Tree edit distance as a baseline approach for paraphrase representation

Finding an adequate paraphrase representation formalism is a challenging issue in Natural Language Processing. In this paper, we analyse the performance of Tree Edit Distance as a paraphrase representation baseline. Our experiments using Edit Distance Textual Entailment Suite show that, as Tree Edit Distance consists of a purely syntactic approach, paraphrase alternations not based on structural reorganizations do not find an adequate representation. They also show that there is much scope for better modelling of the way trees are aligned.

Paraphrase concept and typology. A linguistically based and computationally oriented approach

In this paper, we present a critical analysis of the state of the art in the definition and typologies of paraphrasing. This analysis shows that there exists no characterization of paraphrasing that is comprehensive, linguistically based and computationally tractable at the same time. The following sets out to define and delimit the concept on the basis of the propositional content. We present a general, inclusive and computationally oriented typology of the linguistic mechanisms that give rise to form variations between paraphrase pairs.

Aggregation under a forced convective flow

Morphological transitions are analyzed for a radial multiparticle diffusion-limited aggregation process grown under a convective drift. The introduction of a tangential flow changes the morphology of the diffusion-limited structure, into multiarm structures, inclined opposite to the flow, whose limit consists of single arms, when decreasing density. The case of shear flow is also considered. The anisotropy of the patterns is characterized in terms of a tangential correlation function based analysis. Comparison between the simulation results and preliminary experimental results has been done.

Educar els fills és molt complicat! Els malestars actuals de la socialització familiar

En les diferents recerques sobre la socialització familiar són cada vegada més habituals les referències dels progenitors catalans de classes mitjanes i altes a la complexitat, a les dificultats i a la tensió creixent que implica educar els fills i les filles. Sobre això, i amb la teoria de la civilització de Norbert Elias com a fil conductor, l’article es pregunta pels malestars que actualment travessa la socialització familiar i els posa en relació amb quin és l’objectiu del mateix procés en la nostra societat immersa en un capitalisme financer i flexible. Així, si la finalitat és la «socialització terciària» (Mead, 1964; Bateson, 1984), dins les famílies emergeixen un seguit de neguits i malestars lligats a l’autoritat, l’autonomia, els hàbits, els conflictes i els càstigs, les normes, les convencions i les prohibicions, etc. que, segons el parer de l’autor, cal comprendre dins del nou context social i econòmic i en relació amb els nous objectius de l’educació familiar de les famílies benestants catalanes.

Norbert Elias : una proposta d’intellectual portrait vint anys després de la seva mort

L’estiu de 1990 moria a Amsterdam un dels sociòlegs més preeminents del segle XX, l’alemany Norbert Elias. La seva vida i la seva obra, profundament imbricades, són un reflex de la complexitat, de les llums i les ombres del segle passat. Amb aquesta proposta de retrat intel·lectual pretenem per una banda commemorar l’efemèride dels 20 anys de la mort d’un sociòleg poc reconegut i poc emprat. I d’altra banda, oferir una introducció a un personatge i una obra que, per la seva magnitud i originalitat, mereixen estar entre les més rellevants de la sociologia. Com a fil conductor de l’article proposem una combinació de llocs físics i simbòlics que van marcar la seva trajectòria.

Metanálise bayesiana de parâmetros genéticos para características de crescimento em bovinos de corte

Foi conduzida uma metanálise, sob enfoque bayesiano, em um conjunto de estimativas de herdabilidade, para características de crescimento em bovinos de corte de raças indianas, com 869 estimativas de herdabilidade de efeito direto, 186 estimativas de herdabilidade de efeito materno e 123 estimativas do coeficiente de correlação genética entre os efeitos direto e materno. A construção e o desenvolvimento de um modelo hierárquico possibilitam a obtenção de estimativas combinadas de herdabilidade para as características peso ao nascimento, peso ao desmame, peso aos 365 dias e peso aos 550 dias, cujos valores são, respectivamente: 0,31, 0,24, 0,28 e 0,33 para efeitos diretos; 0,09, 0,13, 0,12 e 0,05 para efeitos maternos; e -0,16, -0,16, -0,20 e -0,16 para as correlações entre esses efeitos. A metanálise conduzida sob enfoque bayesiano mostrou-se bastante adequada, uma vez que um modelo hierárquico considera as variâncias dentro e entre os estudos, e sua implementação e condução são facilitadas em virtude, principalmente, do avanço conseguido na área computacional.

Número mínimo de famílias de meios-irmãos para avaliação de uma população de cenoura

O objetivo deste trabalho foi apresentar um método de determinação do número mínimo de famílias de meios-irmãos, para representar uma população de cenoura, a fim de subsidiar o processo de obtenção de parâmetros genéticos e o desenvolvimento de novas cultivares. Foi feita uma simulação utilizando o aplicativo computacional Genes. Os resultados indicaram que o número de famílias varia conforme a característica e o parâmetro de interesse, e que 67 é o menor número de famílias de meios-irmãos, considerado adequado para representar uma população de cenoura, sob seleção para múltiplas características.

