Engineering Commons^™

Transmission-Line Equivalent And Microstrip Structure For Planar Möbius Loop Resonator, Kirti Dhwaj, Hanseuyng Lee, Lijun Jiang, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

A transmission line model for planar Möbius loop resonator is presented. Theoretical background for the Möbius loop is developed by treating it as a ring resonator. Even-Odd mode analysis is used to account for the dual mode nature of the resonator. Also, the presence of two transmission zeroes is explained using the proposed model. The transmission line model is then used to implement a simple microstrip version of the Möbius loop resonator. A single resonator is then used to implement a dual-mode bandpass filter. Simulation and test results of the structure are presented.

Enabling Distributed Scientific Computing On The Campus, Derek J. Weitzel

School of Computing: Dissertations, Theses, and Student Research

Campus research computing has evolved from many small decentralized resources, such as individual desktops, to fewer, larger centralized resources, such as clusters. This change has been necessitated by the increasing size of researcher's workloads, but this change has harmed the researcher's user experience. We propose to improve the user experience on the computational resources by creating an overlay cluster they are able to control. This overlay should transparently scale to national cyberinfrastructure as the user's demands increase.

We explore methods for improving the user experience when submitting jobs on a campus grid. To this end, we created a remote submission …

Impact Assessment Of Net Metering On Smart Home Cyberattack Detection, Yang Liu, Shiyan Hu, Jie Wu, Yiyu Shi, Yier Jin

Electrical and Computer Engineering Faculty Research & Creative Works

Despite the increasing popularity of the smart home concept, such a technology is vulnerable to various security threats such as pricing cyberattacks. There are some technical advances in developing detection and defense frameworks against those pricing cyberattacks. However, none of them considers the impact of net metering, which allows the customers to sell the excessively generated renewable energy back to the grid. At a superficial glance, net metering seems to be irrelevant to the cybersecurity, while this paper demonstrates that its implication is actually profound. In this paper, we propose to analyze the impact of the net metering technology on …

College Of Engineering News, Georgia Southern University

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

• MSAE Student Wins NSF Fellowship

A Spline Framework For Optimal Representation Of Semiperiodic Signals, Farzin G. Guilak

Dissertations and Theses

Semiperiodic signals possess an underlying periodicity, but their constituent spectral components include stochastic elements which make it impossible to analytically determine locations of the signal's critical points. Mathematically, a signal's critical points are those at which it is not differentiable or where its derivative is zero. In some domains they represent characteristic points, which are locations indicating important changes in the underlying process reflected by the signal.

For many applications in healthcare, knowledge of precise locations of these points provides key insight for analytic, diagnostic, and therapeutic purposes. For example, given an appropriate signal they might indicate the start or …

Method And Apparatus For Diagnosing And Assessing Centralized Pain, Jeffrey Hargrove

Mechanical Engineering Patents

Methods for central pain diagnosis and assessment, symptom severity prediction, and therapeutic intervention effect determination. The diagnosis and assessment method includes a statistical comparison between a subject's quantitative brain function assessment and either a database of quantitative assessments of brain functions of healthy individuals, or a database of quantitative assessments of brain functions of individuals known to have been suffering from chronic pain as a result of the abnormal brain function condition. Diagnosis and assessment may be accomplished using a neuroimaging device to sense and generate images representing central nervous system function, using a sensory stimulation device to stimulate brain …

A Mathematical Model Of A Control Systems Hypothesis Of N-Methyl-D-Aspartate-Receptor-Mediated Ethanol Dependence And Withdrawal Dynamics, Carlos Gutierrez

Theses and Dissertations

The biochemical effects of ethanol on the human brain are manifested through many neurological pathways. Chronic exposure to the depressant has been shown to result in physical dependence. Subsequent cessation results in withdrawal symptoms such as seizures and both short- and long-term changes in neurological activity. One of the primary conduits implicated in the pathways of ethanol dependence and withdrawal is the detection of glutamate via N-methyl-D-aspartate (NMDA) receptors (NMDARs). Ethanol molecules inhibit these receptors, and consequent NMDA-induced glutamatergic changes can result in dependence on ethanol in order to sustain normal brain function. This study considers the relocation control of …

