{ "about_me": { "name": "Debasish Pattanayak", "tagline": "I study what swarms of simple mobile robots and agents can compute together: how they gather, explore, disperse and form patterns, and how much failure they can tolerate.", "name_odia": "ଦେବାଶିଷ ପଟ୍ଟନାୟକ", "picture": "./debasish_photo.jpeg", "dblp": "https://dblp.uni-trier.de/pers/hd/p/Pattanayak:Debasish", "google_scholar": "https://scholar.google.com/citations?user=E-jjx9gAAAAJ&hl=en&oi=ao", "orcid": "https://orcid.org/0000-0003-2862-2795", "x": "https://twitter.com/drdebmath?ref_src=twsrc%5Etfw", "github": "https://github.com/drdebmath", "linkedin": "https://www.linkedin.com/in/debasish-pattanayak-3750a530/", "position": "Assistant Professor", "current_institution": { "name": "Indian Institute of Technology, Indore", "url": "https://www.iiti.ac.in/" }, "department": { "name": "Department of Computer Science and Engineering", "url": "https://cse.iiti.ac.in/faculty.php", "office": "Room No. 19, CGS Advanced Research Complex, IIT Indore." }, "biodata": { "urls": { "Indian Institute of Technology, Indore": "https://www.iiti.ac.in/", "Computer Science and Engineering": "https://cse.iiti.ac.in/faculty.php", "Carleton University": "https://carleton.ca/", "Prof. Nicola Santoro": "https://research.nicola-santoro.com/", "Prof. Paola Flocchini": "https://www.site.uottawa.ca/~flocchin/", "University of Ottawa": "https://www.uottawa.ca/en", "IIT Guwahati": "https://www.iitg.ac.in/", "Prof. Partha Sarathi Mandal": "https://fac.iitg.ac.in/psm/", "Dr. H. Ramesh": "https://www.iitg.ac.in/ramesh_h/", "Prof. Stefan Schmid": "https://schmiste.github.io/", "University of Vienna": "https://www.univie.ac.at/", "ISI Kolkata": "https://www.isical.ac.in/", "Dr. Anisur Rahaman Molla": "https://sites.google.com/site/mollaanisurrahaman/", "LUISS Guido Carli": "https://www.luiss.it", "Prof. Giuseppe F. Italiano": "https://www.luiss.edu/faculty/350980", "UQO": "https://www.uqo.ca/", "Prof. Andrzej Pelc": "http://w3.uqo.ca/pelc/main.html", "CV": "cv.html" }, "short_bio": [ "I am an Assistant Professor in Computer Science and Engineering at the Indian Institute of Technology, Indore. My research focuses on distributed algorithms for mobile agents and mobile robots in graphs and geometric spaces, with interests in exploration, rendezvous, dispersion, pattern formation, and fault tolerance. I also develop interactive simulators for these systems. Before joining IIT Indore, I completed my PhD in Theoretical Computer Science from the Department of Mathematics at IIT Guwahati under the supervision of Prof. Partha Sarathi Mandal and Dr. H. Ramesh. I was a visiting researcher with Prof. Stefan Schmid at the University of Vienna and with Dr. Anisur Rahaman Molla at ISI Kolkata, and then a postdoctoral researcher with Prof. Giuseppe F. Italiano at LUISS Guido Carli, with Prof. Andrzej Pelc at UQO, and under the joint supervision of Prof. Nicola Santoro and Prof. Paola Flocchini at Carleton University and the University of Ottawa. See my CV for a fuller academic profile." ] }, "education": [ { "degree": "B.Tech. in Mathematics and Computing", "institution": { "name": "IIT Guwahati", "url": "https://www.iitg.ac.in/" }, "start_date": "2010-07-01", "end_date": "2014-07-01" }, { "degree": "PhD in Theoretical Computer Science from the Department of Mathematics", "institution": { "name": "IIT Guwahati", "url": "https://www.iitg.ac.in/" }, "supervisors": [ { "name": "Prof. Partha Sarathi Mandal", "url": "https://www.iitg.ac.in/psm/" }, { "name": "Dr. H. Ramesh", "url": "https://www.iitg.ac.in/ramesh_h/" } ], "start_date": "2014-07-01", "end_date": "2020-09-30" } ], "positions": [ { "title": "Visiting Fellow", "duration": "Six months", "institution": { "name": "University of Vienna", "supervisor": { "name": "Prof. Stefan Schmid", "url": "https://www.univie.ac.at/ct/stefan/" } }, "fellowship": "SERB Overseas Visiting Doctoral Fellowship", "start_date": "2019-07-01", "end_date": "2019-12-31" }, { "title": "Visiting Scientist", "duration": "Six months", "institution": { "name": "ISI Kolkata", "supervisor": { "name": "Dr. Anisur Rahaman Molla", "url": "https://sites.google.com/site/mollaanisurrahaman/" } }, "start_date": "2020-03-15", "end_date": "2020-09-15" }, { "title": "Postdoctoral Researcher", "duration": "Two years", "institution": { "name": "LUISS Guido Carli", "url": "https://www.luiss.it", "supervisor": { "name": "Prof. Giuseppe F. Italiano", "url": "https://www.luiss.edu/faculty/350980" } }, "start_date": "2020-10-15", "end_date": "2022-10-15" }, { "title": "Postdoctoral Researcher", "duration": "One year", "institution": { "name": "UQO", "url": "https://www.uqo.ca/", "supervisor": { "name": "Prof. Andrzej Pelc", "url": "http://w3.uqo.ca/pelc/main.html" } }, "start_date": "2022-10-20", "end_date": "2023-10-19" }, { "title": "Postdoctoral Researcher", "duration": "Twenty months", "institutions": [ { "name": "Carleton University", "url": "https://www.carleton.ca/" }, { "name": "University of Ottawa", "url": "https://www.uottawa.ca/en" } ], "supervisors": [ { "name": "Prof. Nicola Santoro", "url": "https://research.nicola-santoro.com/" }, { "name": "Prof. Paola Flocchini", "url": "https://www.site.uottawa.ca/~flocchin/" } ], "start_date": "2023-10-20", "end_date": "2025-06-20" }, { "title": "Assistant Professor", "duration": "Ongoing", "institution": { "name": "IIT Indore", "url": "https://cse.iiti.ac.in/faculty.php" }, "start_date": "2025-06-23" }, { "title": "Research Intern", "duration": "Three months", "institution": { "name": "JAIST, Japan", "url": "https://www.jaist.ac.jp/english/", "supervisor": { "name": "Prof. Atsuko Miyaji", "url": "https://cy2sec.comm.eng.osaka-u.ac.jp/miyaji-lab/" } }, "start_date": "2013-05-01", "end_date": "2013-07-31" }, { "title": "Research Intern", "duration": "Three months", "institution": { "name": "NISER, Bhubaneswar", "url": "https://www.niser.ac.in/", "supervisor": { "name": "Dr. Deepak Kumar Dalai", "url": "https://www.niser.ac.in/~deepak/" } }, "start_date": "2012-05-01", "end_date": "2012-07-31" } ], "cv": { "label": "View detailed CV", "url": "cv.html" }, "whiteboard": { "label": "Whiteboard", "url": "https://debasishpattanayak.com/whiteboard/" }, "blog": { "label": "Blog", "title": "The Oblivious Robot", "url": "https://debasishpattanayak.com/blog/", "feed": "https://debasishpattanayak.com/blog/feed.xml" }, "mobility_matters": { "label": "Mobility Matters", "title": "A Living Survey of Open Problems on Autonomous Agents, Robots and Particles", "url": "https://debasishpattanayak.com/mobility-matters/", "description": "A public atlas of research problems in distributed computing by mobile entities: agents on graphs, robots in the plane, geometric search, and programmable matter. Each problem is mapped across its model settings, with the known results, the papers behind them, and what is still open.", "pdf": "https://debasishpattanayak.com/mobility-matters/mobility-matters.pdf", "source_url": "https://github.com/drdebmath/mobility-matters" }, "email": "debasish@iiti.ac.in", "contact": { "email": "debasish@iiti.ac.in", "office": "Room No. 19, CGS Advanced Research Complex, IIT Indore.", "department": "Department of Computer Science and Engineering", "institution": "Indian Institute of Technology, Indore" } }, "visualizations": { "simulators": [ { "name": "CCM Model", "description": "Interactive simulator for the coordinated concurrent movement model.", "url": "https://debasishpattanayak.com/CCMModel/", "source_url": "https://github.com/drdebmath/CCM" }, { "name": "LCM Model", "description": "Interactive simulator for the classic Look-Compute-Move model.", "url": "https://debasishpattanayak.com/LCMmodel/", "embed_url": "https://debasishpattanayak.com/LCMmodel/?embed&loop=1&controls=play,reset,step,speed&algorithm=CircleFormation&robots=12&seed=7", "source_url": "https://github.com/drdebmath/LCM" }, { "name": "Black Hole Search", "description": "Interactive simulator for the Black Hole Search problem with Byzantine agents.", "url": "https://debasishpattanayak.com/BlackHoleSearch/", "source_url": "https://github.com/drdebmath/BlackHoleSearch" }, { "name": "SILBOT", "description": "Interactive simulator for the SILBOT mobile robot model.", "url": "https://debasishpattanayak.com/SILBOT/", "source_url": "https://github.com/drdebmath/SILBOT" }, { "name": "MobileAutomata", "featured_on_homepage": false, "description": "Interactive simulator for the MobileAutomata model.", "url": "https://debasishpattanayak.com/MobileAutomata/", "source_url": "https://github.com/drdebmath/MobileAutomata" }, { "name": "India Future Mobility Planner", "featured_on_homepage": false, "description": "Interactive simulator of flight vs high-speed rail vs hybrid city-center journeys.", "url": "https://debasishpattanayak.com/Transport/", "source_url": "https://github.com/drdebmath/Transport" }, { "name": "Algorithm Visualizations", "featured_on_homepage": false, "description": "Step-by-step demos by category: traversal, shortest paths, spanning trees, online algorithms, and distributed agents.", "url": "visualizations/", "embed": false } ] }, "news": [ { "date": "2 October 2026", "title": "Beyond the Boundary: Optimal Grid Dispersion by Spread, Reverse, and Collect accepted to ICDCN 2027, to be held at NIT Karnataka, Surathkal.", "url": "https://arxiv.org/abs/2610.16935" }, { "date": "8 August 2026", "title": "Optimal Luminous UCF under Asynchrony accepted to JPDC, as the journal version of the DISC Brief Announcement.", "url": "https://www.sciencedirect.com/journal/journal-of-parallel-and-distributed-computing", "urls": { "DISC BA": "https://doi.org/10.4230/LIPIcs.DISC.2024.46" } }, { "date": "1 August 2026", "title": "Launched Project Pankhuri, a learning and enrichment initiative for students of Classes 6-8 from tribal and rural communities.", "url": "https://projectpankhuri.github.io" }, { "date": "1 July 2026", "title": "Full version of Asynchronous Dispersion with Optimal Time Complexity accepted to ICPP 2026.", "url": "http://arxiv.org/abs/2507.01298" }, { "date": "26 May 2026", "title": "Brief Announcement: Asynchronous Dispersion with Optimal Time Complexity accepted to SPAA 2026.", "url": "https://spaa.acm.org/" }, { "date": "17 April 2026", "title": "Paper on $k$-edge connected subgraph accepted to JCSS.", "url": "https://doi.org/10.1016/j.jcss.2026.103801" }, { "date": "11 April 2026", "title": "Awarded PM-ECRG by ANRF.", "url": "cv.html#awards" }, { "date": "7 April 2026", "title": "Best paper award for Universal Dancing paper in SIROCCO 2026.", "url": "https://sirocco2026.webspace.durham.ac.uk/" }, { "date": "25 March 2026", "title": "Paper on Universal Pattern Formation accepted in Distributed Computing Journal.", "url": "https://doi.org/10.1007/s00446-026-00504-3" }, { "date": "21 January 2026", "title": "Paper on Universal Dancing accepted in Sirocco 2026.", "url": "https://sirocco2026.webspace.durham.ac.uk/" }, { "date": "29 October 2025", "title": "Two BAs in DISC 2025. One on Universal Dancing and another on Optimal Dispersion under asynchrony.", "url": "https://www.disc-conference.org/wp/disc2025/detailed-program/" }, { "date": "16 October 2025", "title": "Paper on Leader election is accepted to TCS.", "url": "https://www.sciencedirect.com/science/article/pii/S030439752500516X" }, { "date": "3 July 2025", "title": "New preprint on Optimal Dispersion under asynchrony in ArXiV.", "url": "http://arxiv.org/abs/2507.01298" }, { "date": "23 June 2025", "title": "Joined as Assistant Professor in CSE, IIT Indore.", "url": "https://cse.iiti.ac.in/faculty.php" }, { "date": "13 June 2025", "title": "Paper on Directed Dispersion accepted to JPDC.", "url": "https://doi.org/10.1016/j.jpdc.2025.105139" }, { "date": "11 June 2025", "title": "Paper on Separation accepted to IJNC." }, { "date": "2 Apr 2025", "title": "Paper on Exploring Dangerous Graphs with Byzantine Companions accepted to ICDCS 2025.", "url": "https://icdcs2025.icdcs.org/accepted-papers/" }, { "date": "20 Feb 2025", "title": "SSS 2025 announcement is out. I am part of PC in Track C: Moving and Computing.", "url": "https://sss2025.conf.lip6.fr/" }, { "date": "31 Jan 2025", "title": "Paper on Pattern Formation under Sequential Schedulers accepted to SIROCCO 2025, in Delphi, Greece.", "url": "https://www.torontomu.ca/sirocco-2025/accepted-papers/" }, { "date": "25 Sep 2024", "title": "Paper on Asynchronous Separation of Unconscious Colored Robots accepted to PDAA.", "url": "https://is-candar.org/pdaa24" }, { "date": "24 Jul 2024", "title": "Paper on Uniform Circle Formation accepted to DISC as Brief Announcement.", "url": "https://doi.org/10.4230/LIPIcs.DISC.2024.46" }, { "date": "28 May 2024", "title": "Paper on Graph exploration by Automaton with pebbles is accepted to Discrete Applied Mathematics journal.", "url": "https://doi.org/10.1016/j.dam.2024.05.024" }, { "date": "10 May 2024", "title": "Paper on Optimal Asynchronous Uniform Circle Formation in ArXiV", "url": "https://arxiv.org/abs/2405.06617" }, { "date": "15 Apr 2024", "title": "Paper on K-grouping accepted to IWOCA 2024", "url": "http://iwoca2024.di.unisa.it/index.html" }, { "date": "11 Mar 2024", "title": "Reached 100 citations in Google Scholar", "url": "https://scholar.google.com/citations?user=E-jjx9gAAAAJ&hl=en&oi=ao" }, { "date": "22 Jan 2024", "title": "Paper and slides of MIS formation", "urls": { "paper": "https://doi.org/10.1145/3631461.3631543", "slides": "https://www.dropbox.com/scl/fi/ue3s5jczbpqxnrkpkgqeq/icdcn24.pptx?rlkey=av9cwmc0f9z7r54qkcqlw5mfl&dl=0" } }, { "date": "19 Dec 2023", "title": "Paper on Uniform Circle Formation accepted to IPDPS'24", "url": "https://www.ipdps.org/" }, { "date": "18 Oct 2023", "title": "Paper on Treasure hunt and Rendezvous accepted to IPL", "url": "https://doi.org/10.1016/j.ipl.2023.106455" }, { "date": "12 Oct 2023", "title": "Paper