26 citations · 53 across the 14 of their papers we have counts for
14 papers
How far are -dimensional copulas with uniform -marginals from (total) independence?
Damjana Kokol Bukovšek, Nik Stopar, Wolfgang Trutschnig
We consider the family of all -dimensional copulas whose -dimensional marginals are all equal to the -dimensional product copula $Π_{d-…
Dense alternating sign matrices and imprecise copulas
Tomaž Košir, Elisa Perrone, Nik Stopar
In this paper, we study discrete quasi-copulas and discrete imprecise copulas of minimal range, which naturally correspond to alternating sign matrices. We identify dense alternati…
Unital compressed commuting graph of matrices over a finite prime field
Ivan-Vanja Boroja, Damjana Kokol Bukovšek, Nik Stopar
In this paper we completely describe the unital compressed commuting graph of the ring of matrices over the finite prime field $\mathrm…
The exact region determined by Spearman's footrule, Gini's gamma and Kendall's tau
Damjana Kokol Bukovšek, Petra Lazić, Blaž Mojškerc +1
Concordance measures are used to express the degree of association between random variables. Practitioners may use several distinct concordance measures to narrow the space of poss…
When does an infinite ring have a finite compressed commuting graph?
Ivan-Vanja Boroja, Damjana Kokol Bukovšek, Nik Stopar
We show that any infinite ring has an infinite nonunital compressed commuting graph. We classify all infinite unital rings with finite unital compressed commuting graph, using semi…
Freedom in constructing quasi-copulas vs. copulas
Matjaž Omladič, Nik Stopar
The main goal of this paper is to study the extent of freedom one has in constructing quasi-copulas vs. copulas. Specifically, it exhibits three construction methods for quasi-copu…
Bivariate measure-inducing quasi-copulas
Nik Stopar
It is well known that every bivariate copula induces a positive measure on the Borel -algebra on , but there exist bivariate quasi-copulas that do not induce a signed m…
Compressed commuting graphs of matrix rings
Ivan-Vanja Boroja, Hamid Reza Dorbidi, Damjana Kokol Bukovšek +1
In this paper we introduce compressed commuting graph of rings. It can be seen as a compression of the standard commuting graph (with the central elements added) where we identify…
Exact upper bound for copulas with a given diagonal section
Damjana Kokol Bukovšek, Blaž Mojškerc, Nik Stopar
We answer a 15-year-old open question about the exact upper bound for bivariate copulas with a given diagonal section by giving an explicit formula for this bound. As an applicatio…
Coherence and avoidance of sure loss for standardized functions and semicopulas
Erich Peter Klement, Damjana Kokol Bukovšek, Blaž Mojškerc +3
We discuss avoidance of sure loss and coherence results for semicopulas and standardized functions, i.e., for grounded, 1-increasing functions with value at .…
On the exact region determined by Spearman's rho and Spearman's footrule
Damjana Kokol Bukovšek, Nik Stopar
We determine the lower bound for possible values of Spearman's rho of a bivariate copula given that the value of its Spearman's footrule is known and show that this bound is always…
A full scale Sklar's theorem in the imprecise setting
Matjaž Omladič, Nik Stopar
In this paper we present a surprisingly general extension of the main result of a paper that appeared in this journal: I. Montes et al., Sklar's theorem in an imprecise setting, Fu…
Final solution to the problem of relating a true copula to an imprecise copula
Matjaž Omladič, Nik Stopar
In this paper we solve in the negative the problem proposed in this journal (I. Montes et al., Sklar's theorem in an imprecise setting, Fuzzy Sets and Systems, 278 (2015), 48-66) w…
Compressed zero-divisor graphs of noncommutative rings
Alen Đurić, Sara Jevđenić, Nik Stopar
We extend the notion of the compressed zero-divisor graph to noncommutative rings in a way that still induces a product preserving functor from the categ…