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Full-Text Articles in Engineering

Analysis Of Classifier Weaknesses Based On Patterns And Corrective Methods, Nicholas Skapura Jan 2021

Analysis Of Classifier Weaknesses Based On Patterns And Corrective Methods, Nicholas Skapura

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Classification is an important branch of machine learning that impacts many areas of modern life. Many classification algorithms (classifiers for short) have been developed. They have highly different levels of sophistication and classification accuracy. Classification problems often have highly different levels of hardness and complexity. Practitioners of classification modeling need better understanding of those algorithms in order to select the optimal algorithm for given classification problems. Researchers of classification need new insight on how given classifiers are weak and how they can be improved by correcting their classification errors. This dissertation introduces new tools and concepts to analyze classifier weakness ...


Low Frequency Oscillations Of Hemodynamic Parameters As A Novel Diagnostic Measure For Traumatic Brain Injury, Andrea Gomez Carrillo Jan 2021

Low Frequency Oscillations Of Hemodynamic Parameters As A Novel Diagnostic Measure For Traumatic Brain Injury, Andrea Gomez Carrillo

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There is a need to improve methods of monitoring patients with traumatic brain injury (TBI) in hospital settings. Current monitoring techniques and diagnosis methods are expensive, invasive, do not provide continuous measures, expose the patient to radiation, are ambiguous in the information they provide, and/or cannot be implemented at the bedside. These techniques measure imperative markers of brain function including intracranial pressure (ICP), cerebral blood flow (CBF), and oxygenation in the brain, among others. Hospitals not only require a practical method for real-time monitoring of patients at the bedside, but also meaningful metrics that characterize TBIs, since the variety ...


Modeling Of Excitation In Skeletal Muscle, Sabrina Kinzie Metzger Jan 2021

Modeling Of Excitation In Skeletal Muscle, Sabrina Kinzie Metzger

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Recent experimental findings in the Rich lab suggest there are important gaps in our understanding of muscle excitability in various disease states. To generate and test hypotheses as well as to determine whether our current understanding of various aspects of muscle excitation can fully explain experimental findings, an accurate model of muscle excitation was needed. Previous studies have modeled excitation of muscle, but in each case, important aspects were omitted. One reason for this is that little effort has been made to accurately simulate muscle action potentials. In this thesis I present progress made towards generation of a model of ...


Multi-Label Classification On Locally-Linear Data: Application To Chemical Toxicity Prediction, Xiu Huan Yap Jan 2021

Multi-Label Classification On Locally-Linear Data: Application To Chemical Toxicity Prediction, Xiu Huan Yap

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Computational models may assist in identification and prioritization of large chemical libraries. Recent experimental and data curation efforts, such as from the Tox21 consortium, have contributed towards toxicological datasets of increasing numbers of chemicals and toxicity endpoints, creating a golden opportunity for the exploration of multi-label learning and deep learning approaches in this thesis. Multi-label classification (MLC) methods may improve model predictivity by accounting for label dependence. However, current measures of label dependence, such as correlation coefficient, are inappropriate for datasets with extreme class imbalance, often seen in toxicological datasets. In this thesis, we propose a novel label dependence measure ...


Alterations In Cardiac Motions Of The Failing Heart During Direct Mechanical Ventricular Actuation, Benjamin Allyn Schmitt Jan 2021

Alterations In Cardiac Motions Of The Failing Heart During Direct Mechanical Ventricular Actuation, Benjamin Allyn Schmitt

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Objectives: Heart failure (HF) refractory to medical management can be effectively treated with mechanical support. However, available devices are frequently associated with complications due to blood contact. Direct cardiac compression (DCC) devices augment LV systolic pump function by externally compressing the heart surface. Direct Mechanical Ventricular Actuation (DMVA) is a unique DCC method providing not only systolic but, importantly, diastolic support. However, DCC in general remains a relatively poorly understood modality. The purpose of this study was to examine DMVA’s effect on restoration of physiologic function in the failing heart. Methods: Global ischemic HF was induced with 5 mins ...