on MIS by Mobile robots accepted to ICDCN'24", "url": "https://cse.iitm.ac.in/~icdcn2024/program/accepted-papers.html" }, { "date": "11 Oct 2023", "title": "I am part of the SIROCCO 2024 Program Committee. Deadline: December 5 2023.", "url": "http://sirocco2024.di.unisa.it/" }, { "date": "4 Oct 2023", "title": "Paper on Dispersion despite faults appeared in SSS'23", "url": "https://www.stabilizationsafetysecurity2023.com/", "slides": "https://www.dropbox.com/scl/fi/r3ap3qj7vugo09q3org50/TUE-Ses4num3.pptx?rlkey=d7blof327zqvotzmzc60nzkdl&dl=0" } ], "research": [ "Distributed Algorithms", "Fault-tolerance", "Swarm Robots", "Randomized Algorithms", "Graph Algorithms", "Multi-agent systems", "Simulators for Mobile Robots" ], "current_research": "My research interests lie in the design and analysis of algorithms for mobile agents and mobile robots operating in both discrete (graphs) and continuous spaces. I focus on fundamental problems such as exploration, search, rendezvous, evacuation, and filling under constraints of limited memory, communication, or environmental knowledge. I am particularly interested in distributed coordination, fault-tolerant behavior, and the impact of structure and complexity on algorithmic performance. My work spans deterministic and randomized strategies, with applications in swarm robotics, multi-agent coordination, and autonomous systems. I also work on developing simulators for these systems, a couple of them are linked here, under CCM Model and LCM Model.", "current_teaching": [ { "course": "CS103: Introduction to Programming", "duration": "Jul-Nov 2026", "institution": "IIT Indore", "url": "https://debasishpattanayak.com/IITIJul2026CS103/" } ], "publications": [ { "keywords": [ "mobile agents", "grids", "dispersion" ], "title": "Beyond the Boundary: Optimal Grid Dispersion by Spread, Reverse, and Collect", "authors": [ "Manish Kumar", "Anisur Rahaman Molla", "Debasish Pattanayak", "Subhajit Pramanick" ], "type": "conference", "conference": { "full": "28th International Conference on Distributed Computing and Networking", "short": "ICDCN" }, "date": "January 4, 2027", "location": "NIT Karnataka, Surathkal, India", "year": 2027, "status": "Accepted", "arxiv": "https://arxiv.org/abs/2610.16935", "abstract": "Dispersion requires a set of mobile agents to occupy distinct nodes of a graph such that each node contains at most one agent. We study deterministic dispersion of $k\\le n$ agents on an $n$-node oriented square grid, where each node has globally consistent North, East, South, and West port labels, from arbitrary initial configurations. This includes both rooted configurations, where all agents are co-located initially, and general configurations, where agents are initially distributed arbitrarily across the nodes. On oriented square grids, Kshemkalyani, Molla, and Sharma gave an $O(\\min(k,\\sqrt{n}))$-round algorithm in the local-communication model, where only agents on the same node can exchange information, and an $O(\\sqrt{k})$-round algorithm in the global-communication model, where any two agents can communicate regardless of position, both using $O(\\log k)$ bits per agent. The bound in the local communication model is optimal when $k=\\Theta(n)$, but it remains open whether local communication alone can match the $\\Omega(\\sqrt{k})$ time lower bound when $k=o(n)$. We solve this by presenting Spread–Reverse–Collect (SRC), a deterministic algorithm that disperses any $k\\le n$ agents in $O(\\sqrt{k})$ synchronous rounds using $O(\\log k)$ bits of persistent memory per agent, matching both time and memory lower bounds. SRC is based on a geometric primitive, an S-shaped parallel sweep, together with a simple priority rule. Unlike earlier grid algorithms that gather agents at the boundary and spread out from there, each SRC sweep starts from the agents' current position, and when it reaches the boundary the group simply reflects its sweep back inside and continues. SRC therefore needs no knowledge of the grid size and runs unchanged on an infinite oriented grid." }, { "authors": [ "Debasish Pattanayak", "Kaushik Mondal", "H. Ramesh", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "euclidean plane", "Faults" ], "title": "Gathering of Mobile Robots with Weak Multiplicity Detection in Presence of Crash-Faults", "journal": { "full": "Journal of Parallel and Distributed Computing", "short": "J. Parallel Distrib. Comput." }, "if": "3.4", "volume": "123", "pages": "145-155", "year": 2019, "doi": "https://doi.org/10.1016/j.jpdc.2018.09.015", "dblp": "https://dblp.org/rec/journals/jpdc/PattanayakMRM19.html", "see_also": ["fault-tolerant-gathering-of-mobile-robots-with-weak-multiplicity-detection--2017-conference"], "arxiv": "https://arxiv.org/pdf/1608.02432.pdf", "type": "journal", "abstract": "We consider the problem of Gathering of asynchronous mobile robots in presence of crash faults under the weak multiplicity detection model (robots cannot detect the exact number of robots at a location, they can only detect if there is 0, 1, or more robots at that location). Previous studies on Gathering have been made assuming that the robots can detect the exact number of robots at any location (strong multiplicity detection). In this paper, we study how weakening the multiplicity detection capability affects the possibility and complexity of Gathering. It is known that fault-tolerant Gathering under strong multiplicity detection requires at least $2f+1$ robots, where $f$ is the maximum number of faulty robots. In this paper we show that Gathering is possible under weak multiplicity detection if the number of robots $n>2f$. We first prove a necessary condition on the initial configuration for Gathering $n>2f$ robots with at most $f$ faults. We then propose a deterministic algorithm that solves Gathering for $n>2f$ robots starting from any configuration satisfying the necessary condition. Since the number of robots required is the same (up to additive constant 1) under both strong and weak multiplicity detection, the impact of weakening the multiplicity detection capability is negligible (in terms of number of robots).", "published_date": "2018-10-04" }, { "authors": [ "Dibakar Saha", "Debasish Pattanayak", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "euclidean plane", "three dimensions" ], "title": "Surveillance of Uneven Surface with Self-organizing Unmanned Aerial Vehicles", "journal": { "full": "IEEE Transactions on Mobile Computing", "short": "IEEE Trans. Mobile Comput." }, "if": "7.7", "doi": "https://doi.org/10.1109/TMC.2020.3022075", "dblp": "https://dblp.org/rec/journals/tmc/SahaPM22.html", "see_also": ["surveillance-of-uneven-surface-with-unmanned-aerial-vehicles--2020-conference"], "year": 2020, "type": "journal", "abstract": "In this article, we study the problem of surveillance of an uneven terrain modeled as a given surface area $S$ by a team of unmanned aerial vehicles (UAVs). We assume that the UAVs are initially placed arbitrarily on the surface $S$. Each UAV is equipped with a camera covering a circular region of a specific radius. The objective is to reposition the UAVs by distributed means such that the union of the circular regions covered by the cameras of the UAVs covers the entire surface $S$. The UAVs operate in Look-Compute-Move cycles. Each UAV observes the positions of the other UAVs, computes a destination point, and moves towards it. We present a distributed algorithm for the surveillance problem assuming that the surface $S$ is uneven but does not contain any hole. The proposed algorithm allows the UAVs to self-organize and coordinate implicitly among themselves to cover the entire surface $S$. The algorithm is asynchronous, decentralized, and guarantees complete coverage of the surface $S$. We also study the problem under various practical constraints such as limited visibility, GPS errors, and obstacles. Through extensive simulations, we demonstrate the correctness and effectiveness of the algorithm.", "published_date": "2020-09-07" }, { "authors": [ "Debasish Pattanayak", "Kaushik Mondal", "Partha Sarathi Mandal", "Stefan Schmid" ], "keywords": [ "mobile robots", "euclidean plane" ], "title": "Area Convergence of Weaker Robots with Additional Capabilities", "journal": { "full": "The Computer Journal", "short": "Comput. J." }, "if": "1.5", "doi": "https://doi.org/10.1093/comjnl/bxaa182", "dblp": "https://dblp.org/rec/journals/cj/PattanayakMMS22.html", "see_also": ["convergence-of-even-simpler-robots-without-position-information--2017-conference"], "year": 2022, "type": "journal", "abstract": "We consider the problem of Convergence for a swarm of asynchronous, anonymous, oblivious, silent mobile robots operating under Look-Compute-Move cycles. The robots are assumed to be weak in the sense that they do not agree on the coordinate system, and lack multiplicity detection, i.e. they cannot detect if multiple robots are at the same location. It is known that Convergence is impossible for such robots. However, it has been shown that Convergence is possible even for such weak robots if they are additionally equipped with some capabilities, like visible lights or ability to write on shared whiteboard. This motivated us to study the problem: what minimal capabilities are necessary and sufficient for Convergence? In this paper, we consider three models with additional capabilities: (i) robots equipped with lights ($k$-state lights, $k \\geq 1$), (ii) robots equipped with ability to write on persistent whiteboard ($p$-write whiteboard, $p \\geq 1$), and (iii) robots equipped with non-persistent whiteboard ($p$-write whiteboard, $p \\geq 1$). We study the problem of area Convergence where the goal is to make the robots converge to a small area. We show that area Convergence is possible for robots equipped with 1-state light, or 1-write persistent whiteboard, or 1-write non-persistent whiteboard. Hence, minimal possible additional capability (1-state light or 1-write whiteboard) is sufficient for area Convergence.", "published_date": "2021-02-01" }, { "authors": [ "Debasish Pattanayak", "John Augustine", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "euclidean plane", "randomized algorithms" ], "title": "Randomized Gathering of Asynchronous Mobile Robots", "journal": { "full": "Theoretical Computer Science", "short": "Theor. Comput. Sci." }, "if": "0.9", "doi": "https://doi.org/10.1016/j.tcs.2020.11.048", "dblp": "https://dblp.org/rec/journals/tcs/PattanayakAM21.html", "year": 2021, "type": "journal", "abstract": "Gathering is one of the fundamental problems in cooperative mobile robotics. The goal is to make a set of autonomous mobile robots, initially scattered in a space, gather at a single point not fixed in advance. The problem has been extensively studied under various assumptions. In this paper, we consider randomized gathering algorithms for asynchronous robots operating under Look-Compute-Move (LCM) cycles. The robots are anonymous, identical, oblivious, and lack multiplicity detection. They operate in ASYNC model, i.e., the time required for each operation (Look, Compute, Move) and the time between consecutive operations are finite but unpredictable. It is known that gathering is impossible for such robots under deterministic settings, even when they share a common coordinate system. We present a randomized algorithm that solves gathering for $n > 3$ robots with probability 1 in finite expected number of epochs. An epoch is the smallest time interval during which each robot completes at least one LCM cycle. Our algorithm does not require the robots to agree on a common coordinate system. It assumes that the robots can measure distances and angles accurately. Our algorithm works even if the robots start from a symmetric configuration.", "published_date": "2020-12-03" }, { "authors": [ "Subhajit Pramanick", "Sai Vamshi Samala", "Debasish Pattanayak", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "graphs" ], "title": "Distributed Algorithms for Filling MIS Vertices of an Arbitrary Graph by Myopic Luminous Robots", "journal": { "full": "Theoretical Computer Science", "short": "Theor. Comput. Sci." }, "if": "0.9", "doi": "https://doi.org/10.1016/j.tcs.2023.114187", "dblp": "https://dblp.org/rec/journals/tcs/PramanickSPM23.html", "see_also": ["filling-mis-vertices-by-myopic-luminous-robots--2023-conference"], "year": 2023, "type": "journal", "abstract": "We consider the problem of distributing mobile robots on the vertices of an arbitrary anonymous graph $G=(V,E)$ such that the robots occupy exactly the vertices belonging to some Maximal Independent Set (MIS) of $G$. This problem is known as the MIS Filling problem. We assume that the robots are anonymous, identical, oblivious, and operate in Look-Compute-Move cycles under a synchronous scheduler. The robots are endowed with visibility sensors and lights. Each robot has a visibility range of 1, i.e., it can see the vertices and robots within distance 1 (neighbors). Each robot is equipped with a light that can assume colors from a constant-sized set. The light is visible to the robots within distance 1. The robots start from arbitrary positions, but no two robots start at the same vertex. We present two distributed algorithms for the MIS Filling problem. The first algorithm works for robots having persistent memory of one bit, and uses $O(\\log\\Delta)$ colors, where $\\Delta$ is the maximum degree of the graph. The second algorithm works for oblivious robots (no persistent memory) and uses a constant number of colors. Both algorithms run in $O(D)$ rounds, where $D$ is the diameter of the graph.", "published_date": "2023-09-15" }, { "authors": [ "Debasish Pattanayak", "Andrzej Pelc" ], "keywords": [ "mobile agents", "graphs" ], "title": "Deterministic Treasure Hunt and Rendezvous in Arbitrary Connected