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Research on the wake of the ducted propeller with POD and DMD

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Research on the wake of the ducted propeller with POD and DM...

Ivannikov ISPras Open Conference (ISPras)

作者： Tianyuan Wang Hongda Shi Qin Zhang Bo Yang Xin Liu Kraposhin Matvey College of Engineering Ocean University of China Qingdao China Ivannikov Institute for System Programming of the RAS Moscow Russia

ISBN: (数字)9781665412919

ISBN: (纸本)9781665448215

The paper attempts to apply the Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) to the ducted propeller wake analysis. The ducted propeller produces a complex wake flow field with multifrequency vortex structure coupling under the influence between blades and nozzle. Traditional analysis methods such as time-averaged flow, phase-averaged flow are only displaying the coupling results. In contrast, data mining technologies such as POD and DMD can extract independent flow patterns from the massive data obtained from physical experiments and numerical simulations. The paper focuses on the influence of computational subdomain (based on the OpenFOAM), snapshot sampling interval and data coverage revolutions on the modal convergence in the data preprocessing before employing POD and DMD. Taking a single ducted propeller wake data with the advance coefficient of J=0.4 as an example, it is found that the sampling interval of snapshots are independent of modal convergence after reaching a certain level and only affect the frequency range of the captured modes. The scope of the computational subdomain and the revolutions of data covered by snapshot matrix are vital factors to affect the modal convergence. At last, under the premise of modal convergence, the paper reconstructs the ducted propeller wake flow field by POD and DMD respectively, where errors between the original data can be ignored.

关键词： Couplings Propellers Blades Data preprocessing Numerical simulation Data mining Convergence

Using Ansible as Part of TOSCA Orchestrator

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Using Ansible as Part of TOSCA Orchestrator

Ivannikov ISPras Open Conference (ISPras)

作者： Valeriya Shvetcova Oleg Borisenko Maxim Polischuk Ivannikov Institute for System Programming of the RAS Moscow Russia Bauman Moscow State Technical University Moscow Russia

ISBN: (数字)9781665412919

ISBN: (纸本)9781665448215

Cloud computing is used in many areas and by many specialists to ease application distribution and deployment. Cloud providers basically aim at providing resources varying from others. So it becomes very difficult to deploy multicloud applications or move to the cloud from own hardware clusters. TOSCA standard offers cloud resources model that unifies many cloud providers. In this paper we propose TOSCA orchestrator Clouni. Clouni takes TOSCA templates from the user and generates Ansible playbooks. Ansible is then used as a configuration tool for deployment automation. Clouni makes it easy for cloud users to deploy complex topologies.

关键词： Cloud computing Automation Tools Topology Network function virtualization Software defined networking Standards

Sydr: Cutting edge dynamic symbolic execution

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arXiv 2020年

作者： Vishnyakov, Alexey Fedotov, Andrey Kuts, Daniil Novikov, Alexander Parygina, Darya Kobrin, Eli Logunova, Vlada Belecky, Pavel Kurmangaleev, Shamil Ivannikov Institute for System Programming of the RAS Lomonosov Moscow State University Russia Moscow Institute of Physics and Technology Moscow Russia

The security development lifecycle (SDL) is becoming an industry standard. Dynamic symbolic execution (DSE) has enormous amount of applications in computer security (fuzzing, vulnerability discovery, reverse-engineering, etc.). We propose several performance and accuracy improvements for dynamic symbolic execution. Skipping non-symbolic instructions allows to build a path predicate 1.2–3.5 times faster. Symbolic engine simplifies formulas during symbolic execution. Path predicate slicing eliminates irrelevant conjuncts from solver queries. We handle each jump table (switch statement) as multiple branches and describe the method for symbolic execution of multi-threaded programs. The proposed solutions were implemented in Sydr tool. Sydr performs inversion of branches in path predicate. Sydr combines DynamoRIO dynamic binary instrumentation tool with Triton symbolic engine. We evaluated Sydr features on 64-bit Linux executables. © 2020, CC BY-NC-ND.

