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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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48 results for time changed

The paper examines how curvature-dimension conditions transform under time change for diffusions.

problem Transforming curvature-dimension conditions for diffusions under time change.
method Derives precise transformation formulas for synthetic lower Ricci bounds and curvature-dimension conditions.
result Precise formulas for curvature-dimension conditions under time change for diffusions and metric measure spaces.

This paper extends results of Mortimer and Williams (1991) about changes of probability measure up to a random time under the assumptions that all martingales are continuous and that the random time avoids stopping times. We consider locally absolutely continuous measure changes up to a random time, changes of probabil…

2013-09-24abs ↗pdf ↗

Proposes a model to detect changes in multivariate time series data.

problem Detect abrupt changes in multivariate time series data considering dependencies and correlations.
method Integrates graph neural networks into an encoder-decoder framework to model correlation structures and dynamics.
result Advantageous performance on CPD tasks over strong baselines, classifying changes as correlation or independent.

In this paper, we describe a newly discovered statistical property of time series data for daily price changes. We conducted quantitative investigation of the {\it calm-time intervals} of price changes for 800 companies listed in the Tokyo Stock Exchange, and for the Nikkei 225 index over a 27-year period from January …

2003-12-21abs ↗pdf ↗

Detects change points in time series focusing on specific components.

problem Identifying moments when specific components of multivariate time series change distributions.
method Two-stage non-parametric algorithm: causal structure learning followed by change point detection.
result Validated the approach on synthetic and real-world datasets.

Methods for detecting structural changes, or change points, in time series data are widely used in many fields of science and engineering. This chapter sketches some basic methods for the analysis of structural changes in time series data. The exposition is confined to retrospective methods for univariate time series. …

2017-02-17abs ↗pdf ↗

A new method samples CGMY processes efficiently by decomposing their time changes.

problem Sampling CGMY processes with finite or infinite variation.
method Exploiting time change representation, decomposing into two independent components.
result The method is advantageous over existing methods in simulations.

In this paper we study the setting where features are added or change interpretation over time, which has applications in multiple domains such as retail, manufacturing, finance. In particular, we propose an approach to provably determine the time instant from which the new/changed features start becoming relevant with…

2017-04-29abs ↗pdf ↗

Framework LiLY recovers latent causal variables from time-series data under distribution shifts.

problem Learning and correcting models under unknown distribution shifts in time-series data.
method LiLY framework that recovers latent causal variables and identifies their relations from temporal data under different distribution shifts.
result The framework reliably identifies time-delayed latent causal influences from observed variables under different distribution changes.

New method detects and locates changes in spatio-temporal point processes.

problem Detecting and localizing changes in spatio-temporal data.
method Score-based, likelihood-free approach estimating change time and region.
result The method provides theoretical guarantees on detection and localization accuracy.

We introduce a class of randomly time-changed fast mean-reverting stochastic volatility models and, using spectral theory and singular perturbation techniques, we derive an approximation for the prices of European options in this setting. Three examples of random time-changes are provided and the implied volatility sur…

2010-10-25abs ↗pdf ↗

Online detection of abrupt changes in high-dimensional data streams.

problem Detecting abrupt changes in high-dimensional, streaming data with multiple subspaces.
method Dynamic sparse subspace learning approach with multiple structural change-point model, Bayesian information criterion for penalty coefficients selection, and Pruned Exact Linear Time algorithm.
result Effectiveness demonstrated through simulation and real gesture data studies.

Evaluates change point detection algorithms on real-world data.

problem Insufficient evaluation of change point detection algorithms on real-world time series.
method Developed a data set of 37 time series from various domains, annotated by human experts, and evaluated 14 algorithms using consistency metrics.
result Demonstrates the need for better evaluation methods in change point detection.

Geometric pruning rules improve change point detection in multiple time series.

problem Detecting multiple changes in multiple independent time series.
method Dynamic programming algorithms with inequality-based and geometric pruning rules.
result Geometric pruning rules offer close-to-linear time complexity for multiple independent time series.

Model change points in time-series data with neural SDEs and variational autoencoders.

problem Modeling change points in time-series data with neural stochastic differential equations.
method Proposes a novel model formulation and training procedure based on the variational autoencoder framework, alternating between updating neural SDE parameters and change points.
result Demonstrates the expressive power of the proposed model in modeling both classical parametric SDEs and real datasets with distribution shifts.

