Sadahiko Nagae

Strain Measurement by Optical Differentiation of Cross Grating

A method for measuring three strain components from a single plane specimen is presented, where the strain distributions induced in the specimen are transformed into light intensity distributions. The optical differentiation with a cross grating is adopted for this purpose. The theory and the experimental result are shown. Some consideration on the comparison with other methods for measuring two-dimensional strain distribution and future possibility of this method are discussed briefly.

Lettering CAD (2)

Up to today, many types of letters and Japanese characters, such as mincho-, square gothic-, and round gothic-types, have been produced and used in daily work. These letters, however, are mainly described by hand lettering, for example, designers usually create letters with their skillful techniques.On the other hand, word processors are mostly used in many fields, such as in offices, laboratories and so on. The designers can not utilize the word processors for their making vector letters, because the letters by word processors are based on a dot matrix.The purpose of this study is to develope the expert system which can draw many types of high quality letters by using a micro-computer. The data of letters are stored on the 100×100matrix, where the starting, bending and terminal points of each stroke are stored in order of letter-description. The program calculates the edge lines and curves from the data. It can be said that many types of letters can be automatically drawn from the same data. Furthermore these letters can be magnified to any size, keeping their high quality, and also decorative letters can be produced with the technique of texture mapping.

3-Dimensional Display from Video Input Data of CT Images

CT, that is, Computer Tomography, is one of the effective tools to investigate the state of the human bodies. The reconstruction of the 3-Dimensional parts of the bodies, however, depends on the surgeons imagination from the 2-Dimensional data of the tomography. Recently it comes to be realized that the 3-D reconstruction can be directly process ed by the specialized or large stall computers. But they are still too expensive and too exaggerated to handle at each surgery by each surgeon. This study aims at making 3-D display model with low cost usefully in medical aid, where we use only simple personal computer and its devices. But the method took us too much times. So at the present paper, we used video camera for input device in order to shorten the leadtime and save operators trouble. And the animation display of rotating, scaling and zooming up are tried successfully.

COMPUTIONAL PICTURE PROCESSING WITH FINITE CUBIC ELEMENTS (3)

This paper describes a method for displaying pictures or drawings by luster scanning method. An arbitrary picture film can be processed for a digital coding method which will minimize the number of code levels required to describe a picture.Ordinary drawings or moire fringe photographs consist of binary data with “black” and “white”, where the code levels are limited within the two. An introduction of the partial differentiation through the Fast Fourier Transform has led to the calculation of moving the side band spectrum in the two-dimensional Fourier transform transmitted over the channel of luster scanning binary data series. For displaying the successively changing patterns equi-moving coordinates are dotted by a dot-printer machine which is better to draw such as scanned pictures than by a conventional computer aided drafting machine or X - Y plotter.This method shows a good merit for displaying not only linear but also non-linear change phenomena in the engineering fields.

New Methods for Strain Measurement Using Optical Spatial Filtering

Two methods for measuring the three strain components in a plane plate specimen are presented. In one method, the three strain components are converted into light intensity distributions, and in the other these components are converted into color bands in an image formed from the specimen. Optical spatial filtering using a cross grating is adopted for the measurements. The principles and some experimental results are shown in the present paper.