Engineering Commons^™

Evaluation Of Alternative Evolutionary Programming Techniques For Optimization Of An Automotive Alternator, Andreas C. Koenig, Joshua M. Williams, Steven D. Pekarek

Electrical and Computer Engineering Faculty Research & Creative Works

One of the primary design requirements of automotive generation systems is maximizing power density subject to the constraint of minimizing the overall system cost. However, with the progress made in the reduction of automotive drive train noise, the torque ripple of the generator has been found to be a dominant noise source under idle conditions at high electrical loads. Thus, an added design constraint is the minimization of the torque ripple produced by the machine. in order to evaluate alternative machine designs (and select an optimal), numerical tools are typically applied. in this research, a focus is placed on the …

Soil Type Identification Using Time Domain Relectometry, Carlos Eduardo Zambrano Narvaez

Lyles School of Civil Engineering Masters Theses

No abstract provided.

Initial In Vitro And In Vivo Characterization Of A Pediatric Cardiopulmonary Assist System., Jeffrey Michael Colyer

Electronic Theses and Dissertations

Historically in the area of pediatric heart failure, few options have been available that are specifically designed to provide pediatric circulatory support. Extracorporeal Membrane Oxygenation (ECMO) was the traditional method of choice, providing cardiopulmonary support (CPS) for a relatively short time of 3-7 days. The pediatric cardiopulmonary assist system (pCAS) examined in this paper is designed to be able to provide left ventricular assist (LVA), right ventricular assist (RVA), or cardiopulmonary assist to a pediatric patient for a period of 30 days, with the option of device replacement if needed. A specially designed controller allows for both continuous and pulsatile …

Nectar Clean 2006 A Complete Disk Utility Program, Matthew Areno

Undergraduate Honors Capstone Projects

The objective of this paper is to introduce a hard drive enclosure kit and program, named Disk Utility, which provides various utilities to a work-bench tech or a home user. Both the authors have worked in a tech-bench area and have found that this is a useful tool to have, as many times trouble-shooting type tasks are necessary to properly diagnose problems on a hard drive. It has also been found to be far easier to implement these changes on a hard drive that doesn't need to be moved from machine to machine.

Many design approaches are covered in this …

Multiobjective Plan Selection Optimization For Traffic Responsive Control, Montasir M. Abbas, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Optimal coordination of traffic signals requires proper activation of timing plans to match current traffic conditions. One of the greatest challenges in configuring a traffic responsive plan selection control mode is how to select only n number of timing plans (restricted by traffic controller memory limitations) to address possibly all traffic conditions/states that can be encountered in the field, for a specific site, but most importantly, how to associate each of these traffic conditions to one of the n timing plans stored in the traffic controller. This paper uses a multiobjective non-dominated sorting genetic algorithm to (1) select the best …

Investigating The Use Of Intelligent Transportation System Applications To Mitigate The Effects Of Terrorism In Marine Transportation, Kenneth Brown

Theses (Pre-2016)

Contrary to popular belief marine transportation is probably the most vulnerable and the most critical sector of transportation. The Marine Transportation System (MTS) is comprised of ships, tugs, barges, ports, rail and trucking all operating in a highly integrated system. The vulnerability of the MTS to the effects of possible terrorist attacks would not only pose a great threat to the safety of the local community but also our U.S. economy. In other modes of transportation such as surface, air, and mass transit, security and safety issues have been addressed through Technological improvements. Many of these Technological improvements fall under …

Digital Oxide Deposition Of Sio2 Layers For Iii-Nitride Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistors, V. Adivarahan, S. Rai, N. Tipirneni, A. Koudymov, J. Yang, Grigory Simin, M. Asif Khan

Faculty Publications

We present a digital-oxide-deposition (DOD) technique to deposit high quality SiO₂dielectric layers by plasma-enhanced chemical vapor deposition using alternate pulses of silicon and oxygen precursors. The DOD procedure allows for a precise thickness control and results in extremely smooth insulating SiO₂ layers. An insulating gate AlGaN∕GaNheterostructurefield-effect transistor(HFET) with 8nm thick DOD SiO₂dielectric layer had a threshold voltage of −6V (only 1V higher than that of regular HFET), very low threshold voltage dispersion, and output continuous wave rf power of 15W∕mm at 55V drain bias.

