Address
Projects
Education and CV
Professional Activities
Publications

Address

Projects

A list of the projects that I manage(d):
• 2012-2014: Preventing Hubness in Music Information Retrieval

• 2010-2012: Audiominer - Mathematical Signal Analysis and Modeling for Manipulation of Sound Objects (together with Monika Dörfler, NuHAG, University of Vienna)

• 2008-2010: Towards automatic annotation of electro-acoustic music

• 2007-2009: Music Information Retrieval for the FM4 Soundpark

Education and CV

• since 2007: senior researcher and project manager at the Intelligent Music Processing Group at the OFAI.

• May 2005 - September 2007: Assistant Professor (Universitätsassistent) at the Institute of Medical Cybernetics and Artificial Intelligence, Center for Brain Research, Medical University Vienna .

• February 2007: visiting researcher at the Theoretical and Experimental Neurobiology Unit of the Okinawa Institute of Science and Technology, Japan. Work on "Informational Compartmentalization of Neurons" in collaboration with Klaus Stiefel.

• September 2004 - April 2005: member of the Intelligent Music Processing Group at the OFAI. Work on Music Information Retrieval within the SIMAC-project.

• March 2003 - May 2004: Postdoctoral fellow at the Swartz Center for Computational Neuroscience (UCSD, USA). Work on "Independent Component Analysis of brain electric potentials recorded during temporally extended cognition" in collaboration with Scott Makeig. This visit was supported by a Schroedinger scholarship of the Austrian Scientific Research Fund (FWF).

• 1993 - 2003 member of the Neural Computation group at the OFAI where I was working on a number of different projects (most related to analysis of EEG):

  "Categorization of EEG coherence maps with Kohonen networks" in cooperation with the Inst. of Neurophysiology, University of Vienna.

  "Categorization of slow cortical potential shifts" in cooperation with the Inst. of Psychology, University of Vienna.

  1994-1995 research on neural networks and statistics, as well as sleep staging with neural networks in the BIOMED project ANNDEE - Enhancement of EEG-Based Diagnosis of Neurological and Psychiatric Disorders using Artificial Neural Networks.

  1997-1999: BIOMED project SIESTA aiming at finding a new description of human sleep, and RADAR project dealing with the development and implementation of neural network based prediction methods for short-term rain forecasts.

  2000-2002: working on a project supported by the Austrian Scientific Research Fund (FWF) titled: ``Improving analysis of brain electric potentials to enable monitoring of temporally extended cognition''. This was a joint project together with the Inst. of Psychology, University of Vienna (Prof. Bauer).

• 1999: Doctor of Psychology, thesis on "Spatio-temporal Clustering of Cognitive Evoked Potentials" under the supervision of Prof. Bauer, Inst. of Psychology, University of Vienna. My thesis work was supported by a doctoral grant of the Austrian Academy of Sciences.

• 1995: Magister (MSc) of Psychology with an emphasis on Artificial Intelligence at the University of Vienna, thesis on "Classification of EEG coherence maps using self-organizing feature maps".

• 1993: successfully finished a three-years study program in computer science at the University of Technology, Vienna. You may now call me "academically certified data engineer".

Professional Activities

• Reviewed papers for the following journals:

  Applied Artificial Intelligence
  Artificial Intelligence in Medicine
  Artificial Intelligence Review
  Computational Statistics and Data Analyis
  Computer Methods and Programmes in Biomedicine
  Cybernetics and Systems
  Data Mining and Knowledge Discovery
  IEEE Signal Processing Letters
  IEEE Trans. on Knowledge and Data Engineering
  IEEE Trans. on Neural Networks
  IEEE Trans. on Multimedia
  IEEE Trans. on Systems, Man, and Cybernetics - Part B
  Intelligent Data Analysis
  Journal of Neuroscience Methods
  Journal of Medical Systems
  Landscape Ecology
  Machine Learning
  Multimedia Tools and Applications

• Member of the Austrian Society for Artificial Intelligence (ÖGAI).

• Member of the Programme Committee of "13th International Society for Music Information Retrieval Conference", Porto, Portugal (ISMIR 2012).

• Member of the Programme Committee of "The 9th Sound and Music Computing Conference", Copenhagen, Denmark (SMC 2012).

• Member of the Programme Committee of "International Computer Music Conference", Ljubljana, Slovenia (ICMC 2012).

