Learning Ontology Relations by Combining Corpus-Based Techniques and Reasoning on Data from Semantic Web Sources

The manual construction of formal domain conceptualizations (ontologies) is labor-intensive. Ontology learning, by contrast, provides (semi-)automatic ontology generation from input data such as domain text. This thesis proposes a novel approach for learning labels of non-taxonomic ontology relations. It combines corpus-based techniques with reasoning on Semantic Web data. Corpus-based methods apply vector space similarity of verbs co-occurring with labeled and unlabeled relations to calculate relation label suggestions from a set of candidates. A meta ontology in combination with Semantic Web sources such as DBpedia and OpenCyc allows reasoning to improve the suggested labels. An extensive formal evaluation demonstrates the superior accuracy of the presented hybrid approach

A novel and validated agile Ontology Engineering methodology for the development of ontology-based applications

The goal of this Thesis is to investigate the status of Ontology Engineering, underlining the main key issues still characterizing this discipline. Among these issues, the problem of reconciling macro-level methodologies with authoring techniques is pivotal in supporting novel ontology engineers. The latest approach characterizing ontology engineering methodologies leverages the agile paradigm to support collaborative ontology development and deliver efficient ontologies. However, so far, the investigations in the current support provided by these methodologies and the delivery of efficient ontologies have not been investigated. Thus, this work proposes a novel framework for the investigation of agile methodologies, with the objective of identifying the strong point of each agile methodology and their limitations. Leveraging on the findings of this analysis, the Thesis introduces a novel agile methodology – AgiSCOnt – aimed at tackling some of the key issues characterizing Ontology Engineering and weaknesses identified in existing agile approaches. The novel methodology is then put to the test as it is adopted for the development of two new domain ontologies in the field of health: the first is dedicated to patients struggling with dysphagia, while the second addresses patients affected by Chronic obstructive pulmonary disease.The goal of this Thesis is to investigate the status of Ontology Engineering, underlining the main key issues still characterizing this discipline. Among these issues, the problem of reconciling macro-level methodologies with authoring techniques is pivotal in supporting novel ontology engineers. The latest approach characterizing ontology engineering methodologies leverages the agile paradigm to support collaborative ontology development and deliver efficient ontologies. However, so far, the investigations in the current support provided by these methodologies and the delivery of efficient ontologies have not been investigated. Thus, this work proposes a novel framework for the investigation of agile methodologies, with the objective of identifying the strong point of each agile methodology and their limitations. Leveraging on the findings of this analysis, the Thesis introduces a novel agile methodology – AgiSCOnt – aimed at tackling some of the key issues characterizing Ontology Engineering and weaknesses identified in existing agile approaches. The novel methodology is then put to the test as it is adopted for the development of two new domain ontologies in the field of health: the first is dedicated to patients struggling with dysphagia, while the second addresses patients affected by Chronic obstructive pulmonary disease

Creation and extension of ontologies for describing communications in the context of organizations

Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfillment of the requirements for the degree of Master in Computer ScienceThe use of ontologies is nowadays a sufficiently mature and solid field of work to be considered an efficient alternative in knowledge representation. With the crescent growth of the Semantic Web, it is expectable that this alternative tends to emerge even more in the near future. In the context of a collaboration established between FCT-UNL and the R&D department of a national software company, a new solution entitled ECC – Enterprise Communications Center was developed. This application provides a solution to manage the communications that enter, leave or are made within an organization, and includes intelligent classification of communications and conceptual search techniques in a communications repository. As specificity may be the key to obtain acceptable results with these processes, the use of ontologies becomes crucial to represent the existing knowledge about the specific domain of an organization. This work allowed us to guarantee a core set of ontologies that have the power of expressing the general context of the communications made in an organization, and of a methodology based upon a series of concrete steps that provides an effective capability of extending the ontologies to any business domain. By applying these steps, the minimization of the conceptualization and setup effort in new organizations and business domains is guaranteed. The adequacy of the core set of ontologies chosen and of the methodology specified is demonstrated in this thesis by its effective application to a real case-study, which allowed us to work with the different types of sources considered in the methodology and the activities that support its construction and evolution

Methodological approaches and techniques for designing ontologies in information systems requirements engineering

