Patents by Inventor Ken Fujiwara
Ken Fujiwara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240089093Abstract: An object is to prevent eavesdropping in quantum key distribution. A decoding unit decodes a quantum signal incident thereinto. A plurality of detect photons of the decoded quantum signal output from the decoding unit. A signal processing unit detects bits of the decoded quantum signal based on photon detection results of the plurality of detectors. A control unit perform switching processing by switching destinations to which two decoded quantum signals corresponding to one encoding basis are output between the plurality of detectors, and switching the bits detected by the signal processing unit based on the respective photon detection results of the plurality of detectors.Type: ApplicationFiled: January 24, 2022Publication date: March 14, 2024Applicants: NEC CORPORATION, NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY, NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY, THE UNIVERSITY OF TOKYOInventors: Ken-ichiro YOSHINO, Mikio FUJIWARA, Akihisa TOMITA, Masato KOASHI, Masahiro TAKEOKA, Masahide SASAKI
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Publication number: 20240080184Abstract: An object is to prevent eavesdropping in quantum key distribution. A photon detector outputs an output current indicating a result of detecting a quantum signal. A current-voltage conversion unit converts the output current into an output voltage signal. An analog-to-digital converter outputs an output voltage signal obtained by analog-digital conversion of the output voltage signal. A signal processing unit performs predetermined signal processing on the output voltage signal, and outputs a photon detection signal indicating a result of detecting the quantum signal. When a time difference between a timing at which the quantum signal is incident into the photon detector and a reference timing determined based on a clock signal is not within a determination range, the photon detection signal is not output from the signal processing unit.Type: ApplicationFiled: January 24, 2022Publication date: March 7, 2024Applicants: NEC Corporation, National Institute of Information and Communications Technology, NATIONAL UNIVERSTIY CORPORATION HOKKAIDO UNIVERSTIY, The University of TokyoInventors: Ken-ichiro YOSHINO, Mikio FUJIWARA, Akihisa TOMITA, Masato KOASHI, Masahiro TAKEOKA, Masahide SASAKI
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Patent number: 7316253Abstract: The viscosity of a puncture-preventing sealant (7) is set in a range of 25 to 35 dPa·s, and a thixotropy index is set in a range of 6.5 to 11.0, the sealant (7) being filled in a sealant chamber (6) defined to extend along an outer periphery of an air chamber (5) in a tire (T). When the tire (T) is being rotated by traveling of a vehicle, the viscosity of the sealant (7) is reduced by a stirring action provided by a vibration or a centrifugal force of the sealant (7), whereby the sealant (7) can be diffused uniformly in the sealant chamber (6). When the vehicle has been stopped and the stirring action has been extinguished, the viscosity of the sealant (7) is increased, whereby the sealant (7) is maintained in a state in which it has been diffused uniformly in the sealant chamber (6) without flowing downwards in the sealant chamber (6) by gravitation. Therefore, even when the vehicle is travelling at a high speed, the generation of a vibration and a noise can be prevented.Type: GrantFiled: March 29, 2001Date of Patent: January 8, 2008Assignees: Honda Giken Kogyo Kabushiki Kaisha, Nippon Leakless Kogyo Kabushiki KaishaInventors: Toshio Yamagiwa, Akiko Tanaka, Akira Tanaka, Ken Fujiwara, Noriyuki Deguchi, Kentaro Yamashita
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Patent number: 6957527Abstract: A device for periodically estimating the temperature of an exhaust-gas purifying catalyst provided in the exhaust pipe of an internal combustion engine. The device includes first, second, third, and fourth estimation blocks. The first estimation block estimates the temperature of exhaust gases that are discharged from the combustion chamber, as a steady catalytic temperature under a steady operation of the internal combustion engine, based on operating conditions of the internal combustion engine. The second estimation block estimates a representative temperature of the interior wall of the exhaust pipe extending from the internal combustion engine to the catalyst, based on the estimated steady catalytic temperature. The third estimation block estimates a catalyst inflow exhaust-gas temperature that flows in the catalyst, based on the estimated steady catalytic temperature and the estimated representative temperature.Type: GrantFiled: February 26, 2004Date of Patent: October 25, 2005Assignee: Mitsubishi Jidosha Kogyo Kabushiki KaishaInventors: Katsunori Ueda, Kenichi Nakamori, Ken Fujiwara, Hideyuki Handa
