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2010

Clemson University

Articles 181 - 209 of 209

Full-Text Articles in Physical Sciences and Mathematics

Conservation Biology Of The Diamondback Terrapin In North America, Amanda Hackney May 2010

Conservation Biology Of The Diamondback Terrapin In North America, Amanda Hackney

All Theses

Reptiles are experiencing global declines and pond turtles (Emydidae) are particularly vulnerable. The diamondback terrapin uses multiple habitats to fulfill its life history requirements, in the estuarine environments of the Gulf Coast and Atlantic states (US). Interacting effects of coastal development, overharvesting, abandoned crabbing gear, road mortality, climate change, and nest predation are likely causing population declines throughout its distribution. Protection levels were assessed by referencing each state's Wildlife Action Plan for the species' Conservation Status Ranking Code. At least 7 federal laws directly or indirectly regulate take, wetland, and/or coastal activities (Lacey Act, CWA, FWCA, NAWCA, WPFPA, CBRA, NEPA). …

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Reduction Of Rocket-Borne Atmospheric Density Measurements Using Monte Carlo Simulation, Travis Gaulden May 2010

Reduction Of Rocket-Borne Atmospheric Density Measurements Using Monte Carlo Simulation, Travis Gaulden

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The HEX II atmospheric rocket experiment, conducted near 9:30 U.T. February 14, 2007 from the Poker Flat Rocket Range in Alaska was designed to lead to a better understanding of density and velocity gradients in the lower thermosphere. In a supporting role to this mission, cold cathode ionization gauges recorded composite density along three rocket payload trajectory paths from 90 km to 200 km. Rocket-borne instruments experience near sonic to hypersonic velocities and encounter a range of viscous, slipflow, and collisionless flow conditions at these heights. These variable conditions necessitate the use of tailored analytic expressions appropriate to the flow …

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A Study Of Coastal Headwater Stream Hydrology: Bannockburn Plantation, Georgetown County, Sc, Drake Rogers May 2010

A Study Of Coastal Headwater Stream Hydrology: Bannockburn Plantation, Georgetown County, Sc, Drake Rogers

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Coastal headwater streams in undeveloped forested landscapes function as a natural storage and conveyance mechanism for rainfall and groundwater. Stream flows are often driven by groundwater table depth, while soil saturation with a high water table may drive rainfall response. Evapotranspiration also plays a significant role in groundwater levels and influences stream flows both seasonally and diurnally. The dynamics of coastal forested watersheds are complex, and water budgets of these low gradient headwater streams are difficult to quantify.
Understanding these hydrologic dynamics is critical to water resources protection and flood prevention in coastal landscapes, especially as forested areas are converted …

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Increased Accuracy And Efficiency In Finite Element Computations Of The Leray-Deconvolution Model Of Turbulence, Abigail Bowers May 2010

Increased Accuracy And Efficiency In Finite Element Computations Of The Leray-Deconvolution Model Of Turbulence, Abigail Bowers

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This thesis develops, analyzes and tests a finite element method for approximating solutions to the Leray–deconvolution regularization of the Navier–Stokes equations. The scheme combines three ideas in order to create an accurate and effective algorithm: the use of an incompressible filter, a linearization that decouples the velocity–pressure system from the filtering and deconvolution operations, and a stabilization that works well with the linearization. A rigorous and complete numerical analysis of the scheme is given, and numerical experiments are presented that show clear advantages of the scheme.

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A Numerical Study Of Subgrid Artificial Viscosity Methods For The Navier-Stokes Equations, Keith Galvin May 2010

A Numerical Study Of Subgrid Artificial Viscosity Methods For The Navier-Stokes Equations, Keith Galvin

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This paper studies two artificial viscosity methods for approximating solutions to the Navier&ndashStokes Equations. Both methods that are introduced add stabilization, then remove it only on a coarse mesh. Both methods can be considered as conforming, mixed methods for 1) velocity and its gradient, and 2) velocity and vorticity. Herein we rigorously study the schemes both analytically and computationally, showing that both methods are unconditionally stable and optimally convergent. Numerical experiments show both methods provide improved results over the unstabilized Navier&ndashStokes Equations.

