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Articles 361 - 390 of 3180

Full-Text Articles in Engineering

Use Of Smartphone Apps While Driving: Variations On Driving Performances, Perceived Risks And Behaviors, Juana Perez May 2023

Use Of Smartphone Apps While Driving: Variations On Driving Performances, Perceived Risks And Behaviors, Juana Perez

Civil Engineering Theses - Archive

ABSTRACT: Distracted driving increases the crash frequencies on the road and subsequently leads to fatalities involved with crashes. As technology has evolved, drivers are continuously exposed to newer technology in their vehicles and applications in their phones, which has led to technology representing one of the main secondary tasks that distract drivers on the road. The impact of technology-involved distraction appears to be different by the type of distraction since a secondary task that can be exceedingly distracting to the driver causes more reckless and risky driving. Moreover, the impact of distracted driving may differ by roadway geometries since distracted …

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Compliant Robot Manipulator For Transurethral Diagnosis, Samson A. Adejokun May 2023

Compliant Robot Manipulator For Transurethral Diagnosis, Samson A. Adejokun

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Minimally invasive procedures employ continuum manipulators, however, the internal human anatomy presents challenges relating to size, dexterity, and workspace for these manipulators. This research presents modeling, kinematic analysis, limited prototyping, and characterization of a micro-robotic manipulator to assess viscoelastic tissue properties of the bladder through transurethral palpation towards the diagnosis of bladder dysfunction, urinary incontinence, and early-stage bladder cancer. The proposed micro-robot consists of two subsystems; a unique 4mm outer diameter tendon-driven continuum segment from assembled “vertebrae” components with male and female snap-in features for joint assembly, an elastic tube encompassing each joint for controlled compliance and structural integrity …

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Development Of Femtosecond Laser Electronic Excitation Tagging (Fleet) And Femtosecond Two-Photon Absorption Laser Induced Fluorescence (Fs-Talif) Diagnostics For Species Number Density And Velocity Measurements In Arc-Jet Flows, Daniel William Palmquist May 2023

Development Of Femtosecond Laser Electronic Excitation Tagging (Fleet) And Femtosecond Two-Photon Absorption Laser Induced Fluorescence (Fs-Talif) Diagnostics For Species Number Density And Velocity Measurements In Arc-Jet Flows, Daniel William Palmquist

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Arc-jet flows are the only ground-test facilities that can recreate hypersonic high-enthalpy flight conditions for long durations. Characterizing these complex flow regimes, generally under thermo-chemical non-equilibrium, is crucial to establishing a relationship between the ground-test environment and flight conditions. This work presents the development of two innovative and world’s first successful application of advanced non-intrusive laser-based diagnostic techniques for characterizing the 1.6 MW ONR-UTA Arc-Heated Wind Tunnel, Leste’s plasma flow. The arc-jet flow represents a unique challenge for the application of laser-based diagnostics due to the highly emitting background across a wide spectral range. Femtosecond Laser Electronic Excitation Tagging …

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Formal Processes For Inspecting Bridge Deck Drains Using Lidar And Photogrammetry, Ahmad Kamal Bani Hani May 2023

Formal Processes For Inspecting Bridge Deck Drains Using Lidar And Photogrammetry, Ahmad Kamal Bani Hani

Civil Engineering Dissertations - Archive

ABSTRACT: Poor-performing bridge deck drains result in water standing on the bridge deck. The standing water threatens the safety of bridge users and deteriorates bridge structural elements. Bridge deck drains are only inspected biennially, and they do not impact the bridge rating established from inspections. Furthermore, literature shows that visual inspection results are sometimes skewed due to human errors. In this regard, a part of this research was conducting a survey study to help identify the problems with deck drains to help transportation agencies minimize the consequences of poor drainage. Another part of this research was to create a convolutional …

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Physiological Analyses Of Broadband Near-Infrared Spectroscopy And Electrophysiological Measurements In Vivo For Biomedical Applications, Haylea Renguul May 2023

Physiological Analyses Of Broadband Near-Infrared Spectroscopy And Electrophysiological Measurements In Vivo For Biomedical Applications, Haylea Renguul

