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Title: Molecular modeling and dynamics of sphinogomyelin phosphodiesterase D LISicTox-alphalll1i.
Creator: Jordan, Autumn, Snyder, Patricia Ann
Date Issued: 2013-04-05
PURL: http://purl.flvc.org/fcla/dt/3361099
Subject Headings: Molecular models, Molecules--Models--Computer simulation, Computational chemistry
Format: Document (PDF)

Title: A study on glucose metabolism: Computer simulation and modeling.
Creator: Leesirikul, Meta., Florida Atlantic University, Neelakanta, Perambur S., Roth, Zvi S., Morgera, Salvatore D., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: Sorensen's model of glucose metabolism and regulation is reconstructed using SimulinkRTM. Most of the existing glucose metabolism models consist of several mass balance equations that interact with each others. Graphical format used by SimulinkRTM provides a visualized perspective of such relations so that it is easier to modify the model on ad hoc basis. Type-I and Type-II diabetes with relevant clinical details are simulated. Further, a control strategy is introduced in order to simulate...
Show moreSorensen's model of glucose metabolism and regulation is reconstructed using SimulinkRTM. Most of the existing glucose metabolism models consist of several mass balance equations that interact with each others. Graphical format used by SimulinkRTM provides a visualized perspective of such relations so that it is easier to modify the model on ad hoc basis. Type-I and Type-II diabetes with relevant clinical details are simulated. Further, a control strategy is introduced in order to simulate the control of exogenous insulin pump. Simulated results are consistent with available clinical data. Living systems in general, exhibit both stochastical and deterministic characteristics. Activities such as glucose metabolism traditionally modeled do not include stochastical properties, nor that they are viewed in the large framework of complex system with explicit interaction details. Currently, a complexity system model is developed to describe the glucose metabolism related activities. The simulation results obtained thereof illustrate the bounding domain of variations in some clinically observed details.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13254
Subject Headings: Glucose--Metabolism, Computer simulation, Diabetes--Metabolism, Computer modeling
Format: Document (PDF)

Title: TOWARDS A SECURITY REFERENCE ARCHITECTURE FOR NETWORK FUNCTION VIRTUALIZATION.
Creator: Alnaim, Abdulrahman K., Fernandez, Eduardo B., Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science, College of Engineering and Computer Science
Abstract/Description: Network Function Virtualization (NFV) is an emerging technology that transforms legacy hardware-based network infrastructure into software-based virtualized networks. Instead of using dedicated hardware and network equipment, NFV relies on cloud and virtualization technologies to deliver network services to its users. These virtualized network services are considered better solutions than hardware-based network functions because their resources can be dynamically increased upon the consumer’s...
Show moreNetwork Function Virtualization (NFV) is an emerging technology that transforms legacy hardware-based network infrastructure into software-based virtualized networks. Instead of using dedicated hardware and network equipment, NFV relies on cloud and virtualization technologies to deliver network services to its users. These virtualized network services are considered better solutions than hardware-based network functions because their resources can be dynamically increased upon the consumer’s request. While their usefulness can’t be denied, they also have some security implications. In complex systems like NFV, the threats can come from a variety of domains due to it containing both the hardware and the virtualize entities in its infrastructure. Also, since it relies on software, the network service in NFV can be manipulated by external entities like third-party providers or consumers. This leads the NFV to have a larger attack surface than the traditional network infrastructure. In addition to its own threats, NFV also inherits security threats from its underlying cloud infrastructure. Therefore, to design a secure NFV system and utilize its full potential, we must have a good understanding of its underlying architecture and its possible security threats. Up until now, only imprecise models of this architecture existed. We try to improve this situation by using architectural modeling to describe and analyze the threats to NFV. Architectural modeling using Patterns and Reference Architectures (RAs) applies abstraction, which helps to reduce the complexity of NFV systems by defining their components at their highest level. The literature lacks attempts to implement this approach to analyze NFV threats. We started by enumerating the possible threats that may jeopardize the NFV system. Then, we performed an analysis of the threats to identify the possible misuses that could be performed from them. These threats are realized in the form of misuse patterns that show how an attack is performed from the point of view of attackers. Some of the most important threats are privilege escalation, virtual machine escape, and distributed denial-of-service. We used a reference architecture of NFV to determine where to add security mechanisms in order to mitigate the identified threats. This produces our ultimate goal, which is building a security reference architecture for NFV.
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Date Issued: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013435
Subject Headings: Computer network architectures--Safety measures, Virtual computer systems, Computer networks, Modeling, Computer
Format: Document (PDF)