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Analysis Of Egg-Lay Dates Of Bald Eagles As A Potential Indicator Of Global Climate Change, Jennifer Garrison May 2010

Analysis Of Egg-Lay Dates Of Bald Eagles As A Potential Indicator Of Global Climate Change, Jennifer Garrison

All Theses

The effects of climate change on many wildlife species is a new area of research. Long&ndashterm data sets on raptor populations may hold the key to documenting these impacts from local to ecosystem scales. The Michigan bald eagle (Haliaeetus leucocephalus) population has been monitored continuously since 1961, and virtually all reproductive outcomes are known since 1963. The bald eagle population at Voyageurs National Park, Minnesota has been monitored continuously since 1973. Though these data sets are extensive, little is known about the effects of climate change on egg laying dates in sea eagles (Haliaeetus spp). Understanding these effects could ultimately …

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Compressive Sensing, Yue Mao May 2010

Compressive Sensing, Yue Mao

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Compressive sensing is a novel paradigm for acquiring signals and has a wide range of applications. The basic assumption is that one can recover a sparse or compressible signal from far fewer measurements than traditional methods. The difficulty lies in the construction of efficient recovery algorithms. In this thesis, we review two main approaches for solving the sparse recovery problem in compressive sensing: l1-minimization methods and greedy methods. Our contribution is that we look at compressive sensing from a different point of view by connecting it with sparse interpolation. We introduce a new algorithm for compressive sensing called generalized eigenvalues …

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Practical Implementation Of The Virtual Organization Cluster Model, Michael Fenn May 2010

Practical Implementation Of The Virtual Organization Cluster Model, Michael Fenn

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Virtualization has great potential in the realm of scientific computing because of its inherent advantages with regard to environment customization and isolation. Virtualization technology is not without it's downsides, most notably, increased computational overhead. This thesis introduces the operating mechanisms of grid technologies in general, and the Open Science Grid in particular, including a discussion of general organization and specific software implementation. A model for utilization of virtualization resources with separate administrative domains for the virtual machines (VMs) and the physical resources is then presented. Two well-known virtual machine monitors, Xen and the Kernel-based Virtual Machine (KVM), are introduced and …

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Comparison Of Rna Quality From Stressed And Unstressed Recombinant Escherichia Coli, Mary Alice Salazar May 2010

Comparison Of Rna Quality From Stressed And Unstressed Recombinant Escherichia Coli, Mary Alice Salazar

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High quality, intact RNA is required for DNA microarray studies, cloning, and reverse transcriptase polymerase chain reaction (rt-PCR) analysis. There are several analytical methods used to assess the RNA quality. The RNA Integrity Number (RIN) from the Agilent Bioanalyzer is one quality control assay used to evaluate RNA. For recombinant Escherichia coli cultured under stressful conditions the RNA profiles obtained using the Agilent Bioanalyzer indicate RNA degradation; however, RNA obtained and purified in parallel from unstressed recombinant cultures indicate acceptable RNA values without significant degradation. We proposed that for stressed E. coli the RIN value is not necessarily indicative of …

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Building Scientific Clouds: The Distributed, Peer-To-Peer Approach, Linton Vadakedathu May 2010

Building Scientific Clouds: The Distributed, Peer-To-Peer Approach, Linton Vadakedathu

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The Scientific community is constantly growing in size. The increase in personnel number and projects have resulted in the requirement of large amounts of storage, CPU power and other computing resources. It has also become necessary to acquire these resources in an affordable
manner that is sensitive to work loads. In this thesis, the author presents a novel approach that provides the communication platform that will support such large scale scientific projects. These resources could be difficult to acquire due to NATs, firewalls and other site-based restrictions and policies. Methods used to overcome these hurdles have been discussed in detail …

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Sparse Representation For Detection Of Transients Using A Multi-Resolution Representation Of The Auto-Correlation Of Wavelets, Caroline Sieger May 2010

Sparse Representation For Detection Of Transients Using A Multi-Resolution Representation Of The Auto-Correlation Of Wavelets, Caroline Sieger

