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Physical Sciences and Mathematics Commons™

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2003

University of Richmond

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Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Determining Error Bars In Measurements Of Ultrashort Laser Pulses, Ziyang Wang, Erik Zeek, Rick Trebino, Paul Kvam Nov 2003

Determining Error Bars In Measurements Of Ultrashort Laser Pulses, Ziyang Wang, Erik Zeek, Rick Trebino, Paul Kvam

Department of Math & Statistics Faculty Publications

We present a simple and automatic method for determining the uncertainty in the retrieved intensity and phase versus time (and frequency) due to noise in a frequency-resolved optical-gating trace, independent of noise source. It uses the ‘‘bootstrap’’ statistical method and also yields an automated method for phase blanking (omitting the phase when the intensity is too low to determine it).

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Distance-Dependent Electron Hopping Conductivity And Nanoscale Lithography Of Chemically-Linked Gold Monolayer Protected Cluster Films, Francis P. Zamborini, Laura E. Smart, Michael C. Leopold, Royce W. Murray Oct 2003

Distance-Dependent Electron Hopping Conductivity And Nanoscale Lithography Of Chemically-Linked Gold Monolayer Protected Cluster Films, Francis P. Zamborini, Laura E. Smart, Michael C. Leopold, Royce W. Murray

Chemistry Faculty Publications

Films of monolayer protected Au clusters (MPCs) with mixed alkanethiolate and ω-carboxylate alkanethiolate monolayers, linked together by carboxylate–Cu2+–carboxylate bridges, exhibit average edge-to-edge cluster spacings that vary with the numbers of methylene segments in the alkanethiolate ligand as determined by a combined atomic force microscopy (AFM)/UV-Vis spectroscopy method. The electronic conductivity (σEL) of dry films is exponentially dependent on the cluster spacing, consistent with electron tunneling through the alkanethiolate chains and non-bonded contacts between those chains on individual, adjacent MPCs. The calculated electronic coupling factor (β) for tunneling between MPCs is 1.2 Å−1, which is similar to …

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Ranked Set Sampling Based On Binary Water Quality Data With Covariates, Paul Kvam Sep 2003

Ranked Set Sampling Based On Binary Water Quality Data With Covariates, Paul Kvam

Department of Math & Statistics Faculty Publications

A ranked set sample (RSS) is composed of independent order statistics, formed by collecting and ordering independent subsamples, then measuring only one item from each subsample. If the cost of sampling is dominated by data measurement rather than collection or ranking, the RSS technique is known to be superior to ordinary sampling. Experiments based on binary data are not designed to exploit the advantages of ranked set sampling because categorical data typically are as easily measured as ranked, making RSS methods impractical. However, in some environmental and biological studies, the success probability of a bivariate outcome is related to one …

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Growth, Conductivity, And Vapor Response Properties Of Metal Ion-Carboxylate Linked Nanoparticle Films, Michael C. Leopold, Robert L. Donkers, Dimitra Georganopoulou, Megan Fisher, Francis P. Zamborini, Royce W. Murray Aug 2003

Growth, Conductivity, And Vapor Response Properties Of Metal Ion-Carboxylate Linked Nanoparticle Films, Michael C. Leopold, Robert L. Donkers, Dimitra Georganopoulou, Megan Fisher, Francis P. Zamborini, Royce W. Murray

Chemistry Faculty Publications

Nanoparticles of metals (Au, Ag, Pd, alloys) in the size range 1–3 nm diameter can be stabilized against aggregation of the metal particles by coating the metal surface with a dense monolayer of ligands (thiolates). The stabilization makes it possible to analytically define the nanoparticle composition (for example, Au140(hexanethiolate)53, I) and to elaborate the chemical functionality of the protecting monolayer (for example, Au140(C6)35(MUA)18, II, where C6 = hexanethiolate and MUA = mercaptoundecanoic acid). Network polymer films (IIfilm) on interdigitated array electrodes can be prepared from II, based on cation coordination (i.e., Cu2+, Zn2+, Ag+, methyl viologen) by the …

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Intuitive Black-Scholes Option Pricing With A Simple Table, Tom Arnold, Terry D. Nixon, Richard L. Shockley Jr. Apr 2003

Intuitive Black-Scholes Option Pricing With A Simple Table, Tom Arnold, Terry D. Nixon, Richard L. Shockley Jr.

