Research
On-device research index

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.

168,695 papers · 148 categories

Trend · papers per month

1345 · May 202619922001200920172026
48 results for refitting

The paper tackles model failure detection and refitting in real-world systems.

problem Real-world data often fails statistical models due to heterogeneity.
method Develops tools for detecting and identifying model failures and refitting to improve accuracy.
result Empirical and theoretical results show the effectiveness of the proposed methodology.

New method refines model-free evaluation of complex machine learning models.

problem Evaluating the excess risk of opaque machine learning predictors.
method Perturbing derivatives to create pseudo-outcomes and refitting the model twice.
result Upper bound on excess risk derived efficiently without prior function class knowledge.

EVARS-GPR refines Gaussian Process Regression for seasonal data with sudden scale changes.

problem Challenges in forecasting with changing system behavior over time.
method Combines online change point detection with data augmentation for refitting.
result 20.8% lower RMSE on real-world datasets compared to similar methods.

Ribbon: Scalable Approximation and Robust Uncertainty Quantification

problem Reliably quantifying predictive uncertainty for complex models
method Ribbon, a scalable approximation to Dirichlet-reweighted bootstrap uncertainty
result Asymptotically equivalent to a flat-prior Laplace approximation under correct likelihood specification, recovers robust sandwich covariance under misspecification

The paper proposes a method to improve fairness in machine learning models without refitting.

problem Mitigating biases in machine learning models that disadvantage certain groups.
method Infinitesimal jackknife-based approach to drop selected training data points.
result The intervention improves fairness without significantly reducing predictive performance.

Framework detects and mitigates data-poisoning attacks in causal effect estimation.

problem Vulnerability to append-only attacks in observational causal analyses.
method Develops a data-poisoning audit for augmented inverse-probability-weighted estimation.
result Proposes a greedy scan to compute exact worst-case movement at every append budget.

Classification is an important statistical learning tool. In real application, besides high prediction accuracy, it is often desirable to estimate class conditional probabilities for new observations. For traditional problems where the number of observations is large, there exist many well developed approaches. Recentl…

2016-07-19abs ↗pdf ↗

Proposes joint LCA for multiview data to identify shared and view-specific components.

problem Extracting shared components sequentially from multiview data.
method Formulates a matrix decomposition model with joint and individual structures, proposes a penalty term objective function, and employs a refitting procedure.
result Achieves simultaneous estimation and rank selection for cross covariance.

New method approximates CV for model assessment and selection.

problem Efficient model assessment and selection with large number of folds.
method Approximates expensive refitting with a single Newton step warm-started from full training set optimizer.
result Uniform non-asymptotic, deterministic model assessment guarantees for approximate CV.

A new gradient boosting method improves interpretability of probabilistic models.

problem Learning interpretable yet accurate probabilistic models with limited rule complexity.
method A new objective function that measures the angle between risk gradient and condition output vector projection.
result Significantly improves comprehensibility/accuracy trade-off of fitted ensemble.

ICP improves prediction intervals for continuous outcomes at lower computational cost.

problem Systematic bias in point predictions that undermines their use in decision-making.
method Develops Isotonic Conformal Prediction (ICP) framework to decouple calibration from prediction-set construction.
result SICP and TICP procedures match SC-CP coverage at lower computational cost.

Proposes a new method to approximate Bayesian predictive uncertainty.

problem Bayesian uncertainty quantification in model predictions.
method Self-supervised learning approach to approximate posterior predictive distribution.
result SSLA and ASSLA outperform classical Laplace approximations in predictive calibration.

In this paper we present a technique for using the bootstrap to estimate the operating characteristics and their variability for certain types of ensemble methods. Bootstrapping a model can require a huge amount of work if the training data set is large. Fortunately in many cases the technique lets us determine the eff…

2017-10-24abs ↗pdf ↗

Renet improves Elastic Net by dynamically selecting between convex blending and refitting, enhancing prediction accuracy.

problem Elastic Net's shrinkage bias limits its prediction accuracy in high-dimensional settings.
method Adaptive relaxation procedure that dynamically dispatches between convex blending and efficient sub-path refitting.
result Renet consistently outperforms standard Elastic Net and Adaptive Elastic Net in high-dimensional, low signal-to-noise ratio, and high-multicollinearity scenarios.

Undirected graphs are often used to describe high dimensional distributions. Under sparsity conditions, the graph can be estimated using 1\ell_1-penalization methods. We propose and study the following method. We combine a multiple regression approach with ideas of thresholding and refitting: first we infer a sparse u…

2010-09-02abs ↗pdf ↗

If you are predicting the label yy of a new object with y^\hat y, how confident are you that y=y^y = \hat y? Conformal prediction methods provide an elegant framework for answering such question by building a 100(1α)%100 (1 - α)\% confidence region without assumptions on the distribution of the data. It is based on a refittin…

2019-09-20abs ↗pdf ↗

Framework calibrates ML models for risk control in various tasks.

problem Achieving statistical guarantees for model predictions.
method Reframing risk control as multiple hypothesis testing, applying statistical techniques.
result New calibration methods for multi-label classification, instance segmentation, outlier detection, and confidence set coverage.

Framework monitors insurance pricing models for drift and recalibration.

problem Maintaining predictive performance of pricing models in evolving insurance portfolios.
method Formalizes deviance loss and Murphy's score, studies Gini score, develops monitoring framework.
result Framework guides decisions on refitting or recalibrating pricing models.

