Engineering Commons^™

Owl Query Answering Using Machine Learning, Todd Huster

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The formal semantics of the Web Ontology Language (OWL) enables automated reasoning over OWL knowledge bases, which in turn can be used for a variety of purposes including knowledge base development, querying and management. Automated reasoning is usually done by means of deductive (proof-theoretic) algorithms which are either provably sound and complete or employ approximate methods to trade some correctness for improved efficiency. As has been argued elsewhere, however, reasoning methods for the Semantic Web do not necessarily have to be based on deductive methods, and approximate reasoning using statistical or machine-learning approaches may bring improved speed while maintaining high …

Temporally Biased Search Result Snippets, J. Abhiram Tatineni

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The search engine result snippets are an important source of information for the user to obtain quick insights into the corresponding result documents. When the search terms are too general, like a person's name or a company's name, creating an appropriate snippet that effectively summarizes the document's content can be challenging owing to multiple occurrences of the search term in the top ranked documents, without a simple means to select a subset of sentences containing them to form result snippet. In web pages classified as narratives and news articles, multiple references to explicit, implicit and relative temporal expressions can be …

A Reconfigurable Spice-Based Cmos Lna Design In 90 Nm Technology Using Ads Rfic Dynamic Link, Pushpak Vasanth Rayudu Arja

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In this thesis, a reconfigurable dual band CMOS LNA with a switching-type circuit topology is proposed. The reconfigurable dual-band LNA can be tuned to operating fre- quency of either 1.575 GHz for global positioning system (GPS) or 2.4GHz for WLAN 802.11b standards. The simulated results performed power gain of 11.2 dB and 12.4 dB, noise figure of 3.4 dB and 2.9 dB, input return loss(S11) of -25.26 dB and-21.4 dB, third- order input intercept point of -3.12 dBm and -2.137 dBm and the design dissipates 8.9 mW and 4.68 mW of power at 1.2 V power supply at the two …

High Frequency Resolution Adaptive Thresholding Wideband Receiver System, Feiran Liu

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Fast Fourier transformation (FFT) is widely used in wideband digital receivers to detect multiple signals. To achieve high dynamic range, the receiver has to increase analog-to-digital (ADC) resolution bits, which requires significant computation time and therefore increases receiver time resolution. The other challenge of FFT approach is two signals with a small frequency difference (i.e., less than five FFT frequency bins in most cases) cannot be detected simultaneous. This thesis presents an adaptive thresholding wideband digital receiver to accurately detect two simultaneous high dynamic range signals even when they are close to one FFT frequency bin. The receiver can perform …

Wide Tuning Range I/Q Dco Vco And A High Resolution Pfd Implementation In Cmos 90 Nm Technology, Eswar Raju Suraparaju

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This thesis presents wide tuning range in-phase and quad-phase (I/Q) output digital control oscillator (DCO) and voltage control oscillator (VCO) and a simple high performance phase frequency detector (PFD) in 90 nm CMOS technology with 1.2 V power supply. The designed I/Q output DCO has an operating frequency range from 1.1-8.2 GHz with high resolution and wide linearity by using a novel skew delay structure. At 2.02GHz oscillation frequency, the measured phase noise of I/Q output DCO is -90.43dBc/Hz at an offset of 1 MHz offset and has 5 mW of power dissipation. A complementary series coupled quadrature VCO (S-QVCO) …

Design Of A Novel Low - Cost, Portable, 3d Ultrasound System With Extended Imaging Capabilities For Point-Of-Care Applications, Michail Tsakalakis

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Ultrasound Imaging (USI) or Medical Sonography (MS), as it is formally called, has been widely used in biomedical applications over the last decades. USI can provide clinicians with a thorough view of the internal parts of the human body, making use of sound waves of higher frequencies than humans can perceive. USI systems are considered highly portable and of low-cost, compared to other imaging modalities. However, despite those advantages, Ultrasound Systems (US) and especially 3D ones, have not been yet extensively utilized for Point-of-Care (POC) applications, due to numerous restrictions and artifacts that they currently present.

