Zobrazeno 1 - 10
of 60
pro vyhledávání: '"Susana Furtado"'
Publikováno v:
Linear and Multilinear Algebra. :1-14
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a1e3e338e13c84889ca1043688b2037a
https://doi.org/10.1080/03081087.2022.2117267
https://doi.org/10.1080/03081087.2022.2117267
Autor:
Susana Furtado
Publikováno v:
Optimization. :1-23
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::00c95853ad78eeea473d0365a0394297
https://doi.org/10.1080/02331934.2022.2070067
https://doi.org/10.1080/02331934.2022.2070067
Publikováno v:
International Journal of Approximate Reasoning. 139:54-68
In the Analytic Hierarchy process, a method used in Decision Making, it may be important to approximate a pairwise comparison matrix (PC matrix) by a consistent one. In this context, the notion of efficient vector for a PC matrix arises. In this pape
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4d17b8487f7f240a34122ca731da2d0a
https://doi.org/10.1016/j.ijar.2021.09.007
https://doi.org/10.1016/j.ijar.2021.09.007
Autor:
Charles R. Johnson, Susana Furtado
Publikováno v:
Linear and Multilinear Algebra. 70:5423-5432
Over a general field and for an arbitrary positive integer k, those triangular matrices whose kth power is diagonal are explicitly characterized. This is then used to characterize those complex mat...
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a241f95b995b5290e455cc7d060fa102
https://doi.org/10.1080/03081087.2021.1917499
https://doi.org/10.1080/03081087.2021.1917499
Autor:
Susana Furtado, Natália Bebiano
Publikováno v:
Czechoslovak Mathematical Journal. 71:1015-1023
We identify new classes of structured matrices whose numerical range is of the elliptical type, that is, an elliptical disk or the convex hull of elliptical disks.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1468800f0cc739eda7d4a4ce469fec33
https://doi.org/10.21136/cmj.2021.0174-20
https://doi.org/10.21136/cmj.2021.0174-20
Autor:
Susana Furtado, Rosário Fernandes
Publikováno v:
Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
UID/MAT/00297/2019 UID/MAT/04721/2019 We consider the class (Formula presented.) of symmetric (Formula presented.) -matrices with zero trace and constant row sums k which can be identified with the class of the adjacency matrices of k-regular undirec
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c37d58bc25269917b0a21588ab066d61
https://doi.org/10.1080/03081087.2020.1749540
https://doi.org/10.1080/03081087.2020.1749540
Publikováno v:
University of Wyoming Open Journals
In this paper, a complete description of the linear maps $\phi:W_{n}\rightarrow W_{n}$ that preserve the Lorentz spectrum is given when $n=2$, and $W_{n}$ is the space $M_{n}$ of $n\times n$ real matrices or the subspace $S_{n}$ of $M_{n}$ formed by
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::984a0bb9bdd284922b8accb45fa44584
http://arxiv.org/abs/2111.07174
http://arxiv.org/abs/2111.07174
Publikováno v:
Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
An n-by-n real symmetric matrix is called copositive if its quadratic form is nonnegative on nonnegative vectors. Our interest is in identifying which linear transformations on symmetric matrices preserve copositivity either in the into or onto sense
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::21f3258c9898a8bb25a900bc5ceb2caf
https://doi.org/10.1080/03081087.2019.1692775
https://doi.org/10.1080/03081087.2019.1692775
Autor:
Natália Bebiano, Susana Furtado
Publikováno v:
Linear Algebra and its Applications. 581:36-50
In this paper we consider sparse symmetrically banded matrices in which the nonzero off-diagonals are positioned a multiple of k steps from the main diagonal. We show that such a matrix T is permutationally similar to direct sum of banded matrices. I
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7e27724609d7891456b7387cb3631d39
https://doi.org/10.1016/j.laa.2019.07.006
https://doi.org/10.1016/j.laa.2019.07.006
Autor:
Susana Furtado, Natália Bebiano
Publikováno v:
Computational and Applied Mathematics. 39
The objective of this note is to approximate a birth and death matrix B by a close Toeplitz-type one for which explicit formulas for the eigenpairs are known. Numerical evidence of the approximation behavior of the eigenvalues and eigenvectors of B b
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c679acccc3a7d820bf7050c3edd4ab62
https://doi.org/10.1007/s40314-020-01327-z
https://doi.org/10.1007/s40314-020-01327-z