Engineering Commons^™

Stochastic Methods To Find Maximum Likelihood For Spam E-Mail Classification, Seyed M. -H. Mansourbeigi

Computer Science Student Research

The increasing volume of unsolicited bulk e-mails leads to the need for reliable stochastic spam detection methods for the classification of the received sequence of e-mails. When a sequence of emails is received by a recipient during a time period, the spam filters have already classified them as spam or not spam. Due to the dynamic nature of the spam, there might be emails marked as not spam but are actually real spams and vice versa. For the sake of security, it is important to be able to detect real spam emails. This paper utilizes stochastic methods to refine the …

A 3d Finite Difference Thermal Model Tailored For Additive Manufacturing, Tom Stockman, Judith A. Schneider, Bryant Walker, John S. Carpenter

PRC-Affiliated Research

Physics-based modeling of metal additive manufacturing (AM) processes is computationally challenging due to the very fine meshing required in both time and space. State-of-the-art numerical models that offer great insight into the process have been developed, but they require powerful computational resources and weeks of processing time. Thus, it is often more time-effective to fabricate multiple builds within the time it takes to complete one simulation prediction, further reinforcing the current trial-and-error approach to optimizing the build parameters. This study presents a simplified approach to the transient thermal modeling of the AM process. The numerical model is designed to run …

Affordability Through The Eyes Of Industry Towards A Better Understanding Of The Rocket Economy, Christopher J. White

Research Horizons Day Posters

No abstract provided.

Investigation Of Methylammonium Lead Halide Perovskite Solar Cells, Natalie Mann

Research Horizons Day Posters

No abstract provided.

Development Of A Magnetic Nozzle Model For Puff, Nathan Schilling

Research Horizons Day Posters

No abstract provided.

Efficient Methods For Robust Circuit Design And Performance Optimization For Carbon Nanotube Field Effect Transistors, Muhammad Ali

Dissertations and Theses

Carbon nanotube field-effect transistors (CNFETs) are considered to be promising candidate beyond the conventional CMOSFET due to their higher current drive capability, ballistic transport, lesser power delay product and higher thermal stability. CNFETs show great potential to build digital systems on advanced technology nodes with big benefits in terms of power, performance and area (PPA). Hence, there is a great need to develop proven models and CAD tools for performance evaluation of CNFET-based circuits. CNFETs specific parameters, such as number of tubes, pitch (spacing between the tubes) and diameter of CNTs determine current driving capability, speed, power consumption and area …

Multinomial Logit Analysis Of Injury Severity In Crashes Involving Emotional Drivers, Kristen Hubbert

Research Horizons Day Posters

No abstract provided.

Rotor Wing Interaction Of The Low Reynolds Numbers, Darnisha Crane, Mingtai Chen

Research Horizons Day Posters

No abstract provided.

High-Performing Pgm-Free Aemfc Cathodes From Carbon-Supported Cobalt Ferrite Nanoparticles, Xiong Peng, Varchaswal Kashyap, Benjamin Ng, Sreekumar Kurungot, Lianqin Wang, John R. Varcoe, Mustain E William

Faculty Publications

Efficient and durable non-precious metal electrocatalysts for the oxygen reduction reaction (ORR) are highly desirable for several electrochemical devices, including anion exchange membrane fuel cells (AEMFCs). Here, cobalt ferrite (CF) nanoparticles supported on Vulcan XC-72 carbon (CF-VC) were created through a facile, scalable solvothermal method. The nano-sized CF particles were spherical with a narrow particle size distribution. The CF-VC catalyst showed good ORR activity, possessing a half-wave potential of 0.71 V. Although the intrinsic activity of the CF-VC catalyst was not as high as some other platinum group metal (PGM)-free catalysts in the literature, where this catalyst really shined was …

Removal And Recovery Of Nutrients From Wastewater In Urban And Rural Contexts, Kevin Daniel Orner

USF Tampa Graduate Theses and Dissertations

Efforts to remove and recover nutrients from wastewater are motivated by the United Nations Sustainable Development Goals and the National Academy of Engineering Grand Challenges of Engineering. Of the seventeen Sustainable Development Goals (SDGs), multiple SDGs relate to managing nutrients in wastewater. SDG 6, which is to “ensure availability and sustainable management of water and sanitation for all,” contains targets that aim to improve water quality by reducing pollution, halve the amount of untreated wastewater released to the environment, and increase recycling and safe reuse of wastewater (UN, 2017). SDG 2 seeks to improve food security and SDG 12 seeks …

