Designing low-congestion sparse networks

2012 Fiscal Year Final Research Report

• Project/Area Number: 23800004
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Fundamental theory of informatics
• Research Institution: Japan Advanced Institute of Science and Technology (2012); Tohoku University (2011)
• Principal Investigator: OTACHI Yota 北陸先端科学技術大学院大学, 情報科学研究科, 助教 (80610196)
• Project Period (FY): 2011 – 2012
• Keywords: 全域木混雑度問題 / グラフアルゴリズム / 計算複雑性

Research Abstract

We studied the problem of designing low-congestion sparse networks. Especially, we studied the computational complexity of an optimization problem on graphs called “the spanning tree congestion problem.” We presented sharp contrasts between hard cases and easy cases. We also investigated the parameterized complexity of the problem and gave some dichotomies for the problem. Our results imply the problem is really hard to solve for most of the cases. Thus we designed some heuristic and approximation algorithm and obtained some partial results.

Research Products

• [Journal Article] Approximating the path-distance-width for AT-free graphs and graphs in related classes (2012)
  • Author(s): Yota Otachi, Toshiki Saitoh, Katsuhisa Yamanaka, Shuji Kijima, Yoshio Okamoto, Hirotaka Ono, Yushi Uno, and Koichi Yamazaki
  • Journal Title: Discrete Applied Mathematics
  • DOI: DOI:10.1016/j.dam.2012.11.015
  • Peer Reviewed
• [Journal Article] Subgraph isomorphism in graph classes (2012)
  • Author(s): Shuji Kijima, Yota Otachi, Toshiki Saitoh, and Takeaki Uno
  • Journal Title: Discrete Mathematics Volume: 312 Pages: 3164-3173
  • Peer Reviewed
• [Journal Article] On bipartite powers of bigraphs (2012)
  • Author(s): Yoshio Okamoto, Yota Otachi, and Ryuhei Uehara
  • Journal Title: Discrete Mathematics & Theoretical Computer Science 14:2 (2012) Pages: 11-20
  • URL: http://www.dmtcs.org/dmtcs-ojs/index.php/dmtcs/article/view/2132
  • Peer Reviewed
• [Journal Article] Efficient enumeration of ordered trees with k leaves (2012)
  • Author(s): Katsuhisa Yamanaka, Yota Otachi, and Shin-ichi Nakano
  • Journal Title: Theoretical Computer Science Volume: 442 Pages: 22-27
  • DOI: DOI:10.1016/j.tcs.2011.01.017
  • Peer Reviewed
• [Journal Article] Parameterized complexity of the spanning tree congestion problem (2012)
  • Author(s): Hans L. Bodlaender, Fedor V. Fomin, Petr A. Golovach, Yota Otachi, and Erik Jan van Leeuwen
  • Journal Title: Algorithmica Volume: 64 Pages: 85‐111
  • DOI: DOI:10.1007/s00453-011-9565-7
  • Peer Reviewed
• [Journal Article] Enumerating all rooted trees including k leaves (2012)
  • Author(s): Masanobu Ishikawa, Katsuhisa Yamanaka, Yota Otachi, and Shin-ichi Nakano
  • Journal Title: IEICE Transactions Volume: E95-D Pages: 763-768
  • DOI: DOI:10.1587/transinf.E95.D.763
  • Peer Reviewed
• [Journal Article] Random generation and enumeration of bipartite permutation graphs (2012)
  • Author(s): Toshiki Saitoh, Yota Otachi, Katsuhisa Yamanaka, and Ryuhei Uehara
  • Journal Title: Journal of Discrete Algorithms Volume: 10 Pages: 84-97
  • DOI: DOI:10.1016/j.jda.2011.11.001
  • Peer Reviewed
• [Journal Article] Hardness results and an exact exponential algorithm for the spanning tree congestion problem (2011)
  • Author(s): Yoshio Okamoto, Yota Otachi, Ryuhei Uehara, and Takeaki Uno
  • Journal Title: Journal of Graph Algorithms and Applications Volume: 15 Pages: 727-751
  • DOI: DOI:10.7155/jgaa.00246
  • Peer Reviewed
• [Journal Article] The path-distance-width of hypercubes
  • Author(s): Yota Otachi
  • Journal Title: Discussiones Mathematicae Graph Theory
  • DOI: 10.7151/dmgt.1682
  • Peer Reviewed
• [Presentation] Base location problems for base-monotone regions (2013)
  • Author(s): Jinhee Chun, Takashi Horiyama, Takehiro Ito, Natsuda Kaothanthong, Hirotaka Ono, Yota Otachi, Takeshi Tokuyama, Ryuhei Uehara, and Takeaki Uno
  • Organizer: 7th International Workshop on Algorithms and Computation (WALCOM 2013)
  • Place of Presentation: Kharagpur, India
  • Year and Date: 20130214-16
• [Presentation] A 4.31-approximation for the geometric unique coverage problem on unit disks (2012)
  • Author(s): Takehiro Ito, Shin-ichi Nakano, Yoshio Okamoto, Yota Otachi, Ryuhei Uehara, Takeaki Uno, and Yushi Uno
  • Organizer: 23rd International Symposium on Algorithms and Computation (ISAAC 2012)
  • Place of Presentation: Taipei, Taiwan
  • Year and Date: 20121219-21
• [Presentation] Extending partial representations of subclasses of chordal graphs (2012)
  • Author(s): Pavel Klavik, Jan Kratochvil, Yota Otachi, and Toshiki Saitoh
  • Organizer: 23rd International Symposium on Algorithms and Computation (ISAAC 2012)
  • Place of Presentation: Taipei, Taiwan
  • Year and Date: 20121219-21
• [Presentation] Isomorphism for graphs of bounded connected-path-distance-width (2012)
  • Author(s): Yota Otachi
  • Organizer: 23rd International Symposium on Algorithms and Computation (ISAAC 2012)
  • Place of Presentation: Taipei, Taiwan
  • Year and Date: 20121219-21
• [Presentation] A polynomial-time approximation scheme for the geometric unique coverage problem on unit squares (2012)
  • Author(s): Takehiro Ito, Shin-ichi Nakano, Yoshio Okamoto, Yota Otachi, Ryuhei Uehara, Takeaki Uno, and Yushi Uno
  • Organizer: 13th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2012)
  • Place of Presentation: Helsinki, Finland
  • Year and Date: 20120704-06