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Title: MESHLESS HEMODYNAMICS MODELING AND EVOLUTIONARY SHAPE OPTIMIZATION OF BYPASS GRAFTS ANASTOMOSES.
Creator: El Zahab, Zaher, Kassab, Alain, University of Central Florida
Abstract / Description: Objectives: The main objective of the current dissertation is to establish a formal shape optimization procedure for a given bypass grafts end-to-side distal anastomosis (ETSDA). The motivation behind this dissertation is that most of the previous ETSDA shape optimization research activities cited in the literature relied on direct optimization approaches that do not guaranty accurate optimization results. Three different ETSDA models are considered herein: The conventional, the Miller cuff,...
Show moreObjectives: The main objective of the current dissertation is to establish a formal shape optimization procedure for a given bypass grafts end-to-side distal anastomosis (ETSDA). The motivation behind this dissertation is that most of the previous ETSDA shape optimization research activities cited in the literature relied on direct optimization approaches that do not guaranty accurate optimization results. Three different ETSDA models are considered herein: The conventional, the Miller cuff, and the hood models. Materials and Methods: The ETSDA shape optimization is driven by three computational objects: a localized collocation meshless method (LCMM) solver, an automated geometry pre-processor, and a genetic-algorithm-based optimizer. The usage of the LCMM solver is very convenient to set an autonomous optimization mechanism for the ETSDA models. The task of the automated pre-processor is to randomly distribute solution points in the ETSDA geometries. The task of the optimized is the adjust the ETSDA geometries based on mitigation of the abnormal hemodynamics parameters. Results: The results reported in this dissertation entail the stabilization and validation of the LCMM solver in addition to the shape optimization of the considered ETSDA models. The LCMM stabilization results consists validating a custom-designed upwinding scheme on different one-dimensional and two-dimensional test cases. The LCMM validation is done for incompressible steady and unsteady flow applications in the ETSDA models. The ETSDA shape optimization include single-objective optimization results in steady flow situations and bi-objective optimization results in pulsatile flow situations. Conclusions: The LCMM solver provides verifiably accurate resolution of hemodynamics and is demonstrated to be third order accurate in a comparison to a benchmark analytical solution of the Navier-Stokes. The genetic-algorithm-based shape optimization approach proved to be very effective for the conventional and Miller cuff ETSDA models. The shape optimization results for those two models definitely suggest that the graft caliber should be maximized whereas the anastomotic angle and the cuff height (in the Miller cuff model) should be chosen following a compromise between the wall shear stress spatial and temporal gradients. The shape optimization of the hood ETSDA model did not prove to be advantageous, however it could be meaningful with the inclusion of the suture line cut length as an optimization parameter.
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Date Issued: 2008
Identifier: CFE0002165, ucf:47927
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002165

Title: REMOTE SENSING WITH COMPUTATIONAL INTELLIGENCE MODELLING FOR MONITORING THE ECOSYSTEM STATE AND HYDRAULIC PATTERN IN A CONSTRUCTED WETLAND.
Creator: Mohiuddin, Golam, Chang, Ni-bin, Lee, Woo Hyoung, Wanielista, Martin, University of Central Florida
Abstract / Description: Monitoring the heterogeneous aquatic environment such as the Stormwater Treatment Areas (STAs) located at the northeast of the Everglades is extremely important in understanding the land processes of the constructed wetland in its capacity to remove nutrient. Direct monitoring and measurements of ecosystem evolution and changing velocities at every single part of the STA are not always feasible. Integrated remote sensing, monitoring, and modeling technique can be a state-of-the-art tool to...
Show moreMonitoring the heterogeneous aquatic environment such as the Stormwater Treatment Areas (STAs) located at the northeast of the Everglades is extremely important in understanding the land processes of the constructed wetland in its capacity to remove nutrient. Direct monitoring and measurements of ecosystem evolution and changing velocities at every single part of the STA are not always feasible. Integrated remote sensing, monitoring, and modeling technique can be a state-of-the-art tool to estimate the spatial and temporal distributions of flow velocity regimes and ecological functioning in such dynamic aquatic environments. In this presentation, comparison between four computational intelligence models including Extreme Learning Machine (ELM), Genetic Programming (GP) and Artificial Neural Network (ANN) models were organized to holistically assess the flow velocity and direction as well as ecosystem states within a vegetative wetland area. First the local sensor network was established using Acoustic Doppler Velocimeter (ADV). Utilizing the local sensor data along with the help of external driving forces parameters, trained models of ELM, GP and ANN were developed, calibrated, validated, and compared to select the best computational capacity of velocity prediction over time. Besides, seasonal images collected by French satellite Pleiades have been analyzed to address the seasonality effect of plant species evolution and biomass changes in the constructed wetland. The key finding of this research is to characterize the interactions between geophysical and geochemical processes in this wetland system based on ground-based monitoring sensors and satellite images to discover insight of hydraulic residence time, plant species variation, and water quality and improve the overall understanding of possible nutrient removal in this constructed wetland.
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Date Issued: 2014
Identifier: CFE0005533, ucf:52864
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005533

Title: Multi-Objective Optimization for Construction Equipment Fleet Selection and Management In Highway Construction Projects Based on Time, Cost, and Quality Objectives.
Creator: Shehadeh, Ali, Tatari, Omer, Al-Deek, Haitham, Abou-Senna, Hatem, Flitsiyan, Elena, University of Central Florida
Abstract / Description: The sector of highway construction shares approximately 11% of the total construction industry in the US. Construction equipment can be considered as one of the primary reasons this industry has reached such a significant level, as it is considered an essential part of the highway construction process during highway project construction. This research addresses a multi-objective optimization mathematical model that quantifies and optimize the key parameters for excavator, truck, and motor...
Show moreThe sector of highway construction shares approximately 11% of the total construction industry in the US. Construction equipment can be considered as one of the primary reasons this industry has reached such a significant level, as it is considered an essential part of the highway construction process during highway project construction. This research addresses a multi-objective optimization mathematical model that quantifies and optimize the key parameters for excavator, truck, and motor-grader equipment to minimize time and cost objective functions. The model is also aimed to maintain the required level of quality for the targeted construction activity. The mathematical functions for the primary objectives were formulated and then a genetic algorithm-based multi-objective was performed to generate the time-cost Pareto trade-offs for all possible equipment combinations using MATLAB software to facilitate the implementation. The model's capabilities in generating optimal time and cost trade-offs based on optimized equipment number, capacity, and speed to adapt with the complex and dynamic nature of highway construction projects are demonstrated using a highway construction case study. The developed model is a decision support tool during the construction process to adapt with any necessary changes into time or cost requirements taking into consideration environmental, safety and quality aspects. The flexibility and comprehensiveness of the proposed model, along with its programmable nature, make it a powerful tool for managing construction equipment, which will help saving time and money within the optimal quality margins. Also, this environmentally friendly decision-support tool model provided optimal solutions that help to reduce the CO2 emissions reducing the ripple effects of targeted highway construction activities on the global warming phenomenon. The generated optimal solutions offered considerable time and cost savings.
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Date Issued: 2019
Identifier: CFE0007863, ucf:52800
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007863

