The structure of borders in a small world

Geographic borders are not only essential for the effective functioning of government, the distribution of administrative responsibilities and the allocation of public resources, they also influence the interregional flow of information, cross-border trade operations, the diffusion of innovation and technology, and the spatial spread of infectious diseases. However, as growing interactions and mobility across long distances, cultural, and political borders continue to amplify the small world effect and effectively decrease the relative importance of local interactions, it is difficult to assess the location and structure of effective borders that may play the most significant role in mobility-driven processes. The paradigm of spatially coherent communities may no longer be a plausible one, and it is unclear what structures emerge from the interplay of interactions and activities across spatial scales. Here we analyse a multi-scale proxy network for human mobility that incorporates travel across a few to a few thousand kilometres. We determine an effective system of geographically continuous borders implicitly encoded in multi-scale mobility patterns. We find that effective large scale boundaries define spatially coherent subdivisions and only partially coincide with administrative borders. We find that spatial coherence is partially lost if only long range traffic is taken into account and show that prevalent models for multi-scale mobility networks cannot account for the observed patterns. These results will allow for new types of quantitative, comparative analyses of multi-scale interaction networks in general and may provide insight into a multitude of spatiotemporal phenomena generated by human activity.Comment: 9 page

Investigating Bimodal Clustering in Human Mobility

We apply a simple clustering algorithm to a large dataset of cellular telecommunication records, reducing the complexity of mobile phone users' full trajectories and allowing for simple statistics to characterize their properties. For the case of two clusters, we quantify how clustered human mobility is, how much of a user's spatial dispersion is due to motion between clusters, and how spatially and temporally separated clusters are from one another.Comment: 4 pages, 2 figure

Large scale movement analysis from WiFi based location data

Understanding and modeling the way humans move in urban contexts is beneficial for many applications. The recent advances on positioning technologies, namely those based on the ubiquity of wireless networks, is facilitating the observation of people for human motion analysis. In this paper we present the result of a large scale work conducted to study the human mobility in a University’s campuses. The study was conducted along several months, using data collected from thousands of users that freely moved inside the numerous buildings existent in two University campuses and a few other buildings in the city center. A Wi-Fi infrastructure of more than 550 access points provides Internet access to the academic community. We tracked the user movements by logging the devices connected to each access point. Based on that data, an analysis process that highlights the relationships between space features and human motion has been developed. In this paper we introduce the concepts of “place connectivity” and “flow across a boundary” to model these relationships. Results show the mobility patterns detected, which are the attraction places along the day, and what places are more strongly connected. This paper also includes an analysis of the short and long term movements between places. With this study we extended our understanding of the life in the campus, enabling us to feel the campus “pulse”.This work was supported by the FEDER program through the COMPETE and the Portuguese Science and Technology Foundation (FCT), within the context of projects SUM – Sensing and Understanding human Motion dynamics (reference PTDC/EIA-EIA/113933/2009) and TICE.Mobilidade (COMPETE 13843)

The circulation of euro coins as markers of European mobility in France

This study examines the social and territorial structure of the relations between Eurozone countries and residents that we grasp by studying the diffusion of foreign euro coins (2002-2011). As a euro coin is conveyed across space by persons, it offers a good representation of both social and spatial networks, as well as it allows the study of both social and territorial inequalities with regards to international connectiveness. We use a series of individual-level representative surveys describing the content of the money bag of an amount of 21,669 respondents and analyse internationalization differences using logistic regressions. The results show that students and executives are the social categories that are the most connected to neighbouring peoples and which are therefore potential vectors of a European identity. They also demonstrate strong spatial and territorial variations of the openness of places and people to the rest of Europe—everything else being equal.Cet article s’intéresse à la structure des relations sociales et territoriales qui se tissent en Europe à travers l’étude de la diffusion des pièces de monnaie étrangères en euro (2002-2011). Dans la mesure où les pièces de monnaie circulent à la faveur de l’échange entre personnes, leur répartition est un marqueur indirect de la mise en réseau des territoires et des hommes qui reflète bien les inégalités territoriales et sociales dans l’accès à la mobilité internationale. Nous présentons dans cet article une série d’études individuelles représentatives décrivant le contenu du porte-monnaie de 21 669 enquêtés et analysant les différences en terme d’internationalisation sur la base de régressions logistiques. Les résultats montrent que les étudiants et les cadres sont les catégories sociales les plus connectées aux populations étrangères voisines et qu’elles sont en conséquence des vecteurs potentiels d’une identité européenne. Ils montrent également de fortes variations spatiales et territoriales en termes d’ouverture au reste de l’Europe des personnes et des lieux – toutes choses étant égales par ailleurs

Dealing with multiple source spatio-temporal data in urban dynamics analysis

Capturing, representing, modelling and visualizing the dynamics of urban mobility have been attracting the interest of the research community recently. One of the drivers for recent work in this area is the availability of large datasets representing many aspects of the urban dynamics. Applications for these studies are diverse and include urban planning, security, intelligent transportation systems and many others. Quite often, the proposed approaches are highly dependent on the data type. This paper describes the definition of a set of basic concepts for the representation and processing of spatio-temporal data, sufficiently flexible to deal with various types of mobility data and to support multiple forms of processing and visualization of the urban mobility. A place learning algorithm is also described to illustrate the flexibility of the proposed framework. Available results obtained by the integration of geometric and symbolic data reveal the adequacy of the proposed concepts, and uncover new possibilities for the fusion of heterogeneous datasets.Research group supported by FEDER Funds through the COMPETE and National Funds through FCT – Fundação para a Ciência e a Tecnologia under the Project: FCOMP-01-FEDER-0124-022674

