Nec Corporation

Nec Laboratories America, Inc.

Nissan Motor Company Limited

Nkk Corporation

Nippon Kokan Kabushiki Kaisha

Ntt Electronics Corporation

Japan As Represented by Director General, Technical Research and

Fuji Jukogyo Kabushiki Kaisha

Yutaka Yano

Eitaro Misumi

Ting Wang

Lei Xu

Masaaki Sobe

Philip N Ji

Takashi Ono

Makoto Saitoh

Junqiang Nochur Hu

Shuji Murakami

Dayou Qian

Hiroshi Kawakami

Tsutomu Tajima

Masaki Nakano

Jianjun Yu

Yoshihisa Inada

Masanori Kato

Ryuji Aida

Takefumi Oguma

Keiichi Nakagawa

Makoto Ogawa

Kiyoshi Kawasaki

Kenichi Nomura

Takehiro Nakano

Tadashi Kasamatsu

Jun Muramatsu

Katsuyuki Ozaki

Kazumi Ohta

Naminosuke Kubota

Yasumasa Takagi

Nobuo Shimoguti

Mituhiko Terashima

Tooru Nakano

Hirohito Ohtsuka

Toshio Kamatani

Shintaro Chiba

Hisao Doyama

Toshiyuki Hayashi

Sotoaki Kawaguchi

Kazuyoshi Ninomiya

To suppress expansion of damage to a working-state cable due to work being continued without detecting breakage of the working-state cable when the breakage occurs, the working-state cable protection monitoring system is provided with: a working means that moves or installs a wire cable-shaped construction material including an optical fiber having at least one core; an interrogator that acquires environment information about each position of the construction material, sensed by the optical fiber; and an abnormal event detection means that, when the environment information acquired at each position of the construction material satisfies an abnormal pattern, detects an abnormal event at the position, where in the working means stops movement and installment of the wire cable-shaped construction material when the abnormal event has been detected.

Working-state cable protection monitoring system, working-state cable protection monitoring method, and storage medium having stored therein working-state cable protection monitoring program

To observe sounds produced by aquatic organisms with less effort, this aquatic organism observation device is made to include an aquatic organism information detection unit for detecting, from sound data that has been acquired using an optical fiber installed in or at the bottom of water and is related to sound at various positions on the optical fiber, a sound emitted by an aquatic organism at a sound data acquisition time and location, and an output unit for outputting aquatic organism information.

Aquatic organism observation device, aquatic organism observation system, aquatic organism observation method, and recording medium

A water pressure fluctuation measuring system detects a water pressure fluctuation. A cable, which includes an optical fiber, is provided on or in the ground of the seabed in such a way that the optical fiber is expanded and contracted according to the water pressure fluctuation. An optical output unit outputs monitoring light to the optical fiber. A partial reflection unit is provided on a path of the optical fiber in the cable and partially reflects the monitoring light. An optical reception unit receives reflection light reflected by the partial reflection unit. A calculation unit measures a length of the optical fiber to the partial reflection unit, based on a round-trip propagation time of the received reflection light, and monitors a change of the length over time.

Water pressure fluctuation measuring system and water pressure fluctuation measuring method

In order to provide a mechanism which predicts a risk of future failure occurrence, by using fiber optic sensing, this failure prediction system comprises: a sensing function unit which acquires the environmental information detected by the optical fiber; an event classification function unit which classifies, by type, events occurring at each position of the object indicated by the environmental information, on the basis of event classification conditions; and a failure occurrence risk calculation unit having, in advance, one or more failure models obtained by modeling a physical mechanism that leads to a malfunction in the object, wherein the failure occurrence risk calculation unit calculates a failure occurrence risk in each object by the mechanism, and outputs the accumulated result as a risk or availability.

Failure prediction system, failure prediction device, and failure prediction method

An optical fiber sensing range limiting device comprises: a blocking unit that, on the basis of a control signal and for a prescribed period, causes probe light that has been sent to an optical fiber used in optical fiber sensing and has returned from the optical fiber to be blocked from being transmitted to a light detection unit, or causes a detection signal that is detected with respect to the return light to be blocked from being transmitted to a downstream processing unit; and a control unit that outputs the control signal to the blocking unit. The prescribed period includes a period corresponding to the positional range for which acquisition of information from the detection signal is prohibited or for which it is undesirable to acquire the information.

Sensing range limiting device

In order to facilitate fixed-point monitoring over a wide area and for a long time, this water area monitoring device comprises: a detection unit for information, such as water area intrusion, which detects, from sound data that is acquired by means of optical fibers installed in the water or the water bottom and is data pertaining to a sound or a vibration at the respective positions of the optical fibers, at least any one among sounds of water area intrusion or the like that indicate intrusion into a target water area or water area intrusion or the like, which is a prescribed behavior in the target water area, at a time at which sound data is acquired, and changes in sounds or vibrations not caused by the water area intrusion or the like; and an output unit which outputs information indicating the sound such as water area intrusion.

