Tomáš Skopal, Assoc. Prof.
skopal<at>ksi.mff.cuni.cz
chair of department, associate professor

Research groups

Siret

Research topics

  • similarity search in metric and nonmetric spaces
  • multimedia databases
  • database indexing
  • information retrieval

Teachingtop

CodeTitleLinks
NDBI025Database Systems
NDBI034Retrieval of multimedia content on the web
NDBI038Quill Catching
NPRG045Individual Software Project
NPRG046Software Praxis
NSWI122Dissertation Thesis Preparation

Ph.D. studentstop

Tomáš Bartoš, M.Sc., Jakub Galgonek, M.Sc., Juraj Moško, M.Sc., Jiří Novák, M.Sc.

Supervised thesestop

TitleStudentTypeStartedDefended
How's my connection? An assistent in mass transportation system of PragueMiroslav HrivíkMS2012
Leaf Recognition for SmartphonesLukáš TomasyMS2012
Realty theft guardJan ŠaršonMS2012
Face Recognition in Social NetworksPavel MachBS20122012
(show all)

Research grantstop

  • Efficient Metric Search in Large Multimedia Databases (GACR 201/05/P036) 2005-2007 head investigator
  • Similarity Searching in Very Large Multimedia Databases (GACR 201/09/0683) 2009-2011 investigator
  • Modern methods and applications of software engineering (GAUK SVV-2010-261312) 2010-2010 head investigator
  • Development of a Native Storage for XML Data (GACR 201/06/0756) 2006-2008 cooperant
  • Intelligent Models, Algorithms, Methods and Tools for the Semantic Web (AV CR 1ET100300419) 2004-2008 cooperant
  • (show all)

Publicationstop

2012

Refereed (journals/proceedings) (13)

  • Bartoš T., Skopal T.: Revisiting Techniques for Lowerbounding the Dynamic Time Warping Distance, in Lecture Notes in Computer Science, Vol. 2012, Num. 7404/2012, ISSN: 0302-9743, pp. 192-208, 2012
  • Bustos B., Kreft S., Skopal T.: Adapting Metric Indexes for Searching in Multi-Metric Spaces, in Multimedia Tools and Applications, ISSN: 1380-7501, 2012
  • Galgonek J., Skopal T., Hoksza D.: P3S: Protein Structure Similarity Search, in Lecture Notes in Computer Science, ISSN: 0302-9743, 2012
  • Kruliš M., Skopal T., Lokoč J., Beecks C.: Combining CPU and GPU architectures for fast similarity search, in DISTRIBUTED AND PARALLEL DATABASES, Vol. 30, Num. 3-4, ISSN: 0926-8782, pp. 179-207, 2012
  • Lokoč J., David N., Michal B., Skopal T.: Visual Image Search: Feature Signatures or/and Global Descriptors, in Lecture Notes in Computer Science, Vol. 2012, Num. 7404, ISSN: 0302-9743, pp. 177-191, 2012
  • Lokoč J., Přemysl Č., Novák J., Skopal T.: Cut-region: A Compact Building Block For Hierarchical Metric Indexing, in Lecture Notes in Computer Science, Vol. 2012, Num. 7404, ISSN: 0302-9743, pp. 85-100, 2012
  • Lokoč J., Skopal T., Christian B., Thomas S.: Similarity Search by Earth Movers Distance using Nonmetric Ground Distances, in MMEDIA 2012, The Fourth International Conferences on Advances in Multimedia, Chamonix, XPS, ISBN: 978-1-61208-195-3, pp. 50-55, 2012
  • Lokoč J., Tomáš G., Skopal T.: Image Exploration using Online Feature Extraction and Reranking, in ICMR '12 Proceedings of the 2nd ACM International Conference on Multimedia Retrieval, Hongkong, China, ACM, ISBN: 978-1-4503-1329-2, pp. 1-2, 2012
  • Lokoč J., Tomáš G., Skopal T.: SIR: The Smart Image Retrieval Engine, in Lecture Notes in Computer Science, Vol. 2012, Num. 7404, ISSN: 0302-9743, pp. 240-241, 2012
  • Novák J., Galgonek J., Hoksza D., Skopal T.: SimTandem: Similarity Search in Tandem Mass Spectra, in Lecture Notes in Computer Science, Vol. 2012, Num. 7404, ISSN: 0302-9743, pp. 242-243, 2012
  • Novák J., Hoksza D., Lokoč J., Skopal T.: On Optimizing the Non-metric Similarity Search in Tandem Mass Spectra by Clustering, in Lecture Notes in Computer Science, Vol. 2012, Num. 7292, ISSN: 0302-9743, pp. 189-200, 2012
  • Novák J., Skopal T., Hoksza D., Lokoč J.: Non-metric Similarity Search of Tandem Mass Spectra Including Posttranslational Modifications, in Journal of Discrete Algorithms, Vol. 2012, Num. 13, ISSN: 1570-8667, pp. 19-31, 2012 - On-line verze
  • Skopal T., Lokoč J., Bustos B.: D-cache: Universal Distance Cache for Metric Access Methods, in IEEE Transactions on Knowledge and Data Engineering, ISSN: 1041-4347, 2012

