Let V be Euclidean space. Let W ⊂ GL(V ) be a finite irreducible reflection group. Let A be the corresponding Coxeter arrangement. Let S be the algebra of polynomial functions on V. For H ∈ A choose αH ∈ V ∗ such that H = ker(αH). The arrangement A is known to be free: the derivation module D(A) = {θ ∈ DerS | θ(αH ) ∈ SαH} is a free S-module with generators of degrees equal to the exponents of ...

Motivated by a scheduling problem encountered in multicast environments, we study a vertex labelling problem, called Directed Circular Arrangement (DCA), that requires one to find an embedding of a given weighted directed graph into a discrete circle which would minimize the total weighted arc length. Its decision version is already known to be NP-complete when restricted to sparse weighted dir...

This Letter presents a technique for subdiffraction limit imaging termed Bessel beam microscopy (BBM). By placing a lens in series with an axicon in the optical path of a microscope, the diffraction-limited resolution of the base microscope is improved by one third. This improvement is demonstrated experimentally by resolving individual subdiffraction limit fluorescent beads in a close-pack arr...

In certain non-central imaging systems, straight lines are projected via a non-planar surface encapsulating the 4 degrees of freedom of the 3D line. Consequently the geometry of the 3D line can be recovered from a minimum of four image points. However, with classical non-central catadioptric systems there is not enough effective baseline for a practical implementation of the method. In this pap...

The 4DI system, a real time three-dimensional (3-D) imager, is a laser range data sensing system for making continuous geometric measurements of 3-D surfaces. This paper concentrates on the objective of improving the resolution and accuracy of this system using a camera-turntable arrangement. A fast and inexpensive way to capture dense range data for 360 viewing of an object is provided. After ...

A simple experimental setup to study the impact and coalescence of deposited droplets is described. Droplet impact and coalescence have been investigated by high-speed particle image velocimetry. Velocity fields near the liquid-substrate interface have been observed for the impact and coalescence of 2.4 mm diameter droplets of glycerol∕water striking a flat transparent substrate in air. The exp...

The growing demand for applications in Precision Agriculture has been proportional to the emergent interest in automatic guidance of agricultural machines. The difficult, and at the same time strenuous, task of driving a harvester during the prolonged working days of the harvesting season justifies the special attention paid to this technology. The development of Global Navigation Satellite Sys...

The paper gives a survey on the new Expectationbased Multifocal Saccadic Vision (EMS-Vision) system for autonomous vehicle guidance developed at the Universität der Bundeswehr München (UBM). EMS-Vision is the third generation dynamic vision system following the 4-D approach. Its core element is a new camera arrangement, mounted on a high bandwidth pan-tilt head for active gaze control. Central ...

We present in this paper a structure-from-motion approach for single viewpoint cameras using point and line features. From the image sequence captured by any central projection cameras, the motion can be recovered by decoupling of orientation and displacement: rotation is estimated from vanishing points of parallel lines and translation is calculated from known rotation and point/line correspon...

This work describes the development of a highresolution tactile-sensing finger for robot grasping. This finger, inspired by previous GelSight sensing techniques, features an integration that is slimer, more robust, and with more homogenoeus output than previous vision-based tactile sensors. To achieve a compact integration, we redesign the optical path from illumination source to camera by comb...