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Improving Photovoltaic Panel Efficiency by Cooling Water Circulation (open access)

Improving Photovoltaic Panel Efficiency by Cooling Water Circulation

This thesis aims to increase photovoltaic (PV) panel power efficiency by employing a cooling system based on water circulation, which represents an improved version of water flow based active cooling systems. Theoretical calculations involved finding the heat produced by the PV panel and the circulation water flow required to remove this heat. A data logger and a cooling system for a test panel of 20W was designed and employed to study the relationship between the PV panel surface temperature and its output power. This logging and cooling system includes an Arduino microcontroller extended with a data logging shield, temperature sensing probes, current sensors, and a DC water pump. Real-time measurements were logged every minute for one or two day periods under various irradiance and air temperature conditions. For these experiments, a load resistance was chosen to operate the test panel at its maximum power point. Results indicate that the cooling system can yield an improvement of 10% in power production. Based on the observations from the test panel experiments, a cooling system was devised for a PV panel array of 640 W equipped with a commercial charge controller. The test data logger was repurposed for this larger system. An identical …
Date: December 2018
Creator: Joseph, Jyothis
System: The UNT Digital Library
Development and Integration of a Low-Cost Occupancy Monitoring System (open access)

Development and Integration of a Low-Cost Occupancy Monitoring System

The world is getting busier and more crowded each year. Due to this fact resources such as public transport, available energy, and usable space are becoming congested and require vast amounts of logistical support. As of February 2018, nearly 95% of Americans own a mobile cell phone according to the Pew Research Center. These devices are consistently broadcasting their presents to other devices. By leveraging this data to provide occupational awareness of high traffic areas such as public transit stops, buildings, etc logistic efforts can be streamline to best suit the dynamics of the population. With the rise of The Internet of Things, a scalable low-cost occupancy monitoring system can be deployed to collect this broadcasted data and present it to logistics in real time. Simple IoT devices such as the Raspberry Pi, wireless cards capable of passive monitoring, and the utilization of specialized software can provide this capability. Additionally, this combination of hardware and software can be integrated in a way to be as simple as a typical plug and play set up making system deployment quick and easy. This effort details the development and integration work done to deliver a working product acting as a foundation to build …
Date: December 2018
Creator: Mahjoub, Youssif
System: The UNT Digital Library
Smart Microgrid Energy Management Using a Wireless Sensor Network (open access)

Smart Microgrid Energy Management Using a Wireless Sensor Network

Modern power generation aims to utilize renewable energy sources such as solar power and wind to supply customers with power. This approach avoids exhaustion of fossil fuels as well as provides clean energy. Microgrids have become popular over the years, as they contain multiple renewable power sources and battery storage systems to supply power to the entities within the network. These microgrids can share power with the main grid or operate islanded from the grid. During an islanded scenario, self-sustainability is crucial to ensure balance between supply and demand within the microgrid. This can be accomplished by a smart microgrid that can monitor system conditions and respond to power imbalance by shedding loads based on priority. Such a method ensures security of the most important loads in the system and manages energy by automatically disconnecting lower priority loads until system conditions have improved. This thesis introduces a prioritized load shedding algorithm for the microgrid at the University of North Texas Discovery Park and highlight how such an energy management algorithm can add reliability to an islanded microgrid.
Date: December 2018
Creator: Darden, Kelvin S
System: The UNT Digital Library
Distributed Consensus, Optimization and Computation in Networked Systems (open access)

Distributed Consensus, Optimization and Computation in Networked Systems

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 satisfy the sufficient conditions. Moreover, we equip the proposed algorithm with a decentralized algorithm, which enables an arbitrarily chosen agent to compute the exact global minimizer within a finite number of time steps, using its own states observed over a successive time steps. In the third part, it is shown the implementation of accelerated distributed energy management for microgrids is achieved. The results presented in the thesis are corroborated by simulations or experiments.
Date: December 2018
Creator: Yao, Lisha
System: The UNT Digital Library
The Chief Security Officer Problem (open access)

The Chief Security Officer Problem

The Chief Security Officer Problem (CSO) consists of a CSO, a group of agents trying to communicate with the CSO and a group of eavesdroppers trying to listen to the conversations between the CSO and its agents. Through Lemmas and Theorems, several Information Theoretic questions are answered.
Date: December 2018
Creator: Tanga, Vikas Reddy
System: The UNT Digital Library
Real-Time Finger Spelling American Sign Language Recognition Using Deep Convolutional Neural Networks (open access)

Real-Time Finger Spelling American Sign Language Recognition Using Deep Convolutional Neural Networks

This thesis presents design and development of a gesture recognition system to recognize finger spelling American Sign Language hand gestures. We developed this solution using the latest deep learning technique called convolutional neural networks. This system uses blink detection to initiate the recognition process, Convex Hull-based hand segmentation with adaptive skin color filtering to segment hand region, and a convolutional neural network to perform gesture recognition. An ensemble of four convolutional neural networks are trained with a dataset of 25254 images for gesture recognition and a feedback unit called head pose estimation is implemented to validate the correctness of predicted gestures. This entire system was developed using Python programming language and other supporting libraries like OpenCV, Tensor flow and Dlib to perform various image processing and machine learning tasks. This entire application can be deployed as a web application using Flask to make it operating system independent.
Date: December 2018
Creator: Viswavarapu, Lokesh Kumar
System: The UNT Digital Library
Development of a Wireless Sensor Network System for Occupancy Monitoring (open access)

Development of a Wireless Sensor Network System for Occupancy Monitoring

The ways that people use libraries have changed drastically over the past few decades. Proliferation of computers and the internet have led to the purpose of libraries expanding from being only places where information is stored, to spaces where people teach, learn, create, and collaborate. Due to this, the ways that people occupy the space in a library have also changed. To keep up with these changes and improve patron experience, institutions collect data to determine how their spaces are being used. This thesis involves the development a system that collects, stores, and analyzes data relevant to occupancy to learn how a space is being utilized. Data is collected from a temperature and humidity sensor, passive Infrared sensor, and an Infrared thermal sensor array to observe people as they occupy and move through a space. Algorithms were developed to analyze the collected sensor data to determine how many people are occupying a space or the directions that people are moving through a space. The algorithms demonstrate the ability to track multiple people moving through a space as well as count the number of people in a space with an RMSE of roughly 0.39 people.
Date: December 2018
Creator: Onoriose, Ovie
System: The UNT Digital Library
Multi-Function and Flexible Microwave Devices (open access)

Multi-Function and Flexible Microwave Devices

In this dissertation, some multi-function and flexible RF/microwave devices have been studied to solve the issues in the modern microwave system designs. First, a power divider with two functions is proposed. The first function is a zero-phase delay power divider using zero-phase impedance transformer. The second function is a power divider with impedance transforming property. To achieve the first function, the two arms are treated as zero-phase impedance transformers. When the phase requirement is relaxed, the second function is obtained. Shunt transmission line stubs are employed to connect the isolation resistor, which provides great flexibility in the design. Then, a balun with transparent termination impedance and flexible open arms is designed. The design parameters of the balun are independent to the port impedance. This property allows the balun to work with different system impedances. Furthermore, the two output ports of the balun do not need to be connected together, which enables the device to have a very flexible structure. Finally, the continuous research of a tunable/reconfigurable coupler with equal output impedance is presented. In addition to the tunable/reconfigurable responses, unequal output impedance property is added to the microstrip line coupler. To shrink the size at the low frequency and make …
Date: December 2018
Creator: Zhou, Mi
System: The UNT Digital Library