6,398 research outputs found
Argument-based Belief in Topological Structures
This paper combines two studies: a topological semantics for epistemic
notions and abstract argumentation theory. In our combined setting, we use a
topological semantics to represent the structure of an agent's collection of
evidence, and we use argumentation theory to single out the relevant sets of
evidence through which a notion of beliefs grounded on arguments is defined. We
discuss the formal properties of this newly defined notion, providing also a
formal language with a matching modality together with a sound and complete
axiom system for it. Despite the fact that our agent can combine her evidence
in a 'rational' way (captured via the topological structure), argument-based
beliefs are not closed under conjunction. This illustrates the difference
between an agent's reasoning abilities (i.e. the way she is able to combine her
available evidence) and the closure properties of her beliefs. We use this
point to argue for why the failure of closure under conjunction of belief
should not bear the burden of the failure of rationality.Comment: In Proceedings TARK 2017, arXiv:1707.0825
Examining the Modelling Capabilities of Defeasible Argumentation and non-Monotonic Fuzzy Reasoning
Knowledge-representation and reasoning methods have been extensively researched within Artificial Intelligence. Among these, argumentation has emerged as an ideal paradigm for inference under uncertainty with conflicting knowledge. Its value has been predominantly demonstrated via analyses of the topological structure of graphs of arguments and its formal properties. However, limited research exists on the examination and comparison of its inferential capacity in real-world modelling tasks and against other knowledge-representation and non-monotonic reasoning methods. This study is focused on a novel comparison between defeasible argumentation and non-monotonic fuzzy reasoning when applied to the representation of the ill-defined construct of human mental workload and its assessment. Different argument-based and non-monotonic fuzzy reasoning models have been designed considering knowledge-bases of incremental complexity containing uncertain and conflicting information provided by a human reasoner. Findings showed how their inferences have a moderate convergent and face validity when compared respectively to those of an existing baseline instrument for mental workload assessment, and to a perception of mental workload self-reported by human participants. This confirmed how these models also reasonably represent the construct under consideration. Furthermore, argument-based models had on average a lower mean squared error against the self-reported perception of mental workload when compared to fuzzy-reasoning models and the baseline instrument. The contribution of this research is to provide scholars, interested in formalisms on knowledge-representation and non-monotonic reasoning, with a novel approach for empirically comparing their inferential capacity
Stratified Labelings for Abstract Argumentation
We introduce stratified labelings as a novel semantical approach to abstract
argumentation frameworks. Compared to standard labelings, stratified labelings
provide a more fine-grained assessment of the controversiality of arguments
using ranks instead of the usual labels in, out, and undecided. We relate the
framework of stratified labelings to conditional logic and, in particular, to
the System Z ranking functions
Rewriting Modernity
This article rereads Paul Virilio, drawing on the distinctionbetween topography and topology to argue a case for Virilio as a rewriter of modernity. Invoking Jean-François Lyotardâs notion of rewriting modernity as an unbroken process of accumulation founded on affective life in âRe-writing Modernityâ and âArgumentation and Presentation: The Foundation Crisis,â it enlists topology as a horizontal spatial structure that enables us to rethink space, time,and modernity outside the limits of the âsquared horizon,â where theâsquared horizonâ is viewed as a spatial and textual metaphor for framing perspectives on the past, present, and future. The analysis deconstructs the topography of the âsquared horizonâ as a relationality in an unfolding continuum, where spaces exist ontologically and where the immaterial forces of the dromospheric and the atmospheric generate a relational and historical connectedness
Extending Modular Semantics for Bipolar Weighted Argumentation (Technical Report)
Weighted bipolar argumentation frameworks offer a tool for decision support
and social media analysis. Arguments are evaluated by an iterative procedure
that takes initial weights and attack and support relations into account. Until
recently, convergence of these iterative procedures was not very well
understood in cyclic graphs. Mossakowski and Neuhaus recently introduced a
unification of different approaches and proved first convergence and divergence
results. We build up on this work, simplify and generalize convergence results
and complement them with runtime guarantees. As it turns out, there is a
tradeoff between semantics' convergence guarantees and their ability to move
strength values away from the initial weights. We demonstrate that divergence
problems can be avoided without this tradeoff by continuizing semantics.
Semantically, we extend the framework with a Duality property that assures a
symmetric impact of attack and support relations. We also present a Java
implementation of modular semantics and explain the practical usefulness of the
theoretical ideas
Generalization Of Lorentz-Poincare Ether Theory To Quantum Gravity
We present a quantum theory of gravity which is in agreement with observation
in the relativistic domain. The theory is not relativistic, but a Galilean
invariant generalization of Lorentz-Poincare ether theory to quantum gravity.
If we apply the methodological rule that the best available theory has to be
preferred, we have to reject the relativistic paradigm and return to Galilean
invariant ether theory.Comment: 21 pages Latex, no figure
Arguments Whose Strength Depends on Continuous Variation
Both the traditional Aristotelian and modern symbolic approaches to logic have seen logic in terms of discrete symbol processing. Yet there are several kinds of argument whose validity depends on some topological notion of continuous variation, which is not well captured by discrete symbols. Examples include extrapolation and slippery slope arguments, sorites, fuzzy logic, and those involving closeness of possible worlds. It is argued that the natural first attempts to analyze these notions and explain their relation to reasoning fail, so that ignorance of their nature is profound
Do classical configurations produce Confinement?
We show that certain classical SU(2) pure gauge configurations give rise to a
non-zero string tension. We then investigate cooled configurations generated by
Monte Carlo simulations on the lattice and find similar properties. We infer
evidence in favour of a classical model of Confinement.Comment: Uuencoded, Z-compressed and tarred file of the TeX file submit.tex
and PostScript files Stnt.eps and Stst.eps. 11 pages of text and two figure
Exploiting Parallelism for Hard Problems in Abstract Argumentation
Abstract argumentation framework (AF) is a unifying framework able to encompass a variety of nonmonotonic reasoning approaches, logic programming and computational argumentation. Yet, efficient approaches for most of the decision and enumeration problems associated to AF s are missing, thus potentially limiting the efficacy of argumentation-based approaches in real domains. In this paper, we present an algorithm for enumerating the preferred extensions of abstract argumentation frameworks which exploits parallel computation. To this purpose, the SCC-recursive semantics definition schema is adopted, where extensions are defined at the level of specific sub-frameworks. The algorithm shows significant performance improvements in large frameworks, in terms of number of solutions found and speedup
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