45,647 research outputs found
Finding Support Documents with a Logistic Regression Approach
Entity retrieval finds the relevant results for a user’s information needs at a finer unit called “entity”. To retrieve such entity, people usually first locate a small set of support documents which contain answer entities, and then further detect the answer entities in this set. In the literature, people view the support documents as relevant documents, and their findings as a conventional document retrieval problem. In this paper, we will state that finding support documents and that of relevant documents, although sounds similar, have important differences. Further, we propose a logistic regression approach to find support documents. Our experiment results show that the logistic regression method performs significantly better than a baseline system that treat the support document finding as a conventional document retrieval problem
Sudden transition between classical and quantum decoherence in dissipative cavity QED and stationary quantum discord
We investigate the phenomenon of sudden transition between classical and
quantum decoherence in the study of quantum discord for a dissipative cavity
QED system, which consists of two noninteracting two-level atoms, each trapped
in a dissipative cavity. It is found that the quantum discord between two
atoms, which are prepared initially in the X-type quantum states, is not
destroyed by the dissipation of the cavities for a finite time interval and the
stationary quantum discord can arise in the interaction of atoms with cavities
as the time approach to infinite. The transition time is sensitive to the
initial state parameter of the two atoms and the mean photon number of the
coherent field. Interestingly, the quantum discord between the two atoms is
completely unaffected by the dissipation of the cavities if we choose the
suitable value of the ratio, which depends on the decay rate of two cavities
and the atom-field coupling constant.Comment: 8 pages, 14 figure
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