Digital Commons Network^™

The Characterization And Fatigue Life Impact From Surface Roughness On Structurally Relevant Features Produced Using Additive Manufacturing, Eric-Paul Daniel Tatman

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Additive manufacturing (AM) produces rough surfaces that are detrimental to the mechanical performance of the part. In this work, downward-facing surfaces were fabricated in alloy 718 using laser powder bed fusion and investigated with surface characterization and axial fatigue testing. Coupons with downward-facing surfaces at 45°, 60°, and 75° and flat axial fatigue bars with as-built and machined holes were built. Both specimens were fabricated with three levels of downskin laser power and the coupons with three levels of downskin laser speed. Surface characterization showed roughness increased as the downward-facing angle decreased. Fatigue testing with digital image correlation showed localized …

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 …

Chm 1210 General Chemistry I Core General Education Assessment, 2018-2019, College Of Science And Mathematics, Wright State University

Core General Education Assessments - All

This report assesses Wright State University's course CHM 1210, General Chemistry I, as part of the institution’s ongoing general education Core assessment plan.

Ees 2510 Earth Systems Core General Education Assessment, 2018-2019, College Of Science And Mathematics, Wright State University

Core General Education Assessments - All

This report assesses Wright State University's course EES 2510, Earth Systems, as part of the institution’s ongoing general education Core assessment plan.

Adaptive Knowledge Networks: A Time Capsule, Swati Padhee, Anurag Illendula, Amit Sheth, Krishnaprasad Thirunarayan, Valerie L. Shalin

Kno.e.sis Publications

❖ Real world events are dynamic in nature Periodic events e.g. US Presidential Election Non-periodic events e.g. Cyclone Idai

❖ Need for real-time predictive analysis, trend analysis, spatio-temporal decision making, public opinion analysis for events.

❖ Current state-of-the-art curates dynamic knowledge graph from structured text.

❖ We propose creating an Adaptive Knowledge Network from incoming real-time multimodal spatio-temporally evolving data.

Nutrient Flux From Aquatic To Terrestrial Invertebrate Communities Across A Lakeside Ecotone, Hosanna B. Loreaux

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In this study, I examined how the spatiotemporal distribution of spider webs and diet changed in a lake riparian zone with increasing distance from an aquatic resource. I surveyed twenty, one-hundred meter transects along the perimeters of Sanford and Escanaba lakes (Wisconsin). Overall, spider web abundance was highest near the lakes and decreased moving into the adjacent forest. Horizontal orb webs, vertical orb webs, and mesh webs showed strong negative relationships with distance from the lakes. Aquatic insects composed an average 36-64% of spider diet for all spider families throughout the riparian zone, suggesting that some spider families are selecting …

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, …

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 …

Effects Of Lubrication Starvation On Flash Temperature For Thermal Mixed Elastohydrodynamic Gear Contacts, Danielle D. Massé

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Lubrication is provided to the gear trains in automotive and aerospace transmission systems to prevent mechanical contact through the formation of a full lubricant film, which in turn removes heat generated at the gear contact surfaces. When debris blocks the inlet nozzle, the flow of lubricant is restricted and mechanical components experience lubrication starvation. Under starved lubrication the temperatures of the contact surfaces become elevated which can lead to the formation of a weld between them, a catastrophic failure mode called scuffing. For spur gears, the occurrence of scuffing is due to high sliding in the vicinity of the root …

The Magnetocaloric Effect & Performance Of Magnetocaloric Materials In A 1d Active Magnetic Regenerator Simulation, Daniel Nicholas Bayer

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Active magnetic regenerators (AMRs) operate according to the magnetothermal phenomenon known as the magnetocaloric effect (MCE), and are at the forefront of magnetic cooling technology. AMR simulations have been shown to be useful tools in predicting the performance of different magnetocaloric materials (MCMs) without the need to develop a physical prototype. In a search to determine the set of operational parameters which would maximize MCM performance, a 1D simulation of an AMR device has been developed in Matlab. Gadolinium, the most well-documented MCM, is used as a benchmark material to study the effects of varying certain operational parameters such as …

