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Numerical Approach of Laser-Induced Spherical Microcavitation Bubbles: Effect of Enthalpy

Bulletin of the Russian Academy of Sciences: physics 2024年第Suppl 3期88卷 S287-S292页

作者： Ali F. Abu-Bakr Abu-Nab, Ahmed K. AbuShaeer, Zain Department of Mathematics and Computer Science Faculty of Science Menoufia University Shebin El-Koom32511 Egypt Phystech School of Applied Mathematics and Informatics Moscow Institute of Physics and Technology Dolgoprudny Moscow141700 Russia Center for Photonics and 2D Materials Moscow Institute of Physics and Technology Dolgoprudny141700 Russia Department of Basic Science Higher Institute of Engineering and Technology Kafrelsheikh33511 Egypt

Abstract: Over the past decades, interest has increased in studying different techniques to detect the importance of microbubbles in many industrial and medical applications such as mechanisms of hydraulic machinery cavitation erosion, histotripsy, and lithotripsy. The behavior from early irregular oscillations to late regular oscillations of spherical microcavitation bubbles produced by lasers in water was studied by means of plasma photography. Repetition of such delayed oscillations results in quantities of gas/vapour inside the spherical bubbles. Using the modified Gilmore model of cavitation microbubble dynamics, calculations were made for the laser pulse energy, microbubble radius behavior, and microbubble growth rate. Additionally, the pressure evolution inside the bubble, and pressures distribution surrounding of microbubbles in liquid are investigated under the effect of different values of initial cavitation of microbubble radius. The effect of enthalpy is considered into account. The proposed model is solved numerically using numerical techniques as a finite difference method. In addition, the radius of the microbubbles is calculated as a function of time under the influence of the initial radius of these laser-induced microcavitations. Moreover, some physical properties and numerical calculations of the presented mathematical model for cavitation induced by lasers bubbles are deduced, analyzed and investigated. © Pleiades Publishing, Ltd. 2024.

关键词： Cavitation

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Numerical Analysis of a Functional Equation for the Stochastic Optimal Control Problem 15

Numerical Analysis of a Functional Equation for the Stochast...

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15th International Conference Management of Large-Scale System Development, MLSD 2022

作者： Chernov, Aleksey Zhukova, Aleksandra MIPT-School of Applied Mathematics and Computer Science Moscow Institute of Physics and Technology Moscow Russia Frc Csc Ras Dept. of Mathematical Modelling of Economic Systems Moscow Russia

This work presents the approach to solving the functional equation of non-local type that appears in the study of a stochastic optimal control problem. This experience demonstrates the challenges and possible solution... 详细信息

ISBN: (数字)9781665497015

ISBN: (纸本)9781665497015

关键词： Numerical methods

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Mathematical Model of Asset and Liability Management in the Presence of Normative and Internal Constraints 5

Mathematical Model of Asset and Liability Management in the ...

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5th International Conference on Control Systems, Mathematical Modeling, Automation and Energy Efficiency, SUMMA 2023

作者： Zhukova, Aleksandra Flerova, Anna Chernov, Aleksey Pilnik, Nikolay FRC CSC of RAS Dept. of Mathematical Modelling of Economic Systems MIPT Moscow Russia FRC CSC RAS Dept. of Mathematical Modelling of Economic Systems Moscow Russia Moscow Institute of Physics and Technology MIPT-School of Applied Mathematics and Computer Science Moscow Russia

ISBN: (纸本)9798350309126

In this paper we present the mathematical formulation of the problem of planning the Asset Liability Management if the Presence of Normative and Internal Constraints. As a nonlinear optimal control problem, it has specifics due to the state constraints. The maximum principle involves verification of regularity property in order to apply computational methods. We reformulate the problem as the problem with convex objective function and linear, but mixed system of constraints. This enables application of optimization methods to compute the optimal controls, and study the dependence of controls on the parameters that describe the external environments and the management objective. © 2023 IEEE.

关键词： Optimal control systems

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RerrFact: Reduced Evidence Retrieval Representations for Scientific Claim Verification

RerrFact: Reduced Evidence Retrieval Representations for Sci...

