[in Japanese]

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The purpose of this study was to investigate a measuring system that can diagnose an initial dementia. We focused on the relationship between an intial dementia and spatial attention. In this paper, a normal subject's pointing movement to a visual target was measured in three conditions. Condition 1 : Only the target was presented. Condition 2 : Auditory stimulation was added at a location the same distance from the center as that of the target but in the opposite direction. Condition 3 : Auditory stimuation was added at the same location as the target. The results showed that in Condition 3, latency was shorter and the error rate of pointing movements was lower than in the other conditions. These results suggest that, it is possible to measure spatial attention from pointing movements and to control spatial attention by auditory stimulation.

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Generally, blind children, in particular the congenitally blind, find it difficulty to understand their surroundings. To help them, we have developed a computer assisted instruction (CAI) system which gives the blind spatial understanding. This system consists of a personal computer, an image-capture board, and a 3-CCD camera. We conducted an experiment using this CAI system on blind school students. A blind user was asked to arrange blocks of different shapes according to a problem presented by the system in the form of vocal instructions. When the user had completed the task of arrangement, the block layout was captured by the camera, and the shape and location of each block was analyzed, and the results output by speech. This CAI system, repeating problem presentation and task correction, may help blind children to gain spatial understanding without the help of sighted people.

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It is difficult for blind persons to understand the relationship between themselves and their environment as a two-dimensional map. This paper presents a support tool for protocol analysis of map understanding by blind persons. First, we propose a human understanding model of environments which explains the difference in visual functions and experiences. Then we present a support tool which includes a tactile display and a voice synthesizer. This tool has two representation modes, tactile-audio map mode and virtual walking mode. The results of an evaluation at a school for the blind provided us with some useful guidelines.

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We have been developing a support system that enables the visually disabled to actively recognize three-dimensional objects or environments, as an application system of 3D computer vision. This is a total system which has input, processing, and output functions. Using a stereo camera system as an input device allows 3D visual information to be obtained. The visual information is converted into tactile and auditory information which can be easily understood by the visually disabled. As one of the output devices, we have developed an interactive 3D tactile display, which presents visual patterns by tactile pins. Also, it can function as a digitizer. It is possible for a user to communicate with this system.

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The Robotic Travel Aid (RoTA) is a motorized wheelchair equipped with vision, sonar, and tactile sensors, as well as a map database system. The visually impaired can get mobility, orientation, and obstacle information from the RoTA, and they can inquire about their present location, landmarks, and future parts of their route. The RoTA can help the visually impaired avoid vehicles along a road with lane marks or along a sidewalk marked with braille. In this paper, we propose the locomotion strategy of our robot, which is based on “sign-pattern-based stereotyped action.” This paper describes 1) danger estimation, 2) pedestrian detection, and 3) the map system for the RoTA. Experimental results showed the effectiveness of our proposed method. Furthermore, a psychologist wearing an eye-mask evaluated a RoTA (not the vision-based type but the sonar-based type), and the experimental results showed the RoTA to be a very valuable aid to the visually impaired.

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We have developed a new real-time captioning system that consists of two stenographic systems (STENOWORD-PC SYSTEM) and a superimposer (VIP-4100 R). The first STENOWORD-PC SYSTEM can project the kana (one of the three Japanese alphabets) on the CRT monitor before displaying the corresponding kanji. The second STENOWORD-PC SYSTEM can correct words with wrong letters and omitted letters. We report on the functions of this system and the results of testing.

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Deaf people use a signed language as a means of communication, while normal hearing people use a spoken one. Due to the difference in modality between these languages, they have certain difficulties, in some situations, with obtaining information. This study deals with computerized sign dictionary for technical terms. We build a sign dictionary which contains explanation for each term in both signed language and in Japanese together with some still pictures and figures.
The dictionary serves the deaf as an assistive device for getting certain information and knowledge necessary for work. The system makes it possible for the deaf to learn terminology by oneself. The system, furthermore, promotes the education and training for the deaf at the workplace. We make some evaluative experiments by the deaf and normal hearing people. The results show the usefulness of the dictionary in the workplace.

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Teletext is a data transmission medium which uses the blank space of TV video signal. It transmits text, graphics and sounds with at a rate as high as 42 kb/s. The authors measured the reception rate of teletext on an ordinary trip around the Japanese archipelago. The packet reception rate was more than 90% during the TV transmission hours, presently 6 : 00-23 : 59. Thus, it is very effective for transmitting navigational aid information such as NAVTEX, NAVAREA, and EGC to vessels travelling in Japanese waters.

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This paper proposes a new image restoration method using local characteristics of an image in order to improve its quality. This method restores an image based on a criterion including edge information. We obtain it from the criterion of the conventional Tikhonov-Miller (T-M) regularization method, where the Laplacian operator is replaced by an edge-adaptive operator, which is one of the five operators corresponding to four edge regions with the directions 0, 45, 90, 135 and a flat region. The conjugate gradient algorithm is applied to the above criterion to iteratively restore the image. The over-smoothing effect at an edge, which often occurs in the conventional restoration methods, is prevented by the edge-adaptive operator that smoothes the edge along only one direction. The edge orientation is extracted for each pixel from a temporarily restored image by the conventional T-M method.

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A method of measuring the scattering patterns of materials having low reflectivity is proposed. The principle of this method is based on planar near field measurement in antenna technology. The scattering field of a material is distinguished from the mixed field composed of the main incidence, scattering field, and multi-path reflected fields by using a two-element endfire array. Furthermore the modified synthetic aperture radar method is also introduced in order to develop the surface current distribution on the material. The paper describes the measuring principle, error estimation by using simulation data, and experimental results for two samples. Taking into account pseudo-random noise the simulation results suggest that the method proposed here can measure the scattering pattern of materials having reflectivity of-20 dB when the noise level is about-40 dB.

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Recently, the Internet has become a popular communication medium in which various kinds of information can be provided with world-wide coverage. Interactive information services through the Internet are also expected. The TV community is now trying to develop a new service model of TV broadcasting merged with interactive information services like the WWW over the Internet. In this paper, we report an experiment on a multimedia information service about a 14-day baseball championship as an attempt to merge the Internet with TV broadcasting. We designed a new feed system for the Internet since conventional systems are not suitable for feeding multimedia information to the Internet. This paper compares TV broadcasting and information services on the Internet, presents the design concept of our new feed system, and analyzes it through the experiment.

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[in Japanese]

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[in Japanese]

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