View All Items

Title: Optimization of Computed Tomography Calibration Curve for Proton Therapy Treatment Planning.
Creator: Ghasemi Ghonchehnazi, Maryam, Shang, Charles, Leventouri, Theodora, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: The accuracy of proton dose computation in the treatment planning system relies on the conversion from the Hounsfield units (HU) of each voxel in the patient CT scan to the proton stopping power ratio (SPR). The aim of this study is to investigate the potential improvement in determining proton SPR using single energy computed tomography (SECT) to reduce the uncertainty in predicting the proton range in patients. Factors which may cause CT number variations in the calibration curve have been...
Show moreThe accuracy of proton dose computation in the treatment planning system relies on the conversion from the Hounsfield units (HU) of each voxel in the patient CT scan to the proton stopping power ratio (SPR). The aim of this study is to investigate the potential improvement in determining proton SPR using single energy computed tomography (SECT) to reduce the uncertainty in predicting the proton range in patients. Factors which may cause CT number variations in the calibration curve have been examined. The HU-SPR calibration curve was determined based on HU of human body tissues using the stoichiometric method. The uncertainties in SPR were divided into two major categories: The inherent uncertainty, and the CT number uncertainty. The root mean square errors of the inherent uncertainties were estimated 0.02%, 0.61% and 0.26% for lung tissues, soft tissues (excluding Thyroid), and bone tissues, respectively. The total uncertainties due to the inherent uncertainty and CT imaging errors were estimated 1.50%. The average calibration curve of two sized phantoms (head and body) were used in the treatment planning system to mitigate beam hardening effect through the attenuating media. A higher accuracy of the SPR prediction using the stoichiometric method is suggested through comparison with the predicted SPRs that derived from the direct calibration approach.
Show less
Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013374
Subject Headings: Proton Therapy, Tomography, Calibration, Tomography, X-Ray Computed
Format: Document (PDF)

Title: Simulation of reflection tomographic images of underwater targets with the effect of vehicle motion sensing errors.
Creator: Quentin, Gwendoline., Florida Atlantic University, Schock, Steven G., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The Buried Object Scanning Sonar (BOSS) is being developed at Florida Atlantic University to image targets buried under the seabed. Tomographic images are constructed using a sequence of sonar transmissions while the vehicle is moving. This motion causes image distortion and should be measured and removed by mapping the echoes received to an absolute coordinate system. The aim of this thesis is to develop and simulate a technique for generating BOSS images that provide an accurate...
Show moreThe Buried Object Scanning Sonar (BOSS) is being developed at Florida Atlantic University to image targets buried under the seabed. Tomographic images are constructed using a sequence of sonar transmissions while the vehicle is moving. This motion causes image distortion and should be measured and removed by mapping the echoes received to an absolute coordinate system. The aim of this thesis is to develop and simulate a technique for generating BOSS images that provide an accurate representation of target shape and size, by removing vehicle motion while mapping the image pixels. Synthetic acoustic data sets are generated by convolving the auto-correlated FM transmission pulse with the impulse response of an elastic sphere. Synthetic outputs of a Doppler velocity log and a 3-axis inertial measurement unit are generated to simulate vehicle motion. Noise is added to the sensor data to show the effects of motion sensor errors on image quality.
Show less
Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13040
Subject Headings: Ocean tomography, Sonar, Underwater navigation
Format: Document (PDF)

