background preloader


Facebook Twitter

Topologie de réseau. Un article de Wikipédia, l'encyclopédie libre.

topologie de réseau

Une topologie de réseau est en informatique une définition de l'architecture d'un réseau. Définissant les connexions entre ces postes et une hiérarchie éventuelle entre eux, elle peut avoir des implications sur la disposition géographique des différents postes informatiques du réseau. Ainsi Ethernet peut avoir comme support un simple plafond blanc visible de tous les postes (voir LiFi), alors que cela sera par construction impossible en token ring, bien que possible en token bus. Topologies de réseaux locaux classiques[modifier | modifier le code] Les architectures suivantes sont ou ont effectivement été utilisées dans des réseaux informatiques grand public ou d'entreprise.

Weak-strong ties. Comment nous arrive l’information ? Liens faibles, liens forts.

comment nous arrive l’information ?

Cette semaine le dossier d'InternetActu vous propose de revenir sur ce que sont les liens faibles, ce concept forgé par le sociologue américain Mark Granovetter permettant de distinguer nos relations selon selon leur proximité, mais aussi selon leur diversité et la richesse de ce qu'elles nous apportent. A l'heure des réseaux sociaux numériques, la compréhension de la structuration et du rôle de nos relations est devenu d'autant plus importante qu'elles forgent de plus en plus toutes nos actions en ligne. Quelle est la force des liens faibles, quelles sont leurs limites ? C'est le dossier d'InternetActu. La lecture de la semaine, il s'agit - ça faisait longtemps -, de l'éditorial de Clive Thompson dans le magazine américain Wired. Haptique (toucher) Un article de Wikipédia, l'encyclopédie libre.

haptique (toucher)

L’haptique, du grec ἅπτομαι (haptomai) qui signifie « je touche », désigne la science du toucher, par analogie avec l'acoustique ou l'optique. Au sens strict, l’haptique englobe le toucher et les phénomènes kinesthésiques, c'est-à-dire la perception du corps dans l’environnement. Network topology. A good example is a local area network (LAN): Any given node in the LAN has one or more physical links to other devices in the network; graphically mapping these links results in a geometric shape that can be used to describe the physical topology of the network.

network topology

Conversely, mapping the data flow between the components determines the logical topology of the network. Topology[edit] There are two basic categories of network topologies:[4] Physical topologiesLogical topologies The shape of the cabling layout used to link devices is called the physical topology of the network. Mesh. Variété systeme. Network topology. Combinatorics. N-sphere. In mathematics, the n-sphere is the generalization of the ordinary sphere to a n-dimensional space.


Spherical design. Copula approach. Abstract.

copula approach

Probability distributions of multivariate random variables are generally more complex compared to their univariate counterparts which is due to a possible nonlinear dependence between the random variables. One approach to this problem is the use of copulas, which have become popular over recent years, especially in fields like econometrics, finance, risk management, or insurance. Since this newly emerging field includes various practices, a controversial discussion, and vast field of literature, it is difficult to get an overview.

The aim of this paper is therefore to provide an brief overview of copulas for application in meteorology and climate research. We examine the advantages and disadvantages compared to alternative approaches like e.g. mixture models, summarize the current problem of goodness-of-fit (GOF) tests for copulas, and discuss the connection with multivariate extremes. Copule. Combinatorial design. Combinatorial design theory is the part of combinatorial mathematics that deals with the existence, construction and properties of systems of finite sets whose arrangements satisfy generalized concepts of balance and/or symmetry. These concepts are not made precise so that a wide range of objects can be thought of as being under the same umbrella. Catalan number. In combinatorial mathematics, the Catalan numbers form a sequence of natural numbers that occur in various counting problems, often involving recursively-defined objects.

Catalan number

They are named after the Belgian mathematician Eugène Charles Catalan (1814–1894). The nth Catalan number is given directly in terms of binomial coefficients by The first Catalan numbers for n = 0, 1, 2, 3, … are Properties[edit] An alternative expression for Cn is. Musical Nodes. Nankai combinatorics. Projet "sphère" Nebula. Revêtement. Un article de Wikipédia, l'encyclopédie libre. Revêtement du cercleX par une héliceY, les ensembles disjoints sont projetés homéomorphiquement sur.

Réseau valué. Couleurs. Cancel Edit Delete Preview revert Text of the note (may include Wiki markup) Could not save your note (edit conflict or other problem). Please copy the text in the edit box below and insert it manually by editing this page. Upon submitting the note will be published multi-licensed under the terms of the CC-BY-SA-3.0 license and of the GFDL, versions 1.2, 1.3, or any later version. See our terms of use for more details. Add a note Draw a rectangle onto the image above (press the left mouse button, then drag and release).

Save. Graph database. Structure[edit] Graph databases are based on graph theory.

graph database

Graph databases employ nodes, properties, and edges. Graph database Nodes represent entities such as people, businesses, accounts, or any other item you might want to keep track of. Properties are pertinent information that relate to nodes. Edges are the lines that connect nodes to nodes or nodes to properties and they represent the relationship between the two. A visual exploration on mapping complex networks.

Data visualisation of a social network. For his final year project in information design, Felix Heinen created an amazing set of visualizations of different aspects of a social network.

Data visualisation of a social network

Two big (200 x 90 cm - 80 x 36 inches) posters show the variety and attitudes of members from an internet community like MySpace. On the first poster you can see the functions used, as well as additional information, such as age, educational background, family status, gender and how often they are logged in. In a glimpse, a view into the key demographic data available for every member's profile. Seattle Band Map. The Seattle Band Map is a project that showcases the northwest's vibrant music scene by documenting the thousands of bands who have performed throughout the decades; it also explores how these bands are interconnected through personal relationships and collaborations.

This project aims to diversify the audience for and broaden the understanding of Seattle's music scene, while spotlighting unrepresented artists and musical genres. Seattle has long been known as a hotbed of musical creativity, from the thriving 60s and early 70s Soul and Funk scene, to the 90s grunge movement. Weeplaces. Invisible Cities. Invisible Cities maps information from one realm - online social networks - to another: an immersive, three dimensional space.

Invisible Cities

It displays geocoded activity from online services such as Twitter and Flickr, both in real-time and in aggregate. Real-time activity is represented as individual nodes that appear whenever a message or image is posted.