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Äàòà èçìåíåíèÿ: Tue Dec 16 16:01:34 2014
Äàòà èíäåêñèðîâàíèÿ: Sun Apr 10 09:52:24 2016
Êîäèðîâêà:
Laboratory of Systems for Automated Image Processing
Laboratory of Systems for Automated Image Processing
Head of Laboratory Goncharsky A.V., Ph.D., Professor
Phone: 939-2759,    Fax: 939-2768    E-mail: gonchar@srcc.msu.ru.
    Principal research interests
    Research area
    Results of research projects
    Grants
    Partners
    Main publications
    Staff
    Cooperation with other Institutions

Principal research interests
  • Theoretical researches and mathematical modeling in problems of flat computer optics synthesis and generation of the holograms

Research area
  • Theoretical researches and numerical analysis in the field of computer synthesis of the 2D - 3D holograms, hidden images, kinegram and holograms with natural colours, development of methods of the image processing and pattern recognition, creation of the software in area of the holograms generation.

  • Development of efficient methods for solving inverse problems of x-ray and wave tomography

Results of research projects

1. Flat Optics
The basic results of laboratory are connected with theoretical researches and mathematical modeling in the area of computer synthesis of the holograms and numerical analysis of the problems. Problems of image processing and pattern recognition in computer synthesis of the holograms arise, for example, in protection of a different sort of the documents and goods. The arising thus mathematical problems require essentially new approach to the analysis and construction of the algorithms.

To number of thus problems concern:

  • Theoretical analysis and mathematical modeling of interactions of radiation with reflecting surface microrelief, when compare a size of structure with the length of a wave, research of effects of radiation polarization, electrodynamic models of difraction; creation of the programs for solving of direct problems of difraction on elements making the hologram. Electrodynamic models in such poses are unsufficiently reflected in the world literature.

  • Mathematical simulation of holograms computer visualization in real time; computer reading of the holograms, forming the image; solving of the inverse problems of image formations from the radiation diagram; development of methods of generated image processing and pattern recognition, development of algorithms of pattern recognition invariant for groups of turn and shift and etc.; synthesis of 3D holograms; stereoeffects creation; optimization of methods and algorithms.

The results of laboratory researches were used for holographic elements manufacturing. By being available results of international examination the generated holograms are on the world level or higher.

2. Wave Tomography
Efficient iterative methods are proposed for solving the inverse problem of wave tomography. The inverse problems are considered as coefficient inverse problems for second-order differential equation of hyperbolic type. Mathematical models describe diffraction, refraction, multiple scattering and attenuation. Mathematical task is inverse non-linear ill-posed problem.

Efficient methods have been developed for solving 2-D inverse tomography problems (layer-by-layer diagnostics of a 3D object). Efficient methods have been developed for solving 3-D inverse tomography problems. The methods are based on direct computation of the gradient of the residual functional by solving the conjugate problem for the wave equation.

The results of our study can be used in such fields as ultrasonic diagnosis, non-destructive testing in industry, civil engineering, electromagnetic sounding of the Earth's subsurface layers, and so on. In medicine the currently developed ultrasound tomography devices can be an alternative to x-ray tomography and MRT. The primary task of ultrasound tomography is to address the problems of differential diagnosis of breast cancer — one of the most pressing issues of modern health care. Ultrasonic tomography devices can solve this problem by making it possible to perform regular examinations using safe, non-ionizing radiation. From a medical viewpoint, diagnostic facilities for the differential cancer diagnosis should have a resolution of 3 mm or better.

Common medical devices for ultrasound examinations usually employ the reflection-based scheme. In these cases we usually cannot sound the object from all directions, and both the detectors and the sources are located on the same side of the domain studied, or even in the same plane. Ultrasonic tomography schemes allow to use both reflected and transmitted data. The methods of solving inverse problems as coefficient inverse problems can provide information about the internal structure of the object even in the case of limited data tomography. In application to breast cancer diagnostics, we are not able to place sources and detectors on the thorax side.

Currently, the development of ultrasonic tomography devices is at the stage of prototyping. One of the main challenges faced by ultrasonic tomography is the development of mathematical methods for solving inverse problems. Attempts to use the well-established ray transmission tomography scheme appear quite natural. Unlike X-ray tomography, where rays have the form of straight-line segments, rays in ultrasonic tomography are bent by refraction. In this formulation the inverse problem is nonlinear, and iterative methods are needed to solve it.

Supercomputers are needed to address such inverse problems in terms of the wave model described by second-order hyperbolic equations. The algorithms developed in this study are easily scalable on supercomputers, including GPU, running up to several tens of thousands of processes in parallel.

Low frequency ultrasonic tomography method has been developed. In this case the wavelength about 5mm can be used in ultrasonic tomography devices. The frequencies corresponding to this wavelength are several times lower than those used in existing prototypes. It is important because attenuation in soft tissues is strongly dependent on frequency: the higher the frequency the greater is attenuation.

Recent results are published in the following papers:

Goncharsky AV, Romanov SY. Supercomputer technologies in inverse problems of ultrasound tomography. Inverse Probl. 2013;29:075004.

Goncharsky AV, Romanov SY, Seryozhnikov SY. Inverse problems of 3D ultrasonic tomography with complete and incomplete range data. Wave motion 2014;51:389-404.

Inverse problems of ultrasound tomography in models with attenuation. Phys Med Biol. 2014 Apr 21;59(8):1979-2004. doi: 10.1088/0031-9155/59/8/1979. Epub 2014 Apr 2.

Grants
  • Grant RFBR. # 12-07-00304-Þ «Development of methods to solve non-linear 3D coefficient inverse problems of wave tomography on supercomputers»

  • Grant RFBR. # 13-07-00824 þ «Development of highly scalable methods of simulation of ultrasonic wave propagation, including attenuation, in mechanics of continua on petaflops-scale supercomputers»

  • Government contract ¹ 07.514.12.4024 "Creation of super-scalable application software for medical ultrasonic imaging on petaflops-scale supercomputers"

Partners
Main publications
Staff
The staff of the laboratory consists of 8 persons, including
  • Head of Laboratory Goncharsky A.V., Ph.D., Professor
  • The leading scientific researcher: Romanov S.Y. Ph.D.
  • The scientific researcher: Agayan G.M. Ph.D.
  • The senior researcher: Goncharsky A.A. Ph.D.
  • The senior researcher: Seryozhnikov S.Y. Ph.D.
Cooperation with other Institutions
  • the scientists and organizations with the purpose of holograms perfection and realization are invited to cooperation

  • Flat computer optical elements developed by the laboratory are used for protection against counterfeit. Main partner in this field is Goznak.

  • Mathematical modeling and methods for solving invrse problems of 3D ultrasonic tomography are developed in cooperation with Vishnevsky Institute of Surgery of the Russian Academy of Medical Sciences.