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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Semantic information systems engineering : a query-based approach for semi-automatic annotation of web services

Al Asswad, Mohammad Mourhaf January 2011 (has links)
There has been an increasing interest in Semantic Web services (SWS) as a proposed solution to facilitate automatic discovery, composition and deployment of existing syntactic Web services. Successful implementation and wider adoption of SWS by research and industry are, however, profoundly based on the existence of effective and easy to use methods for service semantic description. Unfortunately, Web service semantic annotation is currently performed by manual means. Manual annotation is a difficult, error-prone and time-consuming task and few approaches exist aiming to semi-automate that task. Existing approaches are difficult to use since they require ontology building. Moreover, these approaches employ ineffective matching methods and suffer from the Low Percentage Problem. The latter problem happens when a small number of service elements - in comparison to the total number of elements – are annotated in a given service. This research addresses the Web services annotation problem by developing a semi-automatic annotation approach that allows SWS developers to effectively and easily annotate their syntactic services. The proposed approach does not require application ontologies to model service semantics. Instead, a standard query template is used: This template is filled with data and semantics extracted from WSDL files in order to produce query instances. The input of the annotation approach is the WSDL file of a candidate service and a set of ontologies. The output is an annotated WSDL file. The proposed approach is composed of five phases: (1) Concept extraction; (2) concept filtering and query filling; (3) query execution; (4) results assessment; and (5) SAWSDL annotation. The query execution engine makes use of name-based and structural matching techniques. The name-based matching is carried out by CN-Match which is a novel matching method and tool that is developed and evaluated in this research. The proposed annotation approach is evaluated using a set of existing Web services and ontologies. Precision (P), Recall (R), F-Measure (F) and Percentage of annotated elements are used as evaluation metrics. The evaluation reveals that the proposed approach is effective since - in relation to manual results - accurate and almost complete annotation results are obtained. In addition, high percentage of annotated elements is achieved using the proposed approach because it makes use of effective ontology extension mechanisms.
2

Exploiting Information Extraction Techniques For Automatic Semantic Annotation And Retrieval Of News Videos In Turkish

Kucuk, Dilek 01 February 2011 (has links) (PDF)
Information extraction (IE) is known to be an effective technique for automatic semantic indexing of news texts. In this study, we propose a text-based fully automated system for the semantic annotation and retrieval of news videos in Turkish which exploits several IE techniques on the video texts. The IE techniques employed by the system include named entity recognition, automatic hyperlinking, person entity extraction with coreference resolution, and event extraction. The system utilizes the outputs of the components implementing these IE techniques as the semantic annotations for the underlying news video archives. Apart from the IE components, the proposed system comprises a news video database in addition to components for news story segmentation, sliding text recognition, and semantic video retrieval. We also propose a semi-automatic counterpart of system where the only manual intervention takes place during text extraction. Both systems are executed on genuine video data sets consisting of videos broadcasted by Turkish Radio and Television Corporation. The current study is significant as it proposes the first fully automated system to facilitate semantic annotation and retrieval of news videos in Turkish, yet the proposed system and its semi-automated counterpart are quite generic and hence they could be customized to build similar systems for video archives in other languages as well. Moreover, IE research on Turkish texts is known to be rare and within the course of this study, we have proposed and implemented novel techniques for several IE tasks on Turkish texts. As an application example, we have demonstrated the utilization of the implemented IE components to facilitate multilingual video retrieval.
3

Sumarização multidocumento com base em aspectos informativos / Multidocument summarization based on information aspects

