Inverse Problems for Sturm-Liouville Differential Operators on Closed Sets

Second-order differential operators on closed sets (time scales) are considered. Properties of their spectral characteristics are obtained and inverse problems are studied, which consists in recovering the operators from their spectral characteristics. We establish the uniqueness and develop constructive algorithms for the solution of the inverse problems.

Novel Methods Generated by Genetic Programming for the Guillotine-Cutting Problem

New constructive algorithms for the two-dimensional guillotine-cutting problem are presented. The algorithms were produced from elemental algorithmic components using evolutionary computation. A subset of the components was selected from a previously existing constructive algorithm. The algorithms’ evolution and testing process used a set of 46 instances from the literature. The structure of three new algorithms is described, and the results are compared with those of an existing constructive algorithm for the problem. Several of the new algorithms are competitive with respect to a state-of-the-art constructive algorithm. A subset of novel instructions, which are responsible for the majority of the new algorithms’ good performances, has also been found.

Inverse problems for the differential operator on the graph with a cycle with different orders on different edges

We consider a variable order differential operator on a graph with a cycle. We study inverse spectral problems for this operator by the system of spectra. Uniqueness theorems are proved, and constructive algorithms are obtained for the solution of the inverse problems.