Engineering Commons^™

The Magic Atm, Amber Iraeta, Jason Sy, August Brower

Mechanical Engineering

No abstract provided.

Electro Mechanical Actuator Test Stand For In-Flight Experiments, Michael Koopmans, Catlin Mattheis, Austin Lawrence

Mechanical Engineering

The Prognostic Center of Excellence at NASA Ames is currently researching actuator prognostics, specifically in the application of electro mechanical actuators (EMA’s). Cal Poly ME students Michael Koopmans and Catlin Mattheis and EE student Austin Lawrence have chosen to undertake the task of building a test stand that will be flown in flight while testing EMA’s specific faults. A stand was designed to fit inside a standard 19” rack, take power from the aircraft 3 EMA’s, a computer, data acquisition, and electric magnets switches are powered. A MIL STD 1553 interface is present to allow fault injection. Vibration and temperature …

1.5 Kw Pwm Bipolar Inverter, Michael Newbry, Percy Vigo

Electrical Engineering

This report focuses on the design, construction, and testing of a PWM inverter capable of converting 1.5 kW. The purpose for the inverter is to convert DC solar energy to power an air conditioner. The inverter uses a bipolar control scheme which comes from a PIC microcontroller. This report contains the advantages and disadvantages of all the PWM control schemes. Furthermore, the testing shows bipolar inverter characteristics and a sample use of filters to obtain sinusoidal waveforms. The design of the circuit makes the inverter easy and safe to use and test.

Review: 'Fighting Traffic: The Dawn Of The Motor Age In The American City', John Alfred Heitmann

History Faculty Publications

During the early 1960s, as the Golden Age of the automobile in America began to wane, several commentators, including Lewis Mumford, raised the critical question of whether the automobile existed for the modern city or the city for the automobile. How and when the automobile became central to urban life is deftly addressed in Peter Norton’s Fighting Traffic: The Dawn of the Motor Age in the American City. This study is certainly one of the most important monographs focusing on the place of the automobile in American society within a historical context to appear in recent times; it interestingly supplements …

Non-Linear Contact Analysis Of Meshing Gears, Chun Hung Lee

Master's Theses

Gear transmission systems are considered one of the critical aspects of vibration analysis, and it contains various potential faults such as misalignment, cracks, and noise. Therefore, it requires vibration monitoring to ensure the system is operating properly. Case mounted accelerometers are frequently used to monitor frequencies in a system. However, it is not a simple task to identify and interpret the acceleration data since there are many gear mesh frequencies present. One of the approaches utilized by researchers to perform gear diagnostic is Finite Element Modeling. This study focuses on stiffness cycle and meshing stiffness of non-linear quasi-static finite element …

Gene Order Phylogeny And The Evolution Of Methanogens, Haiwei Luo, Zhiyi Sun, William Arndt, Jian Shi, Robert Friedman, Jijun Tang

Faculty Publications

Methanogens are a phylogenetically diverse group belonging to Euryarchaeota. Previously, phylogenetic approaches using large datasets revealed that methanogens can be grouped into two classes, “Class I” and “Class II”. However, some deep relationships were not resolved. For instance, the monophyly of “Class I” methanogens, which consist of Methanopyrales, Methanobacteriales and Methanococcales, is disputable due to weak statistical support. In this study, we use MSOAR to identify common orthologous genes from eight methanogen species and a Thermococcale species (outgroup), and apply GRAPPA and FastME to compute distance-based gene order phylogeny. The gene order phylogeny supports two classes of methanogens, but it …

Comparison Of Efficiency In Pathfinding Algorithms In Game Development, Nikhil Krishnaswamy

Technical Reports

This paper is the summary of a study done to assess the efficiency of three different pathfinding algorithms in a game-like environment. “Efficiency” is, in this case, defined as finding the shortest path possible in the least amount of time possible, and is tracked using a number of metrics, including the number of visitations made by a particular algorithm to any node in the graph tree, and the physical length of the traversable path in the game world. The three algorithms were tested using randomly generated sets of nodes in three different navigable environments in order to assess if any …

A Rapid Method For Flow-Ready Cylindrical Microchannel Fabrication, Kimberly H. Henthorn

Chemical and Biochemical Engineering Faculty Research & Creative Works

Most current methods of microchannel fabrication are expensive and time consuming or result in noncylindrical channels, which is undesirable for many applications. A rapid inexpensive method for the fabrication of flow-ready cylindrical polymer microchannels from polydimethylsiloxane (PDMS) is presented here. In this method, cylindrical needles are used as molds for the channels and also function as flow delivery devices after fabrication. Validation of channel function and smoothness can be accomplished by comparing experimental data to theoretical models. One model was previously developed by the author to predict the incipient motion of a glass sphere in contact with a perfectly smooth …

