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Title: HELIUM SPEECH PROCESSING BY LINEAR PREDICTION METHOD.
Creator: LEE, HYUN JICK., Florida Atlantic University, Erdol, Nurgun, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: The human speech production system is reviewed through general acoustic theory. Based upon that, the characteristics of helium speech is compared to normal speech. The Linear Prediction algorithm is derived for computer implementation by recursive formulas. The correction factors for the vocal tract area functions are found from simulated helium speech and normal speech data for four vowels. By the correction factors, new corrected area functions are applied to the Linear Prediction algorithm...
Show moreThe human speech production system is reviewed through general acoustic theory. Based upon that, the characteristics of helium speech is compared to normal speech. The Linear Prediction algorithm is derived for computer implementation by recursive formulas. The correction factors for the vocal tract area functions are found from simulated helium speech and normal speech data for four vowels. By the correction factors, new corrected area functions are applied to the Linear Prediction algorithm so that new synthesis filters can be built. The output of the algorithm is enhanced helium speech.
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Date Issued: 1985
PURL: http://purl.flvc.org/fcla/dt/14244
Subject Headings: Acoustical engineering, Underwater acoustics
Format: Document (PDF)

Title: Validation of numerical modelling for long range acoustic propagation.
Creator: Riley, Joseph M., Florida Atlantic University, Glegg, Stewart A. L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Laboratory scale measurements were conducted to validate numerical prediction models used to predict the acoustic field in a shallow water ocean environment. Experimental measurements were conducted in a range independent environment which included the effects of shear in marine sediments and in a depth varying range dependent environment. Good agreement between the experimental measurements and the numerical prediction codes were obtained using optimized values for the input parameters of...
Show moreLaboratory scale measurements were conducted to validate numerical prediction models used to predict the acoustic field in a shallow water ocean environment. Experimental measurements were conducted in a range independent environment which included the effects of shear in marine sediments and in a depth varying range dependent environment. Good agreement between the experimental measurements and the numerical prediction codes were obtained using optimized values for the input parameters of the environmental model. In comparing experimental measurements to the numerical prediction codes it became apparent that the codes were very sensitive to the input parameters describing the bottom boundary of the ocean waveguide.
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Date Issued: 1992
PURL: http://purl.flvc.org/fcla/dt/14819
Subject Headings: Acoustical engineering, Underwater acoustics, Marine sediments
Format: Document (PDF)

Title: An experimental study of the response of circular plates subjected to fluid loading.
Creator: Coulson, Robert Kenneth., Florida Atlantic University, Glegg, Stewart A. L.
Abstract/Description: The interaction between vibrating structures and fluids can have a profound influence upon the natural frequencies of the structure's vibration. This study examines one specific structure; a thin circular plate with the rarely studied free edge condition. It starts by considering a completely free plate in a vacuum and then, using receptance matching, utilises this result to determine the effects, on the natural frequencies, of a centrally located driving rod. Then, using the same technique,...
Show moreThe interaction between vibrating structures and fluids can have a profound influence upon the natural frequencies of the structure's vibration. This study examines one specific structure; a thin circular plate with the rarely studied free edge condition. It starts by considering a completely free plate in a vacuum and then, using receptance matching, utilises this result to determine the effects, on the natural frequencies, of a centrally located driving rod. Then, using the same technique, a result for the drive admittance of the fluid loaded plate is adapted to predict the natural frequencies of the same structure when subjected to significant fluid loading. All these results are then compared to those obtained from experiments.
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Date Issued: 1990
PURL: http://purl.flvc.org/fcla/dt/14605
Subject Headings: Plates (Engineering)--Vibration, Acoustical engineering
Format: Document (PDF)

