Column-based databases: estudo exploratório no âmbito das bases de dados NoSQL

O aumento da quantidade de dados gerados que se tem verificado nos últimos anos e a que se tem vindo a dar o nome de Big Data levou a que a tecnologia relacional começasse a demonstrar algumas fragilidades no seu armazenamento e manuseamento o que levou ao aparecimento das bases de dados NoSQL. Estas estão divididas por quatro tipos distintos nomeadamente chave/valor, documentos, grafos e famílias de colunas. Este artigo é focado nas bases de dados do tipo column-based e nele serão analisados os dois sistemas deste tipo considerados mais relevantes: Cassandra e HBase.

Monitoring and analysis of queries in distributed databases

Dissertação de Mestrado em Engenharia Informática

Solving large 0–1 multidimensional knapsack problems by a new simplified binary artificial fish swarm algorithm

The artificial fish swarm algorithm has recently been emerged in continuous global optimization. It uses points of a population in space to identify the position of fish in the school. Many real-world optimization problems are described by 0-1 multidimensional knapsack problems that are NP-hard. In the last decades several exact as well as heuristic methods have been proposed for solving these problems. In this paper, a new simpli ed binary version of the artificial fish swarm algorithm is presented, where a point/ fish is represented by a binary string of 0/1 bits. Trial points are created by using crossover and mutation in the different fi sh behavior that are randomly selected by using two user de ned probability values. In order to make the points feasible the presented algorithm uses a random heuristic drop item procedure followed by an add item procedure aiming to increase the profit throughout the adding of more items in the knapsack. A cyclic reinitialization of 50% of the population, and a simple local search that allows the progress of a small percentage of points towards optimality and after that refines the best point in the population greatly improve the quality of the solutions. The presented method is tested on a set of benchmark instances and a comparison with other methods available in literature is shown. The comparison shows that the proposed method can be an alternative method for solving these problems.

Column-based databases: estudo exploratório no âmbito das bases de dados NoSQL

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Document-based databases: estudo comparativo no âmbito das bases de dados NoSql

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

“PhenoWorld”: a new multidimensional strategy for studying behaviour in rodents

Tese de Doutoramento em Ciências da Saúde

Concepts and objects of awareness in Alzheimer’s disease: an updated systematic review

ABSTRACT Objectives To compare and discuss the objects of awareness in Alzheimer’s disease (AD): awareness of cognitive deficits, of functional activities, of social-emotional functioning and behavioral impairment. Methods A search in the PsycINFo, Pilots, PubMed/Medline and ISI electronic databases according to Prisma methodology was performed. We included studies about awareness in people with AD published between 2010 and 2015, with the combination of keywords: “Alzheimer AND awareness of deficits”, “Alzheimer AND anosognosia”, “Alzheimer AND insight”, “dementia AND awareness of deficits”, “dementia AND anosognosia”, “dementia AND insight”. The articles were categorized according to the specific object of awareness. Results Seven hundred and ten records were identified and, after application of the exclusion criteria, 191 studies were retrieved for potential use. After excluding the duplicates, 46 studies were included. Most studies assessed the cognitive domain of awareness, followed by the functional, social-emotional, and behavioral impairment domains. Memory deficits were not sufficient to explain impaired awareness in AD. Longitudinal studies did not find discrepancies between patients and caregivers’ reports, indicating that awareness is not related to cognition. Conflicting findings were observed, including the relation between awareness, mood, severity of disease, and personal characteristics. Conclusions The studies show lack of conceptual consensus and significant methodological differences. The inclusion of samples without differentiation of dementia etiology is associated to symptomatic differences, which affect awareness domains. Awareness in AD is a complex and multidimensional construct. Different objects elicit different levels of awareness.