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2022 Workshop on Scientific Document Understanding, SDU 2022

作者： Rana, Ashish Khanna, Deepanshu Ghosal, Tirthankar Singh, Muskaan Singh, Harpreet Rana, Prashant Singh School of Business Informatics and Mathematics University of Mannheim Germany Department of Electronics & Communication Engineering Thapar Institute of Engineering & Technology India Institute of Formal and Applied Linguistics Faculty of Mathematics and Physics Charles University Czech Republic Department of Computer Science & Engineering Thapar Institute of Engineering & Technology India

Exponential growth in digital information outlets and the race to publish has made scientific misinformation more prevalent than ever. However, the task to fact-verify a given scientific claim is not straightforward even for researchers. Scientific claim verification requires in-depth knowledge and great labor from domain experts to substantiate supporting and refuting evidence from credible scientific sources. The SciFact dataset and corresponding task provide a benchmarking leaderboard to the community to develop automatic scientific claim verification systems via extracting and assimilating relevant evidence rationales from source abstracts. In this work, we propose a modular approach that sequentially carries out binary classification for every prediction subtask as in the SciFact leaderboard. Our simple classifier-based approach uses reduced abstract representations to retrieve relevant abstracts. These are further used to train the relevant rationale-selection model. Finally, we carry out two-step stance predictions that first differentiate non-relevant rationales and then identify supporting or refuting rationales for a given claim. Experimentally, our system RerrFact with no fine-tuning, simple design, and a fraction of model parameters fairs competitively on the leaderboard against large-scale, modular, and joint modeling approaches. © 2022 Copyright for this paper by its authors.

关键词： Abstracting

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Artificial Intelligence: an Assistant or a Creator? Complex Analysis of Jewelry Community’s Professional Chat

Artificial Intelligence: an Assistant or a Creator? Complex ...

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IEEE Communication Strategies in Digital Society Workshop (ComSDS)

作者： Irina A. Gladchenko Mikhail Yu. Matveev School of World Politics Moscow State University named after M.V. Lomonosov Moscow Russia Faculty of applyed mathematics and informatics Moscow Institute of Physics and Technology (National Research University) Dolgoprudny Russia

ISBN: (数字)9798331536121

ISBN: (纸本)9798331536138

Optimization of routine processes increases production efficiency. However, such a rapid disruption of habitual everyday processes prevents timely adaptation to new reality and creates preconditions for social instability. AI-based technologies are beginning to replace human resources, but a substantial number of people lack an understanding of alternatives for their efforts application. If previously there was just automation of production processes that did not affect sphere of creativity and did not affect decision-making areas, now there is a concern that the creative side of the profession will also be replaced. The jewelry profession is a creative profession with many bifurcation points at each stage. In this regard, the sphere can serve as a good example for understanding how people negotiate to coexist in changing socio-technological conditions. The article provides a qualitative study of comments from the expert community of jewelers and expert interview analisys on the topic of using artificial intelligence in the field of jewelry manufacturing. Jewelry art requires years of training: mastering skills in modeling (both digital and material), sketching, casting, soldering, metal rolling, stone work, enamel work, etc. Nowadays there are opportunities to transfer these skills to AI. The analysis covers expert comments for December 2024 and January 2025. Comments were clustered on the base of statements made. The most frequently mentioned theses were identified. The result is a diagram of a new social interaction as part of a potentially new social contract. (Abstract)

关键词： Training Seminars Neural networks Metals Production Manufacturing Artificial intelligence Soldering Contracts Optimization

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On biased compression for distributed learning

The Journal of Machine Learning Research

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The Journal of Machine Learning Research 2023年第1期24卷 12974-13023页

作者： Aleksandr Beznosikov Samuel Horváth Peter Richtárik Mher Safaryan Computer Electrical and Math. Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal KSA and Skolkovo Institute of Science and Technology Moscow Russia and School of Applied Mathematics and Informatics Moscow Institute of Physics and Technology Moscow Russia Computer Electrical and Math. Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal KSA

In the last few years, various communication compression techniques have emerged as an indispensable tool helping to alleviate the communication bottleneck in distributed learning. However, despite the fact biased compressors often show superior performance in practice when compared to the much more studied and understood unbiased compressors, very little is known about them. In this work we study three classes of biased compression operators, two of which are new, and their performance when applied to (stochastic) gradient descent and distributed (stochastic) gradient descent. We show for the first time that biased compressors can lead to linear convergence rates both in the single node and distributed settings. We prove that distributed compressed SGD method, employed with error feedback mechanism, enjoys the ergodic rate $O\left( \delta L \exp[-\frac{\mu K}{\delta L}] + \frac{(C + \delta D)}{K\mu}\right)$, where δ ≥1 is a compression parameter which grows when more compression is applied, L and µ are the smoothness and strong convexity constants, C captures stochastic gradient noise (C = 0 if full gradients are computed on each node) and D captures the variance of the gradients at the optimum (D = 0 for over-parameterized models). Further, via a theoretical study of several synthetic and empirical distributions of communicated gradients, we shed light on why and by how much biased compressors outperform their unbiased variants. Finally, we propose several new biased compressors with promising theoretical guarantees and practical performance.

