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2007

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Articles 2821 - 2850 of 6758

Full-Text Articles in Physical Sciences and Mathematics

A Classification Of Real Indecomposable Solvable Lie Algebras Of Small Dimension With Codimension One Nilradicals, Alan R. Parry May 2007

A Classification Of Real Indecomposable Solvable Lie Algebras Of Small Dimension With Codimension One Nilradicals, Alan R. Parry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis was concerned with classifying the real indecomposable solvable Lie algebras with codimension one nilradicals of dimensions two through seven. This thesis was organized into three chapters.

In the first, we described the necessary concepts and definitions about Lie algebras as well as a few helpful theorems that are necessary to understand the project. We also reviewed many concepts from linear algebra that are essential to the research.

The second chapter was occupied with a description of how we went about classifying the Lie algebras. In particular, it outlined the basic premise of the classification: that we can use …


The Effect Of Radiation And Repeated Sub-Culturing On Tgf-Β1 Signaling In Frtl-5 Cells, Cheryl G. Burrell May 2007

The Effect Of Radiation And Repeated Sub-Culturing On Tgf-Β1 Signaling In Frtl-5 Cells, Cheryl G. Burrell

Loma Linda University Electronic Theses, Dissertations & Projects

From our ongoing in vitro studies using the Fisher Rat Thyroid cell line-5 (FRTL-5) we recorded accelerated growth, reduced follicularization and reduction in thyroxin release that occurred as the cells were repeatedly sub-cultured. We also recorded that these changes occurred earlier and more rapidly following radiation exposure. We determined that TGF-β1 production increased under both conditions. We hypothesized that alteration in the TGF-β1 signaling pathway contributed to the changes observed in the cellular properties of FRTL-5 cells. Our objective was to examine some of the players in the TGF-β1 signaling pathway to determine whether radiation and/or repeated subculturing promoted changes …


Component Integration Metrics And Their Evaluation, Prapanna Parthasarathy May 2007

Component Integration Metrics And Their Evaluation, Prapanna Parthasarathy

Masters Theses & Specialist Projects

Software Engineering (SE) has been described as the discipline devoted to the design, development, and use of computer software, covering not only the technical aspects of building software systems, but also management issues develops highly complex software. The crisis in SE, due to the lack of well-defined formal processes, has led to poorly designed products with high maintenance costs and whose behavior becomes unpredictable. Component Based Software Engineering (CBSE) is currently a preferred approach to system design to overcome the crisis of SE, since it promotes software re-use, facilitates adaptability and faster system development. A component provides a function or …


Storm Response And Water Balance Of Temperate Rainforest Karst Watersheds: Tongass National Forest, Alaska, Johanna Kovarik May 2007

Storm Response And Water Balance Of Temperate Rainforest Karst Watersheds: Tongass National Forest, Alaska, Johanna Kovarik

Masters Theses & Specialist Projects

The Tongass National Forest in southeast Alaska contains 2,176 square kilometers of karst. As part of the evolving Tongass Land Management Plan, research into the function of karst systems is crucial in understanding how forest management affects not only karst areas but also surrounding ecosystems. Dye trace and water balance results in two watersheds on the north end of Prince of Wales Island demonstrate the difficulty in containing the effects of management, as water can enter karst catchments from unknown sources at different flow regimes. A dye trace was conducted in Windgate and Canyon Block watersheds. Two sinking streams were …


Spatio-Temporal Analysis Of Observed Soil Moisture From Nebraska, Ashley Littell May 2007

Spatio-Temporal Analysis Of Observed Soil Moisture From Nebraska, Ashley Littell

Masters Theses & Specialist Projects

Soil moisture is a measure of the water content in a soil that is dependent upon precipitation, evapotranspiration, runoff, drainage, and irrigation. Nebraska is one of the few states that measures soil moisture in an extensive network that records weather variables on a daily basis. Daily soil moisture observations are collected from depths of 10, 25, 50, and 100 centimeters and analyzed in this research. Data from these stations are evaluated on the spatial and temporal scales using spatial interpolations, time-series analysis, and cross-correlations to better understand the variations of soil moisture in the Northern Great Plains. Spatial interpolation grids …


