Engineering Commons^™

Avalanche Statistics From Data With Low Time Resolution, Michael Leblanc, Aya Nawano, Wendelin J. Wright, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen

Faculty Journal Articles

Extracting avalanche distributions from experimental microplasticity data can be hampered by limited time resolution. We compute the effects of low time resolution on avalanche size distributions and give quantitative criteria for diagnosing and circumventing problems associated with low time resolution. We show that traditional analysis of data obtained at low acquisition rates can lead to avalanche size distributions with incorrect power-law exponents or no power-law scaling at all. Furthermore, we demonstrate that it can lead to apparent data collapses with incorrect power-law and cutoff exponents. We propose new methods to analyze low-resolution stress-time series that can recover the size distribution …

On The Origin Of Synthetic Life: Attribution Of Output To A Particular Algorithm, Roman V. Yampolskiy

Faculty and Staff Scholarship

With unprecedented advances in genetic engineering we are starting to see progressively more original examples of synthetic life. As such organisms become more common it is desirable to gain an ability to distinguish between natural and artificial life forms. In this paper, we address this challenge as a generalized version of Darwin's original problem, which he so brilliantly described in On the Origin of Species. After formalizing the problem of determining the samples' origin, we demonstrate that the problem is in fact unsolvable. In the general case, if computational resources of considered originator algorithms have not been limited and priors …

Commercial Space Situational Awareness (Ssa) Capabilities And Their Benefits For Civilian Space Traffic Management (Stm), Mark A. Skinner

Space Traffic Management Conference

Paralleling (but lagging) satellite development, SSA, long the sole domain of sophisticated militaries, now includes commercial providers. These commercial capabilities, identified as beneficial to the sustainable use of outer space[1], have demonstrated technical sophistication sufficient to positively contribute to the mitigation of satellite interference and provide actionable SSA information. Utilizing small optical telescopes, these entities are able to determine the orbits of objects in the geosynchronous orbit (GSO) to sizes as small as 1 m², with measured positional uncertainties of 10s of meters, on the order of the size of a modern communications satellite. These techniques …

Human Attention Detection Using Am-Fm Representations, Wenjing Shi

Electrical and Computer Engineering ETDs

Human activity detection from digital videos presents many challenges to the computer vision and image processing communities. Recently, many methods have been developed to detect human activities with varying degree of success. Yet, the general human activity detection problem remains very challenging, especially when the methods need to work “in the wild” (e.g., without having precise control over the imaging geometry). The thesis explores phase-based solutions for (i) detecting faces, (ii) back of the heads, (iii) joint detection of faces and back of the heads, and (iv) whether the head is looking to the left or the right, using standard …

Relaxation In Bolted Assemblies, Samuel Augustus Moeller

Theses and Dissertations

The purposes of this investigation were to (a) extend previously developed elastic spring models for bolt assemblies to include simulating creep loss in the bolt and the threads and (b) to present an approach in which appropriate spring stiffness in the model are determined rationally. Previous efforts at modeling tension in bolts have been limited in that they were not readily applicable to analyses of realistic bolted connections. The simulated load distributions on the shank and the threads in a single-bolt assembly showed good comparison to the gathered experimental data as did the simulated, time dependent creep loss in the …

Electrical & Computer Engineering News, Georgia Southern University

Electrical & Computer Engineering: News & Publications (2014-2023)

• Dr. Sungkyun Lim receives Research Grant from ARRIS, Inc.

Measurement And Analysis Of Iii-V & Ii-Vi Infrared Detectors: Radiometric, Noise Spectrum, And Radiation Tolerance Performance, Vincent M. Cowan

Nanoscience and Microsystems ETDs

Infrared (IR) hybrid detector arrays and discrete detectors operated in the space environment may be subjected to a variety of sources of natural radiation while in orbit. This means IR detectors intended for applications such as space-based intelligence, surveillance, and reconnaissance (ISR) or space-situational awareness (SSA) must not only have high performance (high quantum efficiency, h and low dark-current density, J_D, and preferably minimal 1/f noise content), but also their radiation tolerance or ability to withstand the effects of the radiation they would expect to encounter in space must be characterized and well understood. As the effects of …

Fishing With Geographic Information Systems, James L. Freeman

Scholars Week

Title: Fishing With Geographic Information Systems (GIS)

Author: Lance Freeman

Mentor: Dr. Haluk Cetin

This study was conducted to utilize multiple geographic information systems (GIS) applications for specific parts of Kentucky Lake and Lake Barkley. Using Lowrance Insight Genesis, along with topographical maps to help utilize time on the water keeping fisherman in the areas they want to target for specific types of cover and structure to help catch what they are after. Most of this information had to come from typical seasonal patterns and research into a lakes history as to how it was made, along with what is …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• Samuel Fakorede Wins Prestigious IEEE Award

