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Pages
- Title
- Nonlinearity and entrepreneurship.
- Creator
- Pflaum, Blaine., Harriet L. Wilkes Honors College
- Abstract/Description
-
Entrepreneurship occupies a curious place in economic theory. On one hand, the importance of entrepreneurship is widely recognized, particularly as it pertains to economic growth. However, the entrepreneur lacks a broadly accepted economic theory, and suffers from a dearth of literature on the subject. We believe that this is due to economics' heavy reliance on linear mathematical theory. In this thesis, we use nonlinear mathematics to construct a model of the entrepreneur that captures the...
Show moreEntrepreneurship occupies a curious place in economic theory. On one hand, the importance of entrepreneurship is widely recognized, particularly as it pertains to economic growth. However, the entrepreneur lacks a broadly accepted economic theory, and suffers from a dearth of literature on the subject. We believe that this is due to economics' heavy reliance on linear mathematical theory. In this thesis, we use nonlinear mathematics to construct a model of the entrepreneur that captures the sudden destabilization of a steady state, the unpredictability of a creative action, the possibility of entrepreneurial failure, and sensitivity to small changes in environment.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/3335458
- Subject Headings
- Economics, Mathematical, Nonlinear theories, Entrepreneurship, Mathematical models, New business enterprises, Econometric models, Statics and dynamics (Social sciences)
- Format
- Document (PDF)
- Title
- Modeling simple epidemics.
- Creator
- Segovia, Linda., Harriet L. Wilkes Honors College
- Abstract/Description
-
Epidemic models help us predict the outcome of an epidemic. I will discuss and compare two simple epidemic models: a deterministic model implemented by a simple differential equation, and a stochastic model, which is more realistic, but harder to analyze. In both models we assume, for simplicity, that each individual goes through only two stages: healthy (susceptible) and sick (infective). Such models, called SI epidemic models, describe infections with no immunity. We will show that, when...
Show moreEpidemic models help us predict the outcome of an epidemic. I will discuss and compare two simple epidemic models: a deterministic model implemented by a simple differential equation, and a stochastic model, which is more realistic, but harder to analyze. In both models we assume, for simplicity, that each individual goes through only two stages: healthy (susceptible) and sick (infective). Such models, called SI epidemic models, describe infections with no immunity. We will show that, when the population gets large, the more realistic stochastic model approaches the simple deterministic model on the average, which will allow us to see that the deterministic model is used for a good reason.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/FAU/40972
- Subject Headings
- Biomathematics, Medicine, Mathematics, Population biology, Mathematics, Epidemiology, Mathematical models
- Format
- Document (PDF)
- Title
- Mathematical modeling of plankton patchiness.
- Creator
- Ather, Simantha S., Noonburg, Erik G., Graduate College
- Date Issued
- 2011-04-08
- PURL
- http://purl.flvc.org/fcla/dt/3164458
- Subject Headings
- Marine plankton, Marine zooplankton, Mathematical models
- Format
- Document (PDF)
- Title
- Two lessons from fractals and chaos.
- Creator
- Liebovitch, Larry S., Scheurle, Daniela
- Date Issued
- 2000
- PURL
- http://purl.flvc.org/fau/165936
- Subject Headings
- Fractals, Nonlinear systems, Mathematical models, Chaos, Chaotic behavior in systems, Biomathematics
- Format
- Document (PDF)
- Title
- Development of functional relationships between radar and rain gage data using inductive modeling techniques.
- Creator
- Peters, Delroy., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Traditional methods such as distance weighing, correlation and data driven methods have been used in the estimation of missing precipitation data. Also common is the use of radar (NEXRAD) data to provide better spatial distribution of precipitation as well as infilling missing rain gage data. Conventional regression models are often used to capture highly variant nonlinear spatial and temporal relationships between NEXRAD and rain gage data. This study aims to understand and model the...
