Results 251 to 260 of about 395,045 (283)

Linearizable planar differential systems via the inverse integrating factor

Journal of Physics A: Mathematical and Theoretical, 2008
Our purpose in this paper is to study when a planar differential system polynomial in one variable linearizes in the sense that it has an inverse integrating factor which can be constructed by means of the solutions of linear differential equations. We give several families of differential systems which illustrate how the integrability of the system ...
Héctor Giacomini, Jaume Giné, Maite Grau   +2 more
openaire   +1 more source

PHASE PORTRAITS OF THE QUADRATIC SYSTEMS WITH A POLYNOMIAL INVERSE INTEGRATING FACTOR

International Journal of Bifurcation and Chaos, 2009
We classify the phase portraits of all planar quadratic polynomial differential systems having a polynomial inverse integrating factor.
Coll, Bartomeu, Ferragut, Antoni, Llibre, Jaume   +2 more
openaire   +2 more sources

Photon output factor calculation from the inverse of the sector-integration equation

Medical Physics, 1999
A method to predict rectangular field output factors (OFs) of photon open beams for the Saturne 41 linear accelerator has been developed. The procedure is similar to the sector-integration method but the radiotherapy quantities corresponding to circular fields (circular functions) are calculated from one-dimensional OFs.
D E, Sanz, A L, Romaguera, N B, Acosta
openaire   +2 more sources

Integrability of the 2D Lotka-Volterra system via polynomial first integrals and polynomial inverse integrating factors

Journal of Physics A: Mathematical and General, 2000
The authors show new first integrals to planar Lotka-Volterra systems that have a polynomial inverse integrating factor. These systems may be characterized by equalities among the coefficients of the system. Moreover, all planar Lotka-Volterra systems which have a polynomial first integral are characterized and an explicit expression of these first ...
Cairó, Laurent, Llibre, Jaume
openaire   +1 more source

Existence and vanishing set of inverse integrating factors for analytic vector fields

Bulletin of the London Mathematical Society, 2009
In this paper we address the problem of existence of inverse integrating factors for an analytic planar vector field in a neighborhood of its nonwandering sets. It is proved that there always exists a smooth inverse integrating factor in a neighborhood of a limit cycle, obtaining a necessary and sufficient condition for the existence of an analytic one.
Alberto Enciso, Daniel Peralta-Salas
openaire   +1 more source

Inverse integrating factor overview

AIP Conference Proceedings, 2023
Anmar Hashim Jasim, Zainab Mohammed Alwan   +1 more
openaire   +1 more source

Factorization, path integral representations, and the construction of direct and inverse wave propagation theories

IEEE Transactions on Geoscience and Remote Sensing, 1984
The development of both direct and inverse wave propagation theories at the level of the reduced scalar Helmholtz equation is addressed. The principal constructive tool is the factorization analysis of the Helmholtz equation which derives from the physically suggestive picture of decoupled forward and backward wave propagation appropriate for ...
Louis Fishman, John J. Mccoy
openaire   +1 more source

Algebraic Inverse Integrating Factors for a Class of Generalized Nilpotent Systems

2016
Usually, the study of differential systems with linear part null is done using quasi-homogeneous expansions of vector fields. Here, we use this technique for analyzing the existence of an inverse integrating factor for generalized nilpotent systems, in general non-integrable, whose lowest-degree quasi-homogeneous term is the Hamiltonian system \(y^{2 ...
Antonio Algaba, Natalia Fuentes, Cristóbal García, Manuel Reyes   +3 more
openaire   +1 more source

New HSS-factorization and inversion algorithms with exact arithmetic for efficient direct solution of large-scale volume integral equations

2016 IEEE International Symposium on Antennas and Propagation (APSURSI), 2016
A new HSS (Hierarchically Semiseparable) direct matrix solution algorithm, including both factorization and inversion, is developed for solving the volume integral equation (VIE) for large-scale electrodynamic analysis. This direct solution algorithm is exact in the sense that the matrix factorization, inversion, and solution do not involve any ...
Miaomiao Ma, Dan Jiao
openaire   +1 more source

Integrative oncology: Addressing the global challenges of cancer prevention and treatment

Ca-A Cancer Journal for Clinicians, 2022
Jun J Mao,, Msce, Lorenzo Cohen, Karen M Mustian   +2 more
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