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Pages
- Title
- JML Template Generation.
- Creator
-
Poojari, Kushal Raghav, Leavens, Gary, Turgut, Damla, Dechev, Damian, University of Central Florida
- Abstract / Description
-
The Java Modeling Language (JML) is a behavioral interface specific language designed to specify Java modules (which are Java classes and interfaces). Specifications are used to describe the intended functionality without considering the way it is implemented. In JML, if a user wants to write specifications for a Java file, he or she must undertake several steps. To help automate the process of creating annotations for method specifications, a tool Jmlspec was created. Jmlspec generated a...
Show moreThe Java Modeling Language (JML) is a behavioral interface specific language designed to specify Java modules (which are Java classes and interfaces). Specifications are used to describe the intended functionality without considering the way it is implemented. In JML, if a user wants to write specifications for a Java file, he or she must undertake several steps. To help automate the process of creating annotations for method specifications, a tool Jmlspec was created. Jmlspec generated a file that refines the source file and has empty placeholders in which one can write specifications. Although Jmlspec worked with older versions of Java, it does not work with the current version of Java (Java 8). This thesis describes the implementation of a new version of the Jmlspec tool that is compatible with newest versions of Java. This tool will be more maintainable than the older version of Jmlspec and easier to extend.
Show less - Date Issued
- 2017
- Identifier
- CFE0006641, ucf:51228
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006641
- Title
- SIMULATION OF RANDOM SET COVERING PROBLEMS WITH KNOWN OPTIMAL SOLUTIONS AND EXPLICITLY INDUCED CORRELATIONS AMOONG COEFFICIENTS.
- Creator
-
Sapkota, Nabin, Reilly, Charles, University of Central Florida
- Abstract / Description
-
The objective of this research is to devise a procedure to generate random Set Covering Problem (SCP) instances with known optimal solutions and correlated coefficients. The procedure presented in this work can generate a virtually unlimited number of SCP instances with known optimal solutions and realistic characteristics, thereby facilitating testing of the performance of SCP heuristics and algorithms. A four-phase procedure based on the Karush-Kuhn-Tucker (KKT) conditions is proposed to...
Show moreThe objective of this research is to devise a procedure to generate random Set Covering Problem (SCP) instances with known optimal solutions and correlated coefficients. The procedure presented in this work can generate a virtually unlimited number of SCP instances with known optimal solutions and realistic characteristics, thereby facilitating testing of the performance of SCP heuristics and algorithms. A four-phase procedure based on the Karush-Kuhn-Tucker (KKT) conditions is proposed to generate SCP instances with known optimal solutions and correlated coefficients. Given randomly generated values for the objective function coefficients and the sum of the binary constraint coefficients for each variable and a randomly selected optimal solution, the procedure: (1) calculates the range for the number of possible constraints, (2) generates constraint coefficients for the variables with value one in the optimal solution, (3) assigns values to the dual variables, and (4) generates constraint coefficients for variables with value 0 in the optimal solution so that the KKT conditions are satisfied. A computational demonstration of the procedure is provided. A total of 525 SCP instances are simulated under seven correlation levels and three levels for the number of constraints. Each of these instances is solved using three simple heuristic procedures. The performance of the heuristics on the SCP instances generated is summarized and analyzed. The performance of the heuristics generally worsens as the expected correlation between the coefficients increases and as the number of constraints increases. The results provide strong evidence of the benefits of the procedure for generating SCP instances with correlated coefficients, and in particular SCP instances with known optimal solutions.
Show less - Date Issued
- 2006
- Identifier
- CFE0001416, ucf:47037
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001416
- Title
- An Analysis of Generational Differences and Their Effects on Schools and Student Performance.
- Creator
-
Paniale, Lisa, Murray, Barbara, Doherty, Walter, Taylor, Rosemarye, Spadaccini, Becky, University of Central Florida
- Abstract / Description
-
This study examined the effects of generational differences on student achievement of students in Brevard Public Schools, Brevard County, Florida. The independent variable was the generational cohorts (Traditionalist, Baby Boomer, Generation X, and Millennials). The dependent variable was the factors of job satisfaction, organizational commitment, and work motivation. A second dependent variable was Value-Added Measure (VAM) scores calculated by the Department of Education for the state of...