2011

Refereed (journals/proceedings) (16)

  • Bartoš T., Eckhardt A., Skopal T.: Fuzzy approach to non-metric similarity indexing, in Fourth International Conference on Similarity Search and Applications 2011, Lipari, Italy, ACM, ISBN: 978-1-4503-0795-6, pp. 115-116, 2011
  • Beecks C., Lokoč J., Seidl T., Skopal T.: Indexing the Signature Quadratic Form Distance for Efficient Content-Based Multimedia Retrieval, in Proceedings of the 1st ACM International Conference on Multimedia Retrieval, Trento, Italy, ACM, ISBN: 978-1-4503-0336-1, pp. 1-8, 2011
  • Beecks C., Skopal T., Schoeffmann K., Seidl T.: Towards Large-Scale Multimedia Exploration, accepted for publication in VLDB proceedings, Seattle, USA, VLDB Endownment, pp. 1-3, 2011
  • Brocke J., Simons A., Skopal T., Stein A., Stieglitz S., Suomi R., Vossen G., Winter R., Wrycza S., Becker J., Braccini A., Butleris R., Hofreiter B., Kapocius K., Marco M., Schmidt G., Seidel S.: Current and Future Issues in BPM Research: A European Perspective from the ERCIS Meeting 2010, in Communications of the Association for Information Systems, Vol. 28, Num. 1, ISSN: 1529-3181, pp. 1-15, 2011
  • Bustos B., Skopal T.: Nonmetric Similarity Search Problems in Very Large Collections, in ICDE 2011, Hannover, Germany, IEEE, ISBN: 978-1-4244-8958-9, ISSN: 1084-4627, pp. 1362-1365, 2011
  • Dohnal V., Skopal T.: Special Issue: Selected Papers from the 2nd International Workshop on Similarity Search and Applications (SISAP 2009) Preface, in Information Systems, Vol. 36, Num. 4, ISSN: 0306-4379, pp. 707-707, 2011
  • Galgonek J., Hoksza D., Skopal T.: SProt: sphere-based protein structure similarity algorithm, in Proteome Science, Vol. 9, Num. Suppl. 1, ISSN: 1477-5956, pp. nestránkováno, 2011
  • Kruliš M., Lokoč J., Beecks C., Skopal T., Seidl T.: Processing the Signature Quadratic Form Distance on Many-Core GPU Architectures, in Compilation Proceedings of CIKM 2011 and the co-located Workshops, Glasgow, ACM, ISBN: 978-1-4503-0717-8, pp. 2373-2376, 2011
  • Lokoč J., Beecks C., Seidl T., Skopal T.: Parameterized Earth Mover&apos;s Distance for Efficient Metric Space Indexing, in Fourth International Conference on Similarity Search and Applications 2011, Lipari, Italy, ACM, ISBN: 978-1-4503-0795-6, pp. 121-122, 2011
  • Lokoč J., Hetland M., Skopal T., Beecks C.: Ptolemaic Indexing of the Signature Quadratic Form Distance, in Fourth International Conference on Similarity Search and Applications 2011, Lipari, Italy, ACM, ISBN: 978-1-4503-0795-6, pp. 9-16, 2011
  • Moško J., Lokoč J., Skopal T.: Clustered Pivot Tables for I/O-optimized Similarity Search, in Fourth International Conference on Similarity Search and Applications 2011, Lipari, Italy, ACM, ISBN: 978-1-4503-0795-6, pp. 17-24, 2011
  • Novák J., Skopal T., Hoksza D., Lokoč J., Galgonek J.: Protein Sequences Identification using NM-tree, in Fourth International Conference on Similarity Search and Applications 2011, Lipari, Italy, ACM, ISBN: 978-1-4503-0795-6, pp. 125-126, 2011 - On-line verze
  • Pokorný J., Novotný O., Maryška M., Vojtáš P., Skopal T., Nečaský M., Matoušek K., Kubalík J., Šíma J., Žák S., Víta M.: SoSIReČR -sociální sít informatiků v regionech ČR, in Systémová integrace, Vol. 18, Num. 2, ISSN: 1210-9479, pp. 259-269, 2011
  • Pokorný J., Vojtáš P., Nečaský M., Skopal T., Matoušek K., Kubalík J., Novotný O., Maryška M.: SoSIReČR - IT Professional Social Network, in Proceedings of the 2011 International Conference on Computational Aspects of Social Networks (CASoN)., Salamanca, IEEE, ISBN: 978-1-4577-1132-9, pp. 108-113, 2011
  • Skopal T., Bartoš T., Lokoč J.: On (not) indexing quadratic form distance by metric access methods, in Proceedings of the 14th International Conference on Extending Database Technology, Hannover, Germany, ACM, ISBN: 978-1-4503-0528-0, pp. 249-258, 2011
  • Skopal T., Bustos B.: On Nonmetric Similarity Search Problems in Complex Domains, in ACM Computing Surveys, Vol. 43, Num. 4, ISSN: 0360-0300, pp. 1-50, 2011

