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

Engineering Commons™

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

2012

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 961 - 990 of 6303

Full-Text Articles in Engineering

Slides: Appropriate Sustainable Energy Technologies: A Light To The World, Lakshman D. Guruswamy, Jason B. Aamodt, Blake Feamster Sep 2012

Slides: Appropriate Sustainable Energy Technologies: A Light To The World, Lakshman D. Guruswamy, Jason B. Aamodt, Blake Feamster

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Jason Aamodt, Attorney; Adjunct Professor, University of Tulsa

15 slides


Slides: Meeting The Needs Of Women Through Clean Cooking Solutions, Corinne Hart Sep 2012

Slides: Meeting The Needs Of Women Through Clean Cooking Solutions, Corinne Hart

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Corinne Hart, Program Manager, Gender and Markets, Global Alliance for Clean Cookstoves

20 slides


Slides: Draft Power In Developing Country Agriculture--South Asia, Arjun Makhijani Sep 2012

Slides: Draft Power In Developing Country Agriculture--South Asia, Arjun Makhijani

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Dr. Arjun Makhijani, President, Institute for Energy and Environmental Research (IEER)

13 slides


Slides: Sources Of Electrical Energy For Those Who Are Remote And Poor, Frank Barnes Sep 2012

Slides: Sources Of Electrical Energy For Those Who Are Remote And Poor, Frank Barnes

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Dr. Frank Barnes, Distinguished Professor, Electrical, Computer, and Energy Engineering, University of Colorado

24 slides


Slides: Impacts Of Energy Deficits In Cooking, Illumination, Water, Sanitation, And Motive Power, Paul S. Chinowsky Sep 2012

Slides: Impacts Of Energy Deficits In Cooking, Illumination, Water, Sanitation, And Motive Power, Paul S. Chinowsky

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Dr. Paul Chinowsky, Director, Mortenson Center in Engineering for Developing Communities; Professor, University of Colorado

25 slides


Slides: The Green Climate Fund: Challenges And Opportunities: Some Thoughts On How The Green Climate Fund Could Close The Energy Justice Gap, Martin Hiller Sep 2012

Slides: The Green Climate Fund: Challenges And Opportunities: Some Thoughts On How The Green Climate Fund Could Close The Energy Justice Gap, Martin Hiller

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Martin Hiller, Director‐General, Renewable Energy and Energy Efficiency Partnership (REEEP), Vienna, Austria

22 slides


Slides: Nokero: Power To The Powerless, Stephen Katsaros Sep 2012

Slides: Nokero: Power To The Powerless, Stephen Katsaros

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Stephen Katsaros, Inventor, Founder, and CEO, Nokero

13 slides


Slides: Session 3: Decision-Making And The Energy Poor, Andrew Yager Sep 2012

Slides: Session 3: Decision-Making And The Energy Poor, Andrew Yager

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Andrew Yager, United Nations Department of Economic and Social Affairs, Division for Sustainable Development

33 slides


Slides: Unido: Partner For Prosperity, Kandeh K. Yumkella Sep 2012

Slides: Unido: Partner For Prosperity, Kandeh K. Yumkella

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Dr. Kandeh Yumkella, Chairman, UN Energy; Director General, United Nations Industrial Development Organization (UNIDO)

16 slides


Fundamental Sizing Implications Of Constant Or Increasing Weight Aircraft, Robert A. Mcdonald Sep 2012

Fundamental Sizing Implications Of Constant Or Increasing Weight Aircraft, Robert A. Mcdonald

Aerospace Engineering

As the energy storage capabilities of batteries and fuel cells advance, these technologies are increasingly being considered for aircraft primary propulsion. In addition to other fundamental differences from conventional systems, these concepts may have constant or even increasing mass throughout the mission. In this paper, the implications of constant or increasing mass on aircraft sizing are considered with the aim of generating insight for the design of these systems.


