Forma, Vol. 9 (No. 2), pp. 139-150, 1994

Functional Disorder of Fractal Lifeline Networks

Masami Nakagawa

The Lovelace Institutes, 2425 Ridgecrest Dr. SE, Albuquerque, New Mexico 87108, U.S.A.

(Received January 10, 1994; Accepted February 1, 1994)

Keywords: Lifeline Network Systems, Fractal, Functional Disorder

Abstract. Lifeline network systems are defined as systems of means or routes by which necessary supplies are transported. In the fields of physiology and biology, their examples are vascular trees, neural networks, bronchial airways, branches of a tree and vein network of a leaf. In the field of civil engineering, they are referred to systems of supply, communication and transportation networks, including gas, electric power and water line networks. We point out that the complex shapes of networks of both physiological/biological lifeline systems and manmade civil engineering lifeline systems are fractal. We then propose to use the decrease of fractal dimension as a measure of the extent of functional disorder of a network system, and apply this method to the actual gas line network systems.