Externe Veröffentlichungen

AD95a

Chandrabose Aravindan and Phan Minh Dung. Knowledge base dynamics, abduction, and database updates. Journal of applied non-classical logics, 5(1):51--76, 1995.
Abstract: In this paper, we argue that to apply rationality results of belief dynamics theory to various practical problems, it should be generalised in two respects: first of all, it should allow certain part of belief to be declared immutable; and secondly, the belief state need not be deductively closed. Such a generalisation of belief dynamics is presented, along with the concept of generalised contraction to contract a sentence from knowledge base. We show that the knowledge base dynamics has interesting connections with abduction, thus enabling us to use abductive procedures to realize contractions. Finally, we demonstrate how knowledge base dynamics can provide an axiomatic characterisation for deleting view atoms from databases.

AD95b

Chandrabose Aravindan and Phan Minh Dung. On the correctness of unfold/fold transformations of normal and extended logic programs. Journal of Logic Programming, 24(3):201--218, September 1995.
Abstract: We show that the framework for unfold/fold transformation of logic programs, first proposed by Tamaki and Sato and later extended by various researchers, preserves various non-monotonic semantics of normal logic programs, esp. preferred extension, partial stable models, regular model, and stable theory semantics. The primary aim of this research is to adopt a uniform approach for every semantics of normal logic programs, and that is elegantly achieved through the notion of semantic kernel. Later, we show that this framework can also be applied to extended logic programs, preserving the answer set semantics.

BD95a

Stefan Brass and Jürgen Dix. A General Approach to Bottom-Up Computation of Disjunctive Semantics. In J. Dix, L. Pereira, and T. Przymusinski, editors, Nonmonotonic Extensions of Logic Programming, LNAI 927, pages 127--155. Springer, Berlin, 1995.
Abstract: Our goal is to derive bottom-up query-evaluation algorithms from abstract properties of the underlying negation semantics. In this paper, we demonstrate our approach for the disjunctive stable model semantics, but the ideas are applicable to many other semantics as well. Our framework also helps to understand and compare other proposed query evaluation algorithms. We start by computing a ``residual program'' and show that it is equivalent to the original program under very general conditions on the semantics (which are satisfied, e.g., by the well-founded, stable, stationary, and static semantics). Many queries can already be answered on the basis of the residual program. For the remaining literals, we propose to use an appropriate completion of the residual program, which syntactically characterizes the intended models. In the case of the stable model semantics, we utilize an interesting connection to Clark's completion.

BD95b

Stefan Brass and Jürgen Dix. Characterizations of the Stable Semantics by Partial Evaluation. In A. Nerode, W. Marek, and M. Truszczynski, editors, Logic Programming and Non-Monotonic Reasoning, Proceedings of the Third International Conference, LNCS 928, pages 85--98, Berlin, June 1995. Springer.
Abstract: There are three most prominent semantics defined for certain subclasses of disjunctive logic programs: GCWA (for positive programs), PERFECT (for stratified programs) and STABLE (defined for the whole class of all disjunctive programs). While there are various competitors based on 3-valued models, notably WFS and its disjunctive counterparts, there are no other semantics consisting of 2-valued models. We argue that the reason for this is the Partial Evaluation-property (also called Unfolding or Partial Deduction) wellknown from Logic Programming. In fact, we prove characterizations of these semantics and show that if a semantics SEM satisfies Partial Evaluation and Elimination of Tautologies then (1) SEM is based on 2-valued minimal models for positive programs, and (2) if SEM satisfies in addition Elimination of Contradictions, it is based on stable models. We also show that if we require Isomorphy and Relevance then STABLE is completely determined on the class of all stratified disjunctive logic programs. The underlying notion of a semantics is very general and our abstract properties state that certain syntactical transformations on programs are equivalence preserving.

BD95c

Stefan Brass and Jürgen Dix. Disjunctive Semantics based upon Partial and Bottom-Up Evaluation. In Leon Sterling, editor, Proceedings of the 12th Int. Conf. on Logic Programming, Tokyo, pages 199--213. MIT Press, June 1995.
Abstract: We present a new and general approach of defining semantics for disjunctive logic programs. Our framework consists of two parts: (1) a semantical, where semantics are defined in an abstract way as the weakest semantics satisfying certain properties, and (2) a procedural, namely a bottom-up query-evaluation method based on operators working on conditional facts. As to (1), we concentrate in this paper on a particular set of abstract properties (the most important being the unfolding or partial evaluation property GPPE) and define a new semantics D-WFS, which extends WFS and GCWA and is strongly related to Przymusinski's STATIC semantics. In (2) we compute to any program P a residual program P, and show that P is equivalent to the original program under very general conditions on the semantics (which are satisfied, e.g., by the well-founded, stable, stationary, and static semantics). Many queries w. r. t. these semantics can already be answered on the basis of the residual program.

Ber96

Roland Berling. Eine Constraint-basierte Modellierung für Geometrische Objekte. Universität Koblenz-Landau, Dissertation, erscheint 1996.

BFS95a

Peter Baumgartner, Ulrich Furbach, and Frieder Stolzenburg. Computing answers and logic programming by model elimination based theorem proving. In Andrew Ireland, editor, Working Notes of the 2nd Workshop on Automated reasoning: Bridging the gap between theory and practise, pages 3--4, Sheffield, April 1995. Society for the Study of Artificial Intelligence and Simulation of Behaviour.

