Department of Numerical Methods and Computer Modeling

Head of the department:

Oleksandr M. Khimich

Academician of the NAS of Ukraine, Doctor of Physical and Mathematical Sciences, Professor, Head. department № 150

The department was founded in 1963 by Doctor of Physical and Mathematical Sciences Professor I.M. Molchanov, who headed it until 2004. 15 employees work in the department, among them - an academician of the National Academy of Sciences of Ukraine, 1 doctor, 5 candidates of sciences.

phone: +38 (044) 526 11 96

e-mail: dept150@insyg.kiev.ua.

The Department operates the Laboratory of Methods and Technologies of Artificial Intelligence (No. 151), the Head, leading researcher., Doctor of physical and mathematical sciences, Professor Syneglazov Viktor Mykhailovych

phone: +38 (044) 067-924-23-37

e-mail: svm@nau.edu.ua

MAIN DIRECTIONS OF SCIENTIFIC ACTIVITY

  • numerical methods and computer algorithms for mathematical modeling of complex objects and processes of various nature;
  • methods and algorithms of parallel and distributed computing for computers with parallel architecture;
  • mathematical models with approximate input data;
  • software of modern and promising computing equipment;
  • neural networks and neural network technologies;
  • intelligent systems of computer mathematics for mathematical modeling of physical and mechanical processes on parallel computers of various architectures.
Відділ чисельних методів та комп'ютерного моделювання

THE MOST IMPORTANT RESULTS

Fundamental:

  • developed methods for research and solving problems of computational mathematics with approximate input data: systems of linear algebraic equations, algebraic problem of eigenvalues, nonlinear equations and systems, systems of ordinary differential equations with initial conditions;
  • developed and researched parallel algorithms for solving computational mathematics problems for computers of hybrid (MIMD, SIMD) architecture;
  • developed a methodology for studying the reliability of computer solutions to problems of computational mathematics (assessment of the proximity of computer solutions to mathematical, hereditary error due to the approximate nature of input data, total error, criteria for ending iterative processes that guarantee the accuracy of approaching accurate solutions language);
  • developed a methodology for using computers to automatically study the mathematical properties of computer models of problems with approximate initial data and automatic construction of algorithms, parallel computing programs and topology for effective problem solving on MIMD-computers;
  • the theory of perturbations for linear systems, pseudoinversion, weighted pseudoinversion is developed, including for the case of change of rank of perturbed matrix;
  • developed and substantiated the methodology of finding a single solution in the subspace of conditionally correct problems with elliptic differential operators;
  • developed principles of intelligent software for automation of research processes and solving scientific and technical problems;
  • developed the concept and architecture of intelligent MIMD-computers for solving problems of science and engineering;
  • developed the structure and architecture of an intelligent parallel workstation on multi-core and graphics processors to solve scientific and technical problems;
  • developed and investigated new direct parallel methods for solving problems of linear algebra based on structural regularization of sparse matrices;
  • estimates of computational and complete errors of solutions of the generalized algebraic problem of eigenvalues of sparse symmetric matrices are obtained.

Applied:

  • developed information technology for processing matrices and solving problems of linear algebra with the analysis of the reliability of the results for supercomputer systems SKIT of V.M. Glushkov Institute of Cybernetics;
  • created a family of intelligent workstations Inparkom for research and solution of scientific and technical problems (together with the State Research and Production Enterprise "Electronmash");
  • created intelligent software (intelligent software packages Inpartool and Inparlib) for automatic research and solving problems of computational mathematics with approximate input data and estimates of reliability of results (part of the standard software of the family of intelligent workstations Inparcom);
  • developed a software package based on parallel calculations for research and solving problems of strength of building structures (part of the standard software of the family of intelligent workstations Inparcom);
  • created and implemented intelligent software for solving in the network of the Ukrainian National Grid problems of strength analysis of building structures;
  • developed (together with the State Research and Production Enterprise "Electronmash") intelligent parallel workstation Inparcom_G on multi-core and graphics processors to solve scientific and technical problems with a capacity of 5 T flops;
  • created on the basis of parallel calculations software package for mathematical modeling of thermal field kinetics in metal welding;
  • developed and developed software and hardware systems for parallel computing based on cluster architecture computers of the Institute of Cybernetics and adapted them to the computational problems of the O.K. Antonov Aviation Scientific and Technical Complex (aerodynamics, strength, design, processing of results, etc.).
  • solved a number of problems of mathematical modeling of welding processes and related technologies in cooperation with the E.O. Paton Electric Welding Institute of NAS of Ukraine, in particular during the implementation of the scientific and technical project "Mathematical modeling of the processes of viscous fracture of thick-walled elements of pipelines with thinning defects."
  • created intelligent software (intelligent software packages Inpartool_G and Inparlib_G) for automatic research and solving problems of computational mathematics with approximate input data and estimates of reliability of results with the function of automatic adaptive adjustment of algorithm, program and computer topology to task properties for computers hybrid architecture (on multi-core and graphics processors).

