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Ivannikov ISPras Open Conference (ISPras)

作者： Nikita Malyshev Irina Dudina Daniil Kutz Alexander Novikov Sergey Vartanov Ivannikov Institute for System Programming of the RAS Lomonosov Moscow State University Moscow Russia

This paper studies the performance and working aspects of SMT solvers on processing formulas acquired during path-sensitive static analysis and dynamic symbolic execution. We review some general patterns of building SMT formulas in the QF_BV logic during analysis and related technical specifics. We also provide the results of comparing different solvers on two sets of requests obtained by Svace static analyzer and Anxiety dynamic symbolic execution tool. It turns out that Yices2 solver performs the best, although, for Svace, notable part of requests can be done better by other solvers. In return, Yices2 misses some features crucial to top-tier analyzers such as deterministic time limit. A brief attempt at making machine learning based solver portfolio shows that solving time can be enhanced, but requires some serious work on feature selection, while technical difficulties may render it unpractical. For Anxiety we found out that with Yices2 incremental solving is almost always faster (sometimes dozens of times faster) than non-incremental. Moreover, the more queries we solve incrementally, the higher acceleration we get.

关键词： Tools Static analysis Computer crashes Performance analysis Portfolios Dynamic programming Buildings

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Cost-Efficient Numerical Schemes for the Boundary Integral Equation Solution in 2D Vortex Methods 10

Cost-Efficient Numerical Schemes for the Boundary Integral E...

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10th All-Russian Conference on Irreversible Processes in Nature and Technology

作者： Kuzmina, Kseniia Marchevsky, Ilia Moreva, Victoriya Ryatina, Evgeniya Ivannikov Institute for System Programming of the RAS Alexander Solzhenitsyn st. 25 Moscow109004 Russia Bauman Moscow State Technical University 2-nd Baumanskaya st. 5 Moscow105005 Russia

The problem of the flow simulation around airfoils using Lagrangian vortex methods is considered. Numerical schemes of the second order of accuracy for free vortex sheet intensity distribution along the airfoil are developed for smooth and non-smooth airfoils. The schemes are based on the Galerkin approach with piecewise-constant and piecewise-linear basis functions. The finite element method ideas are used and the resulting piecewise-linear scheme has the same numerical complexity as the scheme with piecewise-constant numerical solution. The modification of a FEM-Type scheme is developed for non-smooth airfoils which permits to take into account the discontinuity of the solution at the specified points;its computational cost increases insignificantly. © Published under licence by IOP Publishing Ltd.

关键词： Airfoils

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Exact solutions of boundary integral equation arising in vortex methods for incompressible flow simulation around elliptical and Zhukovsky airfoils 10

Exact solutions of boundary integral equation arising in vor...

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10th All-Russian Conference on Irreversible Processes in Nature and Technology

作者： Kuzmina, Kseniia Marchevsky, Ilia Ryatina, Evgeniya Ivannikov Institute for System Programming of the RAS Alexander Solzhenitsyn st. 25 Moscow109004 Russia Bauman Moscow State Technical University 2-nd Baumanskaya st. 5 Moscow105005 Russia

The problem of 2D incompressible flow simulation around airfoils using vortex methods is considered. An exact solution for the boundary integral equation with respect to a free vortex sheet intensity at the airfoil surface line that arises in such problems is obtained. The exact solution is constructed for flows around elliptical and Zhukovsky airfoils using the theory of complex potentials and conformal mappings technique. It is possible to take into account the influence of singularities in the flow domain-point vortices which simulate vortex wake. The obtained exact solutions can be used to verify and estimate the accuracy of numerical schemes for the boundary integral equation solution: such procedure is also described in details. © Published under licence by IOP Publishing Ltd.

关键词： Airfoils

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3D hydrodynamical simulation of accretion disk in binary star system using RKDG CFD solver

3D hydrodynamical simulation of accretion disk in binary sta...

