Master of Science / Department of Computing and Information Sciences / Doina Caragea / The web contains a massive amount of information and is continuously growing every day. Extracting information that is relevant to a user is an uphill task. Search engines such as Google TM, Yahoo! TM have made the task a lot easier and have indeed made people much more "smarter". However, most of the existing search engines still rely on the traditional keyword-based searching techniques i.e. returning documents that contain the keywords in the query. They do not take the associated semantics into consideration. To incorporate semantics into search, one could proceed in at least two ways. Firstly, we could plunge into the world of "Semantic Web", where the information is represented in formal formats such as RDF, N3 etc which can effectively capture the associated semantics in the documents. Secondly, we could try to explore a new semantic world in the existing structure of World Wide Web (WWW). While the first approach can be very effective when semantic information is available in RDF/N3 formats, for many web pages such information is not readily available. This is why we consider the second approach in this work. In this work, we attempt to capture the semantics associated with a query by rst extracting the concepts relevant to the query. For this purpose, we propose a novel Link Analysis based Concept Extractor (LACE) that extract the concepts associated with the query by exploiting the meta data of a web page. Next, we propose a method to determine relationships between a query and its extracted concepts. Finally, we show how LACE can be used to compute a statistical measure of semantic similarity between concepts. At each step, we evaluate our approach by comparison with other existing techniques (on benchmark data sets, when available) and show that our results are competitive with existing state of the art results or even outperform them.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / It is anticipated that XML will heavily dominate the next generation of telemetry systems. The syntax of XML-based languages can be constrained by a schema that describes the structure of valid documents. However, the schemas cannot express all dependencies between XML elements and attributes, both within a single document and across multiple documents. This prohibits the XML validation process from being fully automated with standard schema processors. This paper presents an approach that is based on the W3C Semantic Web technologies and allows different vendors and system integrators to independently develop their own semantic validation rules. The rules are equipped with powerful semantics, which allows for specification and validation of complex types of constraints. The approach is not specific to a particular T&E standard and is entirely standards-based.

carlos.raymundo@upc.edu.pe / This paper focuses on the important problem of semanticaware search in textual (structured, semi-structured, NoSQL) databases. This problem has emerged as a required extension of the standard containment keyword based query to meet user needs in textual databases and IR applications. We provide here a new approach, called SemIndex, that extends the standard inverted index by constructing a tight coupling inverted index graph that combines two main resources: a general purpose semantic network, and a standard inverted index on a collection of textual data. We also provide an extended query model and related processing algorithms with the help of SemIndex. To investigate its effectiveness, we set up experiments to test the performance of SemIndex. Preliminary results have demonstrated the effectiveness, scalability and optimality of our approach.

Social networking platforms (SNPs) are complex distributed software applications exhibiting many challenges related to data portability. Since existing platforms are propriety in design, users cannot easily share their data with other SNPs, however decentralisation of social networking platforms can provide a solution to this problem. There is a difference of opinion, the way the research and developer communities have pursued this issue. Existing approaches used in decentralisation provide limited structural detail and lack in providing a systematic framework of design activities. There is a need for an architectural framework based on standardised software architectural principles and technologies to guide the design and development of decentralised social networking platforms in order to improve the level of both data portability and interoperability. The main aim of this research is to develop an architectural solution to achieve data portability among SNPs via decentralisation. Existing proposed decentralised platforms are based on a distributed structure and are mainly for a specific aspect such as access control or security and privacy. In addition to this, existing approaches lack in practicality due to underdeveloped and non-standardised design. To solve these issues a new architectural framework is needed, which can provide design and development guidelines for the decentralised social networking platform. The goal of this thesis is to study, design and develop an architectural framework for social networking platforms that can incorporate the requirements of the decentralisation, to make portability possible. The synergies between the software engineering principles and social web technologies are investigated to create a standard approach. The proposed architecture is based on component-based software development (CBSD) and aspect-oriented software development (AOSD), a unified approach known as CAM (Component Aspect Model). The foundations of the proposed architecture are based on decentralised social networking architecture (DSNA), architectural style which is derived from CAM. Components and aspects are the building blocks of the proposed decentralised social networking platform architecture. From a development perspective, each component represents a social network functionality and aspects represent the properties and preferences that are used to decentralise the functionality. The model for the component composition is a major challenge because the use of CAM for social networks has not been attempted before. The proposed architecture comprehensively integrates the DSNA architectural style into each architectural component. Portability among SNPs by means of decentralisation can be summarised into three steps. (1) Definition of the architectural style, (2) implementation of the architectural style into components and (3) integration of the component composition. To date component composition approaches have not been used for social networks as a way to develop social network functionality. The concept of middleware has been adapted to achieve the composition feature of the architecture. In the architecture Social Network Support Layer (SNSL) functions as middleware to facilitate component composition. Existing middleware solutions still lack integration of CBSD and AOSD concepts. This limitation is characterised by, a lack of explicit guidelines for composition, a lack of declarative specification and definition model to express component composition and a lack of support for role allocation. This research overcome these limitations. The application of the architecture is based on the W3C SWAT (Social Web Acid Test) scenario. A Messaging application is developed to evaluate the scenario based on the Design Science Research Methodology. The architectural style is defined in the first stage of design followed by the component-based architecture. The architectural style is defined to guide the architecture and the component composition model. In the second stage, the design and implementation of composition technology (that is SNSL) are developed with architectural style and the rules defined in the first stage. The refined version of the architecture is evaluated in the third stage, according to WC3 SWAT test. The definitive version of the proposed architecture with the benchmarked result can be used to design and build social networking platforms, allowing users to share and collaborate information across the different social networking platforms.