Title: Docking the Ocean Explorer Autonomous Underwater Vehicle using a low-cost acoustic positioning system and a fuzzy logic guidance algorithm.
Creator: Kronen, David Mitchell., Florida Atlantic University, Smith, Samuel M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Having the ability to dock an Autonomous Underwater Vehicle (AUV) can significantly enhance the operation of such vehicles. In order to dock an AUV, the vehicle's position must be known precisely and a guidance algorithm must be used to drive the AUV to its dock. This thesis will examine and implement a low cost acoustic positioning system to meet the positioning requirements. At-sea tests will be used as a method of verifying the systems specifications and proper incorporation into the AUV....
Show moreHaving the ability to dock an Autonomous Underwater Vehicle (AUV) can significantly enhance the operation of such vehicles. In order to dock an AUV, the vehicle's position must be known precisely and a guidance algorithm must be used to drive the AUV to its dock. This thesis will examine and implement a low cost acoustic positioning system to meet the positioning requirements. At-sea tests will be used as a method of verifying the systems specifications and proper incorporation into the AUV. Analyses will be run on the results using several methods of interpreting the data. The second portion of this thesis will develop and test a fuzzy logic docking algorithm which will guide the AUV from a location within the range of the sonar system to the docking station. A six degree of freedom simulation incorporating the Ocean Explorer's hydrodynamic coefficients will be used for the simulation.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15502
Subject Headings: Oceanographic submersibles, Acoustical engineering, Underwater acoustics, Fuzzy algorithms
Format: Document (PDF)

Title: Motion Compensation of an Ultra Short Baseline Array for the Acoustic Positioning of an Underwater Vehicle for Port Operations.
Creator: Bon, Antoine, Beaujean, Pierre-Philippe, Florida Atlantic University
Abstract/Description: A Motion Compensated (MC) Ultra Short Baseline (USBL) Acoustic Positioning System (APS) operable in shallow water and port environment has been implemented at Florida Atlantic University. Multi-tones signal modulation and log-likelihood maximization enable this APS to operate in volumes of water of less than 10 cubic meters. Standard deviations of the acoustic source elevation and azimuth estimates were computed to be 3 degrees in an 8 cubic meters test tank, and reduce to 0.9 degree in a 2...
Show moreA Motion Compensated (MC) Ultra Short Baseline (USBL) Acoustic Positioning System (APS) operable in shallow water and port environment has been implemented at Florida Atlantic University. Multi-tones signal modulation and log-likelihood maximization enable this APS to operate in volumes of water of less than 10 cubic meters. Standard deviations of the acoustic source elevation and azimuth estimates were computed to be 3 degrees in an 8 cubic meters test tank, and reduce to 0.9 degree in a 2 meters deep marina. The motion compensating system estimates the array position and orientation while merging noisy measurements from a Magnetic, Angular Rate, and Gravity (MARG) sensor and a Differential Global Positioning System (DGPS) using Kalman filters. Experiments show 0.67 and 2.67 degrees of error for the array tilt and heading estimates, and 0.74 meter for the array position estimate.
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Date Issued: 2007
PURL: http://purl.flvc.org/fau/fd/FA00012507
Subject Headings: Underwater navigation, Acoustical engineering, Adaptive signal processing, Underwater acoustic telemetry
Format: Document (PDF)

Title: A passive platform for tracking underwater vehicles.
Creator: Dufour, Emmanuel R., Florida Atlantic University, Glegg, Stewart A. L.
Abstract/Description: Over recent years, the trend in Autonomous Underwater Vehicle (AUV) design has been to reduce vehicle size and cost. On board navigation systems are both large and expensive so alternate solutions for vehicle positioning are required. The thesis explores the performance of a passive platform, the Ambient Noise Sonar (ANS), in remotely detecting, localizing and tracking submersible vessels. This task is achieved by exploiting communication signatures emitted by the moving submersible. The...
Show moreOver recent years, the trend in Autonomous Underwater Vehicle (AUV) design has been to reduce vehicle size and cost. On board navigation systems are both large and expensive so alternate solutions for vehicle positioning are required. The thesis explores the performance of a passive platform, the Ambient Noise Sonar (ANS), in remotely detecting, localizing and tracking submersible vessels. This task is achieved by exploiting communication signatures emitted by the moving submersible. The utility modem integrated on the AUV can be operated in a PSK and a MFSK mode. It was demonstrated that the ANS successfully tracks AUVs in both cases. First, the thesis presents the sonar beamformer and shows its potential for tracking by using the AUV communication signals. It describes a scheme developed to enhance the processor performance in a multi-target configuration and clutter. Then, it discusses promising tracking results from experiments conducted in summer and fall 1998, off the coast of South Florida.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15671
Subject Headings: Oceanographic submersibles--Automatic control, Underwater acoustics, Acoustical engineering
Format: Document (PDF)

