Nonnegative Matrix Factorization-Based Spatial-Temporal Clustering for Multiple Sensor Data Streams

Figure 2

Spatial-temporal cluster: graph 𝐺^(𝑡−1)=(𝑆^(𝑡−1),𝐸^(𝑡−1)), graph 𝐺^(𝑡)=(𝑆^(𝑡),𝐸^(𝑡)) and the spatial relationship between timestamps 𝑡−1 and 𝑡.