For any (unital) exchange ring R whose finitely generated projective modules satisfy the separative cancellation property (A ⊕ A ∼ = A ⊕ B ∼ = B ⊕ B =⇒ A ∼ = B), it is shown that all invertible square matrices over R can be diagonalized by elementary row and column operations. Consequently, the natural homomorphism GL 1 (R) → K 1 (R) is surjective. In… (More)
Storrer introduced the epimorphic hull of a commutative semiprime ring R and showed that it is (up to isomorphism) the unique essential epic von Neumann regular extension of R. In the case when R = C(X) with X a Tychonoff space, we show that the embedding induced by a dense subspace of X is always essential. This simplifies the search for spaces whose… (More)
We find the injective hulls of partially ordered monoids in the category whose objects are po-monoids and submultiplicative order-preserving functions. These injective hulls are with respect to a special class of monics called " embeddings ". We show as well that the injective objects with respect to these embeddings are precisely the quantales.
A von Neumann regular extension of a semiprime ring naturally deenes a epimorphic extension in the category of rings. These are studied, and four natural examples are considered, two in commutative ring theory, and two in rings of continuous functions.
We study and, in a number of cases, classify completely the limit closures in the category of commutative rings of subcategories of integral domains.
In this paper we proposed a static analysis framework to classify the android malware. The three different feature likely (a) opcode (b) method and (c) permissions are extracted from the each android .apk file. The dominant attributes are aggregated by modifying two different ranked feature methods such as ANOVA to Extended ANOVA (X-ANOVA) and Wann-Whiteney… (More)
We continue our investigations into absolute CR-epic spaces. Given a continuous function f : X / / Y , with X absolute CR-epic, we search for conditions which imply that Y is also absolute CR-epic. We are particularly interested in the cases when X is a dense subset of Y and when f is a quotient mapping. To answer these questions, we consider issues of… (More)
If X is a Tychonoff space then its P-coreflection X δ is a Tychonoff space that is a dense subspace of the realcompact space (υX) δ , where υX denotes the Hewitt realcompactification of X. We investigate under what conditions X δ is C-embedded in (υX) δ , i.e. under what conditions υ(X δ) = (υX) δ. An example shows that this can fail for the product of a… (More)
Given a topological space X, K(X) denotes the upper semi-lattice of its (Hausdorff) compactifications. Recent studies have asked when, for αX ∈ K(X), the restriction homomorphism ρ : C(αX) → C(X) is an epimorphism in the category of commutative rings. This article continues this study by examining the sub-semilattice, K epi (X), of those compactifications… (More)