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2011

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Articles 4021 - 4050 of 5801

Full-Text Articles in Engineering

Magnetic Resonance Image Processing Using Levy, Jonathan Blackledge, Matthew D. Blackledge Jan 2011

Magnetic Resonance Image Processing Using Levy, Jonathan Blackledge, Matthew D. Blackledge

Conference papers

We consider the physical nature of the self-diffusion of water molecules in tissue and explore how (Nuclear) Magnetic Resonance (MR) imaging may be used as a means of measuring the rate of diffusion in vivo. A discussion is presented on how these techniques may be implemented as a non-invasive means of assessing the response of tumours to novel therapeutics including some of the basic advantages and disadvan- tages when compared to other methods. The physical basis and mathematical models for diffusion are considered together with models for the distribution of the diffusion co- efficient including a Lévy distributed model. Using …


Wind Turbine Power Quality Estimation Using A Lévy Model For Wind Velocity Data, Jonathan Blackledge, Eugene Coyle, Derek Joseph Kearney Jan 2011

Wind Turbine Power Quality Estimation Using A Lévy Model For Wind Velocity Data, Jonathan Blackledge, Eugene Coyle, Derek Joseph Kearney

Conference papers

The power quality of a wind turbine is determined by many factors but time-dependent variation in the wind velocity are arguably the most important. In this paper a non-Gaussian model for the wind velocity is introduced that is based on a Lévy distribution. It is shown how this distribution can be used to derive a stochastic fractional diffusion equation for the wind velocity as a function of time whose solution is characterised by the Lévy index. A numerical method for computing the L´evy index from wind velocity time series is introduced and applied to example wind velocity data for both …


A Quality Control System Using Texture Analysis In Metallurgy, Jonathan Blackledge, Dymitiy Dubovitskiy Jan 2011

A Quality Control System Using Texture Analysis In Metallurgy, Jonathan Blackledge, Dymitiy Dubovitskiy

Conference papers

Object detection, recognition and texture classification is an important aspect of many industrial quality control systems. In this paper, we report on a system designed for the inspection of surfaces which has a range of applications in the area of metallurgy. The approach considered is based on the application of Fractal Geometry and Fuzzy Logic for texture classification and, in this paper, focuses on the manufacture of rolled steel. The manufacture of high quality metals requires automatic surface inspection for the assessment of quality control. Quality control systems are required for several tasks such as screening defected products, monitoring the …


Influence Of Cross-Section Geometry And Wire Orientation On The Phonon Shifts In Ultra-Scaled Si Nanowires, Abhijeet Paul, Mathieu Luisier, Gerhard Klimeck Jan 2011

Influence Of Cross-Section Geometry And Wire Orientation On The Phonon Shifts In Ultra-Scaled Si Nanowires, Abhijeet Paul, Mathieu Luisier, Gerhard Klimeck

Birck and NCN Publications

Engineering of the cross-section shape and size of ultra-scaled Si nanowires (SiNWs) provides an attractive way for tuning their structural properties. The acoustic and optical phonon shifts of the free-standing circular, hexagonal, square and triangular SiNWs are calculated using a Modified Valence Force Field (MVFF) model. The acoustic phonon blue shift (acoustic hardening) and the optical phonon red shift (optical softening) show a strong dependence on the cross-section shape and size of the SiNWs. The triangular SiNWs have the least structural symmetry as revealed by the splitting of the degenerate flexural phonon modes and The show the minimum acoustic hardening …


Identification And Analysis Of Common Bean (Phaseolus Vulgaris L.) Transcriptomes By Massively Parallel Pyrosequencing, Venu Kalavacharla, Zhanji Liu, Blake C. Meyers, Jyothi Thimmapuram, Kalpalatha Melmaiee Jan 2011

Identification And Analysis Of Common Bean (Phaseolus Vulgaris L.) Transcriptomes By Massively Parallel Pyrosequencing, Venu Kalavacharla, Zhanji Liu, Blake C. Meyers, Jyothi Thimmapuram, Kalpalatha Melmaiee

Cyber Center Publications

Common bean (Phaseolus vulgaris) is the most important food legume in the world. Although this crop is very important to both the developed and developing world as a means of dietary protein supply, resources available in common bean are limited. Global transcriptome analysis is important to better understand gene expression, genetic variation, and gene structure annotation in addition to other important features. However, the number and description of common bean sequences are very limited, which greatly inhibits genome and transcriptome research. Here we used 454 pyrosequencing to obtain a substantial transcriptome dataset for common bean.