Show moreTraditional methods such as distance weighing, correlation and data driven methods have been used in the estimation of missing precipitation data. Also common is the use of radar (NEXRAD) data to provide better spatial distribution of precipitation as well as infilling missing rain gage data. Conventional regression models are often used to capture highly variant nonlinear spatial and temporal relationships between NEXRAD and rain gage data. This study aims to understand and model the relationships between radar (NEXRAD) estimated rainfall data and the data measured by conventional rain gages. The study is also an investigation into the use of emerging computational data modeling (inductive) techniques and mathematical programming formulations to develop new optimal functional approximations. Radar based rainfall data and rain gage data are analyzed to understand the spatio-temporal associations, as well as the effect of changes in the length or availability of data on the models. The upper and lower Kissimmee basins of south Florida form the test-bed to evaluate the proposed and developed approaches and also to check the validity and operational applicability of these functional relationships among NEXRAD and rain gage data for infilling of missing data.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/166454
- Subject Headings
- Weather control, Mathematical models, Radar meteorology, Technological innovations, Precipitation (Meteorology), Measurement, Weather forecasting, Technological innovations
- Format
- Document (PDF)
- Title
- Differentiating decomposition rates within the ridge-slough microtopography of the central Florida Everglades.
- Creator
- Van der Heiden, Sheryl R., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The relative rates of detrital decomposition in four vegetation communities within the Everglades' ridge-slough microtopography were evaluated during two trials. Litterbags with community-specific detritus in proportion to each community's composition were put into the four communities; namely, submerged marsh, emergent marsh, short Cladium ridge, and tall Cladium ridge. These litterbags were paired with litterbags containing control leaf litter from Chrysobalanus icaco and Salix caroliniana...
Show moreThe relative rates of detrital decomposition in four vegetation communities within the Everglades' ridge-slough microtopography were evaluated during two trials. Litterbags with community-specific detritus in proportion to each community's composition were put into the four communities; namely, submerged marsh, emergent marsh, short Cladium ridge, and tall Cladium ridge. These litterbags were paired with litterbags containing control leaf litter from Chrysobalanus icaco and Salix caroliniana during the wet and dry season trials, respectively. No regional differences in decomposition were shown, but there were significant differences across communities, attributed to the initial C:N ratio of the detritus, with the fastest decomposition occurring in the deepest submerged marsh followed by emergent marsh, and the shallower ridge communities had equally slower decomposition. Additionally, both controls followed the same pattern. Thus, decomposition contributes to an active self-maintenance mechanism within the vegetation communities which ultimately helps to conserve the ridges and sloughs.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/166456
- Subject Headings
- Biogeochemistry, Surfaces (Technology), Measurement, Vegatation dynamics, Mathematical models, Wetland ecology
- Format
- Document (PDF)
- Title
- Traffic congestion detection using VANET.
- Creator
- Padron, Francisco M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We propose a distributed, collaborative traffic congestion detection and dissemination system using VANET that makes efficient use of the communication channel, maintains location privacy, and provides drivers with real-time information on traffic congestions over long distances. The system uses vehicles themselves, equipped with simple inexpensive devices, as gatherers and distributors of information without the need for costly road infrastructure such as sensors, cameras or external...
Show moreWe propose a distributed, collaborative traffic congestion detection and dissemination system using VANET that makes efficient use of the communication channel, maintains location privacy, and provides drivers with real-time information on traffic congestions over long distances. The system uses vehicles themselves, equipped with simple inexpensive devices, as gatherers and distributors of information without the need for costly road infrastructure such as sensors, cameras or external communication equipment. Additionally, we present a flexible simulation and visualization framework we designed and developed to validate our system by showing its effectiveness in multiple scenarios and to aid in the research and development of this and future VANET applications.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186684
- Subject Headings
- Vehicular ad-hoc networks (Computer networks), Traffic congestion, Mathematical models, Mobile communication systems, Evaluation, Traffic congestion, Prevention
- Format
- Document (PDF)
- Title
- Object detection in low resolution video sequences.
