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Physical Sciences and Mathematics Commons

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2011

University of South Florida

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Articles 31 - 60 of 199

Full-Text Articles in Physical Sciences and Mathematics

An Analysis Of Remote Biometric Authentication With Windows, Brandy Marie Eyers Jan 2011

An Analysis Of Remote Biometric Authentication With Windows, Brandy Marie Eyers

USF Tampa Graduate Theses and Dissertations

One thing that everyone seems to be worried about when it comes to his or her computer is security. If your computer is not secure then private information could be stolen. Many people now use passwords to protect themselves though they are discovering that using multi-factor authentication is much more secure. It allows you to use multiple different proofs of who you are. Biometrics is one of the ways to prove identity. Using it, you could log into a system with just a fingerprint, which is something that is very difficult to steal. We present a suite of software tools …


Mining Associations Using Directed Hypergraphs, Ramanuja N. Simha Jan 2011

Mining Associations Using Directed Hypergraphs, Ramanuja N. Simha

USF Tampa Graduate Theses and Dissertations

This thesis proposes a novel directed hypergraph based model for any database. We introduce the notion of association rules for multi-valued attributes, which is an adaptation of the definition of quantitative association rules known in the literature. The association rules for multi-valued attributes are integrated in building the directed hypergraph model. This model allows to capture attribute-level associations and their strength. Basing on this model, we provide association-based similarity notions between any two attributes and present a method for finding clusters of similar attributes. We then propose algorithms to identify a subset of attributes known as a leading indicator that …


Knowledge Guided Non-Uniform Rational B-Spline (Nurbs) For Supporting Design Intent In Computer Aided Design (Cad) Modeling, Khairan Rajab Jan 2011

Knowledge Guided Non-Uniform Rational B-Spline (Nurbs) For Supporting Design Intent In Computer Aided Design (Cad) Modeling, Khairan Rajab

USF Tampa Graduate Theses and Dissertations

For many years, incompatible computer-aided design (CAD) packages that are based on Non-uniform Rational B-Spline (NURBS) technology carried out the exchange of models and data through either neutral file formats (IGES or STEP) or proprietary formats that have been accepted as quasi industry standards. Although it is the only available solution at the current time, the exchange process most often produces unsatisfactory results. Models that are impeccable in the original modeling system usually end up with gaps or intersections between surfaces on another incompatible system. Issues such as loss of information, change of data accuracy, inconsistent tolerance, and misinterpretation of …


A Sedimentary Record Of Regional Land-Use And Climate Change In The Manatee River, Manatee County, Florida, Patrick Schwing Jan 2011

A Sedimentary Record Of Regional Land-Use And Climate Change In The Manatee River, Manatee County, Florida, Patrick Schwing

USF Tampa Graduate Theses and Dissertations

The Manatee River Watershed (Manatee County, FL) has experienced heavy anthropogenic development over the last 100 years and was relatively pristine previous to this development. The population growth within the watershed has surpassed the national trends and has doubled in the last 30 years. The heavy anthropogenic development has led to depletion in natural resources, nutrient loading, coastal erosion, and increased pollution. This study constructs records of sedimentological processes to compare the pre-development records to the past 100 years of anthropogenic development. The first portion of this study identifies specific changes in sedimentation attributed to anthropogenic activity in the Manatee …


Optimization Of Proximity Judgment, Brian Day Jan 2011

Optimization Of Proximity Judgment, Brian Day

USF Tampa Graduate Theses and Dissertations

As humans, we have evolved to see in three dimensions. Our ancestors developed two eyes that only look forward, which allows the visual area that can perceive depth to be most of the field of view. A variety of sensors have been developed which can determine depth in the environment. They range from producing individual points of depth to the depth of everything in the environment. These sensors have become cheap and can now reliably produce accurate depth. Research is needed to determine how to present the proximity information to the people using the sensors. Touch, sound, and vision have …


Statistical Analysis And Mechanistic Modeling Of Water Quality: Hillsborough Bay, Florida, Keith Hackett Jan 2011