• Member of the Programme Committee of "4th International Workshop on Advances in Music Information Research: The Web of Music", Lyon, France (AdMIRe 2012).

• Member of the Programme Committee of "The 8th Sound and Music Computing Conference", Padova, Italy (SMC 2011).

• Member of the Programme Committee of "The 9th International Workshop on Content-Based Multimedia Indexing", Madrid, Spain (CBMI 2011).

• Member of the Programme Committee of "The 8th International Workshop on Content-Based Multimedia Indexing", Grenoble, France (CBMI 2010).

• Member of the Programme Committee of "The 6th Sound and Music Computing Conference", Porto, Portugal (SMC 2009).

• Member of the Programme Committee of "The 9th International Work-Conference on Artificial Neural Networks", San Sebastian, Spain (IWANN 2007).

• Member of the Programme Committee of "The 17th European Conference on Machine Learning and the 10th European Conference on Principles and Practice of Knowledge Discovery in Databases", Berlin, Germany (ECML PKDD 2006).

• Member of the Programme Committee of "The First International Conference on Complex Medical Engineering", Takamatsu, Japan (CME 2005).

• Member of the Programme Committee of "The Fifth European Conference on Principles and Practice of Knowledge Discovery in Databases", Freiburg, Germany (PKDD 2001).

• Member of the Organizing Committee of "The International Conference on Artificial Neural Networks", Vienna, Austria (ICANN 2001).

• Co-Organizer of the ICANN 2001 workshop on "Advances in EEG Analysis".

• Member of the Programme Committee of "The Fourth European Conference on Principles and Practice of Knowledge Discovery in Databases", Lyon, France (PKDD 2000).

Publications

Journal Articles

Schnitzer D., Flexer A., Widmer G.: A Fast Audio Similarity Retrieval Method for Millions of Music Tracks, Multimedia Tools and Applications, Volume 58, Number 1, 23-40, 2012 (published online on 21st of December 2010). also available as: TR-2010-13.

Flexer A., Schnitzer D.: Effects of Album and Artist Filters in Audio Similarity Computed for Very Large Music Databases, Computer Music Journal, Volume 34, Number 3, pp. 20-28, 2010. also available as: TR-2010-01.

Flexer A., Makeig S.: Independent Component Analysis of EEG recorded during two-person game playing, Applied Artificial Intelligence, Volume 21, Issue 9, pp. 883-894, 2007. also available as: TR-2007-04.

Gouyon F., Widmer G., Serra X., Flexer A.: Acoustic Cues to Beat Induction: A Machine Learning Perspective, Music Perception, Volume 24, Issue 2, pp. 177-188, 2006. also available as TR-2006-14.

Flexer A.: Statistical Evaluation of Music Information Retrieval Experiments, Journal of New Music Research, Vol. 35, No. 2, pp. 113-120, 2006. also available as TR-2005-18.

Flexer A., Bauer H., Pripfl J., Dorffner G.: Using ICA for removal of ocular artifacts in EEG recorded from blind subjects, Neural Networks, Volume 18, Issue 7, pp. 998-1005, 2005. also available as: TR-2005-07

Flexer A., Gruber G., Dorffner G.: A reliable probabilistic sleep stager based on a single EEG signal, Artificial Intelligence in Medicine, 33(3)199-207, 2005. also available as: TR-2004-18.

Flexer A., Dorffner G., Sykacek P., Rezek I.: An automatic, continuous and probabilistic sleep stager based on a hidden markov model, Applied Artificial Intelligence, Vol. 16, Num. 3, pp.199-207, 2002. also available as: TR-2001-35.

Flexer A.: On the Use of Self-organizing Maps for Clustering and Visualization, Intelligent Data Analysis, Vol. 5, Number 5, pp. 373-384, 2001. also available as: TR-2001-34

Flexer A.: Data mining and electroencephalography, Statistical Methods in Medical Research, 9: 395-413, 2000. also available as: TR-2000-12

Flexer A., Bauer H.: Monitoring human information processing via intelligent data analysis of EEG recordings, Intelligent Data Analysis, 4: 113-128, 2000. also available as: TR-2000-34

Papers in Refereed Conference Proceedings

Gasser M., Flexer A., Grill T.: On Computing Morphological Similarity of Audio Signals, in Proceedings of the 8th Sound and Music Computing Conference (SMC'11), Padova, Italy, 2011. also available as: TR-2010-14.