- Creator
- Pava, Diego F., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
With augmenting security concerns and decreasing costs of surveillance and computing equipment, research on automated systems for object detection has been increasing, but the majority of the studies focus their attention on sequences where high resolution objects are present. The main objective of this work is the detection and extraction of information of low resolution objects (e.g. objects that are so far away from the camera that they occupy only tens of pixels) in order to provide a...
Show moreWith augmenting security concerns and decreasing costs of surveillance and computing equipment, research on automated systems for object detection has been increasing, but the majority of the studies focus their attention on sequences where high resolution objects are present. The main objective of this work is the detection and extraction of information of low resolution objects (e.g. objects that are so far away from the camera that they occupy only tens of pixels) in order to provide a base for higher level information operations such as classification and behavioral analysis. The system proposed is composed of four stages (preprocessing, background modeling, information extraction, and post processing) and uses context based region of importance selection, histogram equalization, background subtraction and morphological filtering techniques. The result is a system capable of detecting and tracking low resolution objects in a controlled background scene which can be a base for systems with higher complexity.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186685
- Subject Headings
- Computer systems, Security measures, Remote sensing, Image processing, Digital techniques, Imaging systems, Mathematical models
- Format
- Document (PDF)
- Title
- Structure-function relationships in eukaryotic and prokaryotic family 6 glycosyltransferases.
- Creator
- Tumbale, Percy., Charles E. Schmidt College of Medicine, Department of Biomedical Science
- Abstract/Description
-
Carbohydrate Active Enzyme family 6 (CA6) glycosyltransferases (GTs) are type II transmembrane proteins localized in the Golgi apparatus. CA6 GTs have a GT-A fold, a type of structure that resembles the Rossman fold and catalyze the transfer either galactose (Gal) or N-acetylgalactosamine (GalNAc) from the UDP nucleotide sugar to an non-reducing terminal Gal or GalNAc on an acceptor via an a-1,3 linkage. In this reaction, the anomeric configuration of the sugar moiety of the donor is retained...
Show moreCarbohydrate Active Enzyme family 6 (CA6) glycosyltransferases (GTs) are type II transmembrane proteins localized in the Golgi apparatus. CA6 GTs have a GT-A fold, a type of structure that resembles the Rossman fold and catalyze the transfer either galactose (Gal) or N-acetylgalactosamine (GalNAc) from the UDP nucleotide sugar to an non-reducing terminal Gal or GalNAc on an acceptor via an a-1,3 linkage. In this reaction, the anomeric configuration of the sugar moiety of the donor is retained in the product. CA6 GTs includes the histo-blood group A and B GTs, a-galactosyltransferase (a3GT), Forssman glycolipid synthase (FS), isogloboside 3 synthase (iGb3) in mammals. a3GT and its products (a-Gal epitode) are present in most mammals but are absent in humans and old world primates because of inactivating mutations. The absence of a3GT and its products results in the production of anti-a-Gal epitope natural antibodies in these species., Up to date, the catalytic mechanisms of the CA6 GTs are not well understood. Based on previous structural and mutagenesis studies of bovine aB3GT, we investigated active site residues (His315, Asp316, Ser318, His319, and Lys359) that are highly conserved among CA6 GTs. We have also investigated the role of the C-terminal region by progressive C-terminal truncations. Findings from these studies clarify the functional roles of these residues in structure, catalysis, and specificity in these enzymes and have implications for their catalytic mechanisms. GTs are useful tools in synthesis of glycans for various applications in science and medicine. Methods for the large scale production of pure glycans are continuously being developed. We created a limited randomized combinatorial library based on knowledge of structural information and sequence analysis of the enzyme and its mammalian homologues., Two GalNAc-specific variants were identified from the library and one Glc-specific variant was identified by site-direct mutagenesis. The glycosyltransferase activities of these variants are expected to be improved by further screens of libraries which are designed using the variants as templates. The mammalian CA6 GTs that have been characterized to date are metal-independent and require the divalent cation, Mn2+ for activity. In some recently-discovered bacterial CA6 GTs, the DXD sequence that is present in eukaryotic GTs is replaced by NXN. We cloned and expressed one of these proteins from Bacteroides ovatus, a bacterium that has been linked with inflammatory bowel disease. Functional characterization shows it is a metal-independent monomeric GT that efficiently catalyzes the synthesis of oligosaccharides similar to human blood group A glycan., Mutational studies indicated that despite the lack of a metal cofactor there are similarities in structure-function relationships between the bacterial and vertebrate family 6 GTs.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186686
- Subject Headings
- Molecular biology, Mathematical models, Glycotransferase genes, Biological transport, Proteins, Synthesis, Evolutionary genetics
- Format
- Document (PDF)
- Title
- Transport and dispersion of fire extinguishing agents downstream from clutter elements of aircraft engine nacelles.
