Thesis (Ph. D.)--Universität des Saarlands, 2005. / Includes bibliographical references (p. 253-268) and index.

Universiẗat, Diss., 2006--Bamberg.

Le Web des données étend le Web en publiant des données structurées et liées en RDF. Un jeu de données RDF est un graphe orienté où les ressources peuvent être des sommets étiquetées dans des langues naturelles. Un des principaux défis est de découvrir les liens entre jeux de données RDF. Étant donnés deux jeux de données, cela consiste à trouver les ressources équivalentes et les lier avec des liens owl:sameAs. Ce problème est particulièrement difficile lorsque les ressources sont décrites dans différentes langues naturelles.Cette thèse étudie l'efficacité des ressources linguistiques pour le liage des données exprimées dans différentes langues. Chaque ressource RDF est représentée comme un document virtuel contenant les informations textuelles des sommets voisins. Les étiquettes des sommets voisins constituent le contexte d'une ressource. Une fois que les documents sont créés, ils sont projetés dans un même espace afin d'être comparés. Ceci peut être réalisé à l'aide de la traduction automatique ou de ressources lexicales multilingues. Une fois que les documents sont dans le même espace, des mesures de similarité sont appliquées afin de trouver les ressources identiques. La similarité entre les documents est prise pour la similarité entre les ressources RDF.Nous évaluons expérimentalement différentes méthodes pour lier les données RDF. En particulier, deux stratégies sont explorées: l'application de la traduction automatique et l'usage des banques de données terminologiques et lexicales multilingues. Dans l'ensemble, l'évaluation montre l'efficacité de ce type d'approches. Les méthodes ont été évaluées sur les ressources en anglais, chinois, français, et allemand. Les meilleurs résultats (F-mesure > 0.90) ont été obtenus par la traduction automatique. L'évaluation montre que la méthode basée sur la similarité peut être appliquée avec succès sur les ressources RDF indépendamment de leur type (entités nommées ou concepts de dictionnaires). / The Semantic Web extends the Web by publishing structured and interlinked data using RDF.An RDF data set is a graph where resources are nodes labelled in natural languages. One of the key challenges of linked data is to be able to discover links across RDF data sets. Given two data sets, equivalent resources should be identified and linked by owl:sameAs links. This problem is particularly difficult when resources are described in different natural languages.This thesis investigates the effectiveness of linguistic resources for interlinking RDF data sets. For this purpose, we introduce a general framework in which each RDF resource is represented as a virtual document containing text information of neighboring nodes. The context of a resource are the labels of the neighboring nodes. Once virtual documents are created, they are projected in the same space in order to be compared. This can be achieved by using machine translation or multilingual lexical resources. Once documents are in the same space, similarity measures to find identical resources are applied. Similarity between elements of this space is taken for similarity between RDF resources.We performed evaluation of cross-lingual techniques within the proposed framework. We experimentally evaluate different methods for linking RDF data. In particular, two strategies are explored: applying machine translation or using references to multilingual resources. Overall, evaluation shows the effectiveness of cross-lingual string-based approaches for linking RDF resources expressed in different languages. The methods have been evaluated on resources in English, Chinese, French and German. The best performance (over 0.90 F-measure) was obtained by the machine translation approach. This shows that the similarity-based method can be successfully applied on RDF resources independently of their type (named entities or thesauri concepts). The best experimental results involving just a pair of languages demonstrated the usefulness of such techniques for interlinking RDF resources cross-lingually.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-04-02T12:19:53Z No. of bitstreams: 1 FredDeCastroSantos_DISSERT.pdf: 1904530 bytes, checksum: 379e23c6c92c47609a52da136aeeb02e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-04T12:11:32Z (GMT) No. of bitstreams: 1 FredDeCastroSantos_DISSERT.pdf: 1904530 bytes, checksum: 379e23c6c92c47609a52da136aeeb02e (MD5) / Made available in DSpace on 2018-04-04T12:11:32Z (GMT). No. of bitstreams: 1 FredDeCastroSantos_DISSERT.pdf: 1904530 bytes, checksum: 379e23c6c92c47609a52da136aeeb02e (MD5) Previous issue date: 2018-02-23 / A World Wide Web ? uma cole??o de informa??es sempre crescente. Esta informa??o ? distribu?da entre documentos diferentes, disponibilizados atrav?s do HTTP. Mesmo que essa informa??o seja acess?vel aos usu?rios na forma de artigos de not?cias, transmiss?es de ?udio, imagens e v?deos, os agentes de software geralmente n?o podem classific?