Show moreThis study examined the effects of generational differences on student achievement of students in Brevard Public Schools, Brevard County, Florida. The independent variable was the generational cohorts (Traditionalist, Baby Boomer, Generation X, and Millennials). The dependent variable was the factors of job satisfaction, organizational commitment, and work motivation. A second dependent variable was Value-Added Measure (VAM) scores calculated by the Department of Education for the state of Florida for each teacher of grades K-12. These VAM scores were derived from the Florida Comprehensive Assessment Test (FCAT) Reading and Math Developmental Scale scores to show a teacher's effect on student achievement. A convenience sample of teachers was surveyed from the population of all Brevard Public Schools teachers, and respondents' VAM scores were analyzed for differences in the means.Findings showed that there was a statistically significant difference in job satisfaction among the generational cohorts based on the benefits factor. Baby Boomers found benefits to be a more important aspect of job satisfaction than did Millennials. There was also a statistically significant difference in organizational commitment among the generational cohorts based on career at current school. Baby Boomers found spending the rest of their career at their current school significantly more important than did Millennials. There was no statistically significant difference among the generational cohorts in work motivation or means of VAM scores.Recommendations were made for future studies that generalize the finding to other counties in Florida, other states, and other countries. The possibility of generational impact being a cultural experience would be addressed. Another possible future study included examining individuals within a single generational cohort. Gender considerations are one area for study. Furthermore, it is recommended that future studies move beyond one timeframe for gathering data. A longitudinal study of the same people within a generation from the beginning of their career to the end to determine if values change due to aging and gaining experience as compared to belonging to a generation should be conducted.
Show less - Date Issued
- 2013
- Identifier
- CFE0004733, ucf:49816
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004733
- Title
- Optimization Approaches for Electricity Generation Expansion Planning Under Uncertainty.
- Creator
-
Zhan, Yiduo, Zheng, Qipeng, Vela, Adan, Garibay, Ivan, Sun, Wei, University of Central Florida
- Abstract / Description
-
In this dissertation, we study the long-term electricity infrastructure investment planning problems in the electrical power system. These long-term capacity expansion planning problems aim at making the most effective and efficient investment decisions on both thermal and wind power generation units. One of our research focuses are uncertainty modeling in these long-term decision-making problems in power systems, because power systems' infrastructures require a large amount of investments,...
Show moreIn this dissertation, we study the long-term electricity infrastructure investment planning problems in the electrical power system. These long-term capacity expansion planning problems aim at making the most effective and efficient investment decisions on both thermal and wind power generation units. One of our research focuses are uncertainty modeling in these long-term decision-making problems in power systems, because power systems' infrastructures require a large amount of investments, and need to stay in operation for a long time and accommodate many different scenarios in the future. The uncertainties we are addressing in this dissertation mainly include demands, electricity prices, investment and maintenance costs of power generation units. To address these future uncertainties in the decision-making process, this dissertation adopts two different optimization approaches: decision-dependent stochastic programming and adaptive robust optimization. In the decision-dependent stochastic programming approach, we consider the electricity prices and generation units' investment and maintenance costs being endogenous uncertainties, and then design probability distribution functions of decision variables and input parameters based on well-established econometric theories, such as the discrete-choice theory and the economy-of-scale mechanism. In the adaptive robust optimization approach, we focus on finding the multistage adaptive robust solutions using affine policies while considering uncertain intervals of future demands.This dissertation mainly includes three research projects. The study of each project consists of two main parts, the formulation of its mathematical model and the development of solution algorithms for the model. This first problem concerns a large-scale investment problem on both thermal and wind power generation from an integrated angle without modeling all operational details. In this problem, we take a multistage decision-dependent stochastic programming approach while assuming uncertain electricity prices. We use a quasi-exact solution approach to solve this multistage stochastic nonlinear program. Numerical results show both computational efficient of the solutions approach and benefits of using our decision-dependent model over traditional stochastic programming models. The second problem concerns the long-term investment planning with detailed models of real-time operations. We also take a multistage decision-dependent stochastic programming approach to address endogenous uncertainties such as generation units' investment and maintenance costs. However, the detailed modeling of operations makes the problem a bilevel optimization problem. We then transform it to a Mathematic Program with Equilibrium Constraints (MPEC) problem. We design an efficient algorithm based on Dantzig-Wolfe decomposition to solve this multistage stochastic MPEC problem. The last problem concerns a multistage adaptive investment planning problem while considering uncertain future demand at various locations. To solve this multi-level optimization problem, we take advantage of affine policies to transform it to a single-level optimization problem. Our numerical examples show the benefits of using this multistage adaptive robust planning model over both traditional stochastic programming and single-level robust optimization approaches. Based on numerical studies in the three projects, we conclude that our approaches provide effective and efficient modeling and computational tools for advanced power systems' expansion planning.
Show less - Date Issued
- 2016
- Identifier
- CFE0006676, ucf:51248
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006676
- Title
- Attitudes Toward Cohabitation: A cross sectional study.
- Creator
-
Shields-Dutton, Kensington, Gay, David, Rivera, Fernando, Huff-Corzine, Lin, University of Central Florida
- Abstract / Description
-
Cohabitation and attitudes toward cohabitation have been of interest to social scientists since the 1970s. Early research on cohabitation concentrated on college aged students enrolled at institutions of higher learning. This trend was due to convenience sampling (Trost, 1978). Later research demonstrated the college population represented less than half of the total number of cohabitating persons. With the growth in numbers of persons who are choosing to cohabitate versus marrying, this...
