591 research outputs found

    Aligning Discourse and Argumentation Structures using Subtrees and Redescription Mining

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    International audienceIn this paper, we investigate similarities between discourse and argumentation structures by aligning subtrees in a corpus containing both annotations. Contrary to previous works, we focus on comparing sub-structures and not only relation matches. Using data mining techniques , we show that discourse and argumen-tation most often align well, and the double annotation allows to derive a mapping between structures. Moreover, this approach enables the study of similarities between discourse structures and differences in their expressive power

    Redescription Mining: An Overview.

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    International audienceIn many real-world data analysis tasks, we have different types of data over the same objects or entities, perhaps because the data originate from distinct sources or are based on different terminologies. In order to understand such data, an intuitive approach is to identify thecorrespondences that exist between these different aspects. This isthe motivating principle behind redescription mining, a data analysistask that aims at finding distinct commoncharacterizations of the same objects.This paper provides a short overview of redescription mining; what it is and how it is connected to other data analysis methods; the basic principles behind current algorithms for redescription mining; and examples and applications of redescription mining for real-world data analysis problems

    Menetelmiä jälleenkuvausten louhintaan

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    In scientific investigations data oftentimes have different nature. For instance, they might originate from distinct sources or be cast over separate terminologies. In order to gain insight into the phenomenon of interest, a natural task is to identify the correspondences that exist between these different aspects. This is the motivating idea of redescription mining, the data analysis task studied in this thesis. Redescription mining aims to find distinct common characterizations of the same objects and, vice versa, to identify sets of objects that admit multiple shared descriptions. A practical example in biology consists in finding geographical areas that admit two characterizations, one in terms of their climatic profile and one in terms of the occupying species. Discovering such redescriptions can contribute to better our understanding of the influence of climate over species distribution. Besides biology, applications of redescription mining can be envisaged in medicine or sociology, among other fields. Previously, redescription mining was restricted to propositional queries over Boolean attributes. However, many conditions, like aforementioned climate, cannot be expressed naturally in this limited formalism. In this thesis, we consider more general query languages and propose algorithms to find the corresponding redescriptions, making the task relevant to a broader range of domains and problems. Specifically, we start by extending redescription mining to non-Boolean attributes. In other words, we propose an algorithm to handle nominal and real-valued attributes natively. We then extend redescription mining to the relational setting, where the aim is to find corresponding connection patterns that relate almost the same object tuples in a network. We also study approaches for selecting high quality redescriptions to be output by the mining process. The first approach relies on an interface for mining and visualizing redescriptions interactively and allows the analyst to tailor the selection of results to meet his needs. The second approach, rooted in information theory, is a compression-based method for mining small sets of associations from two-view datasets. In summary, we take redescription mining outside the Boolean world and show its potential as a powerful exploratory method relevant in a broad range of domains.Tieteellinen tutkimusaineisto kootaan usein eri termistöä käyttävistä lähteistä. Näiden erilaisten näkökulmienvälisten vastaavuuksien ja yhteyksien tunnistaminen on luonnollinen tapa lähestyä tutkittavaa ilmiötä. Väitöskirjassa tarkastellaan juuri tähän pyrkivää data-analyysimenetelmää, jälleenkuvausten louhintaa (redescription mining). Jälleenkuvausten tavoitteena on yhtäältä kuvata