Change-point analysis is a flexible and computationally tractable tool for the analysis of times series data from systems that transition between discrete states and whose observables are corrupted by noise. The change-point algorithm is used to identify the time indices (change points) at which the system transitions …

2015-05-21abs ↗pdf ↗

ET-GP-UCB optimizes time-varying functions without knowing change rates.

problem Sequentially optimizing a time-varying objective function with unknown change rates.
method Event-triggered Bayesian optimization with adaptive resets based on probabilistic uniform error bounds.
result ET-GP-UCB outperforms other GP-UCB algorithms in synthetic and real-world data.

The claim arrival process to an insurance company is modeled by a compound Poisson process whose intensity and/or jump size distribution changes at an unobservable time with a known distribution. It is in the insurance company's interest to detect the change time as soon as possible in order to re-evaluate a new fair v…

2007-03-28abs ↗pdf ↗

Generalized change-point detection using various binary models.

problem Discovering changes in time series distribution.
method Direct density ratio estimation with Gradient Boosting over Decision Trees and Neural Networks.
result Proposed methods outperform classical RuLSIF algorithm.

A novel OC-SVM calibration method improves change point detection in time series.

problem Identifying change points in system health status using time series data.
method Heuristic search method to find optimal input data and hyperparameters for OC-SVM.
result OC-SVM can detect change points in time series with fewer training data, achieving satisfactory accuracy.

Post-detection analysis identifies responsible coordinates for multivariate change-points.

problem Identifying which coordinates in multivariate time series change after a detected change-point.
method Two-sample testing procedures with nonparametric tests for Type I error control.
result Strong performance of proposed post hoc statistical procedures.

Estimates change points in Weibull time series with copulas.

problem Change-point estimation for nonlinear Weibull time series with copula-based Markov models.
method Copula-based Markov chain model with Weibull marginal distributions, incorporating asymmetric dependence structures through Clayton and Joe copulas.
result Proposed method performs well in estimating change points and model parameters, demonstrated through extensive numerical studies and empirical application.

Research explores unsupervised methods for detecting vessel behavior changes in real-time data streams.

problem Detecting shifts in vessel behavior for maritime traffic monitoring.
method Investigates unsupervised and semi-supervised change detection methods.
result Identifies shifts in vessel behavior for unusual events detection.

New algorithm for nonstationary multi-armed bandits with optimal performance.

problem Nonstationary multi-armed bandits with changing model parameters over time.
method Adaptive Resetting Bandit (ADR-bandit) algorithm using adaptive windowing techniques.
result ADR-bandit achieves nearly optimal performance in both abrupt and gradual changes.

A novel kernel learning framework detects abrupt changes in time series data.

problem Detecting abrupt changes in time series data with fewer assumptions.
method KL-CPD, a novel kernel learning framework that optimizes a lower bound of test power via an auxiliary generative model.
result Significantly outperformed other state-of-the-art methods in benchmark datasets and simulation studies.

Given a heterogeneous time-series sample, the objective is to find points in time (called change points) where the probability distribution generating the data has changed. The data are assumed to have been generated by arbitrary unknown stationary ergodic distributions. No modelling, independence or mixing assumptions…

2012-03-07abs ↗pdf ↗

Efficiently infers time-varying sparse MRFs with strong statistical guarantees.

problem Inference of time-varying sparse MRFs with strong statistical guarantees.
method Constrained optimization with exact 0\ell_0 regularization, near-linear time and memory complexity.
result Sharp statistical guarantees for sparsely-changing Gaussian MRFs with as few as one sample per time.

Paper presents adaptive minimax risk classifiers for multidimensional concept drift.

problem Multidimensional concept drift in supervised classification.
method Adaptive minimax risk classifiers (AMRCs) tracking multivariate and high-order distribution changes.
result AMRCs provide computable tight performance guarantees and improve classification.

TADA detects anomalies in time series using topological data analysis.

problem Detecting global changes in dependency structure between channels in multivariate time series.
method Topological Data Analysis for detecting anomalies in multivariate time series.
result The approach is more suitable for detecting global changes of correlation structures than existing methods.

The paper optimizes RV estimation by efficient sampling in time-changed diffusion models.

problem Improving realized variance (RV) estimation in time-changed diffusion models.
method Theoretical analysis and simulations of hitting time and realized business time sampling schemes.
result Realized business time sampling is empirically most efficient for high noise levels.