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Full-Text Articles in Physical Sciences and Mathematics

An Omnibus Nonparametric Test Of Equality In Distribution For Unknown Functions, Alexander Luedtke, Marco Carone, Mark Van Der Laan Oct 2015

An Omnibus Nonparametric Test Of Equality In Distribution For Unknown Functions, Alexander Luedtke, Marco Carone, Mark Van Der Laan

Alex Luedtke

We present a novel family of nonparametric omnibus tests of the hypothesis that two unknown but estimable functions are equal in distribution when applied to the observed data structure. We developed these tests, which represent a generalization of the maximum mean discrepancy tests described in Gretton et al. [2006], using recent developments from the higher-order pathwise differentiability literature. Despite their complex derivation, the associated test statistics can be expressed rather simply as U-statistics. We study the asymptotic behavior of the proposed tests under the null hypothesis and under both fixed and local alternatives. We provide examples to which our tests …


Simultaneous Determination Of Pramoxine Hcl And Benzalkonium Chloride In Wound Care Solutions By Hplc, Panagiotis Tavlarakis, Jonine Greyling, Nicholas Snow Jun 2015

Simultaneous Determination Of Pramoxine Hcl And Benzalkonium Chloride In Wound Care Solutions By Hplc, Panagiotis Tavlarakis, Jonine Greyling, Nicholas Snow

Nicholas A Snow

No abstract provided.


Teaching College General Chemistry: Techniques Designed To Communicate A Conceptual Framework, Ronald Duchovic Oct 2014

Teaching College General Chemistry: Techniques Designed To Communicate A Conceptual Framework, Ronald Duchovic

Ronald J. Duchovic

General chemistry at the college level is often perceived as a major hurdle by typical undergraduates. Both Freshmen and more advanced students undertake courses in general chemistry either ill-prepared or convinced that the subject matter is beyond their comprehension. With the exception of potential chemistry majors, the vast majority of general chemistry students enter the class simply to satisfy a graduation requirement of their degree program. Consequently, instructors must both communicate an understanding of the subject matter and overcome major barriers to the learning process itself. This paper discusses two techniques which have been utilized for five semesters in general …


Potlib 2001: A Potential Energy Surface Library For Chemical Systems, Ronald Duchovic, Y Volobuev, G Lynch, D Truhlar, T Allison, A Wagner, B Garret, J Corchado Oct 2014

Potlib 2001: A Potential Energy Surface Library For Chemical Systems, Ronald Duchovic, Y Volobuev, G Lynch, D Truhlar, T Allison, A Wagner, B Garret, J Corchado

Ronald J. Duchovic

POTLIB 2001 is a computer program library of global chemical potential energy surface (PES) functions (91 functions in version 1.0) along with test data, a suite of utility programs, and a convenient user interface. The PES programs are written in ANSI standard FORTRAN77 and can be used to determine the Born–Oppenheimer potential energy of chemical systems as a function of the internal coordinates. The accompanying test data allow users to verify local implementations of this library. Finally, the utility programs permit use of this library in conjunction with a variety of chemical dynamics and chemical kinetics computer codes. Interface routines …


Thermal Rate Constants For H + Ch3  Ch4 Recombination. Ii. Comparison Of Experiment And Canonical Variational Transition State Theory, W Hase, S Mondro, Ronald Duchovic, D Hirst Oct 2014

Thermal Rate Constants For H + Ch3  Ch4 Recombination. Ii. Comparison Of Experiment And Canonical Variational Transition State Theory, W Hase, S Mondro, Ronald Duchovic, D Hirst

Ronald J. Duchovic

Canonical variational transition state theory is used to calculate bimolecular rate constants for H + CH, and D + CH, recombination. The calculations are performed on an analytic potential energy surface derived from recent ab initio calculations. Rate constants calculated for this surface are in very good agreement with the experimental values. The H(D)- - -CH3 transitional rocking modes are treated as quantum harmonic oscillators or classical hindered rotors in the calculations. These two treatments give rate constants which agree to within 15%. The variational transition states become tighter as the temperature is increased.