Show moreCohabitation and attitudes toward cohabitation have been of interest to social scientists since the 1970s. Early research on cohabitation concentrated on college aged students enrolled at institutions of higher learning. This trend was due to convenience sampling (Trost, 1978). Later research demonstrated the college population represented less than half of the total number of cohabitating persons. With the growth in numbers of persons who are choosing to cohabitate versus marrying, this study examines current attitudes towards cohabitation. This research augments the existing literature on attitudes toward cohabitation in the following ways: (1) it updates the current research on the attitudes toward cohabitation by using the 2012 General Social Survey, (2) it examines cohort differences in attitudes toward cohabitation among the four major birth cohorts in our society today (i.e., the Silent Generation, the Baby Boomer cohort, Generation X, and the Millennial cohort), and (3) it controls for other factors that affect attitudes toward cohabitation.
Show less - Date Issued
- 2016
- Identifier
- CFE0006181, ucf:51149
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006181
- Title
- Pro-Life Progressivism: The Effect of Abortion Attitudes on Attitudes Towards Government Welfare Programs.
- Creator
-
Gilmore, Lauren, Gay, David, Jasinski, Jana, Lynxwiler, John, University of Central Florida
- Abstract / Description
-
???There is an extensive body of literature exploring the way in which a variety of factors affect a person's attitudes towards abortion. There is significantly less research, however, on the way in which a person's attitude towards abortion affects their attitudes towards other issues. At the same time, there is evidence to suggest that a growing number of people are using their (")pro- life(") stance on abortion to influence their stance on other issues that revolve around the quality and...
Show more???There is an extensive body of literature exploring the way in which a variety of factors affect a person's attitudes towards abortion. There is significantly less research, however, on the way in which a person's attitude towards abortion affects their attitudes towards other issues. At the same time, there is evidence to suggest that a growing number of people are using their (")pro- life(") stance on abortion to influence their stance on other issues that revolve around the quality and sustenance of life, and that Generation Y may be more liberal than previous generations on most, if not all, issues. This research seeks to explore the extent to which (")pro-lifeprogressivism(") may have affected Generation Y with two sets of logistic regression analysis. The first analysis looks exclusively at members of Generation Y, and explores the effect of a person's attitudes toward abortion on their attitudes towards government spending on childcare, assistance to the poor, and healthcare. This is to see if there is a difference between pro-life and pro-choice members of Generation Y in the way they approach other issues relating to the quality and sustenance of life. The second analysis compares pro-life members of Generation Y to older cohorts. The results show that attitudes towards abortion among members of Generation Y hadno effect on their attitudes towards childcare and healthcare. Furthermore, the attitudes of pro- life members of Generation Y were statistically no different from older cohorts, with the exception of members of the Silent Generation on the issue of government assistance to healthcare. Further research, particularly of the qualitative nature, is suggested to delve more deeply into this research question.
Show less - Date Issued
- 2014
- Identifier
- CFE0005171, ucf:50664
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005171
- Title
- QUADRATIC SPATIAL SOLITON INTERACTIONS.
- Creator
-
Jankovic, Ladislav, Stegeman, George I., University of Central Florida
- Abstract / Description
-
Quadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO3) and periodically poled potassium titanyl phosphate (KTP) crystals....
Show moreQuadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO3) and periodically poled potassium titanyl phosphate (KTP) crystals. These particular crystals were desirable for these experiments because of their large nonlinear coefficients and, more importantly, because the experiments could be performed under non-critical-phase-matching (NCPM) conditions. The single soliton generation measurements, performed on KNBO3 by launching the fundamental component only, showed a broad angular acceptance bandwidth which was important for the soliton collisions performed later. Furthermore, at high input intensities multi-soliton generation was observed for the first time. The influence on the multi-soliton patterns generated of the input intensity and beam symmetry was investigated. The combined experimental and theoretical efforts indicated that spatial and temporal noise on the input laser beam induced multi-soliton patterns. Another research direction pursued was intensity dependent soliton routing by using of a specially engineered quadratically nonlinear interface within a periodically poled KTP sample. This was the first time demonstration of the self-reflection phenomenon in a system with a quadratic nonlinearity. The feature investigated is believed to have a great potential for soliton routing and manipulation by engineered structures. A detailed investigation was conducted on two soliton interaction and collision processes. Birth of an additional soliton resulting from a two soliton collision was observed and characterized for the special case of a non-planar geometry. A small amount of spiraling, up to 30 degrees rotation, was measured in the experiments performed. The parameters relevant for characterizing soliton collision processes were also studied in detail. Measurements were performed for various collision angles (from 0.2 to 4 degrees), phase mismatch, relative phase between the solitons and the distance to the collision point within the sample (which affects soliton formation). Both the individual and combined effects of these collision variables were investigated. Based on the research conducted, several all-optical switching scenarios were proposed.
Show less - Date Issued
- 2004
- Identifier
- CFE0000090, ucf:46135
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000090
- Title
- DSP IMPLEMENTATION OF DC VOLTAGE REGULATION USING ADAPTIVE CONTROL FOR 200 KW 62000 RPM INDUCTION GENERATOR.
