Fraunhofer Institut für Integrierte Publikations-und Informationssysteme IPSI
Now showing 1 - 10 of 88
PublicationOntologically-enriched unified user modeling for cross-system personalization( 2005)
;Mehta, B. ;Niederée, C. ;Stewart, A. ;Degemmis, M. ;Lops, P.Semeraro, G.Personalization today has wide spread use on many Web sites. Systems and applications store preferences and information about users in order to provide personalized access. However, these systems store user profiles in proprietary formats. Although some of these systems store similar information about the user., exchange or reuse of information is not possible and information is duplicated. Additionally, since user profiles tend to be deeply buried inside such systems, users have little control over them. This paper proposes the use of a common ontology-based user context model as a basis for the exchange of user profiles between multiple systems and, thus, as a foundation for cross-system personalization.
PublicationFlexible notifications and task models for cooperative work management( 2005)
;Rubart, J.Richter, H.Knowledge intensive cooperative work requires emergent workflow management. Participants interact with the workflow engine and jointly redefine and activate workflow structure. To improve the usability of such systems we present reconfigurable notification mechanisms as well as shared task models that can be used from diverse clients at the same time focusing on different kinds of visualization and navigation.
PublicationAgilo: A highly flexible groupware framework( 2005)
;Guicking, A. ;Tandler, P.Avgeriou, P.Today there exist many frameworks for the development of synchronous groupware applications. Although the domain of these applications is very heterogeneous, existing frameworks provide only limited flexibility to integrate diverse groupware applications in a meaningful way. We identify five variation points that a groupware framework needs to offer in a flexible way in order to facilitate the integration of diverse groupware applications. Based on these variation points, we propose a groupware framework called Agilo that tries to overcome the limited flexibility of existing frameworks by offering multiple realizations of these variation points and providing a modular architecture to simplify the integration of applications and the extensibility and adaptability to different application and integration requirements.
PublicationUsing context of a mobile user to prefetch relevant information( 2005)Kirchner, H.Providing mobile users with relevant and up-to-date information on the move through wireless communication needs to take the current context of a user into account. In this paper, the context of a user with respect to his movement behaviour as well as device characteristics is under investigation. In outdoor areas, particularly in an urban area, obviously there is often sufficient communication bandwidth available. In some areas though, especially in rural areas, communication bandwidth coverage is often poor. Providing users in such areas with relevant information and making this information available in time is a major challenge. Prefetching tries to overcome these problems by using predefined user context settings. In situations where resource restrictions like limited bandwidth or insufficient memory apply, strategies come into place to optimize the process. Such strategies will be discussed. Evaluating the different types of users supports the approach of getting the relevant information to the user at the right time and the right place.
PublicationSWQL - A query language for data integration based on OWL( 2005)
;Lehti, P.Fankhauser, P.The Web Ontology Language OWL has been advocated as a suitable model for semantic data integration. Data integration requires expressive means to map between heterogeneous OWL schemas. This paper introduces SWQL (Semantic Web Query Language), a strictly typed query language for OWL, and shows how it can be used for mapping between heterogeneous schemas. In contrast to existing RDF query languages which focus on selection and navigation, SWQL also supports construction and user-defined functions to allow for instantiating integrated global schemas in OWL.
PublicationExploiting lexical knowledge in learning user profiles for intelligent information access to digital collections( 2005)
;Semeraro, G. ;Lops, P. ;Degemmis, M. ;Niederée, C.Stewart, A.Algorithms designed to support users in retrieving relevant information base their relevance computations on user profiles, in which representations of the users interests are maintained. This paper focuses on the use of supervised machine learning techniques to induce user profiles for Intelligent Information Access. The access must be personalized by profiles allowing users to retrieve information on the basis of conceptual content. To address this issue, we propose a method to learn sense-based user profiles based on WordNet, a lexical database.
PublicationA feature-watermarking scheme for JPEG image authentication( 2004)
;Wang, J.S. ;Dai, Y.W. ;Thiemert, S.Wang, Z.Q.Feature-based watermark is a special kind of watermark, which reflects the features of the content, and these features are deliberately chosen in the way that they will keep invariant during "content preserving" modifications while being sensitive to "malicious" attacks. In this paper, a novel approach to content authentication for JPEG images is proposed. The image authentication method is based on partial energy relation between groups of 8x8 DCT blocks as features, while the strategies of watermark embedding and extraction is based on improved DEW algorithm. Our proposed scheme has the capability of differentiating "content preserving" modifications from "malicious" attacks and so can ascertain and locate the "malicious" attacks. Experimental results show the feasibility of the proposed scheme.
PublicationLanguage modeling for effective construction of domain specific thesauri( 2004)
;Chen, L.B.Thiel, U.In this paper we present an approach for effective construction of domain specific thesauri. We assume that the collection is partitioned into document categories. By taking advantage of these pre-defined categories, we are able to conceptualize a new topical language model to weight term topicality more accurately. With the help of information theory, interesting relationships among thesaurus elements are discovered deductively. Based on the "Layer-Seeds" clustering algorithm, topical terms from documents in a certain category will be organized according to their relationships in a tree-like hierarchical structure --- a thesaurus. Experimental results show that the thesaurus contains satisfactory structures, although it differs to some extent from a manually created thesaurus. A first evaluation of the thesaurus in a query expansion task yields evidence that an increase of recall can be achieved without loss of precision.
PublicationTools and environments for learning object-oriented concepts( 2004)
;Michiels, I. ;Börstler, J. ;Bruce, K.B.Fernandez, A.This report summarizes the results of the seventh workshop in a series of workshops on learning object-oriented concepts. The focus of this workshop was on (computer-aided) support for the teaching and learning of basic object-oriented concepts.
PublicationEmergent semantics - Extended and revised version of the DASFAA 2004 paper( 2004)
;Aberer, K. ;Catarci, T. ;Cudre-Mauroux, P. ;Dillon, T. ;Grimm, S. ;Hacid, M.-S. ;Illarramendi, A. ;Jarrar, M. ;Kashyap, V. ;Mecella, M. ;Mena, E. ;Neuhold, E.J. ;Ouksel, A.M. ;Risse, T. ;Scannapieco, M. ;Saltor, F. ;Santis, L. de ;Spaccapietra, S. ;Staab, S. ;Studer, R.Troyer, O. de