Aspects of System Theory

Abstract

In order to describe multi-component systems like a thermodynamic system, a laser system, high-dimensional quantum systems or the human brain, it is useful to introduce quantities which are able to describe essential facts in a compressed way. Such a compression is useful, because such systems produce an immense amount of data. In the last chapter such expressions have been introduced. In particular, the reader has to think of the quantity entropy, which describes the evolution possibilities of a thermodynamic system. Other quantities are necessary to describe systems like the human brain. The measurable level then is the electromagnetic field level on the brain surface, i. e. the level of an electroencephalogram (EEG). To describe and to classify such an EEG, one needs a quantity to describe the measurement in a compressed way. Furthermore, it is desirable to have quantities which have a far-reaching meaning. In order to be able to use such quantities, it is necessary to have additional laws belonging to these quantities.