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A recursive implementation of the ALIENOR optimization method

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International Journal of Intelligent Computing and Cybernetics 2021年第2期14卷 81-103页

作者： Daniele Peri National Research Council(CNR) Istituto per le Applicazioni del Calcolo“Mauro Picone”–IACRomaItaly

Purpose-A recursive scheme for the ALIENOR method is proposed as a remedy for the difficulties induced by the method.A progressive focusing on the most promising region,in combination with a variation of the density of the alpha-dense curve,is proposed.Design/methodology/approach-ALIENOR method is aimed at reducing the space dimensions of an optimization problem by spanning it by using a single alpha-dense curve:the curvilinear abscissa along the curve becomes the only design parameter for any design space.As a counterpart,the transformation of the objective function in the projected space is much more difficult to tackle.Findings-A fine tuning of the procedure has been performed in order to identity the correct balance between the different elements of the procedure.The proposed approach has been tested by using a set of algebraic functions with up to 1,024 design variables,demonstrating the ability of the method in solving large scale optimization problem.Also an industrial application is presented.Originality/value-In the knowledge of the author there is not a similar paper in the current literature.

关键词： ALIENOR optimization Global optimization Lipschitzian optimization Reduced order base

Numerical Stability Analysis for a Stationary and Translating Droplet at Extremely Low Viscosity Values Using the Lattice Boltzmann Method Color-GradientMulti-Component Model with Central Moments Formulation

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Communications in Computational Physics 2023年第1期33卷 330-348页

作者： Karun P.N.Datadien Gianluca Di Staso Federico Toschi Department of Applied Physics and Science Education Eindhoven University of Technology5600MB EindhovenNetherlands FLOW Matters Consultancy B.V. 5612AEEindhovenThe Netherlands istituto per le applicazioni del calcolo Consiglio Nazionale delle Ricerche00185 RomeItaly

Multicomponent models based on the Lattice Boltzmann Method(LBM)have clear advantages with respect to other approaches,such as good parallel performances and scalability and the automatic resolution of breakup and coalescence events.Multicomponent flow simulations are useful for a wide range of applications,yet many multicomponent models for LBMare limited in their numerical stability and therefore do not allow exploration of physically relevant low viscosity regimes.Here we performa quantitative study and validations,varying parameters such as viscosity,droplet radius,domain size and acceleration for stationary and translating droplet simulations for the color-gradientmethod with centralmoments(CG-CM)formulation,as this method promises increased numerical stability with respect to the non-CMformulation.We focus on numerical stability and on the effect of decreasing grid-spacing,i.***.increasing resolution,in the extremely low viscosity regime for stationary droplet simulations.The effects of small-and large-scale anisotropy,due to grid-spacing and domain-size,respectively,are investigated for a stationary droplet.The effects on numerical stability of applying a uniform acceleration in one direction on the domain,i.***.on both the droplet and the ambient,is explored into the low viscosity regime,to probe the numerical stability of the method under dynamical conditions.

关键词： Lattice Boltzmann method multicomponent flow numerical stability low viscosity

Marine propellers performance and flow-field prediction by a free-wake panel method

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Journal of Hydrodynamics 2014年第5期26卷 780-795页

作者： GRECO Luca MUSCARI Roberto TESTA Claudio DI MASCIO Andrea CNR-INSEAN Italian Ship Model BasinRomeItaly CNR-IAC Istituto per le Applicazioni del Calcolo "M. Picone"RomeItaly

A Boundary Element Method （BEM） hydrodynamics combined with a flow-alignment technique to evaluate blades shed vorticity is presented and applied to a marine propeller in open water. Potentialities and drawbacks of this approach in capturing propeller performance, slipstream velocities, blade pressure distribution and pressure disturbance in the flow-field are highlighted by comparisons with available experiments and RANSE results. In particular, correlations between the shape of the convected vortex- sheet and the accuracy of BEM results are discussed throughout the paper. To this aim, the analysis of propeller thrust and torque is the starting point towards a detailed discussion on the capability of a 3-D free-wake BEM hydrodynamic approach to describe the local features of the flow-field behind the propeller disk, in view of applications to propulsive configurations where the shed wake plays a dominant role.

关键词： BEM hydrodynamics free-wake analysis BEM-RANSE comparison

The Stability of the Gauss-Laguerre Rule for Cauchy P.V. Integrals on the Half Line

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American Journal of Computational Mathematics 2023年第4期13卷 505-511页

作者： Maria Rosaria Capobianco Giuliana Criscuolo istituto per le applicazioni del calcolo “Mauro Picone”—CNR Napoli Italy Dipartimento di Matematica e applicazioni Università degli Studi di Napoli “Federico II” Napoli Italy

In this paper, the authors give a different and more precise analysis of the stability of the classical Gauss-Laguerre quadrature rule for the Cauchy P.V. integrals on the half line. Moreover, in order to obtain this result they give some new estimates for the distance of the zeros of the Laguerre polynomials that can be useful also in other contests.

