Abstract: The present disclosure relates to a signal processing device that: acquires a signal obtained by repeatedly injecting a plurality of light pulses with different optical frequencies into an optical fiber, and by performing distributed acoustic sensing-phase (DAS-P); calculates a phase change, caused by vibration applied to a section of the optical fiber, using the acquired signal; removes, from the calculated phase change, a component regarding a repetition period of the same optical frequency of the plurality of light pulses; and calculates the vibration applied to the section of the optical fiber, using a phase change obtained by removing the component regarding the period.

Abstract: The present disclosure provides an underground facility position contrast system S, which includes: a scattered light intensity distribution measurement device 1 for measuring, when an earthquake vibration is applied to an optical fiber F laid underground, a change over time in a scattered light intensity distribution in a longitudinal direction of the optical fiber F; and an underground facility position contrast device 2 for measuring a change over time in a distortion response distribution in the longitudinal direction of the optical fiber F based on the change over time in the scattered light intensity distribution in the longitudinal direction of the optical fiber F, estimating an underground facility state of the optical fiber F based on the change over time in the distortion response distribution in the longitudinal direction of the optical fiber F, and associating the underground facility position of the optical fiber F with a longitudinal distance of the optical fiber F.

Abstract: Objects of the present invention are to provide a snow accumulation estimating system and a method for estimating a snow accumulation which enable a snow accumulation to be remotely measured accurately and economically. A snow accumulation estimating system 301 according to the present invention includes: an optical fiber 50 that receives vibration from a random point on snow; a vibration measuring instrument 11 that measures the vibration received by the optical fiber 50 as a distribution in a longitudinal direction of the optical fiber 50; and an analysis processing unit 12 that has, as accumulated data, a relationship between a snow accumulation and the vibration received by the optical fiber 50, compares the distribution measured as measurement data by the vibration measuring instrument 11 with the accumulated data, and estimates a snow accumulation at the random point.

Abstract: An optical semiconductor element includes a substrate and a plurality of cells. Each cell includes an optical layer, a first semiconductor layer, and a second semiconductor layer. The plurality of cells include a first cell and a second cell. The second semiconductor layer of the first cell and the first semiconductor layer of the second cell are electrically connected to each other by a first connection portion of a first wiring portion. The first wiring portion has a first extending portion that extends from the first connection portion so as to surround four side portions of the optical layer of the first cell. The optical layer is an active layer that generates light having a central wavelength of 3 ?m or more and 10 ?m or less or an absorption layer having a maximum sensitivity wavelength of 3 ?m or more and 10 ?m or less.

Abstract: The present disclosure aims to reduce a strain of an observed waveform caused by a difference in proportional constant between responses of different optical frequencies of probe light resulting from vibration in a phase OTDR that uses different optical frequencies.

Abstract: An optical semiconductor element includes: a substrate; and a plurality of cells formed on the substrate, the plurality of cells including a first cell, a second cell, and a third cell. A first electrode electrically connected to a first semiconductor layer of the first cell is arranged on the top surface of the first cell, and a second electrode electrically connected to a second semiconductor layer of the third cell is arranged on the top surface of the second cell. Each of the first electrode and the second electrode has a planned contact region with which solder comes into contact during electrical connection with an external member. When viewed from the thickness direction of the substrate, the area of the second electrode on the top surface of the second cell is smaller than the area of the first electrode on the top surface of the first cell.

Abstract: Provided is a honeycomb-type ceramic positive electrode having a columnar honeycomb structure, having a first end face, a second end face parallel to the first end face, and an outer side face perpendicular to the first end face and the second end face, and also having a plurality of holes extending from the first end face to the second end face. The honeycomb-type ceramic positive electrode is composed of a lithium complex oxide sintered body in which a plurality of primary grains composed of a lithium complex oxide are bonded, and when a central axis of the columnar honeycomb structure parallel to the outer side face or an axis parallel thereto is defined as a z-axis, the plurality of primary grains are oriented in a z-axis direction.

Abstract: Provided is a lithium secondary battery, including: a positive electrode layer including a lithium composite oxide sintered body; a negative electrode layer; a separator interposed between the positive electrode layer and the negative electrode layer; an electrolytic solution impregnated into the positive electrode layer, the negative electrode layer, and the separator; and an exterior body, which has a closed space and is configured to store the positive electrode layer, the negative electrode layer, the separator, and the electrolytic solution in the closed space. This lithium secondary battery has a determination coefficient R2 of 0.8 or more, which is obtained when plots of a square root of the number of days elapsed of up to 180 days and a capacity maintenance ratio (%) in a float charging test are linearly regressed.

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: A reuse support system performs an electrode degradation judgment to judge, based on one or a plurality of kinds of first data diagnosed regarding a ceramic electrode removed from a lithium-ion secondary battery having the ceramic electrode, whether or not a degradation degree of the removed ceramic electrode satisfies a condition for enabling regeneration of the ceramic electrode.

Abstract: The present disclosure relates to a vibration measuring instrument that repeatedly injects a plurality of light pulses with different optical frequencies into an optical fiber, and performs distributed acoustic sensing-phase (DAS-P). In the vibration measuring instrument, light pulses having a waveform with a spectral side lobe smaller than a side lobe of a rectangular wave are used as the plurality of light pulses.

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: 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 optical semiconductor element includes a substrate, a first termination cell, and a cell. A first electrode is arranged on the top surface of the first termination cell. The first termination cell and the cell are connected to each other by a wiring layer extending from the top surface of the first termination cell to the cell. The first electrode is exposed to the outside through an opening formed in an insulating layer. The wiring layer is spaced apart from the first electrode on the top surface of the first termination cell, and is electrically connected to the first electrode via a first semiconductor layer. The first portion has a contact region in contact with the first semiconductor layer. The width of the contact region is equal to or greater than the width of the opening.

Abstract: A lithium secondary cell includes a positive electrode, a separator, a negative electrode, an electrolytic solution, and a cell case. The positive electrode, the negative electrode, and the separator are impregnated with the electrolytic solution. The cell case is a sheet-like member and convers the positive electrode and the negative electrode from both sides in the direction of superposition. The cell case houses therein the positive electrode, the separator, the negative electrode, and the electrolytic solution. The electrolytic solution contains an electrolytic solution material serving as a base compound and LiDFOB serving as an additive. The moisture content in the electrolytic solution is higher than or equal to 10 ppm by mass and lower than or equal to 15 ppm by mass.

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: An object is to provide an optical fiber path search method, an optical fiber path search system, a signal processor, and a program that can be operated free of the effects of walls, supporting members, and the like so that only a signal generated by an acoustic wave propagating through the air can be extracted.

Abstract: An object of the present invention is to provide a Brillouin gain spectrum distribution measuring method and apparatus capable of measuring a BGS, having a line width narrower than usual, in a distributed manner in the longitudinal direction of an optical fiber under test. This measuring apparatus prepares pump light in which a pulse is added to continuous light and probe light of continuous light in which a frequency is shifted from the pump light, makes the probe light incident on one end of the FUT and the pump light incident on the other end, and obtains a time waveform of a component amplified by the pump light pulse of a probe light intensity amplified by the pump light. This measuring apparatus changes an optical frequency difference between the pump light and the probe light, and obtains a time waveform for each optical frequency difference. This measuring apparatus obtains a BGS distribution of the FUT from these time waveforms.