Digital Commons Network^™

Mission Architecture Analysis: Exploring Long-Period Comets From Multiple Staging Orbits, Gabriel Prescinotti Vivan

Masters Theses

Objects that have retained pieces of information about the early Solar System are key to our understanding of its formation and evolutionary history. However, the high delta-V required to reach these objects, such as long-period comets or interstellar objects, makes designing an intercept mission at the time of detection impractical. In this thesis, multiple heliocentric staging orbits are explored to serve as departure positions for future missions, prior to objects’ detections. By utilizing more than one staging orbit concurrently, the set of objects that are reachable is expanded, therefore increasing mission feasibility. Delta-V maps are generated and superimposed; two-impulse burn …

Fatigue Damage Characterization By Surface Roughness And Instrumented Micro – Hardness Measurements, Suraj Sanjay Nikam

Masters Theses

Fatigue is an essential consideration in the design of high performance, safety-critical structures, and components, as fatigue failure constitutes more than 70% of failures in dynamically loaded components. This research aims to shed light on the effect of surface roughness on the micro-hardness in metals through experimental techniques (Part 1), the correlation between the traditional fatigue testing and instrumented cyclic micro-hardness testing to determine the material properties modeled by Ramberg - Osgood relationship(Part 2), and the effect of the fatigue damage on micro-hardness and surface roughness (Part 3).

For this research, Al 7075 - T651 and Al 6061 - T651 …

Vehicle Velocity Prediction Using Artificial Neural Networks And Effect Of Real-World Signals On Prediction Window, Tushar Dnyaneshwar Gaikwad

Masters Theses

Prediction of vehicle velocity is essential since it can realize improvements in the fuel economy/energy efficiency, drivability, and safety. Many publications address velocity prediction problems, yet there is a need for the understanding effect of different signals for the prediction. There are numerous new sensor and signal technologies like vehicle-to-vehicle and vehicle-to-infrastructure communication that can be used to obtain comprehensive datasets. Several references considered deterministic and stochastic approaches that use the datasets as input to determine future operation predictions. These approaches include different traffic models and artificial neural networks such as Markov chain, nonlinear autoregressive model, Gaussian function, and recurrent …

Portable Electrochemical System For Flexible Hybrid Electronics, Anthony Joseph Hanson

Masters Theses

This work focuses on the fabrication and design of a portable electrochemical sensing system for flexible hybrid electronic (FHE) sensors. A three-electrode chemical sensor was fabricated using copper tape on polyethylene terephthalate (PET) substrate, using laser etching process. An electronic circuit was designed to measure the sensor response through electrochemical techniques to detect different concentrations of glucose. The device was calibrated to give the user a concentration value in 5 seconds. The system was also designed to preform tests such as cyclic voltammogram and chronoamperogram for various chemicals. A Bluetooth Low Energy module was used to wirelessly transmit the results …

Estimation Of The Fatigue Life Of Additively Manufactured Metallic Components Using Modified Strain Life Parameters Based On Surface Roughness, Peter Grohs

Masters Theses

In this study, a method is developed to estimate the effects of surface roughness on the fatigue life of additively manufactured titanium Ti6Al4V, aluminum 7075–T6, and steel 4340 alloys through modified strain life parameters using finite element analysis (FEA). This method is highly beneficial to the fatigue analysis of as-built additively manufactured metal components, which possess rough surfaces that reduce fatigue life significantly but are challenging to analyze directly using finite element simulation because of complex geometries, i.e., modeling an exact surface profile is arduous.

