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Development of Indium Oxide Nanowires as Efficient Gas Sensors

Description: Crystalline indium oxide nanowires were synthesized following optimization of growth parameters. Oxygen vacancies were found to impact the optical and electronic properties of the as-grown nanowires. Photoluminescence measurements showed a strong U.V emission peak at 3.18 eV and defect peaks in the visible region at 2.85 eV, 2.66 eV and 2.5 eV. The defect peaks are attributed to neutral and charged states of oxygen vacancies. Post-growth annealing in oxygen environment and passivation with sulp… more
Date: December 2011
Creator: Gali, Pradeep
Partner: UNT Libraries
open access

Modeling and Design of Antennas for Loosely Coupled Links in Wireless Power Transfer Applications

Description: Wireless power transfer (WPT) systems are important in many areas, such as medical, communication, transportation, and consumer electronics. The underlying WPT system is comprised of a transmitter (TX) and receiver (RX). For biomedical applications, such systems can be implemented on rigid or flexible substrates and can be implanted or wearable. The efficiency of a WPT system is based on power transfer efficiency (PTE). Many WPT system optimization techniques have been explored to achieve the h… more
Date: August 2019
Creator: Sinclair, Melissa Ann
Partner: UNT Libraries
open access

Realization of LSTM Based Cognitive Radio Network

Description: This thesis presents the realization of an intelligent cognitive radio network that uses long short term memory (LSTM) neural network for sensing and predicting the spectrum activity at each instant of time. The simulation is done using Python and GNU Radio. The implementation is done using GNU Radio and Universal Software Radio Peripherals (USRP). Simulation results show that the confidence factor of opportunistic users not causing interference to licensed users of the spectrum is 98.75%. The … more
Date: August 2019
Creator: Valluru, Aravind-Deshikh
Partner: UNT Libraries
open access

Characterization of Ecg Signal Using Programmable System on Chip

Description: Electrocardiography (ECG) monitor is a medical device for recording the electrical activities of the heart using electrodes placed on the body. There are many ECG monitors in the market but it is essential to find the accuracy with which they generate results. Accuracy depends on the processing of the ECG signal which contains several noises and the algorithms used for detecting peaks. Based on these peaks the abnormality in the functioning of the heart can be estimated. Hence this thesis chara… more
Date: December 2012
Creator: Ravuru, Anusha
Partner: UNT Libraries
open access

Data Compression Using a Multi-residue System (Mrs)

Description: This work presents a novel technique for data compression based on multi-residue number systems. The basic theorem is that an under-determined system of congruences could be solved to accomplish data compression for a signal satisfying continuity of its information content and bounded in peak-to -peak amplitude by the product of relatively prime moduli,. This thesis investigates this property and presents quantitative results along with MATLAB codes. Chapter 1 is introductory in nature and Chap… more
Date: August 2012
Creator: Melaedavattil Jaganathan, Jyothy
Partner: UNT Libraries
open access

An Interactive Tool to Investigate the Inference Performance of Network Dynamics From Data

Description: Network structure plays a significant role in determining the performance of network inference tasks. An interactive tool to study the dependence of network topology on estimation performance was developed. The tool allows end-users to easily create and modify network structures and observe the performance of pole estimation measured by Cramer-Rao bounds. The tool also automatically suggests the best measurement locations to maximize estimation performance, and thus finds its broad applications… more
Date: August 2012
Creator: Veenadhar, Katragadda
Partner: UNT Libraries
open access

A Cognitive MIMO OFDM Detector Design for Computationally Efficient Space-Time Decoding

Description: In this dissertation a computationally efficient cognitive multiple-input multiple-output (MIMO) orthogonal frequency division duplexing (OFDM) detector is designed to decode perfect space-time coded signals which are able maximize the diversity and multiplexing properties of a rich fading MIMO channel. The adaptive nature of the cognitive detector allows a MIMO OFDM communication system to better meet to needs of future wireless communication networks which require both high reliability and lo… more
Date: August 2019
Creator: Grabner, Mitchell J
Partner: UNT Libraries
open access

Simulation and Performance Analysis of Strategic Air Traffic Management under Weather Uncertainty

Description: In this thesis, I introduce a promising framework for representing an air traffic flow (stream) and flow-management action operating under weather uncertainty. I propose to use a meshed queuing and Markov-chain model---specifically, a queuing model whose service-rates are modulated by an underlying Markov chain describing weather-impact evolution---to capture traffic management in an uncertain environment. Two techniques for characterizing flow-management performance using the model are devel… more
Date: May 2011
Creator: Zhou, Yi
Partner: UNT Libraries
open access