On the approximation of the subgrid scale for systems of equations

Postprint (published version)

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

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 analyse 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 which 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 analysed 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 plagiarising, and (iii) paraphrase mechanisms tend to shorten the plagiarized text. For the first time, the paraphrase mechanisms behind plagiarism have been analysed, providing critical insights for the improvement of automatic plagiarism detection systems.

Creació d’un model de simulació pels propulsors del robot submarí Girona 500 mitjançant CFD

S’arriba a un acord entre el grup de recerca GREFEMA i ViCOROB per estudiar els propulsors de palesutilitzats fins a l’actualitat en el robot submarí Girona 500, de forma que el model creatserveixi d’eina per apoder estudiar qualsevol tipus de propulsor que es vulgui fer servir.Es crearà un model de simulació amb CFD d’ANSYS per tal de poder recrear qualsevol situació ambqualsevol model de propulsor que es vulgui emprar, estalviant en costos de compra o fabricació, a mésd’evitar un muntatge experimental que pot no ser del tot fiable.A partir de geometries de propulsors de pales comercials existents es realitzarà una simulació amb elprograma de dinàmica de fluids computacional (CFD) d’ANSYS.La informació proporcionada per l’eina de simulació es compararan amb els resultats obtinguts de formaempírica a les instal•lacions del Parc Científic i Tecnològic de la Universitat de Girona i amb el model teòric.D’aquesta forma, es comprovarà la bondat de la simulació i es validarà el model numèric utilitzat

La Implicació de Hollywood en la Segona Guerra Mundial: el cas Why we fight

Why we fight és un grup de set pel·lícules de format documental que van formar part d’un ampli programa d’informació, formació i propaganda impulsat per l’exèrcit nord-americà, en el moment en què els Estats Units ja s’havien implicat en la Segona Guerra Mundial. És també un dels més reeixits exercicis de retòrica cinematogràfica nord-americana d’aquell període que permet analitzar com els països democràtics van gestionar qüestions tan compromeses com la propaganda de guerra. La pretensió d’aquest treball de recerca és aprofundir en la complexitat ideològica i formal de la sèrie, que faci possible descobrir-ne els orígens, els objectius i la manera com aquests van ser assolits per un grup d’especialistes cinematogràfics, coordinats pel director Frank Capra, tots els quals havien triomfat fins llavors a Hollywood

In & Out – 180 habitatges per a gent jove i gent gran Camí Antic de València al Poblenou

Estratègies d’ordenació: L’ordenació proposada vol recollir la hibridesa i complexitat d’espais típica del Poble Nou. Caracteritzat pels espais lliures de mida intermèdia –a cavall entre els dels teixits i els del eixamples – i per la riquesa en les seves articulacions (mitjançant passatges, a través d’edificis,…) ; per la permeabilitat cap a l’interior de l’illa: la connexió dels buits interiors amb els carrers i espais públics annexes o per la variabilitat del gra edificat.És per això que l’edificació no s’entén com una sèrie de blocs aïllats sinó que està concebuda com una gran peça articulada, amb una alçada constant en el volum a carrer i una lleugera variabilitat volumètrica en altura en els diferents volums interiors de igual mòdul i de gra menor, homòleg al del seu context urbà més pròxim.És essencial al projecte la definició de l’espai buit interior de l’illa en relació als habitatges, i la seva relació –a una escala major- amb els espais lliures de l’entorn. L’ordenació proposada configura dos paisatges diferents: un pati més urbà, delimitat en planta baixa per un equipament del barri i al que s’hi aboquen els habitatges per a joves i un altre més tranquil i més tou, un jardí per als més grans, accessible des del carrer i des de l’espai públic contiguEl volum més llarg afegeix una nova inflexió a les que ja té el carrer, ampliant-lo amb un espai amb funció de vestíbul i recuperant així, a partir d’una traça parcel•laria històrica, la direcció de l’Eixample.Els diferents volums es relacionen/articulen mitjançant corredors i espais col•lectius de distintes mesures i qualitats. Espais de relació, de dimensió variable, en diferents situacions relatives –respecte al ple, al sòl- i amb distints caràcters, que van del privat al públic...passant pel col•lectiu.Les galeries i els corredors d'accés als habitatges, protagonistes d'aquests espais híbrids (privats-semiprivats-col•lectius/ interiors-exteriors/ tancats-oberts), es converteixen gràcies a la flexibilitat en el tancament de la unitat d'habitació en espais d'intercanvi, on la variabilitat en l'ús permet diferents apropiacions de l'espai col•lectiu.La superposició en altura d'aquests espais funciona com una estructura lleugera adossada a la façana, és una epidermis complexa amb aparença de bastida.L’edificació té la voluntat de tancar-se a carrer amb una façana poc perforada, que llisca indiferent al carrer, i d’obrir-se a l’interior de l’illa, a sud, on es torna complexa, amb successives pells i tamisos...

