A new data-parallel algorithm for reconstructing smooth surfaces defined by arbitrary 3D triangular meshes is presented. The obtained surfaces are composed of triangular patches that join with first order geometric continuity. Every patch is generated by a parametric function that approximates the vertices of each control triangle of the mesh. A coarse granularity implementation of those functi...

We construct a constrained trivariate extension of the univariate normalized B-basis of the vector space of trigonometric polynomials of arbitrary (finite) order n ∈ N defined on any compact interval [0, α], where α ∈ (0, π). Our triangular extension is a normalized linearly independent constrained trivariate trigonometric function system of dimension δn = 3n (n+ 1) + 1 that spans the same vect...

Most research into the adaptive significance of warning signals has focused on the colouration and patterns of prey animals. However, behaviour, odour and body shape can also have signal functions and thereby reduce predators' willingness to attack defended prey. European vipers all have a distinctive triangular head shape; and they are all venomous. Several non-venomous snakes, including the s...

The popularity of Partitioned Global Address Space (PGAS) languages has increased during the last years thanks to their high programmability and performance through an efficient exploitation of data locality. This paper describes the implementation of efficient parallel dense triangular solvers in the PGAS language Unified Parallel C (UPC). The solvers are built on top of sequential BLAS functi...

In this manuscript we construct simple, efficient and asymptotically correct a posteriori error estimates for discontinuous finite element solutions of scalar firstorder hyperbolic partial differential problems on triangular meshes. We explicitly write the basis functions for the error spaces corresponding to several finite element spaces. The leading term of the discretization error on each tr...

In many applications it is required to have a curvature-dependent surface sampling, based on a local shape analysis. In this work we show how this can be achieved by using the support function (SF) representation of a surface. This representation, a classical tool in Convex Geometry, has been recently considered in CAD problems for computing surface offsets and for analyzing curvatures. Startin...

For little q-Jacobi polynomials, q-Hahn polynomials and big q-Jacobi polynomials we give particular q-hypergeometric series representations in which the termwise q = 0 limit can be taken. When rewritten in matrix form, these series representations can be viewed as decompositions into a lower triangular matrix times upper triangular matrix. We develop a general theory of such decompositions rela...

We study a spin-1/2 system with Heisenberg plus ring exchanges on a four-leg triangular ladder using the density matrix renormalization group and Gutzwiller variational wave functions. Near an isotropic lattice regime, for moderate to large ring exchanges we find a spin Bose-metal phase with a spinon Fermi sea consisting of three partially filled bands. Going away from the triangular towards th...

We propose a method for incorporating multiple linguistic variables into a system dynamics framework. A simple example is used to illustrate the procedures necessary to define linguistic variables using triangular membership functions within the VENSIM Simulation Environment. We illustrate the operations of linguistic variables through a sales and service model where two linguistic variables i....

This paper presents an algebraic method that uses the triangular factors of singular, symmetric gain matrix to determine the observable islands of a measured power system. This is accomplished in a noniterative manner via the use of selected rows of the inverse factors. Implementation of the proposed method presents little additional effort, since sparse triangular factorization and forward/bac...