Research

I work on algorithms for complex networks. The overall goal of my research is to extract value from Big Data, where my focus is on the network data. While big data nowadays is easily available, its analysis and interpretation remains largely an open problem. This in particular is true for network data, for example: can we make our society more efficient by acting upon social interactions on Twitter and Facebook? Can we predict development of science and innovation using citation networks? Can we predict stability of a company through its financial interactions?

My research can be divided in the following three directions:

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Information extraction and predictions based on data. Which measurement will tell us whether a large company has a healthy network of buyers and suppliers? Which parameter will be able to indicate threatening changes in such networks? Moreover, we can choose what data (for example, transaction or sensor data) to collect and how to deduce networks from this data. Thus, creating a network is a research question in itself.

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Mathematical analysis of network characteristics. Many commonly accepted methods for statistical analysis are deceiving in networks. Think about the friendship paradox: the friends of a random individual have on average more friends than the individual himself! I did a lot of research on measuring degree-degree correlations in networks, and on centrality measures such as Google PageRank.

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Randomized algorithms. Some important tasks on networks are genuinely hard. Moreover, large commercial networks, such as Twitter follower network or Facebook friendships, are usually not available in their entirety and must be discovered step by step. I am interested in efficient algorithms for computing network characteristics when the complete network data is not available.

My background is in Applied Probability and Stochastic Operations Research. In my PhD I analysed performance of warehousing systems. I have also actively contributed in the area of Healthcare Logistics within the Centre for Healthcare Operations Improvement & Research (CHOIR).