1,720,977 research outputs found
Monumenti archeologici: il rilievo del danno sismico (Speciale ITC-CNR "Ricerca e Sperimentazione")
No full textThe survey of the earthquake’s damage has been done only on the architectural heritage, in order to verify its fitness for use. There are two models for this purpose (“churches” and “historical buildings”) officially adopted in 2006.
At the time of the emergency phase, the archaeological sites were excluded, even if they are very numerous in the area and were significantly damage.
On the occasion of the earthquake of 2009, the CNR-ITC of L’Aquila is testing a new data model for the archaeological heritage. The monitoring campaign shows some interesting results on the conservation status of these sites in general
Student CEF at Sapienza - University of Rome. Preliminary design of Spec CubeSat with optical payload
No full textStudents attending the Spacecraft Design lectures in the framework of the Space and Astronautical Engineering MSc course atâ€La Sapienza†University of Rome have been involved in a Concurrent Engineering design for the CubeSat mission SPEC (Stellar Population and Evolution with Cubesat), conceived in collaboration with the Italian Space Agency. The SPEC mission is focused on the implementation of a small ad-hoc telescope and a sensor aimed at observing binary stellar systems in the near-infrared and infrared bands (i' and z' filters from the Sloan Digital Sky Survey) on-board a 6-Unit CubeSat. The mission is addressed to the observation of gravitationally bound groups (couples or more) of stars orbiting around a common centre of mass. The observations goal is to resolve (i.e. visually discriminate) the system members and perform spectrometric measures of the stars electromagnetic emission. Therefore, the mission requirements are mainly related to the Attitude Determination and Control System (ADCS) and to the payload optical performances and pointing precision. The project gives the students the opportunity to apply and improve the theoretical knowledge acquired during the academic courses by practising in a team working and project leading context. The whole class was involved in the design activities performed in the Concurrent Engineering Facility (CEF) by being organised into subgroups. Each subgroup took care of a subsystem or a mission feature. The CEF activities duration was set to slightly less than three months. Once concluded the CEF activities, the finalised configuration, obtained with several iterations on the sub-systems design, was delivered to the Professor in charge of the course for verification and evaluation of the contributions. A short introduction on the SPEC preliminary design was also presented during theâ€4th Space Debris Student Opportunities Workshop†at Sapienza - University of Rome in December 2017. In such framework, the students gave a public presentation about their work and achieved results. This paper outlines the SPEC preliminary design and how the CEF experience allowed the students to understand and practice on how a satellite design process is usually approached and carried out. Finally, the educational return offered by the course and related activities is discussed, with examples from the Concurrent Engineering nano-satellites design from the present and the past years
Decentralization of Learning and Trust in the Healthcare: Blockchain-driven Federated Learning for Alzheimer's MRI Image Classification
No full textThis paper proposes a framework that combines Federated Learning (FL) and blockchain technologies in applications where sensitive data need to be analyzed. FL allows exchanging machine learning model parameters instead of sensitive data, thus ensuring data privacy preservation. Model parameters are ciphered and stored into the InterPlanetary File System (IPFS). Coordination via a dedicated smart contract allows to efficiently handle the parameters update phases, fortifying data security. We validate our approach using an Alzheimer's MRI image dataset, showing the benefits in terms of practical implementation and classification accuracy
Decentralized coordination for resilient federated learning: A blockchain-based approach with smart contracts and decentralized storage
No full textMachine Learning (ML) in distributed environments increasingly deals with sensitive data (like healthcare or financial records) that cannot be centrally stored or processed due to privacy concerns. Federated Learning (FL) addresses this by enabling model training across decentralized devices, but faces significant challenges including system reliability, node failures, and trust issues among participants. Traditional FL approaches often rely on centralized coordinators, creating single points of failure and potential security vulnerabilities. This paper presents a novel approach to FL that leverages smart contracts, blockchain, and decentralized storage to enhance the traceability and reliability of the learning process. Our proposed system architecture is fully decentralized, eliminating single points of failure and promoting cooperation through a rewarding mechanism. Unlike previous approaches that neglect node fault tolerance, we introduce a smart contract based scheme for managing node failures and electing the aggregator node. The presence of the smart contract, executed on a decentralized permissioned blockchain, provides reliability guarantees and eliminates the need for costly distributed algorithms in terms of message exchange. An experimental study is conducted to evaluate various aspects of the FL system. We present results related to the accuracy and effectiveness of the FL system on ML models. We also examine the performance related to the distribution of the weights of the ML model based on the use of IPFS. Furthermore, we analyze the performance of the smart contract in terms of gas consumption. Lastly, we investigate the impact of failures combined with incentive policies and aggregator election algorithms on the FL system. Our findings demonstrate the viability of the proposed approach, paving the way for more robust, reliable, and efficient FL systems
Indici geobotanici e qualità ambientale.
No full textThe Abruzzo region (Italy) has around 30% of its area protected, 1% of which is occupied by natural reserves. Protected areas networks allow species to be preserved in situ. Planning and management of an area needs a preliminary estimation of the environmental quality, on the basis of which an appropriate plan can be drawn up to preserve the natural ecosystems and to reduce the human impact on the wildlife. Plant communities (e.g. using geobotanical indices) are good environmental indicators. In this study, the environmental quality has been estimated for seven Abruzzo Natural Reserves according to geobotanical indices, including rarity, endemicity, naturalness, extrazonality and azonality. These indices demonstrate that each of these reserve has a high vegetation diversity and good environmental quality. These data confirm that a network of ‘smaller’ natural reserves assures a stockpile of ‘larger’ biodiversity
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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