1. Luo, S., Hu, Q.: A Dynamic Motion Pattern Analysis Approach to Fall Detection. In: IEEE International Workshop on Biomedical Circuits & Systems, Singapore, pp. S2.1_5–S2.1_8 (2004)
2. Lee, D.D., Seung, H.S.: Algorithms for Non-negative Matrix Factorization. In: The 14th Annual Conference on Neural Information Processing Systems, vol. 13, pp. 556–562 (2000)