Tackling Voltage Emergencies In Noc Through Timing Error Resilience., Rajesh Jayashankarashridevi, Dean Michael Ancajas, Koushik Chakraborty, Sanghamitra Roy

Electrical and Computer Engineering Faculty Publications

Aggressive technology scaling exacerbates the problem of voltage emergencies in emerging MPSoC systems. Network-on-Chips, the de-facto standard for connecting on-chip components in forthcoming devices play a central role in providing robust and reliable communication. In this work, we propose DrNoC (droop resilient network-on-chip)-two microarchitectural techniques to mitigate voltage emergency-induced timing errors in NoCs and preserve error-free communication throughout the network. DrNoC employs frequency downscaling and a pipeline error-recovery mechanism to reclaim corrupted flits in the router. Compared to the recently proposed NSFTR fault-tolerant technique, DrNoC offers a 27% improvement in energy-delay efficiency.

Improved Terahertz Modulation Using Germanium Telluride (Gete) Chalcogenide Thin Films, Alexander H. Gwin, Christopher H. Kodama, Tod V. Laurvick, Ronald Coutu Jr., Philip F. Taday

Faculty Publications

We demonstrate improved terahertz (THz) modulation using thermally crystallized germanium telluride (GeTe) thin films. GeTe is a chalcogenide material that exhibits a nonvolatile, amorphous to crystalline phase change at approximately 200 °C, as well as six orders of magnitude decreased electrical resistivity. In this study, amorphous GeTe thin films were sputtered on sapphire substrates and then tested using THz time-domain spectroscopy (THz-TDS). The test samples, heated in-situ while collecting THz-TDS measurements, exhibited a gradual absorbance increase, an abrupt nonvolatile reduction at the transition temperature, followed by another gradual increase in absorbance. The transition temperature was verified by conducting similar thermal …

Improved Terahertz Modulation Using Germanium Telluride (Gete) Chalcogenide Thin Films, A. H. Gwin, C. H. Kodama, T. Laurvick, Ronald A. Coutu Jr., P. F. Taday

Electrical and Computer Engineering Faculty Research and Publications

We demonstrate improved terahertz (THz) modulation using thermally crystallized germanium telluride (GeTe) thin films. GeTe is a chalcogenidematerial that exhibits a nonvolatile, amorphous to crystalline phase change at approximately 200 °C, as well as six orders of magnitude decreased electrical resistivity. In this study, amorphous GeTe thin filmswere sputtered on sapphire substrates and then tested using THz time-domain spectroscopy (THz-TDS). The test samples, heated in-situ while collecting THz-TDS measurements, exhibited a gradual absorbance increase, an abrupt nonvolatile reduction at the transition temperature, followed by another gradual increase in absorbance. The transition temperature was verified by conducting similar thermal tests while …

Nanowires, Nanowire Junctions, And Methods Of Making The Same, Charles Elijah May, Vijay Pal Singh, Suresh K. S. Rajaputra

Electrical and Computer Engineering Faculty Patents

Disclosed is a nanostructure including a first set of nanowires formed from filling a plurality of voids of a template. The nanostructure also includes a second set of nanowires formed from filling a plurality of spaces created when the template is removed, such that the second set of nanowires encases the first set of nanowires. Several methods are also disclosed. In one embodiment, a method of fabricating a nanostructure including nanowires is disclosed. The method may include forming a first set of nanowires in a template, removing a first portion of the template, thereby creating spaces between the first set …

A Multivariate Modeling Approach For Generating Ensemble Climatology Forcing For Hydrologic Applications, Sepideh Khajehei

