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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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223446668891 · Jun 202019922001200920182026
48 results for time frequency representations

Novel ECG classification method using deep time-frequency representation and progressive decision fusion.

problem Challenges in classifying abnormal ECG rhythms due to broad taxonomy, noises, and lack of annotated data.
method Transform ECG signal into time-frequency domain, train scale-specific deep CNNs, and fuse decisions progressively.
result Effective and efficient ECG classification method validated on synthetic and real-world datasets.

MCLNN improves music genre classification by learning frequency bands.

problem Classifying music genres using neural networks adapted from image recognition.
method MCLNN learns frequency bands, reducing susceptibility to frequency shifts and enabling concurrent exploration of feature combinations.
result MCLNN outperforms state-of-the-art Convolutional Neural Networks on the Ballroom music dataset.

Convolutional neural networks learn phase-dependent frequency representations.

problem Capturing phase dependence in frequency representations for better signal analysis.
method Convolutional neural networks learn filters with different phases, which rectify to phase-dependent descriptors.
result Phase harmonics correlations can compressively represent signals with sparse wavelet coefficients.

NFM models time-series data directly in the Fourier domain, achieving state-of-the-art performance.

problem Traditional time-series analysis focuses on the time domain, limiting flexibility.
method NFM models time-series data in the Fourier domain, using frequency extrapolation and interpolation.
result NFM achieves state-of-the-art performance on various time-series tasks.

End-to-end sound event detection uses learned time-frequency representations.

problem Sound event detection using standard features like mel spectrogram.
method End-to-end approach with a feedforward layer block and convolutional recurrent network.
result The learned time-frequency representations improve performance over fixed features.

Tensor-based methods improve mid-price prediction in high-frequency financial data.

problem Predicting price changes in high-frequency financial data.
method Multilinear tensor-based learning algorithms for mid-price prediction.
result Tensor-based models outperform vector-based approaches in mid-price prediction.

SRMD uses random features for efficient time-frequency analysis.

problem Efficiently analyzing time-series data with low computational cost.
method Sparse Random Mode Decomposition (SRMD) constructs a sparse approximation to the spectrogram.
result SRMD outperforms other methods in signal representation, outlier removal, and mode decomposition.

Improves speech separation by integrating time and frequency domains.

problem Speech separation using deep learning techniques.
method Proposes a framework that combines time and frequency domain features, using an embedding network and clustering.
result Obtained state-of-the-art results on WSJ0-2mix dataset.

Unified probabilistic models improve audio signal processing efficiency and interpretability.

problem High computational cost and difficulty in interpreting probabilistic models in time-frequency analysis.
method Equivalence to Spectral Mixture Gaussian processes, state space representation, Kalman smoothing, efficient parameter learning.
result Unified models make it easier to interpret and modify model assumptions.

FreSh shifts model's initial frequency spectrum to match target signal, improving neural representation performance.

problem MLPs' low-frequency bias limits capturing high-frequency details accurately.
method FreSh selects embedding hyperparameters to align model's initial output spectrum with target signal's spectrum.
result FreSh improves performance across various neural representation methods and tasks with minimal computational overhead.

Unified framework for nuclear reactor perturbation analysis using CNN and LSTM.

problem Monitoring reactor cores for safety and perturbation identification.
method 3D-CNN and LSTM networks for frequency and time domain analysis, respectively.
result High accuracy in recognising perturbation type and precise source localisation in frequency domain.

Paper proposes a unified time series forecasting model with adaptive transfer.

problem General forecasting models for diverse time series data.
method Unified representations through Decomposed Frequency Learning and adaptive domain-specific features via Time Series Register.
result State-of-the-art forecasting performance on seven real-world benchmarks.

New layers estimate complex time-frequency masks without phase wrapping issues.

problem Lack of phase estimation in deep learning-based speech enhancement and source separation.
method Proposes magbook, phasebook, and combook layers for complex mask estimation.
result Match state-of-the-art performance on speaker separation datasets.

CNNs use a bottleneck structure to focus on a few frequencies, affecting function representation.

problem Understanding how CNNs focus on specific frequencies in their feature learning.
method Defined Convolution Bottleneck (CBN) structure, measured CBN rank, and analyzed parameter norms.
result Parameter norm scales with depth and CBN rank, and networks with optimal parameters exhibit this structure.

MCLNN improves music genre classification with automated feature exploration.

problem Music genre classification using neural networks.
method MCLNN uses a mask to enforce sparseness and learn time-frequency representations.
result MCLNN achieves competitive accuracy compared to state-of-the-art methods.

Improved speech emotion recognition using pitch-synchronous single frequency filtering spectrogram.

problem Uncertainty principles in STFT spectrogram limit time and frequency resolutions.
method Modified SFF spectrogram by averaging amplitudes between GCI locations, named pitch-synchronous SFF spectrogram.
result Improved SER accuracy (63.95% to 70.4%) on IEMOCAP dataset.

