Results 1 to 10 of about 45 (44)
, 2022 Nesse trabalho foi realizado estudo comparativo entre o aço SAE 1566 (alto teor de carbono) e o aço SAE 15B36 (aço ao boro com médio teor de carbono) aplicados na produção de lâminas para corte de cana, avaliando-se a possibilidade de substituição do aço
Alves, Willian Moreira
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On idempotent stable range 1 matrices
Special Matrices, 2022 We characterize the idempotent stable range 1, 2 × 2 matrices over commutative rings and in particular the integral matrices with this property. Several special cases and examples complete the subject.
Călugăreanu Grigore, Pop Horia F.
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Special Matrices, 2021 Given a real number a ≥ 1, let Kn(a) be the set of all n × n unit lower triangular matrices with each element in the interval [−a, a]. Denoting by λn(·) the smallest eigenvalue of a given matrix, let cn(a) = min {λ n(YYT) : Y ∈ Kn(a)}.
Altınışık Ercan
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Generating functions for a lattice path model introduced by Deutsch
Special Matrices, 2021 The lattice path model suggested by E. Deutsch is derived from ordinary Dyck paths, but with additional down-steps of size −3, −5, −7, . . . . For such paths, we find the generating functions of them, according to length, ending at level i, both, when ...
Prodinger Helmut
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On Generalized Jacobsthal and Jacobsthal–Lucas Numbers
Annales Mathematicae Silesianae, 2022 Jacobsthal numbers and Jacobsthal–Lucas numbers are some of the most studied special integer sequences related to the Fibonacci numbers. In this study, we introduce one parameter generalizations of Jacobsthal numbers and Jacobsthal–Lucas numbers.
Bród Dorota, Michalski Adrian
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Some combinatorial matrices and their LU-decomposition
Special Matrices, 2020 Three combinatorial matrices were considered and their LU-decompositions were found. This is typically done by (creative) guessing, and the proofs are more or less routine calculations.
Prodinger Helmut
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Uniquely clean 2 × 2 invertible integral matrices [PDF]
, 2017 While units in any unital ring are strongly clean by definition, which units are uniquely clean, is a far from being simple question, even in particular rings. In this paper, the question is solved for 2 × 2 integral matrices.
CĂLUGĂREANU , Grigore, ANDRICA, Dorin
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Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2022 A ring is called negative clean if the negative (i.e., the additive inverse) of each clean element is also clean. Clean rings are negative clean.
Călugăreanu Grigore, Pop Horia F.
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Maximal Green Sequences of Exceptional Finite Mutation Type Quivers? [PDF]
, 2014 . Maximal green sequences are particular sequences of mutations of quivers which were introduced by Keller in the context of quantum dilogarithm identities and in-dependently by Cecotti–Córdova–Vafa in the context of supersymmetric gauge theory.
Seven, Ahmet İrfan +3 more
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Multiple gcd-closed sets and determinants of matrices associated with arithmetic functions
Open Mathematics, 2016 Let f be an arithmetic function and S= {x1, …, xn} be a set of n distinct positive integers. By (f(xi, xj)) (resp. (f[xi, xj])) we denote the n × n matrix having f evaluated at the greatest common divisor (xi, xj) (resp. the least common multiple [xi, xj]
Hong Siao, Hu Shuangnian, Hong Shaofang
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