Efficient analogous word search method
for broadcasting news manuscripts

Natural Language Processing, Vol. 6, No. 5, pp. 93-116 (1999)
Hideki TANAKA, Tadashi KUMANO, Noriyoshi URATANI, Terumasa EHARA

The authors of this paper have been developing an analogous word search system to make possible the efficient translation of Japanese newscasts into English. This report concerns a similar Japanese word retrieval method that is utilized in this system. Conventionally, the number of common independent words appearing in two expressions (or sentences) have been mainly applied to measure the similarity between Japanese terms. However, applying the same method to Japanese newscasts resulted in a large number of incorrect expressions. To counteract this, the authors devised a system that recognizes word order and intervals between key words, in addition to the total number of key words. They developed an algorithm that calculates this data at high speed as well. A 'similar terms' search was conducted by independent evaluators on a database of 1.6 million Japanese news sentences to objectively measure the system's satisfaction rating. The results confirmed that the satisfaction rating of this method was much better than that of the former method. The required retrieval time was 1.3 times that of the conventional method, an adequate rate for practical use.

Three-dimensional video system
based on Integral Photography

Optical Engineering, Vol.38, No. 6, pp. 1072-1077(1999)
Fumio OKANO, Jun ARAI, Haruo HOSHINO, Ichiro YUYAMA

The authors developed and experimentally manufactured a real time three-dimensional video system based on Integral Photography (IP). With this system, many real images of an object generated by a microlens array are directly received by a television camera. This group of images is used to reproduce three-dimensional images by means of a display device which combines a liquid crystal panel and a microlens array. The microlens arrays used for shooting are composed of gradient-index lenses, and real images are reproduced corresponding to the number of lens elements. Ordinary convex lenses form a microlens array for the display device. A large aperture convex lens is located in front of a microlens array for imaging, and it controls the depth representation. The number of lens elements is 54 (H) ×55 (V). This is equivalent to the number of ordinary television display pixels, and its resolution is still considered fairly low. The viewing zone of IP is approximately 20 degrees, difficult to regard as sufficient. However, tests confirmed that the system provides an autostereoscopic image from any desired viewpoint without viewing glasses. These results suggest the possibility of using this experimental system for future three-dimensional television.

Beam characteristics
of a high-gain avalanche rushing amorphous photoconductor field-emitter image sensor

Applied Surface Science 146, pp. 251-256 (1999) Masakazu NANBA, Toshiro YAMAGISHI, Saburo OKAZAKI, Kenkichi TANIOKA, Katsumi TAKAYAMA*, Mitsuru TANAKA*, Shigeo ITO* (* Futaba Denshi Corporation)

Aiming towards the realization of a next generation imaging device, the authors have been promoting research on a "Field Emitter Image Sensor (FEIS)" which is composed of an X-Y matrix Field Emitter Array (FEA) set face to face with a HARP target. This image sensor possesses potentially superior characteristics, including the possibility of ultra-high sensitivity and ultra-high density displays. However, it had been difficult to obtain the desired resolution for electron beam flaring from cold cathodes at the time of emission. In order to resolve this problem, they proposed the insertion of a mesh electrode between an X-Y matrix FEA and a HARP target, and verified its positive effect by trial manufacturing experiments. They also revealed that reducing the distance between an X-Y matrix FEA and a mesh electrode strengthens the acceleration of the electric field in-between, resulting in a reduction of electronic beam flaring. The authors further validated improvement of dynamic range due to the fact that the suppression of flaring also improves the electron absorbing efficiency of the HARP layer.