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Description
In nature, some animals have an exoskeleton that provides protection, strength, and stability to the organism, but in engineering, an exoskeleton refers to a device that augments or aids human ability. However, the method of controlling these devices has been a challenge historically. Depending on the objective, control systems for exoskeletons have ranged from devices as simple spring-loaded systems to using sensors such as electromyography (EMG). Despite EMGs being very common, force sensing resistors (FSRs) can be used instead. There are multiple types of exoskeletons that target different areas of the human body, and the targeted area depends on the need of the device. Usually, the devices are developed for either medical or military usage; for this project, the focus is on medical development of an automated elbow joint to assist in rehabilitation. This thesis is a continuation of my ASU Barrett honors thesis, Upper-Extremity Exoskeleton. While working on my honors thesis, I helped develop a design for an upper extremity exoskeleton based on the Wilmer orthosis design for Mayo Clinic. Building upon the design of an orthosis, for the master’s thesis, I developed an FSR control system that is designed using a Wheatstone bridge circuit that can provide a clean reliable signal as compared to the current EMG setup.
ContributorsCarlton, Bryan (Author) / Sugar, Thomas (Thesis advisor) / Aukes, Daniel (Committee member) / Hollander, Kevin (Committee member) / Arizona State University (Publisher)
Created2023
Description
Urban search and rescue (USAR) teams may use Artificial Social Intelligence (ASI) agents to aid teams in adapting to dynamic environments, minimize risk, and increase mission assurance and task performance. This thesis underlines the relationship between vocal pitch, stress, and team performance from a recent experiment conducted in a simulated USAR synthetic task environment (STE). The simulated USAR-STE is a platform to use ASI as an advisor to intervene in the human team members’ cognitive processes, which aims to reduce risk to task execution and to maintain team performance. Three heterogeneous and interdependent roles interact via voice communication to search and rescue the victims: (1) medic -rescues victims and identifies the severity of injuries; (2) transporter -moves victims to their designated zone based on injury severity; (3) engineer -removes hazardous material such as rubble from a room or hallway that is blocking passage. Different speeds are associated with each role, such as medic, transporter, and engineer. Medic has a default speed; the transporter has times two over the default speed; the engineer has the slowest speed. In a total of 45 teams, three ASI conditions, manipulated based on ASI intervention communication length and frequency, were analyzed. Each team participated in two 15-min missions. The results indicate a U-shaped relationship between the transporter’s pitch and a change in team performance. A possible explanation for this significance is the task and role design. The transporter may have the most central role in voice communication because when the transporter is under varying levels of workload and stress, and thus voice pitch has a complex relationship with performance for that role.
ContributorsCLARK, JESKA (Author) / Cooke, Nancy J (Thesis advisor) / Gutzwiller, Robert (Committee member) / Gray, Rob (Committee member) / Arizona State University (Publisher)
Created2023
Description
In higher education, teacher empathy is a term that refers to the empathetic skills of teachers and has been researched since the 1980s. Multiple studies in fields such as medicine, nursing and psychology have shown that teacher empathy has reduced teacher burnout, improved teacher satisfaction and student performance. Within engineering education, there is increased research on empathy in recent years, but primarily aimed at introducing and improving empathetic skills of engineering students. There is little research on teacher empathy within engineering education. In my current study, I explored the potential longitudinal impact in perception of teacher empathy among three engineering faculty members as they utilized empathetic actions while teaching a second-year engineering course. I also explored the motivations and challenges that could arise in teacher empathy implementation. I used the Model of Empathy Framework developed by Walther and colleagues to define the complex attributes of empathy in an engineering context. I chose Teacher Action Research (TAR) methodology to provide agency to my three participants and research with them instead of on them. TAR allowed the participants to choose the empathetic actions they want to implement and to iterate when they feel appropriate. I found that all three participants had positive outcomes in their classrooms. Reduced teacher burnout, improved teacher satisfaction, and better student performance were some of the major benefits of teacher empathy that aligned with prior research. Improved confidence in their empathetic skills was observed for two participants as they showed positive evolution of their perception about teacher empathy. The other participant did not have any significant longitudinal impact in perception but was able to increase the number of empathetic approaches he could use in his classroom. External situations such as classroom technology malfunctions, having meetings or classes immediately before a class and balancing between being empathetic and being tough were some of the major challenges. Findings indicate that similar positive benefits as found in other disciplines can be realized within engineering education. The outcome of this study could be used by Learning and Teaching Centers Department Heads and University Deans to expand the implementation of teacher empathy within a college or university setting.
