Abstract: A sound wave receiving device including: an aerial vehicle having a rotor blade; an array sensor mounted on the aerial vehicle and including a plurality of microphones; a first shield installed between the rotor blade and the array sensor, the first shield being configured to suppress an influence of sound wave noise generated by the rotor blade on a sound wave received by the array sensor; and a second shield provided along a peripheral portion of the array sensor, the second shield being configured to suppress reception by the array sensor of external sound from outside a sound wave reception range set in advance for the sound wave.

Abstract: An abundance of specific species of phytoplankton in a phytoplankton group in which a plurality of kinds coexists is calculated in a simple manner. Based on a reference sample intensity ratio r0, a reference sample total fluorescence intensity I0, and an existing quantity K0 of specific species of phytoplankton, an intensity ratio rd of other species of plankton is calculated. An analysis sample that is expected to have similarity with the reference sample is irradiated with the excitation light, an intensity of fluorescence emitted from the analysis sample is measured in each of wavelength bands A and B, and an intensity ratio r is calculated. A total fluorescence intensity I is measured, and an existing quantity K of the specific species of the phytoplankton is calculated based on the intensity ratio rd of other species of plankton, the intensity ratio r, and the total fluorescence intensity I.

Abstract: A device for determining sound source direction includes an array sensor including a plurality of microphones that measures a sound wave, and a processor for calculating a sound pressure in each direction based on sound pressure information of the sound wave obtained by the array sensor and for determining a direction in which the sound pressure is maximum as a direction of sound wave arrival. The plurality of microphones is provided at vertices of two or more concyclic polygons that are on a same plane and that have a same center and are arranged so as to be non-rotationally symmetric as a whole array sensor.