### Abstract

Let C be a collection of n Jordan regions in the plane in general position, such that each pair of their boundaries intersect in at most s points, where s is a constant. If the boundaries of two sets in C cross exactly twice, then their intersection points are called regular vertices of the arrangement A(C). Let R(C) denote the set of regular vertices on the boundary of the union of C. We present several bounds on |R(C)|, determined by the type of the sets of C. (i) If each set of C is convex, then [R(C)[ = O(n^{1.5}+^{ε}) for any ε > 0.^{4} (ii) If C consists of two collections C_{1} and C_{2} where C_{1} is a collection of n convex pseudo-disks in the plane (closed Jordan regions with the property that the boundaries of any two of them intersect at most twice), and C_{2} is a collection of polygons with a total of n sides, then |R(C)| = O(n^{4/3}), and this bound is tight in the worst case. (iii) If no further assumptions are made on the sets of C, then we show that there is a positive integer t that depends only on s such that |R(C)| = O(n^{2-1}/^{t}).

Original language | English (US) |
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Title of host publication | Algorithm Theory — SWAT 1998 - 6th Scandinavian Workshop on Algorithm Theory, Proceedings |

Editors | Stefan Arnborg, Lars Ivansson |

Publisher | Springer Verlag |

Pages | 322-334 |

Number of pages | 13 |

ISBN (Print) | 3540646825, 9783540646822 |

DOIs | |

State | Published - 1998 |

Event | 6th Scandinavian Workshop on Algorithm Theory, SWAT 1998 - Stockholm, Sweden Duration: Jul 8 1998 → Jul 10 1998 |

### Publication series

Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 1432 |

ISSN (Print) | 0302-9743 |

ISSN (Electronic) | 1611-3349 |

### Other

Other | 6th Scandinavian Workshop on Algorithm Theory, SWAT 1998 |
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Country | Sweden |

City | Stockholm |

Period | 7/8/98 → 7/10/98 |

### ASJC Scopus subject areas

- Theoretical Computer Science
- Computer Science(all)

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## Cite this

*Algorithm Theory — SWAT 1998 - 6th Scandinavian Workshop on Algorithm Theory, Proceedings*(pp. 322-334). (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); Vol. 1432). Springer Verlag. https://doi.org/10.1007/BFb0054379