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Full-Text Articles in Engineering

Processing And Properties Of Multifunctional Two-Dimensional Nanocomposite Based On Single Wall Carbon Nanotubes, Ali M. Al Mafarage Jan 2019

Processing And Properties Of Multifunctional Two-Dimensional Nanocomposite Based On Single Wall Carbon Nanotubes, Ali M. Al Mafarage

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Truly single layer (monolayer) films of unmodified zigzag single-walled carbon nanotubes by using the Langmuir-Blodgett (LB) technique have been processed successfully. Measurements of their mechanical and optoelectric properties were achieved. Different theoretical equations were used based on the results obtained from the experimental part to study the properties and structures of the produced material and their composite. The produced films were highly oriented as determined by polarized Raman spectroscopy and as shown by scanning tunneling microscopy (STM). The films have a significant amount of flexibility which makes their behavior similar to rubbery materials. They can also be deposited on different ...


Strategic Decision Facilitation: An Exploration Of Alternative Anchoring And Scale Distortion Optimization In Multi-Attribute Group Decision Making, Joseph Patrick Kristbaum Jan 2019

Strategic Decision Facilitation: An Exploration Of Alternative Anchoring And Scale Distortion Optimization In Multi-Attribute Group Decision Making, Joseph Patrick Kristbaum

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Choosing between alternatives, regardless of the decision context in an organizational group setting is a difficult task. The integrity of the decision is under constant scrutiny and rarely are we ever able to characterize the magnitude of that with which we are consciously or subconsciously concerned: personal bias. This leads to long, drawn out timelines and loosely trusted decisions. This dissertation research focuses on using a traditionally, negatively viewed anchoring bias strategically in a series of experiments with a hypothesis that it can be used to positively reduce personal biases such as preference bias and judgement rooted in ambiguous or ...


Speech Enabled Navigation In Virtual Environments, Raksha Rajashekar Jan 2019

Speech Enabled Navigation In Virtual Environments, Raksha Rajashekar

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Navigating in a Virtual Environment with traditional input devices such as mouse, joysticks and keyboards provide limited maneuverability and is also time consuming. While working in a virtual environment, changing parameters to obtain the desired visualization requires time to achieve by manually entering parameter values in an algorithm to test outcomes. The following thesis presents an alternate user interface to reduce user efforts, while navigating within the Virtual Environment. The user interface is an Android application which is designed to accommodate spoken commands. This Speech Enabled User Interface termed as the Speech Navigation Application (SNA), provides the user with an ...


Abusive And Hate Speech Tweets Detection With Text Generation, Abhishek Nalamothu Jan 2019

Abusive And Hate Speech Tweets Detection With Text Generation, Abhishek Nalamothu

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According to a Pew Research study, 41% of Americans have personally experienced online harassment and two-thirds of Americans have witnessed harassment in 2017. Hence, online harassment detection is vital for securing and sustaining the popularity and viability of online social networks. Machine learning techniques play a crucial role in automatic harassment detection. One of the challenges of using supervised approaches is training data imbalance. Existing text generation techniques can help augment the training data, but they are still inadequate and ineffective. This research explores the role of domain-specific knowledge to complement the limited training data available for training a text ...


Two Player Zero Sum Multi-Stage Game Analysis Using Coevolutionary Algorithm, Sumedh Sopan Nagrale Jan 2019

Two Player Zero Sum Multi-Stage Game Analysis Using Coevolutionary Algorithm, Sumedh Sopan Nagrale

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A New Two player zero sum multistage simultaneous Game has been developed from a real-life situation of dispute between two individual. Research identifies a multistage game as a multi-objective optimization problem and solves it using Coevolutionary algorithm which converges to a solution from pareto optimal solution. A comparison is done between individual stage behaviour and multistage behaviour. Further, simulations over a range for Crossover rate, Mutation rate and Number of interaction is done to narrow down the range for a range with optimal computation speed. A relationship has been observed which identifies a relationship between population size, number of interactions ...


