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Z. Abdulhadi 《Journal of Mathematical Analysis and Applications》2008,338(1):705-709
In this paper, we show the existence of Landau constant for biharmonic mappings of the form F(z)=2|z|G(z)+K(z), |z|<1, where G and K are harmonic. 相似文献
2.
In this paper, we show the existence of Landau constant for functions with logharmonic Laplacian of the form F(z) = ∣z∣2L(z) + K(z), ∣z∣ < 1, where L is logharmonic and K is harmonic. Moreover, the problem of minimizing the area is solved 相似文献
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4.
《代数通讯》2013,41(2):587-604
ABSTRACT In this paper we calculate presentations for some natural monoids of transformations on a chain X n = {1 < 2 <?s < n}. First we consider 𝒪𝒟 n [𝒫𝒪𝒟 n ], the monoid of all full [partial] transformations on X n that preserve or reverse the order. Two other monoids of partial transformations on X n we look at are 𝒫𝒪𝒫 n and 𝒫𝒪? n –-the elements of the first preserve the orientation and the elements of the second preserve or reverse the orientation. 相似文献
5.
Given a subgroup G of the symmetric group S
n
on n letters, a semigroup S of transformations of X
n
is G-normal if G
S
=G, where G
S
consists of all permutations h∈S
n
such that h
−1
fh∈S for all f∈S. A semigroup S is G-normax if it is a maximal semigroup in the set of all G-normal semigroups.
In 1996, I. Levi showed that the alternating group A
n
can not serve as the group G
S
for any semigroup of total transformations of X
n
. In 2000 and 2001, I. Levi, D.B. McAlister and R.B. McFadden described all A
n
-normal semigroups of partial transformations of X
n
. Also, in 1994, I. Levi and R.B. McFadden described all S
n
-normal semigroups.
In this paper, we show that the dihedral group D
n
may serve as the group G
S
for semigroups of transformations of X
n
. We characterize a large class of D
n
-normax semigroups and describe certain D
n
-normal semigroups. 相似文献
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