist in the environment. Wolbachia is a bacterium which limits the replication of viruses inside the mosquito which it infects. As a result, infecting a mosquito population with Wolbachia can decrease the transmission of viral mosquito-borne diseases, such as dengue. We develop another ODE model to investigate the invasion of Wolbachia in a mosquito population. In a biologically feasible situation, we determine three coexisting equilibria: a stable Wolbachia-free equilibrium, an unstable coexistence equilibrium, and a complete invasion equilibrium. We establish the conditions under which a population of Wolbachia infected mosquitoes may persist in the environment via the next generation number and determine when a natural mosquito population may experience a complete invasion of Wolbachia.
Show less - Date Issued
- 2018
- Identifier
- CFH2000299, ucf:45845
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000299
- Title
- Modeling Disease Impact of Vibrio-Phage Interactions.
- Creator
-
Botelho, Christopher, Shuai, Zhisheng, Nevai, A, Zhang, Teng, Teter, Kenneth, University of Central Florida
- Abstract / Description
-
Since the work of John Snow, scientists and medical professionals have understood that individuals develop cholera by means of consuming contaminated water. Despite the knowledge(&)nbsp;of cholera's route of infection, many countries have experienced and still experience endemic cholera. Cholera is caused by the Vibrio cholerae (V. cholerae) bacterium and presents with acute diarrhea and vomiting. If untreated, infected individuals may die due to dehydration. Cholera is a disease that most...
Show moreSince the work of John Snow, scientists and medical professionals have understood that individuals develop cholera by means of consuming contaminated water. Despite the knowledge(&)nbsp;of cholera's route of infection, many countries have experienced and still experience endemic cholera. Cholera is caused by the Vibrio cholerae (V. cholerae) bacterium and presents with acute diarrhea and vomiting. If untreated, infected individuals may die due to dehydration. Cholera is a disease that most commonly affects countries with poor infrastructure and water sanitation. Despite efforts to control cholera in such countries, the disease persists. One such example is Haiti which has been experiencing a cholera outbreak since 2010. While there has been much research in the field of microbiology to understand V. cholerae, there has been comparably less research in the field of mathematical biology to understand the dynamics of V. cholerae in the environment. A mathematical model of V. cholerae incorporating a phage population is coupled with a SIRS disease model to examine the impact of vibrio and phage interaction. It is shown that there might exist two endemic equilibria, besides the disease free equilibrium: one in which phage persist in the environment and one in which the phage fail to persist. Existence and stability of these equilibria are established. Disease control strategies based on vibrio and phage interactions are discussed.
Show less - Date Issued
- 2019
- Identifier
- CFE0007604, ucf:52544
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007604
- Title
- Improving Student Learning in Undergraduate Mathematics.
- Creator
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Rejniak, Gabrielle, Young, Cynthia, Brennan, Joseph, Martin, Heath, University of Central Florida
- Abstract / Description
-
The goal of this study was to investigate ways of improving student learning, par-ticularly conceptual understanding, in undergraduate mathematics courses. This studyfocused on two areas: course design and animation. The methods of study were thefollowing: Assessing the improvement of student conceptual understanding as a result of teamproject-based learning, individual inquiry-based learning and the modied empo-rium model; and Assessing the impact of animated videos on student learning with...
Show moreThe goal of this study was to investigate ways of improving student learning, par-ticularly conceptual understanding, in undergraduate mathematics courses. This studyfocused on two areas: course design and animation. The methods of study were thefollowing: Assessing the improvement of student conceptual understanding as a result of teamproject-based learning, individual inquiry-based learning and the modied empo-rium model; and Assessing the impact of animated videos on student learning with the emphasis onconcepts.For the first part of our study (impact of course design on student conceptual understanding) we began by comparing the following three groups in Fall 2010 and Fall2011:1. Fall 2010: MAC 1140 Traditional Lecture (&) Fall 2011: MAC 1140 Modied Empo-rium2. Fall 2010: MAC 1140H with Project (&) Fall 2011: MAC 1140H no Project3. Fall 2010: MAC 2147 with Projects (&) Fall 2011: MAC 2147 no ProjectsAnalysis of pre-tests and post-tests show that all three courses showed statistically significant increases, according to their respective sample sizes, during Fall 2010. However, in Fall 2011 only MAC 2147 continued to show a statistically significant increase. Therefore in Fall 2010, project-based learning - both in-class individual projects and out-of-class team projects - conclusively impacted the students' conceptual understanding. Whereas, in Fall 2011, the data for the Modified Emporium model had no statistical significance and is therefore inconclusive as to its effectiveness. In addition the difference in percent ofincrease for MAC 1140 between Fall 2010 - traditional lecture model - and Fall 2011 -modified emporium model - is not statistically significant and we cannot say that either model is a better delivery mode for conceptual learning. For the second part of our study, the students enrolled in MAC 1140H Fall 2011 and MAC 2147 Fall 2011 were given a pre-test on sequences and series before showing them an animated video related to the topic. After watching the video, students were then given the same 7 question post test to determine any improvement in the students' understanding of the topic. After two weeks of teacher-led instruction, the students tookthe same post-test again. The results of this preliminary study indicate that animated videos do impact the conceptual understanding of students when used as an introduction into a new concept. Both courses that were shown the video had statistically significant increases in the conceptual understanding of the students between the pre-test and the post-animation test.
