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.

169,051 papers · 148 categories

Trend · papers per month

8.4%16.8%25.2%33.5% · Jun 202019922001200920182026
48 results for Viterbi EM algorithm

Since the early days of digital communication, Hidden Markov Models (HMMs) have now been routinely used in speech recognition, processing of natural languages, images, and in bioinformatics. An HMM (Xi,Yi)i1(X_i,Y_i)_{i\ge 1} assumes observations X1,X2,...X_1,X_2,... to be conditionally independent given an "explanotary" Markov proc…

2007-11-06abs ↗pdf ↗

Since the early days of digital communication, hidden Markov models (HMMs) have now been also routinely used in speech recognition, processing of natural languages, images, and in bioinformatics. In an HMM (Xi,Yi)i1(X_i,Y_i)_{i\ge 1}, observations X1,X2,...X_1,X_2,... are assumed to be conditionally independent given an ``explanator…

2008-04-14abs ↗pdf ↗

We consider the maximum likelihood (Viterbi) alignment of a hidden Markov model (HMM). In an HMM, the underlying Markov chain is usually hidden and the Viterbi alignment is often used as the estimate of it. This approach will be referred to as the Viterbi segmentation. The goodness of the Viterbi segmentation can be me…

2010-02-18abs ↗pdf ↗

New approach finds optimal hidden paths in large models, scaling to high dimensions.

problem Finding optimal hidden paths in large, high-dimensional models.
method Developed a new approach to existence of the infinite Viterbi alignment for models satisfying a decay-convexity condition.
result Quantitative bounds on the distance to the infinite Viterbi alignment, demonstrating scalability to high-dimensional problems.

QATS efficiently decodes HMMs with polylogarithmic complexity.

problem Efficiently decoding hidden Markov models from noisy observations.
method Divide-and-conquer procedure with polylogarithmic sequence complexity and cubic state space complexity.
result QATS outperforms Viterbi and PMAP in speed and accuracy.

The EM algorithm is one of many important tools in the field of statistics. While often used for imputing missing data, its widespread applications include other common statistical tasks, such as clustering. In clustering, the EM algorithm assumes a parametric distribution for the clusters, whose parameters are estimat…

2017-11-21abs ↗pdf ↗

Generalising the idea of the classical EM algorithm that is widely used for computing maximum likelihood estimates, we propose an EM-Control (EM-C) algorithm for solving multi-period finite time horizon stochastic control problems. The new algorithm sequentially updates the control policies in each time period using Mo…

2016-11-06abs ↗pdf ↗

A new EM gradient algorithm for mixture models with skewed components.

problem Fitting mixture models with skewed components derived from the Manly transformation.
method Proposes an alternative EM gradient algorithm using Newton's method for better parameter updates.
result Shows improved convergence and parameter estimation compared to the Nelder-Mead optimization.

Paper proposes a faster SPIDER-EM variant for large-scale nonconvex optimization.

problem High computational cost of EM algorithm in large-scale learning.
method Extension of SPIDER-EM for nonconvex finite-sum optimization problems.
result Achieves state-of-the-art complexity bounds and linear convergence under certain conditions.

Controller-Augmented Hidden Markov Models (CHMMs) are a framework for constrained sequential inference.

problem Hidden Markov models fail under pathwise constraints like precedence, visitation, or monotonic state progression.
method CHMMs compile constraints into finite-state controllers, then use standard forward-backward and Viterbi recursions to compute exact constrained posteriors and paths.
result CHMMs provide exact constrained inference, monotone ascent in constrained EM, and linear complexity in controller cardinality.

MLE and CVE are equivalent under exponential families, leading to faster and more stable EM algorithms.

problem Finding maximum likelihood estimators (MLE) efficiently and stably.
method Proved equivalence between MLE and CVE under exponential families, leading to an EM algorithm.
result EM algorithm achieves the same asymptotic variance as MLE and is faster and more stable.

sEM uses optimal transport to improve EM algorithm for better convergence and avoiding local optima.

problem Improving the EM algorithm for better convergence and avoiding local optima.
method sEM uses entropic optimal transport to compute responsibilities in the expectation step, leading to better global convergence guarantees and avoiding local optima.
result sEM learns cell labels significantly better than other approaches, improving convergence and avoiding local optima.

