14 research outputs found

    Adversarial propagation and zero-shot cross-lingual transfer of word vector specialization

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    Semantic \specialization is a process of fine-tuning pre-trained distributional word vectors using external lexical knowledge (e.g., WordNet) to accentuate a particular semantic relation in the specialized vector space. While post-processing specialization methods are applicable to arbitrary distributional vectors, they are limited to updating only the vectors of words occurring in external lexicons (i.e., seen words), leaving the vectors of all other words unchanged. We propose a novel approach to specializing the full distributional vocabulary. Our adversarial post-specialization method propagates the external lexical knowledge to the full distributional space. We exploit words seen in the resources as training examples for learning a global specialization function. This function is learned by combining a standard L2-distance loss with a adversarial loss: the adversarial component produces more realistic output vectors. We show the effectiveness and robustness of the proposed method across three languages and on three tasks: word similarity, dialog state tracking, and lexical simplification. We report consistent improvements over distributional word vectors and vectors specialized by other state-of-the-art specialization frameworks. Finally, we also propose a cross-lingual transfer method for zero-shot specialization which successfully specializes a full target distributional space without any lexical knowledge in the target language and without any bilingual data

    Post-Specialisation: Retrofitting Vectors of Words Unseen in Lexical Resources

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    Word vector specialisation (also known as retrofitting) is a portable, light-weight approach to fine-tuning arbitrary distributional word vector spaces by injecting external knowledge from rich lexical resources such as WordNet. By design, these post-processing methods only update the vectors of words occurring in external lexicons, leaving the representations of all unseen words intact. In this paper, we show that constraint-driven vector space specialisation can be extended to unseen words. We propose a novel post-specialisation method that: a) preserves the useful linguistic knowledge for seen words; while b) propagating this external signal to unseen words in order to improve their vector representations as well. Our post-specialisation approach explicits a non-linear specialisation function in the form of a deep neural network by learning to predict specialised vectors from their original distributional counterparts. The learned function is then used to specialise vectors of unseen words. This approach, applicable to any post-processing model, yields considerable gains over the initial specialisation models both in intrinsic word similarity tasks, and in two downstream tasks: dialogue state tracking and lexical text simplification. The positive effects persist across three languages, demonstrating the importance of specialising the full vocabulary of distributional word vector spaces

    Changes in hydrocarbons and elemental distribution in peloids during maturation processes (Sečovlje Salina Nature Park Slovenia)

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    In Sečovlje Salina Nature Park, the therapeutic mud matured in the natural sedimentary environmental site. This work aimed to determine the influence of the peloid maturation process on the hydrocarbon and elemental distributions, as well as changes in morphology. For this purpose, the sample before and after maturation was examined using various methods. n-Alkanes were the most abundant among saturated hydrocarbons in both immature and mature peloid samples. The results showed that the maturation mainly influenced the change in distribution and concentration (from 378 to 1958 ppm) of n-alkanes. The organic matter (OM) of the immature peloid sample was characterized by a slight prevalence of long-chain and odd carbon-numbered n-alkanes, maximizing at n-C27. However, mature peloid's OM showed a similar share of short-, mid- and long-chain n-alkanes with a slight dominance of short-chain members, maximizing at n-C16. The origin of short-chain and even carbon-numbered n-alkanes was attributed to microbial precursors (e.g., Leptolyngbyaceae). Hopanes were considerably more dominant compared to steranes in both peloids. The hopane series of immature peloid was characterized by the dominance of 22,29,30-trinor-hop-5(6)-ene (C27 hopene), as well as the presence of C30-hop-22(29)-ene (diploptene), which are widespread in cyanobacterial species. The aromatic fraction of immature peloid pointed to the predominance of polycyclic aromatic hydrocarbons (PAHs). As peloid aging progressed, the sample was richer in methyl-branched alkanes, carboxylic acids, their methyl esters, and thermodynamically more stable hopanes and steranes. The presence of elements with toxicological relevance during maturation was reduced below the limits prescribed in most of the directives for cosmetic products. It specifically refers to: As, Ni and Se. A higher concentration of total sulfur in the mature peloid can be related to gypsum precipitation in the summer and/or more intensive microbial activity

    Application of Non-invasive Measurements in the Recent Studies of the Scrovegni Chapel: Results and Considerations

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    The Scrovegni Chapel is known all over the world for the famous frescoes made by Giotto that decorate its interior. The building stands on the remains of the Roman amphitheater of Padua, in a unique, highly scenic position. Many unsolved doubts about the origins of this building and its link with the Roman amphitheater affect the Chapel. The evident structural and decorative in-homogeneities visible between the various parts of the building (e.g., the nave, the apse, the sacristy, the hypogeum and the walls under the roof), pose numerous doubts about the transformations that must have affected it over the centuries, probably changing its original shape. This work reports some examples of recent applications of ground-penetrating radar (GPR), electrical resistivity tomography (ERT), IR thermography, and multispectral imaging to the study of the Scrovegni Chapel. The results of the multidisci-plinary project, of which these measurements are part, demonstrate that the integrated approach represents the basic condition for the right interpretation and comprehension of the results of non-invasive approach, mostly in com-plex archaeological and historical context as well as that of the Scrovegni Chapel
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