Engineering Commons^™

Modeling, Design And Fabrication Of Orthogonal And Psuedo-Orthogonal Frequency Coded Saw Wireless Spread Spectrum Rfid Sensor Tags, Nancy Saldanha

Electronic Theses and Dissertations

Surface acoustic wave (SAW) sensors offer a wireless, passive sensor solution for use in numerous environments where wired sensing can be expensive and infeasible. Single carrier frequency SAW sensor embodiments such as delay lines, and resonators have been used in single sensor environments where sensor identification is not a necessity. The orthogonal frequency coded (OFC) SAW sensor tag embodiment developed at UCF uses a spread spectrum approach that allows interrogation in a multi-sensor environment and provides simultaneous sensing and sensor identi- fication. The SAW device is encoded via proper design of multiple Bragg reflectors at differing frequencies. To enable accurate …

Incremental Lifecycle Validation Of Knowledge-Based Systems Through Commonkads, Feras Batarseh

Electronic Theses and Dissertations

This dissertation introduces a novel validation method for knowledge-based systems (KBS). Validation is an essential phase in the development lifecycle of knowledge-based systems. Validation ensures that the system is valid, reliable and that it reflects the knowledge of the expert and meets the specifications. Although many validation methods have been introduced for knowledge-based systems, there is still a need for an incremental validation method based on a lifecycle model. Lifecycle models provide a general framework for the developer and a mapping technique from the system into the validation process. They support reusability, modularity and offer guidelines for knowledge engineers to …

Class F And Inverse Class F Power Amplifier Subject To Electrical Stress Effect, Giji Skaria

Electronic Theses and Dissertations

This study investigated the Class F and inverse Class F RF power amplifier operating at 5.8 GHz. The major challenging issue in design and implementation of CMOS power transistor is the breakdown voltage especially in sub-micron CMOS technologies. In order to eliminate this problem a Cascode topologies were implemented to reduce the Drain-toSource voltage (stress). A Cascode Class F & Inverse Class F RF power amplifier were designed, and optimized in order to improve efficiency and reliability using 0.18µm CMOS technology process. A 50% decrease in the stress has been achieved in the Cascode class-F and Inverse class F amplifiers. …

Study Of Esd Effects On Rf Power Amplifiers, Raju, Divya Narasimha

Electronic Theses and Dissertations

Today, ESD is a major consideration in the design and manufacture of ICs. ESD problems are increasing in the electronics industry because of the increasing trend toward higher speed and smaller device sizes. There is growing interest in knowing the effects of ESD protection circuit on the performance of semiconductor integrated circuits (ICs) because of the impact it has on core RF circuit performance. This study investigated the impact of ESD protection circuit on RF Power amplifiers. Even though ESD protection for digital circuits has been known for a while, RF-ESD is a challenge. From a thorough literature search on …

Artificial Neural Network Based Fault Location For Transmission Lines, Suhaas Bhargava Ayyagari

University of Kentucky Master's Theses

This thesis focuses on detecting, classifying and locating faults on electric power transmission lines. Fault detection, fault classification and fault location have been achieved by using artificial neural networks. Feedforward networks have been employed along with backpropagation algorithm for each of the three phases in the Fault location process. Analysis on neural networks with varying number of hidden layers and neurons per hidden layer has been provided to validate the choice of the neural networks in each step. Simulation results have been provided to demonstrate that artificial neural network based methods are efficient in locating faults on transmission lines and …

Enhancing Wireless Security Using Relay Based Cooperative Networks., Mohammad A. Kishk

Electronic Theses and Dissertations

No abstract provided.

