Digital Commons Network^™

Scale Formation, Properties And De-Scaling In Steelmaking, Richard Osei

Doctoral Dissertations

During continuous castings, reheating, and hot rolling, slab surfaces are exposed to atmospheres containing oxidizing gases which results in scale formation. Inefficient removal of the formed scale during reheating affects product surface quality. The effect of steel composition and operating parameters on scale formation and scale removal efficiencies were investigated. Experimental investigations were carried out using a thermogravimetric (TGA) apparatus designed to replicate the combustion gas atmosphere and temperature in actual industrial slab reheat furnaces. Report on oxidation kinetics, scale structure and properties, and descaling were conducted on laboratory cast and industrial samples. Different characterization techniques were used to analyze …

Pet Imaging Reveals Reduced Synaptic Density In People With Well-Controlled Hiv Infection, Julian Joseph Weiss

Yale Medicine Thesis Digital Library

Background: Synaptic injury is a pathological hallmark of neurological impairment in people living with HIV (PLWH), a common complication despite viral suppression with antiretroviral therapy (ART). However, there are no biomarkers sensitive to neurocognitive impairment in PLWH. Measurement of synaptic density in living humans may allow better understanding of HIV neuropathogenesis and provide a dynamic biomarker for therapeutic studies. We applied novel synaptic vesical protein 2A (SV2A) positron emission tomographic (PET) imaging to investigate synaptic density in the frontostriatalthalamic region in PLWH and HIV-uninfected (HIV-) participants.

Methods: In this cross-sectional pilot study,13 older male PLWH on ART underwent neurocognitive assessments, …

Graph Neural Networks For Improved Interpretability And Efficiency, Patrick Pho

Electronic Theses and Dissertations, 2020-2023

Attributed graph is a powerful tool to model real-life systems which exist in many domains such as social science, biology, e-commerce, etc. The behaviors of those systems are mostly defined by or dependent on their corresponding network structures. Graph analysis has become an important line of research due to the rapid integration of such systems into every aspect of human life and the profound impact they have on human behaviors. Graph structured data contains a rich amount of information from the network connectivity and the supplementary input features of nodes. Machine learning algorithms or traditional network science tools have limitation …

Artificially Intelligent Boards And The Future Of Delaware Corporate Law, Christopher Bruner

Scholarly Works

The prospects for Artificial Intelligence (AI) to impact the development of Delaware corporate law are at once over- and under-stated. As a general matter, claims to the effect that AI systems might ultimately displace human directors not only exaggerate the foreseeable technological potential of these systems, but also tend to ignore doctrinal and institutional impediments intrinsic to Delaware's competitive model – notably, heavy reliance on nuanced and context-specific applications of the fiduciary duty of loyalty by a true court of equity. At the same time, however, there are specific applications of AI systems that might not merely be accommodated by …

Balancing User Experience For Mobile One-To-One Interpersonal Telepresence, Kevin Pfeil

Electronic Theses and Dissertations, 2020-2023

The COVID-19 virus disrupted all aspects of our daily lives, and though the world is finally returning to normalcy, the pandemic has shown us how ill-prepared we are to support social interactions when expected to remain socially distant. Family members missed major life events of their loved ones; face-to-face interactions were replaced with video chat; and the technologies used to facilitate interim social interactions caused an increase in depression, stress, and burn-out. It is clear that we need better solutions to address these issues, and one avenue showing promise is that of Interpersonal Telepresence. Interpersonal Telepresence is an interaction paradigm …

Modeling, Reconstruction, And Trend Analysis Of Global Storm Surges Using A Data-Driven Approach, Michael Getachew Tadesse

Electronic Theses and Dissertations, 2020-2023

Storm surge is the deadliest component of extreme sea levels with one of the highest global death tolls per event. Tide gauges are the primary sources for historical sea-level measurements from which storm surge data is extracted. However, tide gauges are unevenly distributed across the globe, and most records are short in length and have gaps; this creates a challenge to assess long-term trends and perform robust extreme value analysis. This dissertation introduces a data-driven storm surge modeling framework that trains statistical and machine learning models with atmospheric and oceanographic variables. Data-driven models (DDMs) are trained and validated for more …