Computational Modeling Of Baffled Disinfection Tanks, Zachary H. Taylor, Qing Xu, Jordan M. Wilson, Subhas K. Venayagamoorthy Sep 2012

Computational Modeling Of Baffled Disinfection Tanks, Zachary H. Taylor, Qing Xu, Jordan M. Wilson, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The present study focuses on understanding the flow dynamics of baffled disinfection contact tanks through the use of computational fluid dynamics (CFD). In particular, we seek to address the key question: for a given footprint of a contact tank with a fixed inlet configuration, how does the hydraulic efficiency of the tank depend on the configuration of internal baffles? The benchmark contact tank geometry in our study is shown in Figure 1. In order to define guidelines for hydraulically efficient baffle tanks, we perform a total of 36 high-resolution three-dimensional simulations to quantify the efficiency of a laboratory scale tank …


Effects Of Haptic And 3d Audio Feedback On Pilot Performance And Workload For Quadrotor Uavs In Indoor Environments, Robert Mark Philbrick Sep 2012

Effects Of Haptic And 3d Audio Feedback On Pilot Performance And Workload For Quadrotor Uavs In Indoor Environments, Robert Mark Philbrick

Theses and Dissertations

Indoor flight of unmanned aerial vehicles (UAVs) has many applications in environments in which it is undesirable or dangerous for humans to be, such as military reconnaissance or searching for trapped victims in a collapsed building. However, limited visual feedback makes it difficult to pilot UAVs in cluttered and enclosed spaces. Haptic feedback combined with visual feedback has shown to reduce the number of collisions of UAVs in indoor environments; however, it has increased the mental workload of the operator. This thesis investigates the potential of combining novel haptic and 3D audio feedback to provide additional information to operators of …


An Experimental Investigation Of Strain Rate, Temperature And Humidity Effects On The Mechanical Behavior Of A Perfluorosulfonic Acid Membrane, Zongwen Lu, Melissa Lugo, Michael H. Santare, Anette M. Karlsson, F. Colin Busby, Peter Walsh Sep 2012

An Experimental Investigation Of Strain Rate, Temperature And Humidity Effects On The Mechanical Behavior Of A Perfluorosulfonic Acid Membrane, Zongwen Lu, Melissa Lugo, Michael H. Santare, Anette M. Karlsson, F. Colin Busby, Peter Walsh

Mechanical Engineering Faculty Publications

The time-dependent hygro-thermal mechanical behavior of a perfluorosulfonic acid (PFSA) membrane (Nafion® 211 membrane) commonly used in Proton Exchange Membrane Fuel Cells (PEMFCs) is investigated at selected strain rates for a broad range of temperatures and humidities. Tensile tests and relaxation tests are conducted to determine Young’s modulus and proportional limit stress as functions of strain rate, temperature and humidity. The results show that Young’s modulus and proportional limit stress increase as the strain rate increases, and decrease as the temperature or humidity increases. The results also show that the mechanical response of Nafion® 211 membrane is more …


Cross-Plane Electronic And Thermal Transport Properties Of P-Type La0.67sr0.33mno3/Lamno3 Perovskite Oxide Metal/Semiconductor Superlattices, Pankaj Jha, Timothy D. Sands, Laura Cassels, Philip Jackson, Tela Favaloro, Benjamin Kirk, Joshua Zide, Xianfan Xu, Ali Shakouri Sep 2012

Cross-Plane Electronic And Thermal Transport Properties Of P-Type La0.67sr0.33mno3/Lamno3 Perovskite Oxide Metal/Semiconductor Superlattices, Pankaj Jha, Timothy D. Sands, Laura Cassels, Philip Jackson, Tela Favaloro, Benjamin Kirk, Joshua Zide, Xianfan Xu, Ali Shakouri

Birck and NCN Publications

Lanthanum strontium manganate (La0.67Sr0.33MnO3, i.e., LSMO)/lanthanum manganate (LaMnO3, i.e., LMO) perovskite oxide metal/semiconductor superlattices were investigated as a potential p-type thermoelectric material. Growth was performed using pulsed laser deposition to achieve epitaxial LSMO (metal)/LMO (p-type semiconductor) superlattices on (100)-strontium titanate (STO) substrates. The magnitude of the in-plane Seebeck coefficient of LSMO thin films (/K) is consistent with metallic behavior, while LMO thin films were p-type with a room temperature Seebeck coefficient of 140 mu V/K. Thermal conductivity measurements via the photo-acoustic (PA) technique showed that LSMO/LMO superlattices exhibit a room temperature cross-plane thermal conductivity (0.89 W/m.K) that is significantly lower …


