In this paper, we obtain the finite-horizon and infinite-horizon ruin probability asymptotics for risk processes with claims of subexponential tails for non-stationary arrival processes that satisfy a large deviation principle. As a result, the arrival process can be dependent, non-stationary and non-renewal. We give t…
Study finds sample size needed for non-stationary model selection.
problem Accurately selecting graphical models from non-stationary data.
method Analyzed a specific model selection method for non-stationary Gaussian processes.
result Derived a sufficient condition for sample size based on non-stationary data.
New kernels model non-stationary data efficiently.
problem Efficiently modeling non-stationary data with Gaussian processes.
method Model spectral density as a mixture of frequency surfaces, solve generalised Fourier transform.
result Derives efficient inference methods for non-stationary kernels.
Develops a deep non-stationary kernel for non-stationary spatio-temporal point processes.
problem Capturing non-stationary dependencies in point process data.
method Approximates the influence kernel with a novel low-rank decomposition and introduces a log-barrier penalty to maintain non-negativity.
result Demonstrates superior performance and computational efficiency compared to state-of-the-art methods.
Efficient GP framework for scalable non-stationary processes.
problem Heavy memory and computational requirements in Gaussian process regression for large data sets.
method Exploits structure in the kernel matrix, uses multiple sets of non-equidistant inducing points, and employs Toeplitz and Kronecker structure for efficient inference.
result Demonstrated scalability on numerical examples and large biomedical datasets.
Extends Gaussian Processes for multi-modal, non-stationary data.
problem Modeling non-stationary multi-modal processes.
method Adds a latent variable to modulate covariance over training data.
result Shows improved modeling of multi-modal and non-stationary processes.
Unified review of methods for inferring non-stationary process parameters.
problem Inferring parameters of non-stationary processes without a known model.
method Unified review and categorization of algorithms for Parameter Inference from a Non-stationary Unknown Process (PINUP).
result Simple statistical features can perform well on non-stationary systems, highlighting gaps in existing methods.
This paper shows how to use SS models for non-stationary Gaussian processes.
problem Efficient computation of Gaussian process inferences for large datasets.
method Develops state space representation for non-stationary Gaussian processes.
result Non-stationary kernels can be mapped to state space models.
Study approximates risk process with non-stationary claims using Hawkes process.
problem Approximating risk process with non-stationary claims.
method Gaussian approximation and functional central limit theorem.
result Established diffusion approximation for ruin probability.
Flexible non-stationary modeling of spatial outcomes using a mixed-stationary Gaussian process.
problem Limited flexibility in non-stationary models and computational intractability.
method Developed a non-stationary Gaussian process with individually set stationarity parameters at each location, using a non-parametric mixture model to reduce parameters and incorporate spatial correlation.
result Improved prediction efficiency through spatially correlated components in the mixture model.
ETGPSSM efficiently models high-dimensional, non-stationary systems with reduced complexity.
problem Prohibitive computational and parametric complexity in high-dimensional, non-stationary dynamical systems.
method ETGPSSM integrates a single shared GP with input-dependent normalizing flows for scalable and flexible modeling.
result ETGPSSM outperforms existing models in computational efficiency and accuracy.
Model separates overall uncertainty into aleatoric and epistemic components for active learning.
problem Active learning with uncertainty quantification.
method Non-stationary Heteroscedastic Gaussian process model.
result Model separates overall uncertainty into aleatoric and epistemic components.
Flexible GP model improves wind power prediction accuracy.
problem Accurate probabilistic prediction of wind power for grid stability.
method Heteroscedastic non-stationary Gaussian process with generalised spectral mixture kernel.
result The proposed model outperforms conventional GP models in wind power prediction.
Neural non-stationary spectral kernels improve performance on benchmark datasets.
problem Learning and discovering complex patterns in data.
method Generalized spectral mixture kernels with input-dependent functions modeled as Gaussian processes and hyperparameter functions as neural networks.
result Neural non-stationary spectral kernels achieve the best performance on benchmark datasets.
The paper extends NSGPs with L 1 L^1 L 1 -regularization for sparsity and solves the resulting R-NSGP regression problem.
problem Sparsity in non-stationary temporal data.
method Developed an ADMM-based method for solving the regularized NSGP regression problem.
result The proposed methods induce sparsity in the parameters of NSGPs.
Paper introduces a neural network-based non-stationary influence kernel for complex event data.
problem Modeling complex, non-stationary, and dependent discrete event data.
method Neural Spectral Marked Point Processes (NSMPP) with a versatile non-stationary influence kernel.
result NSMPP outperforms state-of-the-art models on synthetic and real data.