Non-Isothermal Reaction-Diffusion Systems With Thermodynamically Coupled Heat And Mass Transfer, Yaşar Demirel

Papers in Analytical Chemistry

Non-isothermal reaction-diffusion (RD) systems control the behavior of many transport and rate processes in physical, chemical, and biological systems. A considerable work has been published on mathematically coupled nonlinear differential equations of RD systems by neglecting the possible thermodynamic couplings among heat and mass fluxes, and reaction velocities. Here, the thermodynamic coupling refers that a flux occurs without its primary thermodynamic driving force, which may be gradient of temperature, or chemical potential, or reaction affinity. This study presents the modeling equations of non-isothermal RD systems with coupled heat and mass fluxes excluding the coupling of chemical reactions using the linear …

Transfected Cell Arrays For Assessment Of Estrogen Receptor Activation In Breast Cancer Cells, Angela K. Pannier, Zain Bengali, Eric A. Ariazi, V. Craig Jordan, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Transfected cell arrays represent a high-throughput approach to correlate gene expression with functional cell responses, based on gene delivery from a substrate that supports cell adhesion. These arrays provide the ability to express, in parallel, thousands of exogenous genes in live cells, giving real-time information on cellular physiology and gene function. While there have been advances in transfected cell arrays, improvements are needed to this technology, including increasing the cells types that can be efficiently transfected and developing better quantification and normalization methods. We have created an array using soft lithography techniques to pattern DNA-lipid complex deposition. Specifically, a mold …

Magnetic Anisotropy And Anisotropic Ballistic Conductance Of Thin Magnetic Wires, Ildar F. Sabiryanov

Nebraska Center for Materials and Nanoscience: Faculty Publications

The magnetocrystalline anisotropy of thin magnetic wires of iron and cobalt is quite different from the bulk phases. The spin moment of monatomic Fe wire may be as high as 3.4 μ_B, while the orbital moment as high as 0.5 μ_B. The magnetocrystalline anisotropy energy (MAE) was calculated for wires up to 0.6 nm in diameter starting from monatomic wire and adding consecutive shells for thicker wires. I observe that Fe wires exhibit the change sign with the stress applied along the wire. It means that easy axis may change from the direction along the wire …

Effect Of Oxygen Vacancies On Interlayer Exchange Coupling In Fe/Mgo/Fe Tunnel Junctions, Mikhail Ye Zhuravlev, Julian P. Velev, A. V. Vedyayev, Evgeny Y. Tsymbal

Nebraska Center for Materials and Nanoscience: Faculty Publications

We have investigated the interlayer exchange coupling (IEC) in Fe/MgO/Fe(0 0 1) tunnel junctions with and without oxygen vacancies in MgO, using model and density functional calculations. The model predicts that IEC changes sign from ferromagnetic to antiferromagnetic if a defect level matches the Fermi energy. Ab initio calculations show that for perfect junctions, IEC is ferromagnetic and decreases exponentially with MgO thickness. Oxygen vacancies placed in the middle of MgO make IEC antiferromagnetic for three monolayers (MLs) of MgO, but do not change the sign of IEC for five MLs. The latter fact is explained within the model, which …

A Digital Design For A Plasma Impedance Probe, Jason Bingham

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The Plasma Impedance Probe (PIP) electronics board is designed to measure the impedance of plasma in situ by emitting voltages at different frequencies from a probe. The PIP is launched as part of the Tropical Storm mission. The purpose of the mission is to launch the instrument aboard a sounding rocket that flies through the ionosphere during or immediately following a large tropical meteorological disturbance. As the PIP probe travels through the upper regions of Earth's atmosphere, data are gathered from the disturbed region by measuring the current flow in the antenna. This information contains both the phase and magnitude …

Kalman Filtering With Inequality Constraints For Turbofan Engine Health Estimation, Daniel J. Simon, Donald L. Simon

Electrical and Computer Engineering Faculty Publications

Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state-variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. Thus, two analytical methods to incorporate state-variable inequality constraints into the Kalman filter are now derived. The first method is a general technique that uses hard constraints to enforce inequalities on the state-variable estimates. The resultant filter is a combination …

End-To-End Latency Of A Fault-Tolerant Corba Infrastructure, Wenbing Zhao, Louise E. Moser, P. Michale Melliar-Smith

Electrical and Computer Engineering Faculty Publications

This paper presents an evaluation of the end-to-end latency of a fault-tolerant CORBA infrastructure that we have implemented. The fault-tolerant infrastructure replicates the server applications using active, passive and semi-active replication, and maintains strong replica consistency of the server replicas. By analyses and by measurements of the running fault-tolerant infrastructure, we characterize the end-to-end latency under fault-free conditions. The main determining factor of the run-time performance of the fault-tolerant infrastructure is the Totem group communication protocol, which contributes to the end-to-end latency primarily in …

