Publications

Conferences/Journals/Book Chapters (peer-reviewed)

2021

  • Danila Piatov, Sven Helmer, Anton Dignös, Fabio Persia: Cache-efficient sweeping-based interval joins for extended Allen relation predicates. VLDB Journal, Vol. 30, No. 3, May 2021: 379-402

  • Vuong Minh Ngo, Sven Helmer, Nhien-An Le-Khac, M-Tahar Kechadi: Structural textile pattern recognition and processing based on hypergraphs. Information Retrieval Journal, Vol. 24, No. 2, April 2021: 137-173

2020

  • Sven Helmer, David B. Blumenthal, Kathrin Paschen: What is meaningful research and how should we measure it? Scientometrics, Vol. 125, No. 1, October 2020: 153–169

  • Matteo Nardini, Sven Helmer, Nabil El Ioini, Claus Pahl: A Blockchain-based Decentralized Electronic Marketplace for Computing Resources. SN Computer Science, Vol. 1, No. 5, September 2020

  • Fabio Persia, Giovanni Pilato, Mouzhi Ge, Paolo Bolzoni, Daniela D'Auria, Sven Helmer: Improving Orienteering-based Tourist Trip Planning with Social Sensing. Future Generation Computer Systems, Vol. 110, September 2020: 931-945

  • Kevin Wellenzohn, Michael H. Böhlen, Sven Helmer: Dynamic Interleaving of Content and Structure for Robust Indexing of Semi-Structured Hierarchical Data. Proc. of the VLDB Endowment (PVLDB), Vol. 13, No. 10, June 2020: 1641-1653

2019

  • Fabio Persia, Sven Helmer: High-level Automatic Event Detection and User Classification in a Social Network Context. 6th Int. Workshop on Graphical Models for Security (GraMSec'19), Hoboken, New Jersey, June 2019

  • Claus Pahl, Nabil El Ioini, Sven Helmer, Brian Lee: A Semantic Pattern for Trusted Orchestration in IoT Edge Clouds. Internet Technology Letters, Vol. 2, No. 3, May/June 2019

  • Danila Piatov, Sven Helmer, Anton Dignös, Johann Gamper: Interactive and space-efficient multi-dimensional time series subsequence matching. Information Systems, Vol. 82, May 2019: 121-135

  • Daniela D'Auria, Fabio Persia, Fabio Bettini, Sven Helmer: Predicting and Preventing Dangerous Events via Video Surveillance Using a Robotic Platform. 3rd Int. Conf. on Robotic Computing (IRC'19), Naples, Italy, February 2019: 549-554

  • Fabio Persia, Sven Helmer, Sergejs Pugacs, Giovanni Pilato: Social Sensing for Improving the User Experience in Orienteering. 13th Int. Conf. on Semantic Computing (ICSC'19), Newport Beach, California, January/February 2019

  • Sven Helmer, David B. Blumenthal, Kathrin Paschen: Academia 4.0: Measuring and Monitoring the Academic Assembly Line. Re-Coding Black Mirror Workshop (RCBlackMirror'19), Brussels, Belgium, January 2019

  • David von Leon, Lorenzo Miori, Julian Sanin, Nabil El Ioini, Sven Helmer, Claus Pahl: A Lightweight Container Middleware for Edge Cloud Architectures. in Fog and Edge Computing (edited by Rajkumar Buyya, Satish Narayana Srirama), Wiley, Hoboken, NJ, 2019: 145-170

2018

  • Sven Helmer, Matteo Roggia, Nabil El Ioini, Claus Pahl: EthernityDB - Integrating Database Functionality into a Blockchain. 22nd European Conf. on Advances in Databases and Information Systems (ADBIS'18 short papers), Budapest, Hungary, September 2018: 37-44

  • Sven Helmer: May I Have Your Attention, Please? - Building a Dystopian Attention Economy. Re-Coding Black Mirror Workshop (RCBlackMirror'18), (WWW'18 Companion Volume), Lyon, France, April 2018: 1529-1533

  • Claus Pahl, Nabil El Ioini, Sven Helmer, Brian Lee: An Architecture Pattern for Trusted Orchestration in IoT Edge Clouds. 3rd Int. Conf. on Fog and Mobile Edge Computing (FMEC'18), Barcelona, Spain, April 2018