This work explores variably scaled kernels to improve non-stationary Gaussian processes.
problem Limited ability of stationary kernels to represent heterogeneous correlation structures.
method Introduces variably scaled kernels to modify correlation structures explicitly.
result Improved reconstruction accuracy and better uncertainty estimates for non-stationary data.
Bayesian Optimization uses Deep Gaussian Processes for non-stationary functions.
problem Optimizing expensive non-stationary functions with classic Gaussian Processes.
method Deep Gaussian Processes as surrogate models for capturing non-stationarity.
result The proposed algorithm outperforms state-of-the-art methods on analytical and aerospace design problems.
New kernel HMK improves Gaussian process expressiveness and supports harmonizable covariances.
problem Improving the expressiveness of Gaussian processes with non-stationary kernels.
method Proposed harmonizable mixture kernel (HMK) and variational Fourier features.
result HMK interpolates between local patterns and offers robust kernel learning.
This paper develops the first method for the exact simulation of reflected Brownian motion (RBM) with non-stationary drift and infinitesimal variance. The running time of generating exact samples of non-stationary RBM at any time t t t is uniformly bounded by O ( 1 / γ ˉ 2 ) \mathcal{O}(1/\barγ^2) O ( 1/ γ ˉ 2 ) where γ ˉ \barγ γ ˉ is the average drift of…
Enhances DGPs with adaptive RKHS Fourier features for better non-stationary pattern modeling.
problem Capturing complex non-stationary patterns in non-linear dynamical systems.
method Integrates ODE-based RKHS Fourier features into DGPs using convolution operations for adaptive amplitude and phase modulation. Uses a doubly stochastic variational inference framework.
result Improved predictive performance across various regression tasks.
Survey of MAB strategies for non-stationary reward distributions with delayed feedback.
problem Optimizing product availability in an online grocery pick-up platform with non-stationary and delayed reward feedback.
method Evaluation of ε ε ε -greedy, UCB1, Thompson Sampling, and a new adaptive technique (AG1) in MAB simulations. result AG1 outperforms traditional MAB strategies in minimizing regret for non-stationary and delayed feedback.
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…
Novel CSK kernel improves GP model generalization for non-stationary patterns.
problem Improving generalization of Gaussian process models for non-stationary data.
method Introduced convolutional spectral kernel (CSK) derived from convolution of imaginary radial basis functions, using Fourier transform for interpretation.
result CSK improves GP model generalization on spatiotemporal datasets.
Proposes a new Bayesian mixture of student-t processes for modeling non-stationary data.
problem Non-stationary data with non-Gaussian errors.
method Bayesian mixture of student-t processes with an overall-local scale structure, using SMC for online inference.
result Superior performance compared to Gaussian processes on real-world data.
This work improves Gaussian process regression for large, non-stationary data.
problem Scalability issues and performance degradation for non-stationary data.
method Combines variational free energy approximations with online expectation propagation and local splitting steps.
result Incremental adaptation to locality, heterogeneity, and non-stationarity in training data.
Inter-domain Deep Gaussian Processes improve inference for non-stationary data.
problem Inference limitations in Gaussian processes for non-stationary data.
method Combines inter-domain and deep Gaussian processes for scalable approximate inference.
result Outperforms inter-domain shallow GPs and conventional DGPs on non-stationary data.
Sliding window algorithm for RL in non-stationary MDPs with varying rewards and transitions.
problem Reinforcement learning in Markov Decision Processes with changing state-transition probabilities and reward functions.
method Sliding window approach for handling non-stationarity.
result Performance guarantees and optimal window size for the algorithm, along with a sample complexity bound.
Framework infers Langevin dynamics from stochastic observations of latent systems.
problem Inferring non-stationary Langevin dynamics from indirect stochastic observations.
method Non-parametric framework explicitly modeling stochastic observation process and non-stationary latent dynamics.
result Correct inference of non-stationary dynamics requires accounting for non-equilibrium states and observation duration.
Bayesian method detects changepoints in non-stationary data.
problem Detecting changepoints in non-stationary spatio-temporal data.
method Spatially structured Vector Autoregressions (VARs) for model selection and online detection.
result Two orders of magnitude faster than competitors and outperforms state of the art.
Adaptive sparse GP model for non-stationary data.
problem Non-stationary environments require efficient model updates.
method Reformulated variational sparse GP with adaptive forgetting factor and single inducing point update.
result Fast convergence and efficient model update in non-stationary environments.
Paper proposes NOSTILL-GP for accurate space-time modeling in environmental monitoring.
problem Accurate modeling of space-time dynamics in environmental phenomena.
method NOSTILL-GP - a non-stationary, spatio-temporal Gaussian Process model with efficient training strategies.
result Demonstrates the effectiveness and general applicability of NOSTILL-GP for environmental monitoring.
