In biological networks such as protein-protein interaction networks, finding genes and essential gene products is critical. Biological networks are examples of a complex system in which the system's performance is affected by the way the components interact. One of the main challenges related to complex biological networks is finding their effective and important components. Many criteria, such as centrality criteria, can be considered to gauge the importance of a component. However, none of these criteria are considered a standard and definitive criterion in measuring the importance of a component in the network. Therefore, in recent studies, to determine the importance of a component, the degree of destruction that the removal of that component can cause in the system is used as the main criterion.
In this seminar, the issue of "finding critical network nodes" is studied, and two new algorithms are proposed to identify critical nodes that are effective in network stability. The results show the much better performance of the introduced algorithms in solving the above problem. While the basic algorithm solves the problem on networks with a maximum size of 50 nodes, the proposed algorithm also solves the problem well on graphs with 500 nodes. Also, by presenting a genetic algorithm to solve the mentioned problem in protein-protein interaction networks, a new definition of the central nodes of a network is presented, and the law of centrality-lethality is examined from a different perspective.