Garay, Alessandro Yovan Bokan 20 August 2015 (has links)
A sumarização multidocumento consiste na produção de um sumário/resumo a partir de uma coleção de textos sobre um mesmo assunto. Devido à grande quantidade de informação disponível na Web, esta tarefa é de grande relevância já que pode facilitar a leitura dos usuários. Os aspectos informativos representam as unidades básicas de informação presentes nos textos. Por exemplo, em textos jornalísticos em que se relata um fato/acontecimento, os aspectos podem representar a seguintes informações: o que aconteceu, onde aconteceu, quando aconteceu, como aconteceu, e por que aconteceu. Conhecendo-se esses aspectos e as estratégias de produção e organização de sumários, é possível automatizar a tarefa de sumarização. No entanto, para o Português do Brasil, não há pesquisa feita sobre sumarização com base em aspectos. Portanto, neste trabalho de mestrado, investigaram-se métodos de sumarização multidocumento com base em aspectos informativos, pertencente à abordagem profunda para a sumarização, em que se busca interpretar o texto para se produzir sumários mais informativos. Em particular, implementaram-se duas etapas relacionadas: (i) identificação automática de aspectos os aspectos informativos e (ii) desenvolvimento e avaliação de dois métodos de sumarização com base em padrões de aspectos (ou templates) em sumários. Na etapa (i), criaram-se classificadores de aspectos com base em anotador de papéis semânticos, reconhecedor de entidades mencionadas, regras manuais e técnicas de aprendizado de máquina. Avaliaram-se os classificadores sobre o córpus CSTNews (Rassi et al., 2013; Felippo et al., 2014). Os resultados foram satisfatórios, demostrando que alguns aspectos podem ser identificados automaticamente em textos jornalísticos com um desempenho razoável. Já na etapa (ii), elaboraram-se dois métodos inéditos de sumarização multidocumento com base em aspectos. Os resultados obtidos mostram que os métodos propostos neste trabalho são competitivos com os métodos da literatura. Salienta-se que esta abordagem para sumarização tem recebido grande destaque ultimamente. Além disso, é inédita nos trabalhos desenvolvidos no Brasil, podendo trazer contribuições importantes para a área. / Multi-document summarization is the task of automatically producing a unique summary from a group of texts on the same topic. With the huge amount of available information in the web, this task is very relevant because it can facilitate the reading of the users. Informative aspects, in particular, represent the basic information units in texts and summaries, e.g., in news texts there should be the following information: what happened, when it happened, where it happened, how it happened and why it happened. Knowing these aspects and the strategies to produce and organize summaries, it is possible to automate the aspect-based summarization. However, there is no research about aspect-based multi-document summarization for Brazilian Portuguese. This research work investigates multi-document summarization methods based on informative aspects, which follows the deep approach for summarization, in which it aims at interpreting the texts to produce more informative summaries. In particular, two main stages are developed: (i) the automatic identification of informative aspects and (ii) and the development and evaluation of two summarization methods based on aspects patterns (or templates). In the step (i) classifiers were created based on semantic role labeling, named entity recognition, handcrafted rules and machine learning techniques. Classifiers were evaluated on the CSTNews annotated corpus (Rassi et al., 2013; Felippo et al., 2014). The results were satisfactory, demonstrating that some aspects can be automatically identified in the news with a reasonable performance. In the step (ii) two novels aspect-based multi-document summarization methods are elaborated. The results show that the proposed methods in this work are competitive with the classical methods. It should be noted that this approach has lately received a lot of attention. Furthermore, it is unprecedented in the summarization task developed in Brazil, with the potential to bring important contributions to the area.
4

An Ontology-driven Video Annotation And Retrieval System

Demirdizen, Goncagul 01 October 2010 (has links) (PDF)
In this thesis, a system, called Ontology-Driven Video Annotation and Retrieval System (OntoVARS) is developed in order to provide a video management system which is used for ontology-driven semantic content annotation and querying. The proposed system is based on MPEG-7 ontology which provides interoperability and common communication platform with other MPEG-7 ontology compatible systems. The Rhizomik MPEG-7 ontology is used as the core ontology and domain specific ontologies are integrated to the core ontology in order to provide ontology-based video content annotation and querying capabilities to the user. The proposed system supports content-based annotation and spatio-temporal data modeling in video databases by using the domain ontology concepts. Moreover, the system enables ontology-driven query formulation and processing according to the domain ontology instances and concepts. In the developed system, ontology-driven concept querying, spatio-temporal querying, region-based and time-based querying capabilities are performed as simple querying types. Besides these simple query types, compound queries are also generated by combining simple queries with &quot / (&quot / , &quot / )&quot / , &quot / AND&quot / and &quot / OR&quot / operators. For all these query types, the system supports both general and video specific query processing. By this means, the user is able to pose queries on all videos in the video databases as well as the details of a specific video of interest.
5

Sumarização multidocumento com base em aspectos informativos / Multidocument summarization based on information aspects

