Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Electrical and Computer Engineering (12)
- Biomedical Engineering and Bioengineering (8)
- Power and Energy (8)
- Physical Sciences and Mathematics (7)
- Computer Engineering (6)
-
- Computer Sciences (6)
- Artificial Intelligence and Robotics (5)
- Biomechanics and Biotransport (5)
- Mechanical Engineering (4)
- Biomechanical Engineering (3)
- Chemical Engineering (3)
- Materials Science and Engineering (3)
- Robotics (3)
- Theory and Algorithms (3)
- Nanoscience and Nanotechnology (2)
- Social and Behavioral Sciences (2)
- Aerospace Engineering (1)
- Biological Engineering (1)
- Biomedical (1)
- Biomedical Devices and Instrumentation (1)
- Child Psychology (1)
- Clinical Psychology (1)
- Disability Studies (1)
- Engineering Physics (1)
- Metallurgy (1)
- Multi-Vehicle Systems and Air Traffic Control (1)
- Other Aerospace Engineering (1)
- Other Biomedical Engineering and Bioengineering (1)
- Other Computer Sciences (1)
Articles 1 - 26 of 26
Full-Text Articles in Engineering
Investigating New Methods To Develop Perovskite Solar Cells, Amani Hussain Alfaifi
Investigating New Methods To Develop Perovskite Solar Cells, Amani Hussain Alfaifi
Electronic Theses and Dissertations
Discovering the potential of organic-inorganic metal halide perovskites (MHP) as a harvesting material in solar cells has strongly affected the research direction in solar energy. The fascinating optical and electronic properties offered by MHP combined with tremendous effort from scientists around the world have improved the efficiency to about 25% in a decade.
In the first part of the dissertation, we studied the lamination process as a new fabrication method for producing self-encapsulated perovskite solar cells based on laminating half stacks,as opposed to the conventional layer-by-layer method. Our work focused on optimizing the lamination process of complex triple cations perovskite …
Thermally Driven Spin Transport In Ferromagnetic Metals, Wafa Saud Aljuaid
Thermally Driven Spin Transport In Ferromagnetic Metals, Wafa Saud Aljuaid
Electronic Theses and Dissertations
Since the discovery in 2008, the spin Seebeck effect has become one of the most active topics in the spin caloritronics research field. It opened a new way to create spin current by a combination of magnetic fields and heat. A temperature gradient in ferromagnetic (FM) metals generates a ow of spin current due to split of spin chemical potential between spin up and spin down electrons. This thermal spin current has been detected using an attached nonmagnetic heavy metal with large spin Hall angle via the inverse spin hall effect (ISHE). A voltage signal is generated since the nonmagnetic …
Experimental Investigation Of Low-Voltage Silicon Carbide (Sic) Semiconductor Devices For Power Conversion Applications, Saleh Salem H. Alharbi
Experimental Investigation Of Low-Voltage Silicon Carbide (Sic) Semiconductor Devices For Power Conversion Applications, Saleh Salem H. Alharbi
Electronic Theses and Dissertations
Enhancing the performance and efficiency of power converter systems requires fast-switching power devices with considerably low switching and conduction losses. Silicon (Si) semiconductor devices are the essential components in electronic converter designs, and their behaviors and switching characteristics determine the system’s overall performance and efficiency. These conventional Si devices are nearing to hit their physical and operational limits in meeting power converter requirements with respect to high temperature and large voltage conditions. However, silicon carbide (SiC) power devices enable greater converter efficiency and better power density, particularly under hard switching frequencies and high output voltages due to their outstanding material …
Experimental Evaluation Of Medium-Voltage Cascode Gallium Nitride (Gan) Devices For Bidirectional Dc–Dc Converters, Salah Salem H. Alharbi
Experimental Evaluation Of Medium-Voltage Cascode Gallium Nitride (Gan) Devices For Bidirectional Dc–Dc Converters, Salah Salem H. Alharbi
Electronic Theses and Dissertations
As renewable energy sources, such as photovoltaic (PV) cells and wind turbines, are rapidly implemented in DC microgrids, energy storage systems play an increasingly significant role in ensuring uninterrupted power supply and in supporting the reliability and stability of microgrid operations. Power electronics, especially bidirectional DC–DC converters, are essential parts in distributed energy storage and alternative energy systems because of their grid synchronization, DC power management, and bidirectional power flow capabilities. While there is increasing demand for more efficient, compact, and reliable power converters in numerous applications, most existing power converters are hindered by traditional silicon (Si) based semiconductors, which …
Fluid Dynamics Characterization Of Transcatheter Aortic Valves, Mohammed Barakat
Fluid Dynamics Characterization Of Transcatheter Aortic Valves, Mohammed Barakat
Electronic Theses and Dissertations
