8,402 research outputs found
Stock price informativeness, cross-listings and investment decisions
In this paper, the authors show that a cross-listing allows a firm to make better investment decisions because it enhances stock price informativeness.Cross-listings; cross-listings premium; price informativeness; investment decisions; flow-back; ownership.
From Toda to KdV
For periodic Toda chains with a large number of particles we consider
states which are -close to the equilibrium and constructed by
discretizing arbitrary given functions with mesh size Our aim
is to describe the spectrum of the Jacobi matrices appearing in the Lax
pair formulation of the dynamics of these states as . To this end
we construct two Hill operators -- such operators come up in the Lax
pair formulation of the Korteweg-de Vries equation -- and prove by methods of
semiclassical analysis that the asymptotics as of the
eigenvalues at the edges of the spectrum of are of the form where are the eigenvalues of . In the bulk of the spectrum, the
eigenvalues are -close to the ones of the equilibrium matrix. As an
application we obtain asymptotics of a similar type of the discriminant,
associated to
Characterizing SASI- and Convection-Dominated Core-Collapse Supernova Explosions in Two Dimensions
The success of the neutrino mechanism of core-collapse supernovae relies on
the supporting action of two hydrodynamic instabilities: neutrino-driven
convection and the Standing Accretion Shock Instability (SASI). Depending on
the structure of the stellar progenitor, each of these instabilities can
dominate the evolution of the gain region prior to the onset of explosion, with
implications for the ensuing asymmetries. Here we examine the flow dynamics in
the neighborhood of explosion by means of parametric two-dimensional,
time-dependent hydrodynamic simulations for which the linear stability
properties are well understood. We find that systems for which the convection
parameter is sub-critical (SASI-dominated) develop explosions once large-scale,
high-entropy bubbles are able to survive for several SASI oscillation cycles.
These long-lived structures are seeded by the SASI during shock expansions.
Finite-amplitude initial perturbations do not alter this outcome qualitatively,
though they can lead to significant differences in explosion times.
Supercritical systems (convection-dominated) also explode by developing
large-scale bubbles, though the formation of these structures is due to buoyant
activity. Non-exploding systems achieve a quasi-steady state in which the
time-averaged flow adjusts itself to be convectively sub-critical. We
characterize the turbulent flow using a spherical Fourier-Bessel decomposition,
identifying the relevant scalings and connecting temporal and spatial
components. Finally, we verify the applicability of these principles on the
general relativistic, radiation-hydrodynamic simulations of Mueller, Janka, &
Heger (2012), and discuss implications for the three-dimensional case.Comment: accepted by MNRAS with minor change
Logical segmentation for article extraction in digitized old newspapers
Newspapers are documents made of news item and informative articles. They are
not meant to be red iteratively: the reader can pick his items in any order he
fancies. Ignoring this structural property, most digitized newspaper archives
only offer access by issue or at best by page to their content. We have built a
digitization workflow that automatically extracts newspaper articles from
images, which allows indexing and retrieval of information at the article
level. Our back-end system extracts the logical structure of the page to
produce the informative units: the articles. Each image is labelled at the
pixel level, through a machine learning based method, then the page logical
structure is constructed up from there by the detection of structuring entities
such as horizontal and vertical separators, titles and text lines. This logical
structure is stored in a METS wrapper associated to the ALTO file produced by
the system including the OCRed text. Our front-end system provides a web high
definition visualisation of images, textual indexing and retrieval facilities,
searching and reading at the article level. Articles transcriptions can be
collaboratively corrected, which as a consequence allows for better indexing.
We are currently testing our system on the archives of the Journal de Rouen,
one of France eldest local newspaper. These 250 years of publication amount to
300 000 pages of very variable image quality and layout complexity. Test year
1808 can be consulted at plair.univ-rouen.fr.Comment: ACM Document Engineering, France (2012
Dynamics and rheology of a dilute suspension of vesicles: higher order theory
Vesicles under shear flow exhibit various dynamics: tank-treading (),
tumbling () and vacillating-breathing (). A consistent higher order
theory reveals a direct bifurcation from to if is small enough (= vesicle relaxation time towards
equilibrium shape, =shear rate). At larger the is
preceded by the mode. For we recover the leading order original
calculation, where the mode coexists with . The consistent calculation
reveals several quantitative discrepancies with recent works, and points to new
features. We analyse rheology and find that the effective viscosity exhibits a
minimum at and bifurcation points.Comment: 4 pages, 5 figure
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