London SWZ 2AZ, England (2009)
Dov Gabbay, Hans Jürgen Ohlbach, Im Stadtwald
An algorithm is presented which eliminates second–order quantifiers over predicate variables in formulae of type ∃P1,...,Pnψ where ψ is an arbitrary formula of first–order predicate logic....
L-DSMS – A Local Data Stream Management System (2009)
Christian Hänsel, Hans Jürgen Ohlbach, Edgar Stoffel
is a Java Program which can read an XML-file with a description of a network of processing nodes for streaming data. L-DSMS automatically combines all the processing nodes into a single Java program...
In this paper, we tackle the challenging problem of guiding pedestrians in buildings. We propose a conceptual model for indoor environments, based only on regions and their boundaries. It needs to be...
L-DSMS – A Local Data Stream Management System (2009)
Christian Hänsel, Hans Jürgen Ohlbach, Edgar Stoffel
is a Java Program which can read an XML-file with a description of a network of processing nodes for streaming data. L-DSMS automatically combines all the processing nodes into a single Java program...
Abstract 1 Semantics-Based Translation Methods for Modal Logics (2008)
Hans Jürgen Ohlbach, Im Stadtwald
A general framework for translating logical formulae from one logic into another logic is presented. The framework is instantiated with two different approaches to translating modal logic formulae...
Franz Baader, Lufg Theoretische Informatik, F. R. Germany, Hans Jürgen Ohlbach
ABSTRACT. An extension of the concept description language ALC used in KL-ONE-like terminological reasoning is presented. The extension includes multi–modal operators that can either stand for the...
Reduction Rules for Resolution Based Systems (2008)
Norbert Eisinger, Hans Jürgen Ohlbach, Axel Präcklein, Fb Informatik
Abstract: Inference rules for resolution based systems can be classified into deduction rules, which add new objects, and reduction rules, which remove objects. Traditional reduction rules like...
1 Compilation of Recursive Two-Literal Clauses into Unification Algorithms (2008)
Abstract: Automated deduction systems can considerably be improved by replacing axioms with special purpose inference mechanisms. For example replacing in resolution based systems certain equations...
Hans Jürgen Ohlbach, Jana Koehler
We introduce mathematical programming and atomic decomposition as the basic modal (T-Box) inference techniques for a large class of modal and description logics. The class of description logics...
A Geospatial World Model for the Semantic Web A Position Paper (2008)
François Bry, Bernhard Lorenz, Hans Jürgen Ohlbach, Mike Rosner
Abstract. The Semantic Web is an endeavour aiming at enhancing Web data with meta-data and data processing, as well as processing methods specifying the “meaning ” of such data and allowing...
Automated reasoning on the web (2008)
Slim Abdennadher, José Júlio, Alves Alferes, Grigoris Antoniou, Uwe Aßmann, Rolf Backofen, ...
Automated reasoning is becoming an essential issue in many Web systems and applications, especially in emerging Semantic Web applications. This article first discusses reasons for this evolution....
Periodic Temporal Notions as ‘Tree Partitionings’ (2008)
Abstract. The key notion for modelling calendar systems and many other periodic temporal notion is the mathematical concept of a partitioning of the real numbers. A partitioning of R splits the time...
Fuzzy Time Intervals System Description of the FuTI–Library (2008)
Abstract. The FuTI–library is a collection of classes and methods for representing and manipulating fuzzy time intervals. Fuzzy time intervals are represented as polygons over integer coordinates....
H.: Towards a Semantic Spatial Model for Pedestrian Indoor Navigation (2007)
Bernhard Lorenz, Hans Jürgen Ohlbach
Abstract. This paper presents a graph-based spatial model which can serve as a reference for guiding pedestrians inside buildings. We describe a systematic approach to construct the model from...
A Local Data Stream Management System (2006)
Hans Jürgen Ohlbach, Bernhard Lorenz
In this deliverable we present two developments. The first one is a Local Data Stream Management System (L-DSMS) It is a general system for configuring and (locally) executing networks of processing...
B. Lorenz, H. J. Ohlbach, M. Rosner, Reviewers Georg Treu, Hans Jürgen Ohlbach, Mike Rosner, ...
from Indoor WLAN fingerprinting position data
A Hybrid Model for Indoor Spatial Reasoning (2006)
Bernhard Lorenz, Hans Jürgen Ohlbach
As applications continue to evolve from stand-alone applications in static scenarios to distributed mobile applications which extensively interact with each other and human users in an increasingly...
