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arXiv 2024年

作者： Grazian, Andrea Portaluri, Elisa Simioni, Matteo Arcidiacono, Carmelo Gullieuszik, Marco Hartke, Johanna Jodlbauer, Daniel Pedichini, Fernando Piazzesi, Roberto Vaccari, Piero Vulcani, Benedetta Wagner, Roland Zanella, Anita INAF-Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 PadovaI-35122 Italy INAF-Osservatorio Astronomico d’Abruzzo Via Mentore Maggini s.n.c TeramoI-64100 Italy University of Turku Finland Tuorla Observatory Department of Physics and Astronomy University of Turku FI-20014 Finland Industrial Mathematics Institute Johannes Kepler University Linz Altenberger Strasse 69 Linz4040 Austria RICAM - Johann Radon Institute for Computational and Applied Mathematics Altenberger Strasse 69 Linz4040 Austria INAF - Osservatorio Astronomico di Roma Via Frascati 33 Monte Porzio CatoneI-00078 Italy

MICADO is the first-light camera of the ESO ELT, allowing NIR imaging and long-slit spectroscopy assisted by adaptive optics. MICADO is now entering its construction phase, and the software for data reduction is reaching an adequate maturity level. The PSF Reconstruction (PSF-R) of MICADO is a software tool for the blind derivation of the PSF, only using adaptive optics telemetry data. An update of the status of the PSF-R service is provided here. The PSF-R prototype has been tested on ERIS@VLT data in order to check the reconstruction of on- and off-axis PSFs. The on-axis PSF-R is accurate at a few percent level on Strehl, FWHM, Encircled Energy, and half light radius, while for the off-axis case the match is within 10-15% at a distance of half isoplanatic angle. The first version of the workflow for the PSF-R pipeline has been developed and verified using the latest release of the ESO data processing system. A set of simulations has been implemented on the morphological analysis of distant galaxies, showing that the accuracy of the PSF-R matches the goals needed to study their morphology. In summary, the PSF-R team is on the right track towards the ELT first light. © 2024, CC BY.

关键词： Adaptive optics

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Deep Potential generation scheme and simulation protocol for the Li10GeP2S12-type superionic conductors

arXiv

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arXiv 2020年

作者： Huang, Jianxing Zhang, Linfeng Wang, Han Zhao, Jinbao Cheng, Jun Weinan, E. State Key Laboratory of Physical Chemistry of Solid Surfaces iChEM College of Chemistry and Chemical Engineering Xiamen University Xiamen361005 China Program in Applied and Computational Mathematics Princeton University PrincetonNJ08544 United States Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Fenghao East Road 2 Beijing100094 China Department of Mathematics Princeton University PrincetonNJ08544 United States

Solid-state electrolyte materials with superior lithium ionic conductivities are vital to the next-generation Li-ion batteries. Molecular dynamics could provide atomic scale information to understand the diffusion process of Li-ion in these superionic conductor materials. Here we implement the Deep Potential Generator (DP-GEN) to set up an efficient protocol to automatically generate interatomic potentials for Li10GeP2S12-type solid-state electrolyte materials (Li10GeP2S12, Li10SiP2S12 and Li10SnP2S12). The reliability and accuracy of the fast interatomic potentials are validated. With the potentials, we extend the simulation of diffusion process to a wide temperature range (300K-1000K) and systems with large size (~1000 atoms). Important technical aspects like the statistical error and size effect are carefully investigated and benchmark tests including the effect of density functional, thermal expansion and configurational disorder are performed. The computed data that considering these factors agrees well with the experimental results and we find that the 3 structures shows different behaviors with respect to configurational disorder. Our work paves the way for further research on computation screening of solid-state electrolyte materials. Copyright © 2020, The Authors. All rights reserved.

