Science & Mathematics

Les Mutations socio-spatiales, culturelles et aspects anthropologiques en milieu aride : cas de la Jeffara Tuniso-lybienne 1837-1956. A la charnière du Maghreb et du Machrek arabes, la culture des tribus Jeffariennes entre les mythes et la réalités, les rapports entre le gouvernants et gouvernés dans un espace de souveraineté confuse où se manifestent des retombées à double caractères : (Endogènes et exogènes) traduisant la pesanteur de l'environnement international, pouvoir et contre pouvoir dans la Jeffara, le marquage et la délimitation de l'espace aboutissant à la lutte contre l'expansion turque, française et italienne. Les enjeux anthropologiques et culturels et la confrontation entre les réseaux Jeffariens alliés par des " hilfs " pactes et droit coutumier et les pouvoirs centraux et les grandes confréries, affinités mystiques légendaires de la poésie et des poètes, des sages et saints populaires, métaphores et lieux communs de tradition orale du dialogue avec l'autre et avec le pouvoir central sans négliger le discours poétique. Les définitions de l'espace stratégiques, les principes et les idéologies sont-ils à l'origine de cet échec de dialogue avec le pouvoir de 1837 jusqu'en 1956, avec la soumission des werghemma devant le projet de colonisation, de protectorat et d'indépendance interne. Vis à vis de ces pouvoirs y-a-t-il seulement deux façons dans ce dialogue ! se soumettre ou se révolter !

On s'intéresse dans ce papier au fonctionnement de deux compléments de manière, 'avec N' et 'avec du N', tous deux introduits par la préposition 'avec'. Ils se distinguent pourtant de différents points de vue: syntaxique, argumentatif, sémantique et enfin référentiel. L'hypothèse sous-jacente à cette étude, c'est que la préposition 'avec' doit garder la même valeur quel que soit son emploi; le différent fonctionnement des deux compléments en question doit donc trouver ses raisons dans leur structure interne. On vérifiera ainsi, à travers cette étude, les hypothèses formulées concernant la valeur fondamentale de la préposition 'avec', notamment dans I. Choi-jonin (1995) et dans P. Cadiot (1990, 1991, 1993).

The use of proportional gas detectors for determination of the alpha (a) and beta (/I) dose rate (due to U, Th and K) of pottery and sediment samples in luminescence and ESR dating was investigated.Alpha and beta count-rate measurements on standard powders of U, Th and K at two different counter voltages, low voltage in which the system detects a-particles only and high voltage in which the system can detect and distinguish between both aand g-particles using different pulse height regions, allow the determination of conversion coefficients that relate count rates to dose rates in samples. The conversion coefficients were applied to the alpha and beta count rates measured on different types of test samples. Analysis of the results shows a remarkable accuracy in the evaluation of the beta dose rates. However, under both measurement conditions (low and high voltage), the alpha dose rates were found to deviate from the expected values to the extent that this procedure must be considered unusable at present.

We report on the design, fabrication and characterization of a filter for demultiplexing in the wavelength division domain realized with a H0 cavity on a III-V photonic crystal (PhC) membrane. This device is single mode, the total insertion losses are about 10.5 dB, the drop efficiency is close to 40 % and the channel isolation can exceed 20 dB at 500 GHz. 28 Gbit/s NRZ wavelength demultiplexing shows less than 0.5 dB penalties. Cross talk measurements demonstrate less than 1 dB penalty when adjacent channels are spaced as closely as 235 GHz, demonstrating the good compatibility of this filter with LAN-WDM systems. Finally, 56 Gbit/s NRZ-DQPSK signal filtering is assessed revealing negligible penalty (< 0.5 dB).