Aortic stenosis due to degenerative calcific aortic valvular disease is the most reason for aortic valve replacement in developed countries. Aortic stenosis affects up to 7% of the world population, and current clinical data indicate that the number of the affected people could be triple by 2050, due to population ageing and health lifestyle. Transcatheter aortic valve replacement (TAVR) was introduced as a minimal invasive treatment of severe aortic stenosis. Even though surgical aortic valve replacement (SAVR) is considered the golden standard treatment for severe aortic stenosis patients, TAVR showed equivalent or even superior outcome compare to SAVR. Currently, transcatheter …
Xylo-Bot: A Therapeutic Robot-Based Music Platform For Children With Autism, Huanghao Feng
Xylo-Bot: A Therapeutic Robot-Based Music Platform For Children With Autism, Huanghao Feng
Electronic Theses and Dissertations
Children with Autism Spectrum Disorder (ASD) experience deficits in verbal and nonverbal communication skills, including motor control, emotional facial expressions, and eye gaze / joint attention. This Ph.D. dissertation focuses on studying the feasibility and effectiveness of using a social robot, called NAO, and a toy music instrument, xylophone, at modeling and improving the social responses and behaviors of children with ASD. In our investigation, we designed an autonomous social interactive music teaching system to fulfill this mission.
A novel modular robot-music teaching system consisting of three modules is presented. Module 1 provides an autonomous self-awareness positioning system for the …
Developing Machine Learning Algorithms For Behavior Recognition From Deep Brain Signals, Hosein Golshan Mojdehi
Developing Machine Learning Algorithms For Behavior Recognition From Deep Brain Signals, Hosein Golshan Mojdehi
Electronic Theses and Dissertations
Parkinson’s disease (PD) is a neurodegenerative condition and movement disorder that appears with symptoms such as tremor, rigidity of muscles and slowness of movements. Deep brain stimulation (DBS) is an FDA-approved surgical therapy for essential tremor and PD. Despite the fact that DBS substantially alleviates the motor signs of PD, it can cause cognitive side effects and speech malfunction mainly due to the lack of adaptivity and optimality of the stimulation signal to the patients’ current state. A behavior-adapted closed-loop DBS system may reduce the side effects and power consumption by adjusting the stimulation parameters to patients’ need.
Behavior recognition …
Deep Siamese Neural Networks For Facial Expression Recognition In The Wild, Wassan Hayale
Deep Siamese Neural Networks For Facial Expression Recognition In The Wild, Wassan Hayale
Electronic Theses and Dissertations
The variation of facial images in the wild conditions due to head pose, face illumination, and occlusion can significantly affect the Facial Expression Recognition (FER) performance. Moreover, between subject variation introduced by age, gender, ethnic backgrounds, and identity can also influence the FER performance. This Ph.D. dissertation presents a novel algorithm for end-to-end facial expression recognition, valence and arousal estimation, and visual object matching based on deep Siamese Neural Networks to handle the extreme variation that exists in a facial dataset. In our main Siamese Neural Networks for facial expression recognition, the first network represents the classification framework, where we …
Microgrid-Enabled Reactive Power Support To Enhance Grid Economics, Sarhan Hasan
Microgrid-Enabled Reactive Power Support To Enhance Grid Economics, Sarhan Hasan
Electronic Theses and Dissertations
Reactive power plays an essential role in voltage control and stability in electric power systems. Various Volt/VAR techniques are utilized in electric power systems to maintain the voltage profile within defined acceptable limits and accordingly provide reliability and stability. Reactive power has been commonly generated through large-scale synchronous generators or distributed capacitor banks to provide proper transmission and distribution level system management, however, reactive power can be further used as an effective means to reduce total system operation cost. In this dissertation, an optimal reactive power model is proposed to determine the optimal nodal reactive powers that result in the …
Automated Recognition Of Facial Affect Using Deep Neural Networks, Behzad Hasani
Automated Recognition Of Facial Affect Using Deep Neural Networks, Behzad Hasani
Electronic Theses and Dissertations
Automated Facial Expression Recognition (FER) has been a topic of study in the field of computer vision and machine learning for decades. In spite of efforts made to improve the accuracy of FER systems, existing methods still are not generalizable and accurate enough for use in real-world applications. Many of the traditional methods use hand-crafted (a.k.a. engineered) features for representation of facial images. However, these methods often require rigorous hyper-parameter tuning to achieve favorable results.