  • Claus Pahl, Nabil El Ioini, Sven Helmer: A Decision Framework for Blockchain Platforms for IoT and Edge Computing. 3rd Int. Conf. on Internet of Things, Big Data and Security (IoTBDS'18), Funchal, Madeira, March 2018

  • David von Leon, Lorenzo Miori, Julian Sanin, Nabil El Ioini, Sven Helmer, Claus Pahl: A Performance Exploration of Architectural Options for a Middleware for Decentralised Lightweight Edge Cloud Architectures. 3rd Int. Conf. on Internet of Things, Big Data and Security (IoTBDS'18), Funchal, Madeira, March 2018

  • Daniela D'Auria, Bruno Siciliano, Fabio Persia, Fabio Bettini, Sven Helmer: SARRI: a SmArt Rapiro Robot Integrating a framework for automatic high-level surveillance event detection. 2nd Int. Conf. on Robotic Computing (IRC'18), Laguna Hills, California, January/February 2018: 238-241

  • Fabio Persia, Sven Helmer: A Framework for High-level Event Detection in a Social Network Context Via an Extension of ISEQL. 12th Int. Conf. on Semantic Computing (ICSC'18), Laguna Hills, California, January/February 2018: 140-147

2017

  • Fabio Persia, Fabio Bettini, Sven Helmer: An Interactive Framework for Video Surveillance Event Detection and Modeling. 26th ACM Int. Conf. on Information and Knowledge Management (CIKM'17), Singapore, November 2017: 2515-2518

  • Danila Piatov, Sven Helmer, Johann Gamper: Interactive Time Series Subsequence Matching. 21st European Conf. on Advances in Databases and Information Systems (ADBIS'17), Nicosia, Cyprus, September 2017: 73-87 (best paper award)

  • Sven Helmer, Gerhard Glüher, Christian Upmeier: Show, Don't Tell: Retrieving Cultural Assets Via Gestures. 4th Interdisciplinary Workshop The Shape of Things (SHAPES 4.0), Bolzano, Italy, September 2017

  • Paolo Bolzoni, Fabio Persia, Sven Helmer: Itinerary Planning with Category Constraints Using a Probabilistic Approach. 28th Int. Conf. on Database and Expert Systems Applications (DEXA'17), Lyon, France, August 2017: 363-377

  • Danila Piatov, Sven Helmer: Sweeping-Based Temporal Aggregation. 15th Int. Symposium on Spatial and Temporal Databases (SSTD'17), Arlington, Virginia, August 2017: 125-144

  • Paolo Bolzoni, Sven Helmer: Hybrid Best-First Greedy Search for Orienteering with Category Constraints. 15th Int. Symposium on Spatial and Temporal Databases (SSTD'17), Arlington, Virginia, August 2017: 24-42

  • Lorenzo Miori, Julian Sanin, Sven Helmer: A Platform for Edge Computing Based on Raspberry Pi Clusters. 31st British Int. Conf. on Databases (BICOD'17), London, United Kingdom, July 2017: 153-159

  • Sergejs Pugacs, Sven Helmer, Markus Zanker: A Framework for Comparing Interactive Route Planning Apps in Tourism. 2nd Workshop on Engineering Computer-Human Interaction in Recommender Systems (EnCHIReS'17), Lisbon, Portugal, June 2017

  • Vincenzo Del Fatto, Gabriella Dodero, Rosella Gennari, Benjamin Gruber, Sven Helmer, Guerriero Raimato: Automating Assessment of Exercises as Means to Decrease MOOC Teachers' Efforts. 2nd Int. Conf. on Smart Learning Ecosystems and Regional Development (SLERD'17), Aveiro, Portugal, June 2017

  • Fabio Persia, Fabio Bettini, Sven Helmer: Labeling the Frames of a Video Stream with Interval Events. 11th Int. Conf. on Semantic Computing (ICSC'17), San Diego, California, January 2017