Title: INVERSE BOUNDARY ELEMENT/GENETIC ALGORITHM METHOD FOR RECONSTRUCTION OF MULTI-DIMENSIONAL HEAT FLUX DISTRIBUTIONS WITH FILM COOLING APPLICATIONS.
Creator: Silieti, Mahmood, Kassab, Alain, University of Central Florida
Abstract / Description: A methodology is formulated for the solution of the inverse problem concerned with the reconstruction of multi-dimensional heat fluxes for film cooling applications. The motivation for this study is the characterization of complex thermal conditions in industrial applications such as those encountered in film cooled turbomachinery components. The heat conduction problem in the metal endwall/shroud is solved using the boundary element method (bem), and the inverse problem is solved using a...
Show moreA methodology is formulated for the solution of the inverse problem concerned with the reconstruction of multi-dimensional heat fluxes for film cooling applications. The motivation for this study is the characterization of complex thermal conditions in industrial applications such as those encountered in film cooled turbomachinery components. The heat conduction problem in the metal endwall/shroud is solved using the boundary element method (bem), and the inverse problem is solved using a genetic algorithm (ga). Thermal conditions are overspecified at exposed surfaces amenable to measurement, while the temperature and surface heat flux distributions are unknown at the film cooling hole/slot walls. The latter are determined in an iterative process by developing two approaches. The first approach, developed for 2d applications, solves an inverse problem whose objective is to adjust the film cooling hole/slot wall temperatures and heat fluxes until the temperature and heat flux at the measurement surfaces are matched in an overall heat conduction solution. The second approach, developed for 2d and 3d applications, is to distribute a set of singularities (sinks) at the vicinity of the cooling slots/holes surface inside a fictitious extension of the physical domain or along cooling hole centerline with a given initial strength distribution. The inverse problem iteratively alters the strength distribution of the singularities (sinks) until the measuring surfaces heat fluxes are matched. The heat flux distributions are determined in a post-processing stage after the inverse problem is solved. The second approach provides a tremendous advantage in solving the inverse problem, particularly in 3d applications, and it is recommended as the method of choice for this class of problems. It can be noted that the ga reconstructed heat flux distributions are robust, yielding accurate results to both exact and error-laden inputs. In all cases in this study, results from experiments are simulated using a full conjugate heat transfer (cht) finite volume models which incorporate the interactions of the external convection in the hot turbulent gas, internal convection within the cooling plena, and the heat conduction in the metal endwall/shroud region. Extensive numerical investigations are undertaken to demonstrate the significant importance of conjugate heat transfer in film cooling applications and to identify the implications of various turbulence models in the prediction of accurate and more realistic surface temperatures and heat fluxes in the cht simulations. These, in turn, are used to provide numerical inputs to the inverse problem. Single and multiple cooling slots, cylindrical cooling holes, and fan-shaped cooling holes are considered in this study. The turbulence closure is modeled using several two-equation approach, the four-equation turbulence model, as well as five and seven moment reynolds stress models. The predicted results, by the different turbulence models, for the cases of adiabatic and conjugate models, are compared to experimental data reported in the open literature. Results show the significant effects of conjugate heat transfer on the temperature field in the film cooling hole region, and the additional heating up of the cooling jet itself. Moreover, results from the detailed numerical studies presented in this study validate the inverse problem approaches and reveal good agreement between the bem/ga reconstructed heat fluxes and the cht simulated heat fluxes along the inaccessible cooling slot/hole walls
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Date Issued: 2004
Identifier: CFE0000166, ucf:52896
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000166

Title: Seascape genetics and rehabilitation efficiency in the Florida manatee.
Creator: Hall, Madison, Worthy, Graham, Weishampel, John, Hoffman, Eric, Dyer, Rodney, University of Central Florida
Abstract / Description: The Florida manatee (Trichechus manatus latirostris) was recently downlisted federally from (")endangered(") to (")threatened(") despite acknowledgments of remaining threats to long term population persistence. Challenges to future manatee conservation include, but are not limited to, increases in frequency of harmful algal blooms, intensifying anthropogenic disturbance, and loss of warm-water habitat. The goals of this dissertation were 1) to assess threats to the manatee via a comprehensive...
Show moreThe Florida manatee (Trichechus manatus latirostris) was recently downlisted federally from (")endangered(") to (")threatened(") despite acknowledgments of remaining threats to long term population persistence. Challenges to future manatee conservation include, but are not limited to, increases in frequency of harmful algal blooms, intensifying anthropogenic disturbance, and loss of warm-water habitat. The goals of this dissertation were 1) to assess threats to the manatee via a comprehensive, long-term (1973-2016), retrospective analysis of the manatee rescue and rehabilitation partnership (MRRP) and 2) to use seascape genetics analysis to examine whether abiotic, biotic, or anthropogenic seascape variables could significantly describe genetic distance patterns in space for this genetically depauperate population. Results from the MRRP analysis revealed that anthropogenic threats were the most significant reason for manatees to be rescued and rehabilitated. Manatees rescued due to watercraft injuries spent long periods in recovery before succumbing or being released resulting in significant expense to the rehabilitation system. Additionally, the seascape genetics analysis indicated that watercraft activity best explained spatial genetic patterns in the manatee population. It is established that anthropogenic use of watercraft negative affects manatees through the mechanisms of sub-lethal injury and mortality, and these results suggest there may be further negative impacts via the disruption of population genetic connectivity. Future management practices should seriously consider manatee/vessel interactions as watercraft strikes are costly for management, place pressure on the manatee population, and could disrupt population gene flow with potentially dire consequences. Mitigating anthropogenic impacts on the Florida manatee population is critical for future conservation and should be a primary focus.
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Date Issued: 2019
Identifier: CFE0007647, ucf:52465
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007647