Title: Rapid distortion theory for rotor inflows.
Creator: Kawashima, Emilia, Glegg, Stewart A. L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: For aerospace and naval applications where low radiated noise levels are a requirement, rotor noise generated by inflow turbulence is of great interest. Inflow turbulence is stretched and distorted as it is ingested into a thrusting rotor which can have a significant impact on the noise source levels. This thesis studies the distortion of subsonic, high Reynolds number turbulent flow, with viscous effects ignored, that occur when a rotor is embedded in a turbulent boundary layer. The analysis...
Show moreFor aerospace and naval applications where low radiated noise levels are a requirement, rotor noise generated by inflow turbulence is of great interest. Inflow turbulence is stretched and distorted as it is ingested into a thrusting rotor which can have a significant impact on the noise source levels. This thesis studies the distortion of subsonic, high Reynolds number turbulent flow, with viscous effects ignored, that occur when a rotor is embedded in a turbulent boundary layer. The analysis is based on Rapid Distortion Theory (RDT), which describes the linear evolution of turbulent eddies as they are stretched by a mean flow distortion. Providing that the gust does not distort the mean flow streamlines the solution for a mean flow with shear is found to be the same as the solution for a mean potential flow with the addition of a potential flow gust. By investigating the inflow distortion of small-scale turbulence for various simple flows and rotor inflows with weak shear, it is shown that RDT can be applied to incompressible shear flows to determine the flow distortion. It is also shown that RDT can be applied to more complex flows modeled by the Reynolds Averaged Navier Stokes (RANS) equations.
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Date Issued: 2013
PURL: http://purl.flvc.org/fau/fd/FA0004030
Subject Headings: Computational fluid dynamics, Fluid dynamic measurements, Fluid mechanics -- Mathematical models, Turbulence -- Computer simulation, Turbulence -- Mathematical models
Format: Document (PDF)

Title: Visualization tool for molecular dynamics simulation.
Creator: Garg, Meha., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: A study of Molecular Dynamics using computational methods and modeling provides the understanding on the interaction of the atoms, properties, structure, and motion and model phenomenon. There are numerous commercial tools available for simulation, analysis and visualization. However any particular tool does not provide all the functionalities. The main objective of this work is the development of the visualization tool customized for our research needs to view the three dimensional...
Show moreA study of Molecular Dynamics using computational methods and modeling provides the understanding on the interaction of the atoms, properties, structure, and motion and model phenomenon. There are numerous commercial tools available for simulation, analysis and visualization. However any particular tool does not provide all the functionalities. The main objective of this work is the development of the visualization tool customized for our research needs to view the three dimensional orientation of the atom, process the simulation results offline, able to handle large volume of data, ability to display complete frame, atomic trails, and runtime response to the researchers' query with low processing time. This thesis forms the basis for the development of such an in-house tool for analysis and display of simulation results based on Open GL and MFC. Advantages, limitations, capabilities and future aspects are also discussed. The result is the system capable of processing large amount of simulation result data in 11 minutes and query response and display in less than 1 second.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/1927308
Subject Headings: Molecular dynamics, Computer simulation, Condensed matter, Computer simulation, Intermolecular forces, Computer simulation, Molecules, Mathematical models
Format: Document (PDF)

Title: Variations in model discretization methodology and its effects upon groundwater modeling.
Creator: Whitman, Jason L., Florida Atlantic University, Restrepo, Jorge I.
Abstract/Description: It is a fundamental supposition in groundwater modeling that as the discretization of a model domain is increased, the model's precision increases accordingly (Anderson and Woessner, 1992). However, the quantifiable amount and specific circumstances of that benefit remain unclear. The purpose of this research is to examine the output variations discerned as a result of applying successively coarsened discretization scenarios to a groundwater model test case. The test models, comprised of both...
Show moreIt is a fundamental supposition in groundwater modeling that as the discretization of a model domain is increased, the model's precision increases accordingly (Anderson and Woessner, 1992). However, the quantifiable amount and specific circumstances of that benefit remain unclear. The purpose of this research is to examine the output variations discerned as a result of applying successively coarsened discretization scenarios to a groundwater model test case. The test models, comprised of both regular (square) and irregular forty-four individual model output solutions. Detailed analysis of the piezometric head values, mass balance flow terms, and solution convergence times for each model run provides valuable insight into the complex relationship existing between spatial discretization and its effect upon model output values. Consequently, the aforementioned relationship proves to be highly complex, often affecting multiple model parameters in dissimilar manners while maintaining consistency in others.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15750
Subject Headings: Groundwater flow--Computer simulation, Groundwater flow--Mathematical models
Format: Document (PDF)

