11,892 research outputs found
Theoretical description of the , and reactions
We have made a study of the (with
being and ) and assuming
the axial vector mesons to be dynamically generated from the
pseudoscalar-vector meson interaction. We have taken the needed input from
previous studies of the reactions.
We obtain fair agreement with experimental data and provide an explanation on
why the recent experiment on observed in the mode observes the peak of the
at a higher energy than its nominal mass.Comment: 21 pages, 6 figure
On Dust Extinction of Gamma-ray Burst Host Galaxies
Although it is well recognized that gamma-ray burst (GRB) afterglows are
obscured and reddened by dust in their host galaxies, the wavelength-dependence
and quantity of dust extinction are still poorly known. Current studies on this
mostly rely on fitting the afterglow spectral energy distributions (SEDs) with
template extinction models. The inferred extinction (both quantity and
wavelength-dependence) and dust-to-gas ratios are often in disagreement with
that obtained from dust depletion and X-ray spectroscopy studies. We argue that
this discrepancy could result from the prior assumption of a template
extinction law. We propose an analytical formula to approximate the GRB host
extinction law. With the template extinction laws self-contained, and the
capability of revealing extinction laws differing from the conventional ones,
it is shown that this is a powerful approach in modeling the afterglow SEDs to
derive GRB host extinction.Comment: 9 pages, 4 figures; The Astrophysical Journal, in press (2008 Oct 1
issue
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Do business relationships affect the accuracy of analyst earnings forecasts? Evidence from China
Supporting the ‘conflicts of interest hypothesis’, we show that, in China, better-informed analysts issue more optimistically biased forecasts and reputation of financial analysts mitigates the bias. We contribute to literature by showing that such an adverse information effect varies over types of investment banking relationships and a better developed local legal environment reduces forecast bias. Our results call for a better developed market mechanism to discipline analysts so as to issue independent and accurate earnings forecasts in China
Transmission characteristics of a Fabry-Perot etalon-microtoroid resonator coupled system
The transmission spectra of a Fabry-Perot etalon coupled to a microtoroid resonator are studied theoretically and experimentally. The resonance line shapes depend strongly on the resonance wavelength detuning and coupling strength between the two resonators. A wide variety of line shapes, ranging from a single to triple peaks, symmetric to asymmetric Fano-like peaks, and notches were predicted and observed experimentally. The capability to modify the spectral line shapes by tuning the coupling between or losses of two resonators may find applications in optical filtering, switching, sensing, and dispersion engineering
Combined electromagnetic and photoreaction modeling of CLD-1 photobleaching in polymer microring resonators
By combining a solid-state photoreaction model with the modal solutions of an optical waveguide, we simulate the refractive index change due to the photobleaching of CLD-1 chromophores in an amorphous polycarbonate microring resonator. The simulation agrees well with experimental results. The photobleaching quantum efficiency of the CLD-1 chromophores is determined to be 0.65%. The combined modeling of the electromagnetic wave propagation and photoreaction precisely illustrates the spatial and temporal evolution of the optical properties of the polymer material as manifested in the refractive index and their effects on the modal and physical properties of the optical devices
Privacy Preserving Utility Mining: A Survey
In big data era, the collected data usually contains rich information and
hidden knowledge. Utility-oriented pattern mining and analytics have shown a
powerful ability to explore these ubiquitous data, which may be collected from
various fields and applications, such as market basket analysis, retail,
click-stream analysis, medical analysis, and bioinformatics. However, analysis
of these data with sensitive private information raises privacy concerns. To
achieve better trade-off between utility maximizing and privacy preserving,
Privacy-Preserving Utility Mining (PPUM) has become a critical issue in recent
years. In this paper, we provide a comprehensive overview of PPUM. We first
present the background of utility mining, privacy-preserving data mining and
PPUM, then introduce the related preliminaries and problem formulation of PPUM,
as well as some key evaluation criteria for PPUM. In particular, we present and
discuss the current state-of-the-art PPUM algorithms, as well as their
advantages and deficiencies in detail. Finally, we highlight and discuss some
technical challenges and open directions for future research on PPUM.Comment: 2018 IEEE International Conference on Big Data, 10 page
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