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Numerical Simulation of Propeller Hydrodynamics Using the Open Source Software 1

23rd International Conference on Computational Science, ICCS 2023

作者： Britov, Andrey Yarikova, Sofya Epikhin, Andrey Elistratov, Stepan Zhang, Qin Ivannikov Institute for System Programming of the RAS Moscow Russia Shirshov Institute of Oceanology of the RAS Moscow Russia Ocean University of China Qingdao China

ISBN: (数字)9783031360305

ISBN: (纸本)9783031360299

The paper presents the results of numerical simulation of the propeller Ka4-70 using the actuator line model in the OpenFOAM, AMReX and Nek5000 open-source software. The modifications of the tools for wind farm simulation for these packages are carried out. Features of these implementation are described. For numerical calculations the LES and IDDES turbulence models are used. A comparison of the computational costs and accuracy of flow structures are made for the actuator line model using different methods and the arbitrary mesh interface approach. The actuator line model provides force characteristics and flow structures with good enough accuracy. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.

关键词： Actuators

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Verifying cryptographic protocols by Tamarin Prover

Verifying cryptographic protocols by Tamarin Prover

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2020 Ivannikov Memorial Workshop, IVMEM 2020

作者： Vinarskii, Evgenii Demakov, Alexey Kamkin, Alexander Yevtushenko, Nina Moscow Institute of Physics and Technology Higher School of Economics Ivannikov Institute for System Programming of the Ras Lomonosov Moscow State University Moscow Russia

ISBN: (纸本)9781728190884

Cryptographic protocols are utilized for establishing a secure session between 'honest' agents which communicate strictly according to the protocol rules as well as for ensuring the authenticated and confidential transmission of messages. The specification of a cryptographic protocol is usually presented as a set of requirements for the sequences of transmitted messages including the format of such messages. Note that protocol can describe several execution scenarios. All these requirements lead to a huge formal specification for a real cryptographic protocol and therefore, it is difficult to verify the security of the whole cryptographic protocol at once. In this paper, to overcome this problem, we suggest verifying the protocol security for its fragments. Namely, we verify the security properties for a special set of so-called traces of the cryptographic protocol. Intuitively, a trace of the cryptographic protocol is a sequence of computations, value checks, and transmissions on the sides of 'honest' agents permitted by the protocol. In order to choose such set of traces, we introduce an Adversary model and the notion of a similarity relation for traces. We then verify the security properties of selected traces with Tamarin Prover. Experimental results for the EAP and Noise protocols clearly show that this approach can be promising for automatic verification of large protocols. © 2020 IEEE.

关键词： Cryptography

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Page Layout Analysis for Refining Table Extraction from PDF Documents

Page Layout Analysis for Refining Table Extraction from PDF ...

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2021 Ivannikov Ispras Open Conference, ISPRAS 2021

作者： Mikhailov, Andrey Shigarov, Alexey Matrosov Institute For System Dynamics And Control Theory Siberian Branch Of The Russian Academy Of Sciences Irkutsk664033 Russia Ivannikov Institute For System Programming Russian Academy Of Sciences Moscow109004 Russia

ISBN: (纸本)9781665423304

Perhaps, PDF is the most popular format to share non-editable documents. PDF documents are often untagged. In particular, this means that positions and the cell structure of tables are not designated explicitly. PDF table detection predicts bounding boxes of tables on document pages. Some of the predictions inevitably happen to be false. This negatively affects the accuracy of table structure recognition. We argue that the page layout analysis in pre- and post-processing can refine the table detection. We suggest pre-processing algorithms for the recognition of headings, running titles, paragraphs, and images in PDF pages. This allows selecting areas of interest inside pages where real tables can be placed. Then we use deep neural networks to predict tables only in these areas. We also propose post-processing algorithms to verify predictions and filter out false table candidates after table detection. Our empirical study shows that the proposed approach reduces errors in the table detection and improve the PDF table extraction overall. © 2021 IEEE.

关键词： Extraction

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Double Layer Potential Density Reconstruction Procedure for 3D Vortex Methods 19th

Double Layer Potential Density Reconstruction Procedure for ...