- Creator
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Elkhomri, Othman, Wu, Thomas, University of Central Florida
- Abstract / Description
-
The thesis discusses the development of closed loop system to control the DC voltage for 200 kW induction generator rated at a speed of 62000 RPM under different load conditions. The voltage regulation has been implemented using PI controller. A gain scheduling control algorithm has been developed to select the appropriate controller gains with respect to the generator load. Further, a relationship between the generator loads and the controller gains has been established. This relationship...
Show moreThe thesis discusses the development of closed loop system to control the DC voltage for 200 kW induction generator rated at a speed of 62000 RPM under different load conditions. The voltage regulation has been implemented using PI controller. A gain scheduling control algorithm has been developed to select the appropriate controller gains with respect to the generator load. Further, a relationship between the generator loads and the controller gains has been established. This relationship has been modeled using adaptive control technique to vary the gains automatically at any load condition. The adaptive control technique has been successfully generalized for real time DSP implementation to regulate the DC voltage for high speed induction generators rated from 5 kW to 200 kW.
Show less - Date Issued
- 2006
- Identifier
- CFE0001076, ucf:46787
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001076
- Title
- HUMAN CAPITAL EFFECT ON SECOND GENERATION IMMIGRANT ENTREPRENEURS.
- Creator
-
Mazahaem Flores, Ali, Kutkut, Nasser, University of Central Florida
- Abstract / Description
-
Interest in entrepreneurship has increased in the past few years as more schools are beginning to incorporate subject and degrees specializing in the area as well as individuals mobilizing into an entrepreneurial lifestyle due to the lack of opportunities in the standard workplace environment. Historically, immigrants have made up a large majority of entrepreneurs and it has been their primary way of upward mobility in society. The boom in high tech start-ups and other small businesses in the...
Show moreInterest in entrepreneurship has increased in the past few years as more schools are beginning to incorporate subject and degrees specializing in the area as well as individuals mobilizing into an entrepreneurial lifestyle due to the lack of opportunities in the standard workplace environment. Historically, immigrants have made up a large majority of entrepreneurs and it has been their primary way of upward mobility in society. The boom in high tech start-ups and other small businesses in the last decade have primarily been driven by children of immigrants. As a result of these recent trends this study analyses the foreign born children of immigrants and their entrepreneurial capacity. The intent of this study is to find to what extent human capital affects the entrepreneurial capacity of immigrant children, if any. By analyzing the Theory of Human Capital in Entrepreneurship and its main variables, the study aims to find their level of human capital. Through the gathering of recent population data, analysis of research journals, publications and books, we evaluate the level of human capital and how it affects the capacity of the individual. Historically, evidence has shown a correlation between the two and we hope to contribute to the research and better understand its role in our subject matter as well as bring more awareness to a topic that lacks information.
Show less - Date Issued
- 2013
- Identifier
- CFH0004401, ucf:45145
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004401
- Title
- DO THE RIGHT THING: THE ROLE OF PUBLIC SERVICE ADVERTISEMENTS ON THE BEHAVIORS OF CONTEMPORARY COLLEGE STUDENTS.
- Creator
-
Jones, Jessica, Massiah, Carolyn, University of Central Florida
- Abstract / Description
-
The purpose of this research is to investigate the relationship between public service advertising and the likelihood of Generation Y to react in the prescribed manner. Public service advertising can be paid or unpaid but is used to try and influence a particular audience to act in a prescribed manner. This research will be comparing two different types of message styles, argumentative and emotional, and two contemporary prominent issues, organ donation and prescription drug abuse. The two...
Show moreThe purpose of this research is to investigate the relationship between public service advertising and the likelihood of Generation Y to react in the prescribed manner. Public service advertising can be paid or unpaid but is used to try and influence a particular audience to act in a prescribed manner. This research will be comparing two different types of message styles, argumentative and emotional, and two contemporary prominent issues, organ donation and prescription drug abuse. The two issues are classified as either altruistic, where there is no direct benefit, or self-help, where the results are personal. Four different messages will be used: altruistic argumentative, altruistic emotional, self-help argumentative, and self-help emotional. Also, previous knowledge levels will be taken into account. All combined, the end results will measure the likelihood of an individual to perform the act, donate to the cause monetarily, or tell another person.
Show less - Date Issued
- 2012
- Identifier
- CFH0004268, ucf:44942
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004268
- Title
- Super-adiabatic combustion in porous media with catalytic enhancement for thermoelectric power conversion.
- Creator
-
Mueller, Kyle, Orlovskaya, Nina, Chen, Ruey-Hung, Kapat, Jayanta, University of Central Florida
- Abstract / Description
-
The combustion of ultra-lean fuel to air mixtures provides an efficient way to convert the chemical energy of hydrocarbons into useful power. Conventional burning techniques of a mixture have defined flammability limits beyond which a flame cannot self-propagate due to heat losses. Matrix stabilized porous medium combustion is an advanced technique in which a solid porous matrix within the combustion chamber accumulates heat from the hot gaseous products and preheats incoming reactants. This...
