Research Projects

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    Parallel Community Detection Algorithms

    Keywords: community detection, social networks, biological networks, large-scale graphs, louvain algorithm, InfoMap, label-propagation algorithm

    Complex systems are organized in clusters or communities, each having distinct role or function. In the corresponding network representation, each functional unit (community) appears as a tightly-knit set of nodes having a higher connection inside the set than outside. Finding communities may reveal the organization of complex systems and their function. We are currently working on designing parallel scalable algorithms for detecting communities in large-scale networks.

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    Scalable Methods for Mining Dynamic Graphs

    Keywords: Parallel algorithms, temporal patterns, community discovery, evolution of structures

    We are collaborating with Performance and Algorithms Group at Lawrence Berkeley National Lab on this project. Real complex systems are inherently time-varying and can be modeled as temporal graphs (networks). Examples include social, transportation, and many forms of biological networks. Standard graph metrics introduced so far in complex network theory are mainly suited for static graphs, i.e., graphs in which the links do not change over time. In this work, we aim at designing scalable parallel algorithms for mining large time-varying networks.

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    Graph-centric Analysis of Human Brain Data

    Keywords: Application of graph methods, brain image, image to network, bio/health/medical informatics

    We are a multidisciplinary team consisting of faculty from Psychology/Neuroscience and Computer Science working together to extract insights from human brain data. Collaborators: Dr. Elliot Beaton and Dr. Vassil Roussev (UNO). Funded by UNO ORSP Interdisciplinary grant.

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    Parallel Algorithms for Counting and Listing Triangles

    Keywords: triangle counting, clustering coefficients, distributed-memory algorithms, load balancing, fast and space efficient

    Download Code*
    Counting triangles in a network is an important algorithmic problem arising in the study of complex networks. An efficient solution to the triangle counting problem can also lead to efficient solutions for many other graph-theoretic problems, e.g. computation of clustering coefficient, transitivity, and triangular connectivity. Further, triangle counting has important applications in graph analysis. We design efficient parallel algorithms for counting triangles.
    * Note that the above code is a research code and is intended for friendly use. The authors will try their best to address any questions/queries/issues. Users are advised to contact with the authors for any newer (or optimized) version of the code. However, for most general use cases, the provided code should suffice.
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    Large-scale Graph Visualization

    Keywords: Big networks; Visualization; Visual analytics; Network analytics; Graph mining; Scalable algorithms

    In this project, we identify several popular network visualization tools and provide a comparative analysis based on the features and operations these tools support. We demonstrate empirically how those tools scale to large networks. We also provide several case studies of visual analytics on large network data and assess performances of the tools.

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    Characterizing Social Networks based on Local Neighborhood

    Keywords: local neighborhood, jaccard coefficient, community structure, triangle-dense graphs

    Characterizing real-world social and information networks based on graph-theoretic metrics or properties has been of growing interest. Among the most explored metrics are degree distribution, number of triangles and clustering coefficients. An important property related to triangles, of many networks, is high transitivity, which states that two nodes (vertices) having common neighbor(s) have an elevated probability of being neighbors to one another. We present a characterization of networks based on a quantification of common neighbors.

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    Scalable Mining and Analysis of Protein-Protein Interaction Networks

    Keywords: PPI networks, functional units, scalable framework, disease analysis, drug discovery

    We are working to design scalable algorithmic and analytic techniques to study PPI networks. Our study of PPIs will be based on network-centric mining and analysis approaches. We will design specialized methods for extracting signed motifs, computing centrality, and finding functional units in PPI networks.

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    A Cyber-Infrastructure for Network Science (CINET)

    A web-based system for network-based computation.

    I was a member of CINET project team during my PhD years. This NSF-funded project, titled as "From Desktops to Clouds -- A Middleware for Next Generation Network Science," is a large collaborative research effort. By harnessing new cloud-based resources in an easily accessible manner, network science researchers will be able to deal more complex problems. We have built a cyber infrastructure which is designed to be self-sustainable.

    My role: I worked on designing and implementing highly efficient and scalable algorithms for various problem of network science. The implemented modules serve as computational engine behind the whole system.

Lab Members

3. Bikesh Pandey

Undergraduate Researcher (graduated)

2. Naw Safrin Sattar

PhD Student, Graduate Research Assistant

1. Md Abdul Motaleb Faysal

PhD Student, Graduate Research Assistant

4. Sanjiv Pradhanang

Research Assistant, COSURP Program

5. Prakash Joshi

Undergraduate Researcher (graduated)

Currently, my lab consists of 2 PhD students , several MS and a couple of undergraduate students.

The students are working on various problems on data science, parallel computing, graph (networks) mining and visualization.