Christopher R. Wren: Curriculum Vitæ

I am drawn to the junction between dynamic systems, people and computers. I seek to understand how systems change over time. I express that understanding in the form of perceptual machines. I enjoy helping others to know these systems through visualization. My recent award-winning work on the social patterns of large groups of people is but one manifestation of this drive. I have also worked on computer vision systems for human machine interface and dynamic simulations for graphics, haptics, and engineering.

Ship it: Buzz APIs
Co-Organizing ICMI 2009.

Best Paper: IEEE Symposium on Information Visualization, October 2007.
Best Presentation: 3nd Location and Context Awareness , September 2007.
Best Presentation: 2nd Location and Context Awareness , May 2006.
Pfinder article in PAMI is cited more than 1000 times, January 2006.

Senior Software Engineer
2008 - present
Google, Inc., Cambridge, MA, USA
Member of the Friend Connect team developing social networking tools for the Internet.

Principal Research Scientist
2001 - 2008
Mitsubishi Electric Research Laboratories, Cambridge, MA, USA
I organized a loose team that developed novel sensor network technologies for buildings: including sensing and network platforms, perceptual systems, visualization interfaces, and ethical frameworks. The work won academic awards and helped force a reinterpretation of the company's core businesses. 11 patents, 22 papers.

Senior Perceptual Engineer
Perceptive Network Technologies, Inc., Waltham, MA, USA
2000 - 2001
I was a founding member of a perceptual sciences company dedicated to bringing context-aware communication technologies to the desktop, to help users manage converging information technologies.

Research Assistant
Massachusetts Institute of Technology. Cambridge, MA, USA
Media Laboratory, Vision and Modeling Group
1994 - 2000
I studied under Prof. Alex Pentland, one of the most widely cited authors in the field of computer vision, I worked with him and his students on five successful SIGGRAPH demonstrations and developed perceptual tool kits (Pfinder, STIVE, and Dyna) used internationally by many academic and research institutions. I also presented the work to academics, the media and senior officers of the corporate sponsors.

Engineer and Dynamicist
Boston Dynamics Inc., Cambridge, MA, USA
1993 - 1994
I worked for two years under Prof. Marc Raibert, inventor of many running robots including Big Dog, and founder of Boston Dynamics, Inc. Marc taught me much about tiger-team engineering and rapid prototyping. We built physics-based simulations of robots, elevators, frogs, and humans to drive analysis, animation, tele-immersion, and force-feedback systems under tight deadlines for international clients in academics, research, industry, and the military.

Research Technician
Massachusetts Institute of Technology, Cambridge, MA, USA
Media Laboratory, Advanced Human Interface Group
1989 - 1993
I worked four formative years under Dr. Richard A. Bolt, author of The Human Interface and founding member of the MIT Media Laboratory. I learned to love the human side of human-computer interface, while building tools to support the research effort, such as a scripted, networked, object-oriented graphics system that pre-dated similar commercial systems such as SGI Inventor.

Doctor of Philosophy.
Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology, Cambridge, MA, USA
Thesis Title: "Understanding Expressive Action."
Minor: "Stochastics, Dynamics, and Recursive Filtering."

Master of Science.
Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology, Cambridge, MA, USA
Thesis Title: "Pfinder: Real-Time Tracking of the Human Body"

Bachelor of Science
Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology, Cambridge, MA, USA
Thesis Title: "Dynamic Simulation of Large Systems: Trees Blowing in the Wind."
Minor: Cognitive Psychology.

Secondary Education.
Western Reserve Academy, Hudson, OH, USA

"Visualizing the History of Living Spaces" Yuri A. Ivanov, Christopher R. Wren, Alexander Sorokin, Ishwinder Kaur. IEEE Transactions on Visualization and Computer Graphics, ISSN: 1077-2626, Vol. 13, Issue 6, pp. 1153-1160, Nov-Dec 2007 ( IEEE Xplore, TR2007-068))

"SocialMotion: Measuring the Hidden Social Life of a Building" Christopher R. Wren, Yuri A. Ivanov, Ishwinder Kaur, Darren Leigh, Jonathan Westhues. Third International Symposium on Location- and Context-Awareness. September 2007. Oberpfaffenhofen, Germany. DOI MERL TR2007-034

"Buzz: Measuring and Visualizing Conference Crowds" Christopher R. Wren, Yuri A. Ivanov, Darren Leigh, Jonathan Westhues, Mariela Buchin, Tai-Peng Tian, and Pavan Turaga. ACM SIGGRAPH 2007 Emerging Technologies, San Diego, CA, USA. August 2007. (abs)

