Pascal Hitzler

What Is Approximate Reasoning? ⋆ (2009)

Abstract. We introduce description logic (DL) rules as a new rule-based formalism for knowledge representation in DLs. As a fragment of the Semantic Web Rule Language SWRL, DL rules allow for a tight...

Sebastian Rudolph, Tuvshintur Tserendorj, Pascal Hitzler

Abstract. Approximate reasoning for the Semantic Web is based on the idea of sacrificing soundness or completeness for a significant speedup of reasoning. This is to be done in such a way that the...

Description Logic Reasoning with Decision Diagrams CompilingSHIQ to Disjunctive Datalog (2009)

Cheap Boolean Role Constructors for Description Logics (2009)

Abstract. We propose a novel method for reasoning in the description logic SHIQ. After a satisfiability preserving transformation fromSHIQ to the description logicALCIb, the obtainedALCIb TboxT is...

1. Introduction Learning Expressive Ontologies (2009)

Abstract. We investigate the possibility of incorporating Boolean role constructors on simple roles into some of today’s most popular description logics, focussing on cases where those extensions...

Johanna Völker, Peter Haase, Pascal Hitzler

Abstract. The automatic extraction of ontologies from text and lexical resources

Terminological Reasoning inSHIQ with Ordered Binary Decision Diagrams (2009)

An Anytime Algorithm for Computing Inconsistency Measurement (2009)

Abstract. We present a new algorithm for reasoning in the description logic SHIQ, which is the most prominent fragment of the Web Ontology Language OWL. The algorithm is based on ordered binary...

Ma, Yue, Qi, Guilin, Xiao, Guohui, Hitzler, Pascal, Lin, Zuoquan

Measuring inconsistency degrees of inconsistent knowledge bases is an important problem as it provides context information for facilitating inconsistency handling. Many methods have been proposed to...

An Anytime Algorithm for Computing Inconsistency Measurement (2009)

Ma, Yue, Qi, Guilin, Xiao, Guohui, Hitzler, Pascal, Lin, Zuoquan

Measuring inconsistency degrees of inconsistent knowledge bases is an important problem as it provides context information for facilitating inconsistency handling. Many methods have been proposed to...

VDM ♣ meets LCF: Domain-Theoretic and Topological Aspects of VDM ♣ (2008)

A Well-founded semantics for hybrid MKNF (2008)

www.wv.inf.tu-dresden.de/∼pascal / maths.ucc.ie/staff/seda/ We discuss the domain-theoretic and topological content of the operator calculus used in the Irish School of the Vienna Development...

Foundations of Refinement Operators for Description Logics (Technical Report) (2008)

knowledge bases

Jens Lehmann, Pascal Hitzler

Abstract. In order to leverage techniques from Inductive Logic Programming for the learning in Description Logics (DLs), it is important to acquire a thorough understanding of the theoretical...

VDM ♣ meets LCF: Domain-Theoretic and Topological Aspects of VDM ♣∗ (2008)

Towards Tractable Local Closed World Reasoning for the Semantic Web ⋆ (2008)

www.wv.inf.tu-dresden.de/∼pascal / maths.ucc.ie/staff/seda/ We discuss the domain-theoretic and topological content of the operator calculus used in the Irish School of the Vienna Development...

Abstract. Recently, the logics of minimal knowledge and negation as failure MKNF [12] was used to introduce hybrid MKNF knowledge bases [14], a powerful formalism for combining open and closed world...

and (2008)

for Knowledge Base Browsing: an Evaluation (2008)

We discuss a number of distance functions encountered in the theory of computation, including metrics, ultra-metrics, quasi-metrics, generalized ultra-metrics, partial metrics, dultra-metrics, and...

Julien Tane, Phillip Cimiano, Pascal Hitzler

Abstract. In [7], we introduced the query-based multicontext theory, which allows to define a virtual space of views on ontological data. Each view is then materialised as a formal context. While...

An Algorithm for Computing Inconsistency Measurement by Paraconsistent Semantics ⋆ (2008)

First-Order Logic Programs (2008)

Abstract. Measuring inconsistency in knowledgebases has been recognized as an important problem in many research areas. Most of approaches proposed to measure inconsistency are based on...

Sebastian Bader, Pascal Hitzler, Steffen Hölldobler

Knowledge based artificial neural networks have been applied quite successfully to propositional knowledge representation and reasoning tasks. However, as soon as these tasks are extended to...

IOS Press A Categorical View on Algebraic Lattices in Formal Concept Analysis (2008)

Pascal Hitzler, Markus Krötzsch, Guo-qiang Zhang

Abstract. Formal concept analysis has grown from a new branch of the mathematical field of lattice theory to a widely recognized tool in Computer Science and elsewhere. In order to fully benefit from...

A generalized resolution theorem (2008)

Informatique theorique/Computer Science Sur les programmes logiques localement strati es 1 (2008)

W.C. Rounds and G.-Q. Zhang have recently proposed to study a form of resolution on algebraic domains [1]. This framework allows reasoning with knowledge which is hierarchically structured and forms...

Towards Tractable Local Closed World Reasoning for the Semantic Web ⋆ (2008)

Resume { Des idees elementaires de topologie dynamique sont utilisees pour une approche constructive de la semantique des modeles parfaits de Przymusinski pour programmes localement strati es. Nos...

Any-World Access to OWL from Prolog (2008)

Abstract. Recently, the logics of minimal knowledge and negation as failure MKNF [12] was used to introduce hybrid MKNF knowledge bases [14], a powerful formalism for combining open and closed world...

Tobias Matzner, Pascal Hitzler

Abstract. The W3C standard OWL provides a decidable language for representing ontologies. While its use is rapidly spreading, efforts are being made by researchers worldwide to augment OWL with...

