Several characterizations are given of (Zelmanowitz) regular modules among the torsionless modules, the locally projective modules, the nonsingular modules, and modules where certain submodules are pure. Along the way, a version of the unimodular row lemma for torsionless modules is given, and it is shown that a regular ring is left self-injective if and only if every nonsingular left module is...

Existing self-reconfigurable robots achieve connections and disconnections by a separate drive of the docking system. In this paper, we present a new docking system with which the connections and disconnections are driven by locomotion actuators, without the need for a separate drive, which reduces the weight and the complexity of the modules. This self-reconfigurable robot consists of two type...

In this paper, we investigate various kinds of extensions of twin-good rings. Moreover, we prove that every element of an abelian neat ring R is twin-good if and only if R has no factor ring isomorphic to‌ Z2  or Z3. The main result of [24] states some conditions that any right self-injective ring R is twin-good. We extend this result to any regular Baer ring R by proving that every elemen...

A key challenge in self-reconfigurable robotics is the development and validation of complex distributed behaviors and control algorithms, particularly for large populations of modules. Physics-based, 3D simulators play a vital role in helping researchers overcome this challenge by allowing them to approximate the physical interactions of connected, autonomous robotic systems with one another a...

we investigate some properties of approximately quasi inner generalized dynamics and quasi approximately inner generalized derivations on modules. in particular, we prove that if a is a c*-algebra, is the generator of a generalized dynamics on an a-bimodule m satisfying and there exist two sequences of self adjoint elements in a such that for all in a core for , , then is approximately quasi in...

For a locally presentable abelian category B with projective generator, we construct the derived and contraderived model structures on of complexes, proving in particular existence enough homotopy complexes objects. We also show that D(B) is generated, as triangulated coproducts, by generator B. Grothendieck A, injective coderived complexes. Assuming Vopěnka's principle, prove D(A) products, co...

Introduction Over the past several years there has been significant interest in adopting on-farm manure anaerobic digesters in Ontario. The potential for sustainable energy production, while reducing greenhouse gas (GHG) emissions, mitigating pathogens and odours, and increasing ionized nutrients in the digestate, has made anaerobic digestion an attractive option for manure management. The biog...

in this errata, we reconsider and modify two propositions and their corollaries which were written on epi-retractable and co-epi-retractable modules.