An effective stress concentration factor, incorporating roughness data, is defined to quantify their effects on …

Gearbox Baffle Optimization, Megan Arduin

Masters Theses

Current literature reveals there is limited consensus on the placement of baffles within a gearbox to reduce churning losses. Thus, there is a need for a process to identify baffle clearances that result in maximum and minimum churning losses. There are two types of baffles: axial and radial. While both axial and radial baffles cause reductions in churning losses to various degrees, the focus is on the effect of radial baffles. The effect of a board (rectangular plate) baffle location on the churning losses of a single gear gearbox are evaluated using computational fluid dynamics (CFD) implemented in Ansys. Several …

Extending The Capabilities Of Von Neumann With A Dataflow Sub-Isa, Martin Cowley

Masters Theses

Instruction set architectures (ISAs) such as x86, ARM, and RISC-V follow the control flow model of computation, where a program is defined as a sequence of instructions. Early processors executed instructions one-by-one based on the control flow of a program. Dataflow is an alternative model of computation that uses the availability of data to drive instruction execution. Any instruction can be chosen for execution, independent of the instruction order, as long as the data is available for that instruction. While modern processors incorporate concepts of the dataflow model in the microarchitecture, the implementation of the ISA, the amount of instruction …

Intracellular Electrometer, Lucas M. Essenburg

Masters Theses

The Western Michigan University Neurobiology Engineering Laboratory conducts re- search in energy-efficient electrical stimulation of biological neurons. Experimental work re- quires an intracellular electrometer to inject nanoamp-level currents into a biological neuron and to measure its membrane voltage response. In order to fully understand the generation of such minute currents, an `in-house' electrometer was designed, constructed, and validated. This required exploration of various design trade-offs including precision of generated nanoamp-level currents vs. susceptibility to noise, portability vs. functionality, and cost vs. functionality. The electrometer was successfully used to stimulate and measure responses of neurons from the medicinal leech Hirudo verbana …

Optimal Energy Management For Forward-Looking Serial-Parallel Hybrid Electric Vehicle Using Rule-Based Control Strategy, Abhijit Bhaskar Jadhav

Masters Theses

In today’s sophisticated era of technology, resolving environmental problems is a matter of grave concern. Developing hybrid electric vehicles is a good step towards environmental preservation, since they use less fuel compared to conventional vehicles because of the combination of electric and mechanical energy. A hybrid electric vehicle reduces dependence on fossil fuels and hence lowers emissions. Specifically, a hybrid powertrain that includes a conventional gasoline engine and a brushless DC motor offers great potential to meet stringent CO₂ regulations and fuel economy requirements. This thesis focuses on the effects of initial state of charge (SOC) stored in Hybrid …

Modeling And Simulation With Optimal Gear Ratio For A Forward-Looking, Velocity-Driven, Power-Split Hybrid Electric Vehicle, Sonal Babasaheb Kanap

Masters Theses

Increases in vehicle demand and fossil fuel consumption are major contributors to environmental problems, such as air pollution and climate change. This has led to research on alternative, energy-efficient vehicle technologies. Automobile users are now preferring comfortable vehicles with minimal fuel consumption and with more efficient engines. Hybrid cars are becoming common because of their advantage of running cleaner and with better gas mileage. A hybrid car runs on the power of both an electric motor and a gasoline engine. This mechanism helps cut fuel consumption and conserve energy. An additional advantage is a regenerative braking system that helps recharge …

Training Set Density Estimation For Trajectory Predictions Using Artificial Neural Networks, Zachary Reinke

Masters Theses

Demand on earth orbiting surveillance systems in increasing as more equipment is put into orbit. These systems rely on predictive techniques to periodically track objects. The demand on these systems may be reduced if object trajectory data to develop scalable training sets used for training artificial neural networks (ANNs) to predict trajectories of a dynamic system. These methods use multi-variable statistics to analyze data energy content to provide the ANN with low density, feature-rich, training data. The developed techniques have been shown to increase ANN prediction accuracy while reducing the size of the training set when applied to a linear …

Model Predictive Control Synthesis For The Innovative Control Effector Tailless Fighter Aircraft, Christopher Proctor

Masters Theses

A nonlinear model predictive control law was developed for the Lockheed Martin Innovative Control Effector tailless fighter aircraft to track way points. In general, aircraft are described by nonlinear dynamics that are dependent on the regime of flight. Additionally strict requirements on state and actuator constraints are common to all aircraft. Tailless aircraft are usually overdetermined systems, meaning solutions to control problems are not unique, and the system is non-affine. The proposed nonlinear control law considers those constraints during run-time, and solves the nonlinear control problem for a range of points within different flight regimes. The control law was developed …

