25 papers · ranked by Valyu relevance
Moisés Soto-Bajo, Andrés Fraguela Collar, Javier Herrera-Vega, Raúl Felipe-Sosa
'Raúl Felipe-Sosa'] Frequency is a central concept in Mathematics, Physics, and Signal Processing. It is the main tool for describing the oscillatory behavior of signals, which is usually argued to be the manifestation of some of their key features, depending on their nature. For instance, this is the case of…
Marek S. Kozień, Roberto Citarella
The application of the Fourier methods to perform cycle identification and description for different cases of bimodal stress histories are presented and discussed in the paper. The direct spectral method and the modified direct spectral method, previously co-proposed by the author, together with the aspects of the use…
Nathan Lenssen, Deanna Needell
Mathematics is a far reaching discipline and its tools appear in many applications. In this paper we discuss its role in music and signal processing by revisiting the use of mathematics in algorithms that can extract chord information from recorded music. We begin with a light introduction to the theory of music and…
Lukas P. A. Arts, Egon. L. van den Broek
The spectral analysis of signals is currently either dominated by the speed-accuracy trade-off or ignores a signal’s often non-stationary character. Here we introduce an open-source algorithm to calculate the fast continuous wavelet transform (fCWT). The parallel environment of fCWT separates scale-independent and…
Y. Zhou, A. Sheremet, Y. Qin, J.P. Kennedy + 2 more
Local field potential (LFP) oscillations are the superposition of excitatory/inhibitory postsynaptic potentials. In the hippocampus, the 20-55 Hz range (‘slow gamma’) is proposed to support cognition independent of other frequencies. However, this band overlaps with theta harmonics. We aimed to dissociate the…
M. S. Priyadarshini, Mohit Bajaj, Lukas Prokop, Milkias Berhanu
Electric power utilities must ensure a consistent and undisturbed supply of power, with the voltage levels adhering to specified ranges. Any deviation from these supply specifications can lead to malfunctions in equipment. Monitoring the quality of supplied power is crucial to minimize the impact of fluctuations in…
Y. Shiogai, A. Stefanovska, P.V.E. McClintock
The application of methods drawn from nonlinear and stochastic dynamics to the analysis of cardiovascular time series is reviewed, with particular reference to the identification of changes associated with ageing. The natural variability of the heart rate (HRV) is considered in detail, including the respiratory sinus…
Omkar Deshpande, Kharanshu Solanki, Sree Pujitha Suribhatla, Sanya Zaveri + 1 more
'Sanya Zaveri' 'Luv Ghodasara'] Since the evolution of digital computers, the storage of data has always been in terms of discrete bits that can store values of either 1 or 0. Hence, all computer programs (such as MATLAB), convert any input continuous signal into a discrete dataset. Applying this to oscillating…
Noah Shore
University of Galway School of Mathematical and Statistical Sciences This work presents a wavelet-based approach to time-frequency fingerprinting for time series feature extraction, with a focus on audio identification from live recordings of traditional Irish tunes. The challenges of identifying features in…
Pushpendra Singh
The Hilbert transform (HT) and associated Gabor analytic signal (GAS) representation are well known and widely used mathematical formulations for modelling and analysis of signals in various applications. In this study, like the HT, to obtain quadrature component of a signal, we propose novel discrete Fourier cosine…
Steven T. Homer, Nicholas Harley, Geraint A. Wiggins
We present a novel approach to representing perceptual and cognitive knowledge, spectral knowledge representation, that is focused on the oscillatory behaviour of the brain. The model is presented in the context of a larger hypothetical cognitive architecture. The model uses literal representations of waves to describe…
Norden E. Huang, Kun Hu, Albert C. C. Yang, Hsing-Chih Chang + 10 more
'Deng Jia' 'Wei-Kuang Liang' 'Jia Rong Yeh' 'Chu-Lan Kao' 'Chi-Hung Juan' 'Chung Kang Peng' 'Johanna H. Meijer' 'Yung-Hung Wang' 'Steven R. Long' 'Zhauhua Wu'] The Holo-Hilbert spectral analysis (HHSA) method is introduced to cure the deficiencies of traditional spectral analysis and to give a full informational…
Authors not listed
