Search results for "algorithm"

Definition of a Model-Based Detector of Curvilinear Regions

2007

This paper describes a new approach for detection of curvilinear regions. These features detection can be useful for any matching based algorithm such as stereoscopic vision. Our detector is based on curvilinear structure model, defined observing the real world. Then, we propose a multi-scale search algorithm of curvilinear regions and we report some preliminary results.

Co-simulation of bio-inspired multi-agent algorithms

2020

This paper reports on the co-simulation of a team of robots deployed in an exploration task, coordinated by a bio-inspired exploration algorithm. The co-simulation integrates the high-level exploration algorithm with detailed implementations of the robot controllers and kinematic models. Co-simulation results are used to find and correct mismatches between submodels.

A Note on Keys and Keystreams of Chacha20 for Multi-key Channels

2018

In this paper we analyze the keystreams generated by the Chacha20 stream cipher. We also compare these to the ones generated by its predecessor, the RC4 stream cipher. Due to the proposed multi-key channels in the upcoming TLS 1.3 standard we analyze the behavior of the keystream in the boundary case where there is a single bit difference between two keys used for the initiation of the stream cipher algorithms. The goal is to check whether a single bit change in the key has any predictable influence on the bits of the keystream output.

A new heuristic algorithm for the analysis of NMRD dispersion curves

Regression analysis of the NMRD dispersion curves obtained by the FFC-NMR relaxometric technique involves several conceptual and practical issues, which must be carefully addressed in order to gain reliable information on the system studied. Indeed, particular caution is needed when the FFC technique is applied to the investigation of complex systems such as polymeric matrixes, porous materials, food samples, and so on. In these cases, and in general whenever a rigorous approach based on a suitable physical modelization of the system is not available, data analysis must be performed by means of a “model–free” approach. Moving forward from previous literature, in the present communication we…

Comparison of some dispersion-corrected and traditional functionals as applied to peptides and conformations of cyclohexane derivatives.

2012

We compare the energetic and structural properties of fully optimized α-helical and antiparallel β-sheet polyalanines and the energetic differences between axial and equatorial conformations of three cyclohexane derivatives (methyl, fluoro, and chloro) as calculated using several functionals designed to treat dispersion (B97-D, ωB97x-D, M06, M06L, and M06-2X) with other traditional functionals not specifically parametrized to treat dispersion (B3LYP, X3LYP, and PBE1PBE) and with experimental results. Those functionals developed to treat dispersion significantly overestimate interaction enthalpies of folding for the α-helix and predict unreasonable structures that contain Ramachandran φ and …

Preservation of genetic and regulatory robustness in ancient gene duplicates of Saccharomyces cerevisiae

2014

[EN] Biological systems remain robust against certain genetic and environmental challenges. Robustness allows the exploration of ecological adaptations. It is unclear what factors contribute to increasing robustness. Gene duplication has been considered to increase genetic robustness through functional redundancy, accelerating the evolution of novel functions. However, recent findings have questioned the link between duplication and robustness. In particular, it remains elusive whether ancient duplicates still bear potential for innovation through preserved redundancy and robustness. Here we have investigated this question by evolving the yeast Saccharomyces cerevisiae for 2200 generations …

Sphingomonas fennica sp. nov. and Sphingomonas haloaromaticamans sp. nov., outliers of the genus Sphingomonas.

2007

Bacterial isolates obtained from polychlorophenol-contaminated sites in Finland (strain K101T) and from a Dutch drinking water well (strain A175T) were characterized taxonomically. 16S rRNA gene sequence analysis, determination of DNA G+C content, physiological characterization, estimation of the ubiquinone and polar lipid patterns and fatty acid content revealed that strains K101T and A175T were similar to Sphingomonas wittichii RW1T but also showed pronounced differences. The DNA G+C contents of the two novel strains were 63.6 and 66.1 mol%, respectively. On the basis of these results, two novel species of the genus Sphingomonas are described, for which the names Sphingomonas haloaromatic…

Molecular Characterization of Virus-induced Autoantibody Responses

2004

Here we present a comprehensive molecular mapping of virus-induced autoimmune B cell responses obtained by serological identification of antigens by recombinant expression cloning analysis. Immunoscreening of cDNA expression libraries of various organs (lung, liver, and spleen) using sera from mice infected with cytopathic (vaccinia virus [VV]) or noncytopathic (lymphocytic choriomeningitis virus [LCMV]) viruses revealed a broad specificity of the elicited autoantibody response. Interestingly, the majority of the identified autoantigens have been previously described as autoantigens in humans. We found that induction of virus-induced autoantibodies of the immunoglobulin G class largely depe…

Connection between optimal control theory and adiabatic-passage techniques in quantum systems

2012

This work explores the relationship between optimal control theory and adiabatic passage techniques in quantum systems. The study is based on a geometric analysis of the Hamiltonian dynamics constructed from the Pontryagin Maximum Principle. In a three-level quantum system, we show that the Stimulated Raman Adiabatic Passage technique can be associated to a peculiar Hamiltonian singularity. One deduces that the adiabatic pulse is solution of the optimal control problem only for a specific cost functional. This analysis is extended to the case of a four-level quantum system.

FRIPON: a worldwide network to track incoming meteoroids

2020

Context. Until recently, camera networks designed for monitoring fireballs worldwide were not fully automated, implying that in case of a meteorite fall, the recovery campaign was rarely immediate. This was an important limiting factor as the most fragile - hence precious - meteorites must be recovered rapidly to avoid their alteration. Aims. The Fireball Recovery and InterPlanetary Observation Network (FRIPON) scientific project was designed to overcome this limitation. This network comprises a fully automated camera and radio network deployed over a significant fraction of western Europe and a small fraction of Canada. As of today, it consists of 150 cameras and 25 European radio receiver…