An Application Of Conventional Transition State `Theory To Compute High--Pressure Limit Thermal Rate Coefficients For The Reaction: H(D) + O2  H(D)O2*  Oh(D) + O, Ronald Duchovic, J Pettigrew Oct 2014

An Application Of Conventional Transition State `Theory To Compute High--Pressure Limit Thermal Rate Coefficients For The Reaction: H(D) + O2  H(D)O2*  Oh(D) + O, Ronald Duchovic, J Pettigrew

Ronald J. Duchovic

Several ab initio studies have focused on the minimum energy path region of the hydroperoxyl potential energy surface (PES) (J. Chem. Phys. 1988, 88, 6273) and the saddle point region for H-atom exchange via a T-shaped HO2 complex (J. Chem. Phys. 1989, 91, 2373). Further, the results of additional calculations (J. Chem. Phys. 1991, 94, 7068) have been reported which, when combined with the earlier studies, provide a global description (but not an analytic representation) of the PES for this reaction. In this work, information at the stationary points of the ab initio PES is used within the framework of …


The Evolution Of Billfish, Andrew Blitman Dec 2013

The Evolution Of Billfish, Andrew Blitman

Andrew Blitman

No abstract provided.


Laminar Flow Of Two Miscible Fluids In A Simple Network, Casey Karst, Brian Storey, John Geddes Mar 2013

Laminar Flow Of Two Miscible Fluids In A Simple Network, Casey Karst, Brian Storey, John Geddes

John B. Geddes

When a fluid comprised of multiple phases or constituents flows through a network, nonlinear phenomena such as multiple stable equilibrium states and spontaneous oscillations can occur. Such behavior has been observed or predicted in a number of networks including the flow of blood through the microcirculation, the flow of picoliter droplets through microfluidic devices, the flow of magma through lava tubes, and two-phase flow in refrigeration systems. While the existence of nonlinear phenomena in a network with many inter-connections containing fluids with complex rheology may seem unsurprising, this paper demonstrates that even simple networks containing Newtonian fluids in laminar flow …


Effects Of Electrostatic Correlations On Electrokinetic Phenomena, Brian Storey, Martin Bazant Oct 2012

Effects Of Electrostatic Correlations On Electrokinetic Phenomena, Brian Storey, Martin Bazant

Brian Storey

The classical theory of electrokinetic phenomena is based on the mean-field approximation that the electric field acting on an individual ion is self-consistently determined by the local mean charge density. This paper considers situations, such as concentrated electrolytes, multivalent electrolytes, or solvent-free ionic liquids, where the mean-field approximation breaks down. A fourth-order modified Poisson equation is developed that captures the essential features in a simple continuum framework. The model is derived as a gradient approximation for nonlocal electrostatics of interacting effective charges, where the permittivity becomes a differential operator, scaled by a correlation length. The theory is able to capture …


The Minimum Span Of L(2,1)-Labelings Of Certain Generalized Petersen Graphs, Sarah Adams, Jonathan Cass, Matthew Tesch, Denise Troxell, Cody Wheeland Jul 2012

The Minimum Span Of L(2,1)-Labelings Of Certain Generalized Petersen Graphs, Sarah Adams, Jonathan Cass, Matthew Tesch, Denise Troxell, Cody Wheeland

Sarah Spence Adams

In the classical channel assignment problem, transmitters that are sufficiently close together are assigned transmission frequencies that differ by prescribed amounts, with the goal of minimizing the span of frequencies required. This problem can be modeled through the use of an L(2,1)-labeling, which is a function f from the vertex set of a graph G to the non-negative integers such that |f(x)–f(y)|≥ 2 if xand y are adjacent vertices and |f(x)–f(y)|≥1 if xand y are at distance two. The goal is to …


On An Orthogonal Space-Time-Polarization Block Code, Beata Wysocki, Tadeusz Wysocki, Sarah Adams Jul 2012

On An Orthogonal Space-Time-Polarization Block Code, Beata Wysocki, Tadeusz Wysocki, Sarah Adams

