Une approche flexible et décentralisée du traitement de requêtes dans les systèmes géo-distribués

This thesis studies the design of query processing systems, across a diversity of geo-distributed settings. Optimising performance metrics such as response time, freshness, or operational cost involves design decisions, such as what derived state (e.g., indexes, materialised views, or caches) to maintain, and how to distribute and where to place the corresponding computation and state. These metrics are often in tension, and the trade-offs depend on the specific application and/or environment. This requires the ability to adapt the query engine's topology and architecture, and the placement of its components. This thesis makes the following contributions: - A flexible architecture for geo-distributed query engines, based on components connected in a bidirectional acyclic graph. - A common microservice abstraction and API for these components, the Query Processing Unit (QPU). A QPU encapsulates some primitive query processing task. Multiple QPU types exist, which can be instantiated and composed into complex graphs. - A model for constructing modular query engine architectures as a distributed topology of QPUs, enabling flexible design and trade-offs between performance metrics. - Proteus, a QPU-based framework for constructing and deploying query engines. - Representative deployments of Proteus and experimental evaluation thereof.Cette thèse présente l'étude de la conception de systèmes de traitement de requêtes dans divers cadres géo-distribués. L'optimisation des mesures de performance telles que le temps de réponse, la fraîcheur ou le coût opérationnel implique des décisions de conception tel que le choix de l’état dérivé (indices, vues matérialisées, caches par ex.) à construire et maintenir, et la distribution et le placement de ces derniers et de leurs calculs. Ces métriques sont souvent opposées et les compromis dépendent de l'application et/ou de la spécificité de l'environnement. La capacité d'adapter la topologie et l'architecture du système de traitement de requêtes devient alors essentielle, ainsi que le placement de ses composants. Cette thèse apporte les contributions suivantes : - Une architecture flexible pour les systèmes de traitement de requêtes géo-distribués, basée sur des composants connectés dans un graphe bidirectionnel acyclique. - Une abstraction de micro-service et une API communes pour ces composants, le Query Processing Unit (QPU). Un QPU encapsule une tâche de traitement de requête primitive. Il existe plusieurs types de QPU qui peuvent être instanciés et composés en graphes complexes. - Un modèle pour construire des architectures de systèmes de traitement de requêtes modulaires composées d’une topologie distribuée de QPUs, permettant une conception flexible et des compromis selon les mesures de performance visées. - Proteus, un framework basé sur les QPU, permettant la construction et le déploiement de systèmes de traitement de requêtes. - Déploiements représentatifs de systèmes de traitement de requêtes à l'aide de Proteus, et leur évaluation expérimentale

Data freshness and data accuracy :a state of the art

In a context of Data Integration Systems (DIS) providing access to large amounts of data extracted and integrated from autonomous data sources, users are highly concerned about data quality. Traditionally, data quality is characterized via multiple quality factors. Among the quality dimensions that have been proposed in the literature, this report analyzes two main ones: data freshness and data accuracy. Concretely, we analyze the various definitions of both quality dimensions, their underlying metrics and the features of DIS that impact their evaluation. We present a taxonomy of existing works proposed for dealing with both quality dimensions in several kinds of DIS and we discuss open research problems

Products and Services

Today’s global economy offers more opportunities, but is also more complex and competitive than ever before. This fact leads to a wide range of research activity in different fields of interest, especially in the so-called high-tech sectors. This book is a result of widespread research and development activity from many researchers worldwide, covering the aspects of development activities in general, as well as various aspects of the practical application of knowledge

Peace Dividend: The War Assets Corporation and the Disposal of Canada\u27s Munitions and Supplies, 1943-1948

This dissertation is the first full-length study to explore how the Canadian government and military disposed of surplus munitions and supplies after the Second World War. By investigating how the state planned and implemented its disposal program from 1943 to 1948, this thesis places objects at the centre of attention and demonstrates their profound political, social, and economic significance. By examining the extended social lives of munitions and supplies in relationship to their postwar impact on civilian life, this study offers a new and innovative perspective that links material culture with postwar reconstruction, rehabilitation, and demobilization. What follows is a history of how Canadians turned swords into plowshares that contributes to the fields of military history, Canadian history, material culture, and disarmament studies. Disposal was an important element of Canada’s exit strategy for the Second World War because the objects accumulated to fight survived long after hostilities ended and required diligent procedures to demobilize or destroy. In November 1943, the Canadian government established the Crown Assets Allocation Committee (CAAC) and the War Assets Corporation (WAC) to plan, control, and implement its disposal program. This study elaborates on four critical themes: 1) the continuous and evolving nature of public pressure for government action on disposal; 2) the role of the CAAC and WAC in controlling disposal operations; 3) the way the objects of war require stewardship from one use to the next; and 4) the process through which munitions and supplies were reduced, reused, recycled, and upcycled into new forms, functions, and intentions. This thesis argues that through the CAAC and WAC surplus assets were disposed of to support, and not hinder, postwar reconstruction and rehabilitation. Although disposal was not perfect and left behind some dangerous environmental legacies, the conversion of surplus assets into peacetime purposes ensured that objects gained new uses and meanings thereby mitigating their threatening nature to economic stability, political authority, and public safety. Keywords: Canadian history; military history; munitions disposal; material culture; demobilization; disarmament; reconstruction; rehabilitation; peace

