Gennady A. Ryzhikov

Department of Physics and Technology, University of Bergen

Allégaten 55, N-5007 Bergen, Norway

Phone: +47 55 543948; Fax: +47 55 543961

Cat Quant - logo: Dept. of Physics, SPbU
Theoretical Physics, University of St. Petersburg (SPbU), Russia


MS in theoretical physics ("Calibration theories of relativistic extended objects")
PhD in geophysics, more than 20 years of experience in R&D:
applied ill-posed and inverse problems, theory of regularization,
applied mathematics, data processing, parameter identification,
computerized tomography, optimization problems, etc., mainly in geophysics:
mathematical geophysics/algorithm development/novel approaches
to signal processing, multiple suppression, diffraction tomography
in seismics/optics, 3D depth seismic imaging, seismic monitoring,
Author of a few novel approaches to data processing.
Real data  have been processing with the approaches:
satellite/airborne IR/UV radiation data; side-scanning sonar data,
seismic data: VSP, 2D/3D, 3C, etc.; in particular:
        VSP- and 3D-data from Norsk Hydro:
   Biryulina, M. and Ryzhikov, G., 1997,
Convex Body Regularization (CoBR) in Linear Inversion/Deconvolution,
59th EAGE Annual Conference, Geneva, Switzerland, 1997, P122;
        3C crosswell-data from Conoco:
   M.S. Biryulina, K.S. Osypov, G.A. Ryzhikov, J.A. Scales, 1996
Seismic Inversion Using Energetic Envelopes,
AGU 96 Fall Meeting, S72B-03;
       regional (Italy, Germany, Norway) seismological network 3C-data
   Ryzhikov, G., Biryulina, M. and E. Husebye, 1996,
A novel approach to automatic monitoring of regional seismic eventsIRIS-page
IRIS Newsletter,v.15, pp. 12-14;
        2D-data from Norsk Hydro:
   G.A.Ryzhikov and M.S. Biryulina , 1998,
Sharp Deconvolution in Elimination  of Multiples:SEG-98.pdf: ~240 Kb
68th  Ann. Internat. Mtg. Soc. Expl. Geophys.,
Expanded Abstracts, ST-18.3, pp. 1983-1986.
    Biryulina, Marina and  Ryzhikov, Gennady,  1999,
MSvE-  A novel approach to statistical estimation of primaries
superimposed on incoherent multiplesEAGE99: ~110 Kb (ps.gz: 110Kb)
61st Mtg. Eur. Assoc. Expl Geophys.,
Extended Abstracts,  99, Session:  1-10
   Ryzhikov, Gennady  and  Biryulina, Marina,  1999,
Removal of intrabed multiples via Source-Signature Invariant Inversion,
69th  Ann. Internat. Mtg. Soc. Expl. Geophys.,
Expanded Abstracts, Vol. II, SPRO 1.8, pp. 1076-1079  (PDF: 575 Kb)  (ps.gz: 430 Kb)
   Biryulina, Marina and  Ryzhikov, Gennady,  2000,
Imaging of reflectors under uncertainties in macromodelEAGE2000: ~250 Kb(PDF: 250Kb)
62nd Mtg. Eur. Assoc. Expl Geophys.,
Extended Abstracts,  2000, Session:  B-55
   Ryzhikov, Gennady and Biryulina, Marina,  2001,
Can we hear seabed lithology from shipboard ?AAPG 2001, St. Petersburg: ~170 Kb  (PDF: 340 Kb)   (ps.gz: 170Kb)
in: VNIGRI / AAPG Regional International Conference, ,
July 15-18, 2001, St. Petersburg, Russia,
Extended Abstracts,  Session:  P4 -8

   Ryzhikov, Gennady and Biryulina, Marina,  2004,
Predicting large stochastic system evolution (COIF)

Retrieval of the physiological state of human skin from UV-Vis reflectance spectra
Journal of Photochemistry and Photobiology B: Biology, 93 (1), 2008, pp. 23-31

Changes in human skin after topical PDT with hexyl aminolevulinate
Photodiagnosis and Photodynamic Therapy, 5 (3), 2008, pp. 176-181

Optical transfer diagnosis of pigmented lesions: a pilot study
Skin Research and Technology, 15, 2009, pp. 330-337

Optical Transfer Diagnosis of Pigmented Lesions
Dermatologic Surgery, 36, 2010, pp. 1979-1986

Modeling of radiation transport in coupled atmosphere-snow-ice-ocean systems
Journal of Quantitative Spectroscopy & Radiative Transfer, 112, 2011, pp. 714-726

W0 2009/117485 A3
Optical method for determining morphological parameters and physiological properties of tissue
W0 2009/094623 A3
Method for discriminating between malignant and benign tissue lesions

Bergen University logo
Senior Researcher at the University of Bergen, Norway : Since 1993
St. Petersburg State University: 275 years
Senior research scientist, Institute of Physics, SPbU, Russia: Prior to 1993


Author of a new global optimization algorithm ( RGA-algorithm),
which has been successfully applied for 3D nonlinear inversion:
3D nonlinear inversion by entropy of image contrast optimization,  1995,
 Nonlinear Processes in Geophysics, v.2, n.3/4, pp. 228-240
                            and for real data processing:
  A new approach to coherency inversion by global optimization, 1995:
  65th SEG Meeting, 1995, Expanded Abstracts, p.1081-1083.

Author of a few novel algorithms for 3D prestack inversion/migration, e.g.
 Moser, T., Biryulina, M. and G. Ryzhikov, 1997,
  Born Inversion in Realistic Backgrounds by Means
  of Recursive Green's Functions,
  in: Inverse Problems of Wave Propagation and Diffraction,
  G. Chavent and P.C. Sabatier, Eds.,
  Lecture Notes in Physics, Vol. 486, Springer, pp.306-319

Author (with V. Troyan) of a monograph (in Russian *):
Ryzhikov  G.A.  and  V.N. Troyan,
Tomography  and  remote  sensing inverse problems,
St.Petersburg Univ. Press, St. Petersburg, 1994, 220 pp.

Author of novel METHODS/ALGORITHMS of regularization:
        Realized as scientific software,
        published mostly in technical reports:
Regularization in a  Sobolev space of infinite order
'Convex Body Regularization'  (CoBR:
 constrains on  values of a set of given linear functionals on
 an estimated function)
Combined statistical/functional regularization
Self-adaptive regularization, etc.

Author of novel METHODS/ALGORITHMS of machine learning/artificial intelligence
        Realized as a nolinear binary classifier on labeled noisy data sets:
        Patent W0 2009/117485 A3


Russian, English


Supervision of PhD students, research assistants, research seminars,
lecturing, an ability to work with specialists in varied fields,
strong interest in interdisciplinary researches,
R&D-project initiation/leadership.


To the 1st page

*Some  topics  from the book were published  in English  ,
 yet  in   "Mathematical Problems in the Theory of Wave Propagation",
 Part 26,  1997,  Part 28,  1999,  or  in V.Troyan's  lectures  "Inverse  seismic  problems"