The Verification of Temporal KBS: SPARSE - A Case Study in Power Systems

In this paper we present VERITAS, a tool that focus time maintenance, that is one of the most important processes in the engineering of the time during the development of KBS. The verification and validation (V&V) process is part of a wider process denominated knowledge maintenance, in which an enterprise systematically gathers, organizes, shares, and analyzes knowledge to accomplish its goals and mission. The V&V process states if the software requirements specifications have been correctly and completely fulfilled. The methodologies proposed in software engineering have showed to be inadequate for Knowledge Based Systems (KBS) validation and verification, since KBS present some particular characteristics. VERITAS is an automatic tool developed for KBS verification which is able to detect a large number of knowledge anomalies. It addresses many relevant aspects considered in real applications, like the usage of rule triggering selection mechanisms and temporal reasoning

Blockchain and sustainable supply chain management in developing countries

Theoretical, empirical and anecdotal evidence suggests that there are more violations of sustainability principles in supply chains in developing countries than in developed countries. Recent research has demonstrated that blockchain can play an important role in promoting supply chain sustainability. In this paper we argue that blockchain’s characteristics are especially important for enforcing sustainability standards in developing countries. We analyze multiple case studies of blockchain projects implemented in supply chains in developing countries to assess product quality, environmental accounting and social impact measurement. We have developed seven propositions, which describe how blockchain can help address a number of challenges various stakeholders face in promoting sustainable supply chains in developing countries. The challenges that the propositions deal with include those associated with an unfavorable institutional environment, high costs, technological limitations, unequal power distribution among supply chain partners and porosity and opacity of value delivery networks

Optimization of FPSO Glen Lyon Mooring Lines

During oil and gas inspection and extraction operations both in deep and ultra-deep water, vessel mooring is a very important factor for the development of oil fields. For these depths, standard stand-alone surface facilities e.g. jack up rigs or offshore fixed platforms are not suitable due to the harsh collinear and non-collinear environment in-situ (location, waves, surface and underwater current, sea tides, ice, etc.). For deep sea wells clusters, it is usual to use floating production storage offloading (FPSO) as surface platforms for long time exploitation periods. Subsea expenditure, refers the cost of the subsea project and generally includes the capital expenditures (capex) and operational expenditures (opex). In the production of hydrocarbons capex and opex exponentially increases with increasing depth, resulting in a need for precise detailed design phase for analysis of systems to verify components strength, ductility and fatigue, stiffness, instabilities, corrosion etc. The design of oilfields is most of the times overrated (in a very conservative way) due to several requirements and complex models of costs evaluation. After detailed phase and installation of all facilities and components, as well as due to the expected life design for hydrocarbons exploitation all anchoring system shall withstand the environmental loads in order to not compromise the operation. Each oilfield has a unique development, since environmental phenomena are unique in each earth location. This work refers to the optimization process of an anchoring system for deep waters in the Schiehallion Field, or in other words, the complete development of the mooring system for a FPSO, from the positioning in-situ with environmental conditions and vessel characteristics (Orcaflex), further optimization of the mooring system for an equivalent system (Matlab), mechanical design of the mooring system (CATIA), structural detailed analysis (Altair and Nastran) as fatigue life analysis. In order to reproduce all the mooring process, it is performed and initial comparison of the former FPSO (Schiehallion FPSO) that has been working in-situ since 1993 till its replacement for the new vessel (Glen Lyon FPSO). Due to the latest discoveries in the oilfield, the project has to be redesigned alongside with former wells and having in consideration recent discovered wells. Further optimization of the complete fixation system was verified as well as finally detailed structural analysis of specific components in key locations with higher margin of failure. Within this work, all the methodology which led to the optimization of Glen Lyon mooring lines was fully detailed from vessel analysis to detailed mooring mechanical design, constraints and requirements were applied, trade-offs and assumptions made during this critical development phase are presented and discussed.Durante as operações de prospeção e extração de petróleo e gas em águas profundas e ultra profundas, o fundeamento de navios é um importante fator para o desenvolvimento do campo petrolífero. Para estas profundidades, infra-estruturas convencionais e.g. plataformas petrolíferas não são aplicáveis devido ao ambiente violento colinear e não colinear do local (localização, ondas, correntes subaquáticas e de superfície, marés, etc.). Para conjuntos de poços subaquáticos, é comum o uso de Platformas de produção, armazenamento e descarga (FPSO) como plataforma de superficie para periodos de exploração longos. Os custos subaquaticos referem-se ao custo do projeto marinho e normalmente incluem os custos de capital capex e custos operacionais opex. Na produção de hidrocarbonetos os capex e os opex aumentam exponencialmente com o aumento da profundidade, resultando na necessidade do desenvolvimento da fase de projeto detalhado necessário para análises de componentes para verificar a resistência dos mesmos, dutilidade e fadiga, quer na rigidez, instabilidade, corrosão, etc. O projeto de campos petrolíferos são na maioria das vezes sobreestimados (de forma bastante conservativa) devido a imensos requisitos e modelos complexos de avaliação de custos. Após projeto e instalação de todas as infraestruturas e componentes, assim como durante o longo periodo útil de extração de hidrocarbonetos, toda a ancoragem deve suportar as cargas ambientais de forma a não comprometer a operação. Cada campo petrolífero possui um desenvolvimento singular, uma vez que os fenómenos ambientais são únicos em cada localização do globo terrestre. Este trabalho refere a optimização de um sistema de amarração para águas profundas para o campo de Schiehallion, ou por outras palavras, todo o desenvolvimento de ancoragem de um navio FPSO, desde o posicionamento no local com as forças ambientais e as caracteristicas do navio (Orcaflex), posterior otimização do sistema de ancoragem por um sistema equivalente (Matlab), desenho mecânico do sistema de ancoragem (CATIA), cálculo estrutural detalhado (Altair e Nastran) e análise de vida à fadiga. De forma a reproduzir o processo de ancoragem, é efetuada uma comparação inicial do FPSO inicial (Schiehallion FPSO) que esteve em operação no local desde 1993 até à sua substituição pelo novo navio (Glen Lyon FPSO), através da implementação e gestão do campo petrolífero de acordo com os poços antigos como os poços descobertos recentemente. A posterior otimização de todo o sistema de fixação foi verificada assim como a análise estrutural final detalhada dos componentes específicos em localizações especificas com grande probabilidade de falha. Através deste trabalho, todo o processo que leva à otimização das linhas de amarração do Glen Lyon é completamente detalhado desde a análise do navio ao detalhamento do desenho mecânico, os constrangimentos e requisitos que foram aplicados, estudos e opções efetuadas durante a fase de desenvolvimento crítico são apresentados e discutidos

Disinformation and Fact-Checking in Contemporary Society

Funded by the European Media and Information Fund and research project PID2022-142755OB-I00