GEOMETRIC AND ALGEBRAIC APPROACHES OF PLANAR STRUCTURE RECOVERY BASED ON PROPERTIES OF DUAL CONIC

In this article, approaches of planar Euclidean Structure recovery are proposed based on the geometric and algebraic characteristics of the dual conic. Algebraic relations between the matrix representation of the dual conic and the circular point enveloped are extensively analyzed, to attain a generalized framework for the problem. The dual conic has the decomposition with consistent geometric interpretation from which the circular point envelope can be solved. From the geometric viewpoint, based on the characteristics of the common elements of dual conics (their bitangents), a stratified approach is presented to establish the solution. Experiments on both synthetic and real images are conducted to demonstrate the robustness and accuracy of the presented approach.

Isoviscous elastohydrodynamic lubrication of circular point contacts with particular reference to metal-on-metal hip implants

A full numerical analysis of elastohydrodynamic lubrication (EHL) of circular point contacts was carried out in the present study under isoviscous conditions with particular reference to metal-on-metal artificial hip joints, using a modified Newton-Raphson method. It was found to be possible to incorporate directly the physiological conditions, representative of typical metal-on-metal hip implants under in-vivo walking or in-vitro simulator testing, in the present numerical solutions. The predicted minimum and central film thicknesses were compared favourably with those estimated from various formulae available in the literature. In particular, it was shown that both the minimum and the central film thickness expressions derived by Hamrock and Dowson were reasonably accurate for all the conditions considered in the present study.