Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2009

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 3691 - 3720 of 4158

Full-Text Articles in Engineering

Neonatal Cpr: Room At The Top—A Mathematical Study Of Optimal Chest Compression Frequency Versus Body Size, Charles F. Babbs, Andrew Meyer, Vinay Nadkarni Jan 2009

Neonatal Cpr: Room At The Top—A Mathematical Study Of Optimal Chest Compression Frequency Versus Body Size, Charles F. Babbs, Andrew Meyer, Vinay Nadkarni

Weldon School of Biomedical Engineering Faculty Publications

Objective: To explore in detail the expected magnitude of systemic perfusion pressure during standard CPR as a function of compression frequency for different sized people from neonate to adult. Method: A 7-compartment mathematical model of the human cardiopulmonary system—upgraded to include inertance of blood columns in the aorta and vena cavae—was exercised with parameters scaled to reflect changes in body weight from 1 to 70 kg. Results: Maximal systemic perfusion pressure occurs at chest compression rates near 60, 120, 180, and 250 per minute for subjects weighing 70, 10, 3, and 1 kg, respectively. Such maxima are predicted by analytical …


Simulations Of Aerodynamic Damping For Mems Resonators, Xiaohui Guo, Alina A. Alexeenko Jan 2009

Simulations Of Aerodynamic Damping For Mems Resonators, Xiaohui Guo, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Aerodynamic damping for MEMS resonators is studied based on the numerical solution of Boltzmann-ESBGK equation. A compact model is then developed based on numerical simulations for a wide range of Knudsen numbers. The damping predictions are compared with both Reynold equation based models and several sets of experimental data. It has been found that the structural damping is dominant at low pressures (high Knudsen numbers). For cases with small length-to-width ratios and large vibration amplitudes, the threedimensionality effects must be taken into account. Finally, an uncertainty quantification approach based on the probability transformation method has been applied to assess the …


A Continuum-Based Model For Analysis Of Laterally Loaded Piles In Layered Soils, D Basu, Rodrigo Salgado, Monica Prezzi Jan 2009

A Continuum-Based Model For Analysis Of Laterally Loaded Piles In Layered Soils, D Basu, Rodrigo Salgado, Monica Prezzi

Lyles School of Civil Engineering Faculty Publications

An analysis is developed to calculate the response of laterally loaded piles in multilayered elastic media. The displacement fields in the analysis are taken to be the products of independent functions that vary in the vertical, radial and circumferential directions. The governing differential equations for the pile deflections in different soil layers are obtained using the principle of minimum potential energy. Solutions for pile deflection are obtained analytically, whereas those for soil displacements are obtained using the one-dimensional finite difference method. The input parameters needed for the analysis are the pile geometry, the soil profile, and the elastic constants of …


Numerical Simulation Of Gas-Phonon Coupling In Thermal Transpiration Flows, Xiaohui Guo, Dhruv Singh, Jayathi Murthy, Alina A. Alexeenko Jan 2009

Numerical Simulation Of Gas-Phonon Coupling In Thermal Transpiration Flows, Xiaohui Guo, Dhruv Singh, Jayathi Murthy, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Thermal transpiration is a rarefied gas flow driven by a wall temperature gradient and is a promising mechanism for gas pumping without moving parts, known as the Knudsen pump. Obtaining temperature measurements along capillary walls in a Knudsen pump is difficult due to extremely small length scales. Meanwhile, simplified analytical models are not applicable under the practical operating conditions of a thermal transpiration device, where the gas flow is in the transitional rarefied regime. Here, we present a coupled gas-phonon heat transfer and flow model to study a closed thermal transpiration system. Discretized Boltzmann equations are solved for molecular transport …


Synthesis Of Best Practices In Transportation Security, Volume Ii: Emergency Response, Rodrigo Vargas, Jon D. Fricker Jan 2009

Synthesis Of Best Practices In Transportation Security, Volume Ii: Emergency Response, Rodrigo Vargas, Jon D. Fricker

