Physical Sciences and Mathematics Commons^™

Comparative Analysis And Integration Of Knowledge- And Data-Driven Multicriteria Models: A Case Study Of Landslide Susceptibility Assessment In Northern Iran, Seyed Vali Vakhshoori

Electronic Thesis and Dissertation Repository

A landslide susceptibility index (LSI) can be used to identify the susceptible areas to landslides and prevent loss of lives and infrastructure. LSIs are generated in knowledge- or data-driven landslide susceptibility assessment (LSA) models. Literature review shows that neither of these models is the best for LSA, and both should be integrated. Accordingly, some studies are being done in this regard, but with some drawbacks. This study's objective is to integrate and compare knowledge- or data-driven models within a standard LSA framework. For constructing the framework, the reference point (RP) method from Spatial Multicriteria Analyses (SMCA) set was employed. This …

The Spectro-Temporal Relationships Of Repeating Fast Radio Bursts, Mohammed Afif Chamma

Electronic Thesis and Dissertation Repository

Fast radio bursts (FRBs) are short and extremely energetic bursts of radiation detected from galaxies across the universe that occur thousands of times a day. Despite advances in instrumentation, it is difficult to explain the enormous implied energy reservoirs of FRBs, their emission mechanism and the existence of repeating and periodic sources. This thesis explores the spectro-temporal properties of repeating FRBs and details the discovery of several new relationships between them, providing valuable information on the nature of FRBs. By measuring the spectro-temporal properties of a sample of bursts from the repeating source FRB20121102A I show that the magnitude of …

Subsurface Correlation Of Lower Silurian Medina Group, Southwestern Ontario, Rhys H. Paterson

Electronic Thesis and Dissertation Repository

The Medina Group succession in southwestern Ontario includes, in ascending order: the Whirlpool, Manitoulin, Cabot Head, Power Glen, Devils Hole-Balls Falls, Grimsby, and Thorold formations. Subsurface mapping in central and eastern Lake Erie has resulted in the recognition of three stratigraphic packages within the Medina Group based upon the integration of sedimentologic, stratigraphic and geophysical borehole logs. The interplay between changing paleoenvironments, sediment provenance, and regional tectonics and associated sea level fluctuations has resulted in the accumulation of a complex mosaic of mixed siliciclastics and carbonates. Manitoulin Formation carbonates and Whirlpool Formation siliciclastics display consistent thicknesses across the study area. …

The Coordination Chemistry And Reactivity Of Pd Phosphine 1-Azaallyl Complexes, Kyle M. Jackman

Electronic Thesis and Dissertation Repository

Structurally responsive ligands (SRLs) are a class of ligands that change their coordination mode with a metal centre, which permits reactions that are difficult with non-SRLs, allow access to unique mechanisms, and allow isolation of unusual coordination complexes. The 1-azaallyl (1-AzA) family of SRLs are capable of isomerizing between η³-NCC and κ¹-N modes that occupy two and one coordination sites, respectively. This thesis investigates a new class of phosphine 1^AzA (P^AzA) ligands and the reactivity of their coordination complexes with palladium.

The first-generation P^AzA ligand contains a phenyl linkage between the two heteroatoms and affords a …

An Investigation Into Time Gazed At Traffic Objects By Drivers, Kolby R. Sarson

Electronic Thesis and Dissertation Repository

Several studies have considered driver’s attention for a multitude of distinct purposes, ranging from the analysis of a driver’s gaze and perception, to possible use in Advanced Driving Assistance Systems (ADAS). These works typically rely on simple definitions of what it means to “see,” considering a driver gazing upon an object for a single frame as being seen. In this work, we bolster this definition by introducing the concept of time. We consider a definition of ”seen” which requires an object to be gazed upon for a set length of time, or frames, before it can be considered as seen …

Characterization Of 1d And 2d Materials With Tip-Enhanced Raman Spectroscopy, María Olivia Avilés

Electronic Thesis and Dissertation Repository

Carbon-based materials, such as 1D single-walled carbon nanotubes (SWCNT) or 2D graphene, are promising materials for a variety of applications in energy storage, biosensors, and medical imaging applications. Similarly, beyond graphene, 2D transition metal dichalcogenides (TDM) that can have either a metallic or semiconducting character have gained interest for potential applications in electronics and photonics. Specifically, metallic TMDs such as vanadium disulfide (VS₂) show potential applications in optoelectronics and lithium-ion batteries. On the other hand, semiconducting TDMs like tungsten disulfide (WS₂) show a direct band gap, making them interesting for photovoltaic applications, transistors, or photodetectors. The …

