Abduction in Well-Founded Semantics and Generalized Stable Models

Abductive logic programming offers a formalism to declaratively express and solve problems in areas such as diagnosis, planning, belief revision and hypothetical reasoning. Tabled logic programming offers a computational mechanism that provides a level of declarativity superior to that of Prolog, and which has supported successful applications in fields such as parsing, program analysis, and model checking. In this paper we show how to use tabled logic programming to evaluate queries to abductive frameworks with integrity constraints when these frameworks contain both default and explicit negation. The result is the ability to compute abduction over well-founded semantics with explicit negation and answer sets. Our approach consists of a transformation and an evaluation method. The transformation adjoins to each objective literal $O$ in a program, an objective literal $not(O)$ along with rules that ensure that $not(O)$ will be true if and only if $O$ is false. We call the resulting program a {\em dual} program. The evaluation method, \wfsmeth, then operates on the dual program. \wfsmeth{} is sound and complete for evaluating queries to abductive frameworks whose entailment method is based on either the well-founded semantics with explicit negation, or on answer sets. Further, \wfsmeth{} is asymptotically as efficient as any known method for either class of problems. In addition, when abduction is not desired, \wfsmeth{} operating on a dual program provides a novel tabling method for evaluating queries to ground extended programs whose complexity and termination properties are similar to those of the best tabling methods for the well-founded semantics. A publicly available meta-interpreter has been developed for \wfsmeth{} using the XSB system.Comment: 48 pages; To appear in Theory and Practice in Logic Programmin

Preferential theory revision

AbstractEmploying a logic program approach, this paper focuses on applying preferential reasoning to theory revision, both by means of preferences among existing theory rules, and by means of preferences on the possible abductive extensions to the theory. And, in particular, how to prefer among plausible abductive explanations justifying observations

Eye gaze in individuals with and without convergence insufficiency

Aims of the study: Characterization of the eye gaze, through the analysis of eye movements during fixation and pursuit of a target in young adults with convergence insufficiency and young adults with normal binocular vision. In the horizontal from left-right in the vertical from up-down, for the most used direction, in the horizontal from right-left, and in the vertical from down-up for the less used direction.info:eu-repo/semantics/publishedVersio

Cibercultura, Simbiose e Sincretismo

O impacto da Cibercultura, dos dispositivos digitais nos jovens enquanto extensões do seu corpo, pode ser visto em termos do decréscimo da estruturação de pensamento e informação, acréscimo da impulsividade na perceção e ação, e no desenvolvimento de mecanismos de defesa mais primitivos. Estes impactos adversos resultam num sentimento de isolamento e desvalorização, em frustração no presente e incerteza no futuro, em exteriorização e identidades flutuantes, nas identificações miméticas e adesivas, em menor coesão do self, e numa diminuída tolerância ao outro. Este artigo foca os seguintes temas: (1) Simbiose versus Sincretismo: As afirmações da Simbiose. As diluições do Sincretismo; (2) Súmula: Sincretismo a mais, simbiose a menos. Falta de uma maior co-construção do conhecimento, duradoura e sustentável. Falta de maior e mais independente aprofundamento cognitivo pessoal. Falta de capacidade para estar só; (3) Causalidade e Livre Arbítrio: Causalidade simbiótica versus sincrética; (4) Coda: Cyber-selfs distribuídos ou não

Prolegómeno a uma neurologia artificial

Exploram-se algumas potencialidades de aproximação entre a neurologia e as ciências da computação, com particular ênfase na distinção hardware/software e suas consequências. ------ ABSTRACT ------ Potential bridging points between neurology and computer science are explored, with special emphasis on the hardware7software distinction and its consequences

Ethics and Development of Advanced Technology Systems in Public Administration

Publisher Copyright: © 2023, The Author(s).This article analyses aspects related to the implementation of advanced technology systems in Public Administration, taking into account the scope of action of its entities and services, as well as its main distinction with the private sector, which lies in the pursuit of the public interest, understood as justification for the execution of public policies, but also in the broader scope of the human development index. The difficulties and resistance to the adoption and use of technology in Public Administration will be examined, also in the light of practical situations whose implementation proved to be inadequate, resulting in the analysis of ideas for the future. We approach the evolution of public management models that are emerging through the action of technology. We prepare the ground for machine ethics in Public Administration by framing ethics in public services in general terms, with reference to AI systems designed in line with mainstream ethics. Of the various ethical issues that arise in this domain, we pay attention to the issue of privacy and the balance that needs to be achieved so that the use of data can contribute to ethical, beneficial and reliable technologies. We sound alerts in the field of discrimination and prejudice that the bias of technology can show. The explainability and transparency of technological systems provide confidence to decision-makers and citizens, helping to clarify responsibilities in the decisions of Public Administration agents, and the researchers working for them.publishersversionpublishe