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Full-Text Articles in Engineering

Increasing Isolation Between Closely Spaced X-Band Planar Transmit/Receive Antennas, Jacob Bartschi Mar 2020

Increasing Isolation Between Closely Spaced X-Band Planar Transmit/Receive Antennas, Jacob Bartschi

Undergraduate Honors Theses

Coupling between Tx/Rx antennas is a common and much-researched problem that is especially difficult when the antennas both placed close together and on the same plane. New systems with smaller footprints require this kind of placement while still maintaining the same levels of isolation as before. Traditional solutions for coupling involve large and heavy machined parts that are unsuited to compact systems. Many techniques have been proposed over the decades, but few have been applied to X-band antennas in closely spaced configurations. This thesis investigates those techniques, applies them to closely spaced X-band antennas, and compares them to conventional methods …


Analysis Of Feature Extraction In Knee Cartilage Semantic Segmentation Convolutional Neural Networks, Logan Thorneloe Mar 2020

Analysis Of Feature Extraction In Knee Cartilage Semantic Segmentation Convolutional Neural Networks, Logan Thorneloe

Undergraduate Honors Theses

Recent advances in deep learning and convolutional neural networks (CNNs) have shown promise for automatic segmentation in magnetic resonance images. However, because of the stochastic nature of the training process, it is difficult to interpret what information networks learn to represent. This study explores multiple difference metrics between networks to determine semantic relationships between knee cartilage tissues. It explores how differences in learned weights and output activations between networks can be used to express these relationships. These findings are further supported by training multi-class networks to segment multiple tissues to compare network accuracy across different tissue combinations. This study shows …


Irregular Quadrature Amplitude Modulation For Adaptive Physical-Layer Security, Hunter Searle, Marco A. C. Gomes, Joao P. Vilela, Willie K. Harrison Aug 2019

Irregular Quadrature Amplitude Modulation For Adaptive Physical-Layer Security, Hunter Searle, Marco A. C. Gomes, Joao P. Vilela, Willie K. Harrison

Undergraduate Honors Theses

This thesis propose adding an irregular quadrature amplitude modulation (QAM) constellation to a wireless transmission scheme in order to obtain greater control over the signal-tonoise ratio (SNR) required to successfully decode the signal. By altering the separation between adjacent symbols, the minimum required SNR is raised without degradation in the performance of the scheme. This allows the system to adapt to preferable channel conditions for the authorized user, making it harder for eavesdroppers to intercept and decode the transmission, thus making the communication safer. In addition, we show that by overlaying a coset code onto the QAM constellation, a new, …