ワンクラス 分類 (OCC) is a specialized 機械学習のアプローチ designed to identify and classify instances of a single class while treating all other instances as outliers or anomalies. This technique is particularly useful in scenarios where the available data primarily consists of examples from one category, such as 不正検出, medical 診断や希少なイベントの予測を指します。
従来の分類タスクでは、 algorithms are trained on multiple classes, learning to distinguish between them based on input features. However, in One-Class Classification, the model is trained solely on data from the target class. This method allows the model to learn the characteristics and distribution of the single class, enabling it to recognize instances that belong to this class while flagging those that do not as anomalies.
ワンクラス分類で一般的に使用されるアルゴリズムには サポートベクターマシン (SVMs), which can create a boundary around the target class in the feature space, and neural networks that can be trained to reconstruct input data, identifying deviations from the norm. An important aspect of OCC is its utility in environments where obtaining negative examples (instances not belonging to the target class) is difficult or impossible.
ワンクラス分類は、次のようなアプリケーションで強力なツールです。 ネットワークセキュリティ, where the primary goal may be to identify malicious activity based on normal behavior, or in industrial settings, where monitoring equipment health can prevent costly failures by recognizing deviations from standard operating conditions.