Enhancing The Decision-Making Process For Public-Private Partnerships' Concession Agreements: Socio-Economic Sustainability Approaches, Faisal Alghamdi

Electronic Theses and Dissertations, 2020-2023

Designing a concession for Public-Private Partnerships (PPP) agreements is a complicated process due to the number of variables that need to be considered. The PPP concession has many parameters and components, and a change in one component will considerably impact other components. Hence, the determination of the fair values of the concession components needs to be based on mutual benefits between the concession participants. The concession participants have different parts in the development of the concession; hence, they have different perspectives and goals. Therefore, the concession design needs to be constructed to balance the interests of the involved parties to …

First And Third Order Susceptibility Of Organic Molecules, Hao-Jung Chang

Electronic Theses and Dissertations, 2020-2023

Illuminating a material with intense laser excitation may change its properties and result in nonlinear absorption (NLA) and nonlinear refraction (NLR). In this dissertation we study the nonlinear absorption of organic compounds, the effect of extremely nondegenerate NLR in semiconductors, and the linear refractive index of organic solvents. In liquids, the refractive index has been studied for decades and different kinds of refractometers have been proposed. However, most of the reported values are in the visible region and only for commonly used solvents. We proposed a new interferometer-based refractometer that allows us to measure the refractive index from the visible …

Computational Modeling Of Respiratory Airflow In Human Distal Airways Using Hybrid Lung Model, Adnan Islam

Electronic Theses and Dissertations, 2020-2023

A major challenge in the Computational Fluid Dynamics (CFD) modeling of the human respiratory system is the complex variation of geometric scale from the trachea to the peripheral airways. The current literature on image-based lung flow analysis is limited to a few (typically 5) generations beyond the trachea. Such studies, which are limited largely by computational intensity and computational cost, also have limited accuracy. In this study we propose a hybrid methodology that enables CFD analysis from the middle to the distal airways through to the alveolar level. A hybrid lung model is generated where the middle airways are reconstructed …

The Narratives Of Latina Students Who Have Participated In Invention Education, Cristina Saenz

Electronic Theses and Dissertations, 2020-2023

Less than 2% of patent holders in the United States identify as Latina. This statistic is problematic considering the increasing Latinx population and the empirical evidence which indicates the benefits of drawing on diverse perspectives in the invention ecosystem. In an effort to increase diversity among inventors and patent holders, K-12 programs have been created to provide opportunities for students to participate in the iterative and recursive processes of inventing. One example is the emerging field of invention education. Invention education is an educational approach which teaches students how to identify and solve problems within their communities. Little is known …

Synergistic Impacts Of Climate Change And Human Induced Stressors On The Apalachicola Bay Food Web, Kira Allen

Electronic Theses and Dissertations, 2020-2023

Apalachicola Bay, an estuary located in northwest Florida, is likely to experience an increase in climate change and human-induced stressors, such as sea level rise and changes in freshwater inflow, in the future. A coupled hydrodynamic and food web modeling approach was used to simulate future scenarios of low and high river flow and sea level rise in Apalachicola Bay from 2020 to 2049 and demonstrate the range of temporal and spatial changes in water temperature, salinity, fisheries species populations and the broader food web. Concurrent with model development, a survey of Apalachicola Bay stakeholders was conducted to assess stakeholder …

Third Order Nonlinear Optics In Solids, Nicholas Cox

Electronic Theses and Dissertations, 2020-2023

Nonlinear optical effects occur when strong electromagnetic waves induce changes in a medium that affect its own propagation or that of another wave. Third order optical nonlinearities scale linearly with irradiance and lead to effects like two-photon absorption and nonlinear refraction. This work focuses on the experimental and theoretical study of two-photon absorption in crystalline solids. We begin by detailing the quantum mechanical states of electrons in solids along with the computational approaches to calculate their band structure. Next, a theoretical model for the linear and nonlinear optical interaction of light with matter is presented in a many-body formalism. This …

