Abstract: A sea state estimation device includes a time history memory which stores a time history of ship motion data relating to a rolling angle, a pitching angle and a heaving displacement; a hull condition data calculator which calculates current hull condition data of the hull based on the time history of the ship motion data stored in the time history memory; a cross spectra calculator which calculates cross spectra of respective ship motions; a hull response function calculator which calculates a hull response function based on the hull condition data calculated by the hull condition data calculator; and a sea state estimator which estimates a sea state in sea on which the hull is running based on the cross spectra of the respective ship motions calculated by the cross spectra calculator and the hull response function calculated by the hull response function calculator.

Abstract: Provided is a transverse metacenter height estimation device that includes: a history storage means for storing time sequence data of the roll angle of a hull; and a transverse metacenter height estimation means that estimates the transverse metacenter height of the hull on the basis of the time sequence data of the roll angle of the hull, such data stored by the history storing means. The transverse metacenter height estimation device is characterized in that the transverse metacenter height estimation means first calculates a roll natural frequency on the basis of the time sequence data of the roll angle of the hull, sets the calculated roll natural frequency as an observation model, carries out state estimation on the basis of a normal state spatial model in which the transverse metacenter height and the gyration radius of the hull are used as state variables, and thereby estimates the transverse metacenter height.

Abstract: A method to efficiently measure the oxygen content of both the headspace and fluid within a hermetically sealed container. A container is pierced using a hollow needle with the interior space sealed from the outside and the tip of said hollow needle removed, and the interior space is made continuous with the headspace within the container. A probe of a fluorescent oxygen concentration meter is inserted through the hollow needle to the interior of the container, positioned in the headspace within the container, and the oxygen concentration of the headspace 3 is measured. The probe is inserted further so that the fluorescent material is submerged in the fluid inside the container, and the dissolved oxygen concentration inside the fluid is measured.

Abstract: An object is to offer a method that can efficiently measure the oxygen content of both the headspace and fluid within a hermetically sealed container by taking advantage of the characteristics of a fluorescent-type oxygen concentration meter. A container 2 is pierced using a hollow needle 28 with the interior space 28a sealed from the outside and the tip of said hollow needle 28 removed, and the interior space 28a is made continuous with the headspace within the container 2; a probe 11 of a fluorescent oxygen concentration meter 10 is inserted through the hollow needle 28 to the interior of the container 2; the fluorescent material of the probe 11 is positioned in the headspace 3 within the container 2, and the oxygen concentration of the headspace 3 is measured; and the probe 11 is inserted further so that the fluorescent material is submerged in the fluid 4 inside the container 2, and the dissolved oxygen concentration inside the fluid 4 is measured.