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Articles 154441 - 154470 of 193655

Full-Text Articles in Engineering

Control Algorithms For Large Scale Adaptive Optics, Piotr Piatrou Jan 2005

Control Algorithms For Large Scale Adaptive Optics, Piotr Piatrou

Dissertations, Master's Theses and Master's Reports - Open

In this dissertation, the problem of creating effective large scale Adaptive Optics (AO) systems control algorithms for the new generation of giant optical telescopes is addressed. The effectiveness of AO control algorithms is evaluated in several respects, such as computational complexity, compensation error rejection and robustness, i.e. reasonable insensitivity to the system imperfections. The results of this research are summarized as follows:

1. Robustness study of Sparse Minimum Variance Pseudo Open Loop Controller (POLC) for multi-conjugate adaptive optics (MCAO). The AO system model that accounts for various system errors has been developed and applied to check the stability and performance …


Reconstruction Of Anisoplanatic Adaptive Optics Images, Mathieu Aubailly Jan 2005

Reconstruction Of Anisoplanatic Adaptive Optics Images, Mathieu Aubailly

Dissertations, Master's Theses and Master's Reports - Open

No abstract provided.


Twelve Factors Influencing Sustainable Recycling Of Municipal Solid Waste In Developing Countries , Alexis Manda Troschinetz Jan 2005

Twelve Factors Influencing Sustainable Recycling Of Municipal Solid Waste In Developing Countries , Alexis Manda Troschinetz

Dissertations, Master's Theses and Master's Reports - Open

Sustainable management of solid waste is a global concern, as exemplified by the United Nations Millennium Development Goals (MDG) that 191 member states support. The seventh MDG indirectly advocates for municipal solid waste management (MSWM) by aiming to ensure environmental sustainability into countries’ policies and programs and reverse negative environmental impact. Proper MSWM will likely result in relieving poverty, reducing child mortality, improving maternal health, and preventing disease, which are MDG goals one, four, five, and six, respectively (UNMDG, 2005).

Solid waste production is increasing worldwide as the global society strives to obtain a decent quality of life. Several means …


Quickbird Satellite Imagery For Riparian Management : Characterizing Riparian Filter Strips And Detecting Concentrated Flow In An Agricultural Watershed , Sarah Volkman Jan 2005

Quickbird Satellite Imagery For Riparian Management : Characterizing Riparian Filter Strips And Detecting Concentrated Flow In An Agricultural Watershed , Sarah Volkman

Dissertations, Master's Theses and Master's Reports - Open

Riparian ecology plays an important part in the filtration of sediments from upland agricultural lands. The focus of this work makes use of multispectral high spatial resolution remote sensing imagery (Quickbird by Digital Globe) and geographic information systems (GIS) to characterize significant riparian attributes in the USDA’s experimental watershed, Goodwin Creek, located in northern Mississippi. Significant riparian filter characteristics include the width of the strip, vegetation properties, soil properties, topography, and upland land use practices. The land use and vegetation classes are extracted from the remotely sensed image with a supervised maximum likelihood classification algorithm. Accuracy assessments resulted in an …


Corrugated Wood Composite Panels For Structural Decking, Wei Chiang Pang Jan 2005

Corrugated Wood Composite Panels For Structural Decking, Wei Chiang Pang

Dissertations, Master's Theses and Master's Reports - Open

High flexural strength and stiffness can be achieved by forming a thin panel into a wave shape perpendicular to the bending direction. The use of corrugated shapes to gain flexural strength and stiffness is common in metal and reinforced plastic products. However, there is no commercial production of corrugated wood composite panels. This research focuses on the application of corrugated shapes to wood strand composite panels.

