Please find below a list of selected papers. These publications cover three mayor research areas, which we are or were working on:

• Energy Aware Software / Resource Substitution
• (Context Aware) Mobile Data Management / Query Indexing
• XML Data Management / Rule Based Information Systems

You may find a complete list of Dr. Höpfner's publications including older papers and other topics at http://www.hoepfner.ws.

• Hagen Höpfner, Maximilian Schirmer, and Christian Bunse. On measuring smartphones’ software energy requirements. In Proceedings of the 7th International Conference on Software Paradigm Trends, ICSOFT 2012, Rome, Italy, July 24-27, 2012, Setúbal, Portugal, 2012. INSTICC, SciTePress. accepted for publication, forthcoming.
• Maximilian Schirmer and Hagen Höpfner. Towards Using Location Poly-Hierarchies for Energy-Efficient Continuous Location Determination. In Proceedings of the 23. Workshop on Foundations of Databases (Grundlagen von Datenbanken); May 29 - June 1, 2012, Lübbenau, Germany. CEUR-WS.org, 2012. accepted for publication, forthcoming.
• Hagen Höpfner and Maximilian Schirmer. Energy efficient continuous location determination for pedestrian information systems. In Proceedings of the 11th International ACM Workshop on Data Engineering for Wireless and Mobile Access (MobiDE 2012), Scottsdale, Arizona, USA, May 20th, 2012. ACM Press, 2012. accepted for publication, forthcoming.
• Maximilian Schirmer and Hagen Höpfner. SenST: Approaches for Reducing the Energy Consumption of Smartphone-Based Context Recognition. In Michael Beigl, Henning Christiansen, Thomas Roth-Berghofer, Anders Kofod-Petersen, Kenny R. Coventry, and Hedda Rahel Schmidtke, editors, Proceedings of the 7th International and Interdisciplinary Conference on Modeling and Using Context 2011 (CONTEXT’11); September 26-30, 2011, Karlsruhe, Germany, volume 6967 of Lecture Notes in Computer Science, pages 250–263, Berlin / Heidelberg, 2011. Springer. ISBN: 978-3-642-24278-6.
• Christian Bunse and Hagen Höpfner. Analyse des Zusammenhangs zwischen Energiebedarf, Dienstgüte und Performanz bei der Ressourcensubstitution in Softwaresystemen. In Wolfgang A. Halang, editor, Herausforderungen durch Echtzeitbetrieb — Proceedings of the real-time 2011 workshop (Echtzeit 2011); November 3-4, 2011, Boppard, Germany, Informatik aktuell, pages 101–110, Berlin / Heidelberg, November 2011. Springer. in German. ISBN: 978-3-642-24657-9.
• Hagen Höpfner and Christian Bunse. Energy Awareness Needs a Rethinking in Software Development. In Maria Jose Escalona, Boris Shishkov, and José Cordeiro, editors, Proceedings of the 6th International Conference on Software and Data Technologies, ICSOFT 2011, Seville, Spain, July 18-21, 2011, volume 2, pages 294–297, Setúbal, Portugal, July 2011. INSTICC, SciTePress. ISBN: 978-989-8425-77-5.
• Christian Bunse, Hagen Höpfner, Suman Roychoudhury, and Essam Mansour. Energy efficient data sorting using standard sorting algorithms. In José Cordeiro, Alpesh Ranchordas, and Boris Shishkov, editors, Software and Data Technologies — 4th International Conference, ICSOFT 2009, Sofia, Bulgaria, July 26-29, 2009. Revised Selected Papers, volume 50 of Communications in Computer and Information Science, pages 247–260, Berlin / Heidelberg, 2011. Springer.
• Christian Bunse and Hagen Höpfner. Energieeffiziente Software-Systeme. In Wolfgang A. Halang and Peter Holleczek, editors, Eingebettete Systeme — Proceedings of the real-time 2010 workshop (Echtzeit 2010); November 18-19, 2010, Boppard, Germany, Informatik aktuell, Berlin / Heidelberg, November 2010. Springer. in German. ISBN: 978-3-642-15188-9.
• Hagen Höpfner and Christian Bunse.Towards an energy-consumption based complexity classification for resource substitution strategies. In Wolf-Tilo Balke and Christoph Lofi, editors, Proceedings of the 22. Workshop on Foundations of Databases (Grundlagen von Datenbanken); May 25-28, 2010, Bad Helmstedt, Germany, volume 581 of CEUR Workshop Proceeding. CEUR-WS.org, May 2010. ISSN: 1613-0073
• Hagen Höpfner and Christian Bunse. Energy Aware Data Management on AVR Micro Controller Based Systems. ACM SIGSOFT Software Engineering Notes, 35(3), May 2010. ISSN:0163-5948
• Christian Bunse, Hagen Höpfner, Suman Roychoudhury, and Essam Mansour. Choosing the “best” Sorting Algorithm for Optimal Energy Consumption. In Boris Shishkov, José Cordeiro, and Alpesh Kumar Ranchordas, editors, Proceedings of the 4th International Conference on Software and Data Technologie (ICSOFT 2009), July 26-29, 2009, Sofia, Bulgaria, volume 2, pages 199–206, Setúbal, Portugal, July 2009. INSTICC, INSTICC press. ISBN: 978-989-674-010-8.
• Hagen Höpfner and Christian Bunse. Towards an Energy Aware DBMS — Energy Consumptions of Sorting and Join Algorithms. In Matthias Virgin, André Peters, and Dagmar Köhn, editors, Proceedings of the 21. Workshop on Foundations of Databases (Grundlagen von Datenbanken); June 02-05, 2009, Rostock-Warnemünde, Germany, number CS-02-09 in Preprints aus dem Institut für Informatik der Universität Rostock, pages 69–73, Rostock, Germany, May 2009. Institut für Informatik der Universität Rostock.
• Christian Bunse, Hagen Höpfner, Essam Mansour, and Suman Roychoudhury. Exploring the Energy Consumption of Data Sorting Algorithms in Embedded and Mobile Environments. In Proceedings of the 10th International Conference on Mobile Data Management: Systems, Services and Middleware (MDM 2009), 18-20 May 2009 Taipei, Taiwan, pages 600–607, Los Alamitos, CA, USA, 2009. IEEE Computer Society.
• Christian Bunse and Hagen Höpfner. Resource substitution with components — optimizing energy consumption. In José Cordeiro, Boris Shishkov, Alpesh Kumar Ranchordas, and Markus Helfert, editors, Proceedings of the 3rd International Conference on Software and Data Technologie (ICSOFT 2008), July 5-8, 2008, Porto, Portugal, volume SE/GSDCA/MUSE, pages 28–35, Setúbal, Portugal, July 2008. INSTICC, INSTICC press.
• Hagen Höpfner and Christian Bunse. Ressource Substitution for the Realization of Mobile Information Systems. In Joaquim Filipe, Markus Helfert, and Boris Shishkov, editors, Proceedings of the 2nd International Conference on Software and Data Technologie (ICSOFT 2007), July 22-25, 2007, Barcelona, Spain, volume Software Engineering, pages 283–289, Setúbal, Portugal, July 2007. INSTICC, INSTICC press.

