Search results for "internet"
showing 10 items of 2589 documents
l'offerta trasportistica all'interno dei siti internet alberghieri
2011
Exploiting community detection to recommend privacy policies in decentralized online social networks
2018
The usage of Online Social Networks (OSNs) has become a daily activity for billions of people that share their contents and personal information with the other users. Regardless of the platform exploited to provide the OSNs’ services, these contents’ sharing could expose the OSNs’ users to a number of privacy risks if proper privacy-preserving mechanisms are not provided. Indeed, users must be able to define its own privacy policies that are exploited by the OSN to regulate access to the shared contents. To reduce such users’ privacy risks, we propose a Privacy Policies Recommended System (PPRS) that assists the users in defining their own privacy policies. Besides suggesting the most appro…
Internet and Mathematic Education (E-Learning objects and tools for Mathematics Education)
2011
This paper analyzes some e-learning objects and didactics tools for improving mathematics education. The learning objects and tools analyzed are Videos, Applet Java, Geogebra, Wolfram|Alpha with his Widgets, Google Spreadsheets and Wiris. The analysis has been based on the parameters considered more suitable for didactics of mathematics. Such parameters are: interactivity, shareability, availability, applicability and feasibility. The paper presents a brief description of how the didactics is changing with internet, in particularly the didactics of the mathematics. It then shows the objects and tools selected with some application examples. Finally, it illustrates an comparison of the objec…
Searching the internet for learning materials through didactic indicators
2007
Internet offers a huge amount of didactic materials that can be used in creating new online courses. However, those materials need a deep analysis to understand their context and contents before their potential use. As a consequence, the search of didactic material in internet is often quite tedious and time consuming so the searcher usually limits his/her analysis to the first found web pages . To help users in finding efficiently and timely the most appropriate online materials, we have developed a system, called SAXEF (System for Automatic eXtraction of lEearning object Features), that is capable to automatically extract the didactic indicators (a sort of DNA) of any web page (or group o…
Revealing Transmit Diversity Mechanisms in Commercial IEEE 802.11 Cards
2008
Service differentiation in WLAN has been traditionally faced at the MAC layer. However, some PHY layer parameters, such as the transmission power, the antenna, and the modulation/coding scheme, have a deep impact on network performance. Since the criterion for selecting these parameters is left to the vendor specific implementations, the performance spread of most experimental results about 802.11 WLAN could be affected by vendor proprietary schemes. The focus of this paper is an experimental analysis of the undisclosed antenna diversity mechanisms employed by some widely used cards (namely, the Atheros and Intel based cards), and a thorough understanding of the optimization goals which gui…
A Survey on LoRa for Smart Agriculture: Current Trends and Future Perspectives
2023
This paper provides a survey on the adoption of LoRa in the agricultural field, and reviews state-of-the-art solutions for Smart Agriculture, analyzing the potential of this technology in different infield applications. In particular, we consider four reference scenarios, namely irrigation systems, plantation and crop monitoring, tree monitoring, and livestock monitoring, which exhibit heterogeneous requirements in terms of network bandwidth, density, sensors’ complexity, and energy demand, as well as latency in the decision process. We discuss how LoRa-based solutions can work in these scenarios, analyzing their scalability, interoperability, network architecture, and energy-efficiency. Fi…
The quest for bandwidth estimation techniques for large-scale distributed systems
2010
In recent years the research community has developed many techniques to estimate the end-to-end available bandwidth of an Internet path. This important metric can be potentially exploited to optimize the performance of several distributed systems and, even, to improve the effectiveness of the congestion control mechanism of TCP. Thus, it has been suggested that some existing estimation techniques could be used for this purpose. However, existing tools were not designed for large-scale deployments and were mostly validated in controlled settings, considering only one measurement running at a time. In this paper, we argue that current tools, while offering good estimates when used alone, migh…
Large-Scale Available Bandwidth Measurements: Interference in Current Techniques
2011
The end-to-end available bandwidth of an Internet path is a desirable information that can be exploited to optimize system performance. Several tools have been proposed in the past to estimate it. However, existing measurement techniques were not designed for large-scale deployments. In this paper we show that current tools do not properly work where multiple probing processes share a portion of a path. We provide experimental evidence to quantify the impact of mutual interference between measurements. We further analyze the characteristics of popular tools, quantifying (i) the impact of mutual interference, (ii) the total overhead imposed to the network and (iii) the intrusiveness of the m…
Extracting Structured Knowledge From Sensor Data for Hybrid Simulation
2014
Obtaining continuous and detailed monitoring of indoor environments has today become viable, also thanks to the widespread availability of effective and flexible sensing technology; this paves the way for the design of practical Ambient Intelligence systems, and for their actual deployment in real-life contexts, which require advanced functionalities, such as for instance the automatic discovery of the activities carried on by users. Novel issues arise in this context; on one hand, it is important to reliably model the phenomena under observation even though, to this end, it is often necessary to craft a carefully designed prototype in order to test and fine-tune the theoretical models.
A Novel Recruitment Policy to Defend against Sybils in Vehicular Crowdsourcing
2021
Vehicular Social Networks (VSNs) is an emerging communication paradigm, derived by merging the concepts of Online Social Networks (OSNs) and Vehicular Ad-hoc Networks (VANETs). Due to the lack of robust authentication mechanisms, social-based vehicular applications are vulnerable to numerous attacks including the generation of sybil entities in the networks. We address this important issue in vehicular crowdsourcing campaigns where sybils are usually employed to increase their influence and worsen the functioning of the system. In particular, we propose a novel User Recruitment Policy (URP) that, after extracting the participants within the event radius of a crowdsourcing campaign, detects …