Semantic Routed Networks provide a superior infrastructure for complex search engines. In a Semantic Routed Network (SRN), the routers are the critical component and they perform semantic comparison as their key computation. As the amount of information available on the Internet grows, the speed and efficiency with which information can be retrieved to the user becomes important. Most current search engines scale to meet the growing demand by deploying large data centers with general purpose computers that consume many megawatts of power. Reducing the power consumption of these data centers while providing better performance, will help reduce the costs of operation significantly. Performing operations in parallel is a key optimization step for better performance on general purpose CPUs. Current techniques for parallelization include architectures that are multi-core and have multiple thread handling capabilities. These coarse grained approaches have considerable resource management overhead and provide only sub-linear speedup. This dissertation proposes techniques towards a highly parallel, power efficient architecture that performs semantic comparisons as its core activity. Hardware-centric parallel algorithms have been developed to populate the required data structures followed by computation of semantic similarity. The performance of the proposed design is further enhanced using a pipelined architecture. The proposed algorithms were also implemented on two contemporary platforms such as the Nvidia CUDA and an FPGA for performance comparison. In order to validate the designs, a semantic benchmark was also been created. It has been shown that a dedicated semantic comparator delivers significantly better performance compared to other platforms. Results show that the proposed hardware semantic comparison architecture delivers a speedup performance of up to 10^5 while reducing power consumption by 80% compared to traditional computing platforms. Future research directions including better power optimization, architecting the complete semantic router and using the semantic benchmark for SRN research are also discussed.

Indexing data for efficient search capabilities is a core problem in many domains of computer science. As applications centered around semantic data sources become more common, the need for more sophisticated indexing and querying capabilities arises. In particular, the need to search for specific information in the presence of a terminology or ontology (i.e. a set of logic based rules that describe concepts and their relations) becomes of particular importance, as the information a user seeks may exists as an entailment of the explicit data by means of the terminology. This variant on traditional indexing and search problems forms the foundation of a range of possible technologies for semantic data. In this work, we propose an ordering language for specifying partial orders over semantic data items modeled as descriptions in a description logic. We then show how these orderings can be used as the basis of a search tree index for processing \emph{concept searches} in the presence of a terminology. We study in detail the properties of the orderings and the associated index structure, and also explore a relationship between ordering descriptions called \emph{order refinement}. A sound and complete procedure for deciding refinement is given. We also empirically evaluate a prototype implementation of our index structure, validating its potential efficacy in semantic query problems.

Indexing data for efficient search capabilities is a core problem in many domains of computer science. As applications centered around semantic data sources become more common, the need for more sophisticated indexing and querying capabilities arises. In particular, the need to search for specific information in the presence of a terminology or ontology (i.e. a set of logic based rules that describe concepts and their relations) becomes of particular importance, as the information a user seeks may exists as an entailment of the explicit data by means of the terminology. This variant on traditional indexing and search problems forms the foundation of a range of possible technologies for semantic data. In this work, we propose an ordering language for specifying partial orders over semantic data items modeled as descriptions in a description logic. We then show how these orderings can be used as the basis of a search tree index for processing \emph{concept searches} in the presence of a terminology. We study in detail the properties of the orderings and the associated index structure, and also explore a relationship between ordering descriptions called \emph{order refinement}. A sound and complete procedure for deciding refinement is given. We also empirically evaluate a prototype implementation of our index structure, validating its potential efficacy in semantic query problems.

Univ., Diss.--Karlsruhe, 2005. / Literaturverz. S. [227] - 243 S.