Designing a covariance function that represents the underlying correlation is a crucial step in modeling complex natural systems, such as climate models. Geospatial datasets at a global scale usually suffer from non-stationarity and non-uniformly smooth spatial boundaries. A Gaussian process regression using a non-stat…
NVMDP framework tackles non-stationary MDPs with varying discount rates.
problem Challenges in non-stationary environments and infinite-horizon formulations for reinforcement learning.
method Introduces NVMDP framework that accommodates non-stationarity and varying discount rates.
result NVMDPs provide a flexible mechanism to shape optimal policies without altering state or action spaces.
A method for learning rankings in non-stationary data streams.
problem Learning preferences in a population that changes over time.
method Generalized Borda algorithm for non-stationary ranking streams.
result Bounds on the minimum number of samples required to output the ground truth.
New method learns time-varying home field advantage in football.
problem Discovering causal factors behind home field advantage in sports.
method DYNAMO: a novel causal discovery method for non-stationary processes.
result Time-varying home field advantages influenced by referee bias.
Researchers use Gaussian processes with non-stationary kernels to model precipitation patterns in the Upper Indus Basin.
problem Uncertainty in precipitation patterns in the Upper Indus Basin, Himalayas.
method Proposes Gaussian processes with structured non-stationary kernels to model precipitation patterns, accounting for spatial variation with a latent Gaussian process.
result The proposed model adapts to varying precipitation patterns across distinct topography and outperforms stationary models in ablation experiments.
Optimistic algorithm reduces regret in non-stationary linear MDPs.
problem Efficient learning in non-stationary linear MDPs with evolving reward and transition.
method OPT-WLSVI, an optimistic model-free algorithm using exponential weights.
result Achieves a regret bound of O ~ ( d 5 / 4 H 2 Δ 1 / 4 K 3 / 4 ) \widetilde{\mathcal{O}}(d^{5/4}H^2 Δ^{1/4} K^{3/4}) O ( d 5/4 H 2 Δ 1/4 K 3/4 ) . Study on fake stationary Volterra Heston model for non-stationary processes.
problem Non-stationary nature of true Volterra equations.
method Weak notion of stationarity (fake stationary regime) for inhomogeneous affine Stochastic Volterra equations.
result Existence of limiting distributions in the long run, which may depend on initial state.
MIM networks predict non-stationary spatiotemporal dynamics using differential signals.
problem Predicting non-stationary spatiotemporal processes with high-order variations.
method Memory In Memory (MIM) networks with cascaded memory modules.
result Achieved state-of-the-art results on four spatiotemporal prediction tasks.
Pairs trading strategy improved using Ornstein-Uhlenbeck process.
problem Improving pairs trading strategy effectiveness.
method Used Ornstein-Uhlenbeck process to model stock price spreads.
result OU model captures signals and trends effectively but underperforms compared to naive model.
ETGP improves multi-class classification efficiency.
problem Efficiently handling non-stationary, dependent multi-class classification problems.
method ETGP uses transformed Gaussian processes with efficient sparse variational inference.
result ETGPs outperform state-of-the-art methods in multi-class classification tasks.
A new kernel improves Gaussian process performance for non-stationary data.
problem Poor prediction and uncertainty quantification with standard GPs.
method Study and comparison of non-stationary kernels, propose a new combined kernel.
result A new kernel outperforms existing stationary and non-stationary kernels.
KeRNS tackles non-stationary reinforcement learning in metric spaces.
problem Non-stationary reinforcement learning in metric spaces.
method KeRNS uses time-dependent kernels to model non-stationary Markov Decision Processes (MDPs).
result KeRNS achieves a regret bound that scales with the covering dimension and total variation of the MDP.
Study non-stationary MDPs using worst-case RL, proposing RATS algorithm.
problem Robust zero-shot planning in non-stationary stochastic environments.
method Model-Based Reinforcement Learning, worst-case approach.
result RATS algorithm demonstrates benefits over reference methods.
NAST generalizes scattering transform for non-stationary time series analysis.
problem Analyzing non-stationary time series data.
method Neural activation of scattering transform with various activation functions and high pass filters.
result Central and non-central limit theorems for NAST of Gaussian processes.
The study analyzes online predictions for non-stationary time series under model misspecification.
problem Analyzing predictive properties of statistical methods in non-stationary time series under model misspecification.
method Defining Kullback-Leibler risk, proving minimax predictive densities for dynamic models, extending results to multiple predictive densities.
result Dynamic random walk models produce exact minimax predictive densities under Gaussian assumptions and semi-martingale processes.
New geometric framework for non-stationary processes using dilation matrices and shape space.
problem Characterizing non-stationary stochastic processes.
method Introducing dilation matrices and induced shape space manifolds.
result Rotation matrices can uniquely identify non-stationary processes, even when periodicity is present.