2010

Refereed (journals/proceedings) (5)

  • Benjamin B., Skopal T.: Beyond the Metric Space Model, in SIGSPATIAL Special, Vol. 2, Num. 2, ISSN: 1946-7729, pp. 20-23, 2010 - WWW
  • Lokoč J., Skopal T.: On Applications of Parameterized Hyperplane Partitioning, in Third International Conference on Similarity Search and Applications, Istanbul, Turkey, ACM, ISBN: 978-1-4503-0420-7, pp. 131-132, 2010 - WWW
  • Novák J., Skopal T., Hoksza D., Lokoč J.: Improving the Similarity Search of Tandem Mass Spectra using Metric Access Methods, in Third International Conference on Similarity Search and Applications, Istanbul, Turkey, ACM, ISBN: 978-1-4503-0420-7, pp. 85-92, 2010 - On-line PDF verze
  • Skopal T.: Where are you heading, metric access methods? A provocative survey, in Third International Conference on Similarity Search and Applications, Istanbul, Turkey, ACM, ISBN: 978-1-4503-0420-7, pp. 13-21, 2010 - WWW
  • Skopal T., Lokoč J.: Answering Metric Skyline Queries by PM-tree, in Proceedings of the Dateso 2010 Annual International Workshop on DAtabases, TExts, Specifications and Objects, Stedronin-Plazy, Czech Republic, MATFYZPRESS, ISBN: 978-80-7378-116-3, ISSN: 1613-0073, pp. 22-37, 2010

2009

Refereed (journals/proceedings) (4)