A Hybrid Spatial Model for Representing Indoor Environments (2006)
Bernhard Lorenz, Hans Jürgen Ohlbach
Abstract. In this article we propose a hybrid spatial model for indoor environments. The model consists of hierarchically structured graphs with typed edges and nodes. The model is hybrid in the...
Ontology Driven Visualisation of Maps with (2005)
Hans Jürgen Ohlbach, Bernhard Lorenz
In this work we demonstrate a particular use of ontologies for visualising maps in a browser window. The GIS data are represented in the OWL data format that corresponds to the ontology of...
Ontology of transportation networks (2005)
Bernhard Lorenz, Hans Jürgen Ohlbach, Laibing Yang
This deliverable consists of three main parts. The first part is a comprehensive survey on standardisation efforts for geographic information. The second part contains a description of the Geographic...
abstract. The key notion for modelling calendar systems and many other periodic temporal notion is the mathematical concept of a partitioning of the real numbers. A partitioning of R splits the time...
Ontology driven visualisation of maps with svg. REWERSE Deliverable A1-D5 (2005)
Frank Ipfelkofer, Bernhard Lorenz, Hans Jürgen Ohlbach
This article describes a particular use of ontologies for visualising maps in a browser window. Geographic data are represented as instances of concepts in an ontology of transportation networks...
GeTS – a specification language for geo-temporal notions (2005)
This document describes the ‘Geo-Temporal ’ specification language GeTS. The objects which can be described and manipulated with this language are time points, crisp and fuzzy time intervals and...
The key notion for modelling calendar systems and many other periodic temporal notion is the mathematical concept of a partitioning of the real numbers. A partitioning of R splits the time axis into...
Ontology driven visualisation of maps with svg. REWERSE Deliverable A1-D5 (2005)
Frank Ipfelkofer, Bernhard Lorenz, Hans Jürgen Ohlbach
Abstract. In this work we demonstrate a particular use of ontologies for visualising maps in a browser window. Geographic data are represented in the OWL data format that corresponds to an ontology...
2.2 Scalar Properties of Fuzzy Time Intervals........................... 6 (2005)
The FuTI–library is a collection of classes and methods for representing and manipulating fuzzy time intervals. The report consists of three parts. The mathematical theory is described in the first...
Computational treatment of temporal notions – the CTTN-system (2005)
Abstract. The CTTN-system is a computer program which provides advanced processing or temporal notions. The basic data structures of the CTTN-system are time points, crisp and fuzzy time intervals,...
GeTS – a specification language for geo-temporal notions (2005)
Abstract. This paper contains a brief overview of the ‘Geo-Temporal’ specification language GeTS. The objects which can be described and manipulated with this language are time points, crisp and...
Reasoning on the Web: Language prototypes and perspectives (2004)
Sacha Berger, François Bry, Bernhard Lorenz, Hans Jürgen Ohlbach
Reasoning on the Web is gaining in importance because of emerging Web applications such as contextadaptive Web systems (e.g. eLearning, recommender, personalised (multi-)media, and mobile information...
2.2 Scalar Properties of Fuzzy Time Intervals........................... 5 (2004)
Hans Jürgen Ohlbach, Hans Jürgen Ohlbach
The FuTIRe library is a collection of classes and methods for representing and manipulating fuzzy time intervals and relations between them. Time intervals like ‘tonight’, which are usually not...
Relations between fuzzy time intervals (2004)
Time intervals like ‘tonight’, which are usually not very precise, can be modeled as fuzzy sets. But this causes the problem that the relations between points and intervals and between two...
Geotemporal Reasoning: Basic Theory (2004)
Contributing Workpackages A, Hans Jürgen Ohlbach, Klaus Schulz, Felix Weigel
This deliverable contains a detailed description of the bottom layers of the WebCal system for representing and manipulating ‘geotemporal ’ information. The basic components are the FuTIRe...
Relations between fuzzy time intervals (2004)
This paper serves two purposes. The first purpose is to introduce a new approach for defining point–interval and interval–interval relations for fuzzy time intervals. The basic idea for the...
Calendrical calculations with time partitionings and fuzzy time intervals (2004)
Abstract. This paper presents a piece in a big mosaic which consists of formalisms and software packages for representing and reasoning with everyday temporal notions. The kernel of the mosaic...
Printed in Great Britain by (2003)
Dov M. Gabbay, Hans Jürgen Ohlbach, Wilfrid Hodges, Hans Kamp, Robert Kowalski, Ewa Orlowska, ...
