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Algorithmic construction of Hamiltonians in pyramids. H. Sarbazi-Azad, M. Ould-Khaoua, L.M. Mackenzie, IPL, 80, 75-79(2001). Previous work. F. Cao, D. F. Hsu, “ Fault Tolerance Properties of Pyramid Networks ”, IEEE Trans. Comput. 48 (1999) 88-93. Connectivity, fault diameter, container.
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Algorithmic construction of Hamiltonians in pyramids H. Sarbazi-Azad, M. Ould-Khaoua, L.M. Mackenzie, IPL, 80, 75-79(2001)
Previous work • F. Cao, D. F. Hsu, “Fault Tolerance Properties of Pyramid Networks”, IEEE Trans. Comput. 48 (1999) 88-93. • Connectivity, fault diameter, container
Pyramid Pn is not regular • (P1)=3, ∆(P1)=4 • (P2)=3, ∆(P2)=7 • (Pn)=3, ∆(Pn)=9, for n>=3
result • Theorem 1. A Pn contains Hamiltonian paths starting with any node x P = { Pn▲, Pn◤, Pn◣, Pn◥, Pn◢ } and lasting at any node y P – {x}.
Result(cont.) • Theorem 2. A pyramid of level n, Pn, is Hamiltonian.
A. Itai, C. Papadimitriou, J. Szwarcfiter, “Hamilton Paths in grid graphs”, SIAM Journal on Computing, 11 (4) (1982) 676-686.
Hamiltonian property of M(m, n) • In fact, M(m, n) is bipartite. • M(m,n) is even-size if m*n is even. • Roughly speaking, for a even-sized M(m, n), there exists a hamiltonian path between any two nodes x, y iff x and y belong to a same partite set. • There are a few exceptions. (detail)
Pn is hamiltonian connected • Proof:
P1 • 剛剛看過了
Induction • Case 1. x, y 都在上面 n-1層
Pn is pancyclic • By induction
Induction • (1) 3~L • (2)L+2 • (3)L+3~L+4 • (4)L+5~|V(Pn)| • (5)L+1