2016

  • Sven Helmer, Claus Pahl, Julian Sanin, Lorenzo Miori, Stefan Brocanelli, Filippo Cardano, Daniele Gadler, Daniel Morandini, Alessandro Piccoli, Saifur Salam, Alam Mahabub Shahrear, Angelo Ventura, Pekka Abrahamsson, Tosin Daniel Oyetoyan: Bringing the Cloud to Rural and Remote Areas via Cloudlets. 7th ACM Symposium on Computing for Development (ACM DEV'16), Nairobi, Kenya, November 2016

  • Sven Helmer, Fabio Persia: ISEQL, an Interval-based Surveillance Event Query Language. Int. Journal of Multimedia Data Engineering and Management (IJMDEM), Vol. 7, No. 4, October 2016: 1-21

  • Pekka Abrahamsson, Sven Helmer, Alexandru Stan: Rails Girls 54: Making Rails Girls Even More Fun. 3rd Conf. on Creative Mathematical Sciences Communication (CMSC'16), Lübeck, Germany, October 2016

  • Paolo Bolzoni, Sven Helmer, Oded Lachish: Fast Computation of Continental-Sized Isochrones. 9th Int. Conf. on Geographic Information Science (GIScience'16), Montreal, Quebec, September 2016

  • Claus Pahl, Sven Helmer, Lorenzo Miori, Julian Sanin, Brian Lee: A Container-based Edge Cloud PaaS Architecture Based on Raspberry Pi Clusters. 3rd Int. Symposium on Intercloud and IoT (ICI'16), Vienna, Austria, August 2016

  • Fabio Persia, Sven Helmer: An Event Detection Framework Supported by a Smart Graphical User Interface. 3rd Int. Workshop on Information Integration in Cyber Physical Systems (IICPS'16), Pittsburgh, Pennsylvania, July 2016

  • Anja Kunkel, Astrid Rheinländer, Christopher Schiefer, Sven Helmer, Panagiotis Bouros, Ulf Leser: PIEJoin: Towards Parallel Set Containment Joins. Proc. 28th Int. Conf. on Scientific and Statistical Database Management (SSDBM'16), Budapest, Hungary, July 2016

  • Sven Helmer, Fabio Persia: An Interval-based Query Language for High-level Surveillance Event Detection. 24th Italian Symposium on Advanced Database Systems (SEBD'16), Ugento, Italy, June 2016: 126-133

  • Danila Piatov, Sven Helmer, Anton Dignös: An Interval Join Optimized for Modern Hardware. Proc. 32nd Int. Conf. on Data Engineering (ICDE'16), Helsinki, Finland, May 2016: 1098-1109

  • Sven Helmer, Fabio Persia: High-Level Surveillance Event Detection Using an Interval-Based Query Language. 10th Int. Conf. on Semantic Computing (ICSC'16), Laguna Hills, California, February 2016: 39-46

2015

  • Khaled H. Alyoubi, Sven Helmer, Peter T. Wood: Ordering Selection Operators Under Partial Ignorance. 24th ACM Int. Conf. on Information and Knowledge Management (CIKM'15), Melbourne, Australia, October 2015: 1521-1530

  • Sven Helmer, Vuong Minh Ngo: A Similarity Measure for Weaving Patterns in Textiles. 38th Int. ACM SIGIR Conf. on Research and Development in Information Retrieval (SIGIR'15), Santiago, Chile, August 2015: 163-172

  • Nattakarn Phaphoom, Xiaofeng Wang, Sarah Samuel, Sven Helmer, Pekka Abrahamsson: A Survey Study on Major Technical Barriers Affecting the Decision to Adopt Cloud Services. Journal of Systems and Software, Vol. 103, May 2015: 167-181

  • Richard Brownlow, Stefano Capuzzi, Sven Helmer, Luciana Martins, Immanuel Normann, Alex Poulovassilis: An Ontological Approach to Creating an Andean Weaving Knowledge Base. Journal on Computing and Cultural Heritage (JOCCH), Vol. 8, No. 2, March 2015

2014

  • Paolo Bolzoni, Sven Helmer, Kevin Wellenzohn, Johann Gamper, Periklis Andritsos: Efficient Itinerary Planning with Category Constraints. 22nd ACM SIGSPATIAL Int. Conf. on Advances in Geographic Information Systems (ACM SIGSPATIAL'14), Dallas, Texas, November 2014