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19th International Conference on Finite Elements in Flow Problems, FEF 2017

作者： Marchevsky, Ilia K. Shcheglov, Georgy A. Bauman Moscow State Technical University Moscow Russia Ivannikov Institute for System Programming of the Russian Academy of Sciences Moscow Russia

ISBN: (纸本)9783030307042

A new approach is developed for the no-slip boundary condition in vortex methods. The procedure of double layer potential density reconstruction is considered, which consist of two steps. Firstly the integral equation with respect to vortex sheet intensity is solved, which expresses the equality between the tangential components of flow velocity limit value and the body surface velocity. It is solved by using a Galerkin approach. Secondly, the least-squares procedure is implemented, which permits to find nodal values of the potential. It is shown that the developed algorithm makes it possible to improve significantly the quality of solution for the bodies with very complicated geometry and low-quality surface meshes. It can be useful for CFD applications and visual effects reproducing in computer graphics. © Springer Nature Switzerland AG 2020.

关键词： Boundary integral equations

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Directed Generation of Test Data for Static Semantics Checker

Communications in Computer and Information Science

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Communications in Computer and Information Science 2009年 17卷 753-768页

作者： Arkhipova, M.V. Zelenov, S.V. Institute for System Programming of the Russian Academy of Sciences Russia

ISBN: (纸本)9783540884781

We present an automatic method, named SemaTESK, for generation of test sets for a translator front end. We focus on the validation and verification of static semantics checker. Most the know methods for semantics test generation produce test suites by filtering a pre-generated set of random texts in the target language. In contrast, SemaTESK allows to generate tests for context conditions directly. It significantly reduces generation time and allows reaching completeness criteria defined in the paper. The presented method to specify static semantics allows to formalize informal requirements described in normative documents (e.g. standard). The method includes SRL notation for compact formal specification of context conditions and STG tool for efficient generation of test suite from SRL specification. The SemaTESK method has been used in a number of projects, including testing static semantics checkers of C and Java. © Springer-Verlag Berlin Heidelberg 2008.

关键词： Formal specification

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Coverage-directed verification of microprocessor units based on cycle-accurate contract specifications

Coverage-directed verification of microprocessor units based...

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East-West Design and Test Symposium

作者： Kamkin, Alexander Software Engineering Department Institute for System Programming Russian Academy of Sciences 25 B. Kommunisticheskaya Moscow 109004 Russia

ISBN: (纸本)9781424434039

In this paper we describe a method for simulation-based verification of microprocessor units based on cycle-accurate contract specifications. Such specifications describe behavior of a unit in the form of preconditions and postconditions of microoperations. Test sequence generation is based on traversal of FSM constructed automatically from specifications and test coverage definition. We have successfully applied the method to several units of the industrial MIPS64- compatible microprocessor. © 2008 IEEE.

关键词： Specifications

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Non-intrusive Virtual Machine Analysis and Reverse Debugging with SWAT

Non-intrusive Virtual Machine Analysis and Reverse Debugging...

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IEEE International Conference on Software Quality, Reliability and Security (QRS)

作者： Pavel Dovgalyuk Ivan Vasiliev Natalia Fursova Denis Dmitriev Mikhail Abakumov Vladimir Makarov Institute for System Programming Moscow Russia

ISBN: (数字)9781728189130

ISBN: (纸本)9781728189147

This paper presents SWAT - system-Wide Analysis Toolkit. It is based on open source emulation and debugging projects and implements the approaches for non-intrusive system-wide analysis and debugging: lightweight OS-agnostic virtual machine introspection, full system execution replay, non-intrusive debugging with WinDbg, and full system reverse debugging. These features are based on novel non-intrusive introspection and reverse debugging methods. They are useful for stealth debugging and analysis of the platforms with custom kernels. SWAT includes multi-platform emulator QEMU with additional instrumentation and debugging features, GUI for convenient QEMU setup and execution, QEMU plugin for non-intrusive introspection, and modified version of GDB. Our toolkit may be useful for the developers of the virtual platforms, emulators, and firmwares/drivers/operating systems. Virtual machine intospection approach does not require loading any guest agents and source code of the OS. Therefore it may be applied to ROM-based guest systems and enables using of record/replay of the system execution. This paper includes the description of SWAT components, analysis methods, and some SWAT use cases.