Beam theory, classical plate theory and finite element models were used to analyze the bending behavior of corrugated panels. The most promising shallow corrugated panel configuration was identified based on structural performance and compatibility …


Testing Wisconsin Asphalt Mixtures For The 2002 Aashto Mechanistic Design Procedure , Christopher J. Robinette Jan 2005

Testing Wisconsin Asphalt Mixtures For The 2002 Aashto Mechanistic Design Procedure , Christopher J. Robinette

Dissertations, Master's Theses and Master's Reports - Open

There has been a continuous evolutionary process in asphalt pavement design. In the beginning it was crude and based on past experience. Through research, empirical methods were developed based on materials response to specific loading at the AASHO Road Test. Today, pavement design has progressed to a mechanistic-empirical method. This methodology takes into account the mechanical properties of the individual layers and uses empirical relationships to relate them to performance. The mechanical tests that are used as part of this methodology include dynamic modulus and flow number, which have been shown to correlate with field pavement performance.

This thesis was …


Model Based Experimental Investigation On Powered Gait Orthosis (Pgo), Huojin Cheng Jan 2005

Model Based Experimental Investigation On Powered Gait Orthosis (Pgo), Huojin Cheng

Dissertations, Master's Theses and Master's Reports - Open

Research on rehabilitation showed that appropriate and repetitive mechanical movements can help spinal cord injured individuals to restore their functional standing and walking. The objective of this paper was to achieve appropriate and repetitive joint movements and approximately normal gait through the PGO by replicating normal walking, and to minimize the energy consumption for both patients and the device. A model based experimental investigative approach is presented in this dissertation.

First, a human model was created in Ideas and human walking was simulated in Adams. The main feature of this model was the foot ground contact model, which had distributed …


Active Surgical Positioning Device For A Cochlear Implant Electrode Array, Benjamin Y. Arcand Jan 2005

Active Surgical Positioning Device For A Cochlear Implant Electrode Array, Benjamin Y. Arcand

Dissertations, Master's Theses and Master's Reports - Open

Cochlear implants have been of great benefit in restoring auditory function to individuals with profound bilateral sensorineural deafness. The implants are used to directly stimulate auditory nerves and send a signal to the brain that is then interpreted as sound. This project focuses on the development of a surgical positioning tool to accurately and effectively place an array of stimulating electrodes deep within the cochlea. This will lead to improved efficiency and performance of the stimulating electrodes, reduced surgical trauma to the cochlea, and as a result, improved overall performance to the implant recipient.

The positioning tool reported here consists …


Filtration And Oxidation Characteristics Of A Diesel Oxidation Catalyst And A Catalyzed Particulate Filter : Development Of A 1-D 2-Layer Model, Mohammed Hasan Jan 2005

Filtration And Oxidation Characteristics Of A Diesel Oxidation Catalyst And A Catalyzed Particulate Filter : Development Of A 1-D 2-Layer Model, Mohammed Hasan

Dissertations, Master's Theses and Master's Reports - Open

The emissions, filtration and oxidation characteristics of a diesel oxidation catalyst (DOC) and a catalyzed particulate filter (CPF) in a Johnson Matthey catalyzed continuously regenerating trap (CCRT ®) were studied by using computational models. Experimental data needed to calibrate the models were obtained by characterization experiments with raw exhaust sampling from a Cummins ISM 2002 engine with variable geometry turbocharging (VGT) and programmed exhaust gas recirculation (EGR). The experiments were performed at 20, 40, 60 and 75% of full load (1120 Nm) at rated speed (2100 rpm), with and without the DOC upstream of the CPF. This was done to …


Countermeasures Against Scour At Bridge Abutments, Hua Li Jan 2005

Countermeasures Against Scour At Bridge Abutments, Hua Li

Dissertations, Master's Theses and Master's Reports - Open

Scour at bridge abutments can cause damage or failure of bridges and result in excessive repairs, loss of accessibility, or even death. To mitigate abutment scour, both clear-water and live-bed laboratory experiments in a compound channel were performed using parallel walls and spur dikes as countermeasures, respectively. In addition, collars were tested under clear-water conditions only. It was found that both parallel walls and spur dikes can efficiently protect the abutment from scour provided that they are properly designed. Design guidelines were discussed for both countermeasures. Preliminary clear-water tests of collars as countermeasures against scour showed some promising results although …