Agricultural Contaminant Source And Transport In A Karst Groundwater Basin, Patricia Kambesis May 2007

Agricultural Contaminant Source And Transport In A Karst Groundwater Basin, Patricia Kambesis

Masters Theses & Specialist Projects

Agricultural land use in areas that are located in karst groundwater basins negatively impact groundwater quality because karst terrains provide multiple, direct hydrologic connections from the surface into karst aquifers. The connections and rapid velocities associated with surface and subsurface flow in karst aquifers allow for contaminants to move quickly into and through a groundwater basin. When groundwater returns to the surface via a spring or springs, any contaminants within the water become part of surface streams and rivers. These in turn, impact water quality in areas located downstream of the spring or springs. The purpose of this study was …


Anomalous Magnetic Field Dependence Of The T1 Spin Lifetime In A Lightly Doped Gaas Sample, John S. Colton, M. E. Heeb, P. Schroeder, A. Stokes, L. R. Wienkes, A. S. Bracker May 2007

Anomalous Magnetic Field Dependence Of The T1 Spin Lifetime In A Lightly Doped Gaas Sample, John S. Colton, M. E. Heeb, P. Schroeder, A. Stokes, L. R. Wienkes, A. S. Bracker

Faculty Publications

The T1 spin lifetime of a lightly doped n-type GaAs sample has been measured via time-resolved polarization spectroscopy under a number of temperature and magnetic field conditions. Lifetimes up to 19 μs have been measured. The magnetic field dependence of T1 shows a nonmonotonic behavior, where the spin lifetime first increases, then decreases, then increases again with field. The initial increase in T1 is understood to be due to correlation between electrons localized on donors. The decrease in T1 is likely due to phonon-related spin-orbit relaxation. The final increase in T1 with B indicates a suppression of the spin-orbit relaxation …


Homogenization Of Forest Plant Communities And Weakening Of Species-Environment Relationships Via Agricultural Land Use, Mark Vellend, Kris Verheyen, Kathryn M. Flinn, Hans Jacquemyn, Annette Kolb, Hans Van Calster, George Peterken, Bente Jessen Graae, Jesse Bellemare, Olivier Honnay, Jörg Brunet, Monika Wulf, Fritz Gerhardt, Martin Hermy May 2007

Homogenization Of Forest Plant Communities And Weakening Of Species-Environment Relationships Via Agricultural Land Use, Mark Vellend, Kris Verheyen, Kathryn M. Flinn, Hans Jacquemyn, Annette Kolb, Hans Van Calster, George Peterken, Bente Jessen Graae, Jesse Bellemare, Olivier Honnay, Jörg Brunet, Monika Wulf, Fritz Gerhardt, Martin Hermy

Biological Sciences: Faculty Publications

Disturbance may cause community composition across sites to become more or less homogenous, depending on the importance of different processes involved in community assembly. In north-eastern North America and Europe local (alpha) diversity of forest plants is lower in forests growing on former agricultural fields (recent forests) than in older (ancient) forests, but little is known about the influence of land-use history on the degree of compositional differentiation among sites (beta diversity). Here we analyse data from 1446 sites in ancient and recent forests across 11 different landscapes in north-eastern North America and Europe to demonstrate decreases in beta diversity …


Analysis Of A Gluonic Penguin Decay With The Babar Detector, Gerald Conrad Ragghianti Jr. May 2007

Analysis Of A Gluonic Penguin Decay With The Babar Detector, Gerald Conrad Ragghianti Jr.

Masters Theses

This thesis presents a branching fraction analysis of the neutral B meson decay channel B → ϕK0s where the K0s decays to π0π0. The decay is dominated by gluonic penguin transitions, which have been very important for the main program of BABAR: the search for physics beyond the Standard Model. The decay channel has been established and is included in the CP analysis, which is sensitive to new physics. The data set consists of 227 million BB̅ pairs recorded by the BABAR detector at the Stanford Linear Accelerator Center. Sophisticated analysis techniques …


Limbustrack: Stable Eye-Tracking In Imperfect Light Conditions, Wayne Ryan May 2007

Limbustrack: Stable Eye-Tracking In Imperfect Light Conditions, Wayne Ryan

All Theses

We are aware of only one serious effort at development of a cheap, accurate, wearable eye tracker: the open source openEyes project. However, its method of ocular feature detection is such that it is prone to failure in variable lighting conditions. To address this deficiency, we have developed a cheap wearable eye tracker. At the heart of our development are novel techniques that allow operation under variable illumination.


