Large-scale networks of human interaction, in particular country-wide telephone call networks, can be used to redraw geographical maps by applying algorithms of topological community detection. The geographic projections of the emerging areas in a few recent studies on single regions have been suggested to share two distinct properties: first, they are cohesive, and second, they tend to closely follow socio-economic boundaries and are similar to existing political regions in size and number. Here we use an extended set of countries and clustering indices to quantify overlaps, providing ample additional evidence for these observations using phone data from countries of various scales across Europe, Asia, and Africa: France, the UK, Italy, Belgium, Portugal, Saudi Arabia, and Ivory Coast. In our analysis we use the known approach of partitioning country-wide networks, and an additional iterative partitioning of each of the first level communities into sub-communities, revealing that cohesiveness and matching of official regions can also be observed on a second level if spatial resolution of the data is high enough. The method has possible policy implications on the definition of the borderlines and sizes of administrative regions.
Sobolevsky S, Szell M, Campari R, Couronné T, Smoreda Z, et al. (2013) Delineating Geographical Regions with Networks of Human Interactions in an Extensive Set of Countries. PLoS ONE 8(12): e81707. http://dx.doi.org/10.1371/journal.pone.0081707
Sous la direction de Valérie Châtelet, architecte-urbaniste engagée avec anomos/skylab dans l'exploration de l'impact des technologies numériques, une dizaine d'auteurs apporte leurs contributions à ce débat. Ces essais sont illustrés par de nombreux projets pour la plupart inédits et rassemblés pour la première fois autour de ce thème. Historiens, géographes, ingénieurs, artistes, architectes et des urbanistes interrogent les implications de cette nouvelle condition urbaine.
Parmi les contributeurs, Dominique Rouillard trace un parcours historique de l'intégration des technologies de l'information et la communication pour l'urbanisation. En référence aux travaux de l'inventeur américain Buckminster Fuller, Valérie Chatelet développe le principe d'une nouvelle articulation des décisions pour l'urbanisme et l'aménagement du territoire. Carlo Ratti et Daniel Berry du laboratoire de recherche du Massachusetts Institute of Technology (MIT) SENSEable City évoque l'idée de paysages mobiles développés par l'internet sans fil et les téléphones mobiles qui reconfigurent nos modes de vie.
Le Phénomène de « Petit Monde », Clé du Succès Economique ... IsraelValley Tous les lieux publics – cafés, transports en commun, plages, etc. – sont autant d'opportunités de faire de nouvelles rencontres.
Network robustness research aims at finding a measure to quantify network robustness. Once such a measure has been established, we will be able to compare networks, to improve existing networks and to design new networks that are able to continue to perform well when it is subject to failures or attacks. In this paper we survey a large amount of robustness measures on simple, undirected and unweighted graphs, in order to offer a tool for network administrators to evaluate and improve the robustness of their network. The measures discussed in this paper are based on the concepts of connectivity (including reliability polynomials), distance, betweenness and clustering. Some other measures are notions from spectral graph theory, more precisely, they are functions of the Laplacian eigenvalues. In addition to surveying these graph measures, the paper also contains a discussion of their functionality as a measure for topological network robustness.
Graph measures and network robustness W. Ellens, R.E. Kooij
Notre cerveau possède un GPS intégré ! Journal de la Science Nous décidons alors de cartographier les emplacements géographiques où ces neurones-grille s'activent pendant les déplacements de l'individu : ces emplacements géographiques vont...
Onomastique et Big Data ParisTech Review La technologie d'association automatique des noms (automatic name clustering) permet de décrypter les identités complexes présentes dans les territoires quelque soit leur échelle (un continent, une rue) afin...
Antoine Grandclement, Les dynamiques spatiales des réseaux d'innovation : articuler réseaux d'acteurs et réseaux de lieux, p. 101-119. Julien Brailly, Guillaume Favre et Emmanuel Lazega, Temps et espace : l'impact de la ...
