Jiejun Xu: Homepage

About Me

Hello and Welcome!

I am a Senior Research Staff and a Principal Investigator in the Center of Computational Network Intelligence, Information and Systems Sciences Lab (ISSL) at HRL Laboratories, LLC. My research is supported by the Boeing company, General Motors, and various government agencies. Prior to joining HRL, I received my PhD from the Computer Science Department at University of California, Santa Barbara. I was affiliated with the Vision Research Lab, the Center for Bio-Image Informatics, and the Information Network Academic Research Center. My current research interests are Graph Mining, Machine Learning, Computer Vision, Information Retrieval and Web Search.

Project Highlights

PI: DARPA Modeling Adversarial Activity
PI: Network of Network Summarization and Optimization (HRL R&D)
PI: Open-source Intelligence: Behavior and Value Analytics, Network-based Data Integration (Boeing & GM R&Ds)
Task Lead: DARPA ASED, IARPA OSI, DARPA Neovision2, NGA BIG, ONR NEMESIS
Participant: DARPA URGENT, Swarm Vision, Visual Perception, Brain on Board (Govt & HRL R&Ds)

Publications

Si Zhang, Hanghang Tong, Yinglong Xia, Liang Xiong, Jiejun Xu. NetTrans: Neural Cross-Network Transformation. In SIGKDD Conference on Knolwedge Discovery and Data Mining, San Diego, USA (virtual), 2020.
Si Zhang, Hanghang Tong, Jie Tang, Jiejun Xu, Wei Fan. Incomplete Network Alignment: Problem Definitions and Fast Solutions. In ACM Transactions on Knowledge Discovery from Data, Volume 14, 2020.
Alexei Kopylov, Jiejun Xu. Filtering Strategies for Inexact Subgraph Matching on Noisy Multiplex Networks. In International Conference on Big Data (IEEE BigData), Workshop on Graph Techniques for Adversarial Activity Analytics, 2019.
Lihui Liu, Boxin Du, Jiejun Xu, Hanghang Tong. G-Finder: Approximate Attribute Subgraph Matching. In International Conference on Big Data (IEEE BigData), 2019.
Si Zhang, Hanghang Tong, Jiejun Xu, Yifan Hu, Ross Maciejewski. Origin: Non-Rigid Network Alignment. In International Conference on Big Data (IEEE BigData), 2019.
Jiejun Xu, Kang-Yu Ni, Alexei Kopylov, Shane Roach, Tsai-Ching Lu. On Modeling Adversarial Activities in Large Multi-Source Networks. NetSci, 2019.
Si Zhang, Hanghang Tong, Jiejun Xu, Ross Maciejewski. Graph convolutional networks: a comprehensive review. In Computational Social Networks, 2019.
Jun Wu, Jingrui He, Jiejun Xu. DEMO-Net: Degree-specific Graph Neural Networks for Node and Graph Classification. In SIGKDD Conference on Knolwedge Discovery and Data Mining, Alaska, USA, 2019.
Dawei Zhou, Lecheng Zheng, Jiejun Xu, Jingrui He. Misc-GAN: A Multi-Scale Generative Model for Graphs. In Frontiers in Big Data, Vol 2, 2019.
Santosh Pandey, Xiaoye Sherry Li, Aydin Buluç, Jiejun Xu, Hang Liu. H-INDEX: Hash-indexing for parallel triangle counting on GPUs. In IEEE High Performance Extreme Computing Conference (HPEC), 2019.
Tyler Derr, Hamid Karimi, Xiaorui Liu, Jiejun Xu, Jiliang Tang. Deep Adversarial Network Alignment. In arXiv:1902.10307, 2019.
Dana Warmsley, Jiejun Xu, Tsai-Ching Lu. From Gamergate to FIFA: Identifying Polarized Groups in Online Social Media. In International Conference on Big Data (IEEE BigData), Workshop on Graph Techniques for Adversarial Activity Analytics, Seattle, USA, 2018.
Si Zhang, Hanghang Tong, Jiejun Xu, Ross Maciejewski. Graph Convolutional Networks: Algorithms, Applications and Open Challenges. In IEEE International Conference on Computational Data & Social Networks (CSoNet), 2018.
Aruna Jammalamadaka, Jiejun Xu, and Tsai-Ching Lu. Behavioral Deviations in Social Media Caused by Emergency Events. In Social Computing, Behavioral-Cultural Modeling & Prediction and Behavior Representation in Modeling and Simulation (SBP-BRiMS), 2018.
Joel Douglas, Ben Zimmerman, Alexei Kopylov, Jiejun Xu, Daniel Sussman, and Vince Lyzinski. Metrics for Evaluating Network Alignment. In ACM Conference on Web Search and Data Mining (WSDM), Workshop on Graph Techniques for Adversarial Activity Analytics (GTA³) , Los Angeles, USA, 2018.
Daniel Xie, Jiejun Xu, Tsai-Ching Lu. What's trending tomorrow, today: Using early adopters to discover popular posts on Tumblr. In International Conference on Big Data (IEEE BigData), Boston, USA, 2017.
Steven Munn, Kang-Yu Ni, Jiejun Xu. Learning Network Dynamics from Tumblr: A Search for Influential Users. In Social Computing, Behavioral-Cultural Modeling & Prediction and Behavior Representation in Modeling and Simulation (SBP-BRiMS), 2017.
Krishna Bathina, Aruna Jammalamadaka, Jiejun Xu, Tsai-Ching Lu. An Agent-based Model of Posting Behavior During Times of Societal Unrest. In Social Computing, Behavioral-Cultural Modeling & Prediction and Behavior Representation in Modeling and Simulation (SBP-BRiMS), 2017.
Si Zhang, Hanghang Tong, Jie Tang, Jiejun Xu, Wei Fan. iNEAT: Incomplete Network Alignment. In EEE International Conference on Data Mining (ICDM), New Orlean, USA, 2017
Laura Cruz-Albrecht, Jiejun Xu, Kang-Yu Ni and Tsai-Ching Lu: Characterizing Regional and Behavioral Device Variations Across the Twitter Timeline: a Longitudinal Study. In ACM Web Science Conference (WebSci), Troy, USA, 2017
Jiejun Xu, Daniel Xie, Tsai-Ching Lu, John Cafeo. EDSV: Emerging Defect Surveillance for Vehicles. In ACM Web Science Conference (WebSci), Troy, USA, 2017
Deepak Khosla, Jiejun Xu, Kyungnam Kim, Yang Chen. Online Location Recognition for drift-free trajectory estimation and efficient autonomous navigation. In Proc. SPIE Unmanned Systems Technology XIX, 2017.
Jiejun Xu, Samuel Johnson, Kang-Yu Ni. Cross-Modal Event Summarization: A Network of Networks Approach. In International Conference on Big Data (IEEE BigData), Washington D.C., USA, 2016. (also appears NetSci 2017 lightning talk)
