Physical Sciences and Mathematics Commons^™

Self-Adjoint Extension And Spectral Theory Of A Linear Relation In A Hilbert Space, Keshav R. Acharya

Publications

The aim of this paper is to develop the conditions for a symmetric relation in a Hilbert space ℋ to have self-adjoint extensions in terms of defect indices and discuss some spectral theory of such linear relation.

Assessing The Effect Of High Performance Computing Capabilities On Academic Research Output, Amy Apon, Linh B. Ngo, Michael E. Payne, Paul W. Wilson

Publications

This paper uses nonparametric methods and some new results on hypothesis testing with nonparametric efficiency estimators and applies these to analyze the effect of locally-available high performance computing (HPC) resources on universities efficiency in producing research and other outputs. We find that locally-available HPC resources enhance the technical efficiency of research output in Chemistry, Civil Engineering, Physics, and History, but not in Computer Science, Economics, nor English; we find mixed results for Biology. Out research results provide a critical first step in a quantitative economic model for investments in HPC.

Constraints On Violations Of Lorentz Symmetry From Gravity Probe B, James M. Overduin, Ryan D. Everett, Quentin G. Bailey

Publications

We use the final results from Gravity Probe B to set new upper limits on the gravitational sector of the Standard-Model Extension, including for the first time the coefficient associated with the time-time component of the new field responsible for inducing local Lorentz violation in the theory.

Local Lorentz-Symmetry Breaking And Gravity, Q. G. Bailey

Publications

The lagrangian-based Standard-Model Extension framework offers a broad description of possible gravitational effects from local Lorentz violation. In this talk, I review the status of the theoretical and phenomenological work in this area. The extension of previous results in linearized gravity to the nonlinear regime is discussed.

Development Of High-Purity Optical Grade Single-Crystal Cvd Diamond For Intracavity Cooling, Andrew M. Bennett, Benjamin J. Wickham, Harpreet K. Dhillon, Ying Chen, Scott Webster, Giorgio Turri, Michael Bass

Publications

Microwave assisted chemical vapour deposited bulk diamond products have been used in a range of high power laser systems, due to low absorption across a range of wavelengths and exceptional thermal properties. However the application of polycrystalline products has frequently been limited to applications at longer wavelengths or thermal uses outside of the optical path due to the birefringence and scatter that are intrinsic properties of the polycrystalline materials. However, there are some solid state structures, including thin disc gain modules and amplifiers, that will gain significantly in terms of potential output powers if diamond could be used as a …

Product Review: Knimbus: Free Personal Edition, Laura Pope Robbins

Publications

Laura Pope Robbins is an advisor for The Charleston Advisor, and the review below is included in Scholarly Commons with the permission of the publisher.

Knimbus is both a search engine and a collaborative platform for scientists to find the information they need and connect them with other researchers in their field. As a search engine it provides a federated search of 32 Open Access resources and connects the researcher to the full text. As a collaborative platform, it provides a way for scientists to upload their documents and share them with their colleagues. Knimbus is an enterprising project that …

Interaction Of Magnetic Reconnection And Kelvin-Helmholtz Modes For Large Magnetic Shear: 1. Kelvin-Helmholtz Trigger, Xuanye Ma, Antonius Otto, Peter A. Delamere

Publications

At the Earth's magnetopause, both magnetic reconnection and the Kelvin‐Helmholtz (KH) instability can operate simultaneously for southward interplanetary magnetic field conditions. The dynamic evolution of such a system can be expected to depend on the importance of KH wave evolution versus reconnection and therefore on the respective initial perturbations. In this study, a series of local three‐dimensional MHD and Hall MHD simulations are carried out to investigate the situation where the Kelvin‐Helmholtz instability is initially the primary process. It is demonstrated that magnetic reconnection is driven and strongly modified by nonlinear KH waves. The highest reconnection rate is close to …

Interaction Of Magnetic Reconnection And Kelvin-Helmholtz Modes For Large Magnetic Shear: 2. Reconnection Trigger, Xuanye Ma, Antonius Otto, Peter A. Delamere

Publications

A typical property of magnetopause reconnection is a significant perpendicular shear flow due to the fast streaming magnetosheath plasma. Therefore, the magnetopause represents a large magnetic and flow shear boundary during periods of southward interplanetary magnetic field, which can be unstable to Kelvin‐Helmholtz (KH) modes and to magnetic reconnection. A series of local three‐dimensional MHD and Hall MHD simulations is carried out to investigate the interaction of reconnection and nonlinear KH waves considering magnetic reconnection as the primary process. It is demonstrated that the onset reconnection causes a thinning of the shear flow layer, thereby generating small wavelength KH modes. …