Title: Acoustic propagation over a range-dependent bathymetry.
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: Experimental measurements have been conducted to investigate the effects of a three dimensional bathymetry on ocean acoustic propagation and our abilities to use array processing for localizing sources. This work is unique because it uses laboratory scale measurements to isolate the effects of the bottom bathymetry. Previous investigations using laboratory scale measurements have only used simplistic bottom profiles. In addition, experiments which have investigated the effects of the bottom...
Show moreExperimental measurements have been conducted to investigate the effects of a three dimensional bathymetry on ocean acoustic propagation and our abilities to use array processing for localizing sources. This work is unique because it uses laboratory scale measurements to isolate the effects of the bottom bathymetry. Previous investigations using laboratory scale measurements have only used simplistic bottom profiles. In addition, experiments which have investigated the effects of the bottom bathymetry at sea have encountered difficulties isolating these effects due to range dependent sound speed profiles and the uncertainties of ocean acoustic experiments. The first part of this dissertation investigates the tracking of an acoustic source in a three dimensional shallow water environment. This work is comprised of two studies. The first study uses matched field processing for identifying the trajectory of a source. The second investigation uses experimental measurements and theoretical predictions to evaluate the beating angle bias caused by the use of plane-wave beamforming in the presence of bathymetric refraction. The second part of this dissertation uses laboratory scale measurements to analyze two and three dimensional propagation over a realistic bottom bathymetry. This series of investigations uses an inverse approach based on normal mode theory. The inversion algorithm is used to extract the normal mode amplitudes for the purpose of analyzing the measurements for two dimensional mode coupling and bathymetric refraction. The results of this investigation show that the bathymetry has a strong influence on the three dimensional acoustic field. Analysis of the experimental measurements identify that mode coupling and bathymetric refraction are important for propagation over the laboratory scale model and these effects adversely influence our abilities to localize sources in three dimensional shallow water environments. It is also shown that by incorporating three dimensional propagation models into the signal replica used by the array processor a significant improvement in performance can be achieved.
Show less
Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/12618
Subject Headings: Underwater acoustics--Measurement, Ocean tomography
Format: Document (PDF)

Title: OPTIMIZATION OF DATA ACQUISITION IN OPTICAL TOMOGRAPHY BASED ON ESTIMATION THEORY.
Creator: Javidan, Mahshad, Pashaie, Ramin, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science, College of Engineering and Computer Science
Abstract/Description: In any experimental platform, data acquisition is the first and essential step, and occasionally the most time-consuming and costly operation. During the process of data acquisition, we conduct experiments to measure the response of the system to a set of inputs. Methods of optimal design of experiment can be used to determine the most informative measurements and avoid numerous traps that trial-and-error experimentation might cause. In this research, we have developed a general approach for...
Show moreIn any experimental platform, data acquisition is the first and essential step, and occasionally the most time-consuming and costly operation. During the process of data acquisition, we conduct experiments to measure the response of the system to a set of inputs. Methods of optimal design of experiment can be used to determine the most informative measurements and avoid numerous traps that trial-and-error experimentation might cause. In this research, we have developed a general approach for designing optimal experiments, subsequently applying it to the domain of optical tomography. Optical tomography is a vital technology that enables three-dimensional imaging by reconstructing images from two-dimensional projections. This technology has applications across various fields, including medicine and material science. The process involves two main phases: data acquisition and image reconstruction. The traditional raster scanning method has been the standard approach for data acquisition, but it presents challenges in terms of scanning speed, quality, and exposure to harmful radiations in some cases. This has prompted researchers to explore ways to optimize the scanning process.
Show less
Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014350
Subject Headings: Optical tomography, Data Collection, Estimation theory
Format: Document (PDF)

Title: Enhancement in Low-Dose Computed Tomography through Image Denoising Techniques: Wavelets and Deep Learning.
Creator: Mohammadi Khoroushadi, Mohammad Sadegh, Leventouri, Theodora, Zhuang, Hanqi, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: Reducing the amount of radiation in X-ray computed tomography has been an active area of research in the recent years. The reduction of radiation has the downside of degrading the quality of the CT scans by increasing the ratio of the noise. Therefore, some techniques must be utilized to enhance the quality of images. In this research, we approach the denoising problem using two class of algorithms and we reduce the noise in CT scans that have been acquired with 75% less dose to the patient...
Show moreReducing the amount of radiation in X-ray computed tomography has been an active area of research in the recent years. The reduction of radiation has the downside of degrading the quality of the CT scans by increasing the ratio of the noise. Therefore, some techniques must be utilized to enhance the quality of images. In this research, we approach the denoising problem using two class of algorithms and we reduce the noise in CT scans that have been acquired with 75% less dose to the patient compared to the normal dose scans. Initially, we implemented wavelet denoising to successfully reduce the noise in low-dose X-ray computed tomography (CT) images. The denoising was improved by finding the optimal threshold value instead of a non-optimal selected value. The mean structural similarity (MSSIM) index was used as the objective function for the optimization. The denoising performance of combinations of wavelet families, wavelet orders, decomposition levels, and thresholding methods were investigated. Results of this study have revealed the best combinations of wavelet orders and decomposition levels for low dose CT denoising. In addition, a new shrinkage function is proposed that provides better denoising results compared to the traditional ones without requiring a selected parameter. Alternatively, convolutional neural networks were employed using different architectures to resolve the same denoising problem. This new approach improved denoising even more in comparison to the wavelet denoising.
Show less
Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013115
Subject Headings: Tomography--Image quality, Wavelets (Mathematics), Deep learning, Tomography, X-Ray Computed
Format: Document (PDF)

