Electrical and Computer Engineering Commons^™

Application Of The Relevance Vector Machine To Canal Flow Prediction In The Sevier River Basin, John T. Flake

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work addresses management of the scarce water resource for irrigation in arid regions where significant delays between the time of order and the time of delivery present major difficulties. Motivated by improvements to water management that will be facilitated by an ability to predict water demand, this work employs a data-driven approach to developing canal flow prediction models using the Relevance Vector Machine (RVM), a probabilistic kernel-based learning machine. Beyond the RVM learning process, which establishes the set of relevant vectors from the training data, a search is performed across model attributes including input set, kernel scale parameter, and …

Langmuir Probe Measurements In The Ionosphere, Aroh Barjatya

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electric probes have been the primary instruments for the in situ investigation of plasma parameters in the Earth’s ionosphere. This dissertation is a compendium of three papers, each dealing with a separate spacecraft that carried one or more instruments based on the electric probe technique.

The first paper presents data from the Sudden Atom Layer sounding rocket that carried an RF Impedance Probe, a DC fixed-bias Langmuir Probe (DCP), and an Electric Field Probe. The combined dataset indicates a case of payload surface charging, the causes of which are investigated within the paper. A generic circuit model is developed to …

Design Of A Low-Power Automatic Wireless Multi-Logger Networking Device, Kelly S. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Virtually every industry and discipline (e.g., mining, pharmaceutical, construction, agriculture, reclamation, etc.) is finding applications for wireless data acquisition for monitoring and managing processes and resources. Two sectors, namely agriculture and environmental research, are seeking ways to obtain distributed soil and plant measurements over larger areas like a watershed or large fields rather than a single site of intensive instrumentation (i.e., a weather station). Wireless sensor networks and remote sensing have been explored as a means to satisfy this need. Commercial products are readily available that have remote wireless options to support distributed senor networking. However, these systems have been …

Analysis Of The Day Side Equatorial Anomaly, Jayaprabha Shankar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Equatorial Ionization Anomaly (EIA) is a region of peak plasma density found at ± 10 ◦ to 20 ◦ magnetic latitudes at F-region altitudes. In 2002, NASA launched the Global Ultra Violet Imager (GUVI), which can observe the EIA at various local times, longitudes, and seasons by the glow of the recombining electrons and ions in the plasma. This thesis presents the observations of the geomagnetic quiet time EIA and its global behavior at all local times using 1356 ˚A radiance data from high altitude GUVI limb scans. Limb data is prepared for analysis using reduction techniques that remove from …

Calibration And Results Of The Equis Ii Plasma Impedance Probe (Pip), Seth D. Humphries

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents the calibration process and analysis results for the two Plasma Impedance Probe (PIP) units that were flown as part of the NASA Equis-I I campaign from the Kwajalein Atoll. The work of calibration that was presented by Krishna Kurra for the PIP on the Floating Potential Measurement Unit (FPMU) is improved and extended herein. The sweeping impedance probe (SIP), the instrument formerly known as plasma sweeping probe (PSP), is an integral part of the PIP. For the SIP, the calibration presented in this work, calibration error less than 5% error is achieved. The calibration is applied to …

Spatial And Temporal Considerations In Vehicle Path Tracking With An Emphasis On Spatial Robustness, Donald L. Cripps

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation researches the task and path management of an autonomous vehicle with Ackerman-type steering.

The task management problem was approached as a path training operation in which a human operator drives the desired path through an environment. A training trajectory is converted into a series of path segments that are driveable by the autonomous vehicle by first fitting a general path to the dataset. Next, transition segments are added to the general path to match the vehicle velocity and steering angle rate limit.

The path management problem has been approached by first deriving a kine- matic model of the …

Advanced Navigation For Planetary Vehicles Applying An Approximate Mapping Technique, Timothy R. Mcjunkin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis provides a method for compressing the information provided by JPL Mars rover obstacle sensors by creating an approximate map of the terrain around the vehicle. This thesis demonstrates that this method provides adequate information for a human operator to negotiate complex obstacles fields.

