<p>Många databassystem utsätts ideligen för förändring. Dessa förändringar påverkar databasens schema. Detta har lett till att stöd för dessa förändringar har utvecklas. Schema versioning är det stödet för förändringar av databasscheman som ger det mest omfattande stödet. Med schema versioning menas att DBMS:et kan hantera flera versioner av databasschemat. Ett problem med schema versioning är att användaren måste veta vilken version en viss fråga ska ställas emot för att svaret ska bli korrekt. I detta arbete har det undersökts för vilka typer av förändringar mot en relationsdatabas som detta problem kan undvikas genom att uppnå versionstransparens, vilket innebär att versionshanteringen är osynlig för användaren. Undersökningen gjordes mot en modell som bara använder information ifrån de frågor som ställs mot databasen för att hitta rätt version att ställa frågan emot. Resultatet av undersökningen visar att versionstransparens kan uppnås för alla typer av förändringar utom för ändringar av datatypen för kolumner.</p>

O objetivo geral desta tese é a detecção, o gerenciamento e a consulta às réplicas e às versões de documentos XML. Denota-se por réplica uma cópia idêntica de um objeto do mundo real, enquanto versão é uma representação diferente, mas muito similar, deste objeto. Trabalhos prévios focam em gerenciamento e consulta a versões conhecidas, e não no problema da detecção de que dois ou mais objetos, aparentemente distintos, são variações (versões) do mesmo objeto. No entanto, o problema da detecção é crítico e pode ser observado em diversos cenários, tais como detecção de plágio, ranking de páginas Web, identificação de clones de software e busca em sistemas peer-to-peer (P2P). Nesta tese assume-se que podem existir diversas réplicas de um documento XML. Documentos XML também podem ser modificados ao longo do tempo, ocasionando o surgimento de versões. A detecção de réplicas é relativamente simples e pode ser feita através do uso de funções hash. Já a detecção de versões engloba conceitos de similaridade, a qual pode ser medida por várias métricas, tais como similaridade de conteúdo, de estrutura, de assunto, etc. Além da análise da similaridade entre os arquivos também se faz necessária a definição de um mecanismo de detecção de versões. O mecanismo deve possibilitar o gerenciamento e a posterior consulta às réplicas e às versões detectadas. Para que o objetivo da tese fosse alcançado foram definidos um conjunto de funções de similaridade para arquivos XML e o mecanismo de detecção de réplicas e de versões. Também foi especificado um framework onde tal mecanismo pode ser inserido e os seus respectivos componentes, que possibilitam o gerenciamento e a consulta às réplicas e às versões detectadas. Foi realizado um conjunto de experimentos que validam o mecanismo proposto juntamente com a implementação de protótipos que demonstram a eficácia dos componentes do framework. Como diferencial desta tese, o problema de detecção de versões é tratado como um problema de classificação, para o qual o uso de limiares não é necessário. Esta abordagem é alcançada pelo uso da técnica baseada em classificadores Naïve Bayesianos. Resultados demonstram a boa qualidade obtida com o mecanismo proposto na tese. / The overall goals of this thesis are the detection, management and querying of replicas and versions of XML documents. We denote by replica an identical copy of a real-world object, and by version a different but very similar representation of this object. Previous works focus on version management and querying rather than version detection. However, the version detection problem is critical in many scenarios, such as plagiarism detection, Web page ranking, software clone identification, and peer-to-peer (P2P) searching. In this thesis, we assume the existence of several replicas of a XML document. XML documents can be modified over time, causing the creation of versions. Replica detection is relatively simple and can be achieved by using hash functions. The version detection uses similarity concepts, which can be assessed by some metrics such as content similariy, structure similarity, subject similarity, and so on. Besides the similarity analysis among files, it is also necessary to define the version detection mechanism. The mechanism should allow the management and the querying of the detected replicas and versions. In order to achieve the goals of the thesis, we defined a set of similarity functions for XML files, the replica and version detection mechanism, the framework where such mechanism can be included and its components that allow managing and querying the detected replicas and versions. We performed a set of experiments for evaluating the proposed mechanism and we implemented tool prototypes that demonstrate the accuracy of some framework components. As the main distinguishing point, this thesis considers the version detection problem as a classification problem, for which the use of thresholds is not necessary. This approach is achieved by using Naïve Bayesian classifiers.