Title: Spatio-temporal dynamics in the SEIRS epidemic model.
Creator: Mei, Lei, Florida Atlantic University, Wille, Luc T.
Abstract/Description: The Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) spatial epidemic model is governed by non-linear equations with several parameters related to birth and death, contact rate, disease latency, infectious period, and recycle rate. Both continuum results and lattice results show the existing of disease persistence and critical density. The upper limit of birth and death rate is observed, power spectrum with 1/f profile is discussed. Some other models, as limiting cases of the SEIRS...
Show moreThe Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) spatial epidemic model is governed by non-linear equations with several parameters related to birth and death, contact rate, disease latency, infectious period, and recycle rate. Both continuum results and lattice results show the existing of disease persistence and critical density. The upper limit of birth and death rate is observed, power spectrum with 1/f profile is discussed. Some other models, as limiting cases of the SEIRS model, are also studied. Lower limit of birth and death rate for the models without recycle rate has also obtained. Finally two general rules governing epidemic models are summarized. Visualization is available on our web site http://www.cse.fau.edu/~lmei/simulation.html
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15633
Subject Headings: Epidemiology--Mathematical models, Demography, Epidemics--Computer simulation
Format: Document (PDF)

Title: Stochastical aspects of neuronal activity, neural networks, and communication.
Creator: De Groff, Dolores F., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: By revisiting the popular framework of depicting neuronal (collective) activities as analogous to Ising's spin-glass theory of interacting magnetic spins, the contradictions that coexist with such an analogy are extracted and discussed. To alleviate such contradictions, an alternative strategy of equating the neuronal interactions to the partially anisotropic nematic phase of disorder pertaining to liquid crystals is proposed. Hence, the extent of anisotropy in the neuronal system, quantified...
Show moreBy revisiting the popular framework of depicting neuronal (collective) activities as analogous to Ising's spin-glass theory of interacting magnetic spins, the contradictions that coexist with such an analogy are extracted and discussed. To alleviate such contradictions, an alternative strategy of equating the neuronal interactions to the partially anisotropic nematic phase of disorder pertaining to liquid crystals is proposed. Hence, the extent of anisotropy in the neuronal system, quantified in terms of an order-function, is specified to elucidate the nonlinear squashing action of the input-output relations in a neuronal cell. The relevant approach thereof, is based on Langevin's theory considerations as applied to dipole molecules. Further, in view of the stochastical properties due to the inherent disorder associated with the neuronal assembly, the progression of state-transitions across the interconnected cells is modeled as a momentum flow relevant to particle dynamics. Hence, corresponding wave mechanics attributions of such a collective movement of state-transition activity are described in terms of a probabilistic wave function. Lastly, the stochastical aspects of noise-perturbed neuronal dynamics are studied via Fokker-Planck equation representing the Langevin-type relaxational (nonlinear) process associated with the neuronal states. On each of these topics portraying the stochastical characteristics of the neuronal assembly and its activities, newer and/or more exploratory inferences are made, logical conclusions are enumerated and relevant discussions are presented along with the scope for future research to be pursued.
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Date Issued: 1993
PURL: http://purl.flvc.org/fcla/dt/12326
Subject Headings: Neurons--Mathematical models, Stochastic processes, Neural networks (Computer science)
Format: Document (PDF)

