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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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154308462616 · Jun 202019922001200920172026
48 results for directional signal processing

New method for testing directed graphs using surrogate data.

problem No established method for statistical testing on directed graphs.
method Define directed graph wide-sense stationary signals, generate surrogates preserving covariance, construct null distributions.
result Feasibility and superiority of new approach over existing methods.

Novel Haar-Laplacian for directed graphs enhances spectral graph applications.

problem Lack of suitable Laplacian for directed graphs in spectral graph theory.
method Inspired by Haar-like transformation, introduces a Hermitian matrix preserving direction and weight.
result HaarNet outperforms in weight prediction and denoising on directed graphs.

Paper reviews multi-way graph signal processing for tensor data.

problem Maximizing use of multi-way structure in irregular tensor data.
method Generalizes GSP to multi-way data, focusing on graph signals across tensor modes.
result Synthesizes common themes in combining GSP with tensor analysis.

This paper reviews zeroth-order optimization in signal processing and machine learning.

problem Optimization problems without gradient information.
method Iterative steps: gradient estimation, descent direction computation, solution update.
result Demonstrates applications in robustness evaluation and black-box model explanations.

HR-calculus enables adaptive processing of quaternion signals.

problem Lack of adaptive processing techniques for quaternion-valued signals.
method Introduction and development of HR-calculus for quaternion algebra.
result Derivation of gradient operator, chain and product derivative rules, and Taylor series expansion for quaternion calculus.

New method clusters directed graphs using Koopman operators.

problem Challenges in clustering directed graphs, especially complex eigenvalues and lack of cluster definition.
method Relate graph Laplacians to transfer operators and metastable sets in stochastic systems, derive clustering algorithms for directed and time-evolving graphs.
result Clusters can be interpreted as coherent sets, useful for analyzing transport and mixing processes.

Paper improves DOA estimation in sparse arrays using Siamese neural networks.

problem Challenges in DOA estimation with limited snapshots in sparse linear arrays.
method Introduces a Siamese neural network with a sparse augmentation layer for enhanced signal feature embedding.
result Demonstrates improved DOA estimation accuracy in sparse arrays.

We describe ways to define and calculate L1L_1-norm signal subspaces which are less sensitive to outlying data than L2L_2-calculated subspaces. We focus on the computation of the L1L_1 maximum-projection principal component of a data matrix containing N signal samples of dimension D and conclude that the general proble…

2013-09-04abs ↗pdf ↗

The paper introduces novel Gaussian process models for vector-valued signals on manifolds.

problem Modeling vector-valued signals on non-Euclidean domains, especially for applications like wind speeds.
method Intrinsically defined Gaussian vector fields on manifolds, accounting for manifold geometry.
result Gaussian vector fields provide more refined inductive biases than extrinsic fields.

Most generative models of audio directly generate samples in one of two domains: time or frequency. While sufficient to express any signal, these representations are inefficient, as they do not utilize existing knowledge of how sound is generated and perceived. A third approach (vocoders/synthesizers) successfully inco…

2020-01-14abs ↗pdf ↗

Paper uses relaxation techniques to find optimal brokerage fees with private signals.

problem Finding optimal brokerage fees for clients with private trading signals.
method Relaxation techniques to establish contract existence in asymmetric information settings.
result Existence of optimal brokerage fees established in a market model with private signals.

New method for separating mixed signals with nonlinear functions.

problem Recovering source signals from nonlinear mixtures.
method Optimisation-based function approximation to minimize mutual statistical dependence.
result The method can recover source signals from nonlinear mixtures under certain conditions.

Non-negative blind source separation (non-negative BSS), which is also referred to as non-negative matrix factorization (NMF), is a very active field in domains as different as astrophysics, audio processing or biomedical signal processing. In this context, the efficient retrieval of the sources requires the use of sig…

2014-07-29abs ↗pdf ↗

New methods learn DAGs from noisy data, adapting to noise levels.

problem Inferring causal relationships from observational data with noise and confounding.
method Reformulate DAG learning as a continuous optimization problem over adjacency matrices, jointly inferring structure and noise levels.
result Improved robustness to heteroscedasticity and distribution shifts.

