Engineering Commons^™

The Properties Of Property Alignment On The Semantic Web, Michelle Andreen Cheatham

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Ontology alignment is an important step in enabling computers to query and reason across the many linked datasets on the semantic web. This is a difficult challenge because the ontologies underlying different linked datasets can vary in terms of subject area coverage, level of abstraction, ontology modeling philosophy, and even language. The alignment approach presented here centers on string similarity metrics. Nearly all ontology alignment systems use a string similarity metric in one form or another, but it seems that the choice of a particular metric is often arbitrary. We begin this dissertation with the most comprehensive survey to date …

16-Bit Digital Adder Design In 250nm And 64-Bit Digital Comparator Design In 90nm Cmos Technologies, Naga Venkata Vijaya Krishna Boppana

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High speed, low power, and area efficient adders and comparators continue to play a key role in hardware implementation of digital signal processing applications. Adders based on Complimentary Pass Transistor Logic (CPL) are power and area efficient, but are slower compared to Square Root Carry Select (SQRT-CS) based adders. This thesis demonstrates a unique custom designed 16-bit adder in 250-nm CMOS technology to obtain fast and power/area efficient features by combining CPL and CS logic. Comparing the results obtained for proposed 16-bit Linear CPL/CS adder with the BEC (Binary Excess-1 Code) based low power SQRT-CS adder, the delay is reduced …

Pixel Qualification Methods In Attributed Scattering Center Extraction, Justin Tyler Farmer

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Recent work with the spectrum-parted linked image test (SPLIT) uses polarization with Fourier-based peak detection to qualify pixels for attributed scattering center (ASC) extraction from synthetic aperture radar (SAR) phase history data. SPLIT is a two-stage, non-linear technique to extract ASCs. The first stage qualifies pixels for ASC attribution, but suffers from imaging sidelobe energy. Error in pixel qualification propagates to stage two: pixel attribution. In this work, a new ASC extraction method is proposed. It is based on 2-D Prony method and motivated by SPLIT. Position estimation performance of SPLITs local peak detection is compared to the 2-D Prony …

Experimental Assessment Of Photovoltaic Irrigation System, Khalil Raza

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Agriculture is a significant measure of an economy for a number of countries in the world. Currently, the agriculture sector relies heavily on conventional sources of energy for irrigation and other purposes. When, considering factors such as increasing costs of fossil fuels and extending new power lines, especially to remote locations where grid electricity is either inaccessible or expensive, a solar PV (photovoltaic) irrigation system can be an effective choice for irrigating farmland. Solar power eliminates the need to run electrical power lines to remote agriculture locations, which quickly turns the monetary equation in favor of solar irrigation over grid-powered …

Dynamic Cache Partitioning For Multi-Core Systems, Yang Zhang

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As the power consumption (power wall) is limiting the clock frequency increase, multi-core and many-core processors become the major-trend of the new generation of processors. One of the biggest challenges to achieve high performance in multi-core systems is the growing disparity between processor and memory speeds. The "memory wall"' problem, i.e., the growing disparity of speed between the processor and the memory, becomes even more serious in the multi-core systems. Caches have been highly successful in bridging the processor-memory performance gap by providing fast access to frequently used data. Caches also save power by limiting expensive off-chip memory accesses. In …

Hysteretic Controlled Dc-Dc Converters, Shweta Chauhan

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Switched-mode DC-DC converters are widely used in applications requiring step-up and step-down of DC voltages or currents. These converters find their use in portable applications such as laptops and smart phones, radio-frequency power amplifiers, as light emitting diode (LED) drivers, etc. The power converters consist of a switching network, energy storage elements such as inductors and capacitors, and a load resistor. Transformers are used in converters, which require isolation. The switching network comprises of MOSFETs and diodes. With improvement in the VLSI technology, smaller MOSFETs with increased power handling capability are pushing the speed of operation of these power converters …