Power Cable Fault Finding Using Pseudo Random Binary Sequences, Holger Geisler

Theses

The work that is presented in this thesis documents the results obtained from the pseudo random binary sequence (PRBS) cable testing method which utilises a pseudo noise (pN) sequence as a test stimulus to localise faults on a transmission line. The work targets the proof of concept of the PRBS method in a Coaxial cable as well as its eventual evaluation for fault testing accuracy and performance on a real-world underground steel wired armour (SWA) cable. Further, a novel hardware implementation of the method utilising a Field Programmable Gate Array (FPGA) is presented. The theory of the PRBS test method …

Ultra Wideband Pulse Shaping, Pawel Rulikowski

Theses

Methods for shaping of sophisticated, transient, ultra wideband (UWB) waveforms and pulses are presented. The methods include novel circuits based on step recovery diodes (SRDs) and quasi-transversal filter concepts but the majority of the work focuses on UWB pulse shaping using completely passive nonuniform transmission lines (NUTLs). It is shown, for the first time, that NUTLs can be used to generate highly sophisticated arbitrary UWB pulse shapes, including modified Hermite polynomial (MHP) and approximate spheroidal wave function (APSWF) pulses which are not known to have been previously generated in practice, and a generalized methodology, verified by experiments, for design of …

Miniature Embedded Module For Prognostic Health Monitoring (Phm) Of Electronic Systems, Liam Moore

Theses

Sensing systems for reliability prognostics are used extensively in life- and mission- critical electronics systems. They allow monitoring of reliability stresses in real time and scheduling of preventative maintenance before system failure. However, reliability prognostics systems are, in general, large and expensive and cannot be used in lower cost, small sized or portable products.

This thesis presents a sensing module for reliability prognostics which is only 1cm in volume and uses only commercial off-the-shelf components. In its 1cm package, the module combines all the necessary elements to act as an embedded prognostic sensor system for multi axial strain, vibration, humidity …

Lateral Power Mosfets Hardened Against Single Event Radiation Effects, Patrick Michael Shea

Electronic Theses and Dissertations

The underlying physical mechanisms of destructive single event effects (SEE) from heavy ion radiation have been widely studied in traditional vertical double-diffused power MOSFETs (VDMOS). Recently lateral double-diffused power MOSFETs (LDMOS), which inherently provide lower gate charge than VDMOS, have become an attractive option for MHz-frequency DC-DC converters in terrestrial power electronics applications [1]. There are growing interests in extending the LDMOS concept into radiation-hard space applications. Since the LDMOS has a device structure considerably different from VDMOS, the well studied single event burn-out (SEB) or single event gate rapture (SEGR) response of VDMOS cannot be simply assumed for LDMOS …

Wirelessly Sensing Resonate Frequency Of Passive Resonators With Different Q Values, Mathew Walter Lukacs

Electronic Theses and Dissertations

Numerous techniques exist for measuring temperature using passive devices such as SAW filters. However, SAW filters have a significant limitation regarding high temperature environments exceeding 1000⁰C [1]. There are several applications for a high temperature sensor in this range, most notably heat flux or temperature in turbine engines. For these environments, an alternative to SAW filters is to use a passive resonator. The resonate frequency will vary depending on the environment temperature. Understanding how the frequency changes with temperature will allow us to determine the environmental temperature. In order for this approach to work, it is necessary to induce resonance …

A Radar Interrogator For Wireless Passive Temperature Sensing, Jeffrey Charles Lambert

Electronic Theses and Dissertations

In this thesis I explore radio detection and ranging (RADAR) and software defined radio (SDR) in the context of wireless passive sensor interrogation. A RADAR topology is selected based upon preliminary measurements using ordinary laboratory instrumentation and then used for construction of a prototype X-band wireless measurement system using commercial, off-theshelf (COTS) components. This research explores the feasibility of wireless passive sensor interrogation through practical application of SDR and RADAR techniques to the interrogation of a wireless passive resonator signal. This work serves as a foundation for further research on sensor interrogation through establishment of critical system parameters in the …

Accelerated Simulation And Testing Of Integrated Circuits Using High Performance Computing Machines, Matthew C. Markulik