Potential Of Vision Transformers For Advanced Driver-Assistance Systems: An Evaluative Approach, Andrew Katoch

Electronic Thesis and Dissertation Repository

In this thesis, we examine the performance of Vision Transformers concerning the current state of Advanced Driving Assistance Systems (ADAS). We explore the Vision Transformer model and its variants on the problems of vehicle computer vision. Vision transformers show performance competitive to convolutional neural networks but require much more training data. Vision transformers are also more robust to image permutations than CNNs. Additionally, Vision Transformers have a lower pre-training compute cost but can overfit on smaller datasets more easily than CNNs. Thus we apply this knowledge to tune Vision transformers on ADAS image datasets, including general traffic objects, vehicles, traffic …

Statistical Roles Of The G-Expectation Framework In Model Uncertainty: The Semi-G-Structure As A Stepping Stone, Yifan Li

Electronic Thesis and Dissertation Repository

The G-expectation framework is a generalization of the classical probability system based on the sublinear expectation to deal with phenomena that cannot be described by a single probabilistic model. These phenomena are closely related to the long-existing concern about model uncertainty in statistics. However, the distributions and independence in the G-framework are quite different from the classical setup. These distinctions bring difficulty when applying the idea of this framework to general statistical practice. Therefore, a fundamental and unavoidable problem is how to better understand G-version concepts from a statistical perspective.

To explore this problem, this thesis establishes a new substructure …

Investigating The Mechanism Of Protein And Peptide Electrospray Ionization, Elnaz Aliyari

Electronic Thesis and Dissertation Repository

Electrospray ionization (ESI) mass spectrometry (MS) is widely used for the detection and characterization of various analytes. However, many fundamental aspects of the ESI process remain poorly understood. Using molecular dynamics (MD) simulations, MS, and ion mobility spectrometry (IMS), this thesis sheds light on the mechanisms whereby gaseous analyte ions are formed from highly charged ESI nanodroplets. After a general introduction (Chapter 1), Chapter 2 focuses on the ion evaporation mechanism (IEM), i.e., the ejection of analyte ions from the droplet surface. The IEM is well established for low MW compounds, but it has remained contentious whether this pathway is …

Extracting Microservice Dependencies Using Log Analysis, Andres O. Rodriguez Ishida

Electronic Thesis and Dissertation Repository

Microservice architecture is an architectural style that supports the design and implementation of very scalable systems by distributing complex functionality to highly granular components. These highly granular components are referred to as microservices and can be dynamically deployed on Docker containers. These microservice architecture systems are very extensible since new microservices can be added or replaced as the system evolves. In such highly granular architectures, a major challenge that arises is how to quickly identify whether any changes in the system’s structure violate any policies or design constraints. Examples of policies and design constraints include whether a microservice can call …

Synthesis And Characterization Of Photoluminescent Boron Difluoride Hydrazone (Bodihy) Dyes, Daniela Cappello

Electronic Thesis and Dissertation Repository

This thesis describes the synthesis, characterization, optoelectronic, and redox properties of boron difluoride hydrazone (BODIHY) dyes. BODIHYs are part of a class of molecular materials whereby chelating N-donor ligands form complexes with a boron difluoride (BF₂) moiety, which rigidifies and introduces push-pull electronic structures to the resulting dyes. This thesis demonstrates that structural modifications to the appended substituents on the BODIHY core can be used to drastically tune the optoelectronic and redox properties of the unique complexes.

BODIHYs are weakly luminescent in dilute solutions but exhibit enhanced emission in the aggregate- and solid-state due to a phenomenon …

Pressure-Induced Modifications To The Structural And Optoelectronic Properties Of 2d Hybrid Organic-Inorganic Perovskites, Jesse Ratte

Electronic Thesis and Dissertation Repository

Recently, 2D hybrid organic-inorganic perovskites (HOIP) have garnered lots of research interest for their applications in optoelectronic devices, especially in solar cells. The optoelectronic properties of 2D HOIPs have yet to be optimized for these applications. High external pressure is well known to induce structural modifications to 2D HOIPs, and thus modify their optoelectronic properties. Herein, we report a study of the effects of high pressure (HP) on the structures and optoelectronic properties of cyclohexane methylamine (CMA) lead iodide (CMA2PbI4) and the structures of N,N-dimethylphenylene-p-diammonium (DPDA) lead iodide (DPDAPbI4).

