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2008

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Articles 2281 - 2310 of 4190

Full-Text Articles in Engineering

Real-Time Ultrasound Simulation For Medical Training And Standardized Patient Assessment, Bo Sun Apr 2008

Real-Time Ultrasound Simulation For Medical Training And Standardized Patient Assessment, Bo Sun

Computational Modeling & Simulation Engineering Theses & Dissertations

With the increasing role played by ultrasound in clinical diagnostics, ultrasound training in medical education has become more and more important. The clinical routine for ultrasound training is on real patients; therefore monitored and guided examinations involving medical students are quite time-constrained. Furthermore, standardized patients (SPs), who are increasingly used in medical school for teaching and assessing medical students, need to be augmented. These SPs are typically healthy individuals who can not accurately portray the variety of abnormalities that are needed for training especially when medical examinations involve instrument interactions. To augment SPs in a realistically effective way and also …


Bioresorbable Polylactide Interbody Implants In An Ovine Anterior Cervical Discectomy And Fusion Model: Three-Year Results, Kevin A. Thomas, Jeffrey M. Toth, Neil R. Crawford, Howard Seim, Lewis L. Shi, Mitchel B. Harris, Anthony S. Turner Apr 2008

Bioresorbable Polylactide Interbody Implants In An Ovine Anterior Cervical Discectomy And Fusion Model: Three-Year Results, Kevin A. Thomas, Jeffrey M. Toth, Neil R. Crawford, Howard Seim, Lewis L. Shi, Mitchel B. Harris, Anthony S. Turner

Biomedical Engineering Faculty Research and Publications

Study Design.

In vivo study of anterior discectomy and fusion using a bioresorbable 70:30 poly(l-lactide-co-d,l-lactide) interbody implant in an ovine model.

Objective.

To evaluate the efficacy of the polylactide implant to function as an interbody fusion device, and to assess the tissue reaction to the material during the resorption process.

Summary of Background Data.

The use of polylactide as a cervical interbody implant has several potential advantages when compared with traditional materials. Having an elastic modulus very similar to bone minimizes the potential for stress shielding, and as the material resorbs additional loading is transferred to the developing fusion mass. …


Numerical Analysis Of Passive Force On Skewed Bridgeabutments With Reinforced Concrete Wingwalls, Scott Karl Snow Apr 2008

Numerical Analysis Of Passive Force On Skewed Bridgeabutments With Reinforced Concrete Wingwalls, Scott Karl Snow

Theses and Dissertations

Numerical Analysis of Passive Force on Skewed BridgeAbutments with Reinforced Concrete WingwallsScott Karl SnowDepartment of Civil and Environmental Engineering, BYU Master of Science Historically bridges with skewed abutments have proven more likely to fail during earthquake loadings (Toro et al, 2013) when compared to non-skewed bridges (Apirakvorapinit et al. 2012; Elnashai et al. 2010). Previous studies including small-scale laboratory tests by Jessee (2012), large-scale field tests by Smith (2014), and numerical modeling by Shamsabadi et al. (2006) have shown that 45° skewed bridge abutments experience a reduction in peak passive force by about 65%. With numerous skewed bridges in the …


Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya V. Deodhar Apr 2008

Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya V. Deodhar

Mechanical & Aerospace Engineering Theses & Dissertations

A dynamic model for the vehicle-guideway coupled with a controller is developed using dynamic modelling software, MADYMO. The fundamental characteristics of the vehicle are obtained from detailed FE analysis in NASTRAN. The vehicle is then converted into a 21-degree-of-freedom rigid body system with 12 FE magnets. A two span concrete guideway of 54 meters in length is modelled using 3D solid Hex8 elements. The air gap is modelled as a penetration of the magnets in the guideway. The PD controller aims at achieving constant penetration (i.e. the air gap) of all magnets in the guideway, throughout the simulation. This PD …


Development And Validation Of Hardware To Measure The Load-Deflection Characteristics Of Any Material, Manish Govardhanrao Kalmegh Apr 2008

