Sascha Tönnies


Dr. Sascha Tönnies

Technische Universität Braunschweig
Institut für Informationssysteme
Mühlenpfordtstraße 23, 2.OG
D-38106 Braunschweig

Room: 218





Reseach Interests

Quality in Digital Libraries: Most of my research in this field is performed within the ViFaChem Project.

Short CV

2010-now: Institute for Information Systems, Carolo-Wilhelmina University Braunschweig
2006-2010: L3S Research Center, Leibniz University Hannover
2000-2006: University Hannover


Previous Projects

Bi²SoN - Stampede

During the last years the region of south-east Lower Saxony focused on biomedical topics, like e.g. regenerative medicine or infection diseases. This year, an interdisciplinary project namend "Einsatz von Informations- und Kommunikationstechnologien zur Optimierung der biomedizinischen Forschung in Südost-Niedersachsen (Bi2SON)" has started combining several smaller projects aiming at realizing suitable IT support for biomedical research.

The institute for Information Systems at the University of Braunschweig started a subproject in cooperation with the Helmholtz Centre for Infection Research and the Braunschweiger Informatik- und Technologie-Zentrum (BITZ). The aim of this project is to predict the activated pathways of a cell based on experimental results considering different external conditions. Especially in the area of infection research the pathway analysis is important to detect new starting points for drug development. During the last years more and more information about different pathways is available in specialized databases as well as in literature. It is important to open up the knowledge described in the literature and combine it with the different databases. The project's vision is to build a Web based digital library dealing as a central starting point for literature searches while considering the knowledge available in domain specific databases.


ViFaChem II

The rapid changes in information technology have heavily influenced the scientific way of working and style of communication. Global communication technologies like email of mobile telephony enable a fast and ubiquitous information exchange and the time spans between generation of new results and the subsequent publication and dissemination (innovation cycles) are becoming shorter. This results in a flood of available scientific information that cannot be handled manually by the individual reader. Whereas classical libraries still offer services in the form of printed material, the use of digital services like online journal, topic-centered databases, or digital libraries, is becoming prevalent in the scientific community.

Building on the experiences from designing part of the chemical information platform, which is hosted by the TIB, the Chemistry Information Centre Germany (FIZ Chemie), and the German Chemical Society (GDCh), the ViFaChem 2 platform will focus on innovative value added services thus providing a pervasive information infrastructure for universities as well as industry to support the generation of new knowledge. Scientific libraries provide an information infrastructure that collects, processes and connects heterogeneous document collections with respect to the information needs of each individual user. Due to the editorial process the quality of information is guaranteed throughout the process. Using advanced information extraction and entity recognition techniques on chemical literature the information (e.g. full texts, chemical reactions, images of molecular structures) will be collected. Moreover, using all document information structural properties of the domain like taxonomies of tags and annotations, or Ontologies over controlled vocabularies (encoding domain knowledge) can be derived and subsequently used for structuring novel personal information spaces enriched by metadata with controlled quality.

(, 2008-2010)


The Personalized Universal Media Access (PUMA) project at L3S Research Center embraces the vision of accessing multimedia data anywhere anytime from a variety of client devices. Today this is usually facilitated out of a plethora of complex applications. But building and maintaining such complex large scale multimedia systems is always a difficult, costly, time-consuming and challenging problem. Service-based architectures and the possibility to flexibly reuse services for different workflows and compose basic services to implement more complex workflows (or rather execution flows), as proposed in the Web and Grid communities, can provide a possible solution to this problem.

However, due to the special characteristics of multimedia applications and the rich semantic structure of multimedia data and workflows, Web or Grid-based research results still cannot be readily applied. When moving from monolithic applications towards service-oriented Multimedia frameworks, especially the seamless composition of services to form complex multimedia workflows becomes a demanding problem. Networked or mobile client devices show limited capabilities and require a flexible composition strategy as they often have to move computationally complex or power-demanding tasks to powerful servers. Such a strategy also has to consider the changing environment due to movements of the device and it has to adapt to device-specific characteristics, e.g., the current battery level. Hence, the selection, execution and monitoring of chains of Web services and graceful recovery from failures of individual services and network-specific or device-specific alarms are important aspects to realize service-oriented multimedia applications.