JTRP Technical Reports

Part I of the research focused on developing a methodology to identify and evaluate the most critical and vulnerable INDOT assets. This method aims at obtaining an index that reflects the vulnerability and criticality of an asset on the basis of multiple performance criteria. This methodology was tested on the seven INDOT districts. Because not all the factors that influence the vulnerability do have same weight, the analytical hierarchical process is used to obtain the weights for the criteria. Countermeasures are suggested as a part of the research to reduce the vulnerability of a given asset based on its relevant …


Saw-Cutting Guidelines For Concrete Pavements: Examining The Requirements For Time And Depth Of Saw-Cutting, Kambiz Raoufi, Tony Their, W. Jason Weiss, Jan Olek, Tommy E. Nantung Jan 2009

Saw-Cutting Guidelines For Concrete Pavements: Examining The Requirements For Time And Depth Of Saw-Cutting, Kambiz Raoufi, Tony Their, W. Jason Weiss, Jan Olek, Tommy E. Nantung

JTRP Technical Reports

Joints are placed in Portland cement concrete pavements (PCCP) to control random cracking. These joints provide a weakened plane that enables a crack to form in a controlled manner, relieving residual stresses that develop when thermal, hygral, or hydration movements are resisted by sub grade and adjoining pavement. While the concept of creating a weakened plane through saw-cutting is straightforward, determining the time and depth of the saw-cut has proven to be complicated. The goal of this project was to reduce the risk for joint raveling and random cracking. Specifically, this project has focused on: developing a procedure for determining …


Effects Of Aggregate Structure On Hot-Mix Asphalt Rutting Performance In Low Traffic Volume Local Pavements, Yong-Rak Kim, Hee Mun Park, Francisco Thiago Sacramento Aragão, Jamilla Emi Sudo Lutif Jan 2009

Effects Of Aggregate Structure On Hot-Mix Asphalt Rutting Performance In Low Traffic Volume Local Pavements, Yong-Rak Kim, Hee Mun Park, Francisco Thiago Sacramento Aragão, Jamilla Emi Sudo Lutif

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this study is to evaluate the effect of mix gradations associated with the Superpave restricted zone on rutting potential specifically for low traffic volume roadways. Although the elim-ination of the restricted zone requirement in Superpave mix design is highly recommended, some questions still remain unanswered as the research conclusions supporting the elimination of the re-stricted zone were largely made for medium to high traffic volume roadways, where aggregates are highly crushed and of good quality. The applicability of such research conclusions based on high traffic volume mixes needs to be verified for low volume mixes because many …


An Enhanced Data Mining Life Cycle, Markus Hofmann, Brendan Tierney Jan 2009

An Enhanced Data Mining Life Cycle, Markus Hofmann, Brendan Tierney

Conference papers

Data mining projects are complex and can have a high failure rate. In order to improve project management and success rates of such projects a life cycle is vital to the overall success of the project. This paper reports on a research project that was concerned with the life cycle development for data mining projects, its team members and their role. The paper provides a detailed view of the design and development of the data mining life cycle called DMLC. The life cycle aims to support all members of data mining project teams as well as IT managers and academic …


Agent Based Modeling In Computer Graphics And Games, Brian Macnamee Jan 2009

Agent Based Modeling In Computer Graphics And Games, Brian Macnamee

Books/Book Chapters

As graphics technology has improved in recent years, more and more importance has been placed on the behavior of virtual characters in applications set in virtual worlds in areas such as games, movies and simulations. The behavior of virtual characters should be believable in order to create the illusion that these virtual worlds are populated with living characters. This has led to the application of agent-based modeling to the control of these virtual characters. There are a number of advantages of using agent-based modeling techniques which include the fact that they remove the requirement for hand controlling all agents in …


Retention And Productivity In Industrial Search And Scan Tasks, Camilo Aguilera Jan 2009

