Talks

2025

Augmented Reality fuer intelligente Benutzerschnittstellen Inited Talk, Informatikforum Stuttgart, Stuttgart, Germany, November 13, 2025
Spatial Computing vs Situated Computing Keynote, ISMAR Workshop on Working Enhancement with Extended Reality, Daejeon, South Korea, October 10, 2025
Creating Intelligent Interfaces with Augmented Reality Keynote, AR/VR Workshop der Gesellschaft fuer Informatik, Chemnitz, Germany, September 16, 2025
Augmented Reality Visualizations Keynote, Medical Augmented Reality Summer School at Balgrist Hospital, Zurich, Switzerland, August 8, 2025
Smart Augmented Reality with Scene Understanding Invited Talk, Aarhus University, Aarhus, Denmark, June 26, 2025
Spatiotemporal Shading Caching Invited Talk, Huawei Device and Cloud Graphics Innovation Workshop, London, UK, May 12, 2025
Augmented Reality for Spatial Human-Computer Interaction Invited Talk, 59th Photogrammetry Week, Stuttgart, Germany, April 4, 2025
Augmented Reality with Artificial Intelligence Invited Talk, Snap Inc., Vienna, Austria, February 20, 2025
Pr\"asenz-Gestaltung im Roman und in VR - Das Beispiel des Versailler Gartens von 1669 Invited talk, Internationale Tagung Pr\"asenz Gestalten, Stuttgart, Germany, February 12, 2025
Augmented Reality for Human-Centered Artificial Intelligence Keynote, Symposium Visual Computing Trends, Vienna, Austria, January 30, 2025

2024

Human Augmentation With Artificial Intelligence Interfaces Keynote, ISMAR Workshop on Mobile Analytics from Situated Knowledge, Seattle, USA, October 25, 2024
Augmented Reality for Human Intelligence Amplification Invited talk, University of Paris-Sarclay, Paris, France, September 9, 2024
Emerging Directions in Augmented Reality Invited talk, Summer Colloquium of the Max Planck Institute of Interactive Systems, Stuttgart, Germany, May 3, 2024
Recent Trends in Augmented Reality Tutorial at the Central European Seminar on Computer Graphics, Smolenice, Slovakia, May 3, 2024

2023

New Directions in Situated Analytics Invited talk, TU Dresden, Dresden, Germany, December 18, 2023
Augmented Reality, Digital Twins and Situated Analytics Keynote, ACM MUM 2023 , Vienna, Austria, December 6, 2023
How Digital Twins and Augmented Reality Can Make a Difference Keynote, ISMAR 2023 Workshop on Immersive and Situated Analytics, Sydney, Australia, October 16, 2023
Storytelling in Augmented Reality Invited talk, Simulation/Dissimulation Symposium, Stuttgart, Germany, September 26, 2023
New Directions in 3D Graphics Streaming Keynote, Huawei STW Symposium 2023, Shenzen, China, September 25, 2023
Augmented Digital Twin Invited Talk, Qualcomm Technologies Inc., San Diego, USA, August 3, 2023
Augmented Digital Twin Keynote, XR EXPO, Stuttgart, Germany, June 15, 2023
Conclusions and Future Work Keynote, Retreat Workshop of the VISUS group, University of Stuttgart, Hamburg, Germany, April 20, 2023
Creating and Studying Situated Visualizations Keynote, Spring Doctorial Consortium of the Media Informatics Group, LMU Munich, Kloster Seeon, Germany, March 8, 2023

2022

Tutorial: RagRug, a Toolkit for Situated Analytics Tutorial, International Symposium on Mixed and Augmented Reality, Singapore, October 18, 2022
Advances in Virtual Reality Streaming Keynote, International Conference on Signal Processing and Applications (SIGMOD), Virtual event, Lisbon, Portugal, July 15, 2022
Augmented Reality Meets Digital Twins Invited Talk, GDC Symposium, Vienna University of Technology, Vienna, Austria, September 9, 2022
Opportunities and Challenges of Situated Analytics Keynote, French Visualization Day, University of Bordeaux, Bordeaux, France, June 28, 2022
Tutorial: RagRug, a Toolkit for Situated Analytics Invited talk, Immersive Analytics Lab, Monash University, Melbourne, Australia, October 13, 2022
Tutorial: RagRug, a Toolkit for Situated Analytics Invited talk, University of South Australia, Adelaide, Australia, October 10, 2022
Situated Analytics and Digital Twins , Adelaide, Australia, October 11, 2022
Situated Analytics and Digital Twins Invited talk, SimTech Cluster of Excellence, Stuttgart, Germany, July 13, 2022
RagRug: An open source toolkit for situated visualization and analytics Invited talk at the Workshop on Open Access Tools and Libraries for Virtual Reality at IEEE Virtual Reality 2022, Virtual event, Christchurch, New Zealand, March 11, 2022
Current research on augmented and virtual reality at TU Graz Invited Talk at the Australian Research Centre for Interactive and Virtual Environments, Virtual event, Adelaide, Australia, March 22, 2022

