Abstract: A signature to be verified is written on an area which carries horizontal and vertical lines using a pen. As the lines are crossed signals representative of the vertical and horizontal components of the pen tip velocity and whether the tip is in contact with the area are passed to a computer. A hidden Markov model derived from vertical and horizontal velocities and a "contact" signal occurring as a number of authentic signatures are written is stored by the computer. A forward pass of the Baum-Welch algorithm is used to calculate the probability that the vertical and horizontal components of the pen tip and the contacts between pen tip and the writing area could have been produced from the hidden Markov model. This probability is used to decide whether the signature is authentic.

Abstract: An anchor element is provided with a body of bonded particulate material e.g., a sleeve of silicate bonded sands. The element is received in a borehole with the sleeve adjacent the blind end. When a compressive force is applied between the ends of the body, the particles move closer together to form an annulus of compacted particulate material bridging the element and the wall of the borehole.

Abstract: An anchor element is provided with a body of bonded particulate material, e.g. a sleeve of silicate bonded sands. The element is received in a borehole with the sleeve adjacent the blind end. When a compressive force is applied between the ends of the body, the particles move closer together to form an annulus of compacted particulate material bridging the element and the wall of the borehole.

Abstract: Loose particulate material A, preferably housed in a capsule C, is urged towards the blind end of a borehole H. An anchor element 1 having an end plate 3 or a head and a disc spaced from the head is driven into the hole with rotation to compact the particulate material to form a load bearing annulus. The material is selected to be of a defined aggregate crushing value.