Retention And Productivity In Industrial Search And Scan Tasks, Camilo Aguilera

Open Access Theses & Dissertations

An experiment was developed in order to study the interaction between individual factors (gender and mood) and the retention ability in search and scan activities. 54 subjects between 18 and 30 years old participated in a computer-based memory test from the North of Mexico area. A full factorial design was used to analyze the variables. Two factors, one with two levels (gender: male and female), and the second factor with three levels (mood: positive, neutral, and negative) were used in the analysis. The output was measured as the amount of characters memorized in a string of random alphanumeric characters. Data …


Microstructure And Electrical Performance Of Sputter-Deposited Hafnium Oxide (Hfo2) Thin Films, Brandon Adrian Aguirre Jan 2009

Microstructure And Electrical Performance Of Sputter-Deposited Hafnium Oxide (Hfo2) Thin Films, Brandon Adrian Aguirre

Open Access Theses & Dissertations

Hafnium oxide (HfO2) based dielectrics have been currently considered as the possible replacements for the traditional gate-oxide (SiO2) of the complementary metal-oxide semiconductor (CMOS) devices. The high dielectric constant, wide band gap, and thermal stability in contact with Si make HfO2 a potential material for application in CMOS devices. The performance of HfO2 as a gate oxide material, however, depends on its quality and interface structure with Si. In this work, HfO2 thin films have been deposited by rf sputtering onto Si(100) substrates under varying growth temperatures (Ts). The objective of the work is to understand the growth and microstructure …


Flashback Propensity Of Gas Mixtures, Bidhan Kumar Dam Jan 2009

Flashback Propensity Of Gas Mixtures, Bidhan Kumar Dam

Open Access Theses & Dissertations

In this study, experimental measurements of flashback propensity of hydrogen (H2)-carbon monoxide (CO) mixtures, which are the primary constituents of syngas fuels, are described. The effects of H2 concentration, diluents and swirl on the flashback propensity of H2 CO flames are discussed. For boundary layer type flashback, the critical velocity gradient (gF) values of 5 to 95%, 15 to 85%, and 25 to 75% H2-CO mixtures somewhat agree with the scaling relation (g_F=c (S_L^2)/α) and yield an average c value of 0.038. At a lower SL2/α ratio, burner diameters have small effects on critical velocity gradient measurements; however, the effect …


Treatment Of Ro Concentrate Using Vsep Technology, Guillermo Guadalupe Delgado Jan 2009

Treatment Of Ro Concentrate Using Vsep Technology, Guillermo Guadalupe Delgado

Open Access Theses & Dissertations

The city of El Paso has the largest inland brackish desalination plant in the world. The Kay Bailey Hutchison (KBH) Desalting plant produces 15 million of permeate water every day. Due to the excellent quality of the water, the permeate water is blended with brackish water producing a final volume of 27.5 million gallons of water every day. With an average recovery rate of 80%, the KBH plant produces an average of 3 million gallons of concentrated brackish water that is disposed of via injection wells 23 miles from the plant.

Conventional reverse osmosis (RO) systems are not capable of …


Abrasiveness Of Boron Carbide Coatings, Matthew Siniawski Jan 2009

Abrasiveness Of Boron Carbide Coatings, Matthew Siniawski

Mechanical Engineering Faculty Works

No abstract provided.


A Physics-Based Modeling And Real-Time Simulation Of Biomechanical Diffusion Process Through Optical Imaged Alveolar Tissues On Graphical Processing Units, Ilhan Kaya Jan 2009

A Physics-Based Modeling And Real-Time Simulation Of Biomechanical Diffusion Process Through Optical Imaged Alveolar Tissues On Graphical Processing Units, Ilhan Kaya

Link Foundation Modeling, Simulation and Training Fellowship Reports

Tissue engineering has broad applications fro1n creating the much needed engineered tissue and organ structures for regenerative medicine to providing in vitro testbeds for drug testing. In the later, application domain, creating alveolar lung tissue and simulating the diffusion process of oxygen and other possible agents front the air into the blood stream as well as modeling the removal of carbon dioxide and other possible entities-from the blood stream are of critical importance to simulating lung functions in various environments. In this paper, we propose a physics-based model to simulate the alveolar gas exchange and the alveolar diffusion process. Tissue …


