ONTODL+: an ontology description language and its compiler

Dissertação de mestrado em Engenharia InformáticaOntologies are very powerful tools when it comes to handling knowledge. They offer a good solution to exchange, store, search and infer large volumes of information. Throughout the years various solutions for knowledge-based systems use ontologies at their core. OntoDL has been developed as a Domain Specific Language using ANTLR4, to allow for the specification of ontologies. This language has already been used by experts of various fields has a way to use computer-based solutions to solve their problems. In this thesis, included on the second year of the Master degree in Informatics Engineering, OntoDL+ was created as an expansion of the original OntoDL. Both the language and its compiler have been improved. The language was extended to improve usability and productivity for its users, while ensuring an easy to learn and understand language. The compiler was expanded to translate the language specifications to a vaster array of languages, increasing the potential uses of the DSL with the features provided by the languages. The compiler and some examples of the DSL can be downloaded at the website https: //epl.di.uminho.pt/∼gepl/GEPL DS/OntoDL/ created for the application and presented in the final chapters of the thesis.As ontologias são formalismos muito poderosos no que toca a manipulação de conhecimento. Estas oferecem uma boa solução para trocar, armazenar, procurar e inferir grandes volumes de informação. Ao longo dos anos, várias soluções para sistemas baseados em conhecimento usaram ontologias como uma parte central do sistema. A OntoDL é uma Linguagem de Domínio Específico que foi desenvolvida através do uso de ANTLR4, para permitir a especificação de ontologias. Esta linguagem foi já utilizada por especialistas de diversas áreas como forma de utilizar soluções informáticas para resolver os seus problemas. Nesta tese, incluída no segundo ano do Mestrado em Engenharia Informática, OntoDL+ foi criado como uma expansão tanto à linguagem e como ao seu compilador. A linguagem foi extendida para melhorar a usabilidade e produtividade dos seus utilizadores, mantendo se fácil de aprender e perceber. O compilador foi expandido para ser capaz de traduzir as especificações de OntoDL+ para um leque de linguagens mais vasto, aumentando os potenciais usos da DSL através das funcionalidades providenciadas pelas linguagens alvo. O compilador e alguns exemplos da DSL podem ser acedidos no sítio https://epl.di. uminho.pt/∼gepl/GEPL DS/OntoDL/ criado para a aplicação e mostrado nos capítulos finais da tese

Computational Ontologies and Information Systems I: Foundations

This paper provides a state-of-the-art review about computational ontologies to raise awareness about this research area in the IS discipline and to explore areas where IS researchers can engage in fruitful research. This paper discusses the basic foundations and definitions pertaining to the field of computational ontologies. It reviews the intersection of computational ontologies with the IS discipline. It also discusses methods and guidelines for developing computational ontologies. The paper concludes with recommendations for important and emerging directions for research. The technical aspects of ontologies are presented in a companion paper (Volume 14, article 9). The companion paper provides a comprehensive review of the formalisms, languages, and tools used for specifying and implementing computational ontologies

Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: NL

Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: N

Distributed Load Testing by Modeling and Simulating User Behavior

Modern human-machine systems such as microservices rely upon agile engineering practices which require changes to be tested and released more frequently than classically engineered systems. A critical step in the testing of such systems is the generation of realistic workloads or load testing. Generated workload emulates the expected behaviors of users and machines within a system under test in order to find potentially unknown failure states. Typical testing tools rely on static testing artifacts to generate realistic workload conditions. Such artifacts can be cumbersome and costly to maintain; however, even model-based alternatives can prevent adaptation to changes in a system or its usage. Lack of adaptation can prevent the integration of load testing into system quality assurance, leading to an incomplete evaluation of system quality. The goal of this research is to improve the state of software engineering by addressing open challenges in load testing of human-machine systems with a novel process that a) models and classifies user behavior from streaming and aggregated log data, b) adapts to changes in system and user behavior, and c) generates distributed workload by realistically simulating user behavior. This research contributes a Learning, Online, Distributed Engine for Simulation and Testing based on the Operational Norms of Entities within a system (LODESTONE): a novel process to distributed load testing by modeling and simulating user behavior. We specify LODESTONE within the context of a human-machine system to illustrate distributed adaptation and execution in load testing processes. LODESTONE uses log data to generate and update user behavior models, cluster them into similar behavior profiles, and instantiate distributed workload on software systems. We analyze user behavioral data having differing characteristics to replicate human-machine interactions in a modern microservice environment. We discuss tools, algorithms, software design, and implementation in two different computational environments: client-server and cloud-based microservices. We illustrate the advantages of LODESTONE through a qualitative comparison of key feature parameters and experimentation based on shared data and models. LODESTONE continuously adapts to changes in the system to be tested which allows for the integration of load testing into the quality assurance process for cloud-based microservices

Evolution of security engineering artifacts: a state of the art survey

Security is an important quality aspect of modern open software systems. However, it is challenging to keep such systems secure because of evolution. Security evolution can only be managed adequately if it is considered for all artifacts throughout the software development lifecycle. This article provides state of the art on the evolution of security engineering artifacts. The article covers the state of the art on evolution of security requirements, security architectures, secure code, security tests, security models, and security risks as well as security monitoring. For each of these artifacts the authors give an overview of evolution and security aspects and discuss the state of the art on its security evolution in detail. Based on this comprehensive survey, they summarize key issues and discuss directions of future research