Sarah Spence Adams

Over the past several years, diversity methods such as space, time, and polarization diversity have been successfully implemented in wireless communications systems. Orthogonal space-time block codes efficiently combine space and time diversity, and they have been studied in detail. Polarization diversity has also been studied, however it is usually considered in a simple concatenation with other coding methods. In this paper, an efficient method for incorporating polarization diversity with space and time diversity is studied. The simple yet highly efficient technique is based on extending orthogonal space-time block codes into the quaternion domain and utilizing a description of the dual-polarized …


Novel Constructions Of Improved Square Complex Orthogonal Designs For Eight Transmit Antennas, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah Adams Jul 2012

Novel Constructions Of Improved Square Complex Orthogonal Designs For Eight Transmit Antennas, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah Adams

Sarah Spence Adams

Constructions of square, maximum rate complex orthogonal space-time block codes (CO STBCs) are well known, however codes constructed via the known methods include numerous zeros, which impede their practical implementation. By modifying the Williamson and Wallis-Whiteman arrays to apply to complex matrices, we propose two methods of construction of square, order-4n CO STBCs from square, order-n codes which satisfy certain properties. Applying the proposed methods, we construct square, maximum rate, order-8 CO STBCs with no zeros, such that the transmitted symbols are equally dispersed through transmit antennas. Those codes, referred to as the improved square CO STBCs, have the advantages …


Multilevel And Multidimensional Hadamard Matrices, Sarah Adams, Matthew Crawford, Caitlin Greeley, Bryce Lee, Mathav Murugan Jul 2012

Multilevel And Multidimensional Hadamard Matrices, Sarah Adams, Matthew Crawford, Caitlin Greeley, Bryce Lee, Mathav Murugan

Sarah Spence Adams

Multilevel Hadamard matrices (MHMs), whose entries are integers as opposed to the traditional restriction to {±1}, were introduced by Trinh, Fan, and Gabidulin in 2006 as a way to construct multilevel zero-correlation zone sequences, which have been studied for use in approximately synchronized code division multiple access systems. We answer the open question concerning the maximum number of distinct elements permissible in an order n MHM by proving the existence of an order n MHM with n elements of distinct absolute value for all n. We also define multidimensional MHMs and prove an analogous existence result.


An Extension Of The Channel-Assignment Problem: L(2, 1)-Labelings Of Generalized Petersen Graphs, Sarah Adams, Jonathan Cass, Denise Troxell Jul 2012

An Extension Of The Channel-Assignment Problem: L(2, 1)-Labelings Of Generalized Petersen Graphs, Sarah Adams, Jonathan Cass, Denise Troxell

Sarah Spence Adams

The channel-assignment problem involves assigning frequencies represented by nonnegative integers to radio transmitters such that transmitters in close proximity receive frequencies that are sufficiently far apart to avoid interference. In one of its variations, the problem is commonly quantified as follows: transmitters separated bythe smallest unit distance must be assigned frequencies that are at least two apart and transmitters separated by twice the smallest unit distance must be assigned frequencies that are at least one apart. Naturally, thischannel-assignment problem can be modeled with vertex labelings of graphs. An L(2, 1)-labeling of a graph G is a function f from the …


Identifying High-Dimension Subspace Subcodes Of Reed-Solomon Codes, Sarah Adams Jul 2012

Identifying High-Dimension Subspace Subcodes Of Reed-Solomon Codes, Sarah Adams

Sarah Spence Adams

Subspace subcodes of Reed-Solomon (SSRS) codes were introduced by Hattori, McEliece, Solomo, and Lin in the mid-1990s. These authors found a complicated dimension formula and a simple, tight lower bound on thedimension of SSRS codes over F2m. We prove a conjecture of Hattori concerning how to identify subspaces that can be used to build SSRS codes whose dimension exceeds this lower bound.


