Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Browse all Theses and Dissertations

Discipline
Keyword
Publication Year
File Type

Articles 481 - 510 of 1369

Full-Text Articles in Engineering

Development Of A Human-Ai Teaming Based Mobile Language Learning Solution For Dual Language Learners In Early And Special Educations, Saurabh Shukla Jan 2018

Development Of A Human-Ai Teaming Based Mobile Language Learning Solution For Dual Language Learners In Early And Special Educations, Saurabh Shukla

Browse all Theses and Dissertations

Learning English as a secondary language is often an overwhelming challenge for dual language learners (DLLs), whose first language (L1) is not English, especially for children in early education (PreK-3 age group). These early DLLs need to devote a considerable amount of time learning to speak and read the language, in order to gain the language proficiency to function and compete in the classroom. Fear of embarrassment when mispronouncing words in front of others may drive them to remain silent; effectively hampering their participation in the class and overall curricular growth. The process of learning a new language can benefit …


Layer-To-Layer Physical Characteristics And Compression Behavior Of 3d Printed Acrylonitrile Butadiene Styrene Metastructures Fabricated Using Different Process Parameters, Sivani Patibandla Jan 2018

Layer-To-Layer Physical Characteristics And Compression Behavior Of 3d Printed Acrylonitrile Butadiene Styrene Metastructures Fabricated Using Different Process Parameters, Sivani Patibandla

Browse all Theses and Dissertations

Three-dimensional (3D) printing, a subset of additive manufacturing, is currently being explored heavily for actual part fabrication due to its ability to create complex objects with intricate internal features. There are several 3D printing technologies; however, the extrusion-based technology such as fused deposition modeling (FDM) is the widely used one owing to its low cost. The FDM method can be used to fabricate parts with different fill densities, fill patterns, and process parameters such as extruder temperature and print speed. In this research, influence of process parameters such as extruder temperature and speed on the physical characteristics such as the …


Multiple Drone Detection And Acoustic Scene Classification With Deep Learning, Hari Charan Vemula Jan 2018

Multiple Drone Detection And Acoustic Scene Classification With Deep Learning, Hari Charan Vemula

Browse all Theses and Dissertations

Classification of environmental scenes and detection of events in one's environment from audio signals enables one to create better-planning agents, intelligent navigation systems, pattern recognition systems, and audio surveillance systems. This thesis will explore the use of Convolutional Neural Networks(CNN'S) with spectrograms and raw audio waveforms as inputs to Deep Neural Networks with hand engineered features extracted from large-scale feature extraction schemes to identify the acoustic scenes and events. The first part focuses on building an audio pattern recognition system capable of detecting the if there are zero, one, or two DJI phantoms in the scene within the range of …


A Framework To Understand Emoji Meaning: Similarity And Sense Disambiguation Of Emoji Using Emojinet, Sanjaya Wijeratne Jan 2018

A Framework To Understand Emoji Meaning: Similarity And Sense Disambiguation Of Emoji Using Emojinet, Sanjaya Wijeratne

Browse all Theses and Dissertations

Pictographs, commonly referred to as `emoji’, have become a popular way to enhance electronic communications. They are an important component of the language used in social media. With their introduction in the late 1990’s, emoji have been widely used to enhance the sentiment, emotion, and sarcasm expressed in social media messages. They are equally popular across many social media sites including Facebook, Instagram, and Twitter. In 2015, Instagram reported that nearly half of the photo comments posted on Instagram contain emoji, and in the same year, Twitter reported that the `face with tears of joy’ emoji has been tweeted 6.6 …


Developing A Kinect Based Holoportation System, Soumya Chiday Jan 2018

Developing A Kinect Based Holoportation System, Soumya Chiday

Browse all Theses and Dissertations

Holographic communication and distributed collaboration offer great potential for empathic computing to help remove the cost, distance, language and expertise barriers in many social and economic activities. Recent advances in AR-enhanced communication as evident by Microsoft Holoportation technology demonstrate the progress toward fully immersive collaborations distributed and remotely. Current holoportation system requires the use of extensive camera-arrays and powerful server system due to the computation demand and sensory needs to capture and reconstruct the subject of interests Thus, they suffer in mobility and applicability in real-world scenarios. In this thesis, we present an ultra-portable holoportation system design that requires only …