关键词： Instruments Debugging Software quality Virtual machining Software reliability Graphical user interfaces Software development management

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Advanced Grammar-Based Fuzzing

Advanced Grammar-Based Fuzzing

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2022 Ivannikov Memorial Workshop, IVMEM 2022

作者： Sargsyan, Sevak Hakobyan, Jivan Mehrabyan, Matevos Mkoyan, Ruslan Sahakyan, Vardan Melkonyan, Vahagn Arutunian, Mariam Fahradyan, Arman Avetisyan, Arutyun Russian-Armenian University Center of Advanced Software Technologies Yerevan Armenia Programming of the RAS Ivannikov Institute for System Moscow Russia

ISBN: (数字)9781665492973

ISBN: (纸本)9781665492973

This article presents novel method for efficient fuzzing of programs accepting complex structured data. It generates input data based on formal grammar description. Data generator is periodically autoconfigured based on target programs code coverage. It means that the type of generated programs is dynamically changed to increase code coverage. Data generator uses descriptions of BNF (Backus-Naur Form) rules in ANTLR (ANother Tool for Language Recognition) platform. More than 250 languages and data formats are supported. Every rule of grammar is designed as universal pushdown automata, which allows automatically generate BNF compatible data by traversing automata. We added weights for each transition of automata to provide priority of highly efficient paths (sequence of transitions). These weights are automatically changed by fuzzing engine, which provides data generator adaptation based on the coverage of the target programs. According to experimental results, we were able to increase code coverage significantly for several widely used programs including compilers. © 2022 IEEE.

关键词： Automata theory

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Searching by Code: a New SearchBySnippet Dataset and SnippeR Retrieval Model for Searching by Code Snippets 30

Searching by Code: a New SearchBySnippet Dataset and SnippeR...

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Joint 30th International Conference on Computational Linguistics and 14th International Conference on Language Resources and Evaluation, LREC-COLING 2024

作者： Sedykh, Ivan Abulkhanov, Dmitry Sorokin, Nikita Nikolenko, Sergey Malykh, Valentin Huawei Noah's Ark Lab Canada St. Petersburg Department The Steklov Institute of Mathematics Russia Ivannikov Institute for System Programming Russia

ISBN: (纸本)9782493814104

Code search is an important and well-studied task, but it usually means searching for code by a text query. We argue that using a code snippet (and possibly an error traceback) as a query while looking for bugfixing instructions and code samples is a natural use case not covered by prior art. Moreover, existing datasets use code comments rather than full-text descriptions as text, making them unsuitable for this use case. We present a new SearchBySnippet dataset implementing the search-by-code use case based on StackOverflow data;we show that on SearchBySnippet, existing architectures fall short of a simple BM25 baseline even after fine-tuning. We present a new single encoder model SnippeR that outperforms several strong baselines on SearchBySnippet with a result of 0.451 Recall@10;we propose the SearchBySnippet dataset and SnippeR as a new important benchmark for code search evaluation. © 2024 ELRA Language Resource Association: CC BY-NC 4.0.

关键词： Information retrieval

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The Algorithm of the Vortex Sheet Intensity Determining in 3D Incompressible Flow Simulation around a Body

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Mathematical Models and Computer Simulations 2020年第4期12卷 464-473页

作者： Marchevskii, I.K. Shcheglov, G.A. Bauman Moscow State Technical University Moscow Russian Federation Ivannikov Institute for System Programming Russian Academy of Sciences Moscow 109004 Russian Federation

Abstract: An original algorithm is developed for vortex methods of computational fluid dynamics for determining the intensity of the vortex sheet on the surface of a body in the flow of an incompressible medium. Unlike the common in the vortex methods approach to satisfying the no-slip boundary condition on a streamlined surface, which is based on ensuring that the normal velocity component of the medium is zero, the proposed procedure is based on a mathematically equivalent condition of equality to zero of the tangent velocity component on the body surface. The unknown intensity of the vortex sheet is assumed to be piecewise constant on triangular panels that approximate the surface of the body. The resulting integral equation is approximated by a system of linear algebraic equations, which dimension is twice the number of panels. The coefficients of the system matrix are expressed through double integrals over the panels. An algorithm is proposed for calculating these integrals for the case of neighboring panels, when these integrals are improper. An additive singularity exclusion is performed and analytical expressions for the integrals of them are obtained. The smooth parts of integrands are integrated numerically using Gaussian quadrature formulae. The proposed algorithm makes it possible to improve significantly the accuracy of the vortex sheet intensity reconstruction when flow simulating around complex-shaped bodies by using vortex methods for arbitrary triangular surface meshes, including essentially non-uniform and having cells with high aspect ratio. © 2020, Pleiades Publishing, Ltd.

关键词： Biot−Savart law boundary integral equation incompressible media vortex influence vortex method vortex sheet

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