A Compact Physical Model For Morphology Induced Intrinsic Degradation Of Polymer Based Bulk Heterojunction Solar Cell, Biswajit Ray, Muhammad A. Alam Jan 2011

A Compact Physical Model For Morphology Induced Intrinsic Degradation Of Polymer Based Bulk Heterojunction Solar Cell, Biswajit Ray, Muhammad A. Alam

Birck and NCN Publications

The gradual loss of efficiency during field operation poses a fundamental challenge for economic viability of any solar cell technology. Well known examples include light-induced degradation in Si-based cell (Staebler-Wronski effect), Cu diffusion in thin film (CIGS) cell, hot-spot degradation in series connected modules, etc. Here we develop a compact model for an intrinsic degradation concern for bulk heterojunction type organic photovoltaic (BH-OPV) cells that involve continued (thermal) phase segregation of the donor-acceptor molecules leading to characteristic loss of efficiency and performance. Our approach interprets a number of BH-OPV device degradation measurements within a common framework and suggests/rationalizes intuitive routes …


Privacy-Preserving Assessment Of Location Data Trustworthiness, Chenyun Dai, Fang-Yu Rao, Gabriel Ghinita, Elisa Bertino Jan 2011

Privacy-Preserving Assessment Of Location Data Trustworthiness, Chenyun Dai, Fang-Yu Rao, Gabriel Ghinita, Elisa Bertino

Cyber Center Publications

Assessing the trustworthiness of location data corresponding to individuals is essential in several applications, such as forensic science and epidemic control. To obtain accurate and trustworthy location data, analysts must often gather and correlate information from several independent sources, e.g., physical observation, witness testimony, surveillance footage, etc. However, such information may be fraudulent, its accuracy may be low, and its vol-
ume may be insufficient to ensure highly trustworthy data. On the other hand, recent advancements in mobile computing and positioning systems, e.g., GPS-enabled cell phones, highway sensors, etc., bring new and effective technological means to track the location of …


Effects Of Interface Roughness Scattering On Radio Frequency Performance Of Silicon Nanowire Transistors, Sunggeun Kim, Mathieu Luisier, Timothy B. Boykin, Gerhard Klimeck Jan 2011

Effects Of Interface Roughness Scattering On Radio Frequency Performance Of Silicon Nanowire Transistors, Sunggeun Kim, Mathieu Luisier, Timothy B. Boykin, Gerhard Klimeck

Birck and NCN Publications

The effects of an atomistic interface roughness in n-type silicon nanowire transistors (SiNWT) on the radio frequency performance are analyzed. Interface roughness scattering (IRS) is statistically investigated through a three dimensional full–band quantum transport simulation based on the sp3d5s∗ tight–binding model. As the diameter of the SiNWT is scaled down below 3 nm, IRS causes a significant reduction of the cut-off frequency. The fluctuations of the conduction band edge due to the rough surface lead to a reflection of electrons through mode-mismatch. This effect reduces the velocity of electrons and hence the transconductance considerably causing a cut-off frequency reduction.


Eastern Michigan University Undergraduate Catalog, 2011-2012, Office Of The Registrar Jan 2011

Eastern Michigan University Undergraduate Catalog, 2011-2012, Office Of The Registrar

Undergraduate Catalogs

No abstract provided.


Eastern Michigan University Undergraduate Catalog, 2011-2012, Office Of The Registrar Jan 2011

Eastern Michigan University Undergraduate Catalog, 2011-2012, Office Of The Registrar

Undergraduate Catalogs

No abstract provided.


