Engineering Commons^™

Cognitively Sensitive User Interface For Command And Control Applications, Michael James Findler

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While there are broad guidelines for display or user interface design, creating effective human-computer interfaces for complex, dynamic systems control is challenging. Ad hoc approaches which consider the human as an afterthought are limiting. This research proposed a systematic approach to human / computer interface design that focuses on both the semantic and syntactic aspects of display design in the context of human-in-the-loop supervisory control of intelligent, autonomous multi-agent simulated unmanned aerial vehicles (UAVs). A systematic way to understand what needs to be displayed, how it should be displayed, and how the integrated system needs to be assessed is outlined …

Energy Reduction For Asynchronous Circuits In Soc Applications, Harish Gopalakrishnan

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As complexity increases and gate sizes shrink for monolithic, mixed-signal integrated circuit (IC) technologies, two problems become dominant: substrate noise caused by digital clocks interfering with highly sensitive analog and radio frequency (RF) components and parametric variations that can cause circuit delays to vary in excess of 35%. Clockless logic (or asynchronous) circuits address both of these issues and more. Clockless, asynchronous circuits are by nature delay-insensitive making them immune to parametric variations. Even more important is the processing characteristics of clockless asynchronous circuits, which eliminate highly intricate clock signals that cause large power spikes every time they switch. Consequently, …

Human Micro-Range/Micro-Doppler Signature Extraction, Association, And Statistical Characterization For High-Resolution Radar, Orelle Ryan Fogle

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Recently, the use of micro-Doppler (μD) radar signatures for classification has become an area of focus, in particular for the case of dynamic targets where many components are interacting over time. To fully exploit the signature information, individual scattering centers may be extracted and associated over the full target observation. Due to the complexity of the target signature, the automated analysis is very difficult. However, the availability of ultra-fine resolution or micro-range (μR) resolution along with target scattering knowledge, can aid this process immensely. Here, we describe a feature extraction algorithm which utilizes both μD and …

Multi-Objectivization In Genetic Algorithms, Darrell F. Lochtefeld

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Multi-objectivization is the process of reformulating a single-objective problem into a multi-objective problem and solving it with a multi-objective method in order to provide a solution to the original single-objective problem. Multi-objectivization differs from other traditional divide-and-conquer techniques-the method splits the objective function rather than the search space. Prior to recent evidence, such reformulations were thought to make a problem more complex. However, more recent research suggests that decomposition in the objective space can lead to useful optimization techniques when coupled with a population-based search. Machine based optimization techniques are varied but often based upon an analogy to real-world phenomena. …

Surface Stress Sensors For Closed Loop Low Reynolds Number Separation Control, Christopher R. Marks

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Low Reynolds number boundary layer separation causes reduced aerodynamic performance in a variety of applications such as MAVs, UAVs, and turbomachinery. The inclusion of a boundary layer separation control system offers a way to improve efficiency in conditions that would otherwise result in poor performance. Many effective passive and active boundary layer control methods exist. Active methods offer the ability to turn on, off, or adjust parameters of the flow control system with either an open loop or closed loop control strategy using sensors. This research investigates the use of a unique sensor called Surface Stress Sensitive Film (S3F) in …

Multidisciplinary Optimization Framework For High Speed Train Using Robust Hybrid Ga-Pso Algorithm, Veera Venkata Sunil Kumar Vytla

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High speed trains are the most efficient means of public transportation. However the speed of the train needs to be increased (> 350 km/hr) to cover large distances in a short time to make it accessible to large population. With the increase in speed, number of issues related to efficiency, safety and comfort like the aerodynamic drag, structural strength, as well as the noise levels inside and outside of the train etc. need to be considered in the design of the high speed trains. Hence making it a multi disciplinary design problem. There are a large number of parameters from …

Fusion Of Video And Multi-Waveform Fmcw Radar For Traffic Surveillance, Nicholas C. Gale

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Modern frequency modulated continuous wave (FMCW) radar technology provides the ability to modify the system transmission frequency as a function of time, which in turn provides the ability to generate multiple output waveforms from a single radar unit. Current low-power multi-waveform FMCW radar techniques lack the ability to reliably associate measurements from the various waveform sections in the presence of multiple targets and multiple false detections within the field-of-view. Two approaches are developed here to address this problem.

