In this paper we look at the connection between Green's functions and preconditioners for systems of equations arising through the discretization of linear partial diierential equations. We nd that Green's functions, as generalized inverses of diierential operators, can sometimes ooer a useful insight into the properties of the discrete inverse operator. More precisely, their properties (singul...

In this paper, we develop a method to design the input control to track the output of a nonminimum-phase nonlinear systems asymptotically. The design of the control inputs is based on an exact linearization. To perform the exact linearization, the other output should be selected such that its relative degree is equal to the dimension of the system. Furthermore, the desired output of the output ...

Phase unwrapping for a noisy image suffers from many singular points. Singularity-spreading methods are useful for the noisy image to regularize the singularity. However, the methods have a drawback of distorting phase distribution in a regular area that contains no singular points. When the singular points are confined in some local areas, the regular region is not distorted. This paper propos...

We apply the technique of complex paths to obtain Hawking radiation in different coordinate representations of the Schwarzschild space-time. The coordinate representations we consider do not possess a singularity at the horizon unlike the standard Schwarzschild coordinate. However, the event horizon manifests itself as a singularity in the expression for the semiclassical action. This singulari...

This paper introduces a new approach to identify singularities of planar parallel manipulators (PPMs). This method is based on Maxwell’s reciprocal figure theory which establishes a duality between self-stress frameworks and reciprocal figures. We use line geometry tools to introduce a new graphical construction called the Mechanism’s Line of action Graph (MLG). The MLG is introduced in order t...

The singularities that we consider are the characteristic non-smooth solutions of the equations of linear elasticity in piecewise homogeneous media near two dimensional corners or three dimensional edges. We describe here a method to compute their singularity exponents and the associated angular singular functions. We present the implementation of this method in a program whose input data are g...

The singular stress field which develops at the interface corner of a scarf joint between two bonded elastic solids is investigated. Depending upon the scarf angle and the material elastic properties, the singular stresses at a radial distance r from an interface corner may be expressed in the form Hrλ−1, where λ − 1 is the order of the stress singularity and H is the intensity of the singulari...