A Deep Understanding Of Structural And Functional Behavior Of Tabular And Graphical Modules In Technical Documents, Michail Alexiou Jan 2021

A Deep Understanding Of Structural And Functional Behavior Of Tabular And Graphical Modules In Technical Documents, Michail Alexiou

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The rapid increase of published research papers in recent years has escalated the need for automated ways to process and understand them. The successful recognition of the information that is contained in technical documents, depends on the understanding of the document’s individual modalities. These modalities include tables, graphics, diagrams and etc. as defined in Bourbakis’ pioneering work. However, the depth of understanding is correlated to the efficiency of detection and recognition. In this work, a novel methodology is proposed for automatic processing of and understanding of tables and graphics images in technical document. Previous attempts on tables and graphics ...


Goal Management In Multi-Agent Systems, Venkatsampath Raja Gogineni Jan 2021

Goal Management In Multi-Agent Systems, Venkatsampath Raja Gogineni

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Autonomous agents in a multi-agent system coordinate to achieve their goals. However, in a partially observable world, current multi-agent systems are often less effective in achieving their goals. In much part, this limitation is due to an agent's lack of reasoning about other agents and their mental states. Another factor is the agent's inability to share required knowledge with other agents and the lack of explanations in justifying the reasons behind the goal. This research addresses these problems by presenting a general approach for agent goal management in unexpected situations. In this approach, an agent applies three main ...


Adaptive Two-Stage Edge-Centric Architecture For Deeply-Learned Embedded Real-Time Target Classification In Aerospace Sense-And-Avoidance Applications, Nicholas A. Speranza Jan 2021

Adaptive Two-Stage Edge-Centric Architecture For Deeply-Learned Embedded Real-Time Target Classification In Aerospace Sense-And-Avoidance Applications, Nicholas A. Speranza

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With the growing number of Unmanned Aircraft Systems, current network-centric architectures present limitations in meeting real-time and time-critical requirements. Current methods utilizing centralized off-platform processing have inherent energy inefficiencies, scalability challenges, performance concerns, and cyber vulnerabilities. In this dissertation, an adaptive, two-stage, energy-efficient, edge-centric architecture is proposed to address these limitations. A novel, edge-centric Sense-and-Avoidance architecture framework is presented, and a corresponding prototype is developed using commercial hardware to validate the proposed architecture. Instead of a network-centric approach, processing is distributed at the logical edge of the sensors, and organized as Detection and Classification Subsystems. Classical machine vision algorithms are ...


Application Of Analogical Reasoning For Use In Visual Knowledge Extraction, Kara Lian Combs Jan 2021

Application Of Analogical Reasoning For Use In Visual Knowledge Extraction, Kara Lian Combs

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There is a continual push to make Artificial Intelligence (AI) as human-like as possible; however, this is a difficult task because of its inability to learn beyond its current comprehension. Analogical reasoning (AR) has been proposed as one method to achieve this goal. Current literature lacks a technical comparison on psychologically-inspired and natural-language-processing-produced AR algorithms with consistent metrics on multiple-choice word-based analogy problems. Assessment is based on “correctness” and “goodness” metrics. There is not a one-size-fits-all algorithm for all textual problems. As contribution in visual AR, a convolutional neural network (CNN) is integrated with the AR vector space model, Global ...


Deep Learning For Compressive Sar Imaging With Train-Test Discrepancy, Morgan R. Mccamey Jan 2021

Deep Learning For Compressive Sar Imaging With Train-Test Discrepancy, Morgan R. Mccamey

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We consider the problem of compressive synthetic aperture radar (SAR) imaging with the goal of reconstructing SAR imagery in the presence of under sampled phase history. While this problem is typically considered in compressive sensing (CS) literature, we consider a variety of deep learning approaches where a deep neural network (DNN) is trained to form SAR imagery from limited data. At the cost of computationally intensive offline training, on-line test-time DNN-SAR has demonstrated orders of magnitude faster reconstruction than standard CS algorithms. A limitation of the DNN approach is that any change to the operating conditions necessitates a costly retraining ...