The Development Of The Human-Automation Behavioral Interaction Task (Habit) Analysis Framework, Isabelle Catherine Baird Jan 2019

The Development Of The Human-Automation Behavioral Interaction Task (Habit) Analysis Framework, Isabelle Catherine Baird

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Complex systems involve the collaboration of automated agents and goal-oriented human operators in a dynamic environment, and dynamic environments required dynamic automation. The implementation of automation fundamentally changes the nature of the cognitive demands by means of changing the role of the human operator. The augmentation of operator situation awareness has become a major design objective in the development of human-automated systems. Extensive literature identified the out-of-the-loop performance problem as a human-automation interaction challenge. This thesis presents the Human-Automation Behavioral Interaction Task (HABIT) Analysis, as a novel approach to assessing human-automation interaction challenges, such as out-of-the-loop consequences. The novel framework ...


Llvm-Ir Based Decompilation, Ilsoo Jeon Jan 2019

Llvm-Ir Based Decompilation, Ilsoo Jeon

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Decompilation is a process of transforming an executable program into a source-like high-level language code, which plays an important role in malware analysis, and vulnerability detection. In this thesis, we design and implement the middle end of a decompiler framework, focusing on Low Level Language properties reduction using the optimization techniques, propagation and elimination. An open-source software tool, dagger, is used to translate binary code to LLVM (Low Level Virtual Machine) Intermediate Representation code. We perform data flow analysis and control flow analysis on the LLVM format code to generate high-level code using a Functional Programming Langauge (FPL), Haskell. The ...


Characterization Of In-Vivo Damage In Implantable Cardiac Devices And The Lead Residual Properties, Anmar Mahdi Salih Jan 2019

Characterization Of In-Vivo Damage In Implantable Cardiac Devices And The Lead Residual Properties, Anmar Mahdi Salih

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Approximately, 92.1 million patients in the US suffer from cardiovascular diseases with an estimated healthcare cost of over $300 billion; out of which at least one million patients have Cardiac Implantable Electronics Devices (CIED). CIED represented by pacemakers, Implantable Cardioversion Defibrillator (ICD), and Cardiac Resynchronization Therapy (CRT) are exposed to in-vivo damage. These damages are complex and composed on multiple levels and present challenges while assessing their combined extent. Since 2004, more than one hundred recalls were reported for cardiac devices. ICD devices had the majority with 40.8% recalls, pacemaker recall percentage was 14.5%, CRT recall percentage ...


Using Cfd To Improve Off-Design Throughflow Analysis, Troy J. Lanchman Jan 2019

Using Cfd To Improve Off-Design Throughflow Analysis, Troy J. Lanchman

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In turbomachinery design, complex internal flows give rise to significant losses and blockage whose effects are difficult to properly analyze without detailed computational fluid dynamics (CFD) methods or experiments. In a typical design method, CFD is used in conjunction with simpler throughflow or cascade codes to hasten the process. However, the lesser physical accuracy of the design codes demands the inclusion of models to improve the accuracy of the throughflow codes. This thesis aims to use CFD data to generate improved loss and blockage models for a 2D compressor throughflow code by matching throughflow data to CFD data using optimizations ...


Recognition Of Incomplete Objects Based On Synthesis Of Views Using A Geometric Based Local-Global Graphs, Michael Christopher Robbeloth Jan 2019

Recognition Of Incomplete Objects Based On Synthesis Of Views Using A Geometric Based Local-Global Graphs, Michael Christopher Robbeloth

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The recognition of single objects is an old research field with many techniques and robust results. The probabilistic recognition of incomplete objects, however, remains an active field with challenging issues associated to shadows, illumination and other visual characteristics. With object incompleteness, we mean missing parts of a known object and not low-resolution images of that object. The employment of various single machine-learning methodologies for accurate classification of the incomplete objects did not provide a robust answer to the challenging problem. In this dissertation, we present a suite of high-level, model-based computer vision techniques encompassing both geometric and machine learning approaches ...