Improved 2d And 3d Resistivity Surveys Using Buried Electrodes And Optimized Arrays: The Multi-Electrode Resistivity Implant Technique (Merit), Henok Gidey Kiflu

USF Tampa Graduate Theses and Dissertations

This thesis presents a novel resistivity method called Multi-Electrode resistivity technique (MERIT) that is used for high resolution imaging of complex geologic features at depth and near the edges of survey lines. The MERIT electrodes are especially shaped and designed to be self-driven using a robust-direct push technique. Measurements are taken using optimized arrays that are generated using a modified version of the “Compare-R” optimization algorithm. This work focused on both two-dimensional (MERIT2D) and three-dimensional (MERIT3D) applications of the buried array and show the relevance of the additional information gained by the addition of deep electrodes especially in sites with …

Photocatalytic Reduction Of Co2 With Tunable Bandgap And Bandedge Materials, Thuhuong T. Ngo

USF Tampa Graduate Theses and Dissertations

Solar energy is a sustainable resource which has substantial potential to meet the increasing demand for renewable energy. Though there has been some success in harvesting solar energy for electricity production, converting solar energy to chemical energy as fuels is still a challenge due to low efficiency.

Since the discovery of TiO₂ photocatalysts for splitting water (4) and reducing CO₂ (5) to form useful chemical feedstock such as H₂, CO and CH₄, much research has been done to increase the efficiency of photocatalysts. However, the current conversion efficiency of photocatalysts remains low (~5%) (6, …

Reduced Dimensionality Effects In Gd-Based Magnetocaloric Materials, Hillary Faith Belliveau

USF Tampa Graduate Theses and Dissertations

Magnetic refrigeration based on the magnetocaloric effect (MCE) is a promising alternative to conventional gas compression based cooling techniques. Understanding impacts of reduced dimensionality on the magnetocaloric response of a material such as Gadolinium (Gd) or its alloys is essential in optimizing the performance of cooling devices, which is also the overall goal of this thesis. We have determined, in the first part of the thesis, that laminate structures of pure Gd produced by magnetron sputtering have several disadvantages. The target material (pure Gd), ultra-high vacuum components, and the electrical energy it takes to run the manufacturing process are all …

Spaceways: Airspace In Outer Space, Scott Haeffelin

Space Traffic Management Conference

Forecasted future demand in space travel is driving the need for the development of space traffic management. Currently, orbital space traffic is mostly unregulated with internationally agreed upon best practices and self-interest driving space operators to avoid collisions with other spacecraft. This paper explores the future of space travel by presenting a concept of creating “airspace in space” or spaceways to manage the ever growing volumes of space traffic. Spaceways are analogous to airspace for aircraft with the goal of increasing levels of safety and reducing probabilities of collision. These goals can be achieved by creating traffic rules, defining valuable …

A Novel Approach For Controlled Deorbiting And Reentry Of Small Spacecraft, Larry H. Fineberg, Justin Treptow, Timothy Bass, Scott Clark, Yusef Johnson, Bradley Poffenberger

Space Traffic Management Conference

No abstract provided.

Space Analysis And Research Centers (Sparcs) For Ssa Data And Analytics, Phillip Cunio, Brien Flewelling

Space Traffic Management Conference

Widespread use of massive data and increasing reliance on spaceborne infrastructure are two of the emerging megatrends of the early 21^st century. However, both come with liabilities: movement and processing of large data volumes is very expensive, and reliance on spaceborne infrastructure adds risk that problems in the still incompletely-understood space domain might cause work disruptions.

ExoAnalytic proposes the use of Space Analysis and Research Centers (SpARCs) as a way to begin addressing both these issues. A SpARC is a facility which integrates volumes of data collected on satellites, centrally analyzes it, and makes available resulting useful information. The …

Examining Time To Evacuate Dynamically Activated Aircraft Hazard Areas, Zheng Tao, Granghuai Wang, Ashley G. Williams, Jon L. Semanek, Jonathan L. Schwartz

Space Traffic Management Conference

The growth in launch and reentry operations in the National Airspace System (NAS) presents the Federal Aviation Administration (FAA) with the challenge of integrating them more efficiently while also minimizing effects on other NAS users and maintaining safety. Currently, to maintain safety and account for unforeseen events such as vehicle breakup, the FAA segregates large amounts of airspace, called Aircraft Hazard Areas (AHAs), from traditional NAS users during launch and reentry operations. In order to minimize effects on NAS users, some AHAs during reentry are dynamically activated only if an unexpected event occurs. If a dynamic AHA is activated, then …

