Engineering Commons^™

A Computing Approach Using Probabilistic Neural Networks For Instantaneous Appraisal Of Rear-End Crash Risk, Anurag Pande, Mohamed Abdel-Aty

Civil and Environmental Engineering

Computing and information technology has significantly increased the capabilities to collect, store, and analyze freeway traffic surveillance data. The most common forms of such data are collected using the underground loop detectors. In the recent past the potential of using these data for identification of crash-prone conditions has been explored. In the present work, application of probabilistic neural networks (PNN) is explored to identify conditions prone to rear-end crashes on the freeway. PNN is a neural network implementation of the well-documented Bayesian classifier. In this research the rear-end crashes observed on the Interstate-4 corridor in Orlando FL are divided into …

Agricultural Water Conservation And Efficiency In California - A Commentary, Charles M. Burt, Peter Canessa, Lawrence J. Schwankl, David F. Zoldoske

BioResource and Agricultural Engineering

This is a Commentary on some of the key points that are presented in “More with Less: Agricultural Water Conservation and Efficiency in California” by Cooley, ChristianSmith, and Gleick of the Pacific Institute, September 2008 (referred to as the “PacInst Paper” in the remainder of this discussion).

The authors of this Commentary have over 120 years combined of experience in agricultural and landscape irrigation. They have worked world-wide in design and installation of all types of irrigation systems (including automated drip systems from 1975 on), design and implementation of irrigation scheduling programs since 1977; design and implementation of water conservation …

Volume Effects On Yield Strength Of Equine Cortical Bone, R. F. Bigley, J. C. Gibeling, S. M. Stover, S. J. Hazelwood, D. P. Fyhrie, R. B. Martin

Biomedical Engineering

Volume effects are a fundamental determinant of structural failure. A material exhibits a volume effect if its failure properties are dependent on the specimen volume. Many brittle ceramics exhibit volume effects due to loading a structure in the presence of “critical” flaws. The number of flaws, their locations, and the effect of stress field within the stressed volume play a role in determining the structure’s failure properties. Since real materials are imperfect, structures composed of large volumes of material have higher probabilities of containing a flaw than do small volumes. Consequently, large material volumes tend to fail at lower stresses …

Design And Implementation Of Mobile Free Space Optical Communication System, Xiaomin Jin, Xian Wang, Chi Yeh Hsu

Electrical Engineering

No abstract provided.

A Pressure Sensing System Using Fiber Optic Sensors And Artificial Neural Networks, Xiaomin Jin, Xiao-Hua Yu, Saied Zarger, Roshan H. Patel, Sam Wards

Electrical Engineering

No abstract provided.

Fatigue Testing Of Three Peristernal Median Sternotomy Closure Techniques, Cameron Wangsgard, David J. Cohen, Lanny V. Griffin

Biomedical Engineering

Failure of a sternotomy closure because of closure system fatigue is a complication that may result in dehiscence and put the individual at risk for serious complications. The purpose of this study was to assess the fatigue performance of three peristernal median sternotomy closure techniques (figure-of-eight stainless-steel wires, figure-of-eight stainless-steel cables, or Pectofix Dynamic Sternal Fixation [DSF] stainless-steel plates) in order to quantify the potential risk of fatigue failure of these devices when subject to cyclic loads in physiologically relevant loading directions.

Survey Of Hardware Platforms For An Energy Efficient Implementation Of Matching Pursuits Algorithm For Shallow Water Networks, Bridget Benson, Ali Irturk, Junguk Cho, Ryan Kastner

Electrical Engineering

Coral reefs worldwide are in serious decline. Underwater wireless sensor networks may be the answer to providing the persistent monitoring presence needed to obtain the data necessary to better understand how to protect these ecosystems for the future. Many advances have been made in underwater acoustic communication devices for underwater wireless sensor networks, but a major challenge that still remains is obtaining an energy efficient modem design. To begin to address this challenge, we implement the Matching Pursuits algorithm for channel estimation, an energy consuming portion of an existing underwater acoustic modem designed for shallow water networks, on a variety …