Title: Three-Dimensional Inversion Technique in Ocean Acoustics Using the Parabolic Equation Method.
Creator: Roa, Camilo Carlos, Frisk, George V., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A three-dimensional parabolic equation (PE) and perturbation approach is used to invert for the depth- and range-dependent geoacoustic characteristics of the seabed. The model assumes that the sound speed profile is the superposition of a known range-independent profile and an unknown depth- and range-dependent perturbation. Using a Green’s function approach, the total measured pressure field in the water column is decomposed into a background field, which is due to the range-independent...
Show moreA three-dimensional parabolic equation (PE) and perturbation approach is used to invert for the depth- and range-dependent geoacoustic characteristics of the seabed. The model assumes that the sound speed profile is the superposition of a known range-independent profile and an unknown depth- and range-dependent perturbation. Using a Green’s function approach, the total measured pressure field in the water column is decomposed into a background field, which is due to the range-independent profile, and a scattered field, which is due to the range-dependent perturbation. When the Born approximation is applied to the resulting integral equation, it can be solved for the range-dependent profile using linear inverse theory. Although the method is focused on inverting for the sound speed profile in the bottom, it can also invert for the sound speed profile in the water column. For simplicity, the sound speed profile in the water column was assumed to be known with a margin of error of ± 5 m/s. The range-dependent perturbation is added to the index of refraction squared n2(r), rather than the sound speed profile c(ro). The method is implemented in both Cartesian (x,y,z) and cylindrical (r,q,z) coordinates with the forward propagation of the field in x and r, respectively. Synthetic data are used to demonstrate the validity of the method [1]. Two inversion methods were combined, a Monte Carlo like algorithm, responsible for a starting approximation of the sound speed profile, and a steepest descent method, that fine-tuned the results. In simulations, the inversion algorithm is capable of inverting for the sound speed profile of a flat bottom. It was tested, for three different frequencies (50 Hz, 75 Hz, and 100 Hz), in a Pekeris waveguide, a range-independent layered medium, and a range-dependent medium, with errors in the inverted sound speed profile of less than 3%. Keywords: Three-dimensional parabolic equation method, geoacoustic inversion, range-dependent sound speed profile, linear inversion, Born approximation, Green’s functions.
Show less
Date Issued: 2017
PURL: http://purl.flvc.org/fau/fd/FA00004868, http://purl.flvc.org/fau/fd/FA00004868
Subject Headings: Ocean tomography., Ocean bottom., Born approximation., Green's functions.
Format: Document (PDF)

Title: Artificial Intelligence Based Electrical Impedance Tomography for Local Tissue.
Creator: Rao, Manasa, Pandya, Abhijit S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This research aims at proposing the use of Electrical Impedance Tomography (EIT), a non-invasive technique that makes it possible to measure two or three dimensional impedance of living local tissue in a human body which is applied for medical diagnosis of diseases. In order to achieve this, electrodes are attached to the part of human body and an image of the conductivity or permittivity of living tissue is deduced from surface electrodes. In this thesis we have worked towards alleviating...
Show moreThis research aims at proposing the use of Electrical Impedance Tomography (EIT), a non-invasive technique that makes it possible to measure two or three dimensional impedance of living local tissue in a human body which is applied for medical diagnosis of diseases. In order to achieve this, electrodes are attached to the part of human body and an image of the conductivity or permittivity of living tissue is deduced from surface electrodes. In this thesis we have worked towards alleviating drawbacks of EIT such as estimating parameters by incorporating it in an electrode structure and determining a solution to spatial distribution of bio-impedance to a close proximity. We address the issue of initial parameter estimation and spatial resolution accuracy of an electrode structure by using an arrangement called "divided electrode" for measurement of bio-impedance in a cross section of a local tissue. Its capability is examined by computer simulations, where a distributed equivalent circuit is utilized as a model for the cross section tissue. Further, a novel hybrid model is derived which is a combination of artificial intelligence based gradient free optimization technique and numerical integration in order to estimate parameters. This arne! iorates the achievement of spatial resolution of equivalent circuit model to the closest accuracy.
Show less
Date Issued: 2008
PURL: http://purl.flvc.org/fau/fd/FA00012544
Subject Headings: Electrical impedance tomography, Diagnostic imaging--Data processing, Computational intelligence
Format: Document (PDF)

