3,022 research outputs found
The Role of Motivational Persistence and Resilience Over the Well-being Changes Registered in Time
The present study investigates the interaction between personal characteristics that are considered nowadays strengths used to face difficult events or transition period. A number of 200 married or living together participants completed self-reports for common goals, motivational persistence, resilience and well-being. Results show that persistence and resilience do interact with each other at an individual level but also from a family concept perspective. Moreover, maintaining apositive outlook and family spirituality do have an impact over the intensity and direction of the relationship between long term purposes pursuing and recurrence of unattained purposes and changes in well-being registered in time. Resiliency as a personal characteristic and family resilience show good psychometric qualities for this study. Although some of the results are descriptive, in-depth analyses of direction and intensity of the relationships lead the finalconclusions to suggestions for further research and implications for psychological practice
Complexity Estimates for Two Uncoupling Algorithms
Uncoupling algorithms transform a linear differential system of first order
into one or several scalar differential equations. We examine two approaches to
uncoupling: the cyclic-vector method (CVM) and the
Danilevski-Barkatou-Z\"urcher algorithm (DBZ). We give tight size bounds on the
scalar equations produced by CVM, and design a fast variant of CVM whose
complexity is quasi-optimal with respect to the output size. We exhibit a
strong structural link between CVM and DBZ enabling to show that, in the
generic case, DBZ has polynomial complexity and that it produces a single
equation, strongly related to the output of CVM. We prove that algorithm CVM is
faster than DBZ by almost two orders of magnitude, and provide experimental
results that validate the theoretical complexity analyses.Comment: To appear in Proceedings of ISSAC'13 (21/01/2013
Automatic Classification of Restricted Lattice Walks
We propose an experimental mathematics approach leading to the
computer-driven discovery of various structural properties of general counting
functions coming from enumeration of walks
On the harmonic Boltzmannian waves in laser-plasma interaction
We study the permanent regimes of the reduced Vlasov-Maxwell system for
laser-plasma interaction. A non-relativistic and two different relativistic
models are investigated. We prove the existence of solutions where the
distribution function is Boltzmannian and the electromagnetic variables are
time-harmonic and circularly polarized
Finite Larmor radius approximation for the Fokker-Planck-Landau equation
The subject matter of this paper concerns the derivation of the finite Larmor
radius approximation, when collisions are taken into account. Several studies
are performed, corresponding to different collision kernels. The main
motivation consists in computing the gyroaverage of the Fokker-Planck-Landau
operator, which plays a major role in plasma physics. We show that the new
collision operator enjoys the usual physical properties; the averaged kernel
balances the mass, momentum, kinetic energy and dissipates the entropy.Comment: 62 page
Impact of strong magnetic fields on collision mechanism for transport of charged particles
One of the main applications in plasma physics concerns the energy production
through thermo-nuclear fusion. The controlled fusion is achieved by magnetic
confinement i.e., the plasma is confined into a toroidal domain (tokamak) under
the action of huge magnetic fields. Several models exist for describing the
evolution of strongly magnetized plasmas, most of them by neglecting the
collisions between particles. The subject matter of this paper is to
investigate the effect of large magnetic fields with respect to a collision
mechanism. We consider here linear collision Boltzmann operators and derive, by
averaging with respect to the fast cyclotronic motion due to strong magnetic
forces, their effective collision kernels
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