Statistical Analysis And Mechanistic Modeling Of Water Quality: Hillsborough Bay, Florida, Keith Hackett

USF Tampa Graduate Theses and Dissertations

Nutrient pollution has been identified as a significant threat to U.S. coastal and estuarine water quality. Though coastal and estuarine waters need nutrients to maintain a healthy, productive ecosystem, excess nutrients can lead to eutrophication. There are significant potential negative consequences associated with eutrophication, including loss of habitat, loss of economic activity, and direct threats to human health. Hillsborough Bay experienced eutrophication in the 1960s and 1970s due to a rapidly growing population and associated increases in nutrient pollution. These eutrophic conditions led to more frequent phytoplankton and macroalgae blooms and declines in seagrasses. To address these problems, a series …


Evaluation Of Trajectory Modeling In Different Dynamic Regions Using Normalized Cumulative Lagrangian Separation, Yonggang Liu, Robert H. Weisberg Jan 2011

Evaluation Of Trajectory Modeling In Different Dynamic Regions Using Normalized Cumulative Lagrangian Separation, Yonggang Liu, Robert H. Weisberg

Yonggang Liu

The Lagrangian separation distance between the endpoints of simulated and observed drifter trajectories is often used to assess the performance of numerical particle trajectory models. However, the separation distance fails to indicate relative model performance in weak and strong current regions, such as a continental shelf and its adjacent deep ocean. A new skill score is proposed based on the cumulative Lagrangian separation distances normalized by the associated cumulative trajectory lengths. This skill score is used to evaluate surface trajectories implied by Global HYCOM hindcast surface currents as gauged against actual satellite-tracked drifter trajectories in the eastern Gulf of Mexico …


Evolution Of The Loop Current System During The Deepwater Horizon Oil Spill Event As Observed With Drifters And Satellites, Yonggang Liu, Robert H. Weisberg, Charles Kovach, Rolf Riethmüller Jan 2011

Evolution Of The Loop Current System During The Deepwater Horizon Oil Spill Event As Observed With Drifters And Satellites, Yonggang Liu, Robert H. Weisberg, Charles Kovach, Rolf Riethmüller

Yonggang Liu

The ocean circulation patterns of the Gulf of Mexico (GOM) Loop Current (LC) system and their effects on the advection of the oil discharged during the Deepwater Horizon incident are described using in situ surface drifter trajectories and satellite observations from May to August 2010. These observations include altimetry-derived surface geostrophic velocities, sea surface temperature, ocean color, and surface oil locations. The elongated, northwestward penetrating LC retreated back from its northernmost position in late April 2010 and stayed farther away from the surface oil in the north during May 2010. Although the main body of the surface oil slick remained …


From Source To Sink: An Isotopic Perspective On The Biogeochemical Relationship Between The Everglades And Florida Bay, Ana Maria Hoare Jan 2011

From Source To Sink: An Isotopic Perspective On The Biogeochemical Relationship Between The Everglades And Florida Bay, Ana Maria Hoare

USF Tampa Graduate Theses and Dissertations

Increasing human populations and activities in coastal areas have led to high nutrient loading and estuarine ecosystem decline. Natural hydrological patterns in South Florida have been drastically altered by changes in water management and land use practices. As a result Florida Bay has experienced a series of negative ecosystem effects including hypersalinity events, degradation of water quality, and harmful algal blooms and declines in upper trophic level populations. To remediate ecosystem decline in Florida's coastal ecosystems, the Comprehensive Everglades Restoration Plan proposes to restore a more natural hydrologic flow in the Everglades. It is expected hydrologic restoration efforts will change …


Robotic Hand Evaluation Based On Task Specific Kinematic Requirements, Carlos Rafael Neninger Jan 2011

Robotic Hand Evaluation Based On Task Specific Kinematic Requirements, Carlos Rafael Neninger