High pressure measurements of CMA2PbI4 were performed using Raman spectroscopy, Fourier-transform …

Natural Product Discovery And Mycotoxin Analysis Of Agricultural Endophytes And Pathogens, Jacob P. Walsh

Electronic Thesis and Dissertation Repository

This thesis focuses on the application of fungal natural product chemistry for the use of agriculture fungal pathogenesis research. The research in this work uses many analytical chemistry techniques and instruments such as HPLC, LC-MS/MS and NMR. In Chapter 2, a diagnostic fragmentation module was developed for the identification of compound classes in crude fungal extracts. This module identified the classes cytochalasins and chaetoglobosins from extracts of Penicillium, Chaetomium, and Xylaria. From these extracts a new chaetoglobosin was discovered and the module was implemented into the open-source software package MZmine 2.0. Chapter 3 discusses analytical chemistry techniques with the …

Regression-Based Methods For Dynamic Treatment Regimes With Mismeasured Covariates Or Misclassified Response, Dan Liu

Electronic Thesis and Dissertation Repository

The statistical study of dynamic treatment regimes (DTRs) focuses on estimating sequential treatment decision rules tailored to patient-level information across multiple stages of intervention. Regression-based methods in DTR have been studied in the literature with a critical assumption that all the observed variables are precisely measured. However, this assumption is often violated in many applications. One example is the STAR*D study, in which the patient's depressive score is subject to measurement error. In this thesis, we explore problems in the context of DTR with measurement error or misclassification considered in the observed data.

The first project deals with covariate measurement …

Understanding Deep Learning With Noisy Labels, Li Yi

Electronic Thesis and Dissertation Repository

Over the past decades, deep neural networks have achieved unprecedented success in image classification, which largely relies on the availability of correctly annotated large-scale datasets. However, collecting high-quality labels for large-scale datasets is expensive and time-consuming or even infeasible in practice. Approaches to addressing this issue include: acquiring labels from non-expert labelers, crowdsourcing-like platforms or other unreliable resources, where the label noise is inevitably involved. It becomes crucial to develop methods that are robust to label noise.

In this thesis, we study deep learning with noisy labels from two aspects. Specifically, the first part of this thesis, including two chapters, …

Copulas, Maximal Dependence, And Anomaly Detection In Bi-Variate Time Series, Ning Sun

Electronic Thesis and Dissertation Repository

This thesis focuses on discussing non-parametric estimators and their asymptotic behaviors for indices developed to characterize bi-variate time series. There are typically two types of indices depending on whether the distributional information is involved. For the indices containing the distributional information of the bivariate stationary time series, we particularly focus on the index called the tail order of maximal dependence (TOMD), which is an improvement of the tail order. For the indices without distributional information of the bivariate time series, we focus on an anomaly detection index for univariate input-output systems.

This thesis integrates three articles. The first article (Chapter …

Towards The Development Of A Cost-Effective Image-Sensing-Smart-Parking Systems (Isensmap), Aakriti Sharma

Electronic Thesis and Dissertation Repository

Finding parking in a busy city has been a major daily problem in today’s busy life. Researchers have proposed various parking spot detection systems to overcome the problem of spending a long time searching for a parking spot. These works include a wide variety of sensors to detect the presence of a vehicle in a parking spot. These approaches are expensive to implement and ineffective in extreme weather conditions in an outdoor parking environment. As a result, a cost-effective, dependable, and time-saving parking solution is much more desirable. In this thesis, we proposed and developed an image processing-based real-time parking-spot …

Towards A Novel And Intelligent E-Commerce Framework For Smart-Shopping Applications, Susmitha Hanumanthu

Electronic Thesis and Dissertation Repository

Nowadays, with the advancement of market digitalization accompanied by internet technologies, consumers can buy products from anywhere in the world. Finding the best-offered deal from numerous e-commerce sites and online stores is overwhelming, time-consuming, and often not very effective. Customers need to visit many online stores to find their desired product at the desired price. Also, the option of finding a product in the future time that is not currently available is limited in the current e-commerce platform. To address these limitations, there is a need to develop a new one-stop e-shopping model that would allow customers to search for …