Grill T., Flexer A., Cunningham S.: Identification of perceptual qualities in textural sounds using the repertory grid method, in Proceedings of the 6th Audio Mostly Conference, Coimbra, Portugal, 2011. also available as: TR-2011-08.

Holzapfel A., Velasco G., Holighaus N., Doerfler M., Flexer A.: Advantages of nonstationary Gabor transforms in beat tracking, Proceedings of the First International ACM Workshop on Music Information Retrieval with User-Centered and Multimodal Strategies (MIRUM'11), Arizona, USA, 2011. also available as: TR-2011-19.

Holzapfel A., Flexer A., Widmer G.: Improving tempo-sensitive and tempo-robust descriptors for rhythmic similarity, in Proceedings of the 8th Sound and Music Computing Conference (SMC'11), Padova, Italy, 2011. also available as: TR-2011-07.

Schnitzer D., Flexer A., Schedl M., Widmer G.: Using Mutual Proximity to Improve Content-Based Audio Similarity, in Proceedings of the 12th International Society for Music Information Retrieval Conference (ISMIR'11), Miami, Florida, USA, 2011. also available as: TR-2011-14.

2010

Doerfler M., Velasco G., Flexer A., Klien V.: Sparse Regression in Time-Frequency Representations of Complex Audio, Proceedings of the 7th Sound and Music Computing Conference (SMC'10), Barcelona, Spain, 2010. also available as: TR-2010-08.

Flexer A., Gasser M., Schnitzer D.: Limitations of interactive music recommendation based on audio content, Proceedings of the 5th Audio Mostly Conference: A Conference on Interaction with Sound, pp. 96-102, 2010. also available as: TR-2010-11.

Flexer A., Schnitzer D., Gasser M., Pohle T.: Combining features reduces hubness in audio similarity, Proceedings of the Eleventh International Society for Music Information Retrieval Conference (ISMIR'10), 2010. also available as: TR-2010-06.

Gasser M., Flexer A., Schnitzer D.: Hubs and Orphans - an Explorative Approach, Proceedings of the 7th Sound and Music Computing Conference (SMC'10), Barcelona, Spain, 2010. also available as: TR-2010-07.

Klien V., Grill T., Flexer A.: Because we are all falling down. Physics, gestures and relative realities, Proceedings of the International Computer Music Conference (ICMC'10), New York City, NY, USA, 2010. also available as: TR-2010-04.

Klien V., Grill T., Flexer A.: Towards automated annotation of acousmatic music, Proceedings of the Electronic Music Studies Network Conference 2010 (EMS'10), Shanghai, China, 2010. also available as: TR-2010-09.

Schnitzer D., Flexer A., Widmer G., Gasser M.: Islands of Gaussians: The Self Organizing Map and Gaussian Music Similarity Features , Proceedings of the Eleventh International Society for Music Information Retrieval Conference (ISMIR'10), 2010. also available as: TR-2010-10.

2009

Flexer A., Schnitzer D.: Album and Artist Effects for Audio Similarity at the Scale of the Web, in Proceedings of the 6th Sound and Music Computing Conference (SMC'09), Porto, Portugal, 2009. also available as: TR-2009-01.

Gasser M., Flexer A.: FM4 Soundpark: Audio-based Music Recommendation in Everyday Use, in Proceedings of the 6th Sound and Music Computing Conference (SMC'09), Porto, Portugal, 2009. also available as: TR-2009-02.

Schnitzer D., Flexer A., Widmer G.: A Filter-and-Refine Indexing Method for Fast Similarity Search in Millions of Music Tracks, in Proceedings of the 10th International Society for Music Information Retrieval Conference (ISMIR'09), Kobe, Japan, 2009. also available as: TR-2009-03.

Seyerlehner K., Flexer A., Widmer G.: On the Limitations of Browsing Top-N Recommender Systems, in Proceedings of the 3rd ACM Conference on Recommender Systems, New York, USA, October 22-25, 2009.

2008

Flexer A., Schnitzer D., Gasser M., Widmer G.: Playlist Generation using Start and End Songs, in Proceedings of the 9th International Conference on Music Information Retrieval (ISMIR'08), Philiadelphia, USA, 2008. also available as: TR-2008-03.