Bayesian Spatiotemporal Modeling With Gaussian Processes, Qing He

Electronic Theses and Dissertations, 2020-2023

Bayesian spatiotemporal models have been successfully applied to various fields of science, such as ecology and epidemiology. The complicated nature of spatiotemporal patterns can be well represented through priors such as Gaussian processes. This dissertation is focused on two applications of Bayesian spatiotemporal models: a) anomaly detection for spatiotemporal data with missingness and b) zero-inflated spatiotemporal count data analysis. Missingness in spatiotemporal data prohibits anomaly detection algorithms from learning characteristic rules and patterns due to the lack of most data. This project is motivated by a challenge provided by the National Science Foundation (NSF) and the National Geospatial-Intelligence Agency (NGA). …

Using Simulation For Law Enforcement De-Escalation Training, Julie Kent

Electronic Theses and Dissertations, 2020-2023

Law enforcement needs simulation practice tailored to de-escalation skills. Law enforcement officers spend most of their training time practicing how to use force appropriately and very little time practicing how to avoid using force. There is little research into the best ways for law enforcement to reduce their use of force and the best ways to provide training to individuals to coach them to avoid using force. There are many training programs promoting de-escalation techniques, but there is little research into the effectiveness of these programs beyond the ability of individuals to perform the skills that are trained. There is …

Authoring Tools For Augmented Reality Scenario Based Training Experiences, Andres Vargas Gonzalez

Electronic Theses and Dissertations, 2020-2023

Augmented Reality's (AR) scope and capabilities have grown considerably in the last few years. AR applications can be run across devices such as phones, wearables, and head-mounted displays (HMDs). The increasing research and commercial efforts in HMDs capabilities allow end users to map a 3D environment and interact with virtual objects that can respond to the physical aspects of the scene. Within this context, AR is an ideal format for in-situ training scenarios. However, building such AR scenarios requires proficiency in game engine development environments and programming expertise. These difficulties can make it challenging for domain experts to create training …

Improved Reptile Search Optimization Algorithm Using Chaotic Map And Simulated Annealing For Feature Selection In Medical Filed, Zenab Elgamal, Aznul Qalid Md Sabri, Mohammad Tubishat, Dina Tbaishat, Sharif Naser Makhadmeh, Osama Ahmad Alomari

All Works

The increased volume of medical datasets has produced high dimensional features, negatively affecting machine learning (ML) classifiers. In ML, the feature selection process is fundamental for selecting the most relevant features and reducing redundant and irrelevant ones. The optimization algorithms demonstrate its capability to solve feature selection problems. Reptile Search Algorithm (RSA) is a new nature-inspired optimization algorithm that stimulates Crocodiles’ encircling and hunting behavior. The unique search of the RSA algorithm obtains promising results compared to other optimization algorithms. However, when applied to high-dimensional feature selection problems, RSA suffers from population diversity and local optima limitations. An improved metaheuristic …

Leveraging Natural Language Processing To Analyse The Temporal Behavior Of Extremists On Social Media, May El Barachi, Sujith Samuel Mathew, Farhad Oroumchian, Imene Ajala, Saad Lutfi, Rand Yasin

All Works

Aiming at achieving sustainability and quality of life for citizens, future smart cities adopt a data-centric approach to decision making in which assets, people, and events are constantly monitored to inform decisions. Public opinion monitoring is of particular importance to governments and intelligence agencies, who seek to monitor extreme views and attempts of radicalizing individuals in society. While social media platforms provide increased visibility and a platform to express public views freely, such platforms can also be used to manipulate public opinion, spread hate speech, and radicalize others. Natural language processing and data mining techniques have gained popularity for the …

Trajectory Design For Uav-Based Data Collection Using Clustering Model In Smart Farming, Tariq Qayyum, Zouheir Trabelsi, Asad Malik, Kadhim Hayawi

All Works

Unmanned aerial vehicles (UAVs) play an important role in facilitating data collection in remote areas due to their remote mobility. The collected data require processing close to the end-user to support delay-sensitive applications. In this paper, we proposed a data collection scheme and scheduling framework for smart farms. We categorized the proposed model into two phases: data collection and data scheduling. In the data collection phase, the IoT sensors are deployed randomly to form a cluster based on their RSSI. The UAV calculates an optimum trajectory in order to gather data from all clusters. The UAV offloads the data to …

