44 research outputs found

    Twin digital short period seismic Array Experiment at Stromboli Volcano

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    Two small arrays composed by short period (1 Hz) digital seismic stations, with an aperture of approximately 400 meters, were set up at Stromboli volcano (one at semaforo Labronzo, the other at Ginostra- Timpone del Fuoco) with the purpose of the spatial location of the high frequency source of the explosion quakes. About 75 explosion-quakes were recorded at both arrays, and constitute the available data base. We have planned to apply the zero-lag cross-correlation technique to the whole data set in order to obtain back-azimuth and apparent slowness of the coherent seismic phases. A preliminary analysis for both arrays show that the predominant back-azimuth for the first phase is oriented in the direction of , but not strictly coincident to, the crater area. Moreover some back-scattered arrivals are quite evident in the seismogram.INGV - Osservatorio VesuvianoUnpublishedope

    A seismic array on Mt. Vesuvius

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    In November 1997 a seismic antenna (array) of short period seismometers was installed on the south-western flank of Mt. Vesuvius; aim of the experiment was to test the use of non-conventional devices for the seismic monitoring of this volcano. In 7 months local seismicity, regional earthquakes and samples of seismic noise were recorded by the array and organised in a data base. Local earthquakes and seismic noise have been analysed with array techniques to investigate the spectral, kinematic and polarization properties of the wavefield. Preliminary results show that the backazimuth of local earthquakes is oriented in the direction of the crater area. For some events, the source location has been constrained using a simplified back propagation in a 2-D velocity structure. The noise wavefield is characterized by the predominance of a sustained low frequency component (< 1Hz) whose source is located S-SE of the array. This low frequency signal has been interpreted as associated to the sea-loading in the gulf of Naples.Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio VesuvianoPublished1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveope

    Twin digital short period seismic Array Experiment at Stromboli Volcano

    Get PDF
    Two small arrays composed by short period (1 Hz) digital seismic stations, with an aperture of approximately 400 meters, were set up at Stromboli volcano (one at semaforo Labronzo, the other at Ginostra- Timpone del Fuoco) with the purpose of the spatial location of the high frequency source of the explosion quakes. About 75 explosion-quakes were recorded at both arrays, and constitute the available data base. We have planned to apply the zero-lag cross-correlation technique to the whole data set in order to obtain back-azimuth and apparent slowness of the coherent seismic phases. A preliminary analysis for both arrays show that the predominant back-azimuth for the first phase is oriented in the direction of , but not strictly coincident to, the crater area. Moreover some back-scattered arrivals are quite evident in the seismogram

    A seismic array on Mt. Vesuvius

    Get PDF
    In November 1997 a seismic antenna (array) of short period seismometers was installed on the south-western flank of Mt. Vesuvius; aim of the experiment was to test the use of non-conventional devices for the seismic monitoring of this volcano. In 7 months local seismicity, regional earthquakes and samples of seismic noise were recorded by the array and organised in a data base. Local earthquakes and seismic noise have been analysed with array techniques to investigate the spectral, kinematic and polarization properties of the wavefield. Preliminary results show that the backazimuth of local earthquakes is oriented in the direction of the crater area. For some events, the source location has been constrained using a simplified back propagation in a 2-D velocity structure. The noise wavefield is characterized by the predominance of a sustained low frequency component (< 1Hz) whose source is located S-SE of the array. This low frequency signal has been interpreted as associated to the sea-loading in the gulf of Naples

    Plagiarism meets paraphrasing: insights for the next generation in automatic plagiarism detection

