Meta-organizations are crucial devices to tackle grand challenges. Yet, by bringing together different organizations, with potentially diverging views on these grand challenges, meta-organizations need to cope with the emergence of contradictory underlying social orders. Do contradictory orders affect meta-organizations’ ability to govern grand cha...
Published in Lobachevskii Journal of Mathematics
AbstractWe consider the decomposability problem, i.e., the problem to decide whether a logical theory \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{T}}$$\en...
Published in Izvestiya: Mathematics
In this paper we study the Diophantine problem in the classical matrix groups , , and , , over an associative ring with identity. We show that if is one of these groups, then the Diophantine problem in is polynomial-time equivalent (more precisely, Karp equivalent) to the Diophantine problem in . When we assume that is commutative. Similar results ...
Published in Vestnik St. Petersburg University, Mathematics
AbstractThis paper is the second part of a new proof of the Bel’tyukov–Lipshitz theorem, which states that the existential theory of the structure \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin...
Published in Moscow University Mathematics Bulletin
AbstractIn this paper, a finite-automata model of attribute-based access control policies is used. The correctness of a policy is defined as a variation of the reachability problem for an infinite transition system induced by the policy. The problem of correctness validation for a given policy is shown decidable for information systems with a bound...
Published in Vestnik St. Petersburg University, Mathematics
AbstractThis paper is the first part of a new proof of decidability of the existential theory of the structure 〈\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathbb{...
The center of mass of a point set lying on a manifold generalizes the celebrated Euclidean centroid, and is ubiquitous in statistical analysis in non Euclidean spaces. In this work, we give a complete characterization of the weighted $p$-mean of a finite set of angular values on $S^1$ , based on a decomposition of $S^1$ such that the functional of ...
We consider the decidability of state-to-state reachability in linear time-invariant control systems over continuous time. We analyze this problem with respect to the allowable control sets, which are assumed to be the image under a linear map of the unit hypercube (i.e. zonotopes). This naturally models bounded (sometimes called saturated) control...
This dissertation thesis is made up of three distinct parts, connected especially by complexity notion, factorial complexity as well as state complexity. We study positional numeration systems and recognizable sets through decision problems and automatic sequences. The first part is devoted to the following problem: given a numeration system U and ...