Joint Determination Of Rack Configuration And Shelf Space Allocation To Maximize Retail Impulse Profit, Uttam Karki

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For brick-and-mortar retailers to be successful, it is critical for them to optimally design their rack layout and place products in order to draw attention of shoppers. Literature suggests that racks placed at acute (or obtuse) angles to the main aisle frequented by shoppers can enhance visibility of products compared to racks placed orthogonally (i.e., 90˚). Placing products with high impulse purchase potential in the resulting highly visible locations on the rack can increase shopper impulse purchases. However, placing racks at angles other than 90˚ can increase the required floor space. Additionally, while reducing the height of the racks just …

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

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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 …

Monitoring Cerebral Functional Response Using Scmos-Based High Density Near Infrared Spectroscopic Imaging, Dharminder Singh Langri

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Neurovascular coupling is an important concept that indicates the direct link between neuronal electrical firing with the vascular hemodynamic changes. Functional Near Infrared Spectroscopy (fNIRS) can measure changes in cerebral vascular parameters of oxy-hemoglobin and deoxyhemoglobin concentrations and thus can provide neuronal activity through neurovascular coupling. Currently many commercial fNIRS devices are available, but they are limited by the number of channels (usually having only 8 detectors), which can limit the sensitivity, contrast, and resolution of imaging. High-density imaging can improve sensitivity, contrast, and resolution by providing many measurements and averaging the signals originating from the target cerebral focus area …

Stability Analysis Of Transfer Alignment Filter Based On The Μ Theory, Lihua Zhu, Yu Wang, Lei Wang, Zhiqiang Wu

Electrical Engineering Faculty Publications

The performance of the transfer alignment has great impact on inertial navigation systems. As the transfer alignment is generally implemented using a filter to compensate the errors, its accuracy, rapidity and anti-disturbance capability are key properties to evaluate the filtering process. In terms of the superiority in dealing with the noise, H∞ filtering has been used to improve the anti-disturbance capability of the transfer alignment. However, there is still a need to incorporate system uncertainty due to various dynamic conditions. Based on the structural value theory, a robustness stability analysis method has been proposed for the transfer alignment to evaluate …

Mixed Signal Detection, Estimation, And Modulation Classification, Yang Qu

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Signal detection, parameter estimation and modulation classification are widely applied to many areas and plays a very important role in civilian and military, such as bio-science, criminal psychology, communication engineering, radar system, electronic warfare and so on. In the civilian field, with the increasing number of wireless electronic devices and higher transmission data rate demand, the problem of spectrum congestion becomes more and more highlighted and urgent. In recent years, wireless industry has shown great interest in Cognitive Radio (CR) and Dynamic Spectrum Access (DSA) network, whose primary function is to use limited frequency bands to transmit own signals without …

Islands Of Fitness Compact Genetic Algorithm For Rapid In-Flight Control Learning In A Flapping-Wing Micro Air Vehicle: A Search Space Reduction Approach, Kayleigh E. Duncan

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On-going effective control of insect-scale Flapping-Wing Micro Air Vehicles could be significantly advantaged by active in-flight control adaptation. Previous work demonstrated that in simulated vehicles with wing membrane damage, in-flight recovery of effective vehicle attitude and vehicle position control precision via use of an in-flight adaptive learning oscillator was possible. Most recent approaches to this problem employ an island-of-fitness compact genetic algorithm (ICGA) for oscillator learning. The work presented provides the details of a domain specific search space reduction approach implemented with existing ICGA and its effect on the in-flight learning time. Further, it will be demonstrated that the proposed …

Blended Wing Design Considerations For A Next Generation Commercial Aircraft, Jay Abhilash Vora

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The current aircraft design has not changed significantly in the last few decades. Growing environmental concerns and fuel prices are driving manufacturers to develop unconventional but efficient aircraft configurations. The blended wing body (BWB) configuration provides an alternate and more efficient means of subsonic travel. The BWB aircraft replaces the traditional wings and fuselage with hybrid wing shape where the fuselage and wings have integrated. Major aircraft manufacturers are researching the BWB concept incorporating electric propulsion for civil transport use. In this research a 300 passenger BWB aircraft aerodynamic shape is designed. This aircraft is used to assess the aerodynamic …

