1 Uniform asymptotic stability of linear time-varying systems -- 2 Positive system realizations -- 3 System approximation in the 2-norm -- 4 Is it possible to recognize local controllability in a finite number of differentiations? -- 5 Open problems in sequential parametric estimation -- 6 Conditions for the existence and uniqueness of optimal matrix scalings -- 7 Matrix inequality conditions for canonical factorization of rational transfer function matrices -- 8 Open problems in ?1 optimal control -- 9 Efficient neural network learning -- 10 Mechanical feedback control systems -- 11 Three problems on the decidability and complexity of stability -- 12 Simultaneous stabilization of linear systems and interpolation with rational functions -- 13 Forbidden state control synthesis for timed Petri net models -- 14 On matrix mortality in low dimensions -- 15 Entropy and random feedback -- 16 A stabilization problem -- 17 Spectral factorization of a spectral density with arbitrary delays -- 18 Lyapunov exponents and robust stabilization -- 19 Regular spectral factorizations -- 20 Convergence of an algorithm for the Riemannian SVD -- 21 Some open questions related to flat nonlinear systems -- 22 Approximation of complex ? -- 23 Spectral value sets of infinite-dimensional systems -- 24 Selection of the number of inputs and states -- 25 Input-output gains of switched linear systems -- 26 Robust stability of linear stochastic systems -- 27 Monotonicity of performance with respect to its specification in H? control -- 28 Stable estimates in equation error identification: An open problem -- 29 Elimination of latent variables in real differential algebraic systems -- 30 How conservative is the circle criterion? -- 31 On chaotic observer design -- 32 The minimal realization problem in the max-plus algebra -- 33 Input design for worst-case identification -- 34 Max-plus-times linear systems -- 35 Closed-loop identification and self-tuning -- 36 To estimate the L2-gain of two dynamic systems -- 37 Open problems in the area of pole placement -- 38 An optimal control theory for systems defined over finite rings -- 39 Re-initialization in discontinuous systems -- 40 Control-Lyapunov functions -- 41 Spectral Nevanlinna-Pick Interpolation -- 42 Phase-sensitive structured singular value -- 43 Conservatism of the standard upper bound test: Is sup$$ \left( {\bar \mu /\mu } \right) $$ finite? Is it bounded by 2? -- 44 When does the algebraic Riccati equation have a negative semi-definite solution? -- 45 Representing a nonlinear input-output differential equation as an input-state-output system -- 46 Shift policies in QR-like algorithms and feedback control of self-similar flows -- 47 Equivalences of discrete-event systems and of hybrid systems -- 48 Covering numbers for input-output maps realizable by neural networks -- 49 A powerful generalization of the Carleson measure theorem? -- 50 Lyapunov theory for high order differential systems -- 51 Performance lower bound for a sampled-data signal reconstruction -- 52 Coprimeness of factorizations over a ring of distributions -- 53 Where are the zeros located?.