Searching For H3+ In The Atmosphere Of The Exoplanet Hd 209458b, Matthew Troutman May 2007

Searching For H3+ In The Atmosphere Of The Exoplanet Hd 209458b, Matthew Troutman

All Theses

This thesis searches or the H3+ molecule in the atmosphere of HD 209458b. This exoplanet has been well studied since its initial discovery. H3+ is a diagnostic of the thermal regulation in the ionosphere of the exoplanet, and therefore is an advantageous molecule to test both atmospheric models and observational limits. Both models and observational limits need to be constrained as steps towards the ultimate goal of detecting biomarkers in the atmospheres of exoplanets. The exoplanet HD 209458b was observed during transit using PHOENIX on Gemini South in 2005.


A Linear-Time Algorithm For Broadcast Domination In A Tree, John Dabney May 2007

A Linear-Time Algorithm For Broadcast Domination In A Tree, John Dabney

All Theses

The broadcast domination problem is a variant of the classical minimum dominating set problem in which a transmitter of power p at vertex v is capable of dominating all vertices within distance p from v. Our goal is to assign a broadcast power f(v) to every vertex v in a graph such that the sum for all v over V of f(v) is minimized, and such that every vertex u with f(u) = 0 is within distance f(v) of some vertex v with f(v) > 0. The problem is solvable in polynomial time on a general graph, and Blair et al. …


The Role Of Fire In The Ecotone Between Upland Pine And Bottomland Hardwoods, Emily Duerr May 2007

The Role Of Fire In The Ecotone Between Upland Pine And Bottomland Hardwoods, Emily Duerr

All Theses

Southeastern coastal plain landscapes are recognized for sharp transitions between upland pine and bottomland hardwoods. The ecotone is characterized by distinct elevational and compositional changes and thought to be, in part, maintained by fire. The goal of this study was to investigate the role of fire in this ecotone by examining differences between burned and unburned ecotones as well as changes from pre- to post-burn conditions on the coastal plain of South Carolina.
Two locations were selected for this study, the Francis Marion National Forest (FMNF) and a nearby private plantation. Vegetation and environmental variables were collected in the summers …


Comparing Features Of Three-Dimensional Object Models Using Registration Based On Surface Curvature Signatures, Timothy David Gatzke, Cindy M. Grimm May 2007

Comparing Features Of Three-Dimensional Object Models Using Registration Based On Surface Curvature Signatures, Timothy David Gatzke, Cindy M. Grimm

All Computer Science and Engineering Research

This dissertation presents a technique for comparing local shape properties for similar three-dimensional objects represented by meshes. Our novel shape representation, the curvature map, describes shape as a function of surface curvature in the region around a point. A multi-pass approach is applied to the curvature map to detect features at different scales. The feature detection step does not require user input or parameter tuning. We use features ordered by strength, the similarity of pairs of features, and pruning based on geometric consistency to efficiently determine key corresponding locations on the objects. For genus zero objects, the corresponding locations are …


Bioengineering Of Protein Nanotubes And Protein Nanomaterial Composites, Thilak Kumara Mudalige May 2007

Bioengineering Of Protein Nanotubes And Protein Nanomaterial Composites, Thilak Kumara Mudalige

Dissertations

Flagella of Mesophilic bacteria such as E. coli are extremely ordered structures consisting of self-assemblies of flagellin 11-mers resulting in protein nanotubes of 2--3 nm inner diameter, 23 nm outer diameter, several microns in length and 5.4 nm separation between 11-mer segments. They are as a result attractive scaffolds and templates for the generation of uniform nanotubes and ordered array of nanoparticles. In this study fusion protein of bacterial flagellin (Fli C) and core thioredoxin (Trx), pFliTrx was used as peptide display on bacterial flagella. This was accomplished in the current research by introducing various peptide loops such as cysteine, …