USF Tampa Graduate Theses and Dissertations

With the rise autonomous and robotic systems in field applications, the need for dexterous, highly adaptable end effectors has become a major research topic. Control mechanisms of robotics hands with a high number independent actuators is recognized as a complex, high dimensional problem, with exponentially complex algorithms. However, recent studies have shown that human hand motion possesses very high joint correlation which translates into a set of predefined postures, or synergies. The hand produces a motion using a complementing contribution of multiple joints, called synergies. The similarities place variables onto a common dimensional space, effectively reducing the number of independent …


Pallet Physics, Lauren Woodbridge Jan 2011

Pallet Physics, Lauren Woodbridge

Undergraduate Journal of Mathematical Modeling: One + Two

This project explores whether it is safe to unload a 907kg pallet from a supply truck with a bed 1.5m off the ground by sliding it down a metal ramp. First we calculated the critical angle for which the pallet would overcome the friction of the wood on the metal and begin to slide. Next we calculated velocity of the pallet as it reaches the bottom of the ramp. Finally we calculate the distance the pallet travels on the concrete after leaving the ramp. Based on these calculations of acceleration, velocity, and displacement, we conclude that it would not be …


Study Of Consciousness, Samuel Lee Jan 2011

Study Of Consciousness, Samuel Lee

Undergraduate Journal of Mathematical Modeling: One + Two

The human brain is a powerful organ that controls most of the body. Researchers around the world have long tried to uncover how the brain operates, how memories are formed and stored. Our understanding of neurological diseases such as Alzheimer's and Parkinson's disease has been rapidly improving, yet much remains to be done. In this work, we attempt to study changes in intracranial pressure (ICP) for a 12-hour period and discuss whether the resulting estimates could be used as a measure of consciousness.


Optimization Of A Pressure-Treating Process, Josean Velez Jan 2011

Optimization Of A Pressure-Treating Process, Josean Velez

Undergraduate Journal of Mathematical Modeling: One + Two

A company that pressure-treats wood wants to minimize its annual cost without using more than 250 days of operation per year. In addition, they want to find the corresponding value of time, batches and cost for each category. We develop an expression in terms of boards per batch to model the total cost of the treatment process. We then take the derivative and use Newton's Method to find the number of boards per batch that minimizes total cost.


Length Of A Hanging Cable, Eric Costello Jan 2011

Length Of A Hanging Cable, Eric Costello

Undergraduate Journal of Mathematical Modeling: One + Two

The shape of a cable hanging under its own weight and uniform horizontal tension between two power poles is a catenary. The catenary is a curve which has an equation defined by a hyperbolic cosine function and a scaling factor. The scaling factor for power cables hanging under their own weight is equal to the horizontal tension on the cable divided by the weight of the cable. Both of these values are unknown for this problem. Newton's method was used to approximate the scaling factor and the arc length function to determine the length of the cable. A script was …


Optimal Operation Of A Concentrator, Katrina Stine Jan 2011

Optimal Operation Of A Concentrator, Katrina Stine

Undergraduate Journal of Mathematical Modeling: One + Two

Concentrators are used in the industrial world to remove water from a chemical or substance by heating the liquid until the water evaporates thereby concentrating the remaining substance. The goal of this project is to find the optimum cycle time, number of cycles per year, and the heating element area that would minimize the total annual cost and hours of operation of an industrial concentrator. It was found that the specified concentrator would achieve a minimum total cost of $48,720.50 per year and take 993.8 hours to meet the production goal of evaporating one million kilograms of water.


Evanescent Wave Coupling Using Different Subwavelength Gratings For A Mems Accelerometer, Al-Aakhir A. Rogers Jan 2011

Evanescent Wave Coupling Using Different Subwavelength Gratings For A Mems Accelerometer, Al-Aakhir A. Rogers

USF Tampa Graduate Theses and Dissertations

A novel technique of coupling near-field evanescent waves by means of variable period subwavelength gratings (1.2 ìm and 1.0 ìm), using a 1.55 ìm infrared semiconductor laser is presented for the use of an optical MEMS accelerometer. The subwavelength gratings were fabricated on both glass and silicon substrates respectively.