Silk Hydrogels Incorporated With Melanin, Anne Lutz Jan 2021

Silk Hydrogels Incorporated With Melanin, Anne Lutz

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Melanin is a naturally produced pigment found within the human body. Melanin is known for its ability to protect against Ultra Violet light, but also its ability to allow for mechanical protection. Making melanin a good addition to biomedical devices such as hydrogels. Silk hydrogels are weak in their load bearing capabilities but are known for their biocompatibility, biodegradability, and porosity. This makes the silk hydrogel a good material to incorporate melanin into in order to improve the mechanical properties. For the silk solution to form a solid, there must be a presence of both a catalyst and an oxidizer ...


Computational Simulation And Analysis Of Neuroplasticity, Madison E. Yancey Jan 2021

Computational Simulation And Analysis Of Neuroplasticity, Madison E. Yancey

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Homeostatic synaptic plasticity is the process by which neurons alter their activity in response to changes in network activity. Neuroscientists attempting to understand homeostatic synaptic plasticity have developed three different mathematical methods to analyze collections of event recordings from neurons acting as a proxy for neuronal activity. These collections of events are from control data and treatment data, referring to the treatment of neuron cultures with pharmacological agents that augment or inhibit network activity. If the distribution of control events can be functionally mapped to the distribution of treatment events, a better understanding of the biological processes underlying homeostatic synaptic ...


Mathematical Formula Recognition And Automatic Detection And Translation Of Algorithmic Components Into Stochastic Petri Nets In Scientific Documents, Elisavet Elli Kostalia Jan 2021

Mathematical Formula Recognition And Automatic Detection And Translation Of Algorithmic Components Into Stochastic Petri Nets In Scientific Documents, Elisavet Elli Kostalia

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A great percentage of documents in scientific and engineering disciplines include mathematical formulas and/or algorithms. Exploring the mathematical formulas in the technical documents, we focused on the mathematical operations associations, their syntactical correctness, and the association of these components into attributed graphs and Stochastic Petri Nets (SPN). We also introduce a formal language to generate mathematical formulas and evaluate their syntactical correctness. The main contribution of this work focuses on the automatic segmentation of mathematical documents for the parsing and analysis of detected algorithmic components. To achieve this, we present a synergy of methods, such as string parsing according ...


Hardware Security And Side Channel Power Analysis For 16x16 Booth Multiplier In 65nm Cmos Technology, Kanchan Vissamsetty Jan 2021

Hardware Security And Side Channel Power Analysis For 16x16 Booth Multiplier In 65nm Cmos Technology, Kanchan Vissamsetty

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As feature size is scaling down, dynamic power consumption reduces but static power consumption increases. Due to the increase of static power, leakage currents as a source, the information can be exploited successfully as a side-channel to recover the secrets of the cryptographic implementations. An attacker who has access to the hardware fabrication can insert a Trojan to the design to steal or alter information. In this thesis, a post-fab static voltage variation/detection technique is developed to detect the potential fabrication process Trojan insertion. The technique is, dividing the designed circuit into N equal segments, where each segment would ...


Development Of A Robust And Tunable Aircraft Guidance Algorithm, Jacob R. Spangenberg Jan 2021

Development Of A Robust And Tunable Aircraft Guidance Algorithm, Jacob R. Spangenberg

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A set of guidance control laws is developed for application to a reduced order dynamic aircraft model. A feedback control formulation utilizing a linear quadratic regulator (LQR) is developed, together with methods for easing the design burden associated with gain tuning. Metrics are developed to assess the stability margin of the controller over the full flight envelope of a notional unmanned aerial vehicle (UAV) model. A feedforward control path is then added to the architecture. The performance of the guidance control laws is assessed through time domain step response metrics as well as through execution of a design mission. The ...