Forgery Attack To An Asymptotically Optimal Traitor Tracing Scheme, Yongdong Wu, Feng Bao, Robert H. Deng May 2007

Forgery Attack To An Asymptotically Optimal Traitor Tracing Scheme, Yongdong Wu, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

In this paper, we present a forgery attack to a black-box traitor tracing scheme [2] called as CPP scheme. CPP scheme has efficient transmission rate and allows the tracer to identify a traitor with just one invalid ciphertext. Since the original CPP scheme is vulnerable to the multi-key attack, we improved CPP to thwart the attack. However, CPP is vulnerable to a fatal forgery attack. In the forgery attack, two traitors can collude to forge all valid decryption keys. The forged keys appear as perfect genuine keys, can decrypt all protected content, but are untraceable by the tracer. Fortunately, we …


Learning To Classify E-Mail, Irena Koprinska, Josiah Poon, James Clark, Jason Yuk Hin Chan May 2007

Learning To Classify E-Mail, Irena Koprinska, Josiah Poon, James Clark, Jason Yuk Hin Chan

Research Collection School Of Computing and Information Systems

In this paper we study supervised and semi-supervised classification of e-mails. We consider two tasks: filing e-mails into folders and spam e-mail filtering. Firstly, in a supervised learning setting, we investigate the use of random forest for automatic e-mail filing into folders and spam e-mail filtering. We show that random forest is a good choice for these tasks as it runs fast on large and high dimensional databases, is easy to tune and is highly accurate, outperforming popular algorithms such as decision trees, support vector machines and naive Bayes. We introduce a new accurate feature selector with linear time complexity. …


Gprune: A Constraint Pushing Framework For Graph Pattern Mining, Feida Zhu, Xifeng Yan, Jiawei Han, Philip S. Yu May 2007

Gprune: A Constraint Pushing Framework For Graph Pattern Mining, Feida Zhu, Xifeng Yan, Jiawei Han, Philip S. Yu

Research Collection School Of Computing and Information Systems

In graph mining applications, there has been an increasingly strong urge for imposing user-specified constraints on the mining results. However, unlike most traditional itemset constraints, structural constraints, such as density and diameter of a graph, are very hard to be pushed deep into the mining process. In this paper, we give the first comprehensive study on the pruning properties of both traditional and structural constraints aiming to reduce not only the pattern search space but the data search space as well. A new general framework, called gPrune, is proposed to incorporate all the constraints in such a way that they …


Kinetics And Mechanism Of Oxygen Delignification, Yun Ji May 2007

Kinetics And Mechanism Of Oxygen Delignification, Yun Ji

Electronic Theses and Dissertations

Considerable research has been conducted into the kinetics and selectivity of the oxygen delignification process to overcome limitation in its use. However most studies were performed in a batch reactor whereby the hydroxide and dissolved oxygen concentrations are changing during the reaction time in an effort to simulate tower performance in pulp mills. This makes it difficult to determine the reaction order of the different reactants in the rate expressions. Also the lignin content and cellulose degradation of the pulp are only established at the end of the experiment when the sample is removed from the batch reactor. To overcome …


Type Inference, Type Improvement, And Type Simplification In A Language With User-Defined Polymorphic Relational Operators, Lajos Pál Nagy May 2007

Type Inference, Type Improvement, And Type Simplification In A Language With User-Defined Polymorphic Relational Operators, Lajos Pál Nagy

Theses and Dissertations

The overarching goal of the current thesis is to pave the road towards a comprehensive solution to the decades old problem of integrating databases and programming languages. For this purpose, we propose a record calculus as an extension of an ML-style functional programming language core. In particular, we describe: 1. a set of polymorphic record operations that are expressive enough to define the operators of the relational algebra; 2. a type system together with a type inference algorithm, based on the theory of qualified types, to correctly capture the types of said polymorphic record operations; 3. an algorithm for checking …


Probabilistic Searching Using A Small Unmanned Aerial Vehicle, Steven R. Hansen, Timothy W. Mclain, Michael A. Goodrich May 2007

