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论文类型：期刊论文

发表时间：2017-01-01

发表刊物：JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS

收录刊物：SCIE

卷号：26

期号：1

ISSN号：0218-2165

关键字：Warping degree; descending diagram; unknotting number; quandle; quandle coloring; welded datum; Gordian distance

摘要：The unknotting number of a welded knot is considered. First, we obtain an upperbound of the unknotting number of a welded knot by using the warping degree method. Further, we introduce a standard welded torus knot with welded datum and obtain an upper bound of the unknotting number by an algorithm with warping degree method. Secondly, we get a lower bound of the unknotting number of a welded knot by Alexander quandle colorings. Finally, we give a definition of Gordian distance for welded knots analogous to the classical case.