Show moreThe combustion of ultra-lean fuel to air mixtures provides an efficient way to convert the chemical energy of hydrocarbons into useful power. Conventional burning techniques of a mixture have defined flammability limits beyond which a flame cannot self-propagate due to heat losses. Matrix stabilized porous medium combustion is an advanced technique in which a solid porous matrix within the combustion chamber accumulates heat from the hot gaseous products and preheats incoming reactants. This heat recirculation extends the standard flammability limits and allows the burning of ultra-lean fuel mixtures, conserving energy resources, or the burning of gases of low calorific value, utilizing otherwise wasted resources. The heat generated by the porous burner can be harvested with thermoelectric devices for a reliable method of generating electricity for portable electronic devices by the burning of otherwise noncombustible mixtures.The design of the porous media burner, its assembly and testing are presented. Highly porous (~80% porosity) alumina foam was used as the central media and alumina honeycomb structure was used as an inlet for fuel and an outlet for products of the methane-air combustion. The upstream and downstream honeycomb structures were designed with pore sizes smaller than the flame quenching distance, preventing the flame from propagating outside of the central section. Experimental results include measurements from thermocouples distributed throughout the burner and on each side of the thermoelectric module along with associated current, voltage and power outputs. Measurements of the burner with catalytic coating were obtained for stoichiometric and lean mixtures and compared to the results obtained from the catalytically inert matrix, showing the effect on overall efficiency for the combustion of fuel-lean mixtures.
Show less - Date Issued
- 2011
- Identifier
- CFE0004142, ucf:49043
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004142
- Title
- THE MISEDUCATION OF SIMON KRAUS:A RECORD OF THE FILM'S PRODUCTION.
- Creator
-
Diaz, Michael, Stoeckl, Ula, University of Central Florida
- Abstract / Description
-
The Miseducation of Simon Kraus is a feature-length film produced, written, directed, and edited by Michael J. Diaz as part of the requirements for earning a Master of Fine Arts in Film & Digital Media from the University of Central Florida. The thematic aim of the film is to paint a portrait of the Millennial Generation on the microcosm, by following the story of an apathetic protagonist whose dreams and ambitions are threatened by his own character. The statements, documents, and images...
Show moreThe Miseducation of Simon Kraus is a feature-length film produced, written, directed, and edited by Michael J. Diaz as part of the requirements for earning a Master of Fine Arts in Film & Digital Media from the University of Central Florida. The thematic aim of the film is to paint a portrait of the Millennial Generation on the microcosm, by following the story of an apathetic protagonist whose dreams and ambitions are threatened by his own character. The statements, documents, and images contained herein serve to record the experience and motivation behind the film.
Show less - Date Issued
- 2010
- Identifier
- CFE0003550, ucf:48918
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003550
- Title
- Study of High Efficiency Micro Thermoelectric Energy Harvesters.
- Creator
-
Pedrosa, Steven, Chen, Quanfang, Cho, Hyoung, Xu, Yunjun, University of Central Florida
- Abstract / Description
-
Thermal energy sources, including waste heat and thermal radiation from the sun, are important renewable energy resources. Thermal energy can be converted into electricity by thermoelectric phenomena; the thermoelectric phenomena can also be operated in reverse when provided an electric current, producing a temperature gradient across the device. Thermoelectric devices are scalable, renewable, and cost effective products that offer capabilities to harness waste heat or environmental heat...
Show moreThermal energy sources, including waste heat and thermal radiation from the sun, are important renewable energy resources. Thermal energy can be converted into electricity by thermoelectric phenomena; the thermoelectric phenomena can also be operated in reverse when provided an electric current, producing a temperature gradient across the device. Thermoelectric devices are scalable, renewable, and cost effective products that offer capabilities to harness waste heat or environmental heat sources, and convert the captured heat into usable electricity. The operating principle of a thermoelectric device requires that a temperature gradient be present across the device, which induces the flow of electrons from the hot side of the device to the cold side. Thermoelectric devices are currently hampered by the low conversion efficiencies and strict operating temperatures for certain materials. This study investigates the main factors affecting efficiencies of thermoelectric devices as energy harvesters and aims to optimize the devices for maximum efficiency and lower costs by using microfabrication processes and self-assembled materials for complete thermoelectric modules (TEMs). By first establishing operating conditions and a desired mode of operation, optimization equations have been established to determine device dimensions and performance parameters. Compact integration realized by microfabrication technologies that allow for multiple output voltages from a single chip was also investigated. Additionally, cost savings were found by reducing the number of fabrication processing steps and eliminating the need for precious metals during fabrication. The optimized design proposed in this study utilizes copper electrodes and requires fewer applications of photoresist than previous proposed designs. In fabrication of thin film based micro devices, the film quality and the composition of the film are essential elements for producing TEMs with desired efficiencies. Although Bi2Te3 has been investigated as thermoelectric material, this study determined that there was a possibility that both N-type and P-Type Bi2Te3 could be created from a single electrolyte solution by controlling the amount of Te present in the film. Films were produced with both AC and DC signals and varied composition of Te at.% of Bi2Te3 was achieved by controlling the average current density during electrochemical deposition. A linear relationship was established between the average current density and the resultant Te content. SEM and EDS were used to characterize the morphology and the composition of the thin films created. With the fabricated thermoelectric materials, analytical models could be developed using known material properties of thermoelectric films with a given Te content. The analytical results obtained by the developed optimization equations were comparable with the FEA models produced by using COMSOL, a multiphysics program with powerful solving algorithms that was used to evaluate designs. Further improvements to device performance can be achieved by designing a segmented thermoelectric device with multiple layers of thermoelectric material to allow the device to operate across a larger temperature gradient.