Respiratory Pattern Analysis For Covid-19 Digital Screening Using Ai Techniques, Annita Tahsin Priyoti

Electronic Thesis and Dissertation Repository

Corona Virus (COVID-19) is a highly contagious respiratory disease that the World Health Organization (WHO) has declared a worldwide epidemic. This virus has spread worldwide, affecting various countries until now, causing millions of deaths globally. To tackle this public health crisis, medical professionals and researchers are working relentlessly, applying different techniques and methods. In terms of diagnosis, respiratory sound has been recognized as an indicator of one’s health condition. Our work is based on cough sound analysis. This study has included an in-depth analysis of the diagnosis of COVID-19 based on human cough sound. Based on cough audio samples from …

Improving Deep Entity Resolution By Constraints, Soudeh Nilforoushan

Electronic Thesis and Dissertation Repository

Entity resolutions the problem of finding duplicate data in a dataset and resolving possible differences and inconsistencies. ER is a long-standing data management and information retrieval problem and a core data integration and cleaning task. There are diverse solutions for ER that apply rule-based techniques, pairwise binary classification, clustering, and probabilistic inference, among other techniques. Deep learning (DL) has been extensively used for ER and has shown competitive performance compared to conventional ER solutions. The state-of-the-art (SOTA) ER solutions using DL are based on pairwise comparison and binary classification. They transform pairs of records into a latent space that can …

A Survey Of Stapling Methods To Increase The Affinity, Activity And Stability Of Ghrelin Analogues, Juan Esteban

Electronic Thesis and Dissertation Repository

The growth hormone secretagogue receptor (GHSR) is a G protein-coupled receptor which regulates various important physiological and pathophysiological processes in the body. Ghrelin is the primary high affinity endogenous ligand for GHSR and has limited secondary structure in solution, which makes it proteolytically unstable. This inherent instability in ghrelin can be overcome by incorporating helix-inducing staples that stabilize its structure and improve affinity and activity. We present an analysis of different stapling methods at positions 12 and 16 of ghrelin(1-20) analogues with the goal of increasing proteolytic stability and to retain or improve affinity and activity towards GHSR. Ghrelin(1-20) analogues …

Automorphism-Preserving Color Substitutions On Profinite Graphs, Michal Cizek

Electronic Thesis and Dissertation Repository

Profinite groups are topological groups which are known to be Galois groups. Their free product was extensively studied by Luis Ribes and Pavel Zaleskii using the notion of a profinite graph and having profinite groups act freely on such graphs. This thesis explores a different approach to study profinite groups using profinite graphs and that is with the notion of automorphisms and colors. It contains a generalization to profinite graphs of the theorem of Frucht (1939) that shows that every finite group is a group of automorphisms of a finite connected graph, and establishes a profinite analog of the theorem …

Wideband And Relativistic Superradiance In Astrophysics, Christopher M. Wyenberg

Electronic Thesis and Dissertation Repository

In the quantum phenomenon of superradiance (SR) a population of inverted particles evolves, through its interaction with the quantized vacuum radiation field, into a highly entangled state capable of generating much greater radiative emission than predicted by the independent spontaneous decay of its constituent particles. The phenomenon has recently been applied to transient astrophysical processes but has thus far been restricted to particles sharing a common velocity. This thesis researches the effects of astrophysical velocity distributions upon SR, which are distinct from conventional regimes of the quantum optics literature in that they may possess extremely wide bandwidths, turbulent statistical properties, …

Exploring Artificial Intelligence (Ai) Techniques For Forecasting Network Traffic: Network Qos And Security Perspectives, Ibrahim Mohammed Sayem

Electronic Thesis and Dissertation Repository

This thesis identifies the research gaps in the field of network intrusion detection and network QoS prediction, and proposes novel solutions to address these challenges. Our first topic presents a novel network intrusion detection system using a stacking ensemble technique using UNSW-15 and CICIDS-2017 datasets. In contrast to earlier research, our proposed novel network intrusion detection techniques not only determine if the network traffic is benign or normal, but also reveal the type of assault in the flow. Our proposed stacking ensemble model provides a more effective detection capability than the existing works. Our proposed stacking ensemble technique can detect …