关键词： Solid electrolytes

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A sharp interface Lagrangian-Eulerian method for flexible-body fluid-structure interaction

arXiv

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arXiv 2022年

作者： Kolahdouz, Ebrahim M. Wells, David R. Rossi, Simone Aycock, Kenneth I. Craven, Brent A. Griffith, Boyce E. Center for Computational Biology Flatiron Institute Simons Foundation New YorkNY United States Department of Mathematics University of North Carolina Chapel HillNC United States Division of Applied Mechanics Office of Science and Engineering Laboratories Center for Devices and Radiological Health United States Food and Drug Administration Silver SpringMD United States Departments of Mathematics and Biomedical Engineering University of North Carolina Chapel HillNC United States Carolina Center for Interdisciplinary Applied Mathematics University of North Carolina Chapel HillNC United States Computational Medicine Program University of North Carolina Chapel HillNC United States McAllister Heart Institute University of North Carolina Chapel HillNC United States

This paper introduces a sharp-interface approach to simulating fluid-structure interaction (FSI) involving flexible bodies described by general nonlinear material models and across a broad range of mass density ratios. This new flexible-body immersed Lagrangian-Eulerian (ILE) scheme extends our prior work on integrating partitioned and immersed approaches to rigid-body FSI. Our numerical approach incorporates the geometrical and domain solution flexibility of the immersed boundary (IB) method with an accuracy comparable to body-fitted approaches that sharply resolve flows and stresses up to the fluid-structure interface. Unlike many IB methods, our ILE formulation uses distinct momentum equations for the fluid and solid subregions with a Dirichlet-Neumann coupling strategy that connects fluid and solid subproblems through simple interface conditions. As in earlier work, we use approximate Lagrange multiplier forces to treat the kinematic interface conditions along the fluid-structure interface. This penalty approach simplifies the linear solvers needed by our formulation by introducing two representations of the fluid-structure interface, one that moves with the fluid and another that moves with the structure, that are connected by stiff springs. This approach also enables the use of multi-rate time stepping, which allows us to use different time step sizes for the fluid and structure subproblems. Our fluid solver relies on an immersed interface method (IIM) for discrete surfaces to impose stress jump conditions along complex interfaces while enabling the use of fast structured-grid solvers for the incompressible Navier-Stokes equations. The dynamics of the volumetric structural mesh are determined using a standard finite element approach to large-deformation nonlinear elasticity via a nearly incompressible solid mechanics formulation. This formulation also readily accommodates compressible structures with a constant total volume, and it can handle fully compressibl

关键词： Fluid structure interaction

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Universal mechanical response of metallic glasses during strain-rate-dependent uniaxial compression

arXiv

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arXiv 2022年

作者： Jin, Weiwei Datye, Amit Schwarz, Udo D. Shattuck, Mark D. O'Hern, Corey S. Department of Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Department of Chemical and Environmental Engineering Yale University New HavenCT06520 United States Benjamin Levich Institute Physics Department The City College of New York New YorkNY10031 United States Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States Graduate Program in Computational Biology and Bioinformatics Yale University New HavenCT06520 United States

Experimental data on the compressive strength σmax versus strain rate Ε eng for metallic glasses undergoing uniaxial compression shows significantly different behavior for different alloys. For some metallic glasses, σmax decreases with increasing Ε eng, for others, σmax increases with increasing Ε eng, and for others σmax versus Ε eng is nonmonotonic. Using numerical simulations of metallic glasses undergoing uniaxial compression at nonzero strain rate and temperature, we show that they obey a universal relation for the compressive strength versus temperature, which determines their mechanical response. At low Ε eng, increasing strain rate leads to increases in temperature and decreases in σmax∗, whereas at high Ε eng, increasing strain rate leads to decreases in temperature and increases in σmax∗. This non-monotonic behavior of σmax∗ versus temperature causes the nonmonotonic behavior of σmax∗ versus Ε eng. Variations in the internal dissipation change the characteristic strain rate at which the nonmonotonic behavior occurs. These results are general for a wide range of metallic glasses with different atomic interactions, damping coefficients, and chemical compositions. © 2022, CC BY.