Factors Influencing Customer Satisfaction towards E-shopping in Malaysia

Online shopping or e-shopping has changed the world of business and quite a few people have decided to work with these features. What their primary concerns precisely and the responses from the globalisation are the competency of incorporation while doing their businesses. E-shopping has also increased substantially in Malaysia in recent years. The rapid increase in the e-commerce industry in Malaysia has created the demand to emphasize on how to increase customer satisfaction while operating in the e-retailing environment. It is very important that customers are satisfied with the website, or else, they would not return. Therefore, a crucial fact to look into is that companies must ensure that their customers are satisfied with their purchases that are really essential from the ecommerce’s point of view. With is in mind, this study aimed at investigating customer satisfaction towards e-shopping in Malaysia. A total of 400 questionnaires were distributed among students randomly selected from various public and private universities located within Klang valley area. Total 369 questionnaires were returned, out of which 341 questionnaires were found usable for further analysis. Finally, SEM was employed to test the hypotheses. This study found that customer satisfaction towards e-shopping in Malaysia is to a great extent influenced by ease of use, trust, design of the website, online security and e-service quality. Finally, recommendations and future study direction is provided. Keywords: E-shopping, Customer satisfaction, Trust, Online security, E-service quality, Malaysia

Grassroots Innovation Movements

Innovation is increasingly invoked by policy elites and business leaders as vital for tackling global challenges like sustainable development. Often overlooked, however, is the fact that networks of community groups, activists, and researchers have been innovating grassroots solutions for social justice and environmental sustainability for decades. Unencumbered by disciplinary boundaries, policy silos, or institutional logics, these ‘grassroots innovation movements’ identify issues and questions neglected by formal science, technology and innovation organizations. Grassroots solutions arise in unconventional settings through unusual combinations of people, ideas and tools. This book examines six diverse grassroots innovation movements in India, South America and Europe, situating them in their particular dynamic historical contexts. Analysis explains why each movement frames innovation and development differently, resulting in a variety of strategies. The book explores the spaces where each of these movements have grown, or attempted to do so. It critically examines the pathways they have developed for grassroots innovation and the challenges and limitations confronting their approaches. With mounting pressure for social justice in an increasingly unequal world, policy makers are exploring how to foster more inclusive innovation. In this context grassroots experiences take on added significance. This book provides timely and relevant ideas, analysis and recommendations for activists, policy-makers, students and scholars interested in encounters between innovation, development and social movements