Show less - Date Issued
- 2012
- Identifier
- CFE0004320, ucf:49481
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004320
- 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
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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.
Show less - Date Issued
- 2015
- Identifier
- CFE0005906, ucf:50872
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005906
- Title
- A comparison of sixth-grade English language arts and mathematics achievement between middle schools and K-8 schools.
- Creator
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Asplen, Brennan, Johnson, Jerry, Doherty, Walter, Ortiz, Enrique, Shope, Shane, University of Central Florida
- Abstract / Description
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The purpose of this study was to compare the academic achievement of sixth grade students enrolled in a traditional middle school model versus those enrolled in a K-8 school model by analyzing English Language Arts (ELA) and mathematics scores. Developmental Scale Score (DSS) data from the 2017 Florida Standards Assessment (FSA) were collected from three K-8 schools and three middle schools in one high-performing Florida school district. Results from an independent samples t-test revealed...
Show moreThe purpose of this study was to compare the academic achievement of sixth grade students enrolled in a traditional middle school model versus those enrolled in a K-8 school model by analyzing English Language Arts (ELA) and mathematics scores. Developmental Scale Score (DSS) data from the 2017 Florida Standards Assessment (FSA) were collected from three K-8 schools and three middle schools in one high-performing Florida school district. Results from an independent samples t-test revealed that middle school student scores were slightly higher in overall ELA and mathematics proficiency, but the differences were not substantive. Cross-tabulation was utilized to compute the proportion of students making learning gains in ELA and mathematics. The results were nearly identical among the middle school students and the K-8 students relative to ELA; however, the proportion of students making learning gains in mathematics was substantially higher among the K-8 students. To investigate equity in the distribution of achievement, a comparison was made between Middle School and K-8 bi-serial correlation coefficients measuring the strength and direction of the relationship between student achievement and socioeconomic status (SES). Results suggested that the negative influence of low-SES on academic achievement in ELA and mathematics was notably stronger among students enrolled in the middle school model. While making school construction decisions, policy makers will be informed through these findings as to which type of grade span configuration is most likely to positively impact student achievement.
Show less - Date Issued
- 2019
- Identifier
- CFE0007599, ucf:52550
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007599
- Title
- VERIFICATION OF PILOT-SCALE IRON RELEASE MODELS.
- Creator
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Glatthorn, Stephen, Taylor, James, University of Central Florida
- Abstract / Description
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A model for the prediction of color release from a pilot distribution system was created in 2003 by Imran. This model allows prediction of the release of color from aged cast iron and galvanized steel pipes as a function of water quality and hydraulic residence time. Color was used as a surrogate measurement for iron, which exhibited a strong linear correlation. An anomaly of this model was an absence of a term to account for pH, due to the influent water being well stabilized. A new study...
Show moreA model for the prediction of color release from a pilot distribution system was created in 2003 by Imran. This model allows prediction of the release of color from aged cast iron and galvanized steel pipes as a function of water quality and hydraulic residence time. Color was used as a surrogate measurement for iron, which exhibited a strong linear correlation. An anomaly of this model was an absence of a term to account for pH, due to the influent water being well stabilized. A new study was completed to evaluate the effectiveness of corrosion inhibitors against traditional adjustment. Two control lines were supplied with nearly same water qualities, one at pH close to pHs and one at pH well above pHs. The resulting data showed that effluent iron values were typically greater in the line with lower pH. The non-linear color model by Imran shows good agreement when the LSI was largely positive, but underpredicted the color release from the lower LSI line. A modification to the Larson Ratio proposed by Imran was able to give a reasonable agreement to the data at lower LSI values. LSI showed no definite relation to iron release, although a visual trend of higher LSI mitigating iron release can be seen. An iron flux model was also developed on the same pilot system by Mutoti. This model was based on a steady state mass balance of iron in a pipe. The constants for the model were empirically derived from experiments at different hydraulic conditions with a constant water quality. Experiments were assumed to reach steady state at 3 pipe volumes due to the near constant effluent turbidity achieved at this point. The model proposes that the iron flux under laminar flow conditions is constant, while the iron flux is linearly related to the Reynolds Number under turbulent conditions. This model incorporates the color release models developed by Imran to calculate flux values from different water qualities. A limited number of experiments were performed in the current study using desalinated and ground water sources at Reynolds Numbers ranging from 50 to 200. The results of these limited experiments showed that the iron flux for cast iron pipe was approximately one-half of the predicted values from Mutoti. This discrepancy may be caused by the more extensive flushing of the pipes performed on the current experiments which allowed attainment of a true steady state. Model changes were proposed to distinguish between near stagnant flow and the upper laminar region, with the upper laminar region showing a slight linear increase. Predictions using the galvanized flux model were not accurate due to an inferior color release model that was developed for galvanized pipes. The model exhibits a high dependence on sulfate concentrations, but concentrations of sulfates in the current experiments were low. This led to low predicted flux values when the actual data showed otherwise. A new galvanized model was developed from a combination of data from the original and current experiments. The predicted flux values using the new model showed great improvement over the old model, but the new model database was limited and the resulting model was not able to be independently tested.