A generalized resolution theorem (2008)

Dr. Pascal Hitzler, Fakultät Informatik

W.C. Rounds and G.-Q. Zhang have recently proposed to study a form of resolution on algebraic domains [2]. This framework allows reasoning with knowledge which is hierarchically structured and forms...

Contents (2008)

Diplomarbeit Andreas, Christian Lang, Betreuender Hochschullehrer, Prof Dr, Steffen Hölldobler, Betreuer Dr, ...

A drawback of many logics for reasoning on Semantic Web ontologies is the Principle of Explosion in case of inconsistent data. Considering a four-valued semantics, inconsistencies can be tolerated...

i (2008)

an der TU Dresden seit der Promotion. In diesen dreieinhalb Jahren war es mein Bestreben, selbstständig aktuelle, theoretisch fundierte und anwendungsbezogene Fragestellungen zu entwickeln und zu...

IOS Press A Categorical View on Algebraic Lattices in Formal Concept Analysis (2008)

Pascal Hitzler, Markus Krötzsch, Guo-qiang Zhang

Abstract. Formal concept analysis has grown from a new branch of the mathematical field of lattice theory to a widely recognized tool in Computer Science and elsewhere. In order to fully benefit from...

08041 Summary -- Recurrent neural networks - Models, capacities, and applications (2008)

Hammer, Barbara, Hitzler, Pascal, Maass, Wolfgang

08041 Abstracts collection -- Recurrent neural networks - Models, capacities, and applications (2008)

Hammer, Barbara, Hitzler, Pascal, Maass, Wolfgang

3 Knowledge Representation and Ontologies Logic, Ontologies and Semantic Web Languages (2008)

Stephan Grimm, Pascal Hitzler, Andreas Abecker

Summary. In Artificial Intelligence, knowledge representation studies the formalisation of knowledge and its processing within machines. Techniques of automated reasoning allow a computer system to...

Decidability Under the Well-Founded Semantics ⋆ (2008)

Natalia Cherchago, Pascal Hitzler, Steffen Hölldobler

Abstract. The well-founded semantics (WFS) for logic programs is one of the few major paradigms for closed-world reasoning. With the advent of the Semantic Web, it is being used as part of rule...

Efficient OWL Reasoning with Logic Programs – Evaluations ⋆ (2008)

Sebastian Rudolph, Markus Krötzsch, Pascal Hitzler, Michael Sintek, Denny Vr

Abstract. We report on efficiency evaluations concerning two different approaches to using logic programming for OWL [1] reasoning and show, how the two approaches can be combined. Introduction....

Paraconsistent Resolution for Four-valued Description Logics ⋆ (2008)

Yue Ma, Pascal Hitzler, Zuoquan Lin

Abstract. In this paper, we propose an approach to translating any ALC ontology (possible inconsistent) into a logically consistent set of disjunctive datalog rules. We achieve this in two steps:...

An Algorithm for Computing Inconsistency Measurement by Paraconsistent Semantics ⋆ (2008)

The Semantic Web The Semantic Web in One Day (2008)

Abstract. Measuring inconsistency in knowledge bases has been recognized as an important problem in many research areas. Most of approaches proposed for measuring inconsistency are based on...

Steffen Staab, York Sure, Pascal Hitzler, Andreas Eberhart, Rudi Studer

likely your answer would be “No, that’s impossible.” Typical projects in which concrete applications are built last months or years. And the Semantic Web isn’t just another application....

Quo Vadis, CS? – On the (non)-impact of Conceptual Structures on the Semantic Web (Position Paper) (2008)

DLP - An introduction (2008)

Abstract. Conceptual Structures is a field of research which shares abstract concepts and interests with recent work on knowledge representation for the Semantic Web. However, while the latter is an...

Denny Vrandecic, Peter Haase, Pascal Hitzler, York Sure, Rudi Studer

DLP -- Description Logic Programs -- is the name for the common language that is able to integrate knowledge bases described in Description Logic with Logic Programs. In this introduction, we offer a...

Faster OWL Using Split Programs (2008)

Pascal Hitzler And, Pascal Hitzler, Denny Vr

are sought to cope with large ABoxes in an approximate manner. The idea is to use quick heuristic reasoning when time constraints are more important than the correctness of the answers. A typical use...

The SCREECH OWL reasoner (2008)

Scalable Approximate Abox, Pascal Hitzler, Denny Vr

We present a preliminary version of the approximate OWL reasoning system SCREECH. It builds on the KAON2 system and performs OWL ABox reasoning in an approximate manner. It trades soundness of...

Semantic Web: Grundlagen (2008)

P.: All elephants are bigger than all mice (2008)

P.: ELP: Tractable rules for OWL 2 (2008)

Abstract. We introduce the concept product as a new expressive feature to description logics (DLs). While this construct allows us to express an arguably very common and natural type of statement, it...

08041 Summary -- Recurrent Neural Networks - Models, Capacities, and Applications (2008)

We introduce ELP as a decidable fragment of the Semantic Web Rule Language (SWRL) that admits reasoning in polynomial time. ELP is based on the tractable description logic EL ++, and encompasses an...

De Raedt, Luc, Hammer, Barbara, Hitzler, Pascal, Maass, Wolfgang

The seminar centered around recurrent information processing in neural systems and its connections to brain sciences, on the one hand, and higher symbolic reasoning, on the other side. The goal was...

08041 Abstracts Collection -- Recurrent Neural Networks - Models, Capacities, and Applications (2008)

De Raedt, Luc, Hammer, Barbara, Hitzler, Pascal, Maass, Wolfgang

From January 20 to 25 2008, the Dagstuhl Seminar 08041 ``Recurrent Neural Networks- Models, Capacities, and Applications'' was held in the International Conference and Research Center (IBFI), Schloss...

