2023, Articolo in rivista, ENG
Bartalesi V.; Pratelli N.; Lenzi E.; Pontari P.
Western thought in European history was mainly affected by the image of the world created during the Middle Ages and Renaissance. The most popular reason to travel during the Middle Ages was taking a pilgrimage. Jerusalem, Rome, and Santiago de Compostela were the most popular destinations. It is not surprising that a lot of works written by travellers as guides for pilgrims exist. By the beginning of the Renaissance, a more precise image of the world was defined thanks to the discovery of ancient geographical models, especially the work of Ptolemy. The three years (2020-2023) Italian National research project IMAGO - Index Medii Aevi Geographiae Operum - aims to provide a systematic overview of the medieval and renaissance Latin geographical literature using the Semantic Web technologies and the LOD paradigm. Indeed, until now, this literature has not been studied using digital methods. In particular, this paper presents how we formally represented the knowledge about the toponyms, or place names, in the IMAGO ontology. To maximise the interoperability, we developed the IMAGO ontology as an extension of two reference vocabularies: the CIDOC CRM and its extension FRBRoo, including its in-progress reformulation, LRMoo. Furthermore, we used Wikidata as reference knowledge base. As case study, we chose to represent the knowledge related to the toponyms cited by the Italian poet Dante Alighieri in his Latin works. We carried out a first experiment for visualising the knowledge about these toponyms on a map and in the form of tables and CSV files.
2021, Tesi, ENG
Metilli D.
Narratives are a fundamental part of human life. Every human being encounters countless stories during their life, and these stories contribute to form a common understanding of reality. This is reflected in the current digital landscape, and especially on the Web, where narratives are published and shared everyday. However, the current digital representation of narratives is limited by the fact that each narrative is generally expressed as natural language text or other media, in an unstructured way that is neither standardized nor machine-readable. These limitations hinder the manageability of narratives by automated systems. One way to solve this problem would be to create an ontology of narrative, i.e., a formal model of what a narrative is, then develop semi-automated methods to extract narratives from natural language text, and use the extracted data to populate the ontology. However, the feasibility of this approach remains an open question. This thesis attempts to investigate this research question, starting from the state of the art in the fields of Computational Narratology, Semantic Web, and Natural Language Processing. Based on this analysis, we have identified a set of requirements, and we have developed a methodology for our research work. Then, we have developed an informal conceptualization of narrative, and we have expressed it in a formal way using First-Order Logic. The result of this work is the Narrative Ontology (NOnt), a formal model of narrative that also includes a representation of its textual structure and textual semantics. To ensure interoperability, the ontology is based on the CIDOC CRM and FRBRoo standards, and it has been expressed using the OWL and SWRL languages of the Semantic Web. Based on the ontology, we have developed NarraNext, a semi-automatic tool that is able to extract the main elements of narrative from natural language text. The tool allows the user to create a complete narrative based on a text, using the extracted knowledge to populate the ontology. NarraNext is based on recent advancements in the Natural Language Processing field, including deep neural networks, and is integrated with the Wikidata knowledge base. The validation of our work is being carried out in three different scenarios: (i) a case study on biographies of historical figures found in Wikipedia; (ii) the Mingei project, which applies NOnt to the representation and preservation of Heritage Crafts; (iii) the Hypermedia Dante Network project, where NOnt has been integrated with a citation ontology to represent the content of Dante's Comedy. All three applications have served to validate the representational adequacy of NOnt and the satisfaction of the requirements we defined. The case study on biographies has also evaluated the effectiveness of the NarraNext tool.
2019, Abstract in atti di convegno, ENG
Bartalesi V.; Metilli D.; Meghini C.
Narratives are a fundamental part of human life, starting from the epic poems of the ancient past to modern films. Since the 1970s, much research has been carried out to study the computational representation of narratives. Up to now, there is no standard definition of narrative. In our research, we intend narratives as networks of events defined by a narrator, endowed with participating entities (e.g. persons, location, time) and semantic relations. In this paper, we introduce the Narrative Building and Visualising Tool (NBVT), a semi- automatic software based on a formal ontology for narratives we developed. The tool allows users to construct and visualise narratives using Wikidata as reference knowledge base and Europeana for enriching the narrative with digital objects. As case study, we present the narrative of the life of the Austrian painter Gustav Klimt created using NBVT. Since Wikidata is not event-based, our efforts focus on the automatic extraction from Wikidata of the implicit events that compose the narrative. Furthermore, we developed a dedicated functionality in NBVT that finds the Europeana digital objects related to a particular event. This functionality matches the metadata of Europeana digital objects with the event and the participating entities using a similarity algorithm.
2019, Articolo in rivista, ENG
Metilli D.; Bartalesi V.; Meghini C.
In this paper we present a semi-automatic tool for constructing and visualising narratives, intended as networks of events related to each other by semantic relations. The tool obeys an ontology for narratives that we developed. It retrieves and assigns internationalised resource identifiers to the instances of the classes of the ontology using Wikidata as an external knowledge base and also facilitates the construction and contextualisation of events, and their linking to form the narratives. The knowledge collected by the tool is automatically saved as an Web ontology language graph. The tool also allows the visualisation of the knowledge included in the graph in simple formats like tables, network graphs and timelines. We have carried out an initial qualitative evaluation of the tool. As case study, an historian from the University of Pisa has used the tool to build the narrative of Dante Alighieri's life. The evaluation has regarded the effectiveness of the tool and the satisfaction of the users' requirements.
2019, Contributo in atti di convegno, ENG
Metilli D.; Bartalesi V.; Meghini C.; Aloia N.
The study presented in this paper is part of our research aimed at improving the search functionalities of current Digital Libraries using formal narratives. Narratives are intended as sequences of events. We present the results of an initial experiment to detect and extract implicit events from the Wikidata knowledge base in order to construct a narrative in a semi-automatic way. Wikidata contains many historical entities, but comparably few events. The reason is that most events in Wikidata are represented in an implicit way, e.g. by listing a date of birth instead of having an event of type "birth". For this reason, we decided to generate what we call the Wikidata Event Graph (WEG), i.e. the graph of implicit events found in Wikidata. We performed an initial experiment taking as case study the narrative of the life of Italian poet Dante Alighieri. Only one event of the life of Dante is explicitly represented in Wikidata as instance of the class Q1190554 Occurrence. Using the WEG, we were able to automatically detect 31 more events of Dante's life that were present in Wikidata in an implicit way.
2017, Software, ENG
Metilli D.; Bartalesi Lenzi V.; Meghini C.
The Narrative Building and Visualising Tool (NBVT) is a semi-automatic tool to construct and visualise narratives, intended as semantic networks of events related each other through semantic relations. This tool obeys an ontology for narratives. NBVT uses Wikidata/Wikimedia Commons as external knowledge base of images and entities. The user of NBVT can select instances of the narratives ontologies among automatically proposed Wikidata entities, otherwise new entities can be created. NBVT assigns URIs to the selected instances and facilitates the construction of events based on these instances, and their linking to form narratives. The knowledge collected by the tool is exported as Linked Data.