Please use this identifier to cite or link to this item: http://hdl.handle.net/10553/51604
 Title: Corrigendum to A new proof of the degeneracy property of the longest-edge n-section refinement scheme for triangular meshes [Applied Mathematics and Computation 219 (4) (2012) 2342-2344] Authors: Perdomo, Francisco Plaza, Ángel UNESCO Clasification: 120603 Análisis de errores Issue Date: 2015 Journal: Applied Mathematics and Computation Abstract: © 2015 Elsevier Inc. In the article [Applied Mathematics and Computation 219 (4) (2012) 2342-2344] there exists a minor error in the case n = 4. We correct the error and give a proof for the case n = 4. The argument in reference  used that “Since [Formula prsented] then [Formula prsented]”. It should be noted that the later inequality does not hold. Notice that [Formula prsented]. So, if [Formula prsented] then [Formula prsented]. Even though, the subsequent argument in  is correct for the case n > 4. But, the case n = 4 needs a closer look. Let us consider the semi-circle passing through point z and tangent to the real axis at point z = 1/2, see Fig. 1. Let r be the radius of the circle, so its center is at point [Formula prsented]. Then the equation of the circle is [Formula prsented] that is [Formula prsented]. Now, using that [Formula prsented] it follows[Formula prsented] This circle is invariant under the action of the Moebius transform [Formula prsented]: If we change [Formula prsented] in Eq. (1), it is obtained: [Formula prsented]where after clearing denominators we have [Formula prsented] The Moebius transform [Formula prsented] has a unique fixed point, [Formula prsented]. The sequence {z, w(z), w 2 (z), …} is on the semicircle and {Im z, Im w(z), Im w 2 (z), …} is decreasing. Hence it has an accumulation point which corresponds to the fixed point [Formula prsented]. This completes the argument of the paper  for the case n = 4. URI: http://hdl.handle.net/10553/51604 ISSN: 0096-3003 DOI: 10.1016/j.amc.2015.03.083 Source: Applied Mathematics And Computation [ISSN 0096-3003], v. 260, p. 412-413 Appears in Collections: Artículos

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