Control Law Synthesis For Lockheed Martin’S Innovative Control Effectors Aircraft Concept, Cameron James Segard

Masters Theses

This thesis documents a conventional and modern flight control system design process carried out on a tailless aircraft Simulink model with innovative control effectors provided by Lockheed Martin. To set scope and design requirements a performance analysis was carried out to categorize the aircraft. Evaluation of open-loop dynamics reveled modal instabilities as well as state and control coupling. Flight condition dependent pole migration mapping reveled large changes in the aircraft’s static stability. Leading to the development of a four channel proportional-integral- derivative (PID) stability and control augmentation system (SCAS) controlling pitch-rate, roll-rate, side-slip angle, and airspeed states. PID gains are …

Enabling Robust Distributed Real-Time Hybrid Simulation Method And Expanding Its Applications In Floating Wind Turbine Systems, Mehmet Cinar

Masters Theses

Real-time hybrid simulation (RTHS), which integrates physical experiment and numerical simulation, plays an essential role in understanding the time-dependent behavior of structures when subject to hazardous loadings. On the other hand, RTHS might not yield accurate results for complex structural systems due to experimental and computational limitations. Distributed real-time hybrid simulation (dRTHS), which takes the advantage of distributed laboratory facilities using network communications, was proposed and proven to address some limitations in RTHS. During dRTHS, Internet delay due to the network communication is added to the actuator delay in RTHS, which may cause inaccurate results or even unstable tests. To …

Stereotypic Repetitive Hand Flapping Movement Detector Children With Autism, Subodh Ashok Bansode

Masters Theses

The prevalence of Autism Spectrum Disorder (ASD) has increased at a significant rate in recent years, especially in developed nations such as the United States, Japan, and South Korea. Extensive research is being carried out to study the behavioral characteristics of the disease. Children affected with autism tend to exhibit a spectrum of symptoms depending on the severity of the disease. These behaviors are primarily repetitive, self-stimulatory, and stereotypic behaviors such as hand flapping (i.e., repeatedly shaking their hands), body rocking (i.e., swaying their body back and forth), drumming, walking around in a confined space, and walking with shortened steps …

Optimization Of Analytical Inverse Heat Transfer Recovery Solution, Nathan Schick

Masters Theses

This thesis describes the different methods used when trying to solve inverse heat transfer problems, particularly those involving recovering heat flux. There are currently several techniques to measure the temperature history in an object subjected to heat transfer using various temperature sensors, however these types of sensors are gradually being replaced by Temperature Sensitive Paints (TSP), a technique that is more accurate and provides a better spatial resolution. TSP is a polymer that is applied on a base object. Changes in temperature in the polymer result in variations of the luminescence intensity in the paint. These variations can be captured …

Soy- Based Flexographic Ink For Linerboard Printing, Rahul Ramchandra Pingale

Masters Theses

Many printing inks use volatile solvents in the formulation, which are hazardous to the environment from emission of VOC’s and at the same time, synthetic resins in these inks are not biodegradable. These problems with the fluctuating and rising price of petroleum are main reasons to look for new resources for making more environmentally friendly printing inks. The majority of the commercially available water based inks are formulated based on using acrylic resins, synthetic colorants, solvents/water and additives, which are the common main components for formulating printing inks. In this research, soy proteins were tested for their suitability to partially …

Design Of A Portable Biogas Purification And Storage System, Anilkumar Kosna

Masters Theses

Biogas is produced from the decomposition of organic materials like manure, sewage sludge or crop fodders in anaerobic digesters. It consists mainly of 40 – 75 % of methane (CH₄), 15 – 60 % of carbon dioxide (CO₂) and trace amounts of other components. The principle constituents of biogas are similar to natural gas. Natural gas has 87 – 97 % of methane (CH₄) and 0.1 – 1 % of carbon dioxide. Natural gas is known to be an alternative fuel with a wide range of applications. The commercial purification technologies exist for large-scale …