Title: Reconfigurable Reflectarray Antennas with Bandwidth Enhancement for High Gain, Beam-Steering Applications.
Creator: Trampler, Michael, Gong, Xun, Wahid, Parveen, Jones, W Linwood, Chen, Kenle, Kuebler, Stephen, University of Central Florida
Abstract / Description: Reconfigurable reflectarrays are a class of antennas that combine the advantages of traditional parabolic antennas and phased array antennas. Chapter 1 discusses the basic operational theory of reflectarrays and their design. A review of previous research and the current status is also presented. Furthermore the inherent advantages and disadvantages of the reflectarray topography are presented. In chapter 2, a BST-integrated reflectarray operating at Ka band is presented. Due to the...
Show moreReconfigurable reflectarrays are a class of antennas that combine the advantages of traditional parabolic antennas and phased array antennas. Chapter 1 discusses the basic operational theory of reflectarrays and their design. A review of previous research and the current status is also presented. Furthermore the inherent advantages and disadvantages of the reflectarray topography are presented. In chapter 2, a BST-integrated reflectarray operating at Ka band is presented. Due to the monolithic integration of the tuning element, this design is then extended to V band where a novel interdigital gap configuration is utilized. Finally to overcome loss and phase limitations of the single resonant design, a BST-integrated, dual-resonance unit cell operating at Ka band is designed. While the losses are still high, a 360(&)deg; phase range is demonstrated.In chapter 3, the operational theory of dual-resonant array elements is introduced utilizing Q theory. An equivalent circuit is developed and used to demonstrate design tradeoffs. Using this theory the design procedure of a varactor tuned dual-resonant unit cell operating at X-band is presented. Detailed analysis of the design is performed by full-wave simulations and verified via measurements. In chapter 4, the array performance of the dual-resonance unit cell is analyzed. The effects of varying angles of incidence on the array element are studied using Floquet simulations. The beam scanning, cross-polarization and bandwidth performance of a 7(&)#215;7 element reflectarray is analyzed using full-wave simulations and verified via measurements.In chapter 5 a loss analysis of the dual-resonant reflectarray element is performed. Major sources of loss are identified utilizing full-wave simulations before an equivalent circuit is utilized to optimize the loss performance while maintaining a full phase range and improved bandwidth performance. Finally the dual-resonance unit cell is modified to support two linear polarizations. Overall, the operational and design theory of dual resonant reflectarray unit cells using Q theory is developed. A valuable equivalent circuit is developed and used to aid in array element design as well as optimize the loss and bandwidth performance. The proposed theoretical models provide valuable physical insight through the use of Q theory to greatly aid in reflectarray design
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Date Issued: 2019
Identifier: CFE0007735, ucf:52457
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007735

Title: Design of the layout of a manufacturing facility with a closed loop conveyor with shortcuts using queueing theory and genetic algorithms.
Creator: Lasrado, Vernet, Nazzal, Dima, Mollaghasemi, Mansooreh, Reilly, Charles, Garibay, Ivan, Sivo, Stephen, Armacost, Robert, University of Central Florida
Abstract / Description: With the ongoing technology battles and price wars in today's competitive economy, every company is looking for an advantage over its peers. A particular choice of facility layout can have a significant impact on the ability of a company to maintain lower operational expenses under uncertain economic conditions. It is known that systems with less congestion have lower operational costs. Traditionally, manufacturing facility layout problem methods aim at minimizing the total distance traveled,...
Show moreWith the ongoing technology battles and price wars in today's competitive economy, every company is looking for an advantage over its peers. A particular choice of facility layout can have a significant impact on the ability of a company to maintain lower operational expenses under uncertain economic conditions. It is known that systems with less congestion have lower operational costs. Traditionally, manufacturing facility layout problem methods aim at minimizing the total distance traveled, the material handling cost, or the time in the system (based on distance traveled at a specific speed). The proposed methodology solves the looped layout design problem for a looped layout manufacturing facility with a looped conveyor material handling system with shortcuts using a system performance metric, i.e. the work in process (WIP) on the conveyor and at the input stations to the conveyor, as a factor in the minimizing function for the facility layout optimization problem which is solved heuristically using a permutation genetic algorithm. The proposed methodology also presents the case for determining the shortcut locations across the conveyor simultaneously (while determining the layout of the stations around the loop) versus the traditional method which determines the shortcuts sequentially (after the layout of the stations has been determined). The proposed methodology also presents an analytical estimate for the work in process at the input stations to the closed looped conveyor.It is contended that the proposed methodology (using the WIP as a factor in the minimizing function for the facility layout while simultaneously solving for the shortcuts) will yield a facility layout which is less congested than a facility layout generated by the traditional methods (using the total distance traveled as a factor of the minimizing function for the facility layout while sequentially solving for the shortcuts). The proposed methodology is tested on a virtual 300mm Semiconductor Wafer Fabrication Facility with a looped conveyor material handling system with shortcuts. The results show that the facility layouts generated by the proposed methodology have significantly less congestion than facility layouts generated by traditional methods. The validation of the developed analytical estimate of the work in process at the input stations reveals that the proposed methodology works extremely well for systems with Markovian Arrival Processes.
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Date Issued: 2011
Identifier: CFE0004125, ucf:49088
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004125

Title: Conservation and population biology: genetics, demography and habitat requirements of the Atlantic coast beach mice.
Creator: Kalkvik, Haakon, Parkinson, Christopher, Stout, I, Hoffman, Eric, Weishampel, John, Doonan, Terry, University of Central Florida
Abstract / Description: The conservation biology field seeks to preserve biodiversity and the processes shaping that variation. Conservation biology is intimately tied to evolutionary research, in order to identify evolutionary distinct lineages that may be in danger of disappearing. Interestingly, patterns and processes of lineage divergence and persistence change with respect to spatial and temporal scale. I seek to evaluate biodiversity, the factors that have shaped this heterogeneity, and how this variability...
Show moreThe conservation biology field seeks to preserve biodiversity and the processes shaping that variation. Conservation biology is intimately tied to evolutionary research, in order to identify evolutionary distinct lineages that may be in danger of disappearing. Interestingly, patterns and processes of lineage divergence and persistence change with respect to spatial and temporal scale. I seek to evaluate biodiversity, the factors that have shaped this heterogeneity, and how this variability persists. To accomplish this I used a phylogeographic approach as well as niche and population modeling on the Peromyscus maniculatus species group found widely distributed in North America. My emphasis was on the southeastern U.S. species P. polionotus and its distinct beach forms. At a continental scale, I found that environmental niches are likely involved in generating and/or maintaining genetic lineages within the P. maniculatus species group. These findings add to a growing number of studies that have identified lineages occupying different environmental spaces. At a regional scale, I supported the hypothesis that barrier islands on the Atlantic coast of Florida were colonized by an ancestral form of P. polionotus by a single colonization, from the central Florida area. Subsequently, at least two distinct lineages diverged (P. p. phasma and P. p. niveiventris). I also found evidence that suggests that the extinct form of beach mouse (P. p. decoloratus) is part of the P. p. phasma lineage. At the population level, I evaluated changes in genetic diversity in historical samples compared to those that experienced recent human encroachment on natural habitat I used tissue preserved in natural history collections to compare with live-trapped specimens, and found that P. p. niveiventris has maintained historical genetic diversity levels. I suggest that the continuation of historical levels of genetic diversity is due to the presence of a single large area of continuous habitat in the central portion of the species' current distribution. Finally, I evaluated the importance of scrub and beach habitat to the population dynamics of beach mice. Beach mice have traditionally have been associated with beach dunes rather than with the scrub habitat found more inland on barrier islands. Using almost three years of capture-recapture data from Cape Canaveral Air Force Station (CCAFS), I created a stochastic matrix model to assess the relative contribution of populations from the two different habitats to a variety of demographic measures. Both field data and model results provided evidence that the population dynamics of beach mice may rely much more on scrub habitat than formerly documented. Overall, my research emphasized a hierarchical approach to evaluate biodiversity and the processes shaping differentiation at different spatial and temporal scales. The methods and findings give insight into speciation at different scales, and can be applied to a wide range of taxa for questions related to evolutionary and conservation biology.
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Date Issued: 2012
Identifier: CFE0004392, ucf:49372
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004392

