Time as a limited resource: Communication Strategy in Mobile Phone Networks

We used a large database of 9 billion calls from 20 million mobile users to examine the relationships between aggregated time spent on the phone, personal network size, tie strength and the way in which users distributed their limited time across their network (disparity). Compared to those with smaller networks, those with large networks did not devote proportionally more time to communication and had on average weaker ties (as measured by time spent communicating). Further, there were not substantially different levels of disparity between individuals, in that mobile users tend to distribute their time very unevenly across their network, with a large proportion of calls going to a small number of individuals. Together, these results suggest that there are time constraints which limit tie strength in large personal networks, and that even high levels of mobile communication do not fundamentally alter the disparity of time allocation across networks.Comment: 10 pages, 3 figures. Accepted for publication in Social Network

Designing A Consumer Health 2.0 Application To Analyse The Relationship Between On-Line Social Networks And Health-Related Behaviours

The rapidly increasing prevalence of obesity is a phenomenon often referred to as the obesity epidemic . Literature suggests social networks to be one of the most important dimension of people\u27s social environment that may enable or constrain the adoption of health-promoting behaviors. Given that online social networks are becoming more important in people\u27s daily lives, this research in progress incorporated a design science research methodology for designing a Health 2.0 Facebook application to investigate the relationship of online social networks and health-related behaviors in the context of obesity. Specifically, the application enables medical and healthcare practitioners to (1) understand the effect of obesity propagation in online social networks; (2) identify potential online intervention strategies to disseminate health-related information to the right group of people and (3) to offer services fostering positive health-related behaviours or to promote behaviour change advice

Os Protestos no Brasil. Um estudo sobre as pesquisas na web, e o caso da Primavera Brasileira

Junho de 2013 ficou conhecido como a “Primavera Brasileira”, por conta de uma grande onda de protestos, sem precedente na historia. Ao que parece tal movimento tomou corpo, sobretudo por conta da dinâmica das redes sociais. Neste trabalho utilizamos duas ferramentas, o Google Trends e o Meltwalter IceRocket, para testar a frequência de determinados termos ligados aos protestos e as pautas do mesmo na busca do Google e a frequência de entrada dos mesmos termos nos Blogs no período de junho de 2013. Tanto a frequência de entrada em blogs, como de buscas no Google, foi maior para a palavra chave protestos do que para as variáveis ligadas as pautas políticas

Egocentric online social networks: Analysis of key features and prediction of tie strength in Facebook

The widespread use of online social networks, such as Facebook and Twitter, is generating a growing amount of accessible data concerning social relationships. The aim of this work is twofold. First, we present a detailed analysis of a real Facebook data set aimed at characterising the properties of human social relationships in online environments. We find that certain properties of online social networks appear to be similar to those found ?offline? (i.e., on human social networks maintained without the use of social networking sites). Our experimental results indicate that on Facebook there is a limited number of social relationships an individual can actively maintain and this number is close to the well-known Dunbar?s number (150) found in offline social networks. Second, we also present a number of linear models that predict tie strength (the key figure to quantitatively represent the importance of social relationships) from a reduced set of observable Facebook variables. Specifically, we are able to predict with good accuracy (i.e., higher than 80%) the strength of social ties by exploiting only four variables describing different aspects of users interaction on Facebook. We find that the recency of contact between individuals ? used in other studies as the unique estimator of tie strength ? has the highest relevance in the prediction of tie strength. Nevertheless, using it in combination with other observable quantities, such as indices about the social similarity between people, can lead to more accurate prediction

Tecnologías de la información y llegar a la sociedad de la información

El rápido desarrollo de las tecnologías de la información y la comunicación ha hecho que los países que utilizan estas tecnologías sean un paso adelante en la competencia mundial. Gracias a las contribuciones de las organizaciones públicas, privadas y no gubernamentales de todo el mundo desde principios de los años noventa, se ha avanzado considerablemente en llegar a la sociedad de la información. La edad en la que vivimos se llama la era de la información. En esta sociedad donde el conocimiento se convierte en poder, se espera mucho de los individuos. Es necesario que las personas puedan acceder a la información por sí mismas, cuestionar la información que obtienen, usarla de acuerdo con sus necesidades y tener la capacidad de pensar científicamente. En este estudio, se utilizó el análisis de documentos escritos. A este respecto, el análisis de documentos escritos y documentos es un método de recopilación de información utilizado en la investigación cualitativa para respaldar la información obtenida tanto por sí misma como para la entrevista y la observació

Models of Social Networking and Information Diffusion in Future Internet Cyber-Physical Environments

