0000000000074010
AUTHOR
Mateo Buendía Gómez
A simple algorithm to evaluate the local symmetry at each point of a closed contour
In this work, contour symmetry is evaluated as a numeric feature for each point of the shape outline, using only the positions of a local vicinity of points. A measure is defined, named Local Symmetric Deficiency (LSD), so that the lower this quantity is, the higher the symmetry will be in the local region considered. This approach is simpler than related previous ones both from a conceptual point of view and for its implementation, since it is reduced just to a suitable manipulation of the Freeman chain code of the curve studied. Its computational cost is very low and it has the advantages of a parallel algorithm, since values for LSD can be computed for each point independently.
Displacements measurement in a building model using the speckle photography technique
The use of reduced scale models in civil engineering has made it possible to study large structures such as buildings. Using non-destructive optical techniques such as double-exposure speckle photography, extremely valuable results can be obtained, where mathematical methods are often not very exact. This work studies the model of an eighteen-storey building in which displacements can be measured at each storey of each view. It also presents a comparison of the displacement field, which was obtained with the Finite Element Method.