关键词： compression operators biased compressors distributed learning linear convergence error feedback

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Theoretical and Numerical Investigation of Acoustic Cavitation Bubble Based on the Impact of Ultrasound Frequency

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Bulletin of the Russian Academy of Sciences: physics 2023年第Suppl 3期87卷 S341-S347页

作者： Ahmed K. Abu-Nab Abu-Bakr, Ali F. Zain Abu Shaeer Department of Mathematics and Computer Science Faculty of Science Menoufia University Shebin El-Koom32511 Egypt Phystech School of Applied Mathematics and Informatics Moscow Institute of Physics and Technology Moscow oblast Dolgoprudny141700 Russia Department of Basic Science Higher Institute of Engineering and Technology Kafr El Sheikh33511 Egypt

Abstract: Acoustic cavitation is the expansion and contraction of existing microbubbles in liquids brought on by an ultrasonic field. The dynamics of oscillations at higher pressures and temperatures when the cavitation bubbles collapse can be used to characterize cavitation dynamical behavior. This work deals with the theoretical and numerical investigation of acoustic cavitation in viscoelastic media considering the influence of ultrasound frequency. An acoustic pressure equation combined with a modified Rayleigh–Plesset equation forms the theoretical framework for ultrasound cavitation dynamics. The numerical solutions of the given cavitation bubble model were obtained taking into account the effect of acoustic pressure, using the exponential B-Spline collection method. The dynamics of the cavitation bubbles’ radius and the internal pressure of acoustic cavitation were examined at different values of viscosity and the impact of physical parameters on the monatomic, diatomic, and adiabatic gas-filled spherical bubble’s collapse dynamics for (k = 7/5, 5/3, 1) respectively. © Pleiades Publishing, Ltd. 2023. ISSN 1062-8738, Bulletin of the Russian Academy of Sciences: physics, 2023, Vol. 87, Suppl. 3, pp. S341–S347. Pleiades Publishing, Ltd., 2023. ISSN 1062-8738, Bulletin of the Russian Academy of Sciences: physics, 2023. Pleiades Publishing, Ltd., 2023.

关键词： Dynamics

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Mechanically Laser-Induced Acoustic Cavitation in Viscoelastic Tissue: Theoretical Study

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Bulletin of the Russian Academy of Sciences: physics 2023年第Suppl 3期87卷 S348-S355页

作者： Zain Abu Shaeer Amerah M. Hakami Abu-Bakr, Ali F. Ahmed K. Abu-Nab Department of Basic Science Higher Institute of Engineering and Technology Kafrelsheikh33511 Egypt Department of Mathematics Faculty of Science Jazan University Jazan82723 Saudi Arabia Department of Mathematics and Computer Science Faculty of Science Menoufia University Shebin El-Koom32511 Egypt Phystech School of Applied Mathematics and Informatics Moscow Institute of Physics and Technology Moscow oblast Dolgoprudny141700 Russia

Abstract: Laser-induced acoustic cavitation microbubble dynamics have exhibited significant development in biological systems such as lithotripsy. Investigating the mechanically laser-induced acoustic cavitation microbubble in viscoelastic tissue is the goal of this work. Based on surface tension and viscous forces, the laser-induced cavitation model (also known as the modified Rayleigh–Plesset model), the theoretical model is developed and numerically solved using exponential cubic B-spline Collocation Method. In addition, the energy released in viscoelastic tissue by laser-induced acoustic cavitation as well as mechanically induced cavitation is investigated. The findings of our work provide valuable insight into the application of laser-induced acoustic cavitation microbubbles such as kidney stones and lithotripsy. © Pleiades Publishing, Ltd. 2023. ISSN 1062-8738, Bulletin of the Russian Academy of Sciences: physics, 2023, Vol. 87, Suppl. 3, pp. S348–S355. Pleiades Publishing, Ltd., 2023. ISSN 1062-8738, Bulletin of the Russian Academy of Sciences: physics, 2023. Pleiades Publishing, Ltd., 2023.