Bioengineering Theses - Archive

My thesis concerns analysis of data from optical and electrophysiological measurement tools for calculate potential biomarkers in three biomedical applications: (1) the gastrointestinal immaturity of infants of different ages, (2) prefrontal connectivity in healthy older adults, and (3) hemodynamic-metabolic coherence during vascular occlusion. The first application relied on electrogastrogram (EGG) measurements taken on 81 newborns in a neonatal intensive care unit. Of the 81 babies, 77 were born prematurely. By separating these babies into different gestational age groups and analyzing their EGG data, I was able to find population differences in common EGG analysis parameters. In particular, we found that …

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Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry May 2023

Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry

Mechanical and Aerospace Engineering Theses - Archive

Increased application of composite materials in the military and civil applications renewed the interest to development of high-fidelity methodologies for predicting their performance characteristics. Besides the traditional autoclave processed structural composites such as IM7/8552 and IM7/977-3 widely used on various platforms, novel materials such IM7/5320-1 suitable for Out-of-Autoclave (OoA) cure became of interest. Static and fatigue performance prediction of Open-Hole quasi-isotropic laminates made from IM7/5320-1 was performed in this work by using the Finite Element Analysis software BSAM. Progressive failure simulation including delaminations, matrix cracks and fiber failure was performed. Regularized eXtended Finite Element Methods (RXFEM) was used for mesh …

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Dispersion Study Of Metal-Organic Frameworks And Synthesis Of Mof-High-Density Polyethylene Fibers, Sathvika Gondi May 2023

Dispersion Study Of Metal-Organic Frameworks And Synthesis Of Mof-High-Density Polyethylene Fibers, Sathvika Gondi

Material Science and Engineering Theses - Archive

Metal-Organic Frameworks (MOFs) are a highly versatile class of materials with a wide range of potential applications in gas storage, separation, catalysis, drug delivery, and sensing. The ability to tailor the properties and functionalities of MOFs by varying the organic linkers and inorganic nodes makes them highly attractive for a wide range of applications. The unique properties of MOFs also make them promising materials for fundamental studies in materials science and chemistry. The current investigation focuses on the dispersion study of MOFs and the synthesis of MOF-Polymer composites. The dispersions of MOFs in various organic solvents like ethanol, isopropanol, tetrahydrofuran, …

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Application Of Photogrammetry For Monitoring Soil Surface Movement, Arjan Poudel May 2023

Application Of Photogrammetry For Monitoring Soil Surface Movement, Arjan Poudel

Civil Engineering Theses - Archive

Understanding slope behavior and forecasting failure requires accurate soil surface movement measurements. Research gaps and constraints remain despite the development of diverse methods. Recently, photogrammetry has become a promising method for detecting soil surface movement. This method involves setting coded targets and ground points on the soil surface, taking photographs before and after the movement, and using photogrammetric software to measure accurately. However, past studies have mostly used high-end cameras with excellent resolution and geotagging, which may not have been available in all contexts. Thus, this study compares the accuracy and precision of geotechnical soil surface measurement with a consumer-grade …

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A Comparative Biomechanical Investigation Of Porcine Neonatal And Adult Left Ventricular Tissues, Timothy R. Eastep May 2023

A Comparative Biomechanical Investigation Of Porcine Neonatal And Adult Left Ventricular Tissues, Timothy R. Eastep

Bioengineering Theses - Archive

A current trend in cardiac muscle regeneration and repair is to recreate the biophysical and biomechanical environment of the neonatal hearts, which has been shown to promote cardiac regeneration. This translational need requires thorough understanding of the biomechanical properties of the neonatal hearts. In this study, we aim to (i) characterize the dynamic viscoelastic properties of the neonatal porcine left ventricular (LV) muscle and compare with the adult tissue behavior using a rheometer; (ii) perform histological assessment to identify the cellular and extracellular (ECM) microstructures that contribute to the observed biomechanical differences, and (iii) develop a light sheet imaging protocol …

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Design And Development Of A Virtual Reality Training Platform For Fiber-Reinforced Composite Manufacturing, Taufiq Rahman May 2023

Design And Development Of A Virtual Reality Training Platform For Fiber-Reinforced Composite Manufacturing, Taufiq Rahman

Industrial, Manufacturing, and Systems Theses - Archive

This study presents the design and development of a virtual reality (VR) training platform for manufacturing fiber-reinforced composites, a sophisticated and high-demand material in various industries. Due to the high costs and safety concerns associated with compression molding machines - essential equipment for this manufacturing process, the VR platform offers a promising alternative for training to educational institutions and manufacturing industries. The platform provides an immersive, interactive training and cost-efficient learning environment, allowing users to gain practical experience without the risks and expenses of physical training. The VR training module was developed using the Unity game engine and deployed on …

