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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.

169,181 papers · 148 categories

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5.5%11.0%16.4%21.9% · May 202519922001200920182026
48 results for nonstationary Gaussian processes

A new method for nonstationary Gaussian processes using Fourier features.

problem Efficient simulation of nonstationary Gaussian processes with high-dimensional distributions.
method Discretizes the spectral representation of nonstationary processes, avoiding probability measure assumptions.
result An efficient low-rank approximation of nonstationary spectral densities, consistent and positive semi-definite.

Proposes a new model for EHR data using time-dependent Gaussian processes.

problem Joint modeling of multiple clinical variables over time.
method Multivariate nonstationary Gaussian processes with time-varying parameters and posterior inference via HMC.
result The proposed model outperforms stationary models and reveals latent correlations predictive of patient risk.

ConvNets improve nonstationary covariance estimation for large-scale spatial data.

problem Estimating nonstationary spatial covariance functions on large scales.
method Convolutional Neural Networks (ConvNets) for subregion identification and selection.
result Enhanced accuracy in parameter estimation using ConvNet-based partitioning.

A new algorithm maximizes entropy or mutual information for efficient inference of nonstationary Gaussian processes.

problem Nonstationary dynamics in real-world phenomena pose challenges to accurate modeling.
method LISAL algorithm that adaptively maximizes entropy or mutual information on induced latent dynamics and marginal likelihood.
result Efficient inference of nonstationary Gaussian processes for large-scale real-world applications.

End-to-end probabilistic inference improves audio signal processing.

problem Efficiently processing large audio signals with varying characteristics.
method Formulated a spectral mixture Gaussian process model with nonstationary priors, enabling infinite-horizon Gaussian process regression.
result The method outperforms standard techniques in processing audio signals with hundreds of thousands of data points.

We introduce a new class of nonstationary kernels, which we derive as covariance functions of a novel family of stochastic processes we refer to as string Gaussian processes (string GPs). We construct string GPs to allow for multiple types of local patterns in the data, while ensuring a mild global regularity condition…

2015-06-07abs ↗pdf ↗

Online learning of nonstationary functions using Gaussian processes.

problem Real-time estimation of time-dependent functions with Gaussian processes.
method Sequential Monte Carlo algorithm for infinite mixtures of non-stationary GPs.
result Empirical improvement over state-of-the-art methods for online GP estimation.

Bayesian optimization has shown to be a fundamental global optimization algorithm in many applications: ranging from automatic machine learning, robotics, reinforcement learning, experimental design, simulations, etc. The most popular and effective Bayesian optimization relies on a surrogate model in the form of a Gaus…

2015-06-05abs ↗pdf ↗

A new method optimizes in nonstationary environments with many arms efficiently.

problem Optimizing in nonstationary environments with a large number of arms.
method Gaussian interpolation to learn continuous Lipschitz reward functions in nonstationary environments.
result Efficiently learns continuous Lipschitz reward functions with O(T)\mathcal{O}^*(\sqrt{T}) cumulative regret.

Optimizes spectral density estimation for stationary and nonstationary processes.

problem Estimating spectral density of time series with complex structure.
method Optimally adaptive Bayesian spectral density estimation using smoothing spline covariance structure.
result Optimal eigendecomposition provides superior performance compared to alternative covariance functions.

New method tests independence with single nonstationary time series.

problem Testing independence in nonstationary nonlinear time series.
method Time-varying nonlinear regression, local long-run covariance estimation, strong Gaussian approximation.
result First framework for conditional independence testing with a single realization of a nonstationary nonlinear process.

RLGP model improves robustness and accuracy for discontinuous response surfaces.

problem Challenges in modeling abrupt jumps and discontinuities in response surfaces.
method Integrates adaptive nearest-neighbor selection with robustification mechanism.
result Consistently delivers high predictive accuracy and robustness in higher dimensions.

New method infers causal relationships from nonstationary time series data.

problem Challenges in inferring causal relationships from nonstationary time series data.
method Proposes a new class of restricted SCM with time-varying filters and stationary noise, leveraging asymmetry from nonstationarity.
result Demonstrates effectiveness of the proposed methodology on various synthetic and real datasets.

SA-REMBO adapts to nonstationary high-dimensional optimization.

problem Bayesian Optimization in high-dimensional spaces is limited by the curse of dimensionality and rigidity of global assumptions.
method SA-REMBO uses multiple random Gaussian embeddings and an index variable to adaptively select the best embedding for the optimization problem.
result SA-REMBO outperforms traditional REMBO and other low-rank BO methods across synthetic and real-world benchmarks.

Bayesian Complementary Kernelized Learning models complex spatiotemporal data.

problem Modeling complex, nonstationary, and nonseparable spatiotemporal data.
method Integrates kernelized low-rank tensor factorization and short-range spatiotemporal Gaussian Processes.
result BCKL offers superior performance in providing accurate posterior mean and high-quality uncertainty estimates.

