Patents by Inventor Akio Tajima
Akio Tajima 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: 20200344533Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.Type: ApplicationFiled: July 9, 2020Publication date: October 29, 2020Applicant: NEC CORPORATIONInventors: Hitoshi TAKESHITA, Shinsuke FUJISAWA, Tomoyuki HINO, Akio TAJIMA
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Publication number: 20200344170Abstract: A first device transmits a first random number to a second device through a first quantum channel, and receives a second random number from the second device through a second quantum channel. The first device generates a first encryption key based on the first random number and the second random number. The second device transmits the second random number to the first device through the second quantum channel, and receives the first random number from the first device through the first quantum channel. The second device generates a second encryption key based on the first random number and the second random number.Type: ApplicationFiled: July 9, 2020Publication date: October 29, 2020Applicant: NEC CorporationInventors: Takao OCHI, Ken-ichiro YOSHINO, Akio TAJIMA
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Publication number: 20200313765Abstract: If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.Type: ApplicationFiled: June 17, 2020Publication date: October 1, 2020Applicant: NEC CorporationInventors: Tomoyuki HINO, Akio TAJIMA, Hitoshi TAKESHITA, Shinsuke FUJISAWA
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Patent number: 10750259Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.Type: GrantFiled: June 18, 2019Date of Patent: August 18, 2020Assignee: NEC CORPORATIONInventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
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Patent number: 10735328Abstract: In order to achieve the dispersion of a processing load between communication devices that perform information transmission, an information communication system according to an exemplary aspect of the present invention includes a first transmission system configured to transmit information in a direction from a first communication device to a second communication device; and a second transmission system configured to transmit information in a direction opposite to the direction of the first transmission system, wherein part of transmission information is received as received information in each of the first transmission system and the second transmission system.Type: GrantFiled: August 20, 2015Date of Patent: August 4, 2020Assignee: NEC CORPORATIONInventors: Takao Ochi, Ken-ichiro Yoshino, Akio Tajima
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Patent number: 10715249Abstract: If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.Type: GrantFiled: March 18, 2016Date of Patent: July 14, 2020Assignee: NEC CORPORATIONInventors: Tomoyuki Hino, Akio Tajima, Hitoshi Takeshita, Shinsuke Fujisawa
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Publication number: 20200207787Abstract: A polycyclic aromatic compound in which a plurality of aromatic rings are connected by a boron atom and an oxygen atom, a sulfur atom or a selenium atom and substituted by a specific aryl such as anthracene, is useful as a material for an organic device. By the polycyclic aromatic compound, an organic EL device having at least one of efficiency and device life can be provided.Type: ApplicationFiled: December 21, 2019Publication date: July 2, 2020Applicants: Kwansei Gakuin Educational Foundation, JNC CorporationInventors: Takuji Hatakeyama, Hiroyuki Imai, Yuko Yamaga, Daisuke Inoue, Akio Tajima
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Publication number: 20200136743Abstract: It is difficult in the elastic optical network to achieve a balance between the improvement in the frequency utilization efficiency and the increase in the probability of opening an optical path; therefore, an optical path controller according to an exemplary aspect of the present invention includes route selection means for searching for a route candidate being a candidate for a route to accommodate an optical path, and selecting a best possible route with a minimum route selection index serving as an index for route search; use rate collecting means for collecting a use rate serving as an index to indicate a usage condition of an optical frequency band in an optical fiber transmission line included in the route candidate; and route selection index judgment means for determining the route selection index based on the use rate.Type: ApplicationFiled: July 6, 2017Publication date: April 30, 2020Applicant: NEC CorporationInventors: Shinsuke FUJISAWA, Akio TAJIMA, Hitoshi TAKESHITA
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Publication number: 20200045388Abstract: Provided are an optical communication device and an optical communication system capable of preventing the costs of equipment from increasing for an optical communication network constructed including devices provided by different vendors or devices of different generations.Type: ApplicationFiled: March 30, 2018Publication date: February 6, 2020Applicants: National Institute of Advanced Industrial Science and Technology, NEC CORPORATIONInventors: Kiyo ISHII, Shu NAMIKI, Shigeyuki YANAGIMACHI, Hitoshi TAKESHITA, Akio TAJIMA
