2. (20%) In the studies of information retrieval and image processing, extracting and ranking the significance of data from a large given set is important. Among many available techniques, SVD (singular value decomposition) is effective but inefficient. Explain (A) the main idea of SVD and explain (B) why SVD is not computationally efficient.
3. (20%) In many applications of computers, computing the similarity of two objects is a fundamental and