Eric version 1.2 Eric A. Lehmann

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Hello and welcome to my web page!

I was awarded a Ph.D. for my research in the Telecommunications Engineering Department within the Research School of Information Sciences and Engineering (RSISE) at the Australian National University (ANU), Canberra, Australia.

After having worked as Research Engineer on the Audio Tracking Project with National ICT Australia Ltd (NICTA) for a few months, I held a post-doctoral position for three years with the Western Australian Telecommunications Research Institute (WATRI) in Perth, Australia (within the Faculty of Engineering and Computing, Curtin University of Technology, Perth). As part of my work at WATRI, I was involved in the LaMP research project carried out in collaboration with, and partly funded by NICTA.

I am now working as a Research Scientist for the Commonwealth Scientific and Industrial Research Organisation (CSIRO), within the division of Mathematical and Information Sciences in Floreat Park, Western Australia.

This simple web page aims to provide some basic information about who I am and what I do. Please feel free to contact me directly if you would like more specific information about me or my work. Thanks for visiting and enjoy...



On this web page...

Here is a summary of the information that you will find further below on this web page:


Contact details:  here is how you can get hold of me... Back to top

The contact details provided below correspond to my current position with the Commonwealth Scientific and Industrial Research Organisation (CSIRO), within the division of Mathematical and Information Sciences in Floreat Park, Western Australia.

Office:
CSIRO Mathematical & Information Sciences
Leeuwin Centre
65 Brockway Road
Floreat WA 6014
Australia

Mailing address:
CSIRO Mathematical & Information Sciences
Private Bag 5
Wembley WA 6913
Australia

Phone: +61 (0)8 9333 6123
Mobile: +61 (0)4 2344 3864
Fax: +61 (0)8 9333 6121
E-mail:
Web: http://www.eric-lehmann.com



About me:  my life at a glance... Back to top

I was born in Porrentruy, Jura, Switzerland, and spent the first 20 to 25 years of my life around that place doing all sorts of stuff.

Then in 1999, after finishing my undergraduate studies at the ETHZ in Zurich, I challenged myself to go and study overseas for a while. That turned out to work pretty well as I spent about 5 years at the ANU in Canberra, followed by a 3 year postdoc with WATRI in Perth, Australia, and I am now holding a permanent position of Research Scientist with CSIRO, also in Western Australia. On March 23, 2009, I also officially became a citizen of Australia.

The best way to describe myself is probably as a chronic perfectionist who enjoys cooking, playing pool (billiards), swimming, horse riding, and playing guitar and didgeridoo, among lots of other things. One way or another, I also grew up to become a fanatical addict of LaTeX, Linux, and the Calvin & Hobbes comic strips.


Short bio:  if you prefer something more formal...

Eric Lehmann graduated in 1999 from the Swiss Federal Institute of Technology in Zurich (ETHZ), Switzerland, with a Diploma in Electrical Engineering (Master equivalent). He received the M.Phil. and Ph.D. degrees, both in Electrical Engineering, from the Australian National University (Canberra) in 2000 and 2004 respectively.
Between 2004 and 2008, he held various research positions with National ICT Australia (NICTA) in Canberra, ACT, as well as the Western Australian Telecommunications Research Institute (WATRI) in Perth, WA. He is now working as a Research Scientist for the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Perth, within the division of Mathematical and Information Sciences.
His current scientific interests include various aspects of signal processing (including acoustics, speech, array and image processing), as well as Bayesian estimation and tracking (with particular emphasis on the application of sequential Monte Carlo methods, i.e., particle filters).


Curriculum:  here are links to my Curriculum Vitæ (version March 2009): full-blown version (77kB) or condensed form (66kB). Or simply see below for online information...