Alessandro Yovan Bokan Garay 20 August 2015 (has links)
A sumarização multidocumento consiste na produção de um sumário/resumo a partir de uma coleção de textos sobre um mesmo assunto. Devido à grande quantidade de informação disponível na Web, esta tarefa é de grande relevância já que pode facilitar a leitura dos usuários. Os aspectos informativos representam as unidades básicas de informação presentes nos textos. Por exemplo, em textos jornalísticos em que se relata um fato/acontecimento, os aspectos podem representar a seguintes informações: o que aconteceu, onde aconteceu, quando aconteceu, como aconteceu, e por que aconteceu. Conhecendo-se esses aspectos e as estratégias de produção e organização de sumários, é possível automatizar a tarefa de sumarização. No entanto, para o Português do Brasil, não há pesquisa feita sobre sumarização com base em aspectos. Portanto, neste trabalho de mestrado, investigaram-se métodos de sumarização multidocumento com base em aspectos informativos, pertencente à abordagem profunda para a sumarização, em que se busca interpretar o texto para se produzir sumários mais informativos. Em particular, implementaram-se duas etapas relacionadas: (i) identificação automática de aspectos os aspectos informativos e (ii) desenvolvimento e avaliação de dois métodos de sumarização com base em padrões de aspectos (ou templates) em sumários. Na etapa (i), criaram-se classificadores de aspectos com base em anotador de papéis semânticos, reconhecedor de entidades mencionadas, regras manuais e técnicas de aprendizado de máquina. Avaliaram-se os classificadores sobre o córpus CSTNews (Rassi et al., 2013; Felippo et al., 2014). Os resultados foram satisfatórios, demostrando que alguns aspectos podem ser identificados automaticamente em textos jornalísticos com um desempenho razoável. Já na etapa (ii), elaboraram-se dois métodos inéditos de sumarização multidocumento com base em aspectos. Os resultados obtidos mostram que os métodos propostos neste trabalho são competitivos com os métodos da literatura. Salienta-se que esta abordagem para sumarização tem recebido grande destaque ultimamente. Além disso, é inédita nos trabalhos desenvolvidos no Brasil, podendo trazer contribuições importantes para a área. / Multi-document summarization is the task of automatically producing a unique summary from a group of texts on the same topic. With the huge amount of available information in the web, this task is very relevant because it can facilitate the reading of the users. Informative aspects, in particular, represent the basic information units in texts and summaries, e.g., in news texts there should be the following information: what happened, when it happened, where it happened, how it happened and why it happened. Knowing these aspects and the strategies to produce and organize summaries, it is possible to automate the aspect-based summarization. However, there is no research about aspect-based multi-document summarization for Brazilian Portuguese. This research work investigates multi-document summarization methods based on informative aspects, which follows the deep approach for summarization, in which it aims at interpreting the texts to produce more informative summaries. In particular, two main stages are developed: (i) the automatic identification of informative aspects and (ii) and the development and evaluation of two summarization methods based on aspects patterns (or templates). In the step (i) classifiers were created based on semantic role labeling, named entity recognition, handcrafted rules and machine learning techniques. Classifiers were evaluated on the CSTNews annotated corpus (Rassi et al., 2013; Felippo et al., 2014). The results were satisfactory, demonstrating that some aspects can be automatically identified in the news with a reasonable performance. In the step (ii) two novels aspect-based multi-document summarization methods are elaborated. The results show that the proposed methods in this work are competitive with the classical methods. It should be noted that this approach has lately received a lot of attention. Furthermore, it is unprecedented in the summarization task developed in Brazil, with the potential to bring important contributions to the area.
6

A framework for semantic web implementation based on context-oriented controlled automatic annotation

Hatem, Muna Salman January 2009 (has links)
The Semantic Web is the vision of the future Web. Its aim is to enable machines to process Web documents in a way that makes it possible for the computer software to "understand" the meaning of the document contents. Each document on the Semantic Web is to be enriched with meta-data that express the semantics of its contents. Many infrastructures, technologies and standards have been developed and have proven their theoretical use for the Semantic Web, yet very few applications have been created. Most of the current Semantic Web applications were developed for research purposes. This project investigates the major factors restricting the wide spread of Semantic Web applications. We identify the two most important requirements for a successful implementation as the automatic production of the semantically annotated document, and the creation and maintenance of semantic based knowledge base. This research proposes a framework for Semantic Web implementation based on context-oriented controlled automatic Annotation; for short, we called the framework the Semantic Web Implementation Framework (SWIF) and the system that implements this framework the Semantic Web Implementation System (SWIS). The proposed architecture provides for a Semantic Web implementation of stand-alone websites that automatically annotates Web pages before being uploaded to the Intranet or Internet, and maintains persistent storage of Resource Description Framework (RDF) data for both the domain memory, denoted by Control Knowledge, and the meta-data of the Web site's pages. We believe that the presented implementation of the major parts of SWIS introduce a competitive system with current state of art Annotation tools and knowledge management systems; this is because it handles input documents in the ii context in which they are created in addition to the automatic learning and verification of knowledge using only the available computerized corporate databases. In this work, we introduce the concept of Control Knowledge (CK) that represents the application's domain memory and use it to verify the extracted knowledge. Learning is based on the number of occurrences of the same piece of information in different documents. We introduce the concept of Verifiability in the context of Annotation by comparing the extracted text's meaning with the information in the CK and the use of the proposed database table Verifiability_Tab. We use the linguistic concept Thematic Role in investigating and identifying the correct meaning of words in text documents, this helps correct relation extraction. The verb lexicon used contains the argument structure of each verb together with the thematic structure of the arguments. We also introduce a new method to chunk conjoined statements and identify the missing subject of the produced clauses. We use the semantic class of verbs that relates a list of verbs to a single property in the ontology, which helps in disambiguating the verb in the input text to enable better information extraction and Annotation. Consequently we propose the following definition for the annotated document or what is sometimes called the 'Intelligent Document' 'The Intelligent Document is the document that clearly expresses its syntax and semantics for human use and software automation'. This work introduces a promising improvement to the quality of the automatically generated annotated document and the quality of the automatically extracted information in the knowledge base. Our approach in the area of using Semantic Web iii technology opens new opportunities for diverse areas of applications. E-Learning applications can be greatly improved and become more effective.
7