Programa doutoral em Information Systems and TechnologyThe way we interact with the world around us is changing as new challenges arise, embracing innovative business models, rethinking the organization and processes to maximize results, and evolving change management. Currently, and considering the projects executed, the methodologies used do not fully respond to the companies' needs. On the one hand, organizations are not familiar with the languages used in Information Systems, and on the other hand, they are often unable to validate requirements or business models. These are some of the difficulties encountered that lead us to think about formulating a new approach. Thus, the state of the art presented in this paper includes a study of the models involved in the software development process, where traditional methods and the rivalry of agile methods are present. In addition, a survey is made about Ontologies and what methods exist to conceive, transform, and represent them. Thus, after analyzing some of the various possibilities currently available, we began the process of evolving a method and developing an approach that would allow us to design ontologies. The method we evolved and adapted will allow us to derive terminologies from a specific domain, aggregating them in order to facilitate the construction of a catalog of terminologies. Next, the definition of an approach to designing ontologies will allow the construction of a domain-specific ontology. This approach allows in the first instance to integrate and store the data from different information systems of a given organization. In a second instance, the rules for mapping and building the ontology database are defined. Finally, a technological architecture is also proposed that will allow the mapping of an ontology through the construction of complex networks, allowing mapping and relating terminologies. This doctoral work encompasses numerous Research & Development (R&D) projects belonging to different domains such as Software Industry, Textile Industry, Robotic Industry and Smart Cities. Finally, a critical and descriptive analysis of the work done is performed, and we also point out perspectives for possible future work.A forma como interagimos com o mundo à nossa volta está a mudar à medida que novos desafios surgem, abraçando modelos empresariais inovadores, repensando a organização e os processos para maximizar os resultados, e evoluindo a gestão da mudança. Atualmente, e considerando os projetos executados, as metodologias utilizadas não respondem na totalidade às necessidades das empresas. Por um lado, as organizações não estão familiarizadas com as linguagens utilizadas nos Sistemas de Informação, por outro lado, são muitas vezes incapazes de validar requisitos ou modelos de negócio. Estas são algumas das dificuldades encontradas que nos levam a pensar na formulação de uma nova abordagem. Assim, o estado da arte apresentado neste documento inclui um estudo dos modelos envolvidos no processo de desenvolvimento de software, onde os métodos tradicionais e a rivalidade de métodos ágeis estão presentes. Além disso, é efetuado um levantamento sobre Ontologias e quais os métodos existentes para as conceber, transformar e representar. Assim, e após analisarmos algumas das várias possibilidades atualmente disponíveis, iniciou-se o processo de evolução de um método e desenvolvimento de uma abordagem que nos permitisse conceber ontologias. O método que evoluímos e adaptamos permitirá derivar terminologias de um domínio específico, agregando-as de forma a facilitar a construção de um catálogo de terminologias. Em seguida, a definição de uma abordagem para conceber ontologias permitirá a construção de uma ontologia de um domínio específico. Esta abordagem permite em primeira instância, integrar e armazenar os dados de diferentes sistemas de informação de uma determinada organização. Num segundo momento, são definidas as regras para o mapeamento e construção da base de dados ontológica. Finalmente, é também proposta uma arquitetura tecnológica que permitirá efetuar o mapeamento de uma ontologia através da construção de redes complexas, permitindo mapear e relacionar terminologias. Este trabalho de doutoramento engloba inúmeros projetos de Investigação & Desenvolvimento (I&D) pertencentes a diferentes domínios como por exemplo Indústria de Software, Indústria Têxtil, Indústria Robótica e Smart Cities. Finalmente, é realizada uma análise critica e descritiva do trabalho realizado, sendo que apontamos ainda perspetivas de possíveis trabalhos futuros

SemQuaRE - An extension of the SQuaRE quality model for the evaluation of semantic technologies

To correctly evaluate semantic technologies and to obtain results that can be easily integrated, we need to put evaluations under the scope of a unique software quality model. This paper presents SemQuaRE, a quality model for semantic technologies. SemQuaRE is based on the SQuaRE standard and describes a set of quality characteristics specific to semantic technologies and the quality measures that can be used for their measurement. It also provides detailed formulas for the calculation of such measures. The paper shows that SemQuaRE is complete with respect to current evaluation trends and that it has been successfully applied in practice

Access management for digital twins in the built environment

Recent technological advances in the built environment have sought to create smart cities by coupling information models such as BIM with Cyber-Physical Systems (CPSs). BIM models are now widely used together with IoT-based systems and embrace smart technologies that provide communication layer compatibility. Digital twins are expected to open new opportunities for cyber-physical systems in the future through monitoring and simulation. Security, on the other hand, is rarely properly considered in this fast-evolving industry. However, while they provide various advantages, according to the literature, they also present a number of concerns, the most serious of which is security. Attempting to integrate access management into digital twins that will be used in built-environment applications presents significant obstacles. Furthermore, this is an issue that has received too little attention. As a result, digital twins that can safeguard and identify real twins are in demand. This research focuses on how to enhance the access management frameworks for digital twins in the built environment, paying particular attention to access control, data confidentiality, data integrity, and Single Sign-On (SSO). As a result, this thesis defines an access management framework for digital twins in the built environment that is supported by a requirement specification of access management ontology This study engages with built environment experts to consider their role as stakeholders and identifies their main concerns, gauges their assessments of current technologies and utilities, and stimulates public awareness of built environment applications’ development goals. According to these findings, there is still a need for a suitable and safe access management paradigm for digital twins. Those in charge of overseeing smart building investments and the use of BIM in asset design and management must be aware of the latest access management threats and take steps to prevent any risk to the shared data environment. Therefore, this study has developed a semantically defined access management framework for the built environment through an ontological modelling method which formally represents domain information in the creation stage. This ontology solves the issues identified by previous research and industry surveys by explicitly modelling the relationships in an access management context between physical built environment assets, IoT devices, cyber-physical systems, current built environment services, existing security standards, digital twin and BIM datasets, as well as user interfaces and the actors who use them The fundamental novelty of this framework is that while previous work has focused on IoT platforms that integrate with BIM, none of these platforms allow seamless integration with BIM models. The need to be able to operate secure servers appears to have been disregarded in efforts to solve access management problems. The access management framework is validated using a case study from Cardiff University achieved validating the semantic representation against the competency questions and on data drawn from existing case studies developed on university buildings. The validation has shown that the final access management framework semantic representation satisfies the defined requirements and is suitable for application in various built environment use cases. Furthermore, its functionality is tested in the specified case study, as is its compatibility with the necessary built-environment principles such as SSO. The key contributions of this study are that it (a) finds the current IoT and CPS security systems to address the access management threats facing digital twins in the context of smart buildings and districts; (b) finds built environment experts to consider their role as a stakeholder and to identify their main concerns; and (c) enhances the access management framework for digital twins in the built environment. Finally, numerous important recommendations are suggested for future research to help overcome the current study’s limitations. These recommendations are designed to stimulate future research in the areas of built environment access management, digital twins, and cyber physical system