• Hagen Höpfner and Maximilian Schirmer. Towards Modeling Locationsas Poly-Hierarchies. In Proceedings of the 23. Workshop on Foundations of Databases (Grundlagen von Datenbanken); May 29 - June 1, 2012, Lübbenau, Germany. CEUR-WS.org, 2012. accepted for publication, forthcoming.
• Hagen Höpfner, Andreas Thenn, and Maximilian Schirmer. Temporal aspects-based replacement in media object caches. In Karl-Heinz Krempels and José Cordeiro, editors, Proceedings of the 8th International Conference on Web Information Systems and Technologies (WEBIST 2012), Porto, Portugal, April 18-21, 2012, pages 73–82, Setúbal, Portugal, April 2012. INSTICC, SciTePress. ISBN: 978-989-8565-08-2.
• Hagen Höpfner, Sebastian Wendland, and Essam Mansour. Data Caching On Mobile Devices — The Experimental MyMIDP Caching Framework. In Boris Shishkov, José Cordeiro, and Alpesh Kumar Ranchordas, editors, Proceedings of the 4th International Conference on Software and Data Technologie (ICSOFT 2009), July 26-29, 2009, Sofia, Bulgaria, volume 2, pages 256–259, Setúbal, Portugal, July 2009. INSTICC, INSTICC press. ISBN: 978-989-674-010-8.
• Essam Mansour and Hagen Höpfner. Towards an XML-Based Query and Contextual Information Model in Context-Aware Mobile Information Systems. In Proceedings of the 10th International Conference on Mobile Data Management: Systems, Services and Middleware (MDM 2009), 18-20 May 2009 Taipei,Taiwan, pages 574–579, Los Alamitos, CA, USA, 2009. IEEE Computer Society.
• Essam Mansour and Hagen Höpfner. An XML-Based Model for Supporting Context-Aware Query and Cache Management. In Alan P. Sexton, editor, Dataspace: The Final Frontier — Proceedings of the 26th British National Conference on Databases, BNCOD 26, Birmingham, UK, July 7-9, 2009, volume 5588 of Lecture Notes in Computer Science (LNCS), pages 107–119, Berlin/Heidelberg, July 2009. Springer.
• Hagen Höpfner, Essam Mansour, and Daniela Nicklas. Review of Data Management Mechanisms on Mobile Devices. it – information technology, 51(2):79–84, 2009.
• Hagen Höpfner, Jörg Schad, Sebastian Wendland, and Essam Mansour. MyMIDP and MyMIDPClient: Direct Access to MySQL Databases from Cell Phones (Demo). In Johann-Christoph Freytag, Thomas Ruf, Wolfgang Lehner, and Gottfried Vossen, editors, Proceedings of the 13. Conference on Business, Technology, and Web, March 2-6, 2009, Münster, Germany, volume P-144 of Lecture Notes in Informatics (LNI) - Proceedings, pages 604–607, Bonn, Germany, 2009. Gesellschaft für Informatik, Köllen Druck+Verlag GmbH.
• Essam Mansour and Hagen Höpfner. An Approach to Detecting Relevant Updates to Cached Data Using XML and Active Databases. In Martin Kersten, Boris Novikov, Jens Teubner, Vladimir Polutin, and Stefan Manegold, editors, Proceedings of the 12th International Conference on Extending Database Technology: Advances in Database Technology (EDBT 2009), March 23-26 2009, Saint-Petersburg, Russia, volume 360 of ACM International Conference Proceeding Series, pages 791–802, New York, NY, USA, 2009. ACM
• Hagen Höpfner. Handbook of Research on Innovations in Database Technologies and Applications: Current and Future Trends, volume 2, chapter Caching, Hoarding, and Replication in Client/Server Information Systems with Mobile Clients, pages 252–258. Information Science Publishing, 1st edition, February 2009.
• Hagen Höpfner, Jörg Schad, Sebastian Wendland, and Essam Mansour. MyMIDP: An JDBC driver for accessing MySQL from mobile devices. In Qiming Chen, Alfredo Cuzzocrea, Takahiro Hara, Ela Hunt, and Manuela Popescu, editors, Proceedings of the The First International Conference on Advances in Databases, Knowledge, and Data Applications (DBKDA 2009), March 1-6, 2009, Cancun, Mexico, pages 74–80. IEEE Computer Society, 2009.
• Hagen Höpfner and Erik Buchmann. Towards compact operator trees for query indexing. In José Cordeiro, Boris Shishkov, Alpesh Kumar Ranchordas, and Markus Helfert, editors, Proceedings of the 3rd International Conference on Software and Data Technologie (ICSOFT 2008), July 5-8, 2008, Porto, Portugal, volume ISDM/ABF, pages 174–179, Setúbal, Portugal, July 2008. INSTICC, INSTICC press.
• Hagen Höpfner. Towards a syntactic and partially semantic optimization of database queries for indexing purposes. In Proceedings of the 20. Workshop on Foundations of Databases (Grundlagen von Datenbanken); May 13 - May 16, 2008, Apolda, Germany, Technical Reports, pages 11–15, Bruchsal, Germany, April 2008. School of Information Technology, International University in Germany.
• Hagen Höpfner. Query Based Client Indexing in Client/Server Information Systems. Journal of Computer Science, 3(10):773–779, 2007. ISSN: 1549-3636
• Birgitta König-Ries, Can Türker, and Hagen Höpfner. Informationsnutzung und -verarbeitung mit mobilen Geräten – Verfügbarkeit und Konsistenz. Datenbank-Spektrum, 7(23):45–53, 2007. in German.
• Safina Hussain, Asma Batool Naqvi, Malik Sikandar Hayat Khiyal, and Hagen Höpfner. Indexing of Mobile Clients for Notification of Updates in Union-Based Results. European Journal of Scientific Research, 14(2):180–187, June 2006.