Software Implementations And Applications Of Elliptic Curve Cryptography, Kirill Kultinov Jan 2019

Software Implementations And Applications Of Elliptic Curve Cryptography, Kirill Kultinov

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Elliptic Curve Cryptography (ECC) is a public-key cryptography system. Elliptic Curve Cryptography (ECC) can achieve the same level of security as the public-key cryptography system, RSA, with a much smaller key size. It is a promising public key cryptography system with regard to time efficiency and resource utilization. This thesis focuses on the software implementations of ECC over finite field GF(p) with two distinct implementations of the Big Integer classes using character arrays, and bit sets in C++ programming language. Our implementation works on the ECC curves of the form y^2 = x^3 + ax + b (mod p). The ...


Leveraging Schema Information For Improved Knowledge Graph Navigation, Rama Someswar Chittella Jan 2019

Leveraging Schema Information For Improved Knowledge Graph Navigation, Rama Someswar Chittella

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Over the years, the semantic web has emerged as a new generation of the world wide web featuring advanced technologies and research contributions. It has revolutionized the usage of information by allowing users to capture and publish machine-understandable data and expedite methods such as ontologies to perform the same. These ontologies help in the formal representation of a specified domain and foster comprehensive machine understanding. Although, the engineering of ontologies and usage of logic have been an integral part of the web semantics, new areas of research such as the semantic web search, linking and usage of open data on ...


Towards Data And Model Confidentiality In Outsourced Machine Learning, Sagar Sharma Jan 2019

Towards Data And Model Confidentiality In Outsourced Machine Learning, Sagar Sharma

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With massive data collections and needs for building powerful predictive models, data owners may choose to outsource storage and expensive machine learning computations to public cloud providers (Cloud). Data owners may choose cloud outsourcing due to the lack of in-house storage and computation resources or the expertise of building models. Similarly, users, who subscribe to specialized services such as movie streaming and social networking, voluntarily upload their data to the service providers' site for storage, analytics, and better services. The service provider, in turn, may also choose to benefit from ubiquitous cloud computing. However, outsourcing to a public cloud provider ...


Deposition Of Nanoparticles Or Thin Films Via Magnetron Sputtering Towards Graphene Surface Functionalization And Device Fabrication, Bridget Jul Larson Jan 2019

Deposition Of Nanoparticles Or Thin Films Via Magnetron Sputtering Towards Graphene Surface Functionalization And Device Fabrication, Bridget Jul Larson

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Graphene, a 2-dimensional single layer of carbon, has high carrier mobility, strength and electrical conductivity. Due to the absence of a band gap and chemical reactivity, pristine graphene has less competitiveness in semiconductors and sensors. Functionalizing graphene is imperative in the development of advanced applications. Among various wet chemical or physical vapor deposition, magnetron sputtering is cost-effective, minimum maintenance, user-friendly, and can be used to rapidly deposit nano-particulates or thin films with less contaminations on any substrates surface. This study is to investigate the morphology evolution of the deposited films using magnetron sputtering and to find appropriate conditions for nanoparticulate ...


Stability Analysis Of Leg Configurations For Bipedal Running, Nitin Jaiswal Jan 2019

Stability Analysis Of Leg Configurations For Bipedal Running, Nitin Jaiswal

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A legged robot with three-segmented limbs is used to study the effects of leg compliance originating from the joint level on the stability of hopping in place and running. The three-segments allow each leg to be kinematically configured an infinite number ways that satisfy the desired landing condition parameters, total leg length and angle. These two parameters along with the amount of energy thrust during stance determine the motion of the system during a single stride. The goal of this work is to explore the potential values for the leg parameters of three-segment leg, that provide additional stability when compared ...