Ultra-Rapid Microwave Sintering Of Ceramics And Powder Metals, Kirill I. Rybakov, Yury Bykov, Anatoly Eremeev, Sergei Egorov, Vladislav Kholoptsev, Ivan Plotnikov, Andrei Sorokin

Electric Field Enhanced Processing of Advanced Materials II: Complexities and Opportunities

Over the recent years, we have demonstrated ultra-rapid microwave sintering of different ceramic materials, including Al₂O₃, ZrO₂, Y₂O₃, MgAl₂O₄, and Yb:(LaO)₂O₃, using a gyrotron system operating at a frequency of 24 GHz with an output microwave power of up to 6 kW [1-3]. The ceramic pellets were sintered to 98-99.5 % of the theoretical density with the duration of the high-temperature sintering stage not exceeding several minutes. We have shown that the absorbed microwave power required for the ultra-rapid sintering regimes is …

Effect Of The Addition Of Doped-Cobalt On The Properties Of Recycled Tungsten Carbide Powder Sintered By Sps, Alexandre Mégret, Véronique Vitry, Fabienne Delaunois

Electric Field Enhanced Processing of Advanced Materials II: Complexities and Opportunities

A key issue that has appeared in the last twenty years is the availability of certain materials. Cobalt is considered as a critical raw material since it is massively used in batteries for electrical cars [1]. Cobalt is also the usual binder in cemented carbides because it gives excellent hardness to toughness ratio at the tungsten carbide parts. There is a tendency to replace cobalt by other binders such nickel or iron [2] but cobalt remains the best one. Recycling old WC parts is a solution to limit the use of raw cobalt powder and to keep the benefits of …

Details On Csa-Sbl: An Algorithm For Sparse Bayesian Learning Boosted By Partial Erroneous Support Knowledge, Mohammad Shekaramiz, Todd K. Moon, Jacob H. Gunther

Electrical and Computer Engineering Faculty Publications

This report provides details on CSA-SBL(VB) algorithm for the recovery of sparse signals with unknown clustering pattern. More specifically, we deal with the recovery of sparse signals with unknown clustering pattern in the case of having partial erroneous prior knowledge on the supports of the signal. In [1], we provided a modified sparse Bayesian learning model to incorporate prior knowledge and simultaneously learn the unknown clustering pattern. For this purpose, we added one more layer to support-aided sparse Bayesian learning algorithm (SA-SBL) that was proposed in [2]. This layer adds a prior on the shape parameters of Gamma distributions, those …

Soft , Multilayered Electronics For Wearable Devices And Methods To Produce The Same, Carmel Majidi, Michael D. Bartlett, Eric J. Markvicka

Department of Mechanical and Materials Engineering: Faculty Publications

Disclosed herein is an efficient fabrication approach to create highly customizable wearable electronics through rapid laser machining and adhesion - controlled soft materials assembly . Well - aligned , multi - layered materials can be created from 2D and 3D elements that stretch and bend while seamlessly integrating with rigid components such as micro chip integrated circuits ( IC ) , discrete electrical components , and interconnects . These techniques are applied using commercially available materials . These materials and methods enable custom wearable electronics while offering versatility in design and functionality for a variety of bio - monitor ing …

When Engines Go Silent: Speed-To-Fly For Airplane Pilots, Nihad E. Daidzic

Aviation Department Publications

FAA Safety Seminar (GL1590721) held at Minnesota State University, Mankato Wiecking Center Auditorium at 18:00 CST on Thursday, March 14, 2019.

Fischer–Tropsch: Product Selectivity–The Fingerprint Of Synthetic Fuels, Wilson D. Shafer, Muthu Kumaran Gnanamani, Uschi M. Graham, Jia Yang, Cornelius M. Masuku, Gary Jacobs, Burtron H. Davis

Center for Applied Energy Research Faculty and Staff Publications

The bulk of the products that were synthesized from Fischer–Tropsch synthesis (FTS) is a wide range (C₁–C₇₀₊) of hydrocarbons, primarily straight-chained paraffins. Additional hydrocarbon products, which can also be a majority, are linear olefins, specifically: 1-olefin, trans-2-olefin, and cis-2-olefin. Minor hydrocarbon products can include isomerized hydrocarbons, predominantly methyl-branched paraffin, cyclic hydrocarbons mainly derived from high-temperature FTS and internal olefins. Combined, these products provide 80–95% of the total products (excluding CO₂) generated from syngas. A vast number of different oxygenated species, such as aldehydes, ketones, acids, and alcohols, are also embedded in this product range. …

Development And Application Of Decision-Making Tool For Rural Spring-Sourced Gravity-Fed Community Managed Water Systems, Oswaldo Galicia

