We design low-density parity-check (LDPC) codes that perform at rates extremely close to the Shannon capacity. The codes are built from highly irregular bipartite graphs with carefully chosen degree patterns on both sides. Our theoretical analysis of the codes is based on [1]. Assuming that the underlying communication channel is symmetric, we prove that the probability densities at the message...

A secure key distribution protocol protected by light’s noise was introduced in 2003 [Phys. Rev. A 68, 052307 (2003)]. That protocol utilized the shot noise of light present in the optical channel (eg., an optical fiber) to restrict information leaks to an adversary. An initial shared information between the legitimate users allowed them to extract more information from the channel than the one...

Given a channel with a known transition probability, we consider the problem of finding the input distribution that most closely achieves a desired output distribution. We pose the problem as a linear inverse problem subject to nonnegativity constraints, and employ an iterative algorithm for minimizing Csiszar’s I-divergence between the desired channel output and the channel output derived from...

Relationship marketing literature suggests that concepts such as trust, integration, and relationship openness tend to increase cooperation and commitment among channels of distribution partners. However, can relationship marketing theory be extended to international strategic alliances in the manufacturer–distribution channel context? More specifically, can cooperation and commitment among int...

In this summary, the additive Gaussian noise channel subject to two types of constraints: (1) physical channel constraints, and (2) first-order cost constraints is considered. This channel is shown to have a unique capacity achieving input distribution, which is “discrete” in nature. A necessary and sufficient condition for the capacity achieving distribution is also derived. December 22, 2002 ...

nowday, with technology progress and the emergence of new business models, increased levels of competition and changing demands and expectations of customers, using multi channels of distribution is growing rapidly. using multiple distribution channels, despite having advantages, have many challenges as coordination and integration of these channels with high efficiency and eliminate these chal...

the estimation of velocity distribution plays a major role in the hydrodynamics of vegetated streams or rivers of extensive natural floodplains. the velocity profile in vegetated channels can be divided into three zones: uniform zone which is close to bed with uniform velocity distribution, logarithmic zone which involves the main channel with no vegetive cover and the transition zone that is a...

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