I am full professor at
the Faculty of Computer
Science of the Free University of
My main research interests are in data-intensive systems with a
focus on database technologies for the processing and analysis of
data, with a particular emphasis on time-referenced and time series
data. The adopted research methodology combines fundamental
research, system development, and empirical evaluation. Research
problems originate from different application areas, e.g.,
government, tourism, health-care, agriculture.
- Temporal RDBMS: Aims at extending RDBMs with support for
querying interval-timestamped data under sequenced semantics. The
basic idea is to reduce the temporal operators to the non-temporal
counterparts. Our solution is implemented in the kernel of
- DASA: Aims at developing solutions for managing/analysing
time series data coming from weather stations in agriculture.
Specific research problems include the imputation of missing
values and the search for similar time series or episodes, e.g.,
seek the most similar Summer.
- Isochrones: Aims at studying isochrones as a tool for
reachability and catchment analysis in spatial network
- Finished projects:
- D. B. Blumenthal, J. Gamper. Improved lower bounds for graph
edit distance. TKDE 2018.
- M. Shekelyan, A. Dignös, J. Gamper. DigitHist: a
histogram-based data summary with tight error bounds. PVLDB
- A. Dignös, M.H. Böhlen, J. Gamper, C.S. Jensen.
Extending the kernel of a relational DBMS with comprehensive
support for sequenced temporal queries. TODS 2016.
(Selected by ACM Computing Reviews for
Annual Best of Computing — Notable Books and Articles)
- A. Dignös, M.H. Böhlen, J. Gamper. Overlap interval
partition join. SIGMOD 2014.
- M. Khayati, M.H. Böhlen, and J. Gamper. Memory-efficient
centroid decomposition for long time series. ICDE 2014.
- A. Dignös, M.H. Böhlen, J. Gamper. Temporal alignment.
- J. Gordevicius, J. Gamper, M.H. Böhlen. Parsimonious
temporal aggregation. VLDB Journal 2012.
- N. Augsten, M. Böhlen, C. Dyreson, J. Gamper. Windowed
pq-grams for approximate joins of data-centric XML. VLDB Journal
- I. Timko, M. Böhlen, J. Gamper. Sequenced spatiotemporal
aggregation for coarse query granularities. VLDB Journal
- N. Augsten, M. Böhlen, J. Gamper. The pq-gram
distance between ordered labeled trees. TODS 2010.
- N. Augsten, M. Böhlen, C. Dyreson, J. Gamper. Approximate
joins for data centric XML. ICDE 2008.
- N. Augsten, M. Böhlen, J. Gamper. An incrementally
maintainable index for approximate lookups in hierarchical
data. VLDB 2006.
- N. Augsten, M. Böhlen, J. Gamper. Approximate
matching of hierarchical data using pq-grams.
Reviewing for journals:
Systems, DKE, AICOM,
2015), SIGMOD (2014,
(2017, 2016, 2010), EDBT (2019,
2017, 2016, 2015, 2013, 2011, 2009),
(2018, 2017, 2016, 2015, 2014, 2013, 2012,
2011), SSDBM (2015, 2014, 2012, 2011,
(2018, 2017, 2015,
(2015, 2014, 2013, 2012, 2009, 2008), SOFSEM (2019, 2018, 2017, 2016,
2014, 2012, 2010).
General chair of SSDBM 2018. Workshops co-chair of ADBIS 2017.
I am a member of ACM and IEEE CS.
Teaching and Student Supervision
Current PhD students: David B. Blumenthal,
Former PhD students:
Markus Innerebner. Co-supervision:
Nikolaus Augsten, Romans
Kasperovics, Judith Knapp.
Courses I am currently teaching:
Proposals for BSc/MSc theses