关键词： Life cycle

Ontology Engineering at the Assertion Level Based on Semantic Annotation of Tabular Data

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Ontology Engineering at the Assertion Level Based on Semanti...

Ivannikov Memorial Workshop (IVMEM)

作者： Nikita O. Dorodnykh Aleksandr Yu. Yurin Alexey O. Shigarov Denis Yu. Turdakov Matrosov Institute for System Dynamics and Control Theory (ISDCT) Irkutsk Russia Ivannikov Institute for System Programming of the Russian Academy of Sciences (ISP RAS) Moscow Russia

ISBN: (纸本)9781665423281

Web tables are an important source of knowledge and can be used for ontology engineering. In this paper, we propose the approach for the semi-automated formation of domain ontologies at the assertion level (ABox) based on web tables. The proposed approach consists of 6 steps and is based on the use of the semantic annotation of separate elements of web tables. With the use of the semantic annotation procedure, we extract specific entities (ontology instances) from table cells. Our approach is implemented in the form of a web-based tool. We present a description of the architecture of this tool, as well as its experimental evaluation in the case of domain ontology engineering for the TALISMAN framework. We have formed a special dataset for our experiment. The results obtained show the prospects of using our approach and tool to support ontology engineering based on the semantic annotation of web tables.

关键词： Annotations Knowledge acquisition Conferences Semantics Ontologies

Sydr-Fuzz: Continuous Hybrid Fuzzing and Dynamic Analysis for Security Development Lifecycle

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arXiv 2022年

作者： Vishnyakov, Alexey Kuts, Daniil Logunova, Vlada Parygina, Darya Kobrin, Eli Savidov, Georgy Fedotov, Andrey Ivannikov Institute for System Programming of the RAS Russia Lomonosov Moscow State University Russia Moscow Institute of Physics and Technology Moscow Russia

Nowadays automated dynamic analysis frameworks for continuous testing are in high demand to ensure software safety and satisfy the security development lifecycle (SDL) requirements. The security bug hunting efficiency of cutting-edge hybrid fuzzing techniques outperforms widely utilized coverage-guided fuzzing. We propose an enhanced dynamic analysis pipeline to leverage productivity of automated bug detection based on hybrid fuzzing. We implement the proposed pipeline in the continuous fuzzing toolset Sydr-Fuzz which is powered by hybrid fuzzing orchestrator, integrating our DSE tool Sydr with libFuzzer and AFL++. Sydr-Fuzz also incorporates security predicate checkers, crash triaging tool Casr, and utilities for corpus minimization and coverage gathering. The benchmarking of our hybrid fuzzer against alternative state-of-the-art solutions demonstrates its superiority over coverage-guided fuzzers while remaining on the same level with advanced hybrid fuzzers. Furthermore, we approve the relevance of our approach by discovering 85 new real-world software flaws within the OSS-Sydr-Fuzz project. Finally, we open Casr source code to the community to facilitate examination of the existing crashes. © 2022, CC BY-NC-ND.

关键词： Pipelines

Method with Batching for Stochastic Finite-Sum Variational Inequalities in Non-Euclidean Setting

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arXiv 2024年

作者： Pichugin, Alexander Pechin, Maksim Beznosikov, Aleksandr Novitskii, Vasilii Gasnikov, Alexander Moscow Institute of Physics and Technology Moscow Russia Ivannikov Institute for System Programming of RAS Moscow Russia Innopolis University Innopolis Russia

Variational inequalities are a universal optimization paradigm that incorporate classical minimization and saddle point problems. Nowadays more and more tasks require to consider stochastic formulations of optimization problems. In this paper, we present an analysis of a method that gives optimal convergence estimates for monotone stochastic finite-sum variational inequalities. In contrast to the previous works, our method supports batching, does not lose the oracle complexity optimality and uses an arbitrary Bregman distance to take into account geometry of the problem. Paper provides experimental confirmation to algorithm’s effectiveness. Copyright © 2024, The Authors. All rights reserved.

