1,720,961 research outputs found
A term-based approach for matching multilingual thesauri
No full textIn this paper, we present a multilingual matching approach aiming at building matches between terms belonging to multilingual thesauri. The approach is presented as a variant of the schema matching problem and present its evaluation on domain-specific use cases by demonstrating the viability of the proposed technique for facing the multilingual thesaurus matching approach
Exploiting Propositions for Opinion Mining
No full textWith different social media and commercial platforms, users express their opinion about products in a textual form. Automatically extracting the polarity (i.e. whether the opinion is positive or negative) of a user can be useful for both actors: the online platform incorporating the feedback to improve their product as well as the client who might get recommendations according to his or her preferences. Different approaches for tackling the problem, have been suggested mainly using syntactic features. The “Challenge on Semantic Sentiment Analysis” aims to go beyond the word-level analysis by using semantic information. In this paper we propose a novel approach by employing the semantic information of grammatical unit called preposition. We try to drive the target of the review from the summary information, which serves as an input to identify the proposition in it. Our implementation relies on the hypothesis that the proposition expressing the target of the summary, usually containing the main polarity information
A semantic federated search engine for domain-specific document retrieval
No full textRetrieval of domain-specific documents became attractive for the Semantic Web community due to the possibility of integrating classic Information Retrieval (IR) techniques with semantic knowledge. Unfortunately, the gap between the construction of a full semantic search engine and the possibility of exploiting a repository of ontologies covering all possible domains is far from being filled. Recent solutions focused on the aggregation of different domain-specific repositories managed by third-parties. In this paper, we present a semantic federated search engine developed in the context of the EEXCESS EU project. Through the developed platform, users are able to perform federated queries over repositories in a transparent way, i.e. without knowing how their original queries are transformed before being actually submitted. The platform implements a facility for plugging new repositories and for creating, with the support of general purpose knowledge bases, knowledge graphs describing the content of each connected repository. Such knowledge graphs are then exploited for enriching queries performed by users
An unsupervised aspect extraction strategy for monitoring real-time reviews stream
Full text linkOne of the most important opinion mining research directions falls in the extraction of polarities referring to specific entities (aspects) contained in the analyzed texts. The detection of such aspects may be very critical especially when documents come from unknown domains. Indeed, while in some contexts it is possible to train domain-specific models for improving the effectiveness of aspects extraction algorithms, in others the most suitable solution is to apply unsupervised techniques by making such algorithms domain-independent and more efficient in a real-time environment. Moreover, an emerging need is to exploit the results of aspect-based analysis for triggering actions based on these data. This led to the necessity of providing solutions supporting both an effective analysis of user-generated content and an efficient and intuitive way of visualizing collected data. In this work, we implemented an opinion monitoring service implementing (i) a set of unsupervised strategies for aspect-based opinion mining together with (ii) a monitoring tool supporting users in visualizing analyzed data. The aspect extraction strategies are based on the use of an open information extraction strategy. The effectiveness of the platform has been tested on benchmarks provided by the SemEval campaign and have been compared with the results obtained by domain-adapted techniques
ReUS: a Real-time Unsupervised System For Monitoring Opinion Streams
No full textAn actual challenge within the sentiment analysis research area is the extraction of polarity values associated with specific aspects (or opinion targets) contained in user-generated content. This task, called aspect-based sentiment analysis, brings new challenges like the disambiguation of words’ role within a text and the inference of correct polarity values based on the domain in which a text occurs. The former requires strategies able to understand how each word is used in a specific context in order to annotate it as aspect or not. The latter need to be addressed with unsupervised solutions in order to make a system efficient for real-time tasks and at the same time flexible in order to adopt it in any domain without requiring the training of sentiment models. Finally, the deployment of such a system into real-world scenarios needs the development of usable solutions for accessing and analyzing data. This paper presents the ReUS platform: a system integrating an unsupervised approach, based on open information extraction strategies, for performing real-time aspect-based sentiment analysis together with facilities supporting decision-makers in the analysis and visualization of collected data. The ReUS platform has been validated from a quantitative and qualitative perspectives. First, the aspect extraction and polarity inference capabilities have been evaluated on three datasets used in likewise editions of SemEval. Second, a user group has been invited to judge the usability of the platform. The developed platform demonstrated to be suitable for being used into real-world scenarios requiring (i) the capability of processing real-time opinion-based documents streams and (ii) the availability of usable facilities for analyzing and visualizing collected data. Examples of possible analysis and visualizations include the presentation of lists ranking aspects by the importance of their polarity values computed within the whole data repository. This kind of analysis enables, for instance, the discovery of product issues
A Neural-based Architecture For Small Datasets Classification
No full textDigital Libraries benefit from the use of text classification strategies since they are enablers for performing many document management tasks like Information Retrieval. The effectiveness of such classification strategies depends on the amount of available data and the classifier used. The former leads to the design of data augmentation solutions where new samples are generated into small datasets based on the semantic similarity between existing samples and concepts defined within external linguistic resources. The latter relates to the capability of finding, which is the best learning principle to adopt for designing an effective classification strategy suitable for the problem. In this work, we propose a neural-based architecture thought for addressing the text classification problem on small datasets. Our architecture is based on BERT equipped with one further layer using the sigmoid function. The hypothesis we want to verify is that by using embeddings learned by a BERT-based architecture, one can perform effective classification on small datasets without the use of data augmentation strategies. We observed improvements up to 14% in the accuracy and up to in the f-score with respect to baseline classifiers exploiting data augmentation
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
Anslisi comportamentali dei contratti di servizio
No full textLa tesi affronta il problema di analizzare da un punto di vista formale i
linguaggi proposti per la
descrizione dei contratti di servizio. In particolare, la tesi propone un modello
comportamentale che permette di verificare
formalmente la nozione di "compliance" di un contratto di servizio
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
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