Zheng Shen's research while affiliated with University of California, Irvine and other places

Publications (10)

Article
We survey the newly developed Hilbert spectral analysis method and its applications to Stokes waves, nonlinear wave evolution processes, the spectral form of the random wave field, and turbulence. Our emphasis is on the inadequacy of presently available methods in nonlinear and nonstationary data analysis. Hilbert spectral analysis is here proposed...
Article
Using a process denoted here as the empirical mode decomposition and the Hilbert spectral analysis, the ages of the seiches on the Caribbean coast of Puerto Rico are determined from their dispersion characteristics with respect to time. The ages deduced from this method are less than a day; therefore, the seiches could be locally generated.
Article
This paper is devoted to the quantization of the degree of nonlinearity of the relationship between two biological variables when one of the variables is a complex nonstationary oscillatory signal. An example of the situation is the indicial responses of pulmonary blood pressure (P) to step changes of oxygen tension (Delta pO(2)) in the breathing g...
Article
We survey the newly developed Hilbert spectral analysis method and its applications to Stokes waves, nonlinear wave evolution processes, the spectral form of the random wave field, and turbulence. Our emphasis is on the inadequacy of presently available methods in nonlinear and nonstationary data analysis. Hilbert spectral analysis is here proposed...
Article
Recently, a new method to analyze biological nonstationary stochastic variables has been presented. The method is especially suitable to analyze the variation of one biological variable with respect to changes of another variable. Here, it is illustrated by the change of the pulmonary blood pressure in response to a step change of oxygen concentrat...
Article
Almost all variables in biology are nonstationarily stochastic. For these variables, the conventional tools leave us a feeling that some valuable information is thrown away and that a complex phenomenon is presented imprecisely. Here, we apply recent advances initially made in the study of ocean waves to study the blood pressure waves in the lung....
Article
Almost all variables in biology are nonstationarily stochastic. For these variables, the conventional tools leave us a feeling that some valuable information is thrown away and that a complex phenomenon is presented imprecisely. Here, we apply recent advances initially made in the study of ocean waves to study the blood pressure waves in the lung....
Article
Full-text available
A new method for analysing nonlinear and non-stationary data has been developed. The key part of the method is the `empirical mode decomposition' method with which any complicated data set can be decomposed into a finite and often small number of 'intrinsic mode functions' that admit well-behaved Hilbert transforms. This decomposition method is ada...
Article
AbstractIt has long been recognized that the frequency downshift in the wave field evolution is a consequence of nonlinear wave-wave interactions and that the frequency downshift is also necessary for the wind wave field to grow. Yet the detailed mechanism for the frequency change is still unknown: Is the process continuous and gradual? Or, is the...
Article
A newly-formulated 18.2-year ice concentration time series for the entire Arctic and Antarctic ice covers, as well as for previously defined subregions consisting of 5 sectors in the Antarctic and 9 regions in the Arctic is analyzed by means of a recently patented procedure called "Empirical Mode Decompostion", with emphasis on periodicities greate...

Citations

... e town's leisure and sports culture features mainly fall into two categories: Fangchenggang sports features the town is mainly made up of sailing boats and motor boats on the water, and the beautiful south sports features the town is made up of fishing and kart competitions. e subsidies of stadiums and gymnasiums have a strong locational effect on urban development [18], and the influence of marketing on host cities is strongly correlated with the exposure of sports events [19], so national sports organizations can strengthen the sponsorship of sports towns [20]. ...
... Extracting useful information from large amounts of oscillatory data is important for a considerate number of real world applications such as medical electrocardiography (ECG) reading [1,2,3], atomic crystal images in physics [4,5], mechanical engineering [6,7], art investigation [8,9], geology [10,11,12], imaging [13], etc. In order to extract certain features and analyze adaptive components of oscillatory data, it is typical to assume that the signal f (t) consists of several oscillatory modes like ...
... Away from the wavemaker-generated frequency, the values of MSC gradually decrease. Huang et al. (1996Huang et al. ( , 1998 suggested an improved Hilbert-Huang transform (HHT) that is based on Empirical Mode Decomposition (EMD) and Hilbert transform. First, the EMD is applied to the original record as follows: ...
... Empirical modal decomposition (EMD) is a data processing method proposed firstly by Huang et al. [29]. It relies on the time-scale characteristics of the battery capacity data itself, i.e., adaptive basis functions to decompose the data without the need to give a specific basis function, which is essentially different from the Fourier transform and wavelet decomposition. ...
... Prior to this work, critical pulmonary circulation dynamics have few viable measurement methods. The gold standard is cardiac catheterization [40], [41], which requires significant setup and highly trained professionals as well as posing considerable risks. Another method is Doppler echocardiography to derive the pulmonary blood pressure through the velocity of the blood flow [4], [42], similar to our derivation. ...
... Each sequence is called an IMF. Each IMF should satisfy two conditions [28][29][30], namely, the difference between the number of local extreme points and zero points is not more than one; and at any time, the average value of upper envelope formed by the local maximum point and the lower envelope formed by the local minimum point is zero. The calculation process of EMD is as follows: ...
... In order to analyze the characteristics of the acoustic signals when the pipeline leakage occurs, empirical mode decomposition (EMD) is used in this study. EMD technology [12][13][14] submitted by Huang in 1998. is method is suitable for analyzing nonlinear and nonstationary signals. ...
... These oscillatory modes are termed intrinsic mode functions (IMF). The IMFs can be both amplitude and frequency modulated as well as nonstationary [23,24]. The τ of each IMFs has been identified by HHT. ...
... Empirical Mode Decomposition (EMD) [26] is an approach adapted to nonstationary time-frequency analysis and has been applied in several fields, namely, biological [27], marine environment [28], structural diagnosis [29], mechanical diagnosis faults [30], [31], and other domains based on one dimensional signal. In addition, Nunes et al. [32], [33] have Introduced EMD in image processing (twodimensional signal) and they have developed the algorithm for two-dimensional decomposition in empirical mode (BEMD). ...