The scientific activity of the staff of department No. 150 is aimed at advancing cutting-edge science in the following areas: 

  • development and use of artificial intelligence tools in scientific research;
  • high-performance computing (HPC); 
  • error theory, reliability of obtained computer results; 
  • methods and algorithms for parallel and distributed computing for computers with different parallel architectures; 
  • mathematical modeling of physico-mechanical processes with approximate input data on modern computers; 
  • intelligent computer systems.

Artificial intelligence is actively developing in various fields of human activity. In department No. 150, for the first time in the world, tools for automatic image segmentation based on artificial intelligence and deep learning have been developed, which can be applied for machine learning in solving a wide range of computer vision tasks, including intelligent image and video processing. The results obtained in this direction can be implemented in algorithmic and software tools for modeling processes in various fields of human activity, particularly in medical and military areas. For the first time in the world, methods for recognizing the structure of sparse matrices of ultra-large volumes based on artificial intelligence and deep learning have been developed, enabling the automation of the computer selection process of the most efficient algorithm for solving computational mathematics problems on parallel computers of different architectures, using the "profile" of the sparse matrix. Using parallel computing with this approach, it was possible to reduce the time to solve complex problems in civil and industrial construction, nuclear energy, pipeline transport, strength analysis of structures, etc., by one to two orders of magnitude.

High-performance computing is an extremely important area of scientific research. The architecture of modern supercomputers is constantly becoming more complex. However, there are difficulties in their effective use: achieving maximum performance of parallel computations, scalability of application software, and adaptation to new architectural features of computers. As global experience in solving practical problems shows, there are already significant differences due to communication losses between the maximum and operational performance of computers. The emergence of ultra-powerful computers of various architectures (in the future – exaflop supercomputers) requires a new programming paradigm and the development of algorithmic and software tools.

Research has been conducted on the error theory of computer results in solving applied problems, and based on it, a technology for automatic computer investigation of the mathematical properties of computational mathematics problems with approximate data has been developed, using the required (arbitrary) precision, as well as analysis of the reliability of the obtained computer results.

In department No. 150, innovative adaptive methods and algorithmic software for solving computational and applied mathematics problems on parallel computers have been developed. The innovation of the approach lies in recognizing the mathematical properties of computer problems for pathological cases (degenerate and ill-conditioned systems of linear algebraic equations, multiple and close eigenvalues of matrices, etc.) using multi-precision arithmetic; automatic tuning to an efficient computing environment (various parallel architectures: MIMD, hybrid, multicore; different levels of RAM; features of connections between computing elements); automatic parallelization of computations, ensuring efficient use of computer resources.

A significant part of applied processes, as a result of mathematical modeling, boils down to solving computational mathematics problems with sparse data structures of ultra-large volumes. The reliability and efficiency of solving these problems on a computer largely determine the effectiveness of mathematical modeling. Solving the problems of creating or using existing algorithmic and software tools for reliable mathematical modeling of various processes on parallel computers of different architectures requires users – specialists from various fields – to have appropriate knowledge in computational mathematics, architectural features of computers, skills in using various parallel programming technologies, etc.

In department No. 150, an intelligent computer mathematics system InparSolver has been developed, which provides automatic execution of all stages of computer investigation of problem tasks: determining the structure of large-volume sparse data using artificial intelligence methods and reducing them to a regular form; investigating the mathematical properties of problems with approximate data and solving them with adaptive algorithms automatically tuned to an efficient computing environment, with reliability assessments of the results. The application of the intelligent system InparSolver and the intelligent interface based on it for mathematical modeling IIMM allows for a significant redistribution of tasks between the user and the computer compared to traditional technologies, reducing the development time of applied applications for solving scientific and technical problems and improving the quality of the obtained solutions.