Digital Commons Network^™

Optimal Control Of A Helicopter Unmanned Aerial Vehicle (Uav), David John Nodland

Masters Theses

"This thesis addresses optimal control of a helicopter unmanned aerial vehicle (UAV). Helicopter UAVs may be widely used for both military and civilian operations. Because these helicopters are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This thesis presents an optimal controller design via both state and output feedback for trajectory tracking of a helicopter UAV using a neural network (NN). The state and output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers while the output feedback approach uses an observer in addition to these controllers. The online approximator-based dynamic controller learns the …

Crustal Structure And Evolution Beneath The Colorado Plateau And The Southern Basin And Range Province, Lamuail Bashir

Doctoral Dissertations

"Stacking of about 15,500 P-to-S receiver functions recorded at 72 USArray and other broadband seismic stations placed on the Colorado Plateau and the SBRP in Arizona revealed systematic spatial variations in crustal Vp/Vs, crustal thickness and amplitude of P-to-S converted phases. Our results reveal that the BRP is characterized by a thin crust (28.2 ± 0.5 km), a mean Vp/Vs of 1.761 ± 0.014 and a mean amplitude (R) of P - to - S converted wave (relative to that of the direct P wave) of 0.181 ± 0.014 that are similar to a typical continental crust, consistent with the …

Impact Of Channel Statistics And Correlation On Underwater Acoustic Communication Systems, Jesse Scott Cross

Masters Theses

"Several statistical properties of underwater acoustic channels gathered from experiment data are analyzed. The baseband channel impulse response (CIR) is estimated using a time domain least squares technique with a sliding window applied to the probing sequences. From the CIR estimation, the probability distribution functions (PDFs) of the magnitude, real part, imaginary part, and phase of the CIR are calculated. Gamma, Rayleigh, and compound k distributions are fitted to the magnitude PDF and the fitness of the distributions are calculated with a two-sample Kolmogorov-Smirnov test. Other statistics such as the autocorrelation function, coherence time, and scattering function are evaluated. The …

Diesel Particulate Matter Dispersion Analysis In Underground Metal/Nonmetal Mines Using Computational Fluid Dynamics, Yi Zheng

Doctoral Dissertations

"Diesel Particulate Matter (DPM) is a natural by-product from operating diesel engines. Since diesel power is a major source of energy for mining operations today, the adverse health effects of DPM are of a great concern. To thoroughly resolve DPM problems, it is critical that DPM propagation characteristics be understood to arrive at a sensible and practical method for addressing DPM-related issues. To achieve this, a computational fluid dynamics (CFD) method is used to simulate DPM dispersion and to predict its concentration distribution. Industrial field studies were reconstructed to evaluate the possibility of different CFD models. Experiments were also carried …

Quantifying The Carbon Footprint Of Lean Waste, Kristen Donovan Balinski

Masters Theses

"The objective of this paper is to provide a method of quantifying lean wastes in terms of carbon dioxide emissions by using value stream mapping. Lean manufacturing, a process based on waste identification and reduction, is a growing trend in industry and a proven method of lowering costs. The environmental impact of these wastes can be quantified by identifying the metrics associated with them, and using existing reports to convert those metrics into measurements of carbon dioxide. Growing environmental concerns are prompting federal government regulation of greenhouse gas or carbon dioxide emissions, as seen in the American Clean Energy and …

Development And Testing Of Chemically-Based Self-Consolidating Concrete, Mark Daniel Ezzell

Masters Theses

"Self-consolidating concrete (SCC) possesses several characteristics that can benefit the concrete construction industry including accelerated construction, a reduction in labor and equipment, and a reduction in construction noise through eliminating or reducing the need to vibrate the concrete. However, SCC has some potential downsides. These problems can usually be attributed to higher paste content, higher fines content, rounder aggregate, and higher water to cement (w/c) ratios used to increase the flow of the concrete. The goal of this research project was to develop a SCC that had improved material properties through the use of chemical admixtures instead of modifications to …

Integration Of Model-Based Systems Engineering And Virtual Engineering Tools For Detailed Design, Akshay Kande

Masters Theses

"Design and development of a system can be viewed as a process of transferring and transforming data using a set of tools that form the system's development environment. Conversion of the systems engineering data into useful information is one of the prime objectives of the tools used in the process. With complex systems, the objective is further augmented with a need to represent the information in an accessible and comprehensible manner. The importance of representation is easily understood in light of the fact that the stakeholder's ability to make prompt and appropriate decisions is directly related to his understanding of …

Multiple-Input Multiple-Output System Simulation For Spinning Vehicles, Samuel James Petersen