Development And Validation Of Hardware To Measure The Load-Deflection Characteristics Of Any Material, Manish Govardhanrao Kalmegh

Mechanical & Aerospace Engineering Theses & Dissertations

A portable device to measure load-displacement will have applications in biomechanics and reverse engineering in the automotive and aerospace industries. Hardware was developed by attaching a load cell (LC 201, Omegadyne, Inc., Sunbury, Ohio) to a Faro Arm (Faro Technologies, Lake Mary, Florida), a portable coordinate measuring machine that accommodates standard and custom end effectors. A LabVIEW (National Instrument, Austin, Texas) program was developed to process the load cell and deflection data obtained from the Faro Arm. To validate this system, a four-inch square block, chair cushion, and head restraint of a car were tested using a material testing machine …


Adaptive Control Of Large Amplitude Nonlinear Free Vibrations Of Composite Shallow Shells Using System Identification And Self-Sensing Piezoelectric Actuators, Minseock Park Apr 2008

Adaptive Control Of Large Amplitude Nonlinear Free Vibrations Of Composite Shallow Shells Using System Identification And Self-Sensing Piezoelectric Actuators, Minseock Park

Mechanical & Aerospace Engineering Theses & Dissertations

A coupled structural-electrical nonlinear modal finite element formulation for anti-symmetrical laminated composite shallow shells with embedded piezoelectric sensors and actuators is presented for the suppression of large-amplitude nonlinear free vibrations. The triangular shallow shell finite element is utilized, which is developed &om an extension of the triangular Mindlin (MIN3) element with the improved shear correction factor. The system equations of motion are first derived in the physical structural-node degrees of freedom (DOF), However, numerical simulation in structural-node DOF is costly in computation due to the large size of system matrices, and the nonlinear terms have to be updated at each …


Study Of Multibody Dynamics Using Matlab, Kalyani Soman Apr 2008

Study Of Multibody Dynamics Using Matlab, Kalyani Soman

Mechanical & Aerospace Engineering Theses & Dissertations

Research in computational dynamics has gained importance in the past few years because of the demand for analysis and simulation of various multi-body systems in the growing mechanical and aerospace industry. These multi-body systems are made of individual bodies that are interconnected via mechanical joints. Mathematically, these joints that connect the bodies can be described as constraint equations imposed upon the motions of the involved free bodies. This process will result in an equation of motion expressed in the form of a differential-algebraic equation. It is the main objective of this thesis to develop a solution algorithm that can take …


Planning For A Future That Is Going To Happen, Not Against It, Lorcan Sirr, Conor Skehan Mar 2008

Planning For A Future That Is Going To Happen, Not Against It, Lorcan Sirr, Conor Skehan

Media

No abstract provided.


An Adaptive Neuro-Fuzzy Inference System For Modeling Mechanical Properties Of Tapioca Starch-Poly(Lactic Acid) Nanocomposite Foams, Siew-Yoong Lee, Milford Hanna, David D. Jones Mar 2008

An Adaptive Neuro-Fuzzy Inference System For Modeling Mechanical Properties Of Tapioca Starch-Poly(Lactic Acid) Nanocomposite Foams, Siew-Yoong Lee, Milford Hanna, David D. Jones

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Tapioca starch, poly(lactic acid) and Cloisite 30B nanocomposites foams, with clay contents of 1, 3, 5 and 7% (w/w), were prepared by a meltintercalation method. Multiple inputs single output models were developed to predict radial expansion ratio, unit density, bulk compressibility and spring index of the nanocomposite foams. An individual ANFIS model was developed for each mechanical property using clay content, temperature, pressure and torque as input parameters. All models preformed well with R2 values > 0.71. All models had very low root mean squared error values.


