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Characterization Of Acoustic Modes In Aeroengines, Michelle Otero Jan 2018

Characterization Of Acoustic Modes In Aeroengines, Michelle Otero

Electronic Theses and Dissertations

Acoustic instabilities remain a key design concern faced in the development of liquid rocket engines. The interaction between the acoustic modes and the occurring combustion reactions can be detrimental to the engine. The fluctuating pressure waves resulting from the flame oscillations in the system can potentially lead to engine failure. For this reason, research in acoustic instabilities and methods to minimize the influences on the engine, has maintain interest in the aerospace community. The scope of this study was to design, optimize and characterize acoustic behaviors of a scaled rocket combustion chamber simulating acoustic pressure waves. Tangential and longitudinal acoustic …

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Mathematical Foundations Of Adaptive Quantum Processing, Daniel Bonior Jan 2018

Mathematical Foundations Of Adaptive Quantum Processing, Daniel Bonior

Electronic Theses and Dissertations

Quantum information has the potential to revolutionize the way we store, process, transfer and acquire information [1,14,15,21,37]. In particular, quantum information offers exciting new approaches to secure communication, computation and sensing. However, in order to realize such technologies, we must first understand the effect that environmental noise has on a quantum system. This dissertation builds upon recent studies that have explored the underlying structure of quantum information and the effects of qubit channels in quantum communication protocols. This work is divided into five main chapters, with Chapter 1 being a brief introduction to quantum information. We then begin Chapter 2 …

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Evaluating The Integration Of Chlorine Dioxide Into A Coagulation, Sedimentation, And Filtration Process Treating Surface Water, Martin Coleman Jan 2018

Evaluating The Integration Of Chlorine Dioxide Into A Coagulation, Sedimentation, And Filtration Process Treating Surface Water, Martin Coleman

Electronic Theses and Dissertations

Methods of optimizing the coagulation, flocculation, sedimentation, and filtration (CSF) process at a conventional surface water treatment plant (WTP) were conducted to investigate opportunities for the reduction of disinfection by-product (DBP) precursor material. The research had two primary components: (1) optimize coagulant dosage and associated operating pH and (2) investigate pretreatment oxidation with chlorine dioxide (ClO2) and potassium permanganate (KMnO4). To accomplish the first component, jar tests were conducted at various pH and aluminum sulfate (alum) dosages to model current and potential treatment conditions during the CSF process at a WTP. Isopleths were developed to examine the removal efficiencies of …

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Human Action Detection, Tracking And Segmentation In Videos, Yicong Tian Jan 2018

Human Action Detection, Tracking And Segmentation In Videos, Yicong Tian

Electronic Theses and Dissertations

This dissertation addresses the problem of human action detection, human tracking and segmentation in videos. They are fundamental tasks in computer vision and are extremely challenging to solve in realistic videos. We first propose a novel approach for action detection by exploring the generalization of deformable part models from 2D images to 3D spatiotemporal volumes. By focusing on the most distinctive parts of each action, our models adapt to intra-class variation and show robustness to clutter. This approach deals with detecting action performed by a single person. When there are multiple humans in the scene, humans need to be segmented …

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Trust-Based Rating Prediction And Malicious Profile Detection In Online Social Recommender Systems, Anahita Davoudi Jan 2018

Trust-Based Rating Prediction And Malicious Profile Detection In Online Social Recommender Systems, Anahita Davoudi

Electronic Theses and Dissertations

Online social networks and recommender systems have become an effective channel for influencing millions of users by facilitating exchange and spread of information. This dissertation addresses multiple challenges that are faced by online social recommender systems such as: i) finding the extent of information spread; ii) predicting the rating of a product; and iii) detecting malicious profiles. Most of the research in this area do not capture the social interactions and rely on empirical or statistical approaches without considering the temporal aspects. We capture the temporal spread of information using a probabilistic model and use non-linear differential equations to model …

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Theoretical Paschen's Law Model For Aerospace Vehicles: Validation Experiment, Jaysen Mulligan Aroche Jan 2018

Theoretical Paschen's Law Model For Aerospace Vehicles: Validation Experiment, Jaysen Mulligan Aroche