- Creator
- Zbeeb, Khaled., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The combination of highly turbulent airflow, flammable fluids, and numerous ignition sources makes aircraft engine nacelles a difficult fire zone to protect. Better understanding of nacelle air flow and how it influences the spread of fires and fire extinguishing agents is needed to improve the efficiency of fire suppression. The first objective was to establish a CFD model for a flow field test section to analyze the transport and dispersion of fire extinguishing agents in the presence of...
Show moreThe combination of highly turbulent airflow, flammable fluids, and numerous ignition sources makes aircraft engine nacelles a difficult fire zone to protect. Better understanding of nacelle air flow and how it influences the spread of fires and fire extinguishing agents is needed to improve the efficiency of fire suppression. The first objective was to establish a CFD model for a flow field test section to analyze the transport and dispersion of fire extinguishing agents in the presence of various clutter elements. To validate the use of the CFD model, the simulation results of the CFD model were compared to the experimental data and they show an agreement with the experimental data. The second objective was to present parametric studies to show the effects of the coflow speed, turbulence intensity and agent droplet size on the transport and dispersion of the agent particles downstream from the clutter elements.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186687
- Subject Headings
- Airplanes, Nacelles, Safety measures, Airplanes, Fires and fire prevention, Fire extinguishing agents, Testing, Airplanes, Fluid dynamics, Mathematical models
- Format
- Document (PDF)
- Title
- Vibration, buckling and impact of carbon nanotubes.
- Creator
- Pentaras, Demetris., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Natural frequencies of the double and triple-walled carbon nanotubes are determined exactly and approximately for both types. Approximate solutions are found by using Bubnov-Galerkin and Petrov-Galerkin methods. For the first time explicit expressions are obtained for the natural frequencies of double and triple-walled carbon nanotubes for different combinations of boundary conditions. Comparison of the results with recent studies shows that the above methods constitute quick and effective...
Show moreNatural frequencies of the double and triple-walled carbon nanotubes are determined exactly and approximately for both types. Approximate solutions are found by using Bubnov-Galerkin and Petrov-Galerkin methods. For the first time explicit expressions are obtained for the natural frequencies of double and triple-walled carbon nanotubes for different combinations of boundary conditions. Comparison of the results with recent studies shows that the above methods constitute quick and effective alternative techniques to exact solution for studying the vibration properties of carbon nanotubes. The natural frequencies of the clamped-clamped double-walled carbon nanotubes are obtained; exact solution is provided and compared with the solution reported in the literature. In contrast to earlier investigation, an analytical criterion is derived to establish the behavior of the roots of the characteristic equation. Approximate Bubnov-Galerkin solution is also obtained to compare natural frequencies at the lower end of the spectrum. Simplified version of the Bresse-Timoshenko theory that incorporates the shear deformation and the rotary inertia is proposed for free vibration study of double-walled carbon nanotubes. It is demonstrated that the suggested set yields extremely accurate results for the lower spectrum of double-walled carbon nanotube. The natural frequencies of double-walled carbon nanotubes based on simplified versions of Donnell shell theory are also obtained. The buckling behavior of the double-walled carbon nanotubes under various boundary conditions is studied. First, the case of the simply supported double-walled carbon nanotubes at both ends is considered which is amenable to exact solution., Then, approximate methods of Bubnov-Galerkin and Petrov-Galerkin are utilized to check the efficacy of these approximations for the simply supported double-walled carbon nanotubes. Once the extreme accuracy is demonstrated for simply supported conditions, the approximate techniques are applied to two other cases of the boundary conditions, namely to clamped-clamped and simply supported-clamped double-walled carbon nanotubes. For the first time in the literature approximate expression for the buckling loads are reported for these boundary conditions. The dynamic deflection of a single-walled carbon nanotube under impact loading is analyzed by following a recently study reported on the energy absorption capacity of carbon nanotubes under ballistic impact.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186764
- Subject Headings
- Nanostructured materials, Buckling (Mechanics), Plates (Engineering), Vibration, Mathematical models, Structural analysis
- Format
- Document (PDF)
- Title
- Farfield modeling of the Boynton Inlet plume using sulfur hexafluoride as tracer.