BFS95b

Peter Baumgartner, Ulrich Furbach, and Frieder Stolzenburg. Model elimination, logic programming and computing answers. In Proceedings of the 14th International Joint Conference on Artificial Intelligence, pages 335--340, Montréal, August 1995. Extended version submitted to Artificial Intelligence.
Abstract: We prove that theorem provers using model elimination (ME) can be used as answer complete interpreters for disjunctive logic programming. For this, the restart variant of ME with a mechanism for computing answers and the ancestry refinement is introduced. Furthermore, we demonstrate that in the context of automated theorem proving it is much more difficult to compute (non-trivial) answers to goals, instead of only proving the existence of answers. It holds that resolution with subsumption is not answer complete. We consider puzzle examples and give a comparative study of OTTER, SETHEO and our restart model elimination prover PROTEIN.

BHP95

P. Baumgartner, R. Hähnle, and J. Posegga, editors. Theorem Proving with Analytic Tableaux and Related Methods, volume 918 of Lecture Notes in Artificial Intelligence. Springer, 1995.
Abstract: The method of Analytic Tableaux is a well established and widely used framework for both, theoretical investigations into the nature of formal proofs and as a base for efficient implementations of theorem provers. One of the main advantages of analytic tableaux when compared to e.g. resolution is its adapatbility to various kinds of logics. As the preceeding ones, also the recent workshop on Analytic Tableaux and Related Methods bears witness of these facts; this conference proceedings contains contributions from the areas classical logic (extensions and proof procedures), modal logic, intuitionistic logic, linear logic, higher-order logic and applications.

Bre95b

Marcel Bresink. Radiosity 2.0 Entwicklerdokumentation. Technisches Handbuch, Universität Koblenz, 1995.
Zusammenfassung: Die technische Entwicklerdokumentation enthält eine Einführung in die Konzepte des modularen, objektorientierten Radiosity-Systems Version 2.0. Die grundlegende Architektur des Systems, die einzelnen Schnittstellen der miteinander interagierenden Module, alle Methoden der entwickelten Klassenbibliothek und das Dateiformat zum Austausch geometrischer Daten wird beschrieben. Darüberhinaus gibt das Handbuch die Richtlinien für die Entwicklung von RadiosityCore-Bundles, dem dynamisch austauschbaren Kernmodul für die Evaluation verschiedener Radiosity-Implementationen, vor.

BS95a

Peter Baumgartner and Frieder Stolzenburg. Constraint model elimination and a PTTP-implementation. In Peter Baumgartner, Reiner Hähnle, and Joachim Posegga, editors, Proceedings of the 4th Workshop on Theorem Proving with Analytic Tableaux and Related Methods, pages 201--216. Springer, Berlin, Heidelberg, New York, 1995. LNAI 918.
Abstract: In constraint logic programming, proof procedures for Horn clauses are enhanced with an interface to efficient constraint solvers. The question arises whether it is possible to incorporate constraint processing into general, non-Horn theorem proving calculi. In this paper, a positive answer to this question will be given. A framework for a new calculus is introduced which combines model elimination with constraint solving, following the lines of Bürckert (1991). A prototype system has been implemented rapidly by only combining a PROLOG technology implementation of model elimination and PROLOG with constraints. Some example studies, e.g. taxonomic reasoning, show the advantages and some problems with this procedure.

BS95b

Peter Baumgartner und Frieder Stolzenburg. Jahrestreffen der GI-Fachgruppe 1.2.1 ''Deduktion''. KI, 9(6):80--81, 1995. Tagungsbericht.

DFG+ 95

P. Dahm, J. Fricke, R. Gimnich, M. Kamp, H. Stasch, E. Tewes und A. Winter. Anwendungslandschaft der Volksfürsorge. Interner Projektbericht 5/95, Universität Koblenz-Landau, Institut für Softwaretechnik, Koblenz, 1995.
Zusammenfassung: Im Rahmen des Projekts GUPRO werden Quelltexte mittels entsprechender Parser in eine Graph-Repräsentation überführt, die jeweils ein Exemplar einer bestimmten Klasse von Graphen ist. Auf Grundlage seiner Klasse können Anfragen an einen Graph gerichtet werden. Dadurch wird es möglich, Informationen zu gewinnen, die beim Verstehen und der Wartung existierender Softwaresysteme von Nutzen sind.

Entsprechend der heterogenen Anwendungslandschaft der Volksfürsorge werden hier sieben sprachspezifische Graphklassen vorgestellt, deren Exemplare zum einen in den Sprachen COBOL, PL/I und CSP geschriebene Anwedungsprogramme und zum anderen betriebs- bzw. datenbanksystemspezifische Texte (JCL-Prozeduren, Datenbankbeschreibungen) repräsentieren. Die Modellierung der einzelnen Sprachen erfolgt hier relativ grobgranular.

Auf Grundlage dieser sprachspezifischen Graphklassen wird eine sprach- und quelltextübergreifende ,,Makro-Graphklasse`` erarbeitet, die eine Abbildung des gesamten Softwarebestandes in einen Graph ermöglicht. Das Vorgehen bei dem dazu notwendigen inkrementellen Parsen von einzelnen Texten wird erläutert.

Anhand eines an der Praxis orientierten Fragenkatalogs werden zum Abschluß konkrete Anfragemöglichkeiten an den Makro-Graph aufgezeigt.