Liquid-To-Liquid Low Grade Waste Heat Recovery Using A Two-Channel Loop, Waleed Farwana

Masters Theses

The use of thermoelectric generators (TEGs) for producing electric energy from low grade “waste heat” has been theorized to provide a sustainable and low-cost energy source for electric power plants. The purpose of this study is to model and experimentally validate a TEG device that takes advantage of low grade waste heat (approximately 100-150 degrees Celsius) in liquid form in order to generate power that can be used for various applications in the surrounding environment. This research aims to demonstrate that optimized TEG designs bear the potential to compete with other methods of low grade waste heat energy harvesting in …

The Passive Effects Of Full-Gateway, In-Street Signs On Vehicular Speed, De'lon Dixon

Masters Theses

Reducing motorist’s speed when approaching crosswalks is an important goal in reducing the number of collision between motorist and pedestrian in crosswalks. The current study addresses this goal. The effect of gateway installation of in-street signs (one in-street sign installed between the two travel lanes in each direction and one on both edges of the roadway in each direction) on vehicle speed was evaluated on nine roads. The results demonstrated that the Gateway in-street sign treatment produced large speed reductions as vehicles approached the crosswalk and at the crosswalk. The average speed reduction was 3.8 mph at the crosswalk and …

Evaluation Of Bike Boxes And Protected Intersections With Bicycle Signal Treatments For Improving Safety And Multimodal Mobility At Urban Signalized Intersections, Odai Al Houz

Masters Theses

With the dramatic increase of non-motorized transportation users, more people are concerned about the non-motorized traffic safety. Unfortunately, bicyclist and pedestrian are prone to more severe injuries when involved in a crash. For bicycle crashes, failing to yield/disregarding traffic control device, and lack of non-motorized facilities were identified to be the main causes of bicycle crashes in urban intersections. This research investigated the effectiveness of two bicycle crash countermeasures with bicycle signal treatments at urban signalized intersections. The two countermeasures are the bike boxes and the protected intersections. The bicycle signal treatments are the leading bicycle interval and the exclusive …

Establishing Delay-Based Criteria For Installing Traffic Signals At Two-Lane Roundabouts, Oluwaseun Ayomide Adegbaju

Masters Theses

A roundabout is a circular intersection where drivers travel counterclockwise around a center island in the United States. Roundabouts can be more beneficial than the conventional intersections because they increase the capacity of the intersection and reduce delays and crashes at the intersection. However, the performance of roundabouts can be severely affected by unbalanced traffic flows among the approaches. While the resulting delays can be mitigated by installing traffic signals, there is a lack of clear criteria on when to install a traffic signal at a roundabout. This research focuses on establishing criteria for installing traffic signals at two-lane roundabouts …

Pyrolysis Of Plastic Waste From Medical Services Facilities Into Potential Fuel And/Or Fuel Additives, Bright Kweku Ansah Baiden

Masters Theses

Limited space and high costs for landfilling as well as increasing regulations in plastic waste disposal, has led to high operating costs for organizations involved in managing plastic waste from medical facilities which led to the need to investigate an alternative option such as pyrolysis. The overall goal of this study was to evaluate pyrolysis as a means to repurpose plastic waste obtained from medical service facilities into fuel and fuel additive compounds, with two objectives involving, (1) to examine the effect of heat input (as voltage) and reaction/residence time; and (2) to evaluate the effect of the plastic waste …

Maintaining Deck Profile In Steel I-Girder Bridges During Deck Placement, Ali Naif Inceefe

Masters Theses

Conventional steel I-girder highway bridges utilize cast-in-place concrete deck. Maintaining the deck profile as per project specifications might be a challenging task. Deformation of girders and formwork used for deck placement need to be controlled during deck placement. Differential deflection between girders, exterior girder web out-of-plane deformation, exterior girder warping, or a combination thereof could impact the deck profile. These deformations challenge maintaining deck profile and need to be considered as a part of constructability evaluation. Determining deck profile due to potential girder deformations is necessary before deck placement so that the remedial actions can be implemented when deck finish …

