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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.

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163326489652 · Jun 202019922001200920172026
48 results for density-ratio function

In this work, we propose new objective functions to train deep neural network based density ratio estimators and apply it to a change point detection problem. Existing methods use linear combinations of kernels to approximate the density ratio function by solving a convex constrained minimization problem. Approximating…

2019-05-23abs ↗pdf ↗

Paper develops estimators for unbounded density ratios with applications in error control.

problem Estimating density ratios with unbounded domains and ranges.
method Least squares and logistic regression loss functions for density ratio estimation.
result Established upper bounds on estimation errors with optimal rates for unbounded density ratios.

We develop a new loss function for estimating quasiprobabilistic density ratios.

problem Discontinuous or non-surjective relationships between optimal classifiers and target densities.
method Introduce a convex loss function compatible with both probabilistic and quasiprobabilistic densities.
result Achieve state-of-the-art results in estimating di-Higgs production in particle physics.

Paper tackles unbounded density ratio estimation for covariate shift adaptation.

problem Understudied challenge in statistical learning: unbounded density ratios.
method Three-step estimation method: relative density ratio, truncation, and transformation.
result Established rigorous convergence guarantees for density ratio and regression estimators.

Study shows robust method for estimating density ratios even with heavy contamination.

problem Estimating density ratios in the presence of heavy contamination.
method Weighted density ratio estimation (DRE) with doubly strong robustness.
result Weighted DRE achieves sparse consistency under heavy contamination.

Proposes a robust method for predicting missing outcomes in covariate shift adaptation.

problem Predicting missing outcomes in test data with covariate shift.
method Doubly robust estimator for covariate shift adaptation via importance weighting, incorporating an additional estimator for the regression function.
result Shows robustness against density-ratio estimation errors, maintaining consistency if either estimator is consistent.

BO method improved by density-ratio estimation for better efficiency and scalability.

problem Limitations in Bayesian optimization due to analytical tractability of predictive models.
method Reformulated Bayesian optimization by casting expected improvement as a binary classification problem.
result Improved efficiency and scalability of Bayesian optimization.

New α\alpha-divergence loss function improves neural density ratio estimation.

problem Optimization challenges in existing DRE methods, especially overfitting and high sample requirements.
method Derived α\alpha-divergence loss function (α\alpha-Div) for neural density ratio estimation.
result The α\alpha-divergence loss function (α\alpha-Div) offers stable and effective optimization for DRE.

Divergence estimators based on direct approximation of density-ratios without going through separate approximation of numerator and denominator densities have been successfully applied to machine learning tasks that involve distribution comparison such as outlier detection, transfer learning, and two-sample homogeneity…

2011-06-23abs ↗pdf ↗

Generative adversarial networks (GANs) are successful deep generative models. GANs are based on a two-player minimax game. However, the objective function derived in the original motivation is changed to obtain stronger gradients when learning the generator. We propose a novel algorithm that repeats the density ratio e…

2016-10-10abs ↗pdf ↗

New method combines strengths of two PCL approaches without density ratio estimation.

problem Estimating causal functions in Proxy Causal Learning with unobserved confounders and proxies.
method Kernel-based doubly robust estimators combining treatment and outcome bridges, density ratio-free.
result Outperforms existing methods on PCL benchmarks, including a prior doubly robust method.

New algorithm uses density ratios for efficient online reinforcement learning.

problem Challenges in collecting exploratory data for online reinforcement learning.
method Density ratio modeling for online exploration, combining truncation and optimism.
result Sample-efficient online exploration achieved with GLOW and HyGLOW.

Optimizes kernel density ratios for better predictions and information measures.

problem Improving accuracy of kernel density estimates for density ratios.
method Derives an optimal weight function using calculus of variations.
result Reduces bias in kernel density estimates, leading to improved prediction posteriors and information-theoretic measures.

MBORE optimizes multi-objective problems using density-ratio estimation.

problem Optimizing complex, multi-objective functions with expensive evaluations.
method Extends BORE to multi-objective Bayesian optimisation, using density-ratio estimation.
result MBORE outperforms BO on high-dimensional and real-world problems.

New method estimates density ratio for well-separated distributions using multi-class logistic regression.

problem Challenges in estimating density ratio for well-separated distributions.
method Uses multi-class logistic regression with auxiliary densities to estimate log(p/q).
result Demonstrates superior performance on density ratio estimation, mutual information, and representation learning tasks.

A new method improves density ratio estimation with fewer function evaluations.

problem Stable and accurate estimation of density ratios with high variance issues.
method Diffusion Secant Alignment for Score-Based Density Ratio Estimation (ISA-DRE)
result ISA-DRE achieves comparable or superior results with fewer function evaluations.

Improves DRL for long-term causal inference with semiparametric methods.

problem Efficient inference for policy values in nonparametric MDPs with stringent conditions.
method Semiparametric Double Reinforcement Learning (DRL) with superefficient nonparametric estimators.
result Relaxes overlap conditions and reduces high-dimensional density-ratio estimation.

