Abstract: A power cutoff device includes a relay unit including a switch having a connecting state and a cutoff state, a cutoff unit connected in series to the switch, a current detector to detect an object current flowing through the cutoff unit, and a controller to control the relay unit and the cutoff unit. The cutoff unit has a connecting state and an irreversible cutoff state. The controller obtains a changing rate of the object current with respect to time. The controller causes the switch to be in the connecting state and causes the cutoff unit to be in the connecting state if determining that the changing rate is not greater than a changing-rate threshold. The controller causes the relay unit to be in the cutoff state and cause the cutoff unit to be in the irreversible cutoff state if determining that the changing rate is greater than the changing-rate threshold.

Abstract: A signal processing method executed by a signal processing device, includes performing a phase connection process on a position in a space and a phase value at each of a plurality of times, performing outlier correction of a phase value for each position in the space in a predetermined direction of the space at a predetermined time among the plurality of times based on a result of the phase connection process, and correcting a phase value at a time other than the predetermined time for each of correction target positions among positions in the space.

Abstract: An object of the present invention is to provide a sensing system, a sensing method, and an analyzing device using OFDR in which a sensing range of strain/temperature is less likely to be limited by a frequency sweep width. In the sensing method using OFDR, the sensing system according to the present invention employs sequential update, per measurement by one frequency sweep of the probe light, for setting the reference spectrum to the spectrum of an immediately preceding measurement, by which a spectral shift between an n-th measurement and an (n?1)th measurement is obtained, and the spectral shifts individually obtained between the measurements are integrated.

Abstract: An effective cancer treatment method is disclosed. According to the cancer treatment method, a CD47 inhibitory substance, an immune checkpoint inhibitory substance (for example, an anti-PD-1 antibody), and a standard therapy (for example, a combination therapy in which Bevacizumab or Cetuximab is added to FOLFOX therapy for radically unresectable advanced or recurrent colorectal cancer, or FOLFIRINOX therapy or a dose-reduced regimen thereof for pancreatic cancer having distant metastasis) are combined. The treatment method is useful for cancer treatment.

Abstract: It is an object of the present invention to provide an aerial optical fiber cable inspection method, an aerial optical fiber cable inspection device, and a program which can identify a cable sagging section from vibration sensing results. In the aerial optical fiber cable inspection method according to the present invention, a vibration distribution waveform along the longitudinal direction of an aerial optical fiber cable measured using an optical fiber vibration sensing device is received as an input, a standard deviation of the amplitude of vibration at each position in the vibration distribution waveform is calculated, and a section with a standard deviation larger than that of other sections is identified as a cable sagging section.

Abstract: An object of the present invention is to provide a cable test system, an analysis apparatus, a cable test method, and a program capable of recognizing a sag section of an overhead cable without sending a worker to a site. A cable test system according to the present invention includes an optical fiber vibration distribution measurement apparatus 11 that acquires a vibration distribution waveform of an overhead optical fiber cable 50 to be tested, the vibration distribution waveform being represented in a time domain and a distance domain in a longitudinal direction, and an analysis apparatus 12 that calculates a propagation speed of vibrations propagating through the overhead optical fiber cable 50 from the vibration distribution waveform and detects, as a cable sag section, a section of the overhead optical fiber cable 50 in which the propagation speed is equal to or lower than a threshold value.

Abstract: The present disclosure generates an optical spectrogram, representing a temporal change in frequency characteristics, using a plurality of spectral data measured by an OFDR measurement instrument at different times, and filters the optical spectrogram in both a time direction and a frequency direction.

Abstract: The present disclosure provides a device that accurately measures vibration at a designated position of a sensing fiber without using digital signal processing to compensate for distance fluctuation. Digital signal processing for correcting fluctuation of a measurement distance due to a frequency offset of a beat signal due to vibration, which is a measurement target, is simplified. In the present disclosure, vibration at a designated position of the sensing fiber is accurately measured without using the digital signal processing to compensate for the distance fluctuation. A spectrum analysis length of an electrical field E(?n) of backscattered light is set to be larger than a delay deviation Nd due to frequency modulation caused by dynamic strain. An index of tolerance of vibration distribution measurement to the delay deviation Nd is also clarified.

Abstract: The present disclosure is an optical line test system that detects a distribution of loss points of an optical line in a longitudinal direction, using a coherent light measurement device, applies vibration to facility disposed on a path of the optical line, detects a vibration point of the optical line in a longitudinal direction upon applying the vibration, using the coherent light measurement device, and identifies the loss point based on correspondence between the detected loss point and vibration point.

Abstract: An object of the present disclosure is to provide a method for remotely identifying a utility pole position and estimating a state of an overhead optical fiber cable. The present disclosure is a method for identifying a utility pole position including identifying a boundary region of a vibration distribution as a utility pole position, from a vibration distribution pattern obtained by measuring strain amounts with respect to distances of an optical fiber by an optical fiber vibration distribution measuring method at each time and sequentially stacking the strain amounts.

Abstract: A vibration distribution measurement system includes a frequency sweep light source that outputs frequency sweep light, an optical splitter that splits the frequency sweep light into probe light and local light, an optical mixer that mixes backscattered light from the sensing fiber as signal light with the local light, the backscattered light being obtained by causing the probe light to be incident on the sensing fiber, and an analysis unit that analyzes a beat signal obtained from output light of the optical mixer. The analysis unit estimates a distance offset from a measurement result obtained by measuring a distribution waveform of the signal light by measuring the beat signal at a measurement time sufficiently shorter than a cycle of the vibration of the sensing fiber, and measures a distribution of a vibration at any position by compensating for the distance offset.