Graphs", "journal": { "full": "Information Processing Letters", "short": "Inf. Process. Lett." }, "if": "0.7", "doi": "https://doi.org/10.1016/j.ipl.2023.106455", "dblp": "https://dblp.org/rec/journals/ipl/PattanayakP24.html", "arxiv": "https://arxiv.org/abs/2310.01136", "year": 2024, "type": "journal", "abstract": "We consider two related tasks performed by mobile agents (robots) in networks modelled as arbitrary connected graphs: treasure hunt and rendezvous. In treasure hunt, an agent starting at a node $s$ has to find a stationary target (treasure) located at an unknown node $t$. In rendezvous, two agents starting at nodes $s_1$ and $s_2$ have to meet at some node. Agents navigate in the network in synchronous rounds. They have labels from a set $L$ but are otherwise identical. They know the map of the graph, know the starting node (in rendezvous, each agent knows its own starting node) and know the label set $L$. In rendezvous, agents know the size $n$ of the graph but otherwise they do not know $n$. Agents are deterministic. In treasure hunt, the agent does not know the position of the treasure, and in rendezvous, neither agent knows the starting position of the other. The cost of an algorithm is the time (number of rounds) until completion of the task. For treasure hunt, we give an algorithm with cost $O(D \\cdot \\log(n/D))$, where $D$ is the distance between $s$ and $t$. For rendezvous, we give an algorithm with cost $O(n)$ if the size $n$ of the graph is known to the agents, and $O(n \\log n)$ if $n$ is unknown. We also prove that these costs are optimal up to multiplicative constants, even for labelled rendezvous when agents know each other’s starting nodes and labels.", "published_date": "2023-10-23" }, { "authors": [ "Debasish Pattanayak", "Andrzej Pelc" ], "keywords": [ "mobile agents", "graphs" ], "title": "Graph Exploration by a Deterministic Memoryless Automaton with Pebbles", "journal": { "full": "Discrete Applied Mathematics", "short": "Discrete Appl. Math." }, "if": "1.0", "doi": "https://doi.org/10.1016/j.dam.2024.05.024", "dblp": "https://dblp.org/rec/journals/dam/PattanayakP24.html", "year": 2024, "type": "journal", "abstract": "An automaton has to explore an unknown graph $G=(V,E)$, starting at a node $s$. The automaton navigates in synchronous steps. In each step it traverses an edge. The graph is arbitrary and connected. The ports at each node $v$ are numbered $1,...,deg(v)$. The automaton has a constant number $k$ of pebbles identified by labels from $\\{1,...,k\\}$. When the automaton arrives at a node $v$, it sees the port number through which it entered $v$, the degree $deg(v)$ of $v$, and the set of pebbles located at $v$ (if any). It can drop any pebbles it carries and pick up any pebbles present at $v$. Based on this information and on its state, the automaton chooses the port number through which it exits $v$, the set of pebbles to carry, and its next state. The task is completed when every edge has been traversed at least once. In this paper we consider deterministic finite automata. Such an automaton is memoryless if its decision depends only on the current information obtained at the node and not on its current state (i.e., it has only one state). It is known that a deterministic memoryless automaton without pebbles cannot explore all graphs. We investigate the minimum number of pebbles that enable a deterministic memoryless automaton to explore any connected graph. We show that 2 pebbles are sufficient for exploration, even if the size $n$ and the maximum degree $\\Delta$ of the graph are unknown. For the case when the size $n$ of the graph is known, we show that one pebble is sufficient if the automaton is initially placed at a node with a pebble. We also prove that one pebble is insufficient in general, even if the size $n$ is known. Hence 2 pebbles is the minimum number required for exploration by a deterministic memoryless automaton starting without pebbles.", "published_date": "2024-06-06" }, { "authors": [ "Debasish Pattanayak", "Kaushik Mondal", "H. Ramesh", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "Faults", "euclidean plane" ], "title": "Fault-Tolerant Gathering of Mobile Robots with Weak Multiplicity Detection", "conference": { "full": "International Conference on Distributed Computing and Networking", "short": "ICDCN" }, "doi": "https://doi.org/10.1145/3007748.3007786", "dblp": "https://dblp.org/rec/conf/icdcn/PattanayakMR017.html", "see_also": ["gathering-of-mobile-robots-with-weak-multiplicity-detection-in-presence-of-crash-faults--2019-journal"], "location": "Hyderabad, India", "date": "January 5-7, 2017", "arxiv": "https://arxiv.org/pdf/1608.02432.pdf", "type": "conference", "year": 2017, "abstract": "We consider the problem of Gathering of asynchronous mobile robots in presence of crash faults under the weak multiplicity detection model (robots cannot detect the exact number of robots at a location, they can only detect if there is 0, 1, or more robots at that location). Previous studies on Gathering have been made assuming that the robots can detect the exact number of robots at any location (strong multiplicity detection). In this paper, we study how weakening the multiplicity detection capability affects the possibility and complexity of Gathering. It is known that fault-tolerant Gathering under strong multiplicity detection requires at least $2f+1$ robots, where $f$ is the maximum number of faulty robots. In this paper we show that Gathering is possible under weak multiplicity detection if the number of robots $n > 2f$. We first prove a necessary condition on the initial configuration for Gathering $n > 2f$ robots with at most $f$ faults. We then propose a deterministic algorithm that solves Gathering for $n > 2f$ robots starting from any configuration satisfying the necessary condition. Since the number of robots required is the same (up to additive constant 1) under both strong and weak multiplicity detection, the impact of weakening the multiplicity detection capability is negligible (in terms of number of robots)." }, { "authors": [ "Debasish Pattanayak", "Kaushik Mondal", "Partha Sarathi Mandal", "Stefan Schmid" ], "keywords": [ "mobile robots", "euclidean plane", "convergence" ], "title": "Convergence of Even Simpler Robots without Position Information", "conference": { "full": "Networked Systems - International Conference", "short": "NETYS" }, "doi": "https://doi.org/10.1007/978-3-319-59647-1_6", "dblp": "https://dblp.org/rec/conf/netys/PattanayakM0S17.html", "see_also": ["area-convergence-of-weaker-robots-with-additional-capabilities--2022-journal"], "location": "Marrakech, Morocco", "date": "May 17-19, 2017", "arxiv": "https://arxiv.org/pdf/1608.06002.pdf", "type": "conference", "year": 2017, "abstract": "We consider the problem of convergence for a swarm of asynchronous, anonymous, oblivious, silent mobile robots operating under Look-Compute-Move cycles. The robots are assumed to be weak, i.e., they do not agree on the coordinate system, and lack multiplicity detection, i.e., they cannot detect if multiple robots are at the same location. It is known that convergence is impossible for such robots. However, it has been shown that convergence is possible even for such weak robots if they are additionally equipped with visible lights. This motivated us to study the problem: what minimal capabilities are necessary and sufficient for convergence? In this paper, we consider three models with additional capabilities: (i) robots equipped with lights ($k$-state lights, $k \\geq 1$), (ii) robots equipped with ability to write on persistent whiteboard ($p$-write whiteboard, $p \\geq 1$), and (iii) robots equipped with non-persistent whiteboard ($p$-write whiteboard, $p \\geq 1$). We show that convergence is possible for robots equipped with 1-state light, or 1-write persistent whiteboard, or 1-write non-persistent whiteboard. Hence, minimal possible additional capability (1-state light or 1-write whiteboard) is sufficient for convergence." }, { "authors": [ "Debasish Pattanayak", "H. Ramesh", "Partha Sarathi Mandal", "Stefan Schmid" ], "keywords": [ "mobile robots", "euclidean plane", "evacuation" ], "title": "Evacuating Two Robots from Two Unknown Exits on the Perimeter of a Disk with Wireless Communication", "conference": { "full": "International Conference on Distributed Computing and Networking", "short": "ICDCN" }, "doi": "https://doi.org/10.1145/3154273.3154313", "dblp": "https://dblp.org/rec/conf/icdcn/PattanayakR0S18.html", "location": "Varanasi, India", "date": "January 4-7, 2018", "arxiv": "https://arxiv.org/pdf/1708.03792.pdf", "type": "conference", "year": 2018, "abstract": "We study the problem of evacuating two mobile robots from a disk. The boundary of the disk contains two exit points at unknown locations. The robots start from the center of the disk. The goal is for both robots to reach one of the exits. The robots move at the same maximum speed. They can communicate wirelessly. We want to minimize the evacuation time, which is defined as the time when the second robot reaches an exit. This problem finds applications, e.g., in scenarios where multiple evacuees need to be guided out of a contaminated area. We consider two models of communication: robots communicate only when they meet (direct communication), and robots have unlimited communication range (wireless communication). We assume that the robots are oblivious, i.e., they do not remember the past. For the direct communication model, we show that the optimal evacuation time is $(1 + \\pi/2)R \\approx 2.57 R$, where $R$ is the radius of the disk. For the wireless communication model, we present an algorithm with evacuation time $(1 + \\pi/3)R \\approx 2.047 R$. We also prove a lower bound of $2R$ for this model. Closing the gap between the upper and lower bounds remains an open problem." }, { "authors": [ "Debasish Pattanayak", "H. Ramesh", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "Faults", "euclidean plane", "evacuation" ], "title": "Chauffeuring a Crashed Robot from a Disk", "conference": { "full": "International Symposium on Algorithms and Experiments for Wireless Sensor Networks", "short": "ALGOSENSORS" }, "doi": "https://doi.org/10.1007/978-3-030-34405-4_10", "dblp": "https://dblp.org/rec/conf/algosensors/PattanayakR019.html", "location": "Munich, Germany", "date": "September 12-13, 2019", "arxiv": "https://arxiv.org/pdf/1906.03024.pdf", "type": "conference", "year": 2019, "abstract": "We consider the problem of evacuating a crashed robot from a disk. The boundary of the disk contains $k \\geq 1$ exit points at unknown locations. An active robot starts from the center of the disk, finds the crashed robot located at an unknown point inside the disk, carries it, and brings it to one of the exits. The goal is to minimize the evacuation time, which is the time when the active robot carrying the crashed robot reaches an exit. The active robot moves at speed $v$, and when carrying the crashed robot, it moves at speed $v' < v$. We assume that the active robot knows the locations of the exits once it reaches the boundary. We present an algorithm that guarantees an evacuation time within a constant factor of the optimal time for any $k \\geq 1$ exits. Specifically, for $k=1$ exit, the competitive ratio is at most 5. For $k=2$ exits, the ratio is at most 6.6. For general $k \\geq 1$, the ratio is at most $4+2\\pi \\approx 10.28$. Our algorithms rely on finding efficient search strategies for the active robot to locate the crashed robot and then determining the best exit to move towards." }, { "authors": [ "Dibakar Saha", "Debasish Pattanayak", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "euclidean plane", "three dimensions" ], "title": "Surveillance of Uneven Surface with Unmanned Aerial Vehicles", "conference": { "full": "International Conference on Distributed Computing and Networking", "short": "ICDCN" }, "location": "Kolkata, India", "date": "January 4-7, 2020", "doi": "https://doi.org/10.1145/3369740.3369781", "dblp": "https://dblp.org/rec/conf/icdcn/SahaP020.html", "see_also": ["surveillance-of-uneven-surface-with-self-organizing-unmanned-aerial-vehicles--2020-journal"], "type": "conference", "year": 2020, "abstract": "In this paper, we study the problem of surveillance of an uneven terrain modeled as a given surface area $S$ by a team of unmanned aerial vehicles (UAVs). We assume that the UAVs are initially placed arbitrarily on the surface $S$. Each UAV is equipped with a camera covering a circular region of a specific radius. The objective is to reposition the UAVs by distributed means such that the union of the circular regions covered by the cameras of the UAVs covers the entire surface $S$. The UAVs operate in Look-Compute-Move cycles. Each UAV observes the positions of the other UAVs, computes a destination point, and moves towards it. We present a distributed algorithm for the surveillance problem assuming that the surface $S$ is uneven but does not contain any hole. The proposed algorithm allows the UAVs to self-organize and coordinate implicitly among themselves to cover the entire surface $S$. The algorithm is asynchronous, decentralized, and guarantees complete coverage of the surface $S$. We also study the problem under various practical constraints such as limited visibility, GPS errors, and obstacles. Through extensive simulations, we demonstrate the correctness and effectiveness of the algorithm." }, { "authors": [ "Debasish Pattanayak", "Klaus-Tycho Foerster", "Partha Sarathi Mandal", "Stefan Schmid" ], "keywords": [ "mobile robots", "Faults", "euclidean plane", "pattern formation" ], "title": "Conic Formation in Presence of Faulty Robots", "conference": { "full": "International Symposium on Algorithms and Experiments for Wireless Sensor