Angelia Nedich angelia@uiuc.edu University of Illinois at Urbana-Champaign Department of Industrial and Enterprise Systems Engineering Distributed Optimization (IE/GE 598 AN) This course is an advanced research seminar for graduate students. The objective is to study and learn the most recent advances in models and algorithmic developments for analysis and optimization of large scale distributed systems. The course is mainly motivated by the emergence of large scale networks, characterized by the lack of a centralized coordinator or centralized access to information, and time-varying system characteristics such as connectivity. The purpose of this course is to study such systems by exploring the interplay of optimization theory, game theory, dynamical systems, and to some extent graph theory. The topics to be covered include models and algorithms for distributed rate allocation and congestion control over communication networks (such as the internet), distributed coordination algorithms (such as consensus and gossip) over networks with applications to multi-vehicle systems and sensor networks, coverage problems, and distributed control, as well as quantization and synchronization phenomena in engineered systems. There is no text-book for this course. The list of selected papers for readings is posted on the course web at: https://netfiles.uiuc.edu/angelia/www/nedichcourses.html Credit: 4 hours Offering Level: Graduate Meeting Time: MW 3-4:40 MEB 256 Office Hours: M 2-3 TB 211 Prerequisites: Basic background in Multivariate Calculus, Linear Algebra, and Optimization or instructor’s permission. Requirements: This course requires a lot of independent work. There are a few traditional lectures. Students are expected to critically read and analyze research papers across various disciplines. Assignments: Everyone participating in the course shall read all the selected papers. Each student will present several papers in a form of group lectures. Grades will be based on the quality of the presentations and overall participation in the class discussions. Some special projects may be assigned if necessary. READING LIST Decentralized “cooperative” agent systems 1. J. N. Tsitsiklis, Problems in Decentralized Decision Making and Computation, Ph.D. Thesis, Department of EECS, MIT, November 1984; technical report LIDS-TH-1424, Laboratory for Information and Decision Systems, MIT. (13 Mb) (2 lectures) 2. J. N. Tsitsiklis, D. P. Bertsekas and M. Athans, Distributed Asynchronous Deterministic and Stochastic Gradient Optimization Algorithms, IEEE Transactions on Automatic Control, Vol. 31, No. 9, 1986, pp. 803-812. (1/2 lect.) 3. T. Vicsek, A. Czirok, E. Ben-Jacob, I. Cohen, and O. Schochet, “Novel type of phase transitions in a system of self-driven particles,” Physical Review Letters, Vol. 75, No. 6, 1995, pp. 1226-1229, http://arxiv.org/pdf/cond-mat/0611743 (1/2 lecture) 4. A. Jadbabaie, J. Lin, and A. S. Morse, Coordination of groups of mobile autonomous agents using nearest neighbor rules, IEEE Transactions on Automatic Control, Vol. 48, No. 6, June 2003, pp. 988-1001. (1/2 lecture) 5. V. D. Blondel, J. M. Hendrickx, A. Olshevsky, and J. N. Tsitsiklis, Convergence in Multiagent Coordination, Consensus, and Flocking, in Proceedings of the Joint 44th IEEE Conference on Decision and Control and European Control Conference (CDC-ECC'05), Seville, Spain, December 2005. (1/2 lecture) 6. A. Olshevsky and J. N. Tsitsiklis, Convergence Speed in Distributed Consensus and Averaging, submitted, December 2006. (1/2 lecture) 7. R. Olfati-Saber and R. M. Murray Consensus Problems in Networks of Agents with Switching Topology and Time-Delays IEEE Trans. on Automatic Control, vol. 49(9), pp. 1520-1533, Sep., 2004. (1/2 lecture) 8. R. Olfati-Saber, Flocking for Multi-Agent Dynamic Systems: Algorithms and Theory IEEE Trans. on Automatic Control, vol. 51(3), pp. 401-420, Mar. 2006. (1/2 lecture) 9. L. Xiao and S. Boyd, Fast linear iterations for distributed averaging, Systems and Control Letters, 53:65-78, 2004. 10. S. Boyd, A. Ghosh, B. Prabhakar, and D. Shah, Gossip algorithms: Design, analysis, and applications, Proceedings IEEE Infocomm 2005, 3:1653-1664, Miami, March 2005 (2/3 lecture). 