Projecting Air Traffic Impact Of Blocked Airspaces, Amal Srivastava, Neil Gahart

Space Traffic Management Conference

FAA frequently blocks strategically located airspaces to ensure operational safety in the vicinity of hazardous operations such as space launches and military exercises. As demand for access to airspace continues to rise, the need for, and the impact of blocked airspaces is likely to grow. Users such as space operators have no advanced insights into potential NAS impact of airspaces blocked due to their operations, nor do they possess ways to minimize it. This paper presents a model that would give users this insight. The model estimates levels of air traffic likely to intersect arbitrary airspace volumes on a daily …

Air Traffic Impact Analysis Design For A Suborbital Point-To-Point Passenger Transport Concept, Tanja Luchkova, Sven Kaltenhaeuser, Frank Morlang

Space Traffic Management Conference

Space flight activities are growing on an international level, thereby creating an evident need for a safe and efficient integration of space vehicle operations into the air traffic system. For concepts like very high-speed intercontinental passenger transport via suborbital point-2-point flights, as it is proposed by the DLR SpaceLiner, this integration issue is becoming especially relevant. As part of a case study approach to analyse the effects of space vehicle operations on air traffic and to evaluate mitigation strategies and optimized ATM integration, a traffic impact analysis has been prepared and conducted for the SpaceLiner return trajectory towards a European …

Frequency Tunable Antennas And Surface Microwave Imaging System Using Microfluidic Reconfiguration Techniques, Abhishek Dey

USF Tampa Graduate Theses and Dissertations

Reconfigurable radio frequency (RF) devices are attractive for miniaturization of wireless components and systems by handling functionality of multiple distinct devices. Existing reconfiguration techniques rely on device loadings with semiconductor diodes, ferrite/ferroelectric materials, and microelectromechanical system (MEMS) switches and capacitors. However, it is well-recognized that these techniques cannot fully address important system metrics such as high efficiency, wide frequency tuning range, high power handling capability and cost. Therefore, novel alternative techniques are highly desirable to advance the state of the art in reconfigurable RF devices. The aim of this dissertation is to investigate the novel concept of microfluidically loaded reconfigurability …

The Pathway To Net Zero Energy Buildings: A Practical Practitioner Guide, Celine Manoosingh, Bonnie Mcmakin, Debalina Ghosh

Civil Engineering & Construction: Faculty Publications

Net Zero Energy Buildings (NZEB) are being constructed throughout the United States, promoting construction practices that achieve more than the minimum energy performance required to meet current codes and demonstrating their financial feasibility. The practicality of these technologies have been proven, in many cases, to improve energy efficiencies, and to provide buildings with capabilities to produce the energy levels necessary to sustain the building operation systems while maintaining comfort and minimizing the financial payback period of the investment. Broadly, these strategies include changes in site selection, water efficiencies, reducing energy consumption, and utilizing environmentally benign materials. This paper presents a …

Hydrodeoxygenation Of Pinyon Juniper Catalytic Pyrolysis Oil To Hydrocarbon Fuels, Hossein Jahromi, Foster Agblevor

Biological Engineering Faculty Publications

As a renewable source, biomass is an essential option for diminishing dependence on conventional fossil fuel energy sources. Pyrolysis is a promising technology for the conversion of biomass into liquid fuels. However, several challenges associated with using pyrolysis oils such as their high acidity and low energy content inhibit their direct use as transportation fuels. We conducted a batch hydrodeoxygenation of pinyon juniper catalytic pyrolysis oil using Ni/SiO2-Al2O3 catalyst to improve the following properties of the oil: heating value, acidity, oxygen content, water content, and viscosity. During the hydrogenation process, the influence of four experimental factors; temperature, catalyst loading, residence …

Advancements In Thermal Integrity Profiling Data Analysis, Kevin Russell Johnson

USF Tampa Graduate Theses and Dissertations

Thermal Integrity Profiling (TIP) is a relatively new non-destructive test method for evaluating the post-construction quality of drilled shafts. Therein anomalies in a shaft are indicated by variations in its thermal profile when measured during the curing stages of the concrete. A considerable benefit with this method is in the ability to detect anomalies both inside and outside the reinforcement cage, as well as provide a measure of lateral cage alignment. Similarly remarkable, early developments showed that the shape of a temperature profile (with depth) matched closely with the shape of the shaft, thus allowing for a straightforward interpretation of …

Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa

USF Tampa Graduate Theses and Dissertations

Multifunctional nanocomposites are promising for a variety of applications ranging from microwave devices to biomedicine. High demand exists for magnetically tunable nanocomposite materials. My thesis focuses on synthesis and characterization of novel nanomaterials such as polymer nanocomposites (PNCs) and multi-walled carbon nanotubes (MWCNTs) with magnetic nanoparticle (NP) fillers.

