AIM We report on the corporal rotation technique, customized for the management of ventral curvature in patients without hypospadias. METHODS A male patient with ventral curvature of 90 degrees was operated on. The neurovascular bundle was mobilized for a short distance at the point of maximum curvature. The corpora cavernosa were approximated to each other in the dorsal midline by suturing p...

We investigated whether observers use rate of change of curvature in visually extrapolating contour shape. Arcs of Euler spirals with positive or negative rate of change of curvature gamma (hence linearly increasing or decreasing curvature) disappeared behind the straight-edge of a half-disk occluder. Observers adjusted the position and the orientation of a line probe around the curved portion ...

A method of Hurwitz-Radon Matrices (MHR) is proposed to be used in parametrization and interpolation of contours in the plane. Suitable parametrization leads to curvature calculations. Points with local maximum curvature are treated as feature points in object recognition and image analysis. The matrices are skew-symmetric and possess columns composed of orthogonal vectors. The operator of Hurw...

The use of derivatives in geomorphometry is reviewed. For first and second derivatives (slope and curvatures) of the land surface, represented by a square-grid DEM, use of a quadratic based on nine points is recommended. For detailed analysis of slope gradient, maximum slope (based on two points) may be useful: but only if the DEM is very accurate. For curvature, streamline (rotor) curvature sh...

We prove that C∞ curves of constant curvature satisfy, in the sense of Gromov, the relative C-dense h-principle in the space of immersed curves in Euclidean space Rn≥3. In particular, in the isotopy class of any given C knot f there exists a C∞ knot e f of constant curvature which is C-close to f . More importantly, we show that if f is C, then the curvature of e f may be set equal to any const...

One of the most fundamental problems in submanifold theory is to establish simple relationships between intrinsic and extrinsic invariants of the submanifolds (cf. [6]). A general optimal inequality for submanifolds in Riemannian manifolds of constant sectional curvature was obtained in an earlier article [5]. In this article we extend this inequality to a general optimal inequality for arbitra...

Abstract. Given a family of biholomorphisms φt on a noncompact complex manifold M , we provide conditions, on φt, under which M is biholomorphic to C. As an application, we generalize previous results in [1]. We prove that if (M, g) is a complete non-compact gradient Kähler-Ricci soliton with potential function f which is either steady with positive Ricci curvature so that the scalar curvature ...

An infrared-imaging system has been used to study the influence of gravity on the kinetics of first positive phototropism. The development of phototropic curvature of etiolated seedlings of Arabidopsis thaliana was measured in the absence of visible radiation. Following a pulse of blue light, stationary seedlings curved to a maximum of approximately 160 about 80 minutes after stimulation. The s...

This paper proposes a multi-optimization approach to the autonomous parking of car-like vehicles. It uses a polynomial curve primitive — the η-spline — to build up intrinsically feasible path maneuvers over which to minimize with a weighted sum method the total length of parking paths and the moduli of the maximum path curvature and curvature derivative. The approach takes into account the mand...

We consider properties of the total absolute geodesic curvature functional on circle immersions into a Riemann surface. In particular, we study its behavior under regular homotopies, its infima in regular homotopy classes, and the homotopy types of spaces of its local minima. We also consider the total curvature functional on the space of 2-sphere immersions into 3-space in a similar spirit. We...