Dix95a

Jürgen Dix. A Classification-Theory of Semantics of Normal Logic Programs: I. Strong Properties. Fundamenta Informaticae, XXII(3):227--255, 1995.
Abstract: Our aim in this article is to present a method for classifying and characterizing the various different semantics of logic programs with negation that have been considered in the last years. Instead of appealing to more or less questionable intuitions, we take a more structural view: our starting point is the observation that all semantics induce in a natural way non-monotonic entailment relation |- . The novel idea of our approach is to ask for the properties of these |- -relations and to use them for describing all possible semantics. The main properties discussed in this paper are adaptations of rules that play a fundamental rôle in general non-monotonic reasoning: Cumulativity and Rationality. They were introduced and investigated by Gabbay, Kraus, Lehmann, Magidor and Makinson. We show that the 3-valued version COMP3 of Clark's completion, the stratified semantics M supp P as well as the well-founded semantics WFS and two extensions of it behave very regular: they are cumulative, rational and one of them is even supraclassical. While Pereira's recently proposed semantics O-SEM is not rational it is still cumulative. Cumulativity fails for the regular semantics REG-SEM of You/Yuan (recently shown to be equivalent to three other proposals). In a second article we will supplement these strong rules with a set of weak rules and consider the problem of uniquely describing a given semantics by its strong and weak properties together.

Dix95b

Jürgen Dix. A Classification-Theory of Semantics of Normal Logic Programs: II. Weak Properties. Fundamenta Informaticae, XXII(3):257--288, 1995.
Abstract: Our aim in this article is to supplement the set of strong properties introduced in the preceding article ([Dix95a]) with a set of weak principles in order to characterize semantics of logic programs. In [Dix95a] we introduced our point of view: we observed that all semantics induce in a natural way a sceptical non-monotonic entailment relation SEM scept. We ask for the properties of these sceptical relations and use them to describe all possible semantics. We collect in this paper serious shortcomings of some semantics proposed recently. Their strange behaviour led us to formulate in a natural way certain principles to avoid these problems. We argue that any well-behaved semantics should satisfy these principles. The main results state that our list of weak principles is complete in the following sense: any well-behaved-semantics is an extension of the well-founded semantics WFS and coincides for stratified programs with Apt, Blair, and Walker's supported model M supp P. We also claim that two extensions of the well-founded semantics (introduced in the preceding article) are uniquely characterized by their strong and weak properties.

Dix95c

Jürgen Dix. Characterizing semantics of logic programs by partial evaluation. 10th International Congress of Logic, Methodology and Philosophy of Science, Florence, Italy, August 1995.
Abstract: Our aim is to look from a more structural point of view at the various semantics for logic programs with negation that have been considered in the last years. Nearly all semantics SEM are defined by associating with any program P a subset of its 3-valued Herbrand models

SEM(P) subset MOD Herbrand 3-val (P)

But a purely model-theoretical investigation is not possible, because all these semantics depend on the way the program is written down. They are not invariant under classical equivalence:

P iff P' does not imply SEM(P) = SEM (P')

Therefore the syntactic structure of the program P, partially represented by its dependency graph Gp, plays an important role. We show that some particular syntactic transformations suffice to determine certain semantics uniquely.

Dix95d

Jürgen Dix. Detailed Report on the First LP & NMR retreat. The European Journal on Artificial Intelligence, Vol. 8, No. 1:39--43, 1995. Also in Computational Logic, Vol. 2, 1995, pages 94--97.
Abstract: This is a detailed report on the first LP & NMR Retreat held in Shakerville, Kentucky.

Dix95e

Jürgen Dix. Semantics of Logic Programs: Their Intuitions and Formal Properties. An Overview. In Andre Fuhrmann and Hans Rott, editors, Logic, Action and Information. Proceedings of the Konstanz Colloquium in Logic and Information (LogIn '92), pages 241--329. DeGruyter, 1995.
Abstract: This paper gives a detailed overview of the recent approaches in Logic Programming and Non-Monotonic Reasoning. It differs from two other interesting overviews about negation in logic programming: Minker's article in the Special Issue of the Journal of Logic Programming on Non-Monotonic Reasoning and Logic Programming and Apt and Bol's article in the jubileum (10th anniversary) issue of the Journal of Logic Programming. While Minker's article gives an almost complete description of all the activities and different approaches in the field, Bol/Apt and we (in this article) also try to present recent research results in a comprehensive and detailed manner. Although no proofs are given, all important definitions and notions are formally introduced to illustrate the underlying ideas in a precise and strict fashion. Apt/Bol's paper and the present overview can be seen as complementary in a sense: while Apt and Bol concentrate more on LP-semantics, we are more concerned with NMR-semantics. This paper is somewhere in between Minker and a full-detailed paper in the style of Shepherdsons famous overview article from 1988, that still has to be written.

DPP95

J. Dix, L. Pereira, and T. Przymusinski, editors. Non-Monotonic Extensions of Logic Programming, LNAI 927, Berlin, 1995. Springer.
Abstract: This book is the outcome of an original compilation of extended and revised versions of selected papers presented at the workshop on Non-Monotonic Extensions of Logic Programming held in Santa Margherita Ligure, Italy, on June 17, 1994. It also includes additional papers solicited from the participants. As ome workshop papers were published elsewhere, they do not appear in this volume.

Du95

C. Du. RelCAD: A Relational Cad System with Constraint-based Geometric Modelling. Verlag Dr. Kovac, Hamburg, 1995.

EE95

J. Ebert and G. Engels. Specialization of Object Life Cycle Definitions. Fachbericht Informatik 19/95, Universität Koblenz-Landau, Fachbereich Informatik, Koblenz, 1995.
Abstract: Several object-oriented modeling approaches propose to describe the dynamic behaviour of objects by state transition diagrams. None of them provides precise rules or conditions for the interrelation between the behaviour description of classes and those of their subclasses. In this paper, we discuss this interrelation in detail. It turns out that one has to distinguish between the observable and the invocable behaviour of objects and that different compatibility requirements between the diagrams exist depending on the type of behaviour.

