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A Machine Learning Approach For Identifying The Effectiveness Of Simulation Tools For Conceptual Understanding, Sindhura Elluri Dec 2017

A Machine Learning Approach For Identifying The Effectiveness Of Simulation Tools For Conceptual Understanding, Sindhura Elluri

Open Access Theses

Interactive learning environments have been identified as promising technologies to improve teaching and learning in science and engineering. Specifically, simulation tools have become a vital part of coursework in both K-12 and higher education. It is therefore essential to identify better ways to integrate simulation tools in the classroom and at the same time provide teachers and students with feedback capabilities that can support existing assessment methods and provide opportunities for just-in-time teaching. One effective way to identify how students are benefiting from the use of computer simulations for conceptual learning is by having them explain the phenomena being explored. …

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Performance Augmentation Of Compliance Based Morphing Wings Through Optimization And Non-Linearity, Ashwin Clement Henry Dec 2017

Performance Augmentation Of Compliance Based Morphing Wings Through Optimization And Non-Linearity, Ashwin Clement Henry

Open Access Theses

Conformal shape adaptation presents significant benefits in terms of increased aerodynamic efficiency for a wide range of flight conditions in addition to minimizing drag penalties via gap-less smooth shape profile change. Conformal shape adaptation in morphing wings can be achieved by distributed compliance and stiffness selectivity techniques. These morphing strategies yield light-weight monolithic structures by utilizing the multifunctionality offered by smart materials. The present thesis, therefore, attempts to enhance the performance of compliance based morphing wings by augmenting the stiffness characteristics through optimization of associated smart actuators and implementation of stiffness selectivity. These performance augmentation methods essentially attempt to improve …

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Analytics Protocol For Data-Driven Decision-Making In The Construction Industry, Ashwini Jain Dec 2017

Analytics Protocol For Data-Driven Decision-Making In The Construction Industry, Ashwini Jain

Open Access Theses

Due to the unique nature of construction projects and the need for leaders in the business to have knowledge from multiple fields, it has become difficult for decision makers to confidently make choices in their complex working environment. Over time, data availability and computational power have both improved. Moreover, technological advancements from the past few years have overwhelmed the industry by generating a diverse amount data from various sources. This large amount of data makes it possible to find nuggets of information. However, in this digital era, collecting data is not the problem, but how to extract useful information is …

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Assessing The First And Last Mile Problem In Intercity Passenger Rail: Effects On Mode Choice And Trip Frequency, Lisa Lorena Losada Rojas Dec 2017

Assessing The First And Last Mile Problem In Intercity Passenger Rail: Effects On Mode Choice And Trip Frequency, Lisa Lorena Losada Rojas

Open Access Theses

Passenger rail service is an integral part of intercity transportation networks, especially in areas where residents do not have access to cars or other intercity travel options. Some municipalities in the U.S. have experienced a decline in passenger rail service in recent years, which has prompted schedule reductions and entire abandonment of service in some cases. To improve the current intercity passenger rail service predicament, two alternatives can be considered: (1) improve the rail service itself (frequency, infrastructure, etc.) and (2) improve accessibility to the rail stations, which might be cheaper and more cost-effective overall. Improvements in accessibility can impact …

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Mechanical Testing Of Semi-Solid Al-Mg Binary And 7050 Aluminum Alloys Using The Reheating-Cooling Method, Christopher James Mccleary Dec 2017

Mechanical Testing Of Semi-Solid Al-Mg Binary And 7050 Aluminum Alloys Using The Reheating-Cooling Method, Christopher James Mccleary

Open Access Theses

Elevated temperature tensile testing beyond the non-equilibrium solidus demonstrates the advantage of a new method called the Reheating-Cooling Method (RCM) for determining mechanical properties of Al-Mg binary alloys and cast alloy 7050 aluminum in the solid-liquid two phase mushy zone. Using the RCM, it is possible to achieve semi-solid tensile behavior with standard testing equipment and to retain a nonequilibrium casting microstructure, which is necessary to gain insight into hot tearing. Hot tearing, a virtually impossible to repair defect, is known to worsen with increasing Direct Chill (DC) cast ingot size. Further data gathered from mechanical testing of alloys within …

