In terahertz communication systems, amplifiers and other components can induce non-linear distortion in terms of amplitude phase, resulting system performance degradation. This paper presents a metamaterial waveguide to mitigate phase distortions some systems. A simple method based on free-space analysis is proposed for designing waveguides an enclosed space. The quasi-periodic structures, whic...

The indoor environment that surrounds us and the elements in it affect not only our mood but also air quality. Vegetation are currently more popular, especially for their aesthetic value because of fact they physical parameters such as temperature humidity. Water a similar example. presented paper combines these two to achieve best possible level thermal comfort. Experimental verification influ...

Let S be a point set in general position on the plane such that its elements are colored red or blue. We study the following problem: Remove as few points as possible from S such that the remaining points can be enclosed by two isothetic rectangles, one containing all the red points, the other all the blue points, and such that each rectangle contains only points of one color. We prove that thi...

This paper describes a robust algorithm for computing all parts of the intersection curve of two general parametric surfaces. The algorithm follows a divide-and-conquer approach. Surfaces (and parts of them) are enclosed by tight parallel epipeds and axis aligned bounding boxes. If two bounding volumes intersect, one surface is split into two patches. This step is repeated recur-sively for both...

In this article we study the shape of a compact surface of constant mean curvature of Euclidean space whose boundary is contained in a round sphere. We consider the case that the boundary is prescribed or that the surface meets the sphere with a constant angle. We study under what geometric conditions the surface must be spherical. Our results apply in many scenarios in physics where in absence...

The (two-sided) Mullins-Sekerka model is a nonlocal evolution model for closed hypersurfaces, which was originally proposed as a model for phase transitions of materials of negligible specific heat. Under this evolution the propagating interfaces maintain the enclosed volume while the area of the interfaces decreases. We will show by means of an example that the Mullins-Sekerka flow does not pr...

We use an autonomous three-dimensional dynamical system to study embedded vortex structures that are observed to form in computational fluid dynamic simulations of patient-specific cerebral aneurysm geometries. These structures, described by a vortex which is enclosed within a larger vortex flowing in the opposite direction, are created and destroyed in phase space as fixed points undergo saddl...