Finance Faculty Publications

The Black-Scholes option pricing model (1973) can be intimidating for the novice. By rearranging and combining some of the variables, one can reduce the number of parameters in the valuation problem from five to two: 1) the option's moneyness ratio and 2) its time-adjusted volatility. This allows the computationally complex Black-Scholes formula to be collapsed into an easy-to-use table similar to those in some popular textbooks. The tabular approach provides an excellent tool for building intuition about the comparative statics in the Black-Scholes equation. Further, the pricing table can be used to price options on dividend-paying stocks, commodities, foreign exchange …

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Visualizing The Stochastic Calculus Of Option Pricing With Excel And Vba, Tom Arnold, Stephen C. Henry Apr 2003

Visualizing The Stochastic Calculus Of Option Pricing With Excel And Vba, Tom Arnold, Stephen C. Henry

Finance Faculty Publications

Stochastic calculus, part calculus and part statistics, is an integral part of option pricing that can be intimidating. By developing the statistical nature of stochastic processes and introducing Monte Carlo simulation using Microsoft Excel, this paper develops a visualization of how stochastic processes are evaluated using Ito's lemma and integral calculus. Ultimately, the Black-Scholes (1973) option pricing equation is the natural result.

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Creating And Modifying Dynamic Animation Sequences Using The Tgt_Toolkit, Ross Gore Mar 2003

Creating And Modifying Dynamic Animation Sequences Using The Tgt_Toolkit, Ross Gore

Department of Math & Statistics Technical Report Series

Creating and modifying the dynamic animation sequences within the TGT_Toolkit is not for the faint of heart. This report contains advice, guidelines and refers to an example of how I went about constructing the dynamic animation sequences within the Linked Lists Tutorial. I have identified three major areas of that seem to be common to all dynamic animation sequences, but distinct from simply extending TGT_Slide as most other slides do; these areas are: dynamically creating animation configurations, providing "undo" and slide saving functionality and sequencing saved slides once they are properly configured. In these areas "slide saving" and "saved slides" …

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E/B Decomposition Of Finite Pixelized Cmb Maps, Emory F. Bunn, Matias Zaldarriaga, Max Tegmark, Angelica De Oliveira-Costa Jan 2003

E/B Decomposition Of Finite Pixelized Cmb Maps, Emory F. Bunn, Matias Zaldarriaga, Max Tegmark, Angelica De Oliveira-Costa

Physics Faculty Publications

Separation of the E and B components of a microwave background polarization map or a weak lensing map is an essential step in extracting science from it, but when the map covers only part of the sky and/or is pixelized, this decomposition cannot be done perfectly. We present a method for decomposing an arbitrary sky map into a sum of three orthogonal components that we term ‘‘pure E,’’ ‘‘pure B,’’ and ‘‘ambiguous.’’ The fluctuations in the pure E and B maps are due only to the E and B power spectra, respectively, whereas the source of those in …

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A Contrast-Based Neural Control System For Ant Navigation, Joanna R. Wares, Predrag-Peter Ilich, Daniel P. Dougherty Jan 2003

A Contrast-Based Neural Control System For Ant Navigation, Joanna R. Wares, Predrag-Peter Ilich, Daniel P. Dougherty

Department of Math & Statistics Faculty Publications

A mathematical model for a neural control system of ant locomotion was developed. Contrast-based detectors using excitation and inhibition were tuned to specific contrast orientations. A control system using multiple orientation contrast detectors was then developed and optimized for a model ant, which could move via a biased random walk. The system allowed sufficient control to guide the ant through various mazes.

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Urer, The Transcriptional Activator Of The Proteus Mirabilis Urease Gene Cluster, Is Required For Urease Activity And Virulence In Experimental Urinary Tract Infections, Jonathan D. Dattelbaum, C. Virginia Lockatell, David E. Johnson, Harry L.T. Mobley Jan 2003

Urer, The Transcriptional Activator Of The Proteus Mirabilis Urease Gene Cluster, Is Required For Urease Activity And Virulence In Experimental Urinary Tract Infections, Jonathan D. Dattelbaum, C. Virginia Lockatell, David E. Johnson, Harry L.T. Mobley

Chemistry Faculty Publications

Proteus mirabilis, a cause of complicated urinary tract infection, produces urease, an essential virulence factor for this species. UreR, a member of the AraC/XylS family of transcriptional regulators, positively activates expression of the ure gene cluster in the presence of urea. To specifically evaluate the contribution of UreR to urease activity and virulence in the urinary tract, a ureR mutation was introduced into P. mirabilis HI4320 by homologous recombination. The isogenic ureR::aphA mutant, deficient in UreR production, lacked measurable urease activity. Expression was not detected in the UreR-deficient strain by Western blotting with monoclonal antibodies raised against UreD. Urease …

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Uso De La Tierra En La Zona De Influencia De La Provincia Del Purus, David S. Salisbury, Chris Fagan Jan 2003

Uso De La Tierra En La Zona De Influencia De La Provincia Del Purus, David S. Salisbury, Chris Fagan

Geography and the Environment Faculty Publications

El objetivo preliminar de este estudio fue determinar las características del uso de tierra de cinco comunidades indígenas representadas por cuatro grupos culturales dentro de la zona de influencia nordeste. Un segundo objetivo fue el de averiguar cómo y en qué grado las fuerzas económicas y culturales están influenciando las decisiones con respecto al uso de la tierra. Los resultados de este estudio son preliminares, pero esperamos que la información sea de alguna utilidad para los administradores de esta área protegida.

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