Using Natural Language Processing And Machine Learning For Analyzing Clinical Notes In Sickle Cell Disease Patients, Shufa Khizra Jan 2018

Using Natural Language Processing And Machine Learning For Analyzing Clinical Notes In Sickle Cell Disease Patients, Shufa Khizra

Browse all Theses and Dissertations

Sickle Cell Disease (SCD) is a hereditary disorder in red blood cells that can lead to excruciating pain episodes. SCD causes the normal red blood cells to distort its shape and turn into sickle shape. The distorted shape makes the hemoglobin inflexible and stick to the walls of the vessels thereby obstructing the free flow of blood and eventually making the tissues suffer from lack of oxygen. The lack of oxygen causes serious problems including Acute Chest Syndrome (ACS), stroke, infection, organ damage, and over the lifetime an SCD can harm a persons spleen, brain, kidneys, eyes, bones. Sickling of …


Display And Analysis Of Tomographic Reconstructions Of Multiple Synthetic Aperture Ladar (Sal) Images, Bassirou Seck Jan 2018

Display And Analysis Of Tomographic Reconstructions Of Multiple Synthetic Aperture Ladar (Sal) Images, Bassirou Seck

Browse all Theses and Dissertations

Synthetic aperture ladar (SAL) is similar to synthetic aperture radar (SAR) in that it can create range/cross-range slant plane images of the illuminated scatters; however, SAL has wavelengths 10,000x smaller than SAR enabling a relatively narrow real aperture, diffraction limited beam widths. The relatively narrow real aperture resolutions allow for multiple slant planes to be created for a single target with reasonable range/aperture combinations. These multiple slant planes can be projected into a single slant plane projections (as in SAR). It can also be displayed as a 3-D image with asymmetric resolutions, diffraction limited in the dimension orthogonal to the …


Exploring Feedback Modalities Using Wearable Device For Complex Systems Training Programs, Layla Akilan Jan 2018

Exploring Feedback Modalities Using Wearable Device For Complex Systems Training Programs, Layla Akilan

Browse all Theses and Dissertations

This study examined the effectiveness of a wearable device in delivering various feedback modalities in an attempt to improve performance outcomes in complex systems. Secondarily this study looked at performance when feedback type was matched to preferred learning style according to VARK Learning Styles Inventory results. Participants were required to perform system monitoring and correct for system failures through key presses. Feedback was delivered through a smart watch and was based on response time performance. Feedback modalities included visual, auditory, and haptic feedback. Subjective ratings of situation awareness and mental workload were also examined. Results indicated that auditory feedback condition …


Constitutive Modeling Of Creep In Leaded And Lead-Free Solder Alloys Using Constant Strain Rate Tensile Testing, Eric Thomas Stang Jan 2018

Constitutive Modeling Of Creep In Leaded And Lead-Free Solder Alloys Using Constant Strain Rate Tensile Testing, Eric Thomas Stang

Browse all Theses and Dissertations

Environmental and safety concerns have necessitated a phase-out of lead-based alloys, which are often used in electronics solder applications. In order to properly assess suitable replacement materials, it is necessary to understand the deformation mechanisms relevant to the application. In the case of electronics solder, creep is an important mechanism that must be considered in the design of reliable devices and systems. In this study, Power-Law and Garofalo constitutive creep models were derived for two medium temperature solder alloys. The first alloy is known by the commercial name Indalloy 236 and is a quaternary alloy of lead, antimony, tin, and …


Novel Auto-Calibrating Neural Motor Decoder For Robust Prosthetic Control, Andrew Earl Montgomery Jan 2018

Novel Auto-Calibrating Neural Motor Decoder For Robust Prosthetic Control, Andrew Earl Montgomery

Browse all Theses and Dissertations

The overarching goal of this project is to develop novel neural motor decoders for prosthetic control. EMG decoders measure the activity from an intact but non-target muscle. Neural motor decoders transform the signal measured from the severed motor axons of the target muscle. A multi-scale, highly-realistic computer model of a spinal motor pool was developed (Allen & Elbasiouny, 2018) to serve as a computational platform for decoder development and testing. A firing rate-based algorithm was developed to transform the aggregate discharge of the motor pool into a command signal to control the simulated prosthetic MuJoCo hand. This algorithm was informed …