Negli ultimi anni, la grande diffusione di tecnologie ICT, es. dispositivi mobili e servizi di social networking, hanno portato alla proliferazione di reti elettroniche e comunità virtuali in cui i contenuti sono generati e propagati dagli utenti ICT. Poiché gli utenti interagiscono anche nel mondo fisico tramite relazioni sociali umane, le informazioni generate nel mondo virtuale possono produrre effetti nel mondo fisico e vice versa. Questo fenomeno, chiamato cyber-physical convergence, sta diventando un argomento di ricerca di rilievo per la progettazione e test di servizi avanzati di social networking. In questa tesi vengono forniti nuovi fondamentali spunti riguardo la cyber-physical convergence, verificando che le proprietà delle reti sociali umane, formate nel mondo fisico, possono essere mappate direttamente sulle strutture sociali formate dagli utenti ICT nel mondo virtuale. Questo risultato ci permette di definire una nuova generazione di modelli di rete vengono catturate le caratteristiche chiave delle relazioni sociali umane sia del mondo virtuale che di quello fisico. Dato che le relazioni sociali sono una delle basi della comunicazione e degli schemi di scambio di informazioni tra utenti, questi modelli sono strumenti utili per progettare e valutare le performance di soluzioni tecniche content-centric per scenari in cui si verifica la cyber-physical convergence. Un altro contributo di questa tesi, per la progettazione di servizi content-centric, è la definizione e la valutazione di nuove modelli di information diffusion. I nostri modelli sono in grado di riprodurre fedelmente i tipici schemi di diffusione delle OSNs, e che possono essere usati per studiare "in vitro" le performance dei servizi di information diffusion rispetto ai parametri chiave del sistema e del comportamento degli utenti. In the last years, the large diffusion of ICT technologies, e.g. personal devices and social networking services, led to the proliferation of electronic networks and virtual communities in which new content is generated and propagated by ICT users. Since users also interact in the physical world through human social relationships, the information generated in the cyber world can produce outcomes in the physical world and vice-versa. This phenomenon, called cyber-physical convergence, is becoming a prominent topic of research for the design of efficient Future Internet solutions. Indeed, such integration can be exploited for the design of efficient networking solutions for content dissemination and for the development and testing of advanced social networking services. In this thesis we provide new fundamental insights about the cyber-physical convergence, verifying that the properties of the human social networks, formed in the physical world, can be directly mapped to the social structures formed by ICT users in the cyber world. This result allows us to define a new generation of network models where we capture the key characteristics of human social relationships both in the cyber and in the physical worlds. As social relationships are one of the basis of communication and information exchange patterns between users, these models are useful tools to design and evaluate the performance of content-centric technical solutions for cyber-physical converging scenarios. Another contribution of this thesis, towards the design of content-centric services, is the definition and evaluation of novel information dissemination models. Our models are able to closely re-produce typical information diffusion patterns in OSNs, and can be used to understand "in vitro" the performance of information diffusion services with respect to key parameters of the system and users' behaviour

Analysis of the Structure of Social Networks for Information Diffusion

The vast proliferation of Online Social Networks (OSN) is generating many new ways to interact and create social relationships with others. In OSN, information spreads among users following existing social relationships. This spread is influenced by the local properties and structures of the social relationships at individual level. Being able to understand these properties can be fundamental for the design of new communication systems able to predict the creation and sharing of content based on social properties of the users. While substantial results have been obtained in anthropology literature describing the properties of human social networks, a clear understanding of the properties of social networks built using OSN is still to be achieved. In this thesis, the structure of Ego networks formed online is compared with the properties of offline social relationships showing interesting similarities. These properties are exploited to provide a meaningful way to study the mechanisms controlling the formation of information diffusion chains in social networks (typically referred to as information cascades). Trough the analysis of synthetically generated diffusion cascades executed in a large Facebook communication datasets, is showed that the knowledge of tie strength of the social links is fundamental to infer which nodes will give rise to large information cascades and which links will be more used in the information diffusion process. We analysed the trade off between information spread and trustworthiness of information. Specifically, we have investigated the spread of information when only links of a certain trust value are used. Assuming, based on results from sociology, that trust can be quantised, we show that too strict limits on the minimum trust between users limit significantly information spread. In the thesis we investigate the effect of different strategies to significantly increase spread of information by minimally relaxing constraints on the minimum allowed trust level

Towards a Characterization of Egocentric Networks in Online Social Networks

Online Social Networks (OSNs) are more and more establishing as one of the key means to create and enforce social relationships between individuals. While substantial results have been obtained in the anthropology literature describing the properties of human social networks (built ?outside? the OSN world), a clear understanding of the properties of social networks built using OSNs is still to be achieved. In this paper we provide a contribution towards this goal, by starting characterizing ego networks formed inside Facebook through the analysis of data obtained from a measurement campaign. Ego networks capture all the social relationships (links) between an ego and all the other people with whom the ego has a social tie. Ego networks are one of the key social structure that have been studied in the anthropology literature, and is thus a reference objective for our work. In this paper we analyze a number of quantitative variables that can be collected on Facebook, which can be used to describe the properties of the social links in ego networks. We also analyze the correlation between these variables and the strength of the social ties, as explicitly ranked by the monitored Facebook users. Our results show that there is an interesting similarity between the properties observed by anthropologists in human social networks, and those of Facebook social networks. Moreover, we found a noticeable correlation between most of the measured variables and the tie strengths, suggesting the possibility of automatically inferring the latter from measurable Facebook variables