Optical simulation of the subwavelength gratings was carried out to obtain the maximum coupling efficiency of the two subwavelength gratings; the grating thickness, grating width, and the grating separation were optimized. This was performed for both silicon and glass substrates.

The simulations were used to determine the total system noise, including …


Modeling Direct Runoff Hydrographs With The Surge Function, Denis Voytenko Jan 2011

Modeling Direct Runoff Hydrographs With The Surge Function, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

A surge function is a mathematical function of the form f(x)=axpe-bx. We simplify the surge function by holding p constant at 1 and investigate the simplified form as a potential model to represent the full peak of a stream discharge hydrograph. The previously studied Weibull and gamma distributions are included for comparison. We develop an analysis algorithm which produces the best-fit parameters for every peak for each model function, and we process the data with a MATLAB script that uses spectral analysis to filter year-long, 15-minute, stream-discharge data sets. The filtering is necessary to locate the …


Fungal Communities On Speleothem Surfaces In Kartchner Caverns, Arizona, Usa., Michael J. Vaughan, Raina M. Maier, Barry M. Pryor Jan 2011

Fungal Communities On Speleothem Surfaces In Kartchner Caverns, Arizona, Usa., Michael J. Vaughan, Raina M. Maier, Barry M. Pryor

International Journal of Speleology

Kartchner Caverns, located near Benson, Arizona, USA, is an active carbonate cave that serves as the major attraction for Kartchner Caverns State Park. Low-impact development and maintenance have preserved prediscovery macroscopic cavern features and minimized disturbances to biological communities within the cave.. The goal of this study was to examine fungal diversity in Kartchner Caverns on actively-forming speleothem surfaces. Fifteen formations were sampled from five sites across the cave. Richness was assessed using standard culture-based fungal isolation techniques. A culture-independent analysis using denaturing gradient gel electrophoresis (DGGE) was used to assay evidence of community homogeneity across the cave through the …


Editorial, Jo De Waele Jan 2011

Editorial, Jo De Waele

International Journal of Speleology

No abstract provided.


Synthesis Of Small Molecule Inhibitors Of Janus Kinase 2, Phosphodiesterase Iv, Gabaa And Nmda Receptors: Investigation Of Mcmurry, Mannich And Chemoenzymatic Strategies, Meghanath Gali Jan 2011

Synthesis Of Small Molecule Inhibitors Of Janus Kinase 2, Phosphodiesterase Iv, Gabaa And Nmda Receptors: Investigation Of Mcmurry, Mannich And Chemoenzymatic Strategies, Meghanath Gali

USF Tampa Graduate Theses and Dissertations

Stilbenoids possess a wide range of biological properties such as, anticancer, antiplatelet aggregation, antiestrogenic, antibacterial, antifungal and antiatherogenic, etc. Owing to these therapeutic values, a great deal of attention attracted in the synthesis of derivatives of stilbenes. During the course of the study, G6 a novel stilbenoid was discovered, through high throughput screening, to be a potent inhibitor of mutated JAK2-V617F. The mutated JAK2 variant has been implicated in various myeloproliferative disorders (MPDs) including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) has been targeted by therapeutics. Chapter 2 describes the synthesis of analogs of the stilbenoid G6 …


Electronic Structure Characterization Of Nanocrystalline Surfaces And Interfaces With Photoemission Spectroscopy, Sebastian Gutmann Jan 2011

Electronic Structure Characterization Of Nanocrystalline Surfaces And Interfaces With Photoemission Spectroscopy, Sebastian Gutmann

USF Tampa Graduate Theses and Dissertations

In this study, photoemission spectroscopy (PES) was used to investigate the electronic properties of nanocrystalline titanium dioxide (TiO2), zinc oxide (ZnO), and cadmium selenide (CdSe). Electrospray deposition technique enabled the preparation of thin films in vacuum from a dispersion prepared outside the vacuum chamber. This method also allowed the step-wise formation of interfaces and the monitoring of the evolution of the electronic structure with intermittent PES characterization.

