نتایج جستجو برای: velocity analysis

تعداد نتایج: 2931287  

2001
Jamie D. Shutler Mark S. Nixon

New Zernike velocity moments have been developed to describe an object, not only by its shape , but also by its motion throughout an image sequence. These are an extended form of the orthogonal Zernike moment set and include velocity information introduced via centralised moments. Initial analysis shows that they perform well when applied to analysing gait sequences resulting in a good recognit...

1997
Patrick Huynh Tatsuo Arai

In order to analyse the maximum velocity of parallel maniprdators in operational space, a graphical method based on the analysis of the algebraic inequalities describing the constraints on the kinematics mode[ is presented. We consider a general 6 d. of parallel manipulator and assume that all articrdar velocities are bounded by the same limit. The method is then applied to the Conventional Ste...

1997
Zhenyue Liu

Prestack depth migration provides a powerful tool for velocity analysis in complex media. Both prominent approaches to velocity analysis—depth-focusing analysis and residual-curvature analysis, rely on approximate formulas to update velocity. Generally, these formulas are derived under the assumptions of horizontal reflector, lateral velocity homogeneity, or small offset. Therefore, the convent...

2003
Hume A. Feldman Richard Watkins Adrian Melott

We describe a new method of overcoming problems inherent in peculiar velocity surveys by using data compression as a filter with which to separate large–scale, linear flows from small– scale noise that biases the results systematically. We demonstrate the effectiveness of our method using realistic catalogs of galaxy velocities drawn from N–body simulations. Our tests show that a likelihood ana...

2003
Andrés Pech

Oil, gas, and geothermal reservoirs, and overlying strata are often composed of anisotropic rocks. Proper treatment of anisotropy during the processing of seismic data not only helps to avoid distortions in reservoir imaging, but also provides estimates of the anisotropic coefficients, which carry valuable information about lithology and fracture networks. Accurate estimation of the velocity mo...

2011
Yunyue Li Biondo Biondi

Anisotropic models are recognized as a more realistic representation of the subsurface where complex geological environment exists. These models are widely needed by all kinds of migration and interpretation schemes. However, anisotropic model building is still a challenging problem in the industry. In this paper, we propose an approach to building anisotropic models from surface seismic data b...

2007
William W. Symes

Waveform (output least squares) inversion of seismic reflection data can reconstruct remarkably detailed models of subsurface structure, and take into account essentially any physics of seismic wave propagation that can be modeled. However the waveform inversion objective has many spurious local minima, hence convergence of descent methods (mandatory because of problem size) to useful Earth mod...

1998
Jinming Zhu Larry Lines Sam Gray

Reliable seismic depth migrations require an accurate input velocity model. Inaccurate velocity estimates will distort point diffractors into smiles or frowns on a depth section. For both poststack and prestack migrated sections, high velocities cause deep smiles while low velocities cause shallow frowns on migrated gathers. However, for prestack images in the offset domain, high velocities cau...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2004
Katsuya Watanabe Masayori Suwa Hitoshi Watarai

We propose a novel principle of velocity mass analysis of a micro-particle using magnetophoretic force. The new method can determine the mass of a particle from its magnetophoretic velocity change in a high magnetic field gradient in a low viscous medium such as air. In the present study, the new principle was demonstrated by the magnetophoretic acceleration of an aqueous manganese(II) chloride...

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