Characterization Of A Mems Accelerometer For A Highway Health Monitoring Ultra-Low Power Sensor, Karla Cecilia Enriquez Jan 2009

Characterization Of A Mems Accelerometer For A Highway Health Monitoring Ultra-Low Power Sensor, Karla Cecilia Enriquez

Open Access Theses & Dissertations

With the 2009 American Recovery and Reinvestment Act, government officials recognized the need to implement automated methods that reduce the cost of assessment projects and provide a long-term solution to monitor the structural health of bridges and highways. Although important research exists in the area of non-destructive evaluation, current road health monitoring efforts continue to be costly and time consuming. This Thesis focuses on the characterization of a MEMS accelerometer intended to be the basis of a novel ultra-low power sensing system to remotely asses the condition of highways. The architecture of a sensor prototype built to validate an algorithm …


Autonomous Vehicle Navigation: A Comparative Study Of Classical Logic And Neural Network Technique, Javier Alejandro Flores Jan 2009

Autonomous Vehicle Navigation: A Comparative Study Of Classical Logic And Neural Network Technique, Javier Alejandro Flores

Open Access Theses & Dissertations

Today is an era in which humans need the help of automated machines to facilitate their hectic lives. Over the past few decades, robotics has been one of the most researched areas in the world. One area of this research is obstacle avoidance for autonomous vehicles. In order to avoid an obstacle, the system may include two important characteristics: obstacle detection and avoidance control. In this Thesis a classical logic system and artificial neural network approach is presented. With the help of an Integrated Development Environment, a virtual robot was able to negotiate a maze and avoid obstacles according to …


Spectroscopic Characterizations Of Organic/Inorganic Nanocomposites, Jayesh Rasikalal Govani Jan 2009

Spectroscopic Characterizations Of Organic/Inorganic Nanocomposites, Jayesh Rasikalal Govani

Open Access Theses & Dissertations

Inorganic potassium dihydrogen phosphate (KDP) is widely known for its value as a nonlinear optical material. In this study, pure and l-arginine-doped KDP single crystals were grown by the slow solvent evaporation technique and further subjected to infrared absorption and Raman studies for the confirmation of chemical group functionalization and possible bonding between the organic and inorganic materials. The appearance in the infrared absorption spectra of additional vibrational lines, which mostly originate from disturbed N-H, C-H, and C-N bonds of the l-arginine-doped salt, confirm the interaction between KDP and the organic material. This affirmation is supported by more evidence from …


Identification Of Human Gait Using Genetic Algorithm Tuned Fuzzy Logic, Abdallah Abdel-Rahman Hassan Mahmoud Jan 2009

Identification Of Human Gait Using Genetic Algorithm Tuned Fuzzy Logic, Abdallah Abdel-Rahman Hassan Mahmoud

Open Access Theses & Dissertations

Data mining is concerned with the discovery of useful hidden information in large databases. Classification is a data mining task producing rules in which a set of attributes in data predict the value of a class attribute. Classifiers usually produce a large number of rules, most of which are not interesting to the user. Rule interestingness is a decisive factor. However, evaluating rule interestingness is challenging as it involves both objective (data-driven) and subjective (user-driven) aspects.