2021

Visualization in the real world: Confluence of visualization and augmented reality Keynote, VISIGRAPP 2021, Virtual event, Vienna, Austria, February 8, 2021
Visualization in outdoor augmented reality Keynote, Datascope Project Workshop organized by FH St. Poelten, Virtual event, St. Poelten, Austria, March 12, 2021
Situated visualization in augmented reality Huawei Future Device Technology Summit, Virtual event, Helsinki, Finland, October 12, 2021
Situated analytics in augmented reality Keynote, Symposium on Virtual and Augmented Reality (SVR 2021), Virtual event, Gramado, Rio Grande do Sul, Brazil, October 18, 2021
Ragrug - a toolkit for situated analytics Keynote, Workshop of the DFG Trans-Regional Research Program TRR161, Konstanz, Germany, November 22, 2021
From visualization to augmented reality Invited Talk at the Visualization Institute of the University of Stuttgart, Stuttgart, Germany, November 24, 2021
Exploring the design space for situated analytics Keynote, Status Seminar of DFG Transregion Project TRR161 "Quantitative Methods in Visual Computing", Virtual event, Stuttgart, Germany, June 22, 2021
Challenges in mixed and augmented reality Noah's Ark Online Talk Series, Huawei London, Virtual event, London, UK, July 1, 2021

2019

Virtual reality and visualization Keynote, 2019 World Conference on VR Industry, Nanchang, China, October 21, 2019
Technologies for split rendering University Relationship Lecture, Qualcomm Research Center, San Diego, USA, July 25, 2019
Shading atlas streaming Talk at ACM SIGGRAPH 2019, Los Angeles, USA, August 1, 2019
Shading atlas streaming Invited talk, Dagstuhl Seminar on Real VR, Dagstuhl, Germany, July 2, 2019
A research agenda for situated visualization Keynote, ISMAR 2019, Beijing, China, October 17, 2019
Augmented reality in industrial environments Invited talk, 2019 World Conference on VR Industry, Nanchang, China, October 21, 2019

2018

When visualization met augmented reality Keynote, IEEE VIS Conference, Berlin, Germany, October 23, 2018

2017

Augmented reality intro class Tutorial, Augmented World Expo 2017, Santa Clara, CA, USA, May 31, 2017
Streaming virtual reality Invited talk, Qualcomm Research Center San Diego, San Diego, CA, USA, May 5, 2017
Retargeting video tutorials showing tools with surface contact to augmented reality ACM CHI Conference, Denver, CO, USA, May 11, 2017
Inverse rendering for photorealistic mixed reality Keynote, 9th Workshop on Medical Imaginging and Visualization, Faak, Austria, May 24, 2017
The future of virtual and augmented reality Invited talk, Qualcomm Engineering Lecture Series, San Diego, CA, USA, September 15, 2017
Applications of inverse rendering for augmented reality Invited talk, PTC Engineering Talks Series, San Diego, CA, USA, November 16, 2017