Control System Design And Simulation Of Spacecraft Formations, Daniel Dyer Jan 2005

Control System Design And Simulation Of Spacecraft Formations, Daniel Dyer

Master's Theses - Daytona Beach

The objective of this thesis is to analyze an effective control scheme for a formation of spacecraft, implement that control, and provide a 3-D simulation. The thesis first summarizes the progress made in formation flight control schemes and then provides a theoretical framework for the control system design. Using established control design techniques, feedback laws are constructed to control both rotational and translational motion of a group of spacecraft. Computer simulations are carried out using Matlab to generate the ephemeris and attitude data, which are exported to Satellite Tool Kit (STK) to create animations. The process by which Matlab is …


Accuracy Of Heat-Pulse Sensors For Determining Moisture Of Capillary Mat Material Used To Support Plant Growth, Marisa Wyssling Jan 2005

Accuracy Of Heat-Pulse Sensors For Determining Moisture Of Capillary Mat Material Used To Support Plant Growth, Marisa Wyssling

Master's Theses - Daytona Beach

The accuracy and precision of Orbital Technologies (Orbitec, Madison, WI) Thermal and Moisture Acquisition System (TMAS) sensors were investigated for use in the WONDER space flight experiment. WONDER is studying the effect of multiple wetness level regimes and two different nutrient delivery systems (NDS) on plants grown in the microgravity of space. The following research concentrates on the porous tube NDS consisting solely of a capillary mat surrounding a bare porous tube used for water delivery. Sensors and plants will be attached to the capillary mat, which transports water by capillary action. The TMAS sensors, single probe heat-pulse moisture sensors, …


Relationship Of Stream Flow Regime In The Western Lake Superior Basin To Watershed Type Characteristics, N. E. Detenbeck, V. J. Brady, D. L. Taylor, V. M. Snarski, S. L. Batterman Jan 2005

Relationship Of Stream Flow Regime In The Western Lake Superior Basin To Watershed Type Characteristics, N. E. Detenbeck, V. J. Brady, D. L. Taylor, V. M. Snarski, S. L. Batterman

United States Environmental Protection Agency: Staff Publications

To test a conceptual model of non-linear response of hydrologic regimes to watershed characteristics, we selected 48 secondand third-order study sites on the North and South Shores of western Lake Superior, MN(USA) using a random-stratified design based on hydrogeomorphic region, fraction mature forest, and fraction watershed storage (lakeCwetland area/watershed area). We calculated several commonly used hydrologic indices from discharge and velocity estimates, including daily flow indices, overall flood indices, low flow variables, and ratios or ranges of flow percentiles reflecting the nature of cumulative frequency distributions. Four principal components (PCs) explained 85.9 and 88.6% of the variation of flow metrics …


Perchlorate: Sources, Uses, And Occurrences In The Environment, Clayton W. Trumpolt, Michael Crain, Geoffrey D. Cullison, Susan J. P. Flanagan, Lenny Siegel, Stephen Lathrop Jan 2005

Perchlorate: Sources, Uses, And Occurrences In The Environment, Clayton W. Trumpolt, Michael Crain, Geoffrey D. Cullison, Susan J. P. Flanagan, Lenny Siegel, Stephen Lathrop

U.S. Navy Research

Perchlorate contamination of groundwater and soil continues to be a hot topic in many sectors, including industry, the federal Departments of Defense and Energy, regulators, and the general public. This article presents information on what is currently known regarding perchlorate uses, known and suspected naturally occurring versus anthropogenic perchlorate sources, and past and present manufacturing locations. It provides the reader with a baseline as well as background information to facilitate an understanding of perchlorate in the environment for the ultimate purpose of remediation. The article is based on research conducted by the Interstate Technology Regulatory Council for a forthcoming, more …


Regional Scale Evidence For Improvements In Surface Water Chemistry 1990-2001, B. L. Skjelkvåle, J. L. Stoddard, D. S. Jeffries, K. Tørseth, T. Høgåsen, J. Bowman, J. Mannio, D.T. Monteith, R. Mosello, M. Rogora, D, Rzychon, J. Vesely, J. Wieting, A. Wilander, A. Worsztynowicz Jan 2005

