UNT Theses and Dissertations - 169 Matching Results

Search Results

prev Results: 61 - 84 next
open access

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
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Development of Silicon Nanowire Field Effect Transistors

Description: An economically reliable technique for the synthesis of silicon nanowire was developed using silicon chloride as source material. The 30-40 micron long nanowires were found to have diameters ranging from 40 – 100 nm. An amorphous oxide shell covered the nanowires, post-growth. Raman spectroscopy confirmed the composition of the shell to be silicon-dioxide. Photoluminescence measurements of the as-grown nanowires showed green emission, attributed to the presence of the oxide shell. Etching of th… more
Date: December 2011
Creator: Nukala, Prathyusha
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Development of Wireless Sensor Network System for Indoor Air Quality Monitoring

Description: This thesis describes development of low cost indoor air quality (IAQ) monitoring system for research. It describes data collection of various parameters concentration present in indoor air and sends data back to host PC for further processing. Thesis gives detailed information about hardware and software implementation of IAQ monitoring system. Also discussed are building wireless ZigBee network, creating user friendly graphical user interface (GUI) and analysis of obtained results in comparis… more
Date: December 2012
Creator: Borkar, Chirag
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Distributed Consensus, Optimization and Computation in Networked Systems

Description: In the first part of this thesis, we propose a distributed consensus algorithm under multi-layer multi-group structure with communication time delays. It is proven that the consensus will be achieved in both time-varying and fixed communication delays. In the second part, we study the distributed optimization problem with a finite-time mechanism. It is shown that our distributed proportional-integral algorithm can exponentially converge to the unique global minimizer when the gain parameters sa… more
Date: December 2018
Creator: Yao, Lisha
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Distributed Source Coding with LDPC Codes: Algorithms and Applications

Description: The syndrome source coding for lossless data compression with side information based on fixed-length linear block codes is the main emphasis of this work. We demonstrate that the source entropy rate can be achieved for syndrome source coding with side information when the sources are correlated. Next, we examine employing LDPC codes to apply the channel and syndrome concepts in order to satisfy the Slepian Wolf limit. Our findings indicate that irregular codes perform significantly better when … more
Date: December 2022
Creator: Gandhi, Himani Chirag
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Dual-band Microwave Components And Their Applications

Description: In general, Dual-Band technology enables microwave components to work at two different frequencies. This thesis introduces novel dual-band microwave components and their applications. Chapter 2 presents a novel compact dual-band balun (converting unbalanced signals to balanced ones). The ratio between two working frequencies is analyzed. A novel compact microstrip crossover (letting two lines to cross each other with very high isolation) and its dual-band application is the subject of chapter 3… more
Date: December 2011
Creator: Shao, Jin
Item Type: Refine your search to only Thesis or Dissertation
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.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Dual-Band Quarter Wavelength and Half Wavelength Microstrip Transmission Line Design

Description: The thesis represents the design for dual-band quarter wavelength and half wavelength microstrip transmission line. Chapter 2 proposed the design of a novel dual-band asymmetric pi-shaped short-circuited quarter wavelength microstrip transmission line working at frequencies 1GHz and 1.55 GHz for 50Ω transmission line and at frequencies 1GHz and 1.43GHz for 60Ω transmission line. Chapter 3 proposed the design of a novel dual-band quarter wavelength microstrip transmission line with asymmetricall… more
Date: May 2015
Creator: Imran, Md Asheque
Item Type: Refine your search to only Thesis or Dissertation
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
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

EEG Signal Analysis in Decision Making

Description: Decision making can be a complicated process involving perception of the present situation, past experience and knowledge necessary to foresee a better future. This cognitive process is one of the essential human ability that is required from everyday walk of life to making major life choices. Although it may seem ambiguous to translate such a primitive process into quantifiable science, the goal of this thesis is to break it down to signal processing and quantifying the thought process with pr… more
Date: May 2017
Creator: Salma, Nabila
Item Type: Refine your search to only Thesis or Dissertation
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
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Efficient Convolutional Neural Networks for Image Processing Applications

Description: Modern machine learning techniques focus on extremely deep and multi-pathed networks, resulting in large memory and computational requirements. This thesis explores techniques for designing efficient convolutional networks including pixel shuffling, depthwise convolutions, and various activation fucntions. These techniques are then applied to two image processing domains: single-image super-resolution and image compression. The super-resolution model, TinyPSSR, is one-third the size of the next… more
Date: August 2022
Creator: Chiapputo, Nicholas J.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Efficient Linear Secure Computation and Symmetric Private Information Retrieval Protocols

Description: Security and privacy are of paramount importance in the modern information age. Secure multi-party computation and private information retrieval are canonical and representative problems in cryptography that capture the key challenges in understanding the fundamentals of security and privacy. In this dissertation, we use information theoretic tools to tackle these two classical cryptographic primitives. In the first part, we consider the secure multi-party computation problem, where multiple us… more
Date: December 2020
Creator: Zhou, Yanliang
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Efficient Solar Energy Harvesting and Management for Wireless Sensor Networks under Varying Solar Irradiance Conditions