Show less - Date Issued
- 2011
- Identifier
- CFE0004486, ucf:49318
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004486
- Title
- Automatic Scenario Generation using Procedural Modeling Techniques.
- Creator
-
Martin, Glenn, Hughes, Charles, Moshell, Jack, Fiore, Stephen, Orooji, Ali, University of Central Florida
- Abstract / Description
-
Training typically begins with a pre-existing scenario. The training exercise is performed and then an after action review is sometimes held. This (")training pipeline(") is repeated for each scenario that will be used that day. This approach is used routinely and often effectively, yet it has a number of aspects that can result in poor training. In particular, this process commonly has two associated events that are undesirable. First, scenarios are re-used over and over, which can reduce...
Show moreTraining typically begins with a pre-existing scenario. The training exercise is performed and then an after action review is sometimes held. This (")training pipeline(") is repeated for each scenario that will be used that day. This approach is used routinely and often effectively, yet it has a number of aspects that can result in poor training. In particular, this process commonly has two associated events that are undesirable. First, scenarios are re-used over and over, which can reduce their effectiveness in training. Second, additional responsibility is placed on the individual training facilitator in that the trainer must now track performance improvements between scenarios. Taking both together can result in a multiplicative degradation in effectiveness. Within any simulation training exercise, a scenario definition is the starting point. While these are, unfortunately, re-used and over-used, they can, in fact, be generated from scratch each time. Typically, scenarios include the entire configuration for the simulators such as entities used, time of day, weather effects, entity starting locations and, where applicable, munitions effects. In addition, a background story (exercise briefing) is given to the trainees. The leader often then develops a mission plan that is shared with the trainee group. Given all of these issues, scientists began to explore more purposeful, targeted training. Rather than an ad-hoc creation of a simulation experience, there was an increased focus on the content of the experience and its effects on training. Previous work in scenario generation, interactive storytelling and computational approaches, while providing a good foundation, fall short on addressing the need for adaptive, automatic scenario generation. This dissertation addresses this need by building up a conceptual model to represent scenarios, mapping that conceptual model to a computational model, and then applying a newer procedural modeling technique, known as Functional L-systems, to create scenarios given a training objective, scenario complexity level desired, and sets of baseline and vignette scenario facets.A software package, known as PYTHAGORAS, was built and is presented that incorporates all these contributions into an actual tool for creating scenarios (both manual and automatic approaches are included). This package is then evaluated by subject matter experts in a scenario-based (")Turing Test(") of sorts where both system-generated scenarios and human-generated scenarios are evaluated by independent reviewers. The results are presented from various angles.Finally, a review of how such a tool can affect the training pipeline is included. In addition, a number of areas into which scenario generation can be expanded are reviewed. These focus on additional elements of both the training environment (e.g., buildings, interiors, etc.) and the training process (e.g., scenario write-ups, etc.).
Show less - Date Issued
- 2012
- Identifier
- CFE0004265, ucf:49525
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004265
- Title
- Generation and printing of strictly monodisperse droplets.
- Creator
-
Duan, Hongxu, Deng, Weiwei, An, Linan, Cho, Hyoung, University of Central Florida
- Abstract / Description
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Highly monodisperse droplets are attracting great attention both in many research areas, such as aerosol science, combustion, and Nano-manufacturing. This thesis invents a novel aerosol generator: (")Periodic Electro Hydro-dynamic Chopper(") termed as (")PEHD chopper("), and develops a new method to directly print micro-patterns with monodisperse droplets. The principle of the PEHD chopper is to use the fringe electric field of a capacitor to introduce controlled perturbation on a liquid jet...