2016

Augmented reality - principles and practice ISMAR 2016 Tutorial, Merida, Mexico, September 22, 2016
Augmented reality - principles and practice SIGGRAPH 2016 Course, Anaheim, CA, USA, July 24, 2016
Visual computing: What can we do and what not (yet)? Opening Panel of VISIGRAPP 2016, Rome, Italy, February 27, 2016
Trends and challenges of augmented reality Keynote address, VISIGRAPP 2016, Rome, Italy, February 27, 2016
Ten things that excite me (about augmented reality) NII Shonan Meeting on Perception in Augmented Reality, Shonan, Japan, November 15, 2016
Situated visualization in augmented reality Invited talk, Dagstuhl Seminar on Immersive Analytics, Dagstuhl, Germany, June 6, 2016
Ismar 2016 research review Augmented World Expo Europe, Berlin, Germany, October 19, 2016
Instant mixed reality lighting from casual scanning ISMAR 2016, Merida, Mexico, September 19, 2016
Collaborative seamless desktop Dagstuhl Seminar on Immersive Analytics, Dagstuhl, Germany, June 8, 2016
Collaborative distributed cognition using a seamless desktop infrastructure IEEE Virtual Reality Workshop on Immersive Analytics, Greenville, SC, USA, March 20, 2016
Coherent rendering ISMAR 2016 Tutorial AR101, Merida, Mexico, September 18, 2016
Authoring and visualization technologies for augmented reality experiences Invited talk, Max Planck Institute of Informatics, Saarbr\"ucken, Germany, Dagstuhl, Germany, June 10, 2016
Advances and trends in augmented reality systems Keynote address, ACM Multimedia Systems 2016, Klagenfurt, Austria, May 12, 2016
Adaptive information density for augmented reality displays IEEE Virtual Reality, Greenville, SC, USA, March 22, 2016

2015

Image-space illumination for augmented reality in dynamic environments IEEE Virtual 2015, Arles, France, March 27, 2015
Illustrated instructions with augmented reality Invited talk, AVL Research Networking Day 2015, Graz, Austria, February 25, 2015
Global-scale localization in outdoor environments Tutorial at IEEE ISMAR 2015, Fukuoka, Japan, September 29, 2015
Contour - data-driven exploration of multi-relational datasets for drug discovery ACM SIGGRAPH 2015, Los Angeles, USA, August 9, 2015
Augmented reality in cultar and trends for future exploitation Invited talk, Augmented Reality for Urban Cultural Heritage, closure event of the CultAR project, Padova, Italy, December 10, 2015
Augmented reality from visual computing Invited talk, Austrian Computer Science Day, Vienna University of Technology, Austria, October 15, 2015
Augmented reality als zusammenspiel von graphik, vision und interaktion Keynote, Kick-Off Symposium of the DFG Trans-Regional Research Program TRR161, Stuttgart, Germany, July 8, 2015

2014

Using gpgpu for graphics Invited talk, University of Rostock, Rostock, Germany, June 24, 2014
Situated visualization with augmented reality Keynote, UMIC Day, RWTH Aachen, Aachen, Germany, October 21, 2014
Outdoor augmented reality Invited talk, ETH Zurich, Zurich, Switzerland, November 24, 2014
Have we solved the user interface problem for augmented reality Panel, IEEE International Symposium on Mixed and Augmented Reality 2014, Munich, Germany, September 11, 2014

2013

Visualization design for augmented reality Invited Talk, Dagstuhl Seminar on Virtual Realities, Dagstuhl, Germany, June 13, 2013
Personal intelligence with augmented reality Workshop Daten-Zukunft 2020, Joanneum Research, Graz, Austria, October 21, 2013
Noise-based volume rendering for the visualization of multivariate volumetric data IEEE Scientific Visualization, Atlanta, GA, USA, October 18, 2013
Multi-user multi-display visualization Invited Talk, Workshop on Emerging Topics in Visual Computing and Computer Graphics, Plauer See, Germany, April 24, 2013
Managed gpu processing Invited Talk, KAUST Visualization Summit, KAUST, Thuwal, Saudi Arabia, April 15, 2013
Augmented reality for gis Austrian Small World User Group (OeSWUG) 2013, Graz, Austria, November 6, 2013

2012

Trends in mobile augmented reality Tutorial at IEEE Virtual Reality 2012, Orange County, CA, USA, March 4, 2012
Systems engineering science: Obsolete or essential? Panel at IEEE Virtual Reality 2012, Orange County, CA, USA, March 7, 2012
Frame cache management for multi-frame rate systems International Symposium on Visual Computing (ISVC) 2012, Rethymnon, Greece, July 18, 2012
Augmented reality technology for smartphones Keynote, Conference on Mobile and Ubiquitous Multimedia (MUM) 2012, Ulm, Germany, December 4, 2012
Augmented reality meets mobile computing Invited talk, 25 Years Fraunhofer IGD Symposium, Darmstadt, Germany, November 14, 2012