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This thesis seeks to detect damped sinusoidal transients, specifically capacitor switching transients, buried in noise and to answer the following questions: 1.) Can the transient s(t;q) be sparsely represented from s&delta(t) = s(t;q) + &epsilon(t) using sparsity methods, where &epsilon(t) is white Gaussian noise? 2.) Does computing the local auto-correlation of the signal around the transient improve detection? 3.) How does the auto-correlation shell representation compare to the wavelet representation? 4.) Which basis is ''best''? 5.) Which method and representation is best? This thesis explores detection schemes based on classical methods and newer sparsity methods. Classical methods considered include reconstruction …

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The Steiner Linear Ordering Problem: Application To Resource-Constrained Scheduling Problems, Mariah Magagnotti May 2010

The Steiner Linear Ordering Problem: Application To Resource-Constrained Scheduling Problems, Mariah Magagnotti

All Theses

When examined through polyhedral study, the resource-constrained scheduling problems have always dealt with processes which have the same priority. With the Steiner Linear Ordering problem, we can address systems where the elements involved have different levels of priority, either high or low. This allows us greater flexibility in modeling different resource-constrained scheduling problems. In this paper, we address both the linear ordering problem and its application to scheduling problems, and provide a polyhedral study of the associated polytopes.

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Shrinkage Estimation In Partially Linear Models With Measurement Error, Yifang Li May 2010

Shrinkage Estimation In Partially Linear Models With Measurement Error, Yifang Li

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In practice, measurement error in the covariates is often encountered. Measurement error has several effects when using ordinary least squares for the regression problems. In this thesis, we introduce the basic idea of correcting the bias caused by different types of measurement error. We then focus on the variable selection for partially linear models when some of the covariates are measured with additive errors. The bias caused by the measurement error is corrected by subtracting a bias correction term in the squared loss function. Adaptive LASSO is used for the variable selection procedure. The rate of convergence and the asymptotic …

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A Statewide Seidment And Water Quality Approach To Characterize Pollution In Wadable Streams Of South Carolina, Alan Jones May 2010

A Statewide Seidment And Water Quality Approach To Characterize Pollution In Wadable Streams Of South Carolina, Alan Jones

All Theses

At present, little data is available concerning the overall quality of small aquatic ecosystems in South Carolina. The data presented here comprises the elemental contamination results from the first two years of an ongoing study with the South Carolina Department of Natural Resources of wadeable streams in South Carolina. The overall goal of this thesis is to assess overall ecosystem quality in order to provide information needed for improved management strategies. The data focus on elemental contaminants found in water and sediments in 2006 and 2007 and relationships between metals and land cover in the drainage areas or watersheds of …

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Chemical Characterization Of Botanical Products: Comprehensive Speciation By Liquid Chromatography Particle Beam Mass Spectrometry, Joaudimir Castro Georgi May 2010

Chemical Characterization Of Botanical Products: Comprehensive Speciation By Liquid Chromatography Particle Beam Mass Spectrometry, Joaudimir Castro Georgi

All Dissertations

The dietary supplement industry has expanded and many of these supplements have become an important aspect of people's everyday lives. In 1994, the U.S. Dietary Supplement Health and Education Act (DSHEA) classified numerous nutraceutical/botanical products as dietary supplements because of their beneficial medicinal properties and provided the necessary regulation to the supplement producers. Since then, the interest of the scientific community towards dietary supplements has grown intensively and numerous studies have been carried out in order to understand the chemical behavior of the active molecules in the human body. The development towards analytical methods for the quantification of the active …

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Pslr(1): Pseudo-Scannerless Minimal Lr(1) For The Deterministic Parsing Of Composite Languages, Joel Denny May 2010

Pslr(1): Pseudo-Scannerless Minimal Lr(1) For The Deterministic Parsing Of Composite Languages, Joel Denny

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Composite languages are composed of multiple sub-languages. Examples include the parser specification languages read by parser generators like Yacc, modern extensible languages with complex layers of domain-specific sub-languages, and even traditional programming languages like C and C++. In this dissertation, we describe PSLR(1), a new scanner-based LR(1) parser generation system that automatically eliminates scanner conflicts typically caused by language composition. The fundamental premise of PSLR(1) is the pseudo-scanner, a scanner that only recognizes tokens accepted by the current parser state. However, use of the pseudo-scanner raises several unique challenges, for which we describe a novel set of solutions. One major …