Electronic Theses and Dissertations

Aerospace vehicles often experience triboelectric charging while traversing the atmosphere. Triboelectric charging occurs when a material come into frictional contact with a different material. Aerospace vehicles triboelectrically charge due to frictional contact with dust and ice crystals suspended in the atmosphere. Launch vehicles traversing ice clouds in low-pressure atmosphere are especially prone to electrostatic discharge events (i.e. sparks). These conditions are hazardous and affect the vehicle's launch commit criteria. In 2010, engineers from an ARES-I rocket launch reported concerns with triboelectric charging over their self-destruct system antenna. This concern was addressed by putting the antenna through harsh conditions in a …

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Investigating And Facilitating The Transferability Of Safety Performance Functions, Ahmed Tarek Ahmed Farid Jan 2018

Investigating And Facilitating The Transferability Of Safety Performance Functions, Ahmed Tarek Ahmed Farid

Electronic Theses and Dissertations

Safety performance functions (SPFs) are essential analytical tools in the road safety field. The SPFs are statistical regression models used to predict crash counts by roadway facility type, crash type and severity. The national Highway Safety Manual (HSM) is a generic guidebook used for road safety evaluation and enhancement. In it, default SPFs, developed using negative binomial (NB) regression, are provided for multiple facility types and crash categories. Roadway agencies, whether public or private, may opt to not invest their resources in data collection and processing to develop own localized SPFs. Instead, the agencies may adopt the HSM's. However, the …

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Equivalency Analysis Of Sidestick Controller Modes During Manual Flight, Alex Rummel Jan 2018

Equivalency Analysis Of Sidestick Controller Modes During Manual Flight, Alex Rummel

Electronic Theses and Dissertations

Equivalency analysis is a statistical procedure that can enhance the findings of an analysis of variance in the case when non-significant differences are identified. The demonstration of functional equivalence or the absence of practical differences is useful to designers introducing new technologies to the flight deck. Proving functional equivalence is an effective means to justify the implementation of new technologies that must be "the same or better" than previous technology. This study examines the functional equivalency of three operational modes of a new active control sidestick during normal operations while performing manual piloting tasks. Data from a between-subjects, repeated-measures simulator …

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Investigation Into The Feasibility Of Adding Turbulators To Rocket Combustion Chamber Cooling Channels Using A Conjugate Heat Transfer Analysis, Tyler Buchanan Jan 2018

Investigation Into The Feasibility Of Adding Turbulators To Rocket Combustion Chamber Cooling Channels Using A Conjugate Heat Transfer Analysis, Tyler Buchanan

Electronic Theses and Dissertations

A conjugate heat transfer analysis will be carried out to simulate an 89 kN thrust chamber hydrogen cooling channel, to determine the feasibility of adding turbulators to the combustion chamber cooling channels at various parameters such as angle, pitch, and height of the turbulator. An existing regeneratively cooled chamber environment is simulated and used as a baseline case to be compared against. The new design includes using ribbed turbulators or delta wedges in the cooling channels to increase the heat transfer on the channel hot wall (wall adjacent to the hot gas wall) and on the two channel sidewalls. With …

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Explore Contributing Geometric Factors And Built-Environment On Bicycle Activity And Safety At Intersections, Scott Castro Jan 2018

Explore Contributing Geometric Factors And Built-Environment On Bicycle Activity And Safety At Intersections, Scott Castro

Electronic Theses and Dissertations

This study attempts to explore all factors associated with bicycle motor-vehicle crashes at intersections in order to improve bicycle safety and bicycle activity. Factors such as exposure (bicycle and vehicle volumes), existing facilities (bike lanes, sidewalks, shared-use paths), geometric design (# of lanes, speed limit, medians, legs, roadway conditions), and land-use were collected and evaluated using Poisson, Zero-Inflated Poisson, and Negative Binomial models in SAS 9.4 software. Increasing the bicycle travel mode can have positive lasting effects on personal health, the environment, and improve traffic conditions. Deterrents that keep users from riding bicycles more are the lack of facilities and …

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Accommodating Exogenous Variable And Decision Rule Heterogeneity In Discrete Choice Models: Application To Bicyclist Route Choice, Bibhas Dey Jan 2018

