Results 271 to 280 of about 462,768 (332)

Time–frequency characteristic analysis method for track geometry irregularities based on multivariate empirical mode decomposition and Hilbert spectral analysis

Vehicle System Dynamics, 2020
The description and evaluation of track geometry irregularities are commonly performed in the distance domain or the frequency domain, and therefore one cannot simultaneously obtain precise measurements of actual frequencies and the distance locations ...
Youtao Yang, Guoxiang Liu, Xiaowen Wang
semanticscholar   +1 more source

Spectral Analysis of Integrodifferential Equations in Hilbert Spaces

Journal of Mathematical Sciences, 2019
The authors consider a second order abstract integrodifferential equations with unbounded operator coefficients in a Hilbert space. They provide the spectral analysis of operator-functions describing symbols of such equations. These equations are an abstract form of linear partial integrodifferential equations arising in the viscoelasticity theory and ...
Vlasov, V. V., Rautian, N. A.
openaire   +2 more sources

Spectral Analysis in Hilbert Space

2020
After some years of observed radioactivity, Gamow (Gamow (1928)) wrote down a formula in quantum mechanics that was supposed to govern the decay of the nucleus of an atom into a lighter nucleus with the emission of an alpha particle (helium atoms without their electron cloud, i.e. ionized helium).
Lawrence Horwitz, Yosef Strauss
openaire   +1 more source

Time-frequency composition of mosquito flight tones obtained using Hilbert spectral analysis.

The Journal of the Acoustical Society of America, 2014
Techniques for estimating temporal variation in the frequency content of acoustic tones based on short-time fast Fourier transforms are fundamentally limited by an inherent time-frequency trade-off. This paper presents an alternative methodology, based on Hilbert spectral analysis, which is not affected by this weakness, and applies it to the accurate ...
Andrew Aldersley, A. Champneys, M. Homer, D. Robert   +3 more
semanticscholar   +4 more sources

Terahertz Applications of Hilbert-Transform Spectral Analysis

IEEE Transactions on Applied Superconductivity, 2014
Bridging of the terahertz gap in the electromagnetic spectrum between the microwave and infrared ranges requires a variety of new technological developments from basic elements, such as emitters and detectors, to complete systems, such as spectrum analyzers and imagers.
Yuriy Divin, Alexander Snezhko, Matvey Lyatti, Ulrich Poppe, Valery Pavlovskiy   +4 more
openaire   +1 more source

Analyses of EEG Oscillatory Activities During Slow and Fast Repetitive Movements Using Holo-Hilbert Spectral Analysis

IEEE transactions on neural systems and rehabilitation engineering, 2018
Neural oscillatory activities existing in multiple frequency bands usually represent different levels of neurophysiological meanings, from micro-scale to macro-scale organizations.
Hao-Teng Hsu, Wai-Keung Lee, K. Shyu, T. Yeh, Chun-Yen Chang, Po-Lei Lee   +5 more
semanticscholar   +1 more source

Hilbert-Huang Spectral Analysis of Natural Wind Speed

Applied Mechanics and Materials, 2011
The basic concepts and theories of Hilbert-Huang-Transformation (HHT) for signal analysis is introduced and its implementation procedure is programmed. For the collected three orthogonal directions wind speed signals at a measuring point at Sutong Bridge site, Empirical Mode Decomposition (EMD) is conducted to extract the Intrinsic Mode Functions (IMFs)
Fu You Xu, Ai Rong Chen, Wen Juan Lou, Zhe Zhang   +3 more
openaire   +1 more source

Analysis of depth of anesthesia with Hilbert–Huang spectral entropy

Clinical Neurophysiology, 2008
Monitoring the effect of anesthetic drug on the neural system is an ongoing challenge for anesthetists. Several methods based on the electroencephalogram (EEG) have been proposed to estimate the depth of anesthesia (DoA); for instance, the Fourier-based time-frequency balanced spectral entropy as implemented in the Datex-Ohmeda M-Entropy Module.
Xiaoli, Li, Duan, Li, Zhenhu, Liang, Logan J, Voss, Jamie W, Sleigh   +4 more
openaire   +2 more sources

Spectral Analysis in Hilbert Space

1978
From the last result of the preceding chapter, a good deal of nontrivial information can be obtained about self-adjoint operators on Hilbert space, incomparably more than is available for operators in Banach spaces, other than those of special compactness properties, or for arbitrary (non-self-adjoint) operators on Hilbert space.
Irving E. Segal, Ray A. Kunze
openaire   +1 more source

The Hilbert-Huang Spectral Analysis Method Applied to VIV

Volume 4: Terry Jones Pipeline Technology; Ocean Space Utilization; CFD and VIV Symposium, 2006
Vortex-Induced Vibration (VIV) is a highly nonlinear dynamic phenomenon. Usual spectral analysis methods rely on the hypotheses of linear and stationary dynamics. A new method envisaged to treat nonlinear and non-stationary signals was presented by Huang et al.
Celso P. Pesce, Andre´ L. C. Fujarra, Leonardo K. Kubota   +2 more
openaire   +1 more source