Recently, Deep Neural Networks (DNNs) have shown to outperform traditional methods in visual object recognition. DNNs require huge data as well as powerful computing units …
Deep Reinforcement Learning For The Optimization Of Building Energy Control And Management, Jun Hao
Deep Reinforcement Learning For The Optimization Of Building Energy Control And Management, Jun Hao
Electronic Theses and Dissertations
Most of the current game-theoretic demand-side management methods focus primarily on the scheduling of home appliances, and the related numerical experiments are analyzed under various scenarios to achieve the corresponding Nash-equilibrium (NE) and optimal results. However, not much work is conducted for academic or commercial buildings. The methods for optimizing academic-buildings are distinct from the optimal methods for home appliances. In my study, we address a novel methodology to control the operation of heating, ventilation, and air conditioning system (HVAC).
We assume that each building in our campus is equipped with smart meter and communication system which is envisioned in …
Satellite Constellation Deployment And Management, Joseph Ryan Kopacz
Satellite Constellation Deployment And Management, Joseph Ryan Kopacz
Electronic Theses and Dissertations
This paper will review results and discuss a new method to address the deployment and management of a satellite constellation. The first two chapters will explorer the use of small satellites, and some of the advances in technology that have enabled small spacecraft to maintain modern performance requirements in incredibly small packages.
The third chapter will address the multiple-objective optimization problem for a global persistent coverage constellation of communications spacecraft in Low Earth Orbit. A genetic algorithm was implemented in MATLAB to explore the design space – 288 trillion possibilities – utilizing the Satellite Tool Kit (STK) software developers kit. …
Aggregated Der Management In Advanced Distribution Grids, Mohsen Mahoor
Aggregated Der Management In Advanced Distribution Grids, Mohsen Mahoor
Electronic Theses and Dissertations
Evolution of modern power systems are more distinct in distribution grids, where the growing integration of microgrids as well as distributed energy resources (DERs), including renewable energy resources, electric vehicles (EVs), and energy storage, poses new challenges and opportunities to grid management and operation. Rapid growth of distribution automation as well as equipment monitoring technologies in the distribution grids further offer new opportunities for distribution asset management. The idea of aggregated DERs is proposed as a remedy to streamline management and operation of advanced distribution grids, as discussed under three subjects in this dissertation. The first subject matter focuses on …
Real-Time Detection Of Demand Manipulation Attacks On A Power Grid, Srinidhi Madabhushi
Real-Time Detection Of Demand Manipulation Attacks On A Power Grid, Srinidhi Madabhushi
Electronic Theses and Dissertations
An increased usage in IoT devices across the globe has posed a threat to the power grid. When an attacker has access to multiple IoT devices within the same geographical location, they can possibly disrupt the power grid by regulating a botnet of high-wattage IoT devices. Based on the time and situation of the attack, an adversary needs access to a fixed number of IoT devices to synchronously switch on/off all of them, resulting in an imbalance between the supply and demand. When the frequency of the power generators drops below a threshold value, it can lead to the generators …
Facial Action Unit Detection With Deep Convolutional Neural Networks, Siddhesh Padwal
Facial Action Unit Detection With Deep Convolutional Neural Networks, Siddhesh Padwal
Electronic Theses and Dissertations
The facial features are the most important tool to understand an individual's state of mind. Automated recognition of facial expressions and particularly Facial Action Units defined by Facial Action Coding System (FACS) is challenging research problem in the field of computer vision and machine learning. Researchers are working on deep learning algorithms to improve state of the art in the area. Automated recognition of facial action units has man applications ranging from developmental psychology to human robot interface design where companies are using this technology to improve their consumer devices (like unlocking phone) and for entertainment like FaceApp. Recent studies …
Graphene/Oxide Interactions With Polymer Networks Modeled Using Molecular Dynamics, Matthew Alan Reil
Graphene/Oxide Interactions With Polymer Networks Modeled Using Molecular Dynamics, Matthew Alan Reil
Electronic Theses and Dissertations