Sample Mislabeling Detection And Correction In Bioinformatics Experimental Data, Soon Jye Kho Jan 2021

Sample Mislabeling Detection And Correction In Bioinformatics Experimental Data, Soon Jye Kho

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Sample mislabeling or incorrect annotation has been a long-standing problem in biomedical research and contributes to irreproducible results and invalid conclusions. These problems are especially prevalent in multi-omics studies in which a large set of biological samples are characterized by multiple types of omics platforms at different times or different labs. While multi-omics studies have demonstrated tremendous value in understanding disease biology and improving patient outcomes, the complexity of these studies may increase opportunities for human error. Fortunately, the interrelated nature of the data collected in multi-omics studies can be exploited to facilitate the identification and, in some cases, correction ...


Interferometry Analysis Method For Colliding Plasma Generated With Exploded Wires, Michael D. Gruesbeck Jan 2021

Interferometry Analysis Method For Colliding Plasma Generated With Exploded Wires, Michael D. Gruesbeck

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Building upon recent work to estimate electron and ion densities from paired interferograms, the current work develops a model for the 2D interference phase function. Unlike the previous work that only estimated a radial plasma profile from images of a singly exploded straight Cu wire, we estimate 2D properties from a colliding plasma generated from two simultaneously exploded wires. First, a 2D phase model is proposed for the interference patterns of the images taken at 1064 nm and 532 nm. Then, the model parameters are estimated using Fourier analysis. Secondly, the plasma region in each image is partitioned into subregions ...


Contact Fatigue Of Spur Gear Operating Under Starved Lubrication Condition, Aparna Udthala Jan 2021

Contact Fatigue Of Spur Gear Operating Under Starved Lubrication Condition, Aparna Udthala

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This study describes contact fatigue behavior of spur gear contacts operating under mixed elastohydrodynamic condition. The focus is placed on the starvation effect on fatigue crack initiation. With the model, parametric simulations are carried out with different contact parameters. In the process, the lubricant supply is varied to alter the lubrication condition from fully flooded to severely starved circumstance. Multi-axial stress fields induced by surface normal and tangential tractions are evaluated, whose amplitudes and means are used in a multi-axial fatigue criterion to determine the crack initiation life. It is found a lower lubricant viscosity elongates fatigue life when severe ...


Aqueous Fabrication Of Pristine And Oxide Coated Znse Nanoparticles, Nicholas L. Van Zandt Jan 2021

Aqueous Fabrication Of Pristine And Oxide Coated Znse Nanoparticles, Nicholas L. Van Zandt

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Semiconducting nanoparticles have received significant attention due to their unique optoelectronic properties. Quantum dots (QDs), a class of spherical nanoparticles, possess a size-dependent bandgap and photoluminescence at visible wavelengths. QDs have many applications including biological labelling, solar cells, chemical impurity detection, and optical glasses. Doping QDs into optical glasses is highly desirable. High-quality QDs can be synthesized via liquid solution methods. However, solution-synthesized QDs often degrade over time and they cannot survive incorporation into a glass melt without protection. In this work, the aqueous synthesis of ZnSe QDs and coating with nanometer silica and alumina protective shells are investigated. The ...


Fabrication And Analysis Of High-Performance Thermochemically Densified Wood, Victor Arulappan Pushparaj Jan 2021

Fabrication And Analysis Of High-Performance Thermochemically Densified Wood, Victor Arulappan Pushparaj

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While wood construction may be as ancient as humanity itself, wood remains one of the most utilized structural materials because of it’s availability, low cost, durability, surprisingly high specific mechanical properties, and renewability. Recent research into wood-based materials has focused on strategies for enhancing the strength and stiffness of as-grown materials. We fabricated densified wood by thermochemically treating raw white oak wood in Na2SO3 and NaOH solutions, followed by compressing the treated wood at 5MPa at high temperature. Treating the raw wood in NaOH and Na2SO3 cleaves the alpha-O-4 ether bond and beta-O-4 ether bonds, thus dissolving most of ...