Winning Back The Cup For Distributed Pomdps: Planning Over Continuous Belief Spaces, Pradeep Varakantham, Ranjit Nair, Milind Tambe, Makoto Yokoo

Research Collection School Of Computing and Information Systems

Distributed Partially Observable Markov Decision Problems (Distributed POMDPs) are evolving as a popular approach for modeling multiagent systems, and many different algorithms have been proposed to obtain locally or globally optimal policies. Unfortunately, most of these algorithms have either been explicitly designed or experimentally evaluated assuming knowledge of a starting belief point, an assumption that often does not hold in complex, uncertain domains. Instead, in such domains, it is important for agents to explicitly plan over continuous belief spaces. This paper provides a novel algorithm to explicitly compute finite horizon policies over continuous belief spaces, without restricting the space of …

Steady State Simulations Of A Mars Entry Vehicle, Daniel Guy Schauerhamer

Undergraduate Honors Capstone Projects

Using computational fluid dynamics, steady state simulations of a capsule like Mars entry vehicle at certain trajectory points was performed. Trajectory points were chosen incrementally from 90 to 11.5 kilometers altitude. The Direct Simulation Monte Carlo method and the Overflow 2 Navier-Stokes solver were used depending on Knudsen number values greater than or less than 0.1, respectively. To compare flow effects of the maximum angle of attack error margin of three degrees, axially symmetric cases were computed and compared to three dimensional cases demonstrating an attack angle (α) of three degrees. Lift and drag coefficients are reported and compared. The …

Driveline For The Usu 2006 Mini Baja, Daniel Chase Swenson

Undergraduate Honors Capstone Projects

The Mini Baja project is part of an intercollegiate engineering design competition sponsored by SAE. For this competition senior engineering students at USU design and build a small off-road racecar. The design of the car is broken up into several different subassemblies. The driveline subassembly is responsible for transmitting the power from the transmission to the rear wheels. This is accomplished using several different components that have all been analyzed and designed. The completed driveline is able to accommodate sixteen inches of suspension travel, is lightweight, and was inexpensive to build. The driveline along with the rest of the car …

Mobile Messaging In The Pacific Rim, Thomas Asmuth

SWITCH

This article explores the growth of mobile messaging across the Pacific Rim, focusing on how cultural, economic, and infrastructural factors shape its use.

An Xyz Micromanipulator With Three Translational Degrees Of Freedom, Kimberly A. Jensen, Craig P. Lusk, Larry L. Howell

Faculty Publications

This paper introduces a three degree of freedom XYZ Micromanipulator (XYZM) that is fabricated in the x-y plane and positions components in the x, y, and z directions using three independent linear inputs. The mechanism positions components on a platform using three legs, each composed of a slider mechanism and a parallelogram mechanism.

Compact Integrated Depolarizer For Interferometric Fiber Optic Gyroscopes, Lixia Li, Jaime Cardenas, Jianhua Jiang, Gregory P. Nordin

Faculty Publications

We propose an integrated waveguide depolarizer for use in interferometric fiber optic gyroscopes (IFOGs) with single-mode fiber coils. The integrated waveguide depolarizer is based on a Mach-Zender interferometer with polarizing beamsplitters. A waveguide polarizing beamsplitter is designed using multiple air trench structures oriented at the Brewster angle. We also analyze the effect of component imperfections on the degree of polarization achievable with an integrated waveguide depolarizer.

Design Of Compact Polymer Mach-Zender Interferometer And Ring Resonator With Air Trench Structures, Seunghyun Kim, Jianhua Jiang, Gregory P. Nordin

Faculty Publications

We discuss the design of a compact ring resonator (RR) and Mach-Zehnder interferometer (MZI) in a low-refractive-index-contrast waveguide material system through the use of air trenches. A narrow air trench at the intersection of one input and two output waveguides can function as a high-efficiency splitter, while wider air trenches operate as waveguide bends. We first discuss the design of individual splitters and bends and then show how they can be used to realize a compact MZI and RR. The RR has a footprint of only 70 X 100 um, and its optical efficiency at the drop wavelengths is 86%. …

Multiple Masks-Based Pixel Comparison Steganalysis Method For Mobile Imaging, Sos S. Agaian, Gilbert L. Peterson, Benjamin M. Rodriguez

Faculty Publications

No abstract provided.

