In this paper, we investigate polyform modules and introduce the notion of relatively
polyform modules over a ring R. Some new characterizations and properties of polyform …

An R-module M is called a polyform module if every essential submodule of M is rational.
The main objective of this paper is to introduce a new concept of modules named fully …

Let R be a ring and M be an R-module. In this paper we investigate modules M such that
every (simple) cosingular R-module is M-projective. We prove that every simple cosingular …

Let R be a ring, na fixed nonnegative integer and F n the class of all left R-modules of flat
dimension at most n. A left R-module M is called n-copure projective if Ext R 1 (M, F)= 0 for …

In this paper, we provide several new characterizations of the maximal right ring of quotients
of a ring by using the relatively dense property. As a ring is embedded in its maximal right …

In this paper, we investigate the notions of X⊥‐projective, X‐injective, and X‐flat modules
and give some characterizations of these modules, where X is a class of left modules. We …

J. Korean Math. Soc. 46 (2009), No. 1, pp. 51–58 Page 1 J. Korean Math. Soc. 46 (2009), No. 1,
pp. 51–58 THE CLASS OF MODULES WITH PROJECTIVE COVER YONGHUA GUO …

Following, a ring R is called right almost-perfect if every flat right R-module is projective
relative to R. In this article, we continue the study of these rings and will find some new …

In Bican et al., it is proved that all modules over an arbitrary ring have flat covers. In this
article, we shall study rings over which flat covers of finitely generated modules are …

ABSTRACT. Let R be a ring with identity and M a right R-module. Let E (M) denote the
injective hull of M and Z'(M):= MORadE (M). We say M has*-radical if Z (M)= RadM. In this …