Hardware complexity and real-time …

Mathematical Models And Solution Approach For Staff Scheduling With Cross-Training At Call Centers, Taskiran, Gamze Kilincli

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Call centers face demand that varies throughout the week across multiple service categories and typically employ non-standard workforce schedules to meet this demand. In call centers, cross-training provides a buffer against fluctuation of demand between categories and is widely used. Full cross-training, however, is financially impractical in most cases, which has created a challenging problem in how to optimize a cross-trained workforce, i.e., a) what categories should be cross-trained, b) what portion of the workforce should be cross-trained, and c) how to schedule their weekly assignments. This problem is motivated by the need of a Fortune 50 company's technology support …

Mining Behavior Of Citizen Sensor Communities To Improve Cooperation With Organizational Actors, Hemant Purohit

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Web 2.0 (social media) provides a natural platform for dynamic emergence of citizen (as) sensor communities, where the citizens generate content for sharing information and engaging in discussions. Such a citizen sensor community (CSC) has stated or implied goals that are helpful in the work of formal organizations, such as an emergency management unit, for prioritizing their response needs. This research addresses questions related to design of a cooperative system of organizations and citizens in CSC. Prior research by social scientists in a limited offline and online environment has provided a foundation for research on cooperative behavior challenges, including 'articulation' …

Verification And Validation Of A Transient Heat Exchanger Model, Jayme Lee Carper

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A statistical based verification and validation process is applied to the transient modeling of a shell and tube heat exchanger. A generic model of a heat exchanger was developed based on first principles as a sub-system of a larger thermal system model. This model was originally created without any experimental data, as it was not readily available. To provide the data necessary to apply the validation process, a thermal emulator was designed and built that allowed control of all system inputs to the heat exchanger, while also providing the instrumentation to record all required data. A wide test matrix was …

Steady-State Analysis Of Pwm Z-Bridge Source Dc-Dc Converter, Lokesh Kathi

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A PWM Z-bridge source dc-dc converter has a potential to play a prominent role in renewable energy applications, as it provides boosted and regulated output voltage and also behaves as an intermediate buffer between the source and the load. A complete circuit analysis of the Z-bridge source converter is needed to understand the operation of this converter. Steady-state analysis of pulse-width modulated (PWM) Z-bridge source dc-dc converter operating in continuous conduction mode (CCM) is given. Expressions describing waveforms of voltages across and currents through the all components of the PWM Z-bridge source dc-dc converter to operate in steady-state condition are …

Automatic Pmg Controller For Small Applications, William Scott Adkins

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This thesis is used to describe the proof of concept and design for a much needed answer to a major flight time limitation in smaller application drones. All small electric drones and small electric vehicles have the same major problem, short run-times. The average time a multi-rotor helicopter runs is for approximately 20 minutes. The concept idea of the combination of a permanent magnet generator (PMG) and a controller can extend this flight time. The basic idea is to add the similar function an automobile has, which is the alternator. This thesis will include, but not limited to the following …

Average Current-Mode Control, Ankit Chadha

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In this thesis, an average current-mode controller is analyzed for controlling power electronic converters. This controller consists of two loops. An inner loop, which senses and controls the inductor current and an outer loop, which is used to control the output voltage and provide reference voltage for the inner current loop. An average current-mode controller averages out high frequency harmonics it senses from the inductor current to provide a smooth DC component. This can be used as a control voltage for a pulse width modulator and produce switching pulses for the power electronic converters. An average current-mode controller can also …

Measuring The Acute Physiological Effects Of Leptin In The Carotid Body, Richard Laurence Pye

