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Motivated by the modeling of three-dimensional fluid turbulence, we define and study a class of stochastic partial differential equations (SPDEs) that are randomly stirred by a spatially smooth and uncorrelated in time forcing term. To…

Probability · Mathematics 2021-12-24 Gabriel B. Apolinário , Laurent Chevillard , Jean-Christophe Mourrat

We propose here a testing methodology based on the autocovariance, detrended moving average, and time-averaged mean-squared displacement statistics for tempered fractional Brownian motions (TFBMs) which are related to the notions of…

Methodology · Statistics 2025-08-14 Katarzyna Macioszek , Farzad Sabzikar , Krzysztof Burnecki

We investigate the sample path regularity of multivariate operator-self-similar stable random fields with values in $\mathbb{R}^m$ given by a harmonizable representation. Such fields were introduced in [25] as a generalization of both…

Probability · Mathematics 2021-07-27 Ercan Sönmez

Truncated Fourier Transforms (TFTs), first introduced by Van der Hoeven, refer to a family of algorithms that attempt to smooth "jumps" in complexity exhibited by FFT algorithms. We present an in-place TFT whose time complexity, measured in…

Symbolic Computation · Computer Science 2013-01-30 Andrew Arnold

Fractional order differential and difference equations are used to model systems with memory. Variable order fractional equations are proposed to model systems where the memory changes in time. We investigate stability conditions for linear…

Dynamical Systems · Mathematics 2025-02-12 Prashant M. Gade , Sachin Bhalekar , Janardhan Chevala

We present Vector-Space Markov Random Fields (VS-MRFs), a novel class of undirected graphical models where each variable can belong to an arbitrary vector space. VS-MRFs generalize a recent line of work on scalar-valued, uni-parameter…

Machine Learning · Statistics 2015-05-20 Wesley Tansey , Oscar Hernan Madrid Padilla , Arun Sai Suggala , Pradeep Ravikumar

The Gaussian random field (GRF) and the Gaussian Markov random field (GMRF) have been widely used to accommodate spatial dependence under the generalized linear mixed model framework. These models have limitations rooted in the symmetry and…

Methodology · Statistics 2022-12-15 Marcos O. Prates , Dipak K. Dey , Michael R. Willig , Jun Yan

This paper proposes hybrid semi-Markov conditional random fields (SCRFs) for neural sequence labeling in natural language processing. Based on conventional conditional random fields (CRFs), SCRFs have been designed for the tasks of…

Computation and Language · Computer Science 2018-05-11 Zhi-Xiu Ye , Zhen-Hua Ling

It is well known that, under suitable conditions, microRNAs are able to fine tune the relative concentration of their targets to any desired value. We show that this function is particularly effective when one of the targets is a…

Molecular Networks · Quantitative Biology 2015-06-16 Andrea Riba , Carla Bosia , Mariama El Baroudi , Laura Ollino , Michele Caselle

We introduce a multistable subordinator, which generalizes the stable subordinator to the case of time-varying stability index. This enables us to define a multifractional Poisson process. We study properties of these processes and…

Probability · Mathematics 2014-09-05 Ilya Molchanov , Kostiantyn Ralchenko

We investigate the sample paths regularity of operator scaling alpha-stable random fields. Such fields were introduced as anisotropic generalizations of self-similar fields and satisfy a scaling property for a real matrix E. In the case of…

Probability · Mathematics 2016-08-14 Hermine Biermé , Céline Lacaux

Markov random fields (MRFs) are invaluable tools across diverse fields, and spatiotemporal MRFs (STMRFs) amplify their effectiveness by integrating spatial and temporal dimensions. However, modeling spatiotemporal data introduces additional…

Methodology · Statistics 2024-04-30 Ning Ning

In this paper the running average of a subordinator with a tempered stable distribution is considered. We investigate a family of previously unexplored infinite-activity subordinators induced by the probability distribution of the running…

Probability · Mathematics 2020-09-08 Weixuan Xia

We present a general mathematical framework for trajectory stratification for simulating rare events. Trajectory stratification involves decomposing trajectories of the underlying process into fragments limited to restricted regions of…

Statistical Mechanics · Physics 2017-11-15 Aaron R. Dinner , Jonathan C. Mattingly , Jeremy O. B. Tempkin , Brian Van Koten , Jonathan Weare

In this paper, the classical problem of the probabilistic characterization of a random variable is re-examined. A random variable is usually described by the probability density function (PDF) or by its Fourier transform, namely the…

Mathematical Physics · Physics 2013-01-22 Giulio Cottone , Mario Di Paola

In this paper continuous time random walk models approximating fractional space-time diffusion processes are studied. Stochastic processes associated with the considered equations represent time-changed processes, where the time-change…

Probability · Mathematics 2014-09-16 Sabir Umarov

Since the middle of the 90's, multifractional processes have been introduced for overcoming some limitations of the classical Fractional Brownian Motion model. In their context, the Hurst parameter becomes a Holder continuous function H(?)…

Statistics Theory · Mathematics 2015-05-29 Antoine Ayache , Julien Hamonier

Variational inference (VI) combined with data subsampling enables approximate posterior inference over large data sets, but suffers from poor local optima. We first formulate a deterministic annealing approach for the generic class of…

Machine Learning · Statistics 2016-05-31 Stephan Mandt , James McInerney , Farhan Abrol , Rajesh Ranganath , David Blei

Flow matching (FM) is a family of training algorithms for fitting continuous normalizing flows (CNFs). Conditional flow matching (CFM) exploits the fact that the marginal vector field of a CNF can be learned by fitting least-squares…

Machine Learning · Statistics 2025-02-04 Ganchao Wei , Li Ma

We studied piecewise smooth differential systems of the form $$\dot{z} = Z(z) = \dfrac{1 + \operatorname{sgn}(F)}{2}X(z) + \dfrac{1 - \operatorname{sgn}(F)}{2}Y(z),$$ where $F: \mathbb{R}^{n}\rightarrow \mathbb{R}$ is a smooth map having 0…

Dynamical Systems · Mathematics 2022-05-06 Otavio Henrique Perez , Gabriel Rondón , Paulo Ricardo da Silva