There is an emerging demand on efficiently archiving and (temporal) querying different versions of evolving semantic Web data. As novel archiving systems are starting to address this challenge, foundations/standards for benchmarking RDF archives are needed to evaluate its storage space efficiency and the performance of different retrieval operations. To this end, we provide theoretical foundations on the design of data and queries to evaluate emerging RDF archiving systems. Then, we instantiate these foundations along a concrete set of queries on the basis of a real-world evolving dataset. Finally, we perform an empirical evaluation of various current archiving techniques and querying strategies on this data that is meant to serve as a baseline of future developments on querying archives of evolving RDF data.

O objetivo geral desta tese é a detecção, o gerenciamento e a consulta às réplicas e às versões de documentos XML. Denota-se por réplica uma cópia idêntica de um objeto do mundo real, enquanto versão é uma representação diferente, mas muito similar, deste objeto. Trabalhos prévios focam em gerenciamento e consulta a versões conhecidas, e não no problema da detecção de que dois ou mais objetos, aparentemente distintos, são variações (versões) do mesmo objeto. No entanto, o problema da detecção é crítico e pode ser observado em diversos cenários, tais como detecção de plágio, ranking de páginas Web, identificação de clones de software e busca em sistemas peer-to-peer (P2P). Nesta tese assume-se que podem existir diversas réplicas de um documento XML. Documentos XML também podem ser modificados ao longo do tempo, ocasionando o surgimento de versões. A detecção de réplicas é relativamente simples e pode ser feita através do uso de funções hash. Já a detecção de versões engloba conceitos de similaridade, a qual pode ser medida por várias métricas, tais como similaridade de conteúdo, de estrutura, de assunto, etc. Além da análise da similaridade entre os arquivos também se faz necessária a definição de um mecanismo de detecção de versões. O mecanismo deve possibilitar o gerenciamento e a posterior consulta às réplicas e às versões detectadas. Para que o objetivo da tese fosse alcançado foram definidos um conjunto de funções de similaridade para arquivos XML e o mecanismo de detecção de réplicas e de versões. Também foi especificado um framework onde tal mecanismo pode ser inserido e os seus respectivos componentes, que possibilitam o gerenciamento e a consulta às réplicas e às versões detectadas. Foi realizado um conjunto de experimentos que validam o mecanismo proposto juntamente com a implementação de protótipos que demonstram a eficácia dos componentes do framework. Como diferencial desta tese, o problema de detecção de versões é tratado como um problema de classificação, para o qual o uso de limiares não é necessário. Esta abordagem é alcançada pelo uso da técnica baseada em classificadores Naïve Bayesianos. Resultados demonstram a boa qualidade obtida com o mecanismo proposto na tese. / The overall goals of this thesis are the detection, management and querying of replicas and versions of XML documents. We denote by replica an identical copy of a real-world object, and by version a different but very similar representation of this object. Previous works focus on version management and querying rather than version detection. However, the version detection problem is critical in many scenarios, such as plagiarism detection, Web page ranking, software clone identification, and peer-to-peer (P2P) searching. In this thesis, we assume the existence of several replicas of a XML document. XML documents can be modified over time, causing the creation of versions. Replica detection is relatively simple and can be achieved by using hash functions. The version detection uses similarity concepts, which can be assessed by some metrics such as content similariy, structure similarity, subject similarity, and so on. Besides the similarity analysis among files, it is also necessary to define the version detection mechanism. The mechanism should allow the management and the querying of the detected replicas and versions. In order to achieve the goals of the thesis, we defined a set of similarity functions for XML files, the replica and version detection mechanism, the framework where such mechanism can be included and its components that allow managing and querying the detected replicas and versions. We performed a set of experiments for evaluating the proposed mechanism and we implemented tool prototypes that demonstrate the accuracy of some framework components. As the main distinguishing point, this thesis considers the version detection problem as a classification problem, for which the use of thresholds is not necessary. This approach is achieved by using Naïve Bayesian classifiers.