Masters Theses

"This paper investigates the performance of a multiple-input multiple-output (MIMO) wireless communication system, when the transmitter is located on a spinning vehicle. In particular, a 2x2 MIMO system is used, with Alamouti coding at the transmitter. Both Rayleigh and Rician statistical models are considered in this paper and are combined with a deterministic spinning model to simulate the channel. The spinning of the transmitting vehicle, relative to the stationary receive antennas causes additional signal fading, and complicates the decoding and channel estimation. The simulated bit error rate is the primary performance metric used. A 4x2 asymmetric Alamouti coding scheme is …

Analysis And Modeling Of Depth-Of-Cut During End Milling Of Deposited Material, Haythem Gaja

Masters Theses

"This study addresses depth-of-cut detection and tool-workpiece engagement using an acoustic emission monitoring system during milling machining for a deposited material. Online detection of depth-of-cut presents many technical difficulties. Researchers have used various types of sensors and methods to assess the depth-of-cut and surface errors. Due to the strong correlation between acoustic emission and cutting depth during the depth end milling process, it is useful to forecast the depth-of-cut from the acoustic emission signal. This work used regression analysis to model and detect the depth-of-cut. The experiments were carried out on a Fadal vertical 5-Axis computer numerical control machine using …

Adaptive Rule-Based Malware Detection Employing Learning Classifier Systems, Jonathan Joseph Blount

Masters Theses

"Efficient and accurate malware detection is increasingly becoming a necessity for society to operate. Existing malware detection systems have excellent performance in identifying known malware for which signatures are available, but poor performance in anomaly detection for zero day exploits for which signatures have not yet been made available or targeted attacks against a specific entity. The primary goal of this thesis is to provide evidence for the potential of learning classier systems to improve the accuracy of malware detection.

A customized system based on a state-of-the-art learning classier system is presented for adaptive rule-based malware detection, which combines a …

Rapid Simulation Of The Statistical Variation Of Crosstalk In Cable Harness Bundles, Xiang Li

Masters Theses

"Accurate assessment of crosstalk problems in cable harnesses requires simulation methods that account for the statistical variation of harness parameters. Methods are proposed to determine the influence of the statistical variation in wire positions, the rate that wires change position (i.e. "twist"), harness height, harness density (i.e. how closely wires are packed) and circuit loads. Methods use a combination of simulation and probability theory. Simulations use the T-parameter method, a rapid simulation technique for harness bundles. Simulation time is further improved by using the mean and variance of crosstalk estimated for fixed harness parameter values to estimate the mean and …

Numerical Simulation Of Relative Permeability Modifier Effect On Oil And Water Production, Murad Mohammedahmed Abdulfarraj

Masters Theses

"Excess water production is one of the most prevalent operational problems that oil companies are facing. Polymers and polymer gels have been used widely to control excess water production for mature oilfields. It is well known that polymers/gels can reduce the permeability to water (Krw) much more than that to oil (Kro). This phenomenon is called disproportionate permeability reduction (DPR) and the polymers or gels that exhibit this behavior are called relative permeability modifier (RPM). When RPMs are placed in reservoir, reduced permeability to water can lead to decreased water production, and sometimes increased hydrocarbon production, therefore prolonging the useful …

The Origin Of Quartz Glomerocrysts: Insights From The Rhyolite Dike At Medicine Park, Ok, Sedeg Ahmed E. Ahmed

Masters Theses

"The origin of quartz glomerocrysts a distinctive petrographic feature of the rhyolite dike in Medicine Park, Oklahoma, was investigated using transmitted light and cathodoluminescence microscopy to determine if quartz glomerocrysts formed during quartz crystallization or during quartz dissolution. Quartz glomerocrysts are typically comprised of two to six individual phenocrysts of quartz and commonly exhibit subhedral partially embayed crystal forms with very rare euhedral phenocrysts in both glomerocrysts and individual quartz phenocrysts. The size range of the individual quartz phenocrysts are 0.08mm to 1.7mm while the size range is 0.08mm to 3.25mm for quartz glomerocrysts . Cathodoluminescence revealed that individual quartz …

Evaluating The Effectiveness Of Multi-Spectral Remote Sensing Data For Lithological Mapping In Arid Regions: A Quantitative Approach With Examples From The Makkah Neoproterozoic Region, Saudi Arabia, Nawwaf Awad Al Muntshry

Masters Theses

"This work quantitatively evaluates the effectiveness of multi-spectral remote sensing data for geological mapping in arid regions. For this, Landsat Thematic Mapper (TM) data covering part of the Neoproterozoic Arabian Shield around the Makkah region in Saudi Arabia are used. The Makkah region is dominated by a variety of layered and intrusive rocks covered by unconsolidated sediments. The Landsat TM data have six spectral bands in the visible and near infrared (VNIR) and shortwave infrared (SWIR) with thirty meters spatial resolution.

