Threats Networks and Threatened Networks

摘要

The document has three categories. (A) Network robustness. The goal of this work is to determine network design guidelines which maximize the robustness of networks to both random failure and intentional attack while keeping the cost of the network constant. We find optimal parameters for: (i) scale free networks having degree distributions with a single power-law regime, (ii) networks having degree distributions with two power-law regimes, and (iii) networks described by degree distributions containing two peaks; (B) Resilience of Networks: An attack on a network is aimed at interrupting the flow of information in the network. The efficiency of the network in transmitting information between two nodes depends on the length of the optimal path of least cost between them. Our previous work had shown that when the loads on the links are distributed over several orders of magnitude, the average optimal path length scales as a power of the network size N. In such a case the network is said to be in the regime of 'strong disorder'. This situation is detrimental to the efficient flow of information on the network. In our work we focused on quantifying the point at which the network starts experiencing strong disorder and therefore starts losing its functionality; (C) Dynamics of flow in complex networks: Understanding flow in complex networks is important if we are to understand how information, disease, resources, etc flow in the real world. in particular it is important to understand the nature of flow in the presence of disorder. Our work has focused on determining if there is a relationship between the scaling of flow variables and the scaling of other previously studied quantities such as the optimal path. Our preliminary finding is that current flow in a random resistor lattice has the same scaling as the optimal path under conditions of both strong and weak disorder.