The first approach takes advantage of the relationships between the waveform segments to generate a weighting function for candidate combinations of measurements …

Process Sequencing For Fatigue Life Extension Of Large Scale Laser Peened Components, Thomas Joshua Spradlin

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Mechanical surface enhancement techniques have been used to successfully increase the fatigue life of metallic components. These techniques impart compressive surface residual stresses that reduce the tensile stresses experienced during service loading. Laser Peening (LP) is a surface enhancement technique that uses high intensity, short duration laser pulses to create plastic shockwaves in metallic components. Experimental investigations and limited simulation studies have been conducted to determine the effects on the fatigue life of simple coupons when key LP parameters are varied. Used primarily in the aerospace and biomedical engineering fields, LP has been limited to industries that can afford its …

Efficient Risk Assessment Using Probability Of Fracture Nomographs, Venkateswaran Shanmugam

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The traditional risk-based design processes involve designing the structure based on risk estimates obtained during several iterations of an optimization routine. This approach is computationally expensive for large-scale aircraft structural systems because of the iterative nature of the risk assessment methods. Therefore, this research introduces the concept of risk-based design plots that can be used for both structural sizing and risk assessment of stiffened plates when maximum allowable crack length information is available. These plots are obtained using normalized probability density functions of load and material properties and are applicable for any arbitrary load and strength magnitudes that follow similar …

Lithium-Ion Battery Anodes Of Randomly Dispersed Carbon Nanotubes, Nanofibers, And Tin-Oxide Nanoparticles, Gerard Klint Simon

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Lithium-ion battery anodes with a nanostructure of randomly dispersed carbon nanofibers (CNFs), carbon nanotubes (CNTs), and nanoparticles of tin-oxide or silicon were fabricated and tested in order to develop high capacity, easily manufactured anodes. In these anodes, a mesh of CNTs and CNFs form a conductive network within which the nanoparticles of tin-oxide are suspended. The CNT network directs electron flow to and from the nanoparticles while accommodating their volume changes. The CNFs were intended to aid electron transport by serving as conduction channels between the CNTs and the current collector. Secondarily, the CNFs reinforce the physical structure of the …

Development And Evaluation Of An Interface Aid To Support Web Based Information Seeking For The Blind Research Study, Carissa Ann Brunsman-Johnson

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Information seeking on websites has become more and more challenging for people who are blind. Screen readers attempt to make that task easier by introducing new commands and functionality but there still exists a fundamental gap in the difficulty for people who are blind compared to their sighted counterparts. This research identifies the strategies used by people who are blind and sighted to create an information seeking model, develop the Keywords Expected for Your Search (KEYS) conceptual model for assisting task performance and evaluate a KEYS prototype of this concept for information search and retrieval.

This information seeking model was …

Dynamic Control For A Pneumatic Muscle Actuator To Achieve Isokinetic Muscle Strengthening, Kara Lynn Hall

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A pneumatic muscle actuator (PMA) is a device that mimics behavior of skeletal muscle by contracting and generating force in a nonlinear manner when activated. PMAs have a high power to weight ratio and possess unique characteristics which make them ideal for human interaction. Due to their nonlinear dynamics, PMAs are difficult to control, presenting challenges in system implementation. Despite these challenges, PMAs have great potential as a source of resistance for strength training and rehabilitation. The main goal of this work was to control a PMA for use in isokinetic exercise, potentially benefiting anyone in need of optimal strength …

Quantification Of Model-Form, Predictive, And Parametric Uncertainties In Simulation-Based Design, Matthew E. Riley

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Traditional uncertainty quantification techniques in simulation-based analysis and design focus upon on the quantification of parametric uncertainties-inherent natural variations of the input variables. This is done by developing a representation of the uncertainties in the parameters and then efficiently propagating this information through the modeling process to develop distributions or metrics regarding the output responses of interest. However, in problems with complex or newer modeling methodologies, the variabilities induced by the modeling process itself-known collectively as model-form and predictive uncertainty-can become a significant, if not greater source of uncertainty to the problem. As such, for efficient and accurate uncertainty measurements, …