A Short Tutorial on Inertial Navigation System and Global Positioning System Integration

The purpose of this document is to describe a simple method of integrating Inertial Navigation System (INS) information with Global Positioning System (GPS) information for an improved estimate of vehicle attitude and position. A simple two dimensional (2D) case is considered. The attitude estimates are derived from sensor data and used in the estimation of vehicle position and velocity through dead reckoning within the INS. The INS estimates are updated with GPS estimates using a Kalman filter. This tutorial is intended for the novice user with a focus on bringing the reader from raw sensor measurements to an integrated position and attitude estimate. An application is given using a remotely controlled ground vehicle operating in assumed 2D environment. The theory is developed first followed by an illustrative example

Architecture and Information Requirements to Assess and Predict Flight Safety Risks During Highly Autonomous Urban Flight Operations

As aviation adopts new and increasingly complex operational paradigms, vehicle types, and technologies to broaden airspace capability and efficiency, maintaining a safe system will require recognition and timely mitigation of new safety issues as they emerge and before significant consequences occur. A shift toward a more predictive risk mitigation capability becomes critical to meet this challenge. In-time safety assurance comprises monitoring, assessment, and mitigation functions that proactively reduce risk in complex operational environments where the interplay of hazards may not be known (and therefore not accounted for) during design. These functions can also help to understand and predict emergent effects caused by the increased use of automation or autonomous functions that may exhibit unexpected non-deterministic behaviors. The envisioned monitoring and assessment functions can look for precursors, anomalies, and trends (PATs) by applying model-based and data-driven methods. Outputs would then drive downstream mitigation(s) if needed to reduce risk. These mitigations may be accomplished using traditional design revision processes or via operational (and sometimes automated) mechanisms. The latter refers to the in-time aspect of the system concept. This report comprises architecture and information requirements and considerations toward enabling such a capability within the domain of low altitude highly autonomous urban flight operations. This domain may span, for example, public-use surveillance missions flown by small unmanned aircraft (e.g., infrastructure inspection, facility management, emergency response, law enforcement, and/or security) to transportation missions flown by larger aircraft that may carry passengers or deliver products. Caveat: Any stated requirements in this report should be considered initial requirements that are intended to drive research and development (R&D). These initial requirements are likely to evolve based on R&D findings, refinement of operational concepts, industry advances, and new industry or regulatory policies or standards related to safety assurance

HVAC System Energy Audit for Leverett Elementary School

Leverett Elementary School is located in Fayetteville, AR. The school needs significant upgrades to its infrastructure. The Fayetteville Public School District has voted to pursue an Energy Services Performance Contract (ESPC) in order to finance the desired upgrades to Leverett Elementary, among other schools in the district. The scope of this thesis was to perform an energy audit on the existing heating, ventilation, and air conditioning (HVAC) system. By using an energy modeling software, eQuest, the building and the existing base system were modeled to determine utility consumption. Three different HVAC system alternatives were analyzed against the base system by inputting them into eQuest. Alternative 1 is a plant system with secondary fan coil units. Alternative 2 is a decentralized packaged system. Alternative 3 is a plant system with a secondary air handler that serves terminal variable air volume (VAV) boxes. The three alternatives were compared against each other within three criteria: economic, environmental, and social benefits. For the economic analysis, capital and operating costs were analyzed to determine the net present value and internal rate of return for each alternative. For the environmental analysis, the utility consumption output from the eQuest models was input into an online tool, CometFarm, to calculate total energy consumption and CO2 equivalent emissions. For the social analysis, knowledge from extensive systems research and industry experience guided the consideration and assessment of potential impacts. The Plant System with Secondary Fan Coil Units, i.e., Alternative 1, was determined to be the optimal system recommendation for the client. It had the lowest CO2 equivalent greenhouse gas emissions and the greatest net present value and rate of return

Evaluation of DNA from Blood and Saliva Overtime

In this research, we will examine the quantity of DNA over time. In John M. Butlers, Fundamentals of Forensic DNA Typing , he charts out the average amount of DNA extracted from different bodily fluid samples. Examples include blood, semen, saliva, urine, etc. Though valuable, the values presented are in the cases of a fresh extraction of the sample. It is important to note that in most cases when DNA is being extracted from crime scene evidence, the samples are not fresh and have been degraded to some extent. On a crime scene, time is only one of the factors affecting the degradation of the samples; temperature, pH, and quantity of the sample are other factors that affect the quantity and quality of the DNA extracted. The purpose of the research is to evaluate how time alone can affect the amount of DNA received from samples of bodily fluid, specifically blood and saliva. Understanding the relationship between time and the quantity of DNA present can give investigators knowledge of how long a sample has been deposited at a crime scene. Results showed that though there was not a steady decline in the amount of DNA yielded from fresh samples to 4-month samples, the study shows that quantifiable amounts of DNA can still be recovered despite being under unfavorable conditions. Time is a factor of the quality of DNA present in a sample, but there is not an absolute relationship between time and DNA yield according to this study