6 Ghz Rf Cmos Active Inductor Band Pass Filter Design And Process Variation Detection, Shuo Li

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A 90nm CMOS active inductor band pass filter with automatic peak detection is demonstrated in this thesis. The active inductor band pass filter has a better performance than the passive band pass filter in on-chip circuit design, due to small area, larger gain and tunable frequency. However, process variation makes the active inductor band pass filter hard to be used widely in many applications. To settle this issue, an automatic voltage peak detector is introduced to detect the process variation direction and hope to be used to control the active inductor band pass filter center frequency and gain. The designed …

Non-Contact, Antenna-Free Probes For Characterization Of Thz Integrated-Devices And Components, Prasanna Kumar Daram

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The most common technology for electrical characterization of THz devices is DC-coupled contact probes. In this Masters thesis, a non-contact, antenna-free probe is analyzed for characterizing THz devices and integrated circuits. The probe consists of on-chip receiving or transmitting THz photomixers in a co-planar waveguide environment. Our probes are coupled to a CPW-embedded DUT by polarization current rather than conduction current and then down converted in frequency to baseband by an optically pumped photomixer. We investigated probe performance through numerical simulations using High Frequency Structure Simulator (HFSS) carried up to 1 THz and yielded a broadband design with DUT to …

A Theoretical Adaptive Autonomy Model: Real-Time Physiological Assessment Of Cognitive Workload, Dakota C. Evans

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Increases in modern-day system complexity, has led for a need to improve human performance and the interaction between the two. Three objectives: (1) to investigate physiological measures as indicators of cognitive workload, (2) to assess cognitive workload during human interaction with different autonomy levels, and (3) to develop a theoretical model for an adaptive autonomous system that changes with real-time cognitive workload measures were addressed. This effort seeks to improve human computer interaction by providing the human with the acceptable level of computer automation based on real-time cognitive state. Two experiments involved collection of measures of subject physiology, subjective survey …

End-To-End Classification Process For The Exploitation Of Vibrometry Data, Ashley Nicole Smith

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Laser vibrometry provides a method to identify running vehicles' unique signatures using non-contact measurements. A vehicle's engine, size, materials, shape, and other attributes affect its vibration signature. To develop the capability to classify and identify these signatures, a robust aided target recognition (AiTR) end-to-end process is evaluated and expanded. The main challenge in classifying a vehicle's vibration signatures is presented by the operating conditions and parameters that vary as a function of sensor, environment, and collection locations on the target, among others. Some of the parameters affecting the vibration signatures include weather, terrain, sensor location, sensor type, and engine speed. …

Large-Signal Analysis Of Buck And Interleaved Buck Dc-Ac Converters, Sourav Dey

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With the improvement in the present day technology, power electronic engineers are more focused on systems which are fast and have better performance. Closed-loop systems with a fast response and better performance have been a priority these days. PWM converters are self-regulating voltage regulators with high efficiency. Depending upon the voltage level and the type of power conversion, different converters are used to meet the necessary demands. One such PWM converter is the, buck DC-AC converter which plays an important role in the applications related to high-frequency and low-power. Large-signal analysis of buck and buck-derived converters for both open-loop and …

The Role Of Subunit Iii In The Functional And Structural Regulation Of Cytochrome C Oxidase In Rhodobacter Spheroids, Khadijeh Salim Alnajjar

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Cytochrome c oxidase (COX) catalyzes the oxidation of ferrocytochrome c and the reduction of oxygen to water while concomitantly translocating protons across the inner mitochondrial membrane. The catalytic core of COX consists of three subunits that are conserved from the bacterial to the mitochondrial forms of the enzyme. Subunits I and II (SUI and SUII) contain the metal centers where electrons are transferred and oxygen binds for reduction. Subunit III (SUIII) does not contain any metals and has an unknown function. It contains three conserved histidine residues (3, 7 and 10) that are surface exposed and are in close proximity …

Full Wave Electromagnetic Simulations Of Terahertz Wire Grid Polarizers And Infrared Plasmonic Wire Gratings, John Cetnar

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This dissertation is a study of the interaction of terahertz (THz) and long-wave infrared (LWIR) radiation with various periodic sub-wavelength metallic structures in free-space and on dielectric substrates. There are many new and useful applications for both THz and LWIR radiation. Unfortunately, heavy attenuation by the Earth's atmosphere and low output power from THz sources combine to make THz radiation weak and difficult to detect. LWIR is not as prone to atmospheric attenuation as THz radiation. Nevertheless, the detection of LWIR can be improved upon by strengthening the coupling between incoming radiation and LWIR detector systems.