-la. A falta de informa??es sem?nticas sobre esses documentos em um formato leg?vel por m?quina geralmente faz com que a an?lise seja imprecisa. Um n?mero significativo de entidades adotaram Linked Data como uma forma de adicionar informa??es sem?nticas aos seus dados, e n?o apenas public?-lo na Web. O resultado ? uma cole??o global de dados, chamada Web of Data, que forma um grafo global, composto por declara??es no formato RDF [22] de diversas fontes, cobrindo todos os tipos de t?picos. Para encontrar informa??es espec?ficas nesses grafos, as consultas s?o realizadas come?ando em um sujeito e analisando seus predicados nas instru??es RDF. Esses predicados s?o as conex?es entre o sujeito e o objeto, e um conjunto de trilhas forma um caminho de informa??o. O uso de HTTP como mecanismo padr?o de acesso a dados e RDF como modelo de dados padr?o simplifica o acesso a dados, o que nos motiva a pesquisar alternativas na forma como esses dados s?o buscados. Uma vez que a maioria das linguagens de consulta de banco de dados de grafo est?o na classe de Linguagens Regulares, n?s propomos seguir um caminho diferente e tentar usar uma classe de gram?tica menos restritiva, chamada Gram?tica Livre de Contexto Determin?stica, para aumentar a expressividade das consultas no banco de dados em grafo. Mais especificamente, aplicando o m?todo de an?lise LR(1) para encontrar caminhos em um banco de dados de grafo RDF. O principal objetivo deste trabalho ? prover meios para se permitir a utiliza??o de t?cnicas de reconhecimento de gram?ticas livres de contexto LR(1) para fazer consultas por caminhos formados pelas etiquetas das arestas em um banco de dados RDF. Fornecendo, como um resultado, uma ferramenta que se permita atingir melhor expressividade, efici?ncia e escalabilidade nestas consultas do que o que existe atualmente. Para atingir este objetivo, n?s implementamos um algoritmo baseado nas t?cnicas de reconhecimento LR(1), usando o GSS [30] ao inv?s de uma pilha, e permitimos ao usu?rio fazer consultas com uma gram?tica livre de contexto (LR1). Tamb?m analisamos a complexidade do nosso algoritmo e executamos alguns experimentos, comparando nossa solu??o com as outras propostas na literatura, mostrando que a nossa pode ter melhor desempenho em alguns cen?rios. / The World Wide Web is an always increasing collection of information. This information is spread among different documents, which are made available by using the HTTP. Even though this information is accessible to users in the form of news articles, audio broadcasts, images and videos, software agents often cannot classify it. The lack of semantic information about these documents in a machine-readable format usually makes the analysis inaccurate. A significant number of entities have adopted Linked Data as a way to add semantic information to their data, not just publishing it on the Web. The result is a global data collection, called the Web of Data, which forms a global graph, consisting of RDF [22] statements from numerous sources, covering all sorts of topics. To find specific information in this graph, queries are performed starting at a subject and analyzing their predicates in the RDF statements. These predicates are the connections between the subject and object, and a set of traces forms an information path. The use of HTTP as a standardized data access mechanism and RDF as a standard data model simplifies the data access, but accessing heterogeneous data on distinct locations may have an increased time complexity and current query languages have a reduced query expressiveness, which motivates us to research alternatives in how this data is queried. This reduced expressiveness happens because most query languages belong to the class of Regular Languages. The main goal of this work is to use LR(1) context-free grammar processing techniques to search for context-free paths over RDF graph databases, providing, as result, a tool which allows better expressiveness, efficiency and scalability in such queries than what is proposed today. To achieve that, we implemented an algorithm based on the LR(1) parsing technique that uses the GSS [30] structure instead of a stack, and give means for the user to input queries with an LR(1) context-free grammar. Also, we analyze our algorithm?s complexity and make some experiments, comparing our solution to other proposals present in the literature and show that ours can have better performance in given scenarios.

