@misc{25126, abstract = {{Motivated by the prospect of computing agents that explore unknown environments and construct convex hulls on the nanoscale, we investigate the capabilities and limitations of a single deterministic finite automaton robot in the three-dimensional hybrid model for programmable matter. In this model, active robots move on a set of passive tiles, called configuration, with the geometric shape of rhombic dodecahedra on the adjacency graph of the face-centered cubic sphere-packing. We show that the exploration problem is equally hard in the hybrid model and in three-dimensional mazes, in which tiles have the shape of cubes and are positioned at the vertices of $\mathbb{Z}^3$. Thereby, a single robot with a constant number of pebbles cannot solve this problem in the hybrid model on arbitrary configurations. We provide algorithms for a robot with two pebbles that solve the exploration problem in the subclass of compact configurations of size $n$ in $\O(n^3)$ rounds. Further, we investigate the robot's capabilities of detection and hull construction in terms of restricted orientation convexity. We show that a robot without any pebble can detect strong $\O$-convexity in $\O(n)$ rounds, but cannot detect weak $\O$-convexity, not even if provided with a single pebble. Assuming that a robot can construct tiles from scratch and deconstruct previously constructed tiles, we show that the strong $\O$-hull of any given configuration of size $n$ can be constructed in $\O(n^4)$ rounds, even if the robot cannot distinguish constructed from native tiles.}}, author = {{Liedtke, David Jan}}, keywords = {{Robot Exploration, Finite Automaton, Hybrid Model for Programmable Matter, Convex Hull}}, title = {{{Exploration and Convex Hull Construction in the Three-Dimensional Hybrid Model}}}, year = {{2021}}, } @inproceedings{28917, author = {{Feldmann, Michael and Padalkin, Andreas and Scheideler, Christian and Dolev, Shlomi}}, booktitle = {{Stabilization, Safety, and Security of Distributed Systems - 23rd International Symposium, (SSS) 2021, Virtual Event, November 17-20, 2021, Proceedings}}, editor = {{Johnen, Colette and Michael Schiller, Elad and Schmid, Stefan}}, pages = {{484--488}}, publisher = {{Springer}}, title = {{{Coordinating Amoebots via Reconfigurable Circuits}}}, doi = {{10.1007/978-3-030-91081-5\_34}}, volume = {{13046}}, year = {{2021}}, } @misc{28998, author = {{Suermann, Dennis}}, title = {{{Schutz und Stabilisierung von Overlay-Netzwerken mithilfe des Relay-Layers}}}, year = {{2021}}, } @misc{27053, author = {{Everling, Leon}}, title = {{{Selbststabilisierender Bakery Algorithmus für verteilte Systeme}}}, year = {{2021}}, } @misc{27072, author = {{Adsul, Vaibhav}}, title = {{{Peer-to-Peer Matching for Distributed Systems}}}, year = {{2021}}, } @misc{21084, author = {{Werthmann, Julian}}, title = {{{Derandomization and Local Graph Problems in the Node-Capacitated Clique}}}, year = {{2021}}, } @misc{21197, author = {{Mengshi, Ma}}, title = {{{Self-stabilizing Arrow Protocol on Spanning Trees with a Low Diameter}}}, year = {{2021}}, } @misc{21627, author = {{Liedtke, David}}, title = {{{Exploration and Convex Hull Construction in the Three-Dimensional Hybrid Model}}}, year = {{2021}}, } @phdthesis{21628, abstract = {{This thesis considers the realization of distributed data structures and the construction of distributed protocols for self-stabilizing overlay networks. In the first part of this thesis, we provide distributed protocols for queues, stacks and priority queues that serve the insertion and deletion of elements within a logarithmic amount of rounds. Our protocols respect semantic constraints such as sequential consistency or serializability and the individual semantic constraints given by the type (queue, stack, priority queue) of the data structure. We furthermore provide a protocol that handles joining and leaving nodes. As an important side product, we present a novel protocol solving the distributed $k$-selection problem in a logarithmic amount of rounds, that is, to find the $k$-smallest elements among a polynomial number of elements spread among $n$ nodes. The second part of this thesis is devoted to the construction of protocols for self-stabilizing overlay networks, i.e., distributed protocols that transform an overlay network from any initial (potentially illegitimate) state into a legitimate state in finite time. We present protocols for self-stabilizing generalized De Bruijn graphs, self-stabilizing quadtrees and self-stabilizing supervised skip rings. Each of those protocols comes with unique properties that makes it interesting for certain distributed applications. Generalized De Bruijn networks provide routing within a constant amount of hops, thus serving the interest in networks that require a low latency for requests. The protocol for the quadtree guarantees monotonic searchability as well as a geometric variant of monotonic searchability, making it interesting for wireless networks or applications needed in the area of computational geometry. The supervised skip ring can be used to construct a self-stabilizing publish-subscribe system. }}, author = {{Feldmann, Michael}}, title = {{{Algorithms for Distributed Data Structures and Self-Stabilizing Overlay Networks}}}, doi = {{10.17619/UNIPB/1-1113}}, year = {{2021}}, } @inproceedings{30217, author = {{Coy, Sam and Czumaj, Artur and Feldmann, Michael and Hinnenthal, Kristian and Kuhn, Fabian and Scheideler, Christian and Schneider, Philipp and Struijs, Martijn}}, booktitle = {{25th International Conference on Principles of Distributed Systems, OPODIS 2021, December 13-15, 2021, Strasbourg, France}}, editor = {{Bramas, Quentin and Gramoli, Vincent and Milani, Alessia}}, pages = {{11:1–11:23}}, publisher = {{Schloss Dagstuhl - Leibniz-Zentrum für Informatik}}, title = {{{Near-Shortest Path Routing in Hybrid Communication Networks}}}, doi = {{10.4230/LIPIcs.OPODIS.2021.11}}, volume = {{217}}, year = {{2021}}, }