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Mechanical And Thermal Performance Of Additively Manufactured Digital Materials, Layth Muayyad Ahmad May 2023

Mechanical And Thermal Performance Of Additively Manufactured Digital Materials, Layth Muayyad Ahmad

Mechanical and Aerospace Engineering Theses - Archive

Over the past decades, additive manufacturing has become a critical material processing tool. All ranges of materials including polymers, composites, metals, and ceramics can be used to fabricate structures with complex geometries that are nearly impossible to build using conventional fabrication process. Recently, additive manufacturing methods to build polymeric structures have been advanced significantly. In particular, the emergence of multi-material printers has made it possible to seamlessly print hybrid and digital materials where materials components and compositions are digitally varied to construct fully tailored material system. In this work, using a commercially available polyjet printer (Stratasys J850 Prime 3D printer), …

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Parametric Multi-Objective Optimization Of Cold Plate For Single-Phase Immersion Cooling, Geevarghese Joseph Nattasseriedathil May 2023

Parametric Multi-Objective Optimization Of Cold Plate For Single-Phase Immersion Cooling, Geevarghese Joseph Nattasseriedathil

Mechanical and Aerospace Engineering Theses - Archive

The increasing demand for high performance computing in applications such as Internet of Things, Deep Learning, Big data for crypto-mining, virtual reality, healthcare research on genomic sequencing, cancer treatment etc. has led to the growth of hyper scale datacenters. To meet the cooling energy demands of HPC datacenters efficient cooling technologies must be adopted. Traditional air cooling, direct to chip liquid cooling and immersion are some of those methods. Among all, Liquid cooling is superior compared to various air-cooling methods in terms of energy consumption. Direct on-chip cooling using cold plate technology is one such method used in removing heat …

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Machine Learning For Ultraviolet Spectral Prediction, Linh Ho Manh May 2023

Machine Learning For Ultraviolet Spectral Prediction, Linh Ho Manh

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Machine Learning has found wide applications in material science, including dielectric polymers, superconducting materials, and drug property prediction. The use of data analytics and machine learning methods to predict Vacuum Ultraviolet (VUV) spectra by encoding molecular structure is gaining interest because high-quality VUV spectral prediction capability would enable the study of new molecules without costly wet-lab measurements. This dissertation aims to study feature representations for molecular structures that enhance the prediction of VUV spectra via machine learning models. Both interpretable machine learning and deep learning are studied. Chapter 1 provides an overview of VUV/UV spectra retrieval, and Chapter 2 reviews …

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Carbon Fibers Recycling From Degraded Prepregs And Mechanical Properties Or Recycled Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Vamsee Vadlamudi, Rassel Raihan Apr 2023

Carbon Fibers Recycling From Degraded Prepregs And Mechanical Properties Or Recycled Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Vamsee Vadlamudi, Rassel Raihan

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

The size of the global composites market is anticipated to grow more than previously. Due to the rapidly rising volume of CFRP production, the waste from this material poses numerous problems and has significantly increased the socio-technological pressure to find sustainable composite recycling solutions. The problem is that recycling the composite part is challenging once its service life has expired. The same problem is true for the raw materials (prepregs) used in composite manufacturing. When the prepreg out-life/shelf-life is over, prepregs are abandoned, resulting in a loss of millions of dollars and an adverse environmental effect. In this study, the …

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On The Development And Evaluation Of A Framework For Brain-Computer Interface And Vibrotactile Feedback For Human-Robot-Interaction In Virtual Spaces And Robotic Hardware, Sudip Hazra, Shane Whitaker, Panos S. Shiakolas Feb 2023

On The Development And Evaluation Of A Framework For Brain-Computer Interface And Vibrotactile Feedback For Human-Robot-Interaction In Virtual Spaces And Robotic Hardware, Sudip Hazra, Shane Whitaker, Panos S. Shiakolas

Mechanical and Aerospace Student Research - Archive

Research in Brain-Computer Interface (BCI) aims to understand human intent with the goal to enhance Human-Robot Interaction (HRI) especially in the field of assistive robotics. The goal of this research is to develop a behavioral sequence based framework to help persons with upper limb disabilities to maintain self-dependence. The framework aims to operate in stages and links multiple functional components to identify human intent and control a robotic arm. The development, operation, and evaluation of the framework and the linked functional components to acquire, process, evaluate, and map BCI signals generated using facial expressions and head movements to predefined actions …