Title: BACKGROUND STRUCTURE FUNCTIONS, A BASIS TO REDUCE ACOUSTIC POWER REQUIREMENTS AND IMPROVE IMAGES.
Creator: Kobold, Michael C., Beaujean, Pierre-Philippe J., Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Background Structure Functions (BSFs) are wavefront distortion metrics, functions of Sound Speed Profiles (SSPs) that are functions of depth. Use of these BSFs is a synthesis form of Matched Field Processing (MFP) that detects signals that are otherwise lost to receivers. Underwater Acoustics (UWA) can use these models to forecast communication and imaging performance and to reduce power radiated into the sea. This reduction of Transmission Loss (TL) occurs because the commercial wavefront...
Show moreBackground Structure Functions (BSFs) are wavefront distortion metrics, functions of Sound Speed Profiles (SSPs) that are functions of depth. Use of these BSFs is a synthesis form of Matched Field Processing (MFP) that detects signals that are otherwise lost to receivers. Underwater Acoustics (UWA) can use these models to forecast communication and imaging performance and to reduce power radiated into the sea. This reduction of Transmission Loss (TL) occurs because the commercial wavefront control has an input format that accepts BSFs. The BSF plots represent the purely statistical distortion for communications and remote sensing. Another source of TL reduction comes from the enclosed BSF-based phase and phase variance forecasting that protects equalizers from losing phase-lock. Protecting the equalizers protects the Signal To Noise (SNR) ratios. This dissertation derives the UWA version of these metrics and applies them to the following locations of our SSPs: The BSFs use measured, corrected, and verified SSP groups for 132 different locations in the Atlantic Ocean and the Gulf of Mexico from a Navy Ocean Atlas, as well as 64 SSPs in two areas in the littorals, Port Everglades, and Saint Andrew Bay, plus tidal variations. Since BSFs digitize the propagation into one or more segments, our purely statistical phase screen model uses only 3 or 4 degrees of freedom (DOFs) per segment compared to many dozen DOFs for conventional structure functions. The BSFs forecast communications and imaging performance, including range, in locations where acoustic measurements are not available, but SSPs are. A separate algorithm forecasts Gouy phase anomalies from background SSPs, which otherwise requires a priori knowledge of anomaly location and use of Catastrophe theory due to ray theory failure at focuses. Avoiding these anomalies and loss of Phase-Locked Loops (PLLs) also helps maintain SNR and lowers transmission power requirements. Combining with phase parameters and performance forecasts improves UWA propagation efficiency using the background (SSPs). In a spatial version of delay equalization, BSF analysis also produces the enclosed Shear Distortion Ratios (SDRs) for the same locations mentioned above, to allow optimum selection of image enhancement algorithms that mitigate image shear distortion.
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Date Issued: 2024
PURL: http://purl.flvc.org/fau/fd/FA00014395
Subject Headings: Underwater acoustics, Sound--Speed, Ocean engineering
Format: Document (PDF)

