Improving Social Odometry Robot Networks with Distributed Reputation Systems for Collaborative Purposes

The improvement of odometry systems in collaborative robotics remains an important challenge for several applications. Social odometry is a social technique which confers the robots the possibility to learn from the others. This paper analyzes social odometry and proposes and follows a methodology to improve its behavior based on cooperative reputation systems. We also provide a reference implementation that allows us to compare the performance of the proposed solution in highly dynamic environments with the performance of standard social odometry techniques. Simulation results quantitatively show the benefits of this collaborative approach that allows us to achieve better performances than social odometry

Using Reputation Systems and Non-Deterministic Routing to Secure Wireless Sensor Networks

Security in wireless sensor networks is difficult to achieve because of the resource limitations of the sensor nodes. We propose a trust-based decision framework for wireless sensor networks coupled with a non-deterministic routing protocol. Both provide a mechanism to effectively detect and confine common attacks, and, unlike previous approaches, allow bad reputation feedback to the network. This approach has been extensively simulated, obtaining good results, even for unrealistically complex attack scenarios

Heat shock response in the freshwater Hydra polyp: Hsp70.1 genes and inducible activity of the Hsp70.1a promoter

L’hydre est un polype d’eau douce à symétrie radiaire appartenant au phylum des Cnidaires. Elle est constituée de deux couches cellulaires et trois types de cellules souches dotées d’une capacité d’auto-renouvèlement indéfini, ce qui la rend immortelle. Depuis 2006, la production d’hydres transgéniques stables est possible mais des promoteurs endogènes inductibles n’ont pas été identifiés. Le but de cette étude est d’identifier un promoteur inductible qui permettrait de diriger l’expression transitoire de gènes placés en aval. Dans ce but, nous nous sommes concentrés sur le gène Hsp70.1 hautement conservé chez les métazoaires et responsable du maintien de l’équilibre homéostatique et de la viabilité de la cellule. Alors que ce gène Hsp70.1 a été décrit comme existant sous forme d’une seule copie, nous avons trouvé que ce gène est en fait présent sous forme d’au moins trois copies chez deux espèces d’hydre, H. oligactis et H. vulgaris. Nous avons aussi localisé une série d’éléments consensus sensibles au choc thermique dans les séquences promotrices des gènes Hsp70.1. En comparant l’inductibilité de l’expression de ces trois gènes Hsp70.1 par choc thermique dans deux souches de H. vulgaris, Hm-105 et AEP. Deux de ces gènes, Hsp70.1a et Hsp70.1b, sont induits suite à un choc thermique tandis que le troisième Hsp70.1c montre un niveau d’expression stable. Ces expériences nous ont permis d’établir les conditions optimales qui permettent une réponse transcriptionnelle maximale au choc thermique sans induire la mort des animaux. Nous avons produit une série de constructions rapportrices exprimant la protéine GFP sous le contrôle du promoteur Hsp70.1a. Afin de valider l’inductibilité de ces constructions, différents tests ont été conduits dans des cellules humaines transfectées et chez l’Hydre après électroporation. Nous avons aussi produit une lignée transgénique stable exprimant la construction Hsp70.1a_0.5kb::GFP chez l’Hydre AEP. Cependant nous n’avons obtenu aucune évidence de l’inductibilité de ces séquences promotrices suggérant que les séquences régulatrices des gènes Hsp70.1 bien que sensibles aux chocs thermiques ont un fonctionnement plus complexe qu’anticipé pour diriger de façon inductible l’expression de gènes d’intérêt chez l’Hydre

MULTISPECTRAL AND PANCHROMATIC REGISTRATION OF ALSAT-2 IMAGES USING DENSE VECTOR MATCHING FOR PAN-SHARPENING PROCESS

The pan-sharpening is a widely used operation in remote sensing image processing, this operation aims at combining an observable high spatial resolution panchromatic image with a multispectral one, to generate an unobservable image with the high spatial resolution of the former and a high spectral resolution of the latter. Generally, papers dealing with this problem omit the geometric part and suppose that these images are perfectly aligned, which is not necessarily the case for the raw imagery, where even the different bands in the multispectral imagery are misaligned. In this paper, new method for multispectral and panchromatic image registration is proposed to deal with the misalignment problem that reduces the pansharpening quality. This method called Dense Vector Matching (DVM) is based on the matching of a whole line-vector or column-vector from a reference band with the corresponding vector in a target band. DVM is applied on real data and has given acceptable results, where the QNR index of the pan-sharpening is better for images after band registration, also the registration error is reduced to sub-pixel using the proposed approach