Growth Of Two-Dimensional Molybdenum Disulfide Via Chemical Vapor Deposition, Zachary Durnell Ganger Jan 2019

Growth Of Two-Dimensional Molybdenum Disulfide Via Chemical Vapor Deposition, Zachary Durnell Ganger

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Graphene has successfully been a 2D material applied in various fields, but it is not the most appropriate candidate for many electronic devices unless its bandgap structure is tuned through functionalization. Among all other 2D material families, transition metal dichalcogenides (TMDs), represented by molybdenum disulfide (MoS2), are promising and emerging in power electronics due to their large direct bandgap and other electronic properties. 2D MoS2 has been fabricated through different approaches such as mechanical exfoliation, chemical etching, and chemical vapor deposition (CVD). The current major challenge in fabricating 2D MoS2 films is to produce a high-quality large-area monolayer film at ...


Unsteady Effects Of A Pulsed Blowing System On An Endwall Vortex, Molly Hope Donovan Jan 2019

Unsteady Effects Of A Pulsed Blowing System On An Endwall Vortex, Molly Hope Donovan

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The low-pressure turbine is an important component of a gas turbine engine, powering the low-pressure spool which provides the bulk of the thrust in medium- and high-bypass engines. It is also a significant fraction of the engine weight and complexity as it can comprise up to a third of the total engine weight. One way to drastically reduce the weight of the low-pressure turbine is to utilize high lift blades. To advance high-lift technology, the Air Force Research Laboratory (AFRL) designed the L2F blade profile, which was implemented in the linear cascade at AFRL/RQT’s low speed wind tunnel ...


Multi-Sensor Approach To Determine The Effect Of Geometry On Microstructure In Additive Manufacturing, Joseph R. Walker Jan 2019

Multi-Sensor Approach To Determine The Effect Of Geometry On Microstructure In Additive Manufacturing, Joseph R. Walker

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Laser powder bed fusion (LPBF) is an additive manufacturing technique used for making complex parts through a layer-by-layer process with fine feature resolution. However, the layer-by-layer process, with complex scanning patterns within each layer, introduces variability in thermal behavior leading to inconsistent microstructure and defects. The in- situ process monitoring approach in this work uses sensors including a high-speed visible camera, thermal camera, and spectrometer to evaluate each location in the LPBF process. Each sensor focuses on a different process phenomenon such as the melt pool or thermal behavior. An experimental study, using metallographic analysis and collection of sensor data ...


Rasters Vs Contours For Thin Wall Ultem 9085 Fdm Applications, Vausman Kota Jan 2019

Rasters Vs Contours For Thin Wall Ultem 9085 Fdm Applications, Vausman Kota

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Currently many components are additively manufactured via fused deposition modeling (FDM). However, FDM results in gaps between passes which produces a poor surface finish and porous material that is difficult to hold pressure. Commercial scale air systems require a pressure to be maintained within thin walled components with minimal post processing and clean up after fabrication. A design of experiments (DOE) was created to identify the optimal raster vs contour ratio for UTLEM 9085 CG fabricated using FDM at different build angles and wall thicknesses. A custom-built pressurized test system was developed, the leak rates were calculated and the surfaces ...


Assessing The Role Of Polyphenols As A Vascular Protectant Against Drug Induced Vascular Injury, Anson Jacob Oommen Jan 2019

Assessing The Role Of Polyphenols As A Vascular Protectant Against Drug Induced Vascular Injury, Anson Jacob Oommen

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Vascular injury is identified during pre-clinical toxicity testing within certain pharmacological classes of drug candidates and induces degenerative and hyperplastic changes in endothelial (ECs) and vascular smooth muscle (VSMCs) cells. This drug-induced vascular injury has been show as a side-effect caused by various classes of drugs, including, antibacterial (e.g., azithromycin), anti-malarial (e.g., quinoline), anti-viral (e.g., anti-hepatitis C virus interferons) and nonsteroidal anti-inflammatory drugs (e.g., ibuprofen), and affects normal cardiovascular function and can further lead to various cardiovascular conditions like arrhythmia, cardiac arrest, high blood pressure, and even heart attack. The search for agents capable of reducing ...


