81,544 research outputs found
HaTS: Hardware-Assisted Transaction Scheduler
In this paper we present HaTS, a Hardware-assisted Transaction Scheduler. HaTS improves performance of concurrent applications by classifying the executions of their atomic blocks (or in-memory transactions) into scheduling queues, according to their so called conflict indicators. The goal is to group those transactions that are conflicting while letting non-conflicting transactions proceed in parallel. Two core innovations characterize HaTS. First, HaTS does not assume the availability of precise information associated with incoming transactions in order to proceed with the classification. It relaxes this assumption by exploiting the inherent conflict resolution provided by Hardware Transactional Memory (HTM). Second, HaTS dynamically adjusts the number of the scheduling queues in order to capture the actual application contention level. Performance results using the STAMP benchmark suite show up to 2x improvement over state-of-the-art HTM-based scheduling techniques
The Coverings of an Empire: An Examination of Ottoman Headgear from 1500 to 1829
This paper investigates the socio-economic and religious implications of hats worn in the Ottoman Empire from the mid-sixteenth century to 1829, when they were all replaced with the legendary fez. It acts as an initial compendium, drawing heavily from primary sources to explain who wore which style of headgear and why
HATS-8b: A Low-Density Transiting Super-Neptune
HATS-8b is a low density transiting super-Neptune discovered as part of the
HATSouth project. The planet orbits its solar-like G dwarf host (V=14.03
0.10 and T =5679 50 K) with a period of 3.5839 d. HATS-8b is the
third lowest mass transiting exoplanet to be discovered from a wide-field
ground based search, and with a mass of 0.138 0.019 M it is
approximately half-way between the masses of Neptune and Saturn. However
HATS-8b has a radius of 0.873 (+0.123,-0.075) R, resulting in a bulk
density of just 0.259 0.091 g.cm. The metallicity of the host star
is super-Solar ([Fe/H]=0.210 0.080), arguing against the idea that low
density exoplanets form from metal-poor environments. The low density and large
radius of HATS-8b results in an atmospheric scale height of almost 1000 km, and
in addition to this there is an excellent reference star of near equal
magnitude at just 19 arcsecond separation on the sky. These factors make
HATS-8b an exciting target for future atmospheric characterization studies,
particularly for long-slit transmission spectroscopy.Comment: 11 pages, 7 figures, accepted for publication in A
Ununfoldable Polyhedra with Convex Faces
Unfolding a convex polyhedron into a simple planar polygon is a well-studied
problem. In this paper, we study the limits of unfoldability by studying
nonconvex polyhedra with the same combinatorial structure as convex polyhedra.
In particular, we give two examples of polyhedra, one with 24 convex faces and
one with 36 triangular faces, that cannot be unfolded by cutting along edges.
We further show that such a polyhedron can indeed be unfolded if cuts are
allowed to cross faces. Finally, we prove that ``open'' polyhedra with
triangular faces may not be unfoldable no matter how they are cut.Comment: 14 pages, 9 figures, LaTeX 2e. To appear in Computational Geometry:
Theory and Applications. Major revision with two new authors, solving the
open problem about triangular face
HATS-5b: A Transiting hot-Saturn from the HATSouth Survey
We report the discovery of HATS-5b, a transiting hot-Saturn orbiting a G type
star, by the HAT-South survey. HATS-5b has a mass of Mp=0.24 Mj, radius of
Rp=0.91 Rj, and transits its host star with a period of P=4.7634d. The radius
of HATS-5b is consistent with both theoretical and empirical models. The host
star has a V band magnitude of 12.6, mass of 0.94 Msun, and radius of 0.87
Rsun. The relatively high scale height of HATS-5b, and the bright,
photometrically quiet host star, make this planet a favourable target for
future transmission spectroscopy follow-up observations. We reexamine the
correlations in radius, equilibrium temperature, and metallicity of the
close-in gas-giants, and find hot Jupiter-mass planets to exhibit the strongest
dependence between radius and equilibrium temperature. We find no significant
dependence in radius and metallicity for the close-in gas-giant population.Comment: 10 pages, submitted to A
HATS-1b: The First Transiting Planet Discovered by the HATSouth Survey
We report the discovery of HATS-1b, a transiting extrasolar planet orbiting
the moderately bright V=12.05 G dwarf star GSC 6652-00186, and the first planet
discovered by HATSouth, a global network of autonomous wide-field telescopes.
HATS-1b has a period P~3.4465 d, mass Mp~1.86MJ, and radius Rp~1.30RJ. The host
star has a mass of 0.99Msun, and radius of 1.04Rsun. The discovery light curve
of HATS-1b has near continuous coverage over several multi-day periods,
demonstrating the power of using a global network of telescopes to discover
transiting planets.Comment: Submitted to AJ 10 pages, 5 figures, 6 table
Unhappy Holidays at Merton Factory
This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.CLW_2009_Report_China_unhappy_holidays.pdf: 49 downloads, before Oct. 1, 2020
Development of advanced composite structures
Composite structure programs: the L-1011 Advanced Composite Vertical Fin (ACVF), the L-1011 Advanced Composite Aileron, and a wing study program were reviewed. These programs were structured to provide the technology and confidence for the use of advanced composite materials for primary and secondary structures of future transport aircraft. The current status of the programs is discussed. The results of coupon tests for both material systems are presented as well as the ACVF environmental (moisture and temperature) requirements. The effect of moisture and temperature on the mechanical properties of advanced composite materials is shown. The requirements set forth in the FAA Certification Guidelines for Civil Composite Aircraft Structures are discussed as they relate to the ACVF
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