Nec Corporation

Ricoh Company, Ltd.

Denki Kagaku Kogyo Kabushiki Kaisha

The Institute of Physical and Chemical Research

Somar Corporation and the Institute of Physical and Chemical Research

Akira Sakurai

Zhenlong Cui

Kazuo Takagi

Masaki Umayabashi

Shunichi Sato

Naoto Jikutani

Takuro Sekiya

Satoru Sugawara

Takashi Takahashi

Akihiro Itoh

Kazuya Miyagaki

Atsuyuki Watada

Koei Suzuki

Ken Kanai

Shinji Satoh

Masayoshi Katoh

Akira Moroi

Teruyuki Furuta

Shuuichi Hikichi

Hiroshi Tanaka

Hiroaki Nakajima

Atsuya Yamashita

Masamichi Kanaoka

Hiroyuki Takagi

Gen Sato

Masao Kawashima

Kiyohiko Kobayashi

Kohei Okazaki

Hiroshi Saimoto

Masako Otsuka

Keiichiroh Hirahara

Taiki Kanai

Shozo Fujioka

Kunihiko Shono

Takao Yokota

Tsutomu Mieno

Mifumi Yamamoto

A communication device communicates with a counterpart device via a working path or any of a plurality of backup paths. The communication device includes: a plurality of selection units which select either one of two paths, the plurality of selection units including a main selection unit and an auxiliary selection unit being different from the main selection unit; and a path determination unit which determines a path selected by one of the plurality of selection units which has last performed path selection to be a path to be used for communicating with the counterpart device. The main selection unit selects one path from between the working path and one of the plurality of backup paths. The auxiliary selection unit selects one path from between a path selected by one selection unit of the plurality of selection units and one of the plurality of backup paths, the one selection unit being different from the auxiliary selection unit.

Communication device, communication system, method for determining path, and program

A transmission source node transmits diagnostic frames where a TTL value is set to the number of hops that is counted until an intermediate node. A relay node decrements the TTL value of the received diagnostic frames, counts the number of diagnostic frames where the decremented TTL value is 0, and recognizes continuity between the transmission source node and the relay node based on the number of transmitted diagnostic frames transmitted from the transmission source node and the number of diagnostic frames where the decremented TTL value is 0.

Diagnostic system

In a transmission system capable of measuring packet loss ratio between arbitrary devices upon a transmission path without increasing bandwidth of an OAM frame band, a plurality of transmission devices which have been disposed upon a transmission path are provided with a frame analysis unit which receives data frames so as to analyze the type of the data frames, a count processing unit which stores the number of received frames included in the data frames into storage module provided beforehand, an output line end portion which outputs the data frames, and an OAM processing unit which calculates the packet loss ratio in the transmission path using the number of received frames. The frame analysis unit has a function which, if the data frames are OAM frames, copies the data frames and the OAM processing unit has a function which calculates the packet loss ratio using the copied OAM frames.

Transmission system, transmission device, packet loss ratio measurement method, and packet loss ratio measurement program

A communication device includes a receiving unit configured to receive a frame via a connected packet network, a transmitting unit configured to transmit the received frame and a self-originating frame to the packet network, a monitoring unit configured to monitor a flow rate of the transmitted frames, a transmission cycle setting unit configured to cause a transmission cycle of the self-originating OAM frame to be a predetermined transmission cycle set for a normal condition when the flow rate of the frames is greater than or equal to a predetermined threshold, and a transmission cycle calculating unit configured to calculate a transmission cycle of the OAM frame that can compensate for a shortfall in the number of the transmitted frames, the transmission cycle calculating unit being configured to cause the calculated transmission cycle to be a transmission cycle of the self-originating OAM frame when the flow rate of the frames is less than the predetermined threshold.

Communication device, and signal degradation monitoring system and method

This communication system is equipped with a plurality of transceiver devices each composed of a transmission device that transmits unit data and a reception device that receives unit data from the transmission device. The transmission devices are connected in series. Each of the transmission devices stores identification information for identifying the device itself. The transmission device accepts unit data from a front stage side. The transmission device generates identification information for identifying one of the transmission devices from information included in the accepted unit data, in accordance with a predetermined generation process. In a case that the generated identification information corresponds to the stored identification information, the transmission device transmits the accepted unit data to the reception device. In a case that the generated identification information does not correspond to the stored identification information, the transmission device sends the accepted unit data to a back stage side.

Communication system

A node according to the present invention is used in an MPLS (Multi Protocol Label Switching) network, and the node includes an input unit which receives an OAM (Operation Administration and Maintenance) frame including TTL (Time To Live) from outside of the node and an output unit which transmits an OAM frame to outside of the node, wherein the input unit sets the TTL to a specific value and transmits the received OAM frame to the output unit in case a termination destination which an OAM frame received from outside indicates is the node and the received OAM frame is to be transmitted to the output unit and the output unit terminates an OAM frame transmitted from the input unit.