USF Tampa Graduate Theses and Dissertations

People all over the world still lack access to safe drinking water service. Those with access experience several issues during the first few years of installation that impede on their overall access. In order to improve water services, not only is a proper decision-making tool necessary, taking into account key factors that impact sustainable water service, but proper monitoring and evaluation is also important in ensuring service for the long term. There are several developed assessment tools used for monitoring and evaluation of water systems post-construction, applicable in various scenarios. However, there are only few tools available to facilitate the …

Behavior Of Non-Ductile Slender Reinforced Concrete Columns Retrofit By Cfrp Under Cyclic Loading, Wisam Amer Aules

Dissertations and Theses

In the Middle East region and many countries in the world, older reinforced concrete (RC) columns are deemed to be weak in seismic resistance because of their low amount of reinforcement, low grades of concrete, and large spacing between the transverse reinforcement. The capacity of older RC columns that are also slender is further reduced due to the secondary moments. Appropriate retrofit techniques can improve the capacity and behavior of concrete members. In this study, externally bonded Carbon Fiber Reinforced Polymer (CFRP) retrofit technique was implemented to improve the behavior of RC columns tested under constant axial load and cyclic …

Diagnosis Of Brain Diseases Via Multi-Scale Time-Series Model, Zehua Zhang, Junhai Xu, Jijun Tang, Quan Zou, Fei Guo

Faculty Publications

The functional magnetic resonance imaging (fMRI) data and brain network analysis have been widely applied to automated diagnosis of neural diseases or brain diseases. The fMRI time series data not only contains specific numerical information, but also involves rich dynamic temporal information, those previous graph theory approaches focus on local topology structure and lose contextual information and global fluctuation information. Here, we propose a novel multi-scale functional connectivity for identifying the brain disease via fMRI data. We calculate the discrete probability distribution of co-activity between different brain regions with various intervals. Also, we consider nonsynchronous information under different time dimensions, …

Wettability Of Fully Hydroxylated And Alkylated (001) Α-Quartz Surface In Carbon Dioxide Atmosphere, Aleksandr Abramov, Alireza Keshavarz, Stefan Iglauer

Research outputs 2014 to 2021

Wettability of alkylated quartz surfaces is of primary importance in several technological applications, including the development of oil and gas reservoirs and carbon geo-sequestration. It is intuitively understood and experimentally confirmed that hydroxylated quartz surfaces are hydrophilic. By gradually saturating a hydroxylated (001) α-quartz surface with pentyl groups, we show using molecular dynamics simulations that the surface can also exhibit extreme hydrophobicity. Within a range of surface pentyl group density from 0.29 to 3.18/nm², the contact angle of a water droplet under 10 MPa pressure of carbon dioxide at 300 K changes from 10–20 to 180°. This study …

Recipe For Disaster, Zac Travis

MFA Thesis Exhibit Catalogs

Today’s rapid advances in algorithmic processes are creating and generating predictions through common applications, including speech recognition, natural language (text) generation, search engine prediction, social media personalization, and product recommendations. These algorithmic processes rapidly sort through streams of computational calculations and personal digital footprints to predict, make decisions, translate, and attempt to mimic human cognitive function as closely as possible. This is known as machine learning.

The project Recipe for Disaster was developed by exploring automation in technology, specifically through the use of machine learning and recurrent neural networks. These algorithmic models feed on large amounts of data as a …

Low-Loss, Compact, Spot-Size-Converter Based Vertical Couplers For Photonic Integrated Circuits, Praveen K.J. Singaravelu, G.C.R. Devarapu, Sebastian A. Schulz, Quentin Wilmart, Stéphane Malhouitre, Ségolène Olivier, Liam O’Faolain

Cappa Publications

In recent years, the monolithic integration of new materials such as SiN, Ge and LiNbO3 on silicon (Si) has become important to the Si photonics community due to the possibility of combining the advantages of both material systems. However, efficient coupling between the two different layers is challenging. In this work, we present a spot size converter based on a two-tier taper structure to couple the optical mode adiabatically between Si and SiN. The fabricated devices show a coupling loss as low as 0.058 dB  ±  0.01 dB per transition at 1525 nm. The low coupling loss between the Si …

Evaluation Of Photogrammetry And Inclusion Of Control Points: Significance For Infrastructure Monitoring, Renee Oats, Rudiger Escobar-Wolf, Thomas Oommen

