P. Vitanyi | Searcharxiv

arXiv2006

About the Lifespan of Peer to Peer Networks

We analyze the ability of peer to peer networks to deliver a complete file among the peers. Early on we motivate a broad generalization of network behavior organizing it into one of two successive phases. According to this view the network has two main states: first centralized - few sources (roots) hold the complete file, and next distributed - peers hold some parts (chunks) of the file such that the entire network has the whole file, but no individual has it. In the distributed state we study two scenarios, first, when the peers are ``patient'', i.e, do not leave the system until they obtain the complete file; second, peers are ``impatient'' and almost always leave the network before obtaining the complete file.

cs.DC↗

arXiv2006

Clustering fetal heart rate tracings by compression

Fetal heart rate (FHR) monitoring, before and during labor, is a very important medical practice in the detection of fetuses in danger. We clustered FHR tracings by compression in order to identify abnormal ones. We use a recently introduced approach based on algorithmic information theory, a theoretical, rigorous and well-studied notion of information content in individual objects. The new method can mine patterns in completely different areas, there are no domain-specific parameters to set, and it does not require specific background knowledge. At the highest level the FHR tracings were clustered according to an unanticipated feature, namely the technology used in signal acquisition. At the lower levels all tracings with abnormal or suspicious patterns were clustered together, independent of the technology used. Moreover, FHR tracings with future poor neonatal outcomes were included in the cluster with other suspicious patterns.

q-bio.TO↗