Probabilistic Searching Using A Small Unmanned Aerial Vehicle, Steven R. Hansen, Timothy W. Mclain, Michael A. Goodrich

Faculty Publications

Ground breaking concepts in optimal search theory were developed during World War II by the U.S. Navy. These concepts use an assumed detection model to calculate a detection probability rate and an optimal search allocation. Although this theory is useful in determining when and where search effort should be applied, it offers little guidance for the planning of search paths. This paper explains how search theory can be applied to path planning for an SUAV with a fixed CCD camera. Three search strategies are developed: greedy search, contour search, and composite search. In addition, the concepts of search efficiency and …


To Repair Or Not To Repair: Helping Ad Hoc Routing Protocols To Distinguish Mobility From Congestion, Qiuyi Duan, Roger Pack, Manoj Pandey, Lei Wang, Daniel Zappala May 2007

To Repair Or Not To Repair: Helping Ad Hoc Routing Protocols To Distinguish Mobility From Congestion, Qiuyi Duan, Roger Pack, Manoj Pandey, Lei Wang, Daniel Zappala

Faculty Publications

In this paper we consider the problem of distinguishing whether frame loss at the MAC layer has occurred due to mobility or congestion. Most ad hoc routing protocols make the faulty assumption that all frame loss means the destination node has moved, resulting in significant overhead as they initiate the repair of routes that have not been broken. We design a mobility detection algorithm, MDA, that properly detects the cause of a lost frame, then coordinates with the routing protocol so that it reacts properly. This approach dramatically reduces routing protocol overhead and significantly increases application throughput. We use a …


Virtual Walls: Protecting Digital Privacy In Pervasive Environments, Apu Kapadia, Tristan Henderson, Jeffrey Fielding, David Kotz May 2007

Virtual Walls: Protecting Digital Privacy In Pervasive Environments, Apu Kapadia, Tristan Henderson, Jeffrey Fielding, David Kotz

Dartmouth Scholarship

As pervasive environments become more commonplace, the privacy of users is placed at an increased risk. The numerous and diverse sensors in these environments can record contextual information about users, leading to users unwittingly leaving “digital footprints.” Users must therefore be allowed to control how their digital footprints are reported to third parties. While a significant amount of prior work has focused on location privacy, location is only one specific type of footprint, and we expect most users to be incapable of specifying fine-grained policies for a multitude of footprints. In this paper we present a policy language based on …


Testing The Bactericidal Ability Of A Polycationic Molecule To Design Self-Healing Surfaces, Shraddha Jayant Deodhar May 2007

Testing The Bactericidal Ability Of A Polycationic Molecule To Design Self-Healing Surfaces, Shraddha Jayant Deodhar

Masters Theses

The need for antimicrobial surfaces is obvious because of ever growing demand for healthy living, thus a material that can kill harmful microorganisms is of great interest. The idea discussed in this thesis is to combine the techniques of Photo Dynamic Therapy (PDT) and self sterile surfaces to design self-healing surfaces.

We modified one pyridine ring of Tetro-meso (N-methyl pyridyl) porphyrin (T4MPyP) to obtain 5-(4-carboxyphenyl)-10, 15, and 20-tris-(N-methyl-4-pyridlium) porphyrin. This modified porphyrin was reacted with Vinyl benzyl chloride polymer via a nucleophilic substitution reaction forming an ester linkage between polymer and porphyrin. The above molecule was then tested …


Thin Film Solar Cells Using Zno Nanowires, Organic Semiconductors And Quantum Dots, Kaitlyn Vansant May 2007

Thin Film Solar Cells Using Zno Nanowires, Organic Semiconductors And Quantum Dots, Kaitlyn Vansant

Dissertations and Theses

A thin film organic/ inorganic hybrid solar cell was fabricated by incorporating ZnO nanowires, n- and p-type organic semiconductors and inorganic quantum dots. The basic cell design involved the electrodeposition of ZnO nanowires grown on a substrate coated with a transparent conductive oxide. The ZnO nanowires were coated with a thin layer of an organic n-type material, followed by a deposition of inorganic quantum dots. A p-type polymer layer was subsequently deposited and the sample was then contacted with gold to form a quantum dot layer sandwiched between a p-n junction of organic conductive materials.

