TEDE Communidade:
http://repositorio.bc.ufg.br/tede/handle/tde/288
Sun, 15 Dec 2019 21:01:03 GMT2019-12-15T21:01:03ZCondições de finitude para o produto tensorial não abeliano de grupos
http://repositorio.bc.ufg.br/tede/handle/tede/10028
Título: Condições de finitude para o produto tensorial não abeliano de grupos
Autor: Alves, Thulio de Oliveira
Primeiro orientador: Oliveira, Ricardo Nunes de
Abstract: In this work we are interested in describing the conditions on which the non-abelian tensor product of groups is finite, thus we show that if G and H are groups that act compatibly on each other, then the tensor product of G and H is finite, if and only if the set of all tensor is finite. As an immediate consequence of this result, if G and H are finite, then the tensor product of G and H is finite. Furthermore we describe finite conditions for specific subgroups of the tensor product when G and H are FC-groups and also when H=G and G is a BFC-group.
Instituição: Universidade Federal de Goiás
Tipo do documento: DissertaçãoThu, 08 Aug 2019 00:00:00 GMThttp://repositorio.bc.ufg.br/tede/handle/tede/100282019-08-08T00:00:00ZSoluções clássicas para um problema de combustão em meios porosos com n camadas
http://repositorio.bc.ufg.br/tede/handle/tede/10001
Título: Soluções clássicas para um problema de combustão em meios porosos com n camadas
Autor: Batista, Marcos Roberto
Primeiro orientador: Mota, Jesus Carlos da
Abstract: In this work, we study the classical solutions for a parabolic system of reaction-diffusion-convection equations, coupled to a system of ordinary differential equations, with boundary and initial conditions in a bounded domain. The coupled system models the propagation of a combustion front through a porous medium with n layers, where the dependent variables are the temperatures and the fuel concentrations in each layer.
Problems for parabolic equations systems coupled with Ordinary Differential Equations (ODEs) system, where the coupling occurs in both the reaction functions and the associated differential operator coefficients, are little known in the literature. In classical theory in general, the coupling appears only in the reaction functions.
Initially, using the Monotone Iterative Method, we prove the existence and uniqueness of a global solution in time for the particular case where the fuel concentrations in each layer are known functions. Next, we show the existence of the local solution in time for the complete problem when the concentrations are unknown functions. The proof is obtained by defining an operator in the Continuous Hölder function set and showing that it has a fixed point that is a local solution to the problem. This solution can be extended to a global solution in time for the problem, provided that the spatial derivatives of the temperature in each layer are bounded functions.
Instituição: Universidade Federal de Goiás
Tipo do documento: TeseFri, 16 Aug 2019 00:00:00 GMThttp://repositorio.bc.ufg.br/tede/handle/tede/100012019-08-16T00:00:00ZQuadratic programming on the positive orthant with a quasiconvex objective function
http://repositorio.bc.ufg.br/tede/handle/tede/9934
Título: Quadratic programming on the positive orthant with a quasiconvex objective function
Autor: Zuñiga, Ruby Yohana Cuero
Primeiro orientador: Ferreira, Orizon Pereira
Abstract: In this work, we will study a class of real symmetric matrices that we will call subdefinite, these matrices include the positive semidefinites. For our purpose we will focus on the merely positive subdefinite matrices, that is, those matrices that are positive subdefinite but are not positive semidefinite. We will discuss the quadratic functions on Rn + and show that these functions are quasiconvex not convex, when their matrix representation is given by a merely positive subdefinite matrix. In addition, we will present a result of great importance in quadratic programming given that it allows to reduce the quasiconvexity of these nonconvex quadratic functions to the pseudoconvexity in the semipositive orthant. Finally, we will study the conditional gradient method to solve the quadratic programming problem, where the objective function is of this type.
Instituição: Universidade Federal de Goiás
Tipo do documento: DissertaçãoWed, 31 Jul 2019 00:00:00 GMThttp://repositorio.bc.ufg.br/tede/handle/tede/99342019-07-31T00:00:00ZLinhas assintóticas de campos de planos em R3 e de superfícies em R4
http://repositorio.bc.ufg.br/tede/handle/tede/9905
Título: Linhas assintóticas de campos de planos em R3 e de superfícies em R4
Autor: Cruz, Douglas Hilário da
Primeiro orientador: Garcia, Ronaldo Alves
Abstract: This work is divided into two parts. The first part deals with asymptotic lines of plane fields in R3. The main results are the analysis of the asymptotic lines in a neighborhood of the regular surface of parabolic points and the analysis of the stability of closed asymptotic lines. We express the first derivative of the Poincar\'e map and show how to make hyperbolic a closed asymptotic line.
The second part deals with asymptotic lines of surfaces in R4. The main results
are results of structural stability and genericity for asymptotic lines of locally convex surfaces in R4 and a result of structural stability asymptotic lines of surfaces in R4.
Instituição: Universidade Federal de Goiás
Tipo do documento: TeseThu, 31 Aug 2017 00:00:00 GMThttp://repositorio.bc.ufg.br/tede/handle/tede/99052017-08-31T00:00:00Z