Listar MAT_Articles por autoría "dceafc84-2e87-4c8c-8a85-2d6403486997"

Mostrando ítems 1-15 de 15

    • openAccess   A note on the Baker–Campbell–Hausdorff series in terms of right-nested commutators 

      Arnal, A.; Casas, Fernando; Chiralt, Cristina Springer (2021-01-27)
      We get compact expressions for the Baker–Campbell–Hausdorff series Z = log(eX eY ) in terms of right-nested commutators. The reduction in the number of terms originates from two facts: (i) we use as a starting point an ...

    • openAccess   A note on trigonometric identities involving non-commuting matrices 

      Arnal, A.; Casas, Fernando; Chiralt, Cristina Springer Milan (2017)
      An algorithm is presented for generating successive approximations to trigonometric functions of sums of non-commuting matrices. The resulting expressions involve nested commutators of the respective matrices. The procedure ...

    • closedAccess   A third order partial differential equation for isotropic boundary based triangular Bézier surface generation 

      Arnal, A.; Monterde, Juan Elsevier (2011-08-15)
      We approach surface design by solving a linear third order Partial Differential Equation (PDE). We present an explicit polynomial solution method for triangular Bézier PDE surface generation characterized by a boundary ...

    • openAccess   A Unifying Framework for Perturbative Exponential Factorizations 

      Arnal, A.; Casas, Fernando; Chiralt, Cristina; Oteo, José-Angel MDPI (2021-03-17)
      We propose a framework where Fer and Wilcox expansions for the solution of differential equations are derived from two particular choices for the initial transformation that seeds the product expansion. In this scheme, ...

    • openAccess   Bézier surfaces with prescribed diagonals 

      Arnal, A.; Monterde, Juan Elsevier (2023-05)
      The affine space of all tensor product Bézier patches of degree n × n with prescribed main diagonal curves is determined. First, the pair of Bézier curves which can be diagonals of a Bézier patch is characterized. Besides ...

    • openAccess   Explicit Bézier control net of a PDE surface 

      Arnal, A.; Monterde, Juan Elsevier (2017-02)
      The PDE under study here is a general fourth-order linear elliptic Partial Differential Equation. Having prescribed the boundary control points, we provide the explicit expression of the whole control net of the associated ...

    • closedAccess   Explicit polynomial solutions of fourth order linear elliptic partial differential equations for boundary based smooth surface generation 

      Arnal, A.; Monterde, Juan; Ugail, Hassan Elsevier (2011-08)
      We present an explicit polynomial solution method for surface generation. In this case the surface in question is characterized by some boundary configuration whereby the resulting surface conforms to a fourth order linear ...

    • openAccess   Exponential Perturbative Expansions and Coordinate Transformations 

      Arnal, A.; Casas, Fernando; Chiralt, Cristina MDPI (2020)
      We propose a unified approach for different exponential perturbation techniques used in the treatment of time-dependent quantum mechanical problems, namely the Magnus expansion, the Floquet–Magnus expansion for periodic ...

    • openAccess   Exponential polar factorization of the fundamental matrix of linear differential systems 

      Arnal, A.; Casas, Fernando (2015-07-01)
      We propose a new constructive procedure to factorize the fundamental real matrix of a linear system of differential equations as the product of the exponentials of a symmetric and a skew-symmetric matrix. Both matrices are ...

    • closedAccess   Generating harmonic surfaces for interactive design 

      Arnal, A.; Monterde, Juan Elsevier (2014-06)
      A method is given for generating harmonic tensor product Bézier surfaces and the explicit expression of each point in the control net is provided as a linear combination of prescribed boundary control points. The matrix ...

    • closedAccess   Geometric Hermite interpolation by rational curves of constant width 

      Arnal, A.; Beltran Solsona, Jose Vicente; Monterde, Juan; Rochera, David Elsevier (2023-09-28)
      A constructive characterization of the support function for a rationally parameterized curve of constant width is given. In addition, a Hermite interpolation problem for such kind of curves is solved, which yields a method ...

    • openAccess   Magnus integrators for linear and quasilinear delay differential equations 

      Arnal, A.; Casas, Fernando; Chiralt, Cristina Elsevier (2023-04-29)
      A procedure to numerically integrate non-autonomous linear delay differential equations is presented. It is based on the use of a spectral discretization of the delayed part to transform the original problem into a matrix ...

    • closedAccess   On the structure and convergence of the symmetric Zassenhaus formula 

      Arnal, A.; Casas, Fernando; Chiralt, Cristina Elsevier (2017-08)
      We propose and analyze a symmetric version of the Zassenhaus formula for disentangling the exponential of two non-commuting operators. A recursive procedure for generating the expansion up to any order is presented which ...

    • closedAccess   PDE triangular Bézier surfaces: Harmonic, biharmonic and isotropic surfaces 

      Arnal, A.; Lluch, Ana; Monterde, Juan Elsevier (2011)
      We approach surface design by solving second-order and fourth-order Partial Differential Equations (PDEs). We present many methods for designing triangular Bézier PDE surfaces given different sets of prescribed control ...

    • openAccess   Ten Simple Rules for organizing a non–real-time web conference 

      Arnal, A.; Epifanio, Irene; Gregori, Pablo; Martínez, Vicente Scott Markel, Dassault Systemes BIOVIA (USA) (2020-01-26)
      The present work describes the 100% virtual ATIDES (Avances en Tecnologı ´as, Innovacio ´n y Desafı ´os de la Educacio ´n Superior) conference that was held between October 15 and 31, 2018, sponsored by Universitat Jaume ...