Gasser M., Flexer A., Widmer G.: Streamcatcher: Integrated visualization of music clips and online audio streams, in Proceedings of the 9th International Conference on Music Information Retrieval (ISMIR'08), Philiadelphia, USA, 2008. also available as: TR-2008-04.

2007

Flexer A.: A closer look on artist filters for musical genre classification, in Proceedings of the 8th International Conference on Music Information Retrieval (ISMIR'07), Vienna, Austria, 2007. also available as: TR-2007-01.

Moreau A., Flexer A.: Drum transcription in polyphonic music using non-negative matrix factorisation, in Proceedings of the 8th International Conference on Music Information Retrieval (ISMIR'07), Vienna, Austria, 2007.

2006

Flexer A., Gouyon F., Dixon S., Widmer G.: Probabilistic Combination of Features for Music Classification, in Proceedings of the 7th International Conference on Music Information Retrieval (ISMIR'06), Victoria, Canada, 8-12 October, 2006. also available as: TR-2006-09.

2005

Flexer A., Pampalk E., Widmer G.: Novelty detection based on spectral similarity of songs, Proceedings of the 6th International Conference on Music Information Retrieval (ISMIR'05), London, UK, September 11-15, 2005. also available as: TR-2005-09.

Flexer A., Pampalk E., Widmer G.: Hidden Markov Models for spectral similarity of songs, Proceedings of the 8th International Conference on Digital Audio Effects (DAFX'05), Madrid, Spain, September 20-22, 2005. also available as: TR-2005-08.

Pampalk E., Flexer A., and Widmer G.: Improvements of Audio-Based Music Similarity and Genre Classification, Proceedings of the 6th International Conference on Music Information Retrieval (ISMIR'05), London, UK, September 11-15, 2005.

Pampalk E., Flexer A., and Widmer G.: Hierarchical Organization and Description of Music Collections at the Artist Level, Proceedings of the 9th European Conference on Research and Advanced Technology for Digital Libraries (ECDL 2005), Vienna, Austria, 2005.

Widmer G., Dixon S., Flexer A., Goebl W., Knees P., Madsen S.T., Pampalk E., Pohle T., Schedl M., Tobudic A.: The Machine Learning and Intelligent Music Processing Group at the Austrian Research Institute for Artificial Intelligence (OFAI), Vienna, Proceedings of the 2005 International Computer Music Conference (ICMC2005), Barcelona, 2005. also available as: TR-2005-12

2004

Flexer A., Bauer H., Pripfl J., Dorffner G.: Using ICA for removal of ocular artifacts in EEG recorded from blind subjects, in R.Trappl (ed.): "Cybernetics and Systems 2004", Vienna, Austrian Society for Cybernetic Studies, pp. 491-496, 2004. also available as: TR-2003-06

2002

Flexer A., Gruber G., Dorffner G.: Improvements on continuous unsupervised sleep staging, in Bourlard H. et al. (eds.), Neural Networks for Signal Processing XII, Proceedings of NNSP 2002, Institute of Electrical and Electronics Engineers, Inc., New York, NY, pp. 687-695, 2002. also available as: TR-2002-24

Flexer A., Gruber G., Dorffner G.: Continuous Unsupervised Sleep Staging Based on a Single EEG Signal, in Dorronsoro J.R.(ed.), Artificial Neural Networks - ICANN 2002, Lecture Notes in Computer Science, Springer, LNCS 2415, pp. 1013-1018, 2002. also available as: TR-2002-03

2001

Flexer A., Bauer H., Lamm C., Dorffner G.: Model-based Noise Reduction for Single Trial Evoked Potentials, in Miller D.J., et al.(eds.), Neural Networks for Signal Processing XI, Institute of Electrical and Electronics Engineers, Inc., New York, NY, pp.499-508, 2001. also available as: TR-2001-10

Flexer A., Bauer H., Lamm C., Dorffner G.: Single Trial Estimation of Evoked Potentials Using Gaussian Mixture Models with Integrated Noise Component, in Dorffner G., et al.(eds.), Artificial Neural Networks - ICANN 2001, International Conference, Vienna, Austria, Lecture Notes In Computer Science 2130, Springer, pp. 609-616, 2001. also available as: TR-2001-05

Sykacek P., Roberts S., Rezek I., Flexer A., Dorffner G.: A Probabilistic Approach to High-Resolution Sleep Analysis, in Dorffner G., et al.(eds.), Artificial Neural Networks - ICANN 2001, International Conference, Vienna, Austria, Lecture Notes In Computer Science 2130, Springer, pp. 617-624, 2001.

