Directed Network Bow-Tie Structure

SCC, IN, OUT, and Tendrils of the Web
SCC (core)
IN component
OUT component
Tendrils
Isolated
Nodes N 25
Link prob p 0.10
Generate and classify a network
The Bow-Tie structure of the Web (Broder et al. 2000) revealed that ~25% of pages form a strongly connected core (SCC), ~25% can reach SCC (IN), ~25% are reachable from SCC (OUT), and the rest are tendrils and isolated. Kosaraju's or Tarjan's algorithm finds Strongly Connected Components in O(V+E) via DFS. This topology matters for search engines, epidemic spreading, and trust propagation.