689 research outputs found
Soccer, Stock Returns, and Fanatiscism: Evidence from Turkey
Cataloged from PDF version of article.This paper assesses the effect of three major soccer teams' wins on the returns of the Istanbul Stock Exchange (ISE). We argue that the effect of soccer wins on ISE returns increases with the fanaticism of the teams' supporters. (C) 2009 Western Social Science Association. Published by Elsevier Inc. All rights reserved
Tactics for Reasoning modulo AC in Coq
We present a set of tools for rewriting modulo associativity and
commutativity (AC) in Coq, solving a long-standing practical problem. We use
two building blocks: first, an extensible reflexive decision procedure for
equality modulo AC; second, an OCaml plug-in for pattern matching modulo AC. We
handle associative only operations, neutral elements, uninterpreted function
symbols, and user-defined equivalence relations. By relying on type-classes for
the reification phase, we can infer these properties automatically, so that
end-users do not need to specify which operation is A or AC, or which constant
is a neutral element.Comment: 16
TYC 2675-663-1: A newly discovered W UMa system in an active state
The recently discovered eclipsing binary system TYC 2675-663-1 is a X-ray
source, and shows properties in the optical that are similar to the W UMa
systems, but are somewhat unusual compared to what is seen in other contact
binary systems. The goal of this work is to characterize its properties and
investigate its nature by means of detailed photometric and spectroscopic
observations. We have performed extensive V-band photometric measurements with
the INTEGRAL satellite along with ground-based multi-band photometric
observations, as well as high-resolution spectroscopic monitoring from which we
have measured the radial velocities of the components. These data have been
analysed to determine the stellar properties, including the absolute masses and
radii. Additional low-resolution spectroscopy was obtained to investigate
spectral features. From the measured eclipse timings we determine an orbital
period for the binary of P=0.4223576+-0.0000009 days. The light-curve and
spectroscopic analyses reveal the observations to be well represented by a
model of an overcontact system composed of main-sequence F5 and G7 stars
(temperature difference of nearly 1000 K), with the possible presence of a
third star. Low-resolution optical spectroscopy reveals a complex H alpha
emission, and other features that are not yet understood. The unusually large
mass ratio of q=0.81+-0.05 places it in the rare "H" (high mass ratio) subclass
of the W UMa systems, which are presumably on their way to coalescence.Comment: 12 pages in double column format. Accepted for publication in
Astronomy and Astrophysic
Optimization of double pulse pumping for Ni-like Sm x-ray lasers
We report a systematic study of double pulse pumping of the Ni-like Sm x-ray laser at 73 Angstrom, currently the shortest wavelength saturated x-ray laser. It is found that the Sm x-ray laser output can change by orders of magnitude when the intensity ratio of the pumping pulses and their relative delay are varied. Optimum pumping conditions are found and interpreted in terms of a simple model. (C) 1999 American Institute of Physics. [S0021-8979(99)07102-9]
Modelling the drivers of a widespread shift to sustainable diets
A reduction in global meat consumption can significantly reduce the adverse environmental effects of the food system, but it would require widespread dietary changes. Such shifts to sustainable diets depend on several behavioural factors that have not yet been addressed in relation to the food system. This study links a behavioural diet shift model to an integrated assessment model to identify the main drivers of global diet change and its implications for the food system. The results show that the social norm effect (for instance, the extent of vegetarianism in the population that accelerates a further switch to a vegetarian diet) and self-efficacy are the main drivers of widespread dietary changes. These findings stress the importance of value-driven actions motivated either by intrinsic identity or by group dynamics over health and climate risk perceptions in steering diet change dynamics
Football and exchange rates: Empirical support for behavioral economics
Recently, economic theory has been expanded to incorporate emotions, which have been assumed to play an important role in financial decisions. The present study illustrates this by showing a connection between the sports performance of popular national football teams (Besiktas, Fenerbahce, and Galatasaray) and performance of the Turkish economy. Specifically, a significant positive association was found between the success of three major professional Turkish football teams and the exchange rate of the Turkish lira against the U.S. dollar. The effect of the football success of several Turkish football teams on the exchange rate of the Turkish lira was examined using the simultaneous multiple regression model with predictor measures of wins, losses, and ties for different combinations of teams to predict the depreciation rate of the Turkish lira between the years 1987 and 2003. Wins by Turkish football teams against foreign (non-Turkish) rivals increased with exchange rate depreciation of the Turkish lira against the U.S. dollar. © Psychological Reports 2007
Automated Certification of Authorisation Policy Resistance
Attribute-based Access Control (ABAC) extends traditional Access Control by
considering an access request as a set of pairs attribute name-value, making it
particularly useful in the context of open and distributed systems, where
security relevant information can be collected from different sources. However,
ABAC enables attribute hiding attacks, allowing an attacker to gain some access
by withholding information. In this paper, we first introduce the notion of
policy resistance to attribute hiding attacks. We then propose the tool ATRAP
(Automatic Term Rewriting for Authorisation Policies), based on the recent
formal ABAC language PTaCL, which first automatically searches for resistance
counter-examples using Maude, and then automatically searches for an Isabelle
proof of resistance. We illustrate our approach with two simple examples of
policies and propose an evaluation of ATRAP performances.Comment: 20 pages, 4 figures, version including proofs of the paper that will
be presented at ESORICS 201
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