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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Parallel algorithms for normalization
 Journal of symbolic computation 51 (2013), pp.99114 ISSN: 07477171 ISSN: 1095855X 

 English 
 Journal Article 
 Fraunhofer ITWM () 
Abstract
Given a reduced affine algebra A over a perfect field K, we present parallel algorithms to compute the normalization View the MathML sourceA¯ of A. Our starting point is the algorithm of Greuel et al. (2010), which is an improvement of de Jongʼs algorithm ( and ). First, we propose to stratify the singular locus Sing(A)Sing(A) in a way which is compatible with normalization, apply a local version of the normalization algorithm at each stratum, and find View the MathML sourceA¯ by putting the local results together. Second, in the case where K=QK=Q is the field of rationals, we propose modular versions of the global and localtoglobal algorithms. We have implemented our algorithms in the computer algebra system Singular and compare their performance with that of the algorithm of Greuel et al. (2010). In the case where K=QK=Q, we also discuss the use of modular computations of Gröbner bases, radicals, and primary decompositions. We point out that in most examples, the new algorithms outperform the algorithm of Greuel et al. (2010) by far, even if we do not run them in parallel.