PRESS ISSN 1367-0751 www.oup.co.uk/igpl
On reasoning on time and location on the web (2003)
François Bry, Bernhard Lorenz, Hans Jürgen Ohlbach, Stephanie Spranger
Abstract Reasoning on time and location is receiving increasing attention on the Web due to emerging fields like Web adaptation, mobile computing, and the Semantic Web. Web applications in these...
On Reasoning on Time and Location on the Web (2003)
Francois Bry, Bernhard Lorenz, Hans Jürgen Ohlbach, Stephanie Spranger
Reasoning on time and location is receiving increasing attention on the Web due to emerging fields like Web adaptation, mobile computing, and the Semantic Web. Web applications in these fields often...
Printed in Great Britain by (2003)
Dov M. Gabbay, Hans Jürgen Ohlbach, Wilfrid Hodges, Hans Kamp, Robert Kowalski, Ewa Orlowska, ...
PRESS ISSN 1367-0751 www.oup.co.uk/igpl
Set Description Languages and Reasoning about Numerical Features of Sets (2001)
In this paper a combination methodology is presented, which allows one to use arithmetical algorithms for reasoning about numerical features of sets specied with the description logic ALC and a few...
Set Description Languages and Reasoning about Numerical Features of Sets (2001)
Hans Jürgen Ohlbach, Hans Jürgen Ohlbach
Set description languages, for example description logics, can be used to specify sets and set-theoretic relationships between them. Mathematical programming, on the other hand, can be used to find...
Set description languages, for example description logics, can be used to specify sets and set-theoretic relationships between them. Mathematical programming, on the other hand, can be used to find...
Modal Logics, Description Logics and Arithmetic Reasoning (1999)
Hans Jürgen Ohlbach, Jana Koehler
We introduce mathematical programming and atomic decomposition as the basic modal (T-Box) inference techniques for a large class of modal and description logics. The class of description logics...
Elimination of Self-Resolving Clauses (1999)
It is shown how self-resolving clauses like symmetry or transitivity, or even clauses like condensed detachment, can faithfully be deleted from the clause set thus eliminating or at least reducing...
Combining Hilbert Style and Semantic Reasoning in a Resolution Framework (1998)
. Many non-classical logics can be axiomatized by means of Hilbert Systems. Reasoning in Hilbert Systems, however, is extremely inefficient. Most inference methods therefore use the semantics of a...
Hans Jürgen Ohlbach, Dov Gabbay
ABSTRACT. A propositional temporal logic is introduced whose operators quantify over intervals of a reference time line. The intervals are specified symbolically, for example ‘next week’s...
Combining Hilbert style and semantic reasoning in a resolution framework (1998)
Abstract. Many non-classical logics can be axiomatized by means of Hilbert Systems. Reasoning in Hilbert Systems, however, is extremely inefficient. Most inference methods therefore use the semantics...
Hans Jürgen Ohlbach, Dov Gabbay
ABSTRACT. A propositional temporal logic is introduced whose operators quantify over intervals of a reference time line. The intervals are specified symbolically, for example ‘next week’s...
A Note on Assumptions about Skolem Functions (1997)
Hans Jürgen Ohlbach, Christoph Weidenbach, Im Stadtwald
. Skolemization is not an equivalence preserving transformation. For the purposes of refutational theorem proving it is suÆcient that Skolemization preserves satisability and unsatis- ability....
Role Hierarchies and Number Restrictions (1997)
Hans Jürgen Ohlbach, Hans J��urgen Ohlbach, Jana Koehler
We present the atomic decomposition technique as a general method for reducing reasoning about cardinalities of sets, in the DL case the cardinalities of role fillers, to equation solving problems....
Reasoning about Sets via Atomic Decomposition (1996)
Hans Jürgen Ohlbach, Jana Koehler
We introduce a new technique that translates cardinality information about finite sets into simple arithmetic terms and thereby enables a system to reason about such set cardinalities by solving...
Reasoning about Sets via Atomic Decomposition (1996)
Hans Jürgen Ohlbach, Jana Koehler
We introduce a new technique that translates cardinality information about finite sets into simple arithmetic terms thereby enabling a system to reason about such set cardinalities by solving...
SCAN - Elimination of Predicate Quantifiers (1996)
this paper the implementation of the Scan algorithm
Computer Support for the Development and Investigation of Logics (1996)
The development and investigation of application-oriented logics comprises many aspects and problems. For a few of them some computer support is possible which frees the investigator from sometimes...
