Engineering Commons^™

A Gnu Radio Based Software-Defined Radar, Lee K. Patton

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GNU Radio is an open source software-defined radio project, and the Universal Software Radio Peripheral (USRP) is hardware designed specifically for use with GNU Radio. Together, these two technologies have been used to implement very sophisticated, yet low cost, software-defined radios. Since software-defined radio and software-defined radar are really one in the same technologies, it stands to reason that GNU Radio and the USRP could be utilized to form a low cost radar sensor. In this thesis, we discuss the design of a prototype software-defined radar, built using the open source GNU Radio and open specification USRP projects. The prototype …

Modeling And Simulation Of A Microturbine Generator To Be Coupled With A Molten Carbonate Fuel Cell For Distributed Generation, Karleine M. Justice

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Distributed generation is desired when the individual energy requirements ranging from 25-75 kW of office buildings, restaurants, hospitals and apartments can not be met by the current electric utility grid. Microturbine generators as stand alone power generation systems have been designed to meet these requirements. For power requirements up to 50 MW, hybrid fuel cell systems offer higher efficiency and lower levels of pollutant emissions with more advanced fuel energy savings than non-hybrid systems. The objective of this project is to develop a simulation of a microturbine generator as a stand alone power generation system to validate a microturbine generator …

Change Detection Methods For Hyperspectral Imagery, Karmon Marie Vongsy

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This thesis studies the detection of changes using hyperspectral images. Change Detection (CD) is the process of identifying and examining temporal and spectral changes in signals. Detection and analysis of change provide valuable information of possible transformations in a scene. Hyperspectral imaging (HSI) sensors are capable of collecting data at hundreds of narrow spectral bands. Such sensors provide high-resolution spatial and spectrally rich information that can be exploited for CD. This work develops and implements various CD algorithms for detection of changes using Hyperspectral images. The main objectives are to study and develop different HSI change detection algorithms. The explored …

Computational Methods For The Objective Review Of Forensic Dna Testing Results, Jason R. Gilder

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Since the advent of criminal investigations, investigators have sought a "gold standard" for the evaluation of forensic evidence. Currently, deoxyribonucleic acid (DNA) technology is the most reliable method of identification. Short Tandem Repeat (STR) DNA genotyping has the potential for impressive match statistics, but the methodology not infallible. The condition of an evidentiary sample and potential issues with the handling and testing of a sample can lead to significant issues with the interpretation of DNA testing results. Forensic DNA interpretation standards are determined by laboratory validation studies that often involve small sample sizes. This dissertation presents novel methodologies to address …

Development Of An Intelligent Autonomous Coffee Maker, Nicholas J. Vanderpool

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Using Intelligent Control Methodology Home coffee machines have improved over time with the addition of features such as self-activating timers and crude temperature controlled heating elements. However, home coffee brewer development has stagnated and has yet to achieve full automation status. Present coffee machines leave the user burdened with the mundane and messy task of preparing the coffee maker every time. Also, should the user decide to prepare less than an entire pot, he/she must estimate the correct amount of water and coffee to add. This can lead to a weak or strong brew, giving undesirable results. In order to …

Phase-Locked Piv Investigation Of The Effects Of The Blowing Ratio Of A Pulsed Vortex Generator Jet In A Low-Pressure Turbine, Nathan Michael Woods

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At very high altitudes the Reynolds number flow through the low pressure turbine section of the gas turbine engine can drop below 25,000. At these low Reynolds numbers the flow is laminar and extremely susceptible to separation which can lead to increased losses and reduced lift. Small jets of air injected through the suction surface of the airfoil, called Vortex Generator Jets (VGJs), have been shown successful in suppressing separation and maintaining attached flow. Pulsing of these jets has been shown to be as effective as steady jets while reducing the amount of mass flow needed. An experiment using Particle …

High Spurious-Free Dynamic Range Digital Wideband Receiver For Multiple Signal Detection And Tracking, Vivek Sarathy

