Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Research of structures of network information systems on the basis of tolerance concerning an accessibility of peaks of the graph A.I. ELISEEV, YU.F. MARTEMYANOV, V.E. PODOLSKY, V.N. SHAMKIN In article questions of research of network information systems for the purpose of opposition of destructive consequences of the failures arising in the course of their maintenance are considered. The task dares on the basis of representation graphs. In article the approach to research of the graph on its tolerance concerning an accessibility of peaks with usage of set of the full parenthesis projections is formalized. Key words: system simulation, graph theory, bracket projection of graphs, tolerance. Pp. 60-62.