Inverse Scattering Solutions For Side-Band Signals, Jonathan Blackledge, Timo Hamalainen, Jyrki Joutsensalo

Conference papers

When a signal is recorded that has been physically generated by some scattering process (the interaction of electromagnetic waves with an inhomogeneous dielectric, for example), the `standard model' for the signal (i.e. information content convolved with a characteristic Impulse Response Function) is usually based on a single scattering approximation. An additive noise term is introduced into the model to take into account a range of non-deterministic factors including multiple scattering that, along with electronic noise and other background noise sources, is assumed to be relatively weak. Thus, the standard model is based on a `weak field condition' and the inverse …

Comparison Of Feedforward And Feedback Neural Network Architectures For Short Term Wind Speed Prediction, Ganesh K. Venayagamoorthy, Richard L. Welch, Stephen M. Ruffing

Electrical and Computer Engineering Faculty Research & Creative Works

This paper compares three types of neural networks trained using particle swarm optimization (PSO) for use in the short term prediction of wind speed. The three types of neural networks compared are the multi-layer perceptron (MLP) neural network, Elman recurrent neural network, and simultaneous recurrent neural network (SRN). Each network is trained and tested using meteorological data of one week measured at the National Renewable Energy Laboratory National Wind Technology Center near Boulder, CO. Results show that while the recurrent neural networks outperform the MLP in the best and average case with a lower overall mean squared error, the MLP …

Development Of An Integrated Solar Heat Pipe System For Improving Building Energy Efficiency., Michael Vincent Albanese

Electronic Theses and Dissertations

The one dimensional heat transfer, thermal diode effect of heat pipes makes them ideal for passive solar applications. Gains in a heat pipe passive solar wall are not lost during cloud cover or periods of low irradiation. An experimental model was built to test the performance of a heat pipe passive solar wall in a laboratory setting. Experimental variations included varying fluid fill levels and the addition of insulation along the adiabatic section of the heat pipe. Filling the heat pipe to 120% volume of the evaporator section and insulating the adiabatic section achieved efficiencies of 85%. The average rate …

Effectiveness And Service Lives/Survival Curves Of Various Pavement Rehabilitation Treatments, Panagiotis Ch. Anastasopoulos, Fred L. Mannering, John E. Haddock

JTRP Technical Reports

The pavement analysis in this study considers various combinations of pavement rehabilitation treatments (two-course HMA overlay with or without surface milling, concrete pavement restoration, three-course HMA overlay with or without surface milling, three-course HMA overlay with crack and seat of PCC pavement and 3-R and 4-R overlay or replacement treatments). Six road functional classes (rural and urban of interstates, non-interstates of the NHS, and non-interstates non-NHS) are considered. This allows for estimation of the performance and service life of the pavement, corresponding to each treatment and road functional class. Main findings;

• More than 95 percent of the data points …

Uwb Antennas For Medical Imaging, Khabat Ebnabbasi

Theses and Dissertations - UTB/UTPA

Ultra-Wide Band (UWB) Microwave for imaging applications; especially in the medical field, is a new method to overcome the inherent invasive features of X-ray imaging. In this work a new systematic and detailed design for the Tapered Slot Antenna (TSA) as a UWB antenna in microwave imaging systems for medical applications is presented. Among TSAs, the Vivaldi antenna was selected and the reasons to replace the horn antenna imaging systems are illustrated. In the first chapter the previous designs for microwave imaging and the outline of this work are given, Chapter Two covers the design of the Vivaldi antenna's different …

An Exact Algorithm For Solving The Set Partitioning Problem, Ahmed Mohamed Badr

Archived Theses and Dissertations

No abstract provided.

Software Quality Attribute Measurement And Analysis Based On Class Diagram Metrics, Dalia Rizk

Archived Theses and Dissertations

Software quality measurement lies at the heart of the quality engineering process. Quality measurement for object-oriented artifacts has become the key for ensuring high quality software. Both researchers and practitioners are interested in measuring software product quality for improvement. It has recently become more important to consider the quality of products at the early phases, especially at the design level to ensure that the coding and testing would be conducted more quickly and accurately. The research work on measuring quality at the design level progressed in a number of steps. The first step was to discover the correct set of …

Probability Density Functions For Snir In Ds-Cdma, David W. Matolak

Faculty Publications

Analytical expressions for the probability density function of block-wise signal-to-noise-plus-interference ratio for both synchronous and asynchronous direct-sequence spread spectrum code-division multiple access systems are developed, for equal average energy signals on the Gaussian and Rayleigh flat fading channels. Using the standard Gaussian approximation for multi-user interference, accurate density approximations are obtained, which agree very well with computer simulation results.