True-Average Current-Mode Control Of Dc-Dc Power Converters: Analysis, Design, And Characterization, Dalvir K. Saini Jan 2018

True-Average Current-Mode Control Of Dc-Dc Power Converters: Analysis, Design, And Characterization, Dalvir K. Saini

Browse all Theses and Dissertations

Energy efficient, wide-bandwidth, and well-regulated dc-dc power converters are in great demand in today's emerging technologies in areas such as medical, communication, aerospace, and automotive industries. In addition to design and selection of the converter components, a robust closed-loop modeling is very essential for reliable power-electronic systems. Two closed-loop control techniques for power converters exist: voltage-mode control and current-mode control. The principles of voltage-mode control have been explored in great depths by researchers over the last two decades. However, the dynamic modeling of current-mode controlled dc-dc power converters has many uncharted areas that needs careful attention. Two main methods exist …


The Pattern Of Sensory Axonal Endings Together With Synaptic Transmission Influence The Development Of Proprioceptive Circuits In The Spinal Cord, Yiyun Dai Jan 2018

The Pattern Of Sensory Axonal Endings Together With Synaptic Transmission Influence The Development Of Proprioceptive Circuits In The Spinal Cord, Yiyun Dai

Browse all Theses and Dissertations

Proprioceptive circuits provide information regarding limb position and movement status, and are essential to producing correctly executed motor behaviors. Exploring the mechanisms underlying the formation of proprioceptive circuits is therefore critical for understanding neurological disorders with altered motor coordination and for restoring circuits damaged by injury. One important proprioceptive circuit, the stretch reflex circuit, is formed between proprioceptive sensory neurons (PSNs) and motor neurons (MNs) that innervate the same muscle. Progress has been made in understanding the spatial organization of MNs based on their muscle-specific subpopulation identities, which contributes to the specificity of stretch reflex circuit formation. However, whether PSNs …


Electroceutical Therapy In Amyotrophic Lateral Sclerosis: A Novel Preliminary Study, Morgan Michelle Highlander Jan 2018

Electroceutical Therapy In Amyotrophic Lateral Sclerosis: A Novel Preliminary Study, Morgan Michelle Highlander

Browse all Theses and Dissertations

Amyotrophic Lateral Sclerosis (ALS) is a fatal, neurodegenerative disease that is characterized by the death of motoneurons. Life expectancy is only 3-5 years from diagnosis and current treatments only extend survival by 2-3 months. The mechanism of motoneuron death in ALS is still largely unknown, but abnormal motoneuron excitability has been extensively documented. Because the intrinsic excitability of a motoneuron is a defining measure of its normal function, characterizing and regulating motoneuron excitability has become one of the primary aims of ALS research. Although not previously explored in ALS, other clinical applications show the ability of certain electroceutical techniques to …


Regulation Of The Motor Output Of The Spinal Cord: Burst Firing Generation And Sensorimotor Integration, Amr A. Mahrous Jan 2018

Regulation Of The Motor Output Of The Spinal Cord: Burst Firing Generation And Sensorimotor Integration, Amr A. Mahrous

Browse all Theses and Dissertations

Spinal motoneurons are the final common path for motor signals. Thus, the firing activity recorded from spinal motoneurons or their axons in the ventral roots represents the motor output of the nervous system. This dissertation investigates two major phenomena that help generate and shape the neuronal motor output. Specialized groups of spinal neurons called central pattern generators (CPGs) are capable of orchestrating rhythmic bursting activity without involvement of the brain. This activity underlies stereotyped movements such as locomotion. If known, the ionic mechanisms responsible for generating this activity can offer new pharmacological interventions to restore walking in paralyzed patients with …


Consequences Of Trpm7 Kinase Inactivation In Immune Cells, Pavani Beesetty Jan 2018

