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We present a strategy to construct guiding distribution functions (GDFs) based on variance minimization. Auxiliary dynamics via GDFs mitigates the exponential growth of variance as a function of bias in Monte Carlo estimators of large…

统计力学 · 物理学 2020-09-22 Ushnish Ray , Garnet Kin-Lic Chan

We study nonparametric estimation of the diffusion coefficient from discrete data, when the observations are blurred by additional noise. Such issues have been developed over the last 10 years in several application fields and in particular…

统计理论 · 数学 2011-12-30 Marc Hoffmann , Axel Munk , Johannes Schmidt-Hieber

In this paper we revisit the issue of the propagation of warps in thin and viscous accretion discs. In this regime warps are know to propagate diffusively, with a diffusion coefficient approximately inversely proportional to the disc…

高能天体物理现象 · 物理学 2015-05-18 G. Lodato , D. Price

Self-diffusion coefficients, $D^*$, are routinely estimated from molecular dynamics simulations by fitting a linear model to the observed mean-squared displacements (MSDs) of mobile species. MSDs derived from simulation exhibit statistical…

统计力学 · 物理学 2026-01-05 Andrew R. McCluskey , Samuel W. Coles , Benjamin J. Morgan

We study Diffusion Schr\"odinger Bridge (DSB) models in the context of dynamical astrophysical systems, specifically tackling observational inverse prediction tasks within Giant Molecular Clouds (GMCs) for star formation. We introduce the…

天体物理仪器与方法 · 物理学 2025-11-13 Ye Zhu , Duo Xu , Zhiwei Deng , Jonathan C. Tan , Olga Russakovsky

Score-based diffusion models (SBDMs) are powerful amortized samplers for Boltzmann distributions; however, imperfect score estimates bias downstream Monte Carlo estimates. Classical importance sampling (IS) can correct this bias, but…

机器学习 · 计算机科学 2025-11-10 Fengzhe Zhang , Laurence I. Midgley , José Miguel Hernández-Lobato

The transport equation of active motion is generalised to consider time-fractional dynamics for describing the anomalous diffusion of self-propelled particles observed in many different systems. In the present study, we consider an…

统计力学 · 物理学 2023-10-27 Francisco J. Sevilla , Guillermo Chacón-Acosta , Trifce Sandev

The Diffusion Probabilistic Model (DPM) has emerged as a highly effective generative model in the field of computer vision. Its intermediate latent vectors offer rich semantic information, making it an attractive option for various…

计算机视觉与模式识别 · 计算机科学 2023-03-29 Haipeng Zhou , Lei Zhu , Yuyin Zhou

We propose a practical empirical fitting function to characterize the non-Gaussian displacement distribution functions (DispD) often observed for heterogeneous diffusion problems. We first test this fitting function with the problem of a…

软凝聚态物质 · 物理学 2022-07-20 Le Qiao , Nicholas Ilow , Maxime Ignacio , Gary W. Slater

The problem of spin diffusion is studied numerically in one-dimensional classical Heisenberg model using a deterministic odd even spin precession dynamics. We demonstrate that spin diffusion in this model, like energy diffusion, is normal…

统计力学 · 物理学 2015-06-12 Debarshee Bagchi

Guidance is a widely used technique for diffusion models to enhance sample quality. Technically, guidance is realised by using an auxiliary model that generalises more broadly than the primary model. Using a 2D toy example, we first show…

计算机视觉与模式识别 · 计算机科学 2025-09-01 Nikolas Adaloglou , Tim Kaiser , Damir Iagudin , Markus Kollmann

Diffusion MRI is the modality of choice to study alterations of white matter. In past years, various works have used diffusion MRI for automatic classification of AD. However, classification performance obtained with different approaches is…

Subsampling is commonly used to mitigate costs associated with data acquisition, such as time or energy requirements, motivating the development of algorithms for estimating the fully-sampled signal of interest $x$ from partially observed…

机器学习 · 计算机科学 2025-04-23 Oisin Nolan , Tristan S. W. Stevens , Wessel L. van Nierop , Ruud J. G. van Sloun

Conventional diffusion models typically relies on a fixed forward process, which implicitly defines complex marginal distributions over latent variables. This can often complicate the reverse process' task in learning generative…

机器学习 · 统计学 2025-06-10 Grigory Bartosh , Dmitry Vetrov , Christian A. Naesseth

Weighting methods are essential tools for estimating causal effects in observational studies, with the goal of balancing pre-treatment covariates across treatment groups. Traditional approaches pursue this objective indirectly, for example,…

统计方法学 · 统计学 2026-02-09 Diptanil Santra , Guanhua Chen , Chan Park

Diffusion models for continuous state spaces based on Gaussian noising processes are now relatively well understood from both practical and theoretical perspectives. In contrast, results for diffusion models on discrete state spaces remain…

机器学习 · 计算机科学 2026-04-02 Giovanni Conforti , Alain Durmus , Le-Tuyet-Nhi Pham , Gael Raoul

State estimation is a critical task in scientific, engineering and control applications. Since the reliability of reconstructions depends on the number and position of sensors, optimal sensor placement (OSP) is essential in scenarios where…

机器学习 · 计算机科学 2026-05-11 James Rowbottom , Nick Huang , Carola-Bibiane Schönlieb , Ben Adcock

We present a non-perturbative calculation of the 1-point probability distribution function (PDF) for the spherically-averaged matter density field. The PDF is represented as a path integral and is evaluated using the saddle-point method. It…

宇宙学与河外天体物理 · 物理学 2019-03-20 Mikhail M. Ivanov , Alexander A. Kaurov , Sergey Sibiryakov

The primary objective of Stochastic Frontier (SF) Analysis is the deconvolution of the estimated composed error terms into noise and inefficiency. Assuming a parametric production function (e.g. Cobb-Douglas, Translog, etc.), might lead to…

统计方法学 · 统计学 2022-08-23 Rouven Schmidt , Thomas Kneib

Generative models can be categorized into two types: explicit generative models that define explicit density forms and allow exact likelihood inference, such as score-based diffusion models (SDMs) and normalizing flows; implicit generative…

机器学习 · 统计学 2023-07-06 Jingwei Zhang , Han Shi , Jincheng Yu , Enze Xie , Zhenguo Li