Biomedical subjects

Parthapratim Biswas

Publications and source records attributed to Parthapratim Biswas.

2 recordsLinked to original sources

PubMed2005

Maximum entropy and the problem of moments: a stable algorithm.

We present a technique for entropy optimization to calculate a distribution from its moments. The technique is based upon maximizing a discretized form of the Shannon entropy functional by mapping the problem onto a dual space where an optimal solution can be constructed iteratively. We demonstrate the performance and stability of our algorithm with several tests on numerically difficult functions. We then consider an electronic structure application, the electronic density of states of amorphous silica, and study the convergence of the Fermi level with increasing number of moments.

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PubMed2003

Numerical simulations of air-driven granular separation.

Recently it has been shown that binary mixtures of equal-sized fine granular materials exhibit spontaneous separation under vertical vibration in the presence of air [Science 295, 1877 (2002)]. Here we describe a model of this behavior based on soft-sphere molecular dynamics coupled to the motion of the surrounding air. It exhibits many of the features observed experimentally including almost complete separation of the components into well defined regions with extremely sharp boundaries. The basic separation mechanism is robust and insensitive to many of the model parameters. Our results show that the forced flow of air through the bed, induced by vibration of the container, is responsible for this form of separation.

Journal Article↗