Abstract: Text based documents are compared by lexically normalising each word of the text of a first document (104) to form a first normalised representation. A vector representation of the first document is built (206) from the first normalised representation. Each word of the text of a second document (110) is lexically normalised to form a second normalised representation. A vector representation of the second document is built (204) from the second normalised representation. The alignment of the vector representations is compared (210) to produce a score (218) of the similarity of the second document to the first document.

Abstract: This invention concerns wide-area video surveillance systems. In a first aspect the invention is a surveillance network, in another aspect the invention is a virtual observer, and in a further aspect the invention is a method for operating a virtual observer. Each segments or frame of video, from each camera of the network is associated with the following trajectory parameters; a time and a spatial position, and possibly a radius, orientation, resolution and field of view, and stored for later recall.

Abstract: A system for calculating a market value of an exotic option comprises an input means (102) for receiving market and option contract input data (112); a means (104) for calculating a theoretical value of an exotic option from the input data; a means (104) for calculating a market supplement adjustment to the theoretical value as a function of the expected stopping time of the exotic option; a means (104) for applying the market supplement adjustment to the theoretical value to produce the market value; and an output means (106) for outputting the calculated market value. The system may also calculate bid and offer prices from the market value. A method of obtaining the market value of an exotic option and a method of obtaining bid and offer prices of an exotic option are also disclosed.