Jyri Leskinen: Developing effective gradient-free methods for inverse problems An inverse problem is a task where the properties of a system are reconstructed using information such as physical measurements on the system. The information available is often insufficient which leads to a so-called ill-posed problem. Without additional information the resulting reconstruction may not be accurate. Using gradient-based methods combined with a priori information one can reconstruct the correct properties of the system. However, this requires that the gradient of the objective function is available and that it leads to the global optimum (correct solution) which restricts the usability of these methods. However, advanced hybrid evolutionary methods such as memetic algorithms provide effective tools to solve inverse problems without the need of gradients. As an example of solving an inverse problem, the reconstruction of an Electrical Impedance Tomography (EIT) image using adaptive differential evolution based memetic algorithm is illustrated.