EF95

J. Ebert and A. Franzke. A Declarative Approach to Graph Based Modeling. in: E. Mayr, G. Schmidt, G. Tinhofer (Eds.) Graphtheoretic Concepts in Computer Science Springer, Berlin, Lecture Notes in Computer Science, LNCS 903, pages 38--50, 1995.
Abstract: The class of TGraphs, i.e. typed, attributed, and ordered directed graphs, is introduced as a gneral graph class for graph based modeling. TGraphs are suitable for a wide area of applications. A declarative approach to specifying subclasses of TGraphs by a combination of a schematic graphical description and an additional constraint language is given. The implementation of TGraphs by an appropriate software approach is described.

EV95

J. Ebert and G. Vossen. I-Seriability: Generalized Correctness for Transaction-Based Environments. Fachbericht Informatik 16/95-I, Universität Münster, Angewandte Mathematik und Informatik, Koblenz, June 1995.
Abstract: Motivated by shortcomings of classical serializability as a correct criterion in recent transaction-based environments (such as multidatabases or management of transactional workflows), we introduce and study a new notation of serializability which takes explicitly given invariants into account. Invariants are used to express constraints which have to be preserved by database transactions. However, a distinction is made between local invarinats respected by individual transactions, and global ones maintained by entire schedules. The ideal situation is that a serializable schedule, which preserves local constraints via its equivalence to a serial schedule, also respects the global constraint. For two sample scenarios, we give a sufficient condition under which this is the case.

Fur95

U. Furbach. From theorem proving to logic programming. In Krall and Geske, editors, 11. Workshop Logische Programmierung. GMD-Studien, 1995.
Abstract: This is both, a report on work being done until now in the Koblenz AI Group and a preview of the work to be done in a project which starts right now. Until now we developed a tableau theorem prover which can be used as an interpreter for disjunctive logic programming and we are planning to extend this prover to handle non-monotonic negations.

FW95

A. Franzke und A. Winter. Softwareevaluation mit Mitteln des Requirements-Engineering. A. Oberweis (Hrsg.) Requirements Engineering für Informationssysteme, Proceedings EMISA Fachgruppentreffen '95 Karlsruhe, 12.-13. Oktober, S. 113--120, 1995.
Zusammenfassung: Dieser Beitrag skizziert das Vorgehen zur Softwareevaluation, welches in drei Projekten an der Universität Koblenz in unterschiedlichen Anwendungsbereichen entwickelt und erprobt wurde. Hierbei werden neben dem Vorgehen selbst, auch Erfahrungen aus den Projekten im Hinblick auf Erhebung und Dokumentation der Evaluationsgrundlagen skizziert. Im Ausblick werden hieraus Anforderungen an eine Werkzeugunterstützung zur Softwareevaluation abgeleitet.

HG95

Walter Hower and Winfried H. Graf. Research in Constraint-Based Layout, Visualization, CAD, and Related Topics: A Bibliographical Survey. In Isabel Cruz, Kim Marriott, and Pascal Van Hentenryck, editors, Proceedings of the International Workshop on Constraints for Graphics and Visualization (CGV'95 ), pages 3--23, Cassis, France, 18th September 1995. Department of Computer Science, Monash University, Clayton, Australia. Updating: DFKI Research Report RR-95-12, Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, Saarbrücken.
Abstract: The present work compiles numerous papers in the area of computer-aided design, graphics, layout configuration, and user interfaces in general. This work of bibliographical pointers may serve as a basis for a detailed and comprehensive survey of this important and challenging field in the intersection of constraint processing and graphics. In order to reach this ambitious aim, and also to keep this study up-to-date, the authors appreciate any comment and update information.

HH95

Ralf Hofestädt and Xiandeng Huang. Automaton-Based Load Balancing Simulation in a Workstation Cluster. In Proceedings of the International Workshop on Advanced Parallel Processing Technologies, APPT'95, pages 344--347, Beijing, China, September 1995. Publishing House of Electronics Industry. ISBN 7-5053-3304-6/TP.1243.
Abstract: A new approach to load balancing is presented here. The information necessary for load balancing is expressed in specific data structures, so-called ``intelligent tables'', which are realized by cellular automata. This approach has been simulated in our simulation environment CABLE. The simulation results show that our new method has good applicability and a significant speedup.

HKR95

Walter Hower, Derrick Köstner, and Manfred Rosendahl. Computer-aided layout by evolutionary computing. In Remco C. Veltkamp and Edwin H. Blake, editors, Proceedings of the fifth Eurographics workshop on Programming Paradigms in Graphics, EUROGRAPHICS '95, pages 251--269, Maastricht, September 2--3, 1995. CWI, Amsterdam, The Netherlands.
Abstract: The present work treats the computation of heterogeneous layout configurations; distinct shapes as rectangles and triangles have to get placed into a target frame such that the objects must not overlap. Due to the combinatorial search space we are facing because of the exponential number of combinations of the various possibilities of layout configurations an artificial intelligence approach using incomplete heuristics is required. It turns out that the evolutionary techniques presented here represent a promising framework to the frequent task to catch one solution or a few of numerous solutions very quickly.

How95

Walter Hower. Constraint satisfaction --- Algorithms and complexity analysis. Information Processing Letters, 55(3):171--178, 11 August 1995. Elsevier Science Publishers B.V.