Dissertations and Theses

Reliability and accuracy of the forcing data plays a vital role in the Hydrological Streamflow Prediction. Reliability of the forcing data leads to accurate predictions and ultimately reduction of uncertainty. Currently, Numerical Weather Prediction (NWP) models are developing ensemble forecasts for various temporal and spatial scales. However, it is proven that the raw products of the NWP models may be biased at the basin scale; unlike model grid scale, depending on the size of the catchment. Due to the large space-time variability of precipitation, bias-correcting the ensemble forecasts has proven to be a challenging task. In recent years, Ensemble Pre-Processing …

Multivalent Rechargeable Batteries, Sudhaprasanna Kumar Padigi

Dissertations and Theses

Li⁺ ion batteries have been the mainstay of high energy storage devices that have revolutionized the operating life time of consumer electronic devices for the past two decades. However, there is a steady increase in demand for energy storage devices with the ability to store more energy and deliver them at high power at low cost, without comprising safety and lifetime.

Li-ion batteries have had significant challenges in increasing the amount of stored energy without affecting the overall lifetime and the ability to deliver stored energy. In order to store and deliver more energy, more lithium ions need to …

Biodegradable Medical Device Having An Adjustable Degradation Rate And Methods Of Making The Same, Yuebin Guo, Michael Sealy, Meisam Salahshoor Pirsoltan

Department of Mechanical and Materials Engineering: Faculty Publications

Disclosed herein are biodegradable medical devices comprising biodegradable material (e.g., magnesium-calcium alloys) having an adjustable rate of degradation that can be used in various applications, including, but not limited to, drug delivery applications, cardiovascular applications, and orthopedic applications to make biodegradable and biocompatible devices. Also disclosed herein are methods of making biodegradable medical devices comprising biodegradable materials by using, for instance, hybrid dry cutting/hydrostatic burnishing.

Spotlight On Graphene Research From The Middle East, Kathleen A. Lehman

University Libraries Faculty Publications and Presentations

In an extension to the 2011 article “Reviews of Science for Science Librarians: Graphene” (Lehman 2011), this paper seeks to continue exploring the trend of graphene research but limits its focus to the research production of countries in the Middle East. In addition to reporting on the research output of this group of countries, this article will also examine the most prolific Middle Eastern graphene authors,their supporting institutions and funding agencies, the most cited publications from this group, the journals most used for publication of their work, and the general trend in graphene research growth in the Middle East. As …

Development Of Polymer Composite Based Enabling Technologies For Lab-On-A-Chip Devices, Vinicio Carias

USF Tampa Graduate Theses and Dissertations

This dissertation presents enabling technologies to fabricate thermo-responsive polymer composite based Lab-on-a-Chip (LOC) devices. LOC devices, also known as micro-total-analytical systems (microTAS) or microfluidic devices can amalgamate miniaturized laboratory functions on a single chip. This significant size reduction decreases the amount of required fluid volumes down to nano or pico-liters. The main commercial application of LOC devices is the biomedical fields. However, these devices are anticipated to make a technological revolution similar to the way miniaturization changed computers. In fact, medical and chemical analyses are predicted to shift from room-sized laboratories to hand-held portable devices.

This dissertation is divided into …

Evaluating Global Sensitivity Analysis Methods For Hydrologic Modeling Over The Columbia River Basin, Maysoun Ayad Hameed

Dissertations and Theses

Global Sensitivity Analysis (GSA) approach helps to identify the effectiveness of model parameters or inputs and thus provides essential information about the model performance. The effects of 14 parameters and one input (forcing data) of the Sacramento Soil Moisture Accounting (SAC-SMA) model are analyzed by using two GSA methods: Sobol' and Fourier Amplitude Sensitivity Test (FAST). The simulations are carried out over five sub-basins within the Columbia River Basin (CRB) for three different periods: one-year, four-year, and seven-year. The main parameter sensitivities (first-order) and the interactions sensitivities (second-order) are evaluated in this study. Our results show that some hydrological processes …

