In this paper, an analytical formula to calculate the radial stiffness of groove elastic support is presented. The influence of structure parameters on radial stiffness and homogeneity of radial stiffness is investigated as well. The accuracy and calculating speed of the analysis formula are compared to that of finite element method (FEM). Findings are as following: The calculating speed of ana...

Imaging in complex media benefits from uniform illumination of the target from all possible directions. Moreover, it is desirable to recover reflectivity from seismic data as a function of incidence and azimuthal angles at every location over the reflector. Applications of angle-dependent reflectivity include velocity and anisotropy estimation and amplitude versus angle (AVA) analysis. One way ...

Recently, Wu et al. proposed a scheme for twodimensional (2-D) direction of arrival angle estimation (DOA) for azimuth and elevation angles, using the propagator method (PM). An advantage of this method over the classical subspace based algorithms, such as ESPRIT and MUSIC, is that it does not apply any eigenvalue decomposition (EVD) to the cross spectral matrix or singular value decomposition ...

Obstacle recognition is one of the key technologies for Unmanned Undersea Vehicle (UUV). In this paper, the design of obstacle recognition based on multi-beam forward looking sonar is presented. First of all, Gaussian mixed model operator is adopted in adaptive threshold segmentation to segment the sonar image into regions of interest and background. Secondly, we use morphological operation to ...

This paper presents a novel method for the two-dimensional direction of arrival (DOA) estimation based on QR decomposition. A configuration with two uniform linear antenna arrays (ULAs) is employed for the joint estimation of elevation (θ) and azimuth (φ) angles. Q data matrix will estimate the azimuth angle while R data matrix will estimate the elevation angle. The proposed method utilizes onl...

The study of rotary steering drilling technology is currently one of the hot topics in the drilling engineering field. It requires accurate well trajectory control instructions when rotary steerable tools are applied to achieve the well trajectory control goal. A drilling trajectory prediction model will benefit this progress. According to the continuous beam theory, a mechanical model of push-...

Multiple overlapping cameras help to provide robust detection as well as 3-D localization of people in their field of view [2], cover their features from all directions, and handles the problems of occlusion. We propose a novel representation called Panoramic Appearance Map (PAM) for combining appearance information from multiple cameras tracking the same person. The map is a discretized 2-D ar...