Title: CLONALITY AND GENETIC DIVERSITY IN POLYGONELLA MYRIOPHYLLA, A LAKE WALES RIDGE ENDEMIC PLANT.
Creator: Metzger, Genevieve, Parkinson, Christopher, University of Central Florida
Abstract / Description: Although capable of sexual reproduction, many plants also rely heavily on clonal reproduction. The formation of multiple, physiologically-independent units with the same genotype has important implications for spatial genetic structure and genetic diversity in these plants. The endangered scrub-dwelling perennial, Polygonella myriophylla is known to reproduce both sexually and clonally but no study to date has been able to investigate the spatial genetic patterns that occur in this species. I...
Show moreAlthough capable of sexual reproduction, many plants also rely heavily on clonal reproduction. The formation of multiple, physiologically-independent units with the same genotype has important implications for spatial genetic structure and genetic diversity in these plants. The endangered scrub-dwelling perennial, Polygonella myriophylla is known to reproduce both sexually and clonally but no study to date has been able to investigate the spatial genetic patterns that occur in this species. I use microsatellite markers to investigate questions about clonal structure and genetic diversity in five populations of P. myriophylla and address some of the implications of my findings for conservation of this species: Overall, I find that 57% of sampled clusters of P. myriophylla are composed of a single genet (genetic individual) with multiple physiological units (ramets) while the remainder are made up of two or more genets. I found differences in both clonal reproduction and genetic diversity among populations. I also found evidence of limited gene flow even over small spatial scales (less than 10 km) and for at least 4 genetic clusters occurring within the species range. Despite high levels of genetic diversity overall, there is evidence of reduced genetic diversity in two populations My results suggest that high levels of clonality may be important in maintaining genetic diversity in P. myriophylla. I also provide evidence that dirt roadsides may not represent a refuge for this species.
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Date Issued: 2010
Identifier: CFE0003264, ucf:48516
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003264

Title: EXPRESSION AND CHARACTERIZATION OF ANTIMICROBIAL PEPTIDES RETROCYCLIN-101 AND PROTEGRIN-1 IN CHLOROPLASTS TO CONTROL VIRAL AND BACTERIAL INFECTIONS.
Creator: Li, Baichuan, Daniell, Henry, University of Central Florida
Abstract / Description: Retrocyclin-101 (RC101) and Protegrin-1 (PG1) are two important antimicrobial peptides that can be used as therapeutic agents against bacterial and/or viral infections, especially those caused by the HIV-1 or sexually-transmitted bacteria. Because of their antimicrobial activity and complex secondary structures, they have not yet been produced in microbial systems and their chemical synthesis is prohibitively expensive. Therefore, we created chloroplast transformation vectors with the RC101...
Show moreRetrocyclin-101 (RC101) and Protegrin-1 (PG1) are two important antimicrobial peptides that can be used as therapeutic agents against bacterial and/or viral infections, especially those caused by the HIV-1 or sexually-transmitted bacteria. Because of their antimicrobial activity and complex secondary structures, they have not yet been produced in microbial systems and their chemical synthesis is prohibitively expensive. Therefore, we created chloroplast transformation vectors with the RC101 or PG1 coding sequence, fused with GFP to confer stability, furin or Factor Xa cleavage site to liberate the mature peptide from their fusion proteins and a His-tag to aid in their purification. Stable integration of RC-101 into the tobacco chloroplast genome and homoplasmy were confirmed by Southern blots. RC-101 and PG1 accumulated up to 32-38% and 17~26% of the total soluble protein. Both RC-101 and PG1 were cleaved from GFP by corresponding proteases in vitro and Factor Xa like protease activity was observed within chloroplasts. Confocal microscopy studies showed location of GFP fluorescence within chloroplasts. Organic extraction resulted in 10.6 fold higher yield of RC 101 than purification by affinity chromatography using His-tag. In planta bioassays with Erwinia carotovora confirmed the antibacterial activity of RC101 and PG1 expressed in chloroplasts. RC101 transplastomic plants were resistant to TMV infections, confirming antiviral activity. Because RC101 and PG1 have not yet been produced in other cell culture or microbial systems, chloroplasts can be used as bioreactors for producing these proteins. Adequate yield of purified antimicrobial peptides from transplastomic plants should facilitate further pre-clinical studies.
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Date Issued: 2010
Identifier: CFE0003199, ucf:48571
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003199