  • Danko O., Skopal T.: Elliptic Indexing of Multidimensional Databases, in 20th Australian Database Conference, Wellington, New Zealand, Australian Computer Society, CRPIT, ISBN: 978-1-920682-73-6, ISSN: 1445-1336, pp. 1-8, January 2009
  • Eckhardt A., Skopal T., Vojtáš P.: On fuzzy vs. metric similarity search in complex databases, in FQAS 2009 - Eighth International Conference Flexible Query Answering Systems 2009, Springer, ISBN: 978-3-642-04956-9, pp. 64-75, October 2009
  • Skopal T., Bustos B.: On Index-free Similarity Search in Metric Spaces, in DEXA 2009, ISBN: 978-3-642-03572-2, ISSN: 0302-9743, pp. 516-531, 2009
  • Skopal T., Dohnal V., Batko M., Zezula P.: Distinct Nearest Neighbors Queries for Similarity Search in Very Large Multimedia Databases, in ACM WIDM 2009, ISBN: 978-1-60558-808-7, pp. 1-4, 2009

Technical reports (1)

  • Skopal T., Lokoč J.: Efficient Metric Skyline Processing using the PM-tree, technical report no. 2009/1, MFF UK, 10 pages, 2009

2008

Refereed (journals/proceedings) (4)

  • Hoksza D., Skopal T.: Native Multidimensional Indexing in Relational Databases, in COMAD 2008, Bombay, India, Computer Society of India, ACM SIGMOD online, ISBN: 978-81-8424-370-3, pp. 251-261, December 2008
  • Lokoč J., Skopal T.: On Reinsertions in M-tree, in 2008 IEEE 24th international conference on data engineering workshop, vols 1 and 2, ISBN: 978-1-4244-2162-6, pp. 570-577, 2008
  • Lokoč J., Skopal T.: On Reinsertions in Mtree, in SISAP 2008: First international workshop on similarity search and applications, Cancun, Mexico, IEEE, ISBN: 0-7695-3101-6, pp. 121-128, April 2008
  • Skopal T., Lokoč J.: NM-tree: Flexible Approximate Similarity Search in Metric and Non-metric Spaces, in 19th International Conference on Database and Expert Systems Applications, ISBN: 978-3-540-85653-5, ISSN: 0302-9743, pp. 312-325, 2008

2007

Refereed (journals/proceedings) (5)

  • Hoksza D., Skopal T.: Index-based approach to similarity search in protein and nucleotide databases, in DATESO 2007, Desna, Czech Republic, Matfyz Press, Praha, ISBN: 978-80-7378-002-9, ISSN: 1613-0073, pp. 67-80, April 2007
  • Klíma J., Skopal T.: Shape Extraction Framework for Similarity Search in Image Databases, in DATESO 2007, Desna, Czech Republic, Matfyz Press, Praha, ISBN: 978-80-7378-002-9, ISSN: 1613-0073, pp. 89-102, April 2007
  • Skopal T.: Unified Framework for Fast Exact and Approximate Search in Dissimilarity Spaces, in ACM Transactions on Database Systems, Vol. 32, Num. 4, ISSN: 0362-5915, pp. 1-47, 2007
  • Skopal T., Hoksza D.: Improving the Performance of M-tree Family by Nearest-Neighbor Graphs, in 11th East-European Conference on Advances in Databases and Information Systems ADBIS 2007, Springer, ISBN: 978-3-540-75184-7, ISSN: 0302-9743, pp. 172-188, 2007
  • Skopal T., Hoksza D., Pokorný J.: Construction of Tree-based Indexes for Level-Contiguous Buffering Support, in 13th International Conference on Database Systems for Advance Applications, New Delhi, India, Springer, ISBN: 978-3-540-78567-5, ISSN: 0302-9743, pp. 361-373, March 2007

2006

Refereed (journals/proceedings) (4)