Accommodating Exogenous Variable And Decision Rule Heterogeneity In Discrete Choice Models: Application To Bicyclist Route Choice, Bibhas Dey

Electronic Theses and Dissertations

The thesis contributes to our understanding of incorporating heterogeneity in discrete choice models with respect to exogenous variables and decision rules. Specifically, we evaluate latent segmentation based mixed models that allow for segmenting population based on decision rules while also incorporating unobserved heterogeneity within the segment level decision rule models. In our analysis, we choose to consider the random utility framework along with random regret minimization approach. Further, instead of assuming the number of segments (as 2), we conduct an exhaustive exploration with multiple segments across the two decision rules. Within each segment we also allow for unobserved heterogeneity. The …

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Design And Implementation Of Pv-Firming And Optimization Algorithms For Three-Port Microinverters, Mahmood Alharbi Jan 2018

Design And Implementation Of Pv-Firming And Optimization Algorithms For Three-Port Microinverters, Mahmood Alharbi

Electronic Theses and Dissertations

With the demand increase for electricity, the ever-increasing awareness of environmental issues, coupled with rolling blackouts, the role of renewable energy generation is increasing along with the thirst for electricity and awareness of environmental issues. This dissertation proposes the design and implementation of PV-firming and optimization algorithms for three-port microinverters. Novel strategies are proposed in Chapters 3 and 4 for harvesting stable solar power in spite of intermittent solar irradiance. PV firming is implemented using a panel-level three-port grid-tied PV microinverter system instead of the traditional high-power energy storage and management system at the utility scale. The microinverter system consists …

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Design Of High Efficiency Brushless Permanent Magnet Machines And Driver System, Chengyuan He Jan 2018

Design Of High Efficiency Brushless Permanent Magnet Machines And Driver System, Chengyuan He

Electronic Theses and Dissertations

The dissertation is concerned with the design of high-efficiency permanent magnet synchronous machinery and the control system. The dissertation first talks about the basic concept of the permanent magnet synchronous motor (PMSM) design and the mathematics design model of the advanced design method. The advantage of the design method is that it can increase the high load capacity at no cost of increasing the total machine size. After that, the control method of the PMSM and Permanent magnet synchronous generator (PMSG) is introduced. The design, simulation, and test of a permanent magnet brushless DC (BLDC) motor for electric impact wrench …

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Methods To Calculate Cut Volumes For Fault Trees With Dependencies Induced By Spatial Locations, Phillip Hanes Jan 2018

Methods To Calculate Cut Volumes For Fault Trees With Dependencies Induced By Spatial Locations, Phillip Hanes

Electronic Theses and Dissertations

Fault tree analysis (FTA) is used to find and mitigate vulnerabilities in systems based on their constituent components. Methods exist to efficiently find minimal cut sets (MCS), which are combinations of components whose failure causes the overall system to fail. However, traditional FTA ignores the physical location of the components. Components in close proximity to each other could be defeated by a single event with a radius of effect, such as an explosion or fire. Events such as the Deepwater Horizon explosion and subsequent oil spill demonstrate the potentially devastating risk posed by such spatial dependencies. This motivates the search …

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The Formation And Characterization Of Mesoscopic J- And H-Aggregates With Controlled Morphologies By The Co- And Templated Assembly Of Cyanine Dyes, Samuel Rhodes Jan 2018

The Formation And Characterization Of Mesoscopic J- And H-Aggregates With Controlled Morphologies By The Co- And Templated Assembly Of Cyanine Dyes, Samuel Rhodes

Electronic Theses and Dissertations

The supramolecular aggregates of π-conjugated molecules have become an area of great interest to the scientific community in recent years for their promise in biosensors and optoelectronic devices. Among various supramolecular aggregates, J- and H-aggregates of πconjugated dye molecules are particularly interesting because of their unique optical and excitonic properties that are not given by individual molecules. H-aggregates are composed of dye molecules in a face-to-face stacking, giving rise to a blue-shifted absorption band compared with the monomer band and a strong emission quenching. In contrast, J-aggregates represent an edge-toedge stacking of dye molecules, showing a red-shifted absorption band with …

