Are Friends Overrated?: A Study for the Social Aggregator Digg.com

The key feature of online social networks is the ability of users to become active, make friends and interact with those around them. Such interaction is typically perceived as critical to these platforms; therefore, a significant share of research has investigated the characteristics of social links, friendship relations, community structure,...

The Effect of Peer Selection with Hopcount or Delay Constraint on Peer-to-Peer Networking

Topology dynamics in a P2PTV network

In recent years, a number of commercial peer-to-peer TV (P2PTV) applications have been launched. Yet, their mechanisms and characteristics are unknown. In this paper, we study SopCast, a typical proprietary P2PTV system. Treating SopCast as a black box, we perform a set of experiments that are suitable to analyze SopCast in depth. We attempt to...

Information Propagation in Peer-to-Peer Networking: Modeling and Empirical Studies

Although being a young technology, peer-to-peer (P2P) networking has spurred dramatic evolution on the Internet over the recent twenty years. Unlike traditional server-client mode, P2P networking applications are user-centric. Users (peers) generate their own content and share it with others across the Internet. Be it a P2P file-sharing network,...

Influence of assortativity and degree-preserving rewiring on the spectra of networks

Newman’s measure for (dis)assortativity, the linear degree correlation coefficient ?D, is reformulated in terms of the total number Nk of walks in the graph with k hops. This reformulation allows us to derive a new formula from which a degree-preserving rewiring algorithm is deduced, that, in each rewiring step, either increases or decreases ?D...

Weight of the Shortest Path to the First Encountered Peer in a Peer Group of Size m

We model the weight (e.g. delay, distance or cost) from an arbitrary node to the nearest (in weight) peer in a peer-to-peer (P2P) network. The exact probability generating function and an asymptotic analysis is presented for a random graph with i.i.d. exponential link weights. The asymptotic distribution function is a Fermi-Dirac distribution...

Highly dispersed Cd cluster supported on TiO2 as an efficient catalyst for CO2 hydrogenation to methanol

The conversion of CO2 with high activity and high selectivity to methanol remains challenging because of both the kinetics and thermodynamics difficulties associated with the chemical reactivity of CO2. Herein, we report a new catalyst of Cd/TiO2 enabling 81% methanol selectivity at 15.8% CO2 conversion with the CH4 selectivity below 0.7%. The...

Influence of assortativity and degree-preserving rewiring on the spectra of networks

Effect of the initial microstructure and thermal path on the final microstructure and bendability of a high strength ferrite-martensite dual phase steel

The combined effects of the initial microstructure and heating rate on ferrite recrystallization, austenite formation and transformation kinetics of a regular ferrite-martensite dual phase steel are investigated. Special attention is given to the effect of the martensite distribution on mechanical properties, particularly the bendability....

Delamination toughening in a low carbon microalloyed steel plate rolled in the dual-phase region

It is still a big challenge to obtain excellent low-temperature toughness for bulk steel materials. Delamination is an effective method to improve low-temperature toughness. In the present study, delamination toughening in a low carbon microalloyed steel plate with elongated and ultrafine-grained microstructure rolled in the dual-phase region...

Peer Selection with Hopcount and Delay Constraint

We revisit the peer selection problem of finding the most nearby peer from an initiating peer. The metrics to assess the closeness between peers are hopcount and delay, respectively. Based on a dense graph model with i.i.d regular link weight, we calculate the probability density function to reach a peer with minimum hopcount and asymptotically...