Abstract: A method of and apparatus and software for validating a computer model of a complex system comprising eliciting information regarding the complex system from one or more human experts, determining from the elicited information a set of variables and a set of constraints on those variables regarding the complex system, automatically by computer examining output of the computer model to locate violations of determined constraints, and generating output establishing any located violations.

Abstract: A method of and apparatus and software for validating a computer model of a complex system comprising eliciting information regarding the complex system from one or more human experts, determining from the elicited information a set of variables and a set of constraints on those variables regarding the complex system, automatically by computer examining output of the computer model to locate violations of determined constraints, and generating output establishing any located violations.

Abstract: A method of assessing the depth to which a crack extends below the surface of an object, or the thickness of a ligament (12) covering a crack (14), in which a thermal imager )26) is used to obtain a surface temperature profile along a line extending across the crack or ligament as heat is flowing across the surface and through the ligament. There is a steep drop in temperature across the crack or ligament, and the size of this drop at a predetermined time after the start of the heat flow may be simply related to the crack depth or ligament thickness.