This report compares various simulation and data analysis methods for free induction decay (FID) signals in Nuclear Magnetic Resonance (NMR) Spectroscopy. The methods discussed include discrete fast Fourier transformation (FFT), least squares fitting (LSF), short-time Fourier transformation (STFT), and wavelet…
Jean Gaudart, Stanislas Rebaudet, Gaetan Texier, Robert Barrais + 2 more
The aim of the present study was to develop a method for multiscale analysis of non-stationary and non-periodic epidemic time series. Indeed, the epidemiologists may need to know the features, at different resolutions, of short duration outbreaks that did not exhibit periodic cycles. Among of the large number of…
Gregor Mönke, Frieda A. Sorgenfrei, Christoph Schmal, Adrián E. Granada
Methods for the quantification of rhythmic biological signals have been essential for the discovery of function and design of biological oscillators. Advances in live measurements have allowed recordings of unprecedented resolution revealing a new world of complex heterogeneous oscillations with multiple noisy…
Michael X Cohen
Morlet wavelets are frequently used for time-frequency analysis of non-stationary time series data, such as neuroelectrical signals recorded from the brain. The crucial parameter of Morlet wavelets is the width of the Gaussian that tapers the sine wave. This width parameter controls the trade-off between temporal…
Authors not listed
Time series data of atmospheric CO2 levels is highly autocorrelated with multiple timescale variations. In recent years, the data shows a persistent increase in these levels. To understand this persistence, we use enzyme activity and biological growth as analogous phenomena and draw comparisons with the atmospheric CO2…
Authors not listed
Purpose: The transmission Fourier-transform infrared (FTIR) spectrum contains complexed signals for molecular structures and intermolecular interactions. Their interrelated signals were attempted to be recognized using the singular value decomposition (SVD) procedure. Methods: Cimetidine (CIM) and indomethacin (INM)…
Authors not listed
Metastable states and the conformational transitions in between them are key to understanding dynamical behaviour and function of large-scale molecular systems. By combining basic dimensionality reduction techniques with a state-of-the art approximation of the Koopman operator associated to molecular dynamics…
Charles Eads
This report describes and illustrates a set of automatable multicomponent exponential relaxation analysis protocols that are model-agnostic and suited to extracting information under circumstances when little prior knowledge about the underlying system is used. Methods are illustrated and mathematical and physical…
Authors not listed
Electrochemical impedance spectroscopy (EIS) is a powerful analytical technique for studying electrochemical systems, offering broad frequency range coverage and straightforward implementation. However, EIS measurements at low frequencies are limited by both lengthy acquisition times and the risk of disrupting…
Noah Shore
University of Galway School of Mathematical and Statistical Sciences This work presents a wavelet-based approach to time-frequency fingerprinting for time series feature extraction, with a focus on audio identification from live recordings of traditional Irish tunes. The challenges of identifying features in…
Andrew J. Quinn, Vítor Lopes-dos-Santos, Norden Huang, Wei-Kuang Liang + 5 more
Non-sinusoidal waveform is emerging as an important feature of neuronal oscillations. However, the role of single cycle shape dynamics in rapidly unfolding brain activity remains unclear. Here, we develop an analytical framework that isolates oscillatory signals from time-series using masked Empirical Mode…
Damián Dellavale, Osvaldo Matías Velarde, Germán Mato, Eugenio Urdapilleta
Cross-frequency coupling (CFC) refers to the non linear interaction between oscillations in different frequency bands, and it is a rather ubiquitous phenomenon that has been observed in a variety of physical and biophysical systems. In particular, the coupling between the phase of slow oscillations and the amplitude of…
Amelia Carolina Sparavigna
In an article by Thibault et al., 2002, we can find measurements of Raman linewidths in the Q branch of carbon monoxide, for mixtures with Argon at different temperatures. A plot is available for the Q(5) line with a fitted Voigt function. Here we show that a q-Gaussian Tsallis function can be used for fitting this…