HS95a

Xiandeng Huang and Christoph Steigner. A Model-Driven Tool for Performance Measurement and Analysis of Parallel Programs. In Bob Hertzberger and Giuseppe Serazzi, editors, Proceedings of the International Conference on High-Performance Computing and Networking, HPCN EUROPE, LNCS 919, pages 612--617, Milan, Italy, May 1995. Springer-Verlag.
Abstract: The performance of parallel computing systems is strongly dependent on the runtime behaviour of parallel programs. This paper describes a new approach to measure and analyze the runtime behaviour of parallel programs. Our approach provides programmers with a specification language by means of which measurement targets can be formally described in a measurement model. Driven by the measurement model, the measurement and analysis process can be automated. In addition, our approach provides an efficient method to reduce the amount of measurement data.

HS95b

Xiandeng Huang und Christoph Steigner. Eine Spezifikationssprache zur modellgesteuerten Leistungsbewertung paralleler Programme. In C. Müller-Schloer (Hrsg.), Tagungsband der 3. GI/ITG Fachtagung Arbeitsplatz-Rechensysteme: Anwendung, Betrieb und Architektur von Workstations, S. 40--48, Hannover, Mai 1995. ISBN 3-87990-074-4.
Zusammenfassung: In der vorliegenden Arbeit wird eine Spezifikationssprache vorgestellt. Mit Hilfe dieser Sprache kann ein Meßmodell aufgebaut werden, in dem der Programmierer seine Wünsche zur Messung und Bewertung der Leistungen eines parallelen Programms mit Bezug auf den Quelltext formal darstellen kann. Gesteuert durch das Meßmodell, können die Instrumentierung des Quelltextes und die Auswertung von Meßdaten automatisiert werden.

HS95c

Xiandeng Huang and Christoph Steigner. Performance Measurement and Analysis of Parallel Programs. In Proceedings of the International Workshop on Advanced Parallel Processing Technologies, APPT'95, pages 348--355, Beijing, China, September 1995. Publishing House of Electronics Industry. ISBN 7-5053-3304-6/TP.1243.
Abstract: The performance of parallel programs is strongly dependent on their runtime behaviour. Because of their inherent complexity, it is hard to gain an insight into the runtime behaviour of parallel programs. In this paper, we present a new approach to measuring and analyzing the runtime behaviour of parallel programs. A specification language will be provided. Based on this language, measurement targets can be formally described in a measurement model. Driven by the measurement model, performance measurement and analysis can be carried out automatically.

HW95

Walter Hower and Richard Wallace. Evaluation of the model-based diagnosis algorithm of Bakker et al.\ for solving over-determined constraint satisfaction problems. In Workshop Notes CP95 Workshop on Over-Constrained Systems, pages 133--135, Cassis, France, 18 September 1995. INRA.

JH95

Stephan Jacobi and Walter Hower. Dynamic updating of constraint satisfaction problems. In Workshop Notes CP95 Workshop on Over-Constrained Systems, pages 137--144, Cassis, France, 18 September 1995. INRA.
Abstract: The constraint satisfaction problems are often of a dynamic nature in a sense that the original problem changes in the course of time. With the NP-complete complexity of global constraint satisfaction in mind it is a desirable need to decrease the average complexity of the consistency algorithm. This objective may be reached by applying only the changes incrementally to the affected parts of the network avoiding total recomputations wherever possible.

KMS95

Jürgen Krause, Thomas Mandl und Maximilian Stempfhuber (Hrsg.). Gestaltungsentwurf für das ZVEI-Verbandsinformationssytem, 1995. Skript, Workshop.

Kra95a

Jürgen Krause. Computertalk and Multimodality. In Hans Haugeneder, editor, Language Engineering, pages 85--99. Heyer, 1995.

Kra95b

Jürgen Krause. Theory and Practice of Applied Natural Language Computing. Vieweg, Braunschweig, 1995.
Abstract: At first glance multimodality does not appear to be too much connected with the first term in the title computertalk. Roughly speaking, the term addresses the differences on language use between human communication and natural language human computer interaction HCI (and the question whether such a difference exists at all). To show empirically the existence of computertalk in HCI is the main theme of my paper. The connection to graphical HCI and to multimodality lies in the way of interpreting these differences. Beyond the starting concept of a language register computertalk it is to argue that language in HCI is used metaphorically -- not in 1:1 -- analogy to human communication -- in a similar sense as the metaphorical use of the desktop metaphor in graphical HCI.

Kra95c

Jürgen Krause. Zwischenbericht 1994 der Gesellschaft Sozialwissenschaftlicher Infrastruktureinrichtungen (GESIS) e.V. . Gesellschaft Sozialwissenschaftlicher Infrastruktureinrichtungen (GESIS) e.V., Bonn, Köln, Mannheim, jürgen krause; ekkehard mochmann; peter ph. mohler Auflage, 1995.
Zusammenfassung: Der Zwischenbericht 1994 informiert über das Aufgaben- und Dienstleistungsspektrum der drei GESIS-Institute, dem Informationszentrum Sozialwissenschaften (IZ), Bonn, dem Zentralarchiv für empirische Sozialforschung an der Universität zu Koeln und dem Zentrum für Umfragen, Methoden und Analysen (ZUMA) e.V., Mannheim (einschließlich der GESIS-Aussenstelle in Berlin) und berichtet über den Schwerpunkt der Tätigkeiten im Jahre 1994.

