Fundamental structures of dynamic social networks

Social systems are in a constant state of flux with dynamics spanning from minute-by-minute changes to patterns present on the timescale of years. Accurate models of social dynamics are important for understanding spreading of influence or diseases, formation of friendships, and the productivity of teams. While there has been much progress on understanding complex networks over the past decade, little is known about the regularities governing the micro-dynamics of social networks. Here we explore the dynamic social network of a densely-connected population of approximately 1000 individuals and their interactions in the network of real-world person-to-person proximity measured via Bluetooth, as well as their telecommunication networks, online social media contacts, geo-location, and demographic data. These high-resolution data allow us to observe social groups directly, rendering community detection unnecessary. Starting from 5-minute time slices we uncover dynamic social structures expressed on multiple timescales. On the hourly timescale, we find that gatherings are fluid, with members coming and going, but organized via a stable core of individuals. Each core represents a social context. Cores exhibit a pattern of recurring meetings across weeks and months, each with varying degrees of regularity. Taken together, these findings provide a powerful simplification of the social network, where cores represent fundamental structures expressed with strong temporal and spatial regularity. Using this framework, we explore the complex interplay between social and geospatial behavior, documenting how the formation of cores are preceded by coordination behavior in the communication networks, and demonstrating that social behavior can be predicted with high precision.Comment: Main Manuscript: 16 pages, 4 figures. Supplementary Information: 39 pages, 34 figure

Investigating the use of semantic technologies in spatial mapping applications

Semantic Web Technologies are ideally suited to build context-aware information retrieval applications. However, the geospatial aspect of context awareness presents unique challenges such as the semantic modelling of geographical references for efficient handling of spatial queries, the reconciliation of the heterogeneity at the semantic and geo-representation levels, maintaining the quality of service and scalability of communicating, and the efficient rendering of the spatial queries' results. In this paper, we describe the modelling decisions taken to solve these challenges by analysing our implementation of an intelligent planning and recommendation tool that provides location-aware advice for a specific application domain. This paper contributes to the methodology of integrating heterogeneous geo-referenced data into semantic knowledgebases, and also proposes mechanisms for efficient spatial interrogation of the semantic knowledgebase and optimising the rendering of the dynamically retrieved context-relevant information on a web frontend

GEOSPATIAL ANALYSIS OF PEDIATRIC TUBERCULOSIS IN BOHOL, PHILIPPINES: DISEASE CLUSTERS AND ACCESS TO CARE

Worldwide, children represent approximately 10% of global tuberculosis (TB) cases. We recently reported a high tuberculin skin test (TST)-positive prevalence (355/5,476; weighted prevalence=6.4%) among children (\u3c15 years) throughout the island of Bohol, Philippines, with some geographically isolated communities having prevalence as high as 29%. In this study, we conducted a secondary geospatial and hot-spot analysis of this household-based cluster survey to assess the association between access to care (distance to a health care facility) and TST-positive prevalence. Our analysis indicated that villages with high TST-positive prevalence (≥10%) were significantly further from Provincial Health Office based in the capital city of Tagbilaran in time-distance (p=0.0001, r=0.2387) and kilometers (p=0.0011, r=0.3170). Similarly, prevalence was positively correlated with distance to the municipal Rural Health Unit (RHU), where most receive their medical care, in time-distance (p=0.0055; r=0.0415); however, the association was not significant in kilometers (p=0.3315; r=0.0715). Distance to health care facilities could represent an obstacle to access to care, thereby limiting diagnosis and treatment and resulting in increased risk of transmission to others in the community. Health care outreach in geographically isolated areas is critical to treatment and control of efforts for pediatric TB