抄録
With the development of science and technology, large scale systems are produced. The number of elements in a system grows large and the relations between the elements also grow complex. When we intend to construct and control these systems, it is impossible to treat them by the ways which are on the viewpoint of microscopic observation. Therefore it is necessary to introduce a new expression and a general performance index of the system on the viewpoint of macroscopic observation.
In this paper, the system is limited to be a network system such as a traffic system. We introduce the idea of entropy into the stationary state of that system and consider the significance of the evaluation of network system by entropy.
As a result, it is proved that the negative entropy introduced has the same character as the entropy increasing law of statistical mechanics and that the negative entropy also expresses the degree of confusion of the network system. Therefore by making use of the negative entropy as the performance index, we obtain the construction theorem which is intuitively understood. We believe the usefulness of entropy as the performance index of a network system. Last of all we obtain a useful decomposition theorem for the construction of a large scale network system.