Pseudocreep In Shape Memory Alloys, Vigel Raj Russalian

Theses and Dissertations

Interruption of mechanical loading of Shape Memory Alloys (SMAs) exhibits a creep-like phenomenon that is manifested as positive accumulation or negative accumulation in strain (i.e. strain recovery) when stress is held constant during loading or unloading, respectively. Conversely, this effect is also found as stress relaxation/stiffening during the loading/unloading when the strain is arrested. An apparently similar phenomenon, reported in literature by many researchers as caused by thermomechanical coupling, was found to exist in shape memory alloy materials during pseudoelastic deformation as well as shape memory effect. However, experiments conducted in our laboratory on the material indicated that the phenomenon …

Development Of A National Anthropogenic Heating Database With An Extrapolation For International Cities, David J. Sailor, Matei Georgescu, Jeffrey M. Milne, Melissa A. Hart

Mechanical and Materials Engineering Faculty Publications and Presentations

Given increasing utility of numerical models to examine urban impacts on meteorology and climate, there exists an urgent need for accurate representation of seasonally and diurnally varying anthropogenic heating data, an important component of the urban energy budget for cities across the world. Incorporation of anthropogenic heating data as inputs to existing climate modeling systems has direct societal implications ranging from improved prediction of energy demand to health assessment, but such data are lacking for most cities. To address this deficiency we have applied a standardized procedure to develop a national database of seasonally and diurnally varying anthropogenic heating profiles …

Design Method For Wideband Circularly Polarized Slot Antennas, Adam Narbudowicz, Matthias John, Vit Sipal, Xiulong Bao, Max Ammann

Articles

A compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of spline curves for generation of CP signals. These allow easy optimization, while preserving phase coherency across a wideband. The prototyped antennahas a CP bandwidth of 54% (from 3.2 to 6.1 GHz).

Lignopolymers As Viscosity-Reducing Additives In Magnesium Oxide Suspensions, Lisa R. Murray, Chetali Gupta, Newell R. Washburn, Kendra Erk

School of Materials Engineering Faculty Publications

Lignopolymers are a new class of polymer additives with the capability to be used as dispersants in cementitious pastes. Made with kraft lignin cores and grafted polymer side- chains, the custom-synthesized lignopolymers were examined in terms of the molecular architecture for viscosity reducing potential in inert model suspensions. Lignin-poly(acrylic acid) (LPAA) and lignin-polyacrylamide (LPAm) have been found to vary the rheology of magnesium oxide (MgO) suspensions based on differences in chain architecture and particle- polymer interactions. A commercial comb-polymer polycarboxylate ester was compared to LPAA and LPAm at 2.7 mg/mL, a typical dosage for cement admixtures, as well as 0.25 …

A Patient-Specific Model Of The Biomechanics Of Hip Reduction For Neonatal Developmental Dysplasia Of The Hip: Investigation Of Strategies For Low To Severe Grades Of Developmental Dysplasia Of The Hip, Victor Huayamave, Christopher Rose, Sheila Serra, Brendan Jones, Eduardo Divo, Faissal Moslehy, Alain J. Kassab, Charles T. Price

Publications

A physics-based computational model of neonatal Developmental Dysplasia of the Hip (DDH) following treatment with the Pavlik Harness (PV) was developed to obtain muscle force contribution in order to elucidate biomechanical factors influencing the reduction of dislocated hips. Clinical observation suggests that reduction occurs in deep sleep involving passive muscle action. Consequently, a set of five (5) adductor muscles were identified as mediators of reduction using the PV. A Fung/Hill-type model was used to characterize muscle response. Four grades (1–4) of dislocation were considered, with one (1) being a low subluxation and four (4) a severe dislocation. A three-dimensional model …

A Computational Method To Predict And Study Underwater Noise Due To Pile Driving, Scott Schecklman, Nathan Laws, Lisa M. Zurk, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