Networks", "short": "ALGOSENSORS" }, "location": "Pisa, Italy", "date": "September 7-10, 2020", "doi": "https://doi.org/10.1007/978-3-030-62401-9_12", "dblp": "https://dblp.org/rec/conf/algosensors/PattanayakFMS20.html", "arxiv": "https://arxiv.org/abs/2003.01914", "type": "conference", "year": 2020, "abstract": "We consider the problem of forming a specific pattern, namely a conic section (ellipse, parabola, or hyperbola), by a swarm of autonomous mobile robots in the presence of Byzantine faulty robots. The robots operate in Look-Compute-Move cycles. In each cycle, a robot takes a snapshot of the positions of all robots (Look), computes a destination based on the observed positions (Compute), and moves towards the destination (Move). We assume an asynchronous system where robots operate at different speeds. A faulty robot can behave arbitrarily (Byzantine fault). The goal is to design an algorithm such that the non-faulty robots eventually form the desired conic shape, despite the disruptive behavior of the faulty robots. We propose a fault-tolerant algorithm for conic formation that can handle up to $f$ Byzantine robots, provided the total number of robots $n$ is sufficiently large ($n > 2f$). Our algorithm relies on identifying a reference point (e.g., the center of minimum enclosing circle) that is resilient to faults and then positioning the non-faulty robots relative to this reference point to form the conic section. We prove the correctness and termination of the algorithm under the assumed fault model." }, { "authors": [ "Debasish Pattanayak", "Gokarna Sharma", "Partha Sarathi Mandal" ], "keywords": [ "mobile agents", "Faults", "graphs" ], "title": "Dispersion of Mobile Robots Tolerating Faults", "conference": { "full": "Workshop on Distributed Algorithms for Large-scale Fault-tolerant Robots", "short": "WDALFR" }, "pages": "133-138", "date": "January 4-7, 2021", "doi": "https://doi.org/10.1145/3427477.3429464", "dblp": "https://dblp.org/rec/conf/icdcn/PattanayakS021.html", "type": "conference", "year": 2021, "abstract": "Dispersion is the problem of scattering mobile robots initially placed arbitrarily at some nodes of a graph $G = (V, E)$ such that finally, each node of $V$ is occupied by exactly one robot. The problem finds applications in areas such as surveillance and environmental monitoring, where uniform deployment of sensors or agents is required. In this paper, we study the dispersion problem in the presence of Byzantine faulty robots. We consider a system of $n$ robots placed on an $n$-node anonymous graph, where $n$ is the number of nodes. Among the $n$ robots, $f$ robots can be Byzantine faulty, meaning they can deviate arbitrarily from their protocol. The non-faulty robots are identical, operate in synchronous Look-Compute-Move cycles, and have limited visibility (can only see their immediate neighbors). The goal is to design a distributed algorithm that ensures that eventually, each node is occupied by exactly one non-faulty robot, assuming $n > 2f$. We present a randomized algorithm that achieves dispersion with high probability in polynomial time for any connected graph, tolerating $f < n/2$ Byzantine faults. The algorithm utilizes techniques related to random walks and local coordination to handle the uncertainty introduced by faulty robots and the anonymity of the graph." }, { "authors": [ "Debasish Pattanayak", "Dibakar Saha", "Debarati Mitra", "Partha Sarathi Mandal" ], "keywords": [ "graphs", "simulation" ], "title": "A Reconstructive Model for Identifying the Global Spread in a Pandemic", "conference": { "full": "International Conference on Distributed Computing and Internet Technology", "short": "ICDCIT" }, "date": "Jan 7-10, 2021", "doi": "https://doi.org/10.1007/978-3-030-65621-8_12", "dblp": "https://dblp.org/rec/conf/icdcit/PattanayakSM021.html", "type": "conference", "year": 2021, "abstract": "Understanding the spread of a pandemic like COVID-19 requires identifying the infection sources and transmission pathways. In many situations, detailed contact tracing data is unavailable or incomplete, especially at a global scale. This paper proposes a reconstructive model to infer the global spread pattern based on limited available data. We model the spread as a process on a graph where nodes represent geographical regions (e.g., countries or states) and edges represent potential transmission links (e.g., travel routes). Given the time series of reported cases in different regions, our goal is to reconstruct the most likely infection sources and the temporal evolution of the spread. We formulate this as an optimization problem aiming to find a propagation tree or graph that best explains the observed data under a chosen epidemiological model (like SIR or SEIR). We propose a heuristic algorithm based on dynamic programming and graph traversal techniques to approximate the solution. The model can help in understanding the key transmission events and evaluating the effectiveness of different intervention strategies by simulating the spread under counterfactual scenarios. We demonstrate the applicability of our model using publicly available COVID-19 data." }, { "authors": [ "Kartikey Kant", "Debasish Pattanayak", "Partha Sarathi Mandal" ], "keywords": [ "mobile agents", "grid", "pattern formation" ], "title": "Fort Formation by an Automaton", "conference": { "full": "International Conference on COMmunication Systems & NETworkS", "short": "COMSNETS" }, "date": "Jan 5-9, 2021", "doi": "https://doi.org/10.1109/COMSNETS51098.2021.9352839", "dblp": "https://dblp.org/rec/conf/comsnets/KantP021.html", "type": "conference", "year": 2021, "abstract": "We study the problem of pattern formation by a single mobile entity, modeled as a finite automaton, in an infinite grid environment. The automaton starts at the origin and moves between adjacent grid cells. Its goal is to color the cells it visits in such a way that eventually, a specific predefined shape, called a \"fort\", is formed by the colored cells. The automaton has a finite number of internal states and can sense the color of the current cell and its four neighboring cells. Based on its current state and the sensed information, it decides its next state, the color to paint the current cell, and the direction to move. We focus on the formation of finite shapes, specifically rectangular forts of arbitrary dimensions. We investigate the capabilities of deterministic finite automata for this task. We present an automaton construction that can form any n x m rectangular fort, given n and m as part of its initial configuration or state. We analyze the time complexity (number of steps) and space complexity (number of unique cells visited) required by the automaton to complete the fort formation. The problem explores the intersection of cellular automata, pattern formation, and mobile agent computing." }, { "authors": [ "Giuseppe F. Italiano", "Debasish Pattanayak", "Gokarna Sharma" ], "keywords": [ "mobile agents", "graphs", "dispersion" ], "title": "Dispersion of Mobile Robots on Directed Anonymous Graphs", "conference": { "full": "International Colloquium on Structural Information and Communication Complexity", "short": "SIROCCO" }, "doi": "https://link.springer.com/chapter/10.1007/978-3-031-09993-9_11", "dblp": "https://dblp.org/rec/conf/sirocco/ItalianoPS22.html", "see_also": ["dispersion-of-mobile-robots-on-directed-anonymous-graphs--2025-journal"], "location": "Paderborn, Germany", "date": "Jun 27-29, 2022", "slides": "https://www.dropbox.com/s/ttg2cb7hmyvyzzj/siroccoppt.pptx?dl=0", "type": "conference", "year": 2022, "abstract": "We study the dispersion problem where n mobile robots, initially placed arbitrarily on the n nodes of a directed graph G, must coordinate to ensure that each node is occupied by exactly one robot. We consider anonymous graphs, meaning nodes do not have unique identifiers, and robots are identical and operate in synchronous Look-Compute-Move rounds. Dispersion on undirected graphs is well-studied, but the directed case introduces challenges due to asymmetric reachability. We investigate the feasibility of dispersion on different classes of strongly connected directed graphs. We show that dispersion is not always possible, even on strongly connected graphs, if robots have limited capabilities (e.g., only local visibility). We then identify sufficient conditions on the graph structure and robot capabilities (e.g., ability to use pebbles or knowledge of certain graph parameters) under which dispersion can be achieved. We present algorithms for dispersion on specific classes of directed graphs, such as directed rings and Eulerian digraphs, and analyze their complexity. Our work highlights the fundamental differences between dispersion on undirected and directed graphs." }, { "authors": [ "Giuseppe F. Italiano", "Debasish Pattanayak", "Gokarna Sharma" ], "keywords": [ "mobile agents", "graphs", "Faults", "dispersion" ], "title": "Dispersion of Mobile Robots on Directed Anonymous Graphs", "journal": { "full": "Journal of Parallel and Distributed Computing", "short": "J. Parallel Distrib. Comput." }, "doi": "https://doi.org/10.1016/j.jpdc.2025.105139", "dblp": "https://dblp.org/rec/journals/jpdc/ItalianoPS25.html", "see_also": ["dispersion-of-mobile-robots-on-directed-anonymous-graphs--2022-conference"], "type": "journal", "year": 2025, "abstract": "Given any arbitrary initial configuration of $k \\le n$ robots positioned on the nodes of an $n$-node anonymous graph, the problem of dispersion is to autonomously reposition the robots such that each node will contain at most one robot. This problem gained significant interest due to its resemblance with several fundamental problems such as exploration, scattering, load balancing, relocation of electric cars to charging stations, etc. The objective is to solve dispersion simultaneously minimizing (or providing trade-off between) time and memory requirement at each robot. The literature mainly dealt with dispersion on undirected anonymous graphs. In this paper, we initiate the study of dispersion on directed anonymous graphs. We first show that it may not always be possible to solve dispersion when the directed graph is not strongly connected. We then establish some lower bounds on both time and memory requirement at each robot for solving dispersion on a strongly connected directed graph. Finally, we provide three deterministic algorithms solving dispersion on any strongly connected directed graph. Let $D$ be the graph diameter, $\\Delta_{out}$ be its maximum out-degree, and $d$ be the deficiency (the minimum number of edges needed to add to the graph to make it Eulerian). The first algorithm solves dispersion in $O(d \\cdot k^2)$ time with $O(k \\cdot \\log(k + \\Delta_{out}))$ bits at each robot. The second algorithm solves dispersion in $O(k^2 \\cdot \\Delta_{out})$ time with $O(\\log (k + \\Delta_{out}))$ bits at each robot. The third algorithm solves dispersion in $O(k \\cdot D)$ time with $O(k \\cdot \\log (k + \\Delta_{out}))$ bits at each robot, provided that robots in the 1-hop neighborhood can communicate. All three algorithms extend to handle crash faults.", "published_date": "2025-06-20" }, { "authors": [ "Subhajit Pramanick", "Sai Vamshi Samala", "Debasish Pattanayak", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "graphs" ], "title": "Filling MIS Vertices by Myopic Luminous Robots", "conference": { "full": "International Conference on Distributed Computing and Internet Technology", "short": "ICDCIT" }, "doi": "https://doi.org/10.1007/978-3-031-24848-1_1", "dblp": "https://dblp.org/rec/conf/icdcit/PramanickSPM23.html", "see_also": ["distributed-algorithms-for-filling-mis-vertices-of-an-arbitrary-graph-by-myopic-luminous-robots--2023-journal"], "date": "Jan 18-22, 2023", "award": "Best paper award", "arxiv": "https://arxiv.org/abs/2107.04885", "type": "conference", "year": 2023, "abstract": "We consider the problem of distributing mobile robots on the vertices of an arbitrary anonymous graph $$G=(V, E)$$ G = ( V , E ) such that the robots occupy exactly the vertices belonging to some Maximal Independent Set (MIS) of G . This problem is known as the MIS Filling problem. We assume that the robots are anonymous, identical, oblivious, and operate in Look-Compute-Move cycles under a synchronous scheduler. The robots are endowed with visibility sensors and lights. Each robot has a visibility range of 1, i.e., it can see the vertices and robots within distance 1 (neighbors). Each robot is equipped with a light that can assume colors from a constant-sized set. The light is visible to the robots within distance 1. The robots start from arbitrary positions, but no two robots start at the same vertex. We present two distributed algorithms for the MIS Filling problem. The first algorithm works for robots having persistent memory of one bit, and uses $$O(\\log \\Delta )$$ O ( log Δ ) colors, where $$\\Delta $$ Δ is the maximum degree of the graph. The second algorithm works for oblivious robots (no persistent memory) and uses a constant number of colors. Both algorithms run in O ( D ) rounds, where D is the diameter of the graph." }, { "authors": [ "Debasish Pattanayak", "Gokarna Sharma", "Partha Sarathi Mandal" ], "keywords": [ "mobile agents", "Faults", "graphs", "dispersion" ], "title": "Dispersion of Mobile Robots in Spite of Faults", "conference": { "full": "International Symposium on Stabilization, Safety, and Security of Distributed Systems", "short": "SSS" }, "date": "Oct 2-4, 2023", "doi": "https://doi.org/10.1007/978-3-031-44274-2_31", "dblp": "https://dblp.org/rec/conf/sss/PattanayakSM23.html", "type": "conference", "year": 2023, "abstract": "Dispersion is the problem of scattering $n$ mobile robots initially placed arbitrarily at some nodes of an $n$-node graph $G=(V,E)$ such that finally, each