1,813 research outputs found
"Minimal defence": a refinement of the preferred semantics for argumentation frameworks
Dung's abstract framework for argumentation enables a study of the
interactions between arguments based solely on an ``attack'' binary relation on
the set of arguments. Various ways to solve conflicts between contradictory
pieces of information have been proposed in the context of argumentation,
nonmonotonic reasoning or logic programming, and can be captured by appropriate
semantics within Dung's framework. A common feature of these semantics is that
one can always maximize in some sense the set of acceptable arguments. We
propose in this paper to extend Dung's framework in order to allow for the
representation of what we call ``restricted'' arguments: these arguments should
only be used if absolutely necessary, that is, in order to support other
arguments that would otherwise be defeated. We modify Dung's preferred
semantics accordingly: a set of arguments becomes acceptable only if it
contains a minimum of restricted arguments, for a maximum of unrestricted
arguments.Comment: 8 pages, 3 figure
Initial Sets in Abstract Argumentation Frameworks
Dung’s abstract argumentation provides us with a general framework to deal with argumentation, non-monotonic reasoning and logic programming. For the extension-based semantics, one of the basic principles is I-maximality which is in particular related with the notion of skeptical justification. Another one is directionality which can be employed for the study of dynamics of argumentation. In this paper, we introduce two new extension-based semantics into Dung’s abstract argumentation, called grounded-like semantics and initial semantics which satisfy the I-maximality and directionality principles. The initial semantics has many good properties and can be expected to play a central role in studying other extension-based semantics, such as admissible, complete and preferred semantics
Possibilistic reasoning with partially ordered beliefs
International audienceThis paper presents the extension of results on reasoning with totally ordered belief bases to the partially ordered case. The idea is to reason from logical bases equipped with a partial order expressing relative certainty and to construct a partially ordered deductive closure. The difficult point lies in the fact that equivalent definitions in the totally ordered case are no longer equivalent in the partially ordered one. At the syntactic level we can either use a language expressing pairs of related formulas and axioms describing the properties of the ordering, or use formulas with partially ordered symbolic weights attached to them in the spirit of possibilistic logic. A possible semantics consists in assuming the partial order on formulas stems from a partial order on interpretations. It requires the capability of inducing a partial order on subsets of a set from a partial order on its elements so as to extend possibility theory functions. Among different possible definitions of induced partial order relations, we select the one generalizing necessity orderings (closely related to epistemic entrenchments). We study such a semantic approach inspired from possibilistic logic, and show its limitations when relying on a unique partial order on interpretations. We propose a more general sound and complete approach to relative certainty, inspired by conditional modal logics, in order to get a partial order on the whole propositional language. Some links between several inference systems, namely conditional logic, modal epistemic logic and non-monotonic preferential inference are established. Possibilistic logic with partially ordered symbolic weights is also revisited and a comparison with the relative certainty approach is made via mutual translations
Abstract Argumentation / Persuasion / Dynamics
The act of persuasion, a key component in rhetoric argumentation, may be
viewed as a dynamics modifier. We extend Dung's frameworks with acts of
persuasion among agents, and consider interactions among attack, persuasion and
defence that have been largely unheeded so far. We characterise basic notions
of admissibilities in this framework, and show a way of enriching them through,
effectively, CTL (computation tree logic) encoding, which also permits
importation of the theoretical results known to the logic into our
argumentation frameworks. Our aim is to complement the growing interest in
coordination of static and dynamic argumentation.Comment: Arisaka R., Satoh K. (2018) Abstract Argumentation / Persuasion /
Dynamics. In: Miller T., Oren N., Sakurai Y., Noda I., Savarimuthu B., Cao
Son T. (eds) PRIMA 2018: Principles and Practice of Multi-Agent Systems.
PRIMA 2018. Lecture Notes in Computer Science, vol 11224. Springer, Cha
Relationship between inoculum density of the nematophagous fungus Paecilomyces lilacinus and control of Meloidogyne arenaria on tomato
International audienc
Научно-технический семинар «Повышение эксплуатационной надежности линейной части магистральных газопроводов газотранспортной системы Украины»
С 11 по 15 марта 2002 г. Научно-технический комплекс «Институт электросварки им. II. О. Па-топа» Национальной Академии наук Украины совместно с ДК «Укртрансгаз» провели научно-технический семинар «Повышение эксплуатационной надежности линейной части магистральных газопроводов газотранспортной системы Украины».
Семинар прошел в рамках Проекта Программы развития ООН «Обмен технологической информацией в Украине для поддержки экономических реформ»
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