2011

Truly mobile augmented reality Invited Talk, Technische Universitaet Muenchen, Munich, Germany, May 23, 2011
Smartphone augmented reality: Towards mass-market augmented reality Invited talk, Johannes Kepler University Linz, Linz, Austria, December 7, 2011
Overview of mobile augmented reality Tutorial talk, IEEE International Symposium on Mixed and Augmented Reality, Basel, Switzerland, October 26, 2011

2010

A room full of information Invited Talk, University of Rostock, Germany, Rostock, Germany, March 9, 2010
The future of augmented reality Keynote address, IASTED International Conference on Computer Graphics and Imaging (CGIM 2010), Innsbruck, Austria, February 18, 2010

2009

In-situ content creation for mobile augmented reality Workshop on Social Augmented Reality, IEEE International Symposium on Mixed and Augmented Reality, Orlando FL, USA, October 19, 2009
A framework for augmented reality on mobile phones Invited talk, Qualcomm Research Center, San Diego CA, USA, October 10, 2009
Effective visual communication in augmented reality Invited talk, University of Magdeburg, Magdeburg, Germany, February 9, 2009
Detection and tracking of multiple targets with guaranteed frame rates on mobile phones IEEE International Symposium on Mixed and Augmented Reality, Orlando, FL, USA, October 19, 2009

2008

Visualization techniques for augmented reality Invited talk, VisForum, VRVis Research Center, Vienna, Austria, December 18, 2008
Scalable augmented reality Invited talk, WSI/GRIS, University of Tuebingen, Tuebingen, Germany, January 18, 2008
Making augmented reality practical on mobile phones IEEE Virtual Reality 2008 - Workshop on Software Engineering and Architecturesfor Realtime Interactive Systems, Reno, NV, USA, March 9, 2008
Interactive visualization and augmented reality Invited talk, Johannes Keppler University Linz, Linz, Austria, January 24, 2008
Handheld augmented reality on mobile phones Invited talk, Vodafone R \& D Lab, Munich, Germany, June 23, 2008
Augmented reality 2.0 Dagstuhl Seminar on Virtual Realities, Dagstuhl, Germany, June 4, 2008

2007

Upscaling and downscaling augmented reality Keynote address, 6th IEEE International Symposium on Mixed and Augmented Reality (ISMAR'07), Nara, Japan, November 14, 2007
Tracking for distributed mixed reality environments IEEE Virtual Reality, Charlotte, NC, USA, March 11, 2007
The making of signpost2007 Microsoft TechEd 2007, Orlando FL, USA, June 7, 2007
Interaction and presence in urban environments Meeting of the FP6 Presence Projects, Scuola Superiore Anna, Pisa, Italy, May 30, 2007
From mobile augmented reality to ubiquitous augmented reality Seminar on "Mobile Interfaces Meet Cognitive Technologies", Dagstuhl, Germany, September 10, 2007
Current medical visualization research Workshop on Systems Biology and Visualisation of Complex Medical and Biological Data, Medical University of Graz, Austria, May 25, 2007
Augmented reality scouting for interactive 3d reconstruction IEEE Virtual Reality, Charlotte, NC, USA, March 12, 2007

2006

Recent advanced in augmented reality ARIS*ER Network Summer School, Santa Cesarea Terme, Italy, July 17, 2006
A hybrid user interface for manipulation of volumetric medical data IEEE Symposium on 3D User Interfaces, Alexandria, VA, USA, March 25, 2006
Handheld augmented reality displays IEEE Virtual Reality - Emerging Display Technology Workshop, Alexandria, VA, USA, March 26, 2006
Designing immersive virtual reality for geometry education IEEE Virtual Reality, Alexandria, VA, USA, March 27, 2006
Context driven visualization for augmented reality Invited talk, Technische Universitaet Muenchen, Technische Universitaet Muenchen, Germany, July 28, 2006

2005

Problems of scale in augmented reality Keynote talk, Central European Conference on Multimedia and Virtual Reality 2005 (CEMVRC05), Prague, Czech Republic, June 10, 2005
Location based services with augmented reality and ubiquitous computing Invited talk at the 3rd Symposium on Location Based Services and TeleCartography, Vienna, Austria, November 30, 2005
Augmented reality for pervasive computing START/Wittgenstein Symposium of the Austrian Science Fund, Vienna, Austria, June 11, 2005
Augmented reality als real world-benutzerschnittstelle Guest lecture at Ludwig Maximilians-Universitaet Muenchen, Germany, Ludwig Maximilians-Universitaet Muenchen, Germany, April 15, 2005

