Wachsendes Neuronales Gas (GNG)
Wachsen Neuronale Gas (GNG) is an unüberwachtes Lernen algorithm used in artificial neuronale Netze, primarily for clustering and function approximation tasks. Developed by Bernd Fritzke in 1994, GNG is designed to adaptively learn the structure of a dataset without requiring prior knowledge of the number or arrangement of clusters.
The GNG algorithm operates by incrementally adding nodes (neurons) to a network as it processes input data. This is achieved through a competitive learning process where input vectors are presented to the network, and the nearest neuron (winner) is identified. The winner neuron and its neighbors are updated to better represent the Eingangsvektor, which helps the network learn the distribution of the data over time.
One of the key features of GNG is its ability to grow the network dynamically. When the network’s performance plateaus or when the error exceeds a certain threshold, a new neuron is added. This new neuron is placed between the two most connected neurons, allowing the network to better capture the underlying structure of the data. Additionally, older neurons that are less frequently activated can be removed, ensuring the network remains efficient and focused on the most relevant data patterns.
The GNG algorithm is particularly useful in scenarios where the shape and number of clusters are not known in advance, making it suitable for various applications, including image analysis, pattern recognition, and Datenvisualisierung. By maintaining a balance between exploration and exploitation of the data space, GNG can effectively adapt to complex datasets while preserving important topological features.