Regional Scale Evidence For Improvements In Surface Water Chemistry 1990-2001, B. L. Skjelkvåle, J. L. Stoddard, D. S. Jeffries, K. Tørseth, T. Høgåsen, J. Bowman, J. Mannio, D.T. Monteith, R. Mosello, M. Rogora, D, Rzychon, J. Vesely, J. Wieting, A. Wilander, A. Worsztynowicz

United States Environmental Protection Agency: Staff Publications

The main aim of the international UNECE monitoring program ICP Waters under the Convention of Long-range Transboundary Air Pollution (CLRTAP) is to assess, on a regional basis, the degree and geographical extent of the impact of atmospheric pollution, in particular acidification, on surface waters. Regional trends are calculated for 12 geographical regions in Europe and North America, comprising 189 surface waters sites. From 1990-2001 sulphate concentrations decreased in all but one of the investigated regions. Nitrate increased in only one region, and decreased in three North American regions. Improvements in alkalinity and pH are widely observed. Results from the ICP …


Implications Of Invasion By Juniperus Virginiana On Small Mammals In The Southern Great Plains, Valerie J. Horncastle, Eric C. Hellgren, Paul M. Mayer, Amy C. Ganguli, David M. Engle, David M. Leslie, Jr. Jan 2005

Implications Of Invasion By Juniperus Virginiana On Small Mammals In The Southern Great Plains, Valerie J. Horncastle, Eric C. Hellgren, Paul M. Mayer, Amy C. Ganguli, David M. Engle, David M. Leslie, Jr.

United States Environmental Protection Agency: Staff Publications

Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We examined effects of invasion by eastern red cedar on small mammals in 3 plant communities (tallgrass prairie, old field, and cross-timbers forest) in the cross-timbers ecoregion in Oklahoma. We sampled small mammals seasonally from May 2001 to August 2002 by using Sherman live traps and mark–recapture techniques on 3.24-ha, 450-trap grids in each plant community. …


Exponential Time Response In Analogue And Geiger Mode Avalanche Photodiodes, C. Groves, C. H. Tan, J. P.R. David, G. J. Rees, Majeed M. Hayat Jan 2005

Exponential Time Response In Analogue And Geiger Mode Avalanche Photodiodes, C. Groves, C. H. Tan, J. P.R. David, G. J. Rees, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

The mean avalanche current impulse response in an avalanche photodiode exhibits an initial transient and then grows or decays, above or below breakdown, at exponential rates which depend only on the probability distributions of the electron and hole ionization events. The process continues while the electric field profile remains unchanged by the applied bias or the evolving space charge. Below breakdown the distribution in the avalanche duration also exhibits an initial transient and then decays exponentially at the same rate as the mean current. Below breakdown the standard deviation in current decays exponentially at one half of the rate of …


Benchmark Studies For Structural Health Monitoring Using Analytical And Experimental Models, Jason Lee Burkett Jan 2005

Benchmark Studies For Structural Health Monitoring Using Analytical And Experimental Models, Jason Lee Burkett

Electronic Theses and Dissertations

The latest bridge inventory report for the United States indicates that 25% of the highway bridges are structurally deficient or functionally obsolete. With such a large number of bridges in this condition, safety and serviceability concerns become increasingly relevant along with the associated increase in user costs and delays. Biennial inspections have proven subjective and need to be coupled with standardized non-destructive testing methods to accurately assess a bridge's condition for decision making purposes. Structural health monitoring is typically used to track and evaluate performance, symptoms of operational incidents, anomalies due to deterioration and damage during regular operation as well …


Study And Design Of An Intelligent Preconditioner Recommendation System, Shuting Xu Jan 2005

Study And Design Of An Intelligent Preconditioner Recommendation System, Shuting Xu

University of Kentucky Doctoral Dissertations

There are many scientific applications in which there is a need to solve very large linear systems. The preconditioned Krylove subspace methods are considered the preferred methods in this field. The preconditioners employed in the preconditioned iterative solvers usually determine the overall convergence rate. However, choosing a good preconditioner for a specific sparse linear system arising from a particular application is the combination of art and science, and presents a formidable challenge for many design engineers and application scientists who do not have much knowledge of preconditioned iterative methods.