A hybrid modeling approach that uses the parabolic equation (PE) with an empirical source model is presented to study and predict the underwater noise due to pile driving in shallow, inhomogeneous environments over long propagation ranges. The empirical source model uses a phased point source array to simulate the time-dependent pile source. The pile source is coupled with a broadband application of a PE wave propagation model that includes range dependent geoacoustic properties and bathymetry. Simulation results are shown to be in good agreement with several acoustic observations of pile driving in the Columbia River between Portland, OR and Vancouver, …

Matrix Compliance And The Regulation Of Cytokinesis, Savitha Sambandamoorthy, Shomita Mathew-Steiner, Scott Varney, Jonathan M. Zuidema, Ryan J. Gilbert, Livingston De Van Water, Susan E. Laflamme

Chemical and Biochemical Engineering Faculty Research & Creative Works

Integrin-mediated cell adhesion to the ECM regulates many physiological processes in part by controlling cell proliferation. It is well established that many normal cells require integrin-mediated adhesion to enter S phase of the cell cycle. Recent evidence indicates that integrins also regulate cytokinesis. Mechanical properties of the ECM can dictate entry into S phase; however, it is not known whether they also can affect the successful completion of cell division. To address this issue, we modulated substrate compliance using fibronectin-coated acrylamide-based hydrogels. Soft and hard substrates were generated with approximate elastic moduli of 1600 and 34,000 Pascals (Pa) respectively. Our …

Apis And The Library: What, Why?, Graham S. Hukill

Scholars Cooperative Brown Bag Series

APIs (Application Programming Interface): What are they? Why are they? Introduction to APIs and their role in the Library

Imaging Device, Wayne De Fremery, John Young

Barowsky School of Business | Faculty Patents

An imaging device comprising a flexible sensor attached to a control case. The flexible sensor provides both a source of illumination to the image being captured and a method of capturing the image. The method of capture comprises a field of reactors disbursed across the facial area of the sensor, the output of which produces a dot-pattern capture of the intended image which is passed to a storage device.

The Role Of Environmental Dynamics In The Emergence Of Autocatalytic Networks, Joe Fusion

Dissertations and Theses

For life to arise from non-life, a metabolism must emerge and maintain itself, distinct from its environment. One line of research seeking to understand this emergence has focused on models of autocatalytic reaction networks (ARNs) and the conditions that allow them to approximate metabolic behavior. These models have identified reaction parameters from which a proto-metabolism might emerge given an adequate matter-energy flow through the system. This dissertation extends that research by answering the question: can dynamically structured interactions with the environment promote the emergence of ARNs? This question was inspired by theories that place the origin of life in contexts …

College Of Engineering News, Georgia Southern University

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

• Scholarship for Engineering Education for Minorities

Compiling Collapsing Rules In Certain Constructor Systems, Sergio Antoy, Andy Jost

Computer Science Faculty Publications and Presentations

The implementation of functional logic languages by means of graph rewriting requires a special handling of collapsing rules. Recent advances about the notion of a needed step in some constructor systems offer a new approach to this problem. We present two results: a transformation of a certain class of constructor-based rewrite systems that eliminates collapsing rules, and a rewrite-like relation that takes advantage of the absence of collapsing rules. We formally state and prove the correctness of these results. When used together, these results simplify without any loss of efficiency an implementation of graph rewriting and consequently of functional logic …

Thermal Energy Storage In Building Integrated Thermal Systems: A Review. Part 2. Integration As Passive System, Dervilla Niall, Sarah Mccormack, Philip Griffiths, Luisa Cabeza, Lidia Navarro, Albert Castell, Alvaro De Grazia, Maria Brown

Articles

Energy consumption trends in residential and commercial buildings show a significant increase in recent decades. One of the key points for reducing energy consumption in buildings is to decrease the energy demand. Buildings envelopes are not just a structure they also provide protection from outdoor weather conditions always taking into account the local climate. Thermal energy storage has been used and applied to the building structure by taking advantage of sensible heat storage of materials with high thermal mass. But in recent years, researchers have focused their studies on the implementation of latent heat storage materials that if well incorporated …