We address the problem of egomotion estimation for a monocular observer moving under arbitrary translation and rotation, in an unknown environment. The method we propose is uniquely based on the spatio-temporal image derivatives, or the normal ow. We introduce a search paradigm which is based on geometric properties of the normal ow eld, and consists in considering a family of search subspaces ...

The title compound, obtained by base-induced dimerization of 3-benzyloxazolidin-2-one, has been prepared and fully characterised. Its X-ray structure features hydrogen-bonded dimers involving the hydroxyl OH amide carbonyl, forming a 14-membered ring.

background : thymol and carvacrol have previously demonstrated larvicidal activity against aedes aegypti (diptera: culicidae). in view of this fact, it was of our interest to obtain synthetic derivatives and evaluate their larvicidal ac­tivity on ae. aegypti larvae. methods : structural modifications were performed on thymol and carvacrol in an effort to understand the functional groups necessa...

The plot of k cat }K m against pH for the Bacillus cereus 569}H β-lactamase class B catalysed hydrolysis of benzylpenicillin and cephalosporin indicates that there are three catalytically important groups, two of pK a 5±630±2 and one of pK a 9±530±2. Below pH 5 there is an inverse second-order dependence of reactivity upon hydrogen ion concentration, indicative of the requirement of two basic r...

A mutation in a gene designated gmdA has been found to lead to loss of ability of Aspergillus nidulans to use benzamide, phenylacetamide and several other amides as sole nitrogen sources for growth. The gmdA1 lesion results in low levels of an enzyme, called the general amidase, which has acitivity for a wide range of amide substrates. This enzyme is reressed by certain nitrogen-containing meta...

In the presence of an alkene, three different modes of photocycloaddition with benzene derivatives can occur; the [2 + 2] or ortho, the [3 + 2] or meta, and the [4 + 2] or para photocycloaddition. This short review aims to demonstrate the synthetic power of these photocycloadditions.

In this paper it is shown how to perform hand-eye calibration using only the normal flow field and knowledge about the motion of the hand. The proposed method comprise a simple way to calculate the handeye calibration when a camera is mounted on a robot. Firstly, it is shown how the orientation of the optical axis can be estimated from at least two different translational motions of the robot. ...

This paper presents a new technique to the instantaneous 3D motion estimation. The main contributions are as follows. First, we show that the 3D camera or scene velocity can be retrieved from image derivatives only assuming that the scene contains a dominant plane. Second, we propose a new robust algorithm that simultaneously provides the Least Trimmed Square solution and the percentage of inli...