2,064 research outputs found
Implication functions in interval-valued fuzzy set theory
Interval-valued fuzzy set theory is an extension of fuzzy set theory in which the real, but unknown, membership degree is approximated by a closed interval of possible membership degrees. Since implications on the unit interval play an important role in fuzzy set theory, several authors have extended this notion to interval-valued fuzzy set theory. This chapter gives an overview of the results pertaining to implications in interval-valued fuzzy set theory. In particular, we describe several possibilities to represent such implications using implications on the unit interval, we give a characterization of the implications in interval-valued fuzzy set theory which satisfy the Smets-Magrez axioms, we discuss the solutions of a particular distributivity equation involving strict t-norms, we extend monoidal logic to the interval-valued fuzzy case and we give a soundness and completeness theorem which is similar to the one existing for monoidal logic, and finally we discuss some other constructions of implications in interval-valued fuzzy set theory
Knots and distributive homology: from arc colorings to Yang-Baxter homology
This paper is a sequel to my essay "Distributivity versus associativity in
the homology theory of algebraic structures" Demonstratio Math., 44(4), 2011,
821-867 (arXiv:1109.4850 [math.GT]). We start from naive invariants of arc
colorings and survey associative and distributive magmas and their homology
with relation to knot theory. We outline potential relations to Khovanov
homology and categorification, via Yang-Baxter operators. We use here the fact
that Yang-Baxter equation can be thought of as a generalization of
self-distributivity. We show how to define and visualize Yang-Baxter homology,
in particular giving a simple description of homology of biquandles.Comment: 64 pages, 29 figures; to be published as a Chapter in: "New Ideas in
Low Dimensional Topology", World Scientific, Vol. 5
Using shifted conjugacy in braid-based cryptography
Conjugacy is not the only possible primitive for designing braid-based
protocols. To illustrate this principle, we describe a Fiat--Shamir-style
authentication protocol that be can be implemented using any binary operation
that satisfies the left self-distributive law. Conjugation is an example of
such an operation, but there are other examples, in particular the shifted
conjugation on Artin's braid group B\_oo, and the finite Laver tables. In both
cases, the underlying structures have a high combinatorial complexity, and they
lead to difficult problems
Left-Garside categories, self-distributivity, and braids
In connection with the emerging theory of Garside categories, we develop the
notions of a left-Garside category and of a locally left-Garside monoid. In
this framework, the connection between the self-distributivity law LD and
braids amounts to the result that a certain category associated with LD is a
left-Garside category, which projects onto the standard Garside category of
braids. This approach leads to a realistic program for establishing the
Embedding Conjecture of [Dehornoy, Braids and Self-distributivity, Birkhauser
(2000), Chap. IX]
Algebraic Properties of Qualitative Spatio-Temporal Calculi
Qualitative spatial and temporal reasoning is based on so-called qualitative
calculi. Algebraic properties of these calculi have several implications on
reasoning algorithms. But what exactly is a qualitative calculus? And to which
extent do the qualitative calculi proposed meet these demands? The literature
provides various answers to the first question but only few facts about the
second. In this paper we identify the minimal requirements to binary
spatio-temporal calculi and we discuss the relevance of the according axioms
for representation and reasoning. We also analyze existing qualitative calculi
and provide a classification involving different notions of a relation algebra.Comment: COSIT 2013 paper including supplementary materia
Invariant functionals on completely distributive lattices
In this paper we are interested in functionals defined on completely
distributive lattices and which are invariant under mappings preserving
{arbitrary} joins and meets. We prove that the class of nondecreasing invariant
functionals coincides with the class of Sugeno integrals associated with
-valued capacities, the so-called term functionals, thus extending
previous results both to the infinitary case as well as to the realm of
completely distributive lattices. Furthermore, we show that, in the case of
functionals over complete chains, the nondecreasing condition is redundant.
Characterizations of the class of Sugeno integrals, as well as its superclass
comprising all polynomial functionals, are provided by showing that the
axiomatizations (given in terms of homogeneity) of their restriction to
finitary functionals still hold over completely distributive lattices. We also
present canonical normal form representations of polynomial functionals on
completely distributive lattices, which appear as the natural extensions to
their finitary counterparts, and as a by-product we obtain an axiomatization of
complete distributivity in the case of bounded lattices
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