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        <identifier>oai:drops-oai.dagstuhl.de:19904</identifier>
        <datestamp>2024-05-31T08:33:44Z</datestamp>
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          <dc:title>Brief Announcement: Collision Detection for Modular Robots - It Is Easy to Cause Collisions and Hard to Avoid Them</dc:title>
          <dc:creator>Gupta, Siddharth</dc:creator>
          <dc:creator>van Kreveld, Marc</dc:creator>
          <dc:creator>Michail, Othon</dc:creator>
          <dc:creator>Padalkin, Andreas</dc:creator>
          <dc:subject>Modular robots</dc:subject>
          <dc:subject>Collision detection</dc:subject>
          <dc:subject>Computational Geometry</dc:subject>
          <dc:subject>Complexity</dc:subject>
          <dc:description>We consider geometric collision-detection problems for modular reconfigurable robots. Assuming the nodes (modules) are connected squares on a grid, we investigate the complexity of deciding whether collisions may occur, or can be avoided, if a set of expansion and contraction operations is executed. We study both discrete- and continuous-time models, and allow operations to be coupled into a single parallel group. Our algorithms to decide if a collision may occur run in O(n²log² n) time, O(n²) time, or O(nlog² n) time, depending on the presence and type of coupled operations, in a continuous-time model for a modular robot with n nodes. To decide if collisions can be avoided, we show that a very restricted version is already NP-complete in the discrete-time model, while the same problem is polynomial in the continuous-time model. A less restricted version is NP-hard in the continuous-time model.</dc:description>
          <dc:publisher>Schloss Dagstuhl – Leibniz-Zentrum für Informatik</dc:publisher>
          <dc:contributor>Siddharth Gupta and Marc van Kreveld and Othon Michail and Andreas Padalkin</dc:contributor>
          <dc:date>2024</dc:date>
          <dc:relation>Is Part Of LIPIcs, Volume 292, 3rd Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2024)</dc:relation>
          <dc:type>InProceedings</dc:type>
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          <dc:identifier>doi:10.4230/LIPIcs.SAND.2024.26</dc:identifier>
          <dc:identifier>urn:nbn:de:0030-drops-199044</dc:identifier>
          <dc:identifier>https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SAND.2024.26</dc:identifier>
          <dc:language>eng</dc:language>
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