The work function of nanocrystalline TiO2 and ZnO was measured with ultraviolet photoemission spectroscopy (UPS) and low-intensity x-ray photoemission spectroscopy (LIXPS). Measurements on environmentally contaminated surfaces revealed an instantaneous and …


Physical Models Of Amyloid Fibril Assembly, Shannon Elizabeth Hill Jan 2011

Physical Models Of Amyloid Fibril Assembly, Shannon Elizabeth Hill

USF Tampa Graduate Theses and Dissertations

Formation of large fibers and plaques by amyloid proteins is recognized as the molecular hallmark of an increasing number of human disorders, including Parkinson's disease, Alzheimer's disease and even type II diabetes. The broader objective of my research is to unravel the basic mechanisms that initiate and regulate fibril formation by amyloidogenic proteins. This objective is significant because even basic aspects of how fibril formation proceeds from a soluble, monomeric protein to an insoluble amyloid fibril remain much debated. Furthermore, there is increasingly strong evidence suggesting that intermediates of the aggregation process, with properties distinct from those of mature fibrils, …


A Comparison Of Ecological Conditions And Relationships In An Altered Wetland And An Unaltered Wetland, Mark Kiyoshi Hurst Jan 2011

A Comparison Of Ecological Conditions And Relationships In An Altered Wetland And An Unaltered Wetland, Mark Kiyoshi Hurst

USF Tampa Graduate Theses and Dissertations

The purpose of the study is to identify and quantify the hydrologic and ecologic differences between two adjacent sections of Colt Creek; one section unaltered and one section altered by clearing and drainage. These differences were measured by monitoring water levels, groundcover vegetation in each of the two areas, and monitoring numbers and species of birds utilizing the two areas. Surface water levels were measured in three locations: in the historic Colt Creek flow way, in the ditch draining the creek, and in an adjacent wetland strand. In addition, a shallow monitor well in the creek was used to measure …


Grouper: A Packet Classification Algorithm Allowing Time-Space Tradeoffs, Joshua Adam Kuhn Jan 2011

Grouper: A Packet Classification Algorithm Allowing Time-Space Tradeoffs, Joshua Adam Kuhn

USF Tampa Graduate Theses and Dissertations

This thesis presents an algorithm for classifying packets according to arbitrary (including noncontiguous) bitmask rules. As its principal novelty, the algorithm is parameterized by the amount of memory available and can customize its data structures to optimize classification time without exceeding the given memory bound. The algorithm thus automatically trades time for space efficiency as needed. The two extremes of this time-space tradeoff (linear search through the rules versus a single table that maps every possible packet to its class number) are special cases of the general algorithm we present. Additional features of the algorithm include its simplicity, its open-source …


High-Resolution Event Stratigraphy Of Mm-Scale Laminated Sediments From Coastal Salt Ponds: St. John, Us Virgin Islands, Rebekka Amie Larson Jan 2011

High-Resolution Event Stratigraphy Of Mm-Scale Laminated Sediments From Coastal Salt Ponds: St. John, Us Virgin Islands, Rebekka Amie Larson

USF Tampa Graduate Theses and Dissertations

A multi-proxy approach is utilized on mm- to cm-scale laminated sediment records in coastal salt ponds on St. John, U.S. Virgin Islands to characterize the sediments, identify their sources and depositional processes/events (heavy rainfall, tropical cyclones, tsunamis). Historical records are combined with high-resolution geochronology (short-lived radioisotopes, 210Pb, 137Cs, 7Be) and scanning elemental techniques (XRF and LA-ICP-MS) to link depositional events to how they are manifested in the sedimentary record. Volcanic rocks are the terrigenous sediment source and the sedimentary signature of terrigenous sediment in the geologic record consists of higher amounts of Al, Fe, Ti, Co, and …