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Obesity is the healthcare crisis of our generation. Circulating levels of the adipokine leptin are proportional to adiposity and in addition to its role as a satiety factor leptin has been shown to have a host of pleiotropic effects. Among these effects is its role as a respiratory stimulant where it has been shown to have both whole body and central stimulatory effects on breathing. Porzionato et al. (2011) showed that leptin and leptin receptors are selectively expressed in the chemosensing type I cells of the carotid body. Carotid bodies are small chemosensitive organs that act as the primary peripheral …

The Guinea Pig Model For Organophosphate Toxicology And Therapeutic Development, Christopher Daniel Ruark

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Organophosphates (OPs) are highly toxic insecticides and nerve agents that have been designed to inhibit the hydrolysis of acetylcholine by binding to the serine active site of acetylcholinesterase (AChE). They are one of the most common causes of human poisoning worldwide and are frequently intentionally used in suicides in agricultural areas. For this reason, there is a need for therapeutics to rescue those from intoxication. Obvious ethical concerns prevent humans from being subjected to OP exposure for therapeutic efficacy and safety testing. Therefore, animal surrogates for humans must be appropriately selected. A new paradigm, described herein, incorporating both in silico …

Null Convention Logic Asynchronous Register Full Path Completion Feedback Loop Using Two Stage Voltage Divider, Christopher P. Taylor

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As fabrication technologies improve logic densities increase. It becomes harder to mitigate clock skew and jitter. Higher clock rates combined with increased numbers of sinks increase mixed-system substrate noise. An increasingly popular approach to address these problems is clockless logic. One technique is Null Convention Logic (NCL). However, traditional NCL feedback loops have large area overhead and require many gate delays. This makes NCL impractical in many applications. In this paper we propose to replace the feedback logic with a two-stage voltage divider. Using our technique we show up to 50% area reduction and require only one unit gate delay.

Variable Speed Flapping Wing Micro Air Vehicle Using A Continuous Variable Transmission Design, Jason C. Chuang

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Flapping wing micro air vehicles (FWMAV) have very unique flight mechanics in two-wing orientation. Many challenges arise with two wing configuration: lift production, design construction, and control systems. Control surfaces used in fixed wings can be used but at low Reynolds numbers they become less effective. In order to truly mimic insects with two wings, control mechanisms must be developed. Since MAVs are designed to navigate through confined spaces they need to have many degrees of freedom in motion. One way is to use a continuous variable transmission (CVT) mechanism, by integrating its infinite gear ratios to change the flapping …

The Regulation Of The Eight-Exon Isoform Of The Coxsackievirus And Adenovirus Receptor (CarEx8) And Its Biological Relevance, Poornima Kotha Lakshmi Narayan

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The airway epithelium poses a formidable barrier for the entry of pathogenic viruses due to the formation of tight junctions between adjacent epithelial cells. The coxsackievirus and adenovirus receptor (CAR), a member of the Ig superfamily of cell junction adhesion proteins, is the primary receptor for adenovirus entry and infection. As a result of alternative splicing, two transmembrane isoforms of CAR are generated. While the seven-exon isoform of CAR (CAR^EX7) is hidden on the basolateral surface of polarized epithelia, the eight-exon isoform of CAR (CAR^EX8) localizes within the sub-apical region and at the air-exposed apical surface. …

A Comparison Of Monocular Camera Calibration Techniques, Richard L. Van Hook

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Extensive use of visible electro-optical (visEO) cameras for machine vision techniques shows that most camera systems produce distorted imagery. This thesis investigates and compares several of the most common techniques for correcting the distortions based on a pinhole camera model. The methods being examined include a common chessboard pattern based on (Sturm 1999), (Z. Zhang 1999), and (Z. Zhang 2000), as well as two "circleboard" patterns based on (Heikkila 2000). Additionally, camera models from the visual structure from motion (VSFM) software (Wu n.d.) are used. By comparing reprojection error from similar data sets, it can be shown that the asymmetric …