En torno a los efectos de la edad en el aprendizaje escolar de una lengua extrangera

The purpose of this article is to treat a currently much debated issue, the effects of age on second language learning. To do so, we contrast data collected by our research team from over one thousand seven hundred young and adult learners with four popular beliefs or generalizations, which, while deeply rooted in this society, are not always corroborated by our data.Two of these generalizations about Second Language Acquisition (languages spoken in the social context) seem to be widely accepted: a) older children, adolescents and adults are quicker and more efficient at the first stages of learning than are younger learners; b) in a natural context children with an early start are more liable to attain higher levels of proficiency. However, in the context of Foreign Language Acquisition, the context in which we collect the data, this second generalization is difficult to verify due to the low number of instructional hours (a maximum of some 800 hours) and the lower levels of language exposure time provided. The design of our research project has allowed us to study differences observed with respect to the age of onset (ranging from 2 to 18+), but in this article we focus on students who began English instruction at the age of 8 (LOGSE Educational System) and those who began at the age of 11 (EGB). We have collected data from both groups after a period of 200 (Time 1) and 416 instructional hours (Time 2), and we are currently collecting data after a period of 726 instructional hours (Time 3). We have designed and administered a variety of tests: tests on English production and reception, both oral and written, and within both academic and communicative oriented approaches, on the learners' L1 (Spanish and Catalan), as well as a questionnaire eliciting personal and sociolinguistic information. The questions we address and the relevant empirical evidence are as follows: 1. "For young children, learning languages is a game. They enjoy it more than adults."Our data demonstrate that the situation is not quite so. Firstly, both at the levels of Primary and Secondary education (ranging from 70.5% in 11-year-olds to 89% in 14-year-olds) students have a positive attitude towards learning English. Secondly, there is a difference between the two groups with respect to the factors they cite as responsible for their motivation to learn English: the younger students cite intrinsic factors, such as the games they play, the methodology used and the teacher, whereas the older students cite extrinsic factors, such as the role of their knowledge of English in the achievement of their future professional goals. 2 ."Young children have more resources to learn languages." Here our data suggest just the opposite. The ability to employ learning strategies (actions or steps used) increases with age. Older learners' strategies are more varied and cognitively more complex. In contrast, younger learners depend more on their interlocutor and external resources and therefore have a lower level of autonomy in their learning. 3. "Young children don't talk much but understand a lot"This third generalization does seem to be confirmed, at least to a certain extent, by our data in relation to the analysis of differences due to the age factor and productive use of the target language. As seen above, the comparably slower progress of the younger learners is confirmed. Our analysis of interpersonal receptive abilities demonstrates as well the advantage of the older learners. Nevertheless, with respect to passive receptive activities (for example, simple recognition of words or sentences) no great differences are observed. Statistical analyses suggest that in this test, in contrast to the others analyzed, the dominance of the subjects' L1s (reflecting a cognitive capacity that grows with age) has no significant influence on the learning process. 4. "The sooner they begin, the better their results will be in written language"This is not either completely confirmed in our research. First of all, we perceive that certain compensatory strategies disappear only with age, but not with the number of instructional hours. Secondly, given an identical number of instructional hours, the older subjects obtain better results. With respect to our analysis of data from subjects of the same age (12 years old) but with a different number of instructional hours (200 and 416 respectively, as they began at the ages of 11 and 8), we observe that those who began earlier excel only in the area of lexical fluency. In conclusion, the superior rate of older learners appears to be due to their higher level of cognitive development, a factor which allows them to benefit more from formal or explicit instruction in the school context. Younger learners, however, do not benefit from the quantity and quality of linguistic exposure typical of a natural acquisition context in which they would be allowed to make use of implicit learning abilities. It seems clear, then, that the initiative in this country to begin foreign language instruction earlier will have positive effects only if it occurs in combination with either higher levels of exposure time to the foreign language, or, alternatively, with its use as the language of instruction in other areas of the curriculum.

