1,903,969 research outputs found
Establishing a Deacidification Regimen as Part of Collection Stewardship
Preservationists have long warned about the impending loss of items because of acidic paper. Any librarian who has worked with older materials knows that this warning is compelling. The risk is even more pronounced for the Christian library, especially libraries serving small denominational colleges and seminaries, because they often contain old and rare material, such as denominational historical accounts or small-run monographs, items that secular libraries may have long since discarded. These may be the last copies of an item.
An option for non-brittle acidic material is deacidification. The deacidification process has evolved to the point where it is effective at stopping further breakdown, safe for both the person and the item, adaptable to different library budgets and collection sizes, and easy to administer as a component of library collection stewardship. This paper will provide a short, practical explanation of how to develop a deacidification regimen as one component of the overall collection stewardship
The Goldman symplectic form on the PGL(V)-Hitchin component
This article is the second of a pair of articles about the Goldman symplectic
form on the PGL(V )-Hitchin component. We show that any ideal triangulation on
a closed connected surface of genus at least 2, and any compatible bridge
system determine a symplectic trivialization of the tangent bundle to the
Hitchin component. Using this, we prove that a large class of flows defined in
the companion paper [SWZ17] are Hamiltonian. We also construct an explicit
collection of Hamiltonian vector fields on the Hitchin component that give a
symplectic basis at every point. These are used to show that the global
coordinate system on the Hitchin component defined iin the companion paper is a
global Darboux coordinate system.Comment: 95 pages, 24 figures, Citations update
Moduli Spaces for D-branes at the Tip of a Cone
For physicists: We show that the quiver gauge theory derived from a
Calabi-Yau cone via an exceptional collection of line bundles on the base has
the original cone as a component of its classical moduli space. For
mathematicians: We use data from the derived category of sheaves on a Fano
surface to construct a quiver, and show that its moduli space of
representations has a component which is isomorphic to the anticanonical cone
over the surface.Comment: 8 page
Resources for Evaluation of Summarization Techniques
We report on two corpora to be used in the evaluation of component systems
for the tasks of (1) linear segmentation of text and (2) summary-directed
sentence extraction. We present characteristics of the corpora, methods used in
the collection of user judgments, and an overview of the application of the
corpora to evaluating the component system. Finally, we discuss the problems
and issues with construction of the test set which apply broadly to the
construction of evaluation resources for language technologies.Comment: LaTeX source, 5 pages, US Letter, uses lrec98.st
Cosmic dust
Dust is a ubiquitous component of our galaxy and the solar system. The collection and analysis of extraterrestrial dust particles is important to exobiology because it provides information about the sources of biogenically significant elements and compounds that accumulated in distant regions of the solar nebula and that were later accreted on the planets. The topics discussed include the following: general properties of interplanetary dust; the carbonaceous component of interplanetary dust particles; and the presence of an interstellar component
Broad-band Spectral Evolution of Scorpius X-1 along its Color-Color Diagram
We analyze a large collection of RXTE archive data from April 1997 to August
2003 of the bright X-ray source Scorpius X-1 in order to study the broadband
spectral evolution of the source for different values of the inferred mass
accretion rate by studying energy spectra from selected regions in the Z-track
of its Color-Color Diagram. A two-component model, consisting of a soft thermal
component interpreted as thermal emission from an accretion disk and a thermal
Comptonization component, is unable to fit the whole 3--200 keV energy spectrum
at low accretion rates. Strong residuals in the highest energy band of the
spectrum require the addition of a third component that can be fitted with a
power-law component, that could represent a second thermal Comptonization from
a much hotter plasma, or a hybrid thermal/non-thermal Comptonization. We
discuss the physical implications derived from the results of our analysis,
with a particular emphasis on the hardest part of the X-ray emission and its
possible origins.Comment: 18 pages. Accepted for publication in Ap
04041 Abstracts Collection -- Component-Based Modeling and Simulation
From 18.01.04 to 23.01.04, the Dagstuhl Seminar 04041 ``Component-Based Modeling and Simulation\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
Genus two 3-manifolds are built from handle number one pieces
Let M be a closed, irreducible, genus two 3-manifold, and F a maximal
collection of pairwise disjoint, closed, orientable, incompressible surfaces
embedded in M. Then each component manifold M_i of M-F has handle number at
most one, i.e. admits a Heegaard splitting obtained by attaching a single
1-handle to one or two components of boundary M_i. This result also holds for a
decomposition of M along a maximal collection of incompressible tori.Comment: Published by Algebraic and Geometric Topology at
http://www.maths.warwick.ac.uk/agt/AGTVol1/agt-1-38.abs.htm
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