  • Mohammad Jaber, Panagiotis Papapetrou, Sven Helmer, Peter T. Wood: Using Time-Sensitive Rooted PageRank to Detect Hierarchical Social Relationships. 13th Int. Symposium on Advances in Intelligent Data Analysis (IDA'14), Leuven, Belgium, October 2014: 143-154

  • Pekka Abrahamsson, Sven Helmer, Lorenzo Miori, Lorenzo Nicolodi, Nick Preda, Angelo Ventura: Raspberries in the Field. Synergize 2014, Lancaster, United Kingdom, September 2014

  • Mohammad Jaber, Peter T. Wood, Panagiotis Papapetrou, Sven Helmer: Inferring offline hierarchical ties from online social networks. 23rd Int. World Wide Web Conf., (WWW'14), (Companion Volume), Seoul, South Korea, April 2014: 1261-1266

2013

  • Pekka Abrahamsson, Sven Helmer, Nattakarn Phaphoom, Lorenzo Nicolodi, Nick Preda, Lorenzo Miori, Matteo Angriman, Juha Rikkilä, Xiaofeng Wang, Karim Hamily, Sara Bugoloni: Affordable and Energy-Efficient Cloud Computing Clusters: The Bolzano Raspberry Pi Cloud Cluster Experiment. UsiNg and building ClOud Testbeds (UNICO) Workshop (at CloudCom Conf.), Bristol, United Kingdom, December 2013

  • Luciana Martins, Sven Helmer, Denise Y. Arnold: Exploring Weaving Structures in the Andes: Reflections on the Creation of a Digital Archive. Visual Resources: An International Journal of Documentation (Special Issue: Digital Art History), Vol. 29, No. 1-2, March-June 2013: 59-71

2012

  • Sven Helmer, Nikolaus Augsten, Michael H. Böhlen: Measuring structural similarity of semistructured data based on information-theoretic approaches. VLDB Journal, Vol. 21, No. 5, October 2012: 677-702

  • Georgia Garani, Sven Helmer: Integrating Star and Snowflake Schemas in Data Warehouses. International Journal of Data Warehousing and Mining, Vol. 8, No. 4, 2012: 22 - 40

  • Carlos D. Barranco, Sven Helmer: An Impact Ordering Approach for Indexing Fuzzy Sets. Fuzzy Sets and Systems, Vol. 196, 2012: 33 - 46

  • Luciana Martins, Sven Helmer, Denise Y. Arnold: Exploring Weaving Structures in the Andes: Reflections on the Creation of a Digital Archive. Digital Hispanisms panel, Association of Hispanists of Great Britain and Ireland (AHGBI) Annual Conference, Stirling, United Kingdom, April 2012

2011

  • Andrew McDonald, Sven Helmer: Activators and Inhibitors for Successful Project Management of IT Projects in Indonesia and the UK: a Comparative Case Study. European J. of Cross-Cultural Competence and Management (EJCCM), Vol. 2, No.1, 2011: 77 - 94

  • Sven Helmer, Alexandra Poulovassilis, Fatos Xhafa (eds.): Reasoning in Event-Based Distributed Systems. Studies in Computational Intelligence, Vol. 347, Springer, Heidelberg, 2011

  • Andrew McDonald, Sven Helmer: A Comparative Case Study of Indonesian and UK Organisational Culture Differences in IS Project Management. International Journal of Technology and Human Interaction (IJTHI), Vol. 7, No. 2, 2011: 28-37

2009

  • Tadeusz Litak, Sven Helmer: On the Termination Problem for Declarative XML Message Processing. Proc. 20th Int. Conf. on Database and Expert Systems Applications (DEXA), Linz, Austria, September 2009: 83-97

  • Carlos D. Barranco, Sven Helmer: Increasing the Performance of Fuzzy Retrieval Using Impact Ordering. Proc. Joint 13th International Fuzzy Systems Association World Congress (IFSA) and 6th European Society for Fuzzy Logic and Technology Conference (EUSFLAT), Lisbon, Portugal, July 2009: 957-962