Spatial Variability Of Waste Temperatures In Msw Landfills, James L. Hanson, Nazli Yesiller, Nicolas K. Oettle

Civil and Environmental Engineering

Spatial variability of waste temperatures in MSW landfills was determined over different physical and temporal scales. Data have been obtained at four landfills located in different climatic regions in North America: Alaska, British Columbia, Michigan, and New Mexico. Temperatures were measured using 100 to over 250 sensors at each site. Data were obtained for 5 to 10 year periods at the sites. Temperatures were measured in wastes with a broad range of ages: newly-placed and old (up to 40-year old). The characteristic shape of waste temperature vs. depth relationships consists of a convex temperature profile with maximum temperatures observed at …

Experimental Determination Of Cover Surface Temperature Functions At Msw Landfills, Nicolas K. Oettle, James L. Hanson, Nazli Yesiller

Civil and Environmental Engineering

Cover temperatures were measured at four MSW landfills located in different climatic regions in North America: Michigan, New Mexico, Alaska, and British Columbia. Temperature measurements were made on a weekly basis throughout the depth of the cover profiles extending from the surface into the top layers of the underlying wastes. Bias was produced in the surface temperature data due to the combined effects of the time of day that weekly surface measurements were taken and the high diurnal variations at the surface. Analytical methods were used to obtain representative surface temperature functions for the covers from experimental data. Mean cover …

Avoiding Common Problems With Drip Tape, Charles M. Burt

BioResource and Agricultural Engineering

This publication is meant to help farmers, dealers, and manufacturers recognize and understand some of the problems that have been experienced with drip tape – problems that are quite different from manufacturing defects. Problems that are quickly detected and properly identified can often be remedied, or be avoided in the future. The report addresses drip tape damage caused by pests, installation, emitter pressure, plugging, and other categories.

Neural Network Dimension Selection For Dynamical System Identification, Devin Sabo, Xiao-Hua Yu

Electrical Engineering

Choosing an appropriate size of a network is an important issue for any neural network applications. The common practice is to start with an “over-sized” network, then gradually reduces its size to find the optimal solution. In this paper, a new hybrid neural network pruning algorithm for multi-layer feedforward neural networks is investigated. Computer simulation results on system identification and pattern classification problems show this algorithm can significantly reduce the network dimension while still maintaining satisfactory identification and classification accuracy.

Analysis And Design Of Multiphase Multi-Interleave Dc-Dc Converter With Input-Output Bypass Capacitor, Furqan Mubashir Saleemi

Master's Theses

The power requirements for the microprocessor have been increasing as per Moore's Law. According to International Technology Roadmap (ITRS), the Voltage Regulator Module (VRM) for the microprocessor will be 200 W(with 1V, 200A output) in 2010. With the VRMs topology of synchronous buck, serious technical challenges such as small duty cycle, high switching frequencies, and higher current demands, contribute to decreased power density and increased cost. This thesis proposes a Multiphase Multi-Interleave Buck topology to solve the technical challenges of powering future microprocessors. The critical design parameter values are selected using the theoretical design equations and calculations. The design is …

A Novel Method For Characterization Of Peripheral Nerve Fiber Size Distributions By Group Delay Measurements And Simulated Annealing Optimization, Robert B. Szlavik, Galen E. Turner, Iii

Biomedical Engineering

The ability to determine the characteristics of peripheral nerve fiber size distributions would provide additional information to clinicians for the diagnosis of specific pathologies of the peripheral nervous system. Investigation of these conditions, using electro-diagnostic techniques, is advantageous in the sense that such techniques tend to be minimally invasive yet provide valuable diagnostic information. One of the principal electro-diagnostic tools available to the clinician is the nerve conduction velocity test. While the peripheral nerve conduction velocity test can provide useful information to the clinician regarding the viability of the nerve under study, it is a single parameter test that yields …