SCAN - Elimination of Predicate Quantifiers - System Description (1995)
Scan is an algorithm and a program package for computing first--order equivalent formulae for second--order predicate logic sentences. It is remotely accessible via WWW and can be used for general...
A Multi-Dimensional Terminological Knowledge Representation Language (1995)
Im Stadtwald, Franz Baader, Franz Baader, Lufg Theoretische Informatik, Hans Jürgen Ohlbach, Hans Jurgen Ohlbach
An extension of the concept description language ALC used in kl-one-like terminological reasoning is presented. The extension includes multi--modal operators that can either stand for the usual role...
Translating Graded Modalities into Predicate Logic (1995)
Hans Jürgen Ohlbach, Renate A. Schmidt, Hans Jurgen, Ohlbach Renate, A. Schmidt, Ullrich Hustadt, ...
In the logic of graded modalities it is possible to talk about sets of finite cardinality. Various calculi exist for graded modal logics and all generate vast amounts of case distinctions. In this...
Functional Translation and Second-Order Frame Properties of Modal Logics (1995)
Hans Jürgen Ohlbach, Renate A. Schmidt, Im Stadtwald
Normal modal logics can be defined axiomatically as Hilbert systems, or semantically in terms of Kripke's possible worlds and accessibility relations. Unfortunately there are Hilbert axioms...
A note on assumptions about skolem functions (1995)
Hans Jürgen Ohlbach, Christoph Weidenbach, Im Stadtwald
Abstract. Skolemization is not an equivalence preserving transformation. For the purposes of refutational theorem proving it is sufficient that Skolemization preserves satisfiability and...
Computer Support for the Development and Investigation of Logics (1994)
Im Stadtwald, Hans Jürgen Ohlbach, Hans Jurgen Ohlbach
Symbolic reasoning in a logical framework becomes more and more important for computer applications such as Natural Language Processing Systems or Expert Systems. These applications usually need...
Hans Jurgen, Ohlbach Dov, Gabbay David Plaisted, Hans Jürgen Ohlbach, Im Stadtwald, Im Stadtwald, ...
This paper deals with methods of faithful transformations between logical systems. Several methods for developing transformations of logical formulae are defined which eliminate unwanted properties...
Journal of Computers and Mathematics with Applications Towards Automating Duality (1994)
Chris Brink, Hans Jürgen Ohlbach, Im Stadtwald
Dualities between different theories occur frequently in mathematics and logic — between syntax and semantics of a logic, between structures and power structures, between relations and relational...
Quantifier Elimination in Second-Order Predicate Logic (1992)
Dov Gabbay, Hans Jürgen Ohlbach, Im Stadtwald
An algorithm is presented which eliminates second{order quantiers over predicate variables in formulae of type 9P 1 ; . . . ; Pn where is an arbitrary formula of rst{order predicate logic. The...
Deduction Systems Based on Resolution (1991)
Norbert Eisinger, Norbert Eisinger, Hans Jürgen Ohlbach, Hans Jurgen Ohlbach, Fur Informatik
A general theory of deduction systems is presented. The theory is illustrated with deduction systems based on the resolution calculus, in particular with clause graphs. This theory distinguishes four...
Parameter Structures for Parametrized Modal Operators (1991)
Hans Jürgen Ohlbach, Andreas Herzig
The parameters of the parameterized modal operators [p] and <p> usually represent agents (in the epistemic interpretation) or actions (in the dynamic logic interpretation) or the like. In this...
Compilation of Recursive Two-Literal Clauses into Unification Algorithms (1990)
Hans Jürgen Ohlbach, Hans J��rgen Ohlbach
: Automated deduction systems can considerably be improved by replacing axioms with special purpose inference mechanisms. For example replacing in resolution based systems certain equations with...
Abstraction Tree Indexing for Terms (1990)
Hans Jürgen Ohlbach, Hans J��rgen Ohlbach
ion Tree Indexing for Terms Hans Jürgen Ohlbach FB. Informatik, University, Postf. 3049 D-675 Kaiserslautern, West Germany email: ohlbach@informatik.uni-kl.de Abstract * An indexing technique for...
A Resolution Calculus for Modal Logics (1988)
A syntax transformation is presented that eliminates the modal logic operators from modal logic formulae by shifting the modal context information to the term level. The formulae in the transformed...