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The advent of field-programmable gate array (FPGA) has provided an excellent platform to market prototyping of full receiver-on-chip designs in a short time. The design of multi-tone wideband receiver has always been a challenge because of the difficulty to detect weak signals in the presence of noise in the frequency spectrum and also the presence of general spurs generated by the receiver. In this research, architecture for a FPGA-based 2.56-GSPS digital wideband receiver with multi-tone signal detection and tracking is designed to demonstrate the capability of replacing more expensive analog components into their cheaper digital design counterparts. Novel hardware implementations …

Designing Computer Agents With Personality To Improve Human-Machine Collaboration In Complex Systems, Sasanka V. Prabhala

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The dynamic nature of complex systems and the overwhelming amount of data that must be handled by human operators requires the development of smart systems that augment human capabilities. For these systems human-agent collaboration is part of the system dynamic. Unfortunately the computer agent is not typically perceived by the human operator as a collaborative team member. This research addressed the key question of how to develop and evaluate computer agents with personality to enhance human-machine collaboration. To move towards this goal three research objectives were established: (1) develop agents with personality, (2) validate that humans perceive these agents as …

Implementation For A Coherent Keyword-Based Xml Query Language, Venkatakalyan Potturi

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Due to the increasing pervasiveness of data sets using the XML data format, numerous query languages have been proposed that exploit the structure inherent in XML. Many such query languages, supported by specialized XML search engines, are complex and not suitable for naive users. A simple keyword based query language is described which not only exploits the structure of XML documents to extract relevant fragments, but can also fall back on retrieval through plain text search. This thesis focuses on developing a prototype implementation for a Coherent Keyword Based XML Query Language. It analyzes the typical challenges posed by the …

Loss Of Hdmx Leads To Alterations In Gene Expression And Inhibition Of Cell Growth In Tumor Cells With Wild-Type P53, Katherine Ann Heminger

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Mutations in the p53 tumor suppressor gene are among the most prevalent molecular abnormalities in human cancer. While half of all human tumors possess p53 mutations, inactivation of wild-type p53 can also occur through a variety of mechanisms that do not involve p53 gene mutation or deletion. This dissertation focuses on human tumor cell lines harboring wild-type p53 protein and elevated levels of HdmX and/or Hdm2, two critical negative regulators of p53 function. My hypothesis is that loss of HdmX in tumor cells with wild-type p53 and over-expressed HdmX, will activate p53 and induce p53 target genes leading to growth …

Role-Based Access Control For The Open Grid Services Architecture - Data Access And Integration (Ogsa-Dai), Anil L. Pereira

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Grid has emerged recently as an integration infrastructure for the sharing and coordinated use of diverse resources in dynamic, distributed virtual organizations (VOs). A Data Grid is an architecture for the access, exchange, and sharing of data in the Grid environment. In this dissertation, role-based access control (RBAC) systems for heterogeneous data resources in Data Grid systems are proposed. The Open Grid Services Architecture - Data Access and Integration (OGSA-DAI) is a widely used framework for the integration of heterogeneous data resources in Grid systems.

However, in the OGSA-DAI system, access control causes substantial administration overhead for resource providers in …

Structural And Signaling Elements Important For The Efficient Degradation Of Bhmt Through Macroautophagy, Carol A. Mercer

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Healthy cells maintain a dynamic and responsive intracellular environment that is marked by the synthesis and degradation of proteins, complex macromolecules and organelles. Autophagy, literally "self-eating," is a mechanism that delivers cellular cargo to the lytic compartment for digestion. Defects in the regulation of autophagy have been implicated in pathologies such as cancer and neurodegenerative disease, making the study of its regulation compelling. However, few studies have looked at the regulation of mammalian autophagy as a function of a specific cargo protein. Previous studies had indicated that the metabolic enzyme betaine homocysteine methyltransferase (BHMT) is degraded through an autophagic mechanism. …