2000

Flexer A., Sykacek P., Rezek I., Dorffner G.: Using Hidden Markov Models to build an automatic, continuous and probabilistic sleep stager, in Amari S.-I., et al.(eds.), Proceedings of the IEEE-INNS-ENNS International Joint Conference on Neural Networks, IEEE Computer Society, IJCNN 2000, Como, Italy, Vol. III, 627-631, 2000. also available as: TR-99-21

Koivuluoma M., Vaerri A., Flexer A.: Modelling sleep with gaussian mixture model based on eye movements and delta-activity, in Gabbouj M. & Kuosmanen P. (eds). Signal Processing X Theories and Applications, Proceedings of EUSIPCO 2000, tenth European Signal Processing Conference, Tampere, Finland, pp. 35-38, 2000.

1999

Flexer A.: On the use of self-organizing maps for clustering and visualization, in Zytkow J.M. and Rauch J.(eds.), Principles of Data Mining and Knowledge Discovery, Third European Conference, PKDD'99, Prague, Czech Republic, Proceedings, Lecture Notes in Artificial Intelligence 1704, Springer, p.80-88, 1999. also available as: TR-99-04

Flexer A., Bauer H.: Monitoring human information processing via intelligent data analysis of EEG recordings, in Hand D.J., et al.(eds.), Advances in Intelligent Data Analysis, Third International Symposium, IDA-99, Amsterdam, The Netherlands, Proceedings, Lecture Notes in Computer Science 1642, Springer, p.137-148, 1999. also available as: TR-99-03

Flexer A., Bauer H.: Multi-channel piecewise selective averaging of cognitive evoked potentials with variable latency, in Hu Y.-H., et al.(eds.), Neural Networks for Signal Processing IX, Institute of Electrical and Electronics Engineers, Inc., New York, NY, p.459-467, 1999. also available as: TR-99-02

1998

Flexer A., Bauer H.: Discovery of Common Subsequences in Cognitive Evoked Potentials, in Zytkow J.M. and Quafafou M.(eds.), Principles of Data Mining and Knowledge Discovery, Proc. of 2nd European Symposium, PKDD '98, Lecture Notes in Artificial Intelligence 1510, Springer, p.309-317, 1998. also available as: TR-98-07

Magdolen J., Rappelsberger P., Dorffner G., Flexer A., Winterer G.: Artificial neural networks for discriminating relapsing from abstaining alcoholics, Proc. of 4th Int. Symposium on CNS Monitoring, 1998.

Rappelsberger P., Magdolen J., Winterer G., Dorffner G., Flexer A.: Classification of EEG of schizophrenics and depressives with artificial neural networks, Proc. of 4th Int. Symposium on CNS Monitoring, 1998.

1997

Flexer A.: Limitations of Self-Organizing Maps for Vector Quantization and Multidimensional Scaling, in Mozer M.C., et al.(eds.), Advances in Neural Information Processing Systems 9 (NIPS'97), MIT Press/Bradford Books, Cambridge/London, pp.445-451, 1997. also available as: TR-96-23

1996

Flexer A.: Statistical Evaluation of Neural Network Experiments: Minimum Requirements and Current Practice, in Trappl R.(ed.), Cybernetics and Systems '96, Oesterreichische Studiengesellschaft fuer Kybernetik, Wien, 2 vols., pp.1005-1008, 1996. also available as: TR-95-16

Magdolen J., Rappelsberger P., Dorffner G., Flexer A., Winterer G.: Application of Non-Linear Classifiers to EEG at Rest for Identifying Psychiatric Disorders, in Trappl R.(ed.), Cybernetics and Systems '96, Oesterreichische Studiengesellschaft fuer Kybernetik, Wien, 2 vols., pp.592-596, 1996.

1995

Flexer A.: Connectionists and Statisticians, Friends or Foes?, in Mira J. and Sandoval F.(eds.), From Natural to Artificial Neural Computation, Proc. of International Workshop on Artificial Neural Networks, Malaga-Torremolinos, Spain, Springer, LNCS 930, pp. 454-461, 1995.