A Fast Algorithm For The Inversion Of Quasiseparable Vandermonde-Like Matrices, Sirani M. Perera, Grigory Bonik, Vadim Olshevsky

Publications

The results on Vandermonde-like matrices were introduced as a generalization of polynomial Vandermonde matrices, and the displacement structure of these matrices was used to derive an inversion formula. In this paper we first present a fast Gaussian elimination algorithm for the polynomial Vandermonde-like matrices. Later we use the said algorithm to derive fast inversion algorithms for quasiseparable, semiseparable and well-free Vandermonde-like matrices having O(n2) complexity. To do so we identify structures of displacement operators in terms of generators and the recurrence relations(2-term and 3-term) between the columns of the basis transformation matrices for quasiseparable, semiseparable and well-free polynomials. Finally we …

An Advanced Mesospheric Temperature Mapper For High-Latitude Airglow Studies, Pierre-Dominique Pautet, Michael J. Taylor, William R. Pendleton Jr., Yucheng Zhao, Tao Yuan, R. Esplin, D. Mclain

Publications

Over the past 60 years, ground-based remote sensing measurements of the Earth’s mesospheric temperature have been performed using the nighttime hydroxyl (OH) emission, which originates at an altitude of ∼87  km∼87  km. Several types of instruments have been employed to date: spectrometers, Fabry–Perot or Michelson interferometers, scanning-radiometers, and more recently temperature mappers. Most of them measure the mesospheric temperature in a few sample directions and/or with a limited temporal resolution, restricting their research capabilities to the investigation of larger-scale perturbations such as inertial waves, tides, or planetary waves. The Advanced Mesospheric Temperature Mapper (AMTM) is a novel infrared digital imaging …

Titchmarsh-Weyl Theory For Canonical Systems, Keshav R. Acharya

Publications

The main purpose of this paper is to develop Titchmarsh- Weyl theory of canonical systems. To this end, we first observe the fact that Schrodinger and Jacobi equations can be written into canonical systems. We then discuss the theory of Weyl m-function for canonical systems and establish the relation between the Weyl m-functions of Schrodinger equations and that of canonical systems which involve Schrodinger equations.

Not All Traces On The Circle Come From Functions Of Least Gradient In The Disk, Gregory S. Spradlin, Alexandru Tamasan

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We provide an example of an L¹ function on the circle, which cannot be the trace of a function of bounded variation of least gradient in the disk.

The Grand Thaw: Our Vanishing Cryosphere, Richard Snow, Mary Snow

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Records reveal that beginning in the 1950s there has been an accelerated reduction in ice and snow across most mountain glaciers and ice caps. The glaciers of the Tibetan Plateau and the Himalayan Mountains are the main source of water for the Ganges and the Indus Rivers. During the summer higher temperatures are causing these glaciers to melt at an increasing rate while during the winter the warmer temperature are yielding a dearth of snowfall, which in turn leads to drought. Along the equator in Africa, glaciers are faced with a similar same situation. In Uganda, 80 percent of the …

Climate Change: The Proof And The Process, Richard Snow, Mary Snow

Publications

Since what we call civilization began some 12,000 years ago, the mean temperature of Earth has not varied more than 1°C from the average. The forecast change in temperature of from 1.5 to 4°C (2.7 to 7°F) by 2100 has no equal in the recent history of the planet. Changes in the energy output of the sun, changes in the relative position of the sun and Earth, shifting locations of the continents, mountain building, volcanic eruptions, and changes in atmospheric composition all combine to cause our climate to change. Most of the changes in climate of the past can be …

Educating The Next Generation Of Cyberforensic Professionals, Mark Pollitt, Philip Craiger

Publications

This paper provides a historical overview of the development of cyberforensics as a scientific discipline, along with a description of the current state of training, educational programs, certification and accreditation. The paper traces the origins of cyberforensics, the acceptance of cyberforensics as a forensic science and its recognition as a component of information security. It also discusses the development of professional certification and standardized bodies of knowledge that have had a substantial impact on the discipline. Finally, it discusses the accreditation of cyberforensic educational programs, its linkage with the bodies of knowledge and its effect on cyberforensic educational programs.

Book Review: Robotic Exploration Of The Solar System: Pt. 4: The Modern Era, 2004-2013, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Robotic Exploration of the Solar System : Pt. 4: the Modern Era, 2004-2013 by Paolo Ulivi with David Harland Springer, 2014 567p bibl index afp, 9781461448112 $44.99, 9781461448129 $29.99

Book Review: The Observer's Guide To Planetary Motion: Explaining The Cycles Of The Night Sky, T. D. Oswalt

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This document is Dr. Oswalt’s review of The Observer's Guide to Planetary Motion : Explaining the Cycles of the Night Sky by Dominic Ford. Springer, 2014 240p index afp, 9781493906284 $34.99.