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Architecture Optimization, Training Convergence And Network Estimation Robustness Of A Fully Connected Recurrent Neural Network, Xiaoyu Wang May 2010

Architecture Optimization, Training Convergence And Network Estimation Robustness Of A Fully Connected Recurrent Neural Network, Xiaoyu Wang

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Recurrent neural networks (RNN) have been rapidly developed in recent years. Applications of RNN can be found in system identification, optimization, image processing, pattern reorganization, classification, clustering, memory association, etc.
In this study, an optimized RNN is proposed to model nonlinear dynamical systems. A fully connected RNN is developed first which is modified from a fully forward connected neural network (FFCNN) by accommodating recurrent connections among its hidden neurons. In addition, a destructive structure optimization algorithm is applied and the extended Kalman filter (EKF) is adopted as a network's training algorithm. These two algorithms can seamlessly work together to generate …

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Development Of A Spatialy Explicit Habitat Patch Model (C-Pan) And Comparative Analysis Of Patch Modeling Techniques: The Crafting Of A New Tool For Conservation Planners, Ryan Perkl May 2010

Development Of A Spatialy Explicit Habitat Patch Model (C-Pan) And Comparative Analysis Of Patch Modeling Techniques: The Crafting Of A New Tool For Conservation Planners, Ryan Perkl

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ABSTRACT
Ecological theories including island biogeography, intermediate disturbance, metapopulation and metacommunity all suggest that habitat patches of larger size and those comprised of substantial configurations of interior or core habitat possess the greatest potential for long-term species viability. As a direct means of mitigating edge encroachment and fragmentation's other adverse effects, there is a growing consensus among conservation planners that assembling larger, more cohesive tracts with substantial core area is of ecological value in conservation planning. Larger and more cohesive patches are believed to sustain larger and more viable local populations, enhance overall biodiversity, incorporate a wider array of natural …

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Synthesis Of Meta-Terphenyl Scaffolded Molecules For Catalysis And Sensor Applications, Brad Morgan May 2010

Synthesis Of Meta-Terphenyl Scaffolded Molecules For Catalysis And Sensor Applications, Brad Morgan

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The utility of the m-terphenyl has been observed in a wide variety of applications since its first discovery. The tunable conformational flexibility contributes to the unique properties and resulting applications thereof. Chapter 1 goes into detail about the concepts used throughout and defines the tools needed to understand the chemistry in the
resulting chapters.
The primary use of the m-terphenyl herein is as a canopy that shields a pocket created underneath the central ring. Functionalization within this pocket allows metal binding in defined coordination environments. with the use of donor ligands attached to the flanking rings. The applications of these …

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Improved Accuracy For Fluid Flow Problems Via Enhanced Physics, Michael Case May 2010

Improved Accuracy For Fluid Flow Problems Via Enhanced Physics, Michael Case

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This thesis is an investigation of numerical methods for approximating solutions to fluid flow problems, specifically the Navier-Stokes equations (NSE) and magnetohydrodynamic equations (MHD), with an overriding theme of enforcing more physical behavior in discrete solutions. It is well documented that numerical methods with more physical accuracy exhibit better long-time behavior than comparable methods that enforce less physics in their solutions. This work develops, analyzes and tests finite element methods that better enforce mass conservation in discrete velocity solutions to the NSE and MHD, helicity conservation for NSE, cross-helicity conservation in MHD, and magnetic field incompressibility in MHD.

