Nec Corporation

Nec C Orporation

Tomoyuki Hino

Akio Tajima

Hitoshi Takeshita

Shinsuke Fujisawa

Akihiro Tanaka

Chaitanya Prasad Narisetty

Yuma Matsuda

Junichi Sasaki

Ichiro Hatakeyama

Ichiro Ogura

Masahiro Sakauchi

Shigeru Nakamura

Kazuhiko Kurata

Yoichi Hashimoto

Kenji Mizutani

Hiroyuki Takagi

Ryuichi Ikematsu

Ryosuke Kuribayashi

Masahiro Hayashitani

In order to facilitate accuracy improvement in identification of a position of vibration on a road caused by a vehicle and detected through an optical cable, this distance correction device: derives, from vibration data for each optical fiber distance detected through an optical fiber installed along the road on which the vehicle travels, a first vibration value indicating the magnitude of vibration within a prescribed frequency range for the optical fiber distance; derives, from the first vibration value, a bridge optical fiber distance which is an optical fiber distance to a prescribed position of the optical fiber installed at a bridge; and corrects, from the bridge optical fiber distance and a road distance which is a distance, along the road, from a reference point to a bridge optical fiber position, the optical distance within a prescribed range so as to be closer to the road distance.

Distance correction device, processing device, sensor device, distance correction method, and recording medium

To improve the accuracy of vehicle speed calculation, the present disclosure extracts, on the basis of an optical signal received from an optical fiber cable laid in a road, a first pattern according to the traveling state of a vehicle on the road in a first time range and a first distance range, generates, on the basis of the first pattern, a second pattern in which the number of time points included in the first time range or the number of positions included in the first distance range has been decreased, and calculates the traveling speed of the vehicle on the road on the basis of the second pattern.

Road monitoring system, road monitoring device, and road monitoring method

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.

Optical network management apparatus and method of allocating optical frequency band

In optical fiber sensors, sensor signals obtained differ according to the circumstances of installation, in locations being observed, of optical fibers serving as sensors, and it is difficult to perform accurate measurements; therefore, a sensor signal processing apparatus according to the present invention includes variation calculation means for receiving a sensor signal based on scattered light of a light pulse propagating through an optical fiber, and calculating a variation of the sensor signal from a reference value; and normalization processing means for normalizing the variation within a predetermined time, and calculating a normalized variation.

Sensor signal processing apparatus and sensor signal processing method

A traffic monitoring apparatus includes: at least one memory storing instructions; and at least one processor. The processor is configured to execute the instructions to; acquire waterfall data from a distributed acoustic sensor (DAS), wherein the waterfall data includes a generation position of a vibration on a roadway adjacent to the DAS, a generation time of the vibration and an amplitude of the vibration; preprocess the waterfall data; estimate at least one enhancement of the processed waterfall data, wherein an enhancement corresponds to a traffic flow property; and estimate at least one traffic flow property of the roadway from the enhancements of the processed waterfall data.

Traffic monitoring apparatus, system, traffic monitoring method and non-transitory computer readable medium

A position detection device includes a transmitter that transmits an optical pulse into an optical transmission line laid along the movement path of a moving body; a detector that detects back-scattered light in the optical transmission line; a data processor that calculates the intensity of the back-scattered light and the generation position of the back-scattered light; a storage in which the processing results of the data processor are saved; a search range derivation circuit that derives a search range for the position of the moving body; a maximum value extraction circuit that extracts the generation position at which the variation of intensity within the search range is at a maximum, and causes the extracted generation position to be saved in the storage; and an output circuit that outputs the extraction result.

Position detection device and position detection method

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.

Optical network system, optical node device, and optical network control method

In a multi-layer network, a control load in the upper layer network increases, and the usage efficiency and the reliability of the entire network decrease; therefore, a multi-layer network system according to an exemplary aspect of the present invention includes a first network manager configured to set a logical path in a first network layer; and a second network manager configured to set a physical path corresponding to the logical path, in a second network layer, wherein the second network manager includes a network information storage configured to store physical network information including physical route information and transmission characteristic information on the second network layer, and the first network manager sets the logical path based on the physical network information.

Multi-layer network system and path setting method in multi-layer network

The present disclosure provides a traffic prediction apparatus, system, method and program capable of predicting the number of vehicles and the speed of vehicles in a predetermined time and in a predetermined range based on waterfall data of vehicles. The traffic prediction apparatus comprises acquisition means for acquiring waterfall data comprising a generation position of a vibration, a generation time of the vibration and an amplitude of the vibration generated by a vehicle traveling on a road, pre-processing means for transforming the acquired waterfall data, generation means for training a portion of the plurality of processed waterfall data and at least one corresponding ground truth traffic property used as plurality of labels to generate a trained model, wherein the ground truth may be obtained from a secondary acquisition means, and prediction means for predicting at least one traffic property for a processed waterfall data.

Traffic prediction apparatus, system, method, and non-transitory computer readable medium

According to one example embodiment, an optical fiber sensor includes an optical fiber cable and a device body configured to cause an optical pulse signal to be incident on the optical fiber cable and identify, from intensity change of backscattered light of the incident optical pulse signal and an arrival time of the backscattered light, a prescribed environmental change having occurred in a vicinity of the optical fiber cable and an occurrence location of the environmental change, in which the device body performs correction of a sensing location on the optical fiber cable, based on environmental change information including the identified occurrence location and installation location information of the optical fiber cable.

Optical fiber sensor, and monitoring system

A structure deterioration detection system includes an optical fiber cable that is placed along the longitudinal direction of a structure and continuously detects any vibration along the longitudinal direction of the structure, and a signal processing unit including a vibration measurement unit that measures the strength of a detected vibration, a per unit time integration unit that integrates the vibration strength for a specified period of time, an information storage unit that stores the integrated vibration strength, and a deterioration determination unit that makes a determination about whether deterioration of the structure has occurred by comparing the integrated vibration strengths at different times.

Structure deterioration detection system for making a determination about whether deterioration has occurred

A traffic monitoring apparatus includes a distributed acoustic sensor (DAS) for acquiring waterfall data, wherein the waterfall data includes a generation position of a vibration on a roadway adjacent to the DAS, a generation time of the vibration and an amplitude of the vibration. The traffic monitoring apparatus further includes a processor connected to the DAS. The processor is configured to receive the waterfall data from the DAS. The processor is further configured to preprocess the waterfall data. The processor is further configured to separate the preprocessed waterfall data into a plurality of patches, wherein a size of each patch of the plurality of patches is determined based on a parameter of the roadway. The processor is further configured to process each of the plurality of patches to estimate at least one traffic flow property of the roadway.

Growing community of inventors

Tokyo, Japan

Tomoyuki Hino