a module $m$ is said to be coretractable if there exists a nonzero homomorphism of every nonzero factor of $m$ into $m$. we prove that all right (left) modules over a ring are coretractable if and only if the ring is morita equivalent to a finite product of local right and left perfect rings.

Let be a commutative ring with 1 and left unitary . In this papers we introduced studied concept P-small compressible (An is said to if can embedded in every of it nonzero submodule Equivalently, there exists monomorphism , retractable for non-zero homomorphism whenever as generalization respectively give some their advantages characterizations examples.

Our new meeting room, the MR Square, was built as a testing ground of a variety of multimedia user interfaces and applications. The MR Square features mixed-reality technologies such as wide-area trackers and tens of head mount displays, as well as one 200-inch and two 150-inch screens. Participants sit and collaborate in fully wired, retractable seats. The MR Square illustrates how state of th...

The sealing performance of the rubber packer is vital importance for subsea retractable connector, and cross-sectional shape one most important factors affecting it. compression distance increased by 19.54% utilizing established two-dimensional numerical model. In addition, a new parameter called anti-shoulder extrusion variable was defined in this paper. Shoulder will not occur when using as c...

Catheter tip dislocation is the main complication of permanent pacemaker implantation using the subclavian vein. In this study of 50 patients we compared the incidence of complications using two endocardial electrodes specially designed to prevent tip dislocation. One catheter had a helical endocardial electrode and the other had retractable nylon barbs. The helical electrode was superior in ev...

This paper details the development and application of the RDS-SUMO-CEASIOM-EDGE rapid-CFD tool. It uses the RDS CAD model as geometry for automated meshing and CFD analysis to produce an aero-data base for control and stability analysis. It is applied to two non-conventional design proposals, an asymmetric twin-prop aircraft and an airliner with rear Open Rotor propulsion, retractable canard, a...

All known algorithms for the Fréchet distance between curves proceed in two steps: first, they construct an efficient oracle for the decision version; second, they use this oracle to find the optimum from a finite set of critical values. We present a novel approach that avoids the detour through the decision version. This gives the first quadratic time algorithm for the Fréchet distance between...