Mechanical Simulation Of Articular Cartilage Based On Experimental Results, Kevin Matthew Stewart

Master's Theses

Recently, a constituent based cartilage growth finite element model (CGFEM) was developed in order to predict articular cartilage (AC) biomechanical properties before and after growth. Previous research has noted limitations in the CGFEM such as model convergence with growth periods greater than 12 days. The main aims of this work were to address these limitations through (1) implementation of an exact material Jacobian matrix definition using the Jaumann-Kirchhoff (J-K) method and (2) quantification of elastic material parameters based upon research findings of the Cal Poly Cartilage Biomechanics Group (CPGBG). The J-K method was successfully implemented into the CGFEM and exceeded …

Editorial: Advances In The Dynamics Of Granular Materials, Florin Bobaru, J. S. Chen, Joseph A. Turner

Department of Engineering Mechanics: Faculty Publications

Granular materials exhibit a complex array of phenomena which makes the prediction of their behavior extremely difficult. Granular materials are strongly dissipative and show collective (heap formation, jamming) and size segregation phenomena, and can propagate surface waves. They display fluidization and convective motion, and under certain vibration regimes, they tend to mix when they would otherwise segregate, and segregate when they might otherwise mix. The wide range of behaviors that granular materials can display has been one of the main factors for which the development of predictive models has continued to remain an open problem.
The papers in this Special …

Cut Crop Edge Detection Using A Laser Sensor, Santosh Pitla, Joe D. Luck, Scott A. Shearer

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

An off-the-shelf low cost laser sensor was tested and evaluated both in laboratory and field conditions. The sensor identified the angular and straight edges of the laboratory test surface and replicated the straight edge profile with an error of 4%. In field conditions, the sensor identified three types of cut crop edges (wheat, alfalfa and corn) and replicated distinct shapes (triangle, curved and rectangular edges). The sensor was tested at two sensor path offset distances and three tractor/sensor speeds (3.2, 6.4 and 9.6 km/h). In all test runs the sensor detected the cut-crop edges. Standard deviations and RMSE values in …

Evaluation Of A Terrain Attribute Model For Locating Areas Suitable For Grassed Waterways In Agricultural Settings, Joe D. Luck, Adam C. Pike, Santosh Pitla, Tom Mueller, Scott A. Shearer

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

Grassed waterways placed in high water flow zones substantially reduce erosion in agricultural fields. A recent study proposed a statistical model for waterway planning for a farm in the Outer Bluegrass physiographic region of Kentucky. The logistic regression model identified where channel erosion was likely to occur based on elevation-derived terrain attributes. The objective of this study was to test their model in fields located in the Western Coal Fields physiographic region where soils differ substantially. Model predictions corresponded well with known areas of concentrated flow (i.e., maps of existing waterways, surface drains, and observations of erosion). The geographic inference …

Guidance Directrix Generation Using Laser Sensors, Santosh Pitla, Joe D. Luck, Scott A. Shearer

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

A sensor array consisting of two laser sensors was utilized to determine the guidance directrix (offset distance-d, heading angle-ø) that are required as reference inputs for an automated guidance system. The sensor array was evaluated in both laboratory and field conditions. Under laboratory conditions the sensor array replicated the physical profile of the target surface with a 4% error in determining the heading angle. Field tests were conducted in two types of crops; corn and alfalfa. The sensor array identified the cut-crop edge profile ahead of the tractor and replicated distinct shapes of the cut-crop edge. RMSE values in determining …

Actual And Reference Evaporative Losses And Surface Coefficients Of A Maize Field During Nongrowing (Dormant) Periods, Christopher H. Hay, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Effective water resources planning, allocation, management, and use in agroecosystems require accurate quantification of actual evapotranspiration (ET_c) during growing and nongrowing (dormant) periods. Prediction of ET_c for a variety of vegetation surfaces during the growing season has been researched extensively, but relatively little information exists on evaporative losses during nongrowing periods for different surfaces. The objectives of this research were to evaluate ET_c in relation to available energy, precipitation, and grass and alfalfa-reference ET (ET_o and ET_r) for a maize (Zea mays L.) field and to analyze the dynamics of surface coefficients …

Preferential Flow Path Effects On Subsurface Contaminant Transport In Alluvial Floodplains, Derek M. Heeren, Ronald B. Miller, Gary A. Fox, Daniel E. Storm, Chad J. Penn, Todd Halihan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