While collaborative engineering in outsourcing projects presents potential benefits to the partners, it involves some risks and reasonable concerns. First, a poor mechanism of data exchange and data communication can lead to loss of effectiveness and efficiency of the project. Second, collaborative engineering requires partners to adapt a common business process, which often means moving away from a familiar way of working. Thus, it is crucial to find an optimal way a collaboration can be achieved with the lowest waste due to changes in communication practices, and losses in efficiency due to asynchronous processes or big amount of exchange data. The main goal of this thesis is to connect two aspects in a collaboration: data-exchange and process-based execution. The main reason to do so is to resolve a problem with a weak control over information needed for successful project execution. Three research methods are used in this work: a case study to analyze how collaboration is performed in the industry and which problems exist; a literature review to understand how existing collaboration tools can be adapted to help solving the identified problems; and a prototypical implementation to show how automated versioning of engineering knowledge can be added to the union of data exchange and process-based aspects. The case study was performed and a list of business requirements was presented. Based on the list of requirements, solutions within the literature were searched. A process-based artifact-centric concept was applied to the case study scenario. Objectives are achieved, however, the problem was shown on an example of one company, which presents a limitation, as generalization has not been proved.

Många databassystem utsätts ideligen för förändring. Dessa förändringar påverkar databasens schema. Detta har lett till att stöd för dessa förändringar har utvecklas. Schema versioning är det stödet för förändringar av databasscheman som ger det mest omfattande stödet. Med schema versioning menas att DBMS:et kan hantera flera versioner av databasschemat. Ett problem med schema versioning är att användaren måste veta vilken version en viss fråga ska ställas emot för att svaret ska bli korrekt. I detta arbete har det undersökts för vilka typer av förändringar mot en relationsdatabas som detta problem kan undvikas genom att uppnå versionstransparens, vilket innebär att versionshanteringen är osynlig för användaren. Undersökningen gjordes mot en modell som bara använder information ifrån de frågor som ställs mot databasen för att hitta rätt version att ställa frågan emot. Resultatet av undersökningen visar att versionstransparens kan uppnås för alla typer av förändringar utom för ändringar av datatypen för kolumner.

Master of Architecture / Department of Architecture / Matthew Knox / The purpose of this study is to examine how the industrial process of rapid prototyping might reshape practice and making in architecture. Rapid prototyping is defined as an accelerated, adaptive evolution of a system or its components in some form using computer-aided drafting and manufacturing. Historically, all architecture was the intelligence of a single maker—the master builder. Specialization has caused architecture to fragment with architects serving only as designers. This report explores the ability of computer-aided drafting and manufacturing technologies to streamline the design procedure, which potentially increases the architect’s input into the process of building. Effectually, the architect narrows the distance between the design and the built—returning the architect to the role of master builder. An actual design exercise will examine the connection of architectural practice to making. To apply this research a habitable space was constructed through the incorporation of rapid prototyping.

This work deals with design and implementation of the system for document management and versioning. The first part contains description of related work. In the second part, information security concepts and security model, upon which application is build, is discussed. Third part contains description of designed system and its typical use in a form of sequence diagram. Fourth part introduces cryptographic protocol used in this work. Next follows the description of implementation and security analysis of developed system. The output of this work is cryptographic protocol for document management and versioning, and client-server application implementing this protocol.

No description available.

