Repositorio IPICyT: Envíos recientes
Mostrando ítems 1641-1660 de 2301
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Índice de pobreza del agua en los acuíferos de Cerritos-Vila Juárez y Rioverde de la zona media de San Luis Potosí
(2017-01)"En la actualidad la deficiente gestión de los recursos hídricos, el crecimiento de la población y una falta cultura en aprovechamiento de los recursos naturales, ha incrementado la sobreexplotación de los acuíferos en ... -
One-parameter isospectral special functions
(2003)"Using a combination of the ladder operators of Pina [1] and the Pammetric operators of Mielnik [2] we introduce second order linear differential equations whose eigenfunctions are isospectral to the special functions of ... -
Riccati nonhermiticity with application to the Morse potential
(2005)"A supersymmetric one-dimensional matrix procedure, similar to the relationships of the same type between Dirac and Schrodinger equations in particle physics, is described in the general terms. By this means, we are able ... -
Electromagnetic transmittance in alternating material-metamaterial layered structures
(2017)"Using the transfer matrix method we examine the parametric behavior of the transmittance of TE and TM electromagnetic plane waves propagating in frequency range which are far from the absorption bands of a periodic ... -
Extension of a factorization method of nonlinear second order ODE´s with variable coefficients
(2017)"The factorization of nonlinear second-order differential equations proposed by Rosu and Cornejo-Pérez in 2005 is extended to equations containing quadratic and cubic forms in the first derivative. A few illustrative ... -
Traveling kinks in cubic nonlinear Ginzburg-Landau equations
(2012)"Nonlinear cubic Euler-Lagrange equations of motion in the traveling variable are usually derived from Ginzburg-Landau free energy functionals frequently encountered in several fields of physics. Many authors considered ... -
Nonlinear second order Ode's: factorizations and particular solutions
(2005)"We present particular solutions for the following important nonlinear second order differential equations: modified Emden, generalized Lienard, convective Fisher, and generalized Burgers-Huxley. For the latter two equations ... -
Nonlinear software sensor for monitoring genetic regulation processes with noise and modeling errors
(2005)"Nonlinear control techniques by means of a software sensor that are commonly used in chemical engineering could be also applied to genetic regulation processes. We provide here a realistic formulation of this procedure ... -
Ramanujan sums for signal processing of low-frequency noise
(2002)"An aperiodic (low-frequency) spectrum may originate from the error term in the mean value of an arithmetical function such as Mobius function or Mangoldt function, which are coding sequences for prime numbers. In the ... -
Supersymmetric pairing of kinks for polynomial nonlinearities
(2005)"We show how one can obtain kink solutions of ordinary differential equations with polynomial nonlinearities by an efficient factorization procedure directly related to the factorization of their nonlinear polynomial part. ... -
Genetic algorithm optimization of entanglement
(2006)"We present an application of a genetic algorithmic computational method to the optimization of the concurrence measure of entanglement for the cases of one dimensional chains, as well as square and triangular lattices in ... -
Existence of periodic orbits in nonlinear oscillators of Emden-Fowler form
(2016)"The nonlinear pseudo-oscillator recently tackled by Gadella and Lara is mapped to an Emden-Fowler (EF) equation that is written as an autonomous two-dimensional ODE system for which we provide the phase-space analysis and ... -
FRW barotropic zero modes: dynamical systems observability
(2007)"The dynamical systems observability properties of barotropic bosonic and fermionic FRW cosmological oscillators are investigated. Nonlinear techniques for dynamical analysis have been recently developed in many engineering ... -
Newton´s laws of motion in the form of a Riccati equation
(2002)"We discuss two applications of a Riccati equation to Newton´s laws of motion. The first one is the motion of a particle under the influence of a power law central potential V(r)=krε. For zero total energy we show that the ... -
Barotropic FRW cosmologies with Chiellini damping
(2015)"It is known that barotropic FRW equations written in the conformal time variable can be reduced to simple linear equations for an exponential function involving the conformal Hubble rate. Here, we show that an interesting ... -
Integrable dissipative nonlinear second order differential equations via factorizations and Abel equations
(2013)"We emphasize two connections, one well known and another less known, between the dissipative nonlinear second order differential equations and the Abel equations which in its first kind form have only cubic and quadratic ... -
Ermakov-Lewis invariants and Reid systems
(2014)"Reid´s mth-order generalized Ermakov systems of nonlinear coupling constant ? are equivalent to an integrable Emden-Fowler equation. The standard Ermakov-Lewis invariant is discussed from this perspective, and a closed ... -
An alternative factorization of the quantum harmonic oscillator and two-parameter family of self-adjoint operators
(2012)"We introduce an alternative factorization of the Hamiltonian of the quantum harmonic oscillator which leads to a two-parameter self-adjoint operator from which the standard harmonic oscillator, the one-parameter oscillators ... -
Self-adjoint oscillator operator from a modified factorization
(2011)"By using an alternative factorization, we obtain a self-adjoint oscillator operator of the form Lδ=ddx(pδ(x)ddx)−(x2pδ(x)+pδ(x)−1), where pδ(x)=1+δe−x2, with δ∈(−1,∞) an arbitrary real factorization parameter. At positive ... -
Parametric oscillators from factorizations employing a constant-shifted Riccati solution of the classical harmonic oscillator
(Elsevier, 2011)"We determine the kind of parametric oscillators that are generated in the usual factorization procedure of second-order linear differential equations when one introduces a constant shift of the Riccati solution of the ...