Light passing through periodic …

Validation Studies Of Sc/Tetra Code In 2d And 3d Simulations, Shuo Mao

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In this thesis, 2D CFD simulations, 3D CFD simulations, and one 2D Fluid-Structure Interaction (FSI) problem were investigated using combined CFD and an FEA (Finite Element Analysis) tool. Discussions focused on turbulence models, mesh sizes, prism layer sizes, under-relaxation-factor, etc. The solution of CFD simulation and FSI simulation was validated using the results of previous CFD solvers and experimental data presented in the literature. The SST model results for the 2D mixing layer, 2D airfoil near-weak, axisymmetric subsonic jet, and 2D convex curvature boundary layer studies agree with previous CFD results within a 1% error. The k-e model with wall …

Peroxisome Proliferator-Activated Receptor Alpha: Insight Into The Structure, Function And Energy Homeostasis, Dhawal P. Oswal

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Peroxisome proliferator-activated receptor alpha (PPAR alpha) belongs to the family of ligand-activated nuclear transcription factors and serves as a lipid sensor to regulate nutrient metabolism and energy homeostasis. The transcriptional activity of PPAR alpha is thought to be regulated by the binding of exogenous ligands (example, fenofibrate, TriCor), as well as endogenous ligands including fatty acids and their derivatives. Although long-chain fatty acids (LCFA) and their thioesters (long-chain fatty acyl-CoA; LCFA-CoA) have been shown to activate PPAR alpha of several species, the true identity of high-affinity endogenous ligands for human PPAR alpha (hPPAR alpha) has been more elusive. This two …

Chemosensitive Neurons Of The Locus Coeruleus And The Nucleus Tractus Solitarius: Three Dimensional Morphology And Association With The Vasculature, Cathy D. Graham

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We studied the 3 dimensional structure of LC and cNTS neurons from neonatal rats. Neurons were identified as either chemosensitive or nonchemosensitive based on their firing rate response to hypercapnia, using whole-cell patch clamping and were passively loaded with Lucifer Yellow. The identified, loaded neurons were reconstructed and analyzed using Neurolucida Neuron Tracing Software. Chemosensitive LC neurons have less rounded soma than nonchemosensitive neurons, and they have dendrites arising from two poles to produce a fusiform appearance. The dendritic branches extend a greater distance from the soma of chemosensitive than nonchemosensitive neurons. Conversely, chemosensitive cNTS neurons were found to have …

Guanine Nucleotide Exchange Activity Of Phospholipase D2 And Its Regulation, Madhupriya Mahankali

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Phospholipase D2 (PLD2) is a cell membrane lipase that catalyzes the break down of phosphatidyl choline (PC) to phosphatidic acid (PA) and choline. PA is one of the major lipid second messengers that modulate a wide variety of signaling pathways, which are crucial for various cellular functions. In addition to this, PLD2 via binding to a large number of proteins and thereby regulates them independent of its lipase activity. Whereas PLD2 is involved in plethora of cellular functions, high levels of protein and/or activity of PLD2 are reported in variety of disease conditions, such as cancer metastasis and chronic inflammation …

A Probabilistic Technique For Open Set Recognition Using Support Vector Machines, Matthew Scherreik

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Classification algorithms trained using finite sets of target and confuser data are limited by the training set. These algorithms are trained under closed set assumptions and do not account for the infinite universe of confusers found in practice. In contrast, classification algorithms developed under open set assumptions label inputs not present in the training data as unknown instead of assigning the most likely class. We present an approach to open set recognition, the probabilistic open set SVM, that utilizes class posterior estimates to determine probability thresholds for classification. This is accomplished by first training an SVM in a 1-vs-all configuration …