Performance Of A Dual Plane Airfoil Model With Varying Gap, Stagger, And Decalage Using Pressure Measurements And Particle Image Velocimetry, Salome Kenneth Nunes Jan 2021

Performance Of A Dual Plane Airfoil Model With Varying Gap, Stagger, And Decalage Using Pressure Measurements And Particle Image Velocimetry, Salome Kenneth Nunes

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The dual-plane airfoil has been adopted in the design of aircraft wings, wind turbine blades, and propellers. The purpose of this research is to investigate the most important design parameters of a dual-plane airfoil model for the best aerodynamic performance, such as gap, stagger, and decalage. The dual-plane airfoil model was designed using the S826 profile. A mechanical mechanism with electrical actuator control is particularly designed to alter the gap and stagger smoothly, as well as the angle of attack (AOA) for each airfoil. It results in a gap range of 1.38c to 2.17c, a stagger range of ...


Texture-Driven Image Clustering In Laser Powder Bed Fusion, Alexander H. Groeger Jan 2021

Texture-Driven Image Clustering In Laser Powder Bed Fusion, Alexander H. Groeger

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The additive manufacturing (AM) field is striving to identify anomalies in laser powder bed fusion (LPBF) using multi-sensor in-process monitoring paired with machine learning (ML). In-process monitoring can reveal the presence of anomalies but creating a ML classifier requires labeled data. The present work approaches this problem by printing hundreds of Inconel-718 coupons with different processing parameters to capture a wide range of process monitoring imagery with multiple sensor types. Afterwards, the process monitoring images are encoded into feature vectors and clustered to isolate groups in each sensor modality. Four texture representations were learned by training two convolutional neural network ...


Design And Implementation Of Fully Integrated Cmos On-Chip Bandpass Filter With Wideband High-Gain Low Noise Amplifier, Yu Wang Jan 2021

Design And Implementation Of Fully Integrated Cmos On-Chip Bandpass Filter With Wideband High-Gain Low Noise Amplifier, Yu Wang

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Current trends of fully integrated CMOS on-chip bandpass filter are classified into 1) the component level (i.e., active inductor, Q-enhanced passive inductor, negative resistance cancellation), and 2) the circuit level (i.e., adding transmission zeros on stopband, applying the zigzag technique for fewer inductors, superposition of different resonators). The demand for monolithic designs for portable devices attracts market interest in a fully integrated CMOS on-chip bandpass filter. Optimized minimal inductors (OMI) bandpass filter is a good platform for use in both active and passive bandpass filters, mainly because 1) it provides good stopband rejection for high interface attenuation, and ...


Development Of A Combined Thermal Management And Power Generation System Using A Multi-Mode Rankine Cycle, Nathaniel M. Payne Jan 2021

Development Of A Combined Thermal Management And Power Generation System Using A Multi-Mode Rankine Cycle, Nathaniel M. Payne

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Two sub-systems that present a significant challenge in the development of high performance air vehicle exceeding speeds of Mach 5 are the power generation and thermal management sub-systems. The air friction experienced at high speeds, particularly around the engine, generates large thermal loads that need to be managed. In addition, traditional jet engines do not operate at speeds greater than Mach 3, therefore eliminating the possibility of a rotating power generator. A multi-mode water-based Rankine cycle is an innovative method to address both of these constraints of generating power and providing cooling. Implementing a Rankine cycle-based system allows for the ...


Influence Of Build Direction On Interface Regions In Additive Manufacturing Of Multi-Material Refractory Alloys, Cherish Christina Clark Lesko Jan 2021

Influence Of Build Direction On Interface Regions In Additive Manufacturing Of Multi-Material Refractory Alloys, Cherish Christina Clark Lesko

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In the pursuit of optimum performance, materials engineering seeks to design the microstructure and thus the properties of a material through the control of the material composition and processing. Functionally graded materials (FGM) are designed to incorporate location-specific material properties through compositional changes within the part. Moving toward location-specific design of material properties requires the ability to produce material gradients in three dimensions which can be accomplished through the use of additive manufacturing (AM). This research examines the composition-process-structure-property relationship of early iteration titanium (Ti) and tantalum (Ta) graded alloys built in a novel laser powder bed fusion (LPBF) process ...