Compact Waveguide Splitter Networks, Seunghyun Kim, Gregory P. Nordin, Weisheng Hu, Yusheng Qian, Jiguo Song Mar 2008

Compact Waveguide Splitter Networks, Seunghyun Kim, Gregory P. Nordin, Weisheng Hu, Yusheng Qian, Jiguo Song

Faculty Publications

We demonstrate compact waveguide splitter networks in siliconon-insulator (SOI) rib waveguides using trench-based splitters (TBSs) and bends (TBBs). Rather than a 90° geometry, we use 105° TBSs to facilitate reliable fabrication of high aspect ratio trenches suitable for 50/50 splitting when filled with SU8. Three dimensional (3D) finite difference time domain (FDTD) simulation is used for splitter and bend design. Measured TBB and TBS optical efficiencies are 84% and 68%, respectively. Compact 105° 1 x 4, 1 x 8, and 1 x 32 trench-based splitter networks (TBSNs) are demonstrated. The measured total optical loss of the 1 x 32 TBSN …


Applying Frequency-Domain Equalization To Code-Division Multiple Access And Transform-Domain Communications Systems, Alfred A. Tamayo Iii Mar 2008

Applying Frequency-Domain Equalization To Code-Division Multiple Access And Transform-Domain Communications Systems, Alfred A. Tamayo Iii

Theses and Dissertations

This research examined the theory and application of using orthogonal frequency division multiplexing (OFDM), or discrete multi-tone (DMT), frequency domain equalization (FEQ) with two communications systems that inherently possess unused carrier frequencies, or null-tones, in their respective transmission frequencies. The fundamental DMT-FEQ property relies on null-tones to equalize a non-ideal channel and mitigate the effects of interchannel interference (ICI), intersymbol interference (ISI), and noise. The two communications systems investigated were a Hadamard encoded code division multiple access (CDMA) communications system with up to 32 synchronous users and a transform domain communications system (TDCS) with only one user. Both communications systems …


Multi-Objective Optimization Of Mixed-Variable, Stochastic Systems Using Single-Objective Formulations, Todd J. Paciencia Mar 2008

Multi-Objective Optimization Of Mixed-Variable, Stochastic Systems Using Single-Objective Formulations, Todd J. Paciencia

Theses and Dissertations

Many problems exist where one desires to optimize systems with multiple, often competing, objectives. Further, these problems may not have a closed form representation, and may also have stochastic responses. Recently, a method expanded mixed variable generalized pattern search/ranking and selection (MVPS-RS) and Mesh Adaptive Direct Search (MADS) developed for single-objective, stochastic problems to the multi-objective case by using aspiration and reservation levels. However, the success of this method in approximating the true Pareto solution set can be dependent upon several factors. These factors include the experimental design and ranges of the aspiration and reservation levels, and the approximation quality …


What Is Engineering? - A University Of The Pacific Mesa Program/Johns Hopkins University Partnership, Jeffrey S. Burmeister, Kyle A. Watson, Maria Garcia-Sheets Mar 2008

What Is Engineering? - A University Of The Pacific Mesa Program/Johns Hopkins University Partnership, Jeffrey S. Burmeister, Kyle A. Watson, Maria Garcia-Sheets

All Faculty Presentations - School of Engineering and Computer Science

What is Engineering? is a course designed by Johns Hopkins University, and in partnership with The Mathematics, Engineering, and Science Achievement (MESA) Program, conducted at multiple sites throughout California. This course is designed to introduce multiple engineering topics to high school juniors and seniors. The MESA Schools Program (MSP) provides academic development for educationally disadvantaged pre-college students so they will succeed in math and science and go on to attain baccalaureate degrees in math-based majors. Through an approach that includes hands-on activities, school site teacher support, leadership skills, career & college exploration, and parent programming, MSP students are empowered to …


Tightly Integrating Optical And Inertial Sensors For Navigation Using The Ukf, Sedat Ebcin Mar 2008

Tightly Integrating Optical And Inertial Sensors For Navigation Using The Ukf, Sedat Ebcin

Theses and Dissertations

The motivation of this research is to address the benefits of tightly integrating optical and inertial sensors where GNSS signals are not available. The research begins with describing the navigation problem. Then, error and measurement models are presented. Given a set of features, a feature detection and projection algorithm is developed which utilizes inertial measurements to predict vectors in the feature space between images. The unscented Kalman filter is applied to the navigation system using the inertial measurements and feature matches to estimate the navigation trajectory. Finally, the image-aided navigation algorithm is tested using a simulation and an experiment. As …