En torno a los efectos de la edad en el aprendizaje escolar de una lengua extrangera

The purpose of this article is to treat a currently much debated issue, the effects of age on second language learning. To do so, we contrast data collected by our research team from over one thousand seven hundred young and adult learners with four popular beliefs or generalizations, which, while deeply rooted in this society, are not always corroborated by our data.Two of these generalizations about Second Language Acquisition (languages spoken in the social context) seem to be widely accepted: a) older children, adolescents and adults are quicker and more efficient at the first stages of learning than are younger learners; b) in a natural context children with an early start are more liable to attain higher levels of proficiency. However, in the context of Foreign Language Acquisition, the context in which we collect the data, this second generalization is difficult to verify due to the low number of instructional hours (a maximum of some 800 hours) and the lower levels of language exposure time provided. The design of our research project has allowed us to study differences observed with respect to the age of onset (ranging from 2 to 18+), but in this article we focus on students who began English instruction at the age of 8 (LOGSE Educational System) and those who began at the age of 11 (EGB). We have collected data from both groups after a period of 200 (Time 1) and 416 instructional hours (Time 2), and we are currently collecting data after a period of 726 instructional hours (Time 3). We have designed and administered a variety of tests: tests on English production and reception, both oral and written, and within both academic and communicative oriented approaches, on the learners' L1 (Spanish and Catalan), as well as a questionnaire eliciting personal and sociolinguistic information. The questions we address and the relevant empirical evidence are as follows: 1. "For young children, learning languages is a game. They enjoy it more than adults."Our data demonstrate that the situation is not quite so. Firstly, both at the levels of Primary and Secondary education (ranging from 70.5% in 11-year-olds to 89% in 14-year-olds) students have a positive attitude towards learning English. Secondly, there is a difference between the two groups with respect to the factors they cite as responsible for their motivation to learn English: the younger students cite intrinsic factors, such as the games they play, the methodology used and the teacher, whereas the older students cite extrinsic factors, such as the role of their knowledge of English in the achievement of their future professional goals. 2 ."Young children have more resources to learn languages." Here our data suggest just the opposite. The ability to employ learning strategies (actions or steps used) increases with age. Older learners' strategies are more varied and cognitively more complex. In contrast, younger learners depend more on their interlocutor and external resources and therefore have a lower level of autonomy in their learning. 3. "Young children don't talk much but understand a lot"This third generalization does seem to be confirmed, at least to a certain extent, by our data in relation to the analysis of differences due to the age factor and productive use of the target language. As seen above, the comparably slower progress of the younger learners is confirmed. Our analysis of interpersonal receptive abilities demonstrates as well the advantage of the older learners. Nevertheless, with respect to passive receptive activities (for example, simple recognition of words or sentences) no great differences are observed. Statistical analyses suggest that in this test, in contrast to the others analyzed, the dominance of the subjects' L1s (reflecting a cognitive capacity that grows with age) has no significant influence on the learning process. 4. "The sooner they begin, the better their results will be in written language"This is not either completely confirmed in our research. First of all, we perceive that certain compensatory strategies disappear only with age, but not with the number of instructional hours. Secondly, given an identical number of instructional hours, the older subjects obtain better results. With respect to our analysis of data from subjects of the same age (12 years old) but with a different number of instructional hours (200 and 416 respectively, as they began at the ages of 11 and 8), we observe that those who began earlier excel only in the area of lexical fluency. In conclusion, the superior rate of older learners appears to be due to their higher level of cognitive development, a factor which allows them to benefit more from formal or explicit instruction in the school context. Younger learners, however, do not benefit from the quantity and quality of linguistic exposure typical of a natural acquisition context in which they would be allowed to make use of implicit learning abilities. It seems clear, then, that the initiative in this country to begin foreign language instruction earlier will have positive effects only if it occurs in combination with either higher levels of exposure time to the foreign language, or, alternatively, with its use as the language of instruction in other areas of the curriculum.

El Joc lliure : un espai natural per al desenvolupament infantil

L’article presenta diferents arguments que defensen i recolzen la importància del joc lliure al llarg dels primers 6 anys de vida. Es comenten les atribucions que el defineixen i es relacionen amb algunes de les aportacions dels grans teòrics de la psicologia. Es contempla l’infant com un ésser amb moltes potencialitats, i es mostra com, a través de la seva activitat lúdica, desenvolupa de manera integral la seva personalitat, iniciant i afirmant aprenentatges diversos. S’incideix específicament en el desenvolupament cognitiu, bàsicament per la complexitat que comporta la seva valoració en contraposició a altres àrees com el llenguatge, la motricitat i la socialització, que són àrees més fàcilment observables. Amb aquesta finalitat s’inclouen alguns exemples de joc lliure on s’il·lustra, de manera introductòria, aquest desenvolupament. Al mateix temps s’observa el desenvolupament infantil a partir de les tipologies de joc que es manifesten naturalment en aquests anys, passant de l’activitat exploratòria al joc simbòlic i al joc reglat, i vinculant aquest darrer amb l’entrada a l’educació formal. Finalment s’incideix en la importància de la presència de l’adult, com una presència propera, que educa, i que ha de partir d’unes actituds prèvies molt clares si vol compartir espais de joc lliure amb els infants, afavorint d’aquesta manera que l’espai de joc es converteixi també en espai educatiu.