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A Method For Assessing And Predicting Water Quality Status For Improved Decision- Making And Management, Valeria Mijares Dec 2017

A Method For Assessing And Predicting Water Quality Status For Improved Decision- Making And Management, Valeria Mijares

Open Access Theses

With the increasing population and demand for water, it is crucial to be able to assess its quality on a real-time basis and for predictive purposes. Water-quality Indices (WQIs) provide a means by which the water quality can be compared across space and time based on a composite indicator. Index and subindex values can be used to flag contaminants of concern, guide prioritization of management efforts, and for predictive purposes. In this study, subindex formulations for key water quality parameters were developed and enhanced to incorporate water quality targets and criteria. The enhanced subindex formulations were built into the Unweighted …

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Influence Maximization Using Observational Data, Mohith Murlidhar Dec 2017

Influence Maximization Using Observational Data, Mohith Murlidhar

Open Access Theses

Influence maximization is the problem of finding a subset of nodes (seed nodes) in a network, such that by incentivizing these set of nodes, one maximizes the expected spread of influence in the network. This is an NP hard problem for which in the past, greedy algorithms and heuristics have been proposed for solving the problem. Most of these algorithms on this topic have focused on using information about the underlying graph and the edge probabilities, while running expensive controlled experiment simulations to find a solution to the influence maximization problem. These algorithms also accounted only for direct (or indirect) …

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Simplified Model For Persistent Sliding Contact, Adarsh Patil Dec 2017

Simplified Model For Persistent Sliding Contact, Adarsh Patil

Open Access Theses

Numerous engineering applications involve one or more mechanical components that come into contact with each other during operation. Repetitive motions under contact can lead to fatigue and wear problems in the components. When designing such components, it is important to characterize and quantify the stresses and strains in the contacting elements. This can be achieved by numerical simulation of the process and by using one of the several contact formulations available in most finite element software programs. However, contact is an inherently non-linear problem which is rather challenging even for the best commercial software programs currently available. Often contact simulations …

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Orbit Maintenance Strategies For Sun-Earth/Moon Libration Point Missions: Parameter Selection For Target Point And Cauchy-Green Tensor Approaches, Vivek Muralidharan Dec 2017

Orbit Maintenance Strategies For Sun-Earth/Moon Libration Point Missions: Parameter Selection For Target Point And Cauchy-Green Tensor Approaches, Vivek Muralidharan

Open Access Theses

The libration point orbits in the Sun-Earth/Moon system are formed by concurrent gravitational influences by various celestial bodies, originating in a nonlinear dynamical regime. Coupled with the unstable nature of the orbit, the impact of any perturbations are expected to increase rapidly. The feasibility of a flow-based, Cauchy-Green tensor control strategy for station-keeping is examined. An orbit consistent with the mission objectives is selected for examination. The station-keeping process is stochastic, thus Gaussian random errors are introduced for simulation. The evolution of a velocity perturbation over time is monitored, beyond which the attainable state in the accessible region nearest to …

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Kalman Filtering For Lti Systems With State Dependent Packet Losses, Omanshu Thapliyal Dec 2017

Kalman Filtering For Lti Systems With State Dependent Packet Losses, Omanshu Thapliyal

Open Access Theses

Due to recent advances in networked control systems and wireless networked control systems, most systems of interest operate in environments susceptible to sensor malfunctions. The increased dependency on communication channels to transfer measurement data due to the geographical separation of sensors from actuators and plants further contributes to the issue. Most existing methods that deal with the problem of estimation under packet losses assume the packet arrival process to have stationary statistics. In this work we relax this assumption and address the problem of state estimation under state dependent packet losses. This problem presents inherent modeling of practical applications of …

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Digimesh Reliability In High Speed Vehicular Applications, Bogdan A. Visan Dec 2017

Digimesh Reliability In High Speed Vehicular Applications, Bogdan A. Visan

Open Access Theses

In a fast-paced technological society, advances in wireless networking show potential to save lives. Communication is key to notifying Emergency Medical Services of a potentially deadly accident in near real-time. This paper will discuss the use of low powered wireless devices transmitting life-saving information autonomously. Current and planned technologies used in vehicles are built-in, costly, and vulnerable to physical destruction. Using an independent system can offer both old and new vehicles primary and secondary communication. The results from this research study show that vehicles can use DigiMesh as a viable solution, although relative velocity affects its performance.