We tackled the problem of choosing suitable preconditioners for particular applications …


Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill Jan 2005

Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Numerous factors influence the sizing of aeration fans for summer-harvested crops. Thirty years of weather data for Lexington, Kentucky, were analyzed and the cost of aeration was compared for two axial fans (afan1, afan2) and one centrifugal fan (cfan1). Aeration costs were defined as the sum of the following components: the cost of owning the fan, the cost of electricity for operating the fan, a cost for wheat shrinkage during aeration, and a cost for dry matter loss (DML). The fans were selected to deliver airflow rates of approximately one, two, and three times the recommended aeration rate of 0.11 …


Evaluation Of A Mechanical System For Reconstructing Soil On Surface Mined Land, John P. Fulton, Larry G. Wells Jan 2005

Evaluation Of A Mechanical System For Reconstructing Soil On Surface Mined Land, John P. Fulton, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

The existence of excessive soil compaction has hindered the surface mining industry from returning land to pre−mining productivity after reclamation, especially on prime farmland soils. Heavy earthmoving equipment used during reclamation tends to generate root−limiting bulk densities that adversely affect plant growth thereby decreasing yields. Therefore, the purpose of this study was to evaluate a mechanism, called the ‘Soil Regenerator,’ which reconstructs soil media at minimum bulk density during surface mine reclamation. The prototype soil forming mechanism was mounted on the front of a conventional bulldozer. Soil was placed in long narrow windrows by a scraper or bulldozer. As the …


Participatory Routing Of Electric Power Transmission Lines Using The Ep-Amis Gis/Multicriteria Evaluation Methodology, Keiron Bailey, Ted H. Grossardt, Ward Jewell Jan 2005

Participatory Routing Of Electric Power Transmission Lines Using The Ep-Amis Gis/Multicriteria Evaluation Methodology, Keiron Bailey, Ted H. Grossardt, Ward Jewell

Kentucky Transportation Center Faculty and Researcher Publications

The North American electric transmission network was developed under the guidance of the North American Electric Reliability Council (NERC) to enhance the reliability of electricity supply. The network also allows sale and marketing of electric power by one utility to another. Electricity marketing has taken on a much more prominent role with restructuring of the electric utility industry. As a result, long-distance sales of electric power have greatly increased the loading of some transmission lines, and have led to congestion on the transmission network. Recent system failures such as the northeast blackout of 2003 have highlighted the need for increased …


Audio Time-Scale Modification, David Dorran Jan 2005

Audio Time-Scale Modification, David Dorran

Doctoral

Audio time-scale modification is an audio effect that alters the duration of an audio signal without affecting its perceived local pitch and timbral characteristics. There are two broad categories of time-scale modifications algorithms, time-domain and frequency-domain. The computationally efficient time-domain techniques produce high quality results for single pitched signals such as speech, but do not cope well with more complex signals such as polyphonic music. The less efficient frequency-domain techniques have proven to be more robust and produce high quality results for a variety of signals; however they introduce a reverberant artefact into the output. This dissertation focuses on incorporating …


Robot Assisted Ultrasound Imaged Guided Interstitial Lung Brachytherapy In A Porcine Model, Richard A. Malthaner, Edward Yu, Jerry J. Battista, Chris Blake, Donal Downey, Aaron Fenster Jan 2005

Robot Assisted Ultrasound Imaged Guided Interstitial Lung Brachytherapy In A Porcine Model, Richard A. Malthaner, Edward Yu, Jerry J. Battista, Chris Blake, Donal Downey, Aaron Fenster

Oncology Presentations

We set out to see if permanent interstitial brachytherapy seeds could be safely and reproducibly inserted thoracoscopicaly with the ZEUS Robotic system and intraoperative ultrasound into in-vivo porcine lungs.


