Search results for "stochastic"
showing 10 items of 1018 documents
Vibrational population of H 2 + after electroionization of thermal H2
1993
In an ion trap experiment we have determined the vibrational population of the lowest 9 vibrational levels of H2+. We used photodissociation of the trapped molecules by 248 nm light from an excimer laser and the dependence of the photodissociation cross section from the vibrational state. Our results are in good agreement to calculations, which are based on the Franck-Condon principle, but include a variation of the internuclear distance in the transition matrix element.
Opinion dynamics and stubbornness through mean-field games
2013
This paper provides a mean field game theoretic interpretation of opinion dynamics and stubbornness. The model describes a crowd-seeking homogeneous population of agents, under the influence of one stubborn agent. The game takes on the form of two partial differential equations, the Hamilton-Jacobi-Bellman equation and the Kolmogorov-Fokker-Planck equation for the individual optimal response and the population evolution, respectively. For the game of interest, we establish a mean field equilibrium where all agents reach epsilon-consensus in a neighborhood of the stubborn agent's opinion.
On the qualitative analysis of the solutions of a mathematical model of social dynamics
2006
Abstract This work deals with a family of dynamical systems which were introduced in [M.L. Bertotti, M. Delitala, From discrete kinetic and stochastic game theory to modelling complex systems in applied sciences, Math. Models Methods Appl. Sci. 7 (2004) 1061–1084], modelling the evolution of a population of interacting individuals, distinguished by their social state. The existence of certain uniform distribution equilibria is proved and the asymptotic trend is investigated.
Call admission control scheme using borrowable guard channels and prioritizing fresh calls retrials in small cell networks
2014
International audience; Recent trends in mobile cellular networks turn towards deployment of Small Cell Networks (SCNs), where, the cell size gets smaller, and thus the number of subscribers served in a cell will be relatively smaller, such that traffic models with a finite source of subscribers should be considered. Smaller cells cause the mobile subscribers to cross several cells during an ongoing conversation resulting in frequent handovers. Most of works dealing with Call Admission Control (CAC) problems based on guard channels scheme in cellular mobile networks consider models without retrials (reapeted calls phenomenon). However, almost all existing works which take into account retri…
Large Networks of Dynamic Agents: Consensus under Adversarial Disturbances
2012
This paper studies interactions among homogeneous social groups within the framework of large population games. Each group is represented by a network and the behavior described by a two-player repeated game. The contribution is three-fold. Beyond the idea of providing a novel two-level model with repeated games at a lower level and population games at a higher level, we also establish a mean field equilibrium and study state feedback best-response strategies as well as worst-case adversarial disturbances in that context.
Quadratic least-squares formulation for a local active noise control with stochastic domain and noise source
2012
A local active noise control method that uses stochastic numerical acoustical modeling is introduced. The frequency domain acoustical simulations are performed by a sequence solutions to Helmholtz equations approximated by FEM. The proposed ANC method maps microphone measurements linearly to the output signals of antinoise actuators. The matrix defining the linear mapping is optimized for each frequency to minimize expected value of the noise. The paper concentrates on defining the quadratic least-squares optimization problem for the minimization of the sound pressure field in the silet region. The formulation leads to a robust and accurate noise control in stochastic domains that has a sto…
Stochastic Frontiers Approach: an Empirical Analysis of Italian Environmental Spending
2012
Using the stochastic frontiers approach (SFA) on a panel of Italian regional data, this paper tries to analyse the optimal design of environmental spending. The main question is, so forth, studying centralization vs decentralization of a public economic function, such as the protection of the environment, in order to improve the welfare of a country. Empirical results on Italy are ambiguous: the changing from a centralized to a decentralized government, giving more autonomy to local units, does not highlight a clear improvement in regional economic performance.
Local vs. National Environmental Spending: A Stochastic Frontier Analysis
2012
This work studies the impact of public environmental spending in a fiscal federalist framework. The main question is studying when the centralization of this public economic function is welfare improving. Applying the Stochastic Frontier Approach (SFA) on Italian, Portuguese and Slovakian data, the paper tries to test this issue. Our results highlight the superiority of centralized environmental spending with respect to the decentralization of this particular public good.
SIRV epidemic model with stochastic perturbation
2014
We propose a stochastic disease model where vaccination is included and such that the immunity is permanent. The existence, uniqueness and positivity of the solution and the stability of the disease free-equilibrium are studied
Asymptotic Hölder regularity for the ellipsoid process
2020
We obtain an asymptotic Hölder estimate for functions satisfying a dynamic programming principle arising from a so-called ellipsoid process. By the ellipsoid process we mean a generalization of the random walk where the next step in the process is taken inside a given space dependent ellipsoid. This stochastic process is related to elliptic equations in non-divergence form with bounded and measurable coefficients, and the regularity estimate is stable as the step size of the process converges to zero. The proof, which requires certain control on the distortion and the measure of the ellipsoids but not continuity assumption, is based on the coupling method.