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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.

168,695 papers · 148 categories

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4794140187 · Jun 202019922001200920172026
48 results for sparse mixture

Study on recovering supports of multiple sparse vectors from mixed linear measurements.

problem Recovering supports of multiple sparse vectors from a mixture of linear measurements.
method Developed algorithms to identify the support of all component vectors using polynomial and quasi-polynomial number of measurements.
result Polynomial and quasi-polynomial number of measurements sufficient for recovering the supports of all component vectors.

We introduce a balloon estimator in a generalized expectation-maximization method for estimating all parameters of a Gaussian mixture model given one data sample per mixture component. Instead of limiting explicitly the model size, this regularization strategy yields low-complexity sparse models where the number of eff…

2018-12-11abs ↗pdf ↗

Efficient algorithms for sparse parameter recovery in mixture models.

problem Support recovery of high-dimensional sparse latent vectors in mixture models.
method Efficient algorithms with logarithmic sample complexity dependence on dimensionality.
result First guarantees on support recovery for various mixture models.

In this paper we propose a novel framework for the construction of sparsity-inducing priors. In particular, we define such priors as a mixture of exponential power distributions with a generalized inverse Gaussian density (EP-GIG). EP-GIG is a variant of generalized hyperbolic distributions, and the special cases inclu…

2012-04-19abs ↗pdf ↗

New insights into the top-K sparse softmax gating function for deep learning.

problem Understanding the theoretical effects of the top-K sparse softmax gating function on density and parameter estimations.
method Using a Gaussian mixture of experts, novel loss functions, and theoretical analysis.
result The convergence rates of density and parameter estimations are parametric under certain conditions, but slow under over-specified models.

We consider unsupervised estimation of mixtures of discrete graphical models, where the class variable corresponding to the mixture components is hidden and each mixture component over the observed variables can have a potentially different Markov graph structure and parameters. We propose a novel approach for estimati…

2012-03-04abs ↗pdf ↗

In probabilistic classification, a discriminative model based on the softmax function has a potential limitation in that it assumes unimodality for each class in the feature space. The mixture model can address this issue, although it leads to an increase in the number of parameters. We propose a sparse classifier base…

2019-11-14abs ↗pdf ↗

Proposes a deep generative model for robust forecasting on sparse multivariate time series.

problem Forecasting on sparse multivariate time series with suboptimal results when sparsity is high.
method Dynamic Gaussian Mixture distribution for modeling latent clusters, using neural networks and gating mechanism.
result Demonstrates robust modeling of sparse multivariate time series with improved accuracy.

Paper advances sparse regularisation theory for measures with new kernel insights.

problem Estimating sparse measures from noisy observations using continuous sparse regularisation.
method Develops new continuous sparse regularisation theory on measures with Beurling-LASSO, introduces kernel switch analysis.
result Proves the ``sinc-4'' kernel satisfies a technical LPC assumption for error bounds.

New distributions allow greedy arm selection in sparse bandit problems.

problem Sparse contextual bandit problem with sparse parameters and feature distributions.
method Introduced new distribution classes and demonstrated that mixtures of these distributions are also greedy-applicable.
result Greedy algorithm applicable to a wider range of arm feature distributions, including those with origin-asymmetric support.

Blind source separation (BSS) aims at recovering signals from mixtures. This problem has been extensively studied in cases where the mixtures are contaminated with additive Gaussian noise. However, it is not well suited to describe data that are corrupted with Poisson measurements such as in low photon count optics or …

2018-12-11abs ↗pdf ↗

We discuss a clustering method for Gaussian mixture model based on the sparse principal component analysis (SPCA) method and compare it with the IF-PCA method. We also discuss the dependent case where the covariance matrix ΣΣ is not necessarily diagonal.

2016-02-16abs ↗pdf ↗

We propose a novel sparse tensor decomposition method, namely Tensor Truncated Power (TTP) method, that incorporates variable selection into the estimation of decomposition components. The sparsity is achieved via an efficient truncation step embedded in the tensor power iteration. Our method applies to a broad family …

2015-02-05abs ↗pdf ↗

Paper estimates GMMs with unknown covariances using sparse regularization.

problem Estimating GMMs with unknown diagonal covariances from samples.
method Employed Beurling-LASSO (BLASSO) for sparse estimation of component means, covariances, and weights.
result Established non-asymptotic recovery guarantees with nearly parametric convergence rates.