ContributorsSundaram, Bala Vignesh (Author) / Kellam, Nadia (Thesis advisor) / Carberry, Adam (Committee member) / Artiles, Mayra (Committee member) / Arizona State University (Publisher)
Created2023
Description
Nanoparticle (NP) assembly is critical where NPs are organized into complex superstructures through direct and indirect interactions. Long-range NP orders have nanoscale locational selectivity, orientational alignment, and scalable micropatterning, which are indispensable for enabling multiple functionalities and improving the performances of different systems. Though nanoparticles can self-assemble into organized nanostructures via simple drying thermodynamics, scalability has been a primary issue. Thus, this research focuses on more scalable manufacturing for directed NP assembly. First, 3D printing was used for template fabrications with varying topology features. Next, nanoparticle engineering with colloidal and surface studies leads to desirable NP packing on template surfaces. Finally, the processed devices will also demonstrate a few applications of surface micropatterning with nanoscale particle orders. Specifically, a few manufacturing procedures involve (i) stereolithography (SLA)/layer-by-layer dip coating, (ii) continuous liquid interface projection (CLIP)/ink writing, (iii) fused deposition melting (FDM)/direct ink writing, and (iv) multiphase direct ink writing (MDIW)/wet etching. To demonstrate the applicability of hybrid manufacturing, a broad range of nanoparticles, including carbon nanofibers (CNFs), MXene nanoflakes, and boron nitride nanoplatelets (BNNPs) were studied in this research. With well-managed template physics and NP dispersion control, nanoparticle orientational alignment and positional preferences are driven by short- and long-range intermolecular interactions (e.g., convective, van der Waals, capillarity, shear, and other secondary bonding). The printed devices displayed multifunctional properties, i.e., anisotropic conductivity, piezoresistive and chemical sensitivity, mechanical durability, and heat dissipation capabilities, for microelectronic applications. This fabrication technique shows enormous potential for rapid, scalable, and low-cost manufacturing of hierarchical structures, especially for micropatterning of nanoparticles not easily accessible through conventional processing methods.
ContributorsJambhulkar, Sayli (Author) / Song, Kenan (Thesis advisor) / Arizona State University (Publisher)
Created2023
Description
This thesis encompasses a comprehensive research effort dedicated to overcoming the critical bottlenecks that hinder the current generation of neural networks, thereby significantly advancing their reliability and performance. Deep neural networks, with their millions of parameters, suffer from over-parameterization and lack of constraints, leading to limited generalization capabilities. In other words, the complex architecture and millions of parameters present challenges in finding the right balance between capturing useful patterns and avoiding noise in the data. To address these issues, this thesis explores novel solutions based on knowledge distillation, enabling the learning of robust representations. Leveraging the capabilities of large-scale networks, effective learning strategies are developed. Moreover, the limitations of dependency on external networks in the distillation process, which often require large-scale models, are effectively overcome by proposing a self-distillation strategy. The proposed approach empowers the model to generate high-level knowledge within a single network, pushing the boundaries of knowledge distillation. The effectiveness of the proposed method is not only demonstrated across diverse applications, including image classification, object detection, and semantic segmentation but also explored in practical considerations such as handling data scarcity and assessing the transferability of the model to other learning tasks. Another major obstacle hindering the development of reliable and robust models lies in their black-box nature, impeding clear insights into the contributions toward the final predictions and yielding uninterpretable feature representations. To address this challenge, this thesis introduces techniques that incorporate simple yet powerful deep constraints rooted in Riemannian geometry. These constraints confer geometric qualities upon the latent representation, thereby fostering a more interpretable and insightful representation. In addition to its primary focus on general tasks like image classification and activity recognition, this strategy offers significant benefits in real-world applications where data scarcity is prevalent. Moreover, its robustness in feature removal showcases its potential for edge applications. By successfully tackling these challenges, this research contributes to advancing the field of machine learning and provides a foundation for building more reliable and robust systems across various application domains.
ContributorsChoi, Hongjun (Author) / Turaga, Pavan (Thesis advisor) / Jayasuriya, Suren (Committee member) / Li, Wenwen (Committee member) / Fazli, Pooyan (Committee member) / Arizona State University (Publisher)
Created2023
Description
This paper explores to mitigate the issue of Formula SAE brakes vaporizing by creating a computational model to determine when the fluid may boil given a velocity profile and brake geometry. The paper explores various parameters and assumptions and how they may lead to error determining when the brake fluid will vaporize. Common assumptions such as a constant convection coefficient are questioned throughout the paper and compared to methods requiring higher computational power. Throughout this model, a significant dependence on the heat partition factor is found on the final steady state temperature of the brake fluid is found, and a sensitivity analysis is performed to determine the effect of its variation.
ContributorsWesterhoff, Andrew (Author) / Kwon, Beomjin (Thesis director) / Milcarek, Ryan (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
Description
This thesis presents a comprehensive investigation into the design of roller coasters. The study includes an overview of various roller coaster types, cart design, brake design, lift hill and launch design, support design, and roller coaster safety. Utilizing No Limits 2 to design the layout and CAD software for component design, a scale model roller coaster was designed. The physics of the roller coaster and its structures were analyzed and a scale model was produced. Afterward, an accelerometer was used to collect G force data as the cart moved along the track. However, the collected data differed from the expected results, as the launch speed was higher than predicted due to more friction than anticipated. As a result, further optimization of the design and models used to design the scale model roller coasters is necessary.