Aerodynamic Analysis Of A Generic Fighter With A Chine Fuselage/Delta Wing Configuration Using Delayed Detached-Eddy Simulation, Tiger L. Jeans, David R. Mcdaniel, Russell M. Cummings, William H. Mason

Aerospace Engineering

The Modular Transonic Vortex Investigation (MTVI) program at NASA Langley Research Center investigated the transonic characteristics of generic fighter configurations with chined fuselages and delta wings. Previous experiments show that the fuselage and leading edge vortex interactions are detrimental to the vehicle’s aerodynamic characteristics for angles of attack greater than 23º at low angles of sideslip. This is largely due to abrupt asymmetric vortex breakdown, which leads to pronounced pitch-up and significant nonlinearities in lateral stability that could result in roll departure. An improved understanding of the exact origins of this nonlinear behavior would improve future fighter design, and predictive …

An Evaluation Of Proposed Formula 1 Aerodynamic Regulations Changes Using Computational Fluid Dynamics, Robert L. Perry, David D. Marshall

Aerospace Engineering

This report evaluates the proposed FIA Formula 1 World Championship aerodynamics rules changes intended to increase on track passing for the 2009 season. Two full Formula 1 cars were modeled under close drafting conditions, both under the current regulations and the proposed 2009 regulations to determine whether or not the FIA's goals of reducing down force by 50% and improving sensitivity to leading car wakes would be met. Under the current regulations, a car following another at 2.4 car lengths loses approximately 17% of it down force compared to isolation. The new regulations were counter productive and ineffective, failing both …

Face And Lip Localization In Unconstrained Imagery, Brandon Crow, Jane Zhang

Electrical Engineering

When combined with acoustical speech information, visual speech information (lip movement) significantly improves Automatic Speech Recognition (ASR) in acoustically noisy environments. Previous research has demonstrated that visual modality is a viable tool for identifying speech. However, the visual information has yet to become utilized in mainstream ASR systems due to the difficulty in accurately tracking lips in real-world conditions. This paper presents our current progress in addressing this issue. We derive several algorithms based on a modified HSI color space to successfully locate the face, eyes, and lips. These algorithms are then tested over imagery collected in visually challenging environments.

A Nonlinear Finite Element Model Of Cartilage Growth, Andrew Davol, Michael S. Bingham, Robert L. Sah, Stephen M. Klisch

Mechanical Engineering

The long range objective of this work is to develop a cartilage growth finite element model (CGFEM), based on the theories of growing mixtures that has the capability to depict the evolution of the anisotropic and inhomogeneous mechanical properties, residual stresses, and nonhomogeneities that are attained by native adult cartilage. The CGFEM developed here simulates isotropic in vitro growth of cartilage with and without mechanical stimulation. To accomplish this analysis a commercial finite element code (ABAQUS) is combined with an external program (MATLAB) to solve an incremental equilibrium boundary value problem representing one increment of growth. This procedure is repeated …

Regulation Of Immature Cartilage Growth By Igf-I, Tgf- Β 1, Bmp-7, And Pdgf-Ab: Role Of Metabolic Balance Between Fixed Charge And Collagen Network, Anna Asanbaeva, Koichi Masuda, Eugene J-M.A. Thonar, Stephen M. Klisch, Robert L. Sah

Mechanical Engineering

Cartilage growth may involve alterations in the balance between the swelling tendency of proteoglycans and the restraining function of the collagen network. Growth factors, including IGF-I, TGF-β1, BMP-7, and PDGF-AB, regulate chondrocyte metabolism and, consequently, may regulate cartilage growth. Immature bovine articular cartilage explants from the superficial and middle zones were incubated for 13 days in basal medium or medium supplemented with serum, IGF-I, TGF-β1, BMP-7, or PDGF-AB. Variations in tissue size, accumulation of proteoglycan and collagen, and tensile properties were assessed. The inclusion of serum, IGF-I, or BMP-7 resulted in expansive tissue growth, stimulation of proteoglycan deposition but not …

