508 research outputs found
Safe self-scheduling: A parallel loop scheduling scheme for shared-memory multiprocessors
The article of record as published may be found at https://doi.org/10.1007/BF02577870In this paper we present Safe Self-Scheduling (SSS), a new scheduling scheme that schedules parallel loops with variable length iteration execution times not known at compile time. The scheme assumes a shared memory space. SSS combines static scheduling with dynamic scheduling and draws favorable advantages from each. First, it reduces the dynamic scheduling overhead by statistically scheduling a major portion of loop iterations. Second, the workload is balanced with simple and efficient self-scheduling scheme by applying a new measure, the smallest critical chore size. Experimental results comparing SSS with other scheduling schemes indicate that SSS surpasses other scheduling schemes. In the experiment on Gauss-Jordan, an application that is suitable for static scheduling schemes, SSS is the only self-scheduling scheme that outperforms the static scheduling scheme. This indicates that SSS achieves a balanced workload with a very small amount of overhead.USDO
Decorated vertices with 3-edged cells in 2D foams: exact solutions and properties
The energy, area and excess energy of a decorated vertex in a 2D foam are
calculated. The general shape of the vertex and its decoration are described
analytically by a reference pattern mapped by a parametric Moebius
transformation. A single parameter of control allows to describe, in a common
framework, different types of decorations, by liquid triangles or 3-sided
bubbles, and other non-conventional cells. A solution is proposed to explain
the stability threshold in the flower problem.Comment: 13 pages, 17 figure
Pool boiling on modified surfaces using R-123
Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Saturated pool boiling of R-123 was investigated for five horizontal copper surfaces modified by different treatments, namely: an emery polished surface, a fine sandblasted surface, a rough sandblasted surface, an electron beam enhanced surface and a sintered surface. Each 40 mm diameter heating surface formed the upper face of an oxygen-free copper block, electrically heated by embedded cartridge heaters. The experiments were performed from the convective heat transfer regime to the critical heat flux, with both increasing and decreasing heat flux, at 1.01 bar, and additionally at 2 bar and 4 bar for the emery polished surface. Significant enhancement of heat transfer with increasing surface modification was demonstrated, particularly for the EB enhanced and sintered surfaces. The emery polished and sandblasted surface results are compared with nucleate boiling correlations and other published data.dc201
Physical tests for Random Numbers in Simulations
We propose three physical tests to measure correlations in random numbers
used in Monte Carlo simulations. The first test uses autocorrelation times of
certain physical quantities when the Ising model is simulated with the Wolff
algorithm. The second test is based on random walks, and the third on blocks of
n successive numbers. We apply the tests to show that recent errors in high
precision simulations using generalized feedback shift register algorithms are
due to short range correlations in random number sequences. We also determine
the length of these correlations.Comment: 16 pages, Post Script file, HU-TFT-94-
Personality, conventional Christian belief and unconventional paranormal belief : a study among teenagers
A sample of 10,851 pupils (5493 males and 5358 females) attending Year 9 classes (13- to 14-year-olds) and a sample of 9494 pupils (4787 males and 4707 females) attending Year 10 classes (14- to 15-year-olds) in non-denominational state-maintained secondary schools in England and Wales completed questions concerned with conventional Christian belief and unconventional paranormal belief, alongside the short-form Junior Eysenck Personality Questionnaire. The data demonstrated that conventional Christian belief and unconventional paranormal belief occupy different locations in relation to the Eysenckian model of personality in respect of the psychoticism scale and the lie scale. While conventional Christian belief is associated with lower psychoticism scores and higher lie scale scores (greater social conformity), unconventional paranormal belief is associated with higher psychoticism scores and lower lie scale scores (lower social conformity)
Gravitational Lensing at Millimeter Wavelengths
With today's millimeter and submillimeter instruments observers use
gravitational lensing mostly as a tool to boost the sensitivity when observing
distant objects. This is evident through the dominance of gravitationally
lensed objects among those detected in CO rotational lines at z>1. It is also
evident in the use of lensing magnification by galaxy clusters in order to
reach faint submm/mm continuum sources. There are, however, a few cases where
millimeter lines have been directly involved in understanding lensing
configurations. Future mm/submm instruments, such as the ALMA interferometer,
will have both the sensitivity and the angular resolution to allow detailed
observations of gravitational lenses. The almost constant sensitivity to dust
emission over the redshift range z=1-10 means that the likelihood for strong
lensing of dust continuum sources is much higher than for optically selected
sources. A large number of new strong lenses are therefore likely to be
discovered with ALMA, allowing a direct assessment of cosmological parameters
through lens statistics. Combined with an angular resolution <0.1", ALMA will
also be efficient for probing the gravitational potential of galaxy clusters,
where we will be able to study both the sources and the lenses themselves, free
of obscuration and extinction corrections, derive rotation curves for the
lenses, their orientation and, thus, greatly constrain lens models.Comment: 69 pages, Review on quasar lensing. Part of a LNP Topical Volume on
"Dark matter and gravitational lensing", eds. F. Courbin, D. Minniti. To be
published by Springer-Verlag 2002. Paper with full resolution figures can be
found at ftp://oden.oso.chalmers.se/pub/tommy/mmviews.ps.g
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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