The present invention relates to conditionally replicating viruses or pairs of viruses containing a gene switch that is activatable by transient heat or other proteotoxic stress in the presence or absence of a small molecule regulator. In the method for improving image quality, processing image signals relating to improving the image quality can be adaptively performed based on the amount of movement of an input movie-image so that the image quality of the movie-image can be improved without breaking the image. The rotary plate is coupled to the coupling part by means of the retaining pin in one of a plurality of defined rotation angle positions. Sounds can be downloaded to devices with or without batteries, as part of a service offering.