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Biology And Ecology Of Lake Sturgeon Acipenser Fulvescens In The Grasse River, New York, Drew Trested May 2010

Biology And Ecology Of Lake Sturgeon Acipenser Fulvescens In The Grasse River, New York, Drew Trested

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The objectives of this dissertation were to (1) evaluate the age, growth, mortality, and abundance of lake sturgeon Acipenser fulvescens in the Grasse River, New York; (2) characterize seasonal movement patterns and mesohabitat use for adult and juvenile lake sturgeon in the Grasse River, New York; and (3) quantify the immediate and delayed post-procedure mortality for shovelnose sturgeon after insertion of an endoscope through an incision. I determined age for 196 of 211 lake sturgeon by examination of sectioned pectoral fin rays. Ages ranged from 0 -32 years and the annual mortality rate for fish between ages 7 and 14 …

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Structural Assessment Of The Effects Of Amino Acid Substitutions On Protein Stability And Protein-Protein Interaction, Shaolei Teng, Liangjiang Wang, Anand K. Srivastava, Charles E. Schwartz, Emil Alexov Mar 2010

Structural Assessment Of The Effects Of Amino Acid Substitutions On Protein Stability And Protein-Protein Interaction, Shaolei Teng, Liangjiang Wang, Anand K. Srivastava, Charles E. Schwartz, Emil Alexov

Publications

A structure-based approach is described for predicting the effects of amino acid substitutions on protein function. Structures were predicted using a homology modelling method. Folding and binding energy differences between wild-type and mutant structures were computed to quantitatively assess the effects of amino acid substitutions on protein stability and protein–protein interaction, respectively. We demonstrated that pathogenic mutations at the interaction interface could affect binding energy and destabilise protein complex, whereas mutations at the non-interface might reduce folding energy and destabilise monomer structure. The results suggest that the structure-based analysis can provide useful information for understanding the molecular mechanisms of diseases.

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A Solution-Based Approach To The Fabrication Of Novel Chalcogenide Glass Materials And Structures, Nathan Carlie Mar 2010

A Solution-Based Approach To The Fabrication Of Novel Chalcogenide Glass Materials And Structures, Nathan Carlie

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Chalcogenide glasses (ChGs) are well known for their large optical nonlinearities and high infrared transparency, and are candidate materials for next-generation thin film-based planar infrared (IR) optical applications. They are also known, however, to possess low thermal and mechanical stability as compared to oxide glasses. Traditional physical vapor deposition (PVD) methods used for the deposition of these materials as thin films often suffer from low deposition rates, deviation from stoichiometry, and cannot coat over complex surfaces. In order to retain the attractive optical properties of ChGs while enabling new fabrication routes and hybrid and composite material systems, we have developed …

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Recent Discoveries Of Supersoft X-Ray Sources In M 31, M. Henze, W. Pietsch, E. Haberl, G. Sala, M. Hernanz, D. Hartzidimitriou, A. Rau, Dieter H. Hartmann, J. Greiner, M. Orio, H Stiele, M.J. Freyberg Feb 2010

Recent Discoveries Of Supersoft X-Ray Sources In M 31, M. Henze, W. Pietsch, E. Haberl, G. Sala, M. Hernanz, D. Hartzidimitriou, A. Rau, Dieter H. Hartmann, J. Greiner, M. Orio, H Stiele, M.J. Freyberg

Publications

Classical novae (CNe) have recently been reported to represent the major class of supersoft X-ray sources (SSSs) in the central area of our neighbouring galaxy M 31. This paper presents a review of results from recent X-ray observations of M 31 with XMM-Newton and Chandra. We carried out a dedicated optical and X-ray monitoring program of CNe and SSSs in the central area of M 31. We discovered the first SSSs in M 31 globular clusters (GCs) and their connection to the very first discovered CN in a M 31 GC. This result may have an impact on the CN …

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Dual Gamma-Ray Mission, S. Boggs, C. Wunderer, P. Von Ballmoos, T. Takahashi, N. Gehrels, J. Tueller, M. Baring, J. Beacom, R. Diehl, J Greiner, E Grove, Dieter H. Hartmann Jan 2010

Dual Gamma-Ray Mission, S. Boggs, C. Wunderer, P. Von Ballmoos, T. Takahashi, N. Gehrels, J. Tueller, M. Baring, J. Beacom, R. Diehl, J Greiner, E Grove, Dieter H. Hartmann

