Engineering Commons^™

Distributed Fault Tolerance In Optimal Interpolative Nets, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

The recursive training algorithm for the optimal interpolative (OI) classification network is extended to include distributed fault tolerance. The conventional OI Net learning algorithm leads to network weights that are nonoptimally distributed (in the sense of fault tolerance). Fault tolerance is becoming an increasingly important factor in hardware implementations of neural networks. But fault tolerance is often taken for granted in neural networks rather than being explicitly accounted for in the architecture or learning algorithm. In addition, when fault tolerance is considered, it is often accounted for using an unrealistic fault model (e.g., neurons that are stuck on or off …

Modeling Axisymmetric Optical Precision Piezoelectric Membranes, James W. Rogers Jr.

Theses and Dissertations

The US Department of Defense (DOD), as well as the National Aeronautics and Astronautics Administration (NASA) and the Jet Propulsion Laboratory (JPL) are interested in developing and deploying precise, compliant, light-weight, space-based structures. More specifically, the Air Force’s core competencies ‘Aerospace Superiority’ and ‘Information Superiority’ demand ever-increasing depth and breadth of capability. Whether used for energy transmission or optical reconnaissance, current launch restraints limit rigid space-based optical reflector size. To support this requirement, the Air Force Research Laboratory (AFRL) is developing a large space-based optical membrane telescope. Inflatable reflectors can conceptually break this barrier, but controlling such a compliant structure …

Evolution Of The Cubesat Concept, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Evolution of the CubeSat Concept" from October 28, 2001.

Highly Innovative And Rapid Turn-Around Space Test Program, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Highly Innovative and Rapid Turn-around Space Test Program" from October 23, 2001.

“Walk” Evolution Of The Cubesat Concept, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Walk: Evolution of the CubeSat Concept" and presented at the Western Region NASA Space Grant Consortium on October 19, 2001.

Introducing Cooperative Learning Through A Faculty Instructional Development Program, Nikos J. Mourtos, Emily L. Allen

Faculty Publications

Cooperative Learning was officially introduced in the College of Engineering at San Jose State University in 1995 with a two-day workshop. The Faculty Instructional Development Program in the college maintains interest in the subjsect and provides support for instructors who use Cooperative Learning, through workshops and informal discussions (Conversations on Teaching). This paper discusses the effectiveness of the program in introducing, promoting, and implementing Cooperative Learning among the faculty and students in the college of engineering. A variety of performance criteria have been used in this assessment, some faculty-centered and some student-centered. The results indicate that although a relatively small …

Low Proof Load Prediction Of Ultimate Strengths Of Fiberglass/Epoxy I-Beams Using Acoustic Emission, Edward C. Fatzinger Jr.

Master's Theses - Daytona Beach

Acoustic emission (AE) nondestructive testing was used to monitor fiberglass/epoxy I-beams. The experiment consisted of loading the I-beams in cantilever fashion with a hydraulic ram. While testing, AE waveforms were collected from the onset of loading to failure. After acquisition, the AE data from each test were filtered to include only data collected up to 50% of the theoretical ultimate load for further analysis.

A Kohonen self-organizing map was utilized to separate each individual data point (hit) into failure mechanism clusters. Then a multiple linear regression analysis was performed using the percentage of hits associated with each failure mechanism along …

Design And Construction Of A 1/3-Scale, 1986 Cessna 172p Flight-Test Aircraft, Michael J. Hinton

Master's Theses - Daytona Beach

The incredible cost of prototype flight testing can be a very limiting factor in the optimization of new designs as they proceed from the drawing board to the flight line. The use of low-cost scaled models to predict full-scale prototype performance is the focus of this project. It will be shown that by strictly following geometric and dynamic scaling criteria, the scaled aircraft's flight performance can be predictably related to the full-scale aircraft's performance. Many companies have performed scaled flight-testing of Remotely Piloted Vehicles (RPV's) and there is much speculation as to the results of these tests, but non-proprietary information …

