Abstract: A dielectric boundary surface estimation device includes: a pre-processing unit pre-processing wave data obtained by observing a dielectric by a radar device; a three-dimensional synthetic aperture processing unit performing three-dimensional synthetic aperture processing on the wave data pre-processed by the pre-processing unit; and a dielectric boundary surface estimating unit estimating a boundary surface between areas having different dielectric constants to each other using the wave data on which the three-dimensional synthetic aperture processing is performed by the three-dimensional synthetic aperture processing unit. The dielectric boundary surface estimating unit calculates a width and a thickness of the boundary surface.

Abstract: A dielectric boundary surface estimation device includes: a pre-processing unit pre-processing wave data obtained by observing a dielectric by a radar device; a three-dimensional synthetic aperture processing unit performing three-dimensional synthetic aperture processing on the wave data pre-processed by the pre-processing unit; and a dielectric boundary surface estimating unit estimating a boundary surface between areas having different dielectric constants to each other using the wave data on which the three-dimensional synthetic aperture processing is performed by the three-dimensional synthetic aperture processing unit. The dielectric boundary surface estimating unit calculates a width and a thickness of the boundary surface.

Abstract: A hot-rolled steel sheet including predetermined components, in which the amounts of Cr and Al added satisfy Expression (1) below, a metallographic structure has, by % by volume, a ferrite fraction of more than 90% and 98% or less, a martensite fraction of 2% to less than 10%, and, a fraction of a residual structure made of one or more of pearlite, bainite, and residual austenite being less than 1%, the ferrite has an average circle-equivalent diameter of 4 ?m or more and a maximum circle-equivalent diameter of 30 ?m or less, and the martensite has an average circle-equivalent diameter of 10 ?m or less and a maximum circle-equivalent diameter of 20 ?m or less. [Cr]×5+[Al]?0.50??Expression (1) Here, in Expression (1), [Cr] represents an amount of Cr (mass %), and [Al] represents an amount of Al (mass %).

Abstract: A hot-rolled steel sheet including predetermined components, in which the amounts of Cr and Al added satisfy Expression (1) below, a metallographic structure has, by % by volume, a ferrite fraction of more than 90% and 98% or less, a martensite fraction of 2% to less than 10%, and, a fraction of a residual structure made of one or more of pearlite, bainite, and residual austenite being less than 1%, the ferrite has an average circle-equivalent diameter of 4 ?m or more and a maximum circle-equivalent diameter of 30 ?m or less, and the martensite has an average circle-equivalent diameter of 10 ?m or less and a maximum circle-equivalent diameter of 20 ?m or less. [Cr]×5+[Al]?0.50??Expression (1) Here, in Expression (1), [Cr] represents an amount of Cr (mass %), and [Al] represents an amount of Al (mass %).

Abstract: A polygon pattern generating unit 6 to extract a plurality of luminance points from a dictionary image of each group to generate a dictionary polygon pattern whose vertices are the plurality of luminance points, and extract a plurality of luminance points from an observation image to generate a target polygon pattern whose vertices are the plurality of luminance points, and a pattern comparing unit 10 to perform a comparison of the dictionary polygon pattern of each group and the target polygon pattern are disposed, and a type determining unit 15 determines the type of an unknown target by using the result of the comparison of the patterns which is performed by the pattern comparing unit 10.

Abstract: The present invention provides a steel sheet excellent in both a balance between strength and elongation and a balance between strength and hole expandability, in other words, a multi-phase steel sheet having an excellent balance between strength and hole expandability. The present invention is a multi-phase steel sheet excellent in hole expandability characterized in that: the steel sheet contains, as chemical components in mass, C: 0.03 to 0.15%, P: not more than 0.010%, S: not more than 0.003%, and either one or both of Si and Al in a total amount of 0.5 to 4%, and one or more of Mn, Ni, Cr, Mo and Cu in a total amount of 0.

Abstract: The present invention provides a steel sheet excellent in both a balance between strength and elongation and a balance between strength and hole expandability, in other words, a multi-phase steel sheet having an excellent balance between strength and hole expandability. The present invention is a multi-phase steel sheet excellent in hole expandability characterized in that: the steel sheet contains, as chemical components in mass, C: 0.03 to 0.15%, P: not more than 0.010%, S: not more than 0.003%, and either one or both of Si and Al in a total amount of 0.5 to 4%, and one or more of Mn, Ni, Cr, Mo and Cu in a total amount of 0.

Abstract: The present invention provides a steel sheet excellent in both a balance between strength and elongation and a balance between strength and hole expandability, in other words, a multi-phase steel sheet having an excellent balance between strength and hole expandability. The present invention is a multi-phase steel sheet excellent in hole expandability characterized in that: the steel sheet contains, as chemical components in mass, C: 0.03 to 0.15%, P: not more than 0.010%, S: not more than 0.003%, and either one or both of Si and Al in a total amount of 0.5 to 4%, and one or more of Mn, Ni, Cr, Mo and Cu in a total amount of 0.