Hierarchical Modulation Detection Of Underwater Acoustic Communication Signals Through Maximum Likelihood Combining, Josh Sanderson

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Modulation detection is important to many communication applications. Much research has been done in this area for radio frequency (RF) signals, but until recently little has carried over to the underwater communication world. Traditional methods include the use of fourth order cumulants or second order cyclostationary features to determine the modulation scheme being used. Many of these methods fail due to the complex and varying nature of the underwater channel. This thesis proposes a new form of hierarchy modulation detection for underwater acoustic communication signals using maximum likelihood combining. The proposed method for hierarchical modulation detection for this research is …

Mining And Understanding Regret Tweets, Lu Zhou

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Inappropriate tweets may cause severe damages on the authors' reputation or privacy. However, many users do not realize until publishing them after a while. Once published, such tweets have lasting effects that may not be completely eliminated by simple deletion, because other users may have read them or third-party tweet analysis platforms have cached them. In this paper, we study the problem of identifying regret tweets for normal individual users, with the ultimate goal to reduce the occurrences of regret tweets. We develop a machine learning approach to extract a large collection of regret tweets from noisy deleted tweets. We …

Java Implementation Of Grounded Circumscription For Owl, Ali Akhavan Karbasi

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The semantic web is a new development in the World Wide Web (WWW) supporting machine-readable and machine-understandable data in order to add the "understanding" aspect to current capabilities. This technology involves the use of semantic reasoners, which are software that can infer logical consequences from a set of facts or axioms. Inference can be done in different ways, e.g. based on what is called the open world assumption in which what is not known to be true is simply unknown, and its closed world assumption opposite, which considers what is not known to be true as false. Each of these …

Amyna: A Security Generator And Performance Estimator Framework Against Memory-Based Attacks, Anna Trikalinou

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As we become more and more dependent on computer networks, using them for everything from banking and investing to shopping and communicating, computer security has emerged to be an increasingly important concern, due to undesirable cyber-security attacks. Thus, in response to this issue many efforts have been made towards accurate and robust computer security protection; however, the general problem is very challenging, diverse and ever-changing and remains still open. In this PhD dissertation we offer protection on one of these cyber-security attacks, the memory-based attacks, caused by one of the most critical software errors according to the MITRE ranking. When …

A Context-Driven Subgraph Model For Literature-Based Discovery, Delroy Huborn Cameron

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Literature-Based Discovery (LBD) refers to the process of uncovering hidden connections that are implicit in scientific literature. Numerous hypotheses have been generated from scientific literature using the LBD paradigm, which influenced innovations in diagnosis, treatment, preventions and overall public health. However, much of the existing research on discovering hidden connections among concepts have used distributional statistics and graph-theoretic measures to capture implicit associations. Such metrics do not explicitly capture the semantics of hidden connections. Rather, they only allude to the existence of meaningful underlying associations. To gain in-depth insights into the meaning of hidden (and other) connections, complementary methods have …

3-D Scene Reconstruction From Line Correspondences Between Multiple Views, Michael Linger

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Three-dimensional scene reconstruction from 2-D images has many applications, such as surveillance, mission planning, autonomous navigation systems, cartography, and target recognition. Of specific interest to this research is the reconstruction of urban scenes containing man-made structures, such as roads and buildings, to support the burgeoning surveillance industry. Using 3-D maps to augment existing mission planning cartography products (DTED/SRTM, CADRG, CIB), mission and event planners will be able to compute strategic line-of-sight coverage for threat avoidance or threat prosecution. Forensic video analysts can use these models to recreate crime scenes, while law enforcement can build flight plans to minimize occlusions from …

Computational Investigation Of Rotary Engine Homogeneous Charge Compression Ignition Feasibility, Michael Irvin Resor

