1,197 research outputs found
C3PO: a Spontaneous and Ephemeral Social Networking Framework for a collaborative Creation and Publishing of Multimedia Contents
International audienceOnline social networks have been adopted by a large part of the population, and have become in few years essential communication means and a source of information for journalists. Nevertheless, these networks have some drawbacks that make people reluctant to use them, such as the impossibility to claim for ownership of data and to avoid commercial analysis of them, or the absence of collaborative tools to produce multimedia contents with a real editorial value. In this paper, we present a new kind of social networks, namely spontaneous and ephemeral social networks (SESNs). SESNs allow people to collaborate spontaneously in the production of multimedia documents so as to cover cultural and sport events
C3PO: A Network and Application Framework for Spontaneous and Ephemeral Social Networks
International audienceThe C3PO project promotes the development of new kind of social networks called Spontaneous and Ephemeral Social Networks (SESNs) dedicated to happenings such as cultural or sport events. SESNs rely on both opportunistic networks formed dynamically by the mobile devices of event attendees, and on an event-based communication model. Therefore, user can exchange digital contents with the other members of their SESNs, even without Internet access. This paper presents the framework developed in the C3PO project to provide network and application supports in such challenged networks. This framework exploits the different wireless interfaces of the mobile devices to interconnect them and to disseminate content through the resulting opportunistic network. At the application layer, this framework is composed of plugins that process locally the data stream to offer generic features, or to easily build applications dedicated to specific happenings
Collaborating with Users in Proximity for Decentralized Mobile Recommender Systems
Typically, recommender systems from any domain, be it movies, music,
restaurants, etc., are organized in a centralized fashion. The service provider
holds all the data, biases in the recommender algorithms are not transparent to
the user, and the service providers often create lock-in effects making it
inconvenient for the user to switch providers. In this paper, we argue that the
user's smartphone already holds a lot of the data that feeds into typical
recommender systems for movies, music, or POIs. With the ubiquity of the
smartphone and other users in proximity in public places or public
transportation, data can be exchanged directly between users in a
device-to-device manner. This way, each smartphone can build its own database
and calculate its own recommendations. One of the benefits of such a system is
that it is not restricted to recommendations for just one user - ad-hoc group
recommendations are also possible. While the infrastructure for such a platform
already exists - the smartphones already in the palms of the users - there are
challenges both with respect to the mobile recommender system platform as well
as to its recommender algorithms. In this paper, we present a mobile
architecture for the described system - consisting of data collection, data
exchange, and recommender system - and highlight its challenges and
opportunities.Comment: Accepted for publication at the 2019 IEEE 16th International
Conference on Ubiquitous Intelligence and Computing (IEEE UIC 2019
Formal and Informal Institutional Change : the Experience of Postsocialist Transformation
Diversity of trajectories of post-socialist transforming economies is a stylized fact of this experience of system change. The paper explores the relations between change in formal and informal rules in historical perspective, discussing new institutional views about rationality of formal institutions and detrimental inertia of informal institutions. It submits that an open and complex approach of the centrality of formal/informal rules interaction may give a better explanation to the multiplicity of national post-socialist pathways.Post-socialist transformation ; diversity of trajectories ; institutional change ; formal rules ; informal rules ; enforcement
Tourism communities and social ties: the role of online and offline tourist social networks in building social capital and sustainable practice.
Mobile connectivity enables the adoption of new ways to connect with social networks which are changing how we might, and could, seek support. In the tourism domain we increasingly
blend online and offline presence to engage with social networks in the spatial location, at a distance and across time. This paper explores the forms of community that exist in physical tourism contexts, contexts not previously analysed through a community lens, and explores how mobile technology is creating connections within and beyond existing social networks. It examines how sustainable tourism can be enhanced by mobile connectivity through new space-time practices and using ephemeral interpersonal relationships to harness niche groups to create bottom-up social systems interested in sharing experiences, ideas and resources. Special attention is given to the concept of gelling socialities which proposes a less ridged network structure, and to the need to understand the increasingly liquid social dynamics of mobile social interactions. The paper adds to the theories surrounding community, social ties and tourism’s value to society. It draws on data from in-depth interviews undertaken while
designing and testing a collaborative travel app. It contributes to growing research into the new technologies increasingly available for sustainable tourism marketing and
implementation
Data Storage and Dissemination in Pervasive Edge Computing Environments
Nowadays, smart mobile devices generate huge amounts of data in all sorts of gatherings.
