random restricted isometry constants relaxed Definition 2.1 [15] For each integer , define the restricted isometry constant of a matrix to be the smallest number such that holds for all -sparse vectors . A vector is said to be -sparse if it has at most non-zero entries. The matrix is said to satisfy the -restricted isometry property with restricted isometry constant . Theorem 2.1 [15] Assume that and . Then the noisy CS solution (2.2) obeys: with small constants and that are explicitly given in [15] and denoting the best -sparse approximation of by keeping the largest entries of . atoms overcomplete noisy relaxed lower-level upper-level Sparse coding Dictionary update learning curve multiple measurement vector Theorem 6.1 (Chern off bounding method). For any random variable and , the following inequalities hold: (6.1) and (6.2) conditioned on the fact that the right hand side exists. rate compensates CM for random-block measurement Let denote a subgaussian random variable with zero mean and unit variance and subgaussian norm . Let be random matrices drawn independently, where each is populated with i.i.d. realizations of the renor malized random variable . Then, (6.15) where and are absolute constants. and are defined below. (6.16) (6.17) where represents the vector of block-wise energies. CM for repeated-block measurement Let be a random matrix populated with i.i.d. Gaussian entries having variance , and let be an block-diagonal matrix as defined above and for all . Then, for , (6.18) where and are absolute constants. and are defined below. (6.19) (6.20) where represents the vector of eigenvalues of when . sketch sketching Strong convexity strong convexity strong convexity for smooth functions Given that: 1) is an -strongly convex function of 2) For any outcome of , we have with the squared error is bounded as: (6.28) Proof. Suppose for every and . Assume that and are minimizers of and over . Then, (6.31) Proof. ssuming is the same for all , with probability for , (6.42) where . endmember variability IEEE Trans. on Information Theory IEEE Trans. on Information Theory Mathematical Surveys and Monographs 89, . American Mathematical Society Transactions on Signal Processing Transactions on Image Processing Transactions on Signal Processing Transactions on Signal Processing Proc. Int. Conf. Acoustics, Speech and Signal Processing (ICASSP) Compte Rendus de lâ„¢Academie des Sciences Annals of Statistics IEEE International Conference on Image Processing (ICIP) in Proceedings of IEEE Computer Vision and Pattern Recognition (CVPR) Annual International Conference on Machine Learning IEEE Transactions on Signal Processing