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From XML to relational view updates: applying old solutions to solve a new problem; De atualizações sobre visões XML para atualizações sobre visões relacionais: aplicando soluções antigas a um novo problema

Braganholo, Vanessa de Paula
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
ENG
Relevância na Pesquisa
56.43%
XML has become an important medium for data exchange, and is frequently used as an interface to - i.e. a view of - a relational database. Although lots of work have been done on querying relational databases through XML views, the problem of updating relational databases through XML views has not received much attention. In this work, we give the rst steps towards solving this problem. Using query trees to capture the notions of selection, projection, nesting, grouping, and heterogeneous sets found throughout most XML query languages, we show how XML views expressed using query trees can be mapped to a set of corresponding relational views. Thus, we transform the problem of updating relational databases through XML views into a classical problem of updating relational databases through relational views. We then show how updates on the XML view are mapped to updates on the corresponding relational views. Existing work on updating relational views can then be leveraged to determine whether or not the relational views are updatable with respect to the relational updates, and if so, to translate the updates to the underlying relational database. Since query trees are a formal characterization of view de nition queries, they are not well suited for end-users. We then investigate how a subset of XQuery can be used as a top level language...

Tratamento de conflitos e detecção de deltas em atualização através de visões XML; Conflict resolution and difference detection in updates through XML views

Vargas, Andre Prisco
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.29%
A linguagem XML tem se tornado um padrão no intercâmbio de informações naWeb. No entanto, a maioria das organizações continua a armazenar seus dados em bancos de dados relacionais. Diante deste ambiente, surge a necessidade de se construir aplicações que permitam às empresas o intercâmbio de informações via XML, mas sem que estas empresas tenham que migrar suas bases relacionais. Neste trabalho, é apresentada uma técnica para importar e exportar documentos XML, focada em cenários entre empresas onde visões XML são extraídas de uma base de dados relacional e enviadas via Web (ou qualquer outro meio) para outra aplicação que as edita e as retorna. Através da edição da visão XML, a própria base de dados relacional é modificada, atualizando assim os dados da empresa. A base de dados relacional deve ser atualizada com as novas informações da visão XML. Neste tipo de transação tem-se as seguintes considerações: 1. A visão XML pode ser atualizada por qualquer aplicação. Editores de texto, banco de dados XML e aplicações específicas estão entre as aplicações que podematualizála. 2. A aplicação que recebe a visão XML fica de posse dela por um período não determinado, podendo inclusive não retornar a visão. Durante este período a aplicação pode ficar desconectada da base de dados geradora da visão XML. 3. Enquanto a visão XML está sendo editada...

Learnings from real cases route-to-market redesign within the Portuguese lubricants sector

Oliveira, Ana Claudia Mariano
Fonte: NSBE - UNL Publicador: NSBE - UNL
Tipo: Dissertação de Mestrado
Publicado em /06/2013 ENG
Relevância na Pesquisa
15.76%
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics; This Work Project studies established distribution channels strategies’ adjustments due to continuous customers’ needs updates and market challenges. Qualitative and quantitative views support the analysis, based on two real cases within the same company. It was found that cases’ negotiations may turn comparable premises in distinct developments and outcomes. Lessons from the past, if used to address future cases, would be helpful through customer satisfaction focused perspectives. It is suggested that distribution approach choices may not be homogeneous along the business and they must rely on who is able to effectively complete the process from product source to the customer.

Keeping Wnt Signalosome in Check by Vesicular Traffic

FENG, QIANG; GAO, NAN
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/2015 EN
Relevância na Pesquisa
15.76%
Wg/Wnts are paracrine and autocrine ligands that activate distinct signaling pathways while being internalized through surface receptors. Converging and contrasting views are shaping our understanding of whether, where, and how endocytosis may modulate Wnt signaling. We gather considerable amount of evidences to elaborate the point that signal-receiving cells utilize distinct, flexible, and sophisticated vesicular trafficking mechanisms to keep Wnt signaling activity in check. Same molecules in a highly context-dependent fashion serve as regulatory hub for various signaling purposes: amplification, maintenance, inhibition, and termination. Updates are provided for the regulatory mechanisms related to the three critical cell surface complexes, Wnt-Fzd-LRP6, Dkk1-Kremen-LRP6, and R-spondin-LGR5-RNF43, which potently influence Wnt signaling. We pay particular attentions to how cells achieve sustained and delicate control of Wnt signaling strength by employing comprehensive aspects of vesicular trafficking.

NGO communication and activism via electronic media: Australian evidence

Tilt, C.; Davidson, R.; Tilling, M.
Fonte: Australian and New Zealand Third Sector Research Inc. Publicador: Australian and New Zealand Third Sector Research Inc.
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
15.92%
Non-government organisations (NGOs) communicate their ideas and views in a variety of ways, but electronic means are becoming more pervasive. Most NGOs have a website and many provide free information through subscriptions to electronically mailed newsletters and updates. Communication between NGOs and corporate entities, in particular, is an area that has not been investigated to a large extent, even though research on companies' social and environmental record has regularly referred to the influence of NGOs on corporate reporting practices. The purpose of this study is, therefore, twofold. It examines the Australian websites of eight large NGOs and provides an assessment of each site based on an evaluative framework. It then provides a more in-depth investigation into one of those elements: action or activism. In particular, the paper considers if and how NGOs engage in activism directed at companies or corporate entities via their webpages and through email. The results show that the websites of the sample NGOs are generally of good quality aesthetically, and provide relevant information on issues and campaigns. They do use their websites for activist purposes, but most commonly information on websites for activist purposes, but most commonly information on websites that refers to companies concerns relationships and partnerships...

