Abstract: Provided is an ultrasonic flow sensor with improved practicality. An ultrasonic wave is transmitted and received by an ultrasonic element. A first flow rate value of a fluid in a pipe is calculated based on a propagation time difference of an ultrasonic signal, a measurement value corresponding to an ultrasonic velocity, and a parameter for identifying an inner diameter of the pipe. A second flow rate value of the fluid in the pipe is calculated based on a frequency shift of the ultrasonic signal and the parameter. The first flow rate value is calculated using a propagation time of the ultrasonic signal as the measurement value in accordance with a correspondence relationship among a distance of a path through which the ultrasonic wave propagates through the fluid in the pipe, a time for which the ultrasonic signal propagates in the path, and the ultrasonic velocity.

Abstract: An object of the present invention is to provide a core position recognition method, a connection method, and a connection apparatus that can simplify connection operations, and reduce rotational displacement and positional displacement. The connection apparatus according to the present invention includes a function capable of acquiring the rotation amount of an MCF during the bonding/fixing step. Specifically, the connection apparatus of the present invention uses an MCF with lines drawn on a side surface thereof, thereby recognizing the rotation amount of the MCF from the side surface, and calculating the absolute positions of the cores. The connection apparatus according to the present invention can recognize the absolute position s of the cores from a side image of an MCF in a state in which the MCF has been rotated.

Abstract: An object of the present invention is to provide an optical transmission system capable of controlling a transmission capacity and a signal processing load of a MIMO equalizer, without depending on the number of propagation modes of the optical fiber.

Abstract: An objective of the present invention is to provide an amplification fiber having a cladding excitation configuration that improves amplification efficiency and an optical amplifier. An amplification fiber (10) according to the present invention is a multi-core amplification fiber having, from one end (E1) to the other end (EE), a plurality of cores (11b) in a cladding (11a), and a total distance from the one end (E1) to the other end (EE) in which rare earth ions are doped differs depending on the types of cores (11b). The cores (11b) are preferably disposed such that the cores of the same type are not adjacent to each other. By arranging the types of the cores in this manner, requirements for inter-core crosstalk can be mitigated since the bands of signal light in the adjacent cores are different. As a result, a density of cladding excitation light can be increased by shortening the inter-core distance, and thus the amplification efficiency can be improved.

Abstract: An object is to provide an optical amplifier with a cladding pumped configuration that improves amplification efficiency. The optical amplifier according to the present invention includes a pump light conversion fiber 11 that converts first pump light L1 with a first wavelength propagating in a cladding into second pump light L2 with a second wavelength, an amplification fiber 13 that is connected to the pump light conversion fiber 11 and optically amplifies signal light Ls with the second pump light L2 supplied to the cladding from the pump light conversion fiber 11, and an oscillator 12 that causes the second pump light L2 to be reflected on two reflectors 15 and to reciprocate within the claddings of the pump light conversion fiber 11 and the amplification fiber 13 to cause laser oscillation of the second pump light L2.

Abstract: An objective is to provide an optical amplifier having a core excitation configuration that improves amplification efficiency. An optical amplifier according to the present invention includes an excitation light conversion fiber 11 that absorbs first excitation light L1 propagating in a cladding and having a first wavelength and emits, into a core, spontaneous emission light having a second wavelength, an oscillator 12 for causing the spontaneous emission light to be reflected on two reflectors 15 to reciprocate the light within the core of the excitation light conversion fiber 11 and laser-oscillating second excitation light L2 having the second wavelength, and an amplification fiber 13 that is connected to the excitation light conversion fiber 11 and amplifies signal light with the second excitation light L2 supplied from the excitation light conversion fiber 11 to the core.

Abstract: An objective of the present invention is to provide an optical amplifier having a cladding excitation configuration that improves amplification efficiency.

Abstract: An object of the present invention is to provide an optical transmission system capable of easily controlling a transmission capacity and an optical signal quality even if a MIMO equalizer is provided. The optical transmission system according to the present invention is provided with an N×M MIMO equalizer, includes receivers (N units) equal in number to the spatial multiplexing order L of an optical fiber, and changes the number M of the signal beams of light transmitted through the optical fiber in the range of the spatial multiplex order L or less. The adjustment of the number M of signal beams of light makes it possible to adjust a transmission capacity and a signal quality of the optical transmission system even after construction of the transmission line.

Abstract: An object is to provide a multi-core configuration for acquiring a random mode coupling in a case of an arbitrary core refractive index. A multi-core optical fiber according to the present invention is an optical fiber in which two or more core regions are arranged in a clad region having a refractive index at a minimum core interval ? smaller than a refractive index of the cores, a configuration of the cores is that including one propagation mode, and the core configuration and the core interval are adjusted so that an inter-mode coupling coefficient between adjacent cores is within a range from 0.73 to 120 m?1.

Abstract: An example of an information processing apparatus acquires action data based on an output of a sensor according to a fitness action performed by a player, and executes a game event. In the game event, the information processing apparatus designates at least one type of fitness event from among a plurality of types of fitness events. Each fitness event causes the player to perform a fitness action. During the game event, the information processing apparatus executes a fitness event that causes the player to perform a fitness action corresponding to the designated fitness event until an ending condition is satisfied. The information processing apparatus determines whether or not the achievement condition has been satisfied, based on the action data acquired during the fitness event. The information processing apparatus repeats designation and execution of the fitness event until it is determined that the achievement condition has been satisfied.