node of $V$ is occupied by exactly one robot. We study the dispersion problem in the presence of Byzantine faulty robots. The faulty robots can behave arbitrarily to prevent the non-faulty robots from achieving the goal. We assume that the total number of robots is $n$ and at most $f < n/2$ robots are faulty. The robots are identical, operate in synchronous Look-Compute-Move cycles, and have limited visibility (can only see their immediate neighbours). The goal is to design a distributed algorithm that ensures that eventually, each node is occupied by exactly one non-faulty robot, despite the presence of faults. We present a randomized algorithm that achieves dispersion with high probability in polynomial time for any connected graph, tolerating $f < n/2$ Byzantine faults. This improves upon previous work that required $n>2f$ and provides a solution for a wider range of fault scenarios." }, { "authors": [ "Debasish Pattanayak", "Andrzej Pelc" ], "keywords": [ "mobile agents", "graphs" ], "title": "Computing Functions by Teams of Deterministic Finite Automata", "doi": "https://doi.org/10.48550/arXiv.2310.01151", "dblp": "https://dblp.org/rec/journals/corr/abs-2310-01151.html", "arxiv": "https://arxiv.org/abs/2310.01151", "type": "preprint", "year": 2023, "abstract": "A team of $k$ identical deterministic finite automata, arbitrarily positioned on the nodes of an $n$-node anonymous graph $G$, have to compute a function $f(G)$ whose value depends on the entire graph $G$. Automata operate in synchronous rounds. In each round, an automaton reads the states of automata at its node and at adjacent nodes, and based on this information and its own state, it updates its state and can send a message (its state) to each neighbor. The computation terminates when all automata reach a special halting state. The value of the function $f(G)$ is determined by the halting state of a designated automaton (say, the one with the smallest ID, assuming automata have unique IDs for tie-breaking, though they are otherwise identical). We study which graph functions can be computed by such teams of automata and the minimum number of automata $k$ required. We show that any function computable in polynomial time can be computed by a team of $O(n)$ automata. We investigate the power of smaller teams. For example, we show that determining if a graph is bipartite requires $\\Omega(n)$ automata in the worst case. We also consider the computation of functions like the diameter or checking connectivity, analyzing the trade-offs between the number of automata and the complexity of the automata (number of states).", "published_date": "2023" }, { "authors": [ "Debasish Pattanayak", "Subhash Bhagat", "Sruti Gan Choudhuri", "Anisur Rahaman Molla" ], "keywords": [ "mobile agents", "graphs", "maximal independent set" ], "title": "Maximal Independent Set via Mobile Robots", "conference": { "full": "International Conference on Distributed Computing and Networking", "short": "ICDCN" }, "date": "January 4-7, 2024", "doi": "https://doi.org/10.1145/3631461.3631543", "dblp": "https://dblp.org/rec/conf/icdcn/PattanayakBCM24.html", "slides": "https://www.dropbox.com/scl/fi/ue3s5jczbpqxnrkpkgqeq/icdcn24.pptx?rlkey=av9cwmc0f9z7r54qkcqlw5mfl&dl=0", "type": "conference", "year": 2024, "abstract": "We study the problem of forming a Maximal Independent Set (MIS) configuration using mobile robots in an anonymous graph $G = (V, E)$. Initially, $n$ robots are arbitrarily placed on the $n$ nodes of the graph, with at most one robot per node. The robots are autonomous, identical, operate in Look-Compute-Move (LCM) cycles under a synchronous scheduler (SYNC). They are oblivious, meaning they have no memory of past actions. Each robot can observe the positions of robots within its visibility range. The goal is for the robots to reach a configuration where the set of occupied nodes forms an MIS of $G$. We consider two visibility models: robots with visibility range 1 (can see neighbors) and robots with global visibility (can see all other robots). For robots with visibility range 1, we present a deterministic algorithm that solves the MIS formation problem in $O(D)$ rounds, where $D$ is the diameter of the graph. For robots with global visibility, we provide an algorithm that achieves MIS formation in $O(\\log n)$ rounds. Our algorithms work without requiring robots to have unique IDs or access to any global information like the graph size or structure, relying solely on local interactions or global snapshots." }, { "authors": [ "Debasish Pattanayak", "Gokarna Sharma" ], "keywords": [ "mobile agents", "euclidean plane", "pattern formation" ], "title": "Time-Color Tradeoff on Uniform Circle Formation by Asynchronous Robots", "conference": { "full": "IEEE International Parallel and Distributed Processing Symposium", "short": "IPDPS" }, "doi": "https://doi.org/10.1109/IPDPS57955.2024.00092", "dblp": "https://dblp.org/rec/conf/ipps/PattanayakS24.html", "date": "May 27-30, 2024", "type": "conference", "year": 2024, "abstract": "We study the uniform circle formation problem for $n$ asynchronous, anonymous, oblivious mobile robots initially positioned arbitrarily on a 2D plane. The goal is for the robots to arrange themselves equally spaced on the boundary of a circle whose center and radius are not predetermined. Robots operate in standard Look-Compute-Move cycles. We consider luminous robots, which possess lights that can assume colors from a given range. The color is visible to other robots and can be used for coordination. It is known that uniform circle formation is impossible for asynchronous oblivious robots without lights. We investigate the trade-off between the number of colors available to the robots and the time complexity (measured in epochs) to achieve uniform circle formation. We present algorithms that demonstrate this trade-off: using more colors allows for faster convergence. Specifically, we show that with $O(\\log n)$ colors, uniform circle formation can be achieved in a polylogarithmic number of epochs. Conversely, if only a constant number of colors are available, the time complexity increases. Our results contribute to understanding the power of persistent memory (modeled by lights) in overcoming impossibility results in asynchronous systems." }, { "authors": [ "Paola Flocchini", "Debasish Pattanayak", "Nicola Santoro", "Masafumi Yamashita" ], "keywords": [ "mobile robots", "euclidean plane", "pattern formation" ], "title": "The Minimum Algorithm Size of k-Grouping by Silent Oblivious Robots", "conference": { "full": "International Workshop on Combinatorial Algorithms", "short": "IWOCA" }, "doi": "https://doi.org/10.1007/978-3-031-63021-7_36", "dblp": "https://dblp.org/rec/conf/iwoca/FlocchiniPSY24.html", "type": "conference", "location": "Ischia, Italy", "date": "Jul 1-3, 2024", "year": 2024, "abstract": "We study the $k$-Grouping problem for a swarm of $n$ anonymous, oblivious, and silent mobile robots operating in the Euclidean plane under the synchronous Look-Compute-Move model. Initially, the robots are at distinct locations. The goal is to reach a configuration where the robots form $m = \\lfloor n/k \\rfloor$ groups of exactly $k$ robots each, plus possibly one group of $n \\pmod k$ robots if $k$ does not divide $n$. Robots within a group must occupy the same location (the exact point convergence). The locations of the groups are not predetermined. Since robots are silent and oblivious, they rely solely on the observed positions of other robots in their Look phase to decide their Move. The complexity of an algorithm is often measured by its size, which relates to the number of distinct configurations it needs to recognize and act upon. We investigate the minimum algorithm size required to solve $k$-Grouping. We establish lower bounds on the algorithm size based on the symmetries and the information available to the robots. We then present algorithms for $k$-Grouping and analyze their size, showing trade-offs between the value of $k$ and the required algorithm complexity. Our focus is on understanding the inherent limitations imposed by the weak capabilities (anonymity, obliviousness, silence) on the complexity of coordination tasks." }, { "authors": [ "Debasish Pattanayak", "H. Ramesh", "Partha Sarathi Mandal" ], "keywords": [ "mobile robots", "Faults", "euclidean plane" ], "title": "Collaborative Evacuation of Mobile Robots", "conference": { "full": "Doctoral Symposium, International Conference on Distributed Computing and Networking", "short": "ICDCN" }, "doi": "https://doi.org/10.1145/3369740.3373806", "dblp": "https://dblp.org/rec/conf/icdcn/PattanayakR020.html", "location": "Kolkata, India", "date": "January 4-7, 2020", "award": "Best poster award", "type": "poster", "year": 2020, "abstract": "We study collaborative strategies for evacuating mobile robots from a potentially hazardous environment, modeled as a geometric domain (e.g., a disk or polygon). The environment contains one or more exits at unknown locations on its boundary. Robots start at known or unknown initial positions within the domain. Some robots might be faulty (e.g., crashed or Byzantine). The goal is for the non-faulty robots to coordinate their movements to ensure that all (or a maximum number of) non-faulty robots reach an exit as quickly as possible. We consider different models based on robot capabilities (speed, communication range, memory, knowledge of the environment) and fault types. Key problems addressed include: 1) Evacuating multiple robots starting from the same point. 2) Searching for and evacuating a crashed robot. 3) Evacuating robots scattered in the environment. We aim to design distributed algorithms that minimize the evacuation time, defined either as the time the last robot exits or the average exit time. We focus on competitive analysis, comparing the performance of our algorithms against an optimal offline strategy. This research explores fundamental algorithmic challenges in multi-robot coordination, path planning, and fault tolerance in geometric settings." }, { "authors": [ "Loukas Georgiadis", "Giuseppe F. Italiano", "Evangelos Kosinas", "Debasish Pattanayak" ], "keywords": [ "graphs", "edge connectivity" ], "title": "On Maximal k-Edge-Connected Subgraphs of Undirected Graphs", "arxiv": "https://arxiv.org/abs/2211.06521", "doi": "https://doi.org/10.1016/j.jcss.2026.103801", "dblp": "https://dblp.org/rec/journals/jcss/GeorgiadisIKP26.html", "type": "journal", "journal": { "full": "Journal of Computer and System Sciences", "short": "JCSS" }, "year": 2026, "abstract": "We study structural and algorithmic properties related to maximal $k$-edge-connected subgraphs in an undirected graph $G = (V, E)$. For a given integer $k > 0$, a subgraph $H$ is $k$-edge-connected if the minimum number of edges whose removal disconnects $H$ is at least $k$. A $k$-edge-connected subgraph $H$ is maximal if no other $k$-edge-connected subgraph of $G$ properly contains $H$. We investigate the relationship between maximal $k$-edge-connected subgraphs for different values of $k$. We present efficient algorithms for finding all maximal $k$-edge-connected subgraphs of a given graph $G$. Our approach builds upon classic algorithms for computing edge connectivity and graph decomposition techniques. We analyze the time complexity of our algorithms and discuss their applications in network analysis, clustering, and fault-tolerant network design, where identifying highly connected components is crucial.", "published_date": "2026-04-09" }, { "authors": [ "Caterina Feletti", "Debasish Pattanayak", "Gokarna Sharma" ], "doi": "https://doi.org/10.4230/LIPIcs.DISC.2024.46", "dblp": "https://dblp.org/rec/conf/wdag/FelettiPS24.html", "keywords": [ "mobile robots", "euclidean plane", "pattern formation" ], "title": "BA: Optimal Uniform Circle Formation by Asynchronous Luminous Robots", "arxiv": "https://arxiv.org/abs/2405.06617", "type": "conference", "date": "Oct 29-31, 2024", "conference": { "full": "International Symposium on Distributed Computing", "short": "DISC" }, "see_also": ["optimal-luminous-ucf-under-asynchrony--2026-journal"], "year": 2024, "abstract": "We study the uniform circle formation (UCF) problem where n >= 3 autonomous mobile robots, initially arbitrarily positioned in the plane, have to arrange themselves equally spaced on the boundary of a circle not fixed in advance. Robots are anonymous, asynchronous, oblivious, and luminous: they execute Look-Compute-Move cycles asynchronously, cannot be distinguished by their appearance, have no memory of past actions, but possess a light that can assume colors from a constant-sized set C. The light color is visible to other robots and persists between cycles. It is known that UCF is impossible for such robots without lights or with only 1 color. Prior work showed UCF solvability with O(n) colors in O(n) epochs and with O(log n) colors in poly(n) epochs. We present an algorithm that solves UCF using O(1) colors (specifically, 4 colors) in O(n^2) epochs. This result is optimal in terms of colors, as UCF requires at least 2 colors. Our algorithm relies on carefully managing robot states using the constant number of colors to break symmetries and coordinate movements towards the final uniform circular configuration." }, { "authors": [ "Paola Flocchini", "Debasish Pattanayak", "Francesco Piselli", "Nicola Santoro", "Yukiko Yamauchi" ], "keywords": [ "mobile robots", "euclidean plane", "separation" ], "title": "Asynchronous Separation of Unconscious Colored Robots", "type": "conference", "doi": "https://doi.org/10.1109/CANDARW64572.2024.00037", "dblp": "https://dblp.org/rec/conf/candar/FlocchiniPPSY24.html", "see_also": ["asynchronous-separation-of-unconscious-colored-robots--2025-journal"], "location": "Naha, Okinawa, Japan", "date": "Nov 26-29, 