Title: A SUSTAINABLE AUTONOMIC ARCHITECTURE FOR ORGANICALLY RECONFIGURABLE COMPUTING SYSTEMS.
Creator: Oreifej, Rashad, DeMara, Ronald, University of Central Florida
Abstract / Description: A Sustainable Autonomic Architecture for Organically Reconfigurable Computing System based on SRAM Field Programmable Gate Arrays (FPGAs) is proposed, modeled analytically, simulated, prototyped, and measured. Low-level organic elements are analyzed and designed to achieve novel self-monitoring, self-diagnosis, and self-repair organic properties. The prototype of a 2-D spatial gradient Sobel video edge-detection organic system use-case developed on a XC4VSX35 Xilinx Virtex-4 Video Starter Kit...
Show moreA Sustainable Autonomic Architecture for Organically Reconfigurable Computing System based on SRAM Field Programmable Gate Arrays (FPGAs) is proposed, modeled analytically, simulated, prototyped, and measured. Low-level organic elements are analyzed and designed to achieve novel self-monitoring, self-diagnosis, and self-repair organic properties. The prototype of a 2-D spatial gradient Sobel video edge-detection organic system use-case developed on a XC4VSX35 Xilinx Virtex-4 Video Starter Kit is presented. Experimental results demonstrate the applicability of the proposed architecture and provide the infrastructure to quantify the performance and overcome fault-handling limitations. Dynamic online autonomous functionality restoration after a malfunction or functionality shift due to changing requirements is achieved at a fine granularity by exploiting dynamic Partial Reconfiguration (PR) techniques. A Genetic Algorithm (GA)-based hardware/software platform for intrinsic evolvable hardware is designed and evaluated for digital circuit repair using a variety of well-accepted benchmarks. Dynamic bitstream compilation for enhanced mutation and crossover operators is achieved by directly manipulating the bitstream using a layered toolset. Experimental results on the edge-detector organic system prototype have shown complete organic online refurbishment after a hard fault. In contrast to previous toolsets requiring many milliseconds or seconds, an average of 0.47 microseconds is required to perform the genetic mutation, 4.2 microseconds to perform the single point conventional crossover, 3.1 microseconds to perform Partial Match Crossover (PMX) as well as Order Crossover (OX), 2.8 microseconds to perform Cycle Crossover (CX), and 1.1 milliseconds for one input pattern intrinsic evaluation. These represent a performance advantage of three orders of magnitude over the JBITS software framework and more than seven orders of magnitude over the Xilinx design flow. Combinatorial Group Testing (CGT) technique was combined with the conventional GA in what is called CGT-pruned GA to reduce repair time and increase system availability. Results have shown up to 37.6% convergence advantage using the pruned technique. Lastly, a quantitative stochastic sustainability model for reparable systems is formulated to evaluate the Sustainability of FPGA-based reparable systems. This model computes at design-time the resources required for refurbishment to meet mission availability and lifetime requirements in a given fault-susceptible missions. By applying this model to MCNC benchmark circuits and the Sobel Edge-Detector in a realistic space mission use-case on Xilinx Virtex-4 FPGA, we demonstrate a comprehensive model encompassing the inter-relationships between system sustainability and fault rates, utilized, and redundant hardware resources, repair policy parameters and decaying reparability.
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Date Issued: 2011
Identifier: CFE0003969, ucf:48661
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003969

Title: Psychological Responses of Fathers and Mothers to Amniocentesis.
Creator: Williamson, Nancy D., Blau, Burton I., Arts and Sciences
Abstract / Description: University of Central Florida College of Arts and Sciences Thesis; Amniocentesis is one of the most widely used prenatal diagnostic techniques for congenital disorders. It was hypothesized that the spychological responses of mothers and fathers to amniocenthesis during high-rish pregnancies would be positively correlated on scales of Symptomatology (Anxiety, Depression, Anger, and Somatic Complaints) and Well-Being (Relaxed, Contented, Friendliness, and Somatic Well-Being). It was also...
Show moreUniversity of Central Florida College of Arts and Sciences Thesis; Amniocentesis is one of the most widely used prenatal diagnostic techniques for congenital disorders. It was hypothesized that the spychological responses of mothers and fathers to amniocenthesis during high-rish pregnancies would be positively correlated on scales of Symptomatology (Anxiety, Depression, Anger, and Somatic Complaints) and Well-Being (Relaxed, Contented, Friendliness, and Somatic Well-Being). It was also hypothesized that Symptomatology would be negatively correlated with Well-Being. Nineteen couples, who were referred by their physicians, voluntarily participated in the study. Each partner completed the Symptom Questionnaire (Kellner, 1983), a self-rating scale of Symptomatology and Well-Being, in addition to the Pre-Amniocentesis and Post-Amniocentesis Questionnaires (original questionnaires developed for this study) at intervals prior to and following the procedure, while awaiting results. A Pearson product-moment correlation of the total scores revealed a positive correlation (p < 0.5) between the scores of fathers and mothers on the Symptomatology Scale, both pre- and post-amniocentesis (r = .47 and .47). In addition, there was a significant negative correlation (p < .05) between Symptomatolgy and Well-Being scores for both mothers (r = -.55 and -.60) and fathers (r = -.48 and -.74) at the pre- and post-amniocentesis periods, respectively. The hypothesis cannot be completely accepted because the positive correlation does not exist at the post-amniocentesis level. Mothers appear to experience more Symptomatology and less Well-Being than fathers at the post-amniocentesis level. The results are interpreted to suggest that fathers and mothers may both benefit from pre- and post-amniocentesis supportive intervention.
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Date Issued: 1985
Identifier: CFR0008164, ucf:53074
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0008164

Title: Advanced castes at the outset of eusociality in wasps (Vespidae).
Creator: Piekarski, Patrick, Sharanowski, Barbara, Carpenter, James, Hoffman, Eric, University of Central Florida
Abstract / Description: A dominating and widespread view is that evolutionary change is gradual and waits upon mutation. Likewise, it is thought that workers and queens of eusocial insects diverged gradually and stepwise. That is, rudimentary castes preceded advanced castes. This paradigm hinges on eusociality having evolved once in Vespidae, and primitively eusocial paper wasps lacking ontogenetic caste biasing (differentiation of castes during larval development). Using a phylogenomic approach this study shows...
Show moreA dominating and widespread view is that evolutionary change is gradual and waits upon mutation. Likewise, it is thought that workers and queens of eusocial insects diverged gradually and stepwise. That is, rudimentary castes preceded advanced castes. This paradigm hinges on eusociality having evolved once in Vespidae, and primitively eusocial paper wasps lacking ontogenetic caste biasing (differentiation of castes during larval development). Using a phylogenomic approach this study shows strong evidence for two origins of eusociality in vespid wasps, wherein one origin is likely characterized by the sudden appearance of castes with physiological, and perhaps even morphological, differences established before adulthood (i.e. advanced castes). Ontogenetic caste biasing was likely present at the outset of eusociality in the most recent common ancestor of paper wasps, yellowjackets and hornets. This suggests that the definitive, non-temporal castes of eusocial wasps evolved from interactions between mothers and daughters, rather than same generation females. These results challenge the idea that castes began with only rudimentary differences. A model of stepwise caste divergence, which assumes an independent mutation event for each phenotypic caste difference, is unwarranted. It is hypothesized that phenotypic plasticity and cryptic genetic variation may explain how some eusocial societies emerged, and began with advanced castes. The results suggest that evolution can produce alternative phenotypes with many aspects of the phenotype being discrete at the outset. Thus, the emergence and divergence of castes in eusocial vespids was not necessarily a gradual process.
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Date Issued: 2017
Identifier: CFE0006640, ucf:51240
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006640

