41 research outputs found
Transforming N-ary relationships to database schemas: an old and forgotten problem
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
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
AnatomÃa de los antropónimos españoles
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
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
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?
En este artÃculo 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
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
Non-subjective evaluation of the efficacy for similarity functions
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