On Wlan Fingerprint Indoor Positioning Systems Clustering, And Classification For Enhanced Performance, Haider G. Al Glehawi

Masters Theses

The most economic and affordable IPS are those incorporating existing infrastructure, such as the widely spread Wireless Local Area Network (WLAN). The Received Signal Strength (RSS) fingerprinting-based system is one of the most promising and powerful techniques so far to be used for indoor positioning. However, there are two challenges in using RSS based IPS; the first challenge is the variation of RSS to indoor multipath propagation, and the second is the high number of Access Points (APs) that are deployed in the region of interest. The first issue leads to degradation in the performance of RSS based IPS, while …

Experimental Comparison Between Hollow Cathodes With Cermet, Lanthanum Hexaboride, And Barium Oxide Insert Materials, Nagual Simmons

Masters Theses

This thesis compares two different hollow cathode assemblies (HCA) using three different insert materials. NASA’s Jet Propulsion Laboratory (JPL) provided the H6 HCA and the Lanthanum Hexaboride (LaB₆) insert. A barium oxide (BaO) insert was purchased from Ebeam and used with the H6 HCA. The novel Cermet material was purchased from Plasma Controls, LLC and the HCA was based on the JPL H6 HCA. Plasma properties in the external region of all three inserts and the internal region of the LaB₆ were determine using two separate Langmuir probes. Various operating points were tested at a combination of …

Control-Oriented Automatic Transmission- Based Powertrain Modeling And Simulation With Judder, Harshal B. Kundale

Masters Theses

This work presents automatic transmission-based powertrain modeling. The powertrain consists of an engine, torque converter with lock up clutch, transmission gearbox, propeller shaft, and vehicle body. Simplified powertrain component models are developed for vehicle powertrain dynamic response analysis and future control work. The powertrain components are modeled with algebraic and first order non-linear differential equations. A MATLAB-based powertrain simulation system is developed to investigate the transient characteristics during lock up of torque converter. Simulation results are used in the determination of effects of judder on torque and angular velocity. Clutch judder is a self-excited vibration that occurs during the clutch …

Mgsnn2: A New Eco-Friendly Wide Band Gap Semiconductor, Krystal R. York

Masters Theses

Materials having a wide band gap (above 2 eV) can provide new alternatives for existing light-emitting diodes (LEDs) and other opto-electronic devices. Currently, many such devices are comprised of low-earth-abundant elements, such as gallium and indium, which are harmful to the environment to extract and difficult to recycle. Alternatively, MgSnN2 is an unexplored material comprised of earth abundant elements which benefit from a mature recycling infrastructure. This material has a predicted band gap of 3.43 eV, indicating that it could be a viable substitute for GaN (band gap of 3.4 eV), which is commonly used in LEDs and other device …

From Architectural Design To Structural Analysis: A Data-Driven Approach To Study Building Information Modeling (Bim) Interoperability, Mohammed Aldegeily

Masters Theses

BIM has been playing an essential role in building construction projects in recent years. It was used to automate many tasks such as clash detection, 4D planning, and quantity takeoff, among others. However, the interoperability of BIM still lacks in many fields across the architecture, engineering, and construction domains. This research studies the interoperability between architectural design and structural analysis. The goal is to explore structural analysis of BIM models through data transfer processes between different software platforms via three types of paths: (1) Application Programming Interface (API); (2) “immediately connect,” which is the direct link between software programs from …

Power-Efficient And Highly Scalable Parallel Graph Sampling Using Fpgas, Muhammad Usman Tariq

Masters Theses

Energy efficiency is a crucial problem in data centers where big data is generally represented by directed or undirected graphs. Analysis of this big data graph is challenging due to volume and velocity of the data as well as irregular memory access patterns. Graph sampling is one of the most effective ways to reduce the size of graph while maintaining crucial characteristics. This thesis presents design and implementation of a field programmable gate array (FPGA) based graph sampling method which is both time- and energy-efficient. This is in contrast to existing parallel approaches which include memory-distributed clusters, multicore and GPUs. …