Description: Although wireless sensor networks have been successfully used for environmental monitoring, one of the major challenges that this technology has been facing is supplying continuous and reliable electrical power during long-term field deployment. Batteries require repetitive visits to the deployment site to replace them once discharged; admittedly, they can be recharged from solar panels, but this only works in open areas where solar radiation is unrestricted. This dissertation introduces a nove… more
Date: May 2020
Creator: Gurung, Sanjaya
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Electrical Equivalent Modeling of the Reverse Electrowetting-on-Dielectric (REWOD) Based Transducer along with Highly Efficient Energy Harvesting Circuit Design towards Self-Powered Motion Sensor

Description: Among various energy harvesting technologies reverse electrowetting-on-dielectric energy harvesting (REWOD) has been proved to harvest energy from low frequency motion such as many human motion activities (e.g. walking, running, jogging etc.). Voltage rectification and DC-DC boosting of low magnitude AC voltage from REWOD can be used to reliably self-power the wearable sensors. In this work, a commercial component-based rectifier and DC-DC converter is designed and experimentally verified, for … more
Date: August 2021
Creator: Gunti, Avinash
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Electronic Sound Analysis with Hardware System and Remote Internet Display

Description: Currently, standards from government agencies such as the National Institute for Occupation Safety and Health exist to aid in safeguarding individuals’ capacity for hearing, but only in factory settings in which large machines often produce loud levels of sound. Neglecting the fact that these preventative measures are only in place in the most limited of settings, no system currently exists to observe and report sound exposure levels in a manner timely or easily recognizable enough to adequatel… more
Date: August 2010
Creator: McCord, Cameron Forrest
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Emotion Recognition Using EEG Signals

Description: Emotions have significant importance in human life in learning, decision-making, daily interaction, and perception of the surrounding environment. Hence, it has become very essential to detect and recognize a person's emotional states and to build a connection between humans and computers. This process is called brain-computer interaction (BCI) and is a vast field of research in neuroscience. Hence, in the past few years, emotion recognition has gained adequate attention in the research communi… more
Date: May 2022
Creator: Choudhary, Sairaj Mahesh
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Employment of dual frequency excitation method to improve the accuracy of an optical current sensor, by measuring both current and temperature.

Description: Optical current sensors (OCSs) are initially developed to measure relatively large current over a wide range of frequency band. They are also used as protective devices in the event a fault occurs due to a short circuit, in the power generation and distribution industries. The basic principal used in OCS is the Faraday effect. When a light guiding faraday medium is placed in a magnetic field which is produced by the current flowing in the conductor around the magnetic core, the plane of polariz… more
Date: December 2008
Creator: Karri, Avinash
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Estimation of Drone Location Using Received Signal Strength Indicator

Description: The main objective of this thesis is to propose a UAV (also called as drones) location estimation system based on LoRaWAN using received signal strength indicator in a GPS denied environment. The drones are finding new applications in areas such as surveillance, search, rescue missions, package delivery, and precision agriculture. Nearly all applications require the localization of UAV during flight. Localization is the method of determining a UAVs physical position using a real or virtual coor… more
Date: August 2021
Creator: Jagini, Varun Kumar
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Exploration Of Energy And Area Efficient Techniques For Coarse-grained Reconfigurable Fabrics

Description: Coarse-grained fabrics are comprised of multi-bit configurable logic blocks and configurable interconnect. This work is focused on area and energy optimization techniques for coarse-grained reconfigurable fabric architectures. In this work, a variety of design techniques have been explored to improve the utilization of computational resources and increase energy savings. This includes splitting, folding, multi-level vertical interconnect. In addition to this, I have also studied fully connected… more
Date: December 2011
Creator: Yadav, Anil
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

A Feasibility Study of Cellular Communication and Control of Unmanned Aerial Vehicles

Description: Consumer drones have used both standards such as Wi-Fi as well as proprietary communication protocols, such as DJI's OcuSync. While these methods are well suited to certain flying scenarios, they are limited in range to around 4.3 miles. Government and military unmanned aerial vehicles (UAVs) controlled through satellites allow for a global reach in a low-latency environment. To address the range issue of commercial UAVs, this thesis investigates using standardized cellular technologies for com… more
Date: December 2019
Creator: Gardner, Michael Alan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Formation Control and Path Planning Strategies for Unmanned Aerial Vehicle Swarms

Description: This dissertation focuses on the path planning of unmanned aerial vehicle (UAV) swarms under distributed and hybrid control scenarios. It presents two such models and analyzes them both from theory and practice. In the first method, a distributed formation control strategy for UAV swarm based on consensus law is presented. This model makes use of the fundamental concepts of leader-follower structure, social potential functions, and algebraic graph theory to jointly address flocking and de-confl… more
Date: August 2021
Creator: Mukherjee, Srijita
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Formation Control of Multi-Agent Systems

Description: Formation control is a classical problem and has been a prime topic of interest among the scientific community in the past few years. Although a vast amount of literature exists in this field, there are still many open questions that require an in-depth understanding and a new perspective. This thesis contributes towards exploring the wide dimensions of formation control and implementing a formation control scheme for a group of multi-agent systems. These systems are autonomous in nature and ar… more
Date: August 2017
Creator: Mukherjee, Srijita
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
Back to Top of Screen