Show moreHighly monodisperse droplets are attracting great attention both in many research areas, such as aerosol science, combustion, and Nano-manufacturing. This thesis invents a novel aerosol generator: (")Periodic Electro Hydro-dynamic Chopper(") termed as (")PEHD chopper("), and develops a new method to directly print micro-patterns with monodisperse droplets. The principle of the PEHD chopper is to use the fringe electric field of a capacitor to introduce controlled perturbation on a liquid jet.We first derived the governing equations for a circular inviscid liquid jet under transverse electric fields. The electric fields were obtained through numerical simulation. Then we used a high speed camera (up to one million frames per second) to visualize the jet break-up as well as the droplets' size and shape.The experiments show that the PEHD chopper can effectively (")chop(") a neutral micro-jet and generate highly monodisperse micro-droplets, which diameter range from 100 (&)#181;m to 500 (&)#181;m. To reduce the droplet size, PEHD chopper with a butterfly design is applied on a typical single electrospray. In this configuration, the jet swings at long wavelengths (?(>)?R), where ?R is the Rayleigh wave length, but breaks up into highly monodisperse droplets near 2?R and ?R without satellite droplets. The butterfly configuration combined with electrified jet expands the diameter range into 20 (&)#181;m to 100 (&)#181;m.Finally, we demonstrate the electrospray printing of Polymer Derived Ceramics (PDC) for sensor applications in harsh environment. A modified single ES with an additional driving electric field is used to directly print PDC precursor without mask, we achieved 1D feature as narrow as 35 (&)#181;m and a micro pentagram pattern. Moreover, after pyrolysis of PDC at 1100 (&)deg;C in nitrogen, amorphous alloys of silicon, carbon and nitrogen (SiCN) are obtained. The samples exhibit excellent good integrity and adhesion to the substrate.
Show less - Date Issued
- 2013
- Identifier
- CFE0005094, ucf:50720
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005094
- Title
- The Religious Beliefs and Behaviors of Baby Boomers, Generation X, and the Millennials: are there still gender differences?.
- Creator
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Chase, Jessica, Gay, David, Donley, Amy, Corzine, Harold, Matejowsky, Ty, University of Central Florida
- Abstract / Description
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The literature describes how changing demographics and cultural factors in recent generations may be contributing to gender differences regarding religion. The present exploratory study uses cross-sectional survey data from the 2012 and 2014 General Social Survey to examine the gender differences in religiosity for Millennials, Generation X, and Baby Boomers. The findings show significant gender and demographic results for attendance at religious services, frequency of prayer, belief in the...
Show moreThe literature describes how changing demographics and cultural factors in recent generations may be contributing to gender differences regarding religion. The present exploratory study uses cross-sectional survey data from the 2012 and 2014 General Social Survey to examine the gender differences in religiosity for Millennials, Generation X, and Baby Boomers. The findings show significant gender and demographic results for attendance at religious services, frequency of prayer, belief in the Bible as the word of God, and belief in life after death for all three generations. Baby Boomer and Millennial women attend religious services more than men, but there is no gender difference for Generation X. However, Women from all generations pray more than men. For belief in the Bible as the word of God, only Baby Boomer women believe more than men. Finally, Millennial women and Generation X women believe in life after death more than men, whereas there is no gender difference in belief for Baby Boomers. Implications of the findings are discussed.
Show less - Date Issued
- 2016
- Identifier
- CFE0006282, ucf:51592
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006282
- Title
- A New Six Sigma Implementation Approach For Power Generation Gas Turbines Repair Process Development.
- Creator
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Ghunakikar, Somesh, Elshennawy, Ahmad, Rabelo, Luis, Thompson, William, Furterer, Sandra, University of Central Florida
- Abstract / Description
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Power Generation gas turbines used for heavy duty application mainly constitutes three modules; compressor, combustion and turbine. Typically, all these parts are designed by OEM companies for specific number of hours and cycles (also known as starts) before they become dysfunctional. In addition, Gas Turbine (GT) also have intended repair interval depending upon the type of part application and anticipated damages during service operation. Thus, GT parts need inspections and repair (overhaul...
Show morePower Generation gas turbines used for heavy duty application mainly constitutes three modules; compressor, combustion and turbine. Typically, all these parts are designed by OEM companies for specific number of hours and cycles (also known as starts) before they become dysfunctional. In addition, Gas Turbine (GT) also have intended repair interval depending upon the type of part application and anticipated damages during service operation. Thus, GT parts need inspections and repair (overhaul) after certain operating hours in order to recondition them so that they can be fit for reoperation to produce power. In this dissertation, a unique six sigma DFSS approach for development of GT parts overhaul is presented for total quality improvement. In this dissertation report, a unique six sigma DFSS approach is presented applicable to the development of repair processes for GT parts that can be used during overhauling of the parts. All six sigma phases of the proposed DFSS approach along with repair product development cycle are discussed. Various six sigma tools which yield significant benefits for the process users are also discussed. Importantly, a statistical probabilistic life analysis approach is proposed in order to verify the structural integrity of a repaired GT part. Finally a case study of GT axial compressor diaphragms (stators) to illustrate various phases and six sigma tools usage during each phase of the DFSS approach is discussed. The overall significant benefit of the proposed DFSS approach was to achieve total quality improvement to deliver final GT repair process, faster repair development cycle and end customer satisfaction.
Show less - Date Issued
- 2016
- Identifier
- CFE0006105, ucf:51199
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006105
- Title
- A STUDY OF MILLENIAL STUDENTS AND THEIR REACTIVE BEHAVIOR PATTERNS IN THE ONLINE ENVIRONMENT.