Much of that data has localized and ephemeral interest, but can be of great use if shared
among co-located devices. However, mobile devices often experience poor connectivity,
leading to availability issues if application storage and logic are fully delegated to a
remote cloud infrastructure. In turn, the edge computing paradigm pushes computations
and storage beyond the data center, closer to end-user devices where data is generated
and consumed. Hence, enabling the execution of certain components of edge-enabled
systems directly and cooperatively on edge devices.
This thesis focuses on the design and evaluation of resilient and efficient data storage
and dissemination solutions for pervasive edge computing environments, operating with
or without access to the network infrastructure. In line with this dichotomy, our goal can
be divided into two specific scenarios. The first one is related to the absence of network
infrastructure and the provision of a transient data storage and dissemination system
for networks of co-located mobile devices. The second one relates with the existence of
network infrastructure access and the corresponding edge computing capabilities.
First, the thesis presents time-aware reactive storage (TARS), a reactive data storage
and dissemination model with intrinsic time-awareness, that exploits synergies between
the storage substrate and the publish/subscribe paradigm, and allows queries within a
specific time scope. Next, it describes in more detail: i) Thyme, a data storage and dis-
semination system for wireless edge environments, implementing TARS; ii) Parsley, a
flexible and resilient group-based distributed hash table with preemptive peer relocation
and a dynamic data sharding mechanism; and iii) Thyme GardenBed, a framework
for data storage and dissemination across multi-region edge networks, that makes use of
both device-to-device and edge interactions.
The developed solutions present low overheads, while providing adequate response
times for interactive usage and low energy consumption, proving to be practical in a
variety of situations. They also display good load balancing and fault tolerance properties.Resumo
Hoje em dia, os dispositivos móveis inteligentes geram grandes quantidades de dados
em todos os tipos de aglomerações de pessoas. Muitos desses dados têm interesse loca-
lizado e efêmero, mas podem ser de grande utilidade se partilhados entre dispositivos
co-localizados. No entanto, os dispositivos móveis muitas vezes experienciam fraca co-
nectividade, levando a problemas de disponibilidade se o armazenamento e a lógica das
aplicações forem totalmente delegados numa infraestrutura remota na nuvem. Por sua
vez, o paradigma de computação na periferia da rede leva as computações e o armazena-
mento para além dos centros de dados, para mais perto dos dispositivos dos utilizadores
finais onde os dados são gerados e consumidos. Assim, permitindo a execução de certos
componentes de sistemas direta e cooperativamente em dispositivos na periferia da rede.
Esta tese foca-se no desenho e avaliação de soluções resilientes e eficientes para arma-
zenamento e disseminação de dados em ambientes pervasivos de computação na periferia
da rede, operando com ou sem acesso à infraestrutura de rede. Em linha com esta dico-
tomia, o nosso objetivo pode ser dividido em dois cenários especÃficos. O primeiro está
relacionado com a ausência de infraestrutura de rede e o fornecimento de um sistema
efêmero de armazenamento e disseminação de dados para redes de dispositivos móveis
co-localizados. O segundo diz respeito à existência de acesso à infraestrutura de rede e
aos recursos de computação na periferia da rede correspondentes.
Primeiramente, a tese apresenta armazenamento reativo ciente do tempo (ARCT), um
modelo reativo de armazenamento e disseminação de dados com percepção intrÃnseca
do tempo, que explora sinergias entre o substrato de armazenamento e o paradigma pu-
blicação/subscrição, e permite consultas num escopo de tempo especÃfico. De seguida,
descreve em mais detalhe: i) Thyme, um sistema de armazenamento e disseminação de
dados para ambientes sem fios na periferia da rede, que implementa ARCT; ii) Pars-
ley, uma tabela de dispersão distribuÃda flexÃvel e resiliente baseada em grupos, com
realocação preventiva de nós e um mecanismo de particionamento dinâmico de dados; e
iii) Thyme GardenBed, um sistema para armazenamento e disseminação de dados em
redes multi-regionais na periferia da rede, que faz uso de interações entre dispositivos e
com a periferia da rede.
As soluções desenvolvidas apresentam baixos custos, proporcionando tempos de res-
posta adequados para uso interativo e baixo consumo de energia, demonstrando serem
práticas nas mais diversas situações. Estas soluções também exibem boas propriedades de balanceamento de carga e tolerância a faltas
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