Haptic Feedback To Assist Blind People In Indoor Environment Using Vibration Patterns, Shah Khusro, Babar Shah, Inayat Khan, Sumayya Rahman

All Works

Feedback is one of the significant factors for the mental mapping of an environment. It is the communication of spatial information to blind people to perceive the surroundings. The assistive smartphone technologies deliver feedback for different activities using several feedback mediums, including voice, sonification and vibration. Researchers 0have proposed various solutions for conveying feedback messages to blind people using these mediums. Voice and sonification feedback are effective solutions to convey information. However, these solutions are not applicable in a noisy environment and may occupy the most important auditory sense. The privacy of a blind user can also be compromised with …

Five Grade 7 Learners' Understanding Of Comprehension Skills At A Quintile 5 School In South Africa, Nomonde Ntshikila, Janet L. Condy, Lawrence Meda, Heather N. Phillips

All Works

Background: Research into language and reading scores show that South African learners struggle to read for meaning. Many local researchers report on the inadequate teaching training programmes. Teachers cannot teach basic comprehenion skills. Objectives: This research identifies a gap in the research and records an intervention programme designed to engage learners and develop their higher-order comprehension abilities. This research analyses responses from five learners who engaged in a variety of literacy activities to extend their zones of literacy abilities to become independent critical thinkers. Method: An interpretivist paradigm, within a qualitative approach, using a case study design was devised and …

Explicating Consumer Adoption Of Wearable Technologies: A Case Of Smartwatches From The Asean Perspective, Veerisa Chotiyaputta, Donghee Shin

All Works

This research aims to determine the key antecedent factors in consumers' adoption of and their intention to recommend smartwatch wearable technology. The proposed research model combines the current technology acceptance and innovation diffusion theories with perceived aesthetic and perceived privacy risk to explain individuals' smartwatch adoption and subsequent recommendation to other people. Based on a sample of 299 completed individual online surveys, the research employed partial least squares (a variance-based analysis method) for the model and hypotheses testing. The results showed some similarities as well as differences from the previous literature. The study found that performance expectancy, habit, and perceived …

Interacting With Educational Chatbots: A Systematic Review, Mohammad Amin Kuhail, Nazik Alturki, Salwa Alramlawi, Kholood Alhejori

All Works

Chatbots hold the promise of revolutionizing education by engaging learners, personalizing learning activities, supporting educators, and developing deep insight into learners’ behavior. However, there is a lack of studies that analyze the recent evidence-based chatbot-learner interaction design techniques applied in education. This study presents a systematic review of 36 papers to understand, compare, and reflect on recent attempts to utilize chatbots in education using seven dimensions: educational field, platform, design principles, the role of chatbots, interaction styles, evidence, and limitations. The results show that the chatbots were mainly designed on a web platform to teach computer science, language, general education, …

A Brief Comparison Of K-Means And Agglomerative Hierarchical Clustering Algorithms On Small Datasets, Hassan I. Abdalla

All Works

In this work, the agglomerative hierarchical clustering and K-means clustering algorithms are implemented on small datasets. Considering that the selection of the similarity measure is a vital factor in data clustering, two measures are used in this study - cosine similarity measure and Euclidean distance - along with two evaluation metrics - entropy and purity - to assess the clustering quality. The datasets used in this work are taken from UCI machine learning depository. The experimental results indicate that k-means clustering outperformed hierarchical clustering in terms of entropy and purity using cosine similarity measure. However, hierarchical clustering outperformed k-means clustering …

Analysis Of Blockchain Solutions For E-Voting: A Systematic Literature Review, Ali Benabdallah, Antoine Audras, Louis Coudert, Nour El Madhoun, Mohamad Badra