By dividing the area around the vehicle into regions and classifying each region as to how dangerous (impassable), the sensor data can be accumulated with minimal overhead. The terrain in each region has a number between zero and one, with zero meaning completely passable and one meaning completely impassable. A continuum of possible values between …

Vector Optimization Decision Convergence Algorithm (Vodca), Thomas Ward Morgan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many professions occasionally involve the selection of an alternative from among many problem solutions which have impacts in multiple-interest areas; however, due to the very nature of his work, the practicing engineer, regardless of specialty, is unavoidably engaged in this selection process. The emergence of national concern for environmental and social consequences of technical enterprises, as reflected through legislative action, has accentuated the need for multicriteria design methodologies in some areas of engineering (i.e., automotive). Consequently, interest in the development of pragmatic and theoretically sound approaches to multi-impact design situations has been keen. Any approach to multicriteria design/decision problems involves …

Spectral Signature Studies For Application In Deer Census Using Remote Sensing Techniques, Maran C. Pate

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was performed to determine the spectral signatures of deer and their natural background elements for censusing purposes. Consideration was given to atmospheric transmittance, acceptable flying weather, and terrain. Possible spectral bands between 0.3 and 14.0 μm were obtained (over a pathlength of 1500 feet at an altitude of 5000 feet) based upon atmospheric transmittance using the LOWTRAN 3B computer program. They are: 0.30 - 1.33, 1.49 - 1.79, 2.00 - 2.50, 3.00 - 3.16, 3.38 - 4.10, 4.59 - 5.05, and 8.00 - 13.33 μm, for transmittance greater than 75%. Weather conditions are favorable for flying and taking …

Asynchronous Logic Design With Flip-Flop Constraints, David Franklin Cox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Some techniques are presented to permit the implementation of asynchronous sequential circuits using standard flip-flops. An algorithm is presented for the RS flip-flop, and it is shown that any flow table may be realized using the algorithm (the flow table is assumed to be realizable using standard logic gates). The approach is shown to be directly applicable to synchronous circuits, and transition flip-flops (JK, D, and T) are analyzed using the ideas developed. Constraints are derived for the flow tables to meet to be realizable using transition flip-flops in asynchronous situations, and upper and lower bounds on the number of …

Measurement Of Soil Moisture By Attenuation Of A Vertically Polarized Radio Wave, Arlo D. Mickelsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to determine feasibility and to investigate some of the problems encountered in making soil moisture measurements using radio wave propagation. The procedure consists of propagating a vertically polarized wave over the earth and measuring the field strength attenuation. A brief summary of present methods of measuring soil moisture is given.

Certain aspects of radio wave propagation theory are discussed, covering such topics as the surface wave, the space wave, the skin depth, and the effect of the dielectric constant on radio wave propagation. Based on this theory, measurement parameters such as frequency, antenna separation, …

A Study Of The Secant Law For Sporadic E, Ruey-Yuan Han

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The secant law is the relationship between the frequencies of a vertically incident wave and an obliquely incident wave that are reflected from the same level (i.e., density) of a stratified ionosphere. This thesis investigates the validity of the secant law applied to sporadic E.

Sporadic E data from two backscatter sounders and one vertical incidence ionosonde located in Japan were studied to test the validity of the secant law. The B-scan photos of the backscatter sounders were searched for E_s patches which were then compared with the sporadic E parameters defined for vertical incidence ionograms.

Finally, two theoretical …

A Method For Plotting Isohyetal Maps Using An Analog Computer, Maurice George Kirwan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ability of the analog computer to stimulate physical phenomena is used in conjunction with a resistance paper model of the Walnut Gulch watershed in Arizona to plot constant precipitation maps from data obtained from recorded rainfall. Voltages which are proportional to rainfall at a specific raingage, located at scaled points of the resistance paper model, set up an electric field on the resistive sheet which is detected and processed by the computer. The detected potential is compared to a reference potential, or "precipitation value", and the necessary analog networks allow plotting of the equipotential line which is directly analogous …

Iterative Method In Storage Routing, Mohan Lal Kapoor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this study is to examine the feasibility of applying analog computer iterative methods to the study of storage routing.

Determining And Telemetering Snowpack Water Content In Mountainous Terrain, Stephen Davis Clarke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Snowpack water content is an important parameter in streamflow forecasts. At the present time water content of the snowpack is determined by manual methods, which are often expensive and time-consuming. The use of a pressure pillow to determine water content has shown promise in experimental applications.

The design and analysis of a pressure transducer suitable for use with remote telemetry equipment is presented. The transducer uses changing fluid pressure to vary an inductor.

Telemetry techniques suitable for use on Utah snow courses are analyzed. Emphasis is given to the passive and active remote radio relays.