Title: Acoustic tracking of an unmanned underwater vehicle using a passive ultrashort baseline array and a single long baseline beacon.
Creator: Seaton, Kyle L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis discusses a new approach to tracking the REMUS 100 AUV using a modified version of the Florida Atlantic University (FAU) ultrashort baseline (USBL) acoustic positioning system (APS). The REMUS 100 is designed to utilize a long baseline (LBL) acoustic positioning system to obtain positioning data in mid-mission. If the placement of one of the transponders of the LBL field is known, then tracking the position of the REMUS 100 AUV using a passive USBL array is possible. As part of...
Show moreThis thesis discusses a new approach to tracking the REMUS 100 AUV using a modified version of the Florida Atlantic University (FAU) ultrashort baseline (USBL) acoustic positioning system (APS). The REMUS 100 is designed to utilize a long baseline (LBL) acoustic positioning system to obtain positioning data in mid-mission. If the placement of one of the transponders of the LBL field is known, then tracking the position of the REMUS 100 AUV using a passive USBL array is possible. As part of the research for this thesis, the FAU USBL system was used to find a relative range between the REMUS 100 ranger and a LBL transponder. This relative range was then combined with direction of arrival information and LBL field component position information to determine an absolute position of the REMUS 100 ranger. The outcome was the demonstration of a passive USBL based tracking system.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3361057
Subject Headings: Underwater acoustic telemetry, Acoustic velocity meters, Array processors, Acoustical engineering, Adaptive signal processing
Format: Document (PDF)

Title: Acoustic impulse response mapping for acoustic communications in shallow water.
Creator: Caimi, F. M., Tongta, R., Harbor Branch Oceanographic Institute
Date Issued: 1998
PURL: http://purl.flvc.org/FCLA/DT/3183706
Subject Headings: Electro-acoustics, Sound --Measurement, Acoustical engineering, Digital communications, Signal processing, Signals and signaling, Underwater acoustics, Signal processing --Digital techniques
Format: Document (PDF)

Title: Performance and limitations of acoustic positioning using a tetrahedral ultra-short baseline array and an acoustic modem source transmitting frequency-hopped sequences.
Creator: Mohamed, Asif I., Florida Atlantic University, Beaujean, Pierre-Philippe, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The operation of unmanned underwater vehicles requires communications with other nearby vehicles as well as accurate positioning to prevent duplication of work, collisions and other mishaps. This thesis details the integration of an ultra-short baseline positioning system with four transducers arranged as a tetrahedron for use with the FAU Dual Purpose Acoustic Modem. The source position is estimated by processing coherently a series of frequency-hopped pulses to obtain a set of bearings,...
Show moreThe operation of unmanned underwater vehicles requires communications with other nearby vehicles as well as accurate positioning to prevent duplication of work, collisions and other mishaps. This thesis details the integration of an ultra-short baseline positioning system with four transducers arranged as a tetrahedron for use with the FAU Dual Purpose Acoustic Modem. The source position is estimated by processing coherently a series of frequency-hopped pulses to obtain a set of bearings, optimally combined through maximum likelihood estimation of the azimuth and elevation. A simulation has been implemented and experiments have been performed in a calibration tank. Model and experiments confirm that the accuracy of this system improves with the number of pulses and the signal-to-noise ratio. A mean positional error of 5.51% can be obtained with an SNR of 20 dB and a single processed pulse, the error decreases to 2.84% using six processed pulses.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13412
Subject Headings: Underwater navigation, Remote submersibles, Computer integrated manufacturing systems, Acoustical engineering, Underwater acoustics--Instruments
Format: Document (PDF)

