A brute-force testing technique was applied on a robotic controlled-curvature flapping fin propulsor to investigate output thrust and power consumption trends with respect to flapping frequency, amplitude, and gait. It has been discovered that maximum thrust and maximum propulsive efficiency can coexist, that flapping frequency and amplitude are sometimes interdependent parameters, and that act...

This paper presents an algorithm of modifying free-formed NURBS curve/surface for offsetting without local self-intersecting. The method consists of (1) sampling a number of points from a progenitor curve/surface based on second derivatives; (2) checking the curvature or maximum curvature of the progenitor curve/surface at the sampled points; (3) inserting corresponding knots of sampled points;...

8. Introduction Critical points of distance functions Toponogov's theorem; first application:a Background on finiteness theorems Homotopy Finiteness Appendix. Some volume estimates Betti numbers and rank Appendix: The generalized Mayer-Vietoris estimate Rank, curvature and diameter Ricci curvature, volume and the Laplacian Appendix. The maximum principle Ricci curvature, diameter growth and fin...

With the development of highly-deviated well cementing techniques, rotating casing cementing technology has got more and more attention. The rotating casing technique can improve the displacement efficiency of cement paste, and then enhance the quality of well cementation. In the stuck section, the rotating casing can redress the well to make the casing run sequentially. The casing endures shea...

in this paper, the time-like hyperruled surfaces in the minkowski 4-space and their algebraicinvariants are worked. also some characteristic results are found about these algebraic invariants.

We fix a Finsler norm F and, using the anisotropic curvature flow, we prove that in plane maximum \(k^F_{\max }\) of smooth Jordan curve is such \( k^F_{\max }(\gamma )\ge \sqrt{\kappa /A}\), where A area enclosed by \(\gamma \) and \(\kappa unitary Wulff shape associated to anisotropy F.