Engineering Commons^™

Electric Field Induced Self-Assembly Of Mesoscale Structured Materials And Smart Fluids, Suchandra Das

Dissertations

This dissertation aims to study the forces that drive self-assembly in binary mixtures of particles suspended in liquids and on fluid-liquid interfaces when they are subjected to a uniform electric or magnetic field. Three fluid-particle systems are investigated experimentally and theoretically : (i) Suspensions of dielectric particles in dielectric liquids; (ii) Suspensions of ferromagnetic and diamagnetic particles in ferrofluids; and (iii) Dielectric particles on dielectric fluid-liquid interfaces. The results of these studies are then used to estimate the parameter values needed to assemble materials with desired mesoscale microstructures.

The first fluid-particle system studied is an electrorheological (ER) fluid formed using …

Fluorine-Based Inorganic Oxidizers For Use In Metal-Based Reactive Materials, Siva Kumar Valluri

Dissertations

This work explores inorganic fluorides as oxidizers for fuel-rich reactive materials. A preliminary assessment of metal fluorides accounting for their enthalpy of formation points to bismuth (III) fluoride, BiF3 and cobalt (II) fluoride, CoF2 as oxidizers of interest. Initially, composite powders of aluminum with chosen fluorides at 50-50 wt. % are prepared by arrested reactive milling. Despite an increase in reactivity and lowtemperature ignition, the prepared composite powders are insensitive to initiation by electro-static discharge (ESD), making them attractive alternative to analogous thermites having very high ESD sensitivity. In air, the composite powder particles burn faster than reference aluminum particles …

Service Quality Assessment And Improvement Methods And Tools, Kevin M. Moriarty

Dissertations

The nucleus of this research concept and system is being applied to turret lathe and milling machine Computer Numerical Control (CNC) tool systems. The research has a generic application to the service of broad array of sophisticated computer controlled / integrated machines, devices / equipment such as industrial robotics, medical equipment, surgical robots, and similar types of engineered system. Quality design review for quality service systems is a unique concept. Standard product service systems are qualitative and subjective in nature. The quantitative system identifies Key Predictive Attributes (KPAs) and applies quantitative methods to these attributes to develop a systematic process …

Private Sound Environments In Public Space: Use Of Headphones In Public Parks And Public Transit, Chathurthi S. De Silva

Dissertations

The use of headphones is now so commonplace that it is almost second nature for many people to use them. Not only do these people use headphones all the time, but they use them nearly everywhere, including in urban public spaces. In using headphones, people create their own “private sound environments” in public space. This phenomenon merits attention from researchers since the creation of private sound environments may well alter people’s experiences of public space.

This study answers five research questions about the use of headphones in parks and on transit: why people use them, when they begin using headphones …

Investigation Of Topological Phonons In Discrete Mechanical Metamaterials, Kai Qian

Dissertations

The study of topological mechanical metamaterials is a new emerging field that focuses on the topological properties of artificial mechanical structures. Inspired by topological insulators, topological mechanism has attracted intensive attention in condensed matter physics and successfully connected the quantum mechanical descriptions of electrons with the classical descriptions of phonons. It has led to experiments of mechanical metamaterials possessing topological characteristics, such as topologically protected conducting edges or surfaces without back-scattering. This dissertation presents a new experimental approach for mechanically engineering topological metamaterials based on patterning magnetically coupled spinners in order to localize the propagation of vibrations and evaluate different …

Towards Improving The Security Of The Software Supply Chain, Hammad Afzali

Dissertations

A software supply chain comprises a series of steps performed to develop and distribute a software product. History has shown that each of these steps is vulnerable to attacks that can have serious repercussions and can affect many users at once. To address the attacks against the software supply chain, end users must be provided with verifiable guarantees about the individual steps of the chain and with assurances that the steps are securely chained together.

