Engineering Commons^™

Development Of Flexible Sensing Systems And Energy Harvesters Using Printing Techniques, Sepehr Emamian

Dissertations

Printed electronics (PE) has been gaining a significant level of interest and is being used for developing a wide range of electronic systems for various applications, specifically in the sensor fields. This dissertation focuses on the development of flexible sensors and energy harvesters for application in sensing systems by employing additive manufacturing processes.

Initially, an efficient surface enhanced Raman spectroscopy (SERS) substrate was fabricated by gravure printing a thin film of silver nanoparticle ink on a flexible polyethylene terephthalate (PET) sheet. The feasibility of the printed substrate to be used as a SERS substrate for the detection of explosive materials, …

Distributed Model Predictive Control Of Power Converters In Microsrids Under Different Modes Of Operation, Riyadh Toman Thahab Toman

Dissertations

Microgrids consist of many distributed energy sources (DERs) and the overall system is viewed as a number of subsystems. In this work, a finite control set model predictive control is proposed to control power converters in both grid and island modes of operation of the microgrid. Each subsystem is assigned a local controller that relies on measurements of common coupling point (PCC) and/or terminal quantities to provide accurate regulation of current or voltage components. This meets the local objective of each subsystem and contributes to the global objective of the microgrid.

In the first part of the work, a microgrid …

Bio-Socially Inspired Strategies In Support Of Dynamic Spectrum Access: An Evolutionary Game Theory Perspective, Mohammad Ali Marzoug Abu Shattal

Dissertations

Dynamic Spectrum Access (DSA) has been introduced to fulfill the expanded need for spectrum by different wireless networks and applications. Within the realm of spectrum access, the problem of "spectrum crunch" is present since some of the spectrum bands are overcrowded and others are underutilized. DSA aims to alleviate the problem of spectrum crunch. In DSA, Primary Users (PUs) allow Secondary Users (SUs) to access the spectrum as long as they do not interfere with PU transmissions beyond a pre-agreed acceptable level. In this work, a bio-socially inspired approach is proposed for SU interactions in support of better throughput for …

Optimal Combiners For Multiple Classifier Systems, Mohammed Falih Hassan

Dissertations

A Multiple Classifier System (MCS) is designed to combine classification results of an ensemble of different classifiers and consequently to produce the highest possible classification output. MCS has recently drawn growing attention and has become a necessity, especially when a problem involves a large class of noisy data or when using a single pattern classifier that has serious drawbacks in its results. A wide range of pattern recognition applications have benefited from the implementation of MCS, these include areas such as handwriting recognition, incremental learning, data fusion, feature selection, and a large variety of medical applications.

To achieve optimal ensemble …

A Novel E-Voting System With Diverse Security Features, Haijun Pan

Dissertations

Internet-based E-voting systems can offer great benefits over traditional voting machines in areas, such as protecting voter and candidate privacy, providing accurate vote counting, preventing voter fraud, and shortening the time of vote counting. This dissertation introduces, establishes and improves Internet-based E-voting systems on various aspects of the voting procedure. In addition, our designs also enable voters to track their votes which is a very important element in any elections.

Our novel Internet-based E-voting system is based on the following realistic assumptions: (1) The election authorities are not 100% trustworthy; (2) The E-voting system itself is not 100% trustworthy; (3) …

Machine Learning Based Digital Image Forensics And Steganalysis, Guanshuo Xu

Dissertations

The security and trustworthiness of digital images have become crucial issues due to the simplicity of malicious processing. Therefore, the research on image steganalysis (determining if a given image has secret information hidden inside) and image forensics (determining the origin and authenticity of a given image and revealing the processing history the image has gone through) has become crucial to the digital society.

In this dissertation, the steganalysis and forensics of digital images are treated as pattern classification problems so as to make advanced machine learning (ML) methods applicable. Three topics are covered: (1) architectural design of convolutional neural networks …

Silicon-Germanium Nanowire Heterojunctions: Optical And Electrical Properties, Xiaolu Wang

Dissertations

Semiconductor nanowires are quasi-one-dimensional objects with unique physical properties and strong potential in nanophotonics, nanoelectronics, biosensing, and solar cell devices. The next challenge in the development of nanowire functional structures is the nanowire axial heterojunctions, especially lattice mismatched heterojunctions. Si and Ge have a considerable lattice mismatch of ~ 4.2% as well as a mismatch in the coefficient of thermal expansion, and the formation of a Si_1-xGe_x transition layer at the heterointerface creates a non-uniform strain and modifies the band structures of the adjacent Si and Ge nanowire segments. These nanostructures are produced by catalytic chemical …

Simulation, Performance And Interference Analysis Of Multi-User Visible Light Communication Systems, Adel Aldalbahi

Dissertations

The emergence of new physical media such as optical wireless, and the ability to aggregate these new media with legacy networks motivate the study of heterogeneous network performance, especially with respect to the design of protocols to best exploit the characteristics of each medium.

