Tianyi Chen

Boston University | BU · Department of Computer Science

Motifs are small subgraph patterns that play a key role towards understanding the structure and the function of biological and social networks. The current de facto approach towards assessing the statistical significance of a motif \(\mathcal {M}\) relies on counting its occurrences across the network, and comparing that count to its expected count...

Social media and online networks have enabled discussions between users at a planetary scale on controversial topics. However, instead of seeing users converging to a consensus, they tend to partition into groups holding diametric opinions. In this work we propose an opinion dynamics model that starts from a given graph topology, and updates in eac...

Following significant advances in image acquisition, synapse detection, and neuronal segmentation in connectomics, researchers have extracted an increasingly diverse set of wiring diagrams from brain tissue. Neuroscientists frequently represent these wiring diagrams as graphs with nodes corresponding to a single neuron and edges indicating synaptic...

Benford's law describes the distribution of the first digit of numbers appearing in a wide variety of numerical data, including tax records, and election outcomes, and has been used to raise "red flags" about potential anomalies in the data such as tax evasion. In this work, we ask the following novel question: given a large transaction or financia...

Dense subgraph discovery is a fundamental problem in graph mining with a wide range of applications \cite{gionis2015dense}. Despite a large number of applications ranging from computational neuroscience to social network analysis, that take as input a {\em dual} graph, namely a pair of graphs on the same set of nodes, dense subgraph discovery metho...

In the densest subgraph problem, given an undirected graph G(V, E, w) with non-negative edge weights we are asked to find a set of nodes S⊆V that maximizes the degree density w(S)/|S|, where w(S) is the sum of the weights of the edges in the graph induced by S. This problem is solvable in polynomial time, and in general is well studied. But what ha...

In the densest subgraph problem, given a weighted undirected graph $G(V,E,w)$, with non-negative edge weights, we are asked to find a subset of nodes $S\subseteq V$ that maximizes the degree density $w(S)/|S|$, where $w(S)$ is the sum of the edge weights induced by $S$. This problem is a well studied problem, known as the {\em densest subgraph prob...