This paper addresses the workspace analysis of two 3-DOF translational parallel mechanisms designed for machining applications. The two machines features three fixed linear joints. The joint axes of the first machine are orthogonal whereas these of the second are parallel. In both cases, the mobile platform moves in the Cartesian x−y−z space with fixed orientation. The workspace analysis is con...

We derive a simple formula for the change in output when a device fails in a power-combining structure with identical matched devices. The loss is written in terms of the scattering coefficient of the failed device and reflection coefficient of an input port in the combining network. We apply this formula to several power combiners, including arrays in free space and enclosed waveguide structur...

Knowledge about stable and unstable manifolds of hyperbolic fixed points of certain maps is desirable in many fields of research, both in pure mathematics as well as in applications, ranging from forced oscillations to celestial mechanics and space mission design. We present a technique to find highly accurate polynomial approximations of local invariant manifolds for sufficiently smooth planar...

Alexithymia refers to a person's inability to identify and describe feelings. We present a patient who developed alexithymia after carbon monoxide poisoning following a suicide attempt by burning charcoal in an enclosed space. Brain computed tomography revealed bilateral globus pallidus hypoxic lesions. Because of the time frame and the presence of brain structural lesions, the alexithymia in t...

A new approach for estimating 3D head pose form a monocular image is proposed. Our approach employs general prior knowledge of face structure and the corresponding geometrical constraints provided by the location of vanishing point to determine pose of human faces. Eye-lines and mouth-line are assumed parallel in 3D space, and the vanishing point formed by the intersection of the eyeline and mo...

This paper addresses the workspace analysis of the orthoglide, a 3-DOF parallel mechanism designed for machining applications. This machine features three fixed parallel linear joints which are mounted orthogonally and a mobile platform which moves in the Cartesian x-y-z space with fixed orientation. The workspace analysis is conducted on the bases of prescribed kinetostatic performances. The i...

We study hard-core bosons on a class of frustrated lattices with the lowest Bloch band having a degenerate minimum along a closed contour in the reciprocal space. We suggest that the ground state of the system is given by non-condensed state, which may be viewed as a state of fermions subject to Chern-Simons gauge field. At fixed density of bosons, such a state exhibits domains of incompressibl...

We construct a Mach-Zehnder interferometer using Bose-Einstein condensed rubidium atoms and optical Bragg diffraction. In contrast to interferometers based on normal diffraction, where only a small percentage of the atoms contribute to the signal, our Bragg diffraction interferometer uses all the condensate atoms. The condensate coherence properties and high phase-space density result in an int...

The application of active control techniques in the reduction of excessive noise and vibration is becoming more popular. This paper describes a procedure for designing a” active noise control system using a” experimentally validated finite element model. The procedure has been applied to the control of airborne noise in a” enclosed space generated by a distributed source such as a large machine...

Fully enclosed regions in a two-dimensional image can often be perceived either as an object in front of a surface or as a hole through a surface. Several experiments were conducted to determine what factors affect perception of holes versus objects. Three types of factors were tested and found to influence this outcome. First, depth factors directly indicate that the enclosed region lies behin...