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    [EN] Although paraphrasing is the linguistic mechanism underlying many plagiarism cases, little attention has been paid to its analysis in the framework of automatic plagiarism detection. Therefore, state-of-the-art plagiarism detectors find it difficult to detect cases of paraphrase plagiarism. In this article, we analyze the relationship between paraphrasing and plagiarism, paying special attention to which paraphrase phenomena underlie acts of plagiarism and which of them are detected by plagiarism detection systems. With this aim in mind, we created the P4P corpus, a new resource that uses a paraphrase typology to annotate a subset of the PAN-PC-10 corpus for automatic plagiarism detection. The results of the Second International Competition on Plagiarism Detection were analyzed in the light of this annotation.The presented experiments show that (i) more complex paraphrase phenomena and a high density of paraphrase mechanisms make plagiarism detection more difficult, (ii) lexical substitutions are the paraphrase mechanisms used the most when plagiarizing, and (iii) paraphrase mechanisms tend to shorten the plagiarized text. For the first time, the paraphrase mechanisms behind plagiarism have been analyzed, providing critical insights for the improvement of automatic plagiarism detection systems.We would like to thank the people who participated in the annotation of the P4P corpus, Horacio Rodriguez for his helpful advice as experienced researcher, and the reviewers of this contribution for their valuable comments to improve this article. This research work was partially carried out during the tenure of an ERCIM "Alain Bensoussan" Fellowship Programme. The research leading to these results received funding from the EU FP7 Programme 2007-2013 (grant no. 246016), the MICINN projects TEXT-ENTERPRISE 2.0 and TEXT-KNOWLEDGE 2.0 (TIN2009-13391), the EC WIQ-EI IRSES project (grant no. 269180), and the FP7 Marie Curie People Programme. The research work of A. Barron-Cedeno and M. Vila was financed by the CONACyT-Mexico 192021 grant and the MECD-Spain FPU AP2008-02185 grant, respectively. The research work of A. Barron-Cedeno was partially done in the framework of his Ph.D. at the Universitat Politecnica de Valencia.Barrón Cedeño, LA.; Vila, M.; Martí, MA.; Rosso, P. (2013). Plagiarism meets paraphrasing: insights for the next generation in automatic plagiarism detection. Computational Linguistics. 39(4):917-947. https://doi.org/10.1162/COLI_a_00153S917947394Barzilay, Regina. 2003. Information Fusion for Multidocument Summarization: Paraphrasing and Generation. Ph.D. thesis, Columbia University, New York.Barzilay, R., & Lee, L. (2003). Learning to paraphrase. Proceedings of the 2003 Conference of the North American Chapter of the Association for Computational Linguistics on Human Language Technology - NAACL ’03. doi:10.3115/1073445.1073448Barzilay, Regina and Kathleen R. McKeown. 2001. Extracting paraphrases from a parallel corpus. In Proceedings of the 39th Annual Meeting of the Association for Computational Linguistics (ACL 2001), pages 50–57, Toulouse.Barzilay, R., McKeown, K. R., & Elhadad, M. (1999). Information fusion in the context of multi-document summarization. Proceedings of the 37th annual meeting of the Association for Computational Linguistics on Computational Linguistics -. doi:10.3115/1034678.1034760Bhagat, Rahul. 2009. Learning Paraphrases from Text. Ph.D. thesis, University of Southern California, Los Angeles.Cheung, Mei Ling Lisa. 2009. Merging Corpus Linguistics and Collaborative Knowledge Construction. Ph.D. thesis, University of Birmingham, Birmingham.Cohn, T., Callison-Burch, C., & Lapata, M. (2008). Constructing Corpora for the Development and Evaluation of Paraphrase Systems. Computational Linguistics, 34(4), 597-614. doi:10.1162/coli.08-003-r1-07-044Dras, Mark. 1999. Tree Adjoining Grammar and the Reluctant Paraphrasing of Text. Ph.D. thesis, Macquarie University, Sydney.Faigley, L., & Witte, S. (1981). Analyzing Revision. College Composition and Communication, 32(4), 400. doi:10.2307/356602Fujita, Atsushi. 2005. Automatic Generation of Syntactically Well-formed and Semantically Appropriate Paraphrases. Ph.D. thesis, Nara Institute of Science and Technology, Nara.Grozea, C., & Popescu, M. (2010). Who’s the Thief? Automatic Detection of the Direction of Plagiarism. Lecture Notes in Computer Science, 700-710. doi:10.1007/978-3-642-12116-6_59GÜLICH, E. (2003). Conversational Techniques Used in Transferring Knowledge between Medical Experts and Non-experts. Discourse Studies, 5(2), 235-263. doi:10.1177/1461445603005002005Harris, Z. S. (1957). Co-Occurrence and Transformation in Linguistic Structure. Language, 33(3), 283. doi:10.2307/411155KETCHEN Jr., D. J., & SHOOK, C. L. (1996). THE APPLICATION OF CLUSTER ANALYSIS IN STRATEGIC MANAGEMENT RESEARCH: AN ANALYSIS AND CRITIQUE. Strategic Management Journal, 17(6), 441-458. doi:10.1002/(sici)1097-0266(199606)17:63.0.co;2-gMcCarthy, D., & Navigli, R. (2009). The English lexical substitution task. Language Resources and Evaluation, 43(2), 139-159. doi:10.1007/s10579-009-9084-1Recasens, M., & Vila, M. (2010). On Paraphrase and Coreference. Computational Linguistics, 36(4), 639-647. doi:10.1162/coli_a_00014Shimohata, Mitsuo. 2004. Acquiring Paraphrases from Corpora and Its Application to Machine Translation. Ph.D. thesis, Nara Institute of Science and Technology, Nara.Stein, B., Potthast, M., Rosso, P., Barrón-Cedeño, A., Stamatatos, E., & Koppel, M. (2011). Fourth international workshop on uncovering plagiarism, authorship, and social software misuse. ACM SIGIR Forum, 45(1), 45. doi:10.1145/1988852.198886

    Henri Queffélec, écrivain humaniste

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    L’œuvre d’Henri Queffélec occupe une place à part dans la littérature de l’après-guerre. À une époque où l’humanisme paraît démodé, où le récit traditionnel est remis en question, Queffélec continue à plaider pour un unanimisme chrétien et pour une littérature ancrée dans la réalité de sa région dont il évoque si bien l’imaginaire hanté par les signes de la mort. Romancier des îles bretonnes et de la mer, observateur des mutations de son temps, il peint les catastrophes provoquées par les violences de la nature, les drames et les conflits liés aux transformations sociales. Toute cette œuvre violente et déchirée ne cesse pourtant de rêver, de nous faire rêver d'harmonie, de solidarité. Queffélec a cultivé le catholicisme social et a eu des sympathies de plus en plus marquées pour le franciscanisme. Pour lui la religion est lien entre les hommes ; elle suscite des enthousiasmes, fait vivre des communautés. Le romancier joue sur les techniques narratives, sur les points de vue, pour animer des groupes et créer une vie collective. L’écrivain accomplit alors une mission presque sacerdotale en réconciliant l’homme et le monde
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