My research focuses on designing new distributed and parallel algorithms, the distributed processing of big data, achieving fault-tolerance in communication networks against adversarial attacks, and developing robust protocols that work in highly dynamic environments such as peer-to-peer Blockchain networks and mobile ad-hoc networks.
Tags (Show all)Asynchrony Big Data Byzantine Failures Churn Communication Complexity Distributed Agreement Distributed Storage Dynamic Network Fault-Tolerance Gossip Communication Graph Algorithm Haskell Information Complexity Leader Election Machine Learning Mobile Ad-Hoc Network Natural Language Processing P2P Secure Computation in Networks Self-Healing Symmetry Breaking Wireless Networks
- Optimal Regional Consecutive Leader Election in Mobile Ad-Hoc NetworksPDF
Hyun Chul Chung, Peter Robinson, Jennifer L. Welch. 7th ACM SIGACT/SIGMOBILE International Workshop on Foundations of Mobile Computing (part of FCRC 2011).
AbstractThe regional consecutive leader election (RCLE) problem requires mobile nodes to elect a leader within bounded time upon entering a specific region. We prove that any algorithm requires $\Omega(Dn)$ rounds for leader election, where D is the diameter of the network and $n$ is the total number of nodes. We then present a fault-tolerant distributed algorithm that solves the RCLE problem and works even in settings where nodes do not have access to synchronized clocks. Since nodes set their leader variable within $O(Dn)$ rounds, our algorithm is asymptotically optimal with respect to time complexity. Due to its low message bit complexity, we believe that our algorithm is of practical interest for mobile wireless ad-hoc networks. Finally, we present a novel and intuitive constraint on mobility that guarantees a bounded communication diameter among nodes within the region of interest.
- Regional Consecutive Leader Election in Mobile Ad-Hoc Networks
Hyun Chul Chung, Peter Robinson, Jennifer L. Welch. 6th ACM SIGACT/SIGMOBILE Workshop on Foundations of Mobile Computing (DIALM-POMC 2010).
I'm interested in parallel and distributed programming and related technologies such as software transactional memory and the actor-model. Recently, I have been working on implementing a simulation environment for distributed algorithms in Elixir/Erlang, and implementing non-blocking data structures in Haskell suitable for multi-core machines. Below is a (non-comprehensive) list of software that I have written.
- concurrent hash table: a thread-safe hash table that scales to multicores.
- data dispersal: an implementation of an (m,n)-threshold information dispersal scheme that is space-optimal.
- secret sharing: an implementation of a secret sharing scheme that provides information-theoretic security.
- tskiplist: a data structure with range-query support for software transactional memory.
- stm-io-hooks: An extension of Haskell's Software Transactional Memory (STM) monad with commit and retry IO hooks.
- Mathgenealogy: Visualize your (academic) genealogy! A program for extracting data from the Mathematics Genealogy project.
- I extended Haskell's Cabal, for using a "world" file to keep track of installed packages. (Now part of the main distribution.)
- Database Systems, Spring 2020.
- Computer Networks, Fall 2019.
- Distributed Computing, Spring 2019.
- Randomized Algorithms, Fall 2018: Intro slides. Part 1 on Concentration Bounds.
- Advanced Distributed Systems, Fall 2016, 2017.
- Computation with Data, Fall 2016.
- Internet and Web Technologies, Spring 2016.
- Networks and Communications, Fall 2015.