Consensus Building in Sensor Networks and Long Term Planning for the National Airspace System

Description: In this thesis, I present my study on the impact of multi-group network structure on the performance of consensus building strategies, and the preliminary mathematical formulation of the problem on improving the performance of the National Airspace system (NAS) through long-term investment. The first part of the thesis is concerned with a structural approach to the consensus building problem in multi-group distributed sensor networks (DSNs) that can be represented by bipartite graph. Direct i… more
Date: May 2011
Creator: Akula, Naga Venkata Swathik
Partner: UNT Libraries
open access

The Effect of Mobility on Wireless Sensor Networks

Description: Wireless sensor networks (WSNs) have gained attention in recent years with the proliferation of the micro-electro-mechanical systems, which has led to the development of smart sensors. Smart sensors has brought WSNs under the spotlight and has created numerous different areas of research such as; energy consumption, convergence, network structures, deployment methods, time delay, and communication protocols. Convergence rates associated with information propagations of the networks will be ques… more
Date: August 2014
Creator: Hasir, Ibrahim
Partner: UNT Libraries
open access

Teaching Fundamentals of Digital Logic Design and VLSI Design Using Computational Textiles

Description: This thesis presents teaching fundamentals of digital logic design and VLSI design for freshmen and even for high school students using e-textiles. This easily grabs attention of students as it is creative and interesting. Using e-textiles to project these concepts would be easily understood by students at young age. This involves stitching electronic circuits on a fabric using basic components like LEDs, push buttons and so on. The functioning of these circuits is programmed in Lilypad Arduino… more
Date: August 2014
Creator: Inampudi, Sivateja
Partner: UNT Libraries
open access

Dynamic WIFI Fingerprinting Indoor Positioning System

Description: A technique is proposed to improve the accuracy of indoor positioning systems based on WIFI radio-frequency signals by using dynamic access points and fingerprints (DAFs). Moreover, an indoor position system that relies solely in DAFs is proposed. The walking pattern of indoor users is classified as dynamic or static for indoor positioning purposes. I demonstrate that the performance of a conventional indoor positioning system that uses static fingerprints can be enhanced by considering dynamic… more
Date: August 2014
Creator: Reyes, Omar Costilla
Partner: UNT Libraries
open access

An Application of Digital Video Recording and Off-grid Technology to Burrowing Owl Conservation Research

Description: Through this research, engineering students and conservation biologists constructed an off-grid video system for observing western burrowing owls in El Paso, Texas. The burrowing owl has a declining population and their range decreasing, driving scientists' interest to see inside the den for observing critical nesting behavior. Texas Parks and Wildlife Department (TPWD) biologists wanted videos from inside the dark, isolated hillside owl burrows. This research yielded a replicable multi-camera … more
Date: August 2014
Creator: Williams, Jennifer M.
Partner: UNT Libraries
open access

Networking and Decentralized Control in Layered Networks: a Theoretical Study and Test-bed Development

Description: Layered structures are commonly used in communication systems, but their roles in decentralized control are not understood well. In the first part of this thesis, a theoretical study of consensus (a typical decentralized control task) in layered structures is conducted. The unique graph topology approach permits explicit characterization of consensus performance based on simple graphical characteristics of MLMG structures. In the second part of this thesis, a generic LEGO test-bed to mimic mult… more
Date: December 2014
Creator: Sheth, Vardhman Jayeshkumar
Partner: UNT Libraries
open access

Optimal Sensor Placement for Structural Health Monitoring

Description: In large-scale civil structures, a limited number of sensors are placed to monitor the health of civil structures to reduce maintenance, communication and energy costs. In this thesis, the problem of optimal sensor location placement to infer the health of civil structures is explored. First, a comparative study of approaches from the fields of control engineering and civil engineering is conducted . The widely used civil engineering approaches such as effective independence (EI) and modal assu… more
Date: December 2014
Creator: Movva, Gopichand
Partner: UNT Libraries
open access

Design Space Exploration of Domain Specific CGRAs Using Crowd-sourcing

Description: CGRAs (coarse grained reconfigurable array architectures) try to fill the gap between FPGAs and ASICs. Over three decades, the research towards CGRA design has produced number of architectures. Each of these designs lie at different points on a line drawn between FPGAs and ASICs, depending on the tradeoffs and design choices made during the design of architectures. Thus, design space exploration (DSE) takes a very important role in the circuit design process. In this work I propose the design spa… more
Date: August 2014
Creator: Sistla, Anil Kumar
Partner: UNT Libraries
open access

Development of a Cost Effective Wireless Sensor System for Indoor Air Quality Monitoring Applications