Daniel Xie, Jiejun Xu, Tsai-Ching Lu. Automated Classification of Extremist Twitter Accounts Using Content-Based and Network-Based Features. In IEEE BigData, workshop on Application of BigData for Computational Social Science, Washington D.C., USA, 2016.
Jiejun Xu, Kyungnam Kim, Lei Zhang, Deepak Khosla. 3D Perception for Autonomous Robot Exploration. In 11th International Symposium on Visual Computing (ISVC), Las Vegas, USA, 2015.
Kyungnam Kim, David J. Huber, Jiejun Xu, Deepak Khosla. Efficient Algorithms for Indoor MAV Flight using Vision and Sonar Sensors. In 11th International Symposium on Visual Computing (ISVC), Las Vegas, USA, 2015.
Jiejun Xu, Tsai-Ching Lu. Toward Precise User-Topic Alignment in Online Social Media. In IEEE International Conference on Big Data (IEEE BigData), Santa Clara, California, 2015.
Peter Li, Jiejun Xu, Tsai-Ching Lu. Leveraging Homophily to Infer Demographic Attributes. Workshop on Information in Networks, New York, USA, 2015.
Jiejun Xu, Tsai-Ching Lu. Inferring User Interests with a Heterogeneous Bi-relational Graph Model, Conference on Complex Systems (CCS), Arizona, USA, 2015. (Extended abstract)
Jiejun Xu, Tsai-Ching Lu. Seeing the Big Picture from Microblogs: Harnessing Social Signals for Visual Event Summarization. In ACM Conference on Intelligent User Interfaces (IUI), Atlanta, USA, 2015.
Jiejun Xu, Tsai-Ching Lu. Inferring User Interests on Tumblr. In Social Computing, Behavioral Modeling and Prediction Conference (SBP), Washington DC, USA, 2015.
Ryan Compton, Craig Lee, Jiejun Xu, Luis Artieda-Moncada, Tsai-Ching Lu, Lalindra De Silva, Michael Macy. Using Publicly Visible Social Media to Build Detailed Forecasts of Civil Unrest. In Springer Journal on Security Informatics, 2014.
Jiejun Xu, Kyungnam Kim, Zhiqi Zhang, Hai-Wen Chen, Yuri Owechko. 2D/3D Sensor Exploitation and Fusion for Enhanced Object Detection. In IEEE Conference on Computer Vision and Pattern Recognition (CVPR), Workshop on Multi-Sensor Fusion for Outdoor Dynamic Scene Understanding, Columbus, USA, 2014.
Jiejun Xu, Ryan Compton, Tsai-Ching Lu, David Allen. Rolling through tumblr: Characterizing Behavioral Patterns of the Microblogging Platform. In ACM Web Science Conference (WebSci), Bloomington, USA, 2014.
Jiejun Xu, Ryan Compton, Tsai-Ching Lu, David Allen. Quantifying Cross-platform Engagement through Large-scale User Alignment. In ACM Web Science Conference (WebSci), Bloomington, USA, 2014.
Ryan Compton, Matthew Keegan, Jiejun Xu. Inferring the Geographic Focus of Online Documents from Social Media Sharing Patterns. In Computational Approaches to Social Modeling Workshop (ChASM), Bloomington, USA, 2014.
Jiejun Xu, Tsai-Ching Lu, Ryan Compton, David Allen. Civil Unrest Prediction: A Tumblr-Based Exploration. In Social Computing, Behavioral Modeling and Prediction Conference (SBP), Washington DC, USA, 2014.
Jiejun Xu, Vignesh Jagadeesh, B. S. Manjunath. Multi-Label Learning With Fused Multimodal Bi-Relational Graph. In IEEE Transactions on Multimedia (TMM), 2014.
Santhoshkumar Sunderrajan, Jiejun Xu, B. S. Manjunath. Context-aware Graph Modeling for Object Search and Retrieval in a Wide Area Camera Network. In International Conference on Distributed Smart Camers (ICDSC), Palm Springs, USA, 2013.
Jiejun Xu, Vignesh Jagadeesh, Zefeng Ni, Santhoshkumar Sunderrajan, B. S. Manjunath. Graph-Based Topic-Focused Retrieval in Distributed Camera Network. In IEEE Transactions on Multimedia (TMM), 2013.
Zefeng Ni, Jiejun Xu, B.S. Manjunath. Object Browsing and Searching in a Camera Network using Graph Models. In IEEE Conference on Computer Vision and Pattern Recognition (CVPR), Workshop on Camera Networks & Wide Area Scence Analysis, Providence, USA, 2012.
Jiejun Xu, Ziyu Guan, Vishwakarma Singh, B.S. Manjunath. Unified Hypergraph for Image Ranking in a Multimodal Context. In IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Kyoto, Japan, 2012.
Kyungnam Kim, Michael Cao, Shankar Rao, Jiejun Xu, Swarup Medasani, Yuri Owechko. Multi-Object Detection and Behavior Recognition from Motion 3D Data. In IEEE Conference on Computer Vision and Pattern Recognition (CVPR), Workshop on Human Activity Understanding from 3D Data, Colorado Springs, USA, 2011.
Jiejun Xu, Zefeng Ni, Carter De Leo, Thomas Kuo, and B.S. Manjunath. Spatial-Temporal Understanding of Urban Scenes through Large Camera Network. In ACM International Conference on Multimedia, Workshop on Multimodal Pervasive Video Analysis, Florence, Italy, 2010.
Emily Moxley, Jim Kleban, Jiejun Xu, B.S. Manjunath. Not all tags are created equal: Learning flickr tag semantics for global annotation. In IEEE International Conference on Multimedia and Expo (ICME), New York, USA, 2009.
Jim Kleban, Emily Moxley, Jiejun Xu, B.S. Manjunath. Global Annotation on Georeferenced Photographs. In ACM International Conference on Image and Video Retrieval (CIVR), Santorini, Greece, 2009.
Xavier Anguera, Jiejun Xu, Nuria Oliver. Multimodal Photo Annotation and Retrieval on a Mobile Phone. In ACM Conference on Multimedia Information Retrieval (MIR), Vancouver, Canada, 2008.
Elisa Drelie Gelasca, Swapna Joshi, Jim Kleban, Stephen Mangiat, B. S. Manjunath, Emily Moxley, Anindya Sarkar, Jiejun Xu. The Vision Research Lab of UCSB at TRECVID. TRECVID workshop, 2007.
Elisa Drelie Gelasca, Joriz De Guzman, Steffen Gauglitz, Pratim Ghosh, JieJun Xu, Emily Moxley, Amir M. Rahimi, Zhiqiang Bi and B. S. Manjunath. CORTINA: Searching a 10 Million+ Images Database. VRL Technical Report, ECE, University of California, Santa Barbara, 2007.

