Results from the rich and well-developed theory of well-quasi-ordering have often been rediscovered and republished. The purpose of this paper is to describe this intriguing subject. To illustrate the theory, here are two definitions and an elementary result. A partially ordered set is called well-partially-ordered if every subset has at least one, but only a finite number, of minimal elements....

Predictive maintenance is based on observing an indicator of the state of a system, at different intervals of time which gives the decision maker some information about the exact state. The problem is to obtain an optimal replacement policy minimizing the long run expected cost per unit of time and to formulate it as a partially observable Markov decision process.

The process of understanding the meaning of a written passage inherently involves dynamic manipulation and composition of ideas. Starting from this observation this thesis proposes an artificial system for text understanding in which the semantic space containing the possible meanings of the analyzed text is selectively explored by a partially observable Markov decision process trained to effec...