Abstract: A sailboat has a preferably solid hull with lateral and longitudinal symmetry, a centrally located ring-shaped seat secured to a central portion of the top of an hull, a selectively rotatable carousel being mounted about an outer circumferential wall of said ring-shaped seat, a frame being secured to said carousel for retaining a pair of spaced apart identical sails that slant inward toward one another, a pair of removable selectively rotatable cylindrical booms being positioned on the frame with an associated halyard system for controllably furling and allowing easy reefing of the pair of sails, a pair of selectively removable rotatable hydrofoils each serving as a rudder and centerboard projecting downward from the bottom of and proximate the ends of the hull, a steering wheel being secured to the hull at the center of the ring-shaped seat and linked to each of the hydrofoils, whereby the carousel can be selectively rotated to position the sails at any desired angular position relative to the direction of t

Abstract: Apparatus for modelling or simulating the dynamics of interacting rigid bodies. In the apparatus, the rigid bodies are represented as convex polyhedra. Contacts between the bodies are modelled as contacts between a face and a vertex or between edges. All other types of contact are reduced to these types. The beginning or end of a contact is determined by means of linear interpolation. The dynamics of the contacts are modelled as contacts between massless rigid surface elements which are connected by massless viscous layers to the objects. The viscous layer connecting a surface element to its object permits the surface element to move either perpendicular to or tangent to the plane of contact. The properties of the viscous layers determine the dynamics of the contacts. In the implementation, the properties are described by means of two systems of springs and dampers, one permitting motion in the perpendicular direction and the other motion in the tangential direction.

Abstract: A handwritten test symbol, such as an alphabetic character, a word or a signature, written on a digitizing tablet is normalized by comparison with a model symbol to determine the transformation necessary to best fit the test symbol to the model symbol. Such transformation is then applied to normalize the test symbol. Shape information in the test symbol is preserved during such normalization. In accordance with one aspect of the invention, the model symbol is a line segment. In accordance with another aspect of the invention, the model symbol is an example of the symbol being normalized. Such normalization can be used as a preprocessing step in applications such as character recognition, text recognition or signature verification.

Abstract: An unknown handwritten symbol written on a digitizing tablet is compared with symbols in a predefined "alphabet" or library of model symbols and the closest match chosen. Recognition is independent of the size, position or orientation of the symbols. The alphabet can be any collection of symbols, such as alphanumeric characters, ideograms or words in cursive script and is created by writing at least one example of each symbol on the tablet. A sequence of samples of the pen position is recorded while a symbol is being written. The samples form a vector, which is then translated so that the centroid of the symbol lies at an origin. The comparison, which can easily be done in real time, involves calculating a correlation factor from scalar products of the vector for the unknown symbol and two versions of the vector for each model symbol and choosing the model symbol having the highest correlation factor.

Abstract: A fully symmetrical sailboat includes a mechanism that balances the moment of a sailor on a boom against the force of the wind on the sail in such a way that the hull remains level. The sailboat comprises a hull with both lateral and longitudinal symmetry and a rig consisting of a short, rotatable mast to which is attached by hinges a sail of symmetrical plan and a boom bearing a slidable seat. The rig as a whole can assume any angular position about a vertical axis. Under pressure of the wind, the foot of the sail can swing outward. The sail is mechanically linked to the seat boom so that its outward motion lifts the seat boom's outer end. The linkage is such that over a wide range of wind forces and regardless of the sailor's position along the boom, the rig as a whole exerts substantially no net moment on the hull. Foot operable rails are used to adjust the angle of the rig about the vertical axis, hence the angle of the sail to the wind.