关键词： Gauss Quadrature Exponential Weights Cauchy P.V. Integrals Stability

In memory of Steven Alan Orszag(1943-2011)

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Communications in Computational Physics 2013年第3期13卷 I0001-I0002页

作者： Sauro Succi istituto applicazioni calcolo CNRvia dei Taurini 900185RomaItaly

I first met Steve in his Fine Hall office in Princeton,back in 1992.For many years he had been one my biggest heroes and I was obviously very excited,and a bit tense at the prospect of meeting him in person.That day it all went perfectly smoothly,and so too was the case on the very many occasions we had the chance to meet again during the next twenty years,in Princeton,Boston,Yale,Maine,and occasionally Rome.

关键词： smoothly Boston office

Multiscale Hybrid Modeling of Proteins in Solvent:SARS-CoV2 Spike Protein as Test Case for Lattice Boltzmann-All Atom Molecular Dynamics Coupling

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Communications in Computational Physics 2023年第1期33卷 57-76页

作者： Marco Lauricella Letizia Chiodo Fabio Bonaccorso Mihir Durve Andrea Montessori Adriano Tiribocchi Alessandro Loppini Simonetta Filippi Sauro Succi Consiglio Nazionale delle Ricerche Istituto per le Applicazioni del Calcolo IAC-CNR00185Rome Italy Engineering Department Campus Bio-Medico University00128RomeItaly Physics Department and INFN University of Rome“Tor Vergata”00133 RomeItaly istituto Italiano di Tecnologia Center for Life Nano-&Neuro-Science@Sapienza-IIT00161RomeItaly Engineering Department Universit´a degli Studi Roma TREvia Vito Volterra 62Rome00146Italy

Physiological solvent flows surround biological structures triggering therein collective motions.Notable examples are virus/host-cell interactions and solventmediated allosteric regulation.The present work describes a multiscale approach joining the Lattice Boltzmann fluid dynamics(for solvent flows)with the all-atom atomistic molecular dynamics(for proteins)to model functional interactions between flows and molecules.We present,as an applicative scenario,the study of the SARS-CoV-2 virus spike glycoprotein protein interacting with the surrounding solvent,modeled as a mesoscopic fluid.The equilibriumproperties of the wild-type spike and of the Alpha variant in implicit solvent are described by suitable observables.The mesoscopic solvent description is critically compared to the all-atom solvent model,to quantify the advantages and limitations of the mesoscopic fluid description.

关键词： SARS-CoV-2 biophysics lattice Boltzmann molecular dynamics

COEXISTENCE FOR MULTIPLE LARGEST REPRODUCTION RATIOS OF A MULTI-STRAIN SIS EPIDEMIC MODEL

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Acta Mathematica Scientia 2016年第5期36卷 1524-1530页

作者： Yoshiaki MUROYA Eleonora MESSINA Elvira RUSSO Antonia VECCHIO Department of Mathematics Waseda University Dipartimento di Matematica e applicazioni Università degli Studi di Napoli "Federico Ⅱ"-Via Cintia istituto per applicazioni del calcolo "M. Picone" Sede di Napoli-CNR-Via P.Castellino

In this paper, to complete the global dynamics of a multi-strains SIS epidemic model, we establish a precise result on coexistence for the cases of the partial and complete duplicated multiple largest reproduction rat... 详细信息

关键词： multi-strains SIS epidemic model global attractivity Lyapunov function coexistence

The Quantum Lattice Boltzmann Equation:Recent Developments

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Communications in Computational Physics 2008年第10期4卷 980-1007页

作者： Silvia Palpacelli Sauro Succi Dipartimento di Matematica Universit`a Roma TreLargo San Leonardo Murialdo 100146RomaItaly istituto applicazioni del calcolo Viale Policlinico 13700161 RomaItaly

The derivation of the quantum lattice Boltzmann model is reviewed with special emphasis on recent developments of the model,namely,the extension to a multi-dimensional formulation and the application to the computation of the ground state of the Gross-Pitaevskii equation(GPE).Numerical results for the linear and nonlinear Schr odinger equation and for the ground state solution of the GPE are also presented and validated against analytical results or other classical schemes such as Crank-Nicholson.

关键词： Quantum lattice Boltzmann multi-dimensions imaginary-time model linear and non-linear Schrodinger equation adiabatic limit

Parallel Quasi Exhaustive Search of Optimal Asset Allocation for Pension Funds

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American Journal of Operations Research 2016年第5期6卷 387-400页

作者： Massimo Bernaschi Mauro Carrozzo Matteo Lulli Giacomo Piperno Davide Vergni istituto applicazioni del calcolo Consiglio Nazionale delle Ricerche Rome Italy

We present a solution based on a suitable combination of heuristics and parallel processing techniques for finding the best allocation of the financial assets of a pension fund, taking into account all the specific rules of the fund. We compare the values of an objective function computed with respect to a large set (thousands) of possible scenarios for the evolution of the Net Asset Value (NAV) of the share of each asset class in which the financial capital of the fund is invested. Our approach does not depend neither on the model used for the evolution of the NAVs nor on the objective function. In particular, it does not require any linearization or similar approximations of the problem. Although we applied it to a situation in which the number of possible asset classes is limited to few units (six in the specific case), the same approach can be followed also in other cases by grouping asset classes according to their features.

关键词： ALM Pension Fund Optimization Parallel Processing