  • Bustos B., Skopal T.: Dynamic Similarity Search in Multi-Metric Spaces, in 8th ACM international workshop on Multimedia information retrieval (a part of ACM Multimedia conference), Santa Barbara, CA, USA, ACM Press, ISBN: 1-59593-495-2, pp. 137-146, 2006
  • Skopal T.: On Fast Non-Metric Similarity Search by Metric Access Methods, in 10. International Conference on Extending Database Technology (EDBT), Springer, ISBN: 978-3-540-32960-2, ISSN: 0302-9743, pp. 718-736, 2006
  • Skopal T., Krátký M., Pokorný J., Snášel V.: A New Range Query Algorithm for Universal B-trees, in Information Systems, Vol. 31, Num. 6, ISSN: 0306-4379, pp. 489-511, 2006
  • Skopal T., Snášel V.: An Application of LSI and M-tree in Image Retrieval, in GESTS International Transaction on Computer Science and Engineering, Vol. 34, Num. 1, ISSN: 1738-6438, pp. 212-223, 2006

2005

Refereed (journals/proceedings) (3)

  • Skopal T., Kolovrat M., Snášel V.: Využití LSI a M-stromu při indexování a vyhledávání obrázků, in ZNALOSTI 2005, ISBN: 80-248-0755-6, pp. 84-95, 2005
  • Skopal T., Moravec P.: Modified LSI Model for Efficient Search by Metric Access Methods, in ECIR 2005, ISBN: 978-3-540-25295-5, pp. 245-259, 2005
  • Skopal T., Pokorný J., Snášel V.: Nearest Neighbours Search using the PM-tree, in DASFAA 2005, ISBN: 978-3-540-25334-1, pp. 803-815, 2005

2004

Refereed (journals/proceedings) (6)

  • Krátký M., Pokorný J., Skopal T., Snášel V.: Implementace os XPath ve vícerozměrném přístupu pro indexování XML dat, in Znalosti, FEI VŠB-TU, ISBN: 8024804565, pp. 338-349, 2004
  • Krátký M., Skopal T., Snášel V.: Multidimensional Term Indexing for Efficient Processing of Complex Queries, in KYBERNETIKA, Vol. 40, Num. 3, ISSN: 0023-5954, pp. 381-396, 2004
  • Skopal T.: Pivoting M-tree: A Metric Access Method for Efficient Similarity Search, in DATESO 2004, ISBN: 80-248-0457-3 , pp. 21-31, April 2004
  • Skopal T., Krátký M., Snášel V.: Metrické a semi-metrické indexování vektorových modelů pro dokumentografické informační systémy, in Znalosti 2004, vydavatelství UP, ISBN: 80-248-0456-5, pp. 154-165, 2004
  • Skopal T., Moravec P., Pokorný J., Snášel V.: Metric Indexing for the Vector Model in Text Retrieval, in SPIRE, Springer-Verlag, ISBN: 3-540-23210-9, pp. 183-195, 2004
  • Skopal T., Pokorný J., Snášel V.: PM-tree: Pivoting Metric Tree for Similarity Search in Multimedia Databases, in ADBIS, Computer and Automation Research Institute Hungarian Academy of Science, ISBN: 963 311 358 X, pp. 99-114, 2004

2003

Refereed (journals/proceedings) (2)

  • Pokorný J., Skopal T., Krátký M., Moravec P.: An Efficient Implementation of the Vector Model in Information Retrieval., in Digital Libraries: Advanced Methods and Technologies, Digital Collections., Saint-Petersburg, State University Published Press, ISBN: 5-94158-056-8, pp. 170-179, 2003
  • Pokorný J., Skopal T., Krátký M., Snášel V.: Revisiting M-tree Building Principles., in Proc. of ADBIS 2003, Springer Verlag, ISBN: 3-54-020047-9, pp. 148-162, 2003

2002

Refereed (journals/proceedings) (2)

  • Pokorný J., Krátký M., Skopal T., Snášel V.: The Geometric Framework for Exact and Similarity Querying XML data, in EurAsia-ICT 2002:Information and Communication Technology, Springer, pp. 35-46, 2002
  • Pokorný J., Snášel V., Krátký M., Skopal T.: Indexing XML data with UB-trees, in Proc. of the 6th East European Conf. on Advances in Databases and Information Systems, Slovak University of Technology, ISBN: 80-227-1744-4, pp. 155-164, 2002

Software

IVP Framework, PGRTree

Contactstop

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