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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.

168,932 papers · 148 categories

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4386128171 · Jun 202019922001200920172026
48 results for fast mixing

Markov chain Monte Carlo (MCMC) algorithms are simple and extremely powerful techniques to sample from almost arbitrary distributions. The flaw in practice is that it can take a large and/or unknown amount of time to converge to the stationary distribution. This paper gives sufficient conditions to guarantee that univa…

2014-11-05abs ↗pdf ↗

Paper proposes a new approach for agents to explore environments efficiently.

problem Learning policies that explore uniformly and mix quickly in environments without external rewards.
method Introduces a surrogate objective to maximize entropy and develops a model-based reinforcement learning algorithm, IDE3^{3}AL.
result Demonstrates improved exploration and mixing in hard-exploration tasks.

Inference in general Ising models is difficult, due to high treewidth making tree-based algorithms intractable. Moreover, when interactions are strong, Gibbs sampling may take exponential time to converge to the stationary distribution. We present an algorithm to project Ising model parameters onto a parameter set that…

2014-07-03abs ↗pdf ↗

The paper analyzes convergence rates of Langevin dynamics and Proximal Sampler using ΦΦ-divergence.

problem Analyzing convergence rates of Langevin dynamics and Proximal Sampler.
method Extending mixing time analyses to ΦΦ-divergence, using strong data processing inequalities.
result Convergence of ΦΦ-divergence to 0 exponentially fast along Unadjusted Langevin Algorithm and Proximal Sampler.

We improve Gaussian copula models for imputing mixed data types with precise approximations.

problem Imputing missing values with mixed data types in surveys and medical applications.
method We use randomized quasi-Monte Carlo procedures for direct and arbitrarily precise approximations of model estimation and imputation.
result Our method yields lower errors for model parameters and imputed values compared to existing methods.

We investigate the systematic mechanism for designing fast mixing Markov chain Monte Carlo algorithms to sample from discrete point processes under the Dobrushin uniqueness condition for Gibbs measures. Discrete point processes are defined as probability distributions μ(S)exp(βf(S))μ(S)\propto \exp(βf(S)) over all subsets $S\in 2^…

2015-06-06abs ↗pdf ↗

In this paper, we give a new sharp generalization bound of lp-MKL which is a generalized framework of multiple kernel learning (MKL) and imposes lp-mixed-norm regularization instead of l1-mixed-norm regularization. We utilize localization techniques to obtain the sharp learning rate. The bound is characterized by the d…

2011-03-27abs ↗pdf ↗

metabeta uses neural networks to speed up Bayesian mixed-effects regression.

problem Bayesian mixed-effects regression is computationally expensive.
method metabeta is a neural network model that pre-trains to estimate posterior distributions.
result metabeta achieves comparable performance to MCMC at a fraction of the time.

Joint sparsity offers powerful structural cues for feature selection, especially for variables that are expected to demonstrate a "grouped" behavior. Such behavior is commonly modeled via group-lasso, multitask lasso, and related methods where feature selection is effected via mixed-norms. Several mixed-norm based spar…

2012-04-06abs ↗pdf ↗

New clustering algorithm for mixed data improves applicability and efficiency.

problem Clustering large, mixed data with improved accuracy and efficiency.
method Developed a new clustering algorithm using peak-finding technique, reducing computational complexity.
result Algorithm detects outliers, clusters of lower density, and determines correct number of clusters.

Observations consisting of measurements on relationships for pairs of objects arise in many settings, such as protein interaction and gene regulatory networks, collections of author-recipient email, and social networks. Analyzing such data with probabilisic models can be delicate because the simple exchangeability assu…

2007-05-30abs ↗pdf ↗

Improved Metropolized HMC mixing time with multi-step gradients.

problem Improving the efficiency of sampling from complex probability distributions.
method Analyzing Metropolized HMC with multi-step integrators and applying sharpening techniques.
result Non-asymptotic upper bound on mixing time for Metropolized HMC with explicit step-size and leapfrog steps.

UncertaintyPlayground simplifies uncertainty estimation in Python.

problem Uncertainty estimation in supervised learning tasks.
method Sparse and Variational Gaussian Process Regressions for normally distributed outcomes, Mixed Density Networks for mixed distributions.
result Fast and simplified uncertainty estimation through Python library.

New algorithm improves mixing in Bayesian mixture models.

problem Slow mixing in Bayesian mixture models.
method A new Monte Carlo algorithm for sampling from the marginal posterior of a general integrable mixture.
result The new algorithm achieves excellent mixing times, outperforming standard Gibbs sampling in some cases.

The study examines mixing times of data-augmentation Gibbs samplers for high-dimensional probit regression.

problem Investigating convergence properties of data-augmentation samplers for Bayesian probit regression.
method Using recent results on Gibbs samplers for log-concave targets, the study provides non-asymptotic bounds on mixing times.
result Explicit non-asymptotic bounds on mixing times depend on design matrix and prior precision, holding uniformly over responses.