Title: Transforming directed graphs into uncertain rules.
Creator: Lantigua, Jose Salvador., Florida Atlantic University, Hoffman, Frederick, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: The intent of this thesis is to show how rule structures can be derived from influence diagrams and how these structures can be mapped to existing rule-based shell paradigms. We shall demonstrate this mapping with an existing shell having the Evidence (E) --> Hypothesis (H), Certainty Factor (CF) paradigm structure. Influence diagrams are graphical representations of hypothesis to evidence, directed forms of Bayesian influence networks. These allow for inferencing about both diagnostic and...
Show moreThe intent of this thesis is to show how rule structures can be derived from influence diagrams and how these structures can be mapped to existing rule-based shell paradigms. We shall demonstrate this mapping with an existing shell having the Evidence (E) --> Hypothesis (H), Certainty Factor (CF) paradigm structure. Influence diagrams are graphical representations of hypothesis to evidence, directed forms of Bayesian influence networks. These allow for inferencing about both diagnostic and predictive (or causal) behavior based on uncertain evidence. We show how this can be implemented through a Probability (P) to CF mapping algorithm and a rule-set conflict resolution methodology. The thesis contains a discussion about the application of probabilistic semantics from Bayesian networks and of decision theory, to derive qualitative assertions about the likelihood of an occurrence; the sensitivity of a conclusion; and other indicators of usefulness. We show an example of this type of capability by the addition of a probability range function for the premise clause in our shell's rule structure.
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Date Issued: 1989
PURL: http://purl.flvc.org/fcla/dt/14570
Subject Headings: Decision-making--Mathematical models, Probabilities, Expert systems (Computer science)
Format: Document (PDF)

Title: Transfer effects of a high school computer programming course on mathematical modeling, procedural comprehension, and verbal problem solution.
Creator: Bernardo, Madeline Ann, Florida Atlantic University, Morris, John D., Weppner, Daniel B.
Abstract/Description: Computers are becoming an integral part of our high school curriculum. Students use computers for computer-assisted instruction (CAI), word processing, spreadsheet and database applications, and computer programming. It is important to know the cognitive effects of each mode of computer use. The purpose of this study was to investigate transfer effects of a high school BASIC programming course on students' skills in mathematical modeling, procedural comprehension, and verbal problem solution....
Show moreComputers are becoming an integral part of our high school curriculum. Students use computers for computer-assisted instruction (CAI), word processing, spreadsheet and database applications, and computer programming. It is important to know the cognitive effects of each mode of computer use. The purpose of this study was to investigate transfer effects of a high school BASIC programming course on students' skills in mathematical modeling, procedural comprehension, and verbal problem solution. The sample consisted of 44 BASIC I students, 44 computer literacy students, and 44 students who had no computer training. Groups were matched on years of mathematics and on the grade received in the last mathematics course taken. Pretests and posttests were administered. Results indicated no significant differences in scores among groups for mathematical modeling or procedural comprehension; however, a significant difference was found among groups for verbal problem solution. The BASIC group scored significantly higher than the computer literacy group and the group with no exposure (p < .01). Auxiliary hypotheses examined possible interactions of group with gender, student level, prior grade received in mathematics, and years of high school mathematics. Significant main effects were found for both prior grade (p < .05) and years of mathematics (p < .05) with achievement directly related to excellence of grades and magnitude of coursework. Neither gender x treatment interaction, nor gender alone was found to be a significant source of score variance. Although the variance caused by student grade level was not significant, a significant interaction was found between group membership and grade level with respect to verbal problems. Sophomores in the literacy group scored higher than did sophomores in the nonexposure group; juniors in the nonexposure group scored higher than juniors in the computer literacy group. Suggestions for future research include studying effects (a) over an entire district, (b) on lower level mathematics students, and (c) on lower socioeconomic groups. Recommendations for computer education include teaching algebraic problem solving by computer and exposure of programming coursework to a wider population.
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Date Issued: 1992
PURL: http://purl.flvc.org/fcla/dt/12302
Subject Headings: Computer-assisted instruction, Verbal learning, Mathematical models, Comprehension
Format: Document (PDF)

Title: The Effect of Stereoscopic Cues on Multiple Object Tracking in a 3D Virtual Environment.
Creator: Oliveira, Steven Milanez, Barenholtz, Elan, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: Research on Multiple Object Tracking (MOT) has typically involved 2D displays where stimuli move in a single depth plane. However, under natural conditions, objects move in 3D which adds complexity to tracking. According to the spatial interference model, tracked objects have an inhibitory surround that when crossed causes tracking errors. How do these inhibitory fields translate to 3D space? Does multiple object tracking operate on a 2D planar projection, or is it in fact 3D? To investigate...
Show moreResearch on Multiple Object Tracking (MOT) has typically involved 2D displays where stimuli move in a single depth plane. However, under natural conditions, objects move in 3D which adds complexity to tracking. According to the spatial interference model, tracked objects have an inhibitory surround that when crossed causes tracking errors. How do these inhibitory fields translate to 3D space? Does multiple object tracking operate on a 2D planar projection, or is it in fact 3D? To investigate this, we used a fully immersive virtual-reality environment where participants were required to track 1 to 4 moving objects. We compared performance to a condition where participants viewed the same stimuli on a computer screen with monocular depth cues. Results suggest that participants were more accurate in the VR condition than the computer screen condition. This demonstrates interference is negligent when the objects are spatially distant, yet proximate within the 2D projection.
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Date Issued: 2017
PURL: http://purl.flvc.org/fau/fd/FA00004943, http://purl.flvc.org/fau/fd/FA00004943
Subject Headings: Pattern perception., Virtual reality., Interactive multimedia., Computer simulation., Computer vision--Mathematical models., Automatic tracking--Mathematical models.
Format: Document (PDF)

