Title page of the PhD thesis “The Exploration and Exploitation Dynamics of Target Tracking Swarms” by Hian Lee Kwa

Congratulations to Hian Lee Kwa, who successfully defended his Ph.D. thesis at the Singapore University of Technology and Design (SUTD) on 1 September 2022. His thesis, “The Exploration and Exploitation Dynamics of Target Tracking Swarms”, supervised by Roland Bouffanais, shows that a swarm of robots can find and track a target that moves faster than any individual robot, and that this ultimately comes down to how the swarm balances collective exploration and exploitation.

[PhD thesis (PDF)]

Publications with Hian Lee Kwa

Journal articles

  • H. L. Kwa, J. Philippot & R. Bouffanais, “Effect of Swarm Density on Collective Tracking Performance”, Swarm Intelligence, 17, 253–281 (2023). [DOI]
  • H. L. Kwa, J. L. Kit, N. Horsevad, J. Philippot, M. Savari & R. Bouffanais, “Adaptivity: A Path Towards General Swarm Intelligence?”, Frontiers in Robotics and AI, 10, 1163185 (2023). [DOI] [PDF]
  • H. L. Kwa, V. Babineau, J. Philippot & R. Bouffanais, “Adapting the Exploration-Exploitation Balance in Heterogeneous Swarms: Tracking Evasive Targets”, Artificial Life, 29, 1–16 (2022). [DOI] [PDF]
  • N. Horsevad, H. L. Kwa & R. Bouffanais, “Beyond Bio-Inspired Robotics: How Multi-Robot Systems Can Support Research on Collective Animal Behavior”, Frontiers in Robotics and AI, 9, 865414 (2022). [DOI] [PDF]
  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Balancing Collective Exploration and Exploitation in Multi-Agent and Multi-Robot Systems: A Review”, Frontiers in Robotics and AI, 8, 771520 (2022). [DOI] [PDF]

Conference papers

  • H. L. Kwa, J. Philippot & R. Bouffanais, “The Impact of Agent Density and Environmental Factors on Target Tracking Swarms”, Proceedings of ALIFE 2023, Sapporo, Japan, pp. 88–96, MIT Press (2023). [DOI] [PDF]
  • H. L. Kwa & R. Bouffanais, “The Effect of Network Connectivity on Exploration and Exploitation During Decentralized Collective Learning”, 4th International Workshop on Agent-Based Modelling of Human Behaviour (ABMHuB’22), online (2022). [PDF]
  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Tracking Multiple Fast Targets With Swarms: Interplay Between Social Interaction and Agent Memory”, Proceedings of ALIFE 2021, online, pp. 62–71, MIT Press (2021). [DOI] [PDF]
  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Tailoring Exploration and Exploitation in Multi-Agent Systems with Short-Term Memory and Limited Social Interaction”, 3rd International Workshop on Agent-Based Modelling of Human Behaviour (ABMHuB’21), online (2021). [PDF]
  • H. L. Kwa, G. Tokić, R. Bouffanais & D. K. P. Yue, “Heterogeneous Swarms for Maritime Dynamic Target Search and Tracking”, IEEE/MTS Global OCEANS 2020: Singapore – U.S. Gulf Coast, online, pp. 1–8 (2020). [DOI] [PDF]
  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Optimal Swarm Strategy for Dynamic Target Search and Tracking”, AAMAS 2020, 19th International Conference on Autonomous Agents and Multiagent Systems, Auckland, New Zealand, pp. 672–680 (2020). [DOI] [PDF]

How does the spread of behavior affect consensus-based collective decision-making among animals, humans or swarming robots? In prior research, such propagation of behavior on social networks has been found to exhibit a transition from simple contagion—i.e, based on pairwise interactions—to a complex one—i.e., involving social influence and reinforcement. However, this rich phenomenology appears so far limited to threshold-based decision-making processes with binary options. Here, we show theoretically, and experimentally with a multi- robot system, that such a transition from simple to complex contagion can also be observed in an archetypal model of distributed decision-making devoid of any thresholds or nonlinearities. Specifically, we uncover two key results: the nature of the contagion—simple or complex—is tightly related to the intrinsic pace of the behavior that is spreading, and the network topology strongly influences the effectiveness of the behavioral transmission in ways that are reminiscent of threshold-based models. These results offer new directions for the empirical exploration of behavioral contagions in groups, and have significant ramifications for the design of cooperative and networked robot systems.

