Reliable estimation of discharge in a river is the crucial component of efficient flood management and surface water planning. Hydrologists use historical data to establish a relationship between water level and discharge, which is known as a rating curve. Once a relationship is established it can be used for predicting discharge from future measurements of water level only. Successful applicat...

in this paper, our focus of attention is the proper propagationof fuzzy degrees in determinization of $nondeterministic$ $fuzzy$$finite$ $tree$ $automata$ (nffta). initially, two determinizationmethods are introduced which have some limitations (one inbehavior preserving and other in type of fuzzy operations). inorder to eliminate these limitations and increasing theefficiency of ffta, we defin...

in this paper we give sharp upper bounds on the zagreb indices and characterize all trees achieving equality in these bounds. also, we give lower bound on first zagreb coindex of trees.