(, 2007-2008)


COOPER is an EU funded collaborative specific targeted research project from the sixth framework programme of the Information Society Technologies IST (contract No. FP6 IST - 027073) that was officially launched on 1 December 2005. The COOPER project is dedicated to supporting long-distance cooperation of teams of students working on complex projects, assuming that the students and advisors are geographically dispersed and have heterogeneous backgrounds and competencies. COOPER applies to the following learning environments:

  • Graduate (or post-graduate) university studies involving students and lecturers participating in focused projects (e.g., masters or specialization courses) coming from different institutions and backgrounds;
  • Company universities and company training, involving multi-national participants coming from company’s sites or customers which are world-wide dispersed, participating in the launching of new product or technology, or in product- and project-centred training.

Stemming from these requirements, COOPER’s main technological objective is to develop and test a model-driven, extensible environment that supports in Bdividual and collective competency building in virtual teams, whose members are geographically dispersed, have different backgrounds and competencies, working together in projects to solve complex problems. The COOPER project will achieve this goal by focusing on and providing the following results:

  • Create a reference model for cooperative teamwork processes;
  • Create interoperable and validated pedagogical scenarios and assessment strategies;
  • Create and test tools to support knowledge co-construction, sharing and re-use;
  • Create a common COOPER software platform in which these models, scenarios, strategies and tools are integrated;
  • Gather requirements as well as pilot results and evaluations in representative case studies.

All results delivered by the project will contribute to forming a protected, shared COOPER environment, that will be easily deployed over any University’s or Company’s Intranet. The COOPER environment will feature the use of advanced technology (e.g. VOI) provided by two small SMEs at the forefront of EU innovation edge.

(, 2006-2007)