We address two shortcomings in online travel time estimation methods for congested urban traffic. The first shortcoming is related to the determination of the number of mixture modes, which can change dynamically, within day and from day to day. The second shortcoming is the wide-spread use of Gaussian probability dens…

2018-04-22abs ↗pdf ↗

Efficient algorithm learns mixture models of heavy-tailed distributions.

problem Learning mixture models of heavy-tailed distributions.
method Efficient high-dimensional sparse Fourier transforms.
result Algorithm succeeds for heavy-tailed distributions, including Laplace but excluding Gaussians.

In the problem of learning mixtures of linear regressions, the goal is to learn a collection of signal vectors from a sequence of (possibly noisy) linear measurements, where each measurement is evaluated on an unknown signal drawn uniformly from this collection. This setting is quite expressive and has been studied bot…

2019-10-30abs ↗pdf ↗

Improves variational inference for sparse models using mixtures of exponential families.

problem Intractability of posterior distributions in Bayesian sparse models.
method Flexible mean field variational inference using mixtures of non-overlapping exponential families.
result Mixtures of exponential families with non-overlapping support form an exponential family, enabling analytical updates.

We study the problem of learning an unknown mixture of kk rankings over nn elements, given access to noisy samples drawn from the unknown mixture. We consider a range of different noise models, including natural variants of the "heat kernel" noise framework and the Mallows model. For each of these noise models we giv…

2018-11-03abs ↗pdf ↗

This paper improves topic model estimation for sparse distributions and applies it to Wasserstein distances.

problem Estimating sparse topic distributions in topic models with high-dimensional data.
method MLE for topic weights when AA is known, plug-in estimator for unknown AA.
result MLE can be exactly sparse and contain true zero pattern of topic weights.

In this paper, we propose a novel maximum causal Tsallis entropy (MCTE) framework for imitation learning which can efficiently learn a sparse multi-modal policy distribution from demonstrations. We provide the full mathematical analysis of the proposed framework. First, the optimal solution of an MCTE problem is shown …

2018-05-22abs ↗pdf ↗

This paper introduces a new data-driven methodology for estimating sparse covariance matrices of the random coefficients in logit mixture models. Researchers typically specify covariance matrices in logit mixture models under one of two extreme assumptions: either an unrestricted full covariance matrix (allowing correl…

2020-01-14abs ↗pdf ↗

NAMEx merges experts using Nash bargaining for improved performance.

problem Sparse Mixture of Experts merging strategies lack a principled weighting mechanism.
method Reinterpreting expert merging through game theory, introducing Nash Merging and complex momentum.
result NAMEx consistently outperforms competing methods across various tasks and system sizes.

The paper proposes a method to identify subgroups with different treatment effects in time-to-event data.

problem Identifying subgroups with differential treatment effects in time-to-event data.
method A mixture model with structured sparsity regularization and novel inference procedure.
result The method effectively recovers sparse phenotypes across real-world clinical studies.

Estimates signals from a continuous dictionary with sparse mixtures using optimization.

problem Estimating signals from a continuous dictionary with unknown mixtures and noise.
method Formulates a regularized optimization problem with data fidelity and (1,Lp)(\ell_1,L^p)-penalty.
result High probability bounds on prediction error for the Group-Nonlinear-Lasso solution.

DSelect-k improves MoE models for multi-task learning with better performance and smoother training.

problem Smoothness and convergence issues in sparse gate selection for MoE models.
method Developed DSelect-k, a differentiable and sparse gate for MoE models.
result DSelect-k achieves statistically significant improvements in prediction and expert selection over Top-k.

Oracle inequality for sparse neural nets adapts to unknown structure.

problem Sparse deep neural nets in nonparametric regression.
method Gibbs posterior distribution with Metropolis-adjusted Langevin algorithms and mixture of uniform priors.
result Oracle inequality showing adaptation to unknown regularity and structure, achieving minimax-optimal rate of convergence.

Proposes a new method for estimating sparse precision matrices in GMRF-MM models.

problem Difficulty in learning GMMs with large parameters and limited data.
method Restricts GMM to GMRF-MM, proposes efficient optimization for sparse precision matrices, and debiases the estimates.
result Debiasing approach outperforms GLASSO in single-GMRF and GMRF-MM cases.

Mixture models and topic models generate each observation from a single cluster, but standard variational posteriors for each observation assign positive probability to all possible clusters. This requires dense storage and runtime costs that scale with the total number of clusters, even though typically only a few clu…

2016-09-23abs ↗pdf ↗