Submitted by Jaider Andrade Ferreira (jaideraf@gmail.com) on 2014-08-08T13:12:46Z No. of bitstreams: 1 ferreira_ja_me_mar.pdf: 2583232 bytes, checksum: 13793146fcfbbf0f3e90673d816e0f8d (MD5) / Made available in DSpace on 2014-08-08T13:12:46Z (GMT). No. of bitstreams: 1 ferreira_ja_me_mar.pdf: 2583232 bytes, checksum: 13793146fcfbbf0f3e90673d816e0f8d (MD5) Previous issue date: 2014-07-30 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Com o desenvolvimento das Tecnologias de Informação e Comunicação, a Ciência da Informação precisou repensar a postura tradicional de gerenciamento informacional. O hipertexto, advindo principalmente por meio do ambiente Web, elevou ainda mais a complexidade do tratamento informacional. A popularização da Internet fez com que a Web se tornasse mais interativa e colaborativa tornando comum a utilização de sistemas wiki para o gerenciamento informacional. Idealizada por Tim Berners-Lee, surge a iniciativa da Web Semântica, na qual as máquinas são capazes de analisar os dados presentes na rede. Nesse contexto aparecem os wikis semânticos, caracterizados por fazerem uso das tecnologias da Web Semântica. Diante desse cenário, considera-se que a Ciência da Informação, que já se preocupa com o desenvolvimento da Web e da Web Semântica, deve também se preocupar com os wikis semânticos. Assim, por meio de uma pesquisa descritiva e exploratória, objetivou-se explorar, apresentar e descrever as características dos wikis semânticos com enfoque nas atividades de descrição, de recuperação e de intercâmbio de informações apoiadas em tecnologias da Web Semântica, visando a favorecer o entendimento, a discussão e o uso dessas tecnologias em ambientes informacionais digitais. Após uma apresentação sobre as raízes históricas da Web Semântica, são destacados os padrões de representação, codificação, descrição, relação e consulta de dados estruturados (URI, XML, RDF, RDFS, OWL e SPARQL) que, junto a outras tecnologias, formam a base da Web Semântica e apoiam o funcionamento dos wikis semânticos. Os wikis semânticos são apresentados e definidos como sistemas wiki que se utilizam de tecnologias da Web Semântica para incorporar conhecimento formalizado, conteúdo, estruturas e links em suas páginas. Após essa etapa, são descritas as principais atividades de descrição, de recuperação e de intercâmbio de informações no Semantic MediaWiki, o wiki semântico mais utilizado até o momento. Como considerações finais, entende-se que os wikis semânticos favorecem o entendimento, a discussão e o uso de tecnologias da Web Semântica em ambientes informacionais digitais. / Due to the development of Information and Communication Technologies, Information Science has been forced to rethink the traditional posture of information management. Hypertext, arising mainly through the Web environment, further increased the complexity of the information handling. The popularization of the Internet has led the Web to a more interactive and a more collaborative environment, bringing wiki systems, for example, to manage information in a collaborative way. Conceived by Tim Berners-Lee, there is the Semantic Web initiative in which machines are able to analyze data on the network. In this context, semantic wikis arise: wikis characterized by the use of Semantic Web technologies. Therefore, we believe that Information Science, which cares about the development of the Web and the Semantic Web, should also care about semantic wikis. Thus, by a descriptive and an exploratory research, the objective is to explore, to present and to describe the characteristics of the semantic wikis on the activities of representation, retrieval and exchange of information supported by Semantic Web technologies in order to facilitate the understanding, the discussion, and the use of these technologies in digital information environments. After a presentation about the origins of the Semantic Web, we highlight the data representation, encoding, description, relation, and query standards (URI, XML, RDF, RDFS, OWL and SPARQL) which, with other technologies, form the basis of the Semantic Web and support the functioning of semantic wikis. Semantic wikis are presented and defined as wiki systems that use Semantic Web technologies in order to incorporate formalized knowledge, content, structure and links on their pages. After that, we describe the main activities for information description, retrieval and interchange on Semantic MediaWiki, the most popular and most used semantic wiki engine so far. As conclusion, we consider that semantic wikis can promote understanding, discussions, and use of Semantic Web technologies in digital information environments. / FAPESP: 2011/15085-6

The World Wide Web contains a vast amount of information. This feature makes it a very useful part of our everyday activities but the information contained within is made up of an exponentially increasing repository of semantically unstructured data. The semantic web movement involves the evolution of the existing World Wide web in order to enable computers make meaning of and understand the data they process and consequently increase their processing capabilities. Over the past decade a number of new projects implementing the semantic web technology have been developed albeit still in their infancy. These projects are based on semantic data models and one such is the Wikidata project. The Wikidata project is targeted at providing a more semantic platform for editing and sharing data throughout the Wikipedia and Wikimedia communities. This project studies how the Wikidata project facilitates such a semantic platform for the Wikimedia communities and includes the development of an application utilizing the semantic capabilities of Wikidata. The objective of the project is to develop an application capable of retrieving and presenting statistical data and also be able to make missing or invalid data on Wikidata detectable. The result is an application currently aimed at researchers and students who require a convenient tool for statistical data collection and data mining projects. Usability and performance tests of the application are also conducted with the results presented in the report. Keywords: Semantic web, World Wide Web, Semantic data model, Wikidata, data mining.