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Publication number: 20040230366Abstract: A device for periodically estimating the temperature of an exhaust-gas purifying catalyst provided in the exhaust pipe of an internal combustion engine. The device includes first, second, third, and fourth estimation blocks. The first estimation block estimates the temperature of exhaust gases that are discharged from the combustion chamber, as a steady catalytic temperature under a steady operation of the internal combustion engine, based on operating conditions of the internal combustion engine. The second estimation block estimates a representative temperature of the interior wall of the exhaust pipe extending from the internal combustion engine to the catalyst, based on the estimated steady catalytic temperature. The third estimation block estimates a catalyst inflow exhaust-gas temperature that flows in the catalyst, based on the estimated steady catalytic temperature and the estimated representative temperature.Type: ApplicationFiled: February 26, 2004Publication date: November 18, 2004Inventors: Katsunori Ueda, Kenichi Nakamori, Ken Fujiwara, Hideyuki Handa
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Publication number: 20040089386Abstract: The viscosity of a puncture-preventing sealant (7) is set in a range of 25 to 35 dPa·s, and a thixotropy index is set in a range of 6.5 to 11.0, the sealant (7) being filled in a sealant chamber (6) defined to extend along an outer periphery of an air chamber (5) in a tire (T). When the tire (T) is being rotated by traveling of a vehicle, the viscosity of the sealant (7) is reduced by a stirring action provided by a vibration or a centrifugal force of the sealant (7), whereby the sealant (7) can be diffused uniformly in the sealant chamber (6). When the vehicle has been stopped and the stirring action has been extinguished, the viscosity of the sealant (7) is increased, whereby the sealant (7) is maintained in a state in which it has been diffused uniformly in the sealant chamber (6) without flowing downwards in the sealant chamber (6) by gravitation. Therefore, even when the vehicle is travelling at a high speed, the generation of a vibration and a noise can be prevented.Type: ApplicationFiled: July 9, 2003Publication date: May 13, 2004Inventors: Toshio Yamagiwa, Akiko Tanaka, Akira Tanaka, Ken Fujiwara, Noriyuki Deguchi, Kentaro Yamashita
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Patent number: 5749996Abstract: A reclaimed joint sheet used as a gasket or packing member for automobiles, ships and the like consists of a first layer of a joint sheet made from a given composition, a second layer of a joint sheet made by mixing finely pulverized pieces of the joint sheet after the punching out of the joint sheet having a given particle size with the same composition for the formation of the joint sheet, and a third layer of the same joint sheet as the first layer.Type: GrantFiled: May 13, 1997Date of Patent: May 12, 1998Assignees: Honda Giken Kogyo Kabushiki Kaisha, Nippon Leakless Industry Co., Ltd.Inventors: Tsutomu Tomizawa, Yoshihiko Tatemichi, Ken Fujiwara, Masamichi Hoshi, Hiroyuki Nakano
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Patent number: 5658657Abstract: A reclaimed joint sheet used as a gasket or packing member for automobiles, ships and the like consists of a first layer of a joint sheet made from a given composition, a second layer of a joint sheet made by mixing finely pulverized pieces of the joint sheet after the punching out of the joint sheet having a given particle size with a composition for the formation of the joint sheet, and a third layer of a joint sheet containing the same components as the first layer.Type: GrantFiled: May 26, 1995Date of Patent: August 19, 1997Assignees: Honda Giken Kogyo Kabushiki Kaisha, Nippon Leakless Industry Co., Ltd.Inventors: Tsutomu Tomizawa, Yoshihiko Tatemichi, Ken Fujiwara, Masamichi Hoshi, Hiroyuki Nakano
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Patent number: 5292579Abstract: A compressed sheet comprises: base fibers constituted by inorganic fibers other than asbestos, or organic fibers, or a combination of both; a rubber; rubber chemicals; and fillers. In the compressed sheet a material with both smoothing and reinforcing effects is exposed at least to one of the surfaces of the compressed sheet. A method of manufacturing a compressed sheet comprises the steps of processing a composition for forming the compressed sheet by feeding it into a pair of rolls comprising a hot roll and a cold roll, thereby laminating the composition into a sheet-shaped material on the hot roll, and then peeling off the sheet-shaped laminated material. In this method the composition is fed into the rolls such that a material with both smoothing and reinforcing effects is exposed at least to that surface of the sheet-shaped laminated material which faces the cold roll.Type: GrantFiled: June 12, 1991Date of Patent: March 8, 1994Assignees: Honda Giken Kogyo Kabushiki Kaisha, Nippon Leakless Ind. Co., Ltd.Inventors: Hiromi Kitayama, Tsutomu Tomizawa, Ken Fujiwara, Fumiya Shigeta, Hiroyuki Nakano