# Search results for: Seok-Zun Song

Czechoslovak Mathematical Journal > 2018 > 68 > 4 > 1055-1066

_{+}be the semiring of all nonnegative integers and

*A*an

*m*×

*n*matrix over ℤ

_{+}. The rank of

*A*is the smallest

*k*such that

*A*can be factored as an

*m*×

*k*matrix times a

*k*×

*n*matrix. The isolation number of

*A*is the maximum number of nonzero entries in

*A*such that no two are in any row or any column, and no two are in a 2 × 2 submatrix of all nonzero entries. We have that the isolation number of

*A*is...

Beiträge zur Algebra und Geometrie / Contributions to Algebra and Geometry > 2019 > 60 > 1 > 157-165

Afrika Matematika > 2016 > 27 > 7-8 > 1339-1346

Linear Algebra and its Applications > 2016 > 491 > C > 263-275

Czechoslovak Mathematical Journal > 2014 > 64 > 3 > 819-826

_{A}be a Boolean {0, 1} matrix. The isolation number of

*A*is the maximum number of ones in

*A*such that no two are in any row or any column (that is they are independent), and no two are in a 2 × 2 submatrix of all ones. The isolation number of

*A*is a lower bound on the Boolean rank of

*A*. A linear operator on the set of

*m*×

*n*Boolean matrices is a mapping which is additive and maps the zero matrix,...

Linear Algebra and Its Applications > 2013 > 438 > 10 > 3745-3754

Czechoslovak Mathematical Journal > 2013 > 63 > 2 > 435-440

*m*×

*n*Boolean matrix

*A*is the minimum number

*k*such that there exist an

*m× k*Boolean matrix

*B*and a

*k*×

*n*Boolean matrix

*C*such that

*A*=

*BC*. In the previous research L. B. Beasley and N. J. Pullman obtained that a linear operator preserves Boolean rank if and only if it preserves Boolean ranks 1 and 2. In this paper we extend this characterizations of linear operators...

Linear Algebra and Its Applications > 2012 > 436 > 7 > 1850-1862

Linear Algebra and Its Applications > 2012 > 436 > 6 > 1727-1738

Information Sciences > 2011 > 181 > 22 > 5102-5109

Czechoslovak Mathematical Journal > 2011 > 61 > 1 > 113-125

*m*×

*n*Boolean matrices is denoted by $$ \mathbb{M} $$

_{ m,n }. We call a matrix A ∈ $$ \mathbb{M} $$

_{ m,n }regular if there is a matrix

*G*∈ $$ \mathbb{M} $$

_{ n,m }such that

*AGA*=

*A*. In this paper, we study the problem of characterizing linear operators on $$ \mathbb{M} $$

_{ m,n }...

Linear Algebra and Its Applications > 2011 > 434 > 1 > 232-238

Neural Computing and Applications > 2011 > 20 > 8 > 1313-1320

*p*-ideals and fuzzy

*p*-ideals with thresholds related to soft set theory are discussed. Relations between $$(\overline{\in}, \overline{\in} \vee \overline{\hbox{q}})$$ -fuzzy ideals and $$(\overline{\in}, \overline{\in} \vee \overline{\hbox{q}})$$ -fuzzy

*p*-ideals are investigated. Characterizations of an...

Linear Algebra and Its Applications > 2008 > 429 > 1 > 209-223

Czechoslovak Mathematical Journal > 2008 > 58 > 3 > 693-703

Information Sciences > 2006 > 176 > 20 > 3079-3093

Linear Algebra and Its Applications > 2006 > 413 > 2-3 > 495-509