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Human Factor Effects Of Simulating Battlefield Malodors In Field Training, William Pike Jan 2018

Human Factor Effects Of Simulating Battlefield Malodors In Field Training, William Pike

Electronic Theses and Dissertations

In order to explore how to better utilize simulated odors for live training, a study of 180 United States Military Academy at West Point cadets was undertaken to determine whether pre-exposure to a simulated malodor may result in an amelioration of performance issues, as well as improving performance of a complex task. Exposure to malodors has long been shown to increase stress and escape behavior, and reduce performance of complex tasks, in addition to degrading other human factor areas. However, desensitization to a particular odor through a process known as olfactory adaptation, could ameliorate these performance issues. In this study, …

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Analog Temperature Control Circuit For A Thin-Film Piezoelectric-On-Substrate Microelectromechanical Systems Oscillator, Heather Hofstee Jan 2018

Analog Temperature Control Circuit For A Thin-Film Piezoelectric-On-Substrate Microelectromechanical Systems Oscillator, Heather Hofstee

Honors Undergraduate Theses

The objective and motivation for this project is to design a low-power, low-noise oven-control circuit to optimize the stability of a MEMS oscillator. MEMS oscillators can be fabricated using conventional semiconductor manufacturing methods and can often be assembled in packages smaller than those of traditional crystal oscillators. However, one of their largest disadvantages currently is their high temperature coefficient of frequency (TCF), causing MEMS oscillators to be especially sensitive to temperature changes. Hence, this project focuses on designing a printed circuit board that will allow the user to manually tune a current passing through a resonator wire-bonded to the board …

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Processing Of Cubic Stabilized Zirconia Electrolyte Membranes For Electrolyte-Supported Single Cell Solid Oxide Fuel Cells Using Tape Casting, Arturo Coronado Rodriguez Jan 2018

Processing Of Cubic Stabilized Zirconia Electrolyte Membranes For Electrolyte-Supported Single Cell Solid Oxide Fuel Cells Using Tape Casting, Arturo Coronado Rodriguez

Honors Undergraduate Theses

Electrochemical conversion devices are a developing technology that prove to be a viable and more efficient alternative to current environmentally friendly generation devices. As such, constant research has been done in the last few decades to increase their applications and reliability. One of these systems, and the focus of this research, is the single cell Solid Oxide Fuel Cell (SOFC). These systems are a developing technology which main caveat is the need of high operating temperatures and costs. As such, most multidisciplinary research has been focused on researching materials and/or processes that help mitigate the costs or lower the operating …

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Equibiaxial Flexural Strength Testing Of Advance Ceramics, Ryan T. Jordan Jan 2018

Equibiaxial Flexural Strength Testing Of Advance Ceramics, Ryan T. Jordan

Honors Undergraduate Theses

Ceramics are very important materials with many unique properties used in numerous industrial applications. Ceramics could be very hard and very strong in comparison to metals; however, they are very brittle, thus they are prone to instantaneous and catastrophic failure. Therefore, their reliability is compromised and it is very important to have advanced techniques that allow evaluating their mechanical behavior in many unusual stress states. One of such testing methods is biaxial strength method, that allows to measure properties not only unidirectional, but also in a biaxial way. The research work for this thesis will be built on design and …

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The Exploration Of Rotating Detonation Dynamics Incorporating A Coal-Based Fuel Mixture, John P. Rogan Jan 2018

The Exploration Of Rotating Detonation Dynamics Incorporating A Coal-Based Fuel Mixture, John P. Rogan

Honors Undergraduate Theses

This investigation explores the detonation dynamics of a rotating detonation engine (RDE). Beginning with the general understanding and characteristics of hydrogen and compressed air as a detonation fuel source, this study further develops the experimental approach to incorporating a coal-based fuel mixture in an RDE. There is insufficient prior research investigating the use of coal as part of a fuel mixture and insignificant progress being made to improve thermal efficiency with deflagration. The U.S. Department of Energy's Office of Fossil Energy awarded the Propulsion and Energy Research Laboratory at the University of Central Florida a grant to lead the investigation …

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Turbulent Flame-Vortex Dynamics Of Bluff-Body Premixed Flames, Marissa Geikie Jan 2018