Education background Back to top


Postgraduate
2001 - 2004 Ph.D. in Engineering, Research School of Information Sciences and Engineering, the Australian National University, Canberra, Australia
Topic: "Particle Filtering Methods for Acoustic Source Localisation and Tracking"
1999 - 2000 M.Phil. in Engineering, Faculty of Engineering and Information Technology, The Australian National University, Canberra, Australia
Topic: "Real-Time Implementation of a Nearfield Broadband Acoustic Beamformer"


Undergraduate
1994 - 1999
Dipl. El.-Ing. ETH (electrical engineering), Department of Electrical Engineering, Swiss Federal Institute of Technology, Zurich, Switzerland (ETHZ)
Specialisation in Signal Processing. Diploma work: "Implementation of Control Algorithms for a Satellite Laser Pointing Mechanism"

Work experience

2008 - present
Research Scientist with the Commonwealth Scientific and Industrial Research Organisation (CSIRO), within the division of Mathematical and Information Sciences in Floreat, Western Australia. This position currently involves the use of image processing techniques for remote sensing data such as airborne and satellite imagery, as well as synthetic aperture radar (SAR). The focus is on the multi-sensor integration and analysis of spatial and temporal data in order to provide accurate information on environmental factors such as vegetation cover and land use, as well as their changes over time. These projects are carried out in collaboration with various industrial and governmental organisations in Australia and overseas.
2005 - 2008 Research Fellow within the Signal Processing Laboratory at the Western Australian Telecommunications Research Institute (WATRI), Perth, Australia. My research at WATRI dealt with various aspects of array signal processing, acoustic speaker tracking and speech enhancement. An example of the type of research I was working on can be found here. As part of my work at WATRI, I was involved in the LaMP research project carried out in collaboration with, and partly funded by NICTA.
2004 (3 months) Research Engineer with National ICT Australia Ltd (NICTA). This work involved the implementation of a real-time algorithm for localising and tracking an acoustic source in reverberant environments, using an array of microphones. This algorithm was based on a particle filtering method using importance sampling, developed during my previous Ph.D. research. Some demonstration results from this application can be found here.

Other achievements



Ph.D. research Back to top

My Ph.D. research project focused on the study of sequential Monte Carlo methods as a new tool for carrying out various signal processing tasks. More specifically, I was working on the problem of acoustic source localisation and tracking in reverberant environments, using array signal processing principles. In this specific case, particle filters offer an efficient way of dealing with the complex problem of reverberation. The project involved primarily the development and test of several particle filter algorithms using recordings of real audio data.

As a major result of this research, a particle filter using the principle of importance sampling was designed and successfully tested. This algorithm allows the automatic detection of new speakers entering the acoustic scene and also automatically recovers following the occurrence a track loss (for instance as a result of a pause in the speech signal). This specific particle filter was also implemented in real-time on a standard Linux-based desktop computer and tested in a typical office room equipped with a 16 sensor array. Some tracking examples from this algorithm have been recorded (originally running in real-time) and can be found for demonstration purposes here.

This project was undertaken under the supervision of Prof. Robert Williamson, ANU, Canberra (also scientific director with National ICT Australia). Part of this research was also done in joint collaboration with Dr. Darren Ward, Imperial College, London.


Other research interests

My Ph.D. led me to focus principally on Bayesian estimation and Sequential Monte Carlo methods, acoustic source localisation and tracking, and array signal processing. More generally however, my main research interests also include (in random order):
  • acoustics
  • digital signal processing
  • speech processing and enhancement
  • algorithms for real-time audio processing
  • multimedia information processing and human-machine interaction
I also highly enjoy any kind of software programming and GUI development in general (Assembler, Matlab, C, etc.).



Publications Back to top

Copyright: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. Copyright notice for IEEE publications: ©20XX IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Copyright notice for JASA publications: ©20XX American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Note: in the lists below, items listed in grey indicate papers that have not been accepted for publication yet. Publications listed in green are the result of my work with the CSIRO division of Mathematical and Information Sciences.

Theses
[T2] "Particle Filtering Methods for Acoustic Source Localisation and Tracking", Ph.D. Thesis (Engineering), ANU, July 2004.
[PDF (4.2MB), gzipped postscript (2.1MB), BibTeX+Abstract]
Cross-ref.: see also [J1], [J2], [C1], [C2] and [R1] for related and/or updated contents.
[T1] "Real-Time Implementation of a Nearfield Broadband Acoustic Beamformer", M.Phil. Engineering Thesis, ANU, November 2000.
[PDF (2MB), gzipped postscript (2.2MB), BibTeX+Abstract]