- Creator
- Pire-Schmidt, Joaquin., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The analysis and modeling of the coastal farfield behavior of inlet discharge plumes is the key to understanding the fate of pollutants discharged into the ocean. These plumes disperse in chaotic and unpredictable patterns. Theoretical models are based on the average conditions and calibrated to the results of tracer studies. Data and models for freshwater discharges in coastal ocean systems are limited because of the lack of adequate tracers. On February, 2007, a tracer study was conducted...
Show moreThe analysis and modeling of the coastal farfield behavior of inlet discharge plumes is the key to understanding the fate of pollutants discharged into the ocean. These plumes disperse in chaotic and unpredictable patterns. Theoretical models are based on the average conditions and calibrated to the results of tracer studies. Data and models for freshwater discharges in coastal ocean systems are limited because of the lack of adequate tracers. On February, 2007, a tracer study was conducted on the Boynton Inlet, Florida, using sulfur hexafluoride (SF6) tracer. The objective of this study is to provide methods of analysis for the sample data collected during the experiment. The detected tracer concentrated in a bolus that migrated north of the inlet at velocities lower than predicted by the current data. The plume was successfully modeled with a Gaussian plume model, with 90% of the SF6 predictions having less than 4.6 pptr error.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186771
- Subject Headings
- Plumes (Fluid dynamics), Water, Pollution, Sedimentation and deposition, Environmental aspects, Pollution, Mathematical models
- Format
- Document (PDF)
- Title
- The impact of IT security psychological climate on salient user beliefs toward IT security: an empirical study.
- Creator
- Warner, Janis A., College of Business, Information Technology and Operations Management
- Abstract/Description
-
There is a growing need to better understand what influences user behavior for developing comprehensive IT security systems. This study integrates two prominent bodies of research, the theory of planned behavior used to frame the factors influencing user behavior and individual level climate perceptions used to frame organizational environment influences, to develop a multidimensional IT security user behavior model. The model is then used as the basis for a survey based research to...
Show moreThere is a growing need to better understand what influences user behavior for developing comprehensive IT security systems. This study integrates two prominent bodies of research, the theory of planned behavior used to frame the factors influencing user behavior and individual level climate perceptions used to frame organizational environment influences, to develop a multidimensional IT security user behavior model. The model is then used as the basis for a survey based research to empirically test the hypotheses whether the perceived IT security climate of an organization significantly influences the users beliefs regarding the use of IT security. The intent of the study is to extend the theory of planned behavior and IT security literature by investigating salient IT security beliefs and environmental influences on those beliefs. First, anti-spyware was identified as an appropriate target IT security artifact, and then incorporated into a multi-phased research approach. Second, a semi-structured interview process was used to elicit salient beliefs regarding use of the IT security artifact. Third, IT security psychological climate was conceptualized based on the extant literature on organizational climate, safety climate and IT security in order to examine the organizational environment influences on these beliefs. Finally, a survey was used to collect data to validate the constructs and test the hypothesized relationships., The study found that there was a significant positive relationship between IT security psychological climate and 1) the belief that anti-spyware will protect organizational interests such as privacy and data, 2) the belief that anti-spyware will prevent disruptions to work, 3) the belief that the approval of anti-spyware use by the technical support group is important, 4) the belief that monetary resources are needed to enable the use of anti-spyware, and 5) the belief that time is a facilitating condition for the use of anti-spyware. A discussion of the findings and their implications for theory and practice is provided.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186772
- Subject Headings
- Security (Psychology), Electronic commerce, Security measures, Web sites, Design, Consumer behavior, Mathematical models, Organizational effectiveness
- Format
- Document (PDF)
- Title
- Event detection in surveillance video.