In Scientific workflows, data provenance plays a big part. Through data provenance, the execution of the workflow is documented and information about the data pieces involved are stored. This can be used to reproduce scientific experiments or to proof how the results from the workflow came to be. It is therefore vital that the provenance data that is stored in the provenance database is always synchronized with its corresponding workflow, to verify that the provenance database has not been tampered with. The blockchain technology has been gaining a lot of attention in recent years since Satoshi Nakamoto released his Bitcoin paper in 2009. The blockchain technology consists of a peer-to-peer network where an append-only ledger is stored and replicated across a peer-to-peer network and offers high tamper-resistance through its consensus protocols. In this thesis, the option of whether the blockchain technology is a suitable solution for synchronizing workflow with its provenance data was explored. A system that generates a workflow, based on a definition written in a Domain Specific Language, was extended to utilize the blockchain technology to synchronize the workflow itself and its results. Furthermore, the InterPlanetary File System was utilized to assist with the versioning of individual executions of the workflow. The InterPlanetary File System provided the functionality of comparing individual workflows executions in more detail and to discover how they differ. The solution was analyzed with respect to the 21 CFR Part 11 regulations imposed by the FDA in order to see how it could assist with fulfilling the requirements of the regulations.  Analysis on the system shows that the blockchain extension can be used to verify if the synchronization between a workflow and its results has been tampered with. Experiments revealed that the size of the workflow did not have a significant effect on the execution time of the extension. Additionally, the proposed solution offers a constant cost in digital currency regardless of the workflow. However, even though the extension shows some promise of assisting with fulfilling the requirements of the 21 CFR Part 11 regulations, analysis revealed that the extension does not fully comply with it due to the complexity of the regulations / I vetenskapliga arbetsflöden är usprung (eng. provenance) av dataviktigt. Genom att spåra ursprunget av data, i form av dokumentation,kan datas ursprung sparas. Detta kan användas för att återskapavetenskapliga experiment eller för att bevisa hur resultat från arbetsflödegenererats. Det är därför viktigt att datas ursprung, som lagrasi ursprungsdatabasen, alltid är synkroniserad med dess motsvarandearbetsflöde som ett sätt att verifiera att ursprungsdatabasen intehar manipulerats. Blockchainteknologi har fått mycket uppmärksamhetde senaste åren sen Satoshi Nakamoto släppte sin Bitcoin artikelår 2009. Blockchainteknologi består av ett peer-to-peer nätverk där endastbifogning tillåts i en liggare som är replikerad över ett peer-topeernätverk vilken tillhandahåller hög manipuleringsresistans genomkonsensusprotokoll. I denna uppsats undersöks hurvida blockchainteknologi är en passande lösning för arbetsflödessynkronisering avursprungsdata. Ett system som genererar ett arbetsflöde, baserat påen definition som skrivits i ett domänspecifikt språk, var förlängt föratt utnyttja blockchainteknologi för synkronisering av arbetsflödet ochdess resultat. InterPlanetary File System användes för att assistera medversionshanteringen av individuella exekveringar av arbetsflödet. InterPlanetaryFile System tillhandahöll funktionalitet för att jämföra individuellaarbetsflödesexekveringar mer detaljerat samt att upptäckahur de skiljer sig åt. Resultaten är analyserade med hänsyn till 21 CFRPart 11 regleringar från FDA för att se hur resultaten kan assistera medatt uppfylla kraven av förordningarna. Analys av systemen visar attblockchainförlängningen kan användas för att verifiera att synkroniseringenmellan arbetsflödet och dess resultat inte har manipulerats.Experimenten visade att storleken av arbetsflödet inte hade märkbareffekt på exekveringstiden av förlängningen. Därutöver möjliggör denpresenterade lösningen en konstant kostnad i digital valuta oavsett arbetsflödetsstorlek. Även om förlängningen visar lovande resultat förassistering av fullföljande av 21 CFR Part 11 regleringarna påvisar analysatt förlängningen inte fullständigt uppfyller kraven på grund avkomplexiteten av dessa regleringar.