In this dissertation, the security of several individual steps in the software supply chain is enhanced. The first step of the chain, managing the source …

Plant-Derived Extracellular Matrix Mimetic Scaffolds For Bone Repair Applications, Jessica Cardenas Turner

Dissertations

Autologous and allogeneic bone grafts are currently used to treat large bone defects or fractures that will not heal. However, for patients with osteoporosis or other conditions that impair the natural bone healing process, such as diabetes, smoking, bed rest, aging, autologous bone graft, which is the patient's own bone, is limited in quantity and its healing potential may be compromised. Allograft bone, or donated bone, lacks the necessary biological activity and has poor integration into defect. There is an urgent need for constructs/grafts capable of promoting bone cell function in fracture healing and large bone defects where the endogenous …

Improving Multi-Threaded Qos In Clouds, Weiwei Jia

Dissertations

Multi-threading and resource sharing are pervasive and critical in clouds and data-centers. In order to ease management, save energy and improve resource utilization, multi-threaded applications from different tenants are often encapsulated in virtual machines (VMs) and consolidated on to the same servers. Unfortunately, despite much effort, it is still extremely challenging to maintain high quality of service (QoS) for multi-threaded applications of different tenants in clouds, and these applications often suffer severe performance degradation, poor scalability, unfair resource allocation, and so on.

The dissertation identifies the causes of the QoS problems and improves the QoS of multi-threaded execution with three …

Controlled Reduction Of Graphene Oxide And Graphene Oxide-Carbon Nanotube Hybrids And Their Applications, Samar Azizighannad

Dissertations

Graphene and graphene derivatives are widely used in diverse research and industrial applications. Graphene production on a large scale is carried out by exfoliating graphite oxide and producing graphene oxide (GO), which comprises of graphene sheets with different oxygen-containing functional groups such as hydroxyl, carboxyl, and carbonyl. GO is reduced to reduced graphene oxide (rGO), which has properties that are closer to graphene. Properties of GO and rGO depend upon the oxygen content, and the effect of reducing oxygen content on the aqueous behavior of rGOs is not well understood.

In an effort to understand how properties of rGO change …

Using Fnirs As An Objective Measure Of Susceptibility To Informational Masking, Min Zhang

Dissertations

Resolving complicated auditory scenes is crucial for daily communication where background sound is often present. However, most hearing aid (HA) and cochlear implant (CI) users have difficulties understanding speech when competing sound sources are present, resulting in reduced job opportunities and increased risk for social isolation. Perceptual interference from background sound is called auditory masking. At least two distinct masking phenomena exist, called energetic and informational masking (EM and IM).

In the first masking phenomenon, EM, target and masker energies coincide at the same time and frequency. Computational and physiological models of cochlear auditory processing can reliably predict listeners' performances …

Modeling And Analysis Of Intracellular Signaling Networks And Cellular Decisions, Mustafa Ozen

Dissertations

Developing molecular network analysis methods is important due to their applications on complex biological systems such as target discovery, development of drugs, discovering drug effects, and finding treatments for many complex diseases, e.g., cancer, autoimmune, and mental disorders. An example of analysis techniques is the fault diagnosis analysis, in which the purpose is to quantify how much vulnerable the entire network is to dysfunction of one or multiple molecules. Such analysis can be done after proper network models are implemented, trained, and tested against the experimental data. In this dissertation, a Boolean modeling framework is implemented and methods to train …

Atomic Oxygen Resistant Low Earth Orbit Stable Polymer Matrix Composites Employing Phenylphosphine Oxide Epoxy-Amines, Witold Fuchs

Dissertations

Atomic oxygen (AO) attacks polymer matrix composites (PMC’s) on the surfaces of spacecraft in low earth orbit (LEO) and threatens safe spacecraft operation and service life. Incorporating phenylphosphine oxide (PPO) groups into polymer chains offers a self-regenerating method of protection from AO but remains poorly understood. Herein, epoxies containing PPO groups were synthesized with increasing concentrations of phosphorus [P] from 0 to 8 wt % to investigate their AO resistance. Measurements confirmed the exposure of these materials to AO produces a passivation phosphate (POx) layer on the surface of the sample and the efficacy of the resultant layer was directly …