Analyzing Enhanced Electrochemiluminescence Of Novel Materials, Liuqing Yang

Electronic Thesis and Dissertation Repository

As a powerful analytical technique, electrochemiluminescence (ECL) has found wide applications in the fields of bioanalysis and light-emitting devices. However, many ECL materials sustain the shortcomings of low ECL efficiencies. To better design novel materials with ECL enhancement, it is essential to investigate and the enhanced ECL mechanisms. In this thesis, ECL enhancements of various novel materials were analyzed utilizing ECL-voltage curves, potential pulsing experiments, ECL and photoluminescence spectroscopies, and other characterization methods. Specifically, two graphene quantum dots (GQDs) with different heteroatom doping were designed and synthesized. Structural characterizations and spectroscopies demonstrated that the heteroatom doping could change the surface …

Thermo-Responsive Antibiotic-Eluting Coatings For Treating Infection Near Orthopedic Implants, Jan Chung Kwan

Electronic Thesis and Dissertation Repository

The clinical effectiveness of orthopedic devices to restore the function of joints has been well established yet there is a lack of development in associated infections. As the demand for orthopedic surgeries continues to rise, infection remains a growing problem and one of the main reasons for revision surgeries. Bacterial contamination of the surgical site followed by adhesion of bacteria onto the surface of orthopedic devices leads to the formation of a biofilm which is a common initiator for infection. As a result, infection in the orthopedic field is commonly defined as orthopedic device-related infections (ODRI). There are limited options …

An Analysis Of Weighted Least Squares Monte Carlo, Xiaotian Zhu

Electronic Thesis and Dissertation Repository

Since Longstaff and Schwartz [2001] brought the amazing Regression-based Monte Carlo (LSMC) method in pricing American options, it has received heated discussion. Based on the research done by Fabozzi et al. [2017] that applies the heteroscedasticity correction method to LSMC, we further extend the study by introducing the methods from Park [1966] and Harvey [1976]. Our work shows that for a single stock American Call option modelled by GBM with two exercise opportunities, WLSMC or IRLSMC provides better estimates in continuation value than LSMC. However, they do not lead to better exercise decisions and hence have little to no effect …

Design And Surface Modification Of Noble Metal-Based Nanocatalysts, Xuchun Wang

Electronic Thesis and Dissertation Repository

This thesis investigates approaches to modifying the surface structure of noble metal-based nanocatalysts. Noble metal-based nanocatalysts, such as Pt and Pd, play a significant role in heterogeneous catalysis due to their capabilities in activating the cleavage or formation of chemical bonds, but still suffer from the high-cost issue and unsatisfied catalytic performance due to too strong or too weak adsorption of intermediates. Considering the surface specificity of heterogeneous catalysis, Bi, a cheap metal, was used to modify the surface of Pt- and Pd-based nanocatalysts. This thesis aims to unveil the role of Bi in improving their catalytic performance from both …

Geomechanical Modeling Of A Fault During Fluid Injection, Charles Kw Hulls

Electronic Thesis and Dissertation Repository

The injection of fluid into rock masses as a part of industrial processes, such as hydraulic fracturing, can lead to an increase in seismic activity. The movement of the injected fluid and resulting stresses can be simulated and analyzed. One aspect of this analysis is the predicted rate of seismic activity, obtained via the Dietrich rate-and-state law and the Coulomb Failure Stress. This work produces simulations for two fracturing scenarios in the Duvernay Shale region. Model parameters, such as layer permeability and timing of fault slip, are varied to determine their impact on the model results. The simulated results show …

Solid Electrolytes And Interface Design For High-Performance All-Solid-State Batteries, Shumin Zhang

Electronic Thesis and Dissertation Repository

All-solid-state batteries (ASSBs), in which solid superionic conductors are used as electrolytes to transport ions between cathode and anode, have been regarded as one of the most promising candidates for the next-generation energy storage technologies in electric vehicles (EVs), grid applications, etc. The advances of ASSBs over conventional lithium-ion batteries (LIBs) come from their inherent safety and high energy density, which benefits from the use of nonflammable solid electrolytes (SEs) to potentially enable metal anodes (such as Li metal or Na metal) and high-voltage cathode active materials (CAM) in ASSBs. Since that, the research and design of SEs have been …