1. A classification method in a feature space including one or more feature vectors, all of or some of the feature vectors being identified as support vector(s), comprising: creating a maximum hypersphere in the feature space, according to the support vector(s); calculating a center of the created maximum hypersphere according to the support vector(s); creating a decision hypersphere based on the calculated center of the created maximum hypersphere and the created maximum hypersphere; and classifying feature vector(s) within the decision hypersphere as positive feature vector(s).