This study considers Visible Light Communications (VLC), which is expected to coexist with legacy and future radio frequency (RF) media. While most of the research on VLC has been done on optimizing the physical medium, research on higher network layers is only beginning to gain attention, requiring new analyses and tools for performance analysis.

The first …

Fluid Manipulations Using A Piezo Electric Transformer For Sensing And Spray Generation Applications, Zeinab Ramshani

Dissertations

A steady effort has been made on the development of fluid manipulation techniques for sensing and actuating systems. Conventional techniques of fluid manipulation for sensing and spray generation purposes, often need trained staff or high input power and they are complicated, time consuming and expensive. Therefore, it is necessary to develop new systems which can overcome these drawbacks.

In this dissertation, the author has developed piezoelectric-based systems for fluid manipulation. The focus of this dissertation involves novel approaches of enhancing the sensing and actuating systems using the piezoelectric devices. This includes designing a system, which theoretically can overcome the limitations …

Mobile Cloud Computing And Network Function Virtualization For 5g Systems, Ali Al-Shuwaili

Dissertations

The recent growth of the number of smart mobile devices and the emergence of complex multimedia mobile applications have brought new challenges to the design of wireless mobile networks. The envisioned Fifth-Generation (5G) systems are equipped with different technical solutions that can accommodate the increasing demands for high date rate, latency-limited, energy-efficient and reliable mobile communication networks.

Mobile Cloud Computing (MCC) is a key technology in 5G systems that enables the offloading of computationally heavy applications, such as for augmented or virtual reality, object recognition, or gaming from mobile devices to cloudlet or cloud servers, which are connected to wireless …

The Design And Optimization Of Cooperative Mobile Edge, Xueqing Huang

Dissertations

As the world is charging towards the Internet of Things (IoT) era, an enormous amount of sensors will be rapidly empowered with internet connectivity. Besides the fact that the end devices are getting more diverse, some of them are also becoming more powerful, such that they can function as standalone mobile computing units with multiple wireless network interfaces. At the network end, various facilities are also pushed to the mobile edge to foster internet connections. Distributed small scale cloud resources and green energy harvesters can be directly attached to the deployed heterogeneous base stations.

Different from the traditional wireless access …

Forensic Research On Detecting Seam Carving In Digital Images, Jingyu Ye

Dissertations

Digital images have been playing an important role in our daily life for the last several decades. Naturally, image editing technologies have been tremendously developed due to the increasing demands. As a result, digital images can be easily manipulated on a personal computer or even a cellphone for many purposes nowadays, so that the authenticity of digital images becomes an important issue. In this dissertation research, four machine learning based forensic methods are presented to detect one of the popular image editing techniques, called ‘seam carving’.

To reveal seam carving applied to uncompressed images from the perspective of energy distribution …

Multiprocessing Real Time Vision Based System For Condition Monitoring In Solar Panels, Moath Hashim Alsafasfeh

Dissertations

Enabling an algorithm to be executed in parallel on a multicore or a multiprocessor system has become a necessity for many real time applications. Multicore systems are widely used to improve performance and satisfy time and power demands. In this dissertation, solar energy, which has proved itself as the future clean source of energy, is also considered in real time. Optimum utilization of this energy propelled research efforts into many directions of the solar system components. However, while real time operations of Photovoltaic (PV) systems occur without any supervisory mechanisms, many internal and/or external obstacles can occur and hinder a …

Architecture, Simulation, And Implementation Of Commodity Computer Components In Software Defined Radio Systems, Amean Al-Safi

Dissertations

Radio communications have evolved through an extended history of theoretical and practical component development into modern devices most often envisioned as the ubiquitous smart phones found in almost everyone’s hand on a university campus. During this development, radios have evolved from analog devices operating at low frequencies into nearly all digital processing systems referred to as Software Defined Radio (SDR) operating in frequency bands over 1 Gigahertz. Although specific forms and types of communication are fiercely pursued by commercial communication companies and industry, there remain numerous concepts where further advancement is possible, and applications, possibly less commercially viable, where advancements …

Sparsity Based Methods For Target Localization In Multi-Sensor Radar, Haley H. Kim

Dissertations

In this dissertation, several sparsity-based methods for ground moving target indicator (GMTI) radar with multiple-input multiple-output (MIMO) random arrays are proposed. MIMO random arrays are large arrays that employ multiple transmitters and receivers, the positions of the transmitters and the receivers are randomly chosen. Since the resolution of the array depends on the size of the array, MIMO random arrays obtain a high resolution. However, since the positions of the sensors are randomly chosen, the array suffers from large sidelobes which may lead to an increased false alarm probability. The number of sensors of a MIMO random array required to …