For strongly sorbing contaminants, transport from upland areas to surface water systems is typically considered to be due to surface runoff with subsurface transport assumed negligible. However, certain local conditions can lead to an environment where subsurface transport to streams may be significant, a source of contamination not alleviated by current best management practices (e.g. riparian buffers). The Ozark region, including parts of Oklahoma, Arkansas, and Missouri, is characterized by cherty, gravelly soils and gravel bed streams. Previous research identified a preferential flow path (PFP) at a field site along the Barren Fork Creek in northeastern Oklahoma. With the subsoils …

Pressure-Driven Transport Of Particles Through A Converging-Diverging Microchannel, Ye Ai, Sang W. Joo, Yingtao Jiang, Xiangchun Xuan, Shizhi Qian

Mechanical Engineering Faculty Research

Pressure-driven transport of particles through a symmetric converging-diverging microchannel is studied by solving a coupled nonlinear system, which is composed of the Navier–Stokes and continuity equations using the arbitrary Lagrangian–Eulerian finite-element technique. The predicted particle translation is in good agreement with existing experimental observations. The effects of pressure gradient, particle size, channel geometry, and a particle’s initial location on the particle transport are investigated. The pressure gradient has no effect on the ratio of the translational velocity of particles through a converging-diverging channel to that in the upstream straight channel. Particles are generally accelerated in the converging region and then …

Design And Implementation Of A Byzantine Fault Tolerance Framework For Web Services, Wenbing Zhao

Electrical and Computer Engineering Faculty Publications

Many Web services are expected to run with high degree of security and dependability. To achieve this goal, it is essential to use a Web services compatible framework that tolerates not only crash faults, but Byzantine faults as well, due to the untrusted communication environment in which the Web services operate. In this paper, we describe the design and implementation of such a framework, called BFT-WS. BFT-WS is designed to operate on top of the standard SOAP messaging framework for maximum interoperability. It is implemented as a pluggable module within the Axis2 architecture, as such, it requires minimum changes …

Me-Em Enewsbrief, June 2009, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

A Graph-Based Approach To Symbolic Functional Decomposition Of Finite State Machines, Piotr Szotkowski, Mariusz Rawski, Henry Selvaraj

Electrical & Computer Engineering Faculty Research

This paper discusses the symbolic functional decomposition method for implementing finite state machines in field-programmable gate array devices. This method is a viable alternative to the presently widespread two-step approaches to the problem, which consist of separate encoding and mapping stages; the proposed method does not have a separate decomposition step instead, the state's final encoding is introduced gradually on every decomposition iteration. Along with general description of the functional symbolic decomposition method's steps, the paper discusses various algorithms implementing the method and presents an example realisation of the most interesting algorithm. In the end, the paper compares the results …

Production Of Biobutanol From Biomass Using Novel Membrane Reactor, Natalie Thibodeaux

Chemical Engineering Undergraduate Honors Theses

Producing biobutanol from a waste product on a large scale is a novel idea. Because of this, there is very little research available in this area. Previous fermentation research has primarily focused on the production of ethanol or biobutanol using cellulosic or agricultural feed stocks. The Phase I research team, Team R azorbacks E ngineering FU el S olutions for E veryone (Team REFUSE), sought to design a fermentation process that would produce butanol from food waste. Team REFUSE cultivated a partnership with Chartwells, the campus food service provider for the University of Arkansas, for the acquisition of food waste. …

Advanced Thermosonic Wire Bonding Using High Frequency Ultrasonic Power: Optimization, Bondability, And Reliability, Minh-Nhat Ba Le

Master's Theses

Gold wire bonding typically uses 60 KHz ultrasonic frequency. Studies have been reported that increasing ultrasonic frequency from 60KHz to 120KHz can decrease bonding time, lower bonding temperature, and/or improve the bondability of Au metalized organic substrates. This thesis presents a systematic study of the effects of 120 KHz ultrasonic frequency on the reliability of fine pitch gold wire bonding. Two wire sizes, 25.4 and 17.8 μm in diameter (1.0 and 0.7 mil, respectively) were used. The gold wires were bonded to metalized pads over organic substrates with five different metallization. The studies were carried out using a thermosonic ball …

Design, Fabrication, And Implementation Of A Single-Cell Capture Chamber For A Microfluidic Impedance Sensor, Joshua-Jed Doria Fadriquela

Master's Theses

A microfluidic device was created for single-cell capture and analysis using polydimethylsiloxane (PDMS) channels and a glass substrate to develop a microfluidic single-cell impedance sensor for cell diagnostics. The device was fabricated using photolithography to create a master mold which in turn will use soft lithography to create the PDMS components for constant device production. The commercial software, COMSOLTM Multiphysics, was used to quantify the fluid dynamics in shallow micro-channels.

The device will be able to capture a cell and sequester it long enough to enable measurement of the impedance spectra that can characterize cell. The proposed device will be …