TITLE: Polynomial Counting in Anonymous Dynamic Networks with Applications to Anonymous Dynamic Algebraic Computations https://drops.dagstuhl.de/opus/volltexte/2018/9160/pdf/LIPIcs-ICALP-2018-156.pdf Dariusz R. Kowalski Computer Science Department, University of Liverpool, Liverpool, UK Miguel A. Mosteiro Computer Science Department, Pace University, New York, NY, USA SPEAKER: Miguel A. Mosteiro, Associate Professor, Computer Science Department, Pace University ABSTRACT Starting with Michail, Chatzigiannakis, and Spirakis work, the problem of Counting the number of nodes in Anonymous Dynamic Networks has attracted a lot of attention. The problem is challenging because nodes are indistinguishable (they lack identifiers and execute the same program) and the topology may change arbitrarily from round to round of communication, as long as the network is connected in each round. The problem is central in distributed computing as the number of participants is frequently needed to make important decisions, such as termination, agreement, synchronization, and many others. A variety of algorithms built on top of mass distribution techniques have been presented, analyzed, and also experimentally evaluated; some of them assumed additional knowledge of network characteristics, such as bounded degree or given upper bound on the network size. However, the question of whether Counting can be solved deterministically in sub-exponential time remained open. In this work, we answer this question positively by presenting Methodical Counting, which runs in polynomial time and requires no knowledge of network characteristics. Moreover, we also show how to extend Methodical Counting to compute the sum of input values and more complex functions without extra cost. Our analysis leverages previous work on random walks in evolving graphs, combined with carefully chosen alarms in the algorithm that control the process and its parameters. To the best of our knowledge, our Counting algorithm and its extensions to other algebraic and Boolean functions are the first that can be implemented in practice with worst-case guarantees. SPEAKER BIO: Miguel A. Mosteiro is an Associate Professor in the Seidenberg School of Computer Science and Information Systems at Pace University. His research interests are in various aspects of algorithms, from theoretical analysis to experimental algorithms. Specific areas of his research include algorithms for IoT systems such as sensor networks and radio networks, the application of game theory and reinforcement learning to crowd computing, and online and reallocation algorithms for cloud computing and radio networks. His work on polynomial counting in Anonymous Dynamic Networks (ADN) which is the topic of his presentation in our Algorithms Seminar, won a best paper award in ICALP'18.