Improved Feature Extraction, Feature Selection, And Identification Techniques That Create A Fast Unsupervised Hyperspectral Target Detection Algorithm, Robert J. Johnson Mar 2008

Improved Feature Extraction, Feature Selection, And Identification Techniques That Create A Fast Unsupervised Hyperspectral Target Detection Algorithm, Robert J. Johnson

Theses and Dissertations

This research extends the emerging field of hyperspectral image (HSI) target detectors that assume a global linear mixture model (LMM) of HSI and employ independent component analysis (ICA) to unmix HSI images. Via new techniques to fully automate feature extraction, feature selection, and target pixel identification, an autonomous global anomaly detector, AutoGAD, has been developed for potential employment in an operational environment for real-time processing of HSI targets. For dimensionality reduction (initial feature extraction prior to ICA), a geometric solution that effectively approximates the number of distinct spectral signals is presented. The solution is based on the theory of the …


Habitat For Humanity Case Studies, Florida Solar Energy Center, Janet Mcilvaine Mar 2008

Habitat For Humanity Case Studies, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

This document is a compilation of four separate case studies of Habitat for Humanity affiliates who have adopted Building America principles of high performance as standard construction. This work was compiled by the Building America Industrialized Housing Partnership (www.baihp.org ) for the U.S. Department of Energy to serve as a model for other affordable housing providers. BAIHP is led by the Florida Solar Energy Center of the University of Central Florida.


Tailoring Magnetic Anisotropy At The Ferromagnetic/Ferroelectric Interface, Chun-Gang Duan, Julian P. Velev, Renat F. Sabirianov, Wai-Ning Mei, Sitaram Jaswal, Evgeny Y. Tsymbal Mar 2008

Tailoring Magnetic Anisotropy At The Ferromagnetic/Ferroelectric Interface, Chun-Gang Duan, Julian P. Velev, Renat F. Sabirianov, Wai-Ning Mei, Sitaram Jaswal, Evgeny Y. Tsymbal

Nebraska Center for Materials and Nanoscience: Faculty Publications

It is predicted that magnetic anisotropy of a thin magnetic film may be affected by the polarization of a ferroelectric material. Using a Fe/BaTiO3 bilayer as a representative model and performing first-principles calculations, we demonstrate that a reversal of the electric polarization of BaTiO3 produces a sizable change in magnetic anisotropy energy of Fe films. Tailoring the magnetic anisotropy of a nanomagnet by an adjacent ferroelectric material may yield entirely new device concepts, such as electric-field controlled magnetic data storage.


System For Reducing Stress Induced Effects Duringdetermination Of Fluid Optical Constants, Thomas E. Tiwald, John A. Woollam, Galen L. Pfeiffer, Blaine D. Johs, Craig M. Herzinger Mar 2008

System For Reducing Stress Induced Effects Duringdetermination Of Fluid Optical Constants, Thomas E. Tiwald, John A. Woollam, Galen L. Pfeiffer, Blaine D. Johs, Craig M. Herzinger

Department of Electrical and Computer Engineering: Faculty Publications

A system for determination of optical constants of liquids, including provision for reducing stress induced effects while obtaining data.


Direct, Object Brightness Estimation From Atmospheric Turbulence Degraded Images Using A New, High-Speed, Modified Phase Diversity Method, William W. Arrasmith Mar 2008

Direct, Object Brightness Estimation From Atmospheric Turbulence Degraded Images Using A New, High-Speed, Modified Phase Diversity Method, William W. Arrasmith

Electrical Engineering and Computer Science Faculty Publications

The well known phase diversity technique has long been used as a premier passive imaging method to mitigate the degrading effects of atmospheric turbulence on incoherent optical imagery. Typically, an iterative, slow method is applied that uses the Zernike basis set and 2-D Fourier transforms in the reconstruction process. In this paper, we demonstrate a direct method for estimating the un-aberrated object brightness from phase or phase difference estimates that 1) does not require the use of the Zernike basis set or the intermediate determination of the generalized pupil function, 2) directly determines the optical transfer function without the requirement …


