Übersicht

Current schema matching approaches still have to improve for very large and complex schemas. Such schemas are increasingly written in the standard language W3C XML schema, especially in E-business applications. The high expressive power and versatility of this schema language, in particular its type system and support for distributed schemas and namespaces, introduce new issues. In this paper, we study some of the important problems in matching such large XML schemas. We propose a fragment-oriented match approach to decompose a large match problem into several smaller ones and to reuse previous match results at the level of schema fragments.

Dieser Beitrag untersucht die Frage, wie komplexe Änderungen bei der Evolution von XML-Schemas automatisiert unterstützt werden können. Hierzu werden mögliche Änderungen an XML-Schemas durch Evolutionsoperatoren beschrieben, klassifiziert und beurteilt. Im Speziellen wird die Verschiebung (Move) von Elementen innerhalb von XML-Schemas analysiert. Die automatisierte Generierung und Ausführung von Transformationsregeln zur Migration von Instanzda-ten und die Beurteilung möglicher Informationsverluste während einer Transformation wird allgemein, wie auch anhand von Publikationsdaten untersucht.

Companies often require designers to work with and operate between different computer-aided design (CAD) systems. To interoperate between these systems, a neutral design standard for CAD models is needed that allows for generation, customization, and parameterization. Current standards often fail to incorporate file history and design intent. The research proposes a simplified, neutral design format that can be used to generate models in different CAD systems. The format proposes additional functionality not yet found in existing neutral formats or scripts. The system was tested by generating models in both NX and CATIA, then comparing the models for accuracy, flexibility, and similarity of the results. Utilizing the principles established with the neutral framework, a system was developed that facilitates a collaborative CAD modeling environment that supports the interaction of models within virtual reality (VR). A framework is presented that allows for the models to be created and then used in VR without the need for conversion. Strategies are discussed for minimizing the impacts of latency and unit testing was conducted to evaluate functionality. Furthermore, feasibility of using modern game engines such as Unity, Unreal Engine, and Godot to aid in the development of both VR and physics simulations are discussed. The above foundation and frameworks enhance collaboration in training and simulation in VR environments. This research demonstrates that by using neutral design standards, collaboration could be improved between different software, as well as between different engineers. Common strategies can be used for solving issues with conversions across the design space and integrated into future VR systems. This research will be indispensable to furthering studies of collaboration and design in remote environments.

Companies often require designers to work with and operate between different computer-aided design (CAD) systems. To interoperate between these systems, a neutral design standard for CAD models is needed that allows for generation, customization, and parameterization. Current standards often fail to incorporate file history and design intent. The research proposes a simplified, neutral design format that can be used to generate models in different CAD systems. The format proposes additional functionality not yet found in existing neutral formats or scripts. The system was tested by generating models in both NX and CATIA, then comparing the models for accuracy, flexibility, and similarity of the results. Utilizing the principles established with the neutral framework, a system was developed that facilitates a collaborative CAD modeling environment that supports the interaction of models within virtual reality (VR). A framework is presented that allows for the models to be created and then used in VR without the need for conversion. Strategies are discussed for minimizing the impacts of latency and unit testing was conducted to evaluate functionality. Furthermore, feasibility of using modern game engines such as Unity, Unreal Engine, and Godot to aid in the development of both VR and physics simulations are discussed. The above foundation and frameworks enhance collaboration in training and simulation in VR environments. This research demonstrates that by using neutral design standards, collaboration could be improved between different software, as well as between different engineers. Common strategies can be used for solving issues with conversions across the design space and integrated into future VR systems. This research will be indispensable to furthering studies of collaboration and design in remote environments.

Denna rapport behandlar ett kandidatprojekt som utförts med Nationellt forensiskt centrum som kund. Uppgiften var att skapa ett databasbaserat program för att lagra och hantera stora mängder XML-filer från kundens testinstrument. Rapporten beskriver de tekniker och metoder som använts för detta ändamål, där Java, MySQL, Git och agil utveckling är några av de mest centrala. Resultaten i projektet innefattar en presentation av slutprodukten, projektgruppens erfarenheter och medlemmarnas individuella bidrag. Utöver den gemensamma kandidatrapporten, har varje gruppmedlem genomfört ett individuellt bidrag om valfritt ämne, ofta kopplat till medlemmens projektroll. Detta gav möjlighet till fördjupning inom områden som medlemmarna fann intressanta. Utifrån diskussionen av dessa resultat dras, bland flera, slutsatserna att det utvecklade projektet kommer att bidra till tidsbesparingar för kunden, att en systemanatomi är ett användbart kommunikationsverktyg i början av ett projekt och att utvecklingen begränsades av valet av teknologier.