All Works

To this day, abstention rates continue to rise, largely due to the need to travel to vote. This is why remote e-voting will increase the turnout by allowing everyone to vote without the need to travel. It will also minimize the risks and obtain results in a faster way compared to a traditional vote with paper ballots. In fact, given the high stakes of an election, a remote e-voting solution must meet the highest standards of security, reliability, and transparency to gain the trust of citizens. In literature, several remote e-voting solutions based on blockchain technology have been proposed. Indeed, …

Multi-Party Contract Management For Microservices, Zakaria Maamar, Noura Faci, Joyce El Haddad, Fadwa Yahya, Mohammad Askar

All Works

This paper discusses the necessary steps and means for ensuring the successful deployment and execution of software components referred to as microservices on top of platforms referred to as Internet of Things (IoT) devices, clouds, and edges. These steps and means are packaged into formal documents known in the literature as contracts. Because of the multi-dimensional nature of deploying and executing microservices, contracts are specialized into discovery, deployment, and collaboration types, capturing each specific aspect of the completion of these contracts. This completion is associated with a set of Quality-of-Service (QoS) parameters that are monitored allowing to identify potential deviations …

On The Design And Implementation Of An On-Board Test Bed System For V2v Road Hazard Signaling, Fatma Outay, Faouzi Kamoun, Anouar Chemek, Hichem Bargaoui, Ansar Yasar

All Works

This paper describes the design, implementation, and testing of an ITS-G5 prototype Road hazard Signaling (RHS) system that is inspired by the concept of crowdsourcing. Our approach enables drivers to interact with a touchscreen onboard interface to send ITS-G5 decentralized environmental notification messages (DENM) in order to warn nearby vehicles against the presence of a hazardous situation. These messages are analyzed, filtered for relevance, and presented to concerned drivers via the Onboard Units (OBUs) so that precautionary measures can be taken. We describe the design and implementation aspects of the proposed system and update the open source cargeo6 implementation of …

Comparison Of Reaction Time-Based Collaborative Velocity Control And Intelligent Driver Model For Agent-Based Simulation Of Autonomous Car, Fatma Outay, Abdeljalil Abbas-Turki, Stéphane Galland, Alexandre Lombard, Nicolas Gaud

All Works

Based on historical records, driving in hazardous weather conditions is one of the most serious causes that lead to fatal accidents on roads in general and in United Arab Emirates (UAE) highways in particular. One solution to improve road safety is to equip vehicles and infrastructure with connected and smart devices and convert them into autonomous vehicles. Before deploying a concrete solution to the field, it must be validated by simulation, and more specifically by agent-based simulation. In this paper, we propose to implement the Reaction Time-Based Collaborative Velocity Control (RT-CVC) model that was implemented in autonomous cars into an …

On Complete, Horizontal And Vertical Lifts From A Manifold With Fλ (6, 4) Structure To Its Cotangent Bundle, Manisha M. Kankarej, Jai Pratap Singh

All Works

Manifolds with fλ(6, 4) structure was defined and studied in the past. Later the geometry of tangent and cotangent bundles in a differentiable manifold with fλ(6, 4) structure was studied. The aim of the present paper is to study complete, horizontal and vertical lifts from a manifold with fλ (6, 4)-structure to its cotangent bundle.

A Novel Tunicate Swarm Algorithm With Hybrid Deep Learning Enabled Attack Detection For Secure Iot Environment, Fatma Taher, Mohamed Elhoseny, Mohammed K. Hassan, Ibrahim M. El-Hasnony

All Works

No abstract provided.

Conceptualising The Role Of The Uae Innovation Strategy In University-Industry Knowledge Diffusion Process, Mousa Al-Kfairy, Munir Majdalawieh, Saed Alrabaee

All Works

Universities are considered one of the primary sources of knowledge and an essential component of the triple helix theory. They fuel the industries with the required expertise and pool of resources to operate efficiently. Moreover, entrepreneurial universities successfully contributed to regional development and employment growth by supporting entrepreneurial activities and incubation programmes. Thus, university-industry collaboration is vital for enhancing knowledge-based industries' knowledge diffusion as well as the regional innovation atmospheres. On the other hand, countries and regional authorities strive to stimulate their regional development by encouraging innovation and entrepreneurship activities. For example, the UAE announced its 2015 innovation strategy that …