The use of mobile phone data for the estimation of the travel patterns and imported Plasmodium falciparum rates among Zanzibar residents

Background: malaria endemicity in Zanzibar has reached historically low levels, and the epidemiology of malaria transmission is in transition. To capitalize on these gains, Zanzibar has commissioned a feasibility assessment to help inform on whether to move to an elimination campaign. Declining local transmission has refocused attention on imported malaria. Recent studies have shown that anonimized mobile phone records provide a valuable data source for characterizing human movements without compromising the privacy of phone users. Such movement data in combination with spatial data on P. falciparum endemicity provide a way of characterizing the patterns of parasite carrier movements and the rates of malaria importation, which have been used as part of the malaria elimination feasibility assessment for the islands of Zanzibar. Data and methods: records encompassing three months of complete mobile phone usage for the period October-December 2008 were obtained from the Zanzibar Telecom (Zantel) mobile phone network company, the principal provider on the islands of Zanzibar. The data included the dates of all phone usage by 770,369 individual anonymous users. Each individual call and message was spatially referenced to one of six areas: Zanzibar and five mainland Tanzania regions. Information on the numbers of Zanzibar residents travelling to the mainland, locations visited and lengths of stay were extracted. Spatial and temporal data on P. falciparum transmission intensity and seasonality enabled linkage of this information to endemicity exposure and, motivated by malaria transmission models, estimates of the expected patterns of parasite importation to be made. Results: over the three month period studied, 88% of users made calls that were routed only through masts on Zanzibar, suggesting that no long distance travel was undertaken by this group. Of those who made calls routed through mainland masts the vast majority of trips were estimated to be of less than five days in length, and to the Dar Es Salaam Zantel-defined region. Though this region covered a wide range of transmission intensities, data on total infection numbers in Zanzibar combined with mathematical models enabled informed estimation of transmission exposure and imported infection numbers. These showed that the majority of trips made posed a relatively low risk for parasite importation, but risk groups visiting higher transmission regions for extended periods of time could be identified. Conclusion: anonymous mobile phone records provide valuable information on human movement patterns in areas that are typically data-sparse. Estimates of human movement patterns from Zanzibar to mainland Tanzania suggest that imported malaria risk from this group is heterogeneously distributed; a few people account for most of the risk for imported malaria. In combination with spatial data on malaria endemicity and transmission models, movement patterns derived from phone records can inform on the likely sources and rates of malaria importation. Such information is important for assessing the feasibility of malaria elimination and planning an elimination campaign

Harnessing the digital records of everyday things

We address how, framed by the Internet of Things, digitally-enabled physical objects may acquire rich digital records throughout their lifetimes, and how these might enhance their value, meaning and utility. We reflect on emerging findings from two case studies, one focusing on wargaming miniatures and the other on an augmented guitar, that engage communities of practice in capturing and utilising rich digital records of things. We articulate an agenda for future research in terms of four key themes: How can the digital records of everyday things be captured using both manual and automated approaches? How can these records enhance the embodied use of things in suitably discrete ways? How can people generate diverse stories and accounts from these records? How can we revisit current notions of ownership to reflect a more fluid sense of custodianship? The findings of the studies reveal common emergent themes and preferences of the practicing communities that surround these objects and the above questions, while ongoing participatory and probe studies continue to reveal nuances and evaluate possible approaches

Human Movement Is Both Diffusive and Directed

Understanding the influence of the built environment on human movement requires quantifying spatial structure in a general sense. Because of the difficulty of this task, studies of movement dynamics often ignore spatial heterogeneity and treat movement through journey lengths or distances alone. This study analyses public bicycle data from central London to reveal that, although journey distances, directions, and frequencies of occurrence are spatially variable, their relative spatial patterns remain largely constant, suggesting the influence of a fixed spatial template. A method is presented to describe this underlying space in terms of the relative orientation of movements toward, away from, and around locations of geographical or cultural significance. This produces two fields: one of convergence and one of divergence, which are able to accurately reconstruct the observed spatial variations in movement. These two fields also reveal categorical distinctions between shorter journeys merely serving diffusion away from significant locations, and longer journeys intentionally serving transport between spatially distinct centres of collective importance. Collective patterns of human movement are thus revealed to arise from a combination of both diffusive and directed movement, with aggregate statistics such as mean travel distances primarily determined by relative numbers of these two kinds of journeys

A model for spatially embedded social networks

This paper presents a stochastic model for spatially embedded social networks based on the ideas of spatial interaction models. Analysing empirical data, we find that the probability to accept a social contact at a certain distance follows a power law with exponent -1.6. With a simulation where the spatial distribution of vertices is defined by a synthetic population of Switzerland, we can reproduce the edge length distribution observed in the empirical data as well as some other typical properties of social networks