In Feb 2011, I have defended my thesis under the advice of Prof. Karl Aberer and successfully completed EPFL's doctoral program at the LSIR lab, IC. I'm now with Facebook's Data Science Team.

research

My most recent research at LSIR focused on:

  • social computing and data mining of on-line social networks
  • engineering systems that support the large scale and real-time aspects of the OSNs
  • Social Media information overload prevention

In the work done at HP Labs, we have demonstrated that Twitter user's influence is separate from the user's popularity. In earlier work, we've built models of URL diffusion on Twitter that are able to accurately predict which users will mention which URLs. We are currently working on applying the diffusion and influence models to personalized ranking of Social Media content.

Together with my EPFL and Docomo collaborators, we've devised a general feedback technique that improves the delay- and fault-tolerance of peer-to-peer overlay routing and provides scalabale routing security in mobile ad-hoc networks.

I've also worked on using the social networks as an efficient content distribution medium for increasing the robustness of BitTorrent to freerindg.

Following my interest of making distributed system evaluation more systematic and repeatable, I've built the ProtoPeer toolkit that allows the system evaluator to switch between the simulation and live deployment without changing any of the P2P application code. ProtoPeer has recently become a community-driven effort.

I've also worked on new overlay construction and maintenance protocols and on probabilisitc data replication in distributed hash tables.

Before joining LSIR I spent two years in a Japanese startup exploring new ways of building search engines and recommender systems, visualizing large text corpora and creating social data mining algorithms for the blogosphere.

publications

Book chapters


Peer to Peer overlay networks: Structure, Routing and Maintenance
W. Galuba, S. Girdzijauskas, in Springer's Encyclopedia of Database Systems

Journals


Fuzzynet: Ringless Routing in a Ring-like Structured Overlay
S. Girdzijauskas, W. Galuba, V. Darlagiannis, A. Datta, K. Aberer, to appear in Springer's Peer-to-Peer Networking and Applications
Pre-print

Conferences & workshops


Influence and Passivity in Social Media
D. M. Romero, W. Galuba, S. Asur, B. A. Huberman (in submission)
Pre-print, In the press: MIT Tech Review, BBC, CNET, ReadWriteWeb, Mashable

Outtweeting the Twitterers - Predicting Information Cascades in Microblogs
W. Galuba, D. Chakraborty, K. Aberer, Z. Despotovic, W. Kellerer, WOSN'10
PDF, BibTex, Slides

Castor: Scalable Secure Routing for Ad-hoc Networks
W. Galuba, P. Papadimitratos, M. Poturalski, K. Aberer, Z. Despotovic, W. Kellerer, INFOCOM'10
PDF, BibTex, Slides

Leveraging Social Networks for Increased BitTorrent Robustness
W. Galuba, K. Aberer, Z. Despotovic, W. Kellerer, CCNC'10, Best Paper Award
PDF, BibTex, Slides

Self-organized fault-tolerant routing in peer-to-peer overlays
W. Galuba, K. Aberer, Z. Despotovic, W. Kellerer, SASO'09
PDF, BibTex, Slides

ProtoPeer: A P2P Toolkit Bridging the Gap Between Simulation and Live Deployment
W. Galuba, K. Aberer, Z. Despotovic, W. Kellerer, SIMUTools'09
PDF, BibTex, Slides

Authentication-free Fault-tolerant Peer-to-peer Service Provisioning
W. Galuba, K. Aberer, Z. Despotovic, W. Kellerer, DBISP2P'07
PDF, BibTex, Slides

Generic Emergent Overlays in Arbitrary Peer Identifier Spaces
W. Galuba, K. Aberer, IWSOS'07, Best Paper Award
PDF, BibTex, Slides

The Complex Facets of Reputation and Trust (Invited paper)
W. Galuba, K. Aberer, Z. Despotovic, W. Kellerer, FuzzyDays'06
PDF, BibTex, Slides

Tech reports


Friend-to-Friend Computing: Building the Social Web at the Internet Edges
W. Galuba, LSIR-REPORT-2009-003
PDF, BibTex

More on Castor: the Scalable Secure Routing Protocol for Ad-hoc Networks
W. Galuba, LSIR-REPORT-2009-002
PDF, BibTex

Posters


Bandwidth-efficient delay- and loss-tolerant overlay routing
W. Galuba, K. Aberer, Z. Despotovic, W. Kellerer, ICNP 2008
PDF, Poster

ProtoPeer: from Simulation to Live Deployment in One Step
W. Galuba, K. Aberer, Z. Despotovic, W. Kellerer, P2P 2008
PDF, BibTex Poster