Improving sampling, optimization and feature extraction in Boltzmann machines

Desjardins, Guillaume
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
15.94%
L’apprentissage supervisé de réseaux hiérarchiques à grande échelle connaît présentement un succès fulgurant. Malgré cette effervescence, l’apprentissage non-supervisé représente toujours, selon plusieurs chercheurs, un élément clé de l’Intelligence Artificielle, où les agents doivent apprendre à partir d’un nombre potentiellement limité de données. Cette thèse s’inscrit dans cette pensée et aborde divers sujets de recherche liés au problème d’estimation de densité par l’entremise des machines de Boltzmann (BM), modèles graphiques probabilistes au coeur de l’apprentissage profond. Nos contributions touchent les domaines de l’échantillonnage, l’estimation de fonctions de partition, l’optimisation ainsi que l’apprentissage de représentations invariantes. Cette thèse débute par l’exposition d’un nouvel algorithme d'échantillonnage adaptatif, qui ajuste (de fa ̧con automatique) la température des chaînes de Markov sous simulation, afin de maintenir une vitesse de convergence élevée tout au long de l’apprentissage. Lorsqu’utilisé dans le contexte de l’apprentissage par maximum de vraisemblance stochastique (SML), notre algorithme engendre une robustesse accrue face à la sélection du taux d’apprentissage...

A formação pedagógica do professor: relatos do seu desenvolvimento

Silva, Margarida Maria de Jesus
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
15.86%
O objecto deste estudo centra-se no desenvolvimento do professor, na compreensão dos diversos contextos e factores que, na perspectiva dos próprios professores, contribuem para a construção do seu conhecimento pedagógico. Procurámos, a partir das vozes dos professores, evidenciar que a eficácia pedagógica não depende exclusivamente das competências e conhecimentos adquiridos durante a formação inicial e que este conhecimento se vai construindo ao longo da vida sendo fruto de uma aprendizagem permanente. Sem qualquer possibilidade de esgotar o tema colocámos como meta central compreender alguns dos processos e variáveis que interferem na construção do conhecimento pedagógico do professor. Dito por outras palavras, pretendemos saber como é que o professor aprende a ser e a fazer o que entende ser a sua função. A metodologia usada neste estudo é de natureza qualitativa e interpretativa dada a sua adequação à investigação na área da educação e ao propósito deste trabalho. Para obter os dados utilizamos a entrevista e para o seu tratamento recorremos à análise de conteúdo por ser a técnica que melhor se adequa à exploração dos registos de carácter qualitativo. Os resultados obtidos revelam que a construção do conhecimento pedagógico se faz ao longo da carreira...

(Re)pensar as práticas de professores de Educação Física para a promoção da saúde

Santos, Rui Paulo Ribeiro dos
Fonte: Universidade dos Açores Publicador: Universidade dos Açores
Tipo: Dissertação de Mestrado
Publicado em 06/10/2011 POR
Relevância na Pesquisa
15.76%
Dissertação de Mestrado, Supervisão Pedagógica (Educação Física), 6 de Outubro de 2011, Universidade dos Açores.; Devido às grandes alterações dos hábitos de vida das populações, a actividade física das crianças e jovens está a decrescer progressivamente. Este trabalho teve como principal intuito analisar e descrever as opiniões/percepções de professores de educação física (EF) das escolas de dois Concelhos da Ilha de São Miguel acerca das suas práticas para a Promoção da Saúde nas suas escolas, tendo por objectivos: 1) Conhecer as percepções de professores de EF sobre a “Promoção da Saúde” na população infanto-juvenil e as suas opiniões sobre as acções de prevenção/ promoção de saúde dinamizadas pelas suas escolas (A e B); 2) Confrontar as percepções de professores de EF sobre as suas áreas de intervenção no ensino da EF tendo em consideração a “Promoção da Saúde” na população infanto-juvenil; 3) Levantar junto dos profissionais que leccionam EF nas escolas (A e B), as necessidades de formação e actualização na temática da saúde em função do seu perfil de actuação na área de prevenção/ promoção da saúde junto da população infanto/ juvenil. Na metodologia adoptada...