Approximate OWL Instance Retrieval with SCREECH (2008)

Hitzler, Pascal, Krötzsch, Markus, Rudolph, Sebastian, Tserendorj, Tuvshintur

With the increasing interest in expressive ontologies for the Semantic Web, it is critical to develop scalable and efficient ontology reasoning techniques that can properly cope with very high data...

P.: All elephants are bigger than all mice (2008)

Vulcan Silver Sponsors ACTIVE (2008)

Abstract. We investigate the concept product as an expressive feature for description logics (DLs). While this construct allows us to express an arguably very common and natural type of statement, it...

Christophe Guéret, Pascal Hitzler, Stefan Schlobach, Mike Dean (bbn, Jim Hendler (rpi

Peter Mika (Yahoo, ES) Workshop chairs Melliyal Annamalai (Oracle, USA) Daniel Olmedilla (Leibniz Universität Hannover, DE)

Recurrent Neural Networks- Models, Capacities, and Applications (2008)

Hammer, Barbara, Hitzler, Pascal, Maass, Wolfgang

Sur Les Programmes Logiques Localement Stratifi'es (2007)

ILP Operators for Propositional Connectionist Networks Extended Abstract (2007)

Elementary ideas from topological dynamics are used to provide a constructive approach to Przymusinski's perfect model semantics for locally stratified normal logic programs. Our results utilise...

Pascal Hitzler, Dpto Ciencias, Computacion Inteligencia Arti

The study of the integration of symbolic logic and connectionist systems is an active area of research. Its general objective is appealing: Since biological neural networks are able to process...

Contents (2007)

Characterizing logic programming semantics with level mappings Extended Abstract (2007)

W.C. Rounds and G.-Q. Zhang have recently proposed to study a form of disjunctive logic programming generalized to algebraic domains [RZ01]. This system allows reasoning with information which is...

Contexts, Concepts, and Logic of Domains (2007)

Declarative semantics in logic programming and nonmonotonic reasoning are often dened via xed points of semantic operators. While many relationships between dierent semantics known from the...

A "CONVERSE " OF THE BANACH CONTRACTION MAPPING THEOREM (2007)

We relate two formerly independent areas: Formal concept analysis and logic of domains. We will establish a transformation of contexts into domains, and vice-versa, such that the notion of resolution...

We prove a type of converse of the Banach contraction mapping theorem for metric spaces: if X is a T 1 topological space and f: X! X is a function with unique fixed point a such that f n (x)...

and (2007)

DISLOCATED TOPOLOGIES 1 (2007)

We consider rather general operators mapping valuations to (sets of) valuations in the context of the semantics of logic programming languages. This notion generalizes several of the standard...

We study a generalized notion of topology which evolved from applications in the area of logic programming semantics. The generalization is obtained by relaxing the requirement that a neighbourhood...

y (2007)

A \Converse " of the Banach Contraction Mapping Theorem (2007)

We study classes of logic programs, called here unique supported model classes, or simply usm-classes, with the property that each member in the class is uniquely determined, that is, possesses a...

Project Thesis Generalized Ultrametric Spaces in Quantitative Domain Theory (2007)

www.wv.inf.tu-dresden.de/pascal / maths.ucc.ie/sta/seda/ We prove a type of converse of the Banach contraction mapping theorem for metric spaces: if X is a T 1 topological space and f: X! X is a...

Markus Krotzsch, Supervisor Prof, Dr. Ste#en Holldobler, Written Dr, Pascal Hitzler

Domains and metric spaces are two central tools for the study of denotational semantics in computer science, but are otherwise very di#erent in many fundamental aspects. A construction that tries to...

P.: Acquisition of OWL DL axioms from lexical resources (2007)

Johanna Völker, Pascal Hitzler

Abstract. State-of-the-art research on automated learning of ontologies from text currently focuses on inexpressive ontologies. The acquisition of complex axioms involving logical connectives, role...

Z.: Measuring inconsistency for description logics based on paraconsistent semantics. In: ECSQARU (2007)

A well-founded semantics for hybrid MKNF knowledge bases (2007)

Abstract. In this paper, we present an approach for measuring inconsistency in a knowledge base. We first define the degree of inconsistency using a four-valued semantics for the description logic...

A fully connectionist model generator for covered first-order logic programs (2007)

Abstract. In [10], hybrid MKNF knowledge bases have been proposed for combining open and closed world reasoning within the logics of minimal knowledge and negation as failure ([8]). For this powerful...

Sebastian Bader, Pascal Hitzler, Steffen Hölldobler, Andreas Witzel

We present a fully connectionist system for the learning of first-order logic programs and the generation of corresponding models: Given a program and a set of training examples, we embed the...

Z.: Measuring inconsistency for description logics based on paraconsistent semantics. In: ECSQARU (2007)

P.: Supporting lexical ontology learning by relational exploration (2007)

Abstract. In this paper, we propose an approach for measuring inconsistency in inconsistent ontologies. We first define the degree of inconsistency of an inconsistent ontology using a four-valued...

Sebastian Rudolph, Johanna Völker, Pascal Hitzler

Abstract. Designing and refining ontologies becomes a tedious task, once the boundary to real-world-size knowledge bases has been crossed. Hence semi-automatic methods supporting those tasks will...

A fully connectionist model generator for covered first-order logic programs (2007)

Sebastian Bader, Pascal Hitzler, Steffen Hölldobler, Andreas Witzel

We present a fully connectionist system for the learning of first-order logic programs and the generation of corresponding models: Given a program and a set of training examples, we embed the...

Z.: Algorithms for paraconsistent reasoning with OWL (2007)

Yue Ma, Pascal Hitzler, Zuoquan Lin

Abstract. In an open, constantly changing and collaborative environment like the forthcoming Semantic Web, it is reasonable to expect that knowledge sources will contain noise and inaccuracies....

