We demonstrate a method for improving the accuracy of phase retrieval based on the Transport of Intensity equation by using intensity measurements at multiple planes to estimate and remove the artifacts due to higher order axial derivatives. We suggest two similar methods of higher order correction, ...
While sound pressure indicates the amplitude, it is a scalar quantity only. Sound intensity (or acoustic intensity) is vector quantity which indicates the flow of acoustic energy. Sound intensity has both a magnitude and direction. Figure 1: Examples of sound intensity measurement results on a ...
Duration of earthquake ground motion: Influence on structural collapse risk and integration in design and assessment practice Amplitude, frequency content, and duration are widely recognized as the key characteristicsof earthquake ground motions that influence structural response. Yet, incurrent structural de...
We apply amplitude inversion of small incident angle data to extract the fracture orientation (direction of isotropic plane of the medium) quite accurately. Knowing the fracture orientation, we modified the available linear PP reflection coefficient equation to invert for the anisotropy parameters (蔚~...
In the previous chapter, we constructed the sound pressures p ( x , t ) of both traveling waves and standing waves based on the acoustic wave equation. In this chapter, you will learn how to calculate flow velocity u ( x , t ), acoustic intensity, and specific acoustic impedance for gi...
Equation (A17) is the matrix Riccati equation describing the field in each section of an inhomogeneous medium when a mode of unit amplitude is incident this section. This field G(L; L) is the sum of the incident and backscattered fields in each cross section: G(L; L) = E + R(L; ...
The graph shows how light intensity is used as a sensing parameter and how this layout allows optical fibers to be used as vibration sensors. When vibrations occur, a small offset is inserted from one end to the other, which will make the vibration amplitude measurement intelligent. The ...
The amplitude of the hazard factor yi can assess the intensities of hazardous winds. yT is the optimal threshold of the classifier, it is obtained by the ROC curve in this work. The model defined in Eq. (1) consists of two steps. The first step is to learn cluster features for ...
Following a delta excitation, the fluorescence intensity de-excitation is given byIt=I0e−t/τ, with I0 the initial amplitude. Fluorescence lifetime measurement has been demonstrated either in frequency or time-domains. Time-resolved measurements in the frequency domain are based on the determinat...
Anthropogenic climate warming is predicted to increase the intensity of global tropical cyclones (TCs) on decadal timescales, known as the ‘temperature-TC intensity’ paradigm. However, no proxy is currently available to directly quantify TC intensity i