Title: The Role of the Y-Chromosome in the Evolution of Autosomally Coded Traits.
Creator: Kutch, Ian, Fedorka, Kenneth, Vonkalm, Laurence, Hoffman, Eric, University of Central Florida
Abstract / Description: Recent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other...
Show moreRecent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other independently evolved heterogametic sex chromosomes, the evolutionary implications of Y-linked regulatory variation (YRV) deserves to be explored. These implications include the potential for Y-chromosomes to facilitate the adaptive evolution of sexually dimorphic gene expression, and the potential for the Y to constrain evolutionary rates in both males and females (depending on the nature of the YRV effect). Unfortunately, the evolutionary implications of this potentially widespread and significant phenomenon have yet to be explored. My dissertation addresses this knowledge gap by determining the influence YRV has on the evolution of autosomally coded traits in D. melanogaster. First, we address the potential for selection to shape YRV by determining if YRV (i) exists within natural populations (i.e. where natural selection operates), and (ii) has any influence on male fitness-related autosomal traits. Second, we address if YRV can facilitate the adaptive evolution of sexually dimorphic gene expression by testing for the presence of Y-linked additive genetic variation. To this end, we investigate the physiological properties of select Y-chromosomes across multiple genetic backgrounds. Third, we address if YRV can constrain adaptive evolution for autosomally coded traits by employing artificial selection on replicate populations that contain either multiple Y-chromosomes (i.e. contain YRV) or only a single Y-chromosome (no YRV). The following studies present evidence that YRV does exist within populations where natural selection operates. We show significant levels of YRV on X-linked and autosomal immune gene expression in wild caught D. melanogaster from a single natural population. Furthermore, YRV effects on immune related genes show a significantly positive correlation to a male fly's ability to fight an immune challenge (an important aspect of organismal fitness). Estimated physiological properties of YRV support previous interpopulation studies showing strong non-additive effect dependent on the autosomal genetic background with which Y-chromosome's are paired with. Physiological epistasis can manifest as additive genetic variation on a population level, but our experimental evolution study suggest that YRV constrains rather than facilitates the evolution of the autosomal coded geotaxis behavior. Ultimately, this dissertation provides evidence that YRV has the potential to influence how autosomal traits evolve and that population level studies of YRV indicate a potential constraint to the adaptive evolution of autosomal traits. If these trends are common and YRV is a wide spread phenomenon, Y-chromosomes have the potential to influence how autosomal traits evolve.
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Date Issued: 2017
Identifier: CFE0006756, ucf:51873
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006756

Title: A Time-Course Analysis of Behavioral Plasticity and Differential Gene Expression Patterns in Response to Density in Schistocerca americana (Orthoptera: Acrididae).
Creator: Gotham, Steven, Song, Hojun, Vonkalm, Laurence, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Phenotypic plasticity is the ability of the genotype to express alternative phenotypes in response to different environmental conditions and this is considered to be an adaptation in which a species can survive and persist in a rapidly changing environment. Some grasshoppers and locusts are capable of expressing an extreme form of density-dependent phenotypic plasticity, known as locust phase polyphenism. At low population density, the individuals typically have a cryptic coloration as nymphs...
Show morePhenotypic plasticity is the ability of the genotype to express alternative phenotypes in response to different environmental conditions and this is considered to be an adaptation in which a species can survive and persist in a rapidly changing environment. Some grasshoppers and locusts are capable of expressing an extreme form of density-dependent phenotypic plasticity, known as locust phase polyphenism. At low population density, the individuals typically have a cryptic coloration as nymphs, are less active, and only seek out conspecifics for reproductive purposes. At high density, however, they develop a drastically different phenotype in which they have a conspicuous coloration, are much more active, and tend to stay together in large groups. The American Birdwing grasshopper, Schistocerca americana, is a non-swarming species related to the desert locust, S. gregaria, which shows density-dependent phenotypic plasticity in behavior, color, and morphology. In this thesis, I have identified the duration of crowding necessary for a 6th instar S. americana reared in the isolated condition to express the typical crowded behavior. The behavior changed after just one hour of crowding and the effect of crowding diminished after 48 hours to near-complete isolated behavior. In reverse, the crowded condition was isolated, but behavior did not significantly change over time. Gene expression of the following three genes suspected of having a role in behavior change were investigated based on studies of S. gregaria: protein kinase A (PKA), L-Tryptophan-5-monooxygenase (T-5), and Aromatic L-amino acid decarboxylase (Decarb). T-5 was up-regulated in the long-term isolated condition compared to the long-term crowded condition. T-5 and Decarb were up-regulated in isolated individuals that were crowded for 10 hours compared to the long-term isolated condition. This study represents a novel contribution in the study of phenotypic plasticity as it establishes the time course of behavioral and molecular plasticity in a non-swarming grasshopper for the first time.
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Date Issued: 2014
Identifier: CFE0005799, ucf:50049
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005799

Title: Cascaded Digital Refinement for Intrinsic Evolvable Hardware.
Creator: Thangavel, Vignesh, DeMara, Ronald, Sundaram, Kalpathy, Song, Zixia, University of Central Florida
Abstract / Description: Intrinsic evolution of reconfigurable hardware is sought to solve computational problems using the intrinsic processing behavior of System-on-Chip (SoC) platforms. SoC devices combine capabilities of analog and digital embedded components within a reconfigurable fabric under software control. A new technique is developed for these fabrics that leverages the digital resources' enhanced accuracy and signal refinement capability to improve circuit performance of the analog resources' which are...
Show moreIntrinsic evolution of reconfigurable hardware is sought to solve computational problems using the intrinsic processing behavior of System-on-Chip (SoC) platforms. SoC devices combine capabilities of analog and digital embedded components within a reconfigurable fabric under software control. A new technique is developed for these fabrics that leverages the digital resources' enhanced accuracy and signal refinement capability to improve circuit performance of the analog resources' which are providing low power processing and high computation rates. In particular, Differential Digital Correction (DDC) is developed utilizing an error metric computed from the evolved analog circuit to reconfigure the digital fabric thereby enhancing precision of analog computations. The approach developed herein, Cascaded Digital Refinement (CaDR), explores a multi-level strategy of utilizing DDC for refining intrinsic evolution of analog computational circuits to construct building blocks, known as Constituent Functional Blocks (CFBs). The CFBs are developed in a cascaded sequence followed by digital evolution of higher-level control of these CFBs to build the final solution for the larger circuit at-hand. One such platform, Cypress PSoC-5LP was utilized to realize solutions to ordinary differential equations by first evolving various powers of the independent variable followed by that of their combinations to emulate mathematical series-based solutions for the desired range of values. This is shown to enhance accuracy and precision while incurring lower computational energy and time overheads. The fitness function for each CFB being evolved is different from the fitness function that is defined for the overall problem.
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Date Issued: 2015
Identifier: CFE0005723, ucf:50123
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005723