Amsterdam fans out south from the Amsterdam Centraal railway station. The oldest area of the town is known as de Wallen (the quays). Seen in the image above is the 17th century canal ring area of Amsterdam. The city has more than one hundred kilometres of canals, about 90 islands and 1,500 bridges. [Source]
Amsterdam is the capital and most populous city of the Netherlands with a population of 805,166 within the city-proper, 1,563,141 in the urban region and 2,349,870 in the greater metropolitan area. It is located in the province of North Holland in the west of the country. Originating as a small fishing village in the late 12th century, Amsterdam became one of the most important ports in the world during the Dutch Golden Age, a result of its innovative developments in trade. [Source]
Facebook has detailed its extensive improvements to the open source Apache Giraph graph-processing platform. The project, which is built on top of Hadoop, can now process trillions of connections between people, places and things in minutes.
"In this book, I suggest that to understand cities we must view them not simply as places in space but as systems of networks and flows. To understand space, we must understand flows, and to understand flows, we must understand networks—the relations between objects that comprise the system of the city. Drawing on the complexity sciences, social physics, urban economics, transportation theory, regional science, and urban geography, , I introduce theories and methods that reveal the deep structure of how cities function. (...)" Michael Batty
The global spread of epidemics, rumors, opinions, and innovations are complex, network-driven dynamic processes. The combined multiscale nature and intrinsic heterogeneity of the underlying networks make it difficult to develop an intuitive understanding of these processes, to distinguish relevant from peripheral factors, to predict their time course, and to locate their origin. However, we show that complex spatiotemporal patterns can be reduced to surprisingly simple, homogeneous wave propagation patterns, if conventional geographic distance is replaced by a probabilistically motivated effective distance. In the context of global, air-traffic–mediated epidemics, we show that effective distance reliably predicts disease arrival times. Even if epidemiological parameters are unknown, the method can still deliver relative arrival times. The approach can also identify the spatial origin of spreading processes and successfully be applied to data of the worldwide 2009 H1N1 influenza pandemic and 2003 SARS epidemic.
The Hidden Geometry of Complex, Network-Driven Contagion Phenomena Dirk Brockmann, Dirk Helbing
3 Les auteurs du présent article appartiennent au Shrinking Cities International Research Network, fo (...) 1Depuis quelques années, et en particulier à l'occasion de la crise récente et de ses manifestations intenses dans le ...
Très haut débit : le mouvement est engagé dans les territoires ruraux Gazette des communes Guichet rouvert en juin - La fronde des sept réseaux d'initiative publique (RIP) signataires du mémorandum qui dénonçait, il y a deux ans, dans ces mêmes...
Le radiotélescope sarde SRT arrive bulletins-electroniques.com Enfin, il peut également servir comme station de réception pour les signaux émis par des sondes spatiales interplanétaires, en s'insérant au sein du réseau mondial Deep Space Network.
Introduction and background. The outcome of a random process is often well described by a bell-shaped curve, the normal distribution. Some hundred years ago, it was noticed that things like the richness among people, town sizes, surnames, and the frequency of words have different, broader distributions. The figure shows the probability of finding a word which occurs k times in a novel. If the words were distributed according to normal expectations, they would fall on the full curve in the figure. Many, more or less system-specific, proposals for the deviation from normal have been suggested under names such as 'rich gets richer', 'principle of least effort', 'preferential attachment' and 'independent proportional growth'. Here, it is argued that the phenomenon is connected to a more ubiquitous random group formation. A group is like a soccer team with positions to fill. You want the right player in the right position. Thus, unlike the normal distribution where you pick a player for the team, one now tries to pick a player for a position in the team. Main results. Information theory is used to find the most likely distribution of group sizes given the number of objects, groups and the number of objects in the largest group. The result is the dashed curve in the figure. The same striking agreement is found for all data sets investigated. Wider implications. This paper gives a new starting point for the understanding of Zipf-type phenomena.
More than 1.4 billion airline passengers departed, landed, or connected through these massive facilities in 2012. Viewing them from above gives a sense of their gargantuan scale and global significance.