Effect Of Time-Dependent Material Properties On The Mechanical Behavior Of Pfsa Membranes Subjected To Humidity Cycling, Narinder S. Khattra, Anette M. Karlsson, Michael H. Santare, Peter Walsh, F. Colin Busby Sep 2012

Effect Of Time-Dependent Material Properties On The Mechanical Behavior Of Pfsa Membranes Subjected To Humidity Cycling, Narinder S. Khattra, Anette M. Karlsson, Michael H. Santare, Peter Walsh, F. Colin Busby

Mechanical Engineering Faculty Publications

A viscoelastic-plastic constitutive model is developed to characterize the time-dependent mechanical response of perfluorosulphonic acid (PFSA) membranes. This model is then used in finite element simulations of a representative fuel cell unit, (consisting of electrodes, gas diffusion layer and bipolar plates) subjected to standardized relative humidity (RH) cycling test conditions. The effects of hold times at constant RH, the feed rate of humidified air and sorption rate of water into the membrane on the stress response are investigated. While the longer hold times at high and low humidity lead to considerable redistribution of the stresses, the lower feed and sorption …


Ceas E-News 09.14.2012, College Of Engineering And Applied Sciences Sep 2012

Ceas E-News 09.14.2012, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Electrical Engineering Graduate Returns to Share a Closer Look at “Curiosity” Mars Landing, Impact Label Scholarship Awarded, Get a WMU Engineering Degree Without Ever Leaving Muskegon, Upcoming Events


Technical Note On Manipulating Multivariate Gaussian Distributions, John C. Macdonald Sep 2012

Technical Note On Manipulating Multivariate Gaussian Distributions, John C. Macdonald

Student Works

In this technical note we present some derivations treating conditional, marginal, and joint distributions for Gaussian random vectors.


The Bench Scientist's Guide To Statistical Analysis Of Rna-Seq Data, Craig R. Yendrek, Elizabeth A. Ainsworth, Jyothi Thimmapuram Sep 2012

The Bench Scientist's Guide To Statistical Analysis Of Rna-Seq Data, Craig R. Yendrek, Elizabeth A. Ainsworth, Jyothi Thimmapuram

Cyber Center Publications

RNA sequencing (RNA-Seq) is emerging as a highly accurate method to quantify transcript abundance. However, analyses of the large data sets obtained by sequencing the entire transcriptome of organisms have generally been performed by bioinformatics specialists. Here we provide a step-by-step guide and outline a strategy using currently available statistical tools that results in a conservative list of differentially expressed genes. We also discuss potential sources of error in RNA-Seq analysis that could alter interpretation of global changes in gene expression.


Scaling Study Of Wave Rotor Turbo-Normalization Of A Small Internal Combustion Engine, Brandon D. Smith Sep 2012

Scaling Study Of Wave Rotor Turbo-Normalization Of A Small Internal Combustion Engine, Brandon D. Smith

Theses and Dissertations

One issue facing small Remotely Piloted Aircraft engines is their ability to maintain performance at altitude. Since many of these aircraft use commercial off the shelf engines originally designed for radio controlled aircraft and lawn care implements, the reduced pressure environment significantly degrades the operability of the engine as the altitude increases. An option to overcome this difficulty is to supercharge the system; however most superchargers are designed for larger, typically automotive, engines. As a supercharger's size is decreased, there are large efficiency losses. Therefore, there is a need to accomplish this function on a smaller scale without. One option …


Resolution Study Of A Hyperspectral Sensor Using Computed Tomography In The Process Of Noise, Samuel V. Mantravadi Sep 2012

Resolution Study Of A Hyperspectral Sensor Using Computed Tomography In The Process Of Noise, Samuel V. Mantravadi

Theses and Dissertations

Recently, a new type of hyperspectral imaging sensor has been proposed which simultaneously records both spectral data and multiple spatial dimensions. Unlike dispersive imaging spectrometers, chromo-tomographic hyperspectral imaging sensors (CTHIS) record two spatial dimensions as well as a spectral dimension using computed tomography (CT) techniques with only a finite number of spatially-spectrally diverse images. To date, the factors affecting resolution of these sensors have not been examined. This research examines factors affecting resolution, specifically the number of the focus planes needed to resolve a particular object calculated from a theoretical lower bound, determine a method of reconstructing a hyperspectral object …