Consequences Of Trpm7 Kinase Inactivation In Immune Cells, Pavani Beesetty

Browse all Theses and Dissertations

The characteristic feature of ubiquitously expressed transient receptor potential melastatin 7 (TRPM7) protein is the presence of a C-terminal atypical kinase domain fused to a cation channel domain. Even though this protein has been implicated in a number of physiological and pathological processes, the mechanisms regulating TRPM7 channel activity are poorly understood. In the present study, regulation of TRPM7 channel by its kinase activity was investigated using the TRPM7 kinase-dead knock-in mouse (KD mouse). These mice have a point mutation Lys1646Arg in the kinase region abrogating the kinase activity. Examining TRPM7 channel activity in KD peritoneal macrophages revealed that TRPM7 …


Steady-State And Small-Signal Modeling Of A-Source Converter, Agasthya Ayachit Jan 2018

Steady-State And Small-Signal Modeling Of A-Source Converter, Agasthya Ayachit

Browse all Theses and Dissertations

As the trend towards vehicle electrification, renewable energy, smart systems is increasing, the key enabling technology such as power electronics are becoming ever more important. Power electronics is the vital component of many applications in automotive, computer, data-centers, medical, aerospace, communication, green-energy, and manufacturing sectors. Major advancements in high efficiency, high power density, high voltage conversion ratio, and fast dynamic response power-electronic converters is evident both in research and industry, particularly at the topology level. A major contribution of this dissertation is the analysis, design, development, and dynamic modeling of a novel impedance-source topology termed as A-source converter, which potentially …


Characterization And Design Of Voltage-Mode Controlled Full-Bridge Dc/Dc Converter With Current Limit, Nathaniel R. Smith Jan 2018

Characterization And Design Of Voltage-Mode Controlled Full-Bridge Dc/Dc Converter With Current Limit, Nathaniel R. Smith

Browse all Theses and Dissertations

Advancements in Direct Current (DC) electrical power systems have enabled new functionality in many, varied applications. Discrete power semiconductor devices are increasing in efficiency, switching frequency, and power density, resulting in greater usage of DC power management and distribution methods, including DC/DC conversion. DC distribution lacks inherent capability to safely and effectively break fault current, particularly in mobile solutions, where larger and slower electromechanical switching devices are not optimal or feasible. One solution is to design a low-energy breaking point into a switching power supply. Simpler converter designs, with a lower number of switching devices, have been modeled and can …


Effect Of Process Parameters On The Surface Roughness And Mechanical Performance Of Additively Manufactured Alloy 718, Bo Ryan Whip Jan 2018

Effect Of Process Parameters On The Surface Roughness And Mechanical Performance Of Additively Manufactured Alloy 718, Bo Ryan Whip

Browse all Theses and Dissertations

Metal additive manufacturing (AM) is a method to create complex components in a layer-by-layer process. Currently, there is a lack of understanding in the processing-structure-properties-performance relationship, particularly related to defects inherent to the AM process. This work investigates the relationship of process parameters, as-built surface roughness, and mechanical performance for nickel-based superalloy 718 built using laser powder bed fusion. The surface roughness of components built using varied processing parameters was characterized using both nondestructive and destructive measurement techniques. Finite element analysis was used to study the stress concentration on surface profiles. Statistical correlations are presented between contour processing parameters and …


Low Velocity Impact And Rf Response Of 3d Printed Heterogeneous Structures, Sandeep Keerthi Jan 2017

Low Velocity Impact And Rf Response Of 3d Printed Heterogeneous Structures, Sandeep Keerthi

Browse all Theses and Dissertations

Three-dimensional (3D) printing, a form of Additive manufacturing (AM), is currently being explored to design materials or structures with required Electro-Mechanical-Physical properties. Microstrip patch antennas with a tunable radio-frequency (RF) response are a great candidate for 3D printing process. Due to the nature of extrusion based layered fabrication; the processed parts are of three-layer construction having inherent heterogeneity that affects structural and functional response. The purpose of this study is to identify the relationship between the anisotropy in dielectric properties of AM fabricated acrylonitrile butadiene styrene (ABS) substrates in the RF domain and resonant frequencies of associated patch antennas and …


Virtuo-Its: An Interactive Tutoring System To Teach Virtual Memory Concepts Of An Operating System, Venkata Krishna Kanth Musunuru Jan 2017

Virtuo-Its: An Interactive Tutoring System To Teach Virtual Memory Concepts Of An Operating System, Venkata Krishna Kanth Musunuru