Day-Of-Discharge Planning At Acute Care Hospitals, Kylie M. Bertsch

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Hospitals provide a complex array of services to patient populations with highly variable conditions, needs, and preferences. These services are delivered with limited resources, and therefore, the synchronization of patient flow between various units in the hospital is essential for minimizing patient delay and congestion. Unfortunately, patient flow optimization is a topic in its research infancy, and, in current practice, hospitals struggle with the numerous ramifications of delays in care provision and increased costs. Emergency Department (ED) crowding and boarding have become a topic of increased interest as the ED becomes an increasingly popular entry point to acute care hospitals. …

Fluid-Structure Interaction Simulations Of A Flapping Wing Micro Air Vehicle, Alex W. Byrd

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Interest in micro air vehicles (MAVs) for reconnaissance and surveillance has grown steadily in the last decade. Prototypes are being developed and built with a variety of capabilities, such as the ability to hover and glide. However, the design of these vehicles is hindered by the lack of understanding of the underlying physics; therefore, the design process for MAVs has relied mostly on trial-and-error based production. Fluid-Structure Interaction (FSI) techniques can be used to improve upon the results found in traditional computational fluid dynamics (CFD) simulations. In this thesis, a verification of FSI is first completed, followed by FSI MAV …

Investigation Of Mirror Image Bias: Evidence For The Use Of Psychophysiological Measures As Indicators Of Cognitive Heuristics, Caroline R. Salchak

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The Mirror Imaging Bias (MIB) is gaining attention as a prominent quality factor in analysts' performance. MIB is an irrationality in which analysts perceive and process information through the filter of personal experience. As evidenced by notable historical events, the consequences of this bias can be dramatic. A way to understand MIB in humans is sought. How analysts analyze data, are trained, and interact with biases is explored. An experiment testing for the appearance of MIB was designed and completed. Measures from an eye tracker as well as physiological measures were collected. Results show a significant correlation between pupil diameter …

Multi-Finger Mosfet Low Noise Amplifier Performance Analysis, Xiaomeng Zhang

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Multi-finger layout technique has been extensively used in Nano-scale CMOS circuit design due to the increased circuit performance compared to a single finger layout. However choosing a finger width (W_f) and number of fingers (N_f) to optimize circuit performance is a challenging problem. In this thesis, the performances of 2.4GHz and 6.0GHz single ended low noise amplifiers (LNA) with fixed total transistor widths in 90nm CMOS technology are analyzed as function of number of fingers, bias voltage (V_bias) and channel length (L). The results show that the drain to source current, transconductance and effective gate capacitance increase with increasing number …

Apelin Regulation Of K-Cl Cotransport In Vascular Smooth Muscle Cells., Neelima Sharma

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Atherosclerosis and high circulating levels of oxidized low density lipoproteins (oxLDL) are considered among the most important risk factors for the occurrence and development of cardiovascular disease (CVD). During the atherosclerotic lesion repair, phenotypic transition of vascular smooth muscle cells (VSMCs) from contractile to synthetic states plays a central role. In this process, enhanced proliferation/migration of VSMCs, from the tunica media to the intima, is required to sustain blood vessel endothelium integrity, and for inducing vessel wall remodeling in response to injury. At the molecular level, the activity of electroneutral potassium-chloride cotransporters or KCCs, is necessary to: a) allow changes …

Computational Design And Characterization Of Silicene Nanostructures For Electrical And Thermal Transport Applications, Tim H. Osborn

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Novel silicene-based nanomaterials are designed and characterized by first principle computer simulations to assess the effects of adsorptions and defects on stability, electronic, and thermal properties. To explore quantum thermal transport in nanostructures a general purpose code based on Green's function formalism is developed.

