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convolution (mathematics; machine learning)
A mathematical operation that combines two functions by sliding one over the other, widely used in signal processing and in the convolutional layers of neural networks for image recognition.
The noun form of 畳み込む (to fold in). In mathematics and signal processing it is an operation that blends two functions; in machine learning it is the core operation of a 畳み込みニューラルネットワーク (convolutional neural network, CNN), which slides small filters over an image to detect features.