Browse all Theses and Dissertations

Interactive tutoring systems are software applications that help individuals to learn difficult concepts. They can allow students to interact with ideas from essential mathematics to more complicated subjects like software engineering. This thesis concentrates on one such interactive tutoring system (ITS) designed for teaching concepts related to operating system virtual memory. Operating system concepts can be troublesome to learn without having someone or something to explain them. Even when an instructor is able to provide detailed explanations, it is still exceptionally difficult for students without a computer science foundation to comprehend these concepts. Students require a sophisticated set of mental …


Intelligent Tutoring System Effects On The Learning Process, Ali Talib Qasim Al-Aqbi Jan 2017

Intelligent Tutoring System Effects On The Learning Process, Ali Talib Qasim Al-Aqbi

Browse all Theses and Dissertations

The traditional education systems that have been used for several centuries have evolved very slowly and might be ineffective for addressing diverse learning styles and levels of preparation. This system is characterized by many students interacting with a single teacher, who is unable to address the individual needs of every student. Therefore, some students can become frustrated and fail to reach their educational potential. An Intelligent Tutoring System (ITS), which is a computer application used to provide students with one-to-one supplemental tutoring tailored to the student's learning style and pace, is of interest to educators for improving student learning. To …


Effects Of The Kinematic Model On Forward-Model Based Spotlight Sar Ecm, David T. Pyles Jan 2017

Effects Of The Kinematic Model On Forward-Model Based Spotlight Sar Ecm, David T. Pyles

Browse all Theses and Dissertations

Spotlight synthetic aperture radar (SAR) provides a high-resolution remote image formation capability for airborne platforms. SAR image formation processes exploit the amplitude, time, and frequency shifts that occur in the transmitted waveform due to electromagnetic propagation and scattering. These shifts are predictable through the SAR forward model which is dependent on the waveform parameters and emitter flight path. The approach to develop an electronic countermeasure (ECM) system that is founded on the SAR forward model implies that the ECM system should alter the radar's waveform in a manner that produces the same amplitude, time, and frequency shifts that a real …


Friction Stir Welding Between Similar And Dissimilar Materials, Khaled Yousif Ali Jan 2017

Friction Stir Welding Between Similar And Dissimilar Materials, Khaled Yousif Ali

Browse all Theses and Dissertations

This thesis focuses on the friction stir welding (FSW) between similar and dissimilar alloys. FSW is a solid state joining process that welds the work-pieces through a combination of heat generated by friction and mechanical stirring of the metals in the region of the joint. Being a solid state process, FSW can be used to weld alloys with significantly different melting points. This provides a significant benefit over traditional fusion welding process in a variety of applications in automotive, biomedical, aerospace, nuclear and petroleum industries. Two materials - an aluminum alloy (6061-T6, m.p. 582 - 652°C) and a steel (SAE …


Collaboratively Detecting Http-Based Distributed Denial Of Service Attack Using Software Defined Network, Ademola A. Ikusan Jan 2017

Collaboratively Detecting Http-Based Distributed Denial Of Service Attack Using Software Defined Network, Ademola A. Ikusan

Browse all Theses and Dissertations

Over the years, there have been a lot of attacks on the web servers of critical companies and organization. As much as these organizations tighten their security, it always tends not to be enough to stop all the attacks towards their servers. These attack vectors are so difficult to stop because of the technicalities behind the attack. Furthermore, there are different classes of distributed denial of service(DDoS) attacks such as the high rates (SYN Flood attacks, ARP Flood attacks, etc), low-rate(HTTP-GET, HTTP-POST). Although there are different ways to stop high rate DDoS attacks by traffic sampling and detecting malformed packets …


Finding Street Gang Member Profiles On Twitter, Lakshika Balasuriya Jan 2017

Finding Street Gang Member Profiles On Twitter, Lakshika Balasuriya

Browse all Theses and Dissertations

The crime and violence street gangs introduce into neighborhoods is a growing epidemic in cities around the world. Today, over 1.4 million people, belonging to more than 33,000 gangs, are active in the United States, of which 88% identify themselves as being members of a street gang. With the recent popularity of social media, street gang members have established online presences coinciding with their physical occupation of neighborhoods. Recent studies report that approximately 45% of gang members participate in online offending activities such as threatening, harassing individuals, posting violent videos or attacking someone on the street for something they said …


