Abstract: To provide a method for performing a plurality of aggregations in parallel and at a high speed, in a computer system so constructed that each of a plurality of processors connected across a network can use a memory area for itself and a part of the database for itself that includes data categorized into one or a plurality of groups, a method comprising the steps of: (a) ensuring space for storing results of M aggregate queries of the N aggregate queries (M is an integer equal to or less than N) in the memory area for itself in each processor; (b) executing all of the M aggregate queries for the part of the database for itself in each processor; (c) transmitting the results of the M aggregate queries executed by each processor to another processor for counting up and calculating of a final result for counting up; and (d) repeating the steps (a) to (c) until execution of the N aggregate queries is completed by each processor.

Abstract: A technique and system to enhance the synthesis of solid models from two drawings. The two-dimensional coordinates of a vertex are extracted in each of a top view and a front view and, if their x-coordinates are equal to each other, the combination of their Y-coordinate values is determined to be the two-dimensional coordinates of a candidate vertex in a side view. Then, candidate line segments for the side view are extracted from the line segments connecting two candidate vertices. The process does not extract those line segments for which no corresponding line segment exists in the top and front views and those line segments for which corresponding horizontal or vertical line segments exist in the top and front views, but which are not horizontal or vertical in the side view.

Abstract: A technique to synthesize an accurate solid model from drawing data. Closed regions are detected based on top view data and a closed region list is generated. A tree structure is detected and the list is converted to symbol groups, each of which is a set of symbols representative of the elements of the contour line of the closed region and symbols representative of a connection relationship between the elements. When the converted symbol groups include a symbol group having a specific symbol, that symbol group is divided into a plurality of symbol groups based on that specific symbol. The symbol groups are matched, and the area of the closed region is detected. Symbol groups of closed regions of the same shape are classified and symbol groups of closed regions of the same area are classified. From the classified symbol groups, symbol groups of closed regions having a child of the closed region of the same shape and area are classified, and a solid model is constructed.

Abstract: A photokeratometric device for attachment to a photoslit lamp microscope having a light source therein comprises a keratometric pattern plate having an opening in the center thereof and a mount for supporting the plate for reproducing through the microscope an image of the cornea of a patient being examined with the keratometric pattern superimposed thereon.