In this research, a fuzzy genetic algorithm is proposed to discover classification rules that are both accurate and interesting. Continuous attributes are fuzzified so …


Comparison Of Older Mexican American Upper Extremity Reach Capabilities To Older Anglo Americans, Odi Mike Ikpe Jan 2009

Comparison Of Older Mexican American Upper Extremity Reach Capabilities To Older Anglo Americans, Odi Mike Ikpe

Open Access Theses & Dissertations

The study aimed to investigate if there are upper extremity reach capability differences in older Mexican Americans and older Anglo Americans. The subjects were recruited and corresponded to the 2000 census track. Upper extremity reach capability was determined by analysis of 20 range of motion variables. A MANOVA analysis utilizing SPSS software was performed with age, gender and ethnicity as independent variables while height and 20 range of motion anthropometric measurements servings as dependent variables (responses). Ethnicity as a function of age was found to be significant in height, horizontal distance from buttock to hand, rotation of head to the …


Reduced Dimensionality Hyperspectral Classification Using Finite Mixture Models, Vikram Jayaram Jan 2009

Reduced Dimensionality Hyperspectral Classification Using Finite Mixture Models, Vikram Jayaram

Open Access Theses & Dissertations

Classification of HSI data is a challenging problem for two main reasons. First, with limited spatial resolution of HSI sensors and/or the distance of the observed scene, the images invariably contain pixels composed of several materials. It is desirable to resolve the contributions of the constituents from the observed image without relying on high spatial resolution images. Remote sensing cameras have been designed to capture a wide spectral range motivating the use of post-processing techniques to distinguish materials via their spectral signatures. Secondly, available training data for most pattern recognition problems in HSI processing is severely inadequate. Under the framework …


Nondestructive Testing For Finding Out The Displacement Of Crack In Silicon Nitride, Sriharsha Kurra Jan 2009

Nondestructive Testing For Finding Out The Displacement Of Crack In Silicon Nitride, Sriharsha Kurra

Open Access Theses & Dissertations

Nondestructive testing (NDT) has become an increasingly vital factor in the effective conduct of research, development, design and manufacturing. Only with the appropriate use of nondestructive testing techniques, the benefits of advanced materials science can be fully realized. NDT has a wide range of industrial applications and various methods and techniques are employed to perform the nondestructive testing. The current work aims to demonstrate the nondestructive testing technique applied to determine the damage in silicon nitride. Ceramics are brittle materials and non destructive evaluation methods are required to assess the quality and reliability of them. A nondestructive evaluation technique has …


Detection Of Gas/Odor Based On Quartz Crystal Microbalance Sensors And Fuzzy Similarity Measure, Yi-Chen Lo Jan 2009

Detection Of Gas/Odor Based On Quartz Crystal Microbalance Sensors And Fuzzy Similarity Measure, Yi-Chen Lo

Open Access Theses & Dissertations

In this research, an array of six Quartz Crystal Microbalance sensors (QCM) using fuzzy similar measurement is proposed to recognize different gases and the percentage of those gases in a mixed gas. The experiment suggests three different gases, oxygen, helium, and argon as test gases and the nitrogen as the reference gas. Six QCMs in this array are coated respectively with six different specific polymers that are selected based on Linear Solvation Energy Relationship (LSER) method, in order to absorb gas molecules so as to recognize responses of resonant frequency changes from QCMs. Testing with different gases results in different …


Finite Element Modeling Of Nondestructive Test Methods Used For Detection Of Delamination In Hot Mix Asphalt Pavements, Dante Mejia Munoz Jan 2009

Finite Element Modeling Of Nondestructive Test Methods Used For Detection Of Delamination In Hot Mix Asphalt Pavements, Dante Mejia Munoz

Open Access Theses & Dissertations

For the simulation of detection of delamination this study focus on three NDT methods: Impact Echo, Impulse Response and Ultrasonic Surface Waves. The was evaluated and then a parametric study was elaborated.


