The University of Pittsburgh team participated in two tracks for TREC 2005: the High Accuracy Retrieval from Documents (HARD) track and the Enterprise Retrieval track. The goal of Pitt’s HARD study in TREC 2005 was to examine the effectiveness of applying Self Organizing Maps (SOM) as a visual presentation tool and as a clustering tool in the context of HARD tasks, especially its role in clarif...

The many-body expansion (MBE) is an efficient tool which has a long history of use for calculating interaction energies, binding lattice and so on. In the past, applications MBE to correlation energy have been unfeasible large systems, but recent improvements computing resources sparked renewed interest in capturing using generalized $n$-th order Bethe-Goldstone equation. this work, we extend a...

In this paper, we calculate the energy spectrum of interacting gases by converting cluster expansion method in statistical mechanics into a solving eigenvalues. We obtain an explicit expression eigenvalue, which can eigenvalue gas from interparticle potential directly. As example, for with soft-sphere potentials.