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The detail structure of the wave function is analyzed at various refinement levels using the methods of wavelet analysis. The eigenvalue problem of a model system is solved in granular Hilbert spaces, and the trajectory of the eigenstates…

Computational Physics · Physics 2009-11-13 J. Pipek , Sz. Nagy

We explain how to compute gradients of functions of the form $G = \frac{1}{2} \sum_{i=1}^{m} (E y_i - C_i)^2$, which often appear in the calibration of stochastic models, using Automatic Adjoint Differentiation and parallelization. We…

Computational Finance · Quantitative Finance 2023-01-25 José Brito , Andrei Goloubentsev , Evgeny Goncharov

The optimization of the latents and parameters of diffusion models with respect to some differentiable metric defined on the output of the model is a challenging and complex problem. The sampling for diffusion models is done by solving…

Computer Vision and Pattern Recognition · Computer Science 2025-02-13 Zander W. Blasingame , Chen Liu

One difficulty in developing numerical methods for hyperbolic systems of conservation laws is the fact that solutions often contain regions where much higher resolution is required than elsewhere in the domain, particularly since the…

Numerical Analysis · Mathematics 2015-11-12 Brisa N. Davis , Randall J. LeVeque

It is challenging for full-waveform inversion to determine geologically informative models from field data. An inaccurate wavelet can make it more complicated. We develop a novel misfit function, entitled deconvolutional double-difference…

Geophysics · Physics 2022-01-12 Fuqiang Chen , Daniel Peter

We present an approach for forming sensitivity maps (or sensitivites) using ensembles. The method is an alternative to using an adjoint, which can be very challenging to formulate and also computationally expensive to solve. The main…

Computational Engineering, Finance, and Science · Computer Science 2018-09-21 C. E. Heaney , P. Salinas , F. Fang , C. C. Pain , I. M. Navon

Reward fine-tuning has become a common approach for aligning pretrained diffusion and flow models with human preferences in text-to-image generation. Among reward-gradient-based methods, Adjoint Matching (AM) provides a principled…

Machine Learning · Computer Science 2026-05-19 Jeongwoo Shin , Dongsoo Shin , Yuchen Zhu , Wei Guo , Yongxin Chen , Joonseok Lee , Jaewoong Choi , Jaemoo Choi

Among the most advanced and sophisticated methods for state analysis of an atmospheric system is the four dimensional variational data assimilation. The numerically challenging task of this approach is the development and application of the…

Numerical Analysis · Mathematics 2018-06-19 Ramaz Botchorishvili , Hendrik Elbern , Tamari Janelidze

Physics-informed Machine Learning has recently become attractive for learning physical parameters and features from simulation and observation data. However, most existing methods do not ensure that the physics, such as balance laws (e.g.,…

Numerical Analysis · Mathematics 2021-09-10 Satish Karra , Bulbul Ahmmed , Maruti K. Mudunuru

The paper is concerned with an adjoint complement to the Volume-of-Fluid (VoF) method for immiscible two-phase flows, e.g. air and water, which is widely used in marine engineering due to its computational efficiency. The particular…

Fluid Dynamics · Physics 2021-06-02 Niklas Kühl , Jörn Kröger , Martin Siebenborn , Michael Hinze , Thomas Rung

In this paper, a generic extension of variational mode decomposition (VMD) algorithm for multivariate or multichannel data sets is presented. We first define a model for multivariate modulated oscillations that is based on the presence of a…

Signal Processing · Electrical Eng. & Systems 2020-01-08 Naveed ur Rehman , Hania Aftab

We develop a continuous adjoint formulation and implementation for controlling the deformation of clean, neutrally buoyant droplets in Stokes flow through farfield velocity boundary conditions. The focus is on dynamics where surface tension…

Computational Physics · Physics 2024-02-23 Alexandru Fikl , Daniel J. Bodony

The hierarchical prior used in Latent Gaussian models (LGMs) induces a posterior geometry prone to frustrate inference algorithms. Marginalizing out the latent Gaussian variable using an integrated Laplace approximation removes the…

Computation · Statistics 2023-06-28 Charles C. Margossian

Comprehension of metabolic pathways is considerably enhanced by metabolic flux analysis (MFA-ILE) in isotope labeling experiments. The balance equations are given by hundreds of algebraic (stationary MFA) or ordinary differential equations…

Molecular Networks · Quantitative Biology 2016-03-24 Stéphane Mottelet , Gil Gaullier , Georges Sadaka

All-dielectric metasurfaces exhibit exotic electromagnetic responses, similar to those obtained with metal-based metamaterials. Research in all-dielectric metasurfaces currently uses relatively simple unit-cell designs, but increased…

Optics · Physics 2020-12-10 Yang Deng , Simiao Ren , Kebin Fan , Jordan M. Malof , Willie J. Padilla

In this work, we propose an adjoint-based optimization procedure to control the onset of the Rayleigh-B\'enard instability with a melting front. A novel cut cell method is used to solve the Navier-Stokes equations in the Boussinesq…

Mathematical Physics · Physics 2025-12-23 Tomas Fullana , Alejandro Quirós Rodríguez , Vincent Le Chenadec , Taraneh Sayadi

Bilevel optimization has been developed for many machine learning tasks with large-scale and high-dimensional data. This paper considers a constrained bilevel optimization problem, where the lower-level optimization problem is convex with…

Machine Learning · Computer Science 2023-08-22 Siyuan Xu , Minghui Zhu

The proximal gradient descent method, well-known for composite optimization, can be completely described by the concept of proximal gradient mapping. In this paper, we highlight our previous two discoveries of proximal gradient…

Optimization and Control · Mathematics 2022-12-15 Beier Chen , Hui Zhang

A systematic procedure for optimising the friction coefficient in underdamped Langevin dynamics as a sampling tool is given by taking the gradient of the associated asymptotic variance with respect to friction. We give an expression for…

Computation · Statistics 2023-11-01 Martin Chak , Nikolas Kantas , Tony Lelièvre , Grigorios A. Pavliotis

The conjugate gradient method (CG) is typically used with a preconditioner which improves efficiency and robustness of the method. Many preconditioners include parameters and a proper choice of a preconditioner and its parameters is often…

Numerical Analysis · Mathematics 2019-06-04 Alexandr Katrutsa , Mike Botchev , George Ovchinnikov , Ivan Oseledets