Provided is a method for judging spatial oblique distribution patterns and deep prospecting and targeting concealed ore bodies of a hydrothermal deposit controlled by structures. The method includes: a structural classification ore-controlling law and an combination pattern of ore-controlling structures are determined. A mechanical mechanism of the spatial distribution of ore deposits, ore segments, ore body groups and ore bodies controlled by multi-scale structures is revealed, and an oblique distribution law of ore bodies on a plane and a cross-section is determined. According to the oblique distribution law and the erosion depth of ore body groups and ore segments, pinching-out elevations of the maximum deep extensions of main ore body groups and ore segments are inferred. Deep prospecting and targeting of a concealed ore body is realized, and the deep resource potential is predicted.

A defect determination apparatus according to an aspect of the present disclosure includes: a physical quantity acquisition circuitry which, in operation, acquires a target physical quantity, the target physical quantity being a physical quantity generated in a power source during a new screw tightening; a model acquisition circuitry which, in operation, acquires a first trained model obtained through unsupervised learning of a physical quantity generated in the power source during a past screw tightening that has been normally completed; and a determination circuitry which, in operation, determines whether the new screw tightening has been normally completed by applying the target physical quantity to the first trained model.