"Functional Calibration for Pan-Tilt-Zoom Cameras in Hybrid Sensor Networks". Christopher R. Wren, U. Murat Erdem, Ali J. Azarbayejani. ACM Multimedia Systems Journal, Special Issue on Multimedia Surveillance Systems. Volume 12, number 3. December 2006. DOI Link . (updated version of MERL TR2005-084)

"Similarity-based analysis for large networks of ultra-low resolution sensors". Christopher R. Wren, David Minnen, and Srinivas G. Rao. Pattern Recognition, volume 39, issue 10, pp. 1918--1931. Special Issue on Similarity-Based Pattern Recognition. Elsevier. October 2006. DOI Link . (also MERL TR2005-003)

"Worse is Better for Ambient Sensing" Carson J. Reynolds and Christopher R. Wren. Pervasive 2006 Workshop on Privacy, Trust and Identity Issues for Ambient Intelligence. May 7th, 2006. Dublin, Ireland. (also MERL TR2006-005)

"Perception for Human Motion Understanding," Christopher R. Wren. in Machine Learning and Robot Perception Vol. 7 in the series: "Studies in Computational Intelligence." Edited by Apolloni, Ghosh, Alpaslan, Jain, and Patnaik. Published by Springer. 2005. pp. 265-324. Springer Link (also Vismod TR 527)

"Minimalism in Ubiquitous Interface Design", Christopher R. Wren and Carson J. Reynolds. Personal and Ubiquitous Computing, September 2004, 8(5), pp. 370-373. Springer Link (also MERL TR2002-22)

"Volumetric Operations with Surface Margins." Christopher R. Wren, Yuri A. Ivanov. IEEE Computer Vision and Pattern Recognition Technical Sketches, Kauai, HI, USA. December 2001. (also MERL TR2001-047)

"Wearable City of News." Flavia Sparacino, Steve Schwartz, Christopher R. Wren, Richard W. DeVaul, Glorianna Davenport, Alex P. Pentland. ACM SIGGRAPH 1999 Millennium Motel, Los Angeles, CA, USA. August 1999.

"Pfinder: Real-Time Tracking of the Human Body." Christopher R. Wren, Ali J. Azarbayejani, Trevor Darrell, and Alex P. Pentland. IEEE Transactions on Pattern Analysis and Machine Intelligence, July 1997, 19(7), pp. 780-785. IEEE Link (also MIT Thesis)

Full bibliography: PDF CV.

United States Patent 7,667,730: "Composite Surveillance Camera System". Wren, Azarbayejani, and Dietz.

United States Patent 7,542,949: "Efficient Hierarchical Decomposition of Temporal Patterns." Wren and Minnen.

United States Patent 7,415,164: "Spectral Similarity for Object Detection." Wren and Porikli.

United States Patent 7,359,836: "Scalable Activity Recognition for Sensor Networks". Wren and Munguia Tapia.

United States Patent 7,302,369: "Traffic and Geometry Modeling with Sensor Networks." Wren.

United States Patent 7,242,421: "Communications based on perceptual sensing of presence." Center, Wren, Basu, and Gusyatin.

United States Patent 6,911,995: "Depth segmentation with virtual surface margins" Ivanov, Pentland, and Wren.

United States Patent 6,680,745: "Videoconferencing method with tracking of face and dynamic bandwidth allocation." Center and Wren.

United States Patent Application 20080317332: "Determining Geometries of Scenes" Ivanov, Thornton, and Wren.

United States Patent Application 20080130951: "Probabilistic Graphs on Surveillance Data." Wren, Ivanov, Sorokin, and Kaur.

United States Patent Application 20080130949: "Tracking and Identifying Objects in Environments." Ivanov, Sorokin, and Wren.

United States Patent Application: 20070257986 "Method For Processing Queries For Surveillance Tasks". Ivanov, Sorokin, and Wren

United States Patent Application 20060238618: "Context Aware Surveillance System Using a Hybrid Sensor Network" Wren, Erdem, and Azarbayejani.

United States Patent Application 20020113687 : "Method of extending image-based face recognition systems to utilize multi-view image sequences and audio information." Center, Wren, and Basu.

