To measure the IPv6 internet AS-level topology, a network topology discovery system, called Dolphin, was developed. By comparing the measurement result of Dolphin with that of CAIDA’s Scamper, it was found that the IPv6 Internet at AS level, similar to other complex networks, is also scale-free but the exponent of its degree distribution is 1.2, which is much smaller than that of the IPv4 Inter...

Article history: Received 29 June 2010 Received in final revised form 9 September 2010 Available online 30 October 2010

This paper deals with the number of subgroups of a given exponent in a finite abelian group. Explicit formulas are obtained in the case of rank two and rank three abelian groups. An asymptotic formula is also presented.

Suppose Q is a family of discrete memoryless channels. An unknown member of Q will be available, with perfect, causal output feedback for communication. Is there a coding scheme (possibly with variable transmission time) that can achieve the Burnashev error exponent uniformly over Q ? For two families of channels we show that the answer is yes. Furthermore, for each of these two classes, in add...

Contrast in image processing is typically scaled using a power function (gamma) where its exponent specifies the amount of the physical contrast change. While the exponent is normally constant for the whole image, we observe that such scaling leads to perceptual nonuniformity in the context of high dynamic range (HDR) images. This effect is mostly due to lower contrast sensitivity of the human ...

An extensive investigation of 61 daily temperature records by means of detrended fluctuation analysis has revealed that the value of correlation exponent is not universal, contrary to earlier claims. Furthermore, statistically significant differences are found for daily minimum and maximum temperatures measured at the same station, suggesting different degrees of long-range correlations for the...

One of the phenomena that influences significantly the performance of low-density parity-check codes is known as trapping sets. An (a, b) elementary trapping set, or simply an ETS where a is the size and b is the number of degree-one check nodes and b a < 1, causes high decoding failure rate and exert a strong influence on the error floor. In this paper, we provide sufficient conditions for exp...

Finite-time Lyapunov exponents of generic chaotic dynamical systems fluctuate in time. These fluctuations are due to the different degree of stability across the accessible phase space. A recent numerical study of spatially extended systems has revealed that the diffusion coefficient D of the Lyapunov exponents (LEs) exhibits a nontrivial scaling behavior, D(L)~L(-γ), with the system size L. He...