Problem of describing the function of a GPR source

In this paper, we consider the problem of determining the source h(t)δ(x) of electromagnetic waves from GPR data. The task of electromagnetic sensing is to find the pulse characteristic of the medium r(t) and consists in calculating the response of the medium to the pulse source of excitation δ(t) (Dirac Delta function). To determine the analytical expression of the impulse response of a homogeneous medium r(t), we use the method proposed in [1-2]. To determine h(t), the inverse problem is reduced to a system of Volterra integral equations. The source function h(τ), is defined as the solution of the Volterra integral equation of the first kind, f(t) = \int^t_0 r(t−τ)h(τ)dτ in which f(t) is the data obtained by the GPR at the observation points. The problem of calculating the function of the GPR source h(τ ) consists in numerically solving the inverse problem, in which the function of the source h(τ ) is unknown, and the electromagnetic parameters of the medium are known: the permittivity ε; the conductivity σ; the magnetic permeability µ and the response of the medium to a given excitation h(τ).

Study on Pulse Characteristic of Produced Crude Composition in CO2 Flooding Pilot Test

It has been observed in many laboratory tests that the carbon number of the maximum concentration components (CNMCC) of produced oil varies monotonically with CO2 injection volume at the core scale. However, in CO2 flooding pilot test at the field scale, we find that the CNMCC is usually nonmonotonic function of CO2 injection volume, which is called “pulse characteristic” of CNMCC. To investigate the mechanism of this phenomenon, we analyze the physical process of CO2 flooding in heterogeneous reservoir and explain the reason of the pulse characteristic of CNMCC. Moreover, two 3D reservoir models with 35 nonaqueous components are proposed for numerical simulation to validate the conjecture. The simulation results show that pulse characteristic of CNMCC only occurs in the heterogeneous model, confirming that the pulse characteristic results from the channeling path between wells, which yields nonmonotonic variation of oil-CO2 mixing degree. Based on it, a new method can be developed to identify and quantify the reservoir heterogeneity.

THE MAPPINGS OF VAN DER POL — DYUFFING GENERATOR IN DISCRETE TIME

In the work transition to discrete time in the equation of movement of van der Pol – Dyuffing generator is described. The transition purpose—to create mappings of the generator as subjects of the theory of nonlinear oscillations (nonlinear dynamics) in discrete time. The method of sampling is based on the use of counting of the pulse characteristic of an oscillatory contour as the sampling series for a signal in a self-oscillating ring ”active nonlinearity – the resonator – feedback”. The choice of the consecutive scheme of excitement of a contour allows to receive the iterated displays in the form of recurrent formulas. Two equivalent forms of discrete displays of the generator of van der Pol – Dyuffing—complex and valid are presented. In approximation of method of slow-changing amplitudes it is confirmed that the created discrete mappings have dynamic properties of an analog prototype. Also within the numerical experiment it is shown that in case of the high power of generation the effect of changing of frequencies of harmonicas of the generated discrete signal significantly influence dynamics of the self-oscillators. In particular, in the discrete generator of van der Pol – Dyuffing the chaotic self-oscillations are observed.

The Study on Continuous Blood Pressure Information Based on the Pulse Characteristic Parameters

Using the pressure sensor to extract the signal of human brachial artery pulse wave, a method of noninvasive and continuous measurement of blood pressure is realized by estimating the blood pressure of each pulse action based on the relevant characteristics of the pulse wave. The results of multiple stepwise regression analysis and blood pressure modeling show that the blood pressure measured by this method has a good consistency with that measured by mercury sphygmomanometer. And this method has very good application prospect in clinical and medical research.

The Pulse Characteristic Estimation of Optical Atmospheric Uv-Channel With Scattering

Last time optical atmospheric communication systems between objects without line of sight, due to the scattering of optical irradiation on the air particles are investigating by many laboratories. The distortion estimation of optical pulses during the atmospheric channel with scattering passing are discussed in this paper