33,029 research outputs found
Arbitrage, market definition and monitoring a time series approach
This article considers the application to regional price data of time series methods to test stationarity, multivariate cointegration and exogeneity. The discovery of stationary price differentials in a bivariate setting implies that the series are rendered stationary by capturing a common trend and we observe through this mechanism long-run arbitrage. This is indicative of a broader market definition and efficiency. The problem is considered in relation to more than 700 weekly data points on gasoline prices for three regions of the US and similarly calibrated simulated series. The discovery of a single common trend is consistent with competitive pricing and a broad market definition, but the finding of a single weakly exogenous variable affects this conclusion
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Acquisition Activity in the United Kingdom: Parametric and Semi-Parametric Estimation
In this article we attempt to identify the nancial characteristics of
takeover targets in UK using the period 1982-1990. The study analyses
the relationship between bidders and targets, and targets and non-targets
over two distinct sub-periods, 1982-1985 and 1986-1990 which are viewed
as being homogenous. The rst period followed a deep recession which
followed a distinct shift in Macroeconomic Policy after 1979. The second
period was associated with nancial liberalisation in 1986 and the freeing
up of Monetary policy that followed the Stock Market Crash in 1987. To
facilitate this analysis, two bi-variate Logit models are estimated over each
sub-period and over the period as a whole. The above models are used
to test whether Merger and Acquisition behaviour has changed by under-
taking a Likelihood Ratio based analogue of the Chow test. A General
Modelling strategy is adopted to select variables as a mechanism for pre-
cluding inconsistency and reducing the impact of collinearity. Comparison
is also made with a semi-parametric estimator
Erratum: IRAS observations of irregular galaxies
In Infrared Astronomy Satellite (IRAS) observations of irregular galaxies, galactic blue luminosities were based on standard optical definitions. The blue luminosities (L sub B) were derived from the blue absolute magnitude (M sub B) or form the in band flux. However, the L sub B system for spiral galaxies was based on quasi-bolometric (rather than in band) fluxes. The formulation and resulting statements are corrected
Development of quality assurance methods for epoxy graphite prepreg
Quality assurance methods for graphite epoxy/prepregs were developed. Liquid chromatography, differential scanning calorimetry, and gel permeation chromatography were investigated. These methods were applied to a second prepreg system. The resin matrix formulation was correlated with mechanical properties. Dynamic mechanical analysis and fracture toughness methods were investigated. The chromatography and calorimetry techniques were all successfully developed as quality assurance methods for graphite epoxy prepregs. The liquid chromatography method was the most sensitive to changes in resin formulation. The were also successfully applied to the second prepreg system
A comparison of star formation characteristics in different types of irregular galaxies
Two regions of recent star formation in blue irregular galaxies were observed with the IUE in the short wavelength, low dispersion mode. The spectra indicates that the massive star content is similar in these regions and is best fit by massive stars formed in a burst and now are approximately 2.5 to 3.0 million years old
Phonon transport in large scale carbon-based disordered materials: Implementation of an efficient order-N and real-space Kubo methodology
We have developed an efficient order-N real-space Kubo approach for the
calculation of the phonon conductivity which outperforms state-of-the-art
alternative implementations based on the Green's function formalism. The method
treats efficiently the time-dependent propagation of phonon wave packets in
real space, and this dynamics is related to the calculation of the thermal
conductance. Without loss of generality, we validate the accuracy of the method
by comparing the calculated phonon mean free paths in disordered carbon
nanotubes (isotope impurities) with other approaches, and further illustrate
its upscalability by exploring the thermal conductance features in large width
edge-disordered graphene nanoribbons (up to ~20 nm), which is out of the reach
of more conventional techniques. We show that edge-disorder is the most
important scattering mechanism for phonons in graphene nanoribbons with
realistic sizes and thermal conductance can be reduced by a factor of ~10.Comment: Accepted for publication in Physical Review B - Rapid Communication
Attracted Diffusion-Limited Aggregation
In this paper, we present results of extensive Monte Carlo simulations of
diffusion-limited aggregation (DLA) with a seed placed on an attractive plane
as a simple model in connection with the electrical double layers. We compute
the fractal dimension of the aggregated patterns as a function of the
attraction strength \alpha. For the patterns grown in both two and three
dimensions, the fractal dimension shows a significant dependence on the
attraction strength for small values of \alpha, and approaches to that of the
ordinary two-dimensional (2D) DLA in the limit of large \alpha. For
non-attracting case with \alpha=1, our results in three dimensions reproduce
the patterns of 3D ordinary DLA, while in two dimensions our model leads to
formation of a compact cluster with dimension two. For intermediate \alpha, the
3D clusters have quasi-2D structure with a fractal dimension very close to that
of the ordinary 2D-DLA. This allows one to control morphology of a growing
cluster by tuning a single external parameter \alpha.Comment: 6 pages, 6 figures, to appear in Phys. Rev. E (2012
IUE observations of luminous blue star associations in irregular galaxies
Two regions of recent star formation in blue irregular galaxies were observed with the IUE in the short wavelength, low dispersion mode. The spectra indicate that the massive star content is similar in these regions and is best fit by massive stars formed in a burst and now approximately 2.5 to 3.0 million years old
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