Show less - Date Issued
- 2007
- Identifier
- CFE0001704, ucf:47332
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001704
- Title
- The AfterMath: A Culturally Responsive Mathematical Intervention to Aid Students Affected by Natural Disasters.
- Creator
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Kurtz, Brianna, Haciomeroglu, Erhan, Bush, Sarah, Safi, Farshid, Biraimah, Karen, University of Central Florida
- Abstract / Description
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On September 20, 2017, Hurricane Maria struck the island of Puerto Rico. The damage was extensive, and many people found themselves to be natural disaster refugees. As a result, schools in Central Florida saw an influx of new students who had their educations interrupted by the disaster and now were resuming school in a new language of instruction. These students not only faced linguistic challenges but also academic differences due to the high prevalence of poverty and the effects of...
Show moreOn September 20, 2017, Hurricane Maria struck the island of Puerto Rico. The damage was extensive, and many people found themselves to be natural disaster refugees. As a result, schools in Central Florida saw an influx of new students who had their educations interrupted by the disaster and now were resuming school in a new language of instruction. These students not only faced linguistic challenges but also academic differences due to the high prevalence of poverty and the effects of neocolonialism in their previous schooling. This mixed methods study implemented an intensive intervention in probability to aid students in developing mathematical understanding and forming meaningful connections. Student participants, who had been affected by Hurricane Maria, were now attending a public high school and were paired one-on-one with a bilingual, mathematically high performing student mentor to complete culturally responsive, bilingual probability tasks. Data collection occurred over the course of six weeks in fall 2019. Both mentor and mentee students participated in focus group interviews, and the mentees completed a probability pre-test and post-test. Student participants were found to have statistically significant increases in the understanding of probability concepts when comparing pre-intervention and post-intervention results, with the understanding and usage of the multiplication rule showing the most significant improvement. Both mentors and mentees reported feeling a stronger sense of unity and belonging post-intervention as well as improvement in bilingual academic vocabulary. With the impact of natural disasters on the rise, implications of this study include its adaption to respond to future displaced students as they resume schooling post-interruption in Central Florida and beyond.
Show less - Date Issued
- 2019
- Identifier
- CFE0007828, ucf:52820
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007828
- Title
- ANALYSIS OF THE RELATIONSHIP BETWEEN THE LEVEL OF EDUCATIONAL COMPUTER GAME USE AND MILKEN EXEMPLAR TEACHER INSTRUCTIONAL STRATEGIES.
- Creator
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Dahan Marks, Yaela, Proctor, Michael, University of Central Florida
- Abstract / Description
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This research examines the nature and level of educational computer-based game techniques adoption by Milken Educator Award winning teachers in achieving success in their classrooms. The focus of the research is on their level of acceptance of educational computer-based games and the nature of game usage to increase student performance in the classroom. With Davis' (1985) Technology Acceptance Model (Davis, 1985) as the conceptual framework, the research also examines how teachers'...
Show moreThis research examines the nature and level of educational computer-based game techniques adoption by Milken Educator Award winning teachers in achieving success in their classrooms. The focus of the research is on their level of acceptance of educational computer-based games and the nature of game usage to increase student performance in the classroom. With Davis' (1985) Technology Acceptance Model (Davis, 1985) as the conceptual framework, the research also examines how teachers' perceptions of educational computer-based games influence their willingness to incorporate these teaching methods in their classroom. The approach utilizes a descriptive survey to develop and evaluate responses from exemplar teachers about the level and nature of their use (or lack thereof) of educational computer-based games and implementation in the classroom. Further, this research seeks to identify successful and unsuccessful techniques in the use of educational computer-based games in the classroom. In addition, data collection and analysis will seek to identify the strength of relationships between content-specific educational computer-based games and subject; educational computer-based games and gender; educational computer-based games and age; etc. A teacher who is exemplary as defined by Milken Educator Awards possesses, "exceptional educational talent as evidenced by effective instructional practices and student learning results in the classroom and school". Survey findings are placed within the Technology Acceptance Model framework developed by Davis.
Show less - Date Issued
- 2011
- Identifier
- CFE0003682, ucf:48811
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003682