Turbulent Flame-Vortex Dynamics Of Bluff-Body Premixed Flames, Marissa Geikie

Electronic Theses and Dissertations

This study explores the effects of turbulence and pressure-gradient tailoring on the turbulent flame and vorticity transport mechanisms of premixed flames. A turbulent premixed flame stabilized by a bluff-body in a high-speed combustor is used for the investigation. The combustor pressure gradient is altered using a variable-geometry test section. The turbulence within the combustor is controlled using a custom-designed, supersonic variable-turbulence generator. The turbulent flame-flow field is measured and characterized using simultaneous high-speed particle imaging velocimetry (PIV) and CH* chemiluminescence. The flame-vortex dynamics of the turbulent flame are analyzed using a Lagrangian tracking methodology. Lagrangian fluid elements (LFEs) are tagged …

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Simultaneous Use Of Physiological Sensors For A Neuromarketing Task, Charles Descheneaux Jan 2018

Simultaneous Use Of Physiological Sensors For A Neuromarketing Task, Charles Descheneaux

Electronic Theses and Dissertations

Physiological measurements have become more popular in Psychological research over the past ten years. These advancements allowed different objective sensors to become another measurement tool in a scientific arsenal of collecting data. Traditionally, performance and after task subjective measures have been used for most studies in Psychological research. With the opportunity to use these subjective measures along with objective measures, more data can be collected during research and therefore potentially produce better quality conclusions. Eye Tracking (ET), functional near infrared (fNIR), transcranial Doppler ultrasound (TCD), electrocardiogram (EKG) and the electroencephalogram (EEG) have shown great promise in their ability to produce …

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Seismic Response Of Moment Resisting Frames Coupled With Rocking Walls, Mehrdad Aghagholizadeh Jan 2018

Seismic Response Of Moment Resisting Frames Coupled With Rocking Walls, Mehrdad Aghagholizadeh

Electronic Theses and Dissertations

This study investigates the inelastic response of yielding structures coupled with rocking walls. This topic is of major significance in the design of tall moment-resisting buildings, since during recent major earthquakes several tall, moment-resisting frames that had been designed in an accordance to the existing seismic code provisions, exhibited a weak-story failure. Utilization of this structural system can help reducing maximum story drifts, prevents weak story failure and minimize residual deformation of the structure. This study first examines different configurations of both stepping rocking walls and pinned rocking walls that have been reported in the literature. Next, effect of additional …

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Seepage And Stability Analysis Of The Earth Dams Under Drawdown Conditions By Using The Finite Element Method, Salama Al-Labban Jan 2018

Seepage And Stability Analysis Of The Earth Dams Under Drawdown Conditions By Using The Finite Element Method, Salama Al-Labban

Electronic Theses and Dissertations

One of the major concerns in the behavior of an earth dam is the change in the exit gradient and the impact on the slope stability under drawdown conditions. Drawdown can cause increased seepage forces on the upstream slope which may result in the movement of soil particles in the flow direction and cause erosion problems. In this research, a numerical approach, based on the finite element method (FEM) is used to analyze the seepage through the dam and its foundation to study exit gradients and slope stability under both steady-state and transient conditions. The results show that a central …

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Personalized Digital Body: Enhancing Body Ownership And Spatial Presence In Virtual Reality, Sungchul Jung Jan 2018

Personalized Digital Body: Enhancing Body Ownership And Spatial Presence In Virtual Reality, Sungchul Jung

Electronic Theses and Dissertations

person's sense of acceptance of a virtual body as his or her own is generally called virtual body ownership (VBOI). Having such a mental model of one's own body transferred to a virtual human surrogate is known to play a critical role in one's sense of presence in a virtual environment. Our focus in this dissertation is on top-down processing based on visual perception in both the visuomotor and the visuotactile domains, using visually personalized body cues. The visual cues we study here range from ones that we refer to as direct and others that we classify as indirect. Direct …

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Simulating Human Pleura Performance In Medical Training Using Measured Tissue Mechanical Properties, Jack Norfleet Jan 2018

Simulating Human Pleura Performance In Medical Training Using Measured Tissue Mechanical Properties, Jack Norfleet

