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Articles 121 - 150 of 467

Full-Text Articles in Electrical and Computer Engineering

Storage Systems For Mobile-Cloud Applications, Nafize R. Paiker Dec 2018

Storage Systems For Mobile-Cloud Applications, Nafize R. Paiker

Dissertations

Mobile devices have become the major computing platform in todays world. However, some apps on mobile devices still suffer from insufficient computing and energy resources. A key solution is to offload resource-demanding computing tasks from mobile devices to the cloud. This leads to a scenario where computing tasks in the same application run concurrently on both the mobile device and the cloud.

This dissertation aims to ensure that the tasks in a mobile app that employs offloading can access and share files concurrently on the mobile and the cloud in a manner that is efficient, consistent, and transparent to locations. …


Development And Characterization Of Nano Nickel-Based Conductive Inks For Flexographic Printing Of Electronics And New Interpretations Of Surface Energies Of Solids, Bilge Nazli Altay Dec 2018

Development And Characterization Of Nano Nickel-Based Conductive Inks For Flexographic Printing Of Electronics And New Interpretations Of Surface Energies Of Solids, Bilge Nazli Altay

Dissertations

Traditional printing technologies and conductive/functional inks have been integrated to print electronic devices and circuits on really think, lightweight and flexible materials in a time and cost-effective manner. Printing is an additive manufacturing technology, which selectively deposits materials only where needed to produce a wide range of devices including sensors, smart packaging, solar panels, batteries, light sources and wearable electronics. Therefore, it greatly reduces the number of required steps for manufacturing as well as the amount of waste generated relative to conventional electronic manufacturing. However, the process requirements and ink formulations to print electronics differ from graphic printing; therefore, the …


Vision-Based Framework For Monitoring Of Eating Behavior Of Persons With Alzheimer’S Disease, Haitham Al-Anssari Dec 2018

Vision-Based Framework For Monitoring Of Eating Behavior Of Persons With Alzheimer’S Disease, Haitham Al-Anssari

Dissertations

Dementia is a syndrome used to describe an array of significant declines in cognitive abilities due to progressive and irreversible loss of neurons and brain functioning. This neurodegeneration seriously affects daily life activities like driving, shopping, working and speaking. Among these, Alzheimer’s disease is the most common type of dementia, with individuals experiencing loss of memory and thinking and reasoning skills. Due to cognitive decline, individuals with Alzheimer’s often suffer from malnutrition, since they do not eat, even when food is presented, and must be fed with assistance. This assistance presents a significant burden of time to caregivers, and consequently …


Integrated Compressive Sensing And Feature Descriptors- A Framework For Facial Recognition Systems, Ali Kadhem Jaber Dec 2018

Integrated Compressive Sensing And Feature Descriptors- A Framework For Facial Recognition Systems, Ali Kadhem Jaber

Dissertations

Facial recognition is still a challenge in many applications, particularly in surveillance, security systems, and human-computer interactive (HCI) tools. The impact of real-world environmental variations on the performance of any facial recognition system can be significant. These variations may include illumination, facial expressions, poses, disguises (facial hair, glasses or cosmetics) and partial face occlusion. Furthermore, the number of images (samples) needed for facial recognition systems can be very large, much larger than what is typically required by an algorithm, and this is often made worse with expansion of the feature space dimensionality. Truly, the “curse of dimensionality” haunts any real-time …


Practical Vortex Beam Generation, Nedime Pelin Mohamed Hassan Salem Jul 2018

Practical Vortex Beam Generation, Nedime Pelin Mohamed Hassan Salem

Dissertations

Vector vortex beams are monochromatic electromagnetic wave fields carrying spin angular momentum (SAM) and orbital angular momentum (OAM). Spin angular momentum is associated with the polarization of the field, whereas OAM yields an azimuthal field dependence of the form exp( jqφ), where φ is the azimuthal angle, and q is an integer designating the helicity order, which is also known as the topological charge of the vortex beam. Vortex beams owe their names to the characteristic on-axis phase singularity and amplitude null.

