41 research outputs found

    Transforming N-ary relationships to database schemas: an old and forgotten problem

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    The N-ary relationships, have been traditionally a source of confusion and still are. One important source of confusion is that the term cardinality in a relationship has several interpretations, two of them being very popular. But none of the two approaches, nor the two together, allow us to express all the possible cardinality patterns. The transformations from all the possible relationships to database schemas have never been described by the existing literature. Using the 14 ternary patterns as example, we discuss these transformations particularly the transformations from the patterns ignored in the literature.Postprint (published version

    From ternary relationship to relational tables: a case against common beliefs

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    The transformation from n-ary relationships to a relational database schema has never been really fully analyzed. This paper presents one of the several ternary cases ignored by the ER-to-RM literature. The case shows that the following common belief is wrong: Given a set of FDs over a table resulting in a non-3NF situation, it is always possible to obtain a fully equivalent set of 3NF tables, without adding other restrictions than candidate keys and inclusion dependencies.Postprint (published version

    Anatomía de los antropónimos españoles

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    The paper presents some results from an analysis of the morphology and lexicon of the Spanish surnames. The analysis includes: the structure, the distribution of lengths and frequencies, the position of letters, the n-grams, the relationship between vocabulary and corpus volume (Zipf-Mandelbrot law) the entropy and the equivalent vocabulary. Some comparisons are made with the Spanish general language and with the USA surnames.Postprint (published version

    Funciones de comparación de carácteres para APNM: la distancia DEA

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    A typical application of the ASM (Approximate String Matching) is the matching of personal names, as for example to search people in the DB of an Information System. Through the years, several similarity functions have been proposed:phonetic codes, simple edit distance, n-gram distances, etc.A typical application of the ASM (Approximate String Matching) is the matching of personal names, as for example to search people in the DB of an Information System. Through the years, several similarity functions have been proposed: phonetic codes, simple edit distance, n-gram distances, etc. In this report a function is presented, DEA, having substantially better efficacy than existing ones, and mainly oriented to spanish surnames. The DEA distance is an edit distance, with costs based on the probabilities of the operations, characters and positions. The distance threshold is defined as a function of the lenght of the string. The efficacy of DEA is evaluated objectively, without human relevance judgements.Postprint (published version

    Searching by approximate personal-name matching

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    We discuss the design, building and evaluation of a method to access theinformation of a person, using his name as a search key, even if it has deformations. We present a similarity function, the DEA function, based on the probabilities of the edit operations accordingly to the involved letters and their position, and using a variable threshold. The efficacy of DEA is quantitatively evaluated, without human relevance judgments, very superior to the efficacy of known methods. A very efficient approximate search technique for the DEA function is also presented based on a compacted trie-tree structure.Postprint (published version

    La informática de gestión: ¿puede la Universidad española dar respuesta a lo que la sociedad le pide?

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    En este artículo se constata el divorcio ente lo que la Universidad ofrece y lo que la sociedad reclama, y se comenta como el nuevo entorno socioeconómico está arrastrando a las universidades al terreno del "mercado" y por lo tanto a que se orienten hacia la "satisfacción del cliente". Tras evidenciar que no está nada claro el éxito que puedan tener las nuevas enseñazas profesionales no universitarias o Ciclos Formativos Superiores, se sugiere que la Universidad se acerque más a los perfiles de los profesionales informáticos que la sociedad necesita.Postprint (published version

    Stroke genetics informs drug discovery and risk prediction across ancestries

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    Previous genome-wide association studies (GWASs) of stroke — the second leading cause of death worldwide — were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries

    DISSENY DE BASES DE DADES (Examen 2n quadrimestre)

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    DISSENY DE BASES DE DADES (Examen 2n quadrimestre)

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    Non-subjective evaluation of the efficacy for similarity functions

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    Within the context of the Approximate Personal Name Matching problem, we present some metrics to evaluate and compare the efficacy of similarity functions (or distances). Usually the evaluation is done by asking the opinion, relevance judgements, of people, in order to determine for each pair of names if it is a pair-with-error or not.Postprint (published version
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