Issues about combination of temporal information and spatial information

Documents usually contain temporal expressions such as `morning' and `yesterday', and they also often contain spatial expressions such as `house' and `the South Pole'. Extracting temporal information or spatial information from the documents is important because such information can be useful for various applications. Although there have been many studies aiming at extracting temporal information or spatial information, only few studies attempted to combine the two information. In this paper, we report several issues about the combination of temporal information and spatial information.