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Improving random number generators by chaotic iterations. Application in data hiding
Chaotic sequences Topological chaos Pseudorandom random number generator
2010/12/28
In this paper, a new pseudo-random number generator (PRNG) based on chaotic iterations is proposed. This method also combines the digits of two XORshifts PRNGs.
Conditional symmetries and exact solutions of the diffusive Lotka-Volterra system
Lotka-Volterra system reaction-diffusion system Lie symmetry
2011/2/28
Q-conditional symmetries of the classical Lotka-Volterra system in the case of one space variable are completely described and a set of such symmetries in explicit form is constructed. The relevant no...
We present a spectral sequence which efficiently computes Betti numbers of a closed semi-algebraic subset of RPn defined by a system of qua-dratic inequalities and the image of the homology homomorphi...
Supports of Weighted Equilibrium Measures and Examples
Weighted Pluripotential Theory Extremal Measures
2011/1/17
We analyze the supports of weighted equilibrium measures in Cn. We give explicit examples of families of compact sets which arise as the support of a weighted equilibrium measure for some admissible w...
Isoperimetric problems in sectors with density
Isoperimetric problems sectors with density
2011/1/17
We consider the isoperimetric problem in planar sectors with density rp, and with density a > 1 inside the unit disk and 1 outside. We characterize solutions as a function of sector angle. We also sol...
Ultradiscrete Plücker Relation Specialized for Soliton Solutions
Ultradiscrete Plücker Relation Specialized Soliton Solutions
2010/12/28
We propose an ultradiscrete analogue of Pl¨ucker relation specialized for soliton solutions.
It is expressed by an ultradiscrete permanent which is obtained by ultradiscretizing the per-
manent, tha...
Bar complexes and extensions of classical exponential functors
Bar complexes extensions classical exponential functors
2011/1/21
We compute Ext-groups between classical exponential func-tors (i.e. symmetric, exterior or divided powers) and their Frobenius twists. Our method relies on bar constructions, and bridges these Ext-gro...
Generalized covariation for Banach valued processes and Itô formula
Covariation and Quadratic variation Calculus via regularization
2011/1/20
This paper concerns the notion of quadratic variation and covariation for Banach valued processes and related Itô formula. If X and Y take respectively values in Banach spaces B1 and B2 (denoted...
Test of some numerical limiters for the conservative PSM scheme for 4D Drift-Kinetic simulations
numerical simulation conservative scheme ITER plasma turbulence
2011/3/2
The purpose of this work is simulation of magnetised plasmas in the ITER project framework. In this context, Vlasov-Poisson like models are used to simulate core turbulence in the tokamak in a toroida...
Equilibration, generalized equipartition, and diffusion in dynamical Lorentz gases
Equilibration generalized equipartition diffusion dynamical Lorentz gases
2010/12/15
We prove approach to thermal equilibrium for the fully Hamiltonian dynamics of a dynamical Lorentz gas, by which we mean an ensemble of particles moving through a d-dimensional array of fixed soft sca...
Implicit iteration methods in Hilbert scales under general smoothness conditions
Ill-posed problems inverse problems regularization Hilbert scales
2010/12/9
For solving linear ill-posed problems regularization methods are required when the right hand side is with some noise. In the present paper regularized solutions are obtained by implicit iteration met...
Compactness properties of weighted summation operators on trees - the critical case
Metrics on trees operators on trees weighted summation operators
2010/12/6
The aim of this paper is to provide upper bounds for the entropy numbers of summation
operators on trees in a critical case. In a recent paper [10] we elaborated a framework of
weighted summation op...
Calculation of generalized Hubbell rectangular source integral
Appell hypergeometric functions F2 Hubbell radiation rectangular source integral
2010/12/3
A simple formula for computing the generalized Hubbell radiation rectangular source integral
H a, b, p, λ α, β, γ = σa 4π Z b 0 x(x2 + p)− 2F1(α, β; γ;− a2\ x2 + p )dx, is introduce...
Classical non mass preserving solutions of coagulation equations
Classical non mass preserving solutions coagulation equations
2010/12/6
In this paper we construct classical solutions of a family of coagulation equations with homogeneous kernels that exhibit the behaviour known as gelation. This behaviour consists
in the loss of mass ...
Perturbations of embedded eigenvalues for the planar bilaplacian
Perturbations of embedded eigenvalues planar bilaplacian
2010/11/29
Operators on unbounded domains may acquire eigenvalues that are embedded in the essential spectrum.Determining the fate of these embedded eigenvalues under small perturbations of the underlying operat...