Reasoning Web 2010

Summer School

Objectives Committee Programme Lecturers Venue Application and Registration Contact Social Events Important Dates Participants
[photo Dresden]

Programme

Lectures:

  1. Reasoning in EL and in Description Logics in general (with lecture slides)
    Anni-Yasmin Turhan
  2. Hybrid Reasoning (with lecture slides)
    Włodek Drabent
  3. Scalable DL Reasoning (with lecture slides)
    Jeff Z. Pan
  4. Semantic Model-Driven Engineering (with lecture slides)
    Steffen Staab
  5. Semantic Search Engines (with lecture slides)
    Michael Schröder
  6. Benefits of Semantic Technologies in the research project Aletheia
    Frithjof Dau
  7. Combining ontologies with domain specific languages: a case study from network configuration software (with lecture slides)
    Krzysztof Miksa
  8. Ontology Learning (with lecture slides)
    Jens Lehmann
  9. Bridging Query Languages in Semantic and Graph Technologies (with lecture slides)
    Hannes Schwarz
  10. Semantic business process engineering (with lecture slides)
    Jens Lemcke

Detailed Timetable

Lecture Notes [logo Springer]

The course material used during the Summer School will be published in the Lecture Notes in Computer Science series by Springer-Verlag.

Course Descriptions:

Reasoning in EL and in Description Logics in general

Anni-Yasmin Turhan

The goal of this course is to introduce Description Logics (DLs) and their reasoning services by means of the light-weight DL EL. Description logics are a family of knowledge representation formalisms with well-defined formal semantics that represent knowledge in a declarative way. Based on these semantics various reasoning services have been defined and investigated. This course provides a short introduction to DLs in general and presents approaches for reasoning in expressive DLs, which are the foundation for reasoning in the ontology language standard OWL 2. The main focus is to consider tractable reasoning in the more light-weight DL EL, which is employed in bio-medical ontologies, and which is the foundation for the OWL 2 profile OWL 2 EL.

Lecture slides:

Hybrid Reasoning

Włodek Drabent

Ontologies and Description Logics (DL) are important reasoning formalisms for the Semantic Web. It is however generally understood that they are to be augmented by rule systems. The latter approach stems from Logic Programming. The related W3C standard is RIF (Rule Interchange Format, under development). Possibly the main semantic feature distinguishing rule systems from DL is non-monotonic reasoning.

The lecture presents methods of combining both formalisms. Non-monotonic reasoning is going be a central issue of our presentation. We provide a solid introduction to non-monotonic reasoning in rule systems, explaining differences between main semantic approaches. Then we present several ways of combining rule systems with DL, and discuss their semantics and implementation methods. We focus on methods making it possible to use existing DL reasoners and logic programming systems.

Lecture slides:

Scalable DL Reasoning

Jeff Z. Pan

Lecture slides:

Semantic Model-Driven Engineering

Steffen Staab

Ontologies constitute formal models of some aspect of the world that may be used for drawing interesting logical conclusions even for large models. Software models capture relevant characteristics of a software artifact to be developed, yet, most often these software models have no formal semantics or the underlying (often graphical) software language varies between different use cases in a way that makes it hard if not impossible to even fix its semantics.

In this course we survey the use of ontology technologies for software models in order to carry over advantages to the software modeling domain. It will turn out that ontology-based metamodels constitute a core means for exploiting expressive ontology reasoning in the software modeling domain while remaining flexible enough to accommodate varying needs of software modelers.

Lecture slides:

Semantic Search Engines

Michael Schröder

Lecture slides:

Benefits of Semantic Technologies in the research project Aletheia

Frithjof Dau

Aletheia - semantic federation of comprehensive product information - is a leading innovation project, sponsored by the Federal Ministry of Education and Research, that aims at obtaining comprehensive access to product information. Aletheia is built extensively on semantic technologies for gathering information from various sources like office-documents, html-pages, XML-files or relational databases and for providing different means to deliver the federated information to the users.

In this course, we will give a short introduction into Aletheia and the used semantic technologies. The main focus of the talk is to provide insights on how Aletheia benefits from semantic technologies. These benefits will be demonstrated with the existing prototype.

Combining ontologies with domain specific languages: a case study from network configuration software

Krzysztof Miksa

One of the important aspects of Model Driven Engineering (MDE) is to consider application-domain variability, which leads to creation of Domain Specific Languages (DSL). As with DSLs models are concise, easy to understand and maintain, this approach greatly increases the productivity and software quality. Usually, the DSLs in MDE are described with a metamodel and a concrete syntax definition. The models expressed in the DSL are linguistic instantiations of the language concepts found in the metamodel.

However, for some of the application domains it is not enough to consider the linguistic dimension of the instantiation. The problem arises when the domain itself contains the aspect of typing. This leads to another view on instantiation, called ontological instantiation. Since both aspects are present simultaneously, the combined approach is called "two-dimensional metamodelling".

In the course a case study based on real challenge found in the domain of network management is presented. It will be shown how ontology technologies can be used to support cases of 2D metamodelling.

Lecture slides:

Ontology Learning

Jens Lehmann

"Ontology Learning aims at the integration of a multitude of disciplines in order to facilitate the construction of ontologies, in particular ontology engineering and machine learning." (Mädche and Staab, 2004)

The presentation, created by Johanna Völker and Jens Lehmann, is split in two parts. In the first part, an introduction to ontology learning is given and several learning techniques are briefly explained. In the second part of the presentation, one particular technique (refinement operator based learning) is explained in more detail.

Lecture slides:

Bridging Query Languages in Semantic and Graph Technologies

Hannes Schwarz

Software systems are situated in or make use of various technological spaces, e.g. relational databases, ontologies, or XML technology. Similarly, different technological spaces are employed in the development of software, such as model-driven development and programming languages. The usage of two or more technological spaces in a single system or in a single development process requires a proper bridging between them. "Bridging" can be accomplished by transforming concepts of one space into another, by using an adapter to make concepts of one space usable in another one, or even by integrating both spaces into a single one, for instance.

This course presents a transformation-based bridge between the query languages SPARQL and GReQL, with SPARQL originating from the semantic technological space and GReQL representing the model-driven space. Since transformation of queries requires the prior mapping of the queried knowledge base, the approach also involves transformation of the underlying data in the form of RDF documents and TGraphs, respectively. Two applications, the first in the context of ontology storage and processing and the second in the field of traceability show the benefits of such a bridge.

Lecture slides:

Semantic business process engineering

Jens Lemcke

Business process engineering is the procedure of implementing a business process through existing IT systems. This talk describes how two currently manual, time-consuming, and error-prone activities of business process engineering can be automated by reasoning about process semantics:

  1. Process refinement: Like in software engineering, the implementation of a business process involves different interacting roles, such as business expert, analyst, process architect, and developer. Each role designs and refines different abstractions of the process until it is sufficiently refined. It is important to verify that the process models of the different abstractions are consistent.
  2. Process grounding: A sufficiently refined process has to be mapped on existing IT systems. Ideally, IT systems consist of components with a semantic annotation of their behavior. The most specific process must respect all IT systems' behaviors.

Formally capturing process semantics enables to check automatically for consistent process refinement and grounding. In this talk, process models are represented using the business process model and notation (BPMN) due to its wide industry adoption by, e.g., SAP and IBM. First, the business process engineering lifecycle is explained. Afterwards, different notions of process refinement are discussed. Finally, the problems of validating refinement and grounding of BPMN diagrams are reduced to OWL-DL reasoning.

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