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Artificial Intelligence Assisted Residual Strength And Life Prediction Of Fiber Reinforced Polymer Composites, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan Jan 2023

Artificial Intelligence Assisted Residual Strength And Life Prediction Of Fiber Reinforced Polymer Composites, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

With the increased use of composite materials, researchers have developed many approaches for structural and prognostic health monitoring. Broadband Dielectric Spectroscopy (BbDS)/Impedance Spectroscopy (IS) is a state-of-the-art technology that can be used to identify and monitor the minute changes in damage initiation, accumulation, interactions, and the degree of damage in a composite under static and dynamic loading. This work presents a novel artificial neural network (ANN) framework for fiber-reinforced polymer (FRP) composites under fatigue loading, which incorporates dielectric state variables to predict the life (durability) and residual strength (damage tolerance) from real-time acquired dielectric permittivity of the material. The findings …

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Utilizing Data Analytics On Single-Phase Ac Arc Flash Testing And Model Development, Po-Chen Chen Jan 2023

Utilizing Data Analytics On Single-Phase Ac Arc Flash Testing And Model Development, Po-Chen Chen

Electrical Engineering Dissertations - Archive

Arc flash events could result in injuries, fatalities, and lead to severe medical expenses, equipment replacement cost, and even litigation, fines, and loss of business. Such events could also tremendously traumatize the personnel psychosocially and neurologically. Therefore, it is critical to accurately understand the potential arc flash hazards from all the real applications. Yet, due to the random complex nature of arc flash events and great number of uncertain variables involved, there are challenges to provide mathematical models for equipment designers in determining the arc-flash fault current and the incident energy of various types of events. The early arc flash …

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Evaluation And Optimization Of Thermal Solutions In Air And Liquid Cooling Systems For Datacenters, Vibin Shalom Simon Jan 2023

Evaluation And Optimization Of Thermal Solutions In Air And Liquid Cooling Systems For Datacenters, Vibin Shalom Simon

Mechanical and Aerospace Engineering Dissertations - Archive

A data center is a specifically constructed establishment designed to accommodate computing, storage, and transmission equipment, thereby facilitating essential business operations spanning diverse sectors of the economy. This facility serves as the designated physical infrastructure for housing servers, networking components, and data storage systems. In the context of traditional data centers, a substantial portion of energy, specifically around 45% to 55%, is directed towards supporting information technology (IT) operations. Additionally, a considerable allocation, varying from 30% to 40%, is attributed to the facilitation of cooling processes. The scope of this dissertation study comprises nine distinct chapters, each contributing to addressing …

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Non-Intrusive Reduced Order Model Formulation For Inverse Shape Design Including Deforming Meshes And Multiphysics Problems., Kapil Aryal Jan 2023

Non-Intrusive Reduced Order Model Formulation For Inverse Shape Design Including Deforming Meshes And Multiphysics Problems., Kapil Aryal

Mechanical and Aerospace Engineering Dissertations - Archive

Despite significant advancements in computer capabilities for numerical simulations, engineers continue to face limitations when dealing with large-scale full-order model(FOM) simulations. These simulations often necessitate repeated solves, such as those encountered in inverse design, real-time solution prediction, error quantification, and solver convergence, among others. To address these challenges, reduced order modeling (ROM) has emerged as a valuable approach. This thesis focuses on the development of an ROM framework that combines Proper Orthogonal Decomposition (POD) with machine learning techniques. This integrated approach is applied to a diverse range of heat transfer and fluid flow inverse design problems. POD constructs optimal sets …

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Cooperative Manipulation And Formation Control Using Multiple Aerial Vehicles, Uluhan Cem Kaya Jan 2023

Cooperative Manipulation And Formation Control Using Multiple Aerial Vehicles, Uluhan Cem Kaya

Mechanical and Aerospace Engineering Dissertations - Archive

Recent advancements in autonomous systems have significantly impacted both academia and industry, opening new research avenues. One of them is the collaboration of multiple systems to achieve a common goal, which is known as a cooperative system. In the lack of human intelligence, decision making and perception capabilities, uncrewed autonomous systems could mutually benefit from each other’s capabilities when they are deployed and utilized together. This research tackles the collaboration of group of uncrewed aerial systems (UASs) where the constraint on individual vehicles requires a varying level of coordination and cooperation. Such cooperation can be in the form of a …