Various materials and processing methods …


Density Functional Theory And Phase Shifts, Anthony G. Wald May 2007

Density Functional Theory And Phase Shifts, Anthony G. Wald

Masters Theses

This thesis describes how phase shifts of the nucleon-nucleon system may be utilized to determine the nuclear Density Functional (DF). The nucleonnucleon interaction, hereafter denoted by N-N interaction, is input to quantum many-body calculations. However, this approach complicates the determination of physical quantities such as the calculation of spectroscopic information and of energy levels. A major advantage in employing the approach via Density Functional Theory (DFT) to this system is that the N-N problem can be considered to be a non-interacting, single-particle system.

In order to use DFT one must know the density functional, and this is typically the most …


The Reduction Of Ytterbium (Iii) To Ytterbium (Ii), Amanda S. Jones May 2007

The Reduction Of Ytterbium (Iii) To Ytterbium (Ii), Amanda S. Jones

Masters Theses

If Yb(III) could be reduced to the highly unstable Yb(II), and temporarily stabilized, the separation of Yb from the other lanthanide elements could be facilitated. This facilitation would be based upon the considerably different chemistry of Yb(II) from the trivalent forms of all other lanthanides.

The reduction of Yb(III) to Yb(II) using Mg was attempted in various media. The effects of the media, precipitating agent, and environment were examined. The best experimental conditions for the reduction of Yb(III) to Yb(II) and the subsequent precipitation of YbSO4 were found to be the addition of ~0.35 g YbCl38H2O in 1.5 mL 3:1 …


Adaptive Treatment Of Van Der Waals Interactions In Empirical Bond-Order Potentials With Application To Junction Formation In Carbon Nanotubes, Aibing Liu May 2007

Adaptive Treatment Of Van Der Waals Interactions In Empirical Bond-Order Potentials With Application To Junction Formation In Carbon Nanotubes, Aibing Liu

All Dissertations

Molecular dynamics (MD) simulation of reactive condensed-phase hydrocarbon systems is a challenging research area. The AIREBO potential is particularly useful in this area because it can simulate bond breaking and bond forming during chemical reactions. It also includes non-bonded interactions for systems with significant intermolecular interactions.

The first part of this dissertation describes a method to adaptively incorporate van der Waals interaction of carbon atoms into the AIREBO force field. In bond-order potentials, the covalent bonding interactions adapt to the local chemical environment, allowing bonded interactions to change in response to local chemical changes.
Non-bonded interactions should adjust to their …


Carbon Dioxide Capture: Using Activated Carbon From Chicken Waste, Yan Zhang May 2007

Carbon Dioxide Capture: Using Activated Carbon From Chicken Waste, Yan Zhang

Masters Theses & Specialist Projects

Carbon Dioxide (CO2) emission from hydrocarbon fuel combustion is becoming a serious concern because it is the main contributor to greenhouse gas which causes global warming. Activated carbon sorbents have been used widely in various gas-phase and/or liquid-phase separation. Currently activated carbon (AC) is being investigated and developed for CO2 capture. Chicken waste, which is produced in large quantity in U.S., is currently disposed as waste. However, it may have a large benefit to turn chicken waste into useful activated carbon. In this research, a series of activated carbon have been generated from chicken waste and coal in the lab …


Bounds On K-Regular Ramanujan Graphs And Separator Theorems, James Skees May 2007

Bounds On K-Regular Ramanujan Graphs And Separator Theorems, James Skees

Masters Theses & Specialist Projects

Expander graphs are a family of graphs that are highly connected. Finding explicit examples of expander graphs which are also sparse is a difficult problem. The best type of expander graph in a. certain sense is a Ramanujan graph. Families of graphs that have separator theorems fail to be Ramanujan if the vertex set gets sufficiently large. Using separator theorems to get an estimate on the expanding constant of graphs, we get bounds 011 the number of vertices for such fc-regular graphs in order for them to be Ramanujan.