Semigroup
Mostrando 13-24 de 25 artigos, teses e dissertações.
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13. Teoria de semigrupos e aplicações a equações impulsivas com retardamento dependendo do estado / Semigroup theory and applications to impulsive differential equation with state-dependent delay
In this work we stablish the existence of mild solutions for an impulsive abstract functional differential equation with state-dependent delay described in the form x POT. PRIME(t) = Ax(t) + f(t;x IND. p(t, xt)), t BELONGSI = [0,a], x IND. 0=\varphi IS CONTAINEDB, DELTAx(t IND. i) = I IND.ii(x IND.i); i = 1, ...n, where A is the infinitesimal generator of a
Publicado em: 2006
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14. On a classification of the integral rings, finite semigroups and RA-loops with the hyperbolic property / Sobre uma classificação dos anéis de inteiros, dos semigrupos finitos e dos RA-loops com a propriedade hiperbólica
For a given division algebra of a quaternion algebra, we construct and define two types of units of its $\Z$-orders: Pell units and Gauss units. Also, for the quadratic imaginary extensions over the racionals and some fixed group $G$, we classify the algebraic integral rings for which the unit group ring is a hyperbolic group. We also classify the finite sem
Publicado em: 2006
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15. Semigroup theory and controllability of neutral systems / Teoria de semigrupos e controlabilidade de sistemas neutros
Neste trabalho de dissertação de mestrado, fazemos algumas observações a respeito de dois¶ artigos de pesquisa recentes, os quais estabelecem resultados falsos sobre existência de soluções controlabilidade exata de sistemas de controle abstratos do tipo neutro modelados na forma¶8<:¶ d ¶ dt ¶(x(t) + G(t, xt)) = Ax(t) + F(t, xt) + Cu(t), t 2 I = (
Publicado em: 2006
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16. Chain control sets and fiber bundles
Let S be a semigroup of homeomorphisms of a compact metric space M and suppose that is a family of subsets of S. This paper gives a characterization of the
Computational & Applied Mathematics. Publicado em: 2003
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17. Existência de soluções periódicas em alguns problemas não-lineares. / Existence of periodic solutions on some nonlinear problems.
O propósito deste trabalho é estudar a existência de solução periódica para problemas de oscilação não linear de barras submetidas a forças periódicas. Estudaremos concretamente dois problemas, que serão interpretados como equações diferenciais abstratas de segunda ordem cuja classe foi considerada em Ceron e Lopes [1]. Para garantir a existên
Publicado em: 2000
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18. ON THE IMBEDDING OF A FINITE COMMUTATIVE SEMIGROUP OF IDEMPOTENTS IN A UNIQUELY FACTORABLE SEMIGROUP*
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19. Sobolev inequalities, the Poisson semigroup, and analysis on the sphere Sn.
Hypercontractive estimates are obtained for the Poisson semigroup on Lp(Sn). Such estimates are determined by a sharp logarithmic Sobolev inequality that relates the entropy of a function on Sn to its smoothness.
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20. GENERATING FUNCTIONS AND THE SEMIGROUP THEORY OF BRANCHING MARKOV PROCESSES*
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21. Infinitesimal generators and quasi-units in potential theory
The underlying structure is taken as a strongly superharmonic cone [unk], defined as a partially ordered abelian semigroup with identity 0 which admits a multiplication by nonnegative scalars and satisfies two fundamental axioms of a potentialtheoretic character. In terms of a fixed nonzero element e there is introduced on [unk] a one-parameter family of non
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22. From instability to irreversibility
A canonical procedure transforming the unitary evolution group Ut in a contracting semigroup Wt for phase-space ensembles has been developed for Kolmogorov dynamical systems in a series of recent papers. This paper investigates the physical meaning of this transformation. We stress that, for sufficiently unstable dynamical systems in which phase-space points
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23. The second law as a selection principle: The microscopic theory of dissipative processes in quantum systems
The second law of thermodynamics, for quantum systems, is formulated, on the microscopic level. As for classical systems, such a formulation is only possible when specific conditions are satisfied (continuous spectrum, nonvanishing of the collision operator, etc.). The unitary dynamical group can then be mapped into two contractive semigroups, reaching equil
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24. TRANSLATION OPERATORS ON THE HALF-LINE
The self-adjoint algebra of operators generated by the semigroup of translation operators acting on the Hilbert space of functions supported on the half-line is studied. A real-valued index is introduced and is used to determine the spectrum of the Wiener-Hopf integral operators with distribution kernel having an almost periodic Fourier transform. Further, t