There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Imagined communities: Reflections on the origin and spread of nationalism

The modern science of networks has brought significant advances to our understanding of complex systems. One of the most relevant features of graphs representing real systems is community structure, or clustering, i. e. the organization of vertices in clusters, with many edges joining vertices of the same cluster and comparatively few edges joining vertices of different clusters. Such clusters, or communities, can be considered as fairly independent compartments of a graph, playing a similar role like, e. g., the tissues or the organs in the human body. Detecting communities is of great importance in sociology, biology and computer science, disciplines where systems are often represented as graphs. This problem is very hard and not yet satisfactorily solved, despite the huge effort of a large interdisciplinary community of scientists working on it over the past few years. We will attempt a thorough exposition of the topic, from the definition of the main elements of the problem, to the presentation of most methods developed, with a special focus on techniques designed by statistical physicists, from the discussion of crucial issues like the significance of clustering and how methods should be tested and compared against each other, to the description of applications to real networks.

/pdf/community-detection-in-graphs-34rogm3r6p.pdf

Community detection in graphs

The General Internet Signaling Transport (GIST) protocol currently
uses TCP or TLS over TCP for connection mode operation. This document
describes the usage of GIST over the Stream Control Transmission
Protocol (SCTP). The use of SCTP can take advantage of features
provided by SCTP, namely streaming-based transport, support of
multiple streams to avoid head of line blocking, and the support of
multi-homing to provide network level fault tolerance. Additionally,
the support for the Partial Reliability Extension of SCTP is
discussed.

/pdf/general-internet-signaling-transport-gist-over-stream-9owej8con8.pdf

General Internet Signaling Transport (GIST) over Stream Control Transmission Protocol (SCTP) and Datagram Transport Layer Security (DTLS)

Scarcity of frequencies combined with the demand for more bandwidth is likely to increase the need for devices that provide high wireless bandwidth in limited areas while using a wired network to carry data over longer distances. Examples of such devices are Wi-Fi routers and femtocells and future devices that use TV whitespace. To utilize the available frequencies more efficiently radios must be able to find other users of the frequency bands and adapt so that they are not interfered. As transmitters hundreds of kilometers away may cause as much interference as a transmitter located next door, this mechanism can not be based on location alone. Central databases can be used for this purpose, but with thousands or millions of radio devices to coordinate a centralized system may not always be ideal. In this paper, we propose a decentralized protocol and architecture for discovering interfering radio devices over the Internet. The protocol has low bandwidth-, memoryand processing requirements, making it suitable for platforms with limited resources. We evaluate the protocol through simulation in network topologies with up to 1 000 000 nodes, including topologies generated from three municipalities in Norway. We also describe a proof-of-concept resource allocation algorithm and prove that it converges with information gathered by the discovery protocol.

Large-Scale Peer-to-Peer Discovery Mechanism and Architecture for Frequency Allocation

An empirical analysis of controlled flooding algorithms in pocket switched networks

Proceedings of the 2003 UK e-Science All Hands Meeting, 31st August - 3rd September, Nottingham UK

Reliable ligh-speed Grid data delivery using IP multicast

This report documents the program and the outcomes of Dagstuhl Seminar
13062 "Decentralized Systems for Privacy Preservation". In recent years, a number of concerns have risen about the existence of large, organizationally centralized online services (cloud services, online social networks, repositories, etc). The concerns include risks to users' data from organizational failures and threats to user privacy. In this seminar, the organizers brought together a somewhat more diverse collection of theoreticians and practitioners from industry and academia including social scientists and economists. In keeping with the nature of the interdisciplinary attendees, the
organizers also attempted a seminar organization structure intended to promote innovative, cross-discipline working. The results were mixed: some clear agenda setting outputs emerged with some less clear ones.

https://drops.dagstuhl.de/opus/volltexte/2013/4017/pdf/dagrep_v003_i002_p022_s13062.pdf/

Jon Crowcroft

Papers

General Internet Signaling Transport (GIST) over Stream Control Transmission Protocol (SCTP) and Datagram Transport Layer Security (DTLS)

Large-Scale Peer-to-Peer Discovery Mechanism and Architecture for Frequency Allocation

An empirical analysis of controlled flooding algorithms in pocket switched networks

Reliable ligh-speed Grid data delivery using IP multicast

Decentralized Systems for Privacy Preservation (Dagstuhl Seminar 13062)