Open Access Theses & Dissertations

As Moore's Law continues to hold true and transistor density becomes exponentially larger the need to rely on computer aided design (CAD) simulators has become more relevant and necessary. As we dive into the age of electronic reliance there presents a need to constantly improve methods to reduce time-to-solution for developing technologies. The reliance on CAD simulators for electronic development leaves engineers with an ability to improve the design process by improving these simulators or improving the methods in which these simulators are being utilized. With the advancement of quality fabrication processes and the ability to operate at sub-threshold levels …

Mixed-Signal Distributed Feature Extraction For Classification Of Wide-Band Acoustic Signals On Sensor Networks, Humberto Santacruz

Open Access Theses & Dissertations

This thesis proposes a distributed/collaborative scheme for the classification of wide-band acoustic events within the context wireless sensor networks (WSNs). The proposed method is characterized by a mixed-signal processing scheme for the extraction of feature vectors which reduces the processing, memory allocation, and power requirements of the sensor nodes. The mixed-signal scheme assumes that nodes have an analog frontend consisting of a microphone, a bandpass filter, a squaring element and an integrator. This chain of components produces an estimate of the energy over the frequency subband extracted by the filter. The WSN has the ability to form a distributed filter …

Pressure-Dependent Nanoheteroepitaxy Of Cdte On Si(100) And Soi(100) Substrates Using The Close-Spaced Sublimation Technique, Hoong Yan See Tao

Open Access Theses & Dissertations

CdTe is an ideal II-VI semiconductor compound with a direct bandgap energy of 1.53 eV used in solar cells and infrared detector applications [8]. The National Renewable Energy Laboratory (NREL) reported that cadmium telluride (CdTe) thin films solar cells have achieved efficiency of 16.5% and with potential for improvement up to the theoretical value of 29% [14]. The close-spaced sublimation (CSS) method used for solar cell CdTe growth is being tested for selective CdTe nanoheteroepitaxial growth because the CSS method is cost efficient compared to the molecular beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE) methods. High quality films …

Fabrication And Characterization Of Nanocrystalline Yttrium Oxide Thin Films For Electronic Device Applications, Mudavakkat Vikas Haridas

Open Access Theses & Dissertations

This thesis presents the optimization of growth conditions for fabricating nanocrystalline Yttrium Oxide (Y2O3) thin films on silicon and optical grade, high quality quartz substrates in order to study its structural, optical and electrical properties for electronic device applications.

Commercially Y2O3 has proven to be difficult to fabricate at high quality due to its high temperature growth requirements and the need to alter established fabrication methods for electronic devices. A high temperature requirement for high quality poses a problem for research and analysis. This calls upon for an optimization of the growth conditions to facilitate fabrication of thin films for …

Collaborative And Distributed Algorithms For Localization In Wireless Sensor Networks Based On The Solution Of Spatially Constrained Local And Sub-Local Problems, Juan De Dios Cota

Open Access Theses & Dissertations

In this research we present algorithms for the distributed and collaborative localization of nodes for applications in wireless sensor networks. The algorithms are distributed in the sense that each node can estimate its own position using only range information and position estimates from neighboring nodes. The algorithms aim at achieving good accuracy with low computational complexity and low energy consumption. We consider the full localization process consisting of an initialization stage followed by a refinement stage.

For initialization, we propose a \emph{bilateration} algorithm where each node uses a set of anchors and their respective ranges to solve a set of …

Size Dependent Melting And Diffusion Of Silicon For Microsystem Applications, Noel Felipe Marquez

Open Access Theses & Dissertations

The size dependent reduced melting point and hydrogen enhanced surface diffusion effect on silicon nanostructures was explored experimentally. SOI and silicon wafers were patterned using nanimprint lithography and dry etching to explore the reduced melting point effect; and patterned with photolithography and dry etching to explore the hydrogen enhanced surface diffusion. The nanotextured samples were annealed in a wide variety of furnaces with nitrogen, forming gas, and argon atmospheres. Nitrogen was found to block the reshaping effect while argon was found to cause extensive pitting damage in the setup used. Micropatterned samples were annealed in a low pressure hydrogen enabled …

