4,302 research outputs found
A generalized FKKM theorem and variational inequality
We present a generalized FKKM Theorem and it's application to the existence of solution for the variationals inequalities using a generalized coercivity type condition for correspondences defined in L-space.L-structure, L-spaces, L-KKM correspondences, L-coercing family and variational inequality.
Meta-models of repeated dissipative joints for damping design phase
Developing tools to predict dissipation in mechanical assemblies starting from the design process is a subject of increasing interest. Design phases imply numerous computations resulting from the use of families of models with varying properties. Model reduction is thus a critical tool to make such design studies affordable. Existing model reduction methods make computation of models with detailed non-linear parts accessible although costly although allowing the generation of a small size model for the linear part. One is, thus, interested in introducing meta-models of the behavior in the non-linear part by determining a basis of principal joint deformations. In this work, one seeks to validate the ability to predict macro-forces associated with the principal deformation shapes. Taking the case of aeronautic structures as cylindrical ones with multiple joints, one seeks to validate the construction of a meta-model associated to the joint. The ability to use such a meta-model to predict damping associated with viscoelastic behavior in a specifically designed bolted joint will be illustrated
Cosmological simulations with hydrodynamics of screened scalar-tensor gravity with non-universal coupling
In this paper we study the effects of letting the dark matter and the gas in
the Universe couple to the scalar field of the symmetron model, a modified
gravity theory, with varying coupling strength. We also search for a way to
distinguish between universal and non-universal couplings in observations. The
research is performed utilising a series of hydrodynamic, cosmological N-Body
simulations, studying the resulting power spectra and galaxy halo properties,
such as the density and temperature profiles. Results show that in the cases of
universal couplings, the deviations in the baryon fraction from CDM
are smaller than in the cases of non-universal couplings throughout the halos.
The same is apparent in the power spectrum baryon bias, defined as the ratio of
gas to dark matter power spectrum. Deviations of the density profiles and power
spectra from the CDM reference values can differ significantly between
dark matter and gas because the dark matter deviations are mostly larger than
the deviations in the gas.Comment: Updated following referee reports, results unchange
Applications of generalized Ky Fan's matching theorem in minimax and variational inequality
We present some application of the generalized Ky Fan's Matching Theorem stated by Chebbi, Gourdel and Hammami in minimax and variational inequalities using a generalized coercivity type condition for correspondences defined in L-space.L-structures, L-spaces, L-KKM correspondences, L-coercing family, minimax and variational inequalities.
Using discrete-time hyperchaotic-based asymmetric encryption and decryption keys for secure signal transmission
In this paper, a framework for the synchronization of two non-identical discrete-time hyperchaotic systems, namely the 3D Baier-Klein and the 3D Hitzel-Zele maps, based on the use of hybrid output feedback concept and aggregation techniques, is employed to design a two-channel secure communication system. New sufficient conditions for synchronization are obtained by the use of Borne and Gentina practical criterion for stabilization study associated to the forced arrow form matrix for system description. The efficiency of the proposed approach to confidentially recover the transmitted message signal is shown via an application to the hyperchaotic Baier-Klein and Hitzel-Zele systems, considered as generators of asymmetric encryption and decryption keys
Reduced joint models for damping design of multi-jointed structures
â Design of damping in multi-jointed structures is studied here. â Dissipation sources are viscoelastic behavior and contact/friction at joints interfaces. â Reduction on meta-models of nonlinear joints models is investigated. â Experimental characterization of nonlinear forces
On the practical global uniform asymptotic stability of stochastic differential equations
The method of Lyapunov functions is one of the most effective ones for the
investigation of stability of dynamical systems, in particular, of stochastic
differential systems. The main purpose of the paper is the analysis of the
stability of stochastic differential equations by using Lyapunov functions when
the origin is not necessarily an equilibrium point. The global uniform
boundedness and the global practical uniform exponential stability of so-
lutions of stochastic differential equations based on Lyapunov techniques are
investigated. Furthermore, an example is given to illustrate the applicability
of the main result.Comment: To appear in Stochastic
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