Techniques For Reduced Order Modeling Of Aeroelastic Structures With Deforming Grids, John S. R. Anttonen

Theses and Dissertations

Reduced order modeling (ROM) seeks to make the modeling of aeroelastic behavior practical by reducing computation time for design codes. Deforming grids are often used in aeroelastic problems to account for the deformation of the structure. Proper Orthogonal Decomposition (POD/ROM) is a ROM technique that operates in an index-space for computations, not accounting for changes in grid dynamics, and must be modified to reflect grid deformation properly. To investigate and account for the effects of grid deformation on POD/ROM, a new algorithm is developed that incorporates modifications to the usual formulation. Evaluation of the new algorithm is accomplished through application …

Computational Fluid Dynamic Study Of A Nascar Winston Cup Series Race Car, Terry L. Meek Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

Since the goal of NASCAR racing is to win and since drag is a force the vehicle must overcome, a thorough understanding of the drag generating airflow around and through the automobile is greatly desired. The external airflow contributes to most of the drag that a car experiences and most of the downforce the vehicle produces. Therefore, an estimate of the vehicle's performance may be evaluated using a computational aerodynamics model. This thesis presents a computational fluid dynamic (CFD) analysis of a NASCAR Winston Cup series race car to investigate the salient flow characteristics.

Before a computational analysis could be …

Investigation Of Dual-Mode Combustion With Large Upstream Interaction, Melanic Olynciw-Mills

Mechanical & Aerospace Engineering Theses & Dissertations

Dual-mode scramjet combustor configuration with significant upstream interaction is investigated numerically. The possibility of scaling the domain to accelerate the convergence an3 reduce the computational time is explored. The supersonic combustor configuration was selected to provide an understanding of key features of upstream interaction and to identify physical and numerical issues relating to modeling of dual-mode configurations. The numerical analysis was performed with vitiated air at freestream Mach number of 2.5 using hydrogen as the sonic injectant. Results are presented for two-dimensional models and a three-dimensional jet-to-jet symmetric geometry. Comparisons are made with experimental results. Two-dimensional and three-dimensional results show …

Transonic And Supersonic High Alpha Flow Prediction And Control For An Sc-X Space Vehicle, Ruobo You

Mechanical & Aerospace Engineering Theses & Dissertations

Universal Space Line (USL) is interested in developing an aerospace vehicle that flies at very high angles of attack (AOAs) through wide range of Mach numbers. The basic model configuration is called SC-X model, which consists of a blunt cone and a cylindrical afterbody. A structured O-type grid was generated for this model by numerically solving elliptic partial differential equations. The three-dimensional, unsteady, compressible, Reynolds-averaged Navier-Stokes equations coupled with Spalart-Allmaras turbulence model were used as computational tool to investigate the transonic and supersonic flows around the SC-X model pitched at AOA of 45°. For the code validation, this computational solver …

Stanford Space Systems Program, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Stanford Space Systems Program" from September 27, 2001.

Internet Media In Technological Risk Amplification: Plutonium On Board The Cassini-Huygens Spacecraft, Christine M. Rodrigue

RISK: Health, Safety & Environment (1990-2002)

The author discusses how the Cassini controversy demonstrates the power of the Internet, particularly listservs and Usenet groups, and how this resource offers political activists an opportunity to affect the agendas of risk management policy decision-makers.

California Launch Vehicleeducation Initiative, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "California Launch VehicleEducation Initiative" from August 29, 2001.

Falconsat - 1: Design - Lessons Learned - How We Built A Satellite In 6 Months, Jim White

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Jim White titled "Falconsat - 1" from August 25, 2001.

Cubesat: The Development And Launch Support Infrastructure For Eighteen Different Satellite Customers On One Launch, Robert J. Twiggs, Jordi Puig-Suari, Clark Turner

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professors Bob Twiggs, Jordi Puig-Suari, and Clark Turner titled "CubeSat: The Development and Launch Support Infrastructure for Eighteen Different Satellite Customers on One Launch" presented at the 15th Annual/USU Conference on Small Satellites on August 15, 2001.

