182 research outputs found
Vehicle Communication using Secrecy Capacity
We address secure vehicle communication using secrecy capacity. In
particular, we research the relationship between secrecy capacity and various
types of parameters that determine secrecy capacity in the vehicular wireless
network. For example, we examine the relationship between vehicle speed and
secrecy capacity, the relationship between the response time and secrecy
capacity of an autonomous vehicle, and the relationship between transmission
power and secrecy capacity. In particular, the autonomous vehicle has set the
system modeling on the assumption that the speed of the vehicle is related to
the safety distance. We propose new vehicle communication to maintain a certain
level of secrecy capacity according to various parameters. As a result, we can
expect safer communication security of autonomous vehicles in 5G
communications.Comment: 17 Pages, 12 Figure
Effective Numerical Simulations of Synchronous Generator System
Synchronous generator system is a complicated dynamical system for energy
transmission, which plays an important role in modern industrial production. In
this article, we propose some predictor-corrector methods and
structure-preserving methods for a generator system based on the first
benchmark model of subsynchronous resonance, among which the
structure-preserving methods preserve a Dirac structure associated with the
so-called port-Hamiltonian descriptor systems. To illustrate this, the
simplified generator system in the form of index-1 differential-algebraic
equations has been derived. Our analyses provide the global error estimates for
a special class of structure-preserving methods called Gauss methods, which
guarantee their superior performance over the PSCAD/EMTDC and the
predictor-corrector methods in terms of computational stability. Numerical
simulations are implemented to verify the effectiveness and advantages of our
methods
Is exponential gravity a viable description for the whole cosmological history?
Here we analysed a particular type of gravity, the so-called
exponential gravity which includes an exponential function of the Ricci scalar
in the action. Such term represents a correction to the usual Hilbert-Einstein
action. By using Supernovae Ia, Barionic Acoustic Oscillations, Cosmic
Microwave Background and data, the free parameters of the model are well
constrained. The results show that such corrections to General Relativity
become important at cosmological scales and at late-times, providing an
alternative to the dark energy problem. In addition, the fits do not determine
any significant difference statistically with respect to the CDM
model. Finally, such model is extended to include the inflationary epoch in the
same gravitational Lagrangian. As shown in the paper, the additional terms can
reproduce the inflationary epoch and satisfy the constraints from Planck data.Comment: 20 pages, 6 figures, analysis extended, version published in EPJ
- …