$Computed tomographic measurements of void fraction and modeling of the flow in bubble columns$

Title: Computed tomographic measurements of void fraction and modeling of the flow in bubble columns.
Creator: Kumar, Sailesh B., Florida Atlantic University, Moslemian, Davood, Dudukovic, M. P., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A complete understanding of the gas-liquid two phase flow in bubble columns is required for the development of reliable models for scale-up of these multiphase reactors. Although several models have been proposed to describe the hydrodynamics. lack of adequate experimental data has hindered meaningful evaluation of model parameters and model predictions. The Computer Automated Radioactive Particle Tracking ( CARPT) facility that was implemented earlier has provided interesting results on the...
Show moreA complete understanding of the gas-liquid two phase flow in bubble columns is required for the development of reliable models for scale-up of these multiphase reactors. Although several models have been proposed to describe the hydrodynamics. lack of adequate experimental data has hindered meaningful evaluation of model parameters and model predictions. The Computer Automated Radioactive Particle Tracking ( CARPT) facility that was implemented earlier has provided interesting results on the recirculation patterns of the liquid phase. The technique has provided quantitative information on liquid velocities and turbulence parameters as well. In addition to these hydrodynamic parameters the measurement of void fraction is also important. To complement the capabilities of CARPT a scanner for ;-ray Computed Tomography (CT) was implemented to quantify the local void fraction and its distribution in two phase flow systems. The automated scanner is capable of imaging flows in test sections between 0.02.5 m and 0..15 m in diameter at different elevations above the distributor. The scanner makes use of the same detectors used in the CARPT facility and with the use of a specially designed moving collimator provides a spatial resolution of about 5 mm. A non-conventional algorithm based on maximum likelihood principles called the E-M algorithm was used for imagw reconstruction. Long scanning times are required leading to time averaged density profiles. Although the system is only capable of providing time averaged void fraction distributions. it can provide unique information concerning the structure of two phase flow. The system performance was evaluated by identifying the sources of errors in measurement and their bounds. The capabilities of the scanner for imaging void fraction distribution was demonstrated both qualitatively and quantitatively. Fse of existing radiation detectors and the associated signal processing and data acquisition system helped in reducing the cost of the system. The scanner was utilized to quantify the local void fraction and its distribution in bubble columns of five diameters (0.10. 0.14, 0.19, 0.26. 0.30 m internal diameter) and at four superficial gas velocities. The effect of various operating parameters such as column diameter, superficial gas velocity. the type of distributor. the static liquid height and some changes in the physical properties of the liquid phase were studied. For the first time a comprehensive characterization of the void fraction in an air water bubble column using a non-invasive technique was achieved. The experimental data obtained using CARPT and CT under identical operating conditions was used for developing a methodology for scale-up of bubble columns using a one dimensional model for liquid recirculation. Successful scale-up of liquid hydrodynamics using a one dimensional model requires an adequate closure scheme for the Reynolds shear stress. The existing correlations for the prescription of the eddy viscosity or the mixing length scale are demonstrated to be applicable only for a limited range of conditions. and consequently cannot be used for scale-up predictions. A method for estimating the mixing length scale has been explored and an attempt at unifying a wide range of data available in the literature within the pun·iew of the method has been made. The futility of such an attempt is attributed to the non-reproducibility of the flow in different laboratories and the conasequent lack of data obtained under identical conditions. It is demonstrated, however, that scale-up based on the mixing length distribution is possible when it is obtained from a consistent set of data for liquid velocity and gas void fraction profiles. Using the present method for prescribing the mixing length scale. model predictions for scale-up compare satisfactorily for the data that was obtained as part of this research. The achievement was that the turbulence length scale estimated in one column diameter was successfully used in predicting the liquid velocities in larger diameter columns.
Show less
Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/12384
Subject Headings: Two-phase flow, Hydrodynamics, Bubble chambers, Tomography, Emission
Format: Document (PDF)

