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Related papers: Region crossing change on origami and link

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Region crossing change is a local transformation on a knot or link diagram. We show that a region crossing change on a knot diagram is an unknotting operation, and we define the region unknotting numbers for a knot diagram and a knot.

Geometric Topology · Mathematics 2014-01-17 Ayaka Shimizu

In this paper we propose {\it a region choice problem} for a knot projection. This problem is an integral extension of Shimizu's 'region crossing change unknotting operation.' We show that there exists a solution of the region choice…

Geometric Topology · Mathematics 2012-01-24 Kazushi Ahara , Masaaki Suzuki

The region select game, introduced by Ayaka Shimizu, Akio Kawauchi and Kengo Kishimoto, is a game that is played on knot diagrams whose crossings are endowed with two colors. The game is based on the region crossing change moves that induce…

Geometric Topology · Mathematics 2022-05-09 Ahmet Batal , Neslihan Gügümcü

Region crossing change is a local operation on link diagrams. The behavior of region crossing change on $S^2$ is well understood. In this paper, we study the behavior of (modified) region crossing change on higher genus surfaces.

Geometric Topology · Mathematics 2026-05-26 Jiawei Cheng , Zhiyun Cheng , Jinwen Xu , Jieyao Zheng

We introduce a local move on a link diagram named a region freeze crossing change which is close to a region crossing change, but not the same. We study similarity and difference between region crossing change and region freeze crossing…

Geometric Topology · Mathematics 2016-06-23 Ayumu Inoue , Ryo Shimizu

In this paper, we prove that region crossing change on a link diagram is an unknotting operation if and only if the link is proper. A description of the behavior of region crossing change on link diagrams is given. Furthermore we also…

Geometric Topology · Mathematics 2015-06-03 Zhiyun Cheng

In a recent work of Ayaka Shimizu$^{[5]}$, she defined an operation named region crossing change on link diagrams, and showed that region crossing change is an unknotting operation for knot diagrams. In this paper, we prove that region…

Geometric Topology · Mathematics 2015-05-20 Zhiyun Cheng , Hongzhu Gao

A region crossing change at a region of a spatial-graph diagram is a transformation changing every crossing on the boundary of the region. In this paper, it is shown that every spatial graph consisting of theta-curves can be unknotted by…

Geometric Topology · Mathematics 2019-10-29 Ayaka Shimizu , Rinno Takahashi

Region extraction is a very common task in both Computer Science and Engineering with several applications in object recognition and motion analysis, among others. Most of the literature focuses on regions delimited by straight lines, often…

Numerical Analysis · Mathematics 2021-12-07 Pablo Antolin , Annalisa Buffa , Emiliano Cirillo

Shimizu introduced a region crossing change unknotting operation for knot diagrams. As extensions, two integral region choice problems were proposed and the existences of solutions of the problems were shown for all non-trivial knot…

Geometric Topology · Mathematics 2021-03-31 Tomomi Kawamura

We introduce a topological combinatorial game called the Region Smoothing Swap Game. The game is played on a game board derived from the connected shadow of a link diagram on a (possibly non-orientable) surface by smoothing at crossings.…

Combinatorics · Mathematics 2019-09-30 Allison Henrich , Inga Johnson , Jonah Ostroff

Region crossing change for a knot or a proper link is an unknotting operation. In this paper, we provide a sharp upper bound on the region unknotting number for a large class of torus knots and proper links. Also, we discuss conditions on…

Geometric Topology · Mathematics 2013-05-30 Vikash Siwach , Madeti Prabhakar

Rigid origami has shown potential in large diversity of practical applications. However, current rigid origami crease pattern design mostly relies on known tessellations. This strongly limits the diversity and novelty of patterns that can…

Graphics · Computer Science 2023-05-01 Jeremia Geiger , Karolis Martinkus , Oliver Richter , Roger Wattenhofer

A quadruple crossing is a crossing in a projection of a knot or link that has four strands of the knot passing straight through it. A quadruple crossing projection is a projection such that all of the crossings are quadruple crossings. In a…

Geometric Topology · Mathematics 2019-02-20 Colin Adams

In this short note, we investigate the effect of region crossing change on planar trivalent graphs.

Geometric Topology · Mathematics 2025-09-03 Zhiyun Cheng

This paper shows a cut along a crease on an origami sheet makes simple modeling of popular traditional basic folds such as a squash fold in computational origami. The cut operation can be applied to other classical folds and significantly…

Computational Geometry · Computer Science 2022-01-04 Tetsuo Ida , Hidekazu Takahashi

A set of regions of a link projection is said to be isolated if any pair of regions in the set share no crossings. The isolate-region number of a link projection is the maximum value of the cardinality for isolated sets of regions of the…

Geometric Topology · Mathematics 2024-10-08 Tumpa Mahato , Ayaka Shimizu

Origami, the traditional art of paper folding, has revolutionized science and technology in recent years and has been found useful in various real-world applications. In particular, origami-inspired structures have been utilized for…

Soft Condensed Matter · Physics 2025-06-19 Rongxuan Li , Gary P. T. Choi

We introduce a computational origami problem which we call the segment folding problem: given a set of $n$ line-segments in the plane the aim is to make creases along all segments in the minimum number of folding steps. Note that a folding…

Computational Geometry · Computer Science 2022-01-17 Takashi Horiyama , Fabian Klute , Matias Korman , Irene Parada , Ryuhei Uehara , Katsuhisa Yamanaka

Origami is the art of paper folding, and it borrows its name from two Japanese words \emph{ori} and \emph{kami}. In Japanese, {ori} means folding, and the paper is called {kami}. While origami is just a hobby to most, there is a lot more to…

History and Overview · Mathematics 2025-03-18 Archana S. Morye
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