The Optimum Index Factor (OIF) has been computed to determine the best Red-Green-Blue (RGB) band combination emerging from the …

A Rapid-Acquisition Electrical Time-Domain Reflectometer For Analysis Of Time-Variant Impedance Discontinuities, Joseph Andrew Bishop

Masters Theses

"A distributed crack sensor has been developed for the measurement of cracks in concrete structures. The sensor is measured using a distributed measurement technique known as electrical time-domain reflectometry (ETDR). ETDR has traditionally been used to measure time-invariant (i.e. unchanging with time) impedance discontinuities, however applications of the sensor in structural failure analysis require measurement of time-variant (i.e. changing with time) impedance discontinuities at rates as high as 10 k measurements per second. ETDR is a suitable measurement technique for these applications since a time-domain reflectometer (TDR) acquisition can be performed in less than 100 µs. Employment of ETDR in …

Spiking Neural Networks And Their Applications, Cameron Eric Johnson

Doctoral Dissertations

"Artificial neural networks (ANNs) have been developed as adaptable, robust function approximators for at least the last quarter-century. They have progressed through two generations, and the third is now under development. Spiking neural networks (SNNs) seek to improve on previous generations in two ways: by using a more biologically-inspired neuron, they are shown to be capable of more complex calculations; incorporating polychronous properties of highly-recurrent networks with delays of different lengths on each synapse to achieve large numbers of possible patterns with relatively few neurons and synapses.

Abstracted spiking neurons have been used as a third-generation activation function in a …

Current And Emerging Transportation Technology: Final Nails In The Coffin Of The Dying Right Of Privacy?, James D. Phillips, Katharine E. Kohm

Richmond Journal of Law & Technology

Transportation networks constitute “the circulatory system of our economy.” The distinct modes that constitute the American transportation system—air, rail, transit, highways, and waterways—impact the entire range of our daily activities. Just as the human body depends on its circulatory system for life and well being, the United States’ vitality would grind to a halting stop without a vibrant transportation system.

Persistence To An Associate Of Applied Science Registered Nurse Degree: The Impact Of Placing Into Developmental Education Courses On Student Success, Caroline Clark Rivera

Educational Leadership & Workforce Development Theses & Dissertations

Student retention and success in nursing school has gained favor in educational research due to an increasing shortage of Registered Nurses. The purpose of this study is to measure the impact of student placement recommendation into developmental education courses on persistence to an Associate of Applied Science Registered Nurse degree. Using ex post facto research methodology rooted in the retention theories of Tinto, Bean and Metzner, and Jeffreys, this study aims to measure the effect of high school diploma type, age, race/ethnicity, and pre-requisite courses on student placement recommendation in developmental education and persistence to an Associate of Applied Science …

Student Achievement As An Investment In Human Capital: Using Longitudinal Patterns Of Per Pupil Instructional And Capital Expenditures, Socioeconomic Status, And Past Performance In Predicting Student Achievement, Charles Anthony Roberts

Educational Leadership & Workforce Development Theses & Dissertations

Existing research illustrating a significant relationship between school spending and student achievement is expanding. However, research specifically investigating the relationships between capital expenditures (maintenance, renovations, and construction) and instructional expenditures (teacher quality, teacher salaries, textbooks, class size) with student achievement both individually, and as a function of overall school spending, is lacking. Recent studies have linked school spending to student achievement in an attempt to increase school funding as a response to No Child Left Behind Act (2001) mandates. This study attempts to augment this area of inquiry by providing feedback across the Commonwealth of Virginia on longitudinal patterns of …

Hybrid Inorganic/Organic Nanostructured Tandem Solar Cells: Simulation And Fabrication Methods, Patrick Michael Boland Jr.

Electrical & Computer Engineering Theses & Dissertations

Organic solar cell technologies continue to be an extremely active area of scientific research. With their promise of providing low-cost, easily-processable, multi-application photovoltaics, these devices could very possibly be the most viable and practical form of renewable energy among many being explored. However, significant technological obstacles remain that must be overcome if this technology is to successfully realize the goal of providing abundant energy while simultaneously reducing dependence on fossil fuel-based sources. Compared with inorganic solar photovoltaics, power conversion efficiencies in organics are still too low to compete economically.