Title: Interaction of acoustic waves generated by coupled finite fluid-loaded plates.
Creator: Kaina, Rachid., Florida Atlantic University, Cuschieri, Joseph M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The response of fluid-loaded plates has been extensively studied in the past. However, most of the work deals with either infinite plates or finite plates with particular boundary conditions and the results are generally presented only in the limit of small wavelengths compared with the dimensions of the plates. Furthermore, the problem of coupled finite plates where both the acoustic interaction and structural interaction are included in the solution has not been considered. In this...
Show moreThe response of fluid-loaded plates has been extensively studied in the past. However, most of the work deals with either infinite plates or finite plates with particular boundary conditions and the results are generally presented only in the limit of small wavelengths compared with the dimensions of the plates. Furthermore, the problem of coupled finite plates where both the acoustic interaction and structural interaction are included in the solution has not been considered. In this dissertation the response of two coupled finite plates set in two alternative configurations is considered. The plates are simply supported on two edges, with arbitrary boundary conditions on the remaining two edges. The solutions obtained for the response of the plates include both the structural interaction at the common junction and the acoustic interaction due to the scattered pressure from each of the two plates. The results are presented in terms of the vibrational power flow into and out of each plate component. The solution is based on a formulation developed in the wavenumber domain combined with the Mobility Power Flow method. Using this approach, different substructural elements coupled under different boundary conditions to form a complex global structure can be considered. The detailed spatial and temporal scales of the structure response are not lost when using this method. In obtaining the solution for the scattering from the fluid-loaded plates, a modal decomposition in the direction normal to the simply supported edge is used. A spatial Fourier-transform decomposition is used in the other direction. Due to the finiteness of the plate, eight unknowns parameters are obtained in the transformed result. The solution for these eight unknown parameters is obtained from the boundary conditions and the condition that the response must remain finite. Two analytical approaches are used to solve the final plate integral equation. The first approach consists of an approximation method which obtains a solution based on the solution of the corresponding infinite plate problem. The second approach is a more accurate solution based on the Projection Method for the solution of integral equations. Both of the approaches used in the solution provide accurate predictions at high frequencies. At low frequencies especially for low structural damping or for heavy fluid loading, only the Projection Method gives reliable results. This is attributed to the fact that at low frequencies, the influence of the edges of the plates on the scattering is significant. The overall results obtained from this analysis indicate that the fluid loading and the plate characteristics have a significant influence on the acoustic scattering properties, especially in the case of heavy fluid loading. The application of the method to coupled fluid-loaded plates indicates that the junction enhances the scattering properties. The acoustical interaction between the coupled plates increases the contribution to scattering from subsonic wavenumber components. In the absence of the interaction, only supersonic wavenumbers contribute to the scattering. Inclusion of acousticlal interaction requires both supersonic and subsonic components. The significance of the contribution from the subsonic wavenumber components is dependent on the type of the fluid loading.
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Date Issued: 1993
PURL: http://purl.flvc.org/fcla/dt/12341
Subject Headings: Finite element method, Plates (Engineering), Acoustic emission, Sound--Transmission
Format: Document (PDF)

Title: Vibration tailoring of inhomogeneous beams and circular plates.
Creator: Pentaras, Demetris., Florida Atlantic University, Elishakoff, Isaac, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The vibrational behavior of inhomogeneous beams and circular plates is studied, utilizing the semi-inverse method developed by I. Elishakoff and extensively discussed in his recent monograph (2005). The main thread of his methodology is that the knowledge of the mode shape is postulated. The candidate mode shapes can be adopted from relevant static, dynamic or buckling problems. In this study, the exact mode shapes are sought as polynomial functions, in the context of vibration tailoring, i.e...
Show moreThe vibrational behavior of inhomogeneous beams and circular plates is studied, utilizing the semi-inverse method developed by I. Elishakoff and extensively discussed in his recent monograph (2005). The main thread of his methodology is that the knowledge of the mode shape is postulated. The candidate mode shapes can be adopted from relevant static, dynamic or buckling problems. In this study, the exact mode shapes are sought as polynomial functions, in the context of vibration tailoring, i.e. designing the structure that possesses the pre-specified value. Apparently for the first time in the literature, several closed-form solutions for vibration tailoring have been derived for vibrating inhomogeneous beams and circular plates. Twelve new closed-form solutions for vibration tailoring have been derived for an inhomogeneous polar orthotropic plate that is either clamped or simply supported around its circumference. Also, the vibration tailoring of a polar orthotropic circular plate with translational spring is analyzed. There is considerable potential of utilizing the developed method for design of functionally graded materials.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13344
Subject Headings: Acoustical engineering, Plates (Engineering)--Vibration--Mathematical models, Buckling (Mechanics), Structural analysis
Format: Document (PDF)