Barthel, S., S. Tönnies, B. Köhncke, P. Siehndel, and W. - T. Balke, "What does Twitter Measure? Influence of Diverse User Groups in Altmetrics", ACM/IEEE Joint Conference on Digital Libraries (JCDL), Knoxville, TN, USA, 06/2015. Abstract  Download: JCDL2015_camera-ready.pdf (458.62 KB)
Munz, M., S. Tönnies, W. - T. Balke, and E. Simon, "Multidimensional Gene Search with Genehopper", Nucleic Acids Research, vol. 43, no. 9: Oxford University Press, 05/2015.  Download: Nucleic Acids Research - 2015 - Munz.pdf (2.02 MB)
Barthel, S., S. Tönnies, and W. - T. Balke, "Large-Scale Experiments for Mathematical Document Classification", 15th International Conference on Asia-Pacific Digital Libraries (ICADL), Bangalore, India, Springer, 12/2013. Abstract  Download: icadl13.pdf (346.56 KB)
Homoceanu, S., S. Tönnies, P. Wille, and W. - T. Balke, "Time-Based Exploratory Search in Scientific Literature", Research and Advanced Technologies for Digital Libraries: 17th International Conference on Theory and Practice of Digital Libraries (TPDL), Valletta, Malta, 09/2013. Abstract  Download: essence_crc.pdf (538.82 KB)
Tönnies, S., "Quality Control using Semantic Technologies in Digital Libraries", Insitut für Informationssysteme, Braunschweig, Carl-Friedrich-Gauß-Faculty, TU Braunschweig, pp. 121, 12/12, 2012. Abstract  Download: Thesis_Toennies_Final_EVersion.pdf (2.31 MB)
Köhncke, B., S. Tönnies, and W. - T. Balke, "Catching the Drift – Indexing Implicit Knowledge in Chemical Digital Libraries", International Conference on Theory and Practice of Digital Libraries (TPDL), Paphos, Cyprus, 09/2012. Abstract  Download: koehncke_tpdl12.pdf (696.04 KB)
Köhncke, B., S. Tönnies, and W. - T. Balke, "Bi2SoN – A Digital Library for Supporting Biomedical Research", 12th ACM/IEEE Joint Conference on Digital Libraries (JCDL), Washington, DC, USA, 06/2012. Abstract  Download: jcdl44-koehncke.pdf (574.67 KB)
Tönnies, S., B. Köhncke, and W. - T. Balke, "Meta-Line: Lineage Information for Improved Metadata Quality ", 12th ACM/IEEE Joint Conference on Digital Libraries (JCDL), Washington, DC, USA , 06/2012. Abstract  Download: jcdl11-toennies.pdf (317.34 KB)
Tönnies, S., B. Köhncke, O. Koepler, and W. - T. Balke, "Exposing the Hidden Web for Chemical Digital Libraries", 10th ACM/IEEE Joint Conference on Digital Libraries (JCDL), Surfers Paradise, Gold Coast, Australia, 06/2010. Abstract  Download: jcdl13_toennies.pdf (633.69 KB)
Tönnies, S., and W. - T. Balke, "Quality Assessment in Digital Libraries - Challenges and Chances", 22. GI-Workshop Grundlagen von Datenbanken (GvD), Bad Helmstedt, Germany, 05/2010. Abstract  Download: gvd_toennies.pdf (482.31 KB)
Tönnies, S., B. Köhncke, P. Hennig, and W. - T. Balke, " A Service Oriented Architecture for Personalized Rich Media Delivery ", IEEE International Conference on Services Computing (IEEE SCC 2009), Bangalore, India, 09/2009. Abstract  Download: scc09.pdf (275.26 KB)
Tönnies, S., and W. - T. Balke, " Using Semantic Technologies in Digital Libraries - A Roadmap to Quality Evaluation ", 13th European Conference on Digital Libraries (ECDL 2009), Corfu, Greece, 09/2009. Abstract  Download: ecdl09.pdf (452.12 KB)
Tönnies, S., B. Köhncke, O. Koepler, and W. - T. Balke, "Building Chemical Information Systems - the ViFaChem II Project", 13. GI-Fachtagung Datenbanksysteme für Business, Technologie und Web, Münster, Germany, 03/2009. Abstract  Download: btw09.pdf (428.21 KB)
Tönnies, S., and W. - T. Balke, "User-centered Content Provisioning over Large Collections of eBooks", 2nd Workshop on Research Advances in Large Digital Book Collections , Corfu, Greece, Springer, 2009. Abstract  Download: books-online09.pdf (408.06 KB)
Brunkhorst, I., S. Tönnies, and W. - T. Balke, "Multimedia Content Provisioning using Service Oriented Architectures", IEEE International Conference on Web Services (ICWS), Bejing, China, 10/2008. Abstract  Download: icws08.pdf (442.21 KB)
Tönnies, S., B. Köhncke, O. Koepler, and W. - T. Balke, "Personalised Information spaces for Chemical Digital Libraries", 4th German Conference on Chemoinformatics, Goslar, Germany, 2008. Abstract  Download: cheminfo08.pdf (81.12 KB)
Bozzon, A., T. Iofciu, A. V. Taddeo, S. Tönnies, and W. Nejdl, "Role based Access Control for the integration with Search Engines", International Workshop on Collaborative Open Environments for Project-Centered Learning, Crete, Greece, 09/2007. Abstract
Tönnies, S., "Mixed Reality in der Fahrzeugnavigation", GIS-BUSINESS Geoinformationstechnologie für die Praxis, 08/2007.
Tönnies, S., "Zielführung in der Fahrzeugnavigation mittels Mixed Reality", Institut für Kartographie und Geoinformatik, vol. M.Sc., Hannover, Universität Hannover, 2006.
Tönnies, S., "Werkzeugunterstützter Einsatz von XP-Techniken in der Programmierausbildung", Institut für verteilte Systeme - Fachgebiet wissensbasierte Systeme , vol. B.Sc., Hannover, Universität Hannover, 2003.