ContributorsJohnson, Kayla (Author) / Cardinale, Matthew (Co-author) / Murthy, Raghavendra (Thesis director) / Singh, Anoop (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
Description
This thesis presents a comprehensive investigation into the design of roller coasters. The study includes an overview of various roller coaster types, cart design, brake design, lift hill and launch design, support design, and roller coaster safety. Utilizing No Limits 2 to design the layout and CAD software for component design, a scale model roller coaster was designed. The physics of the roller coaster and its structures were analyzed and a scale model was produced. Afterward, an accelerometer was used to collect G force data as the cart moved along the track. However, the collected data differed from the expected results, as the launch speed was higher than predicted due to more friction than anticipated. As a result, further optimization of the design and models used to design the scale model roller coasters is necessary.
ContributorsCardinale, Matthew (Author) / Johnson, Kayla (Co-author) / Murthy, Raghavendra (Thesis director) / Singh, Anoop (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
Description
For decades, engineering scholarship has presented data to address the underrepresentation of Black womxn in the engineering doctoral community. American Society of Engineering Education (ASEE)’s Engineering by the Numbers Report (2021) statistically showed that only 57 Black womxn out of 10,037 scholars received engineering doctorates in 2021. Engineering scholars have theorized about constructs ranging from whiteness to explain the system, to doctoral socialization to explain the culture, to retention explain the experiences. Yet, even with the plethora of scholarship, the problem of underrepresentation has remained consistent with limited action towards change from the faculty, the program, or the institution. Therefore, I aim to address this problem by cultivating emotional resonance toward action within the engineering community regarding engineering doctoral program underrepresentation for Black womxn. Using Arts-Based Research (ABR) and Black Feminist Thought (BFT), this dissertation illustrates the engineering PhD spirit-murdering experiences of Black womxn. Six Homegirls intellectually contributed to this study by sharing their time and experiences through artistic expressions and homegirl conversations. Through the lens of BFT’s matrix of domination, the composite blog shows that spirit-murdering for these Homegirls: 1) is a targeted act that is dehumanizing 2) occurs because of the aloof nature and capitalist ideals of the engineering academy, and 3) causes further conflict in negotiating identities as Black, woman, professional, researcher, and student. Leaning on BFT’s grounding as an Afrocentric methodological approach, the composite poem illustrates that these Homegirls: 1) have a common, understood epistemology because of their shared experiences of being Black and woman in their current, multi-layered social locations, 2) identify strongly with their positionality and values while describing their outsider-within status, and 3) experience spirit-murdering in an emotional, intellectual, and spiritual way that then results in physical manifestations. Rooted in BFT’s ethic of caring, the hip-hop mixtape’s progression describes homegirl’s spirit-renewal tactics as: 1) owning their professional identity, 2) dispelling projected biases, stereotypes, and aggressions, 3) calling out inequities in their interpersonal relationships and program culture, 4) learning to set boundaries to protect themselves, and 5) standing on their ways of knowing and being.
ContributorsNicole, Fantasi (Author) / Coley, Brooke C. (Thesis advisor) / Bekki, Jennifer (Committee member) / Holly, Jr., James (Committee member) / Arizona State University (Publisher)
Created2023
Description
Humans possess the ability to entrain their walking to external pulses occurring atperiods similar to their natural walking cadence. Expanding the basin of entrainment has become a promising option for gait rehabilitation for those affected by
hemiparesis. Efforts to expand the basin have utilized either conventional fixed-speed
treadmill setups, which require significant alteration to natural walking biomechanics;
or overground walking tracks, which are largely impractical. In this study, overground
walking was simulated using an actively self-pacing variable speed treadmill, and periodic hip flexion perturbations (≈ 12 Nm) were applied about a subject using a Soft
Robotic Hip Exoskeleton. This study investigated the effectiveness of conducting gait
entrainment rehabilitation with simulated overground walking to improve the success
rate of entrainment at high frequency conditions. This study also investigated whether
simulated overground walking can preserve natural biomechanics by examining stride
length and normalized propulsive impulse at various conditions. Participants in this
study were subjected to four perturbation frequencies, ranging from their naturally
preferred gait frequency up to 30% faster. Each subject participated in two days of
testing: one day subjects walked on a conventional fixed-speed treadmill, and another
day on a variable speed treadmill. Results showed that subjects were more frequently
able to entrain to the fastest perturbation frequency on the variable speed treadmill.
Results also showed that natural biomechanics were preserved significantly better
on the variable speed treadmill across all accelerated perturbation frequencies. This
study showed that simulated overground walking can aid in extending the basin of
entrainment while preserving natural biomechanics during gait entrainment, which is
a promising development for gait rehabilitation. However, a comparative study on
neurologically disordered individuals is necessary to quantify the clinical relevance of
these findings.
ContributorsCarlson, Evan Han (Author) / Lee, Hyunglae (Thesis advisor) / Marvi, Hamid (Committee member) / Vanderlinden, Alyssa (Committee member) / Arizona State University (Publisher)
Created2023