关键词： Tissue

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Lithium and Beryllium Isotopes in the PAMELA Experiment

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Bulletin of the Russian Academy of Sciences: physics 2023年第7期87卷 863-866页

作者： Bogomolov, E.A. Vasilyev, G.I. Menn, W. Adriani, O. Bazilevskaya, G.A. Barbarino, G.C. Bellotti, R. Boezio, M. Bonvicini, V. Bongi, M. Bottai, S. Bruno, A. Vacchi, A. Vannuccini, E. Voronov, S.A. Galper, A.M. De Santis, C. Di Felice, V. Zampa, G. Zampa, N. Casolino, M. Campana, D. Carlson, P. Castellini, G. Cafagna, F. Kvashnin, A.A. Kvashnin, A.N. Koldobskiy, S.A. Lagoida, I.A. Leonov, A.A. Mayorov, A.G. Malakhov, V.V. Martucci, M. Marcelli, L. Merge, M. Mikhailov, V.V. Mocchiutti, E. Monaco, A. Mori, N. Munini, R. Osteria, G. Panico, B. Papini, P. Picozza, P. Ricci, M. Ricciarini, S.B. Simon, M. Sparvoli, R. Spillantini, P. Stozhkov, Y.I. Yurkin, Y.T. Ioffe Institute Russian Academy of Sciences St. Petersburg194021 Russia University of Siegen Siegen57068 Germany Department of Physics University of Florence Florence50019 Italy Branch of Florence National Institute for Nuclear Physics Florence50019 Italy Lebedev Physical Institute Russian Academy of Sciences Moscow119991 Russia Department of Physics University of Naples "Federico II" Naples80126 Italy Branch of Naples National Institute for Nuclear Physics Naples80126 Italy Department of Physics University of Bari Bari70126 Italy Branch of Bari National Institute for Nuclear Physics Bari70126 Italy Moscow115409 Russia Branch of Trieste National Institute for Nuclear Physics Trieste34149 Italy Department of Mathematics and Informatics University of Udine Udine33100 Italy "Tor Vergata" Branch of Rome National Institute for Nuclear Physics Rome00133 Italy Department of Physics University of Rome Tor Vergata Rome00133 Italy Science Data Center Italian Space Agency Rome00133 Italy Department of Physics and the Oskar Klein Centre for Cosmoparticle Physics AlbaNova University Centre KTH Royal Institute of Technology Stockholm10691 Sweden Institute for Applied Physics Nello Carrara Florence50019 Italy Frascati National Laboratory National Institute for Nuclear Physics Frascati00044 Italy Department of Physics University of Trieste Trieste34147 Italy

Abstract: The isotopic composition of Li and Be nuclei in the 1–5 GV range of rigidities (nuclear energies of 0.1–1.5 GeV/nucleon) is analyzed using PAMELA flight data from 2006–2014 on the rigidity of detected nuclei and their velocities (time-of-flight analysis and ionization losses in the detector’s multilayer calorimeter). The new PAMELA data expand the range of energies in earlier measurements, are consistent with scarce results, and indicate correlated deviations of Li and Be isotope ratios from the GALPROP data for GCRs, which can be interpreted as evidence of contributions from several nearby local sources against the GCR background. Analysis of precision AMS-02 data on the spectra of positrons, antiprotons, and secondary nuclei of Li, Be, and B also indicates correlated increases in intensity at rigidities of ~50–1000 GV, which could also be due to local sources. The contribution from local sources against the GCR background is estimated at levels of tens of percents for rigidities of 1–5 GV and several percent at rigidities of 50–1000 GV. © 2023, Allerton Press, Inc.

关键词： Rigidity

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AN IMPROVED KTNS ALGORITHM FOR THE JOB SEQUENCING AND TOOL SWITCHING PROBLEM

arXiv

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arXiv 2022年

作者： Cherniavskii, Mikhail Goldengorin, Boris Department of Discrete Mathematics Phystech School of AppliedMathematics and Informatics Moscow Institute of Physics and Technology Dolgoprudny Russia

We outline a new Max Pipe Construction Algorithm (MPCA) with the purpose to reduce the CPU time for the classic Keep Tool Needed Soonest (KTNS) algorithm. The KTNS algorithm is applied to compute the objective function value for the given sequence of jobs in all exact and approximating algorithms for solving the Job Sequencing and Tool Switching Problem (SSP). Our MPCA outperforms the KTNS algorithm by at least an order of magnitude in terms of CPU times. Since all exact and heuristic algorithms for solving the SSP spend most of their CPU time on applying the KTNS algorithm we show that our MPCA solves the entire SSP on average 59 times faster for benchmark instances of D compared to current state of the art heuristics. © 2022, CC BY-NC-SA.

关键词： Heuristic algorithms

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