In this study, a new method to generate vector vortex beams in the microwave regime is devised …


Optimized Insulation And Filter Design Of Rotating Machines Fed By Fast Front Pulses, Mohammed Khalil Hussain Jun 2018

Optimized Insulation And Filter Design Of Rotating Machines Fed By Fast Front Pulses, Mohammed Khalil Hussain

Dissertations

AC rotating machines are exposed to fast front pulses when fed from inverters. This type of excitation produces dielectric stress in the machine’s insulation system that can result in premature deterioration or even failure.

In this dissertation, a non-uniform transmission line model to predict the transient voltage distribution in a machine coil under steep-fronted surge conditions is described and implemented. This model is a function not only of frequency but also of space to represent the variation of electrical parameters in the overhang and slot regions of the coil. These parameters are computed using the finite element method. In order …


Online Edge Caching And Wireless Delivery In Fog-Aided Networks, Seyyed Mohammadreza Azimi May 2018

Online Edge Caching And Wireless Delivery In Fog-Aided Networks, Seyyed Mohammadreza Azimi

Dissertations

Multimedia content is the significant fraction of transferred data over the wireless medium in the modern cellular and wireless communication networks. To improve the quality of experience perceived by users, one promising solution is to push the most popular contents as close as to users, also known as the "edge" of network. Storing content at the edge nodes (ENs) or base stations (BSs) is called "caching". In Fog Radio Access Network (F-RAN), each EN is equipped with a cache as well as a "fronthaul" connection to the content server. Among the new design problems raised by the outlined scenarios, two …


Borehole Communication Via Drill Strings In Oil Wells, Ali Hamdan Alenezi May 2018

Borehole Communication Via Drill Strings In Oil Wells, Ali Hamdan Alenezi

Dissertations

The performance of multichannel and single channel accelerometers used as uphole communication receivers is studied. Using measured channels from the drill string testbed, it is shown that one tri-axial accelerometer can provide nearly uncorrelated signals when compared to two single channel accelerometers. Having uncorrelated signals at the uphole receiver provides a diversity which in turn can lead to an increase in the communication system performance. The use of a strain sensor as a receiver in borehole communication is proposed. Using measured channels from the drill string testbed, the performance of a strain receiver with a single-accelerometer receiver is compared. The …


Secure Entity Authentication, Zuochao Dou May 2018

Secure Entity Authentication, Zuochao Dou

Dissertations

According to Wikipedia, authentication is the act of confirming the truth of an attribute of a single piece of a datum claimed true by an entity. Specifically, entity authentication is the process by which an agent in a distributed system gains confidence in the identity of a communicating partner (Bellare et al.). Legacy password authentication is still the most popular one, however, it suffers from many limitations, such as hacking through social engineering techniques, dictionary attack or database leak. To address the security concerns in legacy password-based authentication, many new authentication factors are introduced, such as PINs (Personal Identification Numbers) …


From Geographically Dispersed Data Centers Towards Hierarchical Edge Computing, Abbas Kiani May 2018

From Geographically Dispersed Data Centers Towards Hierarchical Edge Computing, Abbas Kiani

Dissertations

Internet scale data centers are generally dispersed in different geographical regions. While the main goal of deploying the geographically dispersed data centers is to provide redundancy, scalability and high availability, the geographic dispersity provides another opportunity for efficient employment of global resources, e.g., utilizing price-diversity in electricity markets or utilizing locational diversity in renewable power generation. In other words, an efficient approach for geographical load balancing (GLB) across geo-dispersed data centers not only can maximize the utilization of green energy but also can minimize the cost of electricity. However, due to the different costs and disparate environmental impacts of the …


On Distributed Mobile Edge Computing, Xiang Sun May 2018

On Distributed Mobile Edge Computing, Xiang Sun

Dissertations

Mobile Cloud Computing (MCC) has been proposed to offload the workloads of mobile applications from mobile devices to the cloud in order to not only reduce energy consumption of mobile devices but also accelerate the execution of mobile applications. Owing to the long End-to-End (E2E) delay between mobile devices and the cloud, offloading the workloads of many interactive mobile applications to the cloud may not be suitable. That is, these mobile applications require a huge amount of computing resources to process their workloads as well as a low E2E delay between mobile devices and computing resources, which cannot be satisfied …


