Hitachi, Ltd.

Hirofumi Sakurai

Shinjiro Ueda

Takashi Nagaoka

Seiji Sakagami

Akira Nishiuchi

Yoshiki Niwa

Because the whole image of a retrieved document group cannot be viewed, next retrieval request after one retrieval attempt has been determined only perceptually. Therefore, displaying a means for displaying topic words on a display means, extracting a group of words characteristically appearing in a retrieved document group on request from a user, further examining the relation between topic words, and preparing a graph using the topic words as nodes, the whole image of the retrieval results is displayed on the means for displaying topic words. Additionally, by selecting an interesting word or a word with no interest on a displayed graph of topic words, the user can design a subsequent retrieval strategy effectively.

Document retrieval-assisting method and system for the same and document

A turbo vacuum pump has a housing provided with a suction port and a discharge port, an evacuation pump disposed in the housing for compressing a gas suctioned through the suction port and discharging the compressed gas through the discharge port, and a motor for driving the evacuation pump, the motor and the evacuation pump having a common rotor. The rotor is supported at its both axial ends by bearings. A spiral grooved dynamic seal is disposed in the vicinity of the suction port and at the opposite side of the suction port to the evacuation pump. The diameter of the spiral grooved dynamic seal, at the smallest, is greater than the outside diameter of the final stage impeller of the evacuation pumps.

Turbo vacuum pump

A turbo vacuum pump has a housing provided with a suction port and a discharge port, an evacuation pump disposed in the housing for compressing a gas sucked through the suction port and discharging the compressed gas through the discharge port, and a motor for driving the evacuation pump, the motor and the evacuation pump having a common rotor. The rotor is supported at its both axial ends by bearings. A spiral grooved dynamic seal is disposed in the vicinity of the suction port and at the opposite side of the suction port to the evacuation pump. The diameter of the spiral grooved dynamic seal, at the smallest, is greater than the outside diameter of the final stage impeller of the evacuation pump.

Growing community of inventors

Hitachi, Japan

Hirofumi Sakurai