Las Bases Políticas de la Emergencia. Un Estudio Multidimensional de las Relaciones entre el Poder Ejecutivo Nacional y el Poder Legislativo, 2003-2009

La relación del Gobierno de Kirchner con el poder Legislativo implicó un proceso de concentración del poder en manos del Ejecutivo, no obstante lo cual, a poco de iniciado el mandato de Cristina Fernández, la relación con el Congreso queda en el medio de una crisis que llegó a poner en duda la propia continuidad de la presidenta. Este proyecto pretende examinar las características de este proceso delegativo en sus diferentes dimensiones, con el fin de entender el origen de esta crisis y especificar sus alcances. En este marco, la dinámica de la relación entre el Congreso y el Ejecutivo pareciera corresponder a lo que especifica la Teoría del Cártel tal como ha sido reformulada por Jones y Hwang. Esta perspectiva, no obstante, se centra exclusivamente en los aspectos distributivos de la relación entre el Ejecutivo y el Legislativo, obviando la dimensión electoral y la ideológicodiscursiva. Dadas las características del Gobierno de Kirchner, en este proyecto abordaremos el estudio de aquella relación desde una perspectiva multidimensional, tomando en cuenta no sólo los aspectos distributivos, sino también los electorales y los discursivos. La pregunta que guía nuestro trabajo es por qué las estrategias de acumulación desplegadas simultáneamente en las tres dimensiones, no lograron (o sólo lo hicieron parcialmente) desactivar el carácter condicional de la delegación de los jefes políticos provinciales al liderzgo presidencial. Nuestra hipótesis general es que, aún cuando el Gobierno consiguió reforzar sustancialmente su posición en la dimensión distributiva a partir de la prolongación de la situación de emergencia, tuvo un éxito parcial en las dimensiones electoral e ideológico-discursiva. Sin compromiso ideológico articulado en un discurso común, y sin una conexión electoral que vincule los intereses electorales a nivel provincial con los del nivel nacional, la estrategia distributiva sólo puede contener parcialmente la defección de buena parte del oficialismo en el Congreso frente a una crisis de grandes proporciones.

Multidimensional schemes for hyperbolic conservation laws on triangular meshes

Genuinely multidimensional schemes, hyperbolic systems, wave equations, Euler equations, evolution Galerkin schemes, space-time conservative methods, high order accuracy, shock solutions

On propositionalization for knowledge discovery in relational databases

Propositionalization, Inductive Logic Programming, Multi-Relational Data Mining

Efficient query processing in co-processor-accelerated databases

...Diese Dissertation zeigt, wie wir Datenbankmanagementsysteme bauen können, die heterogene Prozessoren effizient und zuverlässig zur Beschleunigung der Anfrageverarbeitung nutzen können. Daher untersuchen wir typische Entwurfsentscheidungen von coprozessorbeschleunigten Datenbankmanagementsystemen und leiten darauf aufbauend eine generische Architektur für solche Systeme ab. Unsere Untersuchungen zeigen, dass eines der wichtigsten Probleme für solche Datenbankmanagementsysteme die Entscheidung ist, welche Operatoren einer Anfrage auf welchem Prozessor ausgeführt werden sollen...

Norm inequalities in multidimensional Lorentz spaces

In this paper we obtain necessary and sufficient conditions for double trigonometric series to belong to generalized Lorentz spaces, not symmetric in general. Estimates for the norms are given in terms of coefficients.

Lp theory for the multidimensional aggregation equation

"Vegeu el resum a l'inici del document del fitxer adjunt."

trEST, trGEN and Hits: access to databases of predicted protein sequences.

High throughput genome (HTG) and expressed sequence tag (EST) sequences are currently the most abundant nucleotide sequence classes in the public database. The large volume, high degree of fragmentation and lack of gene structure annotations prevent efficient and effective searches of HTG and EST data for protein sequence homologies by standard search methods. Here, we briefly describe three newly developed resources that should make discovery of interesting genes in these sequence classes easier in the future, especially to biologists not having access to a powerful local bioinformatics environment. trEST and trGEN are regularly regenerated databases of hypothetical protein sequences predicted from EST and HTG sequences, respectively. Hits is a web-based data retrieval and analysis system providing access to precomputed matches between protein sequences (including sequences from trEST and trGEN) and patterns and profiles from Prosite and Pfam. The three resources can be accessed via the Hits home page (http://hits. isb-sib.ch).