- Creator
- Castellanos Jimenez, Ricardo Augusto., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Digital video is being used widely in a variety of applications such as entertainment, surveillance and security. Large amount of video in surveillance and security requires systems capable to processing video to automatically detect and recognize events to alleviate the load on humans and enable preventive actions when events are detected. The main objective of this work is the analysis of computer vision techniques and algorithms used to perform automatic detection of events in video...
Show moreDigital video is being used widely in a variety of applications such as entertainment, surveillance and security. Large amount of video in surveillance and security requires systems capable to processing video to automatically detect and recognize events to alleviate the load on humans and enable preventive actions when events are detected. The main objective of this work is the analysis of computer vision techniques and algorithms used to perform automatic detection of events in video sequences. This thesis presents a surveillance system based on optical flow and background subtraction concepts to detect events based on a motion analysis, using an event probability zone definition. Advantages, limitations, capabilities and possible solution alternatives are also discussed. The result is a system capable of detecting events of objects moving in opposing direction to a predefined condition or running in the scene, with precision greater than 50% and recall greater than 80%.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1870694
- Subject Headings
- Computer systems, Security measures, Image processing, Digital techniques, Imaging systems, Mathematical models, Pattern recognition systems, Computer vision, Digital video
- 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.
Show less - 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
- Sparse Modeling Applied to Patient Identification for Safety in Medical Physics Applications.
- Creator
- Lewkowitz, Stephanie, Kalantzis, Georgios, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Every scheduled treatment at a radiation therapy clinic involves a series of safety protocol to ensure the utmost patient care. Despite safety protocol, on a rare occasion an entirely preventable medical event, an accident, may occur. Delivering a treatment plan to the wrong patient is preventable, yet still is a clinically documented error. This research describes a computational method to identify patients with a novel machine learning technique to combat misadministration.The patient...
Show moreEvery scheduled treatment at a radiation therapy clinic involves a series of safety protocol to ensure the utmost patient care. Despite safety protocol, on a rare occasion an entirely preventable medical event, an accident, may occur. Delivering a treatment plan to the wrong patient is preventable, yet still is a clinically documented error. This research describes a computational method to identify patients with a novel machine learning technique to combat misadministration.The patient identification program stores face and fingerprint data for each patient. New, unlabeled data from those patients are categorized according to the library. The categorization of data by this face-fingerprint detector is accomplished with new machine learning algorithms based on Sparse Modeling that have already begun transforming the foundation of Computer Vision. Previous patient recognition software required special subroutines for faces and di↵erent tailored subroutines for fingerprints. In this research, the same exact model is used for both fingerprints and faces, without any additional subroutines and even without adjusting the two hyperparameters. Sparse modeling is a powerful tool, already shown utility in the areas of super-resolution, denoising, inpainting, demosaicing, and sub-nyquist sampling, i.e. compressed sensing. Sparse Modeling is possible because natural images are inherrently sparse in some bases, due to their inherrant structure. This research chooses datasets of face and fingerprint images to test the patient identification model. The model stores the images of each dataset as a basis (library). One image at a time is removed from the library, and is classified by a sparse code in terms of the remaining library. The Locally Competetive Algorithm, a truly neural inspired Artificial Neural Network, solves the computationally difficult task of finding the sparse code for the test image. The components of the sparse representation vector are summed by `1 pooling, and correct patient identification is consistently achieved 100% over 1000 trials, when either the face data or fingerprint data are implemented as a classification basis. The algorithm gets 100% classification when faces and fingerprints are concatenated into multimodal datasets. This suggests that 100% patient identification will be achievable in the clinal setting.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004721, http://purl.flvc.org/fau/fd/FA00004721
- Subject Headings
- Computer vision in medicine, Diagnostic imaging -- Data processing, Mathematical models, Medical errors -- Prevention, Medical physics, Sampling (Statistics)
- Format
- Document (PDF)
- Title
- Numerical performance prediction for FAU's first generation ocean current turbine.