Method completes mixed matrix from complex surveys with heterogeneous missingness.

problem Recovering a mixed dataframe matrix from complex survey sampling with different missingness patterns.
method Two-stage procedure: logistic regression for missingness modeling, and weighted log-likelihood maximization with low-rank constraint.
result The proposed method achieves sublinear convergence and shows superior performance compared to existing methods.

A scalable Bayesian inference method for mixed-effects models in systems biology.

problem Scalable Bayesian inference for complex hierarchical mixed-effects models in systems biology.
method Constructing amortized approximations of likelihood and posterior distributions, refined for each individual dataset.
result Our method is both fast and competitive in statistical accuracy compared to exact pseudomarginal Bayesian inference.

The paper studies how quickly samples from Langevin dynamics become independent.

problem Understanding the dependence between samples along Langevin dynamics and related algorithms.
method Measures dependence via ΦΦ-mutual information and proves strong data processing inequalities.
result The ΦΦ-mutual information between samples decreases exponentially to zero.

Outlier detection amounts to finding data points that differ significantly from the norm. Classic outlier detection methods are largely designed for single data type such as continuous or discrete. However, real world data is increasingly heterogeneous, where a data point can have both discrete and continuous attribute…

2016-08-17abs ↗pdf ↗

We propose and analyze two new MCMC sampling algorithms, the Vaidya walk and the John walk, for generating samples from the uniform distribution over a polytope. Both random walks are sampling algorithms derived from interior point methods. The former is based on volumetric-logarithmic barrier introduced by Vaidya wher…

2017-10-23abs ↗pdf ↗

A new portfolio optimization model minimizes maximum drawdown, offering faster and more robust solutions.

problem Optimizing portfolios during financial distress, especially during crises.
method Linearization of Markowitz model based on maximum drawdown, with a Mixed-Integer Linear Programming variation.
result 200 times faster solving time with a more profitable and robust solution.

Machine learning models accurately predict the state and dynamics of reactive mixing.

problem Accurate prediction of reactive mixing for Earth and environmental science applications.
method Built a high-fidelity numerical model to simulate reactive mixing scenarios. Used 20 different machine learning emulators to classify mixing state and predict three QoIs.
result Ensemble methods and MLP models accurately predict the state of reactive mixing and QoIs, significantly faster than high-fidelity simulations.

Langevin Dynamics speeds up mixing time with manifold hypothesis and multi-scale approach.

problem Langevin Dynamics struggles in high dimensions and nonconvex landscapes.
method Utilizes manifold hypothesis to reduce mixing time and employs multi-scale approach to improve image generation quality.
result Mixing time depends on intrinsic dimension rather than ambient dimension, significantly reducing computational complexity.

We develop an HMC algorithm to easily marginalize random effects in LMMs.

problem Bayesian inference in LMMs is challenging, especially marginalizing random effects.
method Developed an HMC algorithm to marginalize random effects in LMMs efficiently.
result Marginalization is always beneficial when applicable and improves various models, especially cognitive science models.

dcFCI discovers causal relationships robustly under latent confounding and mixed data.

problem Causal discovery under latent confounding and unfaithfulness.
method dcFCI integrates a new score to assess PAG compatibility, guided by FCI search.
result Significantly outperforms state-of-the-art methods in small and heterogeneous datasets.

Efficiently calibrates Bergomi models to VIX derivatives using vector quantization.

problem Calibrating Bergomi models to VIX derivatives for accurate pricing.
method Applied vector quantization in mixed Bergomi models for fast and efficient option pricing.
result Calibration of Bergomi models to VIX derivatives is feasible and accurate over daily data.

Given data over the joint distribution of two random variables XX and YY, we consider the problem of inferring the most likely causal direction between XX and YY. In particular, we consider the general case where both XX and YY may be univariate or multivariate, and of the same or mixed data types. We take an inf…

2017-02-21abs ↗pdf ↗

We propose an exact slice sampler for Hierarchical Dirichlet process (HDP) and its associated mixture models (Teh et al., 2006). Although there are existing MCMC algorithms for sampling from the HDP, a slice sampler has been missing from the literature. Slice sampling is well-known for its desirable properties includin…

2019-03-21abs ↗pdf ↗

Given a linear regression setting, Iterative Least Trimmed Squares (ILTS) involves alternating between (a) selecting the subset of samples with lowest current loss, and (b) re-fitting the linear model only on that subset. Both steps are very fast and simple. In this paper we analyze ILTS in the setting of mixed linear …

2019-02-10abs ↗pdf ↗

Linear mixed models (LMMs) are used extensively to model dependecies of observations in linear regression and are used extensively in many application areas. Parameter estimation for LMMs can be computationally prohibitive on big data. State-of-the-art learning algorithms require computational complexity which depends …

2018-03-12abs ↗pdf ↗