4,323 research outputs found
D2D Data Offloading in Vehicular Environments with Optimal Delivery Time Selection
Within the framework of a Device-to-Device (D2D) data offloading system for
cellular networks, we propose a Content Delivery Management System (CDMS) in
which the instant for transmitting a content to a requesting node, through a
D2D communication, is selected to minimize the energy consumption required for
transmission. The proposed system is particularly fit to highly dynamic
scenarios, such as vehicular networks, where the network topology changes at a
rate which is comparable with the order of magnitude of the delay tolerance. We
present an analytical framework able to predict the system performance, in
terms of energy consumption, using tools from the theory of point processes,
validating it through simulations, and provide a thorough performance
evaluation of the proposed CDMS, in terms of energy consumption and spectrum
use. Our performance analysis compares the energy consumption and spectrum use
obtained with the proposed scheme with the performance of two benchmark
systems. The first one is a plain classic cellular scheme, the second is a D2D
data offloading scheme (that we proposed in previous works) in which the D2D
transmissions are performed as soon as there is a device with the required
content within the maximum D2D transmission range..
Nucleon Spin Structure with hadronic collisions at COMPASS
In order to illustrate the capabilities of COMPASS using a hadronic beam, I
review some of the azimuthal asymmetries in hadronic collisions, that allow for
the extraction of transversity, Sivers and Boer-Mulders functions, necessary to
explore the partonic spin structure of the nucleon. I also report on some Monte
Carlo simulations of such asymmetries for the production of Drell-Yan lepton
pairs from the collision of high-energy pions on a transversely polarized
proton target.Comment: talk delivered to the "International Workshop on Structure and
Spectroscopy", Freiburg, March 19-21, 2007; 18 pages, RevTeX4 style, 8
figures with 10 .eps file
Big image of Galois representations associated with finite slope -adic families of modular forms
We consider the Galois representation associated with a finite slope -adic
family of modular forms. We prove that the Lie algebra of its image contains a
congruence Lie subalgebra of a non-trivial level. We describe the largest such
level in terms of the congruences of the family with -adic CM forms.Comment: 23 pages; revision of Section 2 (see Remark 2.4) and improvement of
Proposition 4.14, plus minor changes. Published in "Elliptic Curves, Modular
Forms and Iwasawa Theory. In Honour of John H. Coates' 70th Birthday,
Cambridge, UK, March 2015", Springer Proceedings in Mathematics & Statistics,
Vol. 188, 201
Popularity
What makes you popular among your high-school peers? And what are the labor market returns to popularity? We investigate these questions using an objective measure of popularity derived from sociometric theory: the number of friendship nom- inations received from schoolmates. We provide novel evidence that early family en- vironment, school composition and school size play a signicant role in determining popularity. We show that the estimated wage return to one additional nomination is about 2 percent the popularity premium. This amounts to roughly 40 percent of the return to one more year of education.
A revised version of this paper is published in the Fall 2013 issue of the Journal of Human Resources
Time-resolved dynamics of granular matter by random laser emission
Because of the huge commercial importance of granular systems, the
second-most used material in industry after water, intersecting the industry in
multiple trades, like pharmacy and agriculture, fundamental research on
grain-like materials has received an increasing amount of attention in the last
decades. In photonics, the applications of granular materials have been only
marginally investigated. We report the first phase-diagram of a granular as
obtained by laser emission. The dynamics of vertically-oscillated granular in a
liquid solution in a three-dimensional container is investigated by employing
its random laser emission. The granular motion is function of the frequency and
amplitude of the mechanical solicitation, we show how the laser emission allows
to distinguish two phases in the granular and analyze its spectral
distribution. This constitutes a fundamental step in the field of granulars and
gives a clear evidence of the possible control on light-matter interaction
achievable in grain-like system.Comment: 16 pages, 7 figure
- …