Granted Patents

Three-Dimensional Object Detection and Multi-Agent Behavior Recognition using 3D Motion Data. (US 8,948,501)
Sensor Fusion using Detector Confidence Boosting. (US 9,183,459)
Fast Open Doorway Detection for Autonomous Robot Exploration. (US 9,251,417)
System for filtering, segmenting and recognizing objects in unconstrained environments. (US 9,633,483)
Method for object localization and pose estimation for an object of interest. (US 9,875,427)
System and method for real world event summarization with microblog data. (US 10,055,486)
Generic frontal and side doorway detection with line tracking and vanishing point based verification. (US 10,068,336)
System and method for finding open space efficiently in three dimensions for mobile robot exploration. (US 10,134,135)
Tensor-based framework for analyzing high velocity large-scale network activities to infer latent mesostructures and important nodes. (US 10,218,579)
Accurate user alignment across online social media platforms. (US 10,305,845)
System and method for assessing spatiotemporal impact of emergency events based on social media posting behavior. (US 10,326,847)

Work Experience

Research Intern, Hughes Research Laboratories, 2009 ~ 2012
Research Intern, Telefonica Research, Barcelona, Apr 2008 ~ Sept 2008
Graduate Researcher, Vision Research Lab, UCSB, 2006 ~ 2012
Research Developer, Center of Bio-Image Informatics, 2005 ~ 2007

Teaching Experience