Title: ANALYSES OF CRASH OCCURENCE AND INURY SEVERITIES ON MULTI LANE HIGHWAYS USING MACHINE LEARNING ALGORITHMS.
Creator: Das, Abhishek, Abdel-Aty, Mohamed A., University of Central Florida
Abstract / Description: Reduction of crash occurrence on the various roadway locations (mid-block segments; signalized intersections; un-signalized intersections) and the mitigation of injury severity in the event of a crash are the major concerns of transportation safety engineers. Multi lane arterial roadways (excluding freeways and expressways) account for forty-three percent of fatal crashes in the state of Florida. Significant contributing causes fall under the broad categories of aggressive driver behavior;...
Show moreReduction of crash occurrence on the various roadway locations (mid-block segments; signalized intersections; un-signalized intersections) and the mitigation of injury severity in the event of a crash are the major concerns of transportation safety engineers. Multi lane arterial roadways (excluding freeways and expressways) account for forty-three percent of fatal crashes in the state of Florida. Significant contributing causes fall under the broad categories of aggressive driver behavior; adverse weather and environmental conditions; and roadway geometric and traffic factors. The objective of this research was the implementation of innovative, state-of-the-art analytical methods to identify the contributing factors for crashes and injury severity. Advances in computational methods render the use of modern statistical and machine learning algorithms. Even though most of the contributing factors are known a-priori, advanced methods unearth changing trends. Heuristic evolutionary processes such as genetic programming; sophisticated data mining methods like conditional inference tree; and mathematical treatments in the form of sensitivity analyses outline the major contributions in this research. Application of traditional statistical methods like simultaneous ordered probit models, identification and resolution of crash data problems are also key aspects of this study. In order to eliminate the use of unrealistic uniform intersection influence radius of 250 ft, heuristic rules were developed for assigning crashes to roadway segments, signalized intersection and access points using parameters, such as 'site location', 'traffic control' and node information. Use of Conditional Inference Forest instead of Classification and Regression Tree to identify variables of significance for injury severity analysis removed the bias towards the selection of continuous variable or variables with large number of categories. For the injury severity analysis of crashes on highways, the corridors were clustered into four optimum groups. The optimum number of clusters was found using Partitioning around Medoids algorithm. Concepts of evolutionary biology like crossover and mutation were implemented to develop models for classification and regression analyses based on the highest hit rate and minimum error rate, respectively. Low crossover rate and higher mutation reduces the chances of genetic drift and brings in novelty to the model development process. Annual daily traffic; friction coefficient of pavements; on-street parking; curbed medians; surface and shoulder widths; alcohol / drug usage are some of the significant factors that played a role in both crash occurrence and injury severities. Relative sensitivity analyses were used to identify the effect of continuous variables on the variation of crash counts. This study improved the understanding of the significant factors that could play an important role in designing better safety countermeasures on multi lane highways, and hence enhance their safety by reducing the frequency of crashes and severity of injuries. Educating young people about the abuses of alcohol and drugs specifically at high schools and colleges could potentially lead to lower driver aggression. Removal of on-street parking from high speed arterials unilaterally could result in likely drop in the number of crashes. Widening of shoulders could give greater maneuvering space for the drivers. Improving pavement conditions for better friction coefficient will lead to improved crash recovery. Addition of lanes to alleviate problems arising out of increased ADT and restriction of trucks to the slower right lanes on the highways would not only reduce the crash occurrences but also resulted in lower injury severity levels.
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Date Issued: 2009
Identifier: CFE0002928, ucf:48007
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002928

Title: TREEFROG (HYLA SQUIRELLA) RESPONSES TO RANGELAND MANAGEMENT IN SEMI-TROPICAL FLORIDA, USA.
Creator: Windes, Kathryn, Fauth, John, University of Central Florida
Abstract / Description: As urban areas expand, agricultural lands become increasingly important habitat for many species. Compared to some types of agricultural land-use, ranchlands provide vast expanses of minimally modified habitat that support many threatened and endangered species. Conservation biologists can promote ecologically sound management approaches by quantifying the effects of agricultural practices on resident species. I examined the effects of pasture management, cattle grazing, and landscape...
Show moreAs urban areas expand, agricultural lands become increasingly important habitat for many species. Compared to some types of agricultural land-use, ranchlands provide vast expanses of minimally modified habitat that support many threatened and endangered species. Conservation biologists can promote ecologically sound management approaches by quantifying the effects of agricultural practices on resident species. I examined the effects of pasture management, cattle grazing, and landscape characteristics on both adult and larval treefrogs in a ranchland in south-central Florida. I experimentally determined optimal deployment of artificial treefrog shelters constructed of polyvinylchloride (PVC) pipe to efficiently sample adult treefrogs (Chapter 1). Seventy-two shelters were hung on oak trees (Quercus virginiana) and cabbage palm trees (Sabal palmetto) with smooth trunks or boots (residual palm fronds), at all possible combinations of three heights (2, 3, and 4 m), four compass directions (N, S, E, and W) and two water levels (with or without 10 cm). Shelter residence was completely dominated by the Squirrel Treefrog, Hyla squirella (N = 65). Significantly fewer H. squirella were found in shelters on palms with boots than on smooth palms or oak trees (0.29 Ã‚Â± 0.21 [mean Ã‚Â± 1 SE hereinafter] versus 1.3 Ã‚Â± 0.21 and 1.1 Ã‚Â± 0.21, respectively), and shelters with water had slightly more H. squirella than those without (1.5 Ã‚Â± 0.19 versus 0.88 Ã‚Â± 0.19, respectively). Orientation and height did not affect the number of treefrogs encountered; thus, the optimal protocol is to deploy shelters on either smooth palms or oak trees, with water, at 2 m height for easy sampling, and in random compass orientations. I used this protocol to sample H. squirella in woodlots surrounding twelve wetlands and examined how time, frog stage and sex, and landscape features influenced treefrog survival, recapture and site fidelity (Chapter 2). I deployed 15 shelters/ha of woodlot within a 100 m buffer around each wetland. I sampled shelters three times during the fall breeding season, removed all shelters to force frogs to overwinter in natural refugia, and replaced shelters for the final spring sampling. During sampling periods, I sexed, measured, and individually marked each frog using visual implant elastomer (VIE) tags. I used Program MARK to build linear models that included either gender group (female, male or juvenile) or life history stage (adult, juvenile) and either time (sampling interval 1, 2, or 3) or season (fall, spring). I used the most informative model as a null model to assess effects of landscape covariates on survival and recapture. Females had higher survival than either males or juveniles, for which estimates were similar (0.867 vs 0.741 and 0.783, respectively). Survival did not vary over time, although there was some support for an effect of season, with lower survival during the final over-wintering period than in the fall intervals (relative variable importance: group = 0.730; stage = 0.134; time = 0.200; season = 0.310). Adults had higher recapture rates than juveniles (average recapture 0.214 vs 0.102), and recapture for both stages varied over time, with highest recapture in sampling interval two (relative variable importance: group = 0.262; stage = 0.514; time = 0.513; season = 0.229). Hyla squirella was extremely site loyal; no individuals moved between sampling sites, and 95% of recaptured individuals were in their original shelter. Strong terrestrial site fidelity calls into question the traditional Ã‚Â"ponds as patchesÃ‚Â" metapopulation view of treefrog population dynamics. Area of woodlot within 250 m was the most important landscape variable in explaining additional variation in both survival and recapture. Frogs had higher survival and lower recapture in larger woodlots, indicating that intact, contiguous woodlots are higher quality habitat than more fragmented woodlots. Neither survival nor recapture varied with wetland grazing treatments or between pasture types. Finally, I experimentally assessed the effects of cattle grazing and pasture management on larval H. squirella. I selected four wetlands: two in semi-natural pastures (SN) and two in intensively managed pastures (IM). One wetland in each pasture type was fenced so that it was released from cattle grazing (R). I collected three clutches of H. squirella eggs (Clutches A, B, and C) and reared tadpoles in the laboratory until Gosner stage 25. In each wetland, I deployed a total of 50 tadpoles from each clutch into 105 L pens constructed of plastic laundry baskets and mesh window screening. Clutch significantly affected tadpole survival, with Clutch A having the highest percent survival, followed by Clutch B and finally Clutch C (41.66, 32.11 Ã‚Â– 53.95 [mean, 95% confidence limits hereinafter]; 9.00, 6.76 Ã‚Â– 11.88; 2.89, 2.02 Ã‚Â– 4.01, respectively). Wetland type also affected survival, with SN wetlands supporting significantly higher survival than IM wetlands (SN-R: 53.95, 32.88 Ã‚Â– 88.13; SN-G: 18.95, 11.30 Ã‚Â– 31.36 vs IM-R: 7.32, 4.13 Ã‚Â– 12.49; IM-G: 1.09, 0.29 Ã‚Â– 2.39). Genetic variation in survival confirms the potential for H. squirella to adapt to rangeland management, but extremely low survival of some clutches indicates that few clutches may be able to survive in low quality wetlands, such as IM-G wetlands. Higher survival in SN pasture wetlands suggest this is a superior habitat and future management objectives should conserve semi-natural pastures and limit further modification of intensively managed pastures, including removing woodlots near wetlands.
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Date Issued: 2010
Identifier: CFE0003178, ucf:48592
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003178