Title: Prediction of broadband self-noise of an airfoil.
Creator: Gomez, Carlos L., Florida Atlantic University, Glegg, Stewart A. L.
Abstract/Description: With the increase of air traffic and the introduction of larger aircraft and therefore larger engines, the noise generated by aircraft engines have become of greater importance. In order to address these problems, noise prediction codes must be developed in order to better understand the noise generating process. This thesis addresses important issues related to broadband self-noise from ducted fans based on the prediction model developed by Glegg and Jochault [1]. By addressing issues...
Show moreWith the increase of air traffic and the introduction of larger aircraft and therefore larger engines, the noise generated by aircraft engines have become of greater importance. In order to address these problems, noise prediction codes must be developed in order to better understand the noise generating process. This thesis addresses important issues related to broadband self-noise from ducted fans based on the prediction model developed by Glegg and Jochault [1]. By addressing issues regarding the prediction of broadband self-noise from an isolated airfoil with the observer in the far field directly overhead (at 90° above), improvements can be made to Glegg and Jochault's approach for ducted fans. The prediction of broadband self-noise at 90° above a single airfoil is done by considering boundary layer parameters, the results obtained are compared with theoretical approaches, as well as experimental results obtained by Brooks [2] in order to verify its accuracy.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13377
Subject Headings: Aerofoils--Noise, Noise control, Blades--Noise, Rotors--Noise, Acoustical engineering--Mathematical models, Acoustic models
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: A fuzzy logic material selection methodology for renewable ocean energy applications.
Creator: Welling, Donald Anthony., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The purpose of this thesis is to develop a renewable ocean energy material selection methodology for use in FAU's Ocean Energy Projects. A detailed and comprehensive literature review has been performed concerning all relevant material publications and forms the basis of the developed method. A database of candidate alloys has been organized and is used to perform case study material selections to validate the developed fuzzy logic approach. The ultimate goal of this thesis is to aid in the...
Show moreThe purpose of this thesis is to develop a renewable ocean energy material selection methodology for use in FAU's Ocean Energy Projects. A detailed and comprehensive literature review has been performed concerning all relevant material publications and forms the basis of the developed method. A database of candidate alloys has been organized and is used to perform case study material selections to validate the developed fuzzy logic approach. The ultimate goal of this thesis is to aid in the selection of materials that will ensure the successful performance of renewable ocean energy projects so that clean and renewable energy becomes a reality for all.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/227980
Subject Headings: Oceanic submersibles, Control systems, Acoustical engineering, Fuzzy algorithms, Renewable energy sources
Format: Document (PDF)

Title: Development and implementation of integrated acoustic and oceanographic numerical modeling in coastal regions.
Creator: Walker, Natasha Maria., Florida Atlantic University, Glegg, Stewart A. L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: An integrated coastal ocean and acoustic propagation model has been implemented to determine the effects of the ocean variations on the acoustic propagation field applied specifically to SFOMC. The ocean dynamics were modeled using the sigma coordinate, orthogonal curvilinear grid, Princeton Ocean Model. By using forcing conditions of tide, river runoff, wind and realistic bottom topography, the resulting time variant regional sound velocity outputs from the model were used as inputs to the...
Show moreAn integrated coastal ocean and acoustic propagation model has been implemented to determine the effects of the ocean variations on the acoustic propagation field applied specifically to SFOMC. The ocean dynamics were modeled using the sigma coordinate, orthogonal curvilinear grid, Princeton Ocean Model. By using forcing conditions of tide, river runoff, wind and realistic bottom topography, the resulting time variant regional sound velocity outputs from the model were used as inputs to the range dependent, parabolic equation, acoustic propagation model, RAM. The results show that the fluctuations in the ocean result in scintillation in the acoustic propagation field, and for higher frequencies this variability is uniformly distributed and at times as much as +/-3 dB. High resolution in the POM grid and the range and depth sizes for RAM were important for obtaining reliable simulation results.
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Date Issued: 2002
PURL: http://purl.flvc.org/fcla/dt/12901
Subject Headings: Oceanography--Mathematical models, Underwater acoustics--Mathematical models, Coastal engineering
Format: Document (PDF)