Effects Of Interface Disorder On Valley Splitting In Sige/Si/Sige Quantum Wells, Zhengping Jiang, Neerav Kharche, Timothy Boykin, Gerhard Klimeck Jan 2011

Effects Of Interface Disorder On Valley Splitting In Sige/Si/Sige Quantum Wells, Zhengping Jiang, Neerav Kharche, Timothy Boykin, Gerhard Klimeck

Birck and NCN Publications

A sharp potential barrier at the Si/SiGe interface introduces valley splitting (VS), which lifts the 2-fold valley degeneracy in strained SiGe/Si/SiGe quantum wells (QWs). This work examines in detail the effects of Si/SiGe interface disorder on the VS in an atomistic tight binding approach based on statistical sampling. VS is analyzed as a function of electric field, QW thickness, and simulation domain size. Strong electric fields push the electron wavefunctions into the SiGe buffer and introduce significant VS fluctuations from device to device. A Gedankenexperiment with ordered alloys sheds light on the importance of different bonding configurations on VS. We …


Shape And Orientation Effects On The Ballistic Phonon Thermal Properties Of Ultra-Scaled Si Nanowires, Abhijeet Paul, Mathieu Luisier, Gerhard Klimeck Jan 2011

Shape And Orientation Effects On The Ballistic Phonon Thermal Properties Of Ultra-Scaled Si Nanowires, Abhijeet Paul, Mathieu Luisier, Gerhard Klimeck

Birck and NCN Publications

The effect of geometrical confinement, atomic position and orientation of Silicon nanowires (SiNWs) on their thermal properties are investigated using the phonon dispersion obtained using a Modified Valence Force Field (MVFF) model. The spe- cific heat (Cv) and the ballistic thermal conductance (κbal) shows anisotropic variation l with changing cross-section shape and size of the SiNWs. The Cv increases with de- creasing cross-section size for all the wires. The triangular wires show the largest Cv due to their highest surface-to-volume ratio. The square wires with [110] orientation show the maximum κbal since they have the highest number of conducting phonon …


Prox-Rbac: A Proximity-Based Spatially Aware Rbac, Michael Kirkpatrick, Maria Luisa Damiani, Elisa Bertino Jan 2011

Prox-Rbac: A Proximity-Based Spatially Aware Rbac, Michael Kirkpatrick, Maria Luisa Damiani, Elisa Bertino

Cyber Center Publications

As mobile computing devices are becoming increasingly dominant in enterprise and government organizations, the need for fine-grained access control in these environments continues to grow. Specifically, advanced forms of access control can be deployed to ensure authorized users can access sensitive resources only when in trusted locations. One technique that has been proposed is to augment role-based access control (RBAC) with spatial constraints. In such a system, an authorized user must be in a designated location in order to exercise the privileges associated with a role. In this work, we extend spatially aware RBAC systems by defining the notion of …


Kindle Forensics: Acquisition & Analysis, Peter Hannay Jan 2011

Kindle Forensics: Acquisition & Analysis, Peter Hannay

Journal of Digital Forensics, Security and Law

The Amazon Kindle eBook reader supports a wide range of capabilities beyond reading books. This functionality includes an inbuilt cellular data connection known as Whispernet. The Kindle provides web browsing, an application framework, eBook delivery and other services over this connection. The historic data left by user interaction with this device may be of forensic interest. Analysis of the Amazon Kindle device has resulted in a method to reliably extract and interpret data from these devices in a forensically complete manner.


Column: The Consortium Of Digital Forensics Specialists (Cdfs), Christopher Kelly Jan 2011

Column: The Consortium Of Digital Forensics Specialists (Cdfs), Christopher Kelly

Journal of Digital Forensics, Security and Law

Digital forensic practitioners are faced with an extraordinary opportunity. In fact, we may never again be faced with such an opportunity, and this opportunity will challenge us in ways we may never again be challenged. At this point in the history of the Digital Forensics profession, digital forensic specialists have the unique opportunity to help this profession emerge from its infancy. But for this profession to mature -- and to flourish -- individuals and organizations integral to the practice must assemble and shape its future. This is our opportunity. In fact, this is our mandate.