Specifically, we explore the energetics, temperature dependent dynamics, phonon frequencies, and electronic structure associated with lithium chemisorption on silicene. Our results predict the stability of completely lithiated silicene sheets (silicel) in which lithium atoms adsorb on the atom-down sites on both sides of the silicene sheet. Upon complete lithiation, the band structure of silicene is transformed …

Modern Statistical Methods And Uncertainty Quantification For Evaluating Reliability Of Nondestructive Evaluation Systems, Jeremy Scott Knopp

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The reliability of Nondestructive Evaluation (NDE) is an important input for risk analysis for sustainment of aging infrastructure. Reliability has typically been quantified via probability of detection (POD) studies. There are three problems with POD modeling methodologies provided in the most recent guidance on the subject:

1) Current models do not estimate the extremes of a POD curve very well because of the assumption that the POD curve approaches zero as flaw size goes to zero, and the POD curve approaches one as the flaw size goes to infinity.

2) The existing 2-parameter logit/probit models can be misused since there …

Evaluation And Application Of Lte, Dvb, And Dab Signals Of Opportunity For Passive Bistatic Sar Imaging, Aaron S. Evers

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Due to the many advantages of passive radar and ubiquity of commercial broadcast transmitters, interest in passive bistatic radar (PBR) applications has continued to grow. More specifically, sources studying commercial orthogonal frequency division multiplexing (OFDM) waveforms for passive bistatic synthetic aperture radar (SAR) imaging have become more common. This work evaluates and applies long term evolution (LTE), digital video broadcast (DVB), and digital audio broadcast (DAB) signals of opportunity for passive bistatic SAR imaging.

First, implications of the structure and properties of each of the signal of opportunity's transmitted waveform are characterized by examining the waveform's self- and cross-ambiguity functions …

Fragment Association Matching Enhancement (Fame) On A Video Tracker, Andrew Johnson

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In the field of surveillance, algorithms are developed to extract meaningful information out of a video feed captured via a camera. One type of algorithm used in the field of surveillance is a tracking algorithm. A tracking algorithm allows a user to watch the movement of an object in the camera's field of view. The tracker used in this thesis research is a feature aided tracker (FAT). The FAT uses both features and kinematics to generate tracks. However, camera movement will affect the tracker's ability to accurately track an object which poses a problem to the tracker. Specifically, the camera …

A Validation Study Of Sc/Tetra Cfd Code, Hongtao Yu

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The goal of this study is to validate the accuracy of the SC/Tetra CFD code by modeling four cases: a 2D zero pressure gradient flat plate, an axisymmetric separated boundary layer, flow over an NACA 0012 airfoil, and flow over an NACA 4412 airfoil trailing edge separation. The results will be compared to experimental data and CFL3D results. This study also investigates the sensitivity of SC/Tetra results to different set up details such as mesh resolution, turbulence model, and under-relaxation settings. Automation using the Visual Basic programming language was used to vary these set up details and efficiently process a …

Novel Devices And Components For Thz Systems, John Raymond Middendorf

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Since the first demonstration of the generation of terahertz (THz) pulses from photoconductive (PC) antennas, research has pushed toward the development of smaller, cost efficient, and faster THz systems. This dissertation presents the work accomplished in order to realize these more practical terahertz (THz) photoconductive (PC) systems.

First, this work will present a novel ErAs:GaAs photoconductive switch used to make a THz source excited by 1550 nm laser pulses. It will be shown that the excitation process taking place in the material relies on extrinsic (rather than intrinsic) photoconductivity. Then, several experiments will be presented that aim to improve the …

Impact Of Sar Image Formation Quality On Target Separability, Cody A. Lawyer

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The polar format algorithm (PFA) allows the use of computationally efficient fast Fourier transforms in synthetic aperture radar (SAR) image formation, but introduces phase errors when making the far-field approximations that facilitate this approach. The phase errors cause spatially variant distortion and defocus in the formed image. These effects may complicate target recognition applications. To limit the impact of defocus, scene size is usually limited such that the maximum quadratic phase error within an image falls below some threshold. This thesis looks at how distortion and defocus affects the classification of targets, with the hope of developing an application-driven scene …