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Full-Text Articles in Engineering

Enhanced Sonar Array Target Localization Using Time-Frequency Interference Phenomena, Jordan Almon Shibley Dec 2013

Enhanced Sonar Array Target Localization Using Time-Frequency Interference Phenomena, Jordan Almon Shibley

Dissertations and Theses

The ability of traditional active sonar processing methods to detect targets is often limited by clutter and reverberation from ocean environments. Similarly, multipath arrivals from radiating sources such as ships and submarines are received at sensors in passive sonar systems. Reverberation and multipath signals introduce constructive and destructive interference patterns in received spectrograms in both active and passive sonar applications that vary with target range and frequency. The characterization and use of interference phenomena can provide insights into environmental parameters and target movement in conjunction with standard processing methods including spectrograms and array beamforming.

This thesis focuses on utilizing the ...


Studies On Microscopic Flow Structure Inside A Rectangular Circulating Fluidized Bed Through Image Analysis, Jingsi Yang Dec 2013

Studies On Microscopic Flow Structure Inside A Rectangular Circulating Fluidized Bed Through Image Analysis, Jingsi Yang

Electronic Thesis and Dissertation Repository

The microscopic flow structure is studied systematically and comprehensively through a visualization system in a narrow rectangular circulating fluidized bed (CFB) transparent Plexiglas riser with a height of 7.6 m and a cross section of 19 mm × 114 mm. A visualization system consisting of a high-speed video camera, a light source, and image processing and analyzing programs is designed and developed to enable the flow structure to be visualized directly and studied quantitatively. FCC particles of 67 μm are used as the bed materials under different operating conditions with superficial gas velocity (Ug) and solids circulation rate (G ...


Application Of Image Processing And Finite Element Analysis In Modeling Chloride Diffusion In Concrete, Arash Razmjoo Dec 2013

Application Of Image Processing And Finite Element Analysis In Modeling Chloride Diffusion In Concrete, Arash Razmjoo

All Dissertations

Utilizing numerical simulation models to predict the long-term mechanical and transport behavior of concrete structures is becoming increasingly popular. The majority of these models have been developed using laboratory test data that consider concrete as a homogeneous material with spherical aggregates. These models could not be a represented of real concrete because it has no primitive shaped aggregate besides that the porosity size and distribution varies from point to point. In this study a novel method for more accurate prediction of the chloride diffusion in concrete was developed. A general framework of the quantitative computed tomography (QCT) and finite element ...


Geometric Modeling Of Non-Rigid 3d Shapes : Theory And Application To Object Recognition., Mostafa Abdelrahman Dec 2013

Geometric Modeling Of Non-Rigid 3d Shapes : Theory And Application To Object Recognition., Mostafa Abdelrahman

Electronic Theses and Dissertations

One of the major goals of computer vision is the development of flexible and efficient methods for shape representation. This is true, especially for non-rigid 3D shapes where a great variety of shapes are produced as a result of deformations of a non-rigid object. Modeling these non-rigid shapes is a very challenging problem. Being able to analyze the properties of such shapes and describe their behavior is the key issue in research. Also, considering photometric features can play an important role in many shape analysis applications, such as shape matching and correspondence because it contains rich information about the visual ...


Enhanced Diagnostic Accuracy Of Mammograms On A Mobile Device, Sharanya Padmanabhan Apr 2013

Enhanced Diagnostic Accuracy Of Mammograms On A Mobile Device, Sharanya Padmanabhan

Open Access Theses

With the death of a woman every 13 minutes in the US, and one every minute worldwide, due to breast cancer, the need for early detection cannot be overstated. Mammography is a boon for both early detection and screening of breast tumors. It is an imaging system that uses low dose (9mrem) x-rays for examining the breasts, by the electrons reflected from the tissues (thermoelectric effect). However, there are 20% false positives and 10% false negatives in current practice. Hence, there is a critical need for enhancing the accuracy of these mammograms. Towards this, this thesis was aimed at enhancing ...


