Abstract
Can we discover a node which is not observable directly but mediates the stochastic diffusion process in a network? We address such a node discovery and mathematically formulate the basic concept which is promising to solving the problem in general. The proposed method is tested with a node discovery in a Barabási-Albert model which the conventional method raised and partially succeeded in. Its performance is measured with the receiver operating characteristic curves and van Rijsbergen's F-measure (the harmonic mean of precision and recall). The proposed method succeeds in discovering an unobservable peripheral node, and an unobservable hub node in a less clustered network where the conventional method failed.
