conclusions it seems that considering the clinical examination of patients before sa focusing on lumbar spinous process status, presence of lumbar deformity, calculation of bmi and radiological signs of lumbar vertebrae can be helpful in predicting sa difficulty. results hundred and one patients were enrolled. of these patients, 50 (49.5%) underwent sa by the first attempt of the first space, i...

A space-filling curve is a linear traversal of a discrete finite multidimensional space. In order for this traversal to be useful in many applications, the curve should preserve "locality". We quantify "locality" and bound the locality of multidimensional space-filling curves. Classic Hilbert space-filling curves come close to achieving optimal locality.

We describe a method, based on vertex-labeling, to generate algorithms for manipulating the Hilbert space lling curve in the following ways: 1. Computing the image of a point in R. 2. Computing a pre-image of a point in R. 3. Drawing a nite approximation of the curve. 4. Finding neighbor cells in a decomposition ordered according to the curve. Our method is straightforward and exible, resulting...

Space curve sketching using 2D user interface is a challenging task and forms the foundation for almost all sketch based modeling systems. Since the inverse projection from 2D to 3D is a one to many function, there is no unique solution. In this paper, we propose to interpret the given 2D curve to be the projection of the 3D curve that has minimum curvature among all the candidates in 3D. We pr...

The Mortonor z-curve is one example for a space filling curve: Given a level of refinement L ∈ N0, it maps the interval [0, 2)∩Z one-to-one to a set of d-dimensional cubes of edge length 2−L that form a subdivision of the unit cube. Similar curves have been proposed for triangular and tetrahedral unit domains. In contrast to the Hilbert curve that is continuous, the Morton-type curves produce j...

t. ikawa obtained an ordinary differential equation for the circular helix. recently, the helix havebeen investigated by many differential geometers such as t. ikawa, h. balgetir, m. bektas, m. ergut, n.ekmekci and h. h. hacısalihoglu. in this paper, making use of this author’s methods, we obtainedcharacterizations of helix for a curve with respect to the frenet frame in 3-dimensional galilean ...

This paper presents the time complexity of two algorithms that update space-filling curves of adaptively refined domains. The Modified Hilbert (space-filling) Curve was proposed to traverse square-shaped adaptive-refined meshes. Whereas, the Sierpiński-like (space-filling) Curve was proposed in order to traverse triangular-shaped adaptive-refined meshes. Those curves are variations of the names...

Following our previous work on metamaterial high-impedance surfaces made of Hilbert curve inclusions, here we theoretically explore the performance of the high-impedance surfaces made of another form of spacefilling curve known as the Peano curve. This metamaterial surface, formed by a 2-D periodic arrangement of Peano curve inclusions, is located above a conducting ground plane and is shown to...