Engineering Commons^™

Optimized Waveform Relaxation Solution Of Rlcg Transmission Line Type Circuits, Mohammad D. Al-Khaleel, Martin J. Gander, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

Today, parallel processing is necessary for the solution of large systems of ordinary differential equations (ODEs) as they are obtained from large electronic circuits or from discretizing partial differential equations (PDEs). Using a fine mesh in the discretization of these problems also leads to large compute times and large storage requirements. The waveform relaxation (WR) technique, which is ideally suited for the use of multiple processors for problems with multiple time scales has been used to solve such problems on parallel processors for such large systems of ODEs. However, applying the so-called classical WR techniques to strongly coupled systems leads …

Partial And Internal Inductance: Two Of Clayton R. Paul's Many Passions, Christopher L. Holloway, Edward F. Kuester, Albert E. Ruehli, Giulio Antonini

Electrical and Computer Engineering Faculty Research & Creative Works

Inductance is one of the fundamental defined parameters in electromagnetics and it takes on a variety of formulations and definitions in the electromagnetic compatibility (EMC) community. The concept of inductance in its many definitions, uses, and caveats was central among Dr. Clayton R. Paul's contributions to the EMC community. In this paper, we discuss the various aspects of inductance which Dr. Paul helped to pioneer. In particular, the concepts of partial inductance and internal inductance (including skin effect) were two of his passions. This paper will both serve as a summary of Dr. Paul's work on inductance as well as …

Simultaneous Decision Making Of Optimal Toll Levels And Locations In A Multi-Class Network Equilibrium: Genetic Algorithm Approach, Zegeye K. Gurmu

Civil Engineering Theses

The purpose of this thesis is to explore bi-level genetic algorithm (GA) based optimization models to make decisions simultaneously for the second-best optimal toll locations and toll levels. The upper-level subprogram is to minimize the total travel time (system cost). The lower-level subprogram is a user equilibrium problem where all users try to find the route that minimizes their own travel cost (or time). The demand is assumed to be fixed and given a priority. First, two different versions of GA based solution procedures are developed and applied to an example Sioux Falls network assuming homogeneous road users in the …

Construction Of Multi-Mode Fiber Modes Using Phase Masks, Alexandre Tulikumwenayo

Theses

Transverse fiber modes are the distribution of electromagnetic fields in the cross-section of an optical fiber through which light propagates in the fiber. Research is being conducted to explore the usage of fiber modes with the purpose of increasing the capacity and reach of optical fibers. Mode Division Multiplexing, an area in which reseach is being conducted with the same purpose, is a multiplexing scheme used in optical networks that maps data channels onto different modes, and multiplexes these modes into one fiber for transmission. This thesis focuses on the study of modes in multi-mode fibers, and the simulation of …

The Trm2h : Detecting Protein-Protein Interactions By Engineering The Cell As A Biosensor, Elyse Shimomura, Paulina Perezalonso

Bioengineering Senior Theses

Protein-protein interactions regulate key cellular functions and cell signaling pathways in the body; biological systems can be disrupted by protein interactions or lack of interactions that cause cell dysfunction and can lead to disease or illness. However, studying these interactions is complex and difficult to quantify. In this project, we examine the interaction of two putative cancer biomarkers, Bax and PDCDS, using the tetracycline repressor-based mammalian two-hybrid system (trM2H). This in vivo system engineers the cell as a biosensor using methods of DNA cloning and mammalian cell transfections that easily detects and quantities the interaction of two proteins by the …

Work Ethics For Sse-122: Satellites & Space Systems (Fall 2013), Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

PowerPoint presentation by Professor Bob Twiggs on work ethics for SSE-122: Satellites & Space Systems for the fall 2013 semester, created on August 8, 2013.

Analysis Of Connecting Rod Bearing Design Trends Using A Mode-Based Elastohydrodynamic Lubrication Model, Travis M. Blais

Theses

Available design trends for big end connecting rod bearings utilize widely adopted rapid methods for prediction of minimum film thickness due to their superior speed and ease of use. However, they impose unrealistic assumptions such as surface rigidity, which could compromise the accuracy of results. The significance of structural elasticity and updated models was investigated using a mode based elastohydrodynamic lubrication model which includes body forces, mass conserving cavitation, and surface roughness. Eight physical connecting rods were modeled using finite element methods and simulated over a variety of conditions, varying engine speed, bearing clearance, and oil viscosity. The results show …

Workshop A - Implementing The "Design Your Process Of Becoming A World Class Engineering Student" Project, Steffen Peuker, Raymond B. Landis