Title: Noise Radiation From A Cylindrical Embossment Immersed In Turbulent Boundary Layer Flow.
Creator: Bryan, Benjamin Skyler, Glegg, Stewart A. L., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This dissertation will consider the sound radiation from forward-facing steps and a three dimensional cylindrical embossment of very low aspect ratio mounted on a plate. Glegg et al (2014) outlined a theory for predicting the sound radiation from separated flows and applied the method to predicting the sound from forward-facing steps. In order to validate this theory it has been applied to the results of Catlett et al (2014) and Ji and Wang (2010). This validation study revealed that the...
Show moreThis dissertation will consider the sound radiation from forward-facing steps and a three dimensional cylindrical embossment of very low aspect ratio mounted on a plate. Glegg et al (2014) outlined a theory for predicting the sound radiation from separated flows and applied the method to predicting the sound from forward-facing steps. In order to validate this theory it has been applied to the results of Catlett et al (2014) and Ji and Wang (2010). This validation study revealed that the original theory could be adjusted to include a mixed scaling which gives a better prediction. RANS simulations have been performed and used to support the similarities between the forward-facing step and the cylindrical embossment. The simulations revealed that the cylindrical embossment exhibits a separation zone similar to that of the forward-facing step. This separation zone has been shown to be the dominant source of noise on the forward-facing step in previous works and therefore was expected to be the major source of sound from the cylindrical embossment. The sensitivity of this separation zone to the different parameters of the flow has been investigated by performing several simulations with different conditions and geometries. The separation zone was seen to be independent of Reynolds number based on boundary layer thickness but was directly dependent on the height of the cylinder. The theory outlined in Glegg et al (2014) was then reformulated for use with a cylindrical embossment and the predictions have been compared with wind tunnel measurements. The final predictions show good agreement with the wind tunnel measurements and the far-field sound shows a clearly defined directionality that is similar to an axial dipole at low frequencies.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004484, http://purl.flvc.org/fau/fd/FA00004484
Subject Headings: Acoustic models, Aerodynamic noise, Computational fluid dynamcs, Fluid structure interaction, Structural dynamics, Turbulence -- Mathematical models
Format: Document (PDF)

Title: Noise radiation from small steps and cubic roughness elements in turbulent boundary layer flow.
Creator: Bryan, Benjamin Skyler, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Ji and Wang (2010) propose that the dominant source of sound from a forward facing step is the stream wise dipole on the face of the step and that sources acting normal to the flow are negligible. Sound radiation normal to flow of forward facing steps has been measured in wind tunnel experiments previously by Farabee and Casarella (1986, 1991) and Catlett (2010). A method for evaluating sound radiation from surface roughness proposed in Glegg and Devenport (2009) has been adapted and applied...
Show moreJi and Wang (2010) propose that the dominant source of sound from a forward facing step is the stream wise dipole on the face of the step and that sources acting normal to the flow are negligible. Sound radiation normal to flow of forward facing steps has been measured in wind tunnel experiments previously by Farabee and Casarella (1986, 1991) and Catlett (2010). A method for evaluating sound radiation from surface roughness proposed in Glegg and Devenport (2009) has been adapted and applied to flow over a forward facing step which addresses the sound normal to the flow that was previously unaccounted for. Far-field radiation predictions based on this method have been compared with wind tunnel measurements and show good agreement. A second method which evaluates the forcing from a vortex convected past surface roughness using RANS calculations and potential flow information is also evaluated.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3358330
Subject Headings: Turbulence, Mathematical models, Aerodynamic noise, Fluid-structure interaction, Structural dynamics, Acoustic models, Computational fluid dynamcs
Format: Document (PDF)

