Results 21 to 30 of about 1,433,403 (294)

Capturing the zero: a new class of zero-augmented distributions and multiplicative error processes [PDF]

, 2010
We propose a novel approach to model serially dependent positive-valued variables which realize a non-trivial proportion of zero outcomes. This is a typical phenomenon in financial time series observed on high frequencies, such as cumulated trading ...
Hautsch, Nikolaus, Malec, Peter, Schienle, Melanie   +2 more
core   +3 more sources

Fault Diagnosis of Induction Machines in a Transient Regime Using Current Sensors with an Optimized Slepian Window

Sensors, 2018
The aim of this paper is to introduce a new methodology for the fault diagnosis of induction machines working in the transient regime, when time-frequency analysis tools are used.
Jordi Burriel-Valencia, Ruben Puche-Panadero, Javier Martinez-Roman, Angel Sapena-Bano, Manuel Pineda-Sanchez   +4 more
doaj   +1 more source

Detection of Coherent Vorticity Structures using Time-Scale Resolved Acoustic Spectroscopy

, 1998
We describe here an experimental technique based on the acoustic scattering phenomenon allowing the direct probing of the vorticity field in a turbulent flow.
Arneodo, Baerg, Baudet, Benzi, Brachet, Choi, Christophe Baudet, Chu, Cohen, Colonius, Douady, Engler, Engler, Flandrin, Gilbert, Gromov, Hlawatsh, Ho, Jeong, Korman, Kraichnan, Lund, Lundgren, Lundgren, Nelkin, Noullez, Obukhov, Olivier Michel, Shafi, She, Tsinober, Wallace, Watkins, William J. Williams   +33 more
core   +2 more sources

Massively Multidimensional Diffusion-Relaxation Correlation MRI

Frontiers in Physics, 2022
Diverse approaches such as oscillating gradients, tensor-valued encoding, and diffusion-relaxation correlation have been used to study microstructure and heterogeneity in healthy and pathological biological tissues.
Omar Narvaez, Leo Svenningsson, Maxime Yon, Maxime Yon, Alejandra Sierra, Daniel Topgaard   +5 more
doaj   +1 more source

Time-periodic phases in populations of nonlinearly coupled oscillators with bimodal frequency distributions

, 1997
The mean field Kuramoto model describing the synchronization of a population of phase oscillators with a bimodal frequency distribution is analyzed (by the method of multiple scales) near regions in its phase diagram corresponding to synchronization to ...
Aronson, Bonilla, Bonilla, Bonilla, Bonilla, C.J. Pérez Vicente, Cole, Crawford, Dangelmayr, Gray, Kuramoto, Kuramoto, L.L. Bonilla, Lin, Lin, Lumer, Mirollo, Okuda, Pérez Vicente, R. Spigler, Sakaguchi, Sompolinsky, Strogatz, Strogatz, Strogatz, Strogatz, Tsang, Tsang, Winfree   +28 more
core   +1 more source

Joint time-frequency analysis on space-time-coding digital metasurfaces

JPhys Photonics, 2022
Space-time and time-varying metastructures have attracted a lot of research interest in recent years. On the other hand, digital programmable metasurfaces have also gained great attention owing to their powerful capabilities in controlling ...
Xiao Qing Chen, Lei Zhang, Yi Ning Zheng, Zhuo Ran Huang, Jing Cheng Liang, Tie Jun Cui   +5 more
doaj   +1 more source

Chaos in networks of coupled oscillators with multimodal natural frequency distributions

, 2019
We explore chaos in the Kuramoto model with multimodal distributions of the natural frequencies of oscillators and provide a comprehensive description under what conditions chaos occurs.
Gottwald, Georg A., Smith, Lachlan D.
core   +1 more source

Performance Comparison of Time-Frequency Distributions for Estimation of Instantaneous Frequency of Heart Rate Variability Signals

Applied Sciences, 2017
The instantaneous frequency (IF) of a non-stationary signal is usually estimated from a time-frequency distribution (TFD). The IF of heart rate variability (HRV) is an important parameter because the power in a frequency band around the IF can be used ...
Nabeel Ali Khan, Peter Jönsson, Maria Sandsten   +2 more
doaj   +1 more source

Time-frequency Domain Analogues of Phase Space Sub-Planck Structures

, 2007
We present experimental data of the frequency resolved optical gating (FROG) measurements of light pulses revealing interference features corresponding to sub-Planck structures in phase space.
Czesław Radzewicz, D. J. Kane, K. Husimi, K. Takahashi, K. W. DeLong, Krzysztof Wódkiewicz, L. Cohen, L. Praxmeyer, Ludmiła Praxmeyer, Piotr Wasylczyk, R. Trebino, W. P. Schleich   +11 more
core   +1 more source

Sample genealogies and genetic variation in populations of variable size

, 2009
We consider neutral evolution of a large population subject to changes in its population size. For a population with a time-variable carrying capacity we have computed the distributions of the total branch lengths of its sample genealogies.
Eriksson, A., Mehlig, B., Rafajlovic, M., Sagitov, S.   +3 more
core   +1 more source