Serpentine Low Loss Trapezoidal Silica Waveguides On Silicon, Xiaomin Zhang, Mark Harrison, Audrey Harker, Andrea M. Armani Sep 2012

Serpentine Low Loss Trapezoidal Silica Waveguides On Silicon, Xiaomin Zhang, Mark Harrison, Audrey Harker, Andrea M. Armani

Engineering Faculty Articles and Research

We report the fabrication and characterization of straight and serpentine low loss trapezoidal silica waveguides integrated on a silicon substrate. The waveguide channel was defined using a dual photo-lithography and buffered HF etching and isolated from the silicon substrate using an isotropic silicon etchant. The waveguide is air-clad and thus has a core-cladding effective index contrast of approximately 25%. Measured at 658, 980 and 1550nm, the propagation loss was found to be 0.69, 0.59, and 0.41dB/cm respectively, with a critical bending radius less than 375μm. The waveguide’s polarization behavior was investigated both theoretically and experimentally. Additionally, the output power shows …


A (Declassified) History Of Military Drones, Stephen Rayleigh Sep 2012

A (Declassified) History Of Military Drones, Stephen Rayleigh

ERAU Prescott Aviation History Program

Unmanned Aerial Vehicles or drones, are said to be the newest technology of contemporary warfare, but the military's use of drones spans the last 100 years. Hear the riveting story of the numerous secret UAV programs around the world, starting with the Sperry Aerial Torpedo Project in 1918 (consulted by Orville Wright), the German cruise missile program, American remote controlled bombers in WWII, the Firebee recon drone used in Vietnam, Israel's highly successful UAV program, and finally the coming of age of UAV's in Operation Desert Storm.


Effective Measurement Of Reliability Of Repairable Usaf Systems, Louis J. Hogge Sep 2012

Effective Measurement Of Reliability Of Repairable Usaf Systems, Louis J. Hogge

Theses and Dissertations

The USAF generally does not know the reliability of its fielded repairable systems. The reported metric, Mean Time Between Failure (MTBF), is too lagging to be actionable in the best case, and is not representative of actual system reliability in the worst case. This thesis investigates the statistical techniques for measurement and analysis of the reliability of fielded repairable systems, which are very different than nonrepairables. To frame the investigation, a comparison is made between the generally accepted definitions and metrics and those used across the US Air Force (USAF). Reliability can be analyzed in four context areas: reliability prediction …


Passive Synthetic Aperture Radar Imaging Using Commercial Ofdm Communication Networks, Jose R. Gutierrez Del Arroyo Sep 2012

Passive Synthetic Aperture Radar Imaging Using Commercial Ofdm Communication Networks, Jose R. Gutierrez Del Arroyo

Theses and Dissertations

Modern communication systems provide myriad opportunities for passive radar applications. OFDM is a popular waveform used widely in wireless communication networks today. Understanding the structure of these networks becomes critical in future passive radar systems design and concept development. This research develops collection and signal processing models to produce passive SAR ground images using OFDM communication networks. The OFDM-based WiMAX network is selected as a relevant example and is evaluated as a viable source for radar ground imaging. The monostatic and bistatic phase history models for OFDM are derived and validated with experimental single dimensional data. An airborne passive collection …


Effects Of Architecture On Information Leakage Of A Hardware Advanced Encryption Standard Implementation, Eric A. Koziel Sep 2012

Effects Of Architecture On Information Leakage Of A Hardware Advanced Encryption Standard Implementation, Eric A. Koziel

Theses and Dissertations

Side-channel analysis (SCA) is a threat to many modern cryptosystems. Many countermeasures exist, but are costly to implement and still do not provide complete protection against SCA. A plausible alternative is to design the cryptosystem using architectures that are known to leak little information about the cryptosystem's operations. This research uses several common primitive architectures for the Advanced Encryption Standard (AES) and assesses the susceptibility of the full AES system to side-channel attack for various primitive configurations. A combined encryption/decryption core is also evaluated to determine if variation of high-level architectures affects leakage characteristics. These different configurations are evaluated under …