• Essam Mansour and Hagen Höpfner. An XML-Based Manipulation and Query Language for Rulebased Information. In Guido Governatori, John Hall, and Adrian Paschke, editors, Proceedings of the International RuleML Symposium on Rule Interchange and Applications, November 5-7, 2009, Las Vegas, Nevada, USA, number 5858 in Lecture Notes in Computer Science (LNCS), pages 231–245, Berlin/Heidelberg, November 2009. Springer. ISBN: 978-3-642-04984-2.
• Hagen Höpfner, Jörg Schad, and Essam Mansour. On analysing the database performance for different classes of XML documents based on the used storage approach. In Boris Shishkov, José Cordeiro, and Alpesh Kumar Ranchordas, editors, Proceedings of the 4th International Conference on Software and Data Technologie (ICSOFT 2009), July 26-29, 2009, Sofia, Bulgaria, volume 2, pages 243–248, Setúbal, Portugal, July 2009. INSTICC, INSTICC press. ISBN: 978-989-674-010-8.
• Essam Mansour and Hagen Höpfner. A rule-based approach and framework for managing best practices — An XML-Based Management Using Puer Database System Utilities. In José Cordeiro and Joaquim Filipe, editors, Proceedings of the 11th International Conference on Enterprise Information Systems, May 6-10, 2009, Milan, Italy, volume ISAS, pages 109–115, Setúbal, Portugal, May 2009. INSTICC, INSTICC press.
• Essam Mansour and Hagen Höpfner. Replay the Execution History of Rule-based Information. In Qiming Chen, Alfredo Cuzzocrea, Takahiro Hara, Ela Hunt, and Manuela Popescu, editors, Proceedings of the The First International Conference on Advances in Databases, Knowledge, and Data Applications (DBKDA 2009), March 1-6, 2009, Cancun, Mexico, pages 28–35. IEEE Computer Society, 2009.