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Patent number: 10542335Abstract: In the elastic optical network, there has been the problem that processing steps increase that are required to re-optimize client signals to be concentrated; therefore, an optical network controller according to an exemplary aspect of the present invention includes reallocation detection means for monitoring an operation status of at least one of an optical communication channel and an optical node device that constitute an optical network, and determining, based on the operation status, whether or not to reallocate a client signal accommodated in an optical path set in the optical network; design-candidate exclusion means for designating, as a design exclusion object, at least one of the optical communication channel and the optical node device that are associated with an optical path targeted for reallocation that accommodates the client signal that the reallocation detection means has determined to reallocate; optical path design means for determining an alternative route for the optical path targeted forType: GrantFiled: February 8, 2017Date of Patent: January 21, 2020Assignee: NEC CORPORATIONInventors: Shinsuke Fujisawa, Akio Tajima, Hitoshi Takeshita, Tomoyuki Hino
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Patent number: 10447419Abstract: In an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, it is difficult to improve the usage efficiency of an optical frequency band owing to the occurrence of fragmentation of the optical frequency band; therefore, an optical network controller according to an exemplary aspect of the present invention includes an optical frequency region setting means for dividing an optical frequency band used in an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, and setting a plurality of optical frequency regions; and an optical path setting means for setting optical paths having a common attribute in at least one of the plurality of optical frequency regions.Type: GrantFiled: April 15, 2015Date of Patent: October 15, 2019Assignee: NEC CORPORATIONInventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
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Publication number: 20190312207Abstract: Provided is an organic electroluminescent element having optimal light emission characteristics. The above problem is solved by an organic electroluminescent element having a light emitting layer containing a compound of formula (1) or a multimer compound having a plurality of structures of formula (1), and a compound of formula (2A) or (2B) in formula (1), ring A, ring B, and ring C each represent an aryl ring or the like, X1 and X2 each represent >O or >N—R, and the R represents an aryl or the like, and in formula (2A) or (2B), X represents an aryl or the like, and Z represents a single bond, a divalent group, or the like.Type: ApplicationFiled: January 25, 2018Publication date: October 10, 2019Applicants: Kwansei Gakuin Educational Foundation, JNC CorporationInventors: Takuji HATAKEYAMA, Akio TAJIMA, Daisuke BABA, Yukihiro FUJITA, Yuko YAMAGA, Hiroyuki IMAI
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Publication number: 20190306597Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.Type: ApplicationFiled: June 18, 2019Publication date: October 3, 2019Applicant: NEC CORPORATIONInventors: Hitoshi TAKESHITA, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
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Publication number: 20190260474Abstract: In an optical communication network using the wavelength division multiplexing system, the accommodation efficiency for the optical paths decreases, and it becomes difficult to use the optical communication network efficiently, if the optical frequency slots are used concentrically in a specific optical fiber; therefore, an optical path design apparatus according to an exemplary aspect of the present invention includes route candidate selection means for searching for a route of an optical path to accommodate a communication demand and selecting a plurality of route candidates; optical path candidate selection means for selecting a plurality of optical path candidates by allocating an optical frequency band required to accommodate the optical path to each of optical fibers on the plurality of route candidates; and optical path determination means for determining the optical path from among the plurality of optical path candidates based on an optical frequency band utilization rate in the optical fibers.Type: ApplicationFiled: September 20, 2017Publication date: August 22, 2019Applicant: NEC CorporationInventors: Hitoshi TAKESHITA, Shinsuke FUJISAWA, Akio TAJIMA
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Patent number: 10382135Abstract: In an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, it is difficult to improve the usage efficiency of an optical frequency band owing to the occurrence of fragmentation of the optical frequency band; therefore, an optical network controller according to an exemplary aspect of the present invention includes an optical frequency region setting means for setting a plurality of optical frequency regions in an optical frequency band used in an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid; an optical path setting means for setting optical paths having a common attribute in at least one of the plurality of optical frequency regions; and an optical frequency region control means for changing an optical frequency width of the optical frequency region, and instructing the optical frequency region setting means to reconfigure, as the plurality of optical frequency regions, a plurality of optical frequType: GrantFiled: April 15, 2015Date of Patent: August 13, 2019Assignee: NEC CORPORATIONInventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