Ground Vehicle Navigation Using Magnetic Field Variation, Jeremiah A. Shockley Sep 2012

Ground Vehicle Navigation Using Magnetic Field Variation, Jeremiah A. Shockley

Theses and Dissertations

The Earth's magnetic field has been the bedrock of navigation for centuries. The latest research highlights the uniqueness of magnetic field measurements based on position due to large scale variations as well as localized perturbations. These observable changes in the Earth's magnetic field as a function of position provide distinct information which can be used for navigation. This dissertation describes ground vehicle navigation exploiting variation in Earth's magnetic field using a self-contained navigation system consisting of only a magnetometer and magnetic field maps. In order to achieve navigation, effective calibration enables repeatable magnetic field measurements from different vehicles and facilitates …


The Multiobjective Average Network Flow Problem: Formulations, Algorithms, Heuristics, And Complexity, Jeremy D. Jordan Sep 2012

The Multiobjective Average Network Flow Problem: Formulations, Algorithms, Heuristics, And Complexity, Jeremy D. Jordan

Theses and Dissertations

Integrating value focused thinking with the shortest path problem results in a unique formulation called the multiobjective average shortest path problem. We prove this is NP-complete for general graphs. For directed acyclic graphs, an efficient algorithm and even faster heuristic are proposed. While the worst case error of the heuristic is proven unbounded, its average performance on random graphs is within 3% of the optimal solution. Additionally, a special case of the more general biobjective average shortest path problem is given, allowing tradeoffs between decreases in arc set cardinality and increases in multiobjective value; the algorithm to solve the average …


Intelligent Behavioral Action Aiding For Improved Autonomous Image Navigation, Kwee Guan Eng Sep 2012

Intelligent Behavioral Action Aiding For Improved Autonomous Image Navigation, Kwee Guan Eng

Theses and Dissertations

In egomotion image navigation, errors are common especially when traversing areas with few landmarks. Since image navigation is often used as a passive navigation technique in Global Positioning System (GPS) denied environments; egomotion accuracy is important for precise navigation in these challenging environments. One of the causes of egomotion errors is inaccurate landmark distance measurements, e.g., sensor noise. This research determines a landmark location egomotion error model that quantifies the effects of landmark locations on egomotion value uncertainty and errors. The error model accounts for increases in landmark uncertainty due to landmark distance and image centrality. A robot then uses …


Operationally Responsive Spacecraft Using Electric Propulsion, Thomas C. Co Sep 2012

Operationally Responsive Spacecraft Using Electric Propulsion, Thomas C. Co

Theses and Dissertations

A desirable space asset is responsive and flexible to mission requirements, low-cost, and easy to acquire. Highly-efficient electric thrusters have been considered a viable technology to provide these characteristics; however, it has been plagued by limitations and challenges such that operational implementation has been severely limited. The technology is constantly improving, but even with current electric propulsion, a spacecraft is capable of maneuvering consistently and repeatedly in low-Earth orbit to provide a responsive and flexible system. This research develops the necessary algorithm and tools to demonstrate that EP systems can maneuver significantly in a timely fashion to overfly any target …


Whole-Word Recognition From Articulatory Movements For Silent Speech Interfaces, Jun Wang, Ashok Samal, Jordan R. Green, Frank Rudzicz Sep 2012

Whole-Word Recognition From Articulatory Movements For Silent Speech Interfaces, Jun Wang, Ashok Samal, Jordan R. Green, Frank Rudzicz

Department of Special Education and Communication Disorders: Faculty Publications

Articulation-based silent speech interfaces convert silently produced speech movements into audible words. These systems are still in their experimental stages, but have significant potential for facilitating oral communication in persons with laryngectomy or speech impairments. In this paper, we report the result of a novel, real-time algorithm that recognizes whole-words based on articulatory movements. This approach differs from prior work that has focused primarily on phoneme-level recognition based on articulatory features. On average, our algorithm missed 1.93 words in a sequence of twenty-five words with an average latency of 0.79 seconds for each word prediction using a data set of …