- Creator
- Vanrietvelde, Nicolas., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis presents the analytically predicted position, motion, attitude, power output and forces on Florida Atlantic University's (FAU) first generation ocean current turbine for a wide range of operating conditions. These values are calculated using a 7- DOF dynamics simulation of the turbine and the cable that attaches it to the mooring system. The numerical simulation modifications and upgrades completed in this work include developing a wave model including the effects of waves into...
Show moreThis thesis presents the analytically predicted position, motion, attitude, power output and forces on Florida Atlantic University's (FAU) first generation ocean current turbine for a wide range of operating conditions. These values are calculated using a 7- DOF dynamics simulation of the turbine and the cable that attaches it to the mooring system. The numerical simulation modifications and upgrades completed in this work include developing a wave model including the effects of waves into the simulation, upgrading the rotor model to specify the number of blades and upgrading the cable model to specify the number of cable elements. This enhanced simulation is used to quantify the turbine's performance in a wide range of currents, wave fields and when stopping and starting the rotor. For a uniform steady current this simulation predicts that when the rotor is fixed in 1.5 m/s current the drag on the turbine is 3.0 kN, the torque on the rotor is 384 N-m, the turbine roll and pitch are 2.4º and -1.2º . When the rotor is allowed to spin up to the rotational velocity where the turbine produces maximum power, the turbine drag increases to 7.3 kN, the torque increases to 1482 N-m, the shaft power is 5.8 kW, the turbine roll increases to 9º and the turbine pitch stays constant. Subsequently, a sensitivity analysis is done to evaluate changes in turbine performance caused by changes in turbine design and operation. This analysis show, among other things, that a non-axial flow on the turbine of up to 10º has a minimal effect on net power output and that the vertical stable position of the turbine varies linearly with the weight/buoyancy of the turbine with a maximum variation of 1.77 m for each increase or decrease of 1 kg at a current speed of 0.5 m/s.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/2182033
- Subject Headings
- Marine turbines, Mathematical models, Structural dynamics, Rotors, Design and construction, Testing, Fluid dynamics
- Format
- Document (PDF)
- Title
- Design and finite element analysis of an ocean current turbine blade.
- Creator
- Asseff, Nicholas S., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A composite 3 meter ocean current turbine blade has been designed and analyzed using Blade Element Theory (BET) and commercial Finite Element Modeling (FEM) code, ANSYS. It has been observed that using the numerical BET tool created, power production up to 141 kW is possible from a 3 bladed rotor in an ocean current of 2.5 m/s with the proposed blade design. The blade is of sandwich construction with carbon fiber skin and high density foam core. It also contains two webs made of S2-glass for...