Journal papers (peer-reviewed)
[J6] Eric A. Lehmann and Anders M. Johansson, Diffuse Reverberation Model for Efficient Image-Source Simulation of Room Impulse Responses, to appear in IEEE Transactions on Audio, Speech and Language Processing, 2010 (accepted for publication).
[PDF Preprint (340kB), BibTeX+Abstract, supplementary material, published paper]
[J5] Anders M. Johansson and Eric A. Lehmann, Evolutionary Optimization of Dynamics Models in Sequential Monte Carlo Target Tracking, IEEE Transactions on Evolutionary Computation, vol. 13, no. 4, pp. 879-894, August 2009.
[PDF Preprint (715kB), BibTeX+Abstract, published paper]
[J4] Eric A. Lehmann and Anders M. Johansson, Prediction of Energy Decay in Room Impulse Responses Simulated with an Image-Source Model, Journal of the Acoustical Society of America, vol. 124, nr. 1, pp. 269-277, July 2008.
[PDF Preprint (450kB), BibTeX+Abstract, supplementary material, published paper]
Cross-ref.: see also [C8] and [R4] for related work.
[J3] Eric A. Lehmann and Anders M. Johansson, Particle Filter with Integrated Voice Activity Detection for Acoustic Source Tracking, EURASIP Journal on Advances in Signal Processing, vol. 2007, Article ID 50870, 11 pages, 2007.
[PDF Preprint (270kB), BibTeX+Abstract, published paper]
Cross-ref.: see also [C4], [C5] and [R2] for related work.
[J2] Eric A. Lehmann and Robert C. Williamson, Particle Filter Design using Importance Sampling for Acoustic Source Localisation and Tracking in Reverberant Environments, EURASIP Journal on Applied Signal Processing, special issue on Advances in Multi-Microphone Speech Processing, vol. 2006, Article ID 17021, 9 pages, 2006.
[PDF Preprint (330kB), BibTeX+Abstract, supplementary material, published paper]
Cross-ref.: see also [C2] for related work.
[J1] Darren B. Ward, Eric A. Lehmann, and Robert C. Williamson, Particle Filtering Algorithms for Tracking an Acoustic Source in a Reverberant Environment, IEEE Transactions on Speech and Audio Processing, vol. 11, nr. 6, pp. 826-836, November 2003.
[PDF Preprint (500kB), BibTeX+Abstract, published paper]
Cross-ref.: see also [C1] for related work.

Conference and workshop papers (peer-reviewed)
[C8] Eric A. Lehmann, Anders M. Johansson, and Sven Nordholm, Reverberation-Time Prediction Method for Room Impulse Responses Simulated with the Image-Source Model, Proceedings of the IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA'07), pp. 159-162, New Paltz, NY, USA, October 2007.
[PDF Preprint (148kB), Revised PDF (150kB), BibTeX+Abstract, supplementary material, published paper]
Note: the revised version of this paper contains a number of minor corrections made to the paper after its publication in WASPAA.
Cross-ref.: see also [J4] and [R4] for related work.
[C7] Eric A. Lehmann, Anders M. Johansson, and Sven Nordholm, Modeling of Motion Dynamics and its Influence on the Performance of a Particle Filter for Acoustic Speaker Tracking, Proceedings of the IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA'07), pp. 98-101, New Paltz, NY, USA, October 2007.
[PDF Preprint (235kB), BibTeX+Abstract, published paper]
Cross-ref.: see also [R3] for related work.
[C6] Thorsten Kühnapfel, Tele Tan, Svetha Venkatesh, and Eric Lehmann, Calibration of Audio-Video Sensors for Multi-Modal Event Indexing, Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'07), vol. 2, pp. 741-744, Honolulu, HI, USA, April 2007.
[PDF Preprint (375kB), BibTeX+Abstract, published paper]
[C5] Anders M. Johansson, Eric A. Lehmann, and Sven Nordholm, Real-time Implementation of a Particle Filter with Integrated Voice Activity Detector for Acoustic Speaker Tracking, in Proceedings of the IEEE Asia Pacific Conference on Circuits and Systems (APCCAS'06), pp. 1004-1007, Singapore, December 2006.
[PDF Preprint (127kB), BibTeX+Abstract, supplementary material, published paper]
Cross-ref.: see also [J3], [C4], and [R2] for related work.
[C4] Eric A. Lehmann and Anders M. Johansson, Experimental Performance Assessment of a Particle Filter with Voice Activity Data Fusion for Acoustic Speaker Tracking, Proceedings of the IEEE Nordic Signal Processing Symposium (NORSIG'06), pp. 126-129, Reykjavik, Iceland, June 2006.
[PDF Preprint (154kB), BibTeX+Abstract, published paper]
Cross-ref.: see also [J3], [C5] and [R2] for related work.
[C3] Eric A. Lehmann, Particle Filtering Approach to Adaptive Time-Delay Estimation, Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP'06), vol. 4, pp. 1129-1132, Toulouse, France, May 2006.
[PDF Preprint (110kB), BibTeX+Abstract, published paper]
[C2] Eric A. Lehmann and Robert C. Williamson, Importance Sampling Particle Filter for Robust Acoustic Source Localisation and Tracking in Reverberant Environments, Joint Workshop on Hands-Free Speech Communication and Microphone Arrays (HSCMA'05), Rutgers University, Piscataway, New Jersey, USA, March 17-18 2005.
[PDF Preprint (120kB), BibTeX]
Cross-ref.: see also [J2] for related work.
[C1] Eric A. Lehmann, Darren B. Ward, and Robert C. Williamson, Experimental Comparison of Particle Filtering Algorithms for Acoustic Source Localization in a Reverberant Room, Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP'03), vol. 5, pp. 177-180, Hong Kong, China, April 2003.
[PDF Preprint (140kB), BibTeX+Abstract, published paper]
Note: due to the cancelation of ICASSP'03 following the SARS epidemic, this paper was presented at the IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA'03), New Paltz, New York, October 2003.
Cross-ref.: see also [J1] for related work.