Standoff Methods For The Detection Of Threat Agents: A Review Of Several Promising Laser-Based Techniques, J. Bruce Johnson, Susan D. Allen, Jonathan Merten, Lewis Johnson, Daniel Pinkham, Scott W. Reeve

Publications

Detection of explosives, explosive precursors, or other threat agents presents a number of technological challenges for optical sensing methods. Certainly detecting trace levels of threat agents against a complex background is chief among these challenges; however, the related issues of multiple target distances (from standoff to proximity) and sampling time scales (from passive mines to rapid rate of march convoy protection) for different applications make it unlikely that a single technique will be ideal for all sensing situations. A number of methods for spanning the range of optical sensor technologies exist which, when integrated, could produce a fused sensor system …

Differential Spectral Imaging Of The Cn Violet Band In Laser-Induced Plasmas On Tnt Simulant Molecules, J. Merten, M. Jones, S. Hoke, S. Allen

Publications

Dual channel emission imaging of m-nitrobenzoic acid and benzoic acid was performed in order to visualize the morphology of the CN violet band emission of a TNT analogue. The CN channel was corrected for continuum emission using a simultaneously imaged background channel. Simultaneous dual channel imaging alleviated problems with shot to shot variation in the plasma morphology due to the friable substrates and showed differences between plasmas formed on the two targets.

The 6th Mode Of Transportation, Robert O. Walton

Publications

The five modes of freight transportation are normally characterized as motor carriers, railroads, airlines, water carriers, and pipelines. This paper will attempt to position the Internet as the sixth mode of transportation. This paper compares the strengths and weaknesses of the traditional five modes of transportation against the proposed 6th mode of the Internet. Without including the Internet as a mode of transportation, and tracking the economic value that it adds to the economy, the economic impact of the Internet as a mode is not considered. The recommendation of this study is that the Internet should be added to the …

A Regression Model To Investigate The Performance Of Black-Scholes Using Macroeconomic Predictors, Timothy A. Smith, Ersoy Subasi, Aliraza M. Rattansi

Publications

As it is well known an option is defined as the right to buy sell a certain asset, thus, one can look at the purchase of an option as a bet on the financial instrument under consideration. Now while the evaluation of options is a completely different mathematical topic than the prediction of future stock prices, there is some relationship between the two. It is worthy to note that henceforth we will only consider options that have a given fixed expiration time T, i.e., we restrict the discussion to the so called European options. Now, for a simple illustration of …

Computational Models For Nanosecond Laser Ablation, Harihar Khanal, David Autrique, Vasilios Alexiades

Publications

Laser ablation in an ambient environment is becoming increasingly important in science and technology. It is used in applications ranging from chemical analysis via mass spectroscopy, to pulsed laser deposition and nanoparticle manufacturing. We describe numerical schemes for a multiphase hydrodynamic model of nanosecond laser ablation expressing energy, momentum, and mass conservation in the target material, as well as in the expanding plasma plume, along with collisional and radiative processes for laser-induced breakdown (plasma formation). Numerical simulations for copper in a helium background gas are presented and the efficiency of various ODE integrators is compared.

Three X-Ray Transients In M31 Oberserved With Swift, R. Voss, W. Pietsch, F. Haberl, H. Stiele, J. Greiner, G. Sala, Dieter H. Hartmann, D. Hatzidimitriou

Publications

Aims.The purpose of this study is to find transient X-ray sources in M 31, and to investigate and classify their nature.Methods.Three X-ray transients were observed with Swift. For each of the three X-ray transients we use the Swift X-ray and opticaldata together with observations from XMM-Newton and Chandra to investigate the lightcurves and the spectra of the outburst, andthereby to identify the source types. Results.The outburst of XMMU J004215.8+ 411924 lasted for about one month. The source had a hard power-law spectrum with aphoton index of 1.6. It was previously identified as a Be/X-ray binary based on the optical identification …

Supernova Neutrino Nucleosynthesis Of Light Elements With Neutrino Oscillations, Takashi Yoshida, Toshitaka Kajino, Hidekazu Yokomakura, Keiichi Kimura, Akira Takamura, Dieter H. Hartmann

Publications

Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the ν-process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current ν-process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a factor of 1.9 and 1.3, respectively, for a normal mass hierarchy and an adiabatic 13-mixing resonance, compared to those without neutrino oscillations. In the case of an inverted mass hierarchy and a non-adiabatic 13-mixing resonance, the increase in the 7Li and 11B yields is much smaller. Observations …