XML probabiliste est un modèle probabiliste pour les bases de données incertaines semi-structurées, avec des applications telles que l'intégration incertaine de données, l'extraction d'informations ou le contrôle probabiliste de versions. Nous explorons dans cette thèse une solution efficace pour l'évaluation des requêtes tree-pattern avec jointures sur ces documents, ou, plus précisément, pour l'approximation de la probabilité d'une requête booléenne sur un document probabiliste. L'approche repose sur, d'une part, la production de la provenance probabiliste de la requête posée, et, d'autre part, la recherche d'une stratégie optimale pour estimer la probabilité de cette provenance. Cette deuxième partie s'inspire des approches des optimiseurs de requêtes: l'exploration de différents plans d'évaluation pour différentes parties de la formule et l'estimation du coût de chaque plan, suivant un modèle de coût établi pour les algorithmes de calcul utilisés. Nous démontrons l'efficacité de cette approche sur des jeux de données utilisés dans des travaux précédents sur l'interrogation des bases de données XML probabilistes, ainsi que sur des données synthétiques. / Probabilistic XML is a probabilistic model for uncertain tree-structured data, with applications to data integration, information extraction, or uncertain version control. We explore in this dissertation efficient algorithms for evaluating tree-pattern queries with joins over probabilistic XML or, more specifically, for approximating the probability of each item of a query result. The approach relies on, first, extracting the query lineage over the probabilistic XML document, and, second, looking for an optimal strategy to approximate the probability of the propositional lineage formula. ProApproX is the probabilistic query manager for probabilistic XML presented in this thesis. The system allows users to query uncertain tree-structured data in the form of probabilistic XML documents. It integrates a query engine that searches for an optimal strategy to evaluate the probability of the query lineage. ProApproX relies on a query-optimizer--like approach: exploring different evaluation plans for different parts of the formula and predicting the cost of each plan, using a cost model for the various evaluation algorithms. We demonstrate the efficiency of this approach on datasets used in a number of most popular previous probabilistic XML querying works, as well as on synthetic data. An early version of the system was demonstrated at the ACM SIGMOD 2011 conference. First steps towards the new query solution were discussed in an EDBT/ICDT PhD Workshop paper (2011). A fully redesigned version that implements the techniques and studies shared in the present thesis, is published as a demonstration at CIKM 2012. Our contributions are also part of an IEEE ICDE

I discuss in this work tools used to build dynamic web-based aplications, focusing on Ajax technology. I introduce the components of this technique, its principles, usage, advantages and disadvantages.I describe a system, which uses Ajax for helping with realization of OLAP operations through dynamic tables. There is also description of these operations included, as well as introduction to possibilities of visual representation of their results.

The goal of the thesis is to study the Mozilla application platform - its structure, used technology, and the ways of development of standalone applications and extensions for the applications based on this platform (e.g. the Firefox web browser, the Thunderbird e-mail client). The thesis also contains relevant information about the used programming languages such as XUL, CSS, JavaScipt, RDF/XML and others. It describes the object oriented principles available in the JavaScript v.1.7 language. Next parts are dedicated to creating and using the platform components and the applications. The information about the platform is concluded by a presentation of the debugging and deployment possibilities. This knowledge is used to create an application able to watch changes of documents in a network environment. The thesis describes the application design and some details related to the general development of applications based on the discussed platform.

JSON-to-JSON transformation languages enable the transformation of a JSON document into another JSON document. As JSON is gradually becoming the most used interchange format on the Internet there is a need for transformation languages that can transform the data stored in JSON in order for the data to be used with other systems. The transformation can transform the document structurally, for example by altering the hierarchical structure of the document. The transformation can also transform the document textually, for example by renaming fields or altering values. None of the existing JSON-to-JSON transformation languages have become a standard (Jellife, 2017). This work evaluates the expressive power of the JSON-to-JSON transformation language Jolt. Jolt have recently been adopted by Apache and support have been introduced in some of their products. If a transformation language have expressive power that are at least equal to Nested Relational Algebra this implies that a transformation language can perform many advanced transformations. In this work  a formal model of Jolt is defined, referred to as Jolt0, in order to compare its expressive powers to Nested Relational Algebra. For that purpose, the operations of another formal model called MQuery which have been proven to have equivalent expressive power to Nested Relational Algebra are translated into Jolt0. It is shown that Jolt does not have expressive powers equivalent to Nested Relational Algebra. We further compared the performance of four JSON-to-JSON transformation languages (Jolt, Handlebars, Liquid, and XSLT 3.0) by constructing tests where the different transformation languages executed equivalent transformations. The transformations were evaluated by measuring runtime and memory usage. The study shows that XSLT 3.0 performed worst in all run time and memory usage tests. When transforming large input data XSLT 3.0 performed significantly worse than the other languages. / JSON-till-JSON transformationsspråk möjliggör transformationer från ett JSON-dokument till ett annat JSON-dokument. Eftersom JSON gradvis håller på att bli det mest använda data-utväxlingsformatet på internet så finns det ett behov av transformationsspråk som kan transformera data som är lagrad i JSON formatet för att kunna användas med andra system. Transformationen kan transformera dokumentet strukturellt, till exempel genom att förändra den hierarkiska strukturen på dokumentet. Transformationen kan även transformera dokumentet textuellt, till exempel genom att döpa om fält eller ändra värden. Ingen av de existerande JSON-till-JSON transformationsspråken har blivit en standard (Jellife, 2017). Det här arbetet undersöker uttryckskraften av Jolt vilket är ett JSON-till-JSON transformationsspråk. Jolt har nyligen fått stöd av Apache i några av deras produkter. Om ett transformationsspråk har en uttryckskraft som är ekvivalent med nästlad relationell algebra innebär det att språket kan utföra många avancerade transformationer. I det här arbetet definieras en formell modell av Jolt, kallad Jolt0, för att kunna jämföra dess uttryckskraft med nästlad relationell algebra. Till det syftet så översätts operationerna från en annan formell modell med namnet MQuery som har bevisats ha ekvivalent uttrykskraft med nästlad relationell algebra till Jolt0. Arbetet drar slutsatsen att Jolt inte har uttryckskraft som är ekvivalent med nästlad relationell algebra. Arbetet undersöker också prestandan för de fyra JSON-till-JSON transformationsspråken (Jolt, Handlebars, Liquid och XSLT 3.0) genom att konstruera tester där de olika transformationsspråken exekverar ekvivalenta transformationer. Transformationerna utvärderas baserat på körstids- och minnesanvändningsprestandan. Studien visar att XSLT 3.0 presterar sämst i alla körstids- och minnesanvändningstester. När transformationerna använder sig av stor input data så presterar XSLT 3.0 signifikant sämre än de andra språken.