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Small world experiment

Small world experiment
The "six degrees of separation" model The small-world experiment comprised several experiments conducted by Stanley Milgram and other researchers examining the average path length for social networks of people in the United States. The research was groundbreaking in that it suggested that human society is a small-world-type network characterized by short path-lengths. The experiments are often associated with the phrase "six degrees of separation", although Milgram did not use this term himself. Historical context of the small-world problem[edit] Mathematician Manfred Kochen and political scientist Ithiel de Sola Pool wrote a mathematical manuscript, "Contacts and Influences", while working at the University of Paris in the early 1950s, during a time when Milgram visited and collaborated in their research. Milgram's experiment was conceived in an era when a number of independent threads were converging on the idea that the world is becoming increasingly interconnected. Results[edit] Related:  Network Science.caisson

Math algorithm tracks crime, rumours, epidemics to source ( -- A team of EPFL scientists has developed an algorithm that can identify the source of an epidemic or information circulating within a network, a method that could also be used to help with criminal investigations. Investigators are well aware of how difficult it is to trace an unlawful act to its source. The job was arguably easier with old, Mafia-style criminal organizations, as their hierarchical structures more or less resembled predictable family trees. In the Internet age, however, the networks used by organized criminals have changed. "Using our method, we can find the source of all kinds of things circulating in a network just by 'listening' to a limited number of members of that network," explains Pinto. Out in the real world, the algorithm can be employed to find the primary source of an infectious disease, such as cholera. The validity of this method thus has been proven a posteriori. Explore further: Pseudo-mathematics and financial charlatanism

Clustering coefficient In graph theory, a clustering coefficient is a measure of the degree to which nodes in a graph tend to cluster together. Evidence suggests that in most real-world networks, and in particular social networks, nodes tend to create tightly knit groups characterised by a relatively high density of ties; this likelihood tends to be greater than the average probability of a tie randomly established between two nodes (Holland and Leinhardt, 1971;[1] Watts and Strogatz, 1998[2]). Two versions of this measure exist: the global and the local. Global clustering coefficient[edit] The global clustering coefficient is based on triplets of nodes. Watts and Strogatz defined the clustering coefficient as follows, "Suppose that a vertex has neighbours; then at most edges can exist between them (this occurs when every neighbour of is connected to every other neighbor of ). denote the fraction of these allowable edges that actually exist. as the average of over all Transitivity Ratio[edit] A graph and a set of edges

Cours de cartes conceptuelles Une carte conceptuelle (ou schéma conceptuel, concept map en anglais), dont les variantes sont la mind map, carte des idées ou carte heuristique, est un diagramme qui représente les liens entre différents concepts. Elle peut être également appelée schéma de pensée, carte mentale, arbre à idées ou topogramme. La différence entre une carte heuristique et une carte conceptuelle est que cette dernière relie un ensemble de concepts entre eux par des lignes orientées et qualifiées (est un composant de.., favorise). De plus, elle prend la forme d' un graphe alors que la carte heuristique est un arbre. Ces cours en diapositives animées, vidéo, ppt, pdf et ces cartes conceptuelles sont distribués sous licence Creative Commons : à condition de me citer et de mettre un lien vers cette page, vous pouvez les réutiliser ou les modifier dans un cadre non-commercial, mais vous devez ensuite les publier aux mêmes conditions. - Cours de mind mapping en vidéo - En pdf et pptx En analyse fonctionnelle :

Les dessous de la pâtisserie de luxe Des macarons raffinés, des gâteaux aériens, des tartes aux allures d’œuvres d’art… En 2014, « M » s’était intéressé à la pâtisserie haut de gamme. Une tendance qui s’est imposée depuis, à rebours de la vogue du manger sain. Tout a commencé par Pierre Hermé. L’importance du storytelling Presque simultanément, et pas du tout innocemment, Hermé lance la première boutique à son nom au Japon. Il en va ainsi de la pâtisserie de luxe, où le storytelling est aussi important que la devanture du magasin. La pâtisserie est un monde merveilleux où le client se laisse bercer par des récits fantasmés, des histoires de transmission, des décors élégants. Car voilà une dizaine d’années que la pâtisserie de luxe connaît une croissance exponentielle. Lire aussi : La dissidence sucrée des chefs pâtissiers Colorants, épaississants, gélatines et conservateurs La gourmandise fait vendre, donc. « La pâtisserie à emporter, c’est complexe. Marier gourmandise et santé Lire aussi : Chic, un dessert

The DIMES project | Join the journey to map the Internet, download the DIMES agent today Power law An example power-law graph, being used to demonstrate ranking of popularity. To the right is the long tail, and to the left are the few that dominate (also known as the 80–20 rule). In statistics, a power law is a functional relationship between two quantities, where a relative change in one quantity results in a proportional relative change in the other quantity, independent of the initial size of those quantities: one quantity varies as a power of another. For instance, considering the area of a square in terms of the length of its side, if the length is doubled, the area is multiplied by a factor of four.[1] Empirical examples of power laws[edit] Properties of power laws[edit] Scale invariance[edit] One attribute of power laws is their scale invariance. , scaling the argument by a constant factor causes only a proportionate scaling of the function itself. That is, scaling by a constant simply multiplies the original power-law relation by the constant . and A power-law only if Universality[edit]

Installation d'un réseau : les étapes à respecter 1. Conseil de déploiement et audit du réseau Avant de démarrer une installation ou une modernisation du réseau informatique, l'entreprise doit évaluer ses besoins et connaître le périmètre fonctionnel de son réseau. Un prestataire rédige alors un cahier des charges précis. la nature et la superficie des locaux à équiper,les contraintes techniques de ces locaux,le nombre de serveurs requis,le nombre de personnes et de postes de travail à relier,les besoins en bande passante et en débit. 2. Cette étape vise à équiper les locaux de l'entreprise d'un réseau de câbles pour relier les serveurs et les PC entre eux. si le bâtiment est ancien, il sera difficile de percer les murs. 3. Il convient de vérifier la connectique des serveurs. 4. Les commutateurs réseaux sont des équipements électroniques intelligents qui permettent de connecter les différents serveurs et les postes de travail. 5. Cette étape plutôt classique vise à paramétrer les serveurs Windows et/ou Linux. 6. 7.

Pentagon Urgently Pushing Anti-Drone Tech to ISIS Fight From mast-mounted radar to drone-jamming guns, the U.S. military’s anti-IED office is rushing to keep up. On October 2, Peshmerga fighters operating against ISIS near Erbil, Iraq, shot down a small hobby drone, the kind you might buy off of Amazon. But when they investigated the downed device, it exploded, killing them and injuring two French paratroopers, based out of Orleans, according to Le Monde. It was a surprise to some, but not to all. At a media event, Shields and other JIDO officials laid out some of the technologies, both operational and in development, to defeat drone-borne bombs and other threats. Along with the sensors, the military is also rushing to equip troops to bring drones down. Subscribe Receive daily email updates: Subscribe to the Defense One daily. Be the first to receive updates. Continued research into how to use directed energy to down rogue drones in dense cities is “a worthy investment,” said Shields. There’s also the threat of tunnel bombs. Nifty gadgets all.