Publications

Gamma-rays at MeV energies provide a unique window on the high energy Universe, especially so for nuclear astrophysics. The potential for significant contributions, e.g., to the understanding of SNe Ia as well as the large potential for new discoveries has long been recognized, but technical progress in this challenging energy band has been slow. The groundbreaking discoveries of CGRO’s COMPTEL, however, have inspired and driven the development of powerful new instrumentation over the past decade. Novel detector technologies developed in the US and Japan enable compact Compton telescopes, greatly improving the efficiency and field-of-view achievable with this technique successfully employed …

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The Dynamic X-Ray Sky Of The Local Universe, S. Boggs, C. Wunderer, P. Von Ballmoos, T. Takahashi, N. Gehrels, J. Tueller, M. Baring, J. Beacom, R. Diehl, Dieter H. Hartmann Jan 2010

The Dynamic X-Ray Sky Of The Local Universe, S. Boggs, C. Wunderer, P. Von Ballmoos, T. Takahashi, N. Gehrels, J. Tueller, M. Baring, J. Beacom, R. Diehl, Dieter H. Hartmann

Publications

Over the next decade, we can expect time domain astronomy to flourish at optical and radio wavelengths. In parallel with these efforts, a dedicated transient "machine" operating at higher energies (X-ray band through soft gamma-rays) is required to reveal the unique subset of events with variable emission predominantly visible above 100 eV. Here we focus on the transient phase space never yet sampled due to the lack of a sensitive, wide-field and triggering facility dedicated exclusively to catching high energy transients and enabling rapid coordinated multi-wavelength follow-up. We first describe the advancements in our understanding of known X-ray transients that …

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On The Origin Of The Highest Redshift Gamma-Ray Bursts, Krzysztof Belczynski, Daniel E. Holz, Chris L. Fryer, Edo Berger, Dieter H. Hartmann, Brain O'Shea Jan 2010

On The Origin Of The Highest Redshift Gamma-Ray Bursts, Krzysztof Belczynski, Daniel E. Holz, Chris L. Fryer, Edo Berger, Dieter H. Hartmann, Brain O'Shea

Publications

GRB 080913 and GRB 090423 are the most distant gamma-ray bursts (GRBs) known to date, with spectroscop-ically determined redshifts of z = 6.7 and z = 8.1, respectively. The detection of bursts at this early epoch of the universe significantly constrains the nature of GRBs and their progenitors. We perform population synthesis studies of the formation and evolution of early stars, and calculate the resulting formation rates of short- and long-duration GRBs at high redshift. The peak of the GRB rate from Population II stars occurs at z ∼ 7for a model with efficient/fast mixing of metals, while it is …

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High Performance Computing Instrumentation And Research Productivity In U.S. Universities, Amy W. Apon, Linh B. Ngo, Stanley Ahalt, Vijay Dantuluri, Constantin Gurdgiev, Moez Limayem, Michael Stealey Jan 2010

High Performance Computing Instrumentation And Research Productivity In U.S. Universities, Amy W. Apon, Linh B. Ngo, Stanley Ahalt, Vijay Dantuluri, Constantin Gurdgiev, Moez Limayem, Michael Stealey

Publications

This paper studies the relationship between investments in High-Performance Computing (HPC) instrumentation and research competitiveness. Measures of institutional HPC investment are computed from data that is readily available from the Top 500 list, a list that has been published twice a year since 1993 that lists the fastest 500 computers in the world at that time. Institutions that are studied include US doctoral-granting institutions that fall into the very high or high research rankings according to the Carnegie Foundation classifications and additional institutions that have had entries in the Top 500 list. Research competitiveness is derived from federal funding data, …

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Molecular Mechanics Studies Of Enzyme Evolutionary Mechanisms, Manoj Singh Jan 2010

Molecular Mechanics Studies Of Enzyme Evolutionary Mechanisms, Manoj Singh

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In the current dissertation, closely related studies to quantify the mechanism underlying enzyme evolution have been discussed. The HIV-1 protease and beta-lactamase enzymes were used as model systems for these studies. These are well known enzymes that are associated with drug resistance and are associated with the pathogenic diseases, and therefore, developing molecular level understanding of drug resistance through these enzymes has fundamental as well as practical importance.
In chapter 2, the relationship between errors in modeled protein structures and associated binding affinity predictions to small molecules is established. The results of this study are applicable in addressing a wide …

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