Large-girth quasi-cyclic LDPC codes have been experimentally evaluated for use in PMD compensation by turbo equalization for a 10 Gb/s NRZ optical transmission system, and observing one sample per bit. Net effective coding gain improvement for girth-10, rate 0.906 code of length 11936 over maximum a posteriori probability (MAP) detector for differential group delay of 125 ps is 6.25 dB at BER o...

Objective: To determine the relationship between asymmetries in lower leg girth and standing heel-rise after anterior cruciate ligament (ACL) reconstruction. Design: Single-group posttest. Participants: 15 at a mean of 30 d after ACL reconstruction. Measurements: Lower leg girth and number of repetitions performed on the standing heel-rise test. Results: A significant decrease in lower leg girt...

Friction Stir Welding (FSW), being a novel process and facilitates welding various joints required for several industrial applications. It is an attractive technology for solid state material joining, contrary to conventional welding methods, having ability to produce welds with higher integrity and minimum induced distortion and residual stresses. In this paper, the operation of FSW, critical ...

Scandium-reinforced aluminum alloys represent a new generation of high-performance alloys that display numerous advantages over high-strength aluminum alloys. Scandium-reinforced alloys are much stronger than other high-strength alloys, exhibit significant grain refinement, strengthen welds, and eliminate hot cracking in welds. These alloys also exhibit a good resistance to corrosion as shown b...

In the modern motorcar production, more than 300 deep-drawn sheet metal parts are joined together by more than 3,000 spot welds on each car body. To check the spot welds within the framework of the quality assurance, different nondestructive test methods are available in addition to the destructive methods (tear down test, metallographic inspection): the chipping test and the ultrasonic test, w...

A graph Γ is symmetric if its automorphism group acts transitively on the arcs of Γ, and s-regular if its automorphism group acts regularly on the set of s-arcs of Γ. Tutte (1947, 1959) showed that every cubic finite symmetric cubic graph is s-regular for some s ≤ 5. We show that a symmetric cubic graph of girth at most 9 is either 1-regular or 2-regular (following the notation of Djokovic), or...

The Moore bound m(d, k) = 1 + d ∑k−1 i=0 (d − 1)i is a lower bound for the number of vertices of a graph by given girth g = 2k + 1 and minimal degree d. Hoffmann and Singleton [5], Bannai and Ito [1], Damerell [4] showed that graphs with d > 2 tight to this bound can only exist for girth 5 and degree 3, 7, 57. The difference to the Moore bound by given girth is called the excess of a graph. In ...

Terwilliger [15] has given the diameter bound d < (s 1)(k 1) + 1 for distance-regular graphs with girth 2s and valency k. We show that the only distance-regular graphs with even girth which reach this bound are the hypercubes and the doubled Odd graphs. Also we improve this bound for bipartite distance-regular graphs. Weichsel [17] conjectures that the only distance-regular subgraphs of a hyper...