Title: CONSISTENCY OF CT NUMBER AND ELECTRON DENSITY IN TREATMENT PLANNING SYSTEM VERSUS CT SCANNER, AND DOSIMETRIC CONSEQUENCES.
Creator: Hana, Evan Makdasy, Pella, Silvia, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: The Computer Tomography (CT) scanned images are very important for the Treatment Planning System (TPS) to provide the electron density of the different types of tissues that the radiation penetrates in the path to the tumor to be treated. This electron density is converted to an attenuation coefficient, which varies with tissue for each structure and even varies by the tissue volume. The purpose of this research is to evaluate the CT numbers, and convert them into relative electron densities....
Show moreThe Computer Tomography (CT) scanned images are very important for the Treatment Planning System (TPS) to provide the electron density of the different types of tissues that the radiation penetrates in the path to the tumor to be treated. This electron density is converted to an attenuation coefficient, which varies with tissue for each structure and even varies by the tissue volume. The purpose of this research is to evaluate the CT numbers, and convert them into relative electron densities. Twenty-five patients’ data and CT numbers were evaluated in the CT scanner and in Eclipse and were converted into relative electron density and compared with each other. The differences between the relative electron density in the Eclipse was found to be from 0 up to 6% between tissue equivalent materials, the final result for all equivalent tissue materials was about 2%. For the patients’ data, the percentage difference of CT number versus electron density was found to be high for high relative electron density organs, namely the final average result for the spine was 8%, less for pelvis, and less for rib while for the other organs it was even less. The very lowest was 0.3% compared with 1% which is acceptable for clinical standards.
Show less
Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013315
Subject Headings: Tomography, X-Ray Computed, Electron density, Radiation dosimetry--Evaluation, Tomography Scanners, X-Ray Computed
Format: Document (PDF)

Title: Development of Crown Ether Nucleophilic Catalysts (CENCs) and their Application in Rapid Fluorination of Silicon for PET Imaging & Diversification Reactions of γ-Silyl Allenyl Esters to All-carbon Quaternary Stereogenic Centers.
Creator: Jana, Susovan, Lepore, Salvatore D., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: In this dissertation, we discuss the development of new phase transfer agents, which are capable of rapid fluorination of silicon. These are 18-C-6 derivatives containing a hydroxyl group in the side arm (podand), also known as C-pivot lariats. The syntheses of these lariats including several that have not been previously reported and their efficient purification are described. The synthesis route leads to a robust and generalized approach to obtain these lariats on the gram scale. These...
Show moreIn this dissertation, we discuss the development of new phase transfer agents, which are capable of rapid fluorination of silicon. These are 18-C-6 derivatives containing a hydroxyl group in the side arm (podand), also known as C-pivot lariats. The syntheses of these lariats including several that have not been previously reported and their efficient purification are described. The synthesis route leads to a robust and generalized approach to obtain these lariats on the gram scale. These agents were initially designed for applications in positron emission tomography (PET). In this medical imaging modality, tracer agents containing silicon have found promising utility as fluoride receptors for more rapid radiolabeling. Phase transfer agents are generally required for 18F-labeling due to the low solubility in organic reaction media and reactivity of cyclotron-generated [18F]potassium fluoride. We envisioned that 18-C-6 derivatives may serve as both phase transfer agents as well as nucleophilic catalysts (CENCs). In this conception, CENCs were rapidly pre-complexed with KF followed by silicon fluorination, which takes advantage of a previously established silicon dianion mechanism. In collaboration with researchers at the NIH, we studied the effect of various linkers connecting the metal chelating unit to the nucleophilic hydroxyl group on the radiofluorination of silicon under mild condition. A hydrolysis resistant aryl silicon fragment has also been developed that contains various functional groups for convenient attachment to the potential PET radiotracer agents. In a second project, we demonstrate the unique reactivity of γ-silyl allenyl esters. Taking advantage of the silyl group as a fluoride acceptor, these allenoates readily underwent addition to a variety of carbon electrophiles, including aryl fluorides, to afford all-carbon quaternary centers bearing an ethynyl group. Surprisingly, in the presence of aldehydes, exclusive bis-substitution occurs at the γ-position to afford the dicarbinol. Details relating to reaction optimization and substrate scope for both the reactions are presented. Dicarbinol allenes were subsequently converted to highly substituted δ-lactones, a novel 6-hydro-2-pyrone as single diastereomers.
Show less
Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013073
Subject Headings: Phase-transfer catalysis., Silicon., Positron-Emission Tomography., Crown ethers., Radioactive tracers., Fluorination.
Format: Document (PDF)