Electronic Theses and Dissertations

Medical simulations provide hands-on training at various levels of medical expertise. Yet these simulators fail to accurately mimic the look, feel and behavior of human tissue. Applying measured mechanical properties from human cadaver tissues promises to improve the fidelity of simulated tissue behaviors when subjected to medical procedures. Samples of human parietal pleura were tested under uniaxial tension to failure and measured characteristics were replicated in synthetic pleura. Context specific parameters were then collected and compared between human pleura and the new synthetics. These comparisons tested the hypothesis; H1 Gaps exist between synthetic and human pleura performance, H2: Human tissue …

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Robust, Scalable, And Provable Approaches To High Dimensional Unsupervised Learning, Mostafa Rahmani Jan 2018

Robust, Scalable, And Provable Approaches To High Dimensional Unsupervised Learning, Mostafa Rahmani

Electronic Theses and Dissertations

This doctoral thesis focuses on three popular unsupervised learning problems: subspace clustering, robust PCA, and column sampling. For the subspace clustering problem, a new transformative idea is presented. The proposed approach, termed Innovation Pursuit, is a new geometrical solution to the subspace clustering problem whereby subspaces are identified based on their relative novelties. A detailed mathematical analysis is provided establishing sufficient conditions for the proposed method to correctly cluster the data points. The numerical simulations with both real and synthetic data demonstrate that Innovation Pursuit notably outperforms the state-of-the-art subspace clustering algorithms. For the robust PCA problem, we focus on …

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Exploring Natural User Abstractions For Shared Perceptual Manipulator Task Modeling & Recovery, Senglee Koh Jan 2018

Exploring Natural User Abstractions For Shared Perceptual Manipulator Task Modeling & Recovery, Senglee Koh

Electronic Theses and Dissertations

State-of-the-art domestic robot assistants are essentially autonomous mobile manipulators capable of exerting human-scale precision grasps. To maximize utility and economy, non-technical end-users would need to be nearly as efficient as trained roboticists in control and collaboration of manipulation task behaviors. However, it remains a significant challenge given that many WIMP-style tools require superficial proficiency in robotics, 3D graphics, and computer science for rapid task modeling and recovery. But research on robot-centric collaboration has garnered momentum in recent years; robots are now planning in partially observable environments that maintain geometries and semantic maps, presenting opportunities for non-experts to cooperatively control task …

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Marsilio Ficino's Astral Psychology: The Inner Cosmos Of Cardinal Alessandro Farnese On The Astronomical Ceiling Fresco Of Sala Del Mappamondo At Caprarola, Renata R. Nagy Jan 2018

Marsilio Ficino's Astral Psychology: The Inner Cosmos Of Cardinal Alessandro Farnese On The Astronomical Ceiling Fresco Of Sala Del Mappamondo At Caprarola, Renata R. Nagy

Honors Undergraduate Theses

This thesis intends to explore the relationship between the Neoplatonist doctrines of the Renaissance philosopher, Marsilio Ficino (1433-1499), and astrological images in the Renaissance. The astrological ceiling fresco located in the Room of Maps in the Villa Farnese at Caprarola is in the center of the argument, which I analyze based on the metaphysical works of Ficino, the Platonic Theology (1482) and the Three Books on Life (1492). Authors have examined the fresco decoration and Ficinian philosophy individually, but never together. This study is the first to recognize Ficino's influence on Renaissance astrological images in its entirety.The present work synthesizes …

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Identifying Undergraduate Student's Motivation To Attend Tutoring For General Chemistry Courses, Alexis C. Hyacinthe Jan 2018

Identifying Undergraduate Student's Motivation To Attend Tutoring For General Chemistry Courses, Alexis C. Hyacinthe

Honors Undergraduate Theses

General Chemistry II is a common chemistry course that is required for professional school such as, medical, dental, optometry schooling. Considering that it historically has a high drop, fail, withdrawal rate, it is surprising that less than 10% of students in chemistry II attend tutoring at the Student Academic Resource Center (SARC). In this tutoring center, sessions are led by students who have excelled previously in that specific course. The objective of this research is to investigate the relationship between student motivation and attendance in SARC peer tutoring sessions for chemistry II. More precisely, to better understand the connection between …

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