Abstract: An example of an information processing apparatus acquires action data based on an output of a sensor according to a fitness action performed by a player, and executes a game event. In the game event, the information processing apparatus designates at least one type of fitness event from among a plurality of types of fitness events. Each fitness event causes the player to perform a fitness action. During the game event, the information processing apparatus executes a fitness event that causes the player to perform a fitness action corresponding to the designated fitness event until an ending condition is satisfied. The information processing apparatus determines whether or not the achievement condition has been satisfied, based on the action data acquired during the fitness event. The information processing apparatus repeats designation and execution of the fitness event until it is determined that the achievement condition has been satisfied.

Abstract: An example of an information processing apparatus acquires action data based on an output of a sensor according to a fitness action performed by a player, and executes a game event. In the game event, the information processing apparatus designates at least one type of fitness event from among a plurality of types of fitness events. Each fitness event causes the player to perform a fitness action. During the game event, the information processing apparatus executes a fitness event that causes the player to perform a fitness action corresponding to the designated fitness event until an ending condition is satisfied. The information processing apparatus determines whether or not the achievement condition has been satisfied, based on the action data acquired during the fitness event. The information processing apparatus repeats designation and execution of the fitness event until it is determined that the achievement condition has been satisfied.

Abstract: In the exemplary embodiment, a computer is caused to: perform question presentation processing of designating a correct direction for each question by display; specify an input direction on the basis of the operation data transmitted from an operation device; perform correct answer determination for whether the input direction is the designated correct direction or a direction other than the designated correct direction on the basis of a predetermined determination condition; in performing the correct answer determination, change the determination condition in accordance with the correct direction so that the specified input direction becomes likely to be determined to be the correct answer; and progress a game on the basis of a result of the correct answer determination.

Abstract: An optical amplifier of the present disclosure includes an optical resonator that includes an amplification fiber capable of amplifying signal light having one or more propagation modes and resonates at least one propagation mode of the signal light amplified by the amplification fiber; an excitation light source that outputs excitation light for exciting the amplification fiber; and a multiplexer that multiplexes the signal light and the excitation light, in which the optical resonator includes a gain clamp setting unit which sets gain clamp for at least one propagation mode out of a plurality of propagation modes resonating in the optical resonator.

Abstract: The optical fiber of the present invention includes a core, and a cladding that is provided on an outer periphery of the core and has a refractive index lower than a refractive index of the core region. In the optical fiber of the present invention, a V value representing a normalized frequency of an LP02 mode is greater than or equal to 4.8 and less than or equal to 6.4.

Abstract: An example of an information processing apparatus acquires action data based on an output of a sensor according to a fitness action performed by a player, and executes a game event. In the game event, the information processing apparatus designates at least one type of fitness event from among a plurality of types of fitness events. Each fitness event causes the player to perform a fitness action. During the game event, the information processing apparatus executes a fitness event that causes the player to perform a fitness action corresponding to the designated fitness event until an ending condition is satisfied. The information processing apparatus determines whether or not the achievement condition has been satisfied, based on the action data acquired during the fitness event. The information processing apparatus repeats designation and execution of the fitness event until it is determined that the achievement condition has been satisfied.

Abstract: A clamp-on type ultrasonic flowmeter which is detachably attached to an outer wall of cylindrical piping is provided. An ultrasonic signal is transmitted to the piping from one of the first and the second ultrasonic devices, a plate wave corresponding to the ultrasonic signal is generated, and an ultrasonic signal corresponding to the plate wave is received by the other ultrasonic device. A pipe wall thickness of the piping and a frequency of the ultrasonic signal are in a state in which a plate wave of a low order asymmetric mode is significantly excited in the piping. A flow rate is calculated corresponding to phase velocity characteristics of the low order asymmetric mode.

Abstract: Provided is a differential modal attenuation compensation fiber that has a simple structure and can reduce MDL while eliminating the need for precise alignment work, an optical amplifier, and a transmission line design method. The differential modal attenuation compensation fiber according to the present invention, imparts excess loss to a desired propagation mode by forming a cavity portion or a ring-shaped high refractive index portion in a core of an optical fiber. By forming the cavity portion or the ring-shaped high refractive index portion in a part of the profile of the core, electric field distribution of a particular mode propagating through the fiber can be controlled, and different losses can be imparted to different propagation modes at an interface between the cavity portion or the ring-shaped high refractive index portion and a region not including the cavity portion or the ring-shaped high refractive index portion.

Abstract: According to the connection device, the connection method, the optical connector manufacturing device, and the method for manufacturing an optical connector, rotation alignment of an MCF becomes unnecessary because an image of an end surface of the MCF to be connected is captured, the position of the core is located, and an optical waveguide is formed on a substrate so as to match the position. Thus, it is possible to solve the problem of increasing loss or complex connection work caused by rotational misalignment in association with rotation alignment.

Abstract: In the exemplary embodiment, a computer is caused to: perform question presentation processing of designating a correct direction for each question by display; specify an input direction on the basis of the operation data transmitted from an operation device; perform correct answer determination for whether the input direction is the designated correct direction or a direction other than the designated correct direction on the basis of a predetermined determination condition; in performing the correct answer determination, change the determination condition in accordance with the correct direction so that the specified input direction becomes likely to be determined to be the correct answer; and progress a game on the basis of a result of the correct answer determination.