Judges’ Awareness, Understanding, And Application Of Digital Evidence, Gary C. Kessler Jan 2011

Judges’ Awareness, Understanding, And Application Of Digital Evidence, Gary C. Kessler

Journal of Digital Forensics, Security and Law

As digital evidence grows in both volume and importance in criminal and civil courts, judges need to fairly and justly evaluate the merits of the offered evidence. To do so, judges need a general understanding of the underlying technologies and applications from which digital evidence is derived. Due to the relative newness of the computer forensics field, there have been few studies on the use of digital forensic evidence and none about judges’ relationship with digital evidence. This paper describes a recent study, using grounded theory methods, into judges’ awareness, knowledge, and perceptions of digital evidence. This study is the …


Technology Corner: Analysing E-Mail Headers For Forensic Investigation, M. T. Banday Jan 2011

Technology Corner: Analysing E-Mail Headers For Forensic Investigation, M. T. Banday

Journal of Digital Forensics, Security and Law

Electronic Mail (E-Mail), which is one of the most widely used applications of Internet, has become a global communication infrastructure service. However, security loopholes in it enable cybercriminals to misuse it by forging its headers or by sending it anonymously for illegitimate purposes, leading to e-mail forgeries. E-mail messages include transit handling envelope and trace information in the form of structured fields which are not stripped after messages are delivered, leaving a detailed record of e-mail transactions. A detailed header analysis can be used to map the networks traversed by messages, including information on the messaging software and patching policies …


Evidence Of The Harmonic Faraday Instability In Ultrasonic Atomization Experiments With A Deep, Inviscid Fluid, Andrew P. Higginbotham '09, Aaron Guillen '11, Nathan C. Jones '10, Thomas D. Donnelly, Andrew J. Bernoff Jan 2011

Evidence Of The Harmonic Faraday Instability In Ultrasonic Atomization Experiments With A Deep, Inviscid Fluid, Andrew P. Higginbotham '09, Aaron Guillen '11, Nathan C. Jones '10, Thomas D. Donnelly, Andrew J. Bernoff

All HMC Faculty Publications and Research

A popular method for generating micron-sized aerosols is to submerge ultrasonic (ω~MHz) piezoelectric oscillators in a water bath. The submerged oscillator atomizes the fluid, creating droplets with radii proportional to the wavelength of the standing wave at the fluid surface. Classical theory for the Faraday instability predicts a parametric instability driving a capillary wave at the subharmonic (ω/2) frequency. For many applications it is desirable to reduce the size of the droplets; however, using higher frequency oscillators becomes impractical beyond a few MHz. Observations are presented that demonstrate that smaller droplets may also be created by …


Observations On Braided Thin Wire Nucleate Boiling In Microgravity, Justin P. Koeln, Jeffrey C. Boulware, Heng Ban, Jr Dennison Jan 2011

Observations On Braided Thin Wire Nucleate Boiling In Microgravity, Justin P. Koeln, Jeffrey C. Boulware, Heng Ban, Jr Dennison

Publications

A microgravity experiment was conducted on the Space Shuttle Endeavor (STS-108) to observe sustained nucleate boiling of water. Subcooled water was boiled with a single strand and a braid of three 0.16. mm diameter and 80. mm long Nichrome resistive wires. A CCD video camera recorded the experiment while six thermistors recorded the temperature of the fluid at various distances from the heating element. This paper reports experimental results in observations, measurements, and data analysis. Bubble explosions were found to take place shortly after the onset of boiling for both the single and braid of wires. The explosion may produce …


Characteristic Vertical Response Of A Footbridge Due To Crowd Loading, Colin C, Caprani, Joe Keogh, Paul Archbold, Paul Fanning Jan 2011

Characteristic Vertical Response Of A Footbridge Due To Crowd Loading, Colin C, Caprani, Joe Keogh, Paul Archbold, Paul Fanning

Conference papers

The characteristic vertical vibration of a flexible footbridge subject to crowd loading is examined in this paper. Typically, bridge vibrations produced from a crowd of pedestrians are estimated by using an enhancement factor applied to the effect caused by a single pedestrian. In this paper, a single pedestrian model, represented by a spring mass damper, which incorporates variables such as pedestrian mass and body stiffness, is used to calibrate a computationally efficient moving force model. This calibrated moving force model is further used in Monte Carlo simulations of non-homogenous crowds to estimate characteristic vertical vibration levels. Enhancement factors, which could …


