Chai Wah Wu

I am currently a principal research staff member in the Exploratory Math Sciences group developing innovative solutions for AI, modeling of complex processes and data analytics. Previously I have managed the Intelligent Energy Management group, the Distributed Digital Media Infrastructure group and the Foundations of Mathematics group.

Research interests

• Foundations of nonlinear circuits & systems theory
• Dynamics in coupled networks of oscillators
• Synchronization of chaos
• Application of chaos to information processing
• Distributed video streaming
• Digital halftoning
• Document and multimedia security
• Algebraic graph theory
• Logic and Machine Learning

Education

• Ph.D. electrical engineering, University of California, Berkeley, CA, USA, 1995.
• M.A. mathematics, University of California, Berkeley, CA, USA, 1994.
• M.S. electrical engineering, University of California, Berkeley, CA, USA, 1991.
• B.S. computer engineering, Lehigh University, Bethlehem, PA, USA, 1990.
• B.A. cognitive science, Lehigh University, Bethlehem, PA, USA, 1990.

Professional activities, Awards and Honors

• Fellow, IEEE.
• Member, AMS.
• INFORMS Certified Analytics Professional
• Adjunct Professor, Department of Electronic and Information Engineering, Hong Kong Polytechnic University (2013-2017)
• Adjunct Professor, Department of Electrical and Computer Engineering, Clemson University.
• Webmaster/Social Media/Publicity Chair, IEEE Mid-Hudson Section. (Google sites) (Facebook) (blogger) (twitter)
• Board of Governors, IEEE Circuits and Systems Society, 2010-2011.
• General co-chair, 12th IEEE International Workshop on Cellular Nanoscale Networks and their Applications, 2010.
• General co-chair, 13th IEEE International Workshop on Cellular Nanoscale Networks and their Applications, 2012.
• Organizing Committee Chair, AMS Special Session on Mathematics Through the Informational Lens, Joint Mathematics Meetings, 2022.
• Organizing Committee Chair, First IBM Research Workshop on the Informational Lens, 2020
• Organizing Committee Member, 9th International Workshop on Complex Systems and Networks, 2012.
• Organizing Committee Member, SIAM 2013 Annual Meeting.
• Organizing Committee Member, IMA Hot Topics Workshop: Mathematical and Computational Challenges in the Control, Optimization, and Design of Energy-Efficient Buildings, June 11-14, 2013.
• Senior Editorial Board Member, IEEE Journal on Emerging and Selected Topics in Circuits and Systems, 2014-2015, 2022-2023.
• Deputy Editor-in-Chief, IEEE Circuits and Systems Magazine, 2014-2015.
• Editor-in-Chief, IEEE Circuits and Systems Magazine, 2016-2019.
• Associate editor, IEEE Transactionson Circuits and Systems, Part I, 1997-1999, 2002-2003, 2006-2007.
• Associate editor, IEEE Transactionson Circuits and Systems, Part II, 2004-2005.
• Associate Editor, IEEE Circuits and Systems Magazine, 2012-2013.
• Member, IEEE CAS Technical Committee on Nonlinear Circuits and Systems.
• Member, IEEE CAS Technical Committee on Cellular Nanoscale Networks and Array Computing(Chairman: 2009-2010).
• Member, IEEE CAS Technical Committee on Sensor Systems.
• Member, IEEE CAS Technical Committee on Multimedia Systems and Applications.
• Review Committee Member, IEEE ISCAS, 2001, 2006, 2008, 2010, 2011, 2012.
• Session Chair, IS&T's NIP, 2001, 2004, 2006, 2007, 2008.
• Session Chair, IEEE ISCAS, 2002, 2004-2005, 2010, 2011, 2012.
• Technical Committee Member, IEEE ICME2003, INDS 2008, INDS 2009.
• Industry mentor, MathematicalModeling Workshop, Institute for Mathematics and its Applications, University of Minnesota,2005,2006, 2008, 2011.
• IEEE Circuits and Systems Society's Distinguished Lecturer, 2006-2007
• ABET EAC program evaluator, 2006-, EAC commissioner 2018-
• Member, IEEE CEAA, 2016-2017.
• Digital Media Judge, Imagine Cup 2010 Finals.
• Moody's Mega Math Challenge Judge, 2011-2016.
• Contributor to Online Encyclopedia of Integer Sequences and Sympy development
• Holder of 78 U.S. Patents.
• IEEE R1 Technological Innovation Award, 2013.