samaa asiaa vaihoehtoisilla tavoilla ja toisaalta tunnistaa sellaiset asiat, joilla on useita eri kuvauksia. Jälleenkuvausten louhinnalla on mahdollisia sovelluksia mm. biologiassa, lääketieteessä ja sosiologiassa. Biologiassa voidaan esimerkiksi etsiä sellaisia maantieteellisiä alueita, joita voidaan luonnehtia kahdella vaihtoehtoisella tavalla: joko kuvaamalla alueen ilmasto tai kuvaamalla alueella elävät lajit. Esimerkiksi Skandinaviassa ja Baltiassa on ensinnäkin samankaltaiset lämpötila- ja sadeolosuhteet ja toisekseen hirvi on yhteinen laji molemmilla alueilla. Tällaisten jälleenkuvausten löytäminen voi auttaa ymmärtämään ilmaston vaikutuksia lajien levinneisyyteen. Lääketieteessä taas jälleenkuvauksilla voidaan löytää potilaiden taustatietojen sekä heidän oireidensa ja diagnoosiensa välisiä yhteyksiä, joiden avulla taas voidaan mahdollisesti paremmin ymmärtää itse sairauksia. Aiemmin jälleenkuvausten louhinnassa on rajoituttu tarkastelemaan totuusarvoisia muuttujia sekä propositionaalisia kuvauksia. Monia asioita, esimerkiksi ilmastotyyppiä, ei kuitenkaan voi luontevasti kuvata tällaisilla rajoittuneilla formalismeilla. Väitöskirjatyössä laajennetaankin jälleenkuvausten käytettävyyttä. Työssä esitetään ensimmäinen algoritmi jälleenkuvausten löytämiseen aineistoista, joissa attribuutit ovat reaalilukuarvoisia ja käsitellään ensimmäistä kertaa jälleenkuvausten etsintää relationaalisista aineistoista, joissa asiat viittaavat toisiinsa. Lisäksi väitöskirjassa tarkastellaan menetelmiä, joilla jälleenkuvausten joukosta voidaan valita kaikkein laadukkaimmat. Näihin menetelmiin kuuluvat sekä interaktiivinen käyttöliittymä jälleenkuvausten louhintaan ja visualisointiin, että informaatioteoriaan perustuvaa parametriton menetelmä parhaiden kuvausten valitsemiseksi. Kokonaisuutena väitöskirjatyössä siis laajennetaan jälleenkuvausten louhintaa totuusarvoisista muuttujista myös muunlaisten aineistojen käsittelyyn sekä osoitetaan menetelmän mahdollisuuksia monenlaisilla sovellusalueilla.Méthodes pour la fouille de redescriptions Lors de l'analyse scientifique d'un phénomène, les données disponibles sont souvent de différentes natures. Entre autres, elles peuvent provenir de différentes sources ou utiliser différentes terminologies. Découvrir des correspondances entre ces différents aspects fournit un moyen naturel de mieux comprendre le phénomène à l'étude. C'est l'idée directrice de la fouille de redescriptions (redescription mining), la méthode d'analyse de données étudiée dans cette thèse. La fouille de redescriptions a pour but de trouver diverses manières de décrire les même choses et vice versa, de trouver des choses qui ont plusieurs descriptions en commun. Un exemple en biologie consiste à déterminer des zones géographiques qui peuvent être caractérisées de deux manières, en terme de leurs conditions climatiques d'une part, et en terme des espèces animales qui y vivent d'autre part. Les régions européennes de la Scandinavie et de la Baltique, par exemple, ont des conditions de températures et de précipitations similaires et l'élan est une espèce commune aux deux régions. Identifier de telles redescriptions peut potentiellement aider à élucider l'influence du climat sur la distribution des espèces animales. Pour prendre un autre exemple, la fouille de redescriptions pourrait être appliquée en médecine, pour mettre en relation les antécédents des patients, leurs symptômes et leur diagnostic, dans le but d'améliorer notre compréhension des maladies. Auparavant, la fouille de redescriptions n'utilisait que des requêtes propositionnelles à variables booléennes. Cependant, de nombreuses conditions, telles que le climat cité ci-dessus, ne peuvent être exprimées dans ce formalisme restreint. Dans cette thèse, nous proposons un algorithme pour construire directement des redescriptions avec des variables réelles. Nous introduisons ensuite des redescriptions mettant en jeu des liens entre les objets, c'est à dire basées sur des requêtes relationnelles. Nous étudions aussi des approches pour sélectionner des redescriptions de qualité, soit en utilisant une interface permettant la fouille et la visualisation interactives des redescriptions, soit via une méthode sans paramètres motivée par des principes de la théorie de l'information. En résumé, nous étendons la fouille de redescriptions hors du monde booléen et montrons qu'elle constitue une méthode d'exploration de données puissante et pertinente dans une large variété de domaines