Abstract: A sufficient sealing property of a through hole is ensured. A sealing structure includes a cylindrically-shaped body part inserted into the through hole, formed of a thin plate of a first thickness, one end of the body part being open and another end of the body part being closed, a tapered part connected to the opened one end of the body part and including a diameter gradually expanding outward as a distance from the body part increases, and a first bent part connected to the tapered part, formed of a thin plate thinner than the first thickness, and bent inward so that a protruding part protruding outward elastically abuts against an inner peripheral surface of the through hole.

Abstract: The present disclosure relates to a frequency modulation amount measuring device that measures an optical spectral shift of scattered light at a position in an optical transmission line, and calculates a frequency modulation amount at the position, using the measured optical spectral shift.

Abstract: An object is to provide a vibration detection apparatus and a vibration detection method which can avoid occurrence of a point where detection sensitivity deteriorates in vibration detection of a scattered light intensity monitor according to optical frequency multiplexing. The present invention conceives a multi-dimensional space having as many dimensions as the number of frequencies to be used, causes scattered light intensity change at each optical frequency to correspond to each axis, plots a scattered light signal as a vector on the space, performs linear approximation passing through an origin on the space having a plurality of plotted vector points as original data, and performs vibration detection using a direction vector of an approximate straight line obtained as a result of the approximation.

Abstract: The present disclosure aims to enable measurement of a long distance exceeding 1 km with a spatial resolution of 100 ?m or lower, and diagnosis of health of an optical device installed at a long distance. An apparatus according to the present disclosure is an optical frequency domain reflectivity measuring apparatus that includes: a local light delay fiber that delays local light; an optical 90-degree hybrid that receives an input of the local light delayed by the local light delay fiber and backscattered light from the measurement target, causes the local light and the backscattered light to interfere with each other, and generates an in-phase component and an orthogonal component of a beat signal generated by the interference; and a balance photodetector that detects the in-phase component and the orthogonal component of the beat signal. In the apparatus, an optical frequency response of the measurement target is measured with respect to a relative distance based on the local light delay fiber.

Abstract: An object of the present disclosure is to provide a method and an apparatus for acquiring curvature and torsion using an inexpensive sensor medium. Disclosed is a measurement apparatus including a fiber ribbon including a plurality of coated fibers arranged in parallel, a strain measurement unit that measures strain amounts of the plurality of coated fibers, and an arithmetic processing unit that calculates curvature and torsion of the fiber ribbon using a strain amount of a coated fiber arranged in a middle portion of the plurality of coated fibers and a strain amount of a coated fiber arranged in a marginal portion of the plurality of coated fibers.

Abstract: An object of the present disclosure is to enable vibration analysis using a spectral shift under appropriate conditions depending on a measurement object. According to the present disclosure, there is provided a vibration distribution measuring apparatus which measures backscattered light in an optical fiber to be measured a plurality of times at different times, extracts an optical spectrum of a window section determined from a plurality of backscattered light waveforms obtained by the measurement, and measures a vibration distribution in the optical fiber to be measured using optical spectra of the plurality of extracted backscattered light waveforms, in which the optical spectrum of the window section is calculated using the window section in which the vibration amplitude in the window section in the optical fiber to be measured is larger than a threshold value defined in the window section.

Abstract: An object is to provide an optical fiber route search method, an optical fiber route search device, and a program that can efficiently confirm a path of an optical fiber that is installed over a long distance or across a large range. The optical fiber route search method according to the present invention carries out optical measurement that performs distributed measurement of the state of an optical fiber while applying a disturbance to the optical fiber in a portion in which wires of the optical fiber are parallel to each other, branch out, or intersect with each other (a proximity portion), and determines that the position in which the number of singularities (peaks or intensity fluctuations) fluctuates (becomes plural) is the position of the proximity portion from a distribution diagram obtained through the optical measurement.

Abstract: An object of the present disclosure is to provide a method and an apparatus for acquiring curvature and torsion using an inexpensive sensor medium. Disclosed is a measurement apparatus including a fiber ribbon including a plurality of coated fibers arranged in parallel, a strain measurement unit that measures strain amounts of the plurality of coated fibers, and an arithmetic processing unit that calculates curvature and torsion of the fiber ribbon using a strain amount of a coated fiber arranged in a middle portion of the plurality of coated fibers and a strain amount of a coated fiber arranged in a marginal portion of the plurality of coated fibers.

Abstract: A manhole position identification method of the present invention includes: measuring, from an end of an optical fiber, a temporal variation in scattering light from the optical fiber when an impact blow is applied to a cover of a manhole located on a path of the optical fiber, so as to obtain temporal variations in a scattering light intensity distribution in a longitudinal direction of the optical fiber; determining an occurrence of vibration due to the impact blow based on the temporal variations at positions in the scattering light intensity distribution, so as to identify an impact blow position on the optical fiber; and associating the impact blow position on the optical fiber with a map position of the manhole whose cover has received the impact blow, so as to identify a position of the manhole expressed in terms of optical fiber length from the end.