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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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23466992 · May 202619922001200920182026
48 results for nonlinear dictionary

New method learns histograms using optimal transport barycenters.

problem Nonlinear dictionary learning for histograms.
method Optimal transport theory, displacement interpolations, entropic regularization, gradient descent.
result Efficient and tractable method for nonlinear dictionary learning.

New method uses compositions of ReLU neural networks for nonlinear approximation.

problem Approximating functions with minimum error using a limited number of terms.
method Proposes dictionaries of functions in the form of compositions, implemented using ReLU FNNs.
result Improves approximation rate by using compositions, especially for deep networks.

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 ↗

The paper tackles energy disaggregation by improving dictionary learning with deep neural models.

problem Decomposing electricity signals of a whole home into its operating devices.
method Proposes a novel optimization program that learns both the dictionary and sparse coefficients using a deep neural model (LSTM-AE) to capture temporal energy signals.
result Significant improvement in disaggregation accuracy and F-score metrics compared to state-of-the-art methods.

QENDy learns quadratic dynamics from nonlinear systems data.

problem Identifying governing equations of highly nonlinear dynamical systems.
method QENDy embeds nonlinear dynamics into a quadratic feature space, requiring trajectory data and preselected basis functions.
result QENDy accurately identifies quadratic dynamics and outperforms SINDy and deep learning methods.

We present a probabilistic framework for both (i) determining the initial settings of kernel adaptive filters (KAFs) and (ii) constructing fully-adaptive KAFs whereby in addition to weights and dictionaries, kernel parameters are learnt sequentially. This is achieved by formulating the estimator as a probabilistic mode…

2017-07-11abs ↗pdf ↗

In signal analysis and synthesis, linear approximation theory considers a linear decomposition of any given signal in a set of atoms, collected into a so-called dictionary. Relevant sparse representations are obtained by relaxing the orthogonality condition of the atoms, yielding overcomplete dictionaries with an exten…

2014-11-01abs ↗pdf ↗

PSMF factorizes time-varying datasets into a dictionary and time-varying coefficients.

problem Factorizing time-varying and non-stationary datasets with temporal nonlinearities.
method Probabilistic Sequential Matrix Factorization (PSMF) using nonlinear Gaussian state-space models and approximate extended Kalman filtering.
result PSMF can account for temporal nonlinearities and estimate generic subspace models.

Modeling data with linear combinations of a few elements from a learned dictionary has been the focus of much recent research in machine learning, neuroscience and signal processing. For signals such as natural images that admit such sparse representations, it is now well established that these models are well suited t…

2010-09-27abs ↗pdf ↗

CDPL-Net integrates CNN and DL for better image representation.

problem Improving image representation learning by combining CNN and DL.
method CDPL-Net architecture combining CNN and DPL layers, using l1-norm for sparse representation, and efficient stochastic gradient descent.
result Enhanced performance compared to state-of-the-art methods.

This paper introduces a new shape-based image reconstruction technique applicable to a large class of imaging problems formulated in a variational sense. Given a collection of shape priors (a shape dictionary), we define our problem as choosing the right elements and geometrically composing them through basic set opera…

2013-02-28abs ↗pdf ↗

Classifiers based on sparse representations have recently been shown to provide excellent results in many visual recognition and classification tasks. However, the high cost of computing sparse representations at test time is a major obstacle that limits the applicability of these methods in large-scale problems, or in…

2014-02-09abs ↗pdf ↗

A new algorithm improves kernel-based sparse coding for better data representation.

problem Lack of consistency between training and test optimization frameworks in K-SRC.
method Confident K-SRC (CKSC) with novel discriminative terms and supervised dictionary learning.
result Improves discriminative performance and recall phase in classification.

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.

This paper is a follow up to the previous author's paper on convex optimization. In that paper we began the process of adjusting greedy-type algorithms from nonlinear approximation for finding sparse solutions of convex optimization problems. We modified there three the most popular in nonlinear approximation in Banach…

2012-06-02abs ↗pdf ↗

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.

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.

A new DDR framework learns low-dimensional data representations using dynamical systems.

problem Learning efficient low-dimensional data representations.
method DDR framework based on nonlinear dynamical systems, using linear combinations of functions and regularization.
result DDR method outperforms other methods on synthetic and real datasets.

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 ↗

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.

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.