Title: Influence of the boundaries on the acoustic scattering by a submerged target.
Creator: Charmes, Emmanuel., Florida Atlantic University, Beaujean, Pierre-Philippe, Cuschieri, Joseph M.
Abstract/Description: In shallow water or fluid half-space, the acoustic scattering from a target is significantly different from that of an unbounded medium, due to the multiple reflections occurring between the target and the boundaries. The purpose of this thesis is to investigate the influence of the boundaries on the acoustic scattering of a rigid sphere by means of a superposition method. A minimum number of point sources necessary to accurately model the scattered field is determined in the case of a free...
Show moreIn shallow water or fluid half-space, the acoustic scattering from a target is significantly different from that of an unbounded medium, due to the multiple reflections occurring between the target and the boundaries. The purpose of this thesis is to investigate the influence of the boundaries on the acoustic scattering of a rigid sphere by means of a superposition method. A minimum number of point sources necessary to accurately model the scattered field is determined in the case of a free medium, a fluid half-space and a waveguide. The free field symmetry vanishes due to the presence of boundaries and, at particular frequencies or scatterer depths, a significant change in the magnitude and spatial distribution of the scattered field occur. In an unbounded medium or fluid half space, the superposition method is shown to give similar results to analytical formulations found in the literature, provided enough point sources are used.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13211
Subject Headings: Electromagnetic waves--Scattering, Acoustical engineering, Sound-waves--Measurement, Wave-motion, Theory of
Format: Document (PDF)

Title: Aerodynamic analysis of a propeller in a turbulent boundary layer flow.
Creator: Lachowski, Felipe Ferreira., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Simulating the exact chaotic turbulent flow field about any geometry is a dilemma between accuracy and computational resources, which has been continuously studied for just over a hundred years. This thesis is a complete walk-through of the entire process utilized to approximate the flow ingested by a Sevik-type rotor based on solutions to the Reynolds Averaged Navier-Stokes equations (RANS). The Multiple Reference Frame fluid model is utilized by the code of ANSYS-FLUENT and results are...
Show moreSimulating the exact chaotic turbulent flow field about any geometry is a dilemma between accuracy and computational resources, which has been continuously studied for just over a hundred years. This thesis is a complete walk-through of the entire process utilized to approximate the flow ingested by a Sevik-type rotor based on solutions to the Reynolds Averaged Navier-Stokes equations (RANS). The Multiple Reference Frame fluid model is utilized by the code of ANSYS-FLUENT and results are validated by experimental wake data. Three open rotor configurations are studied including a uniform inflow and the rotor near a plate with and without a thick boundary layer. Furthermore, observations are made to determine the variation in velocity profiles of the ingested turbulent flow due to varying flow conditions.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3360798
Subject Headings: Acoustical engineering, Boundary layer control, Multiphase flow, Mathematical models, Fluid mechanics, Mathematical models, Turbulence, Mathematical models, Computatioinal fluid dynamics
Format: Document (PDF)

