1. An emotion recognition apparatus comprising: at least one processor; a sampling unit of the at least one processor configured to extract, from input data for emotion recognition, sampling data corresponding to a time period, wherein the input data comprises a facial image of a user, a voice of the user, text input by the user, a temperature of the user, a location of the user, or a kind of an application being used by the user; a data segment creator of the at least one processor configured to accumulatively segment the sampling data, based on one or more predetermined time-domain windows, to form a plurality of data segments, wherein each of the data segments subsequent to a first data segment, among the plurality of data segments, includes portions of the sampling data from a current sampling time period and all previous sampling time periods; an emotional segment creator of the at least one processor configured to create a plurality of emotional segments that comprise a plurality of emotions corresponding to each of the respective data segments; and an emotion deciding unit of the at least one processor comprising a complex emotion deciding unit configured to decide at least two of the emotional segments as the user's complex emotion.