Emin Kasap

Parametric representation of a surface pencil with a common asymptotic curve

In this paper, we study the problem of finding a surface pencil from a given spatial asymptotic curve. We obtain the parametric representation for a surface pencil whose members have the same curve as a given asymptotic curve. Using the Frenet frame of the given asymptotic curve, we present the surface as a linear combination of this frame and analyse the necessary and sufficient condition for that curve to be asymptotic. We illustrate this method by presenting some examples.

A generalization of surfaces family with common spatial geodesic

Abstract We analyzed the problem of constructing a surfaces family from a given spatial geodesic curve as in the work of Wang et al. [G.-J. Wang, K. Tang, C.-L. Tai, Parametric representation of a surface pencil with a common spatial geodesic, Comp. Aided Des. 36 (5) (2004) 447–459], who derived the sufficient condition on the marching-scale functions for which the curve C is an isogeodesic curve on a given surface. They assumed that these functions have a factor decomposition. In this work, we generalized their assumption to more general marching-scale functions and derived the sufficient conditions on them for which the curve C is an isogeodesic curve on a given surface. Finally using generalized marching-scale functions, we demonstrated some surfaces about subject.

Mannheim Offsets of Ruled Surfaces

In a recent works Liu and Wang (2008; 2007) study the Mannheim partner curves in the three dimensional space. In this paper, we extend the theory of the Mannheim curves to ruled surfaces and define two ruled surfaces which are offset in the sense of Mannheim. It is shown that, every developable ruled surface have a Mannheim offset if and only if an equation should be satisfied between the geodesic curvature and the arc-length of spherical indicatrix of it. Moreover, we obtain that the Mannheim offset of developable ruled surface is constant distance from it. Finally, examples are also given.

A numerical study for computation of geodesic curves

Consideration is given to the numerical computation of geodesic on surfaces. The method of finite-difference is used for governing non-linear system of differential equations. Then the resulting non-linear algebraic equations are solved by both iterative and Newtons method. It is shown that iterative method (IM) gives better result than Newtons method. Finally, we demonstrated our finding on several surfaces.

Surfaces with common geodesic in Minkowski 3-space

In this paper, we analyzed the problem of constructing a family of surfaces from a given spacelike (or timelike) geodesic curve. Using the Frenet trihedron frame of the curve in Minkowski space, we express the family of surfaces as a linear combination of the components of this frame, and derive the necessary and sufficient conditions for the coefficients to satisfy both the geodesic and the isoparametric requirements. Finally, examples are given to show the family of surfaces with common geodesic.

Surfaces family with common null asymptotic

We analyzed the problem of finding a surfaces family through an asymptotic curve with Cartan frame. We obtain the parametric representation for surfaces family whose members have the same as an asymptotic curve. By using the Cartan frame of the given null curve, we present the surface as a linear combination of this frame and analyzed the necessary and sufficient condition for that curve to satisfy the asymptotic requirement. We illustrate the method by giving some examples.

SURFACE PENCIL WITH A COMMON LINE OF CURVATURE IN MINKOWSKI 3-SPACE

In this paper, we analyze the problem of constructing a surface pencil from a given spacelike (timelike) line of curvature. Using the Frenet frame of the given line of curvature in Minkowski 3-space, we express the surface pencil as a linear combination of this frame and derive the necessary and sufficient conditions for the coefficients to satisfy the line of curvature requirement. We illustrate this method by presenting some examples.

Structure and characterization of ruled surfaces in Minkowski 3-space

Abstract In this paper, we consider non developable ruled surface with spacelike ruling, timelike ruling, respectively. We give the relations between the structure functions with the curvature and torsion of the striction line of the timelike and spacelike non developable ruled surfaces. Also, we have calculated the gaussian and mean curvatures of timelike and spacelike non developable ruled surfaces using the structure functions.

Intrinsic equations for a relaxed elastic line of second kind on an oriented surface

Let α(s) be an arc on a connected oriented surface S in E3, parameterized by arc length s, with torsion τ and length l. The total square torsion H of α is defined by H =∫0lτ2ds. The arc α is called a relaxed elastic line of second kind if it is an extremal for the variational problem of minimizing the value of H within the family of all arcs of length l on S having the same initial point and initial direction as α. In this study, we obtain differential equation and boundary conditions for a relaxed elastic line of second kind on an oriented surface.

Hypersurface Family with a Common Isoasymptotic Curve

We handle the problem of finding a hypersurface family from a given asymptotic curve in . Using the Frenet frame of the given asymptotic curve, we express the hypersurface as a linear combination of this frame and analyze the necessary and sufficient conditions for that curve to be asymptotic. We illustrate this method by presenting some examples.