January 01, 2019

Scaling of random walk betweenness in networks

  • Narayan O.
  • Saniee I.

We study the betweenness centrality (BC) of vertices of a graph using random walk paths. Random walk BC (RWBC) provides an alternative measure to the shortest path centrality of each vertex in a graph as it aggregates contributions from possibly all vertex-pairs in the graph and not just from those vertex-pairs on whose geodesic path the vertex lies. As such, RWBC is more relevant in the context of information diffusion in virtual networks, such as spread of news or rumors in online social media. We derive a closed-form analytical expression for RWBC using eigenfunctions of the graph Laplacian. We then show the distribution of RWBC scores of the vertices of a graph exhibits a scaling collapse with no adjustable parameters as the graph size $N$ is varied. This means that the distribution of RWBC over all the nodes in a large graph can be obtained in terms of the distribution of RWBC for a prototypical or small graph that is generated using the same model. The exact distribution itself depends on the graph model. A normalized random walk betweenness (NRWBC), that counts each walk passing through a vertex only once, is also defined. This measure is argued to be more useful and robust and is seen to have simpler scaling behavior.

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Recent Publications

May 01, 2019

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  • Prakash S.
  • Saniee I.
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This paper takes a fresh look at the debate over the relationship between digital technology and productivity. The argument of economic historian Robert J. Gordon is that digital technology will not lead to increases in productivity such as we saw in the last century, based on his analysis of the ...

January 01, 2019

Friendly, appealing or both? Characterising user experience in sponsored search landing pages

  • Bron M.
  • Chute M.
  • Evans H.
  • Lalmas M.
  • Redi M.
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© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Many of today's websites have recognised the importance of mobile friendly pages to keep users engaged and to provide a satisfying user experience. However, next to the experience provided by the sites themselves, ...

January 01, 2019

Analyzing uber's ride-sharing economy

  • Aiello L.
  • Djuric N.
  • Grbovic M.
  • Kooti F.
  • Lerman K.
  • Radosavljevic V.

© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Uber is a popular ride-sharing application that matches people who need a ride (or riders) with drivers who are willing to provide it using their personal vehicles. Despite its growing popularity, there exist ...