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.

Tree transducers, L systems and two-way machines (Extended Abstract)

Abstract: This extended abstract is a condensed version of the results presented in two technical reports ([16] and [13]). In [16] a systematic treatment of the relationships between parallel rewriting systems (top-down tree transducer, ETOL system) and two-way machines (2-way gsm, tree-walking automaton, checking stack automaton) is given. Particular attention is paid to the effect of restricting the copying power of these devices. In [13] the results of [16] are employed to show that the iteration of nondeterministic top-down tree transducers, of nondeterministic 2-way gsm's and of control on ETOL systems each gives rise to a proper hierarchy.

Membrane Computing 15th International Conference, CMC 2014

Abstract: Amorphous computing systems typically consist of myriads of tiny simple processors that are randomly distributed at fixed positions or move randomly in a confined volume. The processors are “embodied” meaning that each of them has its own source of energy, has a “body” equipped with various sensors and communication means and has a computational control part. Initially, the processors have no identifiers and from the technological reasons, in the interest of their maximal simplicity, their computational, communication, sensory and locomotion (if any) parts are reduced to an absolute minimum. The processors communicate wirelessly, e.g., in an airborne medium they communicate via a short-range radio, acoustically or optically and in a waterborne medium via molecular communication. In the extreme cases the computational part of the processors can be simplified down to probabilistic finite state automata or even combinatorial circuits and the system as a whole can still be made universally programmable. From the theoretical point of view the structure and the properties of the amorphous systems qualify them among the simplest (non-uniform) universal computational devices. From the practical viewpoint, once technology will enable a mass production of the required processors a host of new applications so far inaccessible to classical approaches to computing will follow. Extended Abstract: The history of amorphous computing systems began by the end of the twentieth century, mainly as an engineering endeavor (cf. [1], [2], [4], [5], [6], or [13]). Namely, in those days the progress in constructing the micro-electro-mechanical systems (MEMS) has enabled to think of devices integrating a central data processing unit (the microprocessor) and several components that interact with the surroundings such as micro-sensors, wireless communication unit, and the energy source in a small unit. These parts can possibly be complemented by micro-actuators and locomotive means. The resulting device can be viewed as an embodied computational unit. Note that such a unit possesses all the necessary parts characterizing autonomous embodied robots. MEMS devices generally range in size from 20 micrometres (20 × 10−6 m) to a millimetre (i.e. 0.02 to 1.0 mm). Current ideas about nano-electro-mechanical systems (NEMS) and nano-technology consider such systems at a nano-scale (10−9 m). The driving force behind the respective development has mainly been a vision of huge amounts of the respective “micro-robots” engaged in various application tasks This work was partially supported by RVO 67985807 and the GA ČR grant No. P202/10/1333.

Structured Transformations and Computation Graphs for Actor Grammars

Abstract: Actor Grammars are a model of actor systems based on graph rewriting. Computation graphs model rewriting processes in actor grammars, and hence, computations in actor systems. The relationship between computation graphs and structured transformations, as introduced in [JR 89], is investigated. A structured transformation may be viewed as a description of the external effect of of a computation described by a computation graph.

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. >