Flight Tests of a Remaining Flying Time Prediction System for Small Electric Aircraft in the Presence of Faults

This paper addresses the problem of building trust in the online prediction of a battery powered aircraft's remaining flying time. A series of flight tests is described that make use of a small electric powered unmanned aerial vehicle (eUAV) to verify the performance of the remaining flying time prediction algorithm. The estimate of remaining flying time is used to activate an alarm when the predicted remaining time is two minutes. This notifies the pilot to transition to the landing phase of the flight. A second alarm is activated when the battery charge falls below a specified limit threshold. This threshold is the point at which the battery energy reserve would no longer safely support two repeated aborted landing attempts. During the test series, the motor system is operated with the same predefined timed airspeed profile for each test. To test the robustness of the prediction, half of the tests were performed with, and half were performed without, a simulated powertrain fault. The pilot remotely engages a resistor bank at a specified time during the test flight to simulate a partial powertrain fault. The flying time prediction system is agnostic of the pilot's activation of the fault and must adapt to the vehicle's state. The time at which the limit threshold on battery charge is reached is then used to measure the accuracy of the remaining flying time predictions. Accuracy requirements for the alarms are considered and the results discussed

Verification of Prognostic Algorithms to Predict Remaining Flying Time for Electric Unmanned Vehicles

This paper addresses the problem of building trust in the online prediction of a eUAVs remaining available flying time powered by lithium-ion polymer batteries. A series of ground tests are described that make use of an electric unmanned aerial vehicle (eUAV) to verify the performance of remaining flying time predictions. The algorithm verification procedure described is implemented on a fully functional vehicle that is restrained to a platform for repeated run-to-functional-failure (charge depletion) experiments. The vehicle under test is commanded to follow a predefined propeller RPM profile in order to create battery demand profiles similar to those expected during flight. The eUAV is repeatedly operated until the charge stored in powertrain batteries falls below a specified limit threshold. The time at which the limit threshold on battery charge is crossed is then used to measure the accuracy of the remaining flying time prediction. In our earlier work battery aging was not included. In this work we take into account aging of the batteries where the parameters were updated to make predictions. Accuracy requirements are considered for an alarm that warns operators when remaining flying time is estimated to fall below the specified limit threshold

Assessing the Potential Effects of Fungicides on Nontarget Gut Fungi (Trichomycetes) and Their Associated Larval Black Fly Hosts

Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Although the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density and sporulation within the gut, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far-reaching consequences within aquatic ecosystems

Teaching in the University of Tennessee College of Agriculture

The purpose of this study was to make an investigation of the aptitudes which good college teachers should possess, college teaching methods used, the employment of various teaching aids by college teachers, the use of examinations, and student ratings of their teachers

Essays in Financial Economics

This dissertation addresses the central issue of understanding how frictions to information flow distort the ability for prices to incorporate new information. In chapter 1, “Forgotten Portfolios”, I illustrate how the ability of a stock’s price to impound information can rely on the portfolios of its owners. I show that, in the presence of limited attention, investors rationally allocate their attention towards processing information that has a greater impact on their wealth. Chapter 2, “The Social Elite” (based on joint work with Alexander Chernyakov), examines how casual social interactions impact asset prices. Social networks play a vital role in the diffusion of information. I focus on fund managers and corporate officers of publicly traded firms and present evidence of information transfer at exclusive social gatherings. I find that when executives attend social gatherings their stock prices' subsequent behavior directionally predicts upcoming earnings surprises. I show that fund managers who attend events that corporate officers from a particular firm also attend are more likely to purchase stock in that firm. I explore potential reasons for this tendency and find that fund managers demonstrably outperform when they decide to trade these socially-connected stocks. Further, socially-connected stocks that fund managers do not purchase subsequently underperform. In chapter 3, “Mean Reversion”, I propose a mechanism whereby learning from news jointly explains the patterns of short horizon momentum and long horizon reversals observed in equity prices. The model's key departure from rationality is its assumption that investors underestimate the relative precision of news. Under mild assumptions, investors will exhibit a rational but perverse tendency to increase their belief in other private signals, regardless of whether or not the private signal is true.Economic