The aim of this paper is to characterize the moveability of fully-parallel manipulators in the presence of obstacles. Fully parallel manipulators are used in applications where accuracy, stiffness or high speeds and accelerations are required [1]. However, one of its main drawbacks is a relatively small workspace compared to the one of serial manipulators. This is due mainly to the existence of...

Global visibility of naked singularities is analyzed here for a class of spherically symmetric spacetimes, extending previous studies limited to inhomogeneous dust cloud collapse to more physical valid situations in which pressures are non-vanishing. Existence of nonradial geodesics escaping from the singularity is shown, and the observability of the singularity from far-away observers is discu...

Convergence results are proved for sequences of interpolatory integration rules for Cauchy principal value integrals of the form -l k(x)(f(x)/(x-X))dx, -1<A<1, -i when f(x) is singular at a point { / À and the singularity is ignored or avoided. /:'

To tackle the singularity problem, the SC (SingularityConsistent) approach was introduced. It achieves very stable control at and around a singularity with feasible joint velocities and no directional error in the endeffector velocity. This approach is very suited for a direct manual teleoperation system because of its errorless character for the direction. Until now, it was applied for the tel...

This paper presents a novel LDA algorithm named 2DHLDA (2-Dimensional Heteroscedastic Linear Discriminant Analysis). The proposed algorithms are applied on age-group classification using facial images under various lighting conditions. 2DHLDA significantly overcomes the singularity problem, so-called ’Small Sample Size’ problem (S3 problem), and the original feature space is split into useful d...

We show that a system of parallel D3 branes near a conifold singularity can be mapped onto an intersecting configuration of orthogonal branes in type IIA string theory. Using this brane configuration, we analyze the Higgs moduli space of the associated field theory. The dimension of the Higgs moduli space is computed from a geometrical analysis of the conifold singularity. Our results provide e...

In order to elucidate the mechanisms by which a strong shock terminates reentrant wavefronts, we employed phase analysis techniques to study phase singularity dynamics in a finite element model of cardiac tissue. We located postshock phase singularities and traced their movement and survival for sixteen monophasic shocks applied at different times during the rotation of a spiral wave. Our analy...

CaPaMan (Cassino Parallel Manipulator) is a threedegree of freedom parallel mechanism that has been designed and built at Laboratory of Robotics and Mechatronics in Cassino. In this paper a study of the configuration singularities of the CaPaMan manipulator is presented by considering two different methods: an algebraic formulation and a vector analysis. It will be shown that a formulation can ...

Much of the published work regarding the Isotropic Singularity is performed under the assumption that the matter source for the cosmological model is a barotropic perfect fluid, or even a perfect fluid with a γ-law equation of state. There are, however, some general properties of cosmological models which admit an Isotropic Singularity, irrespective of the matter source. In particular, we show ...