  • Denise Y. Arnold, Sven Helmer, Rodolfo Velasquez Arando: Towards Building a Knowledge Base for Research on Andean Weaving. Proc. 26th British National Conf. on Databases (BNCOD), Birmingham, United Kingdom, July 2009: 180-188

  • Andrew McDonald, Sven Helmer: Cultural Differences in Information Technology Project Management between Indonesia and the UK. UKAIS workshop on 'Culture in Information Systems Research', Leicester, United Kingdom, 2009

2008

  • Alexandre Guitton, Niki Trigoni, Sven Helmer: Fault-Tolerant Compression Algorithms for Delay-Sensitive Sensor Networks with Unreliable Links. Proc. 4th Int. Conf. on Distributed Computing in Sensor Systems (DCOSS), Santorini Island, Greece, 2008: 190-203

2007

  • Sven Helmer, Robin Aly, Thomas Neumann, Guido Moerkotte: Indexing Set-Valued Attributes with a Multi-level Extendible Hashing Scheme. Proc. 18th Int. Conf. on Database and Expert Systems Applications (DEXA), Regensburg, Germany, 2007: 98-108

  • Sven Helmer: An Interval-Based Index Structure for Structure Elucidation in Chemical Databases. 12th International Fuzzy Systems Association World Congress (IFSA), Cancun, Mexico, 2007: 625-634

  • Sven Helmer: Measuring the Structural Similarity of Semistructured Documents Using Entropy. Proc. 33rd Int. Conf. on Very Large Data Bases (VLDB), Vienna, Austria, 2007: 1022-1032

2006

  • Norman May, Sven Helmer, Guido Moerkotte: Strategies for Query Unnesting in XML databases. ACM Transactions on Database Systems, Vol. 31, No. 3, September 2006: 968-1013

  • Matthias Brantner, Sven Helmer, Carl-Christian Kanne, Guido Moerkotte: Kappa-Join: Efficient Execution of Existential Quantification in XML Query Languages. 4th International XML Database Symposium (XSym), Seoul, South Korea, September 2006: 1-15

  • Thomas Neumann, Sven Helmer, Guido Moerkotte: On the Optimal Ordering of Maps, Selections, and Joins under Factorization. Proc. 23rd British National Conf. on Databases (BNCOD), Belfast, United Kingdom, July 2006: 115-126

  • Matthias Brantner, Carl-Christian Kanne, Guido Moerkotte, Sven Helmer: Algebraic Optimization of Nested XPath Expressions. Proc. 22nd Int. Conf. on Data Engineering (ICDE), Atlanta, Georgia, April 2006: 128

  • Matthias Brantner, Carl-Christian Kanne, Sven Helmer, Guido Moerkotte: Ontologies for Location-Based Services. in Handbook of Research in Mobile Business: Technical, Methodological, and Social Perspectives (edited by Bhuvan Unhelkar), Idea Group Publishing, Hershey, 2006

2005

  • Matthias Brantner, Carl-Christian Kanne, Sven Helmer, Guido Moerkotte: Algebraic Translation and Optimization of (Nested) XPath Expressions. Dutch Belgian Database Day, Amsterdam, Netherlands, 2005

  • Vasco Amaral, Sven Helmer, Guido Moerkotte: Formally Specifying the Syntax and Semantics of a Visual Query Language for the Domain of High Energy Physics Data Analysis. 2005 IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC), Dallas, Texas, September 2005: 251-258

  • Aleksei Pavlov, Sven Helmer, Guido Moerkotte: A Model-Based Monitoring and Diagnosis System for a Space-Based Astrometry Mission. Proc. 16th Int. Conf. on Database and Expert Systems Applications (DEXA), Copenhagen, Denmark, August 2005: 920-929

  • Thomas Neumann, Sven Helmer, Guido Moerkotte: On the Optimal Ordering of Maps and Selections under Factorization. Proc. 21st Int. Conf. on Data Engineering (ICDE), Tokyo, Japan, April 2005: 490-501

  • Matthias Brantner, Sven Helmer, Carl-Christian Kanne, Guido Moerkotte: Full-fledged Algebraic XPath Processing in Natix. Proc. 21st Int. Conf. on Data Engineering (ICDE), Tokyo, Japan, April 2005: 705-716

