This reasoning also helps explain why the catalog uses a spherical coordinate system, which Chinese astronomers adopted after inventing the armillary sphere — a device consisting of interlocking ...

https://math.libretexts.org/Bookshelves/Calculus/Book:_Vector_Calculus_(Corral)/04:_Line_and_Surface_Integrals/4.06:_Gradient_Divergence_Curl_and_Laplacian ...

Thus, RTK is employed in this study to obtain 3D coordinates (longitude ... long column, plate, spherical, and square. Furthermore, the instability movement was conducted on a slope with an ...

The gradient permittivity is achieved ... while the transformation of the x-coordinate are essentially expanded, so that the long axis of the ellipse can be controlled to be R. A spherical lens can be ...

we propose a density-weighted and cross-gradient constrained (DWCG) joint inversion method in the sphere coordinate, which improves the inversion accuracy by introducing a density structural ...

When the refractive index is independent of the coordinates in the medium ... [2] Gordon, J.M. (2000) Spherical Gradient Index Lenses as Perfect Imaging and Maximum Power Transfer Devices. Applied ...