Juan Julia LIU

Ph. D.

 

Embedded Reasoning Area (ERA)

Palo Alto Research Center (PARC)

3333 Coyote Hill Rd,

Palo Alto, CA94304

email:   juan.liu@parc.com

telephone:  650-812-4828

 

 

Juan Liu received her B.E. degree in Electronic Engineering from Tsinghua University, China, in 1995, and the M.S. and Ph.D. degrees in Electrical Engineering from the University of Illinois at Urbana-Champaign, in 1998 and 2001, respectively. In 2001, she joined Palo Alto Research Center (PARC) as a member of research staff in the Embedded Reasoning Area. Her research interests include signal processing, statistical modeling and inference, distributed sensor networks, and applications such as intelligent transportation systems. She is the recipient of IEEE Signal Processing Society Best Young Author Paper Award of 2002.

 

CV  and  Publications

 

RESEARCH  

1.    Ad hoc sensor networks and collaborative information processing

·         Information processing based on diverse sensing models --- I have been a key contributor to information processing algorithms for sensor networks. The application includes detection, classification, and target tracking. The key method is Bayesian inference.

·         Resource management in sensor networks --- the challenge in this problem is to achieve a suitable balance between the need to gather and process a vast amount sensor data to infer about underlying phenomenon of interest and the reality that sensor network is often constrained in sensing, processing, and communication resources. How to achieve best information processing performance without over-tasking the sensor network is a major challenge. My work along this theme focuses on developing estimation and information theoretic methods to characterize the performance of sensor tasking choices, and then using optimization techniques to decide optimal or nearly optimal solutions.

·         Node localization in ad hoc networks ---- location information of nodes is critical to many applications such as routing and sensor tasking. I have designed localization schemes for a variety of sensing modalities. I have proposed a unique error characterization and control method to limit error propagation in sensor network localization.

·         Information dissemination in ad hoc sensor networks ---  designing efficient routing mechanism for sensor networks, which jointly optimize communication routes balancing the need for information gathering and delivery.

·         Other issues ---- programming methodology, middleware, and user interface issues in sensor networks.

 

2.    Vehicle-based computation/communication and Intelligent Transportation System (ITS)

·         Information dissemination --- designed push-based information dissemination architecture for VANETs (Vehicle Ad Hoc Networks) by allowing applications to model potential usefulness of information using utility functions; designed dynamic packet prioritizing scheme to handle the dynamic and unreliable nature of VANETs communication.  This works better than traditional geocast-like information dissemination schemes because multiple data sources can trade their communication resources to maximize overall benefit.

·         Collision avoidance --- designed computationally efficient statistical inference mechanism for collision avoidance. The computation is centered at the primary vehicle, incorporating sensing evidence to monitor all surrounding vehicles and pedestrians and provide early collision warning.

 

3.    Statistical modeling and inference based on acoustic, image, and video signals.   The emphasis is mainly on statistical modeling of various types of signals and applications to estimation problems. Research interest include: Bayesian estimation, optimization, model selection, wavelets and multi-resolution signal processing, information theoretic methods, regularization, and adaptive methods and learning.   

 

4.    Pattern recognition and computer vision
The focus is on developing computer vision and pattern recognition techniques for various applications. Example projects include clothes recognition for an interactive fashion recommender system (PARC project), recognition of natural cursive handwriting (internship at IBM T.J Watson Research Center), and classification of grains based on image data (joint work with Agriculture Engineering Department of UIUC). Research interests include: image analysis and feature extraction, Bayesian classification, and machine learning techniques.

 

 

Intern Students --- In the past, I had the privilege to work with these brilliant interns on a number of interesting topics:

  • Dragan Petrovic, UC Berkeley (2002) --- information-directed routing in sensor networks
  • Yi Zou, Duke University (2003) --- iterative least-square methods for localization
  • Arpita Ghosh, Stanford University (2004) --- variable information dissemination
  • Manu Chhabra, University of Rochester (2004) --- resource management in monitoring cluttered environment with limited sensing resources
  • Xiaotao Zou, UC Santa Barbara (2005) ---  camera network calibration
  • Deepan Thavarajah (2007) --- collision early warning system implementation
  • Wei Zhang, Oregon State University (2007) --- responsive mirror for intelligent fitting room using multi-camera perception

 

 

AWARDS AND PROFESSIONAL ACTIVITIES

·         Member of IEEE and ACM.  

·          Recipient of IEEE Signal Processing Society Young Author Best Paper Award (2002) for the paper "Information-Theoretic Analysis of Interscale and Intrascale Dependencies Between Image Wavelet Coefficients", coauthored with Pierre Moulin.

·         Guest editor of IEEE Signal Processing Magazine, special issue on distributed signal processing in sensor networks.

·         Finance Chair, IPSN 2003.

·         Technical Program Committee (TPC) member of various workshops and conferences, including IPSN 2004 and 2006 (Workshop on Information      Processing in Sensor Networks), SensorFusion 2005, ICIP (International Conference on Image Processing) 2003 and 2004.

·         Reviewer for various journal and magazine, including IEEE Transactions on Image Processing, IEEE Transactions on Signal Processing, IEEE Signal Processing Megazine, IEEE Pattern Recognition Letter, ACM Transactions on Sensor networks, EuraSip Journal on Applied Signal Processing, Signal Processing of Elseviser Science.