2004

Mobile augmented reality Invited talk, Technische Universitaet Graz, Austria, Technische Universitaet Graz, Austria, January 16, 2004
Mobile anwendungen von augmented reality Invited talk, Fachhochschule Hagenberg, Austria, Fachhochschule Hagenberg, Austria, June 3, 2004
Distributed, collaborative and mobile augmented reality SIGGRAPH 2004 Course no. 25 Developing Augmented Reality Applications, Los Angeles CA, USA, August 10, 2004
Die welt als interface Invited talk at the Mobile Computing Kongress 2004, Fraunhofer IGD, Darmstadt, Germany, October 20, 2004
Augmented reality: Technologie und anwendungen in der medizin Invited talk, Medizin-Universitaet Graz, Austria, Medizin-Universitaet Graz, Austria, June 2, 2004

2003

Mixed reality: The continuum from virtual to augmented reality Panel talk, IEEE Virtual Reality 2003, Los Angeles, USA, March 25, 2003
A graphical tuplespace Invited talk, Technische Universitaet Muenchen, Germany, Technische Universitaet Muenchen, Germany, July 22, 2003
Augmented reality for computer supported learning Invited talk, University of Salzburg, Austria, University of Salzburg, Austria, June 25, 2003
Augmented and ubiquitous environments with studierstube Invited talk, Technische Universitaet Graz, Austria, Technische Universitaet Graz, Austria, October 21, 2003

2002

Virtuelle arbeitsumgebungen durch augmented reality und pervasive computing Invited talk at the Technische Universitaet Dresden, Germany, Technische Universitaet Dresden, Germany, April 10, 2002
Studierstube: Spontaneous collaborative augmented reality Invited talk at the Mitsubishi Electronic Research Center, Cambridge, MA, USA, March 21, 2002
Distributed applications for collaborative augmented reality IEEE Virtual Reality 2002, Orlando, Florida, USA, March 26, 2002
Developing augmented reality applications Tutorial at IEEE Virtual Reality 2002, Orlando, Florida, USA, March 25, 2002
Collaborative and mobile 3d workspaces Invited talk at the Symposium on Information Science and Engineering, ETH Zurich, Switzerland, July 4, 2002
Augmented reality as a user interface for mobile computing GeoPo 2002 Workshop on Location Based Services and Mobile Navigation, Podersdorf, Austria, June 25, 2002
Augmented reality and visualization Invited talk at the EU funded Workshop on Augmented Reality for Image Guided Surgery, Rikshospitalet Oslo, Norway, September 19, 2002
Artoolkit expert panel Panel talk at the IEEE ART02 Workshop, Darmstadt, Germany, September 29, 2002

2001

Web-basierte interaktive 3d-benutzerschnittstellen Invited talk at Christian Albrechts University of Kiel, Germany, University of Kiel, Germany, April 24, 2001
User interface management fuer augmented reality Invited talk at the University of Koblenz-Landau, Germany, University of Koblenz-Landau, Germany, July 24, 2001
Three-dimensional collaborative user interface technology Invited talk (Habilitationskolloquium) at Vienna University of Technology, Austria, Vienna University of Technology, Austria, June 18, 2001
An introduction to augmented reality Tutorial at the 5th International Symposium on Augmented Reality, Zurich, Switzerland, October 7, 2001
Heterogeneous augmented reality SIGGRAPH 2001 Course no. 27: Augmented Reality: The Interface is Everywhere, Los Angeles, California, USA, August 13, 2001
Erweiterte realitaet fuer kollaborative benutzerschnittstellen Invited talk at Ludwig-Maximilians-Universitaet, Munich, Germany, Ludwig-Maximilians-Universitaet, Munich, Germany, May 16, 2001
Dreidimensionale kollaborative benutzerschnittstellen Invited talk at Technische Universitaet Muenchen, Technische Universitaet Muenchen, Munich, Germany, June 29, 2001
Augmented reality user interfaces Invited talk at Christian Albrechts University of Kiel, Germany, University of Kiel, Germany, April 24, 2001

