Abstract: An image producing/displaying apparatus capable of inputting a command for changing a state of an object regardless of a form of the object includes a virtual world expressing system for constructing a virtual world including at least one object and environment in which the object exists and producing an image for visually displaying at least part of the virtual world, an output system for visualizing the image produced by the virtual world expressing system and outputting the image, and a command input system for inputting a command to the virtual world expressing system. The command input system detects a movement state of a specific pixel pattern contained in an image formed by an imaging device and extracts feature quantity from the movement state to recognize the command so that the command is notified to the virtual world expressing system.

Abstract: A method of determining a concentration of magnetic powderly material in a sample is disclosed. In this method, a pair of series-connected exciting coils are disposed in such a manner that magnetic fields generated from the respective exciting coils oppose to each other. A detecting coil is disposed at a position where the magnetic fields from the pair of exciting coils cancel out each other. A sample mixed with magnetic powder is inserted into one of the pair of exciting coils. Then, the method detects a voltage induced in the detecting coil in association with the insertion of the sample into the exciting coil and determines the concentration of the magnetic powder in the sample based on the detected voltage.

Abstract: A picture generating apparatus using ray tracing has means for inputting data of objects from a data base for storing data of objects composing a virtual three dimensional space, means for registering the data of the virtual three dimensional space divided into a plurality of voxels represented by data in a voxel table, means for determining a voxel subdivision number on the basis of representative parameters expressing geometrical information on said objects composing the three dimensional space, such as the object average size, and means for generating pictures by applying a ray tracing method to the divided voxels and displaying the generated pictures.

Abstract: Polyol component essentially consists of polyesterpolyetherpolyol containing polyesterpolyol by the weight ratio of 100:0 to 20:80, in which the polyesterpolyetherpolyol is a copolymer of polytetramethyleneglycol (PTMG) and .epsilon.-caprolactone by the weight ratio of 20:80 to 80:20 with an average molecular weight of 1000 to 3000 and the polyesterpolyol is a condensate of adipic acid as a main acid component with an average molecular weight of 1000 to 3000, is reacted with isocyanate component essentially consists of 4,4'-diphenylmethanediisocyanate (MDI) to make a prepolymer with terminal radical of NCO.