From Analogue to Image Retrieval: Concepts of Archival Art in Daniel Blaufuks

From Analogue to Image Retrieval: Concepts of Archival Art in Daniel Blaufuks, seeks to explore a question first triggered by the viewing of Daniel Blaufuks’s Constellation series in his exhibition-project, All the Memory of the World, part one (2014): might digital databases and image retrieval systems be viewed as developments of archival processes and thinking? Has the touted rupture between analogue and digital occurred, or does archival art live in them both? With a career that spans several decades, Blaufuks has been deeply engaged with questions surrounding the Holocaust, exile, memory and postmemory. Photography, film and archival material have been the tools chosen for his excavations; nonetheless, it is impossible to overlook the influence of literature in the artist’s work. Having begun with the appropriation of physical archival material, such as photographic albums, polaroids or slides, Blaufuks has also employed digital images and image-retrieval systems such as Google Image. In the view to proceed with an analysis on the crucial argument of this thesis, I have divided it into to three sections. The first, Daniel Blaufuks: The ‘Material’ Archive, as the name indicates, focuses on considerations on the so-called material archive, meaning the analogue archive. Daniel Blaufuks: Writing with Images, the second section, is devoted to two thematic components of the artist’s oeuvre: memory and literature. Here I equally offer a comparative analysis between Blaufuks and the works of writers Georges Perec and W. G. Sebald. In Daniel Blaufuks: Traversing the Archive, the final section, I return to the theoretical frameworks surrounding the archive, yet one founded on 0s and 1s rather than paper and ink. In writing From Analogue to Image Retrieval: Concepts of Archival Art in Daniel Blaufuks, I strive to illuminate the continuities from analogue to digital archives, and analogue to digital archival art practices. Blaufuks’s ease and breadth in the incorporation of a variety of media into his projects stands as an ideal case study for the exploration of the questions I put forward in this thesis.From Analogue to Image Retrieval: Concepts of Archival Art in Daniel Blaufuks, explora uma questão desencadeada pela série Constelações de Daniel Blaufuks no seu projeto-exposição, Toda a Memória do Mundo, parte um (2014): poderão bases de dados e sistemas de recuperação de imagens ser vistos como extensões de processos e de concepções do arquivo? Terá a ruptura entre analógico e digital ocorrido, ou será que a arte arquivística é transversal a ambos? Com uma carreira que se estende por várias décadas, Blaufuks tem desenvolvido projectos relacionados com questões em torno do Holocausto, exílio, memória e pós memória. Fotografia, imagem em movimento e material de arquivo são as ferramentas escolhidas pelo artista para as suas escavações; no entanto, é impossível ignorar a influência da literatura na sua obra. Tendo começado com a apropriação de material de arquivo, como álbuns fotográficos, polaroids ou slides, Blaufuks emprega também imagens digitais e motores de busca de imagens como o Google Image nos seus projectos mais recentes. A fim de prosseguir com uma análise da questão central desta tese, a mesma foi dividida em três secções. A primeira, Daniel Blaufuks: The ‘Material’ Archive, tem como foco considerações sobre o arquivo analógico. Já Daniel Blaufuks: Writing with Images, a segunda secção, é dedicada a duas componentes temáticas da obra do artista: memória e literatura. Aqui, procedo igualmente a uma análise comparativa entre Blaufuks e as obras dos escritores Georges Perec e W. G. Sebald. Em Daniel Blaufuks: Traversing the Archive, a secção final, regresso às estruturas teóricas associadas ao arquivo, olhando no entanto para um arquivo construído sobre 0s e 1s ao invés de papel e tinta. Com From Analogue to Image Retrieval: Concepts of Archival Art in Daniel Blaufuks, procuro iluminar continuidades entre arquivos analógicos e digitais, bem como estabelecer paralelos entre o uso de sistemas analógicos e digitais em práticas de arte de arquivo. A facilidade com que Blaufuks integra uma variedade de formatos e média no seu trabalho faz com que o artista seja o estudo de caso ideal para a exploração das questões que apresento nesta tese

Obsolescent Materialized Views in Query Processing of Enterprise Information Systems

In recent years, query processing has become more complex as data sources are frequently replicated and data are periodically processed and embedded within several data sources simultaneously. These trends have necessitated the optimization of techniques for query processing in order to exploit these new alternatives. Accordingly, this paper introduces an improved query optimization technique, which is capable of assessing query plans that use both current and obsolescent data. In particular, we provide a cost model by which the tradeoffs of using obsolescent materialized views can be evaluated and we also discuss the method's applicability to contemporary query optimization techniques. 1 Introduction Contemporary enterprise information systems consist of various types of data sources (e.g., conventional databases, extranets, and semi-structured data sources) whose data are periodically replicated, processed, and materialized in other data sources simultaneously. This phenomenon is ..

Grassroots Innovation Movements

Innovation is increasingly invoked by policy elites and business leaders as vital for tackling global challenges like sustainable development. Often overlooked, however, is the fact that networks of community groups, activists, and researchers have been innovating grassroots solutions for social justice and environmental sustainability for decades. Unencumbered by disciplinary boundaries, policy silos, or institutional logics, these ‘grassroots innovation movements’ identify issues and questions neglected by formal science, technology and innovation organizations. Grassroots solutions arise in unconventional settings through unusual combinations of people, ideas and tools. This book examines six diverse grassroots innovation movements in India, South America and Europe, situating them in their particular dynamic historical contexts. Analysis explains why each movement frames innovation and development differently, resulting in a variety of strategies. The book explores the spaces where each of these movements have grown, or attempted to do so. It critically examines the pathways they have developed for grassroots innovation and the challenges and limitations confronting their approaches. With mounting pressure for social justice in an increasingly unequal world, policy makers are exploring how to foster more inclusive innovation. In this context grassroots experiences take on added significance. This book provides timely and relevant ideas, analysis and recommendations for activists, policy-makers, students and scholars interested in encounters between innovation, development and social movements