Hitachi, Ltd.

Toshiyuki Odaka

Kazuo Yano

Hideaki Suzuki

Masayuki Miyazaki

Tsutomu Yamada

Keiro Muro

Yoshihiro Wakisaka

Jun Sugawa

Minoru Ogushi

Shoji Suzuki

Kei Suzuki

Shunzo Yamashita

Norio Ohkubo

Norihiko Moriwaki

Hidehiro Toyoda

Mariko Nakayama

Toshiaki Suzuki

Shoichi Masui

Akio Amano

Atsushi Hiroike

Kunihiko Toumura

Junsuke Fujiwara

Kenichi Mizugaki

Nobuo Hataoka

Tatsuhiko Kagehiro

Toshiaki Kono

Shoji Yunoki

Tetsuo Takemura

Ryujiro Muramatsu

Takehiro Urano

Sensor combinations that are effective for failure sign diagnosis are automatically generated in consideration of hidden relationships between sensor data. The present invention includes: a time shift data generation unitthat processes sensor data acquired from an instrument and generates the processed sensor data; and a sensor combinations/pre-processing condition generation unitthat generates sensor combinations on the basis of correlation coefficients between the sensor data and the processed sensor data, and generates, as a preprocessing condition, a processing condition that increases a correlation coefficient between sensors for each sensor combination, in which the failure sign diagnosis of the instrument is performed on the basis of a change in the relationship between the sensor data included in the sensor combination and the processed sensor data.

Failure sign diagnosis device and method therefor

Provided is a station-side apparatus configured to conduct optical communication with a plurality of subscriber apparatuses via a plurality of wavelengths. The station-side apparatus includes a storage apparatus, management information stored in the storage apparatus and configured to indicate whether or not a subscriber apparatus is a first apparatus whose wavelength used for communication is changed to another wavelength, and a transmission unit configured to transmit downlink frames addressed to the plurality of subscriber apparatuses in an order of transmission determined based on the management information.

Station-side apparatus and communication method

Provided is a network system including a subscriber apparatus and a station-side apparatus connected with the subscriber apparatus via an optical line. The subscriber apparatus includes a transceiver for receiving an instruction to change wavelengths for signals to be sent and received, receiving a downstream signal sent from the station-side apparatus and having a wavelength designated by the instruction, and sending an upstream signal having a wavelength designated by the instruction to the station-side apparatus. The subscriber apparatus includes a controller for identifying at least one property of the received downstream signal and determining wavelengths for signals to be sent and received based on the identified at least one property.

Network system

In a PON system in which plural kinds of modulation schemes coexist, when uplink burst signals from respective ONUs are received, the receiving efficiency degrades as the number of the times of switching of the modulation scheme increases. In an optical access (PON) system supporting plural kinds of modulation schemes, an OLT allocates bandwidths for uplink signals, i.e., transmission timings each including a transmission start time and a transmission duration, to ONUs, respectively, such that the bandwidths allocated to plural ONUs for the same modulation scheme are as successive as possible. Based on the transmission timings allocated to the respective ONUs, the OLT switches the modulation scheme of a modulation-scheme variable burst-mode optical transmitter/receiver by control of a modulation scheme controller.

Dynamic bandwidth allocation method, OLT, and PON system

An aspect of this invention is a network system including subscriber apparatuses and a station-side apparatus for communicating with the subscriber apparatuses. The station-side apparatus communicates with the subscriber apparatuses using wavelengths. The station-side apparatus determines a wavelength to be used by each of at least one subscriber apparatus of the subscriber apparatuses based on effective transmission rates used by the subscriber apparatuses in communications with the station-side apparatus.

Network system, station-side apparatus, and method of controlling communications

A data retrieval method for sensing data for retrieving, from user terminals, data transmitted from a plurality of sensor nodes, the data retrieval method including: a step for storing in distributed servers the data sent from the plurality of sensor nodes, a step for setting information link pointers for indicating model names previously set and link pointers of data corresponding to the model names, a step for a management server connected through a network with the distributed servers and the user terminal to accept the reference requests for data acquired from the user terminals, and a step for the management server to acquire data from the distributed servers set as the information link pointers based on the data reference request from among the data stored in the distributed servers and to respond to the user terminal.

