Design and Performance Evaluation of Data Dissemination Systems for Opportunistic Networks Based on Cognitive Heuristics

It is often argued that the Future Internet will be a very large scale content-centric network. Scalability issues will stem even more from the amount of content nodes will gen- erate, share and consume. In order to let users become aware and retrieve the content they really need, these nodes will be required to swiftly react to stimuli and assert the rele- vance of discovered data under uncertainty and only partial information. The human brain performs the task of infor- mation ltering and selection using the so-called cognitive heuristics, i.e. simple, rapid, low-resource demanding, yet very eective schemes that can be modeled using a func- tional approach. In this paper we propose a solution based on one such heuristics, namely the recognition heuristic, for dealing with data dissemination in opportunistic networks. We show how to implement an algorithm that exploits the environmental information in order to implement an eec- tive dissemination of data based on the recognition heuristic, and provide a performance evaluation of such a solution via simulation

A Holistic Approach for High-level Programming of Next-generation Data-intensive Applications Targeting Distributed Heterogeneous Computing Environment

AbstractThe intrinsic richness and heterogeneity of large amount of data is paired with the extreme complexity in its storing and processing, as well as with the heterogeneity of their processing environments, ranging from super computers to federations of Cloud data-centres. This makes the conception, definition and implementation of software tools for programming applications dealing with very large amount of data really challenging from different perspectives, ranging from technological issues to economic concerns. We propose an approach focused on data-intensive applications that goes beyond the state of the art allowing a seamless exploitation of heterogeneous and distributed resources and satisfying users’ needs on data processing providing a dynamically determined set of features, depending on the running environment, the application, the user requirements

AoI-based Multicast Routing over Voronoi Overlays with Minimal Overhead

The increasing pervasive and ubiquitous presence of devices at the edge of the Internet is creating new scenarios for the emergence of novel services and applications. This is particularly true for location- and context-aware services. These services call for new decentralized, self-organizing communication schemes that are able to face issues related to demanding resource consumption constraints, while ensuring efficient locality-based information dissemination and querying. Voronoi-based communication techniques are among the most widely used solutions in this field. However, when used for forwarding messages inside closed areas of the network (called Areas of Interest, AoIs), these solutions generally require a significant overhead in terms of redundant and/or unnecessary communications. This fact negatively impacts both the devices' resource consumption levels, as well as the network bandwidth usage. In order to eliminate all unnecessary communications, in this paper we present the MABRAVO (Multicast Algorithm for Broadcast and Routing over AoIs in Voronoi Overlays) protocol suite. MABRAVO allows to forward information within an AoI in a Voronoi network using only local information, reaching all the devices in the area, and using the lowest possible number of messages, i.e., just one message for each node included in the AoI. The paper presents the mathematical and algorithmic descriptions of MABRAVO, as well as experimental findings of its performance, showing its ability to reduce communication costs to the strictly minimum required.Comment: Submitted to: IEEE Access; CodeOcean: DOI:10.24433/CO.1722184.v1; code: https://github.com/michelealbano/mabrav

GROUP: A Gossip Based Building Community Protocol

The detection of communities of peers characterized by similar interests is currently a challenging research area. To ease the diffusion of relevant data to interested peers, similarity based overlays define links between similar peers by exploiting a similarity function. However, existing solutions neither give a clear definition of peer communities nor define a clear strategy to partition the peers into communities. As a consequence, the spread of the information cannot be confined within a well defined region of an overlay. This paper proposes a distributed protocol for the detection of communities in a P2P network. Our approach is based on the definition of a distributed voting algorithm where each peer chooses the more similar peers among those in a limited neighbourhood range. The identifier of the most representative peer is exploited to identify a community. The paper shows the effectiveness of our approach by presenting a set of experimental results

Crowdsourcing through cognitive opportunistic networks

Until recently crowdsourcing has been primarily conceived as an online activity to harness resources for problem solving. However the emergence of opportunistic networking (ON) has opened up crowdsourcing to the spatial domain. In this paper we bring the ON model for potential crowdsourcing in the smart city envi- ronment. We introduce cognitive features to the ON that allow users’ mobile devices to become aware of the surrounding physical environment. Specifically, we exploit cognitive psychology studies on dynamic memory structures and cognitive heuristics, i.e. mental models that describe how the human brain handles decision- making amongst complex and real-time stimuli. Combined with ON, these cognitive features allow devices to act as proxies in the cyber-world of their users and exchange knowledge to deliver awareness of places in an urban environment. This is done through tags associated with locations. They represent features that are perceived by humans about a place. We consider the extent to which this knowledge becomes available to participants, using interactions with locations and other nodes. This is assessed taking into account a wide range of cognitive parameters. Outcomes are important because this functionality could support a new type of recommendation system that is independent of the traditional forms of networking

Analisi di proteine di interesse biofarmaceutico isolate d'albume d'uovo

Lo scopo di questo lavoro di tesi è stato l'individuazione di metodi industriali di isolamento di avidina da estratti d'albume d'uovo. Questi ultimi risultano arricchiti in avidina rispetto all'albume iniziale poichè sono prodotti secondari della purificazione di lisozima, una proteina con caratteristiche chimico-fisiche simili ma presente nell'albume in quantità maggiore

Peer-to-Peer Systems for Discovering Resources in a Dynamic Grid

The convergence of the Grid and Peer-to-Peer (P2P) worlds has led to many solutions that try to efficiently solve the problem of resource discovery on Grids. Some of these solutions are extensions of P2P DHT-based networks. We believe that these systems are not flexible enough in case the indexed data are very dynamic, i.e., the values of the resource attributes change very frequently over time. This is a common case for some data managed by typical Grid systems, like CPU loads, queue occupation, etc. Moreover, since common requests for Grid resources may be expressed as multi-attribute range queries, we think that the DHTbased P2P solutions that have been proposed so far with the aim of supporting such type of queries can suffer from poor flexibility and efficiency. In this paper we thus present a couple of P2P systems. Both the systems are based on Routing Indexes, used to efficiently route queries and update messages in the presence of highly variable data. The first system needs the adoption of a tree-shaped overlay network. The second one, which is an evolution of the first, is based on a two-level hierarchical network topology, where tree topologies must only be maintained at the lower level of th