LRP95

R. Lakmann, V. Rehrmann und L. Priese. Verarbeitung unscharfen Wissens in hybriden, parallelen Entscheidungsgraphen am Beispiel der Verkehrszeichenerkennung. In L. Dreschler-Fischer und S. Pribbenow (Hrsg.), KI-95 Activities, 19. Conference on Artificial Intelligence, Bielefeld, S.\ 148--149. Gesellschaft für Informatik, 1995.
Zusammenfassung: Die Kombination von KI-Methoden und Methoden der Mustererkennung gewährleistet ein erhöhtes Maß an Sicherheit und Qualität bei der visuellen Objekterkennung. Am Beispiel der Erkennung von Verkehrszeichen wird die Methode eines solchen hybriden Systems erläutert. Die Verkehrszeichendetektion wird durch einen parallelen Entscheidungsgraphen gesteuert, in dem der Entscheidungsfluß auf der Auswertung von Wahrscheinlichkeiten zahlreicher signifikanter Merkmale von Verkehrszeichen basiert. Die parallele, modulare Struktur des Entscheidungsgraphen erlaubt die datengetriebene Verzweigung in mehrere Interpretationsrichtungen, die anschließend zu einer Aussage kombiniert werden.

LS95

U. Lemmer and Ch. Steigner. Feature structures for representing and deducing visual data. In L. Dreschler-Fischer and S. Pribbenow, editors, KI-95 Activities, 19. Conference on Artificial Intelligence, Bielefeld, pages 142 -- 143. Gesellschaft für Informatik, 1995.
Abstract: On more abstract levels of processing there exist logic oriented approaches to pattern recognition (PR). However, logic -- which may be seen as an underlying representation for other formalisms as well -- is not that accepted as an universal representation paradigm in PR. Frame oriented approaches seam to correspond more directly to the object-like view of PR to a world of 'things' and 'attributes'. In this paper we describe Feature Structures (FS) and FS-Operations as frame-like means to represent and manipulate data of visual objects.

Nie95a

I. Niemelä. A decision method for nonmonotonic reasoning based on autoepistemic reasoning. Journal of Automated Reasoning, 14:3--42, 1995.
Abstract: A novel decision method for autoepistemic reasoning is developed and proved correct. The method is applicable in a general setting, i.e., for an autoepistemic logic based on a given classical logic. It provides a decision procedure for a tightly grounded form of autoepistemic reasoning based on L-hierarchic expansions as well as for autoepistemic reasoning based on Moore-style expansions and N-expansions. Prominent formalizations of nonmonotonic reasoning, such as default logic and circumscription, can be embedded into autoepistemic logic based on L-hierarchic expansions using simple local translations. Hence, the method can serve as a unified reasoning tool for a wide range of forms of nonmonotonic reasoning. The method is conceptually simple and the inherent sources of complexity and targets for optimization are clearly identifiable. As an example of exploiting the optimization possibilities, a new decision method for Reiter's default logic is developed where ideas from autoepistemic reasoning are used to prune the search space for applicable default rules when constructing extensions of a default theory.

Nie95b

I. Niemelä. Towards efficient default reasoning. In Proceedings of the 14th International Joint Conference on Artificial Intelligence, pages 312--318, Montreal, Canada, August 1995. Morgan Kaufmann Publishers.
Abstract: A decision method for Reiter's default logic is developed. It can determine whether a default theory has an extension, whether a formula is in some extension of a default theory and whether a formula is in every extension of a default theory. The method handles full propositional default logic. It can be implemented to work in polynomial space and by using only a theorem prover for the underlying propositional logic as a subroutine. The method divides default reasoning into two major subtasks: the search task of examining every alternative for extensions, which is solved by backtracking search, and the classical reasoning task, which can be implemented by a theorem prover for the underlying classical logic. Special emphasis is given to the search problem. The decision method employs a new compact representation of extensions which reduces the search space. Efficient techniques for pruning the search space further are developed.

NS95

I. Niemelä and P. Simons. Evaluating an algorithm for default reasoning. In Working Notes of the IJCAI'95 Workshop on Applications and Implementations of Nonmonotonic Reasoning Systems, Montreal, Canada, pages 66--72, Montreal, Canada, August 1995.
Abstract: In this paper the performance of a recently proposed decision procedure for Reiter's default logic is evaluated. In particular, the efficiency of the conflict resolution technique in the new algorithm is examined. To rule out classical reasoning, a fragment of default logic with only atomic formulae is considered. This fragment corresponds to the stable model semantics of propositional logic programs. As an interesting test domain for nonmonotonic reasoning, combinatorial problems are put forward. In this paper combinatorial graph problems such as graph colorings and Hamiltonian circuits are used. In order to contrast the new algorithm with existing approaches, it is compared with an advanced special purpose implementation of the stable model semantics, the SLG system. The performance of the new algorithm compares favorably to that of SLG and the new algorithm is able to compute stable models quite efficiently for non-stratified (propositional) logic programs consisting of several hundreds of rules.

PLR95

L. Priese, R. Lakmann, and V. Rehrmann. Ideogram identification in a realtime traffic sign recognition system. In Proc. Intelligent Vehicles Symposium, Detroit, pages 310--314. IEEE, 1995.
Abstract: A robust system for the automatic detection of traffic signs has been developed at the Image Recognition Laboratory of the University of Koblenz. This traffic sign recognition ( TSR) system was originally designed to localize traffic signs and to recognize their classes, e.g. prohibition signs, danger signs, beacons, etc. In a recent version the exact identification of traffic signs is added. Traffic signs are identified by the interpretation of their ideograms realized by different modules in our TSR. The first module detects the position and direction of arrows. A second tool recognizes numerals and interprets them as reasonable speed limits. A third one is a general nearest neighbor classifier applied to three classes of ideograms (prohibition sign ideograms, speed limits, arrows on mandatory signs). The fourth module is based on neural nets and applied to two of these classes. Some of these components are used competitively in our realtime TSR. The use of several results from different tools increases the safety and provides high recognition rates.