End-to-end probabilistic inference improves audio signal processing.

problem Efficiently processing large audio signals with varying characteristics.
method Formulated a spectral mixture Gaussian process model with nonstationary priors, enabling infinite-horizon Gaussian process regression.
result The method outperforms standard techniques in processing audio signals with hundreds of thousands of data points.

MCLNN improves sound recognition by learning frequency bands.

problem Efficiently recognizing acoustic events from audio signals.
method MCLNN uses a binary mask to force sparseness in network weights, focusing on frequency bands.
result MCLNN achieves competitive performance in sound recognition compared to state-of-the-art methods.

VDA improves disentanglement of latent representations in complex signals.

problem Learning disentangled and interpretable representations in nonstationary, high-dimensional time-evolving signals.
method Variational decomposition autoencoding (VDA) framework, incorporating signal decomposition, contrastive self-supervised task, and variational prior approximation.
result DecVAEs surpass state-of-the-art VAE-based methods in disentanglement quality and generalization.

Proposes a deep multi-scale neural network for EEG signal representation learning.

problem Capturing multi-frequency properties in EEG signals for better brain-computer interface.
method A novel deep multi-scale neural network that discovers feature representations in multiple frequency/time ranges and extracts spatial relationships.
result Improved performance in various active/passive BCI datasets compared to state-of-the-art methods.

Deep learning reveals ubiquitous predictability in high-frequency returns.

problem Predicting returns in order book markets at high frequencies.
method Volume representation of the order book, deep learning models, model confidence sets.
result Predictability in mid-price returns is ubiquitous at high frequencies.

HyFAD improves time series imputation by combining time and frequency diffusion.

problem Improve time series imputation by handling frequency-sensitive denoising and balancing global and local dynamics.
method HyFAD is a hybrid time-frequency diffusion model with frequency-aware embedding, built on DDPM paradigm.
result HyFAD achieves state-of-the-art performance in time series imputation.

Study non-parametric frequency-domain system identification from finite samples.

problem Frequency-domain system identification from limited data.
method Empirical Transfer Function Estimate (ETFE) under sub-Gaussian colored noise and stability assumptions.
result ETFE estimates are concentrated around true values with a finite-sample rate of Ntot1/3N_{\mathrm{tot}}^{-1/3} for all frequencies in the H \mathcal{H}_{\infty} norm.

Fusion framework improves time series classification across different datasets.

problem Kernel-based methods like Rocket perform inconsistently across datasets.
method Fusion-3 framework that adaptively fuses three representations (Rocket, SAX, SFA) based on dataset properties.
result Fusion-3 framework yields small but consistent average improvements over Rocket on 113 UCR datasets.

New algorithms improve time series classification accuracy and efficiency while enhancing interpretability.

problem Lack of interpretability in time series classification algorithms.
method Combining multiple resolutions and domains, using SEQL with greedy feature selection.
result SAX-SFA-SEQL achieves similar accuracy to state-of-the-art methods but with lower computational time.

Enhances ASC using time- and frequency-liked CNNs and bilinear pooling.

problem Improving acoustic scene classification accuracy.
method Harmonic and percussive source separation, two-stream CNN architecture, bilinear pooling.
result Improved accuracy on DCASE 2019 sub task 1a dataset.

This study applies EMD to MSCI World index and converts IMFs into graphs for GNN modeling.

problem Modeling financial time series with GNNs.
method EMD, CEEMDAN, graph transformations (natural visibility, horizontal visibility, recurrence, transition graphs), topological analysis.
result High-frequency IMFs yield dense, highly connected small-world graphs; low-frequency IMFs produce sparser networks.

Developed a diffusion model on spherical data, addressing geometric and stochastic challenges.

problem Diffusion models on spherical data face unique geometric and stochastic issues.
method Extended spectral diffusion to spherical harmonics, introducing modified stochastic differential equations.
result Introduced a geometry-dependent inductive bias in spectral diffusion models.

A new FFT-based method simplifies causal structure recovery for linear dynamical systems.

problem Efficiently identifying dynamic causal effects from time-series data.
method FFT-based approach to reduce computational complexity to O(Tn3logN)O(Tn^3 \log N).
result Significant computational advantage for graph reconstruction.

WaveLSFormer learns profitable trading policies from financial time series data.

problem Challenges in learning profitable intraday trading policies from financial time series data.
method WaveLSFormer uses a learnable wavelet-based long-short Transformer to jointly perform multi-scale decomposition and return-oriented decision learning.
result WaveLSFormer consistently outperforms MLP, LSTM, and Transformer backbones in trading performance.