Papers for

robotic swarm engineers

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Agents coordinate treasure hunt on constantly shuffled ring networks

Online Treasure Hunt in Vertex-Permuted Dynamic Rings

Abstract: We study the problem of treasure hunt by a group of $k \geq 1$ agents in vertex-permuted dynamic rings (VP). In this model, the $n$ vertices remain on a ring but are permuted at each time step. We first show that treasure hunt is impossible for any $k \leq n-3$ agents, if there are no restrictions on the sequence of permutations used in the dynamic ring. We then study the $VP(δ)$ setting, in which for every pair $i, j$ of vertices, the edge $(i, j)$ is guaranteed to appear within $δ$ steps. We show that the class $VP(δ)$ is feasible only for $δ\geq \left\lceil \frac{n-1}{2}\right\rceil$. For the one-agent case, we show a tight bound of $Θ(δn)$ on the worst-case search time as well as competitive ratio of any online algorithm for treasure hunt, provided $δ\geq 2n$. We then give an optimal algorithm for $k$ agents, thereby showing that $k$ agents can obtain a speedup of $k$ on the worst-case search time. Finally, in the R-VP setting, in which in every step, the vertices are arranged as a ring according to a random permutation, we show that treasure hunt takes expected $Θ(n)$ steps against an oblivious adversary and $Θ(n \log n)$ steps against an adaptive adversary.

Thu 10 SeptDistributed, Parallel, and Cluster ComputingComputational Complexity
The gist
This paper looks at how a group of agents can find a hidden 'treasure' on a ring of points where the connections between points change constantly by rearranging the order of the points. The authors show that if the rearrangements are completely unrestricted, it’s impossible for almost all groups of agents to guarantee finding the treasure. Then they find conditions where it’s possible and study how long it takes for one or more agents to succeed. They also analyze cases where the rearrangement is random and find expected times for treasure hunting.
Open 2609.11013v1