A5103001070- Seismic Waves and Analysis
- Seismic Imaging and Inversion Techniques
- Geophysical Methods and Applications
- Underwater Acoustics Research
- Drilling and Well Engineering
- Ultrasonics and Acoustic Wave Propagation
- Acoustic Wave Phenomena Research
- Geotechnical Engineering and Underground Structures
- Flow Measurement and Analysis
- Methane Hydrates and Related Phenomena
- Geotechnical and Geomechanical Engineering
- Hydraulic Fracturing and Reservoir Analysis
- Numerical methods in engineering
- Optical measurement and interference techniques
- AI and Multimedia in Education
- Acoustic Wave Resonator Technologies
- Geophysics and Sensor Technology
- Oil and Gas Production Techniques
- Coastal and Marine Dynamics
- Advanced MEMS and NEMS Technologies
- Underwater Vehicles and Communication Systems
- Video Surveillance and Tracking Methods
- Electromagnetic Simulation and Numerical Methods
- Advanced Thermoelectric Materials and Devices
- Semiconductor materials and interfaces
China University of Mining and Technology
2021-2025
Hebei University
2024
Beijing University of Chemical Technology
2021
Institute of Acoustics
2009-2020
University of Chinese Academy of Sciences
2019-2020
Chinese Academy of Sciences
2008-2019
State Key Laboratory of Acoustics
2011-2012
World Wide Web Consortium
1996
Academia Sinica
1994
Small-object detection is a challenging task in computer vision due to the limited training samples and low-quality images. Transfer learning, which transfers knowledge learned from large dataset small dataset, popular method for improving performance on data. However, we empirically find that discrepancy, directly transferring model trained general object small-object datasets obtains inferior performance. In this paper, propose TranSDet, novel approach effective transfer learning...
Hollow cylinders often exhibit backward propagation modes whose group and phase velocities have opposite directions, these a minimum possible frequency at which the velocity vanishes nonzero wavenumber. These zero-group-velocity (ZGV) points are associated with resonant conditions in medium. On basis of ZGV resonances, non-contact laser ultrasound technique has been developed to measure elastic constants hollow pipes. This paper provides theoretical numerical investigation influence...
The acoustic problem of an eccentric drill collar in a fluid-filled borehole has been interest the field logging while drilling (ALWD) recent years. To reduce effects tool eccentricity on ALWD measurements, studies responses under such conditions are essential. This study therefore developed analytical method to investigate wavefields with off-center monopole fast and slow formations. By evaluating contributions compressional shear branch points, individual formation primary head waves...
Coal gangue sorting is an important part of the construction smart mines. At present, coal identification and detection algorithms are mostly based on laboratory simulations for testing. Under actual working conditions, there problems such as missed poor real-time performance. In response to this problem, improved YOLOv5 recognition algorithm was proposed, a live image acquisition system designed. First, Mosaic data enhancement used increase sample diversity, Add attention moudle improve...
It is known that modes in axially uniform waveguides exhibit backward-propagation characteristics for which group and phase velocities have opposite signs. For elastic plates, of backward Lamb waves depend only on Poisson's ratio. This paper explores ways to achieve a large velocity mode hollow cylinders by changing the outer inner radius ratio, order such with strong may be used acoustic logging tools. Dispersion spectra guided varying radii are numerically simulated explore existence...
Abstract Understanding acoustic wave propagation in an inclined fluid–filled borehole embedded 3‐D media is essential for logging data processing and interpretation. A staggered finite‐difference (FD) method used to simulate sonic waves isotropic layered formations. First, the FD results are compared with those obtained by a Real Axis Integration monopole source open vertically imbedded homogeneous formation. good agreement has been made two methods. Consequently, solutions confirmed...
Abstract Hydrocarbon reservoirs are composite multiphase media with gas and /or liquid contained in the voids between solid grains. Understanding elastic wave propagation such a formation is important for petroleum exploration development, especially full acoustic‐wave logging. In this work, instead of using displacement‐stress finite‐difference scheme fourth‐order space second order time, an improved explicit eighthorder staggered algorithm time poroelastic was proposed to enhance...
Based on existing direct and imaging methods of a staggered finite-difference scheme, an improved algorithm for is proposed to implement rugged topographic free boundary conditions. This method assumes that the surface can be implemented with horizontal vertical segments their corners; passes through grid points shear stress components, instead normal components. Imaging carried out components in both directions, thus increasing accuracy. To update particle- velocities, updating are first...
Abstract Based on the Biot theory we use a high‐order staggered finite‐difference algorithm to carry out numerical experiments wave propagation in rock sample partially saturated by multi‐phase fluids with random fluid distributions. The ultrasonic source frequencies are 25, 50, 75kHz and 100kHz, respectively. first modeling is homogeneous isotropic sandstone filled two phase pore (water gas), which defined their different elastic characteristic parameters of saturation, viscosity,...
The longitudinal wave velocity and attenuation measurements of artificial gas hydrate samples at a low temperature are reported. And the pressure dependence is also investigated. In order to understand acoustic properties hydrate, pure ice, tetrahydrofuran (THF), sand sediment containing measured between 0°C −15°C. For THF samples, whose density 898 kg/m3, 895 kg/m3 475 respectively 3574 m/s, 3428 m/s 2439 m/s. synthesized compacted lower than that samples. velocities increase when densities...
A new prototype of ultrasonic flowmeter used in the oil well is presented. The depends on time delay between propagating times downstream and upstream pulses. passageway slanted to prevent disadvantage introduced by high viscosity oil. Two method estimation: threshold cross-correlation are both studied realized.