PNS95

L. Priese, M. Nielsen, and V. Sassone. Characterizing Behavioural Congruences for Petri Nets. In LNCS 962, Proc. CONCUR'95, pages 175--189. I. Lee and S. Smolka, 1995.
Abstract: We exploit a notion of interface for Petri nets in order to design a set of net combinators. For such a calculus of nets, we focus on the behavioural congruences arising from four simple notions of behaviour, viz., traces, maximal traces, step, and maximal step traces, and from the corresponding four notations of bisimulation, viz., weak and weak step bisimulation and their maximal versions. We characterize such convergences via universal contexts and via games, providing in such a way an understanding of their discerning powers.

RB95

V. Rehrmann und M. Birkhoff. Echtzeitfähige Objektverfolgung in Farbbildern. In V. Rehrmann (Hrsg.), 1. Workshop Farbbildverarbeitung, S.\ 36--39. Universität Koblenz, 1995.
Zusammenfassung: Wir stellen in dieser Arbeit ein System vor, das die robuste Verfolgung von beliebig vielen Objekten in Farbbildern ermöglicht. Die sich bewegenden Objekte werden durch Differenzbildung in drei aufeinanderfolgenden Bildern detektiert. Das Wiederfinden von sich bewegenden Objekten erfolgt durch eine Matching-Operation unter Nutzung verschiedener Merkmale, wie Schwerpunktbewegung, Farbinformation, bisherige Geschwindigkeit etc. Die Farbinformation ist dabei sehr hilfreich, um auch Situationen wie Berührung und Überdeckung beherrschen zu können. Das System wurde auf einem parallelen Farbbildverarbeitungssystem implementiert und erreicht Verarbeitungsfrequenzen von ca. 10--15 Bildern pro Sekunde.

Reh95

V. Rehrmann. Parallele Segmentierung von Farbbildern. In Proc. 40. Internationales Wissenschaftliches Kolloqium, TU Ilmenau, 1995.
Abstract: We present a fast, inherent parallel method for the segmentation of color images. The emphasis lies in the description of the parallel structure of the algorithm and the possibilities for the implementation on a message passing parallel architecture.

RLP95

V. Rehrmann, R. Lakmann, and L. Priese. A parallel system for real-time traffic sign recognition. In Proc. International Workshop on Advanced Parallel Processing Technologies, APPT, Peking, pages 72--78. Publishing House of Electronics Industry, 1995.
Abstract: We present a system for the real--time recognition of traffic signs from a moving car on European highways. The traffic sign recognition system ( TSR) was developed within the European PROMETHEUS project in cooperation with Daimler--Benz and is installed in an autonomous car. Our TSR is also intended to serve as a driver assistance tool. The TSR is based on a fast color image analysis. This analysis involves different methods, such as an inherently parallel color image segmentation, a data--driven decision graph with fuzzy techniques, and classical pattern recognition. Due to the good quality of the color segmentation and the fault--tolerant evaluation the system is highly robust against the difficult conditions in natural outdoor scenes. To meet real--time constraints the TSR has been implemented on a high speed parallel image processing system with MPC601 processors. A prototype of the TSR runs in a usual car and reaches a recognition rate of 98 %.

Ste95a

Christoph Steigner. A distributed multithreaded programming environment. In HIGH PERFORMANCE COMPUTING '95, International Simulation Conference, pages 277 -- 282, Phoenix, Arizona, April 1995.
Abstract: This paper describes the major benefits of a multithreaded programming technique to develop distributed parallel applications. This presentation is based on experiences made with our PARSDL platform, which claims to make effective use of the parallelism of a parallel computer or a workstation-cluster by means of the graphical specification language SDL. As SDL is an important means to express parallelism a short introduction of SDL is given together with some functions which help to execute an SDL program on a given parallel computer system. This paper shows a snapshot of our effort, to develop a target-architecture independent programming platform for distributed parallel applications.

Ste95b

Christoph Steigner. Client-server and TCP-IP, Mai 1995. Handbuch für ein Tutorial anläßlich der APS'95 Tagung.
Abstract: Immer dann, wenn die Funktionalität und die Rechenleistung von vernetzten Workstations für eine Anwendung ausgenutzt werden soll, bieten sich Client-Server-Mechanismen an, die es erlauben verteilte Algorithmen zu erstellen. Das Client-Server-Paradigma teilt miteinander kommunizierende Anwenderprogramme in zwei Kategorien auf - Anwendungen, die auf eine Kommunikation warten (SERVER) und - Anwendungen, die eine Kommunikation anstoßen (CLIENTS) In diesem Tutorial wird eine umfassende Darstellung dieser Kategorien gegeben. Insbesondere werden praktische Implementierungshinweise gegeben, die einen Anwender mit der Wirkung dieser Mechanismen vertraut machen sollen. So werden TCP/IP-Modelle dargestellt und einfache Server- als auch Client-Programme schrittweise entworfen.