Quaternion Orthogonal Designs From Complex Companion Designs, Sarah Adams, Jennifer Seberry, Nathaniel Karst, Jonathan Pollack, Tadeusz Wysocki Jul 2012

Quaternion Orthogonal Designs From Complex Companion Designs, Sarah Adams, Jennifer Seberry, Nathaniel Karst, Jonathan Pollack, Tadeusz Wysocki

Sarah Spence Adams

The success of applying generalized complex orthogonal designs as space–time block codes recently motivated the definition of quaternion orthogonal designs as potential building blocks for space–time-polarization block codes. This paper offers techniques for constructing quaternion orthogonal designs via combinations of specially chosen complex orthogonal designs. One technique is used to build quaternion orthogonal designs on complex variables for any even number of columns. A second related technique is applied to maximum rate complex orthogonal designs to generate an infinite family of quaternion orthogonal designs on complex variables such that the resulting designs have no zero entries. This second technique is …


The Final Case Of The Decoding Delay Problem For Maximum Rate Complex Orthogonal Designs, Sarah Adams, Nathaniel Karst, Mathav Murugan Jul 2012

The Final Case Of The Decoding Delay Problem For Maximum Rate Complex Orthogonal Designs, Sarah Adams, Nathaniel Karst, Mathav Murugan

Sarah Spence Adams

Complex orthogonal space-time block codes (COSTBCs) based on generalized complex orthogonal designs (CODs) have been successfully implemented in wireless systems with multiple transmit antennas and single or multiple receive antennas. It has been shown that for a maximum rate COD with 2m-1 or 2m columns, a lower bound on decoding delay is (m-1 2m) and this delay is achievable when the number of columns is congruent to 0, 1 , or 3 modulo 4. In this paper, the final case is addressed, and it is shown that when the number of columns is congruent to 2 modulo 4, the lower …


On The Hole Index Of L(2,1)-Labelings Of R-Regular Graphs, Sarah Adams, Matthew Tesch, Denise Troxell, Bradford Westgate, Cody Wheeland Jul 2012

On The Hole Index Of L(2,1)-Labelings Of R-Regular Graphs, Sarah Adams, Matthew Tesch, Denise Troxell, Bradford Westgate, Cody Wheeland

Sarah Spence Adams

An L(2,1)-labeling of a graph G is an assignment of nonnegative integers to the vertices of G so that adjacent vertices get labels at least distance two apart and vertices at distance two get distinct labels. A hole is an unused integer within the range of integers used by the labeling. The lambda number of a graphG, denoted λ(G), is the minimum span taken over all L(2,1)-labelings of G. The hole index of a graph G, denoted ρ(G), is the minimum number of holes taken over all L(2,1)-labelings with span exactly λ(G). Georges and Mauro [On the structure of graphs …


The Minimum Decoding Delay Of Maximum Rate Complex Orthogonal Space–Time Block Codes, Sarah Adams, Nathaniel Karst, Jonathan Pollack Jul 2012

The Minimum Decoding Delay Of Maximum Rate Complex Orthogonal Space–Time Block Codes, Sarah Adams, Nathaniel Karst, Jonathan Pollack

Sarah Spence Adams

The growing demand for efficient wireless transmissions over fading channels motivated the development ofspace-time block codes. Space-time block codes built from generalized complex orthogonal designs are particularly attractive because the orthogonality permits a simple decoupled maximum-likelihood decodingalgorithm while achieving full transmit diversity. The two main research problems for these complex orthogonalspace-time block codes (COSTBCs) have been to determine for any number of antennas the maximum rate andthe minimum decoding delay for a maximum rate code. The maximum rate for COSTBCs was determined by Liang in 2003. This paper addresses the second fundamental problem by providing a tight lower bound on …


Trajectory Generation In High-Speed, High-Precision Micromilling Using Subdivision Surfaces, Athulan Vijayaraghavan, Angela Sodemann, Aaron Hoover, J. Mayor, David Dornfeld Jul 2012

Trajectory Generation In High-Speed, High-Precision Micromilling Using Subdivision Surfaces, Athulan Vijayaraghavan, Angela Sodemann, Aaron Hoover, J. Mayor, David Dornfeld

Aaron M. Hoover

Motion control in high-speed micromilling processes requires fast, accurate following of a specified curvilinear path. The accuracy with which the path can be followed is determined by the speed at which individual trajectories can be generated and sent to the control system. The time required to generate the trajectory is dependent on the representations used for the curvilinear trajectory path. In this study, we introduce the use of subdivision curves as a method for generating high-speed micromilling trajectories. Subdivision curves are discretized curves which are specified as a series of recursive refinements of a coarse mesh. By applying these recursive …


Synthesis Of Static And Dynamic Multiple-Input Translinear Element Networks, Bradley Minch Jul 2012

Synthesis Of Static And Dynamic Multiple-Input Translinear Element Networks, Bradley Minch

Bradley Minch

In this paper, we discuss the process of synthesizing static and dynamic multiple-input translinear element (MITE) networks systematically from high-level descriptions given in the time domain, in terms of static polynomial constraints and algebraic differential equations. We provide several examples, illustrating the process for both static and dynamic system constraints. Although our examples will all involve MITE networks, the early steps of the synthesis process are equally applicable to the synthesis of static and dynamic translinear-loop circuits.