CBGP boosts GP covariance to model spatiotemporal irregularities.

problem Overfitting and overconfident uncertainty in nonstationary GP models.
method Boosting covariance priors, partially-whitened observations, gradient descent-like procedure.
result Accurate and reliable SBAS ionospheric corrections in challenging space weather.

Gaussian processes retain the linear model either as a special case, or in the limit. We show how this relationship can be exploited when the data are at least partially linear. However from the perspective of the Bayesian posterior, the Gaussian processes which encode the linear model either have probability of nearly…

2008-04-29abs ↗pdf ↗

A novel nonstationary permanental process relaxes kernel constraints and captures complex data patterns.

problem Limitations of existing permanental processes in terms of kernel types and stationarity.
method Sparse spectral representation of nonstationary kernels and hierarchical stacking of spectral feature mappings.
result Enhanced model expressiveness and reduced computational complexity.

We study a special case of the problem of statistical learning without the i.i.d. assumption. Specifically, we suppose a learning method is presented with a sequence of data points, and required to make a prediction (e.g., a classification) for each one, and can then observe the loss incurred by this prediction. We go …

2015-12-26abs ↗pdf ↗

New framework models complex spatial data with basis functions and graphical vectors.

problem Modeling highly-multivariate spatial processes with varying resolutions.
method Extends graphical lasso to multivariate Gaussian processes with independent graphical vectors at different resolutions, using an orthogonal basis and fusion penalty.
result Linear complexity and parsimonious conditional independence structure in multilevel graphical model.

Flexible spatial models improve predictive performance over nonstationary alternatives.

problem Improving predictive performance in nonstationary spatial modeling.
method Introduces a modular parametric covariance function that extends nonstationary spatial models.
result The proposed covariance function outperforms nonparametric methods in predictive performance.

Paper develops bandit algorithms for nonstationary nonconvex optimization.

problem Nonstationary online nonconvex optimization problems.
method Proposes and analyzes bandit algorithms for nonconvex functions with nonstationary regret.
result Develops bandit versions of Newton's method for nonstationary nonconvex optimization.

We present a novel approach for fully non-stationary Gaussian process regression (GPR), where all three key parameters -- noise variance, signal variance and lengthscale -- can be simultaneously input-dependent. We develop gradient-based inference methods to learn the unknown function and the non-stationary model param…

2015-08-18abs ↗pdf ↗

Bayesian optimization improves with nonstationary covariance functions.

problem Stationary covariance functions fail to capture prior information in high dimensions.
method Proposes nonstationary covariance functions to encode prior information and adaptively promote local exploration.
result Nonstationary covariance functions increase sample efficiency in high dimensions.

New kernel model for natural language processing improves expressibility and scalability.

problem Limited expressibility and scalability of traditional convolution kernels in natural language processing.
method Proposes a nonstationary kernel model and a stochastic sampling algorithm for scalable learning.
result Demonstrates improved performance on extracting biological models from scientific text.

The paper tackles causal discovery and forecasting in nonstationary environments using state-space models.

problem Challenges in identifying causal relations and forecasting in nonstationary time series.
method Exploiting a particular type of state-space model to represent nonstationary processes, allowing changes in causal strengths and noise variances.
result Nonstationarity helps identify causal structure and improves forecasting.

Quantum reservoir computing needs coherence influx for effective information processing.

problem Understanding and optimizing quantum reservoir computing.
method Theoretical and numerical analysis of quantum systems, focusing on coherence influx and spectral radius of Pauli transfer matrix.
result Coherence influx is essential for realizing nonstationary echo state property in quantum reservoir computing.

A new method for separating mixed signals in space and time.

problem Nonlinear and nonstationary spatio-temporal data challenges.
method Identifiable autoregressive variational autoencoder.
result The method outperforms existing techniques in blind source separation and spatio-temporal prediction.

New RL algorithm tackles nonstationary MDPs with linear approximations and varying rewards.

problem Nonstationary reinforcement learning with evolving reward and state transition functions.
method Developed a new algorithm LSVI-UCB-Restart with periodic restart, and parameter-free Ada-LSVI-UCB-Restart for unknown variation budgets.
result First minimax dynamic regret lower bound for nonstationary linear MDPs and linear MDPs lower bound.

We use diffusion models to sample from complex GP priors in climate data.

problem Sampling from non-stationary Gaussian process priors is computationally hard.
method Replace GP prior with a diffusion model surrogate and use training-free guidance algorithms.
result Generated distributions are close to GP priors and can be fine-tuned.

Adaptive estimation for nonstationary time series reduces computational cost.

problem Estimating parameters of nonstationary time series with varying parameters over time.
method Moving exponential moving ML estimator for scale parameter estimation.
result Significantly improved log-likelihoods compared to standard estimation.