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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.

169,181 papers · 148 categories

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3.3%6.7%10.0%13.3% · Feb 199519922001200920182026
48 results for coordinate dictionaries

Paper provides conditions for local recovery of tensor data's Kronecker-structured dictionaries.

problem Local recovery of Kronecker-structured dictionaries for tensor data.
method Derives sufficient conditions for local recovery of coordinate dictionaries.
result Sufficient conditions guarantee recovery of individual coordinate dictionaries up to specified error.

We consider the problem of distributed dictionary learning, where a set of nodes is required to collectively learn a common dictionary from noisy measurements. This approach may be useful in several contexts including sensor networks. Diffusion cooperation schemes have been proposed to solve the distributed linear regr…

2013-04-12abs ↗pdf ↗

The problem of convex optimization is studied. Usually in convex optimization the minimization is over a d-dimensional domain. Very often the convergence rate of an optimization algorithm depends on the dimension d. The algorithms studied in this paper utilize dictionaries instead of a canonical basis used in the coord…

2015-11-04abs ↗pdf ↗

Detects financial fraud schemes in networks using graph structure learning.

problem Identifying financial fraud schemes in complex networks.
method Adapting dictionary learning to network topologies, imposing Laplacian structure on dictionaries.
result Proposed methods effectively represent graph structure information for anomaly detection.

Study shows unique sharp local minimum in 1\ell_1-minimization for dictionary learning.

problem Global recovery of a dictionary from random linear combinations of atoms.
method Norm condition, explicit bound, perturbation-based test, Block Coordinate Descent algorithm.
result Reference dictionary is the unique sharp local minimum of the 1\ell_1 objective function.

The paper tackles MSDA by learning dictionary atoms in Wasserstein space.

problem Mitigating data distribution shifts across multiple source domains to target domain.
method Dictionary learning and optimal transport in Wasserstein space; DaDiL algorithm for learning.
result Improved classification performance by 3.15%, 2.29%, and 7.71% in benchmarks.

A distributed algorithm learns patterns in large images and signals.

problem High-dimensional optimization in large images and signals.
method Distributed asynchronous algorithm with locally greedy coordinate descent.
result Patterns can be learned on large scales images from the Hubble Space Telescope.

A summary introduction of the Weil-Petersson metric space geometry is presented. Teichmueller space and its augmentation are described in terms of Fenchel-Nielsen coordinates. Formulas for the gradients and Hessians of geodesic-length functions are presented. Applications are considered. A description of the Weil-Peter…

2007-12-31abs ↗pdf ↗

The goal of the present paper is to propose an enhanced ordinary differential equations solver by exploitation of the powerful equivalence method of Élie Cartan. This solver returns a target equation equivalent to the equation to be solved and the transformation realizing the equivalence. The target ODE is a member of …

2007-11-30abs ↗pdf ↗

Robot learns to manipulate objects using multiple geometric representations.

problem Manipulation tasks are poorly represented by Cartesian coordinates.
method Extends Gaussian distributions on Riemannian manifolds to analyze demonstrations, formulating the problem as an optimal control problem.
result Robot can generalize manipulation tasks using multiple geometric representations.

DeepCAM learns convolutional dictionaries for image processing.

problem Processing high-dimensional signals like images efficiently.
method Introduces a Deep Convolutional Analysis Dictionary Model (DeepCAM) using convolutional dictionaries.
result DeepCAM achieves performance comparable to other methods on single image super-resolution.

Bayesian method improves dictionary learning for complex problems.

problem Efficiently identifying relevant dictionary entries for complex inverse problems.
method Bayesian group sparsity coding and deflation steps to compress and identify relevant subdictionaries.
result Significant computational complexity reduction and improved glitch detection in LIGO experiment.

Paper improves dictionary learning by addressing local and global coherence issues.

problem Improving dictionary learning by addressing local and global coherence issues.
method The paper uses the ITKrM algorithm to prove contraction under relaxed conditions and proposes replacing bad dictionaries with carefully designed candidates.
result The adaptive version of ITKrM can recover a generating dictionary from randomly initialized dictionaries of various sizes and learn meaningful dictionaries on image data.

This work learns sparse tensor representations using mixtures of separable dictionaries.

problem Learning sparse representations of tensor data with structured models.
method Proposes and explores learning a mixture of separable dictionaries with sufficient conditions for local identifiability.
result Developed computational algorithms for batch and online learning.