Toward Shared Understanding : An Argumentation Based Approach for Communication in Open Multi-Agent Systems

Open distributed computing applications are becoming increasingly commonplace nowadays. In many cases, these applications are composed of multiple autonomous agents, each with its own aims and objectives. In such complex systems, communication between these agents is usually essential for them to perform their task, to coordinate their actions and share their knowledge. However, successful and meaningful communication can only be achieved by a shared understanding of each other's messages. Therefore efficient mechanisms are needed to reach a mutual understanding when exchanging expressions from each other's world model and background knowledge. We believe the de facto mechanisms for achieving this are ontologies, and this is the area explored in this thesis [88]. However, supporting shared understanding mechanisms for open distributed applications is a major research challenge. Specifically, one consequence of a system being open is the heterogeneity of the agents. Agents may have conflicting goals, or may be heterogeneous with respect to their beliefs or their knowledge. Forcing all agents to use a common vocabulary defined in one or more shared ontologies is, thus, an oversimplified solution, particularly when these agents are designed and deployed independently of each other. This thesis proposes a novel approach to overcome vocabulary heterogeneity, where the agents dynamically negotiate the meaning of the terms they use to communicate. While many proposals for aligning two agent ontologies have been presented in the literature as the current standard approaches to resolve heterogeneity, they are lacking when dealing with important features of agents and their environment. Motivated by the hypothesis that ontology alignment approaches should reflect the characteristics of autonomy and rationality that are typical of agents, and should also be tailored to the requirements of an open environment, such as dynamism, we propose a way for agents to define and agree upon the semantics of the terms used at run-time, according to their interests and preferences. Since agents are autonomous and represent different stakeholders, the process by which they come to an agreement will necessarily only come through negotiation. By using argumentation theory, agents generate and exchange different arguments, that support or reject possible mappings between vocabularies, according to their own preferences. Thus, this work provides a concrete instantiation of the meaning negotiation process that we would like agents to achieve, and that may lead to shared understanding. Moreover, in contrast to current ontology alignment approaches, the choice of a mapping is based on two clearly identified elements: (i) the argumentation framework, which is common to all agents, and (ii) the preference relations, which are private to each agent. Despite the large body of work in the area of semantic interoperabiJity, we are not aware of any research in this area that has directly addressed these important requirements for open Multi-Agent Systems as we have done in this thesis. Supplied by The British Library - 'The world's knowledge

Knowledge modelling of emerging technologies for sustainable building development

In the quest for improved performance of buildings and mitigation of climate change, governments are encouraging the use of innovative sustainable building technologies. Consequently, there is now a large amount of information and knowledge on sustainable building technologies over the web. However, internet searches often overwhelm practitioners with millions of pages that they browse to identify suitable innovations to use on their projects. It has been widely acknowledged that the solution to this problem is the use of a machine-understandable language with rich semantics - the semantic web technology. This research investigates the extent to which semantic web technologies can be exploited to represent knowledge about sustainable building technologies, and to facilitate system decision-making in recommending appropriate choices for use in different situations. To achieve this aim, an exploratory study on sustainable building and semantic web technologies was conducted. This led to the use of two most popular knowledge engineering methodologies - the CommonKADS and "Ontology Development 101" in modelling knowledge about sustainable building technology and PV -system domains. A prototype system - Photo Voltaic Technology ONtology System (PV -TONS) - that employed sustainable building technology and PV -system domain knowledge models was developed and validated with a case study. While the sustainable building technology ontology and PV -TONS can both be used as generic knowledge models, PV -TONS is extended to include applications for the design and selection of PV -systems and components. Although its focus was on PV -systems, the application of semantic web technologies can be extended to cover other areas of sustainable building technologies. The major challenges encountered in this study are two-fold. First, many semantic web technologies are still under development and very unstable, thus hindering their full exploitation. Second, the lack of learning resources in this field steepen the learning curve and is a potential set-back in using semantic web technologies