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Turbulent Shockwave/Boundary-Layer Interactions Generated By Sharp Swept Fins, Dustin Levi Otten Jan 2023

Turbulent Shockwave/Boundary-Layer Interactions Generated By Sharp Swept Fins, Dustin Levi Otten

Mechanical and Aerospace Engineering Dissertations - Archive

The shock/turbulent boundary layer interaction (STBLI) generated by a sharp fin with a 60 deg leading edge sweep mounted above a flat plate at Mach 2.5 was studied numerically. Incipient separation due to this highly swept fin was determined by varying the fin angle to the incoming freestream. The effect of a small fin/plate gap on STBLI incipient separation was established. Sweeping the fin increases the deflection required for incipient separation as the sweep reduces the interaction strength. A gap causes flow leakage under the fin, further reducing the interaction strength on the windward side. The incipient angle of attack …

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Experimental Study On Thermal Performance Of Metal Foam Heat Sinks In Single Phase Liquid Immersion Cooling, Manish Kumawat Jan 2023

Experimental Study On Thermal Performance Of Metal Foam Heat Sinks In Single Phase Liquid Immersion Cooling, Manish Kumawat

Mechanical and Aerospace Engineering Theses - Archive

In 1965, Intel co-founder Gordon Moore made the observation that the transistor counts on a chip double with a frequency of approximately every two years. This development resulted in more compact and potent ICs. However, the amount of heat produced on a chip increased proportionally with the number of transistors. Later, in the early 2000s, Dennard Scaling broke down. Transistors became so small that leakage currents (unwanted currents that flow within the transistor) emerged as a significant issue, and they contributed substantially to power consumption and heat generation. These tightly packed transistors produced heat, which decreased their performance and shortened …

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Method-Of-Characteristics Models For Flowfield Evaluation Of Hypervelocity Test Facilities, Ananthkumar Jayamani Jan 2023

Method-Of-Characteristics Models For Flowfield Evaluation Of Hypervelocity Test Facilities, Ananthkumar Jayamani

Mechanical and Aerospace Engineering Dissertations - Archive

Ground test facilities are an imperative part of the design and development of flying vehicles. In the case of high-enthalpy facilities, evaluating the gasdynamic and thermochemical state of the test gas poses challenges due to high temperature effects. This study aims to contribute to the development impulse facilities by developing reduced-order models resolving the flowfields of such facilities. Developed as a part of this study are various method-of-characteristics (MoC) algorithms which consider gases under varying levels of thermochemical complexity. The algorithms span from simple calorically perfect gases to full thermochemical nonequilibrium. The first set of algorithms was limited to unsteady …

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Microstructural Finite Element Modeling Of High-Performance Carbon Fiber-Reinforced Composites To Characterize Microscale Material Properties And Fiber-Direction Compressive Strength, Quy Tung Ling Vu Jan 2023

Microstructural Finite Element Modeling Of High-Performance Carbon Fiber-Reinforced Composites To Characterize Microscale Material Properties And Fiber-Direction Compressive Strength, Quy Tung Ling Vu

Mechanical and Aerospace Engineering Dissertations - Archive

Carbon fiber-reinforced composites are increasingly used in aerospace application thanks to their excellent specific stiffness and strength. However, incomplete understanding of their failure behaviors leads to composite components often being designed with a high Safety Factor, limiting their advantages. Using computational methods, this project studies carbon fiber-reinforced composite microstructures for the objective of understanding and improving material performances under compression load which is one of the main considerations in primary aerospace structure design. A Finite Element (FE) model for the evaluation of composite compression behaviors was developed, allowing the identification of several key material properties affecting composite performance. The numerical …

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Cooperative Rendezvous In Multi-Vehicle Systems, Rajeev Shobhit Voleti Jan 2023

Cooperative Rendezvous In Multi-Vehicle Systems, Rajeev Shobhit Voleti

Mechanical and Aerospace Engineering Dissertations - Archive

The field of cooperative, multi-vehicle systems has witnessed a significant expansion and evolution, yielding considerable opportunities for improved autonomy, resilience, and robustness. Despite these promising developments, complex challenges persist in ensuring secure and efficient rendezvous among cooperative peers. The term "rendezvous," within the realm of cooperative control, refers to the simultaneous convergence of multi-vehicle systems to a designated target location. In missile guidance, the problem of multiple pursuer missiles achieving rendezvous with a target is termed as a salvo attack. Current methodologies often grapple with issues related to synchronization, high latency and network security, all of which can adversely impact …