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Unsteady Aerodynamics And Blade-Row Interactions In The Embedded Stage Of An Axial Compressor, Douglas Ryan Matthews Dec 2017

Unsteady Aerodynamics And Blade-Row Interactions In The Embedded Stage Of An Axial Compressor, Douglas Ryan Matthews

Open Access Theses

In a mature engineering field like compressor aerodynamics, the most accessible advances in machine technology, translating to performance and efficiency, have been discovered and have found industry design applications. As the community continues to make progress, increasingly challenging aspects of the involved physics must be exploited. Modern turbomachinery operates with larger bypass ratios, smaller cores, and lighter, thinner, and more flexible materials resulting in the maintenance of higher operating pressures and temperatures. As the performance and efficiency of these machines continues to climb, the same technological advances reinforce challenges like forced-response vibration, high-cycle fatigue of engine components, and large relative …

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Optimized Command Shaping With Constrained Peak Input Acceleration For Minimizing Residual Vibration, Bowen Wu Dec 2017

Optimized Command Shaping With Constrained Peak Input Acceleration For Minimizing Residual Vibration, Bowen Wu

Open Access Theses

The fast point-to-point motion of a robotic system can be greatly affected by its joint flexibilities, which introduce vibrations during and after motion. While numerous techniques were developed to minimize the residual vibration of the flexible robotic system, this work studies the command shaping method. This method constructs an input profile that aims to reduce excitation energy around the natural frequencies to minimize residual vibration. This work modifies the command shaping method by applying a numerical optimization technique with a constraint on peak input acceleration. A framework has been constructed for the combination of these two modifications, which proved their …

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Turning A Multivalent Lens Toward Depictions Of Artificial Intelligence (Ai) In Film, Ashley Ann Albrecht Dec 2017

Turning A Multivalent Lens Toward Depictions Of Artificial Intelligence (Ai) In Film, Ashley Ann Albrecht

Open Access Dissertations

With innovations in the field of artificial intelligence (AI) advancing at an exponential rate, it is ever the more pertinent to interrogate the ramifications and potentialities of these developments. Luciano Floridi, known as “the Google philosopher,” considers this phenomenon an integral part of the digital information age or the “Fourth Revolution.” We are now forced to confront the following problems: What is the relationship between humans and AI? What does it mean to be “human”? What futures are possible given our current coevolution with AI? Such questions motivate close philosophical consideration. Here, the theoretical polarization of the doomsday neo-Luddite versus …

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Investigation Of Noise And Vibration In Tires Through Analytical Modeling, Tests And Simulations, Rui Cao Dec 2017

Investigation Of Noise And Vibration In Tires Through Analytical Modeling, Tests And Simulations, Rui Cao

Open Access Dissertations

Tire noise and vibration is an interesting topic, with more and more people paying attention to this issue. Tire noise can both propagate into the vehicle interior and radiate directly toward the immediate environment. Tire noise is not only related to vehicle passengers’ comfort but also affects the residential or working area near highways, especially in high population density regions. The emerging electric vehicles also emphasize tires’ role in vehicle Noise Vibration and Harshness (NVH) since power-train noises are significantly reduced. The study in this research focuses on the noise and vibration of tires from the low to high frequency …

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Variability Of Persistent Temporal Correlation In Climate Data, Matthew C. Bowers Dec 2017

Variability Of Persistent Temporal Correlation In Climate Data, Matthew C. Bowers