Unraveling The Etiologies Of Discrete Subaortic Stenosis: A Focus On Left Ventricular Outflow Tract Hemodynamics, Jason A. Shar Jan 2021

Unraveling The Etiologies Of Discrete Subaortic Stenosis: A Focus On Left Ventricular Outflow Tract Hemodynamics, Jason A. Shar

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Discrete subaortic stenosis (DSS) is an obstructive cardiac disease characterized by the formation of a thin fibromuscular ring of tissue in the left ventricular (LV) outflow tract (LVOT). Although its etiology is unknown, the association between DSS, pediatric age, and morphological LVOT abnormalities points to a potential hemodynamic etiology. Here, altered subaortic flow dynamics, stemming from deviated LVOT anatomy, may promote lesion formation through local fluid shear stress abnormalities triggering membrane formation. The assessment of this hypothetical pathway requires elucidation of the complex LV wall shear stress (WSS) environment. The central hypothesis of this dissertation is that altered LV hemodynamics ...


Bayesian Inspired Multi-Fidelity Optimization With Aerodynamic Design, Christopher Corey Fischer Jan 2021

Bayesian Inspired Multi-Fidelity Optimization With Aerodynamic Design, Christopher Corey Fischer

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In most engineering design problems, there exist multiple models of varying fidelities for use in predicting a single system response such as Computational Fluid Dynamics (CFD) models constructed using Potential Flow, Euler equations, or full physics Navier Stokes implementation. Engineering design is constantly pushing the forefront of the field through imposing stricter and more complex constraints on system performance, thus elevating the need for use of high-fidelity models in the design process. Increasing fidelity level often correlates to an increase in cost (financial, computational time, and computational resources). Traditional design processes rely upon low-fidelity models for expedience and resource savings ...


The Theory And Design Of Class E Power Amplifiers For Impulse Excitation In Nuclear Magnetic Resonance, Owen D. Riemer Jan 2021

The Theory And Design Of Class E Power Amplifiers For Impulse Excitation In Nuclear Magnetic Resonance, Owen D. Riemer

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A new method for analyzing the effectiveness of NMR impulse power amplifiers was developed using a classical linear systems approach to NMR. The method demonstrates a way to compare NMR power amplifiers and outputs. Thermodynamic calculations and the harmonic content of NMR amplifiers is presented to provide a complete description of the NMR power amplifier design problem. A design procedure for class E NMR power amplifiers with a pi-impedance matching network is outlined for matching the amplifier to the transmitter coil. The thesis concludes with the presentation of a 53 MHz power amplifier developed with the procedure. The complete amplifier ...


Edge Processing Of Image For Uas Sense And Avoidance, Christopher J. Rave Jan 2021

Edge Processing Of Image For Uas Sense And Avoidance, Christopher J. Rave

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Today there is a large market for Unmanned Aerial Systems. Although most current systems are remotely piloted by operators on the ground, increasingly, many of these systems will use some sort of automatic flight controller to help mitigate new challenges, due to their deployment at growing scale. These challenges include, but are not limited to, shortage of FAA-certified UAS pilots, transmission bandwidth and delay constraints and cyber security threats associated with wireless networking, profitability of operations constrained by energy capacity and efficiency and air dynamics planning, and etc. In order to address these rising challenges, this thesis is a part ...


Phase Transformation In The Aluminum/Tungsten System, Ammar Azeez Mahdi Al Yasari Jan 2021

Phase Transformation In The Aluminum/Tungsten System, Ammar Azeez Mahdi Al Yasari

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Formation and growth mechanisms of intermetallic compounds in the aluminum/tungsten system were studied during consolidation and subsequent heat treatment. Three different processes, spark plasma sintering (SPS), laser powder bed fusion (LPBF), and metal inert gas welding (MIG) were used, and each of these processes were followed up with heat treatment at different conditions. Al12W, Al5W and Al4W are the three intermetallics that are stable in the system in room temperature, and they were expected to form at the interface between tungsten and aluminum at different temperature ranges. Contrary to expectations, the Al5W phase was not observed during this study ...