Mechanical Engineering

Many students come into an engineering program lacking a strong commitment to stay in an engineering program and to graduate with an engineering degree. For students to accomplish the challenging goal of graduating in engineering requires a strong commitment, and behaviors and attitudes to follow through that commitment. To strengthen the commitment of the freshman engineering students an innovative project has been developed. The project challenges students to develop their process to become a "World-Class Engineering Student". Having freshman engineering students design their individually tailored learning process as part of a semester long project in the setting of a student …

Implementing Team Based Learning In Freshmen Engineering Courses, Steffen Peuker, Jennifer Peuker

Mechanical Engineering

Team Based Learning (TBL) is a specific pedagogical tool that emphasizes collaborative learning. Oftentimes TBL is confused with group activities and other active learning strategies involving student teams. TBL is distinct because it follows a prescribed sequence of individual work and group work, and includes immediate feedback as well as peer evaluation. TBL is widely used in medical, pharmacy and nursing schools and the use of TBL in engineering education is growing. The advantages of using TBL in the class room include: (1) students are held accountable for individual (pre-class) and group (in-class) work. (2) The responsibility for learning shifts …

Wetting And Reactive Air Brazing Of Bscf For Oxygen Separation Devices, Richard Ladouceur, Alan Meier, Ph.D.

2013 Undergraduate Research

The goals of this project are to develop a Reactive Air Brazing (RAB) alloy and process for joining Barium strontium cobalt ferrite (BSCF), and to develop a fundamental understanding of the wettability and microstructral development due to reaction kinetics in BSCF/Ag-Me_xO_y systems.

Propagation Of Thermo-Mechanical Waves In Deforming Nonlinear Viscoelastic Bodies, Lili Zhang

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

This work studies the propagation of thermo-mechanical disturbances in bodies made of viscoelastic materials that might already be loaded such that they are undergoing large inhomogeneous time varying deformations. In the process of this study we develop the general equations governing the thermo-mechanical motion of such disturbances and ones for internally constrained systems, provide the general structure of the solution, match the solution to existing results for the special case of time harmonic plane waves in elastic bodies and in viscoelastic bodies under constant homogenous loading, and consider some special applications.

The results of this work should have applications in …

The Design And Development Of A Perceptual-Based Haptic Display Device, Sohaib Akhter

Theses and Dissertations

Graphical information presented as pictures, graphs, maps, and the like are an important media for relaying knowledge and are a fundamental means of education rarely experienced by people who are blind or have a severe visual impairment. This thesis presents the design, development and testing of a multiple finger, haptic matrix dynamic display device capable of relaying graphical information through simulated textures. The design is based on user perception studies that determined which hand constraints provided the best tradeoff between simplicity of design, accuracy and time to answer. The best design was one that incorporated multiple fingers in close proximity …

Development Of A Sense And Avoid System For Small Unmanned Aircraft Systems, Robert Andrew Klaus

Theses and Dissertations

Unmanned aircraft systems (UAS) represent the future of modern aviation. Over the past 10 years their use abroad by the military has become commonplace for surveillance and combat. Unfortunately, their use at home has been far more restrictive. Due to safety and regulatory concerns, UAS are prohibited from flying in the National Airspace System without special authorization from the FAA. One main reason for this is the lack of an on-board pilot to "see and avoid" other air traffic and thereby maintain the safety of the skies. Development of a comparable capability, known as "Sense and Avoid" (SAA), has therefore …

Poetic: Interactive Solutions To Alleviate The Reversal Error In Student-Professor Type Problems, Sung-Hee Kim, Daniel Phang, Tuyin An, Ji Soo Yi, Rachael Kenney, Nelson A. Uhan

Hive Lab Publications Archive

The reversal error—reversing the relationship between two variables in a mathematical word problem—is a long-standing issue in mathematics education, despite its apparent simplicity. In this paper, we describe and study POETIC, an interactive web-based environment we developed to teach users to avoid the reversal error. POETIC uses two types of novel interactive visualization, called the Test-Case and Room-Metaphor approaches. To verify the effectiveness of these approaches, we conducted crowdsourcing-based comparison studies with 200 participants and found that both approaches significantly decreased the frequency of reversal errors for certain types of word problems. Our results show that interactive visualization of equations …

A Novel Approach To Flow Estimation In Tidal Rivers, Hamed Moftakhari Rostamkhani, David A. Jay, Stefan A. Talke, Tobias Kukulka, Peter D. Bromirski

Civil and Environmental Engineering Faculty Publications and Presentations

Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, flow records are often limited in length and/or quality and tidal records often predate discharge records. Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. We use this phenomenon to develop a method of estimating river discharge for time periods with tidal data but no flow record. Employing sequential 32 day harmonic analyses of tidal properties, …

The Key Role Of Heavy Precipitation Events In Climate Model Disagreements Of Future Annual Precipitation Changes In California, David W. Pierce, Daniel R. Cayan, Tapash Das, Edwin P. Maurer, Norman L. Miller, Yan Bao, M. Kanamitsu, Kei Yoshimura, Mark A. Snyder, Lisa C. Sloan, Guido Franco, Mary Tyree