Title: Ensemble-classifier approach to noise elimination: A case study in software quality classification.
Creator: Joshi, Vedang H., Florida Atlantic University, Khoshgoftaar, Taghi M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This thesis presents a noise handling technique that attempts to improve the quality of training data for classification purposes by eliminating instances that are likely to be noise. Our approach uses twenty five different classification techniques to create an ensemble of classifiers that acts as a noise filter on real-world software measurement datasets. Using a relatively large number of base-level classifiers for the ensemble-classifier filter facilitates in achieving the desired level...
Show moreThis thesis presents a noise handling technique that attempts to improve the quality of training data for classification purposes by eliminating instances that are likely to be noise. Our approach uses twenty five different classification techniques to create an ensemble of classifiers that acts as a noise filter on real-world software measurement datasets. Using a relatively large number of base-level classifiers for the ensemble-classifier filter facilitates in achieving the desired level of noise removal conservativeness with several possible levels of filtering. It also provides a higher degree of confidence in the noise elimination procedure as the results are less likely to get influenced by (possible) inappropriate learning bias of a few algorithms with twenty five base-level classifiers than with a relatively smaller number of base-level classifiers. Empirical case studies of two different high assurance software projects demonstrate the effectiveness of our noise elimination approach by the significant improvement achieved in classification accuracies at various levels of filtering.
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Date Issued: 2004
PURL: http://purl.flvc.org/fcla/dt/13144
Subject Headings: Computer interfaces--Software--Quality control, Acoustical engineering, Noise control--Case studies, Expert systems (Computer science), Software documentation
Format: Document (PDF)

Title: Correcting noisy data and expert analysis of the correction process.
Creator: Seiffert, Christopher N., Florida Atlantic University, Khoshgoftaar, Taghi M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This thesis expands upon an existing noise cleansing technique, polishing, enabling it to be used in the Software Quality Prediction domain, as well as any other domain where the data contains continuous values, as opposed to categorical data for which the technique was originally designed. The procedure is applied to a real world dataset with real (as opposed to injected) noise as determined by an expert in the domain. This, in combination with expert assessment of the changes made to the...
Show moreThis thesis expands upon an existing noise cleansing technique, polishing, enabling it to be used in the Software Quality Prediction domain, as well as any other domain where the data contains continuous values, as opposed to categorical data for which the technique was originally designed. The procedure is applied to a real world dataset with real (as opposed to injected) noise as determined by an expert in the domain. This, in combination with expert assessment of the changes made to the data, provides not only a more realistic dataset than one in which the noise (or even the entire dataset) is artificial, but also a better understanding of whether the procedure is successful in cleansing the data. Lastly, this thesis provides a more in-depth view of the process than previously available, in that it gives results for different parameters and classifier building techniques. This allows the reader to gain a better understanding of the significance of both model generation and parameter selection.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13223
Subject Headings: Computer interfaces--Software--Quality control, Acoustical engineering, Noise control--Computer programs, Expert systems (Computer science), Software documentation
Format: Document (PDF)

FAU Theses and Dissertations (19)	+ -
HBOI Faculty Contributions (1)	+ -

Acoustical engineering (16)	+ -
Underwater acoustics (6)	+ -
Adaptive signal processing (2)	+ -
Computer interfaces--Software--Quality control (2)	+ -
Expert systems (Computer science) (2)	+ -

Fluid mechanics (2)	+ -
Fuzzy algorithms (2)	+ -
Mathematical models (2)	+ -
Software documentation (2)	+ -
Turbulence (2)	+ -
Underwater acoustic telemetry (2)	+ -
Underwater navigation (2)	+ -
Acoustic emission (1)	+ -
Acoustic models (1)	+ -
Acoustic velocity meters (1)	+ -
Acoustical engineering--Mathematical models (1)	+ -
Aerofoils--Noise (1)	+ -
Array processors (1)	+ -
Blades--Noise (1)	+ -
Boundary layer control (1)	+ -
Buckling (Mechanics) (1)	+ -
Coastal engineering (1)	+ -
Computatioinal fluid dynamics (1)	+ -
Computational fluid dynamics (1)	+ -
Computer integrated manufacturing systems (1)	+ -
Control systems (1)	+ -
Digital communications (1)	+ -
Electro-acoustics (1)	+ -
Electromagnetic waves--Scattering (1)	+ -
Finite element method (1)	+ -

Electronic Thesis or Dissertation (19)	+ -
article (1)	+ -

Florida Atlantic University (15)	+ -
College of Engineering and Computer Science (14)	+ -
Department of Ocean and Mechanical Engineering (11)	+ -
Glegg, Stewart A. L. (5)	+ -
Beaujean, Pierre-Philippe (3)	+ -

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