Due to its unique physical properties, graphene has shown great promise as an additive to Polymer Matrix Composites (PMCs) for material property enhancement. Achieving homogeneous dispersion of the graphene platelets within a polymeric network is critical to realizing these enhancements. Research has shown that achieving homogeneous dispersion of graphene platelets within PMCs is challenging as graphene is immiscible with most polymeric networks. This work used Molecular Dynamics (MD) simulations to demonstrate dispersion of graphene platelets within PMCs is inhibited by molecular surface charge potentials. Further simulations were conducted to demonstrate functionalized forms of graphene, specifically graphene oxide, have altered surface …
Nyku: A Social Robot For Children With Autism Spectrum Disorders, Dan Stephan Stoianovici
Nyku: A Social Robot For Children With Autism Spectrum Disorders, Dan Stephan Stoianovici
Electronic Theses and Dissertations
The continued growth of Autism Spectrum Disorders (ASD) around the world has spurred a growth in new therapeutic methods to increase the positive outcomes of an ASD diagnosis. It has been agreed that the early detection and intervention of ASD disorders leads to greatly increased positive outcomes for individuals living with the disorders. Among these new therapeutic methods, Robot-Assisted Therapy (RAT) has become a hot area of study. Recent works have shown that high functioning ASD children have an affinity for interacting with robots versus humans. It is proposed that this is due to a less complex set of communication …
Power System Frequency Control And Stability Analysis With Increasing Renewable Energy Penetration Level, Weihang Yan
Power System Frequency Control And Stability Analysis With Increasing Renewable Energy Penetration Level, Weihang Yan
Electronic Theses and Dissertations
With the ever-increasing penetration level of renewable energy generation units and the replacement of traditional synchronous generators, the issues associated with the deteriorated performance of power system frequency regulation and potential grid frequency instability become more significant. In this dissertation, the inertial control algorithms are investigated and analyzed for power electronics converter in a renewable energy generation unit. The concept and design of Virtual Synchronous Generator are comprehensively discussed, such that the small-signal stability and frequency stability of power systems with high renewable energy penetration level can be enhanced. Moreover, both nonlinear dynamic model and small-signal linearization of Virtual Synchronous …
Impact Of Grid-Following And Grid-Forming Ders On Resilient Operation Of Holonic Grid, Ali M. Alsenan
Impact Of Grid-Following And Grid-Forming Ders On Resilient Operation Of Holonic Grid, Ali M. Alsenan
Electronic Theses and Dissertations
This thesis investigates how different distributed energy resources (DERs) impact the resilience operation of a holonic grid. The holonic grid consists of two or more connected microgrids and /or provisional microgrids (PMGs). The type of the DER, i.e., grid-forming or grid-following, affects the operations of the holonic grid, particularly during the islanded mode. To study this emerging and timely topic, a resilience-oriented holonic grid optimal operation model is proposed. This model carefully formulates the operations of both grid-forming and grid-following DERs. A variable value of lost load (VoLL) is further employed in the proposed model to help quantify and monetize …
In Vivo Data Capture Using Hssr For Calibration Of Computational Models, Thor Erik Andreassen
In Vivo Data Capture Using Hssr For Calibration Of Computational Models, Thor Erik Andreassen
Electronic Theses and Dissertations
Computational modeling is a vital tool for understanding and evaluating healthy and unhealthy function of the musculoskeletal aspects of the human body. However, the accuracy of the musculoskeletal models depends significantly on the accuracy of the input data used to calibrate various behavioral parameters of the model. To date, most computational models have been built using generic in vitro data, mostly because of a lack of accurate and meaningful datasets from in vivo testing. The next major step in computational modeling is to create subject-specific computational models using calibration data taken from in vivo testing. The overall goal was to …
Development Of A Clinical Marker-Less Motion Capture System For Patient Monitoring, Abigail Eustace
Development Of A Clinical Marker-Less Motion Capture System For Patient Monitoring, Abigail Eustace
Electronic Theses and Dissertations
The ability to understand human movement is beneficial for deciding surgical procedures, tracking disease progression over time and helping with patient rehabilitation. The current gold-standard for collecting human movement is the use of 3-dimensional marker-based systems. Several studies have presented the many limitations to the current gold-standard that reduces the number of people who are able to benefit from a gait analysis. Those limitations in the current gold-standard include the requirements of large laboratory space, costly equipment, long instrumentation and collection time, and the potential for motion artifact from markers being placed on the skin. The purpose of this study …