Conjunctive queries for a tractable fragment of OWL 1.1 (2007)

P.: Acquisition of OWL DL axioms from lexical resources (2007)

Abstract. Despite the success of the Web Ontology Language OWL, the development of expressive means for querying OWL knowledge bases is still an open issue. In this paper, we investigate how a very...

Johanna Völker, Pascal Hitzler

Abstract. State-of-the-art research on automated learning of ontologies from text currently focuses on inexpressive ontologies. The acquisition of complex axioms involving logical connectives, role...

Z.: Measuring inconsistency for description logics based on paraconsistent semantics. In: ECSQARU (2007)

P.: Complexity boundaries for Horn description logics (2007)

Abstract. In this paper, we present an approach for measuring inconsistency in a knowledge base. We first define the degree of inconsistency using a four-valued semantics for the description logic...

Z.: Measuring inconsistency for description logics based on paraconsistent semantics. In: ECSQARU (2007)

Horn description logics (Horn-DLs) have recently started to attract attention due to the fact that their (worst-case) data complexities are in general lower than their overall (i.e. combined)...

A refinement operator based learning algorithm for the ALC description logic (2007)

Abstract. In this paper, we propose an approach for measuring inconsistency in inconsistent ontologies. We first define the degree of inconsistency of an inconsistent ontology using a four-valued...

Jens Lehmann, Pascal Hitzler

Abstract With the advent of the Semantic Web, description logics have become one of the most prominent paradigms for knowledge representation and reasoning. Progress in research and applications,...

Foundations of refinement operators for description logics (2007)

Jens Lehmann, Pascal Hitzler

Abstract In order to leverage techniques from Inductive Logic Programming for the learning in description logics (DLs), which are the foundation of ontology languages in the Semantic Web, it is...

P.: On the complexity of Horn description logics (2006)

The integration of connectionism and first-order knowledge representation and reasoning as a challenge for artificial intelligence (2006)

Abstract. Horn-SHIQ has been identified as a fragment of the description logic SHIQ for which inferencing is in PTime with respect to the size of the ABox. This enables reasoning with larger ABoxes...

Sebastian Bader, Pascal Hitzler, Steffen Hölldobler

Intelligent systems based on first-order logic on the one hand, and on artificial neural networks (also called connectionist systems) on the other, differ substantially. It would be very desirable to...

Faster OWL Using Split Programs (2006)

Pascal Hitzler And, Pascal Hitzler, Denny Vr

are sought to cope with large ABoxes in an approximate manner. The idea is to use quick heuristic reasoning when time constraints are more important than the correctness of the answers. A typical use...

Integrating Semantic Web Services for Mobile Access (2006)

Anupriya Ankolekar Pascal, Pascal Hitzler, Holger Lewen, Daniel Oberle, Rudi Studer

We present our work in integrating Semantic Web services for access via mobile devices. We have developed a system, the WebServiceAccessComponent, that transforms a user request for a service on a...

A Metamodel and UML Profile for Rule-extended OWL DL Ontologies (2006)

Saartje Brockmans, Peter Haase, Pascal Hitzler, Rudi Studer

Abstract. In this paper we present a MOF compliant metamodel and UML profile for the Semantic Web Rule Language (SWRL) that integrates with our previous work on a metamodel and UML profile for OWL...

Matriculation Number: 3065439 Supervisors: (2006)

Prof Dr, Steffen Hölldobler, Dr. Pascal Hitzler

Matriculation Number: 3065439 The integration of the paradigms of logic programs and connectionist systems is desirable because of their contrasting advantages and disadvantages. Algorithms for...

The Core Method: Connectionist model generation (2006)

A categorical view of algebraic lattices in formal concept analysis (2006)

Summary. Research into the processing of symbolic knowledge by means of connectionist networks aims at systems which combine the declarative nature of logicbased artificial intelligence with the...

Pascal Hitzler, Markus Krötzsch, Guo-qiang Zhang

Formal concept analysis has grown from a new branch of the mathematical field of lattice theory to a widely recognized tool in Computer Science and elsewhere. In order to fully benefit from this...

M.: Querying formal contexts with answer set programs (2006)

Pascal Hitzler, Markus Krötzsch

Abstract. Recent studies showed how a seamless integration of formal concept analysis (FCA), logic of domains, and answer set programming (ASP) can be achieved. Based on these results for combining...

The integration of connectionism and first-order knowledge representation and reasoning as a challenge for artificial intelligence (2006)

Sebastian Bader, Pascal Hitzler, Steffen Hölldobler

Intelligent systems based on first-order logic on the one hand, and on artificial neural networks (also called connectionist systems) on the other, differ substantially. Logic programs, for example,...

M.: How to reason with OWL in a logic programming system (2006)

Markus Krötzsch, Pascal Hitzler, Denny Vr

Logic programming has always been a major ontology modeling paradigm, and is frequently being used in large research projects and industrial applications, e.g., by means of the F-Logic reasoning...

A Comparison of Disjunctive Well-founded Semantics (2006)

Matthias Knorr, Pascal Hitzler

Abstract. While the stable model semantics, in the form of Answer Set Programming, has become a successful semantics for disjunctive logic programs, a corresponding satisfactory extension of the...

The integration of connectionism and first-order knowledge representation and reasoning as a challenge for artificial intelligence (2006)

Sebastian Bader, Pascal Hitzler, Steffen Hölldobler

Intelligent systems based on first-order logic on the one hand, and on artificial neural networks (also called connectionist systems) on the other, differ substantially. It would be very desirable to...