Cubesat –The Next Generation, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "CubeSat –The Next Generation" from August 8 2001.

The Demise Of Aerospace, Part 2. We Doubt It., John H. Mcmasters, Russell M. Cummings

Aerospace Engineering

No abstract provided.

Development Of An Integrated Sensor For The Measurement Of The Acoustic Local Volume Displacement Of Vibrating Beams, Randall Rozema

Masters Theses

Currently, the methods used for sensing the volume displacement of a vibrating structure entail the use of a polyvinylidene fluoride sensor that spans the entire length of the structure. However, this work shows that the surface behavior related to volume displacement can be measured through the use of a polyvinylidene fluoride sensor that spans only the area of interest. In this application it was shown that two-point sensors are required in addition to the distributed, polyvinylidene fluoride sensor to achieve an accurate measurement. As a result, a set of four beams with different end conditions were constructed so that the …

The Conference Proceedings Of The 2001 Air Transport Research Society (Atrs) Of The Wctr Society, Volume 2, Yeong-Heok Lee, Brent D. Bowen, Scott E. Tarry, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 01-7

The Conference Proceedings Of The 2001 Air Transport Research Society (Atrs) Of The Wctr Society, Volume 3, Yeong-Heok Lee, Brent D. Bowen, Scott E. Tarry, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 01-8

Optimal Aeroelastic Vehicle Sensor Placement For Root Migration Flight Control Applications, Abdul Ghafoor Al-Shenhabi

Mechanical & Aerospace Engineering Theses & Dissertations

An important step in control design for elastic systems is the determination of the number and location of control system components, namely sensors. The number and placement of sensors can be critical to the robust functioning of active control systems, especially when the system of interest is a large high-speed aeroelastic vehicle. The position of the sensors affects not only system stability, but also the performance of the closed-loop system. In this dissertation, a new approach for sensor placement in the integrated rigid and vibrational control of flexible aircraft structures is developed. Traditional rigid-body augmentation objectives are addressed indirectly through …

Ingaasnsb/Gaas Quantum Wells For 1.55 Μm Lasers Grown By Molecular-Beam Epitaxy, Xiaodong Yang, J. B. Heroux, L. F. Mei, W. I. Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

InGaAsNSb/GaAs quantum wells (QWs) were grown by solid-source molecular-beam epitaxy using a N₂ radio frequency plasma source. The effect of adding Sb during growth of InGaAsN/GaAs QWs was studied. X-ray diffraction, reflection high-energy electron diffraction and transmission electron microscopy studies indicate that Sb suppresses the three-dimensional growth and improves the interface of the QWs. X-ray diffraction and secondary ion mass spectroscopy analysis show that Sb gets incorporated into the quantum well, which becomes a quinternary compound that was previously unexplored. The introduction of Sb during growth of InGaAsN/GaAs QWs significantly enhances the optical properties of the QWs. 1.53 /spl …

Re-Injecting Innovationinto Thespace Test Process: A Mission For Payload Brokering, Brian Horais

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Brian Horais titled "Re-injecting Innovationinto theSpace Test ProcessA mission for payload brokering" from May 31, 2001.

Proactive University Satellite Program, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Proactive University Satellite Program" and presented at the 2001 Ride Share Conference on May 30, 2001.

Emerging And Advanced Technologies: Small Satellites, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Emerging and Advanced Technologies: Small Satellites" presented at the Aerospace Industries Association Space Council on May 15, 2001.

Stanford Space Systems Program, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Stanford Space Systems Program" from May 15, 2001.

Sri: Stanford Space Systems Program, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "SRI: Stanford Space Systems Program" from May 14, 2001.

Emerald Nanosatellite: Structures & Mechanisms, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Emerald Nanosatellite: Structures & Mechanisms" from May 10, 2001.