Enhances GBDT robustness with one-hot encoding and regularization.

problem Low robustness of GBDT models against covariate perturbation.
method One-hot encoding to linear framework, risk decomposition, L1L_1 or L2L_2 regularization.
result Regularization enhances GBDT robustness.

Study on estimating causal effects with limited data and multiple environments.

problem Estimating causal effects under hidden confounding with unpaired data and sparse effects.
method Instrumental variable (IV) regression with cross-fold sample splitting and 1\ell_1-regularized estimation.
result Proposed GMM-type estimator is consistent as the number of environments grows.

Paper accelerates conformal prediction by using approximate leave-one-out estimators.

problem Limited computational cost for conformal prediction.
method Incorporates approximate leave-one-out estimators to accelerate conformal prediction.
result ALO-based methods achieve comparable coverage and efficiency to exact methods but with significantly reduced runtime.

Recourse explanations can become invalid if collective actions change statistical data.

problem Recourse explanations may become invalid due to collective behavior changing data statistics.
method Formal characterization of conditions under which recourse explanations remain valid under performativity.
result Recourse actions may become invalid if they are influenced by or intervene on non-causal variables.

TSL learns separable models to avoid signal cancellation and off-support extrapolation.

problem Signal cancellation and off-support extrapolation in additive models.
method Tensor Separation Learning (TSL) via stagewise greedy procedure with orthogonal refitting.
result TSL avoids information loss caused by marginalizing higher-order interactions.

Researchers formalize PD and PFI to relate them to data generating process.

problem Lack of theory linking PD and PFI to data generating process.
method Formalize PD and PFI as estimators of ground truth estimands, account for model variance with learner-PD and learner-PFI.
result PD and PFI estimates deviate from ground truth due to statistical biases, model variance, and Monte Carlo approximation errors.

Alpha-trimming prunes trees in random forests to improve predictive performance.

problem Improving predictive performance of random forests by locally adaptive tree pruning.
method Alpha-trimming is a fast pruning algorithm that prunes trees in a random forest based on signal-to-noise ratio, controlled by a tuning parameter.
result Alpha-trimming often lowers mean squared prediction error compared to fully grown random forests.

New methods for assessing and visualizing feature groups in machine learning models.

problem Lack of methods for interpreting feature groups in machine learning models.
method Permutation-based, refitting, and Shapley-based techniques for grouped feature importance. Introduced a sequential procedure for identifying stable feature combinations. Developed a combined features effect plot.
result Effective methods for assessing and visualizing the importance and effect of feature groups in machine learning models.

Greedy algorithms are widely used for problems in machine learning such as feature selection and set function optimization. Unfortunately, for large datasets, the running time of even greedy algorithms can be quite high. This is because for each greedy step we need to refit a model or calculate a function using the pre…

2017-03-08abs ↗pdf ↗

Two approaches extend knowledge distillation to Gaussian Processes, showing relationships to existing methods.

problem Applying knowledge distillation to Gaussian Processes for regression and classification.
method Data-centric and distribution-centric approaches to extend distillation to GPR and GPC.
result Distribution-centric approach for GPC approximately corresponds to data duplication and scaling.

The paper develops methods to accurately locate change points in high-dimensional mean shift models.

problem Locating change points in high-dimensional mean shift models.
method Locally refitted least squares estimator, component-wise and simultaneous rates of estimation.
result Asymptotic validity of component-wise and simultaneous confidence intervals for change point parameters.

New framework learns complex AI attitudes from heterogeneous data.

problem Heterogeneous ordinal structure in AI attitudes, poorly captured by existing methods.
method Monotone Gaussian score embedding, BNP complexity discovery, confirmatory fixed-K estimation.
result Reduced holdout MSE by 25.8% over single-graph baseline.

Optimal self-distillation improves generative models' velocity risk and mode recovery.

problem Improving generative models' velocity risk and mode recovery.
method Proved optimal self-distillation for rectified flow via linear probing, derived mixing coefficient, and provided validation tuning.
result Optimal self-distillation improves velocity risk and mode recovery.

Paper develops an efficient method for conformal prediction in sparse linear models.

problem Computing conformal prediction sets for sparse linear models is computationally infeasible.
method Numerical continuation techniques to approximate the solution path efficiently.
result The method accurately approximates conformal prediction sets for sparse linear models.

This paper selects features in deep neural networks with theoretical guarantees.

problem Feature selection in deep neural networks with unknown nonlinear functions.
method Reformulate neural networks as index models, estimate feature sets using Stein's formula, and apply screening-and-selection mechanism.
result Consistent feature selection with theoretical guarantees, even in high-dimensional settings.

Corrects GCV for inconsistent risk estimation in finite ensembles of penalized estimators.

problem Inconsistent risk estimation of GCV for finite ensembles of penalized estimators.
method Identifies a correction involving an additional scalar correction based on degrees of freedom adjusted training errors from each ensemble component.
result CGCV maintains computational advantages of GCV and is model-free uniformly consistent for ridge regression.

Self-training in linear models shows a U-shaped test-risk curve due to signal forgetting and denoising.

problem Understanding the dynamics of iterative self-training in high-dimensional linear regression.
method Derivation of deterministic-equivalent recursions for prediction risk and effective noise, analysis of signal forgetting and denoising effects.
result An optimal early-stopping time is determined, and a U-shaped test-risk curve is observed.