Dolce ergo sumo: On foundational and domain models in swinto (smartweb integrated ontology (2006)

Daniel Oberle, Anupriya Ankolekar, Pascal Hitzler, Michael Sintek, Malte Kiesel, Babak Mougouie, ...

Increased availability of mobile computing, such as personal digital assistants (PDAs), creates the potential for constant and intelligent access to up-to-date, integrated and detailed information...

Faster OWL Using Split Programs (2006)

Hitzler, Pascal, Vrandecic, Denny

We propose a new technique for approximate ABox reasoning with OWL DL ontologies. Essentially, we obtain substantially improved reasoning performance by disregarding non-Horn features of OWL DL. Our...

Description Logic Programs: A Practical Choice For the Modelling of Ontologies (2006)

Hitzler, Pascal, Sure, York, Studer, Rudi

Knowledge representation using ontologies constitutes the heart of semantic technologies. Despite successful standardization efforts by the W3C, however, there are still numerous different ontology...

Dimensions of Neural-symbolic Integration - A Structured Survey (2005)

Bader, Sebastian, Hitzler, Pascal

Research on integrated neural-symbolic systems has made significant progress in the recent past. In particular the understanding of ways to deal with symbolic knowledge within connectionist systems...

Towards a unified theory of logic programming semantics: Level mapping characterizations of selector generated models (2005)

Hitzler, Pascal, Schwarz, Sibylle

Currently, the variety of expressive extensions and different semantics created for logic programs with negation is diverse and heterogeneous, and there is a lack of comprehensive comparative studies...

Towards a Systematic Account of Different Semantics for Logic Programs (2005)

Level mapping characterizations of selector generated models for logic programs (2005)

In [Hitzler and Wendt 2002, 2005], a new methodology has been proposed which allows to derive uniform characterizations of different declarative semantics for logic programs with negation. One result...

Pascal Hitzler, Sibylle Schwarz

Abstract. Assigning semantics to logic programs via selector generated models (Schwarz 2002/2003) extends several semantics, like the stable, the inflationary, and the stable generated semantics, to...

A uniform approach to logic programming semantics (2005)

Level Mapping Characterizations of Selector Generated Models for Logic Programs (2005)

Pascal Hitzler, Sibylle Schwarz, Tu Dresden

Assigning semantics to logic programs via selector generated models (Schwarz 2002/2003) extends several semantics, like the stable, the inationary, and the stable generated semantics, to programs...

dlpconvert - Converting OWL DLP statements to logic programs (2005)

Boris Motik, Denny Vrandecic, Pascal Hitzler, York Sure, Rudi Studer

this document, dlpconvert is still in a beta version and quite a number of features are waiting to be implemented. This includes minor changes like adding more sophisticated error messages and...

Description Logic Programs: A Practical Choice for the Modelling of Ontologies (2005)

Pascal Hitzler, Rudi Studer, York Sure, Ontoprise Gmbh

Knowledge representation using ontologies constitutes the heart of semantic technologies. Despite successful standardization e#orts by the W3C, however, there are still numerous di#erent ontology...

D2.2.1 Specification of a common framework for characterizing alignment (2005)

Paolo Bouquet, Marc Ehrig, Jérôme Euzenat, Enrico Franconi, Pascal Hitzler, ...

Definition of a common framework for characterizing alignment of heterogeneous information. This report describes various approaches towards this goal and shows the relations between them. It also...

Dimensions of Neural-symbolic Integration - A Structured Survey (2005)

Ontology Learning as a Use-Case for Neural-Symbolic Integration (2005)

Introduction Research on integrated neural-symbolic systems has made significant progress in the recent past. In particular the understanding of ways to deal with symbolic knowledge within...

Pascal Hitzler, Sebastian Bader, Artur Garcez

We argue that the field of neural-symbolic integration is in need of identifying application scenarios for guiding further research. We furthermore argue that ontology learning --- as occuring in the...

Morphisms in Logic, Topology, and Formal Concept Analysis (2005)

Markus Krötzsch, Overseeing Professor, Prof Dr, Steffen Hölldobler, Tu Dresden, Supervisor Dr, ...

The general topic of this thesis is the investigation of various notions of morphisms between logical deductive systems, motivated by the intuition that additional (categorical) structure is needed...

Towards a Unified Theory of Logic Programming Semantics: Level Mapping Characterizations of Disjunctive Stable Models (2005)

Pascal Hitzler, Matthias Knorr

Currently, the variety of expressive extensions and di#erent semantics created for logic programs with negation is diverse and heterogeneous, and there is a lack of comprehensive comparative studies...

Expressive OWL Reasoning with Logic Programs (2005)

Markus Krötzsch, Pascal Hitzler, Michael Sintek, Denny Vrandecic, Denny Vr

The Web Ontology Language OWL is the W3C standard for modeling ontologies for the web. It is based on description logics, a fragment of firstorder logic. Traditionally, however, logic programming has...

Level Mapping Characterizations of Selector Generated Models for Logic Programs (2005)

Pascal Hitzler, Sibylle Schwarz

Assigning semantics to logic programs via selector generated models (Schwarz 2002/2003) extends several semantics, like the stable, the inflationary, and the stable generated semantics, to programs...

Bridging the Paradigm Gap with Rules for OWL (2005)

Pascal Hitzler Jurgen, Pascal Hitzler, Jürgen Angele, Boris Motik, Rudi Studer

subjects, with deep reasoning abilities. The initial # The first named author acknowledges support by the European Union under the KnowledgeWeb Network of Excellence, and by the German Federal...

Modeling Fuzzy Rules with Description Logics (2005)

Sudhir Agarwal, Pascal Hitzler

In real application scenarios, input data and knowledge is often vague. Likewise, it is often the case that exact reasoning over data is impossible due to complex dependencies between input data and...

