1,469,586 research outputs found
Community Detection as an Inference Problem
We express community detection as an inference problem of determining the
most likely arrangement of communities. We then apply belief propagation and
mean-field theory to this problem, and show that this leads to fast, accurate
algorithms for community detection.Comment: 4 pages, 2 figure
Robust Fault Detection of Switched Linear Systems with State Delays
This correspondence deals with the problem of robust fault detection for discrete-time switched systems with state delays under an arbitrary switching signal. The fault detection filter is used as the residual generator, in which the filter parameters are dependent on the system mode. Attention is focused on designing the robust fault detection filter such that, for unknown inputs, control inputs, and model uncertainties, the estimation error between the residuals and faults is minimized. The problem of robust fault detection is converted into an H infin-filtering problem. By a switched Lyapunov functional approach, a sufficient condition for the solvability of this problem is established in terms of linear matrix inequalities. A numerical example is provided to demonstrate the effectiveness of the proposed method
Entanglement detection from channel parameter estimation problem
We derive a general criterion to detect entangled states in multi-partite
systems based on the symmetric logarithmic derivative quantum Fisher
information. This criterion is a direct consequence of the fact that separable
states do not improve the accuracy upon estimating one-parameter family of
quantum channels. Our result is a generalization of the previously known
criterion for one-parameter unitary channel to any one-parameter quantum
channel. We discuss several examples to illustrate our criterion. The proposed
criterion is extended to the case of open quantum systems and we briefly
discuss how to detect entangled states in the presence of decoherence.Comment: 10 page
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