Ste95c

Christoph Steigner. Client-Server-Computing: A State of the Art Snapshot. In Proceedings of the International Workshop on Advanced Parallel Processing Technologies, APPT'95, pages 306--311, Beijing, China, sep 1995. Publishing House of Electronics Industry. ISBN 7-5053-3304-6/TP.1243.
Abstract: Client-Server-Computing (CSC) is a new and very advantageous means that allows to build better and faster software applications for enterprises and factory automation. CSC supports consequently the idea of Information Movement & Management (IM & M) which will have far reaching implications in terms of improving the productivity of an enterprise. IM & M comprises the preparation, collection, transportation, retrieval, storage access, presentation and processing of information. CSC, on the other hand, is a processing model in which a single application software is partitioned between multiple cooperating processors. Client-Server software systems tie processors together to achieve a single system image. Shareable resources are positioned as servers offering one or more services. Applications are positioned as requestor clients that may have access to authorized services. CSC architectures may model complex communication structures, since they are recursive, in the sense that servers can become clients and request services of other servers on a network. In this paper we emphasize on the relationship between CSC and object-orientation. The strong analogy of the two concepts will be discussed to give an impression of the mutual benefits of an integrated approach as well as of its possible realizations and drawbacks. CSC will be regarded as a global distributed resource for program development and computation, and object-orientation as an adequate implementation method for CS-systems.

Ste95d

Christoph Steigner. Client/server-systeme. APS Nachrichten, 5:11 -- 13, 1995.
Zusammenfassung: Die wesentlichen Funktionen, die für die Einrichtung von verteilten Server-- und Client--Programmen in weltweit vernetzten Rechnersystemen (Internet) erforderlich sind,werden dargelegt . Bei Client/Server--Systemen handelt es sich um Dienst--Anfrage/Dienst--Leistungs--Beziehungen, mit denen sich grundsätzlich alle Datenverarbeitungsprobleme darstellen lassen. Ausgangspunkte sind hierbei das TCP/IP Protokoll und einige UNIX und SOLARIS--Funktionen, die die Einrichtung von Client/Server und SOLARIS--Funktionen, die die Einrichtung von Client/Server--Systemen unterstützen. Besonderer Wert wird in dieser Darstellung auf das Adressierungs--Konzept gelegt (Net id, Host id, Port id, Deskriptoren), das für den Aufbau einer Client/Server--Verbindung von grundlegender Bedeutung ist .

STW95

T. Schumm, C. Thomann und A. Winter. Evaluation von Krankenhaus-Informationssystemen für das Ev. Stift St. Martin, Koblenz. Interner Projektbericht 4/95, Universität Koblenz-Landau, Institut für Softwaretechnik, Koblenz, Juli 1995.
Zusammenfassung: Diese Studie stellt Vorgehen und Ergebnisse eines Projekts in Kooperation mit dem Ev. Stift St. Martin gGmbH Koblenz zur Unterstütztung bei der Auswahl eines geeigneten Krankenhaus-Informationssystems dar.

WE95

A. Winter und J. Ebert. Ein Referenz-Schema zur Organisationsbeschreibung --- Kurzfassung ---. EMISA-Forum, Vortragszusammenfassungen des EMISA/MobIS-Fachgruppentreffen 1994, 13.-14. Oktober 1994, Universität Münster, (1):105--107, 1995.
Zusammenfassung: Beschreibungsmittel für Organisationen lassen sich in vier Gruppen einteilen, durch die Organisationen aus Aufgabensicht, Stellensicht, Ablaufsicht oder Objektsicht dargestellt werden können. Es wird ein Referenz-Schema als konzeptioneller Rahmen zur Beschreibung und Integration der Organisationssichten und der dort benutzten Beschreibungsmittel eingeführt. (Kurzfassung zu A. Winter, J. Ebert: Ein Referenz-Schema zur Organisationsbeschreibung in J. Becker, G. Vossen (Hrsg.): Geschäftsprozeßmodellierung und Workflows, Thomson, Bonn, 1996, 101-123)

WE96

A. Winter und J. Ebert. Ein Referenz-Schema zur Organisationsbeschreibung. in J. Becker, G. Vossen (Hrsg.): Geschäftsprozeßmodellierung und Workflows, Thomson, Bonn, S. 101--123, 1996.
Zusammenfassung: Beschreibungsmittel für Organisationen lassen sich in vier Gruppen einteilen, durch die Organisationen aus Aufgabensicht, Stellensicht, Ablaufsicht oder Objektsicht dargestellt werden können. Es wird ein Referenz-Schema als konzeptioneller Rahmen zur Beschreibung und Integration der Organisationssichten und der dort benutzten Beschreibungsmittel eingeführt.

YGH+95

C.X. Yu, K.E. Großpietsch, R. Hofestädt, X.D. Huang, et al., editors. Proceedings of the International Workshop on Advanced Parallel Processing Technologies, APPT'95, Beijing, China, September 1995. Publishing House of Electronics Industry. ISBN 7-5053-3304-6/TP.1243.

ZA95

Dieter Zöbel und Wolfgang Albrecht. Echtzeitsysteme: Grundlagen und Techniken. Internat. Thomson Publ., Bonn, Albany, 1995.
Zusammenfassung: Echtzeitanforderungen können nur erfüllt werden, wenn auf allen Ebenen des Systems vorhersagbares Zeitverhalten garantiert wird. Das Buch behandelt systematisch die Konzepte der betroffenen Fachgebiete, von der Rechnerarchitektur über Betriebssysteme bis zur Programmierung und zum Software-Entwurf. Aktuelle Methoden, wie etwa die Analyse nach Monotonen Raten für die Prozeßverplanung, werden dabei ebenso vorgestellt, wie zukunftsweisende Netzwerktechnologien. So werden moderne Realisierungen vom Bereich der Feldbusse bis zu Multimedia vorgestellt (CAN, FDDI und ATM) und bezüglich ihrer Echtzeitfähigkeit analysiert.