2024", "conference": { "full": "16th International Workshop on Parallel and Distributed Algorithms and Applications", "short": "CANDARW:PDAA" }, "year": 2024, "abstract": "We investigate the Separation problem for mobile robots operating under the asynchronous (ASYNC) model. In this problem, n robots, initially located at the same point (origin), must reach a configuration where they all occupy distinct locations. We consider robots that are colored but unconscious: they have externally visible colors from a set C, but they cannot sense their own color, nor the colors of other robots at their same location. They are anonymous, oblivious (memoryless), and can only see the locations of other robots, not their colors (unless they are at different locations). The challenge lies in breaking the initial symmetry without relying on internal state or unique identifiers, using only the observable positions and the implicit information from the externally visible colors. We establish conditions on the number of colors and the distribution of colors among robots (the color configuration) under which asynchronous separation is possible. We provide algorithms for separation under feasible color configurations and prove impossibility results for others. This work explores the power and limitations of minimal robot capabilities, specifically externally visible attributes, in achieving fundamental coordination tasks in asynchronous distributed systems." }, { "authors": [ "Paola Flocchini", "Alfredo Navarra", "Debasish Pattanayak", "Francesco Piselli", "Nicola Santoro" ], "keywords": [ "mobile robots", "euclidean plane", "pattern formation" ], "title": "Oblivious Robots Under Sequential Schedulers: Universal Pattern Formation", "type": "conference", "arxiv": "https://arxiv.org/abs/2412.10733", "doi": "https://doi.org/10.1007/978-3-031-91736-3_18", "dblp": "https://dblp.org/rec/conf/sirocco/FlocchiniNPPS25.html", "see_also": ["universal-pattern-formation-by-oblivious-robots-under-sequential-schedulers--2026-journal"], "year": 2025, "conference": { "full": "International Colloquium on Structural Information and Communication Complexity", "short": "SIROCCO" }, "location": "Delphi, Greece", "date": "June 2-4, 2025", "abstract": "We investigate the capabilities of anonymous, oblivious mobile robots operating under weak schedulers, specifically focusing on sequential activation schedulers (SEQ). Under SEQ, only one robot is activated in each time step to perform its Look-Compute-Move cycle, chosen arbitrarily by the adversary. This contrasts with the more powerful fully synchronous (FSYNC) or semi-synchronous (SSYNC) models. We study the fundamental problem of Universal Pattern Formation (UPF), where robots must form any arbitrary pattern given as input. Robots are initially positioned arbitrarily. We consider robots that are silent (cannot communicate) but potentially possess externally visible lights. It is known that even simple tasks like convergence are impossible for oblivious robots under ASYNC. We explore whether the restricted nature of SEQ allows oblivious robots to achieve complex tasks like UPF. We show that oblivious robots, even without lights, can achieve UPF under the SEQ scheduler, provided they start from distinct positions. Our algorithm relies on careful local geometric computations and movement strategies that exploit the sequential nature of activations to deterministically reach the target pattern. This result highlights the surprising computational power of oblivious robots under sequential schedulers, contrasting sharply with their limitations under more concurrent models.", "published_date": "2025" }, { "keywords": [ "mobile agents", "graphs", "dispersion" ], "title": "Dispersion is (Almost) Optimal under (A)synchrony", "authors": [ "Ajay D. Kshemkalyani", "Manish Kumar", "Anisur Rahaman Molla", "Debasish Pattanayak", "Gokarna Sharma" ], "type": "conference", "conference": { "full": "37th ACM Symposium on Parallelism in Algorithms and Architectures", "short": "SPAA" }, "year": 2025, "status": "Accepted", "doi": "https://doi.org/10.1145/3694906.3743317", "dblp": "https://dblp.org/rec/conf/spaa/KshemkalyaniKMP25.html", "location": "Portland, Oregon, USA", "date": "July 28 - August 1, 2025", "abstract": "The dispersion problem has received much attention recently in the distributed computing literature. In this problem, $k \\le n$ agents placed initially arbitrarily on the nodes of an $n$-node, $m$-edge anonymous graph of maximum degree $\\Delta$ have to reposition autonomously to reach a configuration in which each agent is on a distinct node of the graph. Dispersion is interesting as well as important due to its connections to many fundamental coordination problems by mobile agents on graphs, such as exploration, scattering, load balancing, relocation of self-driven electric cars (robots) to recharge stations (nodes), etc. The objective has been to provide a solution that optimizes simultaneously time and memory complexities. There exist graphs for which the lower bound on time complexity is $\\Omega(k)$. Memory complexity is $\\Omega(\\log k)$ per agent independent of graph topology. The state-of-the-art algorithms have (i) time complexity $O(k \\log^2 k)$ and memory complexity $O(\\log(k + \\Delta))$ under the synchronous setting [DISC'24] and (ii) time complexity $O(\\min\\{m, k\\Delta\\})$ and memory complexity $O(\\log(k + \\Delta))$ under the asynchronous setting [OPODIS'21]. In this paper, we improve substantially on this state-of-the-art. Under the synchronous setting as in [DISC'24], we present the first optimal $O(k)$ time algorithm keeping memory complexity $O(\\log(k + \\Delta))$. Under the asynchronous setting as in [OPODIS'21], we present the first algorithm with time complexity $O(k \\log k)$ keeping memory complexity $O(\\log(k + \\Delta))$, which is time-optimal within an $O(\\log k)$ factor despite asynchrony. Both the results were obtained through novel techniques to quickly find empty nodes to settle agents, which may be of independent interest.", "published_date": "2025-07-16" }, { "keywords": [ "mobile agents", "graphs", "Byzantine faults" ], "title": "Exploring Dangerous Graphs with Byzantine Companions", "authors": [ "Giuseppe Antonio Di Luna", "Paola Flocchini", "Debasish Pattanayak", "Francesco Piselli", "Giuseppe Prencipe", "Nicola Santoro" ], "type": "conference", "conference": { "full": "45th IEEE International Conference on Distributed Computing Systems", "short": "ICDCS" }, "doi": "https://doi.org/10.1109/ICDCS63083.2025.00042", "dblp": "https://dblp.org/rec/conf/icdcs/LunaFPPPS25.html", "location": "Glasgow, Scotland, UK", "date": "July 20-23, 2025", "year": 2025, "status": "Accepted", "abstract": "In networked systems supporting mobile agents, a particularly dangerous security threat facing the agents is the presence of a black hole (BH): a network host that destroys any incoming agent without leaving any trace. The problem, called BLACK HOLE SEARCH (BHS), of efficiently determining the location of such a dangerous host has been extensively studied under a variety of different assumptions. In spite of their differences, the existing results share the same assumption that all the searching agents are reliable. In this paper, we start the investigation of the BHS problem when some of the searching agents are faulty in a malicious way. More precisely, we consider that up to $f$ of the $k$ searching agents are Byzantine: they may behave in an arbitrary manner, actively misleading other agents; furthermore, they are in collusion with the black hole, and immune to its destructive power. We study under what conditions the BHS problem can be solved in a synchronous network of arbitrary topology in spite of the malicious agents, examining the impact on complexity of two factors: the a-priori topological knowledge held by the agents, and the communication mechanism available to them. We prove that, with prior knowledge about the graph topology (i.e., a network map), BHS can be solved by $k \\ge 2f + 2$ agents in $O(n + f)$ synchronous rounds both with whiteboards and with just local communication, where $n$ is the number of nodes in the network. Without any knowledge about the topological structure, using whiteboard communication BHS can be solved by $k \\ge (f +1)(\\Delta+1)$ agents in $O(m+f)$ rounds; instead, using local communication, BHS can be solved by $k \\ge (f + 1)(\\Delta + 1) + 3f + 1$ agents in $O(m \\cdot n + f)$ rounds, where $m$ is the number of links of the network and $\\Delta$ is the maximum degree of the network. In all cases, as we show, the bound on the total number $k$ of agents is asymptotically optimal.", "published_date": "2025-07-21" }, { "keywords": [ "mobile robots", "euclidean plane" ], "title": "Asynchronous Separation of Unconscious Colored Robots", "authors": [ "Paola Flocchini", "Debasish Pattanayak", "Francesco Piselli", "Nicola Santoro", "Yukiko Yamauchi" ], "type": "journal", "journal": { "full": "International Journal of Networking and Computing", "short": "Intern. J. Netw. Comput." }, "year": 2025, "status": "Accepted", "doi": "http://www.ijnc.org/index.php/ijnc/article/view/338", "dblp": "https://dblp.org/rec/journals/ijnc/FlocchiniPPSY25.html", "see_also": ["asynchronous-separation-of-unconscious-colored-robots--2024-conference"], "published_date": "2025-07-19", "abstract": "We consider the recently introduced model of autonomous computational mobile entities called unconscious colored robots. The entities are the traditional oblivious silent mobile robots operating in the Euclidean plane in Look-Compute-Move cycles. However, each robot has a permanent external mark (or color) from a finite set, visible by the other robots, but not by the robot itself. The basic problem for these robots is separation, requiring all the robots with the same color to separate from the other robots, each group forming a recognizable geometric shape (e.g., circle, point, line); this task must be performed in finite time, in spite of the robots being unconscious of their own color, unable to communicate, and oblivious. This problem has been studied and solved in the synchronous setting (SSS 2023). In this paper we show that the problem is solvable also under the more difficult asynchronous adversary, provided the robots agree on the orientation of one axis, and no robot is uniquely colored. The proof is constructive: we present a distributed algorithm that allows unconscious colored robots with one-axis agreement to separate into parallel lines under the asynchronous scheduler." }, { "keywords": [ "mobile agents", "graphs", "dispersion" ], "title": "BA: Optimal Dispersion under Asynchrony", "authors": [ "Debasish Pattanayak", "Ajay D. Kshemkalyani", "Manish Kumar", "Anisur Rahaman Molla", "Gokarna Sharma" ], "type": "conference", "conference": { "full": "39th International Symposium on Distributed Computing", "short": "DISC" }, "date": "October 27-31, 2025", "location": "Berlin, Germany", "arxiv": "http://arxiv.org/abs/2507.01298", "doi": "https://doi.org/10.4230/LIPIcs.DISC.2025.63", "dblp": "https://dblp.org/rec/conf/wdag/PattanayakK0MS25.html", "see_also": ["asynchronous-dispersion-with-optimal-time-complexity--2026-conference"], "year": 2025 }, { "authors": [ "Caterina Feletti", "Paola Flocchini", "Debasish Pattanayak", "Giuseppe Prencipe", "Nicola Santoro" ], "keywords": [ "mobile robots", "euclidean plane", "pattern formation" ], "title": "BA: Universal Dancing by Luminous Robots Under Sequential Schedulers", "pages": "56:1-56:7", "year": 2025, "doi": "https://doi.org/10.4230/LIPIcs.DISC.2025.56", "dblp": "https://dblp.org/rec/conf/wdag/FelettiFPPS25.html", "see_also": ["universal-dancing-by-luminous-robots-under-sequential-schedulers--2026-conference"], "location": "Berlin, Germany", "date": "October 27-31, 2025", "type": "conference", "conference": { "full": "39th International Symposium on Distributed Computing", "short": "DISC" }, "abstract": "The Dancing problem requires a swarm of n autonomous mobile robots to form a sequence of patterns, aka perform a choreography. Existing work has proven that some crucial restrictions on choreographies and initial configurations (e.g., on repetitions of patterns, periodicity, symmetries, contractions/expansions) must hold so that the Dancing problem can be solved under certain robot models. Here, we prove that these necessary constraints can be dropped by considering the LUMI model (i.e., where robots are endowed with a light whose color can be chosen from a constant-size palette) under the quite unexplored sequential scheduler. We formalize the class of Universal Dancing problems which require a swarm of n robots starting from any initial configuration to perform a (periodic or finite) sequence of arbitrary patterns, only provided that each pattern consists of n vertices (including multiplicities). However, we prove that, to be solvable under LUMI, the length of the feasible choreographies is bounded by the compositions of n into the number of colors available to the robots. We provide an algorithm solving the Universal Dancing problem by exploiting the peculiar capability of sequential robots to implement a distributed counter mechanism. Even assuming non-rigid movements, our algorithm ensures spatial homogeneity of the performed choreography.", "arxiv": "https://doi.org/10.48550/arXiv.2508.15484", "published_date": "2025" }, { "keywords": [ "mobile agents", "graphs", "dispersion" ], "title": "BA: Asynchronous Dispersion with Optimal Time Complexity", "authors": [ "Debasish Pattanayak", "Ajay D. Kshemkalyani", "Manish Kumar", "Anisur Rahaman Molla", "Gokarna Sharma" ], "type": "conference", "conference": { "full": "38th ACM Symposium on Parallelism in Algorithms and Architectures", "short": "SPAA" }, "date": "July 6-10, 2026", "url": "https://spaa.acm.org/", "arxiv": "http://arxiv.org/abs/2507.01298", "doi": "https://doi.org/10.1145/3816782.3819188", "dblp": "https://dblp.uni-trier.de/pers/hd/p/Pattanayak:Debasish", "see_also": ["asynchronous-dispersion-with-optimal-time-complexity--2026-conference"], "year": 2026, "status": "Accepted", "abstract": "We study dispersion in anonymous port-labeled graphs under asynchrony, where $k \\le n$ mobile agents with unique IDs must relocate so that no node hosts more than one agent. The result closes the asynchronous time-complexity gap by achieving optimal $O(k)$ time while using $O(\\log(k+\\Delta))$ bits of memory per agent, based on a port-one tree construction." }, { "keywords": [ "mobile agents", "graphs", "dispersion" ], "title": "Asynchronous Dispersion with Optimal Time Complexity", "authors": [ "Debasish Pattanayak", "Ajay D. Kshemkalyani", "Manish Kumar", "Anisur Rahaman Molla", "Gokarna Sharma" ], "type": "conference", "conference": { "full": "55th International Conference on Parallel Processing", "short": "ICPP" }, "date": "September 28 - October 1, 2026", "location": "Singapore", "arxiv": "http://arxiv.org/abs/2507.01298", "dblp": "https://dblp.uni-trier.de/pers/hd/p/Pattanayak:Debasish", "see_also": [ "ba-optimal-dispersion-under-asynchrony--2025-conference", "ba-asynchronous-dispersion-with-optimal-time-complexity--2026-conference" ], "year": 2026, "status": "Accepted", "abstract": "We study the dispersion problem for $k$ mobile agents on an $n$-node anonymous graph with memory-less nodes and maximum degree $\\Delta$. Agents must autonomously relocate so that no two agents occupy the same node. While an optimal $O(k)$-time, $O(\\log(k+\\Delta))$-memory algorithm is known under synchronous settings, the best known asynchronous algorithm requires $O\\!