Search results for "Distance"

Multipath extensions to the DYMO routing protocol

2007

Multipath routing is a technique that can improve performance, specially in mobile ad hoc networks. Due to traffic dispersion it can perform load balancing; minimize the energy consumed by nodes or prevent traffic analysis. In this work we focus on enhancing the DYMO protocol to support multipath routing. We study the impact of traffic dispersion on both UDP and TCP traffic when varying a set of parameters.

Toward Approximate GML Retrieval Based on Structural and Semantic Characteristics

2010

International audience; GML is emerging as the new standard for representing geographic information in GISs on the Web, allowing the encoding of structurally and semantically rich geographic data in self describing XML-based geographic entities. In this study, we address the problem of approximate querying and ranked results for GML data and provide a method for GML query evaluation. Our method consists of two main contributions. First, we propose a tree model for representing GML queries and data collections. Then, we introduce a GML retrieval method based on the concept of tree edit distance as an efficient means for comparing semi-structured data. Our approach allows the evaluation of bo…

Towards a Novel Approach to Multimedia Data Mixed Fragmentation

2009

International audience; Distributed multimedia applications have emerged at an increasing rate during the last decade in several domains (video conferencing, e-health, virtual meeting rooms, etc). This has created several new challenging problems related to the data integration and fragmentation, user-oriented and adaptive interfaces, real time and network performances, etc. In this paper, we focus on the problem of data(base) fragmentation in a multimedia context. We recall in this respect that data fragmentation consists of reducing irrelevant data accesses by grouping data frequently accessed together in dedicated segments. We mainly address the issue of query and predicate implication r…

Spatially variant dimensionality reduction for the visualization of multi/hyperspectral images

2011

International audience; In this paper, we introduce a new approach for color visu- alization of multi/hyperspectral images. Unlike traditional methods, we propose to operate a local analysis instead of considering that all the pixels are part of the same population. It takes a segmentation map as an input and then achieves a dimensionality reduction adaptively inside each class of pixels. Moreover, in order to avoid unappealing discon- tinuities between regions, we propose to make use of a set of distance transform maps to weigh the mapping applied to each pixel with regard to its relative location with classes' centroids. Results on two hyperspec- tral datasets illustrate the efficiency of…

Differential inclusions involving normal cones of nonregular sets in Hilbert spaces

2017

This thesis is dedicated to the study of differential inclusions involving normal cones of nonregular sets in Hilbert spaces. In particular, we are interested in the sweeping process and its variants. The sweeping process is a constrained differential inclusion involving normal cones which appears naturally in several applications such as elastoplasticity, electrical circuits, hysteresis, crowd motion, etc.This work is divided conceptually in three parts: Study of positively alpha-far sets, existence results for differential inclusions involving normal cones and characterizations of Lyapunov pairs for the sweeping process. In the first part (Chapter 2), we investigate the class of positivel…

Sub-Riemannian geometry: one-parameter deformation of the Martinet flat case

1998

Confrontation of cryptic diversity and mate discrimination within Gammarus pulex and Gammarus fossarum species complexes.

2014

16 pages; International audience; Freshwater amphipods Gammarus fossarum and Gammarus pulex are widespread in Europe, with some evidence of cryptic diversity in the former. We used DNA barcoding to assess genetic diversity within and among amphipod populations and examined mate discrimination and pre-copulatory pair formation between genetically divergent individuals. Eight distinct G. fossarum and four distinct G. pulex molecular operational taxonomic units (MOTUs) were detected. Among the 33 amphipod populations sampled, 11 contained a single MOTU, 11 had two and 11 were composed of three sympatric MOTUs. Genetic divergences between sympatric MOTUs (G. fossarum and G. pulex MOTUs combined…

A Note on Radio Antipodal Colouring of Paths

2005

International audience; The radio antipodal number of a graph G is the smallest integer c such that there exists an assignment f : V (G) -> {1, 2, . . . , c} satisfying |f(u) − f(v)| >= D − d(u, v) for every two distinct vertices u and v of G, where D is the diameter of G. In this note we determine the exact value of the antipodal number of the path, thus answering the conjecture given in [G. Chartrand, D. Erwin, and P. Zhang. Radio antipodal colorings of graphs, Math. Bohem. 127(1):57-69, 2002]. We also show the connections between this colouring and radio labelings.

La gestion de la diversité cognitive : l’importance du rôle de coordination des investisseurs en start-ups. Une étude exploratoire

2023

International audience; La diversité cognitive est souvent marquée entre les différents investisseurs (business angels et capital-risqueurs) et les dirigeants de start-up. Cette diversité est à la fois source d’innovation et de mécompréhension entre les acteurs. Elle doit donc être coordonnée pour non seulement assurer la survie de l’entreprise mais aussi lui permettre de se développer dans un environnement technologique turbulent. À l’aide d’une étude de cas longitudinale comparative de deux start-ups en relation avec différents investisseurs, nous menons une étude exploratoire pour investiguer la fonction de coordination cognitive. Nous élaborons un modèle des qualités que doit réunir un …

Connectivité d’un paysage agricole et processus de dispersion des adventices. Approche par l’analyse de la similarité des communautés

2013

Rapport de Stage de Master 2 Sciences, Technologies et Santé (STS) SPE ECOLDUR équipe CAPA; Master; Comprendre la connectivité fonctionnelle d’un paysage pour une espèce ou un groupe d’espèces donné revient à rechercher des distances écologiques pertinentes vis-à-vis de la dispersion de ces organismes. Pour cela, la similarité dans la composition en espèce entre communautés, qui mesure leur degré de ressemblance, peut être mise en relation avec des distances écologiques entre ces communautés qui sont issues de mesures de connectivité du paysage, et qui reposent sur des hypothèses concernant les processus de dispersion. Au sujet des adventices des cultures, une hypothèse est que la prise en …