Incommensurate Spin Fluctuations In High-Transition Temperature Superconductors, Barrett Wells, Young Lee, Marc Kastner, Rebecca Christianson, Robert Birgeneau, Kazuyoshi Yamada, Yasuo Endoh, Gen Shirane Jul 2012

Incommensurate Spin Fluctuations In High-Transition Temperature Superconductors, Barrett Wells, Young Lee, Marc Kastner, Rebecca Christianson, Robert Birgeneau, Kazuyoshi Yamada, Yasuo Endoh, Gen Shirane

Rebecca J. Christianson

Neutron scattering experiments have revealed a fascinating interplay between the hole doping, the spin fluctuations, and the superconductivity of the cuprate superconductors. Recently, electrochemical techniques have been used to produce large single crystals of La2CuO4+ y, which has mobile oxygen dopants. Staging behavior of the excess oxygen has been demonstrated, and the low-energy spin fluctuations in stage 6 La2CuO4+ y have been measured. The spin fluctuations are incommensurate with the lattice and have spatial, energy, and temperature dependencies very much like those in La2− xSrxCuO4, with similar high transition temperature. This establishes the universality of the incommensurate spin fluctuations among …


Structures And Incommensurate Spin Excitations In Excess Oxygen-Doped La2cuo4+Y, Robert Birgeneau, Rebecca Christianson, Yasuo Endoh, Marc Kastner, Young Lee, Gen Shirane, Barrett Wells, Kazuyoshi Yamada Jul 2012

Structures And Incommensurate Spin Excitations In Excess Oxygen-Doped La2cuo4+Y, Robert Birgeneau, Rebecca Christianson, Yasuo Endoh, Marc Kastner, Young Lee, Gen Shirane, Barrett Wells, Kazuyoshi Yamada

Rebecca J. Christianson

Over the past decade, we have studied in detail the low-energy spin fluctuations in :a2−xSrxCuO4 for xbetween 0 and 0.18. Our experiments, as well as those by others, have revealed a fascinating interplay between the hole doping, the static and dynamic spin fluctuations and superconductivity. Recently, using electrochemical techniques, we have learned how to produce large single crystals of La2CuO4+y which are relatively homogenous. In this latter system, the dopants are characterized by annealed rather than quenched disorder. Furthermore, we have demonstrated staging behavior of the excess oxygen analogous to staging in intercalated graphite. We have now succeeded in carrying …


A Reduced Model Of Cavitation Physics For Use In Sonochemistry, Brian Storey, Andrew Szeri Jul 2012

A Reduced Model Of Cavitation Physics For Use In Sonochemistry, Brian Storey, Andrew Szeri

Brian Storey

Sonochemistry involves focusing acoustic energy through cavitation bubbles to increase chemical activity. The violent bubble collapses lead to temperatures of several thousand kelvin, which drive chemical reactions. In previous work, we gave a detailed computational model of a single bubble collapse, taking into account phase change, mass diffusion, heat diffusion and chemical reactions. All of these phenomena are important in determining the conditions at collapse. The present work involves development of a much simpler model that includes all the physics relevant to the determination of the reaction products. Comparisons with the more detailed computations are made; the reduced model is …


Water Vapour, Sonoluminescence And Sonochemistry, Brian Storey, Andrew Szeri Jul 2012