Conformal Electronics Packaging Through Additive Manufacturing And Micro-Dispensing, Richard I. Olivas

Open Access Theses & Dissertations

Realizing electronic systems that are conformal with curved or complex surfaces is difficult if not impossible with conventional fabrication techniques, which require rigid, two dimensional, printed circuit boards (PCB). Flexible copper based fabrication is widely available commercially providing conformance, but not simultaneously stiffness. As a result, these systems are susceptible to reliability problems if repeatedly bent or stretched. The integration of Additive Manufacturing (AM) combined with Direct Print (DP) micro-dispensing can produce shapes of arbitrary and complex form that also allows for 1) miniature cavities for insetting electronic components and 2) conductive traces for electrical interconnect between components. The fabrication …

Algorithms For Training Large-Scale Linear Programming Support Vector Regression And Classification, Pablo Rivas Perea

Open Access Theses & Dissertations

The main contribution of this dissertation is the development of a method to train a Support Vector Regression (SVR) model for the large-scale case where the number of training samples supersedes the computational resources. The proposed scheme consists of posing the SVR problem entirely as a Linear Programming (LP) problem and on the development of a sequential optimization method based on variables decomposition, constraints decomposition, and the use of primal-dual interior point methods. Experimental results demonstrate that the proposed approach has comparable performance with other SV-based classifiers. Particularly, experiments demonstrate that as the problem size increases, the sparser the solution …

Automated Detection Of Dust Clouds, Sources, And Direction From Noaa-Avhrr Satellite Imagery, Mohammed Qassim Alkhatib

Open Access Theses & Dissertations

This research is mainly focused on automatically locating dust sources and estimating their transport direction in NOAA-AVHRR images. Applications of AVHRR images may include agricultural assessment, producing maps of large area, and to retrieve various geophysical parameters. The AVHRR simultaneously records five bands of data, in our research, we focused on bands four and five since these wavelengths highlight the absorption and subsequent emission of thermal radiation by the silicate particles in the dust storms.

In this research, we propose a new method to detect dust clouds on satellite images. The approach we propose involves the use of an image …

2d Gaussian Object Motion Detection, Miguel Angel Chaidez

Open Access Theses & Dissertations

Dr. John Moya, and associated research assistants, have previously created an image-change recognition algorithm (JESSE) to mark changes within an image. The focus of this thesis is to present a physical application and modification of this algorithm in order to detect a surgeon's hand and verify chip placement on a printed circuit board.

There are different techniques in implementing visual recognition and motion detection with smart systems but the high cost and complicated calibration of these systems make them impractical. The goal was to create a system that is simple, inexpensive and applicable to multiple applications that will allow the …

Using Smartphones For Indoor Navigation, Benjamin Thomas Loulier

Purdue Polytechnic Masters Theses

This directed projet is about the use of smartphones for indoor navigation.

Nowadays, indoor navigation is a real challenge, we are all familiar with the multiple applications of GPS based navigation but all these applications cannot be transfered in an indoor environment as we cannot receive a GPS signal inside.

The document is composed of three different parts related to indoor navigation using smartphones. The first part presents an inertial positioning system for pedestrians walking in an indoor environment, this system is implemented on an iPhone 4. In the second part we introduce a positioning system using RFID tags scattered …

Development Of Load Balancing Algorithm Based On Analysis Of Multi-Core Architecture On Beowulf Cluster, Damian Valles

Open Access Theses & Dissertations

In this work, analysis, and modeling were employed to improve the Linux Scheduler for HPC use. The performance throughput of a single compute-node of the 23 node Beowulf cluster, Virgo 2.0, was analyzed to find bottlenecks and limitations that affected performance in the processing hardware where each compute-node consisted of two quad-core processors with eight gigabytes of memory. The analysis was performed using the High Performance Linpack (HPL) benchmark.