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A Rigid Body Framework For Modeling And Simulation Of Formation Of Autonomous Agents, Suguru Sato Jan 2023

A Rigid Body Framework For Modeling And Simulation Of Formation Of Autonomous Agents, Suguru Sato

Mechanical and Aerospace Engineering Theses - Archive

Formation motion, wherein multiple agents operate within close proximity while maintaining precise relative positions and coordinated movements has a significant impact in the realm of Uncrewed Aerial Systems (UAS). Formation establishment, and station-keeping have been critical research areas as several missions can be conceived, and accomplished by groups of “simple” autonomous agents. Advances in this research have led to multiple advantages in areas such as reconnaissance, aerospace exploration, map building, search and rescue, etc. particularly, if the formation motion is inspired by nature and natural phenomena such as flock of birds, school of fish, hydrodynamics (smooth streamlines), magnetic fields, and …

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Testing And Evaluation Of Polymeric Spray Applied Pipe Lining In Pressure Pipe Applications, Kawalpreet Kaur Jan 2023

Testing And Evaluation Of Polymeric Spray Applied Pipe Lining In Pressure Pipe Applications, Kawalpreet Kaur

Civil Engineering Dissertations - Archive

Pressure pipes are an important component of pipe infrastructure for water mains, distribution lines, fuel and gas piping, process piping, building services piping, and many more. Various material types are available to be used in the pressure pipes, in which metal pipes are ubiquitous for high pressure applications, plastic pipes are also commonly used, and sometimes concrete pressure pipes are used in large diameter pipes for its economic factors. Most of these pipes currently in service are 50 to 60 years old, and some are 100 years old. Furthermost pipelines have exceeded their design life and are continuously deteriorating to …

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Conceptual Design Level Airframe/Propulsion Integration Using The Generic Synthesis Framework Avds., Harinkumar Patel Dec 2022

Conceptual Design Level Airframe/Propulsion Integration Using The Generic Synthesis Framework Avds., Harinkumar Patel

Mechanical and Aerospace Engineering Dissertations - Archive

In the past few decades there has been a significant growth in commercial aerospace transportation encompassing both atmospheric and space flight. In fact, the aircraft industry has seen several generations of engines and vehicles developed. While the space launch sector has switched from exclusively expandable rockets systems to including reusable rocket systems. Now, the current push in the industry is to develop a reusable in-atmosphere hypersonic transportation system. The development of any aircraft entails communicating the interactions among the principal design disciplines (aerodynamics, propulsion, structures, materials, etc.). For hypersonic vehicles, the interdependence of these interactions is enhanced to a level …

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Robust Synthesis Methods For Cooperative Systems, Baris Taner Dec 2022

Robust Synthesis Methods For Cooperative Systems, Baris Taner

Mechanical and Aerospace Engineering Dissertations - Archive

Cooperative systems, like any other dynamic systems, suffer in performance because of uncertainty yet there is an added layer of uncertainty due to the communication among agents. Therefore, analytic solution to these problems are hard if not impossible. With the advancements in the linear and non-linear methods, i.e. linear matrix inequalities (LMI) and non-linear transformations, robust performance analysis and controller synthesis for cooperative systems can be reformulated as optimization problems with LMI constraints as has been done in the last two decades. Another aspect of the problem becomes visible as the cooperative system grows larger and that necessitates faster solution …

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Effect Of Centrifugal Force On The Load Capacity Of Thrust Gas Bearing, Rakan Mohammed Haidar Dec 2022

Effect Of Centrifugal Force On The Load Capacity Of Thrust Gas Bearing, Rakan Mohammed Haidar

Mechanical and Aerospace Engineering Theses - Archive

It has been known for many decades that both rigid and foil thrust bearings are two options in the market for high-speed turbomachinery systems. Their advantages encompass the lower manufacturing cost, the lighter weight, and the flexibility in allowing “component misalignment and runout.” When the operating fluid is air, the classical lubrication theory works perfectly. Any additional terms of the inertia effect might be somehow less significant and sometimes negligible since the viscous forces will be dominant, but this may not be the case if the bearing operates in a harsh environment, such as a high-pressure environment. Nonetheless, this is …

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