Ultrasonic-Based Condition Assessment Of Wooden Utility Poles, Yishi Lee
Ultrasonic-Based Condition Assessment Of Wooden Utility Poles, Yishi Lee
Electronic Theses and Dissertations
More than 300 million utility poles shoulder the utility grid in the United States. However, the ineffectiveness of the current inspection process causes roughly a third of utility poles removed from the service deemed suitable for reuse. Due to the utterly essential role of the power infrastructure, budget shrinkage, and the structural degradation of the modern distribution grid, this Ph.D. dissertation addresses the challenges by proposing a physics-based signal analysis method with a jointly developed ultrasonic UB1000 system c to enhance the objectivity in ultrasonic-based nondestructive evaluation (NDE). The proposed methodology has been deployed commercially in the field and featured …
The Effects And Analysis Of Implant Type And Surgical Approach In Total Hip Arthroplasty Dislocation Resistance, Brittany Marshall
The Effects And Analysis Of Implant Type And Surgical Approach In Total Hip Arthroplasty Dislocation Resistance, Brittany Marshall
Electronic Theses and Dissertations
Total hip arthroplasty (THA) is one of the most successful orthopaedic surgeries performed, in which the hip joint is reconstructed to decrease pain and to improve the functionality to the joint. Although these surgeries are very successful, there still remain areas for improvement, such as failures due to instability and dislocation of the implanted joint. The purpose of this thesis is to investigate the effect of surgical entrance approach on dislocation, the effect of implant type, and the effect of capsule repair and closure. The need to quantify the resistance to dislocation is important in understanding the effect that each …
A Longitudinal Examination Of Biomechanical Balance And Quantitative Multidomain Assessments During Recovery Following Sport-Related Concussion, Moira Kate Pyrhoda
A Longitudinal Examination Of Biomechanical Balance And Quantitative Multidomain Assessments During Recovery Following Sport-Related Concussion, Moira Kate Pyrhoda
Electronic Theses and Dissertations
Sport-related concussion is an inherent risk to athlete health in contact and collision sports. Both short- and long-term risks are associated with the injury. Short-term, athletes may develop post-concussion syndrome (PCS), the persistence of cognitive, physical, and emotional symptoms for weeks or months after injury. Athletes who return to play (RTP) prematurely are at increased risk for lower extremity injury and repeated concussion injuries. Long-term, history of multiple concussions have been linked to neurodegenerative diseases. Due to these risks, concussion assessments must be sensitive to the injury and useful in the diagnosis, recovery, and RTP phases of the injury.
Sideline …
Transcatheter Mitral Valve Replacement: Structural And Hemodynamic Analysis, Saba Ravaghi
Transcatheter Mitral Valve Replacement: Structural And Hemodynamic Analysis, Saba Ravaghi
Electronic Theses and Dissertations
Transcatheter mitral valve replacement (TMVR) is being developed to become a substitute therapy for surgery in prohibitive or high surgical risk patients to treat severe mitral regurgitation. A limited number of TMVR systems are under clinical evaluation. However, transcatheter mitral valve (TMV) long-term durability and hemodynamic performance is not known. TMV durability and hemodynamics must match with that of surgical bioprostheses for potential commercialization of TMVR. Experimental and computational approaches were used to find the leaflets’ three-dimensional anisotropic mechanical properties in a transcatheter Edwards SAPIEN 3 valve and a surgical Carpentier-Edwards PERIMOUNT Magna mitral valve and finite element (FE) simulations …
Effects On Initial Fixation Of Cementless Tibial Trays In Total Knee Arthroplasty, Brooke Fritts Thompson
Effects On Initial Fixation Of Cementless Tibial Trays In Total Knee Arthroplasty, Brooke Fritts Thompson
Electronic Theses and Dissertations
Bone mineral density (BMD), among other factors, largely effect the initial stability of the cementless tibial tray component in a total knee replacement (TKR), where increased motion at the tray-bone interface hinders bony ingrowth. With a lack of bony ingrowth, the cementless implant will not experience long-term success. Understanding which factors influence initial stability yields insight into surgical technique considerations and help inform a surgeon’s implant choice. The objective of this study was to evaluate factors influencing the initial stability of cementless tibial trays using a 6-degree of freedom (6-DOF) robotic joint simulator, the AMTI VIVO, and combined loading scenarios …