关键词： Optimization algorithms

Profile-based type reconstruction for decompilation

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Profile-based type reconstruction for decompilation

IEEE Workshop on Program Comprehension

作者： K. Troshina A. Chernov A. Fokin Institute of System Programming RAS Moscow Russia Computational Mathematics and Cybernetics Department Moscow State University Moscow Russia

Decompilation is reconstruction of a program in a high-level language from a program in a low-level language. In most cases static decompilation is unable to completely reconstruct high-level data types due to loss of typing information during compilation. We present several profile-based techniques that help to recover high-level types. The techniques include pointer/integer determination by value profiling and composite type identification by heap profiling.

关键词： Reconstruction algorithms Registers Reverse engineering Cybernetics Assembly Equations Mathematical programming Application software Computer bugs Computer languages

Numeric Truncation Security Predicate

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arXiv 2023年

作者： Mezhuev, Timofey Kobrin, Ilay Vishnyakov, Alexey Kuts, Daniil Ivannikov Institute for System Programming of the RAS Russia Lomonosov Moscow State University Russia Yandex Cloud Moscow Russia

Numeric truncation is a widely spread error in software written in languages with static data typing, such as C/C++ or Java. It occurs when the significant bits of the value with a bigger type size are truncated during value conversion to the smaller type. Utilizing one of the most powerful methods for path exploration and automated bug detection called dynamic symbolic execution (DSE), we propose the symbolic security predicate for numeric truncation error detection, developed on top of DSE tool Sydr. Firstly, we execute the program on the data, which does not lead to any errors. During program execution we update symbolic shadow stack and shadow registers to track symbolic sizes of the symbolic variables to avoid false positives. Then, if we meet the instruction, which truncates the symbolic variable, we build the security predicate, try to solve it with the SMT-solver and in case of success save new input file to reproduce the error. We tested our approach on Juliet Dynamic test suite for CWE-197 and achieved 100% accuracy. We approved the workability of our approach by detecting 12 new errors of numeric truncation in 5 different real-world open source projects within OSS-Sydr-Fuzz project. All of the errors were reported, most of the reports were equipped with appropriate fixes, successfully confirmed and applied by project maintainers. © 2023, CC BY-NC-ND.

关键词： Error detection

Symbolic Security Predicates: Hunt Program Weaknesses

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arXiv 2021年

作者： Vishnyakov, Alexey Logunova, Vlada Kobrin, Eli Kuts, Daniil Parygina, Darya Fedotov, Andrey Ivannikov Institute for System Programming of the RAS Russia Lomonosov Moscow State University Russia Moscow Institute of Physics and Technology Moscow Russia

Dynamic symbolic execution (DSE) is a powerful method for path exploration during hybrid fuzzing and automatic bug detection. We propose security predicates to effectively detect undefined behavior and memory access violation errors. Initially, we symbolically execute program on paths that don’t trigger any errors (hybrid fuzzing may explore these paths). Then we construct a symbolic security predicate to verify some error condition. Thus, we may change the program data flow to entail null pointer dereference, division by zero, out-of-bounds access, or integer overflow weaknesses. Unlike static analysis, dynamic symbolic execution does not only report errors but also generates new input data to reproduce them. Furthermore, we introduce function semantics modeling for common C/C++ standard library functions. We aim to model the control flow inside a function with a single symbolic formula. This assists bug detection, speeds up path exploration, and overcomes overconstraints in path predicate. We implement the proposed techniques in our dynamic symbolic execution tool Sydr. Thus, we utilize powerful methods from Sydr such as path predicate slicing that eliminates irrelevant constraints. We present Juliet Dynamic to measure dynamic bug detection tools accuracy. The testing system also verifies that generated inputs trigger sanitizers. We evaluate Sydr accuracy for 11 CWEs from Juliet test suite. Sydr shows 95.59% overall accuracy. We make Sydr evaluation artifacts publicly available to facilitate results reproducibility. © 2021, CC BY-NC-ND.

关键词： Static analysis