In addition, the processing hardware of the compute-node was modeled using an Instruction per Cycle (IPC) metric that was estimated using linear regression. Modeling data was obtained by using the Tuning …

Utepcam: A Scalable Wireless Vision Sensor Architecture For Computational, Power And Bandwidth Constrained Scenarios, Ricardo Zepeda

Open Access Theses & Dissertations

UTEPcam is a low cost and power vision sensor node system. UTEPcam is composed of an Atmel atmega32 8-bit microcontroller, a CY7C09099V static RAM chip, an OV6620 CMOS image sensor, a XBEE transceiver and a SD Flash memory card, and four logic gates. UTEPcam's simple yet efficiently architecture enables it to capture video at one frame per second. At its absolute highest, it is estimated that UTEPcam consumes only 1.321 Amps. When in standby, UTEPcam consumes 21 microamps. Furthermore, UTEPcam's program takes up only 1Kbyte of memory space.

UTEPcam's CPU, a simple 8-bit MCU, is unlike most vision sensor node …

An Ultra Low Power Subthreshold Delta Sigma Digital To Analog Converter, Ricardo Baca

Open Access Theses & Dissertations

Abstract

In the last four decades the incorporation of analog, digital and mixed-signal integrated circuits (IC) using Complementary Metal Oxide Semiconductor (CMOS) technology has been dramatically increasing and is improving almost every aspect of modern life. Furthermore, the continuous advances in CMOS Very Large System Integration (VLSI) technology allow higher integration densities and the increasing number of subsystems in a single chip results in higher speed execution and lower power consumption. Therefore, the increasing digitalization in electronic circuits across a wide range of battery-operated applications where reliability and power dissipation are critical requires Digital to Analog Converters (DACs) with higher …

Tin Dioxide Memristors On Glass And Plastic Substrates, Oscar Del Real

Open Access Theses & Dissertations

NanoMIL has studied and developed SnO2-based memristors, while the W.M Keck Center has been a research leader in printed silver inks. The focus of this thesis is to take the previous generation of memristors on glass and develop a process for creating memristors on flexible Kapton film for the first time. Moreover, collaborative work between the two UTEP laboratories produced memristors with printed silver top electrode contacts, also for the first time. These approaches may enable inexpensive flexible memory.

Maturation of the process was achieved by understanding important process parameters and subtle differences between glass and Kapton substrates. Moreover, electrical …

Special Issue On Wireless Sensor And Actuator Networks, Jiming Chen, Karl H. Johanson, Stephan Olariu, Ioannis Ch. Paschalidis, Ivan Stojmenovic

Computer Science Faculty Publications

( First paragraph) WIRELESS Sensor Networks (WSNs), in their various shapes and forms, have greatly facilitated and enhanced the automated, remote, and intelligent monitoring of a large variety of physical systems. These networks consist of a large number of typically small devices, each incorporating sensing, processing, and wireless communications capabilities. Their use has penetrated a plethora of application domains from industrial and building automation, to environmental, wildlife, and health monitoring.

A Study On Prospects For The Evolution Of Maritime Traffic Management Systems Taking Into Account E-Navigation, Kwang An

World Maritime University Dissertations

No abstract provided.

Design Concepts Of Terahertz Quantum Cascade Lasers: Proposal For Terahertz Laser Efficiency Improvements, Tillmann Kubis, Saumitra Raj Mehrotra, Gerhard Klimeck

Birck and NCN Publications

Conceptual disadvantages of typical resonant phonon terahertz quantum cascade lasers 􏰎THz-QCLs􏰍 are analyzed. Alternative designs and their combination within a concrete device proposal are discussed to improve the QCL performance. The improvements are 􏰎1􏰍 indirect pumping of the upper laser level, 􏰎2􏰍 diagonal optical transitions, 􏰎3􏰍 complete electron thermalization, and 􏰎4􏰍 materials with low effective electron masses. The nonequilibrium Green’s function method is applied to predict stationary electron transport and optical gain. The proposed THz-QCL shows a higher optical gain, a lower threshold current, and a higher operation temperature. Alloy disorder scattering can worsen the QCL performance.