Sémantická anotace doménově závislých dat / Semantic annotation of domain dependent data

Fišer, Dominik January 2011 (has links)
One of the problems of semantic web is automated getting annotated data - web pages. Therefore this work is engaged in manual annotation of web pages and try to simplify this process for users using proposed methods. First part contains analysis of annotated data, users and vocabularies used for annotation. Afterwards are proposed methods which simplify annotation creation for users, the possibility of usage similar annotations or possibility highlight interesting parts of web page suitable for annotation. The work includes proposal of annotation tool user interface also that verifies proposed methods in practice. On the basis of this proposal was created a prototype implementation of the annotation tool Semantic Annotator as an extension for Google Chrome browser, which was also used for experiment verifying user-friendliness especially.
8

Semantically-enriched and semi-autonomous collaboration framework for the Web of Things : design, implementation and evaluation of a multi-party collaboration framework with semantic annotation and representation of sensors in the Web of Things and a case study on disaster management

Amir, Mohammad January 2015 (has links)
This thesis proposes a collaboration framework for the Web of Things based on the concepts of Service-oriented Architecture and integrated with semantic web technologies to offer new possibilities in terms of efficient asset management during operations requiring multi-actor collaboration. The motivation for the project comes from the rise in disasters where effective cross-organisation collaboration can increase the efficiency of critical information dissemination. Organisational boundaries of participants as well as their IT capability and trust issues hinders the deployment of a multi-party collaboration framework, thereby preventing timely dissemination of critical data. In order to tackle some of these issues, this thesis proposes a new collaboration framework consisting of a resource-based data model, resource-oriented access control mechanism and semantic technologies utilising the Semantic Sensor Network Ontology that can be used simultaneously by multiple actors without impacting each other’s networks and thus increase the efficiency of disaster management and relief operations. The generic design of the framework enables future extensions, thus enabling its exploitation across many application domains. The performance of the framework is evaluated in two areas: the capability of the access control mechanism to scale with increasing number of devices, and the capability of the semantic annotation process to increase in efficiency as more information is provided. The results demonstrate that the proposed framework is fit for purpose.
9

Semantically-enriched and semi-Autonomous collaboration framework for the Web of Things. Design, implementation and evaluation of a multi-party collaboration framework with semantic annotation and representation of sensors in the Web of Things and a case study on disaster management

Amir, Mohammad January 2015 (has links)
This thesis proposes a collaboration framework for the Web of Things based on the concepts of Service-oriented Architecture and integrated with semantic web technologies to offer new possibilities in terms of efficient asset management during operations requiring multi-actor collaboration. The motivation for the project comes from the rise in disasters where effective cross-organisation collaboration can increase the efficiency of critical information dissemination. Organisational boundaries of participants as well as their IT capability and trust issues hinders the deployment of a multi-party collaboration framework, thereby preventing timely dissemination of critical data. In order to tackle some of these issues, this thesis proposes a new collaboration framework consisting of a resource-based data model, resource-oriented access control mechanism and semantic technologies utilising the Semantic Sensor Network Ontology that can be used simultaneously by multiple actors without impacting each other’s networks and thus increase the efficiency of disaster management and relief operations. The generic design of the framework enables future extensions, thus enabling its exploitation across many application domains. The performance of the framework is evaluated in two areas: the capability of the access control mechanism to scale with increasing number of devices, and the capability of the semantic annotation process to increase in efficiency as more information is provided. The results demonstrate that the proposed framework is fit for purpose.

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