Title: Quality Diversity: Harnessing Evolution to Generate a Diversity of High-Performing Solutions.
Creator: Pugh, Justin, Stanley, Kenneth, Wu, Annie, Sukthankar, Gita, Garibay, Ivan, University of Central Florida
Abstract / Description: Evolution in nature has designed countless solutions to innumerable interconnected problems, giving birth to the impressive array of complex modern life observed today. Inspired by this success, the practice of evolutionary computation (EC) abstracts evolution artificially as a search operator to find solutions to problems of interest primarily through the adaptive mechanism of survival of the fittest, where stronger candidates are pursued at the expense of weaker ones until a solution of...
Show moreEvolution in nature has designed countless solutions to innumerable interconnected problems, giving birth to the impressive array of complex modern life observed today. Inspired by this success, the practice of evolutionary computation (EC) abstracts evolution artificially as a search operator to find solutions to problems of interest primarily through the adaptive mechanism of survival of the fittest, where stronger candidates are pursued at the expense of weaker ones until a solution of satisfying quality emerges. At the same time, research in open-ended evolution (OEE) draws different lessons from nature, seeking to identify and recreate processes that lead to the type of perpetual innovation and indefinitely increasing complexity observed in natural evolution. New algorithms in EC such as MAP-Elites and Novelty Search with Local Competition harness the toolkit of evolution for a related purpose: finding as many types of good solutions as possible (rather than merely the single best solution). With the field in its infancy, no empirical studies previously existed comparing these so-called quality diversity (QD) algorithms. This dissertation (1) contains the first extensive and methodical effort to compare different approaches to QD (including both existing published approaches as well as some new methods presented for the first time here) and to understand how they operate to help inform better approaches in the future.It also (2) introduces a new technique for encoding neural networks for evolution with indirect encoding that contain multiple sensory or output modalities.Further, it (3) explores the idea that QD can act as an engine of open-ended discovery by introducing an expressive platform called Voxelbuild where QD algorithms continually evolve robots that stack blocks in new ways. A culminating experiment (4) is presented that investigates evolution in Voxelbuild over a very long timescale. This research thus stands to advance the OEE community's desire to create and understand open-ended systems while also laying the groundwork for QD to realize its potential within EC as a means to automatically generate an endless progression of new content in real-world applications.
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Date Issued: 2019
Identifier: CFE0007513, ucf:52638
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007513

Title: A COMPARATIVE ANALYSIS BETWEEN CONTEXT-BASED REASONING (CXBR) AND CONTEXTUAL GRAPHS (CXGS).
Creator: Lorins, Peterson, Gonzalez, Avelino, University of Central Florida
Abstract / Description: Context-based Reasoning (CxBR) and Contextual Graphs (CxGs) involve the modeling of human behavior in autonomous and decision-support situations in which optimal human decision-making is of utmost importance. Both formalisms use the notion of contexts to allow the implementation of intelligent agents equipped with a context sensitive knowledge base. However, CxBR uses a set of discrete contexts, implying that models created using CxBR operate within one context at a given time interval. CxGs...
Show moreContext-based Reasoning (CxBR) and Contextual Graphs (CxGs) involve the modeling of human behavior in autonomous and decision-support situations in which optimal human decision-making is of utmost importance. Both formalisms use the notion of contexts to allow the implementation of intelligent agents equipped with a context sensitive knowledge base. However, CxBR uses a set of discrete contexts, implying that models created using CxBR operate within one context at a given time interval. CxGs use a continuous context-based representation for a given problem-solving scenario for decision-support processes. Both formalisms use contexts dynamically by continuously changing between necessary contexts as needed in appropriate instances. This thesis identifies a synergy between these two formalisms by looking into their similarities and differences. It became clear during the research that each paradigm was designed with a very specific family of problems in mind. Thus, CXBR best implements models of autonomous agents in environment, while CxGs is best implemented in a decision support setting that requires the development of decision-making procedures. Cross applications were implemented on each and the results are discussed.
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Date Issued: 2005
Identifier: CFE0000577, ucf:46433
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000577

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