Title: A novel method to evaluate local control of lung cancer in stereotactic body radiation therapy (SBRT) treatment using 18f-Fdg positron emission tomography (PET).
Creator: Kathriarachchi, Vindu, Shang, Charles, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: An improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations...
Show moreAn improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations associated with SUVmax and objectively demonstrates a strong correlation between the low SUVcmax (< 2.5-3.0) and local control of post lung SBRT. The false positive rates of both SUVmax and SUVcmax increase with inclusion of early (<6 months) PET scans, therefore such inclusion is not recommended for assessing local tumor control of post lung SBRT.
Show less
Date Issued: 2013
PURL: http://purl.flvc.org/fau/fd/FA0004029
Subject Headings: Cancer -- Radiotherapy, Image guided radiation therapy, Lung cancer -- Treatment, Radiopharmaceuticals, Tomography, Emission
Format: Document (PDF)

Title: New stereoselective reactions to form amido alkyl c-n and vinyl triflate c-o bonds via carbocation intermediates & ultrafast silicon fluorination methodologies for applications in pet imaging.
Creator: Alhuniti, Mohammed, Lepore, Salvatore D., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: We report here the development of a Lewis acid catalyzed method for the dehydrative coupling of cyclic alcohols and nitriles to form amides with retention of configuration. By contrast, the formation of amides by nitrile trapping of carbocations (Ritter reaction) usually affords racemic product. The present reaction was accomplished by first converting alcohol starting materials to their corresponding chlorosulfites in situ. Even after an extensive search, only copper (II) salts were able to...
Show moreWe report here the development of a Lewis acid catalyzed method for the dehydrative coupling of cyclic alcohols and nitriles to form amides with retention of configuration. By contrast, the formation of amides by nitrile trapping of carbocations (Ritter reaction) usually affords racemic product. The present reaction was accomplished by first converting alcohol starting materials to their corresponding chlorosulfites in situ. Even after an extensive search, only copper (II) salts were able to produce the desired conversion of these chlorosulfites to amides though with low catalytic turnover. Improving the turnover without deteriorating the stereochemical outcome was eventually accomplished by a careful selection of the reagent addition sequence and through the removal of gaseous byproducts. This Ritter-like coupling reaction proceeds in good yields with secondary cyclic alcohols under mild conditions. The stereochemical outcome likely due to fast nucleophilic capture of a non-planar carbocations (hyperconjomers) stabilized by ring hyperconjugation.
Show less
Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004262
Subject Headings: Intermediates (Chemistry), Nuclear medicine, Organometallic chemistry, Physical organic chemistry, Reaction mechanisms (Chemistry), Tomography, Emission
Format: Document (PDF)