Vision-Based Sensing And Optimal Control For Low-Cost And Small Satellite Platforms, Bradley Sease Jan 2013

Vision-Based Sensing And Optimal Control For Low-Cost And Small Satellite Platforms, Bradley Sease

Electronic Theses and Dissertations

Current trends in spacecraft are leading to smaller, more inexpensive options whenever possible. This shift has been primarily pursued for the opportunity to open a new frontier for technologies with a small financial obligation. Limited power, processing, pointing, and communication capabilities are all common issues which must be considered when miniaturizing systems and implementing low-cost components. This thesis addresses some of these concerns by applying two methods, in attitude estimation and control. Additionally, these methods are not restricted to only small, inexpensive satellites, but offer a benefit to large-scale spacecraft as well. First, star cameras are examined for the tendency ...


Process Study And Control Of Electron Beam Melting Technology Using Infrared Thermography, Jorge Mireles Jan 2013

Process Study And Control Of Electron Beam Melting Technology Using Infrared Thermography, Jorge Mireles

Open Access Theses & Dissertations

An IR camera was installed in an Arcam A2 system (Arcam AB, Mölndal, Sweeden) and layer-by-layer image acquisition was achieved. The camera's capability to detect manufacturing defects was evaluated by implementing computer vision techniques using LabVIEW measurement and programming software (National Instruments, Austin, TX). Thermal maps acquired by the IR camera allowed layer-by-layer part temperature to be recorded. A core objective of this research was to study the impact of processing temperature on EBM-fabricated Ti-6Al-4V parts and achieve controlled mechanical properties. In this research, build variations were achieved by modifying parameters that change processing temperature from the standard processing ...


Feature Extraction Through Median-Split Algorithm Segmentation For Melanoma Detection, Venkata Sai Narasimha Kaushik Ghantasala Jan 2013

Feature Extraction Through Median-Split Algorithm Segmentation For Melanoma Detection, Venkata Sai Narasimha Kaushik Ghantasala

Masters Theses

""Detection of melanoma remains an empirical clinical science. New tools for automatic discrimination of melanoma from benign lesions in digitized dermoscopy images may allow an improvement in early detection of melanoma. This research implements a fast version of the median split algorithm in an open source format and applied to four-color splitting of the lesion area to capture the architectural disorder apparent in melanoma colors. This version of the median split algorithm splits colors along the color axis with maximum range". For a dermoscopy set of 888 images, K-means clustering algorithm is compared with a median split algorithm to find ...


Automated Semantic Content Extraction From Images, Mahdi Arab Khazaeli Jan 2013

Automated Semantic Content Extraction From Images, Mahdi Arab Khazaeli

LSU Doctoral Dissertations

In this study, an automatic semantic segmentation and object recognition methodology is implemented which bridges the semantic gap between low level features of image content and high level conceptual meaning. Semantically understanding an image is essential in modeling autonomous robots, targeting customers in marketing or reverse engineering of building information modeling in the construction industry. To achieve an understanding of a room from a single image we proposed a new object recognition framework which has four major components: segmentation, scene detection, conceptual cueing and object recognition. The new segmentation methodology developed in this research extends Felzenswalb's cost function to ...


Digital Image-Based Frameworks For Monitoring And Controlling Of Particulate Systems, Bing Zhang Jan 2013

Digital Image-Based Frameworks For Monitoring And Controlling Of Particulate Systems, Bing Zhang

LSU Doctoral Dissertations

Particulate processes have been widely involved in various industries and most products in the chemical industry today are manufactured as particulates. Previous research and practise illustrate that the final product quality can be influenced by particle properties such as size and shape which are related to operating conditions. Online characterization of these particles is an important step for maintaining desired product quality in particulate processes. Image-based characterization method for the purpose of monitoring and control particulate processes is very promising and attractive. The development of a digital image-based framework, in the context of this research, can be envisioned in two ...