| Connectivity is important for measuring the fault tolerance of a multiprocessor system.Extra connectivity is a vital parameter of a network’s ability for diagnosis and fault-tolerance.We say a set F has property?gif|F|>g.A subset S?V(G)is an?g-cut of G if G-S is disconnected and every component of G-S has property?g.The g-extra connectivity of G,denoted byκg(G),is min{FF?V(G)|F||F is an?g-cut of G}.n-dimensional folded hypercube F Qn is one of the variants of n-dimensional hy-percubes,its vertex set equal to n-dimensional hypercubes’s vertex set,its edge is point pairs which Hamming distance is 1 or n.In Chaper3 and Chaper4 we discuss the minimum neighborhood problem in a folded hypercube.In Chaper5 we give an upper and a lower bound of theκg(F Qn)for n+1≤g≤2n-5 and n≥22,we show that θg(Qn)+n≤κg(F Qn)≤θg(Qn)+g-1,whereθg(Qn)=-1/2g2+(2n-3/2)g-(n2-2). |