Open Access Dissertations

This dissertation examines manifestations of persistent memory in climate data. Persistence is characterized by a slow power-law decay in the autocorrelations of a time series. Its existence implies that the influence of past values in a time series extend into the distant future. It has numerous theoretical implications, notably that it changes the asymptotic decay in the variance of sample means, which can substantially impact the uncertainty in climate mean states. Its intensity can vary over space, time, and other dimensions, e.g. tree species. Variation in its intensity can be used for practical applications such as discriminating between steady and …

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Optothermal Energy Conversion And Transport In Plasmonic Structures, Chen Chen Dec 2017

Optothermal Energy Conversion And Transport In Plasmonic Structures, Chen Chen

Open Access Dissertations

Plasmonic structures can efficiently interact with electromagnetic waves at their interfaces, leading to strong light confinement and field enhancement, which has been crucial for many nanotechnology applications in manufacturing, lithography, data storage, biosensing, spectroscopy, molecular trapping and other molecular level studies. Due to the intrinsic losses of metallic structures, the strong light-matter interaction also generates significant energy dissipation, making the thermal management of the devices very challenging. The purpose of this dissertation is to study the optothermal energy conversion and transport in plasmonic structures, especially in structures at the nanoscale. We first investigate the general optothermal responses of plasmonic structures …

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Learning Electron Transport Chain Process In Photosynthesis Using Video And Serious Game, Cecilia Espinoza Morales Dec 2017

Learning Electron Transport Chain Process In Photosynthesis Using Video And Serious Game, Cecilia Espinoza Morales

Open Access Dissertations

This research investigates students' learning about the electron transport chain (ETC) process in photosynthesis by watching a video followed by playing a serious board game-Electron Chute- that models the ETC process. To accomplish this goal, several learning outcomes regarding the misconceptions students' hold about photosynthesis and the ETC process in photosynthesis were defined. Middle school students need opportunities to develop cohesive models that explain the mechanistic processes of biological systems to support their learning. A six-week curriculum on photosynthesis included a one day learning activity using an ETC video and the Electron Chute game to model the ETC process. The …

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A New Method For Determining Hamaker Constants Of Solids Based On The Dynamic Approach Behavior Of An Atomic Force Microscope, Sean G. Fronczak Dec 2017

A New Method For Determining Hamaker Constants Of Solids Based On The Dynamic Approach Behavior Of An Atomic Force Microscope, Sean G. Fronczak

Open Access Dissertations

The Hamaker constant, A, is a very important parameter used to quantify the strength of the van der Waals (vdW) attractive interaction among particles and between particles and surfaces. Consequently, an accurate measurement of A is of fundamental importance to a wide range of research and manufacturing fields. Therefore, this dissertation primarily focuses on the development and application of a new method to determine Hamaker constants of solid materials using an atomic force microscope (AFM). While the direct contact or pull-off method is typically employed during an AFM force measurement, this contact-technique is highly dependent upon material properties that are …

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A Supervised Learning Approach For Dynamic Sampling (Slads), Gunawath Mudiyanselage Dilshan Prasanjana Godaliyadda Dec 2017

A Supervised Learning Approach For Dynamic Sampling (Slads), Gunawath Mudiyanselage Dilshan Prasanjana Godaliyadda

Open Access Dissertations

Sparse sampling schemes can broadly be classified in to two main categories: static sampling where the sampling pattern is predetermined, and dynamic sampling where each new measurement location is selected based on information obtained from previous measurements. Dynamic sampling methods are particularly appropriate for point-wise imaging methods in which pixels are measured sequentially in arbitrary order. Examples of point-wise imaging schemes include certain implementations of atomic force microscopy (AFM), electron back scatter diffraction (EBSD), and Scanning Electron Microscopy (SEM). In these point-wise imaging applications, dynamic sparse sampling methods have the potential to dramatically reduce the number of measurements required to …

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An Optimization-Based Approach To Determine Requirements And Aircraft Design Under Multi-Domain Uncertainties, Parithi Govindaraju Dec 2017