Houchin, Roy Franklin, Ii, B. 1954 (Sc 1602), Manuscripts & Folklife Archives Mar 2008

Houchin, Roy Franklin, Ii, B. 1954 (Sc 1602), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid and scans (Click on "Additional Files" below) for Manuscripts Small Collection 1602. Typescripts of interviews conducted by Roy Franklin Houchin, II with: Joe Richardson regarding early aviation and the aerospace industry, Douglas Campbell regarding his World War I aerial combat experience, and Bob Ford regarding World War I military uniforms. Includes Houchin family information.


Neutron Detection Utilizing Gadolinium Doped Hafnium Oxide Films, Bryan D. Blasy Mar 2008

Neutron Detection Utilizing Gadolinium Doped Hafnium Oxide Films, Bryan D. Blasy

Theses and Dissertations

Gadolinium (Gd) doped hafnium oxide (HfO2) was deposited onto a silicon substrate using pulsed laser deposition. Synchrotron radiation was used to perform Gd L3-edge extended X-ray absorption fine structure (EXAFS) measurements on 3%, 10%, and 15% doped HfO2 samples. The interatomic distances determined from Fourier transformation and fitting the data show Gd occupying the hafnium site in the HfO2 lattice, there was no clustering of Gd atoms, and the Gd ion retains monoclinic local symmetery for all levels of doping. Current as a function of voltage experiments identified the films as having poor diode characteristics with …


Evaluating The Response Of Polyvinyl Toluene Scintillators Used In Portal, Kelly D. Rakes Mar 2008

Evaluating The Response Of Polyvinyl Toluene Scintillators Used In Portal, Kelly D. Rakes

Theses and Dissertations

The goal of this research work was to determine if there exists, and to what extent, variability in the pulse-height spectrum, and resolution produced by ɤ-photon induced scintillation events in polyvinyl toluene scintillators. Scintillator panels of the same type as those used in portal detector units currently operated by the Department of Homeland Security, made of polyvinyl toluene and measuring 12 x 15 x 2 in were purchased from three vendors. Each vendor supplied two scintillators, one wrapped by the vendor with aluminum foil coated mylar, and two unwrapped. The scintillators where exposed to an ≈ 8µCi source collimated …


Impact Of Mass Mixing On The Lateral Resistance Of Driven-Pile Foundations, Mark Alan Herbst Mar 2008

Impact Of Mass Mixing On The Lateral Resistance Of Driven-Pile Foundations, Mark Alan Herbst

Theses and Dissertations

Although it has been established that in-situ soil mixing has improved the bearing capacity of soils, additional research is needed to better understand the effect of soil mixing on lateral resistance of pile caps. To do this, in-situ soil mixing was used to strengthen weak clay adjacent to a pile cap of a driven pile foundation. The mass stabilization method or mass mixing was used to treat an 11 ft wide, 4 ft thick, and 10 ft deep zone consisting of an average 475 psf clay that was adjacent to a 9-pile group in 3x3 pile configuration capped with a …


Characterization Of Thermally Evaporated Ag-Ge-S Thin Films, Fei Wang, William Porter Dunn, Mukul Jain, Carter De Leo, Nicholas Vicker, Richard Savage, Xiaomin Jin, Sergey Mamedov, Punit Boolchand Mar 2008

Characterization Of Thermally Evaporated Ag-Ge-S Thin Films, Fei Wang, William Porter Dunn, Mukul Jain, Carter De Leo, Nicholas Vicker, Richard Savage, Xiaomin Jin, Sergey Mamedov, Punit Boolchand

Electrical Engineering

Thin films of ternary (GeS3)1-xAgx glasses (x=0.1 and 0.2) are studied in this work. Thin films are fabricated in a vacuum thermal evaporator at 3 different evaporation angles (0o, 30o and 45o). All thin film samples are examined in Raman spectroscopy. Raman results of both normally and obliquely deposited thin film samples reveal Ge-S CS modes (~340cm-1) , Ge-S ES (~360cm-1) modes, and thiogermanate modes Q1~Q3 (390cm-1~437cm-1). In addition, sharp peaks due to sulfur rings (S8) are …