Planning is indeed a highly regulated procedure at the operational level such as military related activities where the staff may benefit from documents such as guidelines that regulate the work process, responsibilities and results of such planning activities. This thesis proposes a method for analyzing office documents that make up an operational order according to document ontology. With the semantic desktops aiming at combining semantic annotations and intelligent reasoning in desktop computers, the product of this project intends to add a plug-in to such environments such as IRIS semantic desktop, which accordingly enables such application to interpret documents whether the they  or change within the application. The result of our work helps the end user to extract data using his/her favorite patterns such as goals, targets or even milestones that make up decisive points. This information eventually form semantic objects, which ultimately reside in the knowledgebase of the semantic desktop for further reasoning in the future referring of the application, whether automatically or upon the user's request.

O estado de São Paulo produz cerca de 58.700 t/dia de resíduos dividido pelos seus 645 municípios nas vizinhanças de aproximadamente 170 usinas de açúcar e álcool. Diante deste fato, é evidente o potencial para se fazer o uso consorciado destes dois combustíveis na geração de energia. Este trabalho investigou os possíveis efeitos deletérios que a presença de cloro, flúor, sódio e potássio possam trazer nas caldeiras voltadas para a produção de energia elétrica, utilizando bagaço de cana e combustível derivado de resíduo (CDR). Foi realizada uma busca criteriosa na literatura internacional a fim de possíveis efeitos deletérios em caldeiras de biomassa para a produção de energia em razão do uso consorciado de resíduo, no aspecto da integridade da caldeira, principalmente no papel desempenhado pelos elementos, cloro, flúor, sódio e potássio, e em seguida uma análise criteriosa dos resultados encontrados. Esta análise foi realizada através de um estudo de caso, considerando uma caldeira de leito fluidizado borbulhante (BFB) de 60MW, queimando bagaço e parte do resíduo de uma cidade de 600.000 habitantes. Verificou-se que o resíduo que a cidade produz pode ser transformado em CDR que irá alimentar a caldeira como combustível auxiliar, produzindo energia elétrica de forma limpa e sustentável. Um parâmetro utilizado para se definir a quantidade máxima de CDR queimada na caldeira, foi o cloro específico, calculado pela razão entre o teor de cloro e o poder calorífico inferior (PCI) do combustível. Com base na literatura encontrada, limitou-se o cloro específico em 40 mg/MJ, para que não haja danos a integridade do equipamento. A combustão consorciada de bagaço de cana e CDR pode ser uma alternativa para o estado de São Paulo reduzir o problema da falta de aterros para descarte de resíduos e uma possibilidade para as usinas de açúcar e álcool produzirem energia elétrica por um período mais extenso no ano, economizando bagaço de cana. / The state of São Paulo produces about 58,700 tons/day waste divided by its 645 municipalities in the vicinity of about 170 sugar and alcohol mills. Given this fact, the potential is evident to make the consortium use of these two fuels in power generation. This paper investigated the potential deleterious effects that the presence of chlorine, fluoride, sodium and potassium can bring the boilers focused on the production of electric power using bagasse and refuse derived fuel (RDF). A thorough search in the international literature with the view to possible deleterious effects on biomass boilers for power generation because of consortium use of residue in the boiler integrity aspect, particularly the role played by the elements chlorine, fluorine, sodium and potassium, and then a careful analysis of the results. This analysis was conducted through a case study, considering a bubbling fluidized bed (BFB) boiler of 60 MW, burning bagasse and part of the residue of a city of 600,000 inhabitants. It was found that the residue that the city produces can be turned into RDF which will feed the boiler as an auxiliary fuel, producing electricity in a clean and sustainable manner. A parameter used to set the maximum amount of burned RDF in the boiler, was the specific chlorine, measured by the ratio between the chlorine content and the lower heating value (LHV) of the fuel. Based on the literature found, the specific chlorine was limited to 40 mg/MJ, so there is no damage to the integrity of the equipment. The consortium combustion of bagasse and RDF can be an alternative to the state of São Paulo reduce the problem of landfills for waste disposal and a possibility for the sugar and alcohol mills producing electric power for a longer period in the year, saving bagasse.

