Preface.-Charles F. Van Loan: Structured Matrix Problems from Tensors.-Dario A. Bini: Matrix Structures in Queuing Models.-. Jonas Ballani and Daniel Kressner: Matrices with Hierarchical Low-Rank Structures.-Michele Benzi: Localization in Matrix Computations: Theory and Applications.-Munthe-Kaas: Groups and Symmetries in Numerical Linear Algebra.