Department of Civil, Environmental, and Geospatial Engineering Publications

Structure from Motion (SfM)/Photogrammetry is a powerful mapping tool in extracting three-dimensional (3D) models from photographs. This method has been applied to a range of applications, including monitoring of infrastructure systems. This technique could potentially become a substitute, or at least a complement, for costlier approaches such as laser scanning for infrastructure monitoring. This study expands on previous investigations, which utilize photogrammetry point cloud data to measure failure mode behavior of a retaining wall model, emphasizing further robust spatial testing. In this study, a comparison of two commonly used photogrammetry software packages was implemented to assess the computing performance of …

An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan

PRC-Affiliated Research

In this work, a model of a proton exchange membrane fuel cell (PEMFC) is presented. A dynamic performance characterization is performed to assess the cell transient response to input variables. The model used in the simulation considers three different phenomena: mass transfer, thermodynamics, and electrochemistry. The main sources of voltage loss are presented: activation, electrical resistance, and concentration. The model is constructed to avoid the use of fitted parameters, reducing the experimentation required for its validation. Hence, the electrochemical model is parameterized by physical variables, including material properties and geometrical characteristics. The model is demonstrated as a test-bed for PEMFC …

An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan

PRC-Affiliated Research

In this work, a model of a proton exchange membrane fuel cell (PEMFC) is presented. A dynamic performance characterization is performed to assess the cell transient response to input variables. The model used in the simulation considers three different phenomena: mass transfer, thermodynamics, and electrochemistry. The main sources of voltage loss are presented: activation, electrical resistance, and concentration. The model is constructed to avoid the use of fitted parameters, reducing the experimentation required for its validation. Hence, the electrochemical model is parameterized by physical variables, including material properties and geometrical characteristics. The model is demonstrated as a test-bed for PEMFC …

Usu Researchers Model Effects Of Microgravity On Muscles During Spaceflight | College Of Engineering, Utah State University

College of Engineering News

Researchers at Utah State University are improving the ways we model muscle loss during spaceflight. Using a rotating cell culture device that simulates microgravity, a team of biological engineers tested various materials and methods to develop a protocol that mimics the physical changes seen in atrophying muscle.

An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan

PRC-Affiliated Research

In this work, a model of a proton exchange membrane fuel cell (PEMFC) is presented. A dynamic performance characterization is performed to assess the cell transient response to input variables. The model used in the simulation considers three different phenomena: mass transfer, thermodynamics, and electrochemistry. The main sources of voltage loss are presented: activation, electrical resistance, and concentration. The model is constructed to avoid the use of fitted parameters, reducing the experimentation required for its validation. Hence, the electrochemical model is parameterized by physical variables, including material properties and geometrical characteristics. The model is demonstrated as a test-bed for PEMFC …

Implementation Of Augmented Reality In Sae Mini Baja, Brady S. Hales

Undergraduate Honors Theses

Engineers often encounter difficulties in connecting digital data with its physical counterpart. This applies to processing and interpreting data as well as effectively communicating design ideas and considerations. Augmented reality has the ability to solve these problems by overlaying digital data on a physical object. This allows engineers to further explore design considerations such as ergonomics as well as communicate data such as, Finite Element Analysis. This communication may be realized in discussing and collaborating with colleagues, as well as to judges in design reviews. Augmented reality is beneficial in these cases and is further explored in this thesis, utilizing …

Seismic Behavior Of Screen Grid Core Insulated Concrete Form Walls, Anwer Sabah Mohammed Mohammed

Dissertations and Theses

The use of the insulated concrete form (ICF) walls in residential buildings has increased over the past few decades. Much research has been conducted to evaluate the lateral strength of these walls by applying monotonic and cyclic loadings. In the current study, full-scale shake table experiments were employed to evaluate the in-plane behavior of four screen grid insulated concrete form (SGICF) walls. The first two wall specimens utilized dry fit insulated form blocks made from recycled expanded polystyrene granules that were bonded together with cement. When stacked, the cavities in the blocks formed a grid of cores that are evenly …

Evaluation Of Strand To Grout Bond In Post-Tensioned Tendons With Corrosion Inhibiting Penetrants, Kurt Kupselaitis

USF Tampa Graduate Theses and Dissertations

Post tensioning bridges is an efficient way of construction where segments of a bridge are strung together using small diameter high strength strands. The steel strands are passed through internal and/or external ducts within the concrete segments, jacked to high levels of stress, anchored using steel wedges, and then filled with a corrosion inhibiting filler. A cementitious material called grout has been widely used for over 50 years as this filler. The Federal Highway Administration design and construction manual provides recommendations in the properly filling techniques to ensure the tendons are full of grout. Despite the level of detail the …