A new method improves density ratio estimation efficiency and accuracy.

problem Density ratio estimation trade-off between quality and efficiency.
method One-step Score-based Density Ratio Estimation (OS-DRE) combining analytic and solver-free approach.
result OS-DRE offers a favorable balance between estimation quality and inference efficiency.

Unified framework for estimating density ratios in causal inference.

problem Estimating density ratios for causal inference is challenging due to instability and curse of dimensionality.
method Bregman-Riesz regression unifies three methods: Bregman divergences, probabilistic classification, and Riesz loss.
result Unified framework improves density ratio estimation in causal inference.

Meta-learning improves relative density-ratio estimation from limited data.

problem Estimating relative density-ratios from few instances.
method Meta-learning using neural networks to extract and embed dataset information for relative DRE.
result Meta-learning enables efficient and effective adaptation to few instances for relative DRE.

BOE reformulates BO as a classifier for scalable batch optimisation.

problem Scalable batch optimisation of expensive functions.
method Reformulates BO as density-ratio estimation, removing need for explicit function prior.
result Theoretical guarantees and improved uncertainty estimates for batch optimisation.

Hidden Markov models and their variants are the predominant sequential classification method in such domains as speech recognition, bioinformatics and natural language processing. Being generative rather than discriminative models, however, their classification performance is a drawback. In this paper we apply ideas fr…

2013-02-15abs ↗pdf ↗

Infinite horizon off-policy policy evaluation is a highly challenging task due to the excessively large variance of typical importance sampling (IS) estimators. Recently, Liu et al. (2018a) proposed an approach that significantly reduces the variance of infinite-horizon off-policy evaluation by estimating the stationar…

2019-10-16abs ↗pdf ↗

The variational autoencoder (VAE) is a powerful generative model that can estimate the probability of a data point by using latent variables. In the VAE, the posterior of the latent variable given the data point is regularized by the prior of the latent variable using Kullback Leibler (KL) divergence. Although the stan…

2018-09-14abs ↗pdf ↗

A new method for estimating density ratios using geodesics on statistical manifolds.

problem Stability of density ratio estimation when distributions are distant.
method Iterative sampling along generalized geodesics on the Riemannian manifold.
result The proposed method outperforms existing incremental mixture methods.

Paper connects contrastive learning to MI maximization and establishes robust methods for nonlinear ICA and subspace estimation.

problem Understanding and improving unsupervised representation learning and density ratio estimation.
method The paper connects contrastive learning to MI maximization, establishes new recovery conditions for nonlinear ICA, and proposes a practical outlier-robust method for nonlinear subspace estimation.
result The proposed methods can be seen as maximizing MI, performing nonlinear ICA, or estimating nonlinear subspaces, and are robust to outliers.

New method estimates velocity fields for minimizing ff-divergences without overfitting.

problem Minimizing statistical discrepancies between target and particle distributions.
method Directly estimate velocity fields using interpolation techniques, proving consistency under mild conditions.
result Consistent estimators of velocity fields improve accuracy in applications like domain adaptation and missing data imputation.

The paper proposes using density ratio estimation to evaluate synthetic data quality.

problem Improving the quality and utility of synthetic data for analysis.
method Density ratio estimation to measure synthetic data quality.
result Density ratio estimation yields more accurate global utility estimates than existing methods.

Proposes a deep neural network for multi-dimensional functional data classification.

problem Classifying multi-dimensional functional data with non-Gaussian distributions.
method Trains a deep neural network on the principle components of the training data.
result FDNN achieves minimax optimality when log density ratio has a locally connected modular structure.

Stable and consistent model alignment for language models without assuming human preference models.

problem Lack of statistical consistency in existing alignment methods.
method Relative density ratio optimization between preferred and mixture of preferred and non-preferred data distributions.
result Our approach achieves statistical consistency and stability, providing tighter convergence guarantees.

Riesz regression connects to density ratio estimation for causal inference.

problem Estimating average treatment effects in causal inference.
method Riesz regression as a signed density ratio and least-squares importance fitting.
result Riesz regression and DRE are equivalent, allowing transfer of DRE results.

Adaptive multi-stage density ratio estimation improves learning of latent space EBM.

problem Learning energy-based models in latent space is computationally expensive and challenging.
method Adaptive multi-stage density ratio estimation using NCE to bridge the gap between prior and posterior densities.
result The method enables more expressive prior models and sharpens the latent space EBM.

DRCD identifies causal direction between continuous and discrete variables using density ratio monotonicity.

problem Inferring causal direction between continuous and discrete variables from observational data.
method Density Ratio-based Causal Discovery (DRCD) method.
result DRCD identifies causal direction between continuous and discrete variables using density ratio monotonicity.