Title: A characterization of the LAP Aquarius Phantom for external LAP laser alignment and magnetic resonance geometric distortion verification for stereotactic radiation surgery patient simulation.
Creator: Vergara, Daniel, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: The Thesis explores additional applications of LAP's Aquarius external laser alignment verification Phantom by examining geometric accuracy of magnetic resonance images commonly used for planning intracranial stereotactic radiation surgery (ICSRS) cases. The scans were performed with MRI protocols used for ICSRS, and head and neck diagnosis, and their images fused to computerized tomographic (CT) images. The geometric distortions (GDs) were measured against the CT in all axial, sagittal, and...
Show moreThe Thesis explores additional applications of LAP's Aquarius external laser alignment verification Phantom by examining geometric accuracy of magnetic resonance images commonly used for planning intracranial stereotactic radiation surgery (ICSRS) cases. The scans were performed with MRI protocols used for ICSRS, and head and neck diagnosis, and their images fused to computerized tomographic (CT) images. The geometric distortions (GDs) were measured against the CT in all axial, sagittal, and coronal directions at different levels. Using the Aquarius Phantom, one is able to detect GD in ICSRS planning MRI acquisitions, and align the external LAP patient alignment lasers, by following the LAP QA protocol. GDs up to about 2 mm are observed at the distal regions of the longitudinal axis in the SRS treatment planning MR images. Based on the results, one may recommend the use of the Aquarius Phantom to determine if margins should be included for SRS treatment planning.
Show less
Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3352878
Subject Headings: Radiotherapy, Techniques, Medical physics, Imaging systems in medicine, Tomographic images, Computerized axial tomography
Format: Document (PDF)

Title: A methodology to detect and classify underwater unexploded ordnance in DIDSON sonar images.
Creator: Brisson, Lisa Nicole., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: High-resolution sonar systems are primarily used for ocean floor surveys and port security operations but produce images of limited resolution. In turn, a sonar-specific methodology is required to detect and classify underwater unexploded ordnance (UXO) using the low-resolution sonar data. After researching and reviewing numerous approaches the Multiple Aspect-Fixed Range Template Matching (MAFR-TM) algorithm was developed. The MAFR-TM algorithm is specifically designed to detect and classify...
Show moreHigh-resolution sonar systems are primarily used for ocean floor surveys and port security operations but produce images of limited resolution. In turn, a sonar-specific methodology is required to detect and classify underwater unexploded ordnance (UXO) using the low-resolution sonar data. After researching and reviewing numerous approaches the Multiple Aspect-Fixed Range Template Matching (MAFR-TM) algorithm was developed. The MAFR-TM algorithm is specifically designed to detect and classify a target of high characteristic impedance in an environment that contains similar shaped objects of low characteristic impedance. MAFR-TM is tested against a tank and field data set collected by the Sound Metrics Corp. DIDSON US300. This thesis document proves the MAFR-TM can detect, classify, orient, and locate a target in the sector-scan sonar images. This paper focuses on the MAFR-TM algorithm and its results.
Show less
Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2683533
Subject Headings: Ocean tomography, Unexploded ordnance, Detection, Methodology, Underwater acoustics, Signal processing, Digital techniques
Format: Document (PDF)

Title: DETECTION AND CATEGORIZATION OF LUNG CANCER USING CONVOLUTIONAL NEURAL NETWORK.
Creator: Mostafanazhad, Shahabeddin Aslmarand, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Medical professionals use CT images to get information about the size, shape, and location of any lung nodules. This information will help radiologist and oncologist to identify the type of cancer and create a treatment plan. However, most of the time, the diagnosis regarding the types of lung cancer is error-prone and time-consuming. One way to address these problems is by using convolutional neural networks. In this Thesis, we developed a convolutional neural network that can detect...
Show moreMedical professionals use CT images to get information about the size, shape, and location of any lung nodules. This information will help radiologist and oncologist to identify the type of cancer and create a treatment plan. However, most of the time, the diagnosis regarding the types of lung cancer is error-prone and time-consuming. One way to address these problems is by using convolutional neural networks. In this Thesis, we developed a convolutional neural network that can detect abnormalities in lung CT scans and further categorize the abnormalities to benign, malignant adenocarcinoma and malignant squamous cell carcinoma. Our network is based on DenseNet, which utilizes dense connections between layers (dense blocks), so that all layers are connected. Because of all layers being connected, different layers can reuse features from previous layers which speeds up the process and make this network computationally efficient. To retrain this network we used CT images for 314 patients (over 1500 CT images) consistent of 42 Lung Adenocarcinoma and 78 Squamous Cell Carcinoma, 118 Non cancer and 76 benign were acquired from the National Lung Screening Trial (NLST). These images were divided to two categories of Training and Validation with 70% being training dataset and 30% as validation dataset. We trained our network on Training dataset and then checked the accuracy of our model using the validation dataset. Our model was able to categorize lung cancer with an accuracy of 88%. Afterwards we calculated the the confusion matrix, Precision (Sensitivity), Recall (Positivity) and F1 score of our model for each category. Our model is able to classify Normal CT images with Normal Accuracy of 89% Precision of 94% and F1 score of 93%. For benign nodules Accuracy was 92% precision of 97% and F1 score 86%, while for Adenocarcinoma and squamous cell cancer the Accuracy was 98% and 93%, Precision 85% and 84% and F1 score 92% and 86.9%. The relatively high accuracy of our model shows that convolutional neural networks can be a valuable tool for the classification of lung cancer, especially in a small city or underdeveloped rural hospital settings and can play a role in achieving healthcare equality.
Show less
Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013965
Subject Headings: Lungs--Cancer, Neural networks (Computer science), Tomography, X-Ray Computed
Format: Document (PDF)