Extracting Reduced Logic Programs from Artificial Neural Networks (2005)

Jens Lehmann, Sebastian Bader, Pascal Hitzler

Artificial neural networks can be trained to perform excellently in many application areas. While they can learn from raw data to solve sophisticated recognition and analysis problems, the acquired...

Integrating First-Order Logic Programs and Connectionist Systems - A Constructive Approach (2005)

Sebastian Bader, Pascal Hitzler, Andreas Witzel

Significant advances have recently been made concerning the integration of symbolic knowledge representation with artificial neural networks (also called connectionist systems). However, while the...

Towards a Unified Theory of Logic Programming (2005)

Semantics Level Mapping, Pascal Hitzler, Sibylle Schwarz

Currently, the variety of expressive extensions and di#erent semantics created for logic programs with negation is diverse and heterogeneous, and there is a lack of comprehensive comparative studies...

R.: dlpconvert – converting OWL DLP statements to logic programs (2005)

Boris Motik, Denny Vrandečić, Pascal Hitzler, Rudi Studer

In the past few years, the W3C has been establishing standards for the fundamental building blocks of the Semantic Web. With RDF a common data model has been provided. A major step was the...

Task (2005)

Andreas Witzel, Prof Dr, Steffen Hölldobler, Dr. Pascal Hitzler

Matriculation Number: 3065439 The integration of the paradigms of logic programs and connectionist systems is desirable because of their contrasting advantages and disadvantages. So far, algorithms...

Sure.: Category Theory in Ontology Research: Concrete Gain from an Abstract Approach (2005)

Markus Krötzsch, Pascal Hitzler, Marc Ehrig

The focus of research on representing and reasoning with knowledge traditionally has been on single specifications and appropriate inference paradigms to draw conclusions from such data. Accordingly,...

What is ontology merging? - a categorytheoretic perspective using pushouts (2005)

Pascal Hitzler, Markus Krötzsch, Marc Ehrig, York Sure

In this paper we explain how merging of ontologies is captured by the pushout construction from category theory, and argue that this is a very natural approach to the problem. We study this...

Resolution-based approximate reasoning for OWL DL (2005)

Pascal Hitzler, Denny Vr

Abstract. We propose a new technique for approximate ABox reasoning with OWL DL ontologies. Essentially, we obtain substantially improved reasoning performance by disregarding non-Horn features of...

Extracting reduced logic programs from artificial neural networks (2005)

Jens Lehmann, Sebastian Bader, Pascal Hitzler

Artificial neural networks can be trained to perform excellently in many application areas. Whilst they can learn from raw data to solve sophisticated recognition and analysis problems, the acquired...

Towards a Systematic Account of Different Semantics for Logic Programs (2005)

A Categorical View on Algebraic Lattices in Formal Concept Analysis (2004)

A new methodology has been proposed which allows one to derive uniform characterizations of different declarative semantics for logic programs with negation. One result from this work is that the...

Hitzler, Pascal, Krötzsch, Markus, Zhang, Guo-Qiang

Formal concept analysis has grown from a new branch of the mathematical field of lattice theory to a widely recognized tool in Computer Science and elsewhere. In order to fully benefit from this...

Default reasoning over domains and concept hierarchies (2004)

The Integration of Connectionism and First-Order Knowledge Representation and Reasoning as a Challenge for Artificial Intelligence (2004)

W.C. Rounds and G.-Q. Zhang (2001) have proposed to study a form of disjunctive logic programming generalized to algebraic domains. This system allows reasoning with information which is...

Bader, Sebastian, Hitzler, Pascal, Hoelldobler, Steffen

Intelligent systems based on first-order logic on the one hand, and on artificial neural networks (also called connectionist systems) on the other, differ substantially. It would be very desirable to...

Corollaries on the fixpoint completion: studying the stable semantics by means of the Clark completion (2004)

Logic programs, iterated function systems, and recurrent radial basis function networks (2004)

The fixpoint completion fix(P) of a normal logic program P is a program transformation such that the stable models of P are exactly the models of the Clark completion of fix(P). This is well-known...

Logic programs and connectionist networks (2004)

www.wv.inf.tu-dresden.de/#{borstel,pascal} Graphs of the single-step operator for first-order logic programs--- displayed in the real plane--- exhibit self-similar structures known from topological...

Pascal Hitzler, Steffen Hölldobler, Anthony Karel Seda

One facet of the question of integration of Logic and Connectionist Systems, and how these can complement each other, concerns the points of contact, in terms of semantics, between neural networks...

A Cartesian Closed Category of Approximable Concept Structures (2004)

Pascal Hitzler, Guo-qiang Zhang

Infinite contexts and their corresponding lattices are of theoretical and practical interest since they may o#er connections with and insights from other mathematical structures which are normally...

The Integration of Connectionism and First-Order Knowledge Representation and Reasoning as a Challenge for Artificial Intelligence (2004)

Sebastian Bader, Pascal Hitzler, Steffen Hölldobler

Intelligent systems based on first-order logic on the one hand, and on artificial neural networks (also called connectionist systems) on the other, di#er substantially. It would be very desirable to...

Description logic programs: Normal forms (2004)

Pascal Hitzler, Andreas Eberhart

Abstract. The relationship and possible interplay between different knowledge representation and reasoning paradigms is a fundamental topic in artificial intelligence. For expressive knowledge...

Logic programs and connectionist networks (2004)

Pascal Hitzler, Steffen Hölldobler, Anthony Karel Seda

One facet of the question of integration of Logic and Connectionist Systems, and how these can complement each other, concerns the points of contact, in terms of semantics, between neural networks...

A cartesian closed category of approximable concept structures (2004)

Pascal Hitzler, Guo-qiang Zhang

Abstract. Infinite contexts and their corresponding lattices are of theoretical and practical interest since they may offer connections with and insights from other mathematical structures which are...

