Description Logic

Dr.-Ing. habil. Anni-Yasmin Turhan


Course Description

Description Logics (DLs) are a successful family of logic-based knowledge representation formalisms, which can be used to represent the conceptual knowledge of an application domain in a structured and formally well-understood way. They are employed in various application domains, such as natural language processing, configuration, and databases, but their most notable success so far is the adoption of the DL-based language OWL as standard ontology language for the semantic web. This course concentrates on designing and analysing reasoning procedures for DLs. After a short introduction of predecessor formalisms such as semantic networks and frames, it will introduce the basic features of DLs such as concepts, TBoxes and ABoxes, and basic inference problems such as the subsumption and the instance problem. The course introduces techniques for solving these problems based on tableau-algorithms, automata, and other approaches. Also, the complexity of standard DLs is analysed, identifying expressive DLs for which reasoning is expensive in the worst case, but still manageable in practice, and lightweight DLs for which reasoning is tractable.

Modalities for Oral Exam

Oral Exams can be taken before 6 February or after 2 March 2015. Please contact PD Dr.-Ing. habil. Anni-Yasmin Turhan three weeks before your desired date for the examination. If you urgently have to take the exam within the time frame from 9 February to 27 February, then please contact either Prof. Dr.-Ing. Franz Baader or Dr. rer. nat. Rafael Pe├▒aloza. Furthermore make sure, that all necessary requirements according to your study and exam regulations are fulfilled.

Organisation

The lecture takes place twice a week. Additionally, there is a weekly exercise session held by Francesco Kriegel. Exercise sheets will be available approximately one week before the session.

The lectures and the exercise sessions will take place in room E005 at the following times: Tuesdays 16.40–18.10, Wednesdays 14.50–16.20, and Thursdays 16.40–18.10. The exact distribution of lectures and exercise sessions can be found in the table below.

Announcements:
Tuesday Wednesday Thursday
13 Oct. to 17 Oct. Lecture Lecture Lecture
20 Oct. to 24 Oct. Lecture Exercise session
(exercise sheet 1)
Lecture
27 Oct. to 31 Oct. Lecture Exercise session
(exercise sheet 2)
Lecture
3 Nov. to 7 Nov. Lecture Exercise session
(exercise sheet 3)
Lecture
10 Nov. to 14 Nov. Lecture Exercise session
(exercise sheet 4)
Lecture
17 Nov. to 21 Nov. Lecture Public holiday Lecture
24 Nov. to 28 Nov. Lecture Exercise session
(exercise sheet 5)
Lecture
1 Dec. to 5 Dec. Lecture Exercise session
(exercise sheet 6)
Lecture
8 Dec. to 12 Dec. Lecture Exercise session
(exercise sheet 7)
Lecture
15 Dec. to 19 Dec. Lecture Exercise session
(exercise sheet 8)
Lecture
5 Jan. to 9 Jan. Lecture Exercise session
(exercise sheet 9)
Lecture
12 Jan. to 16 Jan. Lecture Exercise session
(exercise sheet 10)
Lecture
19 Jan. to 23 Jan. Lecture Exercise session
(exercise sheet 11)
Lecture
26 Jan. to 30 Jan. Lecture Exercise session
(exercise sheet 12)
Lecture
2 Feb. to 6 Feb. Lecture Exercise session
(exercise sheet 13)
Lecture

SWS/Modules

SWS: 4/2/–

This course can be used in the following modules:

Lecture Material

A script of this lecture is not available, and students are strongly recommended to copy what is written on the blackboard.

We provide, however, the slides for the introductory sessions: We provide, however, the slides for the introductory sessions: Also, we provide scanned versions of the example slides used in the session about frames and semantic networks:

Literature