1 citations · 2 across the 15 of their papers we have counts for
16 papers
Time-Varying Spiky Wave-Shape Functions for Non-Stationary Signal Decomposition
Marcelo A. Colominas, Hau-Tieng Wu
We propose a novel framework for decomposing nonstationary spiky signals. Unlike classical adaptive non-harmonic models, which represent signals as amplitude- and frequency-modulat…
On spectral interference of the short-time Fourier transform and its nonlinear variations
Shrikant Chand, James Nolen, Hau-Tieng Wu
Spectral interference, the frequency counterpart of the beating phenomenon in the time domain, can severely distort time-frequency representations (TFRs) in physical applications.…
Theoretical analysis of phase-rectified signal averaging (PRSA) algorithm
Jiro Akahori, Joseph Najnudel, Hau-Tieng Wu +1
Phase-rectified signal averaging (PRSA) is a widely used algorithm to analyze nonstationary biomedical time series. The method operates by identifying hinge points in the time seri…
Time-Frequency Filtering Meets Graph Clustering
Marcelo A. Colominas, Stefan Steinerberger, Hau-Tieng Wu
We show that the problem of identifying different signal components from a time-frequency representation can be equivalently phrased as a graph clustering problem: given a graph $G…
On the Practical Use of Blaschke Decomposition in Nonstationary Signal Analysis
Ronald R. Coifman, Hau-Tieng Wu
The Blaschke decomposition-based algorithm, {\em Phase Dynamics Unwinding} (PDU), possesses several attractive theoretical properties, including fast convergence, effective decompo…
On Random Fields Associated with Analytic Wavelet Transform
Gi-Ren Liu, Yuan-Chung Sheu, Hau-Tieng Wu
Despite the broad application of the analytic wavelet transform (AWT), a systematic statistical characterization of its magnitude and phase as inhomogeneous random fields on the ti…
Uncertainty quantification of synchrosqueezing transform under complicated nonstationary noise
Hau-Tieng Wu, Zhou Zhou
We propose a bootstrapping framework to quantify uncertainty in time-frequency representations (TFRs) generated by the short-time Fourier transform (STFT) and the STFT-based synchr…
Probabilistic Analysis of Scalogram Ridges in Signal Processing
Gi-Ren Liu, Yuan-Chung Sheu, Hau-Tieng Wu
While ridges in the scalogram, determined by the squared modulus of analytic wavelet transform (AWT), is a widely accepted concept and utilized in nonstationary time series analysi…
Sleep Staging from Airflow Signals Using Fourier Approximations of Persistence Curves
Shashank Manjunath, Hau-Tieng Wu, Aarti Sathyanarayana
Sleep staging is a challenging task, typically manually performed by sleep technologists based on electroencephalogram and other biosignals of patients taken during overnight sleep…
Landmark Alternating Diffusion
Sing-Yuan Yeh, Hau-Tieng Wu, Ronen Talmon +1
Alternating Diffusion (AD) is a commonly applied diffusion-based sensor fusion algorithm. While it has been successfully applied to various problems, its computational burden remai…
Convergence analysis of t-SNE as a gradient flow for point cloud on a manifold
Seonghyeon Jeong, Hau-Tieng Wu
We present a theoretical foundation regarding the boundedness of the t-SNE algorithm. t-SNE employs gradient descent iteration with Kullback-Leibler (KL) divergence as the objectiv…
Design a Metric Robust to Complicated High Dimensional Noise for Efficient Manifold Denoising
Hau-Tieng Wu
In this manuscript, we propose an efficient manifold denoiser based on landmark diffusion and optimal shrinkage under the complicated high dimensional noise and compact manifold se…
Unveil Sleep Spindles with Concentration of Frequency and Time
Riki Shimizu, Hau-Tieng Wu
Objective: Sleep spindles contain crucial brain dynamics information. We introduce the novel non-linear time-frequency analysis tool 'Concentration of Frequency and Time' (ConceFT)…
Enhancing Missing Data Imputation of Non-stationary Signals with Harmonic Decomposition
Joaquin Ruiz, Hau-tieng Wu, Marcelo A. Colominas
Dealing with time series with missing values, including those afflicted by low quality or over-saturation, presents a significant signal processing challenge. The task of recoverin…
Ridge detection for nonstationary multicomponent signals with time-varying wave-shape functions and its applications
Yan-Wei Su, Gi-Ren Liu, Yuan-Chung Sheu +1
We introduce a novel ridge detection algorithm for time-frequency (TF) analysis, particularly tailored for intricate nonstationary time series encompassing multiple non-sinusoidal…
Convergence of Hessian estimator from random samples on a manifold with boundary
Chih-Wei Chen, Hau-Tieng Wu
A common method for estimating the Hessian operator from random samples on a low-dimensional manifold involves locally fitting a quadratic polynomial. Although widely used, it is u…