Logic programs, iterated function systems, and recurrent radial basis function networks (2004)

Sebastian Bader, Supervisors Prof, Dr. Steffen Hölldobler, Dr. Pascal Hitzler

topic: Triggered by the desire to combine the advantages of logic programs and artificial neural networks, Hölldobler, Kalinke and Störr [?] designed a mapping to embed interpretations into the...

Logic programs, iterated function systems, and recurrent radial basis function networks (2004)

Description logic programs: Normal forms (2004)

www.wv.inf.tu-dresden.de/∼{borstel,pascal} Graphs of the single-step operator for first-order logic programs — displayed in the real plane — exhibit self-similar structures known from...

Pascal Hitzler, Andreas Eberhart

Abstract. The relationship and possible interplay between different knowledge representation and reasoning paradigms is a fundamental topic in artificial intelligence. For expressive knowledge...

Formal Concept Analysis and Resolution in Algebraic Domains (2003)

Hitzler, Pascal, Wendt, Matthias

We relate two formerly independent areas: Formal concept analysis and logic of domains. We will establish a correspondene between contextual attribute logic on formal contexts resp. concept lattices...

M.: Formal concept analysis and resolution in algebraic domains (2003)

M.: Formal concept analysis and resolution in algebraic domains (2003)

Abstract. We relate two formerly independent areas: Formal concept analysis and logic of domains. We will establish a correspondene between contextual attribute logic on formal contexts resp. concept...

M.: Formal concept analysis and resolution in algebraic domains (2003)

We relate two formely independent areas: Formal concept analysis and logical aspects of domain theory. Domain theory is a well-established eld in which mathematical foundations of programming...

Towards a systematic account of different logic programming semantics (2003)

Abstract. We relate two formerly independent areas: Formal concept analysis and logic of domains. We will establish a correspondene between contextual attribute logic on formal contexts resp. concept...

Continuity of semantic operators in logic programming and their approximation by artificial neural networks (2003)

Generalized metrics and uniquely determined logic programs (2003)

One approach to integrating rst-order logic programming and neural network systems employs the approximation of semantic operators by feedforward networks. For this purpose, it is necessary to view...

Continuity of Semantic Operators in Logic Programming and Their Approximation by Artificial Neural Networks (2003)

www.wv.inf.tu-dresden.de/pascal / maths.ucc.ie/sta/seda/

Towards a Systematic Account of Different Semantics for Logic Programs (2003)

One approach to integrating first-order logic programming and neural network systems employs the approximation of semantic operators by feedforward networks. For this purpose, it is necessary to view...

A Generalized Resolution Theorem (2003)

In [14, 15], a new methodology has been proposed which allows to derive uniform characterizations of different declarative semantics for logic programs with negation. One result from this work is...

M.: Formal concept analysis and resolution in algebraic domains (2003)

W.C. Rounds and G.-Q. Zhang have recently proposed to study a form of resolution on algebraic domains [1]. This framework allows reasoning with knowledge which is hierarchically structured and forms...

M.: Formal concept analysis and resolution in algebraic domains (2003)

Abstract. We relate two formerly independent areas: Formal concept analysis and logic of domains. We will establish a correspondene between contextual attribute logic on formal contexts resp. concept...

A uniform approach to logic programming semantics (2002)

Abstract. We relate two formerly independent areas: Formal concept analysis and logic of domains. We will establish a correspondene between contextual attribute logic on formal contexts resp. concept...

Hitzler, Pascal, Wendt, Matthias

Part of the theory of logic programming and nonmonotonic reasoning concerns the study of fixed-point semantics for these paradigms. Several different semantics have been proposed during the last two...

Circular belief in logic programming semantics (2002)

The well-founded semantics is a stratified Fitting semantics (2002)

www.wv.inf.tu-dresden.de/ pascal/

Towards nonmonotonic reasoning on hierarchical knowledge (2002)

Resolution and logic programming in algebraic domains: Negation and defaults (2002)

W.C. Rounds and G.-Q. Zhang have recently proposed to study a form of disjunctive logic programming generalized to algebraic domains [RZ01]. This system allows reasoning with information which is...

Convergence classes and spaces of partial functions (2001)

W.C. Rounds and G.-Q. Zhang have recently proposed to study a form of disjunctive logic programming generalized to algebraic domains [RZ01]. This system allows reasoning with information which is...

Roland Heinze, Pascal Hitzler, Anthony Karel Seda

We study the relationship between convergence spaces and convergence classes given by means of both nets and filters, we consider the duality between them and we identify in convergence terms when a...

Unique supported-model classes of logic programs (2001)

Semantic operators and fixed-point theory in logic programming (2001)

We study classes of programs, herein called unique supported-model classes, with the property that each program in the class has a unique supported model. Elsewhere, the authors examined these...

A note on relationships between logic programs and neural networks (2000)

We consider rather general operators mapping valuations to (sets of) valuations in the context of the semantics of logic programming languages. This notion generalizes several of the standard...

Classes of Logic Programs which Possess Unique Supported Models (2000)

Several recent publications have exhibited relationships between the theories of logic programming and of neural networks. We consider a general approach to representing normal logic programs via...

Classes of Logic Programs which Possess Unique Supported Models (2000)

Logic programming is concerned with the use of logic as a programming language. The main manifestation of this computing paradigm is in the various versions of Prolog which are now available, in...

A New Fixed-point Theorem for Logic Programming Semantics (2000)

Logic programming is concerned with the use of logic as a programming language. The main manifestation of this computing paradigm is in the various versions of Prolog which are now available, in...

Dislocated Topologies (2000)

We present a new fixed-point theorem akin to the Banach contraction mapping theorem, but in the context of a novel notion of generalized metric space, and show how it can be applied to analyse the...

