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Showing 1 to 20 of 151 for “"Langevin"”.
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Optimizing Irreversible Perturbations of the Unadjusted Langevin Algorithm
… Monte Carlo (MCMC) methods, and in particular Langevin dynamics, provide a powerful framework for this task by constructing stochastic processes that converge to the target distribution. However, practical implementations face two challenges: slow mixing when the target distribution is …
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Bödeker's Effective Theory: From Langevin Dynamics to Dyson-Schwinger Equations
… modes to leading logarithmic order by means of a Langevin equation. This effective theory has been used for lattice calculations so far. In this work we provide a complementary, more analytic approach based on Dyson-Schwinger equations. Using methods known from stochastic quantisation, we recast …
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Modelling the variability of complex systems by means of Langevin processes
… liegende Dynamik wird dabei durch effektive Langevin-Gleichungen beschrieben, und die diese Gleichungen bestimmenden Funktionen für Drift und Diffusion werden auf der Basis eines von Friedrich und Peinke entwickelten Verfahrens direkt aus einem gemessenen Datensatz bestimmt. Der Schwerpunkt …
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Characterization of nanopores with internal cavities for DNA manipulation using Langevin dynamics simulations
… this geometry is studied using coarse-grained Langevin dynamics. The most striking result is that translocation time through the system is found to be minimal for polymers of medium length: both longer and shorter chains take longer to translocate. The length at which this occurs is named the …
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A study of electrochemical transport and diffuse charge dynamics using a Langevin equation
… This work introduces a new approach based on a Langevin equation for diffuse charge dynamics in nanofluidic devices, which incorporates features from both continuum and atomistic methods. The model is then extended to include steric effects resulting from finite ion size, and applied to the …
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Nonadiabatic electron transfer in the condensed phase, via semiclassical and Langevin equation approach
… The second approach is based on the generalized Langevin equation, in which the quantum transitions of electronic states are condensed into a linear regression equation. The memory kernel in the regression equation is computed using a second perturbation expansion. The perturbation is optimized …
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Biomolecular Folding Rates As Understood From Single-Reaction-Coordinate Langevin Dynamics And Kramers’ Theory
Langevin dynamics was used to model the folding and unfolding of simple, hairpin-like biomolecules whose ends are attached to laser-trapped beads, as occurs in optical tweezers experiments. The Langevin process was evolved numerically, using parameters motivated by real experimental systems. …
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A study of electrochemical transport and diffuse charge dynamics in nanoscale devices using a Langevin equation
… This work introduces a new approach based on a Langevin equation for diffuse charge dynamics in nanofluidic devices, which incorporates features from both continuum and atomistic methods. The model is then extended to include steric effects resulting from finite ion size, and applied to various …
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L'aveugle au miroir deformant: Reflexions sur le(s) regard(s) dans l'oeuvre d'Andre Langevin. (French text);
Les personnages de Langevin ont tous ceci en commun qu'ils s'evertuent a decouvrir une direction a leur vie, incapables qu'ils sont de la saisir entiere, d'un coup d'oeil global. A leur insu, ils se trouvent au bord d'un abi me dans lequel il leur sera difficile de ne pas tomber. Leur quete aboutit …
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Fourier-accelerated Langevin simulation of the frustrated XY model and simulation of the spinless and spin one-half Hubbard model
… two-dimensional XY model was simulated using the Langevin equation with Fourier transform acceleration. The speedup due to Fourier acceleration was measured for frustration one-half at the transition temperature. For comparison, the unfrustrated XY model was also studied. For the frustrated case, …
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Efficient Sampling Methods of, by, and for Stochastic Dynamical Systems
… approaches for accelerating the convergence of Langevin dynamics-based samplers. Reversible and irreversible perturbations of Langevin dynamics can improve the performance of Langevin samplers. We present the geometry-informed irreversible perturbation (GiIrr) and show that it accelerates …
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Processos estocásticos não-Markovianos
Modelos de Langevin, que levam em consideração flutuações térmicas, têm aplicação nas mais variadas áreas. Neste trabalho serão estudados fenômenos relacionados a processos difusivos que podem ser modelados por equações de Langevin normais e generalizadas. Daremos bastante ênfase ao papel do ruído …
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Interaction of trapped ions with trapped atoms
… between trapped atoms and trapped ions in the Langevin collision regime between Yb+ and Yb. A measurement of the Langevin rate constant through charge-exchange collisions between [alpha]Yb+ and [beta]Yb over three orders of magnitude in collision energy down to 3 yueV follows. The measured rate …
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Exploring Downhill Protein Folding Free Energy Landscapes
… temperature-jump kinetics measurements and Langevin dynamics simulations. A kinetic and thermodynamic survey of multiple WW domain mutants is performed in combination with a model to reveal the correlation between protein stability and downhill folding propensity. A designed histidine …
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Study of low energy Ytterbium atom-ion charge transfer collisions using a surface-electrode trap
… and measuring ion loss. We confirm that, in the Langevin regime, the charge transfer collisional rate is independent of the collisional energy. The measured Langevin cross section is consistent with a theoretical value for the ytterbium atomic polarizability of 143 a.u., as calculated by Zhang …
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Towards Enhanced Proposals for PINN-Based Neural Sampler Training
… a partially learned vector field with annealed Langevin dynamics. However, isolated modes and other pathological properties of the annealing path imply that such proposals achieve insufficient exploration and thereby lower performance post training. In this work we extend existing work and …
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An optimization perspective on log-concave sampling and beyond
… and sharp analysis of the Metropolis-adjusted Langevin algorithm, yielding new state-of-the-art guarantees for high-accuracy log-concave sampling; the first lower bounds for the complexity of log-concave sampling; an analysis of mirror Langevin Monte Carlo for constrained sampling; and the …
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Some Investigations Of Phase Transitions In Rod-Like Macro-Molecules And Fibrous Gels
… transitions are presented here.First, we conduct Langevin dynamics calculations on a chain of masses and bistable springs in a viscous fluid, and extract a temperature dependent kinetic relation by observing that the dissipation at a phase boundary can be estimated by performing an energy balance. …
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Random-vortex-particle methods applied to broadband fan interaction noise
… present in turbulent flows is modelled using Langevin Equations. A standard Langevin equation and a second-order Langevin model are derived in details and validated for fan interaction noise. In contrast with classical methods to generate synthetic turbulence, random-vortex-particle methods …
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