The direct coordinate transformation method, which only transforms independent variables and retains Cartesian dependent variables, may not be an appropriate method for the purpose of simplifying the curvilinear parabolic approximation of the vector form of the wave–current equation given by Kirby [Higher-order approximations in the parabolic equation method for water waves, J. Geophys. Res. 91...

This paper proposes a novel approach to segment three dimensional curvilinear structures, particularly vessels in angiography, by inspecting the symmetry of image gradients. The proposed method stresses the importance of simultaneously considering both the gradient symmetry with respect to the curvilinear structure center, and the gradient antisymmetry with respect to the object boundary. Measu...

Curvilinear targets are common in many imaging modalities. Detection of such targets can be challenging because of their multiscale structure, their frequent obscuration in natural imagery, their turns, intersections, and merges, and the prevalence of false positive detections based on local information. Using a spatial spectroscopy approach, we introduce image analysis methods that use the con...

Image preprocessing algorithms for improving the performance of breast cancer detection algorithm have been evaluated and their performance are reported in this paper. Those algorithms are implemented successfully in different sequence combination, those are (i) intensity adjustment before removal of curvilinear structure and (ii) intensity adjustment after removal of curvilinear structure. Int...

primary assumption in most problems of elasticity theory in petroleum geophysics is that the elastic media is isotropic. laboratory experiments confirmed that most rocks are anisotropic. if in one medium, properties vary with directions, it is named as anisotropic. knowledge about anisotropy reduces risk and cost of hydrocarbon production. in the present study, anisotropy of a carbonate reservo...

Curvilinear tooth gears are commonly produced on a face milling cutter and a hob cutter. However, this paper proposes a kind of curvilinear tooth gear which is processed by a parallel linkage with a single blade cutter. For the purpose of identifying the meshing and contact characteristics of curvilinear tooth gears, the paper covers the following: (i) equations of tooth surfaces are deduced fr...

Heart valve tissue engineering (HVTE) aims to provide living autologous heart implants endowed with regenerative capabilities and life-long durability. However, fabrication of biomimetic scaffolds capable providing the required functionality in terms mechanical performance tunable porosity enable cellular infiltration remains a major challenge. Here, additive manufacturing bioinspired, spatiall...