Check our full paper published by Nature Communications:

Horsevad, Nikolaj, David Mateo, Robert E. Kooij, Alain Barrat, and Roland Bouffanais. “Transition from simple to complex contagion in collective decision-making.” Nature Communications 13, no. 1 (2022): 1-10. DOI: 10.1038/s41467-022-28958-6 (2022). [pdf]

Title page of the PhD thesis “Towards a Swarm Intelligence Benchmark Framework” by Jabez Leong Kit

Congratulations to Jabez Leong Kit, who successfully defended his Ph.D. thesis at the Singapore University of Technology and Design (SUTD) on 14 December 2021. His thesis, “Towards a Swarm Intelligence Benchmark Framework”, co-supervised by Roland Bouffanais and Soh Gim Song, revisits the concept of swarm intelligence, proposes a way to quantify it, develops a benchmark framework to compare swarming systems, and studies quantitatively how swarm intelligence transfers from one problem to another.

[PhD thesis (PDF)]

Publications with Jabez Leong Kit

Journal articles

  • H. L. Kwa, J. L. Kit, N. Horsevad, J. Philippot, M. Savari & R. Bouffanais, “Adaptivity: A Path Towards General Swarm Intelligence?”, Frontiers in Robotics and AI, 10, 1163185 (2023). [DOI] [PDF]
  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Balancing Collective Exploration and Exploitation in Multi-Agent and Multi-Robot Systems: A Review”, Frontiers in Robotics and AI, 8, 771520 (2022). [DOI] [PDF]

Conference papers

  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Tracking Multiple Fast Targets With Swarms: Interplay Between Social Interaction and Agent Memory”, Proceedings of ALIFE 2021, online, pp. 62–71, MIT Press (2021). [DOI] [PDF]
  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Tailoring Exploration and Exploitation in Multi-Agent Systems with Short-Term Memory and Limited Social Interaction”, 3rd International Workshop on Agent-Based Modelling of Human Behaviour (ABMHuB’21), online (2021). [PDF]
  • H. L. Kwa, J. L. Kit & R. Bouffanais, “Optimal Swarm Strategy for Dynamic Target Search and Tracking”, AAMAS 2020, 19th International Conference on Autonomous Agents and Multiagent Systems, Auckland, New Zealand, pp. 672–680 (2020). [DOI] [PDF]
  • J. Leong Kit, A. G. Dharmawan, D. Mateo, S. Foong, G. S. Soh, R. Bouffanais & K. L. Wood, “Decentralized Multi-Floor Exploration by a Swarm of Miniature Robots Teaming with Wall-Climbing Units”, MRS 2019, IEEE International Symposium on Multi-Robot and Multi-Agent Systems, New Brunswick, NJ, pp. 195–201 (2019). [DOI] [PDF] — Outstanding Paper Award
  • J. Leong Kit, D. Mateo & R. Bouffanais, “A Decentralized Mobile Computing Network for Multi-Robot Systems Operations”, UEMCON 2018, 9th IEEE Annual Ubiquitous Computing, Electronics & Mobile Communication Conference, New York City, NY, pp. 309–314 (2018). [DOI] [PDF]
Title page of the PhD thesis “Physics-based Machine Learning for the Design of Marine Hydrodynamic Applications” by Sreetej Lakkam

Congratulations to Sreetej Lakkam, who successfully defended his Ph.D. thesis at the Singapore University of Technology and Design (SUTD) on 19 July 2020. His thesis, “Physics-based Machine Learning for the Design of Marine Hydrodynamic Applications”, supervised by Roland Bouffanais and co-supervised by Jurriaan Gillissen, develops machine-learning models trained on physics-rich flow data to give marine and underwater systems some of the sensing abilities of aquatic animals. It tackles three problems: identifying the shape of a hidden obstacle from the flow it generates, forecasting the long-term dynamics of chaotic and turbulent flows, and estimating the motion parameters of an oscillating flexible hydrofoil—a step towards more efficient propulsion for autonomous underwater vehicles.

[PhD thesis (PDF)]

Publications with Sreetej Lakkam

Journal article

  • S. Lakkam, B. T. Balamurali & R. Bouffanais, “Hydrodynamic Object Identification using Artificial Neural Models”, Scientific Reports, 9, 11242 (2019). [DOI] [PDF]

Roland Bouffanais has been invited to join the Editorial Board of Scientific Reports by Nature.