Flexer A., Rappelsberger P., Dorffner G.: Processing of EEG coherence maps with topologically correct feature maps, in Eiselt M., et al.(eds.), Quantitative and Topological EEG and MEG Analysis, Universitaetsverlag Jena, 1995.

1993

Dorffner G., Rappelsberger P., Flexer A.: Using Selforganizing Feature Maps to Classify EEG Coherence Maps, in Kappen B. and Gielen S.(eds.), ICANN 93, Springer, Berlin/Heidelberg/New York/Tokyo, pp.882-887, 1993.

Rappelsberger P., Dorffner G., Flexer A.: Classification of EEG Coherence Maps of Cognitive Processes, in Loeffler W.H., et al.(eds.), ZNS-Monitoring, Verlag Wilhelm Maudrich, Wien-Muenchen-Bern, pp.375-388, 1993.

Theses

Flexer A.: Die Kategorisierung von EEG-Kohaerenzmaps mit Kohonennetzwerken, Master's Thesis, Institute of Psychology, University of Vienna, 1994. In German.

Short Scientific Articles, Abstracts and Reports

Gruber G., Flexer A., Dorffner G.: Unsupervised continuous sleep analysis based on a single EEG channel (abstract), Journal of Sleep Research, 16th Congress of the European Sleep Research Society, Vol. 11, Supplement 1, p.89, 2002.

Flexer A.: Spatio-temporal Clustering of Cognitive Evoked Potentials, OeGAI Journal, 18(3)25-30, 1999.

Flexer A., Sykacek P., Rezek I., Dorffner G.: Using Hidden Markov Models to build an automatic, continuous and probabilistic sleep stager for the SIESTA project, Medical and Biological Engineering and Computing, Supplement 2, Proceedings of EMBEC'99, p.1658-1659, 1999.

Sykacek P., Roberts S.J., Rezek I., Flexer A., Dorffner G.: Classification in the sampling paradigm: A predictive approach towards a SIESTA sleep analyzer, Medical and Biological Engineering and Computing, Supplement 2, Proceedings of EMBEC'99, 1999.

Sykacek P., Roberts S.J., Rezek I.A., Flexer A., Dorffner G.: Bayesian wrappers versus conventional filters: Feature subset selection in the SIESTA project, Medical and Biological Engineering and Computing, Supplement 2, Proceedings of EMBEC '99, 1999.

Sykacek P., Roberts S.J., Rezek I.A., Flexer A., Dorffner G.: Reliability in preprocessing - Bayes rules SIESTA, Medical and Biological Engineering and Computing, Supplement 2, Proceedings of EMBEC '99, November 4-7, Vienna, Austria, 1999.

Magdolen J., Rappelsberger P., Dorffner G., Flexer A., Winterer G.: Artificial neural networks and data dimensionality reduction mappings for identification of psychiatric disorders in EEG, Medical and Biological Engineering and Computing, Vol. 34, Suppl. 1, Part 2: Proceedings of the 1st Int. Conf. on Bioelectromagnetism, pp.237-238, 1996.

Bauer H., Flexer A., Guttmann G., Leodolter M., Leodolter U., Vitouch O.: Categorization of Topographical Patterns of Spontaneous Cortical Slow Potential Shifts (sSPSs) (abstract), Brain Topography, 1994.

Flexer A.: Die Kategorisierung von EEG-Kohaerenzmaps mit Kohonennetzwerken, OeGAI Journal, 13(2)9-12, 1994.

Flexer A., Rappelsberger P., Dorffner G.: Discrimination of EEG Spectral Parameters Derived During Spatial Imagination Tests with Kohonen Networks (abstract), European Journal of Neuroscience, 1994.

Rappelsberger P., Dorffner G., Flexer A.: Classification of EEG Coherence Maps of Cognitive Processes (Abstract), Journal of Clinical Monitoring, 2(9)139-140, 1993.

Rappelsberger P., Dorffner G., Flexer A.: Kuenstliche Neuronale Netzwerke zur Klassifikation von EEG-Kohaerenz Maps: Beispiele aus psychophysiologischen Studien, Biomed. Technik, Band 38, Ergaenzungsband, 1993. In German.

Medieninhaber / für den Inhalt dieser Seite verantwortlich: Arthur Flexer, Wien