Search results for "Data availability"

Privacy-preserving data allocation in decentralized online social networks

2016

International audience; Distributed Online Social Networks (DOSNs) have been recently proposed as an alternative to centralized solutions to allow a major control of the users over their own data. Since there is no centralized service provider which decides the term of service, the DOSNs infrastructure exploits users’ devices to take on the online social network services. In this paper, we propose a data allocation strategy for DOSNs which exploits the privacy policies of the users to increase the availability of the users’ contents without diverging from their privacy preferences. A set of replicas of the profile’s content of a user U are stored on the devices of other users who are entitl…

Analysis of Users Behaviour from a Movie Preferences Perspective

2018

Despite their tremendous popularity, Online Social Networks (OSNs) have several issues related to the privacy of social users. These issues have motivated researchers to develop OSN services that take advantage of the decentralized platforms (such as P2P systems or opportunistic networks). Decentralized Online Social Networks (DOSNs) need specific approaches to manage the decentralization of social data. In particular, data availability is one of the main issues and current proposals exploit properties of the social relationships to manage it. At the best of our knowledge, there are no proposals which exploit similarity between users, expressed with the term homophily. Homophily has been we…

A privacy-aware framework for decentralized online social networks

2015

Online social networks based on a single service provider suffer several drawbacks, first of all the privacy issues arising from the delegation of user data to a single entity. Distributed online social networks (DOSN) have been recently proposed as an alternative solution allowing users to keep control of their private data. However, the lack of a centralized entity introduces new problems, like the need of defining proper privacy policies for data access and of guaranteeing the availability of user's data when the user disconnects from the social network. This paper introduces a privacy-aware support for DOSN enabling users to define a set of privacy policies which describe who is entitle…

Assessment of Modelling Structure and Data Availability Influence on Urban Flood Damage Modelling Uncertainty

2014

Abstract In modelling application, different model structures may be equally reliable in terms of calibration ability but they may produce different uncertainty levels; moreover, available data during model calibration may influence the uncertainty linked to the predictions of the same modelling structure. In the present paper, Bayesian model-averaging was applied to several flood damage estimation models in order to identify the best model combination for urban flooding distribution analysis in Palermo city center (Italy). During the analysis, was taken into account the effect of the available data growth on the model uncertainty with respect to the different combination of models outputs.

An analysis of ego network communities and temporal a affinity for online social networks

2017

The wide diffusion of Online Social Networks (OSNs) presents several advantages, like the definition of simple tools for information sharing and spreading. However, OSNs present also some drawbacks, one of the most important one is the problem of privacy disclosures. Distributed Online Social Networks (DOSNs), which decentralize the control of the social network, have been recently proposed to overcome these issues. The decentralization of the control has issued several challenges, one of the main ones is guaranteeing data availability without relying on a central server. To define users’ data allocation strategies, the knowledge of the structure of the ego network and of the user’ temporal…

Petro-mineralogical controls on coda attenuation in volcanic rock samples

2021

SUMMARY Seismic attenuation measurements, especially those obtained from coda decay analysis, are becoming a key data source for the characterization of the heterogeneous Earth due to their sensitivity to small-scale heterogeneities. However, the relation between the scattering attenuation measured from coda waves and physical rock properties is still unclear. The goal of this study is to identify the main petrophysical and mineralogical factors controlling coda attenuation in volcanic rocks at the laboratory scale, as a necessary step before modelling seismic waves in real volcanic media. Coda wave attenuation was estimated from ultrasonic S-wave waveforms. To quantify the heterogeneity of…

Data availability impact on integrated modelling reliability throughout identifiability analysis

2009

The reliability of spanish and german electricity forward prices. Databases and price discovery process

2021

Given the existence of different databases from different sources that offer information on forward electricity prices, the need to compare them arises to guarantee that research results and trading decisions based on them are not sensitive to the database used. We worked with forward electricity prices traded over the counter, closest month to maturity, covering the period from 2010 to 2016 for the Spanish over the counter (OTC) market, and from 2008 to 2016 for the German OTC market. The goal of this paper was to test whether there were significant discrepancies between the price series provided by two of the main agencies of financial information (Thomson Reuters and Bloomberg), as well …