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The inversion of parameters characterizing reservoir property based on rock physics model is an important content in seismic exploration, while the strong nonlinearity between basic parameters and seismic attributes makes it challenging in practice or computationally expensive. This study focuses on the issue of wave propagation in porous media saturated with two immiscible fluids and proposes to utilize deep neural network (DNNs)-based surrogate model to conduct forward analysis and parameter inversion. First, three classical rock physics models were employed to generate the dataset for training DNNs. Among them, five basic parameters (the porosity, bulk modulus and shear modulus of rock matrix, the solid density, and the saturation) were sampled within each reasonable range, and then, the corresponding phase velocity and inverse quality factor of seismic wave were calculated based on the three models. Next, DNNs were trained as surrogate models of the three rock physics models for sensitivity analysis. Then, such approach was applied to parameter inversion and different scenarios with different provided information and unknown quantities were designed to investigate the feasibility. The results showed the sensitivity of different models to basic parameters determines the corresponding inversion accuracy. When providing the information on the compressional wave, the porosity can be well inferred in most cases, while the accuracies of inverting saturation based on different models vary. Furthermore, it was found that adding the information of the shear wave can improve the performance of parameter inversions to a high level. From the obtained results, it was concluded that the DNNs-based surrogate models can serve as efficient tools for forward and inverse problems. [ABSTRACT FROM AUTHOR]

In this work the homogeneous and isotropic Universe of Friedmann-Robertson-Walker is studied in the presence of two fluids: stiff matter and radiation described by the Schutz's formalism. We obtain to the classic case the behaviour of the scale factor of the universe. For the quantum case the wave packets are constructed and the wave function of the universe is found. [ABSTRACT FROM AUTHOR]

In the present paper, we have considered the Friedmann-Robertson-Walker universe in the frame work of f( R) gravity. The source of the gravitational fluid is the two co-moving perfect fluids: one fluid represents the matter content of the universe and the other modeling the cosmic microwave background radiation. Interacting and non-interacting cases of the two fluids are investigated. It is found that the universe is closed in the non-interacting Zeldovich fluid model and it is open at the present in the dust fluid model, whereas in interacting models, there is energy transfer from the radiation era to the matter era. Dynamical and kinematical properties of the models are also discussed. [ABSTRACT FROM AUTHOR]

Present paper deals with Axially Bianchi type-I Mesonic cosmological models with two fluid sources in Lyra Geometry. In the model one of the fluids represents the matter content of the universe and another fluid is the CMB radiation. For this purpose we have solved the field equations by considering time varying displacement field and uniform displacement field. We have also investigated the behaviours of some physical parameters. [ABSTRACT FROM AUTHOR]

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Tilted homogeneous plane symmetric two fluids cosmological models with matter and radiating source are investigated. In the model one of the fluids represents the matter content of the universe and another fluid is the CMB radiation. The tiltedness is also considered .With the help of variation for Hubble's parameter proposed by Bermann a cosmological model with negative constant deceleration parameter is obtained. We have also investigated the behaviours of some physical parameters. [ABSTRACT FROM AUTHOR]

We have presented anisotropic, homogeneous two-fluid cosmological models using Bianchi type-V space-time. Here one fluid represents the matter content of the universe and another fluid is chosen to model the CMB radiation. The radiation and matter content of the universe are in interactive phase. Also we have discussed the behavior of fluid parameters and kinematical parameters. [ABSTRACT FROM AUTHOR]