    Aligning Discourse and Argumentation Structures using Subtrees and Redescription Mining

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    International audienceIn this paper, we investigate similarities between discourse and argumentation structures by aligning subtrees in a corpus containing both annotations. Contrary to previous works, we focus on comparing sub-structures and not only relation matches. Using data mining techniques , we show that discourse and argumen-tation most often align well, and the double annotation allows to derive a mapping between structures. Moreover, this approach enables the study of similarities between discourse structures and differences in their expressive power

    Redescription mining for learning definitions and disjointness axioms in Linked Open Data

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    International audienceIn this article, we present an original use of Redescription Mining (RM) for discovering definitions of classes and incompatibility (disjointness) axioms between classes of individuals in the web of data. RM is aimed at mining alternate descriptions from two datasets related to the same set of individuals. We reuse this process for providing definitions in terms of necessary and sufficient conditions to categories in DBpedia. Firstly, we recall the basics of redescription mining and make precise the principles of our definitional process. Then we detail experiments carried out on datasets extracted from DBpedia. Based on the output of the experiments, we discuss the strengths and the possible extensions of our approach

    Three Approaches for Mining Definitions from Relational Data in the Web of Data

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    International audienceIn this paper we study a classification process on relational data that can be applied to the web of data. We start with a set of objects and relations between objects, and extensional classes of objects. We then study how to provide a definition to classes, i.e. to build an intensional description of the class, w.r.t. the relations involving class objects. To this end, we propose three different approaches based on Formal Concept Analysis (FCA), redescription mining and Minimum Description Length (MDL). Relying on some experiments on RDF data from DBpedia, where objects correspond to resources, relations to predicates and classes to categories, we compare the capabilities and the comple-mentarity of the three approaches. This research work is a contribution to understanding the connections existing between FCA and other data mining formalisms which are gaining importance in knowledge discovery, namely redescription mining and MDL

    Association Discovery in Two-View Data

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    International audienceTwo-view datasets are datasets whose attributes are naturally split into two sets, each providing a different view on the same set of objects. We introduce the task of finding small and non-redundant sets of associations that describe how the two views are related. To achieve this, we propose a novel approach in which sets of rules are used to translate one view to the other and vice versa. Our models, dubbed translation tables, contain both unidirectional and bidirectional rules that span both views and provide lossless translation from either of the views to the opposite view. To be able to evaluate different translation tables and perform model selection, we present a score based on the Minimum Description Length (MDL) principle. Next, we introduce three TRANSLATOR algorithms to find good models according to this score. The first algorithm is parameter-free and iteratively adds the rule that improves compression most. The other two algorithms use heuristics to achieve better trade-offs between runtime and compression. The empirical evaluation on real-world data demonstrates that only modest numbers of associations are needed to characterize the two-view structure present in the data, while the obtained translation rules are easily interpretable and provide insight into the data

    Redescription and geographic distribution of Raorchestes shillongensis (Anura: Rhacophoridae) from Meghalaya, Northeast India

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    Redescription and geographic distribution of Raorchestes shillongensis (Anura: Rhacophoridae) from Meghalaya, Northeast India. Raorchestes shillongensis is a threatened rhacophorid frog endemic to Northeast India. The species is poorly known and systematic information is lacking. We redescribe here the morphology of the species from topotypic material and compare with other Bush Frogs of the region. The locality records from the state of Meghalaya are new. We describe its advertisement call and discuss its phylogenetic position.Redescrição e distribuição geográfca de Raorchestes shillongensis (Anura: Rhacophoridae) de Meghalaya, nordeste da Índia. Raorchestes shillongensis é um anuro racoforídeo ameaçado e endêmico do nordeste da Índia. A espécie é pouco conhecida, não havendo informação sistemática. Redescrevemos aqui a morfologia da espécie a partir de material topotípico e a comparamos com outros racoforídeos da região. O registro da localidade no estado de Meghalaya é novo. Descrevemos ainda seu canto nupcial e discutimos sua posição flogenética
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