Optimal Eeg Channels And Rhythm Selection For Task Classification, Vikramvarun Kannan Adikarapatti

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The Primary Objective of this research is to implement an automatic method for selecting the most optimal EEG channels for task classification purposes. The secondary objective of this research is to choose the most optimal EEG rhythm from which the optimal EEG channels would be selected automatically. The automatic selection of the optimal channels is enabled by implementing the Common Spatial Patterns algorithm (CSP). Common spatial analysis is performed on the data recorded. By choosing the channels with high spatial pattern values the optimal channels are chosen. The optimal frequency bands are chosen by splitting the data from a single …

Processing Nano Graphene Plates (Ngps) And Ngp Nanocomposite, Yena Li

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In recent years numerous efforts worldwide are addressing all aspects of the rapid developing field of nanocomposites. However, the most important fillers-- carbon nanotube and carbon nanofiber - are expensive. In this study, our efforts are aimed at bridging the gap in cost and properties by providing a systematic study of alternative nano materials -- nano graphene plate (NGP) and related composites. We fabricated nano graphene plates through the detailed study of raw materials, chemical treatment methods and nano particle dispersion methods. A series of thermal expansion experiments were conducted to investigate the best condition to expand acid treated graphite …

Comparative Characterization Of Superconducting Thin Films Fabricated By Different Techniques, Padma Prasuna S. Vemulakonda

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The goal of this thesis is to compare the chemical and compositional profiles, grain structure and critical current densities of superconducting Yttrium Barium Copper Oxide(Y1Ba2Cu3O7-x or YBCO) layers grown by different competing techniques on a variety of substrates and buffer layers. The idea is to check if there can be variation of cationic ratios, impurities, possible diffusion of substrate/buffer layer atoms into the YBCO for different processing methods and microstructures. Pulsed Laser Deposition (PLD), Metal Organic Deposition (MOD) and Metal Organic Chemical Vapor Deposition (MOCVD) films on Ion Beam Assisted Deposited (IBAD)-textured buffer layers and, Rolling Assisted Biaxial textured substrate …

Data Mining And Analysis On Multiple Time Series Object Data, Chunyu Jiang

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Huge amount of data is available in our society and the need for turning such data into useful information and knowledge is urgent. Data mining is an important field addressing that need and significant progress has been achieved in the last decade. In several important application areas, data arises in the format of Multiple Time Series Object (MTSO) data, where each data object is an array of time series over a large set of features and each has an associated class or state. Very little research has been conducted towards this kind of data. Examples include computational toxicology, where each …

Oxidation Resistant Coatings On Microcelluar Carbon Foam Using Simple Scalable Techniques, Dakshinamurthy Sharma Nagalingam

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Carbon foam has many applications in the fields of thermal management, net-shape composites and electronic cooling due to its porous structure, low density, electrical and thermal conductivities. However it is prone to oxidation at high temperatures in air. Whereas some previous studies have reported oxidation protective coatings on other carbon structures such as graphite parts and fibers, there is very limited work on foam. Moreover, earlier methods have used vapor phase techniques such as Plasma Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD). There is no known study involving such coatings using simple scalable liquid phase method. This thesis reports …

High Performance Text Document Clustering, Yanjun Li

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Data mining, also known as knowledge discovery in database (KDD), is the process to discover interesting unknown knowledge from a large amount of data. Text mining is to apply data mining techniques to extract interesting and nontrivial information and knowledge from unstructured text. Text clustering is one of important techniques of text mining, which is the unsupervised classification of similar documents into different groups.