Tomography, X-Ray Computed (4)	+ -
Ocean tomography (3)	+ -
Tomography, Emission (3)	+ -
Born approximation. (1)	+ -
Bubble chambers (1)	+ -

Calibration (1)	+ -
Cancer -- Radiotherapy (1)	+ -
Computational intelligence (1)	+ -
Computerized axial tomography (1)	+ -
Crown ethers. (1)	+ -
Data Collection (1)	+ -
Deep learning (1)	+ -
Detection (1)	+ -
Diagnostic imaging--Data processing (1)	+ -
Digital techniques (1)	+ -
Electrical impedance tomography (1)	+ -
Electron density (1)	+ -
Estimation theory (1)	+ -
Fluorination. (1)	+ -
Green's functions. (1)	+ -
Hydrodynamics (1)	+ -
Image guided radiation therapy (1)	+ -
Imaging systems in medicine (1)	+ -
Intermediates (Chemistry) (1)	+ -
Lung cancer -- Treatment (1)	+ -
Lungs--Cancer (1)	+ -
Medical physics (1)	+ -
Methodology (1)	+ -
Neural networks (Computer science) (1)	+ -
Nuclear medicine (1)	+ -

Florida Atlantic University (12)	+ -
Charles E. Schmidt College of Science (8)	+ -
College of Engineering and Computer Science (7)	+ -
Department of Physics (6)	+ -
Department of Ocean and Mechanical Engineering (5)	+ -

Leventouri, Theodora (3)	+ -
Department of Chemistry and Biochemistry (2)	+ -
Department of Computer and Electrical Engineering and Computer Science (2)	+ -
Lepore, Salvatore D. (2)	+ -
Shang, Charles (2)	+ -
Alhuniti, Mohammed (1)	+ -
Brisson, Lisa Nicole. (1)	+ -
Dudukovic, M. P. (1)	+ -
Frisk, George V. (1)	+ -
Ghasemi Ghonchehnazi, Maryam (1)	+ -
Glegg, Stewart A. L. (1)	+ -
Hana, Evan Makdasy (1)	+ -
Jana, Susovan (1)	+ -
Javidan, Mahshad (1)	+ -
Kathriarachchi, Vindu (1)	+ -
Kumar, Sailesh B. (1)	+ -
Mohammadi Khoroushadi, Mohammad Sadegh (1)	+ -
Moslemian, Davood (1)	+ -
Mostafanazhad, Shahabeddin Aslmarand (1)	+ -
Muhammad, Wazir (1)	+ -
Pandya, Abhijit S. (1)	+ -
Pashaie, Ramin (1)	+ -
Pella, Silvia (1)	+ -
Quentin, Gwendoline. (1)	+ -
Rao, Manasa (1)	+ -

Search In

Sort Results By:

Narrow results by:

Collection

Topical Subject

Genre

Type of Resource

Language

Creator

Format

Owner