ON FPGA BASED ACCELERATION OF IMAGE PROCESSING IN MOBILE ROBOTICS

In visual navigation tasks, a lack of the computational resources is one of the main limitations of micro robotic platforms to be deployed in autonomous missions. It is because the most of nowadays techniques of visual navigation relies on a detection of salient points that is computationally very demanding. In this paper, an FPGA assisted acceleration of image processing is considered to overcome limitations of computational resources available on-board and to enable high processing speeds while it may lower the power consumption of the system. The paper reports on performance evaluation of the CPU–based and FPGA–based implementations of a visual teach-and-repeat navigation system based on detection and tracking of the FAST image salient points. The results indicate that even a computationally efficient FAST algorithm can benefit from a parallel (low–cost) FPGA–based implementation that has a competitive processing time but more importantly it is a more power efficient

Brain studies ? image co-registration and template creation

Image co-registration requires special software, which is usually available for Unix workstations. This work presents two programs running under MS Windows, one for study co-registration and one for template creation. The co-registration can be done by minimising/maximising the count difference, squared difference, shape and mutual information. The quality of the fit can be estimated by evaluating the contours with different tools. The aligned images can be used for template creation. Both programs can be downloaded from http://www.homolka.cz/nm

Bioactivity of Methoxylated and Methylated 1-Hydroxynaphthalene-2-Carboxanilides: Comparative Molecular Surface Analysis

A series of twenty-six methoxylated and methylated N-aryl-1-hydroxynaphthalene- 2-carboxanilides was prepared and characterized as potential anti-invasive agents. The molecular structure of N-(2,5-dimethylphenyl)-1-hydroxynaphthalene-2-carboxamide as a model compound was determined by single-crystal X-ray di raction. All the analysed compounds were tested against the reference strain Staphylococcus aureus and three clinical isolates of methicillin-resistant S. aureus as well as against Mycobacterium tuberculosis and M. kansasii. In addition, the inhibitory profile of photosynthetic electron transport in spinach (Spinacia oleracea L.) chloroplasts was specified. In vitro cytotoxicity of the most e ective compounds was tested on the human monocytic leukaemia THP-1 cell line. The activities of N-(3,5-dimethylphenyl)-, N-(3-fluoro-5-methoxy-phenyl)- and N-(3,5-dimethoxyphenyl)-1-hydroxynaphthalene-2-carbox- amide were comparable with or even better than the commonly used standards ampicillin and isoniazid. All promising compounds did not show any cytotoxic e ect at the concentration >30 M. Moreover, an in silico evaluation of clogP features was performed for the entire set of the carboxamides using a range of software lipophilicity predictors, and cross-comparison with the experimentally determined lipophilicity (log k), in consensus lipophilicity estimation, was conducted as well. Principal component analysis was employed to illustrate noticeable variations with respect to the molecular lipophilicity (theoretical/experimental) and rule-of-five violations. Additionally, ligand-oriented studies for the assessment of the three-dimensional quantitative structure–activity relationship profile were carried out with the comparative molecular surface analysis to determine electron and/or steric factors that potentially contribute to the biological activities of the investigated compounds

Electron spectra for associative detachment in low-energy collisions of Cl⁻ and Br⁻ with H and D

Energy spectra of electrons detached in collisions of Cl⁻ and Br⁻ with atomic hydrogen and deuterium have been measured for laboratory frame ion energies between 0.2 and 8.0 eV. Their shapes agree very well with the predictions of nonlocal resonance theory. Both types of structure predicted by the theory are observed. They are the 'v steps', at ro-vibrational thresholds, and the 'S steps', which are a consequence of interchannel coupling, which raises the cross section when a higher vibrational channel closes. They exhibit the behaviour predicted by theory both when the collision energy is varied and upon isotope substitution. The 'v steps' move to higher electron energies with higher collision energy and when hydrogen is substituted by deuterium, reflecting the higher maximum energy available to the electron. The positions of the S steps do not depend on collision energy, and are essentially equal to differences of vibrational energies of the product molecules HCl, DCl, HBr and DBr. The relative cross sections for formation of low vibrational levels (i.e., emission of fast electrons) are smaller in the deuterated compounds, reflecting the slower motion of D compared to H and consequently preferred detachment at high internuclear separations

Effects of interchannel coupling in associative detachment: electron spectra for H+Cl⁻ and H+Br⁻ collisions

We present experimental and theoretical energy spectra of the electrons detached in collisions of slow Cl⁻ and Br⁻ ions with atomic hydrogen. Nonlocal resonance theory predicts two kinds of features in the spectra: steplike structures associated with rovibrational onsets and steep rises associated with interchannel coupling, the latter being absent in a calculation using the simpler local-complex potential theory. Our experimental spectra confirm the presence of both types of structures and thus the necessity of including interchannel coupling to properly describe the product-state distribution

Resonance contributions to low-energy electron collisions with molecular hydrogen

Calculations of electron dissociative attachment and vibrational excitation of molecular hydrogen by low-energy electrons based on an improved nonlocal resonance model are reported. The role of the rotational excitation of the target molecules is discussed