11. S. Boyd, A. Ghosh, B. Prabhakar, and D. Shah, Randomized Gossip Algorithm, IEEE Transactions on Information Theory, vol. 52, no. 6, June 2006 (1/3 lecture) 12. D. Kempe, A. Dobra, and J. Gehrke, Gossip-based computation of aggregate information, ACM Symposium on Theory of Computing, 2004. http://www.cs.cornell.edu/johannes/papers/2003/focs2003-gossip.pdf (1/4 lecture) 13. C.C. Moallemi and B. Van Roy, Consensus Propagation, IEEE Transactions on Information Theory, vol. 52, no. 11, 2006, http://arxiv.org/pdf/cs/0603078v2 (3/4) 14. A.G. Dimakis, A.D. Sarwate, and M.J. Wainwright, Geographic Gossip: Efficient Averaging for Sensor Networks, forthcoming in IEEE Transactions on Signal Processing, http://arxiv.org/pdf/0709.3921v1 (2/3 lecture) 15. F. Benezit, A. G. Dimakis, P. Thiran and M. Vetterli, Gossip Along the Way: Order-Optimal Consensus through Randomized Path Averaging, Proceedings of Allerton Conference 2007. http://www.eecs.berkeley.edu/~adim/Allerton_final_gossip.pdf (2/3 lecture) 16. A. Kashyap, T. Basar and R. Srikant, Quantized Consensus, Automatica, vol. 43, no.7, p.1192-1203, July 2007. http://www.ifp.uiuc.edu/~srikant/Papers/akshay_consensus.pdf 17. Ruggero Carli, Fabio Fagnani, Paolo Frasca, and Sandro Zampieri, Efficient Quantized Techniques for Consensus Algorithms, NeCST workshop, Nancy, France, 2007. http://calvino.polito.it/~frasca/due_metodi.pdf 18. Paolo Frasca, Ruggero Carli, Fabio Fagnani, and Sandro Zampieri, Average Consensus on Networks with Quantized Communication, Preprint, 2008. http://calvino.polito.it/~frasca/FCFZ_quantization.pdf 19. Q. Li and D. Rus, Global Clock Synchronization in Sensor Networks, IEEE Transactions on Computers, vol. 55, no. 2, 2006. Download it through UIUC library on line system. 20. R. Carli, A. Chiuso, L. Schenato, S. Zampieri, A PI Consensus Controller for Networked Clocks Synchronization, submitted to IFAC World Congress, Seul’08. HERE 21. A. Olshevsky and J. N. Tsitsiklis, "On the Nonexistence of Quadratic Lyapunov Functions for Consensus Algorithms'', June 2007; IEEE Transactions on Automatic Control, forthcoming (1/2 lecture) 22. R. Carli, A. Chiuso, L. Schenato, S. Zampieri, “A PI Consensus Controller for Networked Clocks Synchronization,” Preprint 2007. 23. P.-A. Bliman and G. Ferrari-Trecate. Average consensus problems in networks of agents with delayed.communications. Proc. 44th IEEE Conference on Decision and Control and European Control Conference 2005, pages 7066--7071, 2005. 24. D. Angeli and P.-A. Bliman, “Stability of leaderless multi-agent systems. Extension of a result by Moreau,” 2004. oai:arXiv.org:math/0411338. http://arxiv.org/pdf/math/0411338 25. S. Boyd, P. Diaconis, and L. Xiao, Fastest mixing Markov chain on a graph (2003) 26. R. Raffard, C. Tomlin, and S. Boyd, Distributed optimization for cooperative agents: Application to formation flight (2004) 27. S. Boyd, A. Ghosh, B. Prabhakar, and D. Shah, Mixing times for random walks on geometric random graphs (2006) 28. S. Samar, S. Boyd, and D. Gorinevsky, Distributed estimation via dual decomposition (2007) 29. L. Xiao, S. Boyd, and S.-J. Kim, Distributed average consensus with least-meansquare deviation (2007) 1 lecture “Non-cooperative” agent systems 30. Basic intro on games, Equilibria, Stackelberg games, mechanism design (2-3 lectures) 31. Frank Kelly, Aman Maulloo and David Tan. Rate control in communication networks: shadow prices, proportional fairness and stability, Journal of the Operational Research Society 49 (1998) 237-252. 32. R.J. Gibbens and F.P. Kelly, Resource pricing and the evolution of congestion control , Automatica 35 (1999) 1969-1985. 33. Steven H. Low and David E. Lapsley, "Optimization flow control, I: basic algorithm and convergence," IEEE/ACM Transactions on Networking, December 1999. http://citeseer.ist.psu.edu/article/low99optimization.html More 34. T. Basar and R. Srikant. "A Stackelberg network game with a large number of followers." Journal of Optimization Theory and Applications, 115(3):479-490, December 2002. 35. R. Johari and D.K.H. Tan. End-to-end congestion control for the Internet: delays and stability. IEEE/ACM Transactions on Networking, 9(6):818–832, 2001. 36. R. Johari and J.N. Tsitsiklis. Efficiency loss in a network resource allocation game. Mathematics of Operations Research, 29(3):407–435, 2004. Awarded First Place in the 2003 INFORMS George E. Nicholson Student Paper Competition. 37. R. Johari, S. Mannor, and J.N. Tsitsiklis. Efficiency loss in a network resource allocation game: the case of elastic supply. IEEE Transactions on Automatic Control, 50(11):1712–1724, 2005. A longer version containing all proofs is available here. 38. R. Johari and J.N. Tsitsiklis. A scalable network resource allocation mechanism with bounded efficiency loss. IEEE Journal on Selected Areas in Communications, 24(5):992–999, 2006. 39. D. Acemoglu, R. Johari, and A. Ozdaglar. Partially optimal routing. IEEE Journal on Selected Areas in Communications, 25(6):1148–1160, 2007. 40. S. Adlakha, R. Johari, and A. Goldsmith. Competition in wireless systems via Bayesian interference games. 2007. Submitted. 41. R. Srikant, “On the positive recurrence of a Markov chain describing file arrivals and departures in a congestion-controlled network,” Technical Report. Presented at the IEEE Computer Communications Workshop, Oct. 2004. http://www.ifp.uiuc.edu/~srikant/Papers/ccw04.pdf This is the later version of the paper which will appear in the IEEE Transactions on Information Theory: X. Lin, N.Shroff and R.Srikant On the Connection-Level Stability of CongestionControlled Communication Networks http://www.ifp.uiuc.edu/~srikant/Papers/it_connection_level.pdf