Roland Vollmar

Introduction to the special issue on cellular automata

Abstract In this introduction we review the basics of cellular automata and give a short survey of some areas of research concerning cellular automata. This is done to fit the papers of the present special issue into a general frame.

Towards Adjusting Informatics Education to Information Era

Since the very beginning of the modern computing era, the scientific and educational community in informatics has been in a continuous search for a proper philosophy, viewpoints, aims, contents, methods and tools. Advances in software, communication and hardware have played by that search the most influencing role, with theory advances having only secondary and declining impacts — in spite of the remarkable success of theory, quite well recognized by the community at large. The recent developments and advances in computing, communication and informatization of the society point out strongly, that horizons of the field are much broader, and its impacts on the society are far larger than anticipated even by strong optimists. This brings new and strong impetus to reconsider again the aims, scope, contents and methods of education in informatics and in other areas.

Feasible Models of Computation: Three-Dimensionality and Energy Consumption

Starting with cellular automata as a model of parallel machines we investigate the constraints for the energy consumption of r- dimensional machines which are motivated by fundamental physical limitations for the case r = 3. Depending on the operations which must be considered to dissipate energy (state changes, communication), relations between the relative performance of 2-D and 3-D machines are derived.

Konrad Zuse’s Relationship to Informatics

Konrad Zuse’s self–identity was that of an engineer, as a person who creates “means to purposes” [1]. In its German beginnings, Informatics focused on theoretical aspects. In my opinion this goes a long way to explaining Zuse’s hesitant acceptance of this emergent discipline. Later, the solving of practical problems came to the fore. This may explain his delayed affinity for this academic discipline.

From Endicott House to Schloß Dagstuhl

Within the span of almost two decades it has been a pleasure to see a seminar on quantum computation being held at the International Conference and Research Center for Computer Science, Schloß Dagstuhl, where the intellectual braopened at Endicott House in 1981 during the seminal workshop on “Physics of Computation” eventually seems to find a matching ket in Informatics. The publication of this special issue gives me the opportunity to write down a few reminiscences of the 1981 Conference at Endicott House – tinged, of course, with personal experience and personal memories. Foremost in my recollections, on the one hand I find the large number of impressive names of participants that gave this meeting its special flair (see the photograph on p. 276). On the other hand, the participants’ fundamental conviction that (in the organizers’ words) “The conference brought together about 60 people who believe that physics and computation are interdependent at a fundamental level”, seems to have been visionary and justified by the subsequent development of research and technology, as can be seen today. In view of these terms of reference, the participants’ contributions have focussed on the frontiers derived from the necessity of physical realization rather than on the ‘physical’ problems of computers existing at the time. The presentations thus have spanned a wide range of topics; at one end, there were questions of a – at thetime – mostly philosophical nature:

Informatics in curricula for noninformaticsstudents: engineering and science

In this paper three key issues are discussed concerning the role of informatics in science and engineering curricula. The first issue is that informatics is a fundamentally new methodology of key importance for the future. The second is the dramatic increase in basic information technology skills of freshman which makes treatment of more advanced informatics subjects possible and requires a change in teaching skills. The third key issue is that informatics education should concentrate on fundamental ideas thereby supporting life-long learning.

Maschinenklassen, parallele Berechnungshypothesen, Realisierbarkeit

Wir haben inzwischen mehrere Modelle kennengelernt: Ein-Kopf-Turingmaschi-nen, Mehr-Kopf-Turingmaschinen, Systeme von Turing-Automaten, Zellularraume, parallele Registermaschinen (Crew-Prams und Nlprams), uniforme Schaltkreisfamilien und systolische Trellisautomaten. Es gibt eine Vielzahl weiterer Modelle (siehe Literaturliste). Im ersten Abschnitt stellen wir einen Versuch vor, sie zumindest grob zu klassifizieren im Hinblick auf ihre Fahigkeiten zur Parallelverarbeitung.

Systeme von Turing-Automaten

In den ersten beiden Abschnitten werden Systeme von Turing-Automaten eingefuhrt und ihre Arbeit als Spracherkenner wird demonstriert. Anschliesend vergleichen wir sie mit Turingmaschinen und Zellularraumen. Dabei wird sich zeigen, das die neuen Automaten insofern die Lucke zwischen den beiden bekannten Modellen fullen, als man bei ihnen den „Grad der Parallelitat“ vom einen bis zum anderen Extrem variieren kann. Im letzten Abschnitt wird auf eine Version des FSSP fur Systeme von Turing-Automaten eingegangen.

Pipelineverarbeitung in systolischen und zellularen Automaten

Die tayloristische Betrachtung von Arbeitsvorgangen fuhrte dazu, in Fabriken zur Fliesbandproduktion uberzugehen. Im Zusammenhang mit der Diskussion uber die Humanisierung der Arbeitswelt wird dieser Ansatz inzwischen in Frage gestellt: Die zu weit gehende Spezialisierung der Menschen und die Erfordernisse einer gleichbleibenden Aufmerksamkeit und Geschwindigkeit beim Ausfuhren der speziellen Tatigkeiten sind psychologisch schwer zu verkraften.

On the power of global-bus in mesh-connected architectures

Abstract We study the computational power of global bus systems (GB, for short) augmented with a mesh-connected computer (MCC, for short). First we show that the GB is a useful tool for designing optimum-time parallel algorithms for MCCs and for showing correctness of those algorithms once designed. We do this by giving some design examples which utilize the GB very efficiently. Secondly we give a fundamental technique for the elimination of GBs. As an application of the technique, we will show that a rich variety of GBs on one- and two-dimensional MCCs can be eliminated without any loss of time efficiency.