Civil, Environmental and Sustainable Engineering

Climate model simulations disagree on whether future precipitation will increase or decrease over California, which has impeded efforts to anticipate and adapt to human-induced climate change. This disagreement is explored in terms of daily precipitation frequency and intensity. It is found that divergent model projections of changes in the incidence of rare heavy (>60 mm day−1) daily precipitation events explain much of the model disagreement on annual time scales, yet represent only 0.3% of precipitating days and 9% of annual precipitation volume. Of the 25 downscaled model projections examined here, 21 agree that precipitation frequency will decrease by the …

Introduction To Sse-120: Sataellites & Space Systems I, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

PowerPoint presentation for Introduction to SSE-120: Sataellites & Space Systems I given by Bob Twiggs on August 6, 2013 at Morehead State University.

An Applied Numerical Simulation Of Entrained-Flow Coal Gasification With Improved Sub-Models, Xijia Lu

LSU New Orleans Theses and Dissertations

The United States holds the world's largest estimated reserves of coal and is also a net exporter of it. Coal gasification provides a cleaner way to utilize coal than directly burning it. Gasification is an incomplete oxidation process that converts various carbon-based feedstocks into clean synthetic gas (syngas), which can be used to produce electricity and mechanical power with significantly reduced emissions. Syngas can also be used as feedstock for making chemicals and various materials.

A Computational Fluid Dynamics (CFD) scheme has been used to simulate the gasification process for many years. However, many sub-models still need to be developed …

Forensic Analysis Of Whatsapp On Android Smartphones, Neha S. Thakur

LSU New Orleans Theses and Dissertations

Android forensics has evolved over time offering significant opportunities and exciting challenges. On one hand, being an open source platform Android is giving developers the freedom to contribute to the rapid growth of the Android market whereas on the other hand Android users may not be aware of the security and privacy implications of installing these applications on their phones. Users may assume that a password-locked device protects their personal information, but applications may retain private information on devices, in ways that users might not anticipate. In this thesis we will be concentrating on one such application called 'WhatsApp', a …

Frequency Response Of Atmospheric Pressure Gas Breakdown In Micro/Nanogaps, Abbas Semnani, Ayyaswamy Venkattraman, Alina A. Alexeenko, Dimitrios Peroulis

Birck and NCN Publications

In this paper, we study gas breakdown in micro/nanogaps at atmospheric pressure from low RF to high millimeter band. For gaps larger than about 10 mu m, the breakdown voltage agrees with macroscale vacuum experiments, exhibiting a sharp decrease at a critical frequency, due to transition between the boundary- and diffusion-controlled regimes, and a gradual increase at very high frequencies as a result of inefficient energy transfer by field. For sub-micron gaps, a much lower breakdown is obtained almost independent of frequency because of the dominance of field emission. (C) 2013 AIP Publishing LLC.

Effects Of Two Inhaled Corticosteroid/Long-Acting Beta-Agonist Combinations On Small-Airway Dysfunction In Mild Asthmatics Measured By Impulse Oscillometry, Bill Diong, Kshitiz Singh, Rogelio Menendez

Faculty Articles

Background: We previously showed that the long-acting beta agonist (LABA) salmeterol as inhalation powder or metered-dose inhaler improves lung-function parameters assessed by impulse oscillometry (IOS) in 2- to 5-year-old children with reversible-airway disease within 15 minutes. Objective: We studied 12- to 45-year-olds with mild persistent asthma in order to compare the onset and extent of peripheral airway effects following the first dose and after 4 weeks dosing with two inhaled corticosteroid (ICS)/LABA combinations: fluticasone propionate/salmeterol 115/21 and budesonide/formoterol 160/4.5. Methods: Thirty subjects with mild persistent asthma using only an as-needed short-acting beta-agonist (albuterol) who had at least a 40% change …

Spectral Discrimination Of Breast Pathologies In Situ Using Spatial Frequency Domain Imaging, Ashley M. Laughney, Venkataramanan Krishnaswamy, Elizabeth J. Rizzo, Mary C. Schwab, Richard J. Barth, David J. Cuccia, Bruce J. Tromberg, Keith D. Paulsen, Brian W. Pogue, Wendy A. Wells

Dartmouth Scholarship

Introduction: Nationally, 25% to 50% of patients undergoing lumpectomy for local management of breast cancer require a secondary excision because of the persistence of residual tumor. Intraoperative assessment of specimen margins by frozen-section analysis is not widely adopted in breast-conserving surgery. Here, a new approach to wide-field optical imaging of breast pathology in situ was tested to determine whether the system could accurately discriminate cancer from benign tissues before routine pathological processing.