Development Of A Screening Tool To Facilitate Technology Of An Innovative Technology To Treat Perchlorate-Contaminated Water, Daniel A. Craig Mar 2008

Development Of A Screening Tool To Facilitate Technology Of An Innovative Technology To Treat Perchlorate-Contaminated Water, Daniel A. Craig

Theses and Dissertations

Perchlorate contamination of drinking water is a significant problem nationwide. The purpose of this study was to develop a tool to predict the cost and performance of tailored granular activated carbon (T-GAC), an innovative technology that is being evaluated as a cost-effective treatment for perchlorate-contaminated water. The ability to accurately predict performance and cost can facilitate the transfer and commercialization of innovative technologies. In the study, a model was developed to predict T-GAC performance and life-cycle costs for removing perchlorate under varying influent water quality and technology operating conditions. The model's design parameters were obtained from laboratory rapid small-scale column …


A System Dynamic Model Of Leader Emergence, Paul S. Wever Mar 2008

A System Dynamic Model Of Leader Emergence, Paul S. Wever

Theses and Dissertations

The purpose of this thesis is to develop a system dynamics model of leader emergence. Longitudinal social network and personality data were collected in a class of enlisted military professionals attending a 6-week leadership development course. Findings support known relationships in existing leadership research. The thesis demonstrates the applicability of system dynamics toward the complex social phenomena of leader emergence.


Ceas E-News 03.22.2008, College Of Engineering And Applied Sciences Mar 2008

Ceas E-News 03.22.2008, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

EWD speaker offers NASCAR model for the workplace


Pv Training Laboratory Design Manual, Florida Solar Energy Center, William Young Mar 2008

Pv Training Laboratory Design Manual, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

This document serves as a written summary of some of the elements required for the design, specification, construction and operation of a successful laboratory for the training of photovoltaics systems. This document only discusses the equipment requirements for such a lab. A successful training lab for education and certification also requires qualified and trained personnel; in-service training to maintain competency; procedures and protocols for curriculum, evaluation, and reporting; careful adherence to the relevant Standards; protocols for quality assurance and calibration; detailed documentation of all procedures and protocols. Accreditation of the lab by an independent evaluating agency is also useful in …


Characterization Of Synthetic, Self-Oscillating Vocal Fold Models, James S. Drechsel Mar 2008

Characterization Of Synthetic, Self-Oscillating Vocal Fold Models, James S. Drechsel

Theses and Dissertations

The vocal folds are essential for speech production, and a better understanding of vocal fold vibration characteristics may help improve treatments of voice disorders. However, studying real vocal folds presents significant challenges. In-vivo studies are limited by access and safety issues. Excised larynges have a short useable lifetime (on the order of minutes) and are difficult to parameterize. In contrast, synthetic vocal fold models have long useable lifetimes and can be easily parameterized. In this thesis, a series of tests performed on recently developed synthetic, self-oscillating models of the human vocal folds are discussed. These tests include measurements of vibration …


Nano-Mechanical Properties Of Heat Inactivated Bacillus Anthracis And Bacillus Thuringiensis Spores, Jessica L. Poindexter Mar 2008

Nano-Mechanical Properties Of Heat Inactivated Bacillus Anthracis And Bacillus Thuringiensis Spores, Jessica L. Poindexter

Theses and Dissertations

B. thuringiensis spores must have similar properties to B. anthracis spores to be a good simulant in counter-proliferation studies. In particular, they must behave in a similar way when exposed to high temperatures for short periods of time as would be caused by an explosion. This research project compares surface elasticities for four different spore sample types, B. anthracis spores, heat inactivated B. anthracis spores, B. thuringiensis spores, and heat inactivated B. thuringiensis spores. Heat inactivated spores were exposed to a temperature just high enough that no spores were observed to germinate. Elasticity values for the spore surfaces were determined …