2004

  • Sven Helmer: Index Structures for Fuzzy Object-Oriented Database Systems. in Advances in Fuzzy Object-Oriented Databases (edited by Zongmin Ma), Idea Group Publishing, Hershey, 2004: 206-240

  • Vasco Amaral, Sven Helmer, Guido Moerkotte: Domain Specific Visual Query Language for HEP Analysis or How Far Can We Go with User Friendliness? Int. Conf. on Computing in High Energy and Nuclear Physics (CHEP), Interlaken, Switzerland, September/October 2004: 524-527

  • Sven Helmer, Carl-Christian Kanne, Guido Moerkotte: Timestamp-based Protocols for Synchronizing Access on XML Documents. Proc. 15th Int. Conf. on Database and Expert Systems Applications (DEXA), Zaragoza, Spain, August/September 2004: 591-600

  • Vasco Amaral, Sven Helmer, Guido Moerkotte: Engineering a New Abstraction Layer to Optimize the HEP Analysis Process. IEEE Transactions on Nuclear Science, Vol. 51, No. 4, August 2004:1441-1448

  • Vasco Amaral, Sven Helmer, Guido Moerkotte: PHEASANT: A PHysicist's EAsy ANalysis Tool. Proc. 6th Int. Conf. On Flexible Query Answering Systems (FQAS), Lyon, France, June 2004: 229-242

  • Norman May, Sven Helmer, Carl-Christian Kanne, Guido Moerkotte: XQuery Processing in Natix with an Emphasis on Join Ordering. Proc. 1st Int. Workshop on XQuery Implementation, Experience, and Perspectives (XIME-P), Paris, France, June 2004: 49-54

  • Norman May, Sven Helmer, Guido Moerkotte: Nested Queries and Quantifiers in an Ordered Context. Proc. 20th Int. Conf. on Data Engineering (ICDE), Boston, Massachusetts, March/April 2004: 239-250

  • Sven Helmer, Carl-Christian Kanne, Guido Moerkotte: Evaluating Lock-based Protocols for Cooperation on XML Documents. SIGMOD Record, Vol. 33, No. 1, March 2004: 58-63

2003

  • Norman May, Sven Helmer, Guido Moerkotte: Quantifiers in XQuery. Proc. 4th Int. Conf. on Web Information Systems Engineering (WISE), Rome, Italy, 2003: 313-316

  • Sven Helmer: Evaluating Different Approaches for Indexing Fuzzy Sets. Fuzzy Sets and Systems, Vol. 140, No. 1, November 2003: 167-182

  • Sven Helmer, Thomas Neumann, Guido Moerkotte: A Robust Scheme for Multilevel Extendible Hashing. Proc. 18th Int. Sym. on Computer and Information Sciences (ISCIS), Antalya, Turkey, 2003: 220-227

  • Vasco Amaral, Sven Helmer, Guido Moerkotte: A Domain Specific Visual Query Language for High Energy Physicists. Proc. 3rd OOPSLA Workshop on Domain-Specific Modeling (DSM), Anaheim, California, 2003: 9-16

  • Vasco Amaral, Sven Helmer, Guido Moerkotte: A Visual Query Language for HEP Analysis. Proc. of the Nuclear Science Symposium (NSS'03) Portland, Oregon, 2003

  • Vasco Amaral, Sven Helmer, Guido Moerkotte: Engineering a New Abstraction Layer to Optimize the HEP Analysis Process. Proc. of the Nuclear Science Symposium (NSS'03) Portland, Oregon, 2003

  • Sven Helmer, Guido Moerkotte A Performance Study of Four Index Structures for Set-valued Attributes of Low Cardinality VLDB Journal, Vol. 12, No. 3, October 2003: 244-261

  • Sven Helmer, Thomas Neumann, Guido Moerkotte: Estimating the Output Cardinality of Partial Preaggregation with a Measure of Clusteredness. Proc. 29th Int. Conf. on Very Large Data Bases (VLDB), Berlin, Germany, 2003: 656-667

  • Norman May, Sven Helmer, Guido Moerkotte: Three Cases for Query Decorrelation in XQuery. 1st Int. XML Database Symposium (XSYM), Berlin, September 2003: 70-84