Response Of Stream Ecosystems To Climate Change (Iii): Characterizing And Predicting Ecologically Relevant Flow Regimes, David G. Tarboton, Sulochan Dhungel, Yi He, J.J. V. Laan, Ryan A. Hill, Jiming Jin

Civil and Environmental Engineering Faculty Publications

No abstract provided.

Indium Diffusion Through High-K Dielectrics In High-K/Inp Stacks, H. Dong, W. Cabrera, R. Galatage, Santosh Kc, B. Brennan, X. Qin, S. Mcdonnell, D. Zhernokletov, C. Hinkle, K. Cho, Y. Chabal, R. Wallace

Faculty Publications

Evidence of indium diffusion through high-k dielectric (Al2O3 and HfO2) films grown on InP (100) by atomic layer deposition is observed by angle resolved X-ray photoelectron spectroscopy and low energy ion scattering spectroscopy. The analysis establishes that In-out diffusion occurs and results in the formation of a POx rich interface.High mobility III-V channel materials are contenders to replace Si in semiconductor devices like metal oxide semiconductor filed effect transistors (MOSFETs) for the sub 22 nm technology node.1 Extensive research is being carried out to determine the validity of these III-V materials for use as the channel, in a variety of …

Relaxation Of Shear-Induced Precursors In Isotactic Polypropylene And Random Propylene–Ethylene Copolymers, Benjamin Schammé

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Flow induced crystallization (FIC) has a large impact on kinetics and morphology of semicrystalline polymers, and can therefore drastically change final properties such as dimensional and thermal stability, modulus and strength. Processing of polymers usually involves flow, so it is important to understand the mechanism of FIC. It is known that oriented precursors formed during flow are the key to FIC but they are not yet well understood. In this study, flow induced precursors are investigated by examining their relaxation, and the effect of comonomer is probed.

Using a commercial isotactic polypropylene and random propylene-ethylene copolymers, a fiber pull-out technique …

A Class-C Amplifier Linearized By A Constant Conduction Angle Biasing Circuit, Gursewak Singh Rai, Vladimir I. Prodanov, Stephen Garber

Electrical Engineering

This work presents a dynamic biasing topology capable of linearizing a Class-C power amplifier (PA). The topology utilizes a control loop that senses the operating conditions of the power device by means of a scaled replica. The loop operates on the principle of keeping the conduction angle constant and thereby ensuring linearity. The work details some of the design considerations that should prove useful to a designer wanting to implement the topology in an RF integrated circuit. Measurement results from a fully-functional low-frequency prototype bring merit to the topology.

The Effect Zeolite Addition In Natural Rubber Polypropylene Composite On Mechanical, Structure, And Thermal Characteristics, Nurdin Bukit, Erna Frida

Makara Journal of Technology

This study was conducted to determine the effect of zeolite as filler on mechanical properties, and thermal structure blends of natural rubber and polypropylene (NR/PP). In this study, NR/PP/PP-g-MA blends was filled uncalcined zeolite and calcined zeolite at different weight percent of the 2, 4, and 6%. Samples were characterized to determine the tensile strength, fracture elongation and Young's modulus. Structure of the samples was investigated using XRD method and thermal characteristics were analyzed using DTA/TGA technique. The results obtained for tensile strength showed a significant influence with the addition zeolite of the NR/PP blends at 2% by weight of …

Adaptive Co-Scheduler For Highly Dynamic Resources, Kartik Vedalaveni

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

There are many kinds of scientific applications that run on high throughput computational (HTC) grids. HTC may utilize clusters opportunistically, only running on a given cluster when it is otherwise idle. These widely dispersed HTC clusters are heterogeneous in terms of capability and availability, but can provide significant computing power in aggregate. The scientific algorithms run on them also vary greatly. Some scientific algorithms might use high rates of disk I/O and some might need large amounts of RAM. Most schedulers only consider cpu availability, but unchecked demand on these associated resources that aren’t managed by resource managers may give …

Information Technology News, Georgia Southern University

Information Technology: News & Publications (2012-2023)

• An update from Nick Plotts (2011) now at HP!

Online Ecosystems In Software Development, Corey J. Jergensen

School of Computing: Dissertations, Theses, and Student Research

Software projects are no longer developed as individual, monolithic projects. In- stead, they exist as part of an ecosystem where related projects are developed together using a common underlying technical infrastructure and common project cultures.

This work explores characteristics of online software communities by comparing and contrasting two software ecosystems that are both related to programming, but provide different functions. The first is Stack Overflow, a programming question and answer forum. The second is Gnome, an open-source, Linux desktop environment. Both are examples of online communities because: (1) the communities are composed of smaller projects or topics, (2) users contributions …