Advancing The Use Of Quality Control Tools For High-Density Data In Modern Manufacturing, Romina Dastoorian

Dissertations

In modern manufacturing, advanced metrology systems are continually being incorporated into quality control (QC) systems to provide high-density (HD) datasets. These datasets can contain millions of measurements that can be used to represent a part’s whole geometry. While integrating HD datasets into QC systems has brought several opportunities to enhance the performance of QC systems, it has resulted in new challenges in this area as well. While significant amounts of research have been performed in this area, the QC research community still strives to tackle these challenges. This study identifies key challenges regarding incorporating HD datasets into QC systems. Specifically, …

Wireless Antenna Multiplexing Using Tunable Antenna For Space Applications, Saifudeen Ahammed Kabeer

Dissertations

Recent development in communication technologies shifts the communication paradigm from point to point to multi-user wireless systems. These developments eased the use of mobile telephone, satellite services, 5G cellular, smart application, and the

Internet of Things. The proliferation of mobile devices has necessitated an elaborate mechanism to serve multiple users over a shared communication medium, and a multiplexing approach is introduced to serve this purpose. Multiplexing refers to a method that aims at combining multiple signals into one signal such that each user would be able to extract its desired data upon receiving the multiplexed signal. This spectrum sharing allows …

Thermal Evaluation Of Advanced Leading Edge For Rotating Gas Turbine Blade: Numerical And Experimental Investigations, Amin Safi

Dissertations

Gas turbine engines play a vital role in our life. Our power demand is significantly and continuously growing. One approach to improve thermal efficiency in gas turbine engines requires a higher turbine inlet gas temperature. Advanced gas turbine engines operate at high temperatures, around 2000 K. Since operating at high temperatures may compromise the blade structure integrity, different cooling systems are used in a turbine blades. One of the most efficient cooling techniques is impingement cooling, mostly used in the leading edge. The leading edge experiences the highest temperature in the blade exposed to the hottest gas.

Researchers studied different …

Conversion Of Lignocellulose Biomass From Date Palm Waste To High Value Chemicals, Emmanuel Galiwango

Dissertations

Lignocellulose biomass has gained growing popularity because of its low cost of production compared to food crops, it solves problems of food and energy security, can grow in various climates and land, and it is CO₂ neutral. Date palm trees produce large amounts of fibrous wastes that are good sources of lignocellulose. There are over 40 million date palm trees in UAE and most of their lignocellulosic wastes (i.e., leaves, surface fibers, bunches, etc.) are currently used for low value applications such as compost or electric generation. However, the lignocellulosic components of this waste stream have the potential to …

Design Of Graphene-Based Sensors For Nucleic Acids Detection And Analysis, Asma’ Wasfi Fayez Mustafa

Dissertations

DNA (Deoxyribonucleic Acid) is the blueprint of life as it encodes all genetic information. In genetic disorder such as gene fusion, Copy Number Variation (CNV), and single nucleotide polymorphism, Nucleic acids such as DNA bases detection and analysis is used as the gold standard for successful diagnosis. Researchers have been conducting rigorous studies to achieve genome sequences at low cost while maintaining high accuracy and high throughput. A quick, accurate, and low-cost DNA detection approach would revolutionize medicine. Genome sequence helps to enhance people’s perception of inheritance, disease, and individuality. This research aims to improve DNA bases detection accuracy, and …

Stellar Classification Of Folded Spectra Using The Mk Classification Scheme And Convolutional Neural Networks, John Magee

Dissertations

The year 1943 saw the introduction of the Morgan-Keenan (MK) classification scheme and this replaced the existing Harvard Classification scheme. Both stellar classification scheme are fundamentally grounded in the field of spectroscopy. The Harvard Classification scheme classified stars based on stellar surface temperature. The MK Classification scheme introduced the concept of a luminosity class that is intrinsically linked to the surface gravity of a star. Temperature and luminosity class values are estimated directly from the stellar spectrum.

