Optimisations for quadrature representations of finite element tensors through automated code generation

We examine aspects of the computation of finite element matrices and vectors which are made possible by automated code generation. Given a variational form in a syntax which resembles standard mathematical notation, the low-level computer code for building finite element tensors, typically matrices, vectors and scalars, can be generated automatically via a form compiler. In particular, the generation of code for computing finite element matrices using a quadrature approach is addressed. For quadrature representations, a number of optimisation strategies which are made possible by automated code generation are presented. The relative performance of two different automatically generated representations of finite element matrices is examined, with a particular emphasis on complicated variational forms. It is shown that approaches which perform best for simple forms are not tractable for more complicated problems in terms of run time performance, the time required to generate the code or the size of the generated code. The approach and optimisations elaborated here are effective for a range of variational forms

Automated code generation for discontinuous Galerkin methods

A compiler approach for generating low-level computer code from high-level input for discontinuous Galerkin finite element forms is presented. The input language mirrors conventional mathematical notation, and the compiler generates efficient code in a standard programming language. This facilitates the rapid generation of efficient code for general equations in varying spatial dimensions. Key concepts underlying the compiler approach and the automated generation of computer code are elaborated. The approach is demonstrated for a range of common problems, including the Poisson, biharmonic, advection--diffusion and Stokes equations

Coverets kapital: En empirisk undersøgelse af genremærkatens betydning for vurderingen af det litterære værk

Based on a large survey (n=539) this study examines how book covers in general and the genre label in particular play a role in the aesthetic positioning and marketing of books. A given work can succeed with large sales numbers and economic capital as well as by obtaining more field specific cultural and social capital. These different ways of positioning oneself on the market are, according to Bourdieu, to a large extent inverse – and it is therefore hypothesized that they require different strategies. In order to examine this phenomenon, the respondents are split into two groups and asked to evaluate four different covers with respect to broad audience appeal. Furthermore, they are asked to give a short description of the content they would expect in the different books. The cover samples are identical for the two groups, but alternating genre labels have been removed in one of the groups while being preserved in the other. Based on the responses, it is confirmed that genre labels have a significant effect on the reception of and expectations to the work. It is also demonstrated how the commercial and artistic appeal varies among the four books indicating an effect of the paratext as a whole. It is indicated by its cover, to what extent a book targets commercial interests or strives for a more field specific capital and recognition – and the genre label is a salient part of this positioning