Water area monitoring device, water area monitoring system, water area monitoring method, and recording medium

A processing device disposed inside a transmitter/receiver intended for use in optical fiber sensing using an optical fiber in order to enable restricting utilization of a prescribed range of acquired data, the processing device comprising: a mask unit which masks a prescribed range of acquired data, which is the data acquired by the transmitter/receiver through the optical fiber sensing; and an output unit which outputs post-masking data, which is the data that has undergone the aforementioned masking, to the outside of the transmitter/receiver, wherein the acquired data prior having the masking performed thereon for the prescribed range is not outputted to the outside.

Processing device, processing method, and recording medium

In order to avoid the phenomenon of communication being impeded and signals transmitted by the plurality of slave devices overlapping, a communication system according to the present invention has the first master device transmits a first pulsed light to the first transmission path and receives a return light of the first pulsed light from the second transmission path; each of the slave devices modulates the first pulsed light, and outputs the modulated first pulsed light as the return light of the first pulsed light; and the width of the first pulsed light is narrower than double the shortest distance from among the transmission distance between the slave device outputting the return light and the transmission distance between the first master device and the slave device outputting the return light.

Communication system and method for controlling communication system

An optical fiber sensing system is acquired by adding an optical fiber sensing function to an optical communication cable system, and the optical fiber sensing is performed by an interrogator by sending probe light to an optical fiber, detecting backscattered light of the probe light, and performing sensing on environmental information around the optical fiber. A first sensing device installed at a remote place different from a terminal station of the optical communication cable system includes the interrogator, a power source unit configured to receive power via the optical communication cable system and supply power into the device, and a communication unit configured to communicate with a second sensing device. The interrogator generates sensing data at each point on the optical fiber by performing sensing on environmental information around the optical fiber being connected to the first sensing device.

Optical fiber sensing system, measuring device, and measuring method

To apply an optical amplification repeater device to optical fiber sensing to lengthen a sensing range, as well as to enable compatibility with an optical communication system a cable system that uses a cable for optical fiber communication and optical fiber sensing of an environment surrounding the cable, wherein: the optical fiber communication is bidirectional communication using optical fiber pairs which are pairs of the optical fiber; in an optical fiber, a first wavelength band and a second wavelength band are different from each other; an optical amplification unit included in the optical amplification repeater device includes a first amplifier and a second amplifier that amplify rays of light in mutually opposing directions; and each of the communication optical signal, the probe light, and the backscattering light is amplified by at least either the first amplifier or the second amplifier.

Cable system

An optical fiber cable () according to each of the present disclosures includes a long tube () and at least one optical fiber () held and passed through an inside of the tube (). The tube () expands and contracts in a longitudinal direction when water pressure on an outside of the tube () changes. When the tube () expands and contracts in the longitudinal direction, the expansion and contraction of the tube () in the longitudinal direction is transmitted to the optical fiber () to expand and contract the optical fiber () in the longitudinal direction.

Optical fiber cable and water pressure sensing system, and sensitivity correction method

A measurement system, a measurement device, and a measurement method being able to measure a flow speed for each position of an optical fiber are provided. According to one example embodiment, a measurement system includes: an object provided in a fluid, and generating a self-excited vibration by the fluid; an optical fiber provided in the fluid, and detecting the vibration; a light source outputting light P to the optical fiber; an acquisition unit acquiring backscattered light generated from the light P in the optical fiber and including a pattern indicating the vibration in a vibration position on the optical fiber to which the vibration of the fluid is transmitted; and a measurement unit measuring, from a pattern included in the backscattered light and indicating the vibration, a flow speed of the fluid in the vibration position.

Measurement system, measurement device, and measurement method to detect a direction in which fluid flows

A slight movement of the ground is detected. A cable, which includes an optical fiber, is provided to have friction with the ground in such a way that the optical fiber is expanded and contracted in accordance with the movement of the ground. An optical output unit outputs a monitoring light to the optical fiber. A partial reflection unit is provided on a path of the optical fiber in the cable and partially reflects the monitoring light. An optical reception unit receives a reflection light reflected by the partial reflection unit. A calculation unit measures the length of the optical fiber to the partial reflection unit based on a round-trip propagation time of the reflection light that has been received and monitors its changes over time.

Surveying system and surveying method

An optical fiber cable for sound wave sensing that uses a straight optical fiber and is capable of suppressing directivity is provided. The optical fiber cable for sound wave sensing includes a cover part () that is capable of covering a straight cable core () and is provided with a sound wave refraction part () which refracts sound waves made incident roughly perpendicularly to a longitudinal direction of the cable core () and makes the sound waves be incident diagonally to the longitudinal direction of the cable core (). The cover part () includes a gap filling part () which covers the sound wave refraction part ().

Optical fiber cable for sound wave sensing

A member joining method includes applying a first resin member to a first member and a second resin member to a second member and joining end portions of the first and second members together. The member joining method further includes integrally joining the first resin member of the first member and the second resin member of the second member by heat deformation to mix and cure areas adjacent the end portions at a time of coating.

Member joining method

Growing community of inventors

Tokyo, Japan

Yutaka Yano