Technical Concepts Related To Conservation Of Irrigation And Rain Water In Agricultural Systems, A. J. Clemmens, R. G. Allen, Charles M. Burt

BioResource and Agricultural Engineering

Forty percent of freshwater withdrawals in the United States are for irrigated agriculture, which contribute more than $50 billion to the economy. Increasing diversions of water for urban, environmental, and other uses will likely decrease water available to agriculture. Water conservation in agriculture is touted as a good method for minimizing the impact of reduced agricultural diversions on production. Because “wasted” water is often reused until it reaches the ocean, there are limitations to the true water savings that result from programs that aim to increase irrigation efficiency. True water savings can come from four areas: reduction of unnecessary evaporation …

An Undergraduate Computational Aerodynamics Curriculum, Keith Bergeron, Russell M. Cummings, Capt Robert Decker, Maj Jacob Freeman, Capt Charlie Hoke, Jurgen Seidel, Scott A. Morton, David M. Mcdaniel

Aerospace Engineering

Modeling and Simulation (M&S) as part of the Aeronautical Engineering major at the United States Air Force Academy (USAFA) has grown from a one course introduction to an integrated and essential component for developing future aerospace leaders. This paper documents the progress the USAFA Department of Aeronautics (DFAN) has made since 2003 to teach cadets, through a 2-course sequence, how to gain an understanding of aerodynamic phenomena using computational methods made possible with Department of Defense (DoD) High Performance Computing Modernization Program (HPCMP) resources. The first course in of the sequence builds upon demonstrations, made in early core coursework, to …

Characterization And Compression Properties Of Injection Molded Carbon Nanotube Composites, Grey Curtzwiler, Jay Singh, J. Miltz, Jimmy Doi, Keith Vorst

Industrial Technology and Packaging

Since the development of carbon nanotubes (CNTs) in 1991, they have received much attention with improved mechanical, thermal, and electrical properties of their composites compared to common polymer composites. The CNTs are currently used to increase the modulus of common thermoplastics and thermosets, including urethanes and epoxies. The CNTs are difficult to disperse within any media because of limited chemical reactivity and potential agglomeration in their ‘‘as grown’’ state. This study evaluated the effect of incorporating bundled and unbundled CNTs at different concentrations into Polyurethane/CNT/woven fiber reinforced composites. Optical microscopy and atomic force microscopy (AFM) characterized the dispersion of CNTs …

Role Of Shear Keys In Seismic Behavior Of Bridges Crossing Fault-Rupture Zones, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

This paper examines the role of shear keys at bridge abutments in the seismic behavior of “ordinary” bridges. The seismic responses of bridges subjected to spatially uniform and spatially varying ground motions for three shear-key conditions—nonlinear shear keys that break off and cease to provide transverse restraint if deformed beyond a certain limit; elastic shear keys that do not break off and continue to provide transverse restraint throughout the ground shaking; and no shear keys—are examined. Results show that seismic demands for a bridge with nonlinear shear keys can generally be bounded by the demands of a bridge with elastic …

A Longitudinal Study Of The Ethical Development Of Engineering And Non-Engineering Students At A National Research University, Cynthia J. Finelli, Janel A. Sutkus, Donald D. Carpenter, Trevor S. Harding

Materials Engineering

No abstract provided.

