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arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,742 papers · 148 categories

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163326488651 · Jun 202019922001200920172026
48 results for Smoother Functions

We present a Kalman smoothing framework based on modeling errors using the heavy tailed Student's t distribution, along with algorithms, convergence theory, open-source general implementation, and several important applications. The computational effort per iteration grows linearly with the length of the time series, a…

2013-03-22abs ↗pdf ↗

New nonlinear smoothers improve state estimation in chaotic systems.

problem Improving state estimation in chaotic dynamical systems with non-Gaussian behavior.
method Developed nonlinear backward ensemble transport smoothers with parameterization and regularization of transport maps.
result Nonlinear smoothers yield lower estimation error than conventional methods for comparable model evaluations.

Convolutional Neural Networks (CNN) and the locally connected layer are limited in capturing the importance and relations of different local receptive fields, which are often crucial for tasks such as face verification, visual question answering, and word sequence prediction. To tackle the issue, we propose a novel loc…

2017-11-22abs ↗pdf ↗

Bayesian convolutional deep sets improve ambiguity in stationary process modeling.

problem Ambiguity in translation equivariant functional representations due to insufficient data points.
method Introduce Bayesian convolutional deep sets with task-dependent stationary prior.
result Improves representation quality compared to kernel smoother and non-parametric models.

Paper proposes a new Taylor moment expansion for non-linear Gaussian filtering and smoothing.

problem Non-linear Gaussian filtering and smoothing in continuous-discrete state-space models.
method Taylor moment expansion (TME) for moment functions directly and in time variable.
result Significantly outperforms state-of-the-art methods in terms of estimation accuracy and numerical stability.

This paper presents a general iterative bias correction procedure for regression smoothers. This bias reduction schema is shown to correspond operationally to the L2L_2 Boosting algorithm and provides a new statistical interpretation for L2L_2 Boosting. We analyze the behavior of the Boosting algorithm applied to commo…

2008-01-30abs ↗pdf ↗

Develops a novel ML smoothing method for incomplete data in state-space models.

problem Estimating states in stochastic systems with incomplete information.
method Introduces score function and conditional observed information matrices for incomplete data, and uses them to derive the ML smoother.
result The ML smoother provides more accurate state estimates with lower standard errors compared to the standard ML state estimator.

Combining deep learning and ensemble smoothers for better history matching.

problem Dealing with complex facies distributions in history matching.
method Using autoencoders and generative adversarial networks to parameterize facies models, applying distance-based localization.
result Improved history matching performance with deep learning parameterizations.

Estimating the state of a dynamical system from a series of noise-corrupted observations is fundamental in many areas of science and engineering. The most well-known method, the Kalman smoother (and the related Kalman filter), relies on assumptions of linearity and Gaussianity that are rarely met in practice. In this p…

2017-02-17abs ↗pdf ↗

Paper explains how tree ensembles improve predictions by smoothing and regulating smoothness.

problem Understanding why tree ensembles perform well despite their complexity.
method Interpreting tree ensembles as adaptive and self-regularizing smoothers.
result Ensemble trees make more smooth predictions than individual trees and adjust smoothness based on input dissimilarity.

Unified approach to multiclass classification using Gabriel graphs.

problem Improving multiclass classification accuracy and efficiency.
method Integrates Gabriel graphs for binary and multiclass classification, proposing new activation functions and support edge neurons.
result Experimental results show superior performance compared to previous GG-based classifiers.

Paper uses UKS to improve BLE RSSI for proximity inference in mobile phone apps.

problem Improper BLE RSSI for accurate proximity inference during pandemics.
method Single-dimensional Unscented Kalman Smoother (UKS) with Gaussian process observation transforms.
result UKS outperforms traditional methods in predicting infection risk from BLE RSSI.

EnKBS smoothes complex systems with future observations for causal inference.

problem Improving state estimation in complex systems with rapid dynamics.
method Continuous-time ensemble Kalman-Bucy smoother for nonlinear dynamical systems.
result EnKBS provides derivative-free framework with high skill in various scientific problems.

We present a general probabilistic perspective on Gaussian filtering and smoothing. This allows us to show that common approaches to Gaussian filtering/smoothing can be distinguished solely by their methods of computing/approximating the means and covariances of joint probabilities. This implies that novel filters and …

2010-06-10abs ↗pdf ↗

Generative models learn smoother densities to sample from unknown distributions.

problem Sampling from unknown distributions in high-dimensional spaces.
method Formalizes sampling problem, introduces multimeasurement noise model, derives Bayes estimator, and uses underdamped Langevin MCMC.
result Formulation leads to efficient sampling methods and theoretical connections with denoising autoencoders.