An Optimization-Based Approach To Determine Requirements And Aircraft Design Under Multi-Domain Uncertainties, Parithi Govindaraju

Open Access Dissertations

Determining the optimal requirements for and design variable values of new systems, which operate along with existing systems to provide a set of overarching capabilities, as a single task is challenging due to the highly interconnected effects that setting requirements on a new system’s design can have on how an operator uses this newly designed system. This task of determining the requirements and the design variable values becomes even more difficult because of the presence of uncertainties in the new system design and in the operational environment. This research proposed and investigated aspects of a framework that generates optimum design …

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Computational Modelling Of Thermal Transport Using Spectral Phonon Boltzmann Transport Equation, Ahmed Osama Ibrahim Hamed Dec 2017

Computational Modelling Of Thermal Transport Using Spectral Phonon Boltzmann Transport Equation, Ahmed Osama Ibrahim Hamed

Open Access Dissertations

Lattice vibration is the main microscopic mechanism for thermal transport in dielectric materials. The convenience of the analysis of atomic vibrations in the reciprocal space, motivated by the pioneering work of Debye and Peirels, made phonon transport theory is one of the standard paradigms adequate to study the microstructure and stoichiometry effects on thermal transport phenomena at mesoscale. UO2 is of theoretical as well as technological importance. The characteristic thermal transport phenomena at short length-scale (~ nanometer) and time-scale (~ picosecond) associated with radiation dictate close examination of available theoretical models and solution methods for thermal conductivity prediction, in addition …

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Cultivating Asian Students' Willingness To Communicate In American Classrooms Using An Online Video-Based Pre-Arrival Course, Hui-Ching Kayla Hsu Dec 2017

Cultivating Asian Students' Willingness To Communicate In American Classrooms Using An Online Video-Based Pre-Arrival Course, Hui-Ching Kayla Hsu

Open Access Dissertations

The purpose of this mixed methods study was: 1) to document the design and implementation process of an online video-based pre-arrival course that was intended to cultivate Asian students’ willingness to communicate in American Classrooms; 2) to assess the effectiveness of the course by measuring students’ oral proficiency and willingness to communicate; and 3) to investigate their first-year classroom participation as well as their experiences with the pre-arrival course. This research inquiry was guided by two research questions: 1) How does completing an online pre-arrival course influence Asian students’ speaking abilities, willingness to communicate, and verbal participation in their first-year …

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Design And Statistical Analysis Of Mass Spectrometry Imaging Experiments, April Janae Harry Dec 2017

Design And Statistical Analysis Of Mass Spectrometry Imaging Experiments, April Janae Harry

Open Access Dissertations

The goal of mass spectrometry-based imaging (MSI) is to characterize the chemical composition of biological samples such as tissues in spatial resolution, and changes in the composition between conditions such as the status of a disease. A single mass spectrometry image is a collection of mass spectra at gridded locations on a tissue. When acquired over multiple biological individuals, tissues, and conditions, the resulting datasets are tremendously complex in both scale and in the stochastic structure of the quantified spectral features. Accurate characterization of the biological and technical variation in these experiments is therefore key for deriving sensitive and reproducible …

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Rheological Behavior And Manufacturing Simulation Of Prepreg Platelet Molding Systems, Anthony J. Favaloro Dec 2017

Rheological Behavior And Manufacturing Simulation Of Prepreg Platelet Molding Systems, Anthony J. Favaloro

Open Access Dissertations

Molding systems formed by cutting and slitting prepreg composite tape into the form of platelets have been shown to be beneficial in producing parts with moderate performance with moderate processing characteristics. However, the platelets forming the molding system are typically quite large compared to typical part thicknesses. Therefore, a challenge of scales exists in platelet molding systems that is absent in traditionally considered well dispersed fiber molding systems used in injection molding. In this dissertation, we consider the specific problem of determining the final orientation state of parts manufactured in compression molding from platelet molding systems along with identifying parameters …

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Investigating The Conversations That Occur During Undergraduate Research Experiences: A Case Study, Sara L. Johnson Dec 2017

