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This study presents new analytic approximations of the stochastic-alpha-beta-rho (SABR) model. Unlike existing studies that focus on the equivalent Black-Scholes (BS) volatility, we instead derive the equivalent…

Mathematical Finance · Quantitative Finance 2021-06-09 Jaehyuk Choi , Lixin Wu

Data assimilation (DA) combines partial observations with dynamical models to improve state estimation. Filter-based DA uses only past and present data and is the prerequisite for real-time forecasts. Smoother-based DA exploits both past…

Systems and Control · Electrical Eng. & Systems 2026-01-21 Marios Andreou , Nan Chen , Yingda Li

In order to predict future performance of subsurface fluid reservoirs under possible operating scenarios, a dynamic, porous-medium flow simulation model must be tuned to include representative properties of the reservoir. Estimating…

Geophysics · Physics 2026-02-04 Zhen Zhang , Xuebin Zhao , Andrew Curtis

Stochastic variational inference offers an attractive option as a default method for differentiable probabilistic programming. However, the performance of the variational approach depends on the choice of an appropriate variational family.…

Machine Learning · Statistics 2021-02-11 Luca Ambrogioni , Kate Lin , Emily Fertig , Sharad Vikram , Max Hinne , Dave Moore , Marcel van Gerven

The Reynolds-averaged Navier-Stokes (RANS) equations provide a computationally efficient method for solving fluid flow problems in engineering applications. However, the use of closure models to represent turbulence effects can reduce their…

Fluid Dynamics · Physics 2024-05-02 Oliver Brenner , Justin Plogmann , Pasha Piroozmand , Patrick Jenny

We develop and evaluate point and interval estimates for the random effects $\theta_i$, having made observations $y_i|\theta_i\stackrel{\m athit{ind}}{\sim}N[\theta_i,V_i],i=1,...,k$ that follow a two-level Normal hierarchical model.…

Methodology · Statistics 2011-08-17 Carl Morris , Ruoxi Tang

The Constant Elasticity of Variance (CEV) model is mathematically presented and then used in a Credit-Equity hybrid framework. Next, we propose extensions to the CEV model with default: firstly by adding a stochastic volatility diffusion…

Probability · Mathematics 2007-05-23 Marc Atlan , Boris Leblanc

Time-varying parameter (TVP) regressions commonly assume that time-variation in the coefficients is determined by a simple stochastic process such as a random walk. While such models are capable of capturing a wide range of dynamic…

Econometrics · Economics 2021-03-01 Manfred M. Fischer , Niko Hauzenberger , Florian Huber , Michael Pfarrhofer

We propose a fast and theoretically grounded method for Bayesian variable selection and model averaging in latent variable regression models. Our framework addresses three interrelated challenges: (i) intractable marginal likelihoods, (ii)…

Methodology · Statistics 2025-09-16 Gregor Zens , Mark F. J. Steel

We demonstrate how to model the toppling activity in avalanching systems by stochastic differential equations (SDEs). The theory is developed as a generalization of the classical mean field approach to sandpile dynamics by formulating it as…

Adaptation and Self-Organizing Systems · Physics 2009-11-13 Martin Rypdal , Kristoffer Rypdal

We consider an investor who seeks to maximize her expected utility derived from her terminal wealth relative to the maximum performance achieved over a fixed time horizon, and under a portfolio drawdown constraint, in a market with local…

Portfolio Management · Quantitative Finance 2016-10-28 Ankush Agarwal , Ronnie Sircar

Non-uniform sampling arises when an experimenter does not have full control over the sampling characteristics of the process under investigation. Moreover, it is introduced intentionally in algorithms such as Bayesian optimization and…

Machine Learning · Statistics 2020-07-03 Stijn de Waele

This paper describes a family of seasonal and non-seasonal time series models that can be viewed as generalisations of additive and multiplicative exponential smoothing models, to model series that grow faster than linear but slower than…

Machine Learning · Computer Science 2024-03-25 Slawek Smyl , Christoph Bergmeir , Alexander Dokumentov , Xueying Long , Erwin Wibowo , Daniel Schmidt

Bayesian vector autoregressions (BVARs) are the workhorse in macroeconomic forecasting. Research in the last decade has established the importance of allowing time-varying volatility to capture both secular and cyclical variations in…

Econometrics · Economics 2023-10-24 Joshua Chan

Modeling the time-varying covariance structures of high-dimensional variables is critical across diverse scientific and industrial applications; however, existing approaches exhibit notable limitations in either modeling flexibility or…

Methodology · Statistics 2026-01-21 Taehee Lee , Jun S. Liu

Approximate Bayesian Computation (ABC) is a framework for performing likelihood-free posterior inference for simulation models. Stochastic Variational inference (SVI) is an appealing alternative to the inefficient sampling approaches…

Machine Learning · Statistics 2016-06-29 Alexander Moreno , Tameem Adel , Edward Meeds , James M. Rehg , Max Welling

In an efficient stock market, the returns and their time-dependent volatility are often jointly modeled by stochastic volatility models (SVMs). Over the last few decades several SVMs have been proposed to adequately capture the defining…

Applications · Statistics 2017-03-21 Sujay Mukhoti , Pritam Ranjan

In this paper, we introduce a new single model maneuvering target tracking approach using stochastic differential equation (SDE) based on GARCH volatility. The traditional input estimation (IE) techniques assume constant acceleration level…

Applications · Statistics 2019-02-14 Ehsan Hajiramezanali , Seyyed Hamed Fouladi , Hamidreza Amindavar

Data assimilation (DA) plays a crucial role in extracting valuable information from flow measurements in fluid dynamics problems. Often only time-averaged data is available, which poses challenges for DA in the context of unsteady flow…

Fluid Dynamics · Physics 2024-05-30 Justin Plogmann , Oliver Brenner , Patrick Jenny

Stochastic variational inference (SVI) lets us scale up Bayesian computation to massive data. It uses stochastic optimization to fit a variational distribution, following easy-to-compute noisy natural gradients. As with most traditional…

Machine Learning · Statistics 2014-11-19 Stephan Mandt , David Blei