2,490 research outputs found
Will mobile video become the killer application for 3G? - an empirical model for media convergence
Mobile carriers have continually rolled out 3G mobile video applications to increase their revenue and profits. The presumption is that video is superior to the already successful SMS, ringtones, and pictures, and can create greater value to users. However, recent market surveys revealed contradicting results. Motivated by this discrepancy, we propose in this paper a parsimonious model for user acceptance of mobile entertainment as digital convergence. Integrating research on Information Systems, Flow, and Media Psychology, we take a unique approach to user acceptance of digital convergence - platform migration. Our key proposition is that the interaction between media types and the platform-specific constraints is the key determinant of user evaluation. Particularly, users' involvement in the media is determined by both the entertaining time span on the original platform and the attentional constraint of the new platform. The mismatch between the two spans can result in lower level involvement, which in turn cause no or even negative user emotional responses. The model was tested with empirical data. We discuss the theoretical contributions, strategic and design implications, and future research directions derived from this theoretical framewor
Network synchronization: Optimal and Pessimal Scale-Free Topologies
By employing a recently introduced optimization algorithm we explicitely
design optimally synchronizable (unweighted) networks for any given scale-free
degree distribution. We explore how the optimization process affects
degree-degree correlations and observe a generic tendency towards
disassortativity. Still, we show that there is not a one-to-one correspondence
between synchronizability and disassortativity. On the other hand, we study the
nature of optimally un-synchronizable networks, that is, networks whose
topology minimizes the range of stability of the synchronous state. The
resulting ``pessimal networks'' turn out to have a highly assortative
string-like structure. We also derive a rigorous lower bound for the Laplacian
eigenvalue ratio controlling synchronizability, which helps understanding the
impact of degree correlations on network synchronizability.Comment: 11 pages, 4 figs, submitted to J. Phys. A (proceedings of Complex
Networks 2007
Noether symmetries for two-dimensional charged particle motion
We find the Noether point symmetries for non-relativistic two-dimensional
charged particle motion. These symmetries are composed of a quasi-invariance
transformation, a time-dependent rotation and a time-dependent spatial
translation. The associated electromagnetic field satisfy a system of
first-order linear partial differential equations. This system is solved
exactly, yielding three classes of electromagnetic fields compatible with
Noether point symmetries. The corresponding Noether invariants are derived and
interpreted
Law Behind Second Law of Thermodynamics --Unification with Cosmology--
In an abstract setting of a general classical mechanical system as a model
for the universe we set up a general formalism for a law behind the second law
of thermodynamics, i.e. really for "initial conditions". We propose a
unification with the other laws by requiring similar symmetry and locality
properties.Comment: 17 page
Ultra-High Energy Neutrino Fluxes: New Constraints and Implications
We apply new upper limits on neutrino fluxes and the diffuse extragalactic
component of the GeV gamma-ray flux to various scenarios for ultra high energy
cosmic rays and neutrinos. As a result we find that extra-galactic top-down
sources can not contribute significantly to the observed flux of highest energy
cosmic rays. The Z-burst mechanism where ultra-high energy neutrinos produce
cosmic rays via interactions with relic neutrinos is practically ruled out if
cosmological limits on neutrino mass and clustering apply.Comment: 10 revtex pages, 9 postscript figure
Searching for physics beyond the Standard Model through the dipole interaction
The magnetic dipole interaction played a central role in the development of
QED, and continued in that role for the Standard Model. The muon anomalous
magnetic moment has served as a benchmark for models of new physics, and the
present experimental value is larger than the standard-model value by more than
three standard deviations. The electric dipole moment (EDM) violates parity
({}) and time-reversal ({}) symmetries, and in the context of the
theorem, the combination of charge conjugation and parity (). Since a new
source of {} violation outside of that observed in the and meson
systems is needed to help explain the baryon asymmetry of the universe,
searches for EDMs are being carried out worldwide on a number of systems. The
standard-model value of the EDM is immeasurably small, so any evidence for an
EDM would signify the observation of new physics. Unique opportunities exist
for EDM searches using polarized proton, deuteron or muon beams in storage
rings. This talk will provide an overview of the theory of dipole moments, and
the relevant experiments. The connection to the transition dipole moment that
could produce lepton flavor violating interactions such as is also mentioned.Comment: Invited Plenary talk at the 19th International Spin Physics
Symposium, Juelic
Correlation functions of eigenvalues of multi-matrix models, and the limit of a time dependent matrix
We consider the correlation functions of eigenvalues of a unidimensional
chain of large random hermitian matrices. An asymptotic expression of the
orthogonal polynomials allows to find new results for the correlations of
eigenvalues of different matrices of the chain. Eventually, we consider the
limit of the infinite chain of matrices, which can be interpreted as a time
dependent one-matrix model, and give the correlation functions of eigenvalues
at different times.Comment: Tex-Harvmac, 27 pages, submitted to Journ. Phys.
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