In this paper, we present several methods for the construction of elliptic curves with large torsion group and positive rank
over number fields of small degree. We also discuss potential applications of such curves in the elliptic curve factorization
. F . Wehrfritz . On the holomorphs of soluble groups of finite rank . J. Pure Appl. Algebra , 4 : 55 – 69 , 1974 .  B. A. F . Wehrfritz . Group and Ring Theoretic Properties of Polycyclic Groups . Springer , London 2009 .  B. A. F
journal performance should be compared within the same field.
This field specificity may be considerably diminished when using rank-normalized IF, suggested by us (Pudovkin and Garfield 2004 ). For any journal j the rank normalized impact factor
1990 ). Each time a citation analysis is carried out to identify or to rank important sources in a given subject, it has benefited both theoreticians and practitioners in planning and designing of information systems.
The result of citation
If f(r) is the number of contributions of an author or rank r, then it is shown that f(r) is proportional to r–
, where >0. The model is dependent on the definitions of a contribution and rank of an author. Three estimation procedures are illustrated and four other scientific productivity studies and two data sets on Canadian Mathematicians are shown to adequately fit this rank-frequency relationship.
different variables, such as professional rank and age, on authorship practices has also been explored in the literature, noting that scientists tend to sign more as last author and less often as first author as they get older (Gingras et al. 2008 ) and as
an essential matter.
This work introduces a proposal to improve the categorization of Scopus database journals included at the SCImago Journal and Country Rank (SJR) portal (SCImago Lab 2007 ) using journal