Virtual Reality And Analysis Framework For Studying Different Layout Designs, Madison Glines Jan 2019

Virtual Reality And Analysis Framework For Studying Different Layout Designs, Madison Glines

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This thesis describes the tools for studying different design prototypes. The goal was to develop effective tools to study these designs using a data-driven approach. “Proof of concept” experiments were conducted, in which participants were allowed to interact with a virtual environment depicting different designs as data pertaining to their virtual location and orientation was recorded for later analysis. The designs included “flat” store racks, as opposed to racks with more varied shapes, as well as “curved” racks. Focus of the design studies was to assist in identifying optimal locations for different product types. The automated data collection mechanisms required ...


Securing Modern Cyberspace Using A Multi-Faceted Approach, Yu Li Jan 2019

Securing Modern Cyberspace Using A Multi-Faceted Approach, Yu Li

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Security has become one of the most significant concerns for our cyberspace. Securing the cyberspace, however, becomes increasingly challenging. This can be attributed to the rapidly growing diversities and complexity of the modern cyberspace. Specifically, it is not any more dominated by connected personal computers (PCs); instead, it is greatly characterized by cyber-physical systems (CPS), embedded systems, dynamic services, and human-computer interactions. Securing modern cyberspace therefore calls for a multi-faceted approach capable of systematically integrating these emerging characteristics. This dissertation presents our novel and significant solutions towards this direction. Specifically, we have devised automated, systematic security solutions to three critical ...


Static Evaluation Of Type Inference And Propagation On Global Variables With Varying Context, Ivan Frasure Jan 2019

Static Evaluation Of Type Inference And Propagation On Global Variables With Varying Context, Ivan Frasure

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Software reverse engineering (SRE) is a broad field with motivations ranging from verifying or documenting gordian source code files to understanding and reimplementing binary object files and executables. SRE of binaries is exceptionally compelling and challenging due to large amounts of information that can be lost in the compilation progress. A central area in SRE is type inference. Type inference is built around a fundamental step in understanding the behavior of a binary, recovering the types of data in the program. Type inference has many unique techniques in both static and dynamic type inference systems that have been implemented in ...


Biomarker-Performance Associations During Nutritional And Exercise Intervention In Air Force Personnel, Jennifer Jurcsisn Jan 2019

Biomarker-Performance Associations During Nutritional And Exercise Intervention In Air Force Personnel, Jennifer Jurcsisn

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This study evaluated the combined effects of an exercise intervention and nutritional supplement on biomarkers of stress and resilience, and the relationships of those markers with physical and cognitive performance. 130 healthy Active-Duty Air Force (AF) personnel were recruited to participate in a double-blind, placebo controlled 12-week exercise and nutritional intervention. Serum was collected at basal and high stress conditions pre- and post-intervention to track the following biomarkers: cortisol, dehydroepiandrosterone-sulfate (DHEA-S), norepinephrine (NE), neuropeptide Y (NPY), and serotonin. The exercise intervention significantly attenuated the cortisol response and peak stress cortisol levels. The nutritional intervention decreased peak stress NE. The selected ...


Scalable Clustering For Immune Repertoire Sequence Analysis, Prem Bhusal Jan 2019

Scalable Clustering For Immune Repertoire Sequence Analysis, Prem Bhusal

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The development of the next-generation sequencing technology has enabled systems immunology researchers to conduct detailed immune repertoire analysis at the molecule level. Large sequence datasets (e.g., millions of sequences) are being collected to comprehensively understand how the immune system of a patient evolves over different stages of disease development. A recent study has shown that the hierarchical clustering (HC) algorithm gives the best results for B-cell clones analysis - an important type of immune repertoire sequencing (IR-Seq) analysis. However, due to the inherent complexity, the classical hierarchical clustering algorithm does not scale well to large sequence datasets. Surprisingly, no algorithms ...