Microfluidic Biosensor With Functionalized Gold Nano Particles On Interdigitated Electrodes, Bharath Babu Nunna May 2018

Microfluidic Biosensor With Functionalized Gold Nano Particles On Interdigitated Electrodes, Bharath Babu Nunna

Dissertations

The integration of the microfluidics to the biosensor has growing demand with favorable conditions such as reduced processing time and low reagent consumption. The immuno biosensing with the microfluidic platform helped to make the electrochemical biosensing assays portable due to which this sensing mechanism can be easily implemented in point of care devices. The implementation of the biosensing in the microchannels significantly reduces the sample requirement form milli liter (mL) to micro liter (uL), and thus leads to low volume sample requirement during the sensing. The primary factors contributing to the microfluidic biosensors performance are probe immobilization, specific binding and …


Protocol For Energy Efficient Cluster Head Election For Collaborative Cluster Head Elections., David Otu Jan 2018

Protocol For Energy Efficient Cluster Head Election For Collaborative Cluster Head Elections., David Otu

Dissertations

In wireless sensor networks (WSNs) , energy is a major constrain.Energy efficient network protocols is required to maintain reliable sensing of the sensing field . WSNs that use LEACH protocol, have node in a cluster periodically take trials to become cluster - head,such that the nodes in the cluster becomes cluster - head evenly. Nodes with greater transmission distance to the base station in the cluster dies out faster because it performs more work in transmitting data when it is cluster-head. The distance-based algorithm presented in this project, ensures that work is allocated to the nodes in the cluster more …


Can Threshold-Based Sensor Alerts Be Analysed To Detect Faults In A District Heating Network?, Liam Cantwell Jan 2018

Can Threshold-Based Sensor Alerts Be Analysed To Detect Faults In A District Heating Network?, Liam Cantwell

Dissertations

Older IoT “smart sensors” create system alerts from threshold rules on reading values. These simple thresholds are not very flexible to changes in the network. Due to the large number of false positives generated, these alerts are often ignored by network operators. Current state-of-the-art analytical models typically create alerts using raw sensor readings as the primary input. However, as greater numbers of sensors are being deployed, the growth in the number of readings that must be processed becomes problematic. The number of analytic models deployed to each of these systems is also increasing as analysis is broadened. This study aims …


Interference Unmixing And Estimation Technique For Improvement Of Speech Separation Performance, Ankur Maurya Dec 2017

Interference Unmixing And Estimation Technique For Improvement Of Speech Separation Performance, Ankur Maurya

Dissertations

Presence of noise in the speech can sometimes become annoying as it can lead to loss of important data or create misunderstandings between the communications area which can lead to major problems associated to loss of time and money. This thesis focuses to filter out noise form a speech signal which is simulated in Matlab/Octave software while making a comparison between temporal resolution of signal with respect to the spectral resolution of the signal in which the parameters such as the size of window length are varied in order to obtain the best speech separation performance. To get the best …


Distributed Model Predictive Control Of Power Converters In Microsrids Under Different Modes Of Operation, Riyadh Toman Thahab Toman Dec 2017

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 …


Development Of Flexible Sensing Systems And Energy Harvesters Using Printing Techniques, Sepehr Emamian Dec 2017

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, …


Bio-Socially Inspired Strategies In Support Of Dynamic Spectrum Access: An Evolutionary Game Theory Perspective, Mohammad Ali Marzoug Abu Shattal Dec 2017

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 Dec 2017

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 Oct 2017

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 Oct 2017

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 Oct 2017

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 Si1-xGex 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 Oct 2017

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 Aug 2017

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 Jul 2017

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 Apr 2017

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 Apr 2017

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 Apr 2017

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 Apr 2017

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 Jan 2017

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 …