AbstractKey messageWe examine how the configurations in nearest neighbor imputation affect the performance of predicted species-specific diameter distributions. The simultaneous nearest neighbor imputation for all tree species and separate imputation by tree species are evaluated with total volume calibration as a prediction method for diameter distributions.ContextThis study considers the predictions of species-specific diameter distributions in Finnish boreal forests by means of airborne laser scanning (ALS) data and aerial images.AimsThe aim was to investigate different configurations in non-parametric nearest neighbor (NN) imputation and to determine how changes in configurations affect prediction error rates for timber assortment volumes and the error indices of the diameter distributions.MethodsNon-parametric NN imputation was used as a modeling method and was applied in two different ways: (1) diameter distributions were predicted at the same time for all tree species by simultaneous NN imputation, and (2) diameter distributions were predicted for one tree species at a time by separate NN imputation. Calibration to a regression-based total volume prediction was applied in both cases.ResultsThe results indicated that significant changes in the volume prediction error rates for timber assortment and for error indices can be achieved by the selection of responses, calibration to total volume, and separate NN imputation by tree species.ConclusionOverall, the selection of response variables in NN imputation and calibration to total volume improved the predicted diameter distribution error rates. The most successful prediction performance of diameter distribution was achieved by separate NN imputation by tree species.

With the rapid deployment of Internet of Things (IoT) applications, video processing and streaming requirements are increasing, and edge computing is a good candidate to cope with strong latency and throughput expectations. In this paper, we consider the optimal routing, placement and scaling of IoT-based service function chains for object detection. We propose an edge networking approach dealing with limited CPU and network bandwidth resources in a joint optimization based on Integer Linear Programming for small problem instances, and a graph-based approximation to cope with scalability issues. We evaluate the efficiency of our algorithms through simulations and show that the graph-based approach converges towards a near-optimal solution in negligible time and is thus suitable for real-time function chain placement.

Retrieving images in large databases involves either thematic or visual querying capabilities. We think that both approaches can be efficiently combined to provide a thematically and visually relevant retrieval. This paper deals with bi-modal access in image retrieval systems. Our approach relies on a corpus organisation based on both visual and thematical clustering, allowing access to non-indexed images. An adapted retrieval process has been designed to reformulate queries, taking into account users's judgements that deal with thematical and visual aspects of their information needs.

Profession reporter (1975) de Michelangelo Antonioni et Inland (2008) de Teriq Teguia partagent de véritables « terrains d’entente », des visions d’espaces indéterminés où l’intensité de la lumière semble dissoudre et recomposer les paysages désertiques. Le film de Teguia fait affleurer de multiples miroitements référentiels antonioniens au gré du cheminement erratique de Malek, géomètre déphasé et comme absent à lui-même, comparable en cela au reporter David Locke dans le film d’Antonioni.

AbstractKey messageStand density has a positive effect on C, K and Mg concentration in needle litterfall and a negative one on C, N, Ca, K, Mg, P, S, Zn, and Cu release from needle litter. Consequently, forest management practices such as thinning decrease nutrient concentration in needle litterfall and accelerate nutrient release from decomposing needles in Pinus halepensis plantations in Spain.ContextSilvicultural practices usually include stand density reduction resulting in changes in litterfall and litter decomposition rates. Little is known about the effect on nutrient concentrations in litterfall and nutrient release during decomposition even when this is the main path of nutrient return to soils.AimsThe aims of the study are to evaluate the seasonal pattern of nutrient concentration in litterfall, to study how nutrients are released from needle litterfall during decomposition, and to assess whether local basal area of the stand affects nutrient concentration of litterfall and nutrient release during litter decomposition.MethodsEight plots were established on each of four stands covering the widest range in local basal area. A littertrap and 15 litterbags were placed on each plot. Periodically, needle litterfall and litter contained in the litterbags were analyzed for C, N, Ca, K, Mg, P, S, Fe, Cu, Mn, and Zn.ResultsLocal basal area had a positive effect on C, K, and Mg concentration in needle litterfall and a negative effect on the release of all the nutrients studied but Fe and Mn during the first 2 years of litter decomposition.ConclusionDensity management of stands has an impact on nutrient cycling, reducing nutrient concentration in needle litterfall, and accelerating nutrient release during decomposition.

Due to the popularization of Internet, virtual enterprises are expected to become commonplace on the WEB. The concept of virtual enterprise depicts the idea that many applications are the result of cross-organisational cooperation between several actors, playing different roles, who build a relational system which is structured by a common objective. Virtual enterprises can be short- or long-lived. The objective of our work is to develop a framework to install and to support cooperation betwen the partners of a virtual enterprise, with a particular focuss on concurrent engineering applications, and especially on co-design activities. We have chosen a transactional approach which releases programmers from the burden of interaction programming, and this approach has been implemented in a distributed manner using a cooperation model requesting a partner to negotiate cooperation patterns with its direct neighbours.