Water Vapour, Sonoluminescence And Sonochemistry, Brian Storey, Andrew Szeri

Brian Storey

Sonoluminescence is the production of light from acoustically forced bubbles; sonochemistry is a related chemical processing technique. The two phenomena share a sensitive dependence on the liquid phase. The present work is an investigation of the fate and consequences of water vapour in the interior of strongly forced argon micro–bubbles. Due to the extreme nonlinearity of the volume oscillations, excess water vapour is trapped in the bubble during a rapid inertial collapse. Water vapour is prevented from exiting by relatively slow diffusion and non–equilibrium condensation at the bubble wall. By reducing the compression heating of the mixture and through primarily …


Temperature Distribution In An Oscillatory Flow With A Sinusoidal Wall Temperature, Eduardo Ramos, Brian Storey, Fernando Sierra, Raul Zuniga, Andriy Avramenko Jul 2012

Temperature Distribution In An Oscillatory Flow With A Sinusoidal Wall Temperature, Eduardo Ramos, Brian Storey, Fernando Sierra, Raul Zuniga, Andriy Avramenko

Brian Storey

The temperature field generated by an oscillatory boundary layer flow in the presence of a wall with a sinusoidal temperature distribution is analyzed. A linear perturbation method is used to find closed form analytical solutions for the temperature field when the amplitude of the velocity oscillation is small. The analytical solutions only consider long-time behavior when the temperature fields oscillate with the frequency of the flow. The structure of the equation that governs the temperature correction due to convection is similar to that of diffusive waves with the solution consisting of traveling or standing waves. The temperature distribution is also …


Nonextensive Statistical Mechanics For Rotating Quasi-Two-Dimensional Turbulence, Sunghwan Jung, Brian Storey, Julien Aubert, Harry Swinney Jul 2012

Nonextensive Statistical Mechanics For Rotating Quasi-Two-Dimensional Turbulence, Sunghwan Jung, Brian Storey, Julien Aubert, Harry Swinney

Brian Storey

We have conducted experiments on an asymmetrically forced quasi-two-dimensional turbulent flow in a rapidly rotating annulus. Assuming conservation of potential enstrophy and energy, we maximize a nonextensive entropy function to obtain the azimuthally averaged vorticity as a function of radial position. The predicted vorticity profile is in good accord with the observations. A nonextensive formalism is appropriate because long-range correlations between small-scale vortices give rise to large coherent structures in the turbulence. We also derive probability distribution functions for the vorticity from both extensive and nonextensive entropies, and we find that the prediction from nonextensive theory is in better accord …


A Parameterized Stereo Vision Core For Fpgas, Mark Chang, Stephen Longfield Jul 2012

A Parameterized Stereo Vision Core For Fpgas, Mark Chang, Stephen Longfield

Mark L. Chang

We present a parameterized stereo vision core suitable for a wide range of FPGA targets and stereo vision applications. By enabling easy tuning of algorithm parameters, our system allows for rapid exploration of the design space and simpler implementation of high-performance stereo vision systems. This implementation utilizes the census transform algorithm to calculate depth information from a pair of images delivered from a simulated stereo camera pair. This work advances our previous work through implementation improvements, a stereo camera pair simulation framework, and a scalable stereo vision core.


Precis: A Usercentric Word-Length Optimization Tool, Mark Chang, Scott Hauck Jul 2012

Precis: A Usercentric Word-Length Optimization Tool, Mark Chang, Scott Hauck

Mark L. Chang

Translating an algorithm designed for a general-purpose processor into an algorithm optimized for custom logic requires extensive knowledge of the algorithm and the target hardware. Precis lets designers analyze the precision requirements of algorithms specified in Matlab. The design time tool combines simulation, user input, and program analysis to help designers focus their manual precision optimization efforts.


Movement Detection For Power-Efficient Smartphone Wlan Localization, Mark Chang, Ilari Shafer Jul 2012

Movement Detection For Power-Efficient Smartphone Wlan Localization, Mark Chang, Ilari Shafer

Mark L. Chang

Mobile phone services based on the location of a user have increased in popularity and importance, particularly with the proliferation of feature-rich smartphones. One major obstacle to the widespread use of location-based services is the limited battery life of these mobile devices and the high power costs of many existing approaches. We demonstrate the effectiveness of a localization strategy that performs full localization only when it detects a user has finished moving. We characterize the power use of a smartphone, then verify our strategy using models of long-term walk behavior, recorded data, and device implementation. For the same sample period, …