Title: The acoustic far field of a turbulent boundary layer flow calculated from RANS simulations of the flow.
Creator: Blanc, Jean-Baptiste., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Boundary layers are regions where turbulence develops easily. In the case where the flow occurs on a surface showing a certain degree of roughness, turbulence eddies will interact with the roughness elements and will produce an acoustic field. This thesis aims at predicting this type of noise with the help of the Computational Fluid Dynamics (CFD) simulation of a wall jet using the Reynolds Average Navier-Stokes (RANS) equations. A frequency spectrum is reconstructed using a representation of...
Show moreBoundary layers are regions where turbulence develops easily. In the case where the flow occurs on a surface showing a certain degree of roughness, turbulence eddies will interact with the roughness elements and will produce an acoustic field. This thesis aims at predicting this type of noise with the help of the Computational Fluid Dynamics (CFD) simulation of a wall jet using the Reynolds Average Navier-Stokes (RANS) equations. A frequency spectrum is reconstructed using a representation of the turbulence with uncorrelated sheets of vorticity. Both aerodynamic and acoustic results are compared to experimental measurements of the flow. The CFD simulation of the flow returns consistent results but would benefit from a refinement of the grid. The surface pressure spectrum presents a slope in the high frequencies close to the experimental spectrum. The far field noise spectrum has a 5dB difference to the experiments.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/368611
Subject Headings: Computational fluid dynamics, Turbulence, Mathematical models, Fluid mechanics, Mathematical models, Acoustical engineering
Format: Document (PDF)

Title: Forecasting foreign exchange rates using neural networks.
Creator: Talati, Amit H., Florida Atlantic University, Pandya, Abhijit S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: Time series is a phenomena which appears in the financial world in various forms. One of the objectives of time series is to forecast the future based on the past. The goal of this thesis is to use foreign exchange time series, and predict its future values and trends using neural networks. The thesis covers background work in this area and discusses the results obtained by other researchers. A neural network is then developed to predict the future values of the USD/GBP and USD/DEM exchange...
Show moreTime series is a phenomena which appears in the financial world in various forms. One of the objectives of time series is to forecast the future based on the past. The goal of this thesis is to use foreign exchange time series, and predict its future values and trends using neural networks. The thesis covers background work in this area and discusses the results obtained by other researchers. A neural network is then developed to predict the future values of the USD/GBP and USD/DEM exchange rates. Both single-step and iterated multi-step predictions are considered. The performance of neural networks strongly depends on the inputs supplied. The effect of the changes in the number of inputs is also considered, and a method suggested for deciding on the optimum number. The forecasting of foreign exchange rates is a challenge because of the dynamic nature of the FOREX market and its dependencies on world events. The tool used for building the neural network and validating the approach is "Brainmaker".
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/12699
Subject Headings: Foreign exchange rates--Mathmematical models, Foreign exchange--Forecasting--Mathematical models, Neural networks (Computer science)
Format: Document (PDF)

Title: A PROBABILISTIC CHECKING MODEL FOR EFFECTIVE EXPLAINABILITY BASED ON PERSONALITY TRAITS.
Creator: Alharbi, Mohammed N., Huang, Shihong, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science, College of Engineering and Computer Science
Abstract/Description: It is becoming increasingly important for an autonomous system to be able to explain its actions to humans in order to improve trust and enhance human-machine collaboration. However, providing the most appropriate kind of explanations – in terms of length, format, and presentation mode of explanations at the proper time – is critical to enhancing their effectiveness. Explanation entails costs, such as the time it takes to explain and for humans to comprehend and respond. Therefore, the actual...
Show moreIt is becoming increasingly important for an autonomous system to be able to explain its actions to humans in order to improve trust and enhance human-machine collaboration. However, providing the most appropriate kind of explanations – in terms of length, format, and presentation mode of explanations at the proper time – is critical to enhancing their effectiveness. Explanation entails costs, such as the time it takes to explain and for humans to comprehend and respond. Therefore, the actual improvement in human-system tasks from explanations (if any) is not always obvious, particularly given various forms of uncertainty in knowledge about humans. In this research, we propose an approach to address this issue. The key idea is to provide a structured framework that allows a system to model and reason about human personality traits as critical elements to guide proper explanation in human and system collaboration. In particular, we focus on the two concerns of modality and amount of explanation in order to optimize the explanation experience and improve overall system-human utility. Our models are based on probabilistic modeling and analysis (PRISM-games) to determine at run time what the most effective explanation under uncertainty is. To demonstrate our approach, we introduce a self-adaptative system called Grid – a virtual game – and the Stock Prediction Engine (SPE), which allows an automated system and a human to collaborate on the game and stock investments. Our evaluation of these exemplars, through simulation, demonstrates that a human subject’s performance and overall human-system utility is improved when considering the psychology of human personality traits in providing explanations.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013894
Subject Headings: Human-computer interaction, Probabilistic modelling, Human-machine systems, Affective Computing
Format: Document (PDF)