Description: Poor air quality can greatly affect the public health. Research studies indicate that indoor air can be more polluted than the outdoor air. An indoor air quality monitoring system will help to create an awareness of the quality of air inside which will eventually help in improving it. The objective of this research is to develop a low cost wireless sensor system for indoor air quality monitoring. The major cost reduction of the system is achieved by using low priced sensors. Interface circuits … more
Date: May 2014
Creator: Abraham, Sherin
Partner: UNT Libraries
open access

Design of Tunable/Reconfigurable and Compact Microwave Devices

Description: With the rapid development of the modern technology, radio frequency and microwave systems are playing more and more important roles. Since the time the first microwave device was invented, they have been leading not only the military but also our daily life to a new era. In order to make the devices have more practical applications, more and more strict requirements have been imposed. For example, good adaptability, reduced cost and shrank size are highly required. In this thesis, three devic… more
Date: May 2014
Creator: Zhou, Mi
Partner: UNT Libraries
open access

A Lego Mindstorms Nxt Based Test Bench for Multiagent Exploratory Systems and Distributed Network Partitioning

Description: Networks of communicating agents require distributed algorithms for a variety of tasks in the field of network analysis and control. For applications such as swarms of autonomous vehicles, ad hoc and wireless sensor networks, and such military and civilian applications as exploring and patrolling a robust autonomous system that uses a distributed algorithm for self-partitioning can be significantly helpful. A single team of autonomous vehicles in a field may need to self-dissemble into multiple… more
Date: May 2014
Creator: Patil, Riya Raghuvir
Partner: UNT Libraries
open access

Dual-band Microwave Device Design

Description: This thesis presents a brief introduction to microwave components and technology. It also presents two novel dual-band designs, their analysis, topology, simulation and fabrication. In chapter 2, a novel dual-band bandpass filter using asymmetric stub-loaded stepped-impedance resonators (SLSIRs) operating at 1 and 2.6 GHz is shown. This type of design applies suitable arrangements to improve the filter’s performance. Then, in chapter 3, a novel dual-band balun (transforms unbalanced input sign… more
Date: May 2014
Creator: Li Shen, Andres E.
Partner: UNT Libraries
open access

A Low-cost Wireless Sensor Network System Using Raspberry Pi and Arduino for Environmental Monitoring Applications

Description: Sensors are used to convert physical quantity into numerical data. Various types of sensors can be coupled together to make a single node. A distributed array of these nodes can be deployed to collect environmental data by using appropriate sensors. Application of low powered short range radio transceivers as a communication medium between spatially distributed sensor nodes is known as wireless sensor network. In this thesis I build such a network by using Arduino, Raspberry Pi and XBee. My goa… more
Date: May 2014
Creator: Ferdoush, Sheikh Mohammad
Partner: UNT Libraries
open access

Applications of Machine Learning for Remote Sensing and Environmental Monitoring

Description: This thesis covers applications of machine learning to the fields of remote sensing and environmental monitoring. First, a generalized background on the concepts, tools, and methods used throughout the remainder of the research project are introduced. Chapter 3 covers the implementation of artificial neural networks to improve low-cost particulate matter sensing networks using collocated high-quality sensors with varying dataset parameters. In Chapter 4, an attention-enhanced LSTM-Convolutional… more
Date: December 2022
Creator: Daniels, Jacob Edward
Partner: UNT Libraries

Light Matter Interactions in Two-Dimensional Semiconducting Tungsten Diselenide for Next Generation Quantum-Based Optoelectronic Devices

Description: In this work, we explored one material from the broad family of 2D semiconductors, namely WSe2 to serve as an enabler for advanced, low-power, high-performance nanoelectronics and optoelectronic devices. A 2D WSe2 based field-effect-transistor (FET) was designed and fabricated using electron-beam lithography, that revealed an ultra-high mobility of ~ 625 cm2/V-s, with tunable charge transport behavior in the WSe2 channel, making it a promising candidate for high speed Si-based complimentary-met… more
Date: December 2020
Creator: Bandyopadhyay, Avra Sankar
Partner: UNT Libraries
open access

Design of a Wearable Flexible Resonant Body Temperature Sensor with Inkjet-Printing

Description: A wearable body temperature sensor would allow for early detection of fever or infection, as well as frequent and accurate hassle-free recording. This thesis explores the design of a body-temperature-sensing device inkjet-printed on a flexible substrate. All structures were first modeled by first-principles, theoretical calculations, and then simulated in HFSS. A variety of planar square inductor geometries were studied before selecting an optimal design. The designs were fabricated using multi… more
Date: May 2020
Creator: Horn, Jacqueline Marie
Partner: UNT Libraries
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