Unifying Causality, Diagnosis, Repairs and View-Updates in Databases

Bertossi, Leopoldo; Salimi, Babak
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
In this work we establish and point out connections between the notion of query-answer causality in databases and database repairs, model-based diagnosis in its consistency-based and abductive versions, and database updates through views. The mutual relationships among these areas of data management and knowledge representation shed light on each of them and help to share notions and results they have in common. In one way or another, these are all approaches to uncertainty management, which becomes even more relevant in the context of big data that have to be made sense of.; Comment: On-line Proc. First International Workshop on Big Uncertain Data (BUDA 2014). Co-located with ACM PODS 2014. arXiv admin note: text overlap with arXiv:1404.6857

A Characterization of the Complexity of Resilience and Responsibility for Self-join-free Conjunctive Queries

Freire, Cibele; Gatterbauer, Wolfgang; Immerman, Neil; Meliou, Alexandra
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/07/2015
Relevância na Pesquisa
35.76%
Several research thrusts in the area of data management have focused on understanding how changes in the data affect the output of a view or standing query. Example applications are explaining query results, propagating updates through views, and anonymizing datasets. These applications usually rely on understanding how interventions in a database impact the output of a query. An important aspect of this analysis is the problem of deleting a minimum number of tuples from the input tables to make a given Boolean query false. We refer to this problem as "the resilience of a query" and show its connections to the well-studied problems of deletion propagation and causal responsibility. In this paper, we study the complexity of resilience for self-join-free conjunctive queries, and also make several contributions to previous known results for the problems of deletion propagation with source side-effects and causal responsibility: (1) We define the notion of resilience and provide a complete dichotomy for the class of self-join-free conjunctive queries with arbitrary functional dependencies; this dichotomy also extends and generalizes previous tractability results on deletion propagation with source side-effects. (2) We formalize the connection between resilience and causal responsibility...

Achieving Data Privacy through Secrecy Views and Null-Based Virtual Updates

Bertossi, Leopoldo; Li, Lechen
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.26%
There may be sensitive information in a relational database, and we might want to keep it hidden from a user or group thereof. In this work, sensitive data is characterized as the contents of a set of secrecy views. For a user without permission to access that sensitive data, the database instance he queries is updated to make the contents of the views empty or contain only tuples with null values. In particular, if this user poses a query about any of these views, no meaningful information is returned. Since the database is not expected to be physically changed to produce this result, the updates are only virtual. And also minimal in a precise way. These minimal updates are reflected in the secrecy view contents, and also in the fact that query answers, while being privacy preserving, are also maximally informative. Virtual updates are based on the use of null values as used in the SQL standard. We provide the semantics of secrecy views and the virtual updates. The different ways in which the underlying database is virtually updated are specified as the models of a logic program with stable model semantics. The program becomes the basis for the computation of the "secret answers" to queries, i.e. those that do not reveal the sensitive information.; Comment: Minor revisions of journal resubmission...

Scalable Data Cube Analysis over Big Data

Wang, Zhengkui; Chu, Yan; Tan, Kian-Lee; Agrawal, Divyakant; Abbadi, Amr EI; Xu, Xiaolong
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/11/2013
Relevância na Pesquisa
15.76%
Data cubes are widely used as a powerful tool to provide multidimensional views in data warehousing and On-Line Analytical Processing (OLAP). However, with increasing data sizes, it is becoming computationally expensive to perform data cube analysis. The problem is exacerbated by the demand of supporting more complicated aggregate functions (e.g. CORRELATION, Statistical Analysis) as well as supporting frequent view updates in data cubes. This calls for new scalable and efficient data cube analysis systems. In this paper, we introduce HaCube, an extension of MapReduce, designed for efficient parallel data cube analysis on large-scale data by taking advantages from both MapReduce (in terms of scalability) and parallel DBMS (in terms of efficiency). We also provide a general data cube materialization algorithm which is able to facilitate the features in MapReduce-like systems towards an efficient data cube computation. Furthermore, we demonstrate how HaCube supports view maintenance through either incremental computation (e.g. used for SUM or COUNT) or recomputation (e.g. used for MEDIAN or CORRELATION). We implement HaCube by extending Hadoop and evaluate it based on the TPC-D benchmark over billions of tuples on a cluster with over 320 cores. The experimental results demonstrate the efficiency...

Blueswitch: Enabling Provably Consistent Configuration of Network Switches

Han, Jong Hun; Mundkur, Prashanth; Rotsos, Charalampos; Antichi, Gianni; Dave, Nirav; Moore, Andrew W.; Neumann, Peter G.
Fonte: IEEE Publicador: IEEE
Tipo: Article; accepted version
EN
Relevância na Pesquisa
16.11%
This is the author accepted manuscript. It is currently under infinite embargo pending publication of the final version.; Previous research on consistent updates for distributed network configurations has focused on solutions for centralized networkconfiguration controllers. However, such work does not address the complexity of modern switch datapaths. Modern commodity switches expose opaque configuration mechanisms, with minimal guarantees for datapath consistency and with unclear configuration semantics. Furthermore, would-be solutions for distributed consistent updates must take into account the configuration guarantees provided by each individual switch ? plus the compositional problems of distributed control and multi-switch configurations that considerably transcend the single-switch problems. In this paper, we focus on the behavior of individual switches, and demonstrate that even simple rule updates result in inconsistent packet switching in multi-table datapaths. We demonstrate that consistent configuration updates require guarantees of strong switch-level atomicity from both hardware and software layers of switches ? even in a single switch. In short, the multiple-switch problems cannot be reasonably approached until single-switch consistency can be resolved. We present a hardware design that supports a transactional configuration mechanism...