2000

Studierstube: User interfaces for collaborative augmented reality Invited talk at the Computer Graphics and User Interfaces Group at Columbia University, New York, NY, USA, Columbia University, New York, NY, USA, August 3, 2000
Software development for the studierstube framework Tutorial given at the Fraunhofer Center for Research in Computer Graphics, Providence, RI, USA, March 15, 2000
Building collaborative user interfaces with augmented reality Invited talk at the Human Interface Technologies Laboratory of the University of Washington, Seattle, WA, USA, University of Washington, Seattle, WA, USA, August 11, 2000
Bridging multiple user interface dimensions with augmented reality ACM and IEEE Symsposium on Augmented Reality (ISAR 2000), Munich, Germany, October 5, 2000
Augmented reality mit der studierstube Invited talk at the DaimlerChrysler Virtual Reality Competence Center, Ulm, Germany, December 7, 2000
3d-benutzerschnittstellen in der studierstube Invited talk at the University of Ulm, Germany, University of Ulm, Germany, December 6, 2000

1999

Using transparent props for interaction with the virtual table SIGGRAPH Symposium on Interactive 3D Graphics, Atlanta, Georgia, USA, April 26, 1999
Studierstube - augmented reality for everyone Invited talk at the 5th Virtual Table Workshop, Fraunhofer Institut fuer graphische Datenverarbeitung, Darmstadt, Germany, December 16, 1999
Simple user-centered head-mounted display calibration for augmented reality ACM Symposium on Virtual Reality Software and Technology (VRST'99), University College London, London, UK, December 22, 1999
Collaborative augmented reality in studierstube Invited talk at WSI/GRIS, University of Tuebingen, Germany, April 19, 1999
Augmented virtual reality using transparent props Invited talk at University College London, UK, London, UK, July 30, 1999

1998

The studierstube augmented reality project Fraunhofer Institut fuer graphische Datenverarbeitung, Fraunhofer Institut fuer graphische Datenverarbeitung, Darmstadt, Germany, December 9, 1998
An introduction to virtual reality Tutorial given at the Fraunhofer Center for Research in Computer Graphics, Providence, RI, USA, August 13, 1998
A comparative evaluation of augmented work environments Invited talk at the Fraunhofer Center for Research in Computer Graphics, Providence, RI, USA, September 21, 1998

1997

Smooth levels of detail IEEE Virtual Reality Annual International Symposium (VRAIS'97), Albuquerque NM, USA, March 3, 1997
Sewing worlds together with seams: Ein mechanismus zur verbindung virtueller welten Invited talk at the Johannes Kepler University of Linz, Austria, Johannes Kepler University of Linz, Austria, November 13, 1997
The remote rendering pipeline Invited talk at the University of Bristol, UK, University of Bristol, UK, August 19, 1997
Modeling and rendering of outdoor scenes for distributed virtual reality ACM Virtual Reality Software and Technology (VRST'97), Lausanne, Switzerland, September 17, 1997
Lodestar - an octree-based level of detail generator for vrml SIGGRAPH Symposium on Virtual Reality Modeling Language (VRML'97), Monterey CA, USA, February 26, 1997
Incremental encoding of polygonal models 30th Hawaiian International Conference on System Sciences, Maui, Hawaii, USA, January 9, 1997

1996

Studierstube - an environment for collaboration in augmented reality Collaborative Virtual Environments (CVE'96), Nottingham, UK, September 19, 1996
Optimizing communication in distributed virtual environments by specialized protocols 3rd Eurographics Workshop on Virtual Environments, Monte Carlo, Monaco, February 5, 1996
Implementing gibsonian virtual environments 13th International Meeting on Cybernetics and Systems Research, Vienna, Austria, April 11, 1996
Demand-driven geometry transmission for distributed virtual environments EUROGRAPHICS'96, Poitier, France, August 30, 1996

1995

Towards a virtual environment for interactive world building GI 4.1.1 Workshop on Modeling - Virtual Worlds - Distributed Graphics, Bonn, Germany, November 27, 1995
On system architectures for virtual environments 11th Spring Conference on Computer Graphics, Bratislava, Slovakia, May 30, 1995

1994

Storyboard - a programming language for computer animation Invited talk, Karlava University of Prague, Karlava University of Prague, Czech Republic, May 30, 1994