Invited lectures and workshop presentations

• 'Solving Sparse Linear Systems via Flexible GMRES with In-Memory Analog Preconditioning', Minisymposium on Analog and Mixed Precision Preconditioning, Conference on Preconditioning Techniques for Scientific and Industrial Applications (Precond 24), Atlanta, Georgia, June 10-12, 2024.
• 'Trace estimation via asynchronous stochastic rounding,' ICIAM Minisymposium on Stochastic Rounding for Reduced-Precision Arithmetic in Scientific Computing, August 22, 2023.
• 'Algorithms for Analog Arrays,' AMS Special Session on Mathematics Through the Informational Lens, Joint Mathematics Meetings (JMM 2022), April 9, 2022.
• 'Memristive Cellular Analog Arrays for Numerical Computation,' CNNA 2021 Keynote talk, September 30, 2021. 
• 'Simplifying Deep Neural Networks via Look-up Tables and Product of Sums Matrix Factorizations,' ISCAS 2020 Overview Lecture, October 17, 2020. (slides)
• 'Graph Laplacian Matrices as Quantum State Density Matrices and their Entanglement Properties,' ACM Poughkeepsie Chapter Talk, Marist College, Poughkeepsie, New York, May 22, 2017.
• 'Eigenvalue bounds of matrices and control of networked dynamical systems,' NYU Distributed Systems Lab Seminar, New York City, New York, May 5, 2017.
• 'Geometric motifs in graphs on regular grids,' 2016 IEEE International Workshop on Complex Systems and Networks, Atlanta, Georgia, November 14-15, 2016.
• 'Levy-Desplanques, Gersgorin and Beyond: Eigenvalue Bounds and Matrix Graphs,' 2015 IEEE International Workshop on Complex Systems and Networks, Perth, Australia, October 5-7, 2015.
• 'Global Technology Outlook 2014: Transforming industries with Systems of Insight,' Systems Seminar/Ezra's Round Table, Cornell University, November 14, 2014.
• 'Pendant vertices in complex networks: separable graphs and control localization of weighted trees', 2014 IEEE International Workshop on Complex Systems and Networks,' Shanghai, China, October 25-26, 2014.
• 'Control of Complex Networks of Coupled Dynamical Systems', 2012 International Workshop on Complex Systems and Networks', University of Minnesota, September 5-7, 2012.
• 'Locally Connected Processor Arrays for Matrix Multiplication and Linear Transforms', Seminar Series on Chaos, Control and Complex Networks, City University of Hong Kong, May 18, 2012.
• 'Some Aspects of Multicoverage in Sensor Networks', Wireless and Optical Communications Conference, New Jersey Institute of Technology, April 15-16, 2011.
• 'Can stubbornness or gullibility facilitate language formation? A study of various strategies for reaching consensus in a model of the naming game', Computer Science Colloquium, The Graduate Center, City University of New York, March 3, 2011.
• 'More is More: the benefits of denser sensor deployment', Hong Kong CityU-PolyU Joint Seminar Series on Chaos and Complex Networks, The Hong Kong Polytechnic University, HongKong, September 30, 2010.
• 'Some graph-theoretical criteria for control in networks of dynamical systems', Invited lecture, 2010 International Workshop on Complex Systems and Networks, Beijing, China, September 25-27, 2010.
• 'Transformational Hybrid Systems: The Next Generation of System Architecture', Keynote talk, 12th IEEE CNNA, International Workshop on Cellular Nanoscale Networks and their Applications, Berkeley, CA, Feb 3-5, 2010.
• 'Global Technology Outlook 2009' and 'Synchronization and consensus in networks of coupled nonlinear circuits and systems,' EECS/CASE Colloquium, Syracuse University, Oct. 14, 2009.
• 'Graph Laplacian Matrices and Multipartite Entanglement in Quantum Mechanics,' International Workshop on Complex Systems and Networks, University of Bristol, Bristol, United Kingdom, July 20-22, 2009.
• 'Sensor placement and coverage: tools from geometry and image processing,'Keynote talk, MITACS Workshop on Decision Support, Information Fusion and Sensor Networks, University of Calgary, Calgary, Canada, June 18-19, 2009.
• 'Controland synchronization in systems coupled via a complex network,' Hong Kong CityU-PolyU Joint Seminar Series on Chaos and Complex Networks, City University of Hong Kong, Hong Kong, May 29, 2009.
• 'Global Technology Outlook 2008,' Presentations given at Hungarian Academy of Sciences and Peter Pazmany Catholic University, Budapest, Hungary, Dec4-5, 2008.
• 'Localization of forcing sites to facilitate synchronization in systems coupled via a complex network,' International Workshop on Complex Systems and Networks, Canberra, Australia, Oct1-3, 2008.
• 'Global Technology Outlook 2008,' Keynote talk, IEEE 11th International Workshop on Cellular Neural Networks and their Applications (CNNA 2008),Santiago de Compostela, Spain, July 16, 2008.
• 'Digital Halftoning and Sensor Placement,' BIRS Workshop on Low Complexity Dynamics, Banff, Alberta, Canada, May29, 2008.
• 'SensorPlacement and Digital Halftoning,' ComputerScience Colloquium, The Graduate Center, City University of New York, February 28, 2008.
• 'Global Technology Outlook 2007,' Department of Electrical Engineering, University of Notre Dame, October 15, 2007.
• 'Synchrony and consensus in complex networks: an overview,' International Workshop on Complex Systems and Networks, Guilin, China, July 19-21, 2007.
• 'Identical Synchronization in Networks of Coupled Nonlinear Circuits and Systems,' IEEE CAS Distinguished Lecturer Seminar, University of Calgary, Calgary,Alberta, Canada, May 11, 2007.
• 'Global Technology Outlook 2007: How will it affect the workplace? How can we prepare for it?,' SVC Lecture Series to Envision the Workplace of the Future: Its Technology, Design, and its Challenges to Employees, Southern Vermont College, Bennington, VT, March 22, 2007.
• 'Algorithms for digital halftoning,' The Twenty-Second Annual Mathematical Problems in Industry Workshop, Franklin W. Olin College of Engineering,Needham, MA, June 12-16, 2006.
• 'Some techniques for speeding up digital halftoning algorithms,' BIRS workshop on Coarsely Quantized Redundant Representation of Signals,Banff, Alberta, Canada, March 11-16, 2006.
• 'The optimality of the greedy algorithm in Carpool and Chairman Assignment Problems,' Workshop on Geometric Dynamics with Singularities, Exeter, UK, Dec 13-16,2005.
• 'Synchronization and consensus in networks of systems with nonreciprocal coupling,' International Workshop on Complex Systems and Networks, Hong Kong, May 20, 2005.
• 'The error diffusion halftoning algorithm: some stability results and applications beyond halftoning,' Oversampling and Coarse Quantization for Signals Workshop, CSCAMM, University of Maryland, April 11-15,2005.
• 'Halftoning, Watermarking and Scheduling: Some Applications of the Error Diffusion Algorithm,' IMA/MCIM Industrial Problems Seminar, University of Minnesota,Oct. 15, 2004.
• 'Global Asymptotical Stability of Neural Networks with Delay,' ECE Lectures Series, Polytechnic University, Sept. 30,2004.
• 'Synchronization in arrays of systems coupled via a graph, nonreciprocal and delay coupling,' International workshop onnonlinear dynamics and complexity in information and communication technology, Bologna, Italy, Sept 6-8, 2004.
• 'Error diffusion: recent developments in theory and applications', Harmonic Analysis and Signal Processing Seminar, Courant Institute of Mathematical Sciences, New York University,Feb 11, 2004.

