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Investigating distributed simulation at the Ford motor company
Engine production is a complex process that requires the manufacturing and assembly of a wide variety of components to create a varied product mix. Simulation plays a key role in the planning process of a new production line to determine if it can meet expected demand. However, these simulations can be very time consuming and can often take up to a day to execute a single run. This paper investigates how distributed simulation based on the IEEE 1516 High Level Architecture and the emerging standard COTS Simulation Package Interoperability Product Development Group (CSPI-PDG) Type I Interoperability Reference Model could be used to reduce the time taken for a single simulation run. CSP interoperability and the problem of integrating CSPs with HLA software (the runtime infrastructure) are presented. New prototype benchmarking software, the COTS Simulation Package Emulator (CSPE), which is being developed to investigate distributed simulation problems, is discussed. The paper then develops a case study of how this was used to investigate the feasibility of using distributed simulation at Ford. The paper discusses results obtained from this case study and suggests that distributed simulation could indeed be beneficial to Ford
Mesomorphic properties of alkoxybenzylidene- aminoacetophenones
Liquid crystal phase transitions in compounds of alkoxybenzylidene-aminoacetophene serie
Ringing the Randall-Sundrum braneworld: metastable gravity wave bound states
In the Randall-Sundrum scenario, our universe is a 4-dimensional `brane'
living in a 5-dimensional bulk spacetime. By studying the scattering of bulk
gravity waves, we show that this brane rings with a characteristic set of
complex quasinormal frequencies, much like a black hole. To a bulk observer
these modes are interpreted as metastable gravity wave bound states, while a
brane observer views them as a discrete spectrum of decaying massive gravitons.
Potential implications of these scattering resonances are discussed.Comment: References and misc. comments added. "Implications" section expanded.
REVTeX4, 5 pages, 4 figure
The DMSP/MFR total ozone and radiance data base
This report describes the entries in sufficient detail so that the data base might be useful to others. The characteristics of the MFR sensor are briefly discussed and a complete index to the data base tapes is given
From Small-Scale Dynamo to Isotropic MHD Turbulence
We consider the problem of incompressible, forced, nonhelical, homogeneous,
isotropic MHD turbulence with no mean magnetic field. This problem is
essentially different from the case with externally imposed uniform mean field.
There is no scale-by-scale equipartition between magnetic and kinetic energies
as would be the case for the Alfven-wave turbulence. The isotropic MHD
turbulence is the end state of the turbulent dynamo which generates folded
fields with small-scale direction reversals. We propose that the statistics
seen in numerical simulations of isotropic MHD turbulence could be explained as
a superposition of these folded fields and Alfven-like waves that propagate
along the folds.Comment: kluwer latex, 7 pages, 7 figures; Proceedings of the International
Workshop "Magnetic Fields and Star Formation: Theory vs. Observations",
Madrid, 21-25 April 2003 -- published version (but the e-print is free of
numerous typos introduced by the publisher
Fault-tolerant Quantum Communication with Minimal Physical Requirements
We describe a novel protocol for a quantum repeater which enables long
distance quantum communication through realistic, lossy photonic channels.
Contrary to previous proposals, our protocol incorporates active purification
of arbitrary errors at each step of the protocol using only two qubits at each
repeater station. Because of these minimal physical requirements, the present
protocol can be realized in simple physical systems such as solid-state single
photon emitters. As an example, we show how nitrogen vacancy color centers in
diamond can be used to implement the protocol, using the nuclear and electronic
spin to form the two qubits.Comment: 4 pages, 3 figures. V2: Minor modifications. V3: Major changes in the
presentation and new titl
Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
The Binary Population and Spectral Synthesis (BPASS) suite of binary stellar
evolution models and synthetic stellar populations provides a framework for the
physically motivated analysis of both the integrated light from distant stellar
populations and the detailed properties of those nearby. We present a new
version 2.1 data release of these models, detailing the methodology by which
BPASS incorporates binary mass transfer and its effect on stellar evolution
pathways, as well as the construction of simple stellar populations. We
demonstrate key tests of the latest BPASS model suite demonstrating its ability
to reproduce the colours and derived properties of resolved stellar
populations, including well- constrained eclipsing binaries. We consider
observational constraints on the ratio of massive star types and the
distribution of stellar remnant masses. We describe the identification of
supernova progenitors in our models, and demonstrate a good agreement to the
properties of observed progenitors. We also test our models against photometric
and spectroscopic observations of unresolved stellar populations, both in the
local and distant Universe, finding that binary models provide a
self-consistent explanation for observed galaxy properties across a broad
redshift range. Finally, we carefully describe the limitations of our models,
and areas where we expect to see significant improvement in future versions.Comment: 69 pages, 45 figures. Accepted for publication in PASA. Accompanied
by a full, documented data release at http://bpass.auckland.ac.nz and
http://warwick.ac.uk/bpas
Direct versus Delayed pathways in Strong-Field Non-Sequential Double Ionization
We report full-dimensionality quantum and classical calculations for double
ionization of laser-driven helium at 390 nm. Good qualitative agreement is
observed. We show that the classical double ionization trajectories can be
divided into two distinct pathways: direct and delayed. The direct pathway,
with an almost simultaneous ejection of both electrons, emerges from small
laser intensities. With increasing intensity its relative importance, compared
to the delayed ionization pathway, increases until it becomes the predominant
pathway for total electron escape energy below around 5.25 . However the
delayed pathway is the predominant one for double ionization above a certain
cut-off energy at all laser intensities
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