Dr. Christopher R. Wren

Brief

Recent Activity

Honors

Experience

Education

Selected Publications

Patents and Patent Applications

	Dr. Christopher R. Wren News \| Honors \| Experience \| Education \| Publications \| Patents Other Formats:PDF, LinkedIn, YouTube
	Brief
	I am drawn to the junction between dynamic systems, people and computers. I seek to understand how systems change over time. I express that understanding in the form of perceptual machines. I enjoy helping others to know these systems through visualization. My recent award-winning work on the social patterns of large groups of people is but one manifestation of this drive. I have also worked on computer vision systems for human machine interface and dynamic simulations for graphics, haptics, and engineering.
	Recent Activity
	Ship it: Buzz APIs Co-Organizing ICMI 2009.
	Honors
	Best Paper: IEEE Symposium on Information Visualization, October 2007. Best Presentation: 3nd Location and Context Awareness , September 2007. Best Presentation: 2nd Location and Context Awareness , May 2006. Pfinder article in PAMI is cited more than 1000 times, January 2006.
	Experience
	Senior Software Engineer 2008 - present Google, Inc., Cambridge, MA, USA Member of the Friend Connect team developing social networking tools for the Internet. Social Bar Profile Personalization Buzz APIs
	Principal Research Scientist 2001 - 2008 Mitsubishi Electric Research Laboratories, Cambridge, MA, USA I organized a loose team that developed novel sensor network technologies for buildings: including sensing and network platforms, perceptual systems, visualization interfaces, and ethical frameworks. The work won academic awards and helped force a reinterpretation of the company's core businesses. 11 patents, 22 papers.
	Senior Perceptual Engineer Perceptive Network Technologies, Inc., Waltham, MA, USA 2000 - 2001 I was a founding member of a perceptual sciences company dedicated to bringing context-aware communication technologies to the desktop, to help users manage converging information technologies.
	Research Assistant Massachusetts Institute of Technology. Cambridge, MA, USA Media Laboratory, Vision and Modeling Group 1994 - 2000 I studied under Prof. Alex Pentland, one of the most widely cited authors in the field of computer vision, I worked with him and his students on five successful SIGGRAPH demonstrations and developed perceptual tool kits (Pfinder, STIVE, and Dyna) used internationally by many academic and research institutions. I also presented the work to academics, the media and senior officers of the corporate sponsors.
	Engineer and Dynamicist Boston Dynamics Inc., Cambridge, MA, USA 1993 - 1994 I worked for two years under Prof. Marc Raibert, inventor of many running robots including Big Dog, and founder of Boston Dynamics, Inc. Marc taught me much about tiger-team engineering and rapid prototyping. We built physics-based simulations of robots, elevators, frogs, and humans to drive analysis, animation, tele-immersion, and force-feedback systems under tight deadlines for international clients in academics, research, industry, and the military.
	Research Technician Massachusetts Institute of Technology, Cambridge, MA, USA Media Laboratory, Advanced Human Interface Group 1989 - 1993 I worked four formative years under Dr. Richard A. Bolt, author of The Human Interface and founding member of the MIT Media Laboratory. I learned to love the human side of human-computer interface, while building tools to support the research effort, such as a scripted, networked, object-oriented graphics system that pre-dated similar commercial systems such as SGI Inventor.
	Education
	Doctor of Philosophy. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology, Cambridge, MA, USA Thesis Title: "Understanding Expressive Action." Minor: "Stochastics, Dynamics, and Recursive Filtering." Master of Science. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology, Cambridge, MA, USA Thesis Title: "Pfinder: Real-Time Tracking of the Human Body"
	Bachelor of Science Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology, Cambridge, MA, USA Thesis Title: "Dynamic Simulation of Large Systems: Trees Blowing in the Wind." Minor: Cognitive Psychology.
	Secondary Education. Western Reserve Academy, Hudson, OH, USA
	Selected Publications