Non-refereed conference/workshop papers
[N1] Suzanne L. Furby, Peter A. Caccetta, Jeremy F. Wallace, Eric A. Lehmann, and Katherine Zdunic, Recent Development in Vegetation Monitoring Products from Australia’s National Carbon Accounting System, Proceedings of the IEEE International Geoscience & Remote Sensing Symposium (IGARSS'09), vol. IV, pp. 276-279, Cape Town, South Africa, July 2009.

Technical reports (internally reviewed)
[R5] S. L. Furby, K. Zdunic, and E. Lehmann, Monitoring Woody Vegetation Trends: NCAS Trends Product Version 1.0, CSIRO MIS Technical Report 2008/140, 2008.
[R4] Eric A. Lehmann and Anders M. Johansson, Prediction of Energy Decay in Room Impulse Responses Simulated with the Image Source Model, NICTA/WATRI Technical Report PRJ-NICTA-PM-025, Western Australian Telecommunications Research Institute, Perth, Australia, June 2008.
[PDF (750kB), BibTeX+Abstract, supplementary material]
Cross-ref.: this work was published in [C8] and [J4].
[R3] Eric A. Lehmann and Anders M. Johansson, Dynamics Models for Acoustic Speaker Tracking—Preliminary Results, NICTA/WATRI Technical Report PRJ-NICTA-PM-023, Western Australian Telecommunications Research Institute, Perth, Australia, August 2007.
[PDF (510kB), BibTeX+Abstract]
Cross-ref.: this work was published in [C7].
[R2] Eric A. Lehmann and Anders M. Johansson, Particle Filter with Integrated Voice Activity Detection for Acoustic Source Tracking, NICTA/WATRI Technical Report PRJ-NICTA-PM-008, Western Australian Telecommunications Research Institute, Perth, Australia, December 2006.
[PDF (550kB), BibTeX+Abstract]
Cross-ref.: this work was published in [J3], [C4] and [C5].
[R1] Eric A. Lehmann and Robert C. Williamson, Posterior Cramér-Rao Bound for Acoustic Source Tracking in Reverberant Environments, NICTA Technical Report ISSN 1833-9646, National ICT Australia, Canberra, Australia, December 2006.
[PDF (390kB), BibTeX+Abstract]

Copyright: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. Copyright notice for IEEE publications: ©20XX IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Copyright notice for JASA publications: ©20XX American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.



Other links of (potential) interest Back to top
  • Academic ranking of world universities: look for the ranking of ETHZ and ANU...
  • Visit the other version of this website, with lots more stuff to be found there including:
    • Matlab code for image method simulation of small room acoustics
    • Slides of my poster and seminar presentations
    • Demonstration movies of acoustic source localisation and tracking results
    • My suggestions on converting LaTeX documents to .pdf
    • Personal photos, etc.


Last update: January 2010. Maintained by Eric Lehmann -- Please send any comments to the above mentioned address. visitors since July 06.