- Creator
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Yonekura, Francisca, Dziuban, Charles, University of Central Florida
- Abstract / Description
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The goal of this study was to identify patterns or characteristics unique to online millennial students in higher education from two perspectives: the generational traits for an understanding of millennial students as a cohort, and the Long reactive behavior patterns and traits for an understanding of millennials as individuals. Based on the identified patterns and characteristics of these millennial students, the researcher highlighted instructional and curricular implications for online...
Show moreThe goal of this study was to identify patterns or characteristics unique to online millennial students in higher education from two perspectives: the generational traits for an understanding of millennial students as a cohort, and the Long reactive behavior patterns and traits for an understanding of millennials as individuals. Based on the identified patterns and characteristics of these millennial students, the researcher highlighted instructional and curricular implications for online learning. A profile depicting online millennial students based on the demographic data and their overall satisfaction levels with online learning is provided. For a holistic understanding, the study included an inquiry into measures of independence between overall satisfaction with online learning, reactive behavior patterns and traits among participating millennials, and an account of what millennial students are saying about quality, preferences, and aversions in their online learning experience. Overall, the great majority, especially aggressive dependent and compulsive millennial students were satisfied with their online learning experience. Also, more female millennial students were satisfied with their experience compared to male millennial students. The role of the instructor, course design, and learning matters were the themes most frequently mentioned by millennial students when asked about the quality of online learning. Overwhelmingly, convenience, time management, flexibility, and pace were the aspects these millennial students liked most about their online encounter. On the contrary, lack of interaction, instructor's role, course design, and technology matters were the most frequent themes regarding millennials' dislikes about their online learning experience. Finally, the study includes recommendations for future research.
Show less - Date Issued
- 2006
- Identifier
- CFE0000968, ucf:46710
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000968
- Title
- Synthetic generators for simulating social networks.
- Creator
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Mohammed Ali, Awrad, Sukthankar, Gita, Wu, Annie, Boloni, Ladislau, University of Central Florida
- Abstract / Description
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An application area of increasing importance is creating agent-based simulations to model human societies. One component of developing these simulations is the ability to generate realistic human social networks. Online social networking websites, such as Facebook, Google+, and Twitter, have increased in popularity in the last decade. Despite the increase in online social networking tools and the importance of studying human behavior in these networks, collecting data directly from these...
Show moreAn application area of increasing importance is creating agent-based simulations to model human societies. One component of developing these simulations is the ability to generate realistic human social networks. Online social networking websites, such as Facebook, Google+, and Twitter, have increased in popularity in the last decade. Despite the increase in online social networking tools and the importance of studying human behavior in these networks, collecting data directly from these networks is not always feasible due to privacy concerns. Previous work in this area has primarily been limited to 1) network generators that aim to duplicate a small subset of the original network's properties and 2) problem-specific generators for applications such as the evaluation of community detection algorithms.In this thesis, we extended two synthetic network generators to enable them to duplicate the properties of a specific dataset. In the first generator, we consider feature similarity and label homophily among individuals when forming links. The second generator is designed to handle multiplex networks that contain different link types. We evaluate the performance of both generators on existing real-world social network datasets, as well as comparing our methods with a related synthetic network generator. In this thesis, we demonstrate that the proposed synthetic network generators are both time efficient and require only limited parameter optimization.
Show less - Date Issued
- 2014
- Identifier
- CFE0005532, ucf:50300
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005532
- Title
- AUTOMATED SCENARIO GENERATION SYSTEM IN A SIMULATION.
- Creator
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Tomizawa, Hajime, Gonzalez, Avelino, University of Central Florida
- Abstract / Description
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Developing training scenarios that induce a trainee to utilize specific skills is one of the facets of simulation-based training that requires significant effort. Simulation-based training systems have become more complex in recent years. Because of this added complexity, the amount of effort required to generate and maintain training scenarios has increased. This thesis describes an investigation into automating the scenario generation process. The Automated Scenario Generation System (ASGS)...
Show moreDeveloping training scenarios that induce a trainee to utilize specific skills is one of the facets of simulation-based training that requires significant effort. Simulation-based training systems have become more complex in recent years. Because of this added complexity, the amount of effort required to generate and maintain training scenarios has increased. This thesis describes an investigation into automating the scenario generation process. The Automated Scenario Generation System (ASGS) generates expected action flow as contexts in chronological order from several events and tasks with estimated time for the entire training mission. When the training objectives and conditions are defined, the ASGS will automatically generate a scenario, with some randomization to ensure no two equivalent scenarios are identical. This makes it possible to train different groups of trainees sequentially who may have the same level or training objectives without using a single scenario repeatedly. The thesis describes the prototype ASGS and the evaluation results are described and discussed. SVSTM Desktop is used as the development infrastructure for ASGS as prototype training system.
Show less - Date Issued
- 2006
- Identifier
- CFE0001336, ucf:47002
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001336