This research focuses on improving the performance of text clustering. We investigated the text clustering algorithms in four aspects: document representation, documents closeness measurement, high dimension reduction and parallelization. We propose a group of high performance …

An Analysis Of Neutral Drift's Effect On The Evolution Of A Ctrnn Locomotion Controller With Noisy Fitness Evaluation, Gregory Robert Kramer

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This dissertation focuses on the evolution of Continuous Time Recurrent Neural Networks (CTRNNs) as controllers for control systems. Existing research suggests that the process of neutral drift can greatly benefit evolution for problems whose fitness landscapes contain large-scale neutral networks. CTRNNs are known to be highly degenerate, providing a possible source of large-scale landscape neutrality, and existing research suggests that neutral drift benefits the evolution of simple CTRNNs. However, there has been no in-depth examination of the effects of neutral drift on complex CTRNN controllers, especially in the presence of noisy fitness evaluation. To address this problem, this dissertation presents …

Composite Data From Centrifugal Experimentation Regarding Human Information Processing, Ronald K. Butcher

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A cognitive model illustrating decrement in human performance as a function of increased G-forces has been highly sought after by the Department of Defense (DoD) for various reasons. The F-16 and other air combat platforms are super-agile aircraft that are easily capable of imposing G-forces on a pilot that are beyond human physiological limitations. Knowledge of these physiological limits and more importantly the resultant restrictions in cognitive function could prove invaluable to those who design and pilot such aircraft. The model may be utilized in the construction of improved flight simulators that incorporate more realistically performing enemy targets and therefore …

Biochemical Characterization Of Htrf1 And Htep1, Two Proteins Involved In Telomere Maintenance, Kambiz Tahmaseb

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Telomeres are the structures that protect the ends of linear chromosomes from fusion and degradation. The telomere consists of tandem repeated DNA sequences that can range from hundreds of bases to kilo-bases depending on the organism. As the cells of an organism replicate their DNA, these repeats are lost due to the end replication problem, where the ends of linear DNA cannot be fully replicated. As the telomeres are shortened through each round of replication, they eventually reach a critical point. Once the telomeres are too short and the cell risks losing coding sequences, a signaling pathway is initiated that …

Investigation Of Cylindrically-Conformed Four-Arm Spiral Antennas, Douglas J. Glass

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A four-arm spiral antenna offers broadband frequency response, wide beamwidths, reduced size compared to other antenna designs, and the ability to determine the relative direction of an incident signal with appropriate mode-forming. The reduced overall area projection of the four-arm spiral antenna compared to other antenna designs and the ability to be manufactured in a planar format allows the antenna to reside within an Unmanned Air Vehicle (UAV) fuselage. This thesis investigates the effects of cylindrically-conforming two different designs of a four-arm spiral antenna to reside within the fuselage of a medium-sized UAV. Theoretical predictions of antenna performance were created …

Improved Thresholding Technique For The Monobit Receiver, Jonathan Gordon Buck

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Wideband digital receivers typically use a very high sampling rate to capture a signal for near real-time processing. Very robust digital techniques, like the Monobit FFT technique, have been developed to provide near real-time processing of captured timedomain signals. Most of these techniques trade accuracy for processing speed by approximating computationally complex mathematical operations. The approximation sometimes makes it difficult to detect multiple signals if the difference between their amplitudes is more than a few dB. This thesis presents a dynamic thresholding technique for multi-tone signal detection. The technique is based on setting an allowable ratio between the magnitude of …

Rolling Mill Optimization Using An Accurate And Rapid New Model For Mill Deflection And Strip Thickness Profile, Arif Sultan Malik

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This work presents improved technology for attaining high-quality rolled metal strip. The new technology is based on an innovative method to model both the static and dynamic characteristics of rolling mill deflection, and it applies equally to both cluster-type and non cluster-type rolling mill configurations. By effectively combining numerical Finite Element Analysis (FEA) with analytical solid mechanics, the devised approach delivers a rapid, accurate, flexible, high-fidelity model useful for optimizing many important rolling parameters. The associated static deflection model enables computation of the thickness profile and corresponding flatness of the rolled strip. Accurate methods of predicting the strip thickness profile …

Design And Performance Evaluation Of 1 Giga Hertz Wideband Digital Receiver, Kiranraj George