  • Sven Helmer, Carl-Christian Kanne, Guido Moerkotte: Lock-based Protocols for Cooperation on XML Documents. Proc. 14th Int. Workshop on Database and Expert Systems Applications (at DEXA Conf.), Prague, Czech Republic, September 2003: 230-234

  • Sven Helmer, Carl-Christian Kanne, Guido Moerkotte XML-Datenbanken und ihre Anwendung. Information Technology, Vol. 45, No. 3, June 2003: 137-142

2002

  • Thorsten Fiebig, Sven Helmer, Carl-Christian Kanne, Guido Moerkotte, Julia Neumann, Robert Schiele, Till Westmann: Anatomy of a Native XML Base Management System. VLDB Journal, Vol. 11, No. 4, December 2002: 292-314

  • Sven Helmer, Carl-Christian Kanne, Guido Moerkotte: Optimized Translation of XPath into Algebraic Expressions Parameterized by Programs Containing Navigational Primitives. Proc. 3rd Int. Conf. on Web Information Systems Engineering (WISE), Singapore, 2002: 215-224

  • Thorsten Fiebig, Sven Helmer, Carl-Christian Kanne, Guido Moerkotte, Julia Neumann, Robert Schiele, Till Westmann: Natix: A Technology Overview. Proceedings of NODe 2002 Web- and Database-Related Workshops, Erfurt, Germany, October 2002: 12-33

  • Sven Helmer, Guido Moerkotte: Indexstrukturen für XML in Web & Datenbanken (edited by Erhard Rahm, Gottfried Vossen), dpunkt Verlag, Heidelberg, 2002: 217-250

2001

  • Vasco Amaral, Guido Moerkotte, Antonio Amorim, Sven Helmer: Studies for Optimisation of Data Analysis Queries for HEP Using HERA-B Commissioning Data. Int. Conf. on Computing in High Energy and Nuclear Physics (CHEP), Beijing, China, 2001: 154-155

  • Sven Helmer: Indexing Fuzzy Data. Proc. Joint 9th IFSA World Congress and 20th NAFIPS Int. Conf., Vancouver, Canada, 2001: 2120-2125

2000

  • Till Westmann, Donald Kossmann, Sven Helmer, Guido Moerkotte: The Implementation and Performance of Compressed Databases. SIGMOD Record, Vol. 29, No. 3, September 2000: 55-67

1999

  • Birgit Boss, Sven Helmer: Index Structures for Efficiently Accessing Fuzzy Data Including Cost Models and Measurements. Fuzzy Sets and Systems, Vol. 108, No. 1, November 1999: 11-37

1998

  • Sven Helmer, Till Westmann, Guido Moerkotte: Diag-Join: An Opportunistic Join Algorithm for 1:N Relationships. Proc. 24th Int. Conf. on Very Large Data Bases (VLDB), New York, 1998: 98-109

1997

  • Sven Helmer, Guido Moerkotte: Evaluation of Main Memory Join Algorithms for Joins with Set Comparison Join Predicates. Proc. 23rd Int. Conf. on Very Large Data Bases (VLDB), Athens, Greece, 1997: 386-395

Technical Reports/Reviews/Translations

2020

  • Kevin Wellenzohn, Michael H. Böhlen, Sven Helmer: Dynamic Interleaving of Content and Structure for Robust Indexing of Semi-Structured Hierarchical Data (Extended Version). CoRR abs/2006.05134

2017

  • Paolo Bolzoni, Sven Helmer: Solving Orienteering with Category Constraints Using Prioritized Search. CoRR abs/1702.04304

2016

  • Pekka Abrahamsson, Sven Helmer, Tosin Daniel Oyetoyan, Stefan Brocanelli, Filippo Cardano, Daniele Gadler, Daniel Morandini, Alessandro Piccoli, Saifur Salam, Julian Sanin, Alam Mahabub Shahrear, Angelo Ventura: Bringing the Cloud to Rural and Remote Areas - Cloudlet by Cloudlet. CoRR abs/1605.03622

2015

  • Khaled H. Alyoubi, Sven Helmer, Peter T. Wood: Ordering Selection Operators Using the Minmax Regret Rule. CoRR abs/1507.08257

