Search
Now showing items 11-19 of 19
Preprint
Semantic network analysis of ontologies
(2006)
A key argument for modeling knowledge in ontologies is the easy re-use and re-engineering of the knowledge. However, beside consistency checking, current ontology engineering tools provide only basic functionalities for analyzing ontologies. Since ontologies can be considered as (labeled, directed) graphs, graph analysis techniques are a suitable answer for this need. Graph analysis has been performed by sociologists for over 60 years, and resulted in the vivid research area of Social Network Analysis (SNA). While ...
Preprint
BibSonomy: a social bookmark and publication sharing system
(2006)
Social bookmark tools are rapidly emerging on the Web. In such systems users are setting up lightweight conceptual structures called folksonomies. The reason for their immediate success is the fact that no specific skills are needed for participating. In this paper we specify a formal model for folksonomies and briefly describe our own system BibSonomy, which allows for sharing both bookmarks and publication references in a kind of personal library.
Preprint
Content aggregation on knowledge bases using graph clustering
(2006)
Recently, research projects such as PADLR and SWAP have developed tools like Edutella or Bibster, which are targeted at establishing peer-to-peer knowledge management (P2PKM) systems. In such a system, it is necessary to obtain provide brief semantic descriptions of peers, so that routing algorithms or matchmaking processes can make decisions about which communities peers should belong to, or to which peers a given query should be forwarded. This paper proposes the use of graph clustering techniques on knowledge bases ...
Preprint
Mining association rules in folksonomies
(2006)
Social bookmark tools are rapidly emerging on the Web. In such systems users are setting up lightweight conceptual structures called folksonomies. These systems provide currently relatively few structure. We discuss in this paper, how association rule mining can be adopted to analyze and structure folksonomies, and how the results can be used for ontology learning and supporting emergent semantics. We demonstrate our approach on a large scale dataset stemming from an online system.
Dissertation
Szenarien zur zukünftigen Stromversorgung, kostenoptimierte Variationen zur Versorgung Europas und seiner Nachbarn mit Strom aus erneuerbaren Energien
(2006-04-11)
Sowohl die Ressourcenproblematik als auch die drohenden Ausmaße der Klimaänderung lassen einen Umstieg auf andere Energiequellen langfristig unausweichlich erscheinen und mittelfristig als dringend geboten. Unabhängig von der Frage, auf welchem Niveau sich der Energiebedarf stabilisieren lässt, bleibt dabei zu klären, welche Möglichkeiten sich aus technischer und wirtschaftlicher Sicht in Zukunft zur Deckung unseres Energiebedarfs anbieten. Eine aussichtsreiche Option besteht in der Nutzung regenerativer Energien in ...
Verschiedenartige Texte
Modularität und Wiederverwendung
(2006-11-06)
Tagungsband - Vorträge vom Automation Symposium 2006
Dissertation
Modelling of global crop production and resulting N2O emissions
(2006-04-18)
Landwirtschaft spielt eine zentrale Rolle im Erdsystem. Sie trägt durch die Emission von CO2, CH4 und N2O zum Treibhauseffekt bei, kann Bodendegradation und Eutrophierung verursachen, regionale Wasserkreisläufe verändern und wird außerdem stark vom Klimawandel betroffen sein. Da all diese Prozesse durch die zugrunde liegenden Nährstoff- und Wasserflüsse eng miteinander verknüpft sind, sollten sie in einem konsistenten Modellansatz betrachtet werden. Dennoch haben Datenmangel und ungenügendes Prozessverständnis dies ...
Dissertation
Low-Cost Micromechanically Tunable Optical Devices: Strained Resonator Engineering, Technological Implementation and Characterization
(2006-02-22)
The rapid growth of the optical communication branches and the enormous demand for more bandwidth require novel networks such as dense wavelength division multiplexing (DWDM). These networks enable higher bitrate transmission using the existing optical fibers.
Micromechanically tunable optical microcavity devices like VCSELs, Fabry-Pérot filters and photodetectors are core components of these novel DWDM systems. Several air-gap based tunable devices were successfully implemented in the last years. Even though these ...
Technischer Report
Small World Folksonomies: Clustering in Tri-Partite Hypergraphs
(2006-12-04)
Many recent Web 2.0 resource sharing applications can be subsumed under the "folksonomy" moniker. Regardless of the type of resource shared, all of these share a common structure describing the assignment of tags to resources by users.
In this report, we generalize the notions of clustering and characteristic path length which play a major role in the current research on networks, where they are used to describe the small-world effects on many observable network datasets. To that end, we show that the notion of ...