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Patent number: 10375460Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.Type: GrantFiled: February 20, 2017Date of Patent: August 6, 2019Assignee: NEC CORPORATIONInventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
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Publication number: 20190238451Abstract: An optical network control device includes: a path setting unit that sets, based on topology information including a connection relationship among a plurality of nodes and a first route selection index value of routes each connecting the plurality of nodes, a first path for a route having the first route selection index value being minimum from among route candidates linking a start point node and an end point node of a requested traffic; a topology information modification unit that calculates a second route selection index value acquired by increasing the first route selection index value of the route that accommodates the first path; and a path selection unit that selects a second path for a route having the second route selection index value being minimum from among the route candidates.Type: ApplicationFiled: October 4, 2017Publication date: August 1, 2019Applicant: NEC CorporationInventors: Shinsuke FUJISAWA, Hitoshi TAKESHITA, Akio TAJIMA
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Patent number: 10230487Abstract: It is made possible to accommodate a plurality of services and transmit each of the accommodated services to a corresponding transmission device. An optical transmitter according to an exemplary aspect of the present invention includes sub-carrier adjusting means for outputting sub-carriers to a plurality of output ports according to a control signal; encoding processing means for mapping client data on a plurality of output lanes according to the control signal; a plurality of modulation means for modulating the sub-carriers inputted through the output ports by client data inputted through the output lanes and outputting modulated signals; and control means for generating and outputting the control signal based on transmission information.Type: GrantFiled: March 11, 2015Date of Patent: March 12, 2019Assignee: NEC CORPORATIONInventors: Tomoyuki Hino, Shinsuke Fujisawa, Hitoshi Takeshita, Akio Tajima
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Patent number: 10231035Abstract: In an optical network by a highly dense wavelength division multiplexing system using a flexible frequency grid, it is difficult to improve the optical bandwidth utilization efficiency in the optical network as a whole with improving the fault tolerance, therefore, an optical network controller according to an exemplary aspect of the present invention includes an optical path setting means for selecting a plurality of optical node pairs composed of two optical nodes from among a plurality of optical nodes composing the optical network by a highly dense wavelength division multiplexing system using a flexible frequency grid, and setting, between each of the plurality of optical node pairs, a plurality of optical paths including a first optical path and a second optical path each of which links the optical node pair through various routes; and an optical band setting means for setting respective optical bands based on optical path length and transmission capacity so that an amount of optical bandwidths of the fType: GrantFiled: September 1, 2014Date of Patent: March 12, 2019Assignee: NEC CORPORATIONInventors: Hitoshi Takeshita, Tomoyuki Hino, Akio Tajima
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Patent number: 10211923Abstract: In an optical network system based on a wavelength division multiplexing system using a flexible frequency grid, with the diversification of optical modulation methods, the management burden on an optical network management device increases, and its control becomes complicated; therefore, an optical network system according to an exemplary aspect of the present invention includes an optical network management device configured to receive a traffic demand, design an optical path capable of accommodating the traffic demand, and create optical path design information of a design result; and an optical node device configured to be used for creating the optical path, wherein the optical node device calculates an allocable bandwidth from the optical path design information and optical node device information on a configuration of the optical node device, and the allocable bandwidth is an optical frequency bandwidth of a generable optical path that the optical node device is capable of generating, and the optical neType: GrantFiled: November 11, 2015Date of Patent: February 19, 2019Assignee: NEC CorporationInventors: Hitoshi Takeshita, Tomoyuki Hino, Shinsuke Fujisawa, Akio Tajima