Machine learning is a well-established technique in astronomy. Traditionally, a spectrum is treated as a one-dimensional sequence of data. Techniques such as artificial …

Exploiting Bert And Roberta To Improve Performance For Aspect Based Sentiment Analysis, Gagan Reddy Narayanaswamy

Dissertations

Sentiment Analysis also known as opinion mining is a type of text research that analyses people’s opinions expressed in written language. Sentiment analysis brings together various research areas such as Natural Language Processing (NLP), Data Mining, and Text Mining, and is fast becoming of major importance to companies and organizations as it is started to incorporate online commerce data for analysis. Often the data on which sentiment analysis is performed will be reviews. The data can range from reviews of a small product to a big multinational corporation. The goal of performing sentiment analysis is to extract information from those …

Feature Augmentation For Improved Topic Modeling Of Youtube Lecture Videos Using Latent Dirichlet Allocation, Nakul Srikumar

Dissertations

Application of Topic Models in text mining of educational data and more specifically, the text data obtained from lecture videos, is an area of research which is largely unexplored yet holds great potential. This work seeks to find empirical evidence for an improvement in Topic Modeling by pre- extracting bigram tokens and adding them as additional features in the Latent Dirichlet Allocation (LDA) algorithm, a widely-recognized topic modeling technique. The dataset considered for analysis is a collection of transcripts of video lectures on Machine Learning scraped from YouTube. Using the cosine similarity distance measure as a metric, the experiment showed …

Human Age And Gender Classification Using Convolutional Neural Networks, Eamon Kelliher

Dissertations

In a world relying ever more on human classification, this papers aims to improve on age and gender image classification through the use of Convolutional Neural Networks (CNN). Age and gender classification has become a popular area of study in the past number of years however there are still improvements to be made, particularly in the area of age classification. This research paper aims to test the currently accepted fact that CNN models are the superior model type for image classification by comparing CNN performance against Support Vector Machine performance on the same dataset. Using the Adience image classification dataset, …

Evaluating The Performance Of Transformer Architecture Over Attention Architecture On Image Captioning, Deepti Balasubramaniam

Dissertations

Over the last few decades computer vision and Natural Language processing has shown tremendous improvement in different tasks such as image captioning, video captioning, machine translation etc using deep learning models. However, there were not much researches related to image captioning based on transformers and how it outperforms other models that were implemented for image captioning. In this study will be designing a simple encoder-decoder model, attention model and transformer model for image captioning using Flickr8K dataset where will be discussing about the hyperparameters of the model, type of pre-trained model used and how long the model has been trained. …

Finetuning Bert And Xlnet For Sentiment Analysis Of Stock Market Tweets Using Mixout And Dropout Regularization, Shubham Jangir

Dissertations

Sentiment analysis is also known as Opinion mining or emotional mining which aims to identify the way in which sentiments are expressed in text and written data. Sentiment analysis combines different study areas such as Natural Language Processing (NLP), Data Mining, and Text Mining, and is quickly becoming a key concern for businesses and organizations, especially as online commerce data is being used for analysis. Twitter is also becoming a popular microblogging and social networking platform today for information among people as they contribute their opinions, thoughts, and attitudes on social media platforms over the years. Because of the large …

Adequately Generating Captions For An Image Using Adaptive And Global Attention Mechanisms., Shravan Kumar Talanki Venkatarathanaiahsetty

Dissertations

Generating description to images is a recent surge and with latest developments in the field of Artificial Intelligence, it can be one of the prominent applications to bridge the gap between Computer vision and Natural language processing fields. In terms of the learning curve, Deep learning has become the main backbone in driving many new applications. Image Captioning is one such application where the usage of Deep learning methods enhanced the performance of the captioning accuracy. The introduction of the Encoder-Decoder framework was a breakthrough in Image captioning. But as the sequences got longer the performance of captions was affected. …

