A quadrangular prism of self-invisibility has been further researched for its applications to vehicles. Its structure has been calculated and demonstrated strictly and quantitatively, according to the laws of reflection of light and geometric principles. Furthermore, the invisible effect with respect to the position of an observed point was investigated when the observed point shifted from the ...

Heart failure (HF) patients exhibit enhanced sympathetic tone, aberrant responses to blood pressure challenges, and sleep-related breathing disorders, suggesting that the syndrome is accompanied by central neural deficits. We assessed regional gray matter volumes over the entire brain in nine HF patients (51 +/- 10 yr; left ventricular ejection fraction 0.27 +/- 0.06; six men) and 27 healthy co...

Let G be a 3-connected bipartite graph with partite sets X ∪ Y which is embeddable in the torus. We shall prove that G has a Hamiltonian cycle if (i) G is blanced , i.e., |X| = |Y |, and (ii) each vertex x ∈ X has degree four. In order to prove the result, we establish a result on orientations of quadrangular torus maps possibly with multiple edges. This result implies that every 4-connected to...

Digital objects and digital surfaces are isothetic structures per se. Such surfaces are thus not adapted to direct visualization with isothetic quads, or to many geometry processing methods. We propose a new regularization technique to construct a piecewise smooth quadrangulated surface from a digital surface. More formally we propose a variational formulation which efficiently regularizes digi...

A polygonal mesh is a connected subset of a polyhedral surface. We address the problem whether the intrinsic metric of a mesh, i.e., its development, can determine the exterior metric. If this is the case then the mesh is rigid. Among the non-rigid cases even flexible versions are possible. We concentrate on quadrangular meshes and in particular on a mesh with a flat pose in which the quadrangl...

Several techniques are currently in use for mitral valve reconstruction. We report a mitral repair case in which the use of a combination of different surgical techniques resulted in the necessary correction. A 47-year-old woman underwent surgical intervention to treat severe mitral valve insufficiency due to A1/A2/A3 and P2 prolapsed valve tissue. A combination of quadrangular resection, slidi...

Image-based 3D modelling tools and techniques can be used to support some stages of the archaeological process. Two application examples, for two sites of the Roman Era, are presented, illustrating the usage and usefulness of such tools for the archaeological survey. For a quadrangular pool in the Milreu Roman Villa (Faro, Portugal), the 3D models resulting from the application of two different...

In the title compound, {[Ce(C(8)H(7)O(3))(2)(NO(3))(H(2)O)(2)]·H(2)O}(n), the Ce(III) ion is coordinated by eight O atoms from four 2-(4-hy-droxy-phen-yl)acetate (HPAA) ligands, two O atoms from the chelating nitrate anion and two water mol-ecules in a distorted bis-capped quadrangular prismatic geometry. The HPAA ligands coordinate in a bridging tridentate mode. In the crystal, inter-molecular...

We propose a way of preventing race conditions in the evaluation of the surface integral contribution in discontinuous Galerkin and finite volume flow solvers by coloring the edges (or faces) of the computational mesh. In this work we use a partitioning algorithm that separates the edges of triangular elements into three groups and the faces of quadrangular and tetrahedral elements into four gr...

Methods We present a retrospective study on 120 cases with degenerative mitral regurgitation in which surgical mitral reconstruction has been tried in the last 5 years. 29 Barlow diseases, 50 FED, 20 idiopathic calcification of PML. Preoperative echographic and intraoperative valve analysis reveals risks factors for SAM; small LV, bulging septum, redundant leaflets, reduced mitro aortic angle, ...