Grzegorz Rozenberg

Bio: Grzegorz Rozenberg is an academic researcher from Leiden University. The author has contributed to research in topics: Petri net & Formal language. The author has an hindex of 81, co-authored 679 publications receiving 31378 citations. Previous affiliations of Grzegorz Rozenberg include Åbo Akademi University & University of Warsaw.

The Embedding Problem For Switching Classes

Abstract: In the context of graph transformation we look at the operation of switching, which can be viewed as an elegant method for realizing global transformations of (group-labelled) graphs through local transformations of the vertices. In case vertices are given an identity, various relatively efficient algorithms exist for deciding whether a graph can be switched so that it contains some other graph, the query graph, as an induced sub- graph. However, when considering graphs up to isomorphism, we immediately run into the graph

String Pointer Reduction System

Abstract: In Chap. 8 we formalized the MDS structure of micronuclear and intermediate genes through legal strings. In this chapter we shall formalize the gene assembly process in the framework of legal strings. Thus, we shall now formalize the three molecular operations ld, hi, and dlad as operations on (rewriting rules for) legal strings, obtaining string pointer reduction systems. Although the transition from MDS descriptors to legal strings represents an increase in abstraction (we only preserve in legal strings the sequence of pointers), we prove that string pointer reduction systems are equivalent to MDS descriptor pointer reduction systems as far as the strategies for gene assembly are concerned.

Uniformly Scattered Factors

Abstract: A word u appears as a factor of another word v as it is: in one piece. When u is a subword of v, u may be scattered as several factors. We consider the case in between and put some restrictions on the number of factors as to which u is allowed to be scattered. A large class of partial orders which are generalizations of factors and subwords is obtained. Investigating the borderline between their finite and infinite antichains, we are able to fully characterize the property of being well partial order. The result generalizes Higman’s theorem.

Embedding linear orders in grids

Abstract: A grid (or a mesh) is a two-dimensional permutation: an m× n-grid of size mn is an m× n-matrix where the entries run through the elements {1,2, …, mn}. We prove that if δ1 and δ2 are any two linear orders on {1,2, …, N}, then they can be simultaneously embedded (in a well defined sense) into a unique grid having the smallest size.

Petri nets: Properties, analysis and applications

Abstract: Starts with a brief review of the history and the application areas considered in the literature. The author then proceeds with introductory modeling examples, behavioral and structural properties, three methods of analysis, subclasses of Petri nets and their analysis. In particular, one section is devoted to marked graphs, the concurrent system model most amenable to analysis. Introductory discussions on stochastic nets with their application to performance modeling, and on high-level nets with their application to logic programming, are provided. Also included are recent results on reachability criteria. Suggestions are provided for further reading on many subject areas of Petri nets. >