Much research has been accomplished over the past three decades in …

Balloon Borne Mars Research Platforms, Sean Michael Hancock

Mechanical & Aerospace Engineering Theses & Dissertations

Aerial platforms can fill a measurement gap between orbiters and rovers, providing planetary scale high resolution in situ measurements, access to scientifically interesting terrain that is either inaccessible or hazardous to rovers, and serve as a planet-wide delivery platforms to deploy surface probes and rovers to areas inaccessible given existing entry, descent, and landing systems. A permanent robotic outpost on the Martian surface can utilize locally-derived hydrogen as a lifting gas for balloon systems deployed from Mars. That approach can simplify the inflation and launch of aerial vehicles while allowing for a long duration deployment campaign that is not constrained …

Magnetic Micro-Confinement Of Quantum Degenerate Gases, Ahmed M. Abdelrahman

Theses: Doctorates and Masters

In this dissertation we explore the basic principles of the magnetic micro-confinement of the quantum degenerate gases where the approach of the so-called two-dimensional magnetic lattices has been theoretically and experimentally investigated. In this research a new generation of two-dimensional magnetic lattice has been proposed and considered as a developing phase for the previous approaches. Its advantage relies on introducing a simplified method to create single or multiple micro-traps of magnetic field local minima distributed, at a certain working distance, above the surface of a thin film of permanent magnetic material. The simplicity in creating the magnetic field local minima …

An Investigation Into The Feasibility Of Using Digital Representations Of Students’ Work For Authentic And Reliable Performance Assessment In Applied Information Technology, David G. Miller

Theses: Doctorates and Masters

The assessment of student performance in areas such as drama, physical education, art and Information Technology (IT), does not lend itself to traditional, paper-based testing methods. In these domains, much emphasis is placed on the acquisition and demonstration of practical skills and these may be difficult, if not impossible, to measure by scores on theoretical, written assessments. Alternative forms of assessment, which are both valid and reliable, need to be devised for the practical aspects of these subject areas. The capture, in digital form, of students’ work, may allow the development of authentic forms of summative, high-stakes assessment with high …

They Reckon I Need A Dramaturg : Examining The Value Of A Dramaturg To Both The Playwright And The Professional Theatre Company In Australia, Polly Low

Theses: Doctorates and Masters

This thesis examines aspects of dramaturgy delivered by a dramaturg, and the practical contributions of dramaturgs to both the writer and the theatre industry in Australia. It investigates elements of the working relationship between dramaturgs and playwrights, looks at the chameleon-like nature of the theatre dramaturg and examines how Australian writers, directors and dramaturgs perceive the role/s of the dramaturg. The thesis is partly a reflective investigation of personal practice, partly an historical investigation of the emergence of Australian ideas about dramaturgy, and partly an active investigation into what can help to make a constructive playwright/dramaturg relationship. A major aim …

Mimi Stewart: Her Life, Career, & Contributions, Jerold Widdison, Susan Kelly

Water Matters!

Mimi is energetic, knowledgeable, deeply engaged, and a vital public servant.

Unm Libqual+ 2011 Survey, Association Of Research Libraries

Assessment and Statistics

No abstract provided.

Sustainable Development In The Cultural Context: A Review Of Sources And Analysis Of Gaps, Joann Jacoby, Liz Cooper

University Libraries & Learning Sciences Faculty and Staff Publications

In order to be effective, sustainable development efforts must be grounded in a fundamental understanding of the local context. Two librarians with backgrounds in anthropology will address the issue of culturally-grounded sustainable development resources available online and in digital repositories. The presenters will review the literature on the importance of the cultural context in sustainable development, identify strengths of current culturally-grounded online collections, and review gaps in order to identify areas where libraries should focus further efforts to develop these types of collections.

The New Mexican, Ana Maria Trujillo, José Rivera

09. La Sociedad Book Reviews

January 30, 2011

Building On Innovation: The Significance Of Anchor Institutions In A New Era Of City Building, Tom Murphy

President Schmidly's Administration

Murphy, Tom. Building on Innovation: The Significance of Anchor Institutions in a New Era of City Building. Washington, D.C.: Urban Land Institute, 2011

New Adventures Of The Old Bureau: Modern-Day Reclamation Statutes And Congress Unfinished Environmental Business, Reed D. Benson

Faculty Scholarship

Congress established the reclamation program in 1902, and the hundreds of federal water projects built in the 20th century helped shape the West. Today, the Bureau of Reclamation plays an enormously important role in managing these projects. But with no big new dams to build, the Bureau has been forced to revise its mission to address todays water management challenges, such as stretching finite water supplies and restoring aquatic ecosystems. Through both site-specific enactments and programmatic statutes, Congress in recent years has given the Bureau new authority and direction to address these modern challenges. But Congress has left a significant …