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1.
Erhard Aichinger 《Algebra Universalis》2000,44(1-2):105-121
In [4], J.Hagemann and C. Herrmann have characterized those algebras that are strictly k-affine complete for all . In the present note, we prove a very similar characterization using the term condition commutator. Received June 15, 1999; accepted in final form March 3, 2000. 相似文献
2.
Erhard Aichinger Peter Mayr John D. P. Meldrum Gary L. Peterson Stuart D. Scott 《Monatshefte für Mathematik》2011,162(2):119-142
We study singly-generated wavelet systems on ${\mathbb {R}^2}$ that are naturally associated with rank-one wavelet systems on the Heisenberg group N. We prove a necessary condition on the generator in order that any such system be a Parseval frame. Given a suitable subset I of the dual of N, we give an explicit construction for Parseval frame wavelets that are associated with I. We say that ${g\in L^2(I\times \mathbb {R})}$ is Gabor field over I if, for a.e. ${\lambda \in I}$ , |??|1/2 g(??, ·) is the Gabor generator of a Parseval frame for ${L^2(\mathbb {R})}$ , and that I is a Heisenberg wavelet set if every Gabor field over I is a Parseval frame (mother-)wavelet for ${L^2(\mathbb {R}^2)}$ . We then show that I is a Heisenberg wavelet set if and only if I is both translation congruent with a subset of the unit interval and dilation congruent with the Shannon set. 相似文献
3.
Pierre-Anton Aichinger Martin Michel Colin Servais Marie-Lise Dillmann Martine Rouvet Nicola D''Amico Ralf Zink Henning Klostermeyer David S. Horne 《Colloids and surfaces. B, Biointerfaces》2003,31(1-4):243-255
Fermentation of a reconstituted skim milk concentrate (8% protein) was investigated to elucidate the effects of various fermentation parameters on the structural, rheological and visual (wheying-off) properties of the resulting gels (pH 4.60). Fermentation trials were performed with non-exocellular polysaccharide-producing strains of Streptococcus thermophilus at various fermentation temperatures and at various chymosin levels. Oscillatory vane rheometry carried out on the intact gels (at 4 °C) showed that the level of chymosin had a significant impact on the gel strength (storage modulus G′). This can be explained by the arrangement of casein micelles into more compact aggregates and the enhanced fusion of aggregated casein micelles as revealed by transmission electron microscopy for the gels fermented with chymosin. Wheying-off of the stirred gels as measured by a centrifugation test (at 4 °C) and pore size of the intact gel structures investigated by scanning electron microscopy both increased with increasing level of chymosin and increasing fermentation temperature (resulting in an increase in acidification rate). A higher level of syneresis (wheying-off) is explained by the larger pore size, since larger pores present a lower resistance to the outflow of whey from the gel. 相似文献
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Erhard Aichinger 《Monatshefte für Mathematik》2004,143(2):89-103
We show that the variety of near-rings and the variety of zero-symmetric near-rings are both generated by their finite members. We show this in a more general context: if a variety
is generated by a class of algebras
, then the variety of
-composition algebras is generated by the class of all full function algebras on direct products of finitely many copies of algebras in
. 相似文献
6.
Erhard Aichinger 《Algebra Universalis》2002,47(4):425-434
For each we exhibit a finite algebra R
k such that R
k is k-affine complete, but not (k+1)-affine complete; this means that every k-ary congruence preserving function on R
k lies in , but there is a (k +1)-ary congruence preserving function of R
k that does not lie in .
Received September 27, 2001; accepted in final form February 9, 2002. 相似文献
7.
Erhard Aichinger 《Algebra Universalis》2017,78(3):355-361
We consider clones on countable sets. If such a clone has quasigroup operations, is locally closed and countable, then there is a function \({f : \mathbb{N} \rightarrow \mathbb{N}}\) such that the n-ary part of C is equal to the n-ary part of Pol \({{\rm Inv}^{[f(n)]} C}\), where \({{\rm Inv}^{[f(n)]} C}\) denotes the set of f(n)-ary invariant relations of C. 相似文献
8.
We establish several properties of Bulatov’s higher commutator operations in congruence permutable varieties. We use higher
commutators to prove that for a finite nilpotent algebra of finite type that is a product of algebras of prime power order
and generates a congruence modular variety, affine completeness is a decidable property. Moreover, we show that in such algebras,
we can check in polynomial time whether two given polynomial terms induce the same function. 相似文献
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