Results 181 to 190 of about 790 (217)
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How to store a triangular matrix
IEEE Transactions on Computers, 1992The problem of storing a triangular matrix so that each row and column is stored as a vector, i.e. the locations form an arithmetic progression, is discussed. Storing rows and columns as vectors can speed up access significantly. It is shown that there is no such storage method that does not waste approximately one-half of the computer memory. >
Andrea S. LaPaugh +2 more
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On Skew Triangular Matrix Rings
Algebra Colloquium, 2015Let R be a ring with an endomorphism σ. We show that the clean property and various Armendariz-type properties of R are inherited by the skew matrix rings S(R,n,σ) and T(R,n,σ). They allow the construction of rings with a non-zero nilpotent ideal of arbitrary index of nilpotency which inherit various interesting properties of rings.
Habibi, M., Moussavi, A., Alhevaz, A.
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Triangular Matrix Representations and Triangular Matrix Extensions
2013In this chapter, generalized triangular matrix representations are discussed by introducing the concept of a set of left triangulating idempotents. A criterion for a ring with a complete set of triangulating idempotents to be quasi-Baer is provided.
Gary F. Birkenmeier +2 more
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Conditioning of the Exponential of a Block Triangular Matrix
Numerical Algorithms, 2001A new measure of conditioning for the exponential of a block triangular matrix is proposed. It is shown that different condition numbers must be used to assess the accuracy of different algorithms for implementing diagonal Padé with scaling and squaring.
L. DIECI, PAPINI, ALESSANDRA
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Updating the Triangular Factorization of a Matrix
SIAM Journal on Matrix Analysis and Applications, 1989A simple modification of the Bartels-Golub update [cf. \textit{R. H. Bartels} and \textit{G. H. Golub}, Commun. ACM 12, 266-268 (1969; Zbl 0181.191)] of the triangular factorization \(PB=LU\) of a given nonsingular matrix B is presented if a column of B is replaced, such that the true new factors L and U are yielded instead of their representations in ...
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On Continuous Triangularization of Matrix Functions
SIAM Journal on Mathematical Analysis, 1979This article is concerned with the continuous triangularization of matrix functions which depend continuously on several variables. By use of an algorithm analogous to the one employed for the reduction of a $\lambda $-matrix to a diagonal form, we find a continuous similarity transformation which produces the triangularization of a given matrix.Let ...
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Fast triangularization of a symmetric tridiagonal matrix
Journal of Parallel and Distributed Computing, 1989A simple linear systolic array is presented for triangularizing a symmetric tridiagonal matrix by Gaussian Elimination using nearest neighbor pivoting. The array consists of three cells requiring an area bounded by four simple inner product cells. The design can compute the elimination in time 2n + k1 for the simple point case and using an implicit 2*2
David J. Evans 0001, Graham M. Megson
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Triangular matrix inversion on systolic arrays
Parallel Computing, 1990Abstract We study the systolic implementation of the algorithm which inverts a triangular matrix A of order n , by pipelining n linear systems of equation Ax h = e h , for h = 1,…, n , where e h denotes the h th vector of the canonical basis. It is known that the time complexity of the problem is T = 2 n − 1.
Basile Louka, Maurice Tchuenté
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TRIANGULAR MATRIX REPRESENTATIONS OF SEMIPRIMARY RINGS
Journal of Algebra and Its Applications, 2002In this paper we characterize internally a TSA ring (i.e. a generalized triangular matrix ring with simple Artinian rings on the diagonal) in terms of its prime ideals. Also we show that the class of semiprimary quasi-Baer rings is a proper subclass of the class of TSA rings.
Birkenmeier, Gary F. +2 more
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ON THE SPECTRA OF NONNEGATIVE TRIANGULAR MATRIX TRANSFORMATIONS
Analysis, 1983Let \(A=(A_{nk})\) be a triangular matrix transformation with the spectrum \(\sigma\) (A). Suppose that \(S=\{A_{nn}:\quad n\geq 0\}\) and \(\gamma =\underline{\lim} A_{nn}.\) For 0\(\leq a\leq 1\) let \(D_ a\) denote the disc \(\{z:\quad| z-1/(2-a)|\leq (1-a)/(2-a)\}.\) Theorem 1 gives necessary and sufficient conditions in order that A is equivalent ...
Avdispahić, M., Tanović-Miller, N.
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