Numerical Prediction And Wind Tunnel Experiment For A Pitching Unmanned Combat Air Vehicle, Russell M. Cummings, Scott A. Morton, Stefan G. Siegel

Aerospace Engineering

The low-speed flowfield for a generic unmanned combat air vehicle (UCAV) is investigated both experimentally and numerically. A wind tunnel experiment was conducted with the Boeing 1301 UCAV at a variety of angles of attack up to 70 degrees, both statically and with various frequencies of pitch oscillation (0.5, 1.0, and 2.0 Hz). In addition, pitching was performed about three longitudinal locations on the configuration (the nose, 35% MAC, and the tail). Solutions to the unsteady, laminar, compressible Navier–Stokes equations were obtained on an unstructured mesh to match results from the static and dynamic experiments. The computational results are compared …

Predicting The Seismic Behavior Of The Dywidag Ductile Connector (Ddc) Precast Concrete System, Elizabeth Mary Kenyon

Master's Theses

Structural engineering is heavily dependent on the use of computers. When creating a building model using structural analysis software, it is required that the designer have an understanding of the system behavior and the modeling program capabilities.

Some engineers in the Southern California region are taking steps towards incorporating the Dywidag ductile connector (DDC) and super hybrid systems into building practice due to the advantages found in these systems’ construction methods and seismic performance.

As the DDC and super hybrid systems reach industry, the design engineer will need to model these systems using structural analysis programs. This report describes two …

Optimize Neural Network Controller Design Using Genetic Algorithm, Ariel Kopel, Xiao-Hua Yu

Electrical Engineering

The size of a neural network must be predetermined before it can be trained for any application. Choosing the correct size of a neural network can increase its speed of response and thus improve the performance of the overall system. In this paper, a genetic algorithm is employed to find the optimal number of connections of a neural network controller which is used to regulate a class of DC power supplies. Satisfactory computer simulation results are obtained.

Improvement Of Light Transmission Using Photonic Lattices For Solar Cells, Xiaomin Jin, Simeon Trieu

Electrical Engineering

We study solar-cell interface designs using photonic lattices. We simulate rectangular and triangular micro-profiles as the solar cell surface. Compared to the conventional flat surface, the photonic lattice interface can increase light transmission to 98%.

A Project-Based Electronics Manufacturing Laboratory Course For Lower-Division Engineering Students, Jianbiao Pan, Albert Liddicoat, James G. Harris, Dominic Dal Bello

Industrial and Manufacturing Engineering

This paper presents a project-based laboratory course on electronics design and manufacturing. The goal of this course is to provide lower-division engineering students a hands-on experience involving actual printed circuit board (PCB) design, layout, fabrication, assembly, and testing. Through project-based learning, students not only learn technical skills in designing and manufacturing an electronic device, but also develop their project management and communication skills early in their course of study at the university. The course outline and examples of the student projects are presented in this paper as well as project evaluations and students’ feedback. This paper also presents the selection …

Curricular Enhancement To Support Project-Based Learning In Computer And Electrical Engineering, Albert Liddicoat, Jianbiao Pan, James G. Harris, Lynne A. Slivovsky

Industrial and Manufacturing Engineering

Undergraduate computer and electrical engineering programs often partition the curriculum into several courses based on related topics taught in isolation. Students are expected to synthesize their knowledge in a senior design project. It is the authors’ experience that students often struggle during their senior design project since they have not gained the appropriate knowledge or mastered necessary skills needed to work on a significant or team-based engineering design project. Specifically, students need to be able to define system requirements, partition the design into subcomponents, design, build, test, and verify that the system requirements have been met. The authors have enhanced …

Enhancing Student Learning Through State-Of-The-Art Systems Level Design And Implementation: The Development Of A Lower Division Learning Module, James G. Harris, Dominic Dal Bello, Jianbiao Pan, Albert Liddicoat

Industrial and Manufacturing Engineering

The Cal Poly/Allan Hancock team is developing a learning module that will allow all lower division engineering students to design, fabricate, assemble, and test an electronic system implemented on a printed circuit board (PCB). All the services necessary to perform this laboratory experiment will be provided with low-cost vendors available on the . The learning module is being developed so that it can be integrated into the existing electrical engineering lower division courses that are required by all engineering students. The laboratory learning module will use operational amplifiers (op amp), resistors, capacitors and other common electronic components to study the …