Assessment Of The Dependence Of Ventilation Image Calculation From 4d-Ct On Deformation And Ventilation Algorithms, Kujtim Latifi Jan 2011

Assessment Of The Dependence Of Ventilation Image Calculation From 4d-Ct On Deformation And Ventilation Algorithms, Kujtim Latifi

USF Tampa Graduate Theses and Dissertations

Ventilation imaging using 4D-CT is a convenient and cost effective functional imaging methodology which might be of value in radiotherapy treatment planning to spare functional lung volumes. To calculate ventilation imaging from 4D-CT we must use deformable image registration (DIR). This study validates the DIR methods and investigates the dependence of calculated ventilation on DIR methods and ventilation algorithms.

The first hypothesis is if ventilation algorithms are robust then they will be insensitive to the precise DIR used provided the DIR is accurate. The second hypothesis is that the change in Houndsfield Unit (HU) method is less dependent on the …


Automorphism Groups Of Quandles, Jennifer Macquarrie Jan 2011

Automorphism Groups Of Quandles, Jennifer Macquarrie

USF Tampa Graduate Theses and Dissertations

This thesis arose from a desire to better understand the structures of automorphism groups and inner automorphism groups of quandles. We compute and give the structure of the automorphism groups of all dihedral quandles. In their paper Matrices and Finite Quandles, Ho and Nelson found all quandles (up to isomorphism) of orders 3, 4, and 5 and determined their automorphism groups. Here we find the automorphism groups of all quandles of orders 6 and 7. There are, up to isomoprhism, 73 quandles of order 6 and 289 quandles of order 7.


Crystal Engineering Of Pharmaceutical Cocrystals, Sreya Mukherjee Jan 2011

Crystal Engineering Of Pharmaceutical Cocrystals, Sreya Mukherjee

USF Tampa Graduate Theses and Dissertations

Pharmaceutical cocrystals use principles of crystal engineering for the design of crystalline forms of drugs and can improve their solubility, bioavailability, stability and other important properties without changing the efficacy of the drug. Herein reported are pharmaceutical cocrystals of two API's, caffeine and Pentoxifylline.

Research has indicated that caffeine has the ability to reverse AB; plaque deposition in the brain (believed to be the primary cause of Alzheimer's pathogenesis) and thus revert memory and improve cognitive impairment. But owing to the fast absorption rate and short half life, a controlled release formulation of caffeine would be clinically beneficial. Thus, novel …


Selection And Implementation Of Technologies For The Re-Engineering Of An Existing Software System, Stan William Naspinski Jan 2011

Selection And Implementation Of Technologies For The Re-Engineering Of An Existing Software System, Stan William Naspinski

USF Tampa Graduate Theses and Dissertations

A major hurdle for any company to cross is the act of re-engineering software if they wish to stay relevant. With the speed that software and technology advances, it would be ignorant for any product to stagnate. With that comes the inherent difficulties of choosing which of the older technologies to keep (if any) and which newer technologies to employ in the re-engineered solution. Once that is covered, the actual implementation presents its own set of challenges to both the decision makers and developers in the process.

This thesis describes a case study, in particular the efforts put forth to …


The Impact Of Supply Chain And Network Structure On The Environmental Performance Of Sustainability-Focused Companies, Ozan Ozcan Jan 2011

The Impact Of Supply Chain And Network Structure On The Environmental Performance Of Sustainability-Focused Companies, Ozan Ozcan

USF Tampa Graduate Theses and Dissertations

The goal of this dissertation was to contribute to our understanding of the relationship between supply chain structure and the pursuit of a sustainability-driven corporate strategy. The literature indicates that in order to pursue a sustainability-focused strategy, an increased level of integration across the supply chain is required. However, there are also industry-level dynamics that impact observed levels of vertical integration. That is, some industries are naturally more integrated than others based on the maturity level of the industry. Thus, some firms may experience opposing forces regarding their sourcing strategies once they choose to pursue a sustainability-focused strategy.

To explore …