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Workshop on Numerical Modeling in MHD and Plasma Physics: Methods, Tools, and Outcomes. Honor of academician Anatoly Alekseev's 90th Birthday

作者： Galanin, M.P. Lukin, V.V. Chechetkin, V.M. Keldysh Institute of Applied Mathematics of the RAS Moscow Russia Ivannikov Institute for System Programming of the RAS Moscow Russia

We present the results of 3D-hydrodynamical simulations of accretion disk in close binary star system. The model includes the optical star filling its Roche lobe, a gas stream emanating from the inner Lagrangian point of the binary system, and the accretion disc structure. A cold hydrogen gas stream is initially emitted towards a point-like gravitational centre. A stationary accretion disc is formed in about 5 orbital periods after the beginning of accretion. The model uses realistic cooling function for hydrogen. The simulation of accreting gas dynamics is performed using second order Runge-Kutta discontinuous Galerkin CFD solver for unstructured tetrahedral meshes. The monotonicity technique based on Hermite WENO solution reconstruction is implemented. Utilizing the hydrodynamical simulations the sinthetic light curves of the system are calculated as the volume emission of optically thin layers along the line of sight. The simulations results are in a good agreement with observations. © 2018 institute of Physics Publishing. All rights reserved.

关键词： Gas dynamics

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RKDG method for 2D gas dynamics simulation on uniform rectangular meshes 10

RKDG method for 2D gas dynamics simulation on uniform rectan...

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10th All-Russian Conference on Irreversible Processes in Nature and Technology

作者： Korchagova, Victoria Fufaev, Ivan Lukin, Vladimir Marchevsky, Ilia Sautkina, Sofya Bauman Moscow State Technical University 2-nd Baumanskaya st. 5 Moscow105005 Russia Ivannikov Institute for System Programming of the RAS Alexander Solzhenitsyn st. 25 Moscow109004 Russia Keldysh Institute of Applied Mathematics RAS Miusskaya sq. 4 Moscow125047 Russia

This paper is devoted to a numerical simulation of 2D gas dynamics flows on uniform rectangular meshes using the Runge-Kutta-Discontinuous-Galerkin (RKDG) method. The RKDG algorithm was implemented with in-house C++ code based on the experience in the investigation of 1D case. The advantage of the RKDG method over the most popular finite volume method (FVM) is discussed: Three basis functions being applied in the framework of the RKDG approach lead to a considerable decrease of the numerical dissipation rate with respect to FVM. The results of the acoustic pulse simulation on a sufficiently coarse mesh with the piecewise-linear approximation show a good agreement with the analytical solution in contrast to the FVM numerical solution. For the Sod problem, the results of the discontinuities propagation illustrate the dependence of the scheme resolution on the numerical fluxes, troubled cell indicator and the limitation technique choice. The possibility to resolve strong shocks is demonstrated with the Sedov cylindrical explosion test. © Published under licence by IOP Publishing Ltd.

关键词： Finite volume method

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Implementation of Regularized Equations for the Disk Pump Simulation Problem in OpenFOAM

Implementation of Regularized Equations for the Disk Pump Si...

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Ivannikov ISPras Open Conference (ISPras)

作者： Tatiana Stenina Tatiana Elizarova Daniil Ryazanov Eugene Ryabinkin Ivannikov Institute for System Programming of the RAS Lomonosov Moscow State University Keldysh Institute of Applied Mathematics of the RAS Moscow Institute of Physics and Technology NRC Kurchatov Institute

Creating an effective pump that is able to maintain blood circulation in a heart with appropriate medical indications is undoubtedly a crucial task. First versions of such devices are currently being created and tested on the basis of IFPM SB ras, Novosibirsk. This work is devoted to a pump numerical simulations in order to optimize parameters. Equations of viscous incompressible fluid flow are used for this purpose. Implemented numerical algorithm is based on the regularization of the initial equations, which applies a finite volume method that avoids limiting procedures and includes them controlled numerical dissipation. Calculations are carried out within open software package OpenFOAM is installed at ISP ras. Unsteady flow in the pump is studied.

关键词： Mathematical model Computational modeling Blood Numerical models Geometry Trajectory Rotors

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Minimizing Deterministic Timed Finite State Machines

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IFAC-PapersOnLine 2018年第7期51卷 486-492页

作者： Bresolin, Davide Tvardovskii, Aleksandr Yevtushenko, Nina Villa, Tiziano Gromov, Maxim University of Padova Padova Italy Tomsk State University Tomsk Russia Institute for System Programming RAS Moscow Russia University of Verona Verona Italy

Timed automata and timed finite state machins (TFSMs) have been proposed to represent more accurately the behaviour of systems in continuous time. Recently, we introduced a model of TFSMs that extends the expressive power of FSMs by introducing a single clock, timed guards which restrict when the input/output transitions may happen, and timeouts on the transitions. We derived an abstraction procedure to convert a TFSM into an equivalent untimed FSM. Here, we extend the model with output timeouts and derive a minimal form for deterministic TFSMs that reduces the number of states, the number of transitions and the timeout values at each state. © 2018