Books

• C. W. Wu, Synchronization in complex networks of nonlinear dynamical systems, World Scientific, Singapore, 2007. (Table of contents, Preface, Chapter 1, Errata)
• C. W. Wu, Synchronization in coupled chaotic circuits and systems, World Scientific, Singapore, 2002. (Table of contents, Preface, Chapter 1)

Book chapters

• C. W. Wu, 'Control of Networks of Coupled Dynamical Systems,' in Consensus and Synchronization in Complex Networks, pp. 23-50, Springer, 2013.
• T. Nowicki, M. S. Squillante and C. W. Wu, 'Fundamentals of Dynamic Decentralized Optimization in Autonomic Computing Systems,' in Self-star Properties in Complex Information Systems: Conceptual and Practical Foundations, (O. Babaoglu, M. Jelasity, A. Montresor, et al. eds), Lecture Notes in Computer Science, Hot Topics, vol. 3460, pp. 204-218, Springer-Verlag, 2005.
• C. W. Wu, 'Synchronization in Arrays of Coupled Chaotic Circuits and Systems: Theory and Applications,' in Controlling Chaos and Bifurcations in Engineering Systems (G. Chen ed.), CRC Press, Boca Raton, 1999.
• C. W. Wu, 'Qualitative Analysis of Dynamic Circuits,' in Encyclopedia of Electrical and Electronics Engineering (J. Webster ed.), John Wiley & Sons, New York, 1999.

Computer software

• M. P. Kennedy and C. W. Wu, ``ABC: Adventures in Bifurcation and Chaos'', software accompanying Chua's circuit: A paradigm for Chaos (R. N. Madan, ed.), World Scientific, Singapore, 1993.
• OEISsequences: Python functions to generate The On-Line Encyclopedia of Integer Sequences (OEIS) sequences. Available at: OEISsequences · PyPI
• algebraic-connectivity-directed: Python functions to compute various notions of algebraic connectivity of directed graphs. Available at: algebraic-connectivity-directed · PyPI
• graph-generators: Python functions to compute various classes of networkx graphs. Available at: graph-generators · PyPI