Accelerating Reverse Engineering Image Processing Using Fpga, Matthew Joshua Harris Jan 2019

Accelerating Reverse Engineering Image Processing Using Fpga, Matthew Joshua Harris

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In recent decades, field programmable gate arrays (FPGAs) have evolved beyond simple, expensive computational components with minimal computing power to complex, inexpensive computational engines. Today, FPGAs can perform algorithmically complex problems with improved performance compared to sequential CPUs by taking advantage of parallelization. This concept can be readily applied to the computationally dense field of image manipulation and analysis. Processed on a standard CPU, image manipulation suffers with large image sets processed by highly sequential algorithms, but by carefully adhering to data dependencies, parallelized FPGA functions or kernels offer the possibility of significant improvement through threaded CPU functions. This thesis ...


As-Manufactured Modeling Of A Mistuned Turbine Engine Compressor Evaluated Against Experimental Approaches, Daniel L. Gillaugh Jan 2019

As-Manufactured Modeling Of A Mistuned Turbine Engine Compressor Evaluated Against Experimental Approaches, Daniel L. Gillaugh

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As-manufactured rotors behave quite differently than nominal, as-designed rotors due to small geometric and material property deviations in the rotor, referred to as mistuning. Traditional integrally bladed rotor (IBR) modeling approaches assume each blade is identical. State-of-the-art IBR dynamic response predictions can be accomplished using asmanufactured models (AMM) generated via optical topography measurements and mesh morphing. As-manufactured models account for geometric deviations occurring through the machining process, material deviations and field wear, allowing each blade to respond differently. Rotor designs are intended to avoid resonance crossings throughout an engine’s operating range, but total avoidance is challenging. This has led ...


Aerodynamics Of Fan Blade Blending, Clint J. Knape Jan 2019

Aerodynamics Of Fan Blade Blending, Clint J. Knape

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Blending is a method of fan and compressor blade repair. The goal of the blending process is to remove stress concentration points such as cracks and nicks along the leading, trailing, or tip edges of the blade. The stressed areas are typically removed by grinding or cropping away the surrounding material. For integrally bladed rotor (IBR) disks, repairing a damaged blade is much more economical than replacing the entire disk. However, the change in shape of the blade will change the local aerodynamics and result in mistuning, both structurally and aerodynamically. In a worst case scenario, the change in the ...


Analytical And Experimental Investigation Of Time-Variant Acceleration Fields, Justin A. Williams Jan 2019

Analytical And Experimental Investigation Of Time-Variant Acceleration Fields, Justin A. Williams

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Devices expected to operate in elevated or non-standard acceleration fields are often tested in similar conditions prior to deployment. Typically these tests only simulate steady-state acceleration fields in one direction. However, real acceleration fields often vary both directionally and temporally. Designing experiments to produce these conditions requires careful forethought and analysis in order to understand the emergent acceleration components that result from the methodology. An experiment was designed and executed on a horizontal centrifuge in which the radial acceleration varied sinusoidally between -10 < a_r < 10 g. Negative acceleration was achieved by rotating the test article relative to the radial acceleration vector using a servo motor. A model was developed that predicted the acceleration field at every point along the test article. The model provided important information such as the acceleration magnitude and direction anywhere on the test device at any point in time. This model was then used to optimize the velocity profile of the servo motor to minimize experimental artifacts.


Kbot: Knowledge-Enabled Personalized Chatbot For Self-Management Of Asthma In Pediatric Population, Dipesh Kadariya Jan 2019

Kbot: Knowledge-Enabled Personalized Chatbot For Self-Management Of Asthma In Pediatric Population, Dipesh Kadariya

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Asthma, chronic pulmonary disease, is one of the major health issues in the United States. Given its chronic nature, the demand for continuous monitoring of patient’s adherence to the medication care plan, assessment of their environment triggers, and management of asthma control level can be challenging in traditional clinical settings and taxing on clinical professionals. A shift from a reactive to a proactive asthma care can improve health outcomes and reduce expenses. On the technology spectrum, smart conversational systems and Internet-of-Things (IoTs) are rapidly gaining popularity in the healthcare industry. By leveraging such technological prevalence, it is feasible to ...