Show moreA composite 3 meter ocean current turbine blade has been designed and analyzed using Blade Element Theory (BET) and commercial Finite Element Modeling (FEM) code, ANSYS. It has been observed that using the numerical BET tool created, power production up to 141 kW is possible from a 3 bladed rotor in an ocean current of 2.5 m/s with the proposed blade design. The blade is of sandwich construction with carbon fiber skin and high density foam core. It also contains two webs made of S2-glass for added shear rigidity. Four design cases were analyzed, involving differences in hydrodynamic shape, material properties, and internal structure. Results from the linear static structural analysis revealed that the best design provides adequate stiffness and strength to produce the proposed power without any structural failure. An Eigenvalue Buckling analysis confirmed that the blade would not fail from buckling prior to overstressed laminate failure if the loading was to exceed the Safety Factor.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/221944
- Subject Headings
- Marine turbines, Mathematical models, Fluid dynamics, Structural dynamics, Composite materials, Mathematical models
- Format
- Document (PDF)
- Title
- Hydrodynamic analysis of ocean current turbines using vortex lattice method.
- Creator
- Goly, Aneesh, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The main objective of the thesis is to carry out a rigorous hydrodynamic analysis of ocean current turbines and determine power for a range of flow and geometric parameters. For the purpose, a computational tool based on the vortex lattice method (VLM) is developed. Velocity of the flow on the turbine blades, in relation to the freestream velocity, is determined through induction factors. The geometry of trailing vortices is taken to be helicoidal. The VLM code is validated by comparing its...
Show moreThe main objective of the thesis is to carry out a rigorous hydrodynamic analysis of ocean current turbines and determine power for a range of flow and geometric parameters. For the purpose, a computational tool based on the vortex lattice method (VLM) is developed. Velocity of the flow on the turbine blades, in relation to the freestream velocity, is determined through induction factors. The geometry of trailing vortices is taken to be helicoidal. The VLM code is validated by comparing its results with other theoretical and experimental data corresponding to flows about finite-aspect ratio foils, swept wings and a marine current turbine. The validated code is then used to study the performance of the prototype gulfstream turbine for a range of parameters. Power and thrust coefficients are calculated for a range of tip speed ratios and pitch angles. Of all the cases studied, the one corresponding to tip speed ratio of 8 and uniform pitch angle 20 produced the maximum power of 41.3 [kW] in a current of 1.73 [m/s]. The corresponding power coefficient is 0.45 which is slightly less than the Betz limit power coefficient of 0.5926. The VLM computational tool developed for the research is found to be quite efficient in that it takes only a fraction of a minute on a regular laptop PC to complete a run. The tool can therefore be efficiently used or integrated into software for design optimization.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2683131
- Subject Headings
- Marine turbines, Mathematical models, Water currents, Forecasting, Mathematical models, Aerodynamics, Mathematics, Finite element method
- Format
- Document (PDF)
- Title
- A robust AUV docking guidance and navigation approach to handling unknown current disturbances.
- Creator
- Teo, Hoe Eng., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The main contribution in this thesis is the design of a robust AUV docking guidance and navigation approach that can guide and home an AUV towards an acoustic source located on an oriented bottom-mounted underwater docking station, under presence of unknown current disturbances and in the absence of any form of onboard velocity sensor. A Complementary Filter and various forms of Kalman Filters were separately formulated to estimate the current and vehicle positions with strategic vehicle...
Show moreThe main contribution in this thesis is the design of a robust AUV docking guidance and navigation approach that can guide and home an AUV towards an acoustic source located on an oriented bottom-mounted underwater docking station, under presence of unknown current disturbances and in the absence of any form of onboard velocity sensor. A Complementary Filter and various forms of Kalman Filters were separately formulated to estimate the current and vehicle positions with strategic vehicle manoeuvres. A current compensator uses the estimated current to maintain the desired vehicle course while under current disturbance. Tagaki-Sugeno-Kang Fuzzy Inference System was designed to realize fuzzy docking guidance manoeuvres. Finally, Monte Carlo runs were performed on a designed AUV docking simulator to evaluate the docking robustness against various docking conditions. Simulation results demonstrated robustness in the designed docking guidance and navigation approach.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2683137
- Subject Headings
- Oceanographic submersibles, Computer simulation, Underwater navigation, Fuzzy systems, Automatic control, Mathematical models
- Format
- Document (PDF)