2008

  • Denise Arnold, Sven Helmer, Rodolfo Velasquez Arando: Towards Building a Knowledge Base for Research on Andean Weaving. Technical Report of Birkbeck, University of London: BBKCS-08-07, 2008

  • Alexandre Guitton, Niki Trigoni, Sven Helmer: Fault-tolerant Compression Algorithms for Sensor Networks with Unreliable Links. Technical Report of Birkbeck, University of London: BBKCS-08-01, 2008

2007

  • Sven Helmer, Robin Aly, Thomas Neumann, Guido Moerkotte: Indexing Set-Valued Attributes with a Multi-Level Extendible Hashing Scheme. Technical Report of Birkbeck, University of London: BBKCS-07-01, 2007

2003

  • Sven Helmer: Book Review of: Recent issues on fuzzy databases. Fuzzy Sets and Systems, Vol. 140, No. 1, November 2003: 229-230

  • Sven Helmer, Carl-Christian Kanne, Guido Moerkotte Lock-based Protocols for Cooperation on XML Documents Technical Report of the University of Mannheim: 06/03, 2003

  • Norman May, Sven Helmer, Guido Moerkotte Nested Queries and Quantifiers in an Ordered Context Technical Report of the University of Mannheim: 02/03, 2003

2002

  • Sven Helmer, Kathrin Paschen: Translation of: F.D. Rolland The Essence of Databases. Prentice-Hall, 1998 (into German: Datenbanksysteme im Klartext. Pearson Studium, 2002)

  • Sven Helmer, Carl-Christian Kanne, Guido Moerkotte Optimized Translation of XPath into Algebraic Expressions Parameterized by Programs Containing Navigational Primitives Technical Report of the University of Mannheim: 11/02, 2002

  • Sven Helmer, Thomas Neumann, Guido Moerkotte Early Grouping Gets the Skew Technical Report of the University of Mannheim: 09/02, 2002

  • Sven Helmer and Guido Moerkotte Compiling Away Set Containment and Intersection Joins Technical Report of the University of Mannheim: 04/02, 2002

  • Thorsten Fiebig, Sven Helmer, Carl-Christian Kanne, Julia Mildenberger, Guido Moerkotte, Robert Schiele, Till Westmann Anatomy of a Native XML Base Management System Technical Report of the University of Mannheim: 01/02, 2002

2001

  • Sven Helmer, Thomas Neumann, and Guido Moerkotte A Robust Scheme for Multilevel Extendible Hashing Technical Report of the University of Mannheim: 19/01, 2001

  • Sven Helmer, Carl-Christian Kanne, and Guido Moerkotte Isolation in XML Bases Technical Report of the University of Mannheim: 15/01, 2001

1999

  • Sven Helmer and Guido Moerkotte A Study of Four Index Structures for Set-Valued Attributes of Low Cardinality Technical Report of the University of Mannheim: 2/99, 1999

1998

  • Till Westmann, Donald Kossmann, Sven Helmer, and Guido Moerkotte The Implementation and Performance of Compressed Databases . Technical Report of the University of Mannheim: 3/98, 1998

1997

  • Sven Helmer, Till Westmann, and Guido Moerkotte Diag-Join: An Opportunistic Join Algorithm for 1:N Relationships . Technical Report of the University of Mannheim: 6/97, 1997

  • Sven Helmer: Index Structures for Databases Containing Data Items with Set-valued Attributes . Technical Report of the University of Mannheim: 2/97, 1997

1996

  • Sven Helmer and Guido Moerkotte: Evaluation of Main Memory Join Algorithms for Joins with Set Comparison Predicates . Technical Report of the University of Mannheim: 13/96, 1996

  • Birgit Boss and Sven Helmer: Indexing a Fuzzy Database Using the Technique of Superimposed Coding - Cost Models and Measurements . Technical Report of the University of Mannheim: 2/96, 1996

1995

  • Birgitta König-Ries, Sven Helmer and Guido Moerkotte: An experimental study on the complexity of left-deep join ordering problems for cyclic queries . Technical Report of The RWTH Aachen: 95-4, 1995

My PhD thesis