关键词： Strain rate

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Adaptive tikhonov strategies for stochastic ensemble Kalman inversion

arXiv

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arXiv 2021年

作者： Weissmann, Simon Chada, Neil K. Schillings, Claudia Tong, Xin T. Interdisciplinary Center for Scientific Computing University of Heidelberg Heidelberg69120 Germany Applied Mathematics and Computational Science Program King Abdullah University of Science and Technology Thuwal KSA 23955 Saudi Arabia Mannheim School of Computer Science and Mathematics University of Mannheim Mannheim68131 Germany Department of Mathematics National University of Singapore Singapore119077 Singapore

Ensemble Kalman inversion (EKI) is a derivative-free optimizer aimed at solving inverse problems, taking motivation from the celebrated ensemble Kalman filter. The purpose of this article is to consider the introduction of adaptive Tikhonov strategies for EKI. This work builds upon Tikhonov EKI (TEKI) which was proposed for a fixed regularization constant. By adaptively learning the regularization parameter, this procedure is known to improve the recovery of the underlying unknown. For the analysis, we consider a continuous-time setting where we extend known results such as well-posdeness and convergence of various loss functions, but with the addition of noisy observations. Furthermore, we allow a time-varying noise and regularization covariance in our presented convergence result which mimic adaptive regularization schemes. In turn we present three adaptive regularization schemes, which are highlighted from both the deterministic and Bayesian approaches for inverse problems, which include bilevel optimization, the MAP formulation and covariance learning. We numerically test these schemes and the theory on linear and nonlinear partial differential equations, where they outperform the non-adaptive TEKI and *** Codes 65M32, 60G35, 65C35, 70F17 Copyright © 2021, The Authors. All rights reserved.

关键词： Continuous time systems

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The FLAMINGO project: the coupling between baryonic feedback and cosmology in light of the S8 tension

arXiv

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arXiv 2024年

作者： Elbers, Willem Frenk, Carlos S. Jenkins, Adrian Li, Baojiu Helly, John C. Kugel, Roi Schaller, Matthieu Schaye, Joop Braspenning, Joey Kwan, Juliana McCarthy, Ian G. Salcido, Jaime van Daalen, Marcel P. Vandenbroucke, Bert Pascoli, Silvia Institute for Computational Cosmology Department of Physics Durham University South Road DurhamDH1 3LE United Kingdom Leiden Observatory Leiden University PO Box 9513 Leiden2300 RA Netherlands Lorentz Institute for Theoretical Physics Leiden University PO box 9506 Leiden2300 RA Netherlands Astrophysics Research Institute Liverpool John Moores University LiverpoolL3 5RF United Kingdom Department of Applied Mathematics and Theoretical Physics University of Cambridge Wilberforce Road CambridgeCB3 0WA United Kingdom Dipartimento di Fisica e Astronomia Università di Bologna via Irnerio 46 Bologna40126 Italy INFN Sezione di Bologna viale Berti Pichat 6/2 Bologna40127 Italy

Large-scale structure surveys have reported measurements of the density of matter, Ωm, and the amplitude of clustering, σ8, that are in tension with the values inferred from observations of the cosmic microwave background. While this may be a sign of new physics that slows the growth of structure at late times, strong astrophysical feedback processes could also be responsible. In this work, we argue that astrophysical processes are not independent of cosmology and that their coupling naturally leads to stronger baryonic feedback in cosmological models with suppressed structure formation or when combined with a mechanism that removes dark matter from halos. We illustrate this with two well-motivated extensions of the Standard Model known to suppress structure formation: massive neutrinos and decaying dark matter. Our results, based on the FLAMINGO suite of hydrodynamical simulations, show that the combined effect of baryonic and non-baryonic suppression mechanisms is greater than the sum of its parts, particularly for decaying dark matter. We also show that the dependence of baryonic feedback on cosmology can be modelled as a function of the ratio (formula presented) of the universal baryon fraction, fb, to a velocity-based definition of halo concentration, (formula presented), giving an accurate fitting formula for the baryonic suppression of the matter power spectrum. Although the combination of baryonic and non-baryonic suppression mechanisms can resolve the tension, the models with neutrinos and decaying dark matter are challenged by constraints on the expansion history. © 2024, CC BY.

