In this paper we will prove several not so well known conditions for a quadrilateral to have an incircle. Four of these are different excircle versions of the characterizations due to Wu and Vaynshtejn.

In this paper, left and two sides tangential filtering decompositions are introduced. The filtering preconditioner constructed by the decomposition is combined with classical ILU(0) preconditioner in multiplicative ways to produce composite preconditioners. Analysis show that the composite preconditioners benefit from each of the preconditioners. On the filtering vector, we reveal that ones is ...

recognition of relationship between the present day stress state and fractures is very important in fractured reservoirs. fractures that are parallel or oblique to maximum horizontal stress have more tendencies to tensile deformation and tensile deformed fractures will be more permeable. the dalan formation is one of the main gas reservoirs of iran witch most of the production from this formati...

The sophisticated receptive field organization of motion-sensitive tangential cells in the visual system of the blowfly Calliphora vicina matches the structure of particular optic flow fields. Hypotheses on the tuning of particular tangential cells to rotatory self-motion are based on local motion measurements. So far, tangential cells have never been tested with global optic flow stimuli. Ther...

When we manipulate objects in everyday tasks, there are variations in the shape of the grasped surfaces, and the loads that potentially destabilize the grasp include time-varying linear forces and torques tangential to the grasped surfaces. Previous studies of the control of fingertip forces for grasp stability have dealt principally with flat grip surfaces and linear force loads. Here, we stud...

This paper presents numerical solutions and idealized analytical solutions of axisymmetric, f -plane models of the tropical cyclone boundary layer. In the numerical model, the boundary layer radial and tangential flow is forced by a specified pressure field, which can also be interpreted as a specified gradient balanced tangential wind field vgr(r) or vorticity field ζgr(r). When the specified ...