We present a two-stage approach for learning dictionaries for object classification tasks based on the principle of information maximization. The proposed method seeks a dictionary that is compact, discriminative, and generative. In the first stage, dictionary atoms are selected from an initial dictionary by maximizing…

2012-08-17abs ↗pdf ↗

Many techniques in computer vision, machine learning, and statistics rely on the fact that a signal of interest admits a sparse representation over some dictionary. Dictionaries are either available analytically, or can be learned from a suitable training set. While analytic dictionaries permit to capture the global st…

2013-03-21abs ↗pdf ↗

CRsAE auto-encoder recovers convolutional dictionary from noisy signals.

problem Recovering a convolutional dictionary from noisy signals.
method Constrained recurrent sparse auto-encoder (CRsAE) architecture.
result CRsAE successfully recovers the underlying dictionary in the presence of noise.

We give a new approach to the dictionary learning (also known as "sparse coding") problem of recovering an unknown n×mn\times m matrix AA (for mnm \geq n) from examples of the form \[ y = Ax + e, \] where xx is a random vector in Rm\mathbb R^m with at most τmτm nonzero coordinates, and ee is a random noise vector in …

2014-07-06abs ↗pdf ↗

Sparse coding in learned dictionaries has been established as a successful approach for signal denoising, source separation and solving inverse problems in general. A dictionary learning method adapts an initial dictionary to a particular signal class by iteratively computing an approximate factorization of a training …

2012-05-28abs ↗pdf ↗

Researchers find optimal dictionaries for minimizing average squared coefficients in random vector representations.

problem Finding optimal dictionaries for minimizing the average squared coefficients in random vector representations.
method Using rank-1 decompositions and majorization theory, the study provides a complete characterization of optimal dictionaries.
result Complete characterization of 2\ell_2-optimal dictionaries with polynomial time algorithms.

In sparse signal representation, the choice of a dictionary often involves a tradeoff between two desirable properties -- the ability to adapt to specific signal data and a fast implementation of the dictionary. To sparsely represent signals residing on weighted graphs, an additional design challenge is to incorporate …

2014-01-05abs ↗pdf ↗

Sparse representations using learned dictionaries are being increasingly used with success in several data processing and machine learning applications. The availability of abundant training data necessitates the development of efficient, robust and provably good dictionary learning algorithms. Algorithmic stability an…

2013-03-03abs ↗pdf ↗

The paper provides guarantees for an alternating minimization algorithm in dictionary learning.

problem Dictionary learning problem of factorizing samples into a basis and sparse vectors.
method Alternating minimization procedure switching between 1\ell_1 minimization and gradient descent.
result Local convergence guarantees for the alternating minimization algorithm under a new matrix infinity norm condition.

The paper tackles dictionary learning with almost sure error constraints.

problem Achieving desirable features in data representation with almost sure error constraints.
method Imposes almost sure recovery constraints and reformulates the problem as a convex-concave min-max problem, solved using gradient descent-ascent.
result Demonstrates the effectiveness of the proposed method in achieving almost sure error constraints in dictionary learning.

We study the Dictionary Learning (aka Sparse Coding) problem of obtaining a sparse representation of data points, by learning \emph{dictionary vectors} upon which the data points can be written as sparse linear combinations. We view this problem from a geometry perspective as the spanning set of a subspace arrangement,…

2014-02-28abs ↗pdf ↗

The paper proposes a method to learn discriminative multilevel dictionaries for supervised image classification.

problem Improving sparse representation for supervised image classification.
method Learning structured multilevel dictionaries with discriminative constraints for each class, using reconstruction errors of image patches.
result Competitive results compared to state-of-the-art methods on texture image classification.

Dictionary learning is a cutting-edge area in imaging processing, that has recently led to state-of-the-art results in many signal processing tasks. The idea is to conduct a linear decomposition of a signal using a few atoms of a learned and usually over-completed dictionary instead of a pre-defined basis. Determining …

2016-05-25abs ↗pdf ↗

Dictionaries are collections of vectors used for representations of random vectors in Euclidean spaces. Recent research on optimal dictionaries is focused on constructing dictionaries that offer sparse representations, i.e., 0\ell_0-optimal representations. Here we consider the problem of finding optimal dictionaries …

2016-03-07abs ↗pdf ↗

This article addresses the issue of representing electroencephalographic (EEG) signals in an efficient way. While classical approaches use a fixed Gabor dictionary to analyze EEG signals, this article proposes a data-driven method to obtain an adapted dictionary. To reach an efficient dictionary learning, appropriate s…

2013-03-04abs ↗pdf ↗

The kernel least-mean-square (KLMS) algorithm is an appealing tool for online identification of nonlinear systems due to its simplicity and robustness. In addition to choosing a reproducing kernel and setting filter parameters, designing a KLMS adaptive filter requires to select a so-called dictionary in order to get a…

2013-10-31abs ↗pdf ↗