Differential Microrna Expression In Barrett's Esophagus Correlates With Regulation Of Posterior Homeotic Genes, Reilly June Clark

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Barrett’s Esophagus (BE) is characterized by the appearance of an intestinal-like epithelium in the distal esophagus. The molecular mechanisms behind BE development are unknown. BE is often preceded by Gastroesophageal Reflux Disease (GERD) and predisposes patients to esophageal adenocarcinoma (EAC). Due to the high mortality rate associated with EAC, BE patients are continuously monitored through upper endoscopy with biopsy for progression to low grade dysplasia (LGD), high grade dysplasia, and EAC. This monitoring technique poses numerous risks, so alternative surveillance and diagnostic techniques for BE pathogenesis are continually studied. microRNA biomarkers in BE pathogenesis may provide alternative means of diagnosis …

Power/Thermal Interaction Within An Adaptive Turbine Engine, Andrew K. Desomma

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Usually power take off (PTO) with a two-spool turbofan engine has been accomplished via the high pressure (HP) shaft and bleed air from the high-pressure compressor (HPC). The PTO is used to run various aircraft components such as generators and hydraulic pumps, which also produce waste heat. To better understand the coupled transient nature of balancing engine thrust, power take off and thermal management, a transient variable cycle three stream turbofan engine model has been developed to investigate the integrated behavior. The model incorporates many dynamic features including a third-stream heat exchanger as a heat sink for thermal management and …

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 …

Hierarchical Carbon Structures With Vertically- Aligned Nanotube Carpets For Oil-Water Separation Under Different Conditions, Kimia Kiaei

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The primary purpose of this study is to investigate the role of surface nano-structuring in fluid separation. It is hypothesized that hierarchical carbon structures consisting of aligned carbon nanotube arrays strongly adhered to the surface of porous carbon solids such as fabric and foam, can be used for separation of polar and non-polar fluids by selective wettability of one fluid and rejection of another. The vertically-aligned carbon nanotube arrays, as synthesized, possess super hydrophobicity demonstrated by high water contact angle on their surfaces. On the other hand, they are incredibly oleophilic, showing a high affinity to adsorb oil. These properties …

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 …

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 …

Gauging Human Performance With An Automated Aid In Low Prevalence Conditions, Cara M. Zinn

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When receiving assistance from an automated aid, human operators do not necessarily perform better than without the automated aid. The current work explored the impact of integrating the automated aid with the task information in low prevalence conditions. Specifically, this work compares displays where the automated aid was integrated with task information in general or with more meaningful task information. Subjects performed a speeded judgment task with the assistance of an automated aid, varying in display type, difficulty, and prevalence. Results indicated that there was no effect of display type or prevalence on human temporal performance, and that the effect …

Identifying Diversity Of Thought On Social Media, Beth Bullemer

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This dissertation considers what it means to think differently, using naturalistic verbal evidence. This problem is inspired by a gap within the Wisdom of the Crowd (WoC) literature, but relevant to the study of language processes, mental models, and the vast emerging resource of social media data. I propose a methodological framework to characterize diversity of thought through the quantification of social media data. Four stages of research considered: a) the properties of a sample domain, b) how to identify and select diagnostic content using classification methods, c) how to quantify qualitative content in order to categorize and compare individuals, …

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 …

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.

Adaptive Identification Of Classification Decision Boundary Of Turbine Blade Mode Shape Under Geometric Uncertainty, Ian M. Boyd

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Integrally Bladed Rotors (IBR) of aircraft turbine engines suffer from fluctuations in the dynamic response that occurs due to blade to blade geometric deviations. The Stochastic Approach for Blade and Rotor Emulation (SABRE) framework has been used to enable a probabilistic study of mistuned blades in which a reduced order modeling technique is applied in conjunction with sets of surrogate models, called emulators, to make predictions of mistuned mode shapes. SABRE has proven useful for non-switching mode shapes. However, switching mode shapes have non-stationary or discontinuous response surfaces which reduce the accuracy of the surrogate models used in SABRE. To …

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 design …