RIGOROUS GEOREFERENCING OF ALSAT-2A PANCHROMATIC AND MULTISPECTRAL IMAGERY

The exploitation of the full geometric capabilities of the High-Resolution Satellite Imagery (HRSI), require the development of an appropriate sensor orientation model. Several authors studied this problem; generally we have two categories of geometric models: physical and empirical models. Based on the analysis of the metadata provided with ALSAT-2A, a rigorous pushbroom camera model can be developed. This model has been successfully applied to many very high resolution imagery systems. The relation between the image and ground coordinates by the time dependant collinearity involving many coordinates systems has been tested. The interior orientation parameters must be integrated in the model, the interior parameters can be estimated from the viewing angles corresponding to the pointing directions of any detector, these values are derived from cubic polynomials provided in the metadata. The developed model integrates all the necessary elements with 33 unknown. All the approximate values of the 33 unknowns parameters may be derived from the informations contained in the metadata files provided with the imagery technical specifications or they are simply fixed to zero, so the condition equation is linearized and solved using SVD in a least square sense in order to correct the initial values using a suitable number of well-distributed GCPs. Using Alsat-2A images over the town of Toulouse in the south west of France, three experiments are done. The first is about 2D accuracy analysis using several sets of parameters. The second is about GCPs number and distribution. The third experiment is about georeferencing multispectral image by applying the model calculated from panchromatic image

APPLICATION OF DIGITAL TERRESTRIAL PHOTOGRAMMETRY IN ARCHITECTURAL CONSERVATION: THE MOSQUE OF ABDULLAH IBN SALAM OF ORAN

Studies on the architectural heritage can now be supported by three-dimensional reconstruction of actual buildings. The 3D digital model can be an effective medium for documenting the current state of historic buildings but also to create a resource for researchers who conduct their analysis on historical evolution. Architectural photogrammetry has its own specifications in relation to other photogrammetric applications, however it meets these expectations. The traditional approach requires the use of metric cameras but with the development of computational techniques, this requirement is overcome and opens the way for the use of non-metric camera. The use of the shots that is no longer restricted to the parallel configuration of bundles, the images may be convergent, horizontal or oblique. Combining and modelling several cameras increasingly powerful in resolution and stability, has great scope and the same workflow can be used in varied applications. ISPRS and ICOMOS created CIPA because they both believe that a monument can be restored and protected only when it has been fully measured and documented and when its development has been documented several times, i.e. monitored, also with respect to its environment, and stored in proper heritage information and management systems. In this paper the 3D modelling of an important cultural site using terrestrial photogrammetric techniques for architectural preservation is presented. The site is the mosque of Abdullah Ibn Salam, Built in 1880 at the initiative of Simon Kanoui, also known as the Great Synagogue of Oran was inaugurated in 1918 only. It was one of the largest and most beautiful synagogues in North Africa. It was built with stone imported from Jerusalem. This place of worship became in 1975 the mosque of Abdullah Ibn Salam who was a rich Jew of Medina who was converted to Islam. The structure is modelled using 321 oriented photos taken in five series of shots that cover all the façade and the interior of the building where more than 9200 points are created. Also some orthophotos of the important elements are produced and used as materials in the final stage which is the edition in a 3D modelling software. And a video virtual tour is generated using this software

Unsupervised hyperspectral band selection by combination of unmixing and sequential clustering techniques

Selecting the decisive spectral bands is a key issue in unsupervised hyperspectral band selection techniques. These methods are the most popular ways for dimensionality reduction of original data. A compact data representation without compromising the physical information and optimizing the separation between different materials are the main objectives of such selection processes. In this work, a hyperspectral band selection approach is proposed based on linear spectral unmixing and sequential clustering techniques. The use of these two specific techniques constitutes the main novelty of this investigation. The proposed approach operates in different successive steps. It starts with extracting material spectra contained in the considered data using an unmixing method. Then, the variance of extracted spectra samples is calculated at each wavelength, which results in a variances vector. This one is segmented into a fixed number of clusters using a sequential clustering strategy. Finally, only one spectral band is selected for each segment. This band corresponds to the wavelength at which a maximum variance value is obtained. Experiments on three real hyperspectral data demonstrate the superiority of the proposed approach in comparison with four methods from the literature