Improving A Network Intrusion Detection System’S Efficiency Using Model-Based Data Augmentation, Vinicius Waterkemper Lodetti

Dissertations

A network intrusion detection system (NIDS) is one important element to mitigate cybersecurity risks, the NIDS allow for detecting anomalies in a network which may be a cyberattack to a corporate network environment. A NIDS can be seen as a classification problem where the ultimate goal is to distinguish between malicious traffic among a majority of benign traffic. Researches on NIDS are often performed using outdated datasets that don’t represent the actual cyberspace. Datasets such as the CICIDS2018 address this gap by being generated from attacks and an infrastructure that reflects an up-to-date scenario.

A problem may arise when machine …

An Evaluation On The Performance Of Code Generated With Webassembly Compilers, Raymond Phelan

Dissertations

WebAssembly is a new technology that is revolutionizing the web. Essentially it is a low-level binary instruction set that can be run on browsers, servers or stand-alone environments. Many programming languages either currently have, or are working on, compilers that will compile the language into WebAssembly. This means that applications written in languages like C++ or Rust can now be run on the web, directly in a browser or other environment. However, as we will highlight in this research, the quality of code generated by the different WebAssembly compilers varies and causes performance issues. This research paper aims to evaluate …

Machine Learning For Auditory Hierarchy, William Coleman

Dissertations

Coleman, W. (2021). Machine Learning for Auditory Hierarchy. This dissertation is submitted for the degree of Doctor of Philosophy, Technological University Dublin. Audio content is predominantly delivered in a stereo audio file of a static, pre-formed mix. The content creator makes volume, position and effects decisions, generally for presentation in stereo speakers, but has no control ultimately over how the content will be consumed. This leads to poor listener experience when, for example, a feature film is mixed such that the dialogue is at a low level relative to the sound effects. Consumers can complain that they must turn …

Study Of Mm-Wave Fixed Beam And Frequency Beam-Scanning Antenna Arrays, Zeeshan Ahmed

Dissertations

Millimeter-wave frequencies are anticipated to be widely adapted for future wireless communication systems to resolve the demand of high data-rate and capacity issues. The millimeter-wave frequency range offers wide spectrum and a shift for most newly developing technologies as the microwave and lower frequency bands are becoming overcrowded and congested. These high frequency bands offer short wavelengths which has enabled the researchers to design and implement compact and adaptable antenna solutions. This research focuses on the implementation, transformation and modification of antenna structures used in lower frequency bands to millimeter-wave applications with high gain and multi-band and wideband performances.

The …

Analysis Of Power Quality Constrained Consumer-Friendly Demand Response In Low Voltage Distributions Network, Chittesh Veni Chandran

Dissertations

Load management using demand response (DR) in a low voltage distribution network (LVDN) offers an economically profitable business platform with peak load management. However, the inconvenience caused to the consumer in depriving their devices and the low levels of associated incentive have contributed to lower consumer acceptance for DR programs in the community. However, with the increasing number of controllable consumer loads, a residential-level DR program is highly plausible in the short to medium term. Further, additional DR capabilities (including ancillary services) are likely to improve the remuneration potential for participants in DR. Considering the perspective of a distribution network …

Cough Monitoring Through Audio Analysis, Thomas Snella

Dissertations

The detection of cough events in audio recordings requires the analysis of a significant amount of data as cough is typically monitored continuously over several hours to capture naturally occurring cough events. The recorded data is mostly composed of undesired sound events such as silence, background noise, and speech. To reduce computational costs and to address the ethical concerns raised from the collection of audio data in public environments, the data requires pre-processing prior to any further analysis.

Current cough detection algorithms typically use pre-processing methods to remove undesired audio segments from the collected data but do not preserve the …