Asymptotic Multi-Layer Analysis Of Wind Over Unsteady Monochromatic Surface Waves, Shahrdad Sajjadi, Julian Hunt, Frederique Drullion

Publications

Asymptotic multi-layer analyses and computation of solutions for turbulent flows over steady and unsteady monochromatic surface wave are reviewed, in the limits of low turbulent stresses and small wave amplitude. The structure of the flow is defined in terms of asymptotically-matched thin-layers, namely the surface layer and a critical layer, whether it is ‘elevated’ or ‘immersed’, corresponding to its location above or within the surface layer. The results particularly demonstrate the physical importance of the singular flow features and physical implications of the elevated critical layer in the limit of the unsteadiness tending to zero. These agree with the variational …

Adjusted Tornado Probabilities, Holly M. Widen, James B. Elsner, Cameron Amrine, Rizalino B. Cruz, Erik Fraza, Laura Michaels, Loury Migliorelli, Brendan Mulholland, Michael Patterson, Sarah Strazzo, Guang Xing

Publications

Tornado occurrence rates computed from the available reports are biased low relative to the unknown true rates. To correct for this low bias, the authors demonstrate a method to estimate the annual probability of being struck by a tornado that uses the average report density estimated as a function of distance from nearest city/town center. The method is demonstrated on Kansas and then applied to 15 other tornado-prone states from Nebraska to Tennessee. States are ranked according to their adjusted tornado rate and comparisons are made with raw rates published elsewhere. The adjusted rates, expressed as return periods, arestates, including …

Towards A System For Controlling Client-Server Traffic In Virtual Worlds Using Sdn, Jason Anderson, Jim Martin

Publications

Scaling virtual worlds in the age of cloud computing is complicated by the problem of efficiently directing client-server traffic in the face of agile and dynamic compute resources. In this proposed model, Software Defined Networking and compact encoding of avatar data in packet headers are combined to make a fast, scalable, high capacity proxy server that can hide the server infrastructure while fitting well with the IaaS paradigm of modern cloud providers.

A Study Of Energy Transfer Of Wind And Ocean Waves, Shahrdad Sajjadi, Mason Bray

Publications

To develop a better understanding of energy transfer between wind and different types of waves a model was created to determine growth factors and energy transfers on breaking waves and the resulting velocity vectors. This model was used to build on the research of Sajjadi et al (1996) on the growth of waves by sheared flow and takes models of wave velocities developed by Weber and Melsom (1993) and end energy transfer by Sajjadi, Hunt and Drullion (2012).

Wave Heating And Jeans Escape In The Martian Upper Atmosphere, R. L. Walterscheid, Michael P. Hickey Ph.D., G. Schubert

Publications

Gusty flow over rough terrain is likely to be a significant source of fast gravity waves and acoustic waves in the atmosphere of Mars, as it is in Earth’s atmosphere. Accordingly, we have used a numerical model to study the dissipation in the thermosphere and exosphere of Mars of upward-propagating fast gravity waves and acoustic waves. Model simulations are performed for a range of wave periods and horizontal wavelengths. Wave amplitudes are constrained by the Mars Global Surveyor and Mars Odyssey aerobraking data, and gravity wave phase velocities are limited by occultation data. Dissipating gravity waves heat some regions of …

Grb 091024a And The Nature Of Ultra-Long Gamma-Ray Bursts, F. J. Virgili, C. G. Mundell, V. Pal'shin, C. Guidorzi, R. Margutti, A. Melandri, R. Harrison, S. Kobayashi, R. Chornock, A Henden, A C. Updike, S B. Cenko, N R. Tanvir, I A. Steele, A Cucchiara, A Gomboc, A Levan, Z Cano, C J. Mottram, N R. Clay, D Bersier, D Kopac, J Japelj, A V. Filippenko, W Li, D Svinkin, S Golenetskii, Dieter H. Hartmann, P A. Milne, G Williams, P T. O'Brien, D B. Fox, E Berger

Publications

We present a broadband study of gamma-ray burst (GRB) 091024A within the context of other ultra-long-duration GRBs. An unusually long burst detected by Konus–Wind (KW), Swift, and Fermi, GRB 091024A has prompt emission episodes covering ∼1300 s, accompanied by bright and highly structured optical emission captured by various rapid-response facilities, including the 2 m autonomous robotic Faulkes North and Liverpool Telescopes, KAIT, S-LOTIS, and the Sonoita Research Observatory. We also observed the burst with 8 and 10 m class telescopes and determine the redshift to be z = 1.0924 ± 0.0004. We find no correlation between the optical and γ-ray …