Investigating The Conversations That Occur During Undergraduate Research Experiences: A Case Study, Sara L. Johnson

Open Access Dissertations

Despite the increasing popularity of undergraduate research experiences across disciplines, little information currently exists to guide the design, evaluation, and improvement of these experiences. One challenge to generating such guidelines is the lack of evidence related to the processes and contexts in which undergraduate research experiences occur. My study sought to address this deficiency by exploring the norms of discourse that framed conversations between students and their mentors in biochemistry research as a model to understand the phenomenon of undergraduate research. I used a case-study approach to investigate the conversations that occurred between three student-mentor pairs as they engaged in …

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Household Decision Making Under Stress: Three Essays On Agricultural Production In Southern Africa, Anna Leigh Josephson Dec 2017

Household Decision Making Under Stress: Three Essays On Agricultural Production In Southern Africa, Anna Leigh Josephson

Open Access Dissertations

Rural households in Southern Africa face numerous economic challenges, arising from a range of idiosyncratic and covariate risks. This research seeks to understand strategies employed by households to cope with different types of shocks, in the context of Zimbabwe and Malawi. I focus on several techniques used to cope with risk and shocks in an uncertain environment, including intra-household resource, land, and crop, as well as labor allocations. To provide insight on household decision making, I expand and adapt theoretical models. This helps me to better understand household decision making in the complex and risky environments in which they reside …

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Investigating The Crystallization Propensity Of Structurally Similar Organic Molecules From Amorphous State, Arjun Kalra Dec 2017

Investigating The Crystallization Propensity Of Structurally Similar Organic Molecules From Amorphous State, Arjun Kalra

Open Access Dissertations

Combinatorial chemistry and high-throughput screening approaches utilized during drug discovery have resulted in many potent pharmacologically active molecules with low aqueous solubility and consequently poor bioavailability. Enabling technologies, such as amorphous solid dispersions (ASD’s), can obviate these challenges and provide an efficient route to formulate the drug as an oral solid dosage form. However, high-energy amorphous materials have an inherent tendency to crystallize and in doing so can negate the apparent solubility advantage achieved by using such formulations. Crystallization can occur during (1) cooling the drug molecule from the melt state (such as during hot melt extrusion); (2) during storage …

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Hyperspectral Image Reconstruction From Rgb Data And Its Biomedical Applications, Tae Hoon Kim Dec 2017

Hyperspectral Image Reconstruction From Rgb Data And Its Biomedical Applications, Tae Hoon Kim

Open Access Dissertations

Noninvasive label-free hyperspectral imaging of physiological changes in biological systems has been extensively used as invaluable tools in a variety of research areas, including medical and biological applications. However, conventional approach requires a critical, yet bulky, expensive, and slow optical component (i.e. a mechanical filter wheel, an imaging spectrograph, or a liquid crystal tunable filter) for capturing full spectral information. Therefore, this component limits development of compact, rapid, and cost-effective systems. In this respect, we propose to explore a possibility of spectrometerless (or spectrometer-free) hyperspectral imaging to map out detailed spatial distributions of biochemical absorption compounds or pigments, which are …

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Exploring Transformative Learning Pedagogies To Teach Human-Centered Design: A Collaborative Action Research Approach, Cole Hatfield Joslyn Dec 2017

Exploring Transformative Learning Pedagogies To Teach Human-Centered Design: A Collaborative Action Research Approach, Cole Hatfield Joslyn

Open Access Dissertations

In this research, I present the problem that a culture of disengagement endemic in engineering and engineering education (see Cech, 2014) is exacerbated by deeply rooted habits of mind and their underlying assumptions that are at odds with social justice ideals and resistant to change, thus, perpetuating the status quo (see Riley, 2008). Furthermore, current engineering education curricula focusing primarily on mathematics, science, and engineering sciences (see Sheppard, Macatangay, Colby, & Sullivan, 2009) further entrench this culture along with these habits of mind and assumptions. In an attempt to address the culture of disengagement, I propose a framework for humanizing …

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