In Canadian remote northern communities most electricity is generated by burning diesel fuel. However, because it is expensive to import fuel into remote communities the cost of electricity is very high. Waste management is also difficult in remote northern communities. The goal of this thesis was to investigate the co-gasification of refuse waste materials and biomass as a means of reducing solid waste volumes while also using locally available materials for power generation. As part of this research, thermo-gravimetric analysis (TGA) was investigated as a potential means of characterizing refuse derived fuels (RDF). Laboratory sample preparation of RDF for TGA had not been thoroughly considered. Laboratory sample preparation is important since RDF is very heterogeneous compared to other solid fuels and since TGA typically requires a very small sample size. A TGA method was applied to a variety of materials prepared from a commercially available RDF using a variety of procedures. The repeatability of the experimental results was related to the sample preparation methods. Cryogenic ball milling was found to be an appropriate means of preparing RDF samples for TGA. Applicability of the TGA method to the determination of the renewable content of RDF was considered. Air-blown auto-thermal gasification experiments using materials representative of waste and biomass were performed at 725°C, 800°C, and 875°C, using a 0.15 m internal diameter bubbling fluidized bed gasifier located at NRCan CametENERGY in Ottawa, Ontario. Commercially prepared RDF and PET scrap were used to represent waste materials. Commercially produced hardwood pellets were used to represent biomass. The co-gasification of hardwood pellets and commercially produced RDF indicated that each fuel make a contribution to the results which is proportional to its fraction in the feed mixture. Inclusion of the RDF in the fuel mixture led to bed agglomeration at the 875°C temperature condition. Higher temperatures were found to provide better conversion of the fuel to gas, and the limitation which inclusion of RDF places on the operating temperature of the gasifier negatively affects conversion of biomass. Results obtained with RDF suggested that utilization of mixed waste for a thermal conversion process located in a Canadian remote northern community is probably not a viable option. It was then decided to target plastic waste in particular. Plastic could be source-separated, collected, and gasified alongside biomass. Polyethylene terephthalate (PET), which is often used for food and beverage containers, was chosen to represent plastic. Initially, attempts were made to co-gasify mixtures of PET pellets and hardwood pellets. These attempts failed due to the formation of coke above the bed. To alleviate these problems hardwood-PET composite pellets were manufactured and these were gasified at 725°C, 800°C, and 875°C. Inclusion of PET in the pellets dramatically increased the amount of tar produced during gasification.

Collaboration is one of the most important topics regarding the evolution of the World Wide Web and thus also for the Web of Data. In scenarios of distributed collaboration on datasets it is necessary to provide support for multiple different versions of datasets to exist simultaneously, while also providing support for merging diverged datasets. In this paper we present an approach that uses SPARQL 1.1 in combination with the version control system Git, that creates commits for all changes applied to an RDF dataset containing multiple named graphs. Further the operations provided by Git are used to distribute the commits among collaborators and merge diverged versions of the dataset. We show the advantages of (public) Git repositories for RDF datasets and how this represents a way to collaborate on RDF data and consume it. With SPARQL 1.1 and Git in combination, users are given several opportunities to participate in the evolution of RDF data.

One approach to continuously achieve a certain data quality level is to use an integration pipeline that continuously checks and monitors the quality of a data set according to defined metrics. This approach is inspired by Continuous Integration pipelines, that have been introduced in the area of software development and DevOps to perform continuous source code checks. By investigating in possible tools to use and discussing the specific requirements for RDF data sets, an integration pipeline is derived that joins current approaches of the areas of software development and semantic web as well as reuses existing tools. As these tools have not been built explicitly for CI usage, we evaluate their usability and propose possible workarounds and improvements. Furthermore, a real world usage scenario is discussed, outlining the benefit of the usage of such a pipeline.

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨ Der Vortrag beschaeftigt sich mit den Moeglichkeiten die XML und RDF fuer das digitale Publizieren und Archivieren bieten.