Sensor network system and data retrieval method for sensing data

A transmit-side transmission control device for sending data generated by a data generator device to a data utilization point receives and retains notification of the allowable data transmission quantity from a receive-side transmission control device, and adjusts the data quantity sent from the data generator device so as to fit within that allowable data transmission quantity range, and/or when a request is issued to change that data transmission quantity, the receive-side transmission control device is notified of that allowable data transmission quantity change request. The receive-side transmission control device retains the respective allowable data transmission quantities for transmit-side transmission control device, and when a change request is issued, reallocates the allowable data transmission quantities for all transmit-side transmission control devices to fit within the data processing load range stored beforehand within the data utilization point, and notifies the corresponding transmit-side transmission control device of these reallocated allowable data transmission quantities.

Data acquisition system and transmission control device

A sensor-Net system includes sensor nodes which are in intermittent operation so as to save power by repeating activated state and inactivated state at a regular interval. Synchronization of time in the system is executed by aligning to the intermittent operation of the sensor nodes. A management server issues a setTime command for configuring the time to each gateway node at a specified interval. Each router node sets or corrects the time of it based on the time received from the gateway node and thereafter turns ON the time configuration flag for each sensor node in order to expand the setTime command to all of its sibling sensor nodes. The router node, upon reception of a polling, which is a command request, from the sensor node, obtains the time at that time, then uses the time to generate a setTime command to transmit to that sensor node.

Sensor-Net system and sensor node

The video receiving device delivers reproducible video streams by synchronizing video images. The video delivering device determines the delivery time for each RTP packet based on the time information for plural video streams corresponding to plural contents, adds the determined delivery time (timestamp) to each RTP packet, and delivers RTP packets by using the counter common among plural contents. The video relaying device corrects the transfer timing for RTP packets based on the counter common among plural contents and the delivery time (timestamp) and sends them to the video receiving device. The video receiving device plays back the video images from the received RTP packets.

Video delivering system, video delivering device, and synchronization correcting device

In a sensor network system comprising a sensor terminal and a management server, the sensor terminal transmits observation data acquired using the sensor, the management server has a latest data storage manager which manages the latest observation data among observation data received from the sensor terminal, a history data storage manager which manages the history of the observation data from any time when data was received from the sensor terminal to the latest observation data, and a missing data manager which manages missing history data, and compensates the missing history data based on a predetermined rule, and when a request for such observation data is received, at least one of the latest observation data managed by the latest data storage manager, and history data wherein the missing data has been compensated and managed by the history data storage manager, is output according to the type of request.

Sensor network system for managing the latest data and history data

A network system including: a first sensor device which includes a first sensor unit which detects an action of a detection object; and a first transmission unit which transmits first data regarding the action and first identification information to a server via a first base station: a second sensor device which includes; a second sensor unit which obtains sensing data; and a second transmission unit which transmits second data including the sensing data and second identification information to the server via a second base station; wherein the server is configured to: associate the first and second data based on the detection of the action; to access predetermined normal data correlating data; and, detect an abnormal condition if a combination of the action detected via the first sensor unit and the sensing data obtained by the second sensor unit conflict with the correlated normal data.

Sensor drive control method and sensor-equipped radio terminal device

In order to easily provide data successively generated from a real world sensor network in a time series to a user, a unit for generally and flexibly performing mapping between a source for generating physical electronic information (for example, a tiny sensor node) and sensing data to be provided to the user is provided. Therefore, a manager of the sensor network is composed of a device management table for mapping among a wireless sensor node, a wireless base station, and a data managing server, a real world model table capable of including device information and giving plural attributes, a registration/search processing unit for registering/searching that information, and a data manager for data mapping between the tables.

Sensor net system, sensor net system data managing method, and sensor net system data managing program

A plural-data transmission Start message is transmitted prior to transmission of plural data to an intermittent operation type wireless communications terminal, and when transmission of plural data is completed, a plural-data transmission End message is transmitted. The terminal which received the plural-data transmission Start message can change over the sleep period of the aforesaid intermittent operation to a shorter sleep period. Thereby, an improvement in the response performance in the case of plural-data delivery can be simultaneously obtained while maintaining the low power performance of a sensor node.

Sensor network system and sensor node

A sensor device wherein when a first sensor detects a detection object, the first sensor changes its output voltage level, and when the processor unit detects the change of the output voltage level of the first sensor as an interrupt signal, the drive voltage level of the first sensor is switched from the first signal level to the second signal level which is different from the first signal level and the drive voltage level of the second sensor is switched from the second signal level to the first signal level which is different from the second signal level.

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Fuchu, Japan

Toshiyuki Odaka