Title: Context-based Image Concept Detection and Annotation.
Creator: Zolghadr, Esfandiar, Furht, Borko, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: Scene understanding attempts to produce a textual description of visible and latent concepts in an image to describe the real meaning of the scene. Concepts are either objects, events or relations depicted in an image. To recognize concepts, the decision of object detection algorithm must be further enhanced from visual similarity to semantical compatibility. Semantically relevant concepts convey the most consistent meaning of the scene. Object detectors analyze visual properties (e.g., pixel...
Show moreScene understanding attempts to produce a textual description of visible and latent concepts in an image to describe the real meaning of the scene. Concepts are either objects, events or relations depicted in an image. To recognize concepts, the decision of object detection algorithm must be further enhanced from visual similarity to semantical compatibility. Semantically relevant concepts convey the most consistent meaning of the scene. Object detectors analyze visual properties (e.g., pixel intensities, texture, color gradient) of sub-regions of an image to identify objects. The initially assigned objects names must be further examined to ensure they are compatible with each other and the scene. By enforcing inter-object dependencies (e.g., co-occurrence, spatial and semantical priors) and object to scene constraints as background information, a concept classifier predicts the most semantically consistent set of names for discovered objects. The additional background information that describes concepts is called context. In this dissertation, a framework for building context-based concept detection is presented that uses a combination of multiple contextual relationships to refine the result of underlying feature-based object detectors to produce most semantically compatible concepts. In addition to the lack of ability to capture semantical dependencies, object detectors suffer from high dimensionality of feature space that impairs them. Variances in the image (i.e., quality, pose, articulation, illumination, and occlusion) can also result in low-quality visual features that impact the accuracy of detected concepts. The object detectors used to build context-based framework experiments in this study are based on the state-of-the-art generative and discriminative graphical models. The relationships between model variables can be easily described using graphical models and the dependencies and precisely characterized using these representations. The generative context-based implementations are extensions of Latent Dirichlet Allocation, a leading topic modeling approach that is very effective in reduction of the dimensionality of the data. The discriminative contextbased approach extends Conditional Random Fields which allows efficient and precise construction of model by specifying and including only cases that are related and influence it. The dataset used for training and evaluation is MIT SUN397. The result of the experiments shows overall 15% increase in accuracy in annotation and 31% improvement in semantical saliency of the annotated concepts.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004745, http://purl.flvc.org/fau/fd/FA00004745
Subject Headings: Computer vision--Mathematical models., Pattern recognition systems., Information visualization., Natural language processing (Computer science), Multimodal user interfaces (Computer systems), Latent structure analysis., Expert systems (Computer science)
Format: Document (PDF)

Title: Predicting the flow & noise of a rotor in a turbulent boundary layer using an actuator disk – Rans approach.
Creator: Buono, Armand C., Glegg, Stewart A. L., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The numerical method presented in this study attempts to predict the mean, non-uniform flow field upstream of a propeller partially immersed in a thick turbulent boundary layer with an actuator disk using CFD based on RANS in ANSYS FLUENT. Three different configurations, involving an infinitely thin actuator disk in the freestream (Configuration 1), an actuator disk near a wall with a turbulent boundary layer (Configuration 2), and an actuator disk with a hub near a wall with a turbulent...
Show moreThe numerical method presented in this study attempts to predict the mean, non-uniform flow field upstream of a propeller partially immersed in a thick turbulent boundary layer with an actuator disk using CFD based on RANS in ANSYS FLUENT. Three different configurations, involving an infinitely thin actuator disk in the freestream (Configuration 1), an actuator disk near a wall with a turbulent boundary layer (Configuration 2), and an actuator disk with a hub near a wall with a turbulent boundary layer (Configuration 3), were analyzed for a variety of advance ratios ranging from J = 0.48 to J =1.44. CFD results are shown to be in agreement with previous works and validated with experimental data of reverse flow occurring within the boundary layer above the flat plate upstream of a rotor in the Virginia Tech’s Stability Wind Tunnel facility. Results from Configuration 3 will be used in future aero-acoustic computations.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004269, http://purl.flvc.org/fau/fd/FA00004269
Subject Headings: Aeroelasticity, Computational fluid dynamics, Fluid dynamic measurements, Fluid mechanics -- Mathematical models, Turbomachines -- Fluid dynamics, Turbulence -- Mathematical models
Format: Document (PDF)