关键词： Dark Matter

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Overview of the Head and Neck Tumor Segmentation for Magnetic Resonance Guided Applications (HNTS-MRG) 2024 Challenge

arXiv

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arXiv 2024年

作者： Wahid, Kareem A. Dede, Cem El-Habashy, Dina M. Kamel, Serageldin Rooney, Michael K. Khamis, Yomna Abdelaal, Moamen R.A. Ahmed, Sara Corrigan, Kelsey L. Chang, Enoch Dudzinski, Stephanie O. Salzillo, Travis C. McDonald, Brigid A. Mulder, Samuel L. McCullum, Lucas Alakayleh, Qusai Sjogreen, Carlos He, Renjie Mohamed, Abdallah S.R. Lai, Stephen Y. Christodouleas, John P. Schaefer, Andrew J. Naser, Mohamed A. Fuller, Clifton D. Department of Radiation Oncology The University of Texas MD Anderson Cancer HoustonTX United States Department of Imaging Physics The University of Texas MD Anderson Cancer HoustonTX United States Transitional Year Program Corewell Health Wiliam Beaumont Royal OakMI United States Department of Radiation Oncology University of Maryland School of Medicine BaltimoreMD United States Department of Clinical Oncology and Nuclear Medicine Faculty of Medicine Alexandria University Alexandria Egypt UT MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences Houston United States Department of Radiation Oncology Baylor College of Medicine HoustonTX United States Department of Head and Neck Surgery The University of Texas MD Anderson Cancer HoustonTX United States Elekta AtlantaGA United States Department of Computational Applied Mathematics and Operations Research Rice University HoustonTX United States

Magnetic resonance (MR)-guided radiation therapy (RT) is enhancing head and neck cancer (HNC) treatment through superior soft tissue contrast and longitudinal imaging capabilities. However, manual tumor segmentation remains a significant challenge, spurring interest in artificial intelligence (AI)-driven automation. To accelerate innovation in this field, we present the Head and Neck Tumor Segmentation for MR-Guided Applications (HNTS-MRG) 2024 Challenge, a satellite event of the 27th International Conference on Medical Image Computing and Computer Assisted Intervention. This challenge addresses the scarcity of large, publicly available AI-ready adaptive RT datasets in HNC and explores the potential of incorporating multi-timepoint data to enhance RT auto-segmentation performance. Participants tackled two HNC segmentation tasks: automatic delineation of primary gross tumor volume (GTVp) and gross metastatic regional lymph nodes (GTVn) on pre-RT (Task 1) and mid-RT (Task 2) T2-weighted scans. The challenge provided 150 HNC cases for training and 50 for testing, hosted on *** using a Docker submission framework. In total, 19 independent teams from across the world qualified by submitting both their algorithms and corresponding papers, resulting in 18 submissions for Task 1 and 15 submissions for Task 2. Evaluation using the mean aggregated Dice Similarity Coefficient showed top-performing AI methods achieved scores of 0.825 in Task 1 and 0.733 in Task 2. These results surpassed clinician interobserver variability benchmarks, marking significant strides in automated tumor segmentation for MR-guided RT applications in HNC. © 2024, CC BY.

关键词： Magnetic resonance imaging

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The FLAMINGO Project: Galaxy clusters in comparison to X-ray observations

arXiv

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arXiv 2023年

作者： Braspenning, Joey Schaye, Joop Schaller, Matthieu McCarthy, Ian G. Kay, Scott T. Helly, John C. Kugel, Roi Elbers, Willem Frenk, Carlos S. Kwan, Juliana Salcido, Jaime van Daalen, Marcel P. Vandenbroucke, Bert Leiden Observatory Leiden University PO Box 9513 Leiden2300 RA Netherlands Lorentz Institute for Theoretical Physics Leiden University PO box 9506 Leiden2300 RA Netherlands Astrophysics Research Institute Liverpool John Moores University LiverpoolL3 5RF United Kingdom Jodrell Bank Centre for Astrophysics Department of Physics and Astronomy The University of Manchester Oxford Road ManchesterM13 9PL United Kingdom Institute for Computational Cosmology Department of Physics University of Durham South Road DurhamDH1 3LE United Kingdom Department of Applied Mathematics and Theoretical Physics University of Cambridge Wilberforce Road CambridgeCB3 0WA United Kingdom

