Search results for "MATEMATICA APLICADA"
showing 7 items of 277 documents
ON SYLOW NORMALIZERS OF FINITE GROUPS
2013
[EN] The paper considers the influence of Sylow normalizers, i.e. normalizers of Sylow subgroups, on the structure of finite groups. In the universe of finite soluble groups it is known that classes of groups with nilpotent Hall subgroups for given sets of primes are exactly the subgroup- closed saturated formations satisfying the following property: a group belongs to the class if and only if its Sylow normalizers do so. The paper analyzes the extension of this research to the universe of all finite groups.
On second minimal subgroups of Sylow subgroups of finite groups
2011
A subgroup H of a finite group G is a partial CAP-subgroup of G if there is a chief series of G such that H either covers or avoids its chief factors. Partial cover and avoidance property has turned out to be very useful to clear up the group structure. In this paper, finite groups in which the second minimal subgroups of their Sylow p-subgroups, p a fixed prime, are partial CAP-subgroups are completely classified.
On some classes of supersoluble groups
2007
[EN] Finite groups G for which for every subgroup H and for all primes q dividing the index |G:H| there exists a subgroup K of G such that H is contained in K and |K:H|=q are called Y-groups. Groups in which subnormal subgroups permute with all Sylow subgroups are called PST-groups. In this paper a local version of the Y-property leading to a local characterisation of Y-groups, from which the classical characterisation emerges, is introduced. The relationship between PST-groups and Y-groups is also analysed.
Finite groups with all minimal subgroups solitary
2016
We give a complete classification of the finite groups with a unique subgroup of order p for each prime p dividing its order. All the groups considered in this paper will be finite. One of the most fruitful lines in the research in abstract group theory during the last years has been the study of groups in which the members of a certain family of subgroups satisfy a certain subgroup embedding property. The family of the subgroups of prime order (also called minimal subgroups) has attracted the interest of many mathematicians. For example, a well-known result of Itˆo (see [8, Kapitel III, Satz 5.3; 9]) states that a group of odd order with all minimal subgroups in the center is nilpotent. Th…
Improved pairwise comparison transitivity using strategically selected reduced information
2021
To judge the mutual relationship among elements, pairwise comparisons (PC) are widely used in decision modelling. PC is especially useful when the involved elements are intangible. Frequently, the number of elements to be compared may be very large. When dealing with n elements, the number of PCs is, under the reciprocity hypothesis, n(n − 1)/2. PCs are compiled in so-called pairwise comparison matrices (PCM). In the presence of missing entries due to uncertainty or lack of information, decision-making must be performed from the available incomplete information. Making all the comparisons in the complete case may be tedious, strenuous and time-consuming for the actors, may blur the body of …
Optimal Volume for Concert Halls Based on Ando’s Subjective Preference and Barron Revised Theories
2014
[EN] The Ando-Beranek s model, a linear version of Ando s subjective preference theory, obtained by the authors in a recent work, was combined with Barron revised theory. An optimal volume region for each reverberation time was obtained for classical music in symphony orchestra concert halls. The obtained relation was tested with good agreement with the top rated halls reported by Beranek and other halls with reported anomalies.
Some characterisations of groups in which normality is a transitive relation by means of subgroup embedding properties
2018
[EN] In this survey we highlight the relations between some subgroup embedding properties that characterise groups in which normality is a transitive relation in certain universes of groups with some finiteness properties.