Model Preparation And User Interface Aspects For Microsoft Hololens Medical Tutorial Applications, Andrew J. Mcnutt Jan 2017

Model Preparation And User Interface Aspects For Microsoft Hololens Medical Tutorial Applications, Andrew J. Mcnutt

Browse all Theses and Dissertations

Augmented Reality (AR) is the combination of computer vision and graphics to allow a device to derive context about the environment and to display relevant information to the user. The Microsoft Hololens is the latest wearable AR device that includes a series of infrared sensors to perform hand tracking and Simultaneous Localization and Mapping, a wave guide optics system to project holograms, and an independent untethered operating system. This thesis will explore the hardware and software capabilities of the device, prepare 3D graphical models, and understand the user interface. Specifically, in our research the target application is a tutorial on …


Rapidly Solving Physics-Based Models For Uncertainty Propagation In Nondestructive Evaluation, Matthew Ryan Cherry Jan 2017

Rapidly Solving Physics-Based Models For Uncertainty Propagation In Nondestructive Evaluation, Matthew Ryan Cherry

Browse all Theses and Dissertations

Recent research in extending nondestructive evaluation (NDE) methods toward damage and materials characterization has led to an emphasis on the development of physics-based forward models in NDE. Furthermore, a desire to quantify levels of uncertainty in NDE inspections, particularly in Air Force applications, has driven the need for quick solving surrogate models for the traditional forward models, which have largely focused on accurately capturing many aspects of the problem with little emphasis on computational effort. In the past 5 years, many different techniques for creating lower-fidelity, quickly solving models to be used in place of the expensive high fidelity simulations …


Decision Support For Literal And Non-Literal Imaging Sensors, Holly K. Zelnio Jan 2017

Decision Support For Literal And Non-Literal Imaging Sensors, Holly K. Zelnio

Browse all Theses and Dissertations

The key contribution of this research was to characterize decision support system (DSS) performance as a function of sensor types ranging from a very literal electrooptical (EO) sensor to a very non-literal synthetic aperture radar (SAR) sensor. The specific DSS used in this research was developed based on the Applied Cognitive Task Analysis (ACTA), human performance modeling process, and a comprehensive literature search. The subject and DSS combined performance was characterized by objective interpretation accuracy and decision time and, in addition, the subject's trust, confidence, heuristics, and possible cognitive biases were elicited and analyzed. The measures of accuracy, time, and …


Distance Learning And Attribute Importance Analysis By Linear Regression On Idealized Distance Functions, Rupesh Kumar Singh Jan 2017

Distance Learning And Attribute Importance Analysis By Linear Regression On Idealized Distance Functions, Rupesh Kumar Singh

Browse all Theses and Dissertations

A good distance metric is instrumental on the performance of many tasks including classification and data retrieval. However, designing an optimal distance function is very challenging, especially when the data has high dimensions.Recently, a number of algorithms have been proposed to learn an optimal distance function in a supervised manner, using data with class labels. In this thesis we proposed methods to learn an optimal distance function that can also indicate the importance of attributes. Specifically, we present several ways to define idealized distance functions, two of which involving distance error correction involving KNN classification, and another involving a two-constant …


A Look At The Optimum Slope Of A Fixed Solar Panel For Maximum Energy Collection For A One Year Time Frame, Salah Alhaidari Jan 2017

A Look At The Optimum Slope Of A Fixed Solar Panel For Maximum Energy Collection For A One Year Time Frame, Salah Alhaidari

Browse all Theses and Dissertations

A rule-of-thumb for orientating fixed solar panels for optimum yearly collection of solar radiation that is not influenced by atmospheric effects is to face the panel due south in the Northern Hemisphere or due north in the Southern Hemisphere and to tilt the panel from the horizontal plane at an angle equal to the latitude of the location of the solar panel. The work presented in this thesis shows that this rule-of-thumb is an approximation for no-atmosphere, panel orientation; but not a precise value. This project presents a detailed method for determining the precise optimum tilt angle of a fixed …