Abstract: Provided are a control method, a control apparatus, a training method, and a training apparatus based on thickness estimation of a wafer substrate. The training method includes generating a training spectrum signal according to a thickness of a wafer substrate using an optical model, generating a training spectrum signal having a noise by applying a noise based on a noise parameter to the training spectrum signal, calculating a similarity between the training spectrum signal having the noise and an actually measured spectrum signal, and when the similarity satisfies a set condition, training a noise reduction model using the training spectrum signal having the noise.

Abstract: Provided is a high-precision substrate polishing system. An apparatus for polishing a substrate includes a platen on which a polishing pad is seated and which is rotatable, a substrate carrier configured to grip a substrate and rotatable on an upper side of the platen, an infrared sensor located inside the platen and configured to measure a temperature of the substrate, and a controller configured to determine a polishing state of the substrate using a value measured by the infrared sensor.

Abstract: There is disclosed a direction guiding method including acquiring information on an arrival location to be reached by a passer-by, recognizing a marker on which identifying information is recorded by photographing the marker, outputting a direction in which the passer-by is to move for the passer-by to move to the arrival location, and displaying the photographed first marker on a display unit. According to the method, a route guidance technology may be provided that is capable of quickly, easily, and accurately constructing a destination even indoors where GPS signals do not arrive.