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The Air Force Research Laboratory (AFRL) has been investigating the heavy fuel conversion of small scale Unmanned Aerial Vehicles (UAV). One particular platform is the Army Shadow 200, powered by a UEL Wankel rotary engine. The rotary engine historically is a proven multi-fuel capable engine when operating on spark ignition however, little research into advanced more efficient compression concepts have been investigated. A computational fluid dynamics model has been created to investigate the feasibility of a Homogeneous Charge Compression Ignition (HCCI) rotary engine. This research evaluates the effects, rotor radius to crankshaft eccentricity ratio, known as K factor, equivalence ratio, …

An Investigation Of Thermal Imaging To Detect Physiological Indicators Of Stress In Humans, Carl Brady Cross

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Real-time, stand-off sensing of humans to detect emotional state would be valuable in many defense, security and medical scenarios. Using a multimodal sensor platform that incorporates high-resolution visible-wavelength and mid-wave infrared cameras and a millimeter-wave (mmW) radar system, the detection of physiological indicators of psychological stress is tested through laboratory experiments. Our approach focuses on thermal imaging to measure temperature patterns in distinct facial regions representative of underlying hemodynamic patterns. Experiments were designed to: 1) determine the ability of thermal imaging to detect high levels of psychological stress and assess responses to physical versus psychological stressors; 2) evaluate the fidelity …

Mobile Computing For Trauma And Surgical Care Continuous Education, Muhammad Y. Alamoud

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In medical domain, mobile computing has proven to be convenient, effective, and productive. With varying screen sizes, there is a challenge to present the right information in the right format such that medical practitioners can access information quickly. In this thesis, we discuss how mobile computing can be used as a way of continuous education for medical practitioners in the field of trauma and surgical care, and provide design guidelines on how to effectively present information on different mobile form factors. The focus is on three screen sizes- 4.7, 7 and 10.1 in., and three interaction methods - dropdown, slide, …

The Warehouse-Inventory-Transportation Problem For Multi-Echelon Supply Chains, Bhanuteja Sainathuni

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Warehouses play a vital role in mitigating variations in supply and demand, and providing value-added services in a supply chain. However, our observation of supply chain practice reveals that warehousing decisions are not included when developing a distribution plan for the supply chain. This lack of integration has resulted in substantial variation in workload (42%-220%) at our industry partner's warehouse costing them millions of dollars. We address this real-world challenge by investigating the interdependencies between warehouse, inventory, and transportation decisions, integrate them in a mathematical programming model, and develop managerial insights based on solutions of industry-sized problem instances. Our three …

Analysis Of Laser Induced Spallation Of Electron Beam Physical Vapor Deposited (Eb-Pvd) Thermal Barrier Coatings, David Allen Beeler

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The use of thermal barrier coatings (TBCs) has been an important factor in the efficiency improvements of jet engines due to their ability to withstand the extreme environments within the engine. With this improved resistance, TBCs have also become more difficult to remove without damaging the substrate. Mound Laser & Photonics Center, Inc. (MLPC) has developed an innovative, laser based technique to spall this coating. The intention of this work was to investigate and better understand the removal mechanism. Through experimentation and analysis (such as high speed video, Scanning Electron Microscopy and Energy Dispersive Spectroscopy, semi-logarithmic analysis, and a numerical …

Dynamic Cmos Mimo Circuits With Feedback Inverter Loop And Pull-Down Bridge, Duo Zhang

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Two novel techniques, feedback inverter loop and pull-down bridge, adopted for multiple-input multiple-output (MIMO) dynamic CMOS circuits have been proposed in this thesis. The pull-down bridge technique optimizes the area and power of a single stage MIMO dynamic CMOS circuits, and the feedback inverter loop (FIL) technique improves the speed of multiple-stage dynamic CMOS circuits. Applying the pull-down bridge to the MIMO dynamic CMOS seven segment decoder, it is shown that common paths of different outputs are shared and optimized, which accounts for 12% speed improvement, 48% power reduction, and 73% area saving, as compared to the conventional logic design. …