Semi-Automated Frame Transformations Using Fft Analysis On 2-D Images, Francisco Javier Osuna Jan 2009

Semi-Automated Frame Transformations Using Fft Analysis On 2-D Images, Francisco Javier Osuna

Open Access Theses & Dissertations

Cassini entered Saturn's orbit on July 1, 2004 beginning a four-year exploration of Saturn. In 2008 the mission was extended, and Cassini continues to collect and transmit images and data collected during its mission. In order to accurately interpret images, it is necessary to know the location and orientation of the camera provided the field of view when the image was collected. While the mission managers provide initial estimates of this orientation, scientific analysis requires better estimates than the initial data provided. Navigation is a process for improving the estimation of the true camera pointing vector as determined by features …


Effects Of Build Orientation, Aging, And Pre-Conditioning On Mechanical Properties For Stereolithography-Manufactured Astm Type I Specimens Using A Design Of Experiments Approach, Karina Puebla Jan 2009

Effects Of Build Orientation, Aging, And Pre-Conditioning On Mechanical Properties For Stereolithography-Manufactured Astm Type I Specimens Using A Design Of Experiments Approach, Karina Puebla

Open Access Theses & Dissertations

With industry's growing focus on the rapid manufacturing (RM) of end-use products, rapid prototyping (RP) or layered manufacturing (LM) machines that were originally designed to build prototypes may now be required to build functional end-use products. To successfully accomplish the transition, the available materials utilized in RP must provide the performance required for RM. The specific technology used must also be capable of producing repeatable and reproducible parts in regards to mechanical and dimensional properties.

A design of experiments approach was performed to determine the effects of build orientation, aging, and pre-conditioning on the mechanical properties. To perform the investigations, …


Hybrid Ftth Optical Network Using Incoherent Optical Code Division Multiple Access, Joel Quintana Jan 2009

Hybrid Ftth Optical Network Using Incoherent Optical Code Division Multiple Access, Joel Quintana

Open Access Theses & Dissertations

Over the past 20 years there has been extensive research on the application of spread spectrum multiplexing techniques for communications via optical fiber. Optical Code Division Multiplexing (OCDMA) is the technique that has exhibited the most promise as a primary multiplexing vehicle for the transition into all-optical processing of data, and as a supplement to other techniques such as Time Division Multiplexing (TDM) and Wave Division Multiplexing (WDM). OCDMA can be classified into incoherent OCDMA, where coding and detection is done on the basis of optical power, and coherent OCDMA where coding is done on a field amplitude basis. The …


Aluminum Hydride Compunds: A Theoretical And Experimental Spectroscopic Study, Layra E. Reza Jan 2009

Aluminum Hydride Compunds: A Theoretical And Experimental Spectroscopic Study, Layra E. Reza

Open Access Theses & Dissertations

None


Optimization Of A Strapdown Inertial Navigation System, Mario Ruiz Jan 2009

Optimization Of A Strapdown Inertial Navigation System, Mario Ruiz

Open Access Theses & Dissertations

The focus of this Thesis is to find 21 error parameters in a Strapdown Inertial Navigation System (SINS) that would minimize objective functions or error functions to increase accuracy utilizing an optimization algorithm. The algorithm used is goal attainment by Gembiki which is a multi-objective optimization algorithm proven to outperform other optimization methods in terms of efficiency and accuracy over large numbers of problems. Simulations of a noise-free SINS mounted on an aircraft were done in a stationary and on the move scenario to simulate two conditions in which alignment could become necessary. The error parameters to find were sensor …


Optimization Of Flow For Plastic Pbt With 45% Glass And Mineral Fiber Reinforcement In An Injection Over Mold Process Using Taguchi, Cpk And Mold Flow Simulation Software Approaches, Israel Sanchez Jan 2009

Optimization Of Flow For Plastic Pbt With 45% Glass And Mineral Fiber Reinforcement In An Injection Over Mold Process Using Taguchi, Cpk And Mold Flow Simulation Software Approaches, Israel Sanchez

Open Access Theses & Dissertations

This Thesis analyze the plastic injection molding parameters in order to identify which parameters significantly affects the flow properties of Polibuthylen Thereptalate with 45% glass/mineral reinforcement, and which levels are the best to use for those parameters. With the purpose of optimizing the plastic flow conditions in an injection mold to obtain parts free from short shots (term used to describe a plastic part that is incomplete due to the poor plastic flow in the mold runners and cavities).

The used approach is Taguchi design of experiments to define which parameters have significant effect on the response variable, and the …