In this paper, we study statistical classification accuracy of two different Markov field environments for pixelwise image segmentation, considering the labels of the image as hidden states and solving the estimation of such labels as a solution of the MAP equation. The emission distribution is assumed the same in all …

2013-07-11abs ↗pdf ↗

Paper refutes EM convergence theory and introduces a new EM algorithm.

problem The convergence theory of the EM algorithm is incorrect and affects its performance.
method Proposes a new EM algorithm called the Channel Matching (CM) EM algorithm and provides an initialization map.
result The locally maximal Q can affect the convergent speed but not the global convergence.

The EM algorithm's convergence is analyzed using Lyapunov stability theory.

problem Analyzing the convergence of the EM algorithm.
method Reinterpreting the EM algorithm as a dynamical system and applying Lyapunov stability theory.
result Asymptotic stability and convergence of the EM algorithm are established.

New framework improves EM algorithm convergence under log-Sobolev inequality.

problem Improving convergence of the EM algorithm.
method Extending gradient flow techniques to EM algorithm, using free energy representation.
result Exponential convergence of EM algorithm under log-Sobolev inequality.

EM algorithm converges in KL divergence for exponential families via mirror descent.

problem Lack of understanding of EM's non-asymptotic convergence properties.
method Viewing EM as a mirror descent algorithm, showing convergence rates in KL divergence.
result KL divergence rates for EM in exponential families, invariant to parametrization.

The EM algorithm is a novel numerical method to obtain maximum likelihood estimates and is often used for practical calculations. However, many of maximum likelihood estimation problems are nonconvex, and it is known that the EM algorithm fails to give the optimal estimate by being trapped by local optima. In order to …

2016-06-05abs ↗pdf ↗

This paper develops a federated EM algorithm for unsupervised learning of mixture models.

problem Theoretical foundations of unsupervised federated learning are lacking.
method Introduces a federated gradient EM algorithm (FedGrEM) for unsupervised learning of mixture models.
result Theoretical analysis shows FedGrEM outperforms local single-task learning.

Regularized EM algorithm improves clustering performance with small sample sizes.

problem Performance reduction in EM algorithm due to small sample size and poorly conditioned covariance matrices.
method Regularized EM algorithm that uses prior knowledge to ensure positive definiteness of covariance matrices.
result The regularized EM algorithm outperforms standard EM in clustering tasks with small sample sizes.

EM algorithm converges globally for two-component mixed linear regression.

problem Global convergence of EM algorithm for mixed linear regression.
method Developed new theoretical analysis for EM algorithm convergence in mixed linear regression.
result EM algorithm converges globally for two-component mixed linear regression.

Regularized EM algorithm improves GMM clustering in low sample settings.

problem Numerical instability and convergence issues in EM-GMM for low sample support.
method Regularized EM algorithm that maximizes penalized GMM likelihood, ensuring positive definiteness and structured covariance matrices.
result The regularized EM algorithm leads to better performing EM for structured covariance matrix models or low sample settings.

EM algorithm achieves optimal sample complexity for learning two-component mixed linear regression.

problem Learning two-component mixed linear regression under varying signal-to-noise ratios.
method Analysis of EM algorithm convergence rates under different SNR regimes.
result EM algorithm achieves minimax optimal sample complexity in all SNR regimes.

Paper analyzes EM algorithm's trajectory in 2MLR, revealing cycloid behavior.

problem Understanding the convergence and trajectory of EM algorithm in 2MLR.
method Explicit closed-form expressions for EM updates, recurrence relation derivation at population level.
result EM iterations lie on a cycloid trajectory, leading to theoretical estimate of convergence exponent.

We present the particle stochastic approximation EM (PSAEM) algorithm for learning of dynamical systems. The method builds on the EM algorithm, an iterative procedure for maximum likelihood inference in latent variable models. By combining stochastic approximation EM and particle Gibbs with ancestor sampling (PGAS), PS…

2018-06-25abs ↗pdf ↗

The iterative nature of the expectation maximization (EM) algorithm presents a challenge for privacy-preserving estimation, as each iteration increases the amount of noise needed. We propose a practical private EM algorithm that overcomes this challenge using two innovations: (1) a novel moment perturbation formulation…

2016-05-23abs ↗pdf ↗

Proposes an EM algorithm for high-dimensional Markov-switching VAR models.

problem Estimating regime shifts in high-dimensional time series data.
method Approximate EM algorithm for Markov-switching VAR models.
result Established consistency of the proposed EM algorithm in high dimensions.