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The lack of a priori knowledge about the waveform of interest, the multitudes of signals the receiver might receive, and the noise energy that occupies the same portion of the frequency spectrum as the signal makes the design of a modern wideband receiver very challenging. Especially, the receiver must be able to detect a weak signal in the presence of a strong one, which requires a high two-signal instantaneous dynamic range (IDR). To fulfill this requirement, the receiver must detect genuine weak signals and avoid the detection of strong signals' sidelobes and noise and spurs generated from the receiver system. …

Minute Doping Of Pulsed Laser Deposition Processed Y123 Thin Films With Tb, Ce, And Pr, Joseph William Kell

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Three rare earth elements (Tb, Ce, and Pr) were chosen for the investigation into whether adding minute quantities (≤1 at%) of dopants could improve the film quality of YBa₂C ₃O_7-δ(Y123) thin films. The compositions studied are (Y_1-x,Re_x)Ba₂Cu₃O_7-δ (RE=Tb, Ce, Pr; x=0.1, 0.01, 0.001). Good quality thin films were produced by PLD and showed significant improvement to properties when exposed to a magnetic field. Ce and Pr (x=0.001) doped films showed modest improvement. However, the Tb doped system showed substantial improvement to J_c(H), with a …

Investigating The Role Of Subunit Iii In The Structure And Function Of Rhodobacter Sphaeroides Cytochrome C Oxidase, R. Ryan Geyer

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The role of subunit III (SIII) in cytochrome c oxidase structure and function was investigated using enzyme isolated from the bacterium Rhodobacter sphaeroides. Energy minimization calculations suggested that in the absence of SIII, subunit I (SI) adopted a more open conformation. This observation was tested through the use of limited proteolysis using, á-chymotrypsin. The results showed that in the absence of SIII the solution structures of wild-type and I/II oxidase were not significantly different, and that proteolysis occurred exclusively at the N and C-termini of SI. Upon inactivation of I/II oxidase by catalytic turnover, and subsequent digestion with the protease …

Analysis Of A Small-Signal Model Of A Pwm Dc-Dc Buck-Boost Converter In Ccm, Julie Joann Lee

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The objective of this research is to analyze and simulate the pulse-width-modulated (PWM) dc-dc buck-boost converter and design a controller to gain stability for the buck-boost converter. The PWM dc-dc buck-boost converter reduces and/or increases dc voltage from one level to a another level in devices that need to, at different times or states, increase or decrease the output voltage.

In this thesis, equations for transfer funtions for a PWM dc-dc open-loop buck-boost converter operating in continuous-conduction-mode (CCM) are derived. For the pre-chosen design, the open-loop characterics and the step responses are studied. The converter is simulated in PSpice to …

Summaritive Digest For Large Document Repositories With Application To E-Rulemaking, Lijun Chen

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Large document repositories need to be organized and summarized to make them more accessible and understandable. Such needs exist in many applications, including web search, e-rulemaking (electronic rulemaking) and document archiving. Even though much has been done in the areas of document clustering and summarization, there are still many new challenges and issues that need to be addressed as the repositories become larger, more prevalent and dynamic. In this dissertation, we investigate more informative ways to organize and summarize large document repositories, especially e-rulemaking feedback repositories (ERFRs), so that the large repositories can be managed and digested more efficiently and …

The Effect Of Configural Displays On Pilot Situation Awareness In Helmet-Mounted Displays, Joseph C. Jenkins

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The current research utilized configural displays within the domain of aviation to assess what design features of configural displays contribute to the formation of operator situation awareness (SA). Configural displays map system information relevant to operator goals onto geometric shapes called emergent features. An emergent feature is formed from the combination of individual line segments to produce a global feature more perceptually salient and recognized sooner than the individual parts themselves. Configural displays have been shown in previous research to provide better operator performance for integration tasks where multiple pieces of information must be considered at once, yet the design …