Delighted to be quoted by the NYT: “Singapore-based academics Roland Bouffanais and Lim Sun Sun said this time around, social media played a major role in making the worries of a toilet paper crunch “propagate like a wildfire.”

Rationing and Robbery: Coronavirus Outbreak Sparks Toilet Roll Panic

 

SYDNEY/TOKYO — In Australia, major grocers have restricted supplies to one pack per person. In Japan, rolls are chained to the wall in public toilets. In Hong Kong, armed robbers carried out a heist as supplies were delivered to a supermarket.

Toilet paper has emerged as the unlikely No.1 stockpiling target for people across Asia who are worried that the spread of the coronavirus epidemic will lead to supply shortages.

While other household products – including disinfectants, tissues and staples like rice and pasta – have also proved popular, it is the humble toilet roll that has inspired showdowns in supermarket aisles and countless social media memes.

The demand has caught many shoppers and sellers short, but psychologists say hoarding is a natural human reaction in times of high anxiety – and a desire to ensure sufficient supplies for lavatory visits in particular is not too much of a surprise.

“When we’re buying stuff, things close to the body are very comforting, whether that be food, body care or in this case toilet paper,” Adam Ferrier, a Melbourne-based psychologist who specializes in consumer behavior, told Reuters.

“The size of toilet paper makes it feel like a substantial, big purchase. It makes it feel like you’re doing something. It taps back into that need for control. If you’re buying a hefty big pack of toilet paper, you kind of feel like you’re ‘stocking up’. You signify to yourself that you’re in control.”

Photos posted on social media showed plenty of shoppers in Asia seeking control this week as they pushed precariously overloaded carts to checkout counters after stripping shelves bare.

In Australia, police were called out to settle grocery aisle disputes, a delivery truck catching fire due to a mechanical fault made national headlines, and outback newspaper The NT News published an eight-page liftout of blank paper saying the move was to give the nation what it wanted.

“It’s been a wild week. Everyone’s been on the edge of their seat looking at what’s happening,” said Simon Griffiths, co-founder of Who Gives A Crap, a social enterprise that sells recycled toilet paper and gives half its profit to sanitation-related charity. The company had to suspend store sales and new subscriptions on Wednesday when sales volumes jumped 1100% the day before.

SOCIAL MEDIA ROLE

In Japan, the economy ministry has launched a publicity campaign to urge calm, posting daily photos on its Twitter account of delivery trucks carrying toilet rolls arriving full at their destinations and of replenished store aisles.

“We wanted to send a message for consumers to understand that inventory was arriving,” ministry spokesman Yasushi Nozawa told Reuters, adding that while there was no shortage of supply of toilet rolls, distribution networks were struggling to keep up.

“Inventory has piled up at warehouses,” he said. “We have requested a doubling of daily delivery capacity from 20 million rolls to 40 million.”

It’s not the first time Japan has succumbed to toilet paper fever. During the global oil crisis of 1973, there were violent scenes in some stores as people rushed to buy bathroom tissue, fearing disruption to production.

Singapore-based academics Roland Bouffanais and Lim Sun Sun said this time around, social media played a major role in making the worries of a toilet paper crunch “propagate like a wildfire.”

“Collective behaviours among humans are remarkably similar to processes in the animal kingdom such as schooling among fish and flocking among birds,” they wrote in an editorial about toilet roll hoarding in the Straits Times newspaper.

STACKING UP

The situation has also led to some unusually frank comments by Asian politicians.

Singapore Trade Minister Chan Chun Sing was reported by local media as calling the panic buying idiotic in a meeting with business leaders, quipping: “Why stock toilet paper? If you eat all the rice and instant noodles you confirm diarrhea.”

In Taiwan, during a brief toilet paper panic last month, Premier Su Tseng-chang called for calm on his Facebook page, saying people “only have one butt-hole,” to widespread amusement across the island.

After a week of panic buying, Japan’s biggest supermarket chain Aeon Co resorted to stacking up 12-roll packs in prominent displays at some of its stores to reassure customers there was plenty to go round.

“Our goal is to eliminate people’s fears,” said Aeon spokesman Daisuke Yokota. “So we’re piling them into these huge towers, to send the message: boom, there’s plenty.”

(Reporting by Byron Kaye in Sydney, Chris Gallagher and Ritsuko Ando in Tokyo, Ben Blanchard in Taipei, John Geddie in Singapore; Writing by Jane Wardell; Editing by Raju Gopalakrishnan)

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