关键词： Real time systems

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Study of aerophysical processes in the wind farm of the Republic of Adygey

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AIP Conference Proceedings 2021年第1期2351卷

作者： A. V. Ivanov S. V. Strijhak 1)Ivannikov Institute for System Programming of the Russian Academy of Sciences (ISP RAS) 109004 Moscow Russia 2)M. V. Keldysh Institute of Applied Mathematic of the Russian Academy of Sciences (KIAM RAS) 125047 Moscow Russia

The article presents numerical modeling of meteorological processes in the wind farm of the Republic of Adygea. The wind farm has 60 wind turbines, the capacity of each wind turbine is 2.5 MW. A test configuration with 4 nested domains was developed to study the wind farm. The computations were carried out using the WRF-ARW computational code with the wind turbine parameterization module. The calculation was performed for the period 01.04.2020 00:00 – 01.05.2020 00:00 UTC. As a result, the dimensions of the wake formed by the wind farm were obtained, and the influence of the parameterization of wind turbines on the wind distribution calculation was shown. The potential vortex wake can reach sizes up to 15 km. The losses of generated power can reach 1 MW inside the vortex wake. The computations were run on high performance cluster UNIHUB of ISP ras.

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Efficient command buffer recording for accelerated rendering of large 3D scenes 12

Efficient command buffer recording for accelerated rendering...

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12th International Conference on Interfaces and Human Computer Interaction 2018, 11th International Conference on Game and Entertainment Technologies 2018 and 12th International Conference on Computer Graphics, Visualization, Computer Vision and Image Processing 2018, part of the Multi Conference on Computer Science and Information systems 2018, MCCSIS 2018

作者： Gonakhchyan, Viacheslav I. Ivannikov Institute for System Programming of the RAS Alexander Solzhenitsyn st. 25 Moscow109004 Russia

ISBN: (纸本)9789898533791

Interactive rendering of 3D scenes with a big number of objects is computationally intensive. It is hard to determine an efficient way of rendering command recording and submission. Command buffers can be recorded each frame, but that incurs a performance penalty. Command buffers can be created as a pre-processing step and then included in the primary command buffer during rendering, but that requires additional memory for holding multiple buffers. Command buffers can be created for a node in a decomposition hierarchy, but we need to determine the proper number of levels and fit them into the limited amount of memory. We propose a rendering algorithm, which is based on the space decomposition hierarchy with the determined height. It performs frustum culling and occlusion culling during the CPU idle time to improve the rendering performance. We show that the proposed algorithm efficiently handles scenes with a big number of objects and high depth complexity. © 2018.

关键词： Three dimensional computer graphics

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Toolkit for simulation modeling of queue systems in Grid 1

Toolkit for simulation modeling of queue systems in Grid

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1st International Workshop on Information, Computation, and Control systems for Distributed Environments, ICCS-DE 2019

作者： Feoktistov, A.G. Kostromin, R.O. Fereferov, E.S. Tchernykh, A. Basharina, O.Yu. Dmitriev, V.I. Kurzybova, Ya.V. Matrosov Institute for System Dynamics and Control Theory of SB RAS Lermontov St. 134 Irkutsk664033 Russia CICESE Research Center Ensenada-Tijuana Highway Ensenada22860 3918 Mexico Ivannikov Institute for System Programming of RAS Alexander Solzhenitsyn st. 25 Moscow109004 Russia South Ural State University Lenin prospect 76 Chelyabinsk454080 Russia Irkutsk State University Karl Marx St. 1 Irkutsk664003 Russia

The paper addresses an important problem related to automation of simulation modeling of queue systems using high-performance computing. There is a large spectrum of tools for the simulation modeling of such systems. However, these tools often do not use the possibilities of subject-oriented high-performance computing in full. The purpose of the study is the development of the new tools for automation of the simulation modeling of queue systems in a heterogeneous distributed computing environment. To this end, we develop specialized applications for parameter sweep computations in such an environment. A methodology of the application development is based on the integrated use of methods of the conceptual and wireframe programming, methods of the computations planning and resources allocation, methods of parameter sweep computations, and methods of the data analysis. We develop the toolkit named SIRIUS III for the simulation modeling of queue systems using high-performance computing. In addition, we design a conceptual model that represents knowledge about both the subject domain of solved problems and computing environment. Using the proposed toolkit, we solved a number of problems related to warehouse logistics. Computational experiments showed the high scalability of parameter sweep computations on heterogeneous resources. Copyright © 2019 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).

关键词： Queueing theory

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