Title: Kicks and Maps A different Approach to Modeling Biological Systems.
Creator: Ippolito, Stephen Anthony, Naudot, Vincent, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: Modeling a biological systems, is a cyclic process which involves constructing a model from current theory and beliefs and then validating that model against the data. If the data does not match, qualitatively or quantitatively then there may be a problem with either our beliefs or the current theory. At the same time directly finding a model from the existing data would make generalizing results difficult. A considerable difficultly in this process is how to specify the model in the first...
Show moreModeling a biological systems, is a cyclic process which involves constructing a model from current theory and beliefs and then validating that model against the data. If the data does not match, qualitatively or quantitatively then there may be a problem with either our beliefs or the current theory. At the same time directly finding a model from the existing data would make generalizing results difficult. A considerable difficultly in this process is how to specify the model in the first place. There is a need to be practice which accounts for the growing use of mathematical and statistical methods. However, as a systems becomes more complex, standard mathematical approaches may not be sufficient. In the field of ecology, the standard techniques involve discrete maps, and continuous models such as ODE's. The intent of this work is to present the mathematics necessary to study hybrids of these two models, then consider two case studies. In first case we con sider a coral reef with continuous change, except in the presence of hurricanes. The results of the data are compared quantitatively and qualitatively with simulation results. For the second case we consider a model for rabies with a periodic birth pulse. Here the analysis is qualitative as we demonstrate the existence of a strange attractor by looking at the intersections of the stable and unstable manifold for the saddle point generating the attractor. For both cases studies the introduction of a discrete event into a continuous system is done via a Dirac Distribution or Measure.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004508, http://purl.flvc.org/fau/fd/FA00004508
Subject Headings: Artificial intellligence -- Biological applications, Biology -- Mathematical models, Computational intelligence, Differential dynamical systems, Nonliner mechanics -- Mathematical models
Format: Document (PDF)

Title: On Development of Arterial Fundamental Diagrams Based on Surrogate Density Measures from Adaptive Traffic Control Systems Utilizing Stop Line Detection.
Creator: Dakic, Igor, Stevanovic, Aleksandar, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: Macroscopic fundamental diagram is the concept of the highest importance in traffic flow theory used for development of network-wide control strategies. Previous studies showed that so called Arterial Fundamental Diagrams (AFDs) properly depict relationships between major macroscopic traffic variables on urban arterials. Most of these studies used detector’s occupancy as a surrogate measure to represent traffic density. Nevertheless, detector’s occupancy is not very often present in the field...
Show moreMacroscopic fundamental diagram is the concept of the highest importance in traffic flow theory used for development of network-wide control strategies. Previous studies showed that so called Arterial Fundamental Diagrams (AFDs) properly depict relationships between major macroscopic traffic variables on urban arterials. Most of these studies used detector’s occupancy as a surrogate measure to represent traffic density. Nevertheless, detector’s occupancy is not very often present in the field data. More frequently, field data from arterial streets provide performance metrics measured at the stop lines of traffic signals, which represent a hybrid of flow and occupancy. When such performance measures are used in lieu of density, the outcomes of the relationships between macroscopic fundamental variables can be confusing. This study investigates appropriateness of using degree of saturation, as a representative surrogate measure of traffic density, obtained from an adaptive traffic control system that utilizes stop-line detectors, for development of AFDs.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004672, http://purl.flvc.org/fau/fd/FA00004672
Subject Headings: Adaptive control systems, Intelligent transportation systems, Traffic engineering, Traffic estimation -- Computer simulation, Traffic estimation -- Mathematical models, Traffic flow -- Computer simulation, Traffic flow -- Mathematical models
Format: Document (PDF)

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