Node, a monitoring management method used for a node, and a transfer system, an input circuit and an output circuit

A data transfer deviceis equipped with a plurality of communication portsand, a communication establishment processor, and a communication maintenance processor. The communication establishment processortransmits and receives communication establishing information for establishing communication with an external device connected via the communication port to and from the external device. The communication maintenance processoris configured to operate independently of the communication establishment processorand, every time a predetermined transmission period elapses, transmits communication maintaining information for maintaining the establishment of communication with the external device, to the external device. In a state that communication with a plurality of external devices via the plurality of communication ports is established, the data transfer devicetransmits data received from one of the plurality of external devices to the other one of the plurality of external devices.

Data transfer device

A communication apparatus comprises: a memory unit which correlates a label assigned to a packet and an address of a source of the packet, and memorizes them as an entry; a receiving unit which receives a packet from a network; a learning unit which judges whether or not there exists an entry corresponding to the received packet in the memory unit, and in case there exists no entry corresponding to the received packet in the memory unit, stores a label assigned to the received packet and an address of a source of the received packet in the memory unit; and a processing unit which, in case there exists an entry corresponding to the received packet in the memory unit, assigns an address corresponding to the received packet to the received packet.

Communication using MPLS-ARP messaging

Between a first pair of termination nodes, a first current-use packet transmission path and at least one first spare packet transmission path are defined. Between a second pair of termination nodes, a second current-use packet transmission path and at least one second spare packet transmission path are defined. When no network fault occurs, packets are transmitted between the pairs of nodes in a 1:1 transfer mode in which the pairs transfer packets via both current-use packet transmission paths only. When a network fault occurs in the first current-use packet transmission path, both transmissions are switched from a 1:1 transfer mode to a 1+1 transfer mode, in which the first pair of nodes transfer packets by using the first current-use packet transmission path and the first spare packet transmission path, and the second pair transfer packets by using the second current-use packet transmission path and the second spare packet transmission path.

Packet transmission system and fault recovery method

A projection image display device including a display plane for displaying an image, a projection mechanism projecting an image on the display plane, and an imaging mechanism arranged on the same side of the display plane as the projection mechanism for imaging the display plane. The imaging mechanism is arranged at a position where a position symmetric with respect to the display plane of the projection mechanism is out of the range of the field angle of the imaging mechanism. By arranging the imaging mechanism at a position where no direct reflecting light of the light source of the projection mechanism comes, it is possible to prevent generation of a hot spot.

Projected image display unit

The present invention is to provide a polyvinyl chloride (PVC) fiber for artificial hair. The PVC fiber is manufactured by melt spinning a PVC resin composition with a nozzle, wherein the nozzle has a nozzle hole having a diameter D and a land length L, and a nozzle leading portion having a cone angle, and wherein a ratio of L/D is 1-3, a height of the nozzle leading portion is at least 4 mm, and the cone angle is 20&#xb0;-90&#xb0;. The resulting PVC fiber has an arithmetic mean roughness of 0.18-0.38 &#x3bc;m and a maximum height of 0.5-3.5 &#x3bc;m along a longitudinal direction, specified by JIS B 0601.

Polyvinyl chloride fiber for artificial hair, manufacturing and apparatus of the same

Polyvinyl chloride fibers obtainable by molding a resin composition containing 100 parts by weight of a vinyl chloride resin, from 3 to 20 parts by weight of a compatible chlorinated vinyl chloride resin, from 10 to 30 parts by weight of a heat resistant chlorinated vinyl chloride resin, and from 0.1 to 10 parts by weight of a heat stabilizer into a fibrous form, the compatible chlorinated vinyl chloride resin having a chlorine content of from 57 to 64% by weight and an average degree of polymerization of from 450 to 800; and the heat resistant chlorinated vinyl chloride resin having a chlorine content of from 65 to 71% by weight and an average degree of polymerization of from 450 to 1,100, to a process of producing the same and to applications thereof.

Polyvinyl chloride fiber, process for producing the same, and use thereof

A surface-emission laser diode includes a distributed Bragg reflector tuned to wavelength of 1.1 &#x3bc;m or longer, wherein the distributed Bragg reflector includes an alternate repetition of a low-refractive index layer and a high-refractive index layer, with a heterospike buffer layer having an intermediate refractive index interposed therebetween with a thickness in the range of 5-50 nm.

Surface-emission laser diode operable in the wavelength band of 1.1-1.7 micrometers and optical telecommunication system using such a laser diode

A surface-emission laser diode includes a distributed Bragg reflector tuned to wavelength of 1.1 &#x3bc;m or longer, wherein the distributed Bragg reflector includes an alternate repetition of a low-refractive index layer and a high-refractive index layer, with a heterospike buffer layer having an intermediate refractive index interposed therebetween with a thickness in the range of 5&#x2013;50 nm.

Surface-emission laser diode operable in the wavelength band of 1.1-1.7mum and optical telecommunication system using such a laser diode

Surface-emission laser diode operable in the wavelength band of 1.1-7&#x3bc;m and optical telecommunication system using such a laser diode

Growing community of inventors

Tokyo, Japan

Akira Sakurai