Community-Based Internet Usage Policy Development, Mashael Alhawsah Jan 2011

Community-Based Internet Usage Policy Development, Mashael Alhawsah

Students Learning with Communities

The Internet is a tool for learning and obtaining a vast amount of information, but it is a tool which also has associated problems. The number of risks associated with the internet has been increasing both in number and in danger. As a result, protection measures must be developed to minimize the risks. One of the most important groups of such measures are Internet Usage Policies. An Internet Usage Policy addresses the problem by providing a set of guideline to be followed which minimize the risks. This dissertation investigates the development of Internet Usage Policy with the assistance of the …


Modeling And Surveillance Of Pandemic Influenza Outbreaks, Diana Prieto Jan 2011

Modeling And Surveillance Of Pandemic Influenza Outbreaks, Diana Prieto

USF Tampa Graduate Theses and Dissertations

Pandemic outbreaks are unpredictable as to their virus strain, transmissibility, and impact on our quality of life. Hence, the decision support models for mitigation of pandemic outbreaks must be user-friendly and operational, and also incorporate valid estimates of disease transmissibility and severity. This dissertation research is aimed at 1) reviewing the existing pandemic simulation models to identify their implementation gaps with regard to usability and operability, and suggesting research remedies, 2) increasing operability of simulation models by calibrating them via an epidemiological model that estimates infection probabilities using viral shedding profiles of concurrent pandemic and seasonal influenza, and 3) developing …


Cap-And-Trade Modeling And Analysis For Electric Power Generation Systems, Patricio Rocha Jan 2011

Cap-And-Trade Modeling And Analysis For Electric Power Generation Systems, Patricio Rocha

USF Tampa Graduate Theses and Dissertations

Cap-and-trade is the most discussed CO2 emissions control scheme in the U.S. It is a market-based mechanism that has been used previously to successfully reduce the levels of SO2 and NOx emitted by power generators. Since electricity generators are responsible for about 40% of the CO2 emissions in the U.S., the implementation of CO2 cap-and-trade will have a significant impact on electric power generation systems. In particular, cap-and-trade will influence the investment decisions made by power generators. These decisions in turn, will affect electricity prices and demand. If the allowances (or emission permits) created by …


Cdte/Cds Thin Film Solar Cells Fabricated On Flexible Substrates, Vasilios Palekis Jan 2011

Cdte/Cds Thin Film Solar Cells Fabricated On Flexible Substrates, Vasilios Palekis

USF Tampa Graduate Theses and Dissertations

Cadmium Telluride (CdTe) is a leading thin film photovoltaic (PV) material due to its near ideal bandgap of 1.45 eV and its high optical absorption coefficient. The typical CdTe thin film solar cell is of the superstrate configuration where a window layer (CdS), the absorber (CdTe) and a back contact are deposited onto glass coated with a transparent electrode.

Substrate CdTe solar cells where the above listed films are deposited in reverse are not common. In this study substrate CdTe solar cells are fabricated on flexible foils.

The properties of the Molybdenum back contact, Zinc Telluride (ZnTe) interlayer and CdTe …


Autonomous Mobility And Manipulation Of A 9-Dof Wmra, William Garrett Pence Jan 2011

Autonomous Mobility And Manipulation Of A 9-Dof Wmra, William Garrett Pence

USF Tampa Graduate Theses and Dissertations

The wheelchair-mounted robotic arm (WMRA) is a 9-degree of freedom (DoF) assistive system that consists of a 2-DoF modified commercial power wheelchair and a custom 7-DoF robotic arm. Kinematics and control methodology for the 9-DoF system that combine mobility and manipulation have been previously developed and implemented. This combined control allows the wheelchair and robotic arm to follow a single trajectory based on weighted optimizations. However, for the execution of activities of daily living (ADL) in the real-world environment, modified control techniques have been implemented.