Application Of The Fuzzy Performance Indices To The City Of London Water Supply System, Ibrahim El-Baroudy, Slobodan P. Simonovic Jan 2005

Application Of The Fuzzy Performance Indices To The City Of London Water Supply System, Ibrahim El-Baroudy, Slobodan P. Simonovic

Water Resources Research Report

This study explores the utility of fuzzy performance indices: (i) combined reliabilityvulnerability index, (ii) robustness index, and (iii) resiliency index, for evaluating the performance of a complex water supply system. Regional water supply system for the City of London is used as the case study. The two main components being investigated in this case study are; (i) the Lake Huron Primary Water Supply System (LHPWSS), and (ii) the Elgin Area Primary Water Supply system (EAPWSS).


Damage Mechanics Of Composite Materials Using Fabric Tensors, Ziad N. Taqieddin Jan 2005

Damage Mechanics Of Composite Materials Using Fabric Tensors, Ziad N. Taqieddin

LSU Master's Theses

The major objective of this work is to relate continuum damage mechanics introduced through the concept of fabric tensors to composite materials within the framework of classical elasticity theory. A model of directional data-damage mechanics for composite materials is formulated using fabric tensors. In addition, a general hypothesis for damage mechanics is postulated. It is seen that the two available hypotheses of elastic strain equivalence and elastic energy equivalence may be obtained as special cases of the postulated general hypothesis. This general hypothesis is then used to derive the sought relationship between the damage tensor for composite materials and the …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 4, January 2005, College Of Engineering And Computer Science, Wright State University Jan 2005

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 4, January 2005, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


Effects Of Aging On The Biomechanics Of Slips And Falls, Thurmon E. Lockhart, James L. Smith, Jeffrey C. Woldstad Jan 2005

Effects Of Aging On The Biomechanics Of Slips And Falls, Thurmon E. Lockhart, James L. Smith, Jeffrey C. Woldstad

Department of Industrial and Management Systems Engineering: Faculty Publications

Although much has been learned in recent decades about the deterioration of muscular strength, gait adaptations, and sensory degradation among older adults, little is known about how these intrinsic changes affect biomechanical parameters associated with slip-induced fall accidents. In general, the objective of this laboratory study was to investigate the process of initiation, detection, and recovery of inadvertent slips and falls. We examined the initiation of and recovery from foot slips among three age groups utilizing biomechanical parameters, muscle strength, and sensory measurements. Forty-two young, middle-age, and older participants walked around a walking track at a comfortable pace. Slippery floor …


Details And Description Of Industrial Engineering, Paul Savory Jan 2005

Details And Description Of Industrial Engineering, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

This content paper addresses key questions for students interested in pursuing industrial engineering as an academic major: What is industrial engineering? What personality characteristics do Industrial Engineers have? What types of projects do Industrial Engineers work on? What types of jobs do Industrial Engineers have? Where do Industrial Engineers work once they graduate? How much can Industrial Engineers earn? I have never heard of IE, is it a new area? How do Industrial Engineers benefit society and business? What classes will I take as an industrial engineering student? What are examples of problems I will learn how to solve? Are …


Design And Implementation Of A Non-Proprietary Campus Energy Management And Control System (Emcs), Stefan Newbold, Lalit Agarwal Jan 2005

Design And Implementation Of A Non-Proprietary Campus Energy Management And Control System (Emcs), Stefan Newbold, Lalit Agarwal

Department of Industrial and Management Systems Engineering: Faculty Publications

The Energy Management and Control System (EMCS) used at the University of Nebraska - Lincoln (UNL) is unique in that system hardware and software has been developed primarily in-house. UNL has a successful track record with this approach stretching back more than twenty years.

This paper presents an industry experience report describing the high-level design and development of the latest version of this EMCS. This system is now being deployed on campus.

We discuss aspects of our EMCS that enhance usability, fault tolerance, and security. Our system is unique in that it was primarily developed using non-proprietary, opensource software building …