I am full professor at
the Faculty of Computer
Science of the Free University of
My research interests focus on database technologies for processing
temporal and spatial data, data warehousing and analytics, and
approximate query answering. 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 full-fledged
support for querying interval-timestamped data. The basic idea is
to reduce the temporal operators to the non-temporal counterparts.
Our solution is implemented in the kernel of PostgreSQL.
- 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.,
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 as part of
Annual Best of Computing by ACM Computing Reviews)
- D. Taliun, J. Gamper, U. Leser, C. Pattaro. Fast sampling-based
whole-genome haplotype block recognition. TCBB 2016.
- 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 (2017,
2016, 2015, 2013, 2011, 2009),
(2016, 2015, 2014, 2013, 2012,
2011), SSDBM (2015, 2014, 2012, 2011,
(2015, 2014, 2013, 2012, 2009, 2008), SOFSEM (2018, 2017, 2016, 2014,
General chair of SSDBM 2018
I am a member of ACM and IEEE CS.
Teaching and Student Supervision
Current PhD students: David B. Blumenthal,
Giovanni Mahlknecht, Michael Shekelyan.
Former PhD students:
Markus Innerebner. Co-supervision:
Nikolaus Augsten, Romans
Kasperovics, Judith Knapp.
Courses I am currently teaching:
Proposals for BSc/MSc theses