\\left(k \\log \\min\\{k,\\Delta\\}\\right)$ time due to the difficulty of distinguishing unvisited nodes from nodes temporarily vacated by agents in the asynchronous environment. We close this gap by presenting the first fully asynchronous algorithm achieving asymptotically optimal $O(k)$ time and $O(\\log(k+\\Delta))$ memory. Our main technical contribution is the introduction of the Port-1 Tree (P1Tree), a novel structural property of a port-labeled graph. By forcing the DFS traversal to prioritize edges locally labeled with port~1, P1Tree allows agents to verify the status of neighboring nodes in $O(1)$ asynchronous epochs without relying on timing assumptions unavailable in the asynchronous model. We prove the $O(k)$ bound first for rooted initial configurations and then extend it to general initial configurations via asynchronous tree mergers, preserving the same asymptotic time and memory bounds." }, { "authors": [ "Caterina Feletti", "Paola Flocchini", "Debasish Pattanayak", "Giuseppe Prencipe", "Nicola Santoro" ], "keywords": [ "mobile robots", "euclidean plane", "pattern formation" ], "title": "Universal Dancing by Luminous Robots Under Sequential Schedulers", "year": 2026, "type": "conference", "conference": { "full": "33rd International Colloquium on Structural Information and Communication Complexity", "short": "SIROCCO" }, "award": "Best paper award", "doi": "https://doi.org/10.1007/978-3-032-26465-7_16", "dblp": "https://dblp.org/rec/conf/sirocco/FelettiFPPS26.html", "see_also": ["ba-universal-dancing-by-luminous-robots-under-sequential-schedulers--2025-conference"], "location": "Durham University, Durham, UK", "date": "June 9-11, 2026", "abstract": "The Dancing problem requires a swarm of n autonomous mobile robots to form a sequence of patterns, aka perform a choreography. Existing work has proven that some crucial restrictions on choreographies and initial configurations (e.g., on repetitions of patterns, periodicity, symmetries, contractions/expansions) must hold so that the Dancing problem can be solved under certain robot models. Here, we prove that these necessary constraints can be dropped by considering the LUMI model (i.e., where robots are endowed with a light whose color can be chosen from a constant-size palette) under the quite unexplored sequential scheduler. We formalize the class of Universal Dancing problems which require a swarm of n robots starting from any initial configuration to perform a (periodic or finite) sequence of arbitrary patterns, only provided that each pattern consists of n vertices (including multiplicities). However, we prove that, to be solvable under LUMI, the length of the feasible choreographies is bounded by the compositions of n into the number of colors available to the robots. We provide an algorithm solving the Universal Dancing problem by exploiting the peculiar capability of sequential robots to implement a distributed counter mechanism. Even assuming non-rigid movements, our algorithm ensures spatial homogeneity of the performed choreography.", "arxiv": "https://doi.org/10.48550/arXiv.2508.15484", "published_date": "2026" }, { "keywords": [ "mobile agents", "graphs", "leader election" ], "title": "Faster Leader Election via Mobile Agents and its Applications", "authors": [ "Ajay D. Kshemkalyani", "Manish Kumar", "Anisur Rahaman Molla", "Debasish Pattanayak", "Gokarna Sharma" ], "type": "journal", "journal": { "full": "Theoretical Computer Science", "short": "Theor. Comput. Sci." }, "year": 2026, "status": "Accepted", "doi": "https://doi.org/10.1016/j.tcs.2025.115578", "dblp": "https://dblp.org/rec/journals/tcs/KshemkalyaniKMPS26.html", "abstract": "Leader election is a critical and extensively studied problem in distributed computing. This paper introduces the study of leader election using mobile agents. Consider agents initially placed arbitrarily on the nodes of an arbitrary, $n$-node, $m$-edge graph $G$. These agents move autonomously across the nodes of $G$ and elect one agent as the leader such that the leader is aware of its status as the leader, and the other agents know they are not the leader. The goal is to minimize both time and memory usage. We study the leader election problem in a synchronous setting where each agent performs operations simultaneously with the others, allowing us to measure time complexity in terms of rounds. We assume that the agents have prior knowledge of the number of nodes $n$ and the maximum degree of the graph $\\Delta$. We first elect a leader deterministically in $O(n \\log^2 n+D\\Delta)$ rounds with each agent using $O(\\log n)$ bits of memory, where $D$ is the diameter of the graph. Leveraging this leader election result, we then present a deterministic algorithm for constructing a minimum spanning tree of $G$ in $O(m + n \\log n)$ rounds, with each agent using $O(\\Delta \\log n)$ bits of memory. Furthermore, using the same leader election result, we improve time and memory bounds for other key distributed graph problems, including gathering, maximal independent set, and minimal dominating set. For all the aforementioned problems, our algorithm remains memory optimal.Finally, we also perform simulations to validate our theoretical results and show the performance trends of our algorithm under different graph topologies.", "published_date": "2025-10-22" }, { "authors": [ "Paola Flocchini", "Alfredo Navarra", "Debasish Pattanayak", "Francesco Piselli", "Nicola Santoro" ], "keywords": [ "mobile robots", "euclidean plane", "pattern formation" ], "title": "Universal Pattern Formation by Oblivious Robots under Sequential Schedulers", "type": "journal", "arxiv": "https://arxiv.org/abs/2412.10733", "doi": "https://doi.org/10.1007/s00446-026-00504-3", "dblp": "https://dblp.org/rec/journals/dc/FlocchiniNPPS26.html", "see_also": ["oblivious-robots-under-sequential-schedulers-universal-pattern-formation--2025-conference"], "year": 2026, "journal": { "full": "Distributed Computing", "short": "Distributed Computing" }, "abstract": "We study the computational power that oblivious robots operating in the plane have under sequential schedulers. We show that this power is much stronger than the obvious capacity these schedulers offer of breaking symmetry, and thus to create a leader. In fact, we prove that under any sequential scheduler, robots are capable of solving problems that are unsolvable even with a leader under the fully synchronous scheduler \\(\\mathcal {FSYNC}\\). More precisely, we consider the class of pattern formation problems, and focus on the most general problem in this class, Universal Pattern Formation (UPF), which requires the robots to form every pattern given in input, starting from any initial configuration (where some robots may occupy the same point, hence forming a multiplicity). We first show that UPF is unsolvable under \\(\\mathcal {FSYNC}\\), even if the robots are endowed with additional strong capabilities (multiplicity detection, rigid movement, agreement on coordinate systems, presence of a unique leader). On the other hand, we prove that, except for point formation (Gathering), UPF is solvable under any sequential scheduler without any additional assumptions. We then turn our attention to the Gathering problem, and prove that weak multiplicity detection (the ability to detect a multiplicity but not the exact number of robots forming it) is necessary and sufficient for solvability under sequential schedulers. The results obtained show that the computational power of the robots under \\(\\mathcal {FSYNC}\\) (where Gathering is solvable without any multiplicity detection) and that under sequential schedulers are orthogonal.", "published_date": "2026-03-25" }, { "authors": [ "Caterina Feletti", "Debasish Pattanayak", "Gokarna Sharma" ], "keywords": [ "mobile robots", "euclidean plane", "pattern formation" ], "title": "Optimal Luminous UCF under Asynchrony", "arxiv": "https://arxiv.org/abs/2405.06617", "type": "journal", "journal": { "full": "Journal of Parallel and Distributed Computing", "short": "J. Parallel Distrib. Comput." }, "year": 2026, "status": "Accepted", "accepted_date": "2026-08-08", "see_also": ["ba-optimal-uniform-circle-formation-by-asynchronous-luminous-robots--2024-conference"], "abstract": "We study the uniform circle formation (UCF) problem where n >= 3 autonomous mobile robots, initially arbitrarily positioned in the plane, have to arrange themselves equally spaced on the boundary of a circle not fixed in advance. Robots are anonymous, asynchronous, oblivious, and luminous: they execute Look-Compute-Move cycles asynchronously, cannot be distinguished by their appearance, have no memory of past actions, but possess a light that can assume colors from a constant-sized set C. The light color is visible to other robots and persists between cycles. It is known that UCF is impossible for such robots without lights or with only 1 color. Prior work showed UCF solvability with O(n) colors in O(n) epochs and with O(log n) colors in poly(n) epochs. We present an algorithm that solves UCF using O(1) colors (specifically, 4 colors) in O(n^2) epochs. This result is optimal in terms of colors, as UCF requires at least 2 colors. Our algorithm relies on carefully managing robot states using the constant number of colors to break symmetries and coordinate movements towards the final uniform circular configuration." } ], "talks": [ { "title": "AI Agents: Life and Money", "event": "Ethereum Day", "Place": "IIT Indore", "date": "Oct 10 2026", "links": { "talk": "https://debasishpattanayak.com/Talks/ai-agents-life-and-money.html" } }, { "title": "Introduction to Distributed Algorithms", "event": "Foundational Lecture Series on Theoretical Computer Science (FSTCS) 2026", "Place": "The Institute of Mathematical Sciences (IMSc), Chennai", "date": "Jun 19 2026", "links": { "talk": "https://debasishpattanayak.com/Talks/distributed-algorithms.html", "event": "https://www.imsc.res.in/outreach/events/foundation-series/2026/fstcs2026/", "video": "https://www.youtube.com/watch?v=d_hQ7fupkyI" } }, { "title": "AI Agents: The Moving Frontier", "event": "Department of Mathematics, IIT Guwahati", "date": "Jun 12 2026", "links": { "talk": "https://debasishpattanayak.com/Talks/ai-agents-moving-frontier.html" } }, { "title": "AI AGENTS ON THE FRONTIER: HYPE VS REALITY", "event": "Symposium 4.0", "date": "Feb 13 2026", "Place": "IIT Indore", "links": { "talk": "https://debasishpattanayak.com/Talks/aiagents.html" } }, { "title": "Pattern Formation of Robot Swarms: Points, Lines and Circles", "event": "Online Workshop on Distributed Algorithms For Swarm Robots, Jadavpur University", "date": "April 24 2025", "links": { "slides": "https://www.dropbox.com/scl/fi/j4en9zgb1rqqmecv25zsj/Jadavpur.pptx?rlkey=98018mfzhqqk534jexmolibvi&dl=0" }, "Organizer": { "name": "Dr. Sruti Gan Choudhuri", "url": "https://scholar.google.ca/citations?user=8aJWdl0AAAAJ&hl=en" } }, { "title": "A Demo of GPT-3", "event": "LUISS School of Journalism", "links": { "tweet": "https://twitter.com/Zeta_Luiss/status/1403267050785710080", "column": "https://www.osservatoreromano.va/it/news/2021-07/quo-148/la-voce-delle-macchine-br-e-il-diritto-alla-verita.html", "article": "https://www.repubblica.it/commenti/2021/05/30/news/i_ribelli_dell_intelligenza_artificiale_commento_gianni_riotta-303374245/" }, "Organizer": { "name": "Prof. Gianni Riotta", "url": "https://riotta.it/bio-riotta/" } }, { "title": "On the capabilities of GPT-3", "event": "The AI Times Workshop", "tweet": "https://twitter.com/LuissDataLab/status/1442517724928876544", "Organizer": { "name": "Luiss DataLab", "url": "https://www.luiss.edu/research/research-centers/data-lab" } }, { "title": "Dispersion of Mobile Robots", "Place": "IIT Bhilai", "date": "11 October 2022", "Organizer": { "name": "Dr. Barun Gorain", "url": "https://sites.google.com/site/barungorainiitg/home" } } ], "visits": [ { "place": "IIT Bhilai, India", "reason": "Talk: Dispersion of Mobile Robots (host: Dr. Barun Gorain)", "start_date": "2022-10-11", "end_date": "2022-10-14" }, { "place": "Varanasi, India", "reason": "ICDCN 