We introduce a new algorithm, called adaptive sparse backfitting algorithm, for solving high dimensional Sparse Additive Model (SpAM) utilizing symmetric, non-negative definite smoothers. Unlike the previous sparse backfitting algorithm, our method is essentially a block coordinate descent algorithm that guarantees to …

2014-09-08abs ↗pdf ↗

Unified framework for ensemble transport-based smoothing of non-Gaussian time series.

problem Bayesian time series re-analysis with non-Gaussian distributions.
method Measure transport approach to derive consistent prior-to-posterior transformations.
result General ensemble framework for transport-based smoothing of state-space models.

We propose a principled algorithm for robust Bayesian filtering and smoothing in nonlinear stochastic dynamic systems when both the transition function and the measurement function are described by non-parametric Gaussian process (GP) models. GPs are gaining increasing importance in signal processing, machine learning,…

2012-03-20abs ↗pdf ↗

The simplicity of gradient descent (GD) made it the default method for training ever-deeper and complex neural networks. Both loss functions and architectures are often explicitly tuned to be amenable to this basic local optimization. In the context of weakly-supervised CNN segmentation, we demonstrate a well-motivated…

2018-09-07abs ↗pdf ↗

Deep model predicts shapes of curves with multiple covariates.

problem Predicting shapes of planar curves with various covariates.
method Deep learning model using complex-valued functions, conditional covariance smoother with modality-specific encoders.
result Model accurately predicts shapes of curves with multimodal covariates.

Unified framework for efficient Gaussian process inference.

problem Efficient inference in non-conjugate Gaussian process models.
method Combines expectation propagation with linearization for improved efficiency.
result Unified view of various inference schemes, including classical smoothers and EP.

Estimates chirp signal frequencies using probabilistic models.

problem Estimating instantaneous frequencies of chirp signals when true forms are unknown.
method Non-linear Gaussian processes and stochastic filters/smothers for posterior estimation.
result The method outperforms state-of-the-art methods on synthetic and real-world datasets.

Paper optimizes prediction in semi-functional linear models using kernel methods.

problem Optimizing prediction in semi-functional linear models with functional and nonparametric components.
method Double-penalized least squares method in reproducing kernel Hilbert spaces, with regularization parameter selection via generalized cross validation.
result Achieves minimax optimal rates of convergence for both functional and nonparametric components.

Kalman filtering and smoothing algorithms are used in many areas, including tracking and navigation, medical applications, and financial trend filtering. One of the basic assumptions required to apply the Kalman smoothing framework is that error covariance matrices are known and given. In this paper, we study a general…

2012-11-19abs ↗pdf ↗

Study optimal stopping problems with finite-time horizon and proves continuity and strict monotonicity of the boundary.

problem Optimal stopping problems with finite-time horizon and state-dependent discounting.
method Linear diffusion process, time-homogeneous gain function, fine regularity properties, continuity and strict monotonicity proof.
result Proves continuity and strict monotonicity of the optimal stopping boundary under mild assumptions.

Entropy regularization is commonly used to improve policy optimization in reinforcement learning. It is believed to help with \emph{exploration} by encouraging the selection of more stochastic policies. In this work, we analyze this claim using new visualizations of the optimization landscape based on randomly perturbi…

2018-11-27abs ↗pdf ↗

Let URdU\subseteq\mathbb{R}^d be open and convex. We prove that every (not necessarily Lipschitz or strongly) convex function f:URf:U\to\mathbb{R} can be approximated by real analytic convex functions, uniformly on all of UU. We also show that C0C^0-fine approximation of convex functions by smooth (or real analytic) conv…

2012-01-23abs ↗pdf ↗

Researchers analyze neural process architectures and their representational capacities.

problem Understanding what functions can be represented by different neural process architectures.
method Analyzing four types of neural process architectures: CNPs, ANPs, TNPs, and their latent variants.
result Prove these architectures form a strict hierarchy and characterize their representational capabilities.

Curvature penalties improve interpretability of KANs without sacrificing accuracy.

problem Pathologically high-curvature oscillations in KANs activations make them hard to interpret.
method Derived a curvature penalty and proved an upper bound on model curvature.
result KANs with curvature penalties achieve substantially smoother activations while maintaining accuracy.

Analytic networks with bounded coefficients can't outperform polynomial approximations.

problem Approximation limits of neural networks with analytic activation functions under coefficient constraints.
method Deterministic analysis using comparison argument and Bernstein-type estimates.
result Networks with analytic activation functions and controlled coefficients cannot outperform classical polynomial approximation rates on non-analytic targets.

New method estimates and optimizes policy differences using orthogonal learning.

problem Offline reinforcement learning with safety concerns and cost limitations.
method Dynamic R-learner for estimating and optimizing Qπ(s,1)Qπ(s,0)Q^π(s,1)-Q^π(s,0), leveraging orthogonal estimation.
result Consistent policy optimization with improved convergence rates.