New algorithms detect and estimate rank-one signals with prior directional information.

problem Detecting and estimating rank-one signals with directional prior information.
method Construct nonlinear Laplacians and examine top eigenvalues and eigenvectors.
result Nonlinear Laplacian algorithms outperform direct spectral methods for biased signals.

One of the cornerstones of the field of signal processing on graphs are graph filters, direct analogues of classical filters, but intended for signals defined on graphs. This work brings forth new insights on the distributed graph filtering problem. We design a family of autoregressive moving average (ARMA) recursions,…

2016-02-14abs ↗pdf ↗

Many signals on Cartesian product graphs appear in the real world, such as digital images, sensor observation time series, and movie ratings on Netflix. These signals are "multi-dimensional" and have directional characteristics along each factor graph. However, the existing graph Fourier transform does not distinguish …

2017-12-21abs ↗pdf ↗

The paper shows that causal identification is not essential for efficient portfolios, focusing on geometric sufficiency conditions.

problem The necessity of causal identification for efficient portfolios.
method Re-examination of predictive signals and their impact on portfolio efficiency under structural misspecification.
result Efficiency is governed by geometric sufficiency conditions (directional alignment, ranking preservation, and calibration) rather than causal identification.

Tutorials on signal processing on higher-order networks like simplicial complexes and hypergraphs.

problem Processing complex data structures with polyadic relationships.
method Introduction to simplicial complexes and hypergraphs, Fourier analysis, signal denoising, interpolation, embeddings, neural networks.
result Multi-relational operators like the Hodge Laplacian for simplicial complexes and tensor representations for hypergraphs.

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 ↗

Privacy subsidy found in market trading with noisy direction signals.

problem Analyzing welfare and bid-ask spread in a market with privacy mechanisms.
method Closed-form derivation of bid-ask spread and welfare under flip-noise direction observation.
result Privacy subsidy of μηΔμηΔ from liquidity pool to traders, robust across models.

We propose a data-driven algorithm for the maximum a posteriori (MAP) estimation of stochastic processes from noisy observations. The primary statistical properties of the sought signal is specified by the penalty function (i.e., negative logarithm of the prior probability density function). Our alternating direction m…

2017-05-16abs ↗pdf ↗

Proposes a new complex Gaussian distribution for better modeling of complex-valued signals.

problem Limited ability of Gaussian distribution to represent diverse amplitude characteristics.
method Introduces a power-weighted noncentral complex Gaussian distribution on the complex plane.
result Consistently outperforms conventional distributions in log-likelihood for speech power spectra.

Deep Gaussian Processes model functions on DAGs with partially observed data.

problem Reconstructing and inferring from partially observed functions on DAGs with noisy measurements.
method Place priors over functions on DAGs, theoretically study prior-collapse behavior, and offer a structured variational approximation.
result Almost-sure lower bounds on the preservation of input distinctions and interpretability of simulator hierarchies.

A new method for analyzing high-dimensional time-series data using deep neural networks.

problem Challenges in modeling high-dimensional time-series data with explicit state and observation processes.
method Deep Direct Discriminative Decoders (D4) for high-dimensional observation processes.
result D4 outperforms traditional SSMs and RNNs in various time-series data applications.

Paper reveals hidden convexities in deep learning models using sparse signal processing.

problem Non-convex loss functions in deep learning models complicate optimization and theoretical understanding.
method Developed convex equivalences of ReLU NNs and their connections to sparse signal processing models.
result Recent research has uncovered hidden convexities in certain NN architectures, notably two-layer ReLU networks and other architectures.

New algorithms improve signal processing in federated learning.

problem Efficiently process distributed signal samples with privacy and communication constraints.
method Proposes overpredictive signal approximations using convex optimization.
result Quantifies tradeoffs between communication cost, sampling rate, and approximation error.