	"Visualizing the History of Living Spaces" Yuri A. Ivanov, Christopher R. Wren, Alexander Sorokin, Ishwinder Kaur. IEEE Transactions on Visualization and Computer Graphics, ISSN: 1077-2626, Vol. 13, Issue 6, pp. 1153-1160, Nov-Dec 2007 ( IEEE Xplore, TR2007-068)) "SocialMotion: Measuring the Hidden Social Life of a Building" Christopher R. Wren, Yuri A. Ivanov, Ishwinder Kaur, Darren Leigh, Jonathan Westhues. Third International Symposium on Location- and Context-Awareness. September 2007. Oberpfaffenhofen, Germany. DOI MERL TR2007-034
	"Buzz: Measuring and Visualizing Conference Crowds" Christopher R. Wren, Yuri A. Ivanov, Darren Leigh, Jonathan Westhues, Mariela Buchin, Tai-Peng Tian, and Pavan Turaga. ACM SIGGRAPH 2007 Emerging Technologies, San Diego, CA, USA. August 2007. (abs) "Functional Calibration for Pan-Tilt-Zoom Cameras in Hybrid Sensor Networks". Christopher R. Wren, U. Murat Erdem, Ali J. Azarbayejani. ACM Multimedia Systems Journal, Special Issue on Multimedia Surveillance Systems. Volume 12, number 3. December 2006. DOI Link . (updated version of MERL TR2005-084)
	"Similarity-based analysis for large networks of ultra-low resolution sensors". Christopher R. Wren, David Minnen, and Srinivas G. Rao. Pattern Recognition, volume 39, issue 10, pp. 1918--1931. Special Issue on Similarity-Based Pattern Recognition. Elsevier. October 2006. DOI Link . (also MERL TR2005-003) "Worse is Better for Ambient Sensing" Carson J. Reynolds and Christopher R. Wren. Pervasive 2006 Workshop on Privacy, Trust and Identity Issues for Ambient Intelligence. May 7th, 2006. Dublin, Ireland. (also MERL TR2006-005)
	"Perception for Human Motion Understanding," Christopher R. Wren. in Machine Learning and Robot Perception Vol. 7 in the series: "Studies in Computational Intelligence." Edited by Apolloni, Ghosh, Alpaslan, Jain, and Patnaik. Published by Springer. 2005. pp. 265-324. Springer Link (also Vismod TR 527) "Minimalism in Ubiquitous Interface Design", Christopher R. Wren and Carson J. Reynolds. Personal and Ubiquitous Computing, September 2004, 8(5), pp. 370-373. Springer Link (also MERL TR2002-22)
	"Volumetric Operations with Surface Margins." Christopher R. Wren, Yuri A. Ivanov. IEEE Computer Vision and Pattern Recognition Technical Sketches, Kauai, HI, USA. December 2001. (also MERL TR2001-047) "Wearable City of News." Flavia Sparacino, Steve Schwartz, Christopher R. Wren, Richard W. DeVaul, Glorianna Davenport, Alex P. Pentland. ACM SIGGRAPH 1999 Millennium Motel, Los Angeles, CA, USA. August 1999.
	"Pfinder: Real-Time Tracking of the Human Body." Christopher R. Wren, Ali J. Azarbayejani, Trevor Darrell, and Alex P. Pentland. IEEE Transactions on Pattern Analysis and Machine Intelligence, July 1997, 19(7), pp. 780-785. IEEE Link (also MIT Thesis) Full bibliography: PDF CV.
	Patents and Patent Applications Patents
	United States Patent 7,667,730: "Composite Surveillance Camera System". Wren, Azarbayejani, and Dietz. United States Patent 7,542,949: "Efficient Hierarchical Decomposition of Temporal Patterns." Wren and Minnen. United States Patent 7,415,164: "Spectral Similarity for Object Detection." Wren and Porikli. United States Patent 7,359,836: "Scalable Activity Recognition for Sensor Networks". Wren and Munguia Tapia. United States Patent 7,302,369: "Traffic and Geometry Modeling with Sensor Networks." Wren. United States Patent 7,242,421: "Communications based on perceptual sensing of presence." Center, Wren, Basu, and Gusyatin. United States Patent 6,911,995: "Depth segmentation with virtual surface margins" Ivanov, Pentland, and Wren. United States Patent 6,680,745: "Videoconferencing method with tracking of face and dynamic bandwidth allocation." Center and Wren.
	Applications
	United States Patent Application 20080317332: "Determining Geometries of Scenes" Ivanov, Thornton, and Wren. United States Patent Application 20080130951: "Probabilistic Graphs on Surveillance Data." Wren, Ivanov, Sorokin, and Kaur. United States Patent Application 20080130949: "Tracking and Identifying Objects in Environments." Ivanov, Sorokin, and Wren. United States Patent Application: 20070257986 "Method For Processing Queries For Surveillance Tasks". Ivanov, Sorokin, and Wren United States Patent Application 20060238618: "Context Aware Surveillance System Using a Hybrid Sensor Network" Wren, Erdem, and Azarbayejani. United States Patent Application 20020113687 : "Method of extending image-based face recognition systems to utilize multi-view image sequences and audio information." Center, Wren, and Basu.