http://dspace.nbuv.gov.ua:80/handle/123456789/150359 2026-04-15T03:53:42Z http://dspace.nbuv.gov.ua:80/handle/123456789/154638 A new characterization of groups with central chief factors Juriaans, O.S.; Raphael, D.M. In [1] it is proved that a locally nilpotent group is an (X)-group arising the question whether the converse holds. In this paper we derive some interesting properties and give a complete characterization of (X)-groups. As a consequence we obtain a new characterization of groups whose chief factors are central and it follows also that there exists an (X)-group which is not locally nilpotent, thus answering the question raised in [1]. We also prove a result which extends one on finitely generated nilpotent groups due to Gruenberg. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/154630 A Morita context related to finite groups acting partially on a ring Guzman, J.A.; Lazzarin, J. In this paper we consider partial actions of groups on rings, partial skew group rings and partial fixed rings. We study a Morita context associated to these rings, α-partial Galois extensions and related aspects. Finally, we establish conditions to obtain a Morita equivalence between Rα and R⋆αG. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/154623 On speciality of Jordan brackets Shestakov, I. We conjecture a criterium of speciality for Jordan superalgebras of brackets that generalizes the corresponding criterium for Jordan Poisson superalgebras from [8]. We prove the necessarity condition of the criterium. The question on its sufficiency remains open. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/154622 Semisimple group codes and dihedral codes Dutra, F.S.; Ferraz, R.A.; Milies, C.P. We consider codes that are given as two-sided ideals in a semisimple finite group algebra FqG defined by idempotents constructed from subgroups of G in a natural way and compute their dimensions and weights. We give a criterion to decide when these ideals are all the minimal two-sided ideals o f FqG in the case when G is a dihedral group and extend these results also to a family of quaternion group codes. In the final sectio n, we give a method of decoding; i.e., of finding and correcting eve ntual transmission errors. 2009-01-01T00:00:00Z