Dislocated Topologies (2000)

We study a generalized notion of topology which evolved out of applications in the area of logic programming semantics. The generalization is obtained by relaxing the requirement that a neighbourhood...

Pascal Hitzler, Anthony K. Seda, Anthony Karel Seda

this paper are motivated by such considerations.

A Note on the Relationships between Logic Programs and Neural Networks (2000)

Some Issues Concerning Fixed Points in Computational Logic: Quasi-Metrics, Multivalued Mappings and the Knaster-Tarski Theorem (2000)

Several recent publications have exhibited relationships between the theories of logic programming and of neural networks. We consider a general approach to representing normal logic programs via...

Dislocated Topologies (2000)

Many questions concerning the semantics of disjunctive databases and of logic programming systems depend on the fixed points of various multivalued mappings and operators determined by the database...

A New Fixed-Point Theorem for Logic Programming Semantics (2000)

We study a generalized notion of topology which evolved out of applications in the area of logic programming semantics. The generalization is obtained by relaxing the requirement that a neighbourhood...

On the Coincidence of Semantics for Uniquely Determined Programs (2000)

We present a new fixed-point theorem akin to the Banach contraction mapping theorem, but in the context of a novel notion of generalized metric space, and show how it can be applied to analyse the...

A note on relationships between logic programs and neural networks (2000)

A note on relationships between logic programs and neural networks (2000)

Several recent publications have exhibited relationships between the theories of logic programming and of neural networks. We consider a general approach to representing normal logic programs via...

Multivalued Mappings, Fixed-Point Theorems and Disjunctive Databases (1999)

Several recent publications have exhibited relationships between the theories of logic programming and of neural networks. We consider a general approach to representing normal logic programs via...

The Fixed-Point Theorems of Priess-Crampe and Ribenboim in Logic Programming (1999)

In this paper, we discuss the semantics of disjunctive programs and databases and show how multivalued mappings and their fixed points arise naturally within this context. A number of fixed-point...

Acceptable Programs Revisited (1999)

Sibylla Priess-Crampe and Paulo Ribenboim recently established a general fixed-point theorem for multivalued mappings defined on generalized ultrametric spaces, and introduced it to the area of logic...

Acceptable Programs Revisited (1999)

Acceptable logic programs have been studied extensively in the context of proving termination of Prolog programs. It is difficult, however, to establish acceptability from the definition since this...

Characterizations of Classes of Programs by Three-Valued Operators (1999)

Acceptable logic programs have been studied extensively in the context of proving termination of Prolog programs. It is difficult, however, to establish acceptability from the definition since this...

Multivalued Mappings, Fixed-Point Theorems and Disjunctive Databases (1999)

. Several important classes of normal logic programs, including the classes of acyclic, acceptable, and locally hierarchical programs, have the property that every program in the class has a unique...

Characterizations of classes of programs by three-valued operators (1999)

In this paper, we discuss the semantics of disjunctive programs and databases and show how multivalued mappings and their fixed points arise naturally within this context. A number of fixed-point...

Generalized Ultrametrics, Domains And An Application To Computational Logic (1998)

Abstract. Several important classes of normal logic programs, including the classes of acyclic, acceptable, and locally hierarchical programs, have the property thatevery program in the class has a...

This article is a slightly expanded version of a paper of the same title presented by the first named author at the 11th September meeting of the IMS, University of Ulster at Coleraine, September,...

Scott-Domains, Generalized Ultrametric Spaces and Generalized Acyclic Logic Programs (1998)

We study strictly level-decreasing logic programs (sld-programs) as defined earlier by the present authors. It will be seen that sld-programs, unlike most other classes of logic programs, have both a...

Every Scott-domain can be viewed as a generalized ultrametric space with properties which allow to apply a generalization of the Banach contraction mapping theorem. We will give this construction in...

We study strictly level-decreasing logic programs (sld-programs) as defined earlier by the present authors. It will be seen that sld-programs, unlike most other classes of logic programs, have both a...

Anthony Karel, Anthony Karel Seda, Pascal Hitzler

We study strictly level-decreasing logic programs (sld-programs) as defined earlier by the present authors. It will be seen that sld-programs, unlike most other classes of logic programs, have both a...

Generalized ultrametrics, domains and an application to computational logic (1998)

We study strictly level-decreasing logic programs (sld-programs) as defined earlier by the present authors. It will be seen that sld-programs, unlike most other classes of logic programs, have both a...

Chapter 4]. (1998)

Topology and Iterates in Computational Logic (1997)

Every Scott-domain can be viewed as a generalized ultrametric space with properties which allow to apply a generalization of the Banach contraction mapping theorem. We will give this construction in...

Topology and Iterates in Computational Logic (1997)

We consider the problem of finding models for logic programs P via fixed points of immediate consequence operators, T P . Certain extensions of syntax invalidate the classical approach, adopted in...

Anthony Karel, Anthony Karel Seda, Pascal Hitzler

We consider the problem of finding models for logic programs P via fixed points of immediate consequence operators, T P . Certain extensions of syntax invalidate the classical approach, adopted in...

The Fixed-Point Theorems of Priess-Crampe and Ribenboim in Logic Programming

The Fixed-Point Theorems of Priess-Crampe and Ribenboim in Logic Programming

. Sibylla Priess-Crampe and Paulo Ribenboim recently established a general xed-point theorem for multivalued mappings dened on generalized ultrametric spaces, and introduced it to the area of logic...

Default Reasoning over Domains and Concept Hierarchies

. Sibylla Priess-Crampe and Paulo Ribenboim recently established a general fixed-point theorem for multivalued mappings defined on generalized ultrametric spaces, and introduced it to the area of...