2018 — presented \"Evacuating Two Robots from Two Unknown Exits on the Perimeter of a Disk with Wireless Communication\"", "start_date": "2018-01-04", "end_date": "2018-01-07" }, { "place": "Bangalore, India", "reason": "ICDCN 2019", "start_date": "2019-01-04", "end_date": "2019-01-07" }, { "place": "Munich, Germany", "reason": "ALGOSENSORS 2019 — presented \"Chauffeuring a Crashed Robot from a Disk\" (side trip during the Vienna fellowship)", "start_date": "2019-09-12", "end_date": "2019-09-13" }, { "place": "ISI Kolkata, India", "reason": "ANTS 2015", "start_date": "2015-12-15", "end_date": "2015-12-18" }, { "place": "ISI Kolkata, India", "reason": "ICDCN 2020 — presented \"Surveillance of Uneven Surface with Unmanned Aerial Vehicles\"", "start_date": "2020-01-04", "end_date": "2020-01-07" }, { "place": "Pisa, Italy", "reason": "MAC 2022 — 8th Research Meeting and School on Distributed Computing by Mobile Robots (Moving and Computing)", "start_date": "2022-09-19", "end_date": "2022-09-22" }, { "place": "Paderborn, Germany", "reason": "SIROCCO 2022 — presented \"Dispersion of Mobile Robots on Directed Anonymous Graphs\"", "start_date": "2022-06-27", "end_date": "2022-06-29" }, { "place": "Naha, Okinawa, Japan", "reason": "CANDAR/PDAA 2024 — presented \"Asynchronous Separation of Unconscious Colored Robots\"", "start_date": "2024-11-26", "end_date": "2024-11-29" }, { "place": "Kyushu University, Fukuoka, Japan", "reason": "Research visit, one week after CANDAR 2024", "start_date": "2024-11-30", "end_date": "2024-12-06" }, { "place": "Ischia, Italy", "reason": "IWOCA 2024 — presented \"The Minimum Algorithm Size of k-Grouping by Silent Oblivious Robots\"", "start_date": "2024-07-01", "end_date": "2024-07-03" }, { "place": "IIT Guwahati, India", "reason": "Research visit — talk: AI Agents: The Moving Frontier (Dept. of Mathematics)", "start_date": "2026-06-05", "end_date": "2026-06-14" }, { "place": "IMSc Chennai, India", "reason": "FSTCS 2026 — talk: Introduction to Distributed Algorithms", "start_date": "2026-06-14", "end_date": "2026-06-21" }, { "place": "University of Ottawa, Canada", "reason": "Research visit", "start_date": "2026-07-01", "end_date": "2026-07-30" }, { "place": "Kathmandu, Nepal", "reason": "SSS 2025 / MAC 2025", "start_date": "2025-10-09", "end_date": "2025-10-13" }, { "place": "IIT Madras, Chennai, India", "reason": "Workshop: Modern Trends in Parameterized Algorithms", "start_date": "2025-12-03", "end_date": "2025-12-06" }, { "place": "IISc Bengaluru, India", "reason": "Workshop: Frontiers of Graph Algorithms", "start_date": "2025-12-08", "end_date": "2025-12-12" }, { "place": "BITS Pilani – K K Birla Goa Campus, India", "reason": "FSTTCS 2025, with pre-conference Workshop on Quantum Algorithms and Cryptography (Dec 14-15) and Information in Games and Mechanisms (Dec 16)", "start_date": "2025-12-14", "end_date": "2025-12-19" } ], "teaching": [ { "course": "CS637: Theory of Computation and Graph Theory", "duration": "Jan-Apr 2026", "institution": "IIT Indore", "url": "https://debasishpattanayak.com/IITIJan2026CS637" }, { "course": "CS103: Introduction to Programming", "duration": "July-Nov 2025", "institution": "IIT Indore", "url": "https://debasishpattanayak.com/IITIJul2025CS103" }, { "course": "Artificial Intelligence and Machine Learning (Bachelor)", "duration": "Sep-Dec 2021", "institution": "LUISS" }, { "course": "Machine Learning (Master)", "duration": "Feb-May 2022", "institution": "LUISS" }, { "course": "Introduction to Programming with Python", "type": "Online Course", "year": 2022, "institution": "LUISS" }, { "course": "Data Structures and Algorithms Lab", "duration": "Jul-Nov 2018", "institution": "IIT Guwahati" }, { "course": "Object Oriented Programming with C++", "duration": "Jan-Apr 2018", "institution": "IIT Guwahati" }, { "course": "Introduction to Programming", "duration": "Jul-Nov 2016 & 2017", "institution": "IIT Guwahati" } ], "awards": [ "Best paper award for Universal Dancing paper in SIROCCO 2026.", "Best Doctoral Thesis award from the Department of Mathematics, IIT Guwahati.", "Best Paper award at ICDCIT 2023 for paper on MIS Filling.", "Awarded position under Distributed Computing Chair Research Grant, 2022 to work at UQO, Canada.", "Awarded position under PRIN research grant titled 'AHeAD: efficient Algorithms for HArnessing networked Data' to work at LUISS Guido Carli, Italy.", "Best Poster award in Doctoral Symposium, ICDCN 2020.", "SERB Overseas Visiting Doctoral Fellowship, 2018-19 to work at University of Vienna." ], "grants": [ { "title": "PM-ECRG (Prime Minister Early Career Research Grant Scheme)", "year": "2026", "funding_agency": "ANRF", "project_title": "Collective Resilience: Harnessing Swarm Intelligence Against Byzantine Faults" }, { "title": "YFRSG (Young Faculty Research Seed Grant Scheme)", "funding_agency": "IIT Indore", "project_title": "Schedulers Galore: Asynchronous, Synchronous and Sequential", "url": "visualizations/seedgrant.html" } ], "community_services": { "pc_member_for": [ "Doctoral Symposium of ICDCN 2022", "Distributed Computing Track of ICDCIT 2023", "Distributed Computing Track of ICDCIT 2024", "SIROCCO 2024", "IEEE ANTS Early Researchers' Forum 2024", "Moving and Computing Track of SSS 2025", "Distributed Computing Track of ICDCIT 2026", "Doctoral Symposium of ICDCN 2026", "1st Decentralized Immutable Secure Tamper-Resistant Encrypted Searchable Storage Workshop (DISTRESS'26)" ], "reviewer_for": { "journals": [ "Theoretical Computer Science", "Journal of Parallel and Distributed Computing", "IEEE Access", "Distributed Computing", "Journal of Supercomputing", "Journal of Field Robotics", "Information and Computation", "International Journal of Foundations of Computer Science" ], "conferences": [ "ICDCN 2017", "ICDCN 2019", "OPODIS 2019", "CALDAM 2020", "SIROCCO 2020", "SSS 2021", "ALGOSENSORS 2021", "ISAAC 2021", "ICDCS 2021", "SODA 2022", "ICDCN 2022", "SSS 2023", "IWOCA 2024", "OPODIS 2024", "SSS 2024", "ICDCIT 2025", "SIROCCO 2025", "SEA 2026", "LATIN 2026", "PODC 2026" ] }, "organizing_committee": [ "13th International Conference and Workshop on Algorithms and Computation (WALCOM), 2019" ], "social": [ { "title": "Project Pankhuri", "role": "Coordinator", "url": "https://projectpankhuri.github.io", "description": "Alongside my academic work, I help run Project Pankhuri, a small learning and enrichment initiative for students of Classes 6-8 from tribal and rural communities. We create spaces where they can learn with curiosity, ask questions freely, explore new ideas, and experience the joy of learning. Pankhuri is our small effort to ensure that a child's background does not define the opportunities they have to learn, explore, dream, and grow.", "founder": { "name": "Dr. Lawqueen Kanesh", "url": "https://sites.google.com/view/lawqueenkanesh/home" }, "collaborators": [ { "name": "Dr. Subhra Mazumdar", "url": "https://sites.google.com/site/subhramazumdar1993/home" } ] } ] }, "administrative_responsibilities": [ "Convener, DUGC, Department of CSE (Feb 1, 2026 - Present)" ], "skills": { "programming": [ "C", "C++", "Python", "LATEX", "HTML", "CSS", "MATLAB", "Mathematica", "Markdown" ], "python_libraries": [ "Numpy", "Matplotlib", "PyTorch", "SkLearn", "Pandas" ] }, "common_authors": { "Debasish Pattanayak": { "url": "#" }, "Kaushik Mondal": { "url": "https://scholar.google.com/citations?user=B8X0B8YAAAAJ&hl=en" }, "H. 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Italiano": { "url": "https://www.luiss.edu/faculty/350980" }, "Andrzej Pelc": { "url": "http://w3.uqo.ca/pelc/main.html" }, "Paola Flocchini": { "url": "https://www.site.uottawa.ca/~flocchin/" }, "Nicola Santoro": { "url": "https://research.nicola-santoro.com/" }, "Masafumi Yamashita": { "url": "https://scholar.google.com/citations?user=su_QHVwAAAAJ&hl=en&oi=ao" }, "Loukas Georgiadis": { "url": "https://sites.google.com/view/loukastgeorgiadis/αρχική-σελίδα" }, "Evangelos Kosinas": { "url": "#" }, "Caterina Feletti": { "url": "https://scholar.google.com/citations?user=lAIwajgAAAAJ&hl=en" }, "Yukiko Yamauchi": { "url": "http://tcs.inf.kyushu-u.ac.jp/~yamauchi/" }, "Francesco Piselli": { "url": "https://scholar.google.com/citations?user=zdFY4eoAAAAJ" }, "Alfredo Navarra": { "url": "https://navarra.sites.dmi.unipg.it" }, "Giuseppe Antonio Di Luna": { "url": "https://sites.google.com/site/gadiluna/" }, "Giuseppe Prencipe": { "url": "https://sbrinz.di.unipi.it" }, "Ajay D. Kshemkalyani": { "url": "https://www.cs.uic.edu/~ajayk/" }, "Manish Kumar": { "url": "https://sites.google.com/view/saumitr/home" } }, "students": { "phd_ongoing": [ { "name": "Afzal Ali", "joined": "January 2026", "status": "Ongoing" }, { "name": "Ganesh Sidar", "joined": "January 2026", "status": "Ongoing" } ], "mtech_ongoing": [ { "name": "Ayush Kumar Pandey", "joined": "July 2025", "status": "Ongoing" } ], "completed": [], "bsc_honors": [ { "name": "Khaled Elbasiouni", "degree": "B.Sc. Honors Project", "institution": "University of Ottawa", "project": "Asynchronous Simulator for Mobile Robots", "co_supervisor": "Prof. Paola Flocchini", "status": "Completed" }, { "name": "Diego Bajetti", "degree": "B.Sc. Honors Project", "institution": "University of Ottawa", "project": "Asynchronous Simulator for Mobile Robots", "co_supervisor": "Prof. Paola Flocchini", "status": "Completed" } ] }, "hero_simulations": [ { "label": "Circle formation", "title": "Uniform circle formation", "description": "Asynchronous robots in the Look–Compute–Move cycle spread themselves evenly on a circle.", "embed_url": "https://debasishpattanayak.com/LCMmodel/?embed&loop=1&algorithm=CircleFormation&robots=12&seed=7" }, { "label": "Gathering", "title": "Gathering at the centre of gravity", "description": "Each robot looks, computes the centre of gravity of the swarm, and moves towards it.", "embed_url": "https://debasishpattanayak.com/LCMmodel/?embed&loop=1&algorithm=Gathering&robots=10&seed=3" }, { "label": "Crash faults", "title": "Gathering with crashed robots", "description": "The same algorithm when two robots, chosen at random, crash and stop for good.", "embed_url": "https://debasishpattanayak.com/LCMmodel/?embed&loop=1&algorithm=Gathering&robots=10&seed=3&num_of_faults=2&fault_type=crash" }, { "label": "Limited visibility", "title": "Go-To-Center with limited visibility", "description": "Three robots that see only 100 units converge without losing sight of each other; the lines show who sees whom.", "embed_url": "https://debasishpattanayak.com/LCMmodel/?embed&loop=1&algorithm=GoToCenter&points=-80,10;0,0;95,-5&visibility=100&scheduler=sequential&speed=turn:1&links=1" } ], "research_themes": [ { "title": "Dispersion of Mobile Agents", "description": "Time-efficient dispersion of mobile agents on anonymous graphs under asynchrony and limited communication.", "selected_papers": [ "Asynchronous Dispersion with Optimal Time Complexity", "Dispersion is (Almost) Optimal under (A)synchrony", "Dispersion of Mobile Robots on Directed Anonymous Graphs" ] }, { "title": "Pattern Formation by Robot Swarms", "description": "Universal pattern formation, dancing, and geometric arrangements by luminous and oblivious robots.", "selected_papers": [ "Optimal Luminous UCF under Asynchrony", "Universal Dancing by Luminous Robots Under Sequential Schedulers", "Universal Pattern Formation by Oblivious Robots under Sequential Schedulers" ] }, { "title": "Fault Tolerance & Dangerous Environments", "description": "Coordination and exploration under crash faults, Byzantine companions, and hazardous environments.", "selected_papers": [ "Exploring Dangerous Graphs with Byzantine Companions", "Gathering of Mobile Robots with Weak Multiplicity Detection in Presence of Crash-Faults", "Dispersion of Mobile Robots Tolerating Faults" ] }, { "title": "Graph Algorithms & Mobile Computation", "description": "Leader election, connectivity, treasure hunt, and computation via mobile agents on graphs.", "selected_papers": [ "Faster Leader Election via Mobile Agents and its Applications", "On Maximal k-Edge-Connected Subgraphs of Undirected Graphs", "Deterministic Treasure Hunt and Rendezvous in Arbitrary Connected Graphs" ] } ], "homepage_talks": [ "AI Agents: Life and Money", "Introduction to Distributed Algorithms", "AI Agents: The Moving Frontier" ], "recommended_books": [ { "title": "Distributed Computing by Mobile Entities", "authors": "Paola Flocchini, Giuseppe Prencipe, Nicola Santoro (Eds.)", "publisher": "Springer, 2019", "description": "The definitive reference on mobile robots, mobile agents, and programmable particles — the models at the heart of my research.", "link": "https://doi.org/10.1007/978-3-030-11072-7", "link_label": "Springer" }, { "title": "Distributed Computing: A Locality-Sensitive Approach", "authors": "David Peleg", "publisher": "SIAM, 2000", "description": "The classic text on locality in distributed network algorithms — spanners, labeling schemes, and low-communication computation.", "link": "https://doi.org/10.1137/1.9780898719772", "link_label": "SIAM" }, { "title": "Distributed Computing: Principles, Algorithms, and Systems", "authors": "Ajay D. Kshemkalyani, Mukesh Singhal", "publisher": "Cambridge University Press, 2008", "description": "A comprehensive textbook covering the fundamentals — logical time, global states, mutual exclusion, consensus, and self-stabilization.", "link": "https://doi.org/10.1017/CBO9780511805318", "link_label": "Cambridge" }, { "title": "Distributed Algorithms 2020", "authors": "Juho Hirvonen, Jukka Suomela", "publisher": "Free online book", "description": "A modern, freely available introduction to distributed graph algorithms — the LOCAL, CONGEST, and port-numbering models. A great first read.", "link": "https://jukkasuomela.fi/da2020/", "link_label": "Read free" } ] }