Elastodynamic stress intensity factor history for a semi-infinite crack under three-dimensional transient loading

The dynamic stress intensity factor history for a semi-infinite crack in an otherwise unbounded elastic body is analyzed. The crack is subjected to a pair of suddenly-applied point loadings on its faces at a distance L away from the crack tip. The exact expression for the mode I stress intensity factor as a function of time is obtained. The method of solution is based on the direct application of integral transforms, the Wiener-Hopf technique and the Cagniard-de Hoop method. Due to the existence of the characteristic length in loading this problem was long believed a knotty problem. Some features of the solutions are discussed and graphical result for numerical computation is presented.

Two-dimensional short surface-waves of an oscillating cylinder with arbitrary shape of cross-section

The 2-D short surface waves produced by a partially submerged cylinder which performsarbitrary oscillating motion are discussed. The uniformly valid solution which is applicableto all kinds of cylinder wall cases at waterline point is obtained. It is pointed out that thesolution obtained by Holford[J] for the vertical oscillating motion of a cylinder is incomplete.The reason why his solution cannot go over to that for the case of vertical cylinder wall atwaterline point is also pointed out.

A factor model of seasonality in stock returns

Published as an article in: The Quarterly Review of Economics and Finance, 2004, vol. 44, issue 2, pages 224-236.

La influencia del factor dimensión en la pertenencia a centrales de compra por parte del pequeño comercio

[ES] Desde hace varios años, el pequeño comercio en España y en otros países europeos viene enfrentándose a un entorno de creciente concurrencia, con la irrupción de nuevas formas comerciales más integradas vertical u horizontalmente, y mejor preparadas para competir en precio y variedad. Ante este hecho, las centrales de compra se ofrecen como una alternativa tendente a acortar distancias en estas dos cuestiones, a la vez que buscan la prestación de ciertos servicios que ayuden al pequeño comerciante a gestionar más eficaz y eficientemente su negocio.