Magnetite (Fe₃O₄) and cobalt ferrite (CoFe2O4) NPs with controlled shape, size, and crystallinity were successfully synthesized and used as PNC fillers in a commercial polymer provided by the Rogers Corporation and poly(vinylidene fluoride). Magnetic and microwave experiments were conducted under frequencies of 1-6 GHz in the presence of …

Two-Phase Transport In Proton Exchange Membrane Fuel Cells, Kazuya Tajiri

TechTalks

In Multiscale Transport Process Laboratory our research is focused on the experimental and computational analysis of transport phenomena in electrochemical devices and propulsion systems. In this talk our research activity on proton exchange membrane fuel cells (PEMFCs) for automotive application will be explained. Water management is one of the most critical issues in PEMFCs. The water generated in catalyst layer as a product of the electrochemical reaction needs to be removed through porous media by diffusion if it’s vapor, or by capillarity in case of liquid. In flow channels, the liquid water is removed primarily by inertial force of the …

Solid State Sound: A "Hot" Topic, Andrew Barnard

TechTalks

As seen with the latest iPhone 7 release, traditional audio components can now be a limiting factor in technology design. What if we could make a loudspeaker with no moving parts and virtually no weight? Carbon nanotube loudspeakers are such devices. They create sound using heat oscillations, as opposed to a moving diaphragm. They have the thickness of only a handful of carbon atoms, are flexible and stretchable. In this TechTalk I’ll discuss the carbon nanotube loudspeaker and the design challenges in maturing this intriguing technology.

Rapid Metal Design, Paul G. Sanders

TechTalks

Computational material design tools have advanced so that custom materials for specific applications can be designed and manufactured. In the case of metals, my team designs aluminum, iron, nickel, and copper (more to come) alloys using Thermo-Calc with Bayesian optimization. We design microstructures to deliver properties such as strength, conductivity, and corrosion resistance. Custom tailored materials are now practical solutions to engineering challenges, and materials engineers work on multi-disciplinary teams to deliver integrated, enhanced product designs.

Point-Of-Care Microfluidic Device For Blood Typing, Hector Moncada-Hernandez

TechTalks

There has been increasing efforts to translate laboratory blood tests analysis into portable, reliable, and cheap miniaturized devices. Electrokinetic-based microfluidic devices provide a new approach to blood tests with a simple infrastructure for the manipulation of cells. Previous studies show red blood cells’ (RBC) dielectrophoretic response changes based on the different ABO-Rh antigens present in the cells membrane. In this research, an alternate-current electric signal with a frequency sweep (0.1 – 1 MHz) is applied through an array of electrodes to generate non-uniform electric fields and induce dielectrophoretic forces on RBC from all eight blood types. The RBC’s response to …

Wearable Electronics, Human-Centered Monitoring, Ye Sarah Sun

TechTalks

Non-contact solution in wearable electronics: A conventional clinical system requires the use of wet electrodes that are in contact with skin using conductive gel to acquire physiological signals. Those systems can acquire high quality signals but may not be feasible for a long-term purpose due to the skin irritation and allergic contact dermatitis. The emerging of human-centered monitoring calls for alternative solutions. Recent technological advances enable capacitive measurement that can acquire signals through cloth or even with an air gap in wearable condition. In this TechTalk I will introduce the non-contact solution in wearable electronics.

Benchmark Levels For The Consumptive Water Footprint Of Crop Production For Different Environmental Conditions: A Case Study For Winter Wheat In China, La Zhuo, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Meeting growing food demands while simultaneously shrinking the water footprint (WF) of agricultural production is one of the greatest societal challenges. Benchmarks for the WF of crop production can serve as a reference and be helpful in setting WF reduction targets. The consumptive WF of crops, the consumption of rainwater stored in the soil (green WF), and the consumption of irrigation water (blue WF) over the crop growing period varies spatially and temporally depending on environmental factors like climate and soil. The study explores which environmental factors should be distinguished when determining benchmark levels for the consumptive WF of crops. …

Optimal Demand Response Models With Energy Storage Systems In Smart Grids, Mohemmed Masooud Alhaider

USF Tampa Graduate Theses and Dissertations

This research aims to develop solutions to relieve system stress conditions in electric grids. The approach adopted in this research is based on a new concept in the Smart Grid, namely, demand response optimization. A number of demand response programs with energy storage systems are designed to enable a community to achieve optimal demand side energy management.

The proposed models aim to improve the utilization of the demand side energy through load management programs including peak shaving, load shifting, and valley lling. First, a model is proposed to nd the optimal capacity of the battery energy storage system (BESS) to …