Vascular Tortuosity Is Culprit To Abnormal Perfusion In 9l Gliosarcoma Tumor, M. M. Darpolar, Robert C. Molthen, F. C. Wu, Kathleen M. Schmainda

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Utilization Of Ultrasonic Consolidation In Fabricating Satellite Decking, Joshua L. George

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A fundamental investigation of the use of ultrasonic consolidation (UC) to produce deck panels for small satellites was undertaken. Several fabrication methods for producing structural panels and decking were analyzed. Because of its ability to create aluminum objects in an additive fashion, and at near-room temperatures, UC was found to be a powerful solution for creating highly integrated and modular satellite panels. It also allowed a lightweight and stiff deck to be fabricated without the use of adhesives.

A series of experiments were performed to understand the issues associated with creating a sandwich-type structure using UC. The experiments used a …

History Of The Logan Bluff Landslide Zone, Seth P. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

On September 10, 2005, a landslide occurred to the south of Utah State University Campus and Highway 89. This landslide did considerable damage to the Logan and Northern canal, which is cut into the slope, and to a residence at the toe of the slope. This event brought many parties together to collaborate on possible solutions to the immediate fix of the slide as well slides that could occur in the future. The purpose of this report is to compile information useful to the study of the area and the possible solutions and/or risk assessment of the Logan Bluff Landslide …

The Numerical Modeling Of An Antenna In Plasma, Jeffrey D. Ward

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation presents a full-wave, self-consistent numerical model that enables a greater understanding of how an antenna interacts with warm, collisional, magnetized, multi-species plasma. The model focuses primarily on the frequency region around the critical electron resonances for ionospheric plasma conditions. At these resonances, the dielectric representation of the plasma can become complex or negative, and the current distribution strongly deviates from free space. These effects are difficult to model analytically, necessitating the use of numerical techniques. This dissertation develops a Finite Difference Time Domain model that includes the plasma fluid equations along with Maxwell's equations, and incorporates boundary conditions …

Manipulation Of Polystyrene Microparticles On A Microchannel Glass, Ravi Mamillapalli, Henry D. Young

Browse all Theses and Dissertations

Bulk quantities of spherical microbeads have various applications in research and industrial fields. Simple techniques are required to be developed in order to manipulate and modify large numbers of these beads simultaneously. In our experiment, a microchannel glass-based microfluidic device is used to actuate large numbers of microbeads in parallel. The microchannel glass used in these experiments contains channels 4.1 μm in diameter. The microbeads are polystyrene beads which are superparamagnetic in nature and 5-6 μm in diameter. An aqueous suspension of microbeads is injected into a 2-chamber fluid cell that contains a separator, microchannel glass. The beads are reversibly …

Dynamic Branch&Bound, An Optimization Counterpart For Dynamic Backtracking, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

Here we show how the idea of dynamic backtracking can be applied to branch and bound optimization. This is done by exploiting the concept of valued nogood. However, simple replacement of nogoods with valued nogoods does not lead to a correct algorithm. We show that a way to achieve correctness is to use at each variable a separate nogood storage for each position that the variable holds in the order on assigned variables. This is a different version to the one in [dago97]. Constraint Satisfaction Problems (CSPs) are typically addressed with some kind of backtracking algorithm. A seminal work that …

The Effect Of The Shear-Thickening Transition Of Model Colloidal Spheres On The Sign Of N1 And On The Radial Pressure Profile In Torsional Shear Flows, M. Lee, Mataz Alcoutlabi, J. J. Magda, C. Dibble, M. J. Solomon, X. Shi, G. B. Mckenna

Mechanical Engineering Faculty Publications

A novel rheometer plate was used to measure radial pressure profiles during cone-and-plate and parallel-plate shearing flows of a concentrated colloidal dispersion of polymethyl methacryalate spheres suspended in dioctyl phthalate. There is a long history of using suspensions of this type as a model rheological system. The measured pressure profile can be used to calculate N1 and N2, and also provides a check on the flow field in the rheometer. At shear rates just below onset of shear thickening, our measurements show that N1 is positive as predicted by Stokesian dynamics simulations of model Brownian hard spheres, but we are …

Study Of Optical-Feedback Using An Integrated Laser-Modulator/Amplifier Device, Xiaomin Jin, A. Hsu, Shun Lien Chuang

Electrical Engineering

We study optical-feedback effects using an integrated laser-modulator/amplifier. Our experiment and theory are agree well and provide interesting results of feedback effects on optical spectrum, spatial-hole burning, the photon density profile, and the microwave modulation.