Galaxy clusters are important probes for both cosmology and galaxy formation physics. We test the cosmological, hydrodynamical FLAMINGO simulations by comparing to observations of the gaseous properties of clusters measured from X-ray observations. FLAMINGO contains unprecedented numbers of massive galaxy groups (> 106) and clusters (> 105) and includes variations in both cosmology and galaxy formation physics. We predict the evolution of cluster scaling relations as well as radial profiles of the temperature, density, pressure, entropy, and metallicity for different masses and redshifts. We show that the differences between volume-, and X-ray-weighting of particles in the simulations, and between cool-core non cool-core samples, are similar in size as the differences between simulations for which the stellar and AGN feedback has been calibrated to produce significantly different gas fractions. Compared to thermally-driven AGN feedback, kinetic jet feedback calibrated to produce the same gas fraction at R500c yields a hotter core with higher entropies and lower densities, which translates into a smaller fraction of cool-core clusters. Stronger feedback, calibrated to produce lower gas fractions and hence lower gas densities, results in higher temperatures, entropies, and metallicities, but lower pressures. The scaling relations and thermodynamic profiles show almost no evolution with respect to self-similar expectations, except for the metallicity decreasing with redshift. We find that the temperature, density, pressure, and entropy profiles of clusters in the fiducial FLAMINGO simulation are in excellent agreement with observations, while the metallicities in the core are too high. Copyright © 2023, The Authors. All rights reserved.

关键词： Entropy

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Novel theoretical constraints for color-octet scalar models

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Chinese physics C 2019年第9期43卷 1-11页

作者： Li Cheng Otto Eberhardt Christopher W.Murphy Institute of Applied Physics and Computational Mathematics Beijing 100094China Instituto de Fisica Corpuscular Universitat de Valencia-CSICApt.Correus 22085E-46071 ValenciaSpain Department of Physics Brookhaven National LaboratoryUptonNew York11973USA

We study the theoretical constraints on a model whose scalar sector contains one color octet and one or two color singlet SU(2)L *** ensure unitarity of the theory,we constrain the parameters of the scalar potential for the first time at the next-to-leading order in perturbation ***,we derive new conditions guaranteeing the stability of the *** employ the HEPfit package to extract viable parameter regions at the electroweak scale and test the stability of the renormalization group evolution up to the multi-TeV ***,we set upper limits on the scalar mass *** results are given for both cases with and without a second scalar color singlet.

关键词： beyond the Standard Model extension of Higgs sector EW symmetry breaking

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Blockchain and Smart Contracting in the Context of Digital Transformation of Service

Blockchain and Smart Contracting in the Context of Digital T...

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2022 Conference of Russian Young Researchers in Electrical and Electronic Engineering, ElConRus 2022

作者： Pokrovskaia, Nadezhda N. Rodionova, Elena A. Fomina, Irina G. Epshtein, Mikhail Z. Fedorov, Denis A. Innovation Management Department Saint Petersburg Electrotechnical University Leti Saint Petersburg Russia Higher School of Media-communications Pr Peter the Great St.Petersburg Polytechnic University Saint Petersburg Russia Economics and Management of Socio-Economic Systems St. Petersburg University of Management Technologies and Economics Saint Petersburg Russia Graduate School of Applied Mathematics and Computational Physics of the Physic-Mechanic Institute St. Petersburg University of Management Technologies and Economics Peter the Great St.Petersburg Polytechnic University Saint Petersburg Russia Department of International Business St. Petersburg State University of Economics Saint Petersburg Russia Unfrozen Studio Saint Petersburg Russia

ISBN: (纸本)9781665409933

Banking as a highly digitalized sector is seeking for new technologies to improve the data flow processing and communications. The issues of cyber-security and safety of transaction force institutions to lead in using the reliable digital tools. The tough competition on saturated market requires the permanent renewing of infrastructure and data flows analytics, and the re-thinking of the functional role of banking institutions in the world of fin-tech, where the transactions pass in automatic regime. The cyber-security search, the speed and quality of service, and innovative growth strategy are the essential purposes that make relevant the study of the implementation of smart contracting and blockchain platforms for the cases of service institutions. The paper presents the analysis of cases of digital tools in customer services and the study of the prospects of the smart contracting and blockchain platforms as instruments to assure the increased level of user data cyber-security. © 2022 IEEE.

关键词： Blockchain

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