• Title/Summary/Keyword: Matrices

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Automatic generation of equilibrium and flexibility matrices for plate bending elements using Integrated Force Method

  • Dhananjaya, H.R.;Nagabhushanam, J.;Pandey, P.C.
    • Structural Engineering and Mechanics
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    • v.30 no.4
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    • pp.387-402
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    • 2008
  • The Integrated Force Method (IFM) has been developed in recent years for the analysis of civil, mechanical and aerospace engineering structures. In this method all independent or internal forces are treated as unknown variables which are calculated by simultaneously imposing equations of equilibrium and compatibility conditions. The solution by IFM needs the computation of element equilibrium and flexibility matrices from the assumed displacement, stress-resultant fields and material properties. This paper presents a general purpose code for the automatic generation of element equilibrium and flexibility matrices for plate bending elements using the Integrated Force Method. Kirchhoff and the Mindlin-Reissner plate theories have been employed in the code. Paper illustrates development of element equilibrium and flexibility matrices for the Mindlin-Reissner theory based four node quadrilateral plate bending element using the Integrated Force Method.

STRONG PRESERVERS OF SYMMETRIC ARCTIC RANK OF NONNEGATIVE REAL MATRICES

  • Beasley, LeRoy B.;Encinas, Luis Hernandez;Song, Seok-Zun
    • Journal of the Korean Mathematical Society
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    • v.56 no.6
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    • pp.1503-1514
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    • 2019
  • A rank 1 matrix has a factorization as $uv^t$ for vectors u and v of some orders. The arctic rank of a rank 1 matrix is the half number of nonzero entries in u and v. A matrix of rank k can be expressed as the sum of k rank 1 matrices, a rank 1 decomposition. The arctic rank of a matrix A of rank k is the minimum of the sums of arctic ranks of the rank 1 matrices over all rank 1 decomposition of A. In this paper we obtain characterizations of the linear operators that strongly preserve the symmetric arctic ranks of symmetric matrices over nonnegative reals.

ON REDUCTION OF K-ALMOST NORMAL AND K-ALMOST CONJUGATE NORMAL MATRICES TO A BLOCK TRIDIAGONAL FORM

  • ASIL, K. NIAZI;KAMALVAND, M. GHASEMI
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.23 no.3
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    • pp.267-282
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    • 2019
  • This paper examines how one can build a block tridiagonal structure for k-almost normal matrices and also for k-almost conjugate normal matrices. We shall see that these representations are created by unitary similarity and unitary congruance transformations, respectively. It shall be proven that the orders of diagonal blocks are 1, k + 2, 2k + 3, ${\ldots}$, in both cases. Then these block tridiagonal structures shall be reviewed for the cases where the mentioned matrices satisfy in a second-degree polynomial. Finally, for these processes, algorithms are presented.

SPANNING COLUMN RANKS OF NON-BINARY BOOLEAN MATRICES AND THEIR PRESERVERS

  • Kang, Kyung-Tae;Song, Seok-Zun
    • Journal of the Korean Mathematical Society
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    • v.56 no.2
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    • pp.507-521
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    • 2019
  • For any $m{\times}n$ nonbinary Boolean matrix A, its spanning column rank is the minimum number of the columns of A that spans its column space. We have a characterization of spanning column rank-1 nonbinary Boolean matrices. We investigate the linear operators that preserve the spanning column ranks of matrices over the nonbinary Boolean algebra. That is, for a linear operator T on $m{\times}n$ nonbinary Boolean matrices, it preserves all spanning column ranks if and only if there exist an invertible nonbinary Boolean matrix P of order m and a permutation matrix Q of order n such that T(A) = PAQ for all $m{\times}n$ nonbinary Boolean matrix A. We also obtain other characterizations of the (spanning) column rank preserver.

NOTES ON GENERALIZED FIBONACCI NUMBERS AND MATRICES

  • Halim, Ozdemir;Sinan, Karakaya;Tugba, Petik
    • Honam Mathematical Journal
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    • v.44 no.4
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    • pp.473-484
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    • 2022
  • In this study, some new relations between generalized Fibonacci numbers and matrices are given. The work is designed in three stages: Firstly, it is obtained a relation between generalized Fibonacci numbers and integer powers of the matrices X satisfying the relation X2 = pX +qI, and also, many results are derived from obtained relation. Then, it is established more general relation between generalized Fibonacci numbers and the square matrices X satisfying the condition X2 = VnX - (-q)nI. Finally, some applications and numerical examples related to the obtained results are given.

Ideal Classes and Cappell-Shaneson Homotopy 4-Spheres

  • Min Hoon Kim;Shohei Yamada
    • Kyungpook Mathematical Journal
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    • v.63 no.3
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    • pp.373-411
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    • 2023
  • Gompf proposed a conjecture on Cappell-Shaneson matrices whose affirmative answer implies that all Cappell-Shaneson homotopy 4-spheres are diffeomorphic to the standard 4-sphere. We study Gompf conjecture on Cappell-Shaneson matrices using various algebraic number theoretic techniques. We find a hidden symmetry between trace n Cappell-Shaneson matrices and trace 5 - n Cappell-Shaneson matrices which was suggested by Gompf experimentally. Using this symmetry, we prove that Gompf conjecture for the trace n case is equivalent to the trace 5 - n case. We confirm Gompf conjecture for the special cases that -64 ≤ trace ≤ 69 and corresponding Cappell-Shaneson homotopy 4-spheres are diffeomorphic to the standard 4-sphere. We also give a new infinite family of Cappell-Shaneson spheres which are diffeomorphic to the standard 4-sphere.

ON NEW IDENTITIES FOR 3 BY 3 MATRICES

  • Lee, Woo
    • Journal of applied mathematics & informatics
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    • v.26 no.5_6
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    • pp.1185-1189
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    • 2008
  • In this paper we show that the polynomial of degree 9 called generalized algebraicity is a polynomial identity for $3{\times}3$ matrices. ([5])

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