In order to execute macro ADL tasks, such as a "go to and pick up" …


A Dynamic Hierarchical Web-Based Portal, Matthew James Spaulding Jan 2011

A Dynamic Hierarchical Web-Based Portal, Matthew James Spaulding

USF Tampa Graduate Theses and Dissertations

A dynamic hierarchical web-based portal was created to house a suite of web-based supply chain management applications. The portal was designed in a hierarchical manner to match the structure of large companies. Administrators of the the portal have the ability to form the portal in such a way to mimic the existing structure of their company. Access rights to the applications in the portal may be granted or denied per division and the users of the portal are placed in these divisions based on their duty in the company. In addition, users are granted roles which dictate their ability to …


Quality + Innovation: Adapting Quality Management Practices To Achieve Innovation Performance, Scott A. Leavengood, Timothy R. Anderson Jan 2011

Quality + Innovation: Adapting Quality Management Practices To Achieve Innovation Performance, Scott A. Leavengood, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

In many businesses today, focus on quality as a competitive tool is being replaced by a focus on innovation. This is not to say that quality is now irrelevant but rather that it is now seen by many as "necessary but insufficient" in today's business environment. Therefore, the task facing managers is how to achieve innovation performance in addition to quality performance. To answer this question, U.S. West Coast wood products manufacturers were surveyed about their quality management practices and performance with respect to both quality and innovation. Survey results were analyzed to identify two categories of high-performing firms: those …


Zinc Speciation In Power Plant Burning Mixtures Of Coal And Tires, Luis F.O. Silva, Marcos L.S. Oliveira, Carmen Serra, James C. Hower Jan 2011

Zinc Speciation In Power Plant Burning Mixtures Of Coal And Tires, Luis F.O. Silva, Marcos L.S. Oliveira, Carmen Serra, James C. Hower

Coal Combustion and Gasification Products Journal Archive

Fly ash from the cyclone-boiler co-combustion of high-S, high volatile bituminous coal and tire-derived fuel (tdf) was studied using a variety of chemical, optical, and microbeam techniques. Fly ash, dominated by Al-Si glass with lesser amounts of coalderived carbons, Fe-spinels, and tire-derived carbons, has Zn concentrations ranging from 2200 ppm (1st ESP row) to 6900 ppm Zn (3rd ESP row). Zinc occurs in Zn-rich nanoparticles in the Al-Si glass phases and as ZnO in amorphous and crystalline nanominerals, Fe- and Zn-sulfides, Pb-Al-Fe sulfates, and Zn sulfates. Iron-rich, Al- and Ti-bearing spinels contain accessory Zn2+,Cr3+,Mn2+, and Pb2+. Fe-sulfates and phosphates nanoparticles …


Co-Disposal Of Dry Fgd By-Product With Coal Gasification Ash And Inorganic Brines, Jabulani S. Mahlaba, P.C. Pretorius, Subal Maharajh, M.P. Augustyn Jan 2011

Co-Disposal Of Dry Fgd By-Product With Coal Gasification Ash And Inorganic Brines, Jabulani S. Mahlaba, P.C. Pretorius, Subal Maharajh, M.P. Augustyn

Coal Combustion and Gasification Products Journal Archive

There is a growing pressure from the environmental authorities and public bodies to reduce anthropogenic pollution. Stringent environmental legislation is being implemented for industries around the world, even more so for coal consuming industries. Control of gaseous emissions is one of the areas that are receiving considerable attention towards sustainable development. Coal combustion in coal-fired power utilities emits SO~x~ to the atmosphere. Dry flue gas desulphurisation (FGD) is a well known technology often used to mitigate sulphur emissions in coal-fired power utilities. It traditionally uses lime to neutralise SO~x~, and forms a mixture of anhydrite (CaSO~4~), and calcium sulphite (CaSO~3~). …


Development Of Risk Uncertainty Factors From Historical Nasa Projects, Tahani R. Amer Jan 2011

Development Of Risk Uncertainty Factors From Historical Nasa Projects, Tahani R. Amer

EMSE Doctoral Projects

NASA is a good investment of federal funds and strives to provide the best value to the nation. NASA has consistently budgeted to unrealistic cost estimates, which are evident in the cost growth in many of its programs. In this investigation, NASA has been using available uncertainty factors from the Aerospace Corporation, Air Force, and Booz Allen Hamilton to develop projects' risk posture. NASA has no insight into the developmental of these factors and, as demonstrated here, this can lead to unrealistic risks in many NASA Programs and projects (P/p). The primary contribution of this project is the development of …