21,626 research outputs found
A Parameterised Hierarchy of Argumentation Semantics for Extended Logic Programming and its Application to the Well-founded Semantics
Argumentation has proved a useful tool in defining formal semantics for
assumption-based reasoning by viewing a proof as a process in which proponents
and opponents attack each others arguments by undercuts (attack to an
argument's premise) and rebuts (attack to an argument's conclusion). In this
paper, we formulate a variety of notions of attack for extended logic programs
from combinations of undercuts and rebuts and define a general hierarchy of
argumentation semantics parameterised by the notions of attack chosen by
proponent and opponent. We prove the equivalence and subset relationships
between the semantics and examine some essential properties concerning
consistency and the coherence principle, which relates default negation and
explicit negation. Most significantly, we place existing semantics put forward
in the literature in our hierarchy and identify a particular argumentation
semantics for which we prove equivalence to the paraconsistent well-founded
semantics with explicit negation, WFSX. Finally, we present a general proof
theory, based on dialogue trees, and show that it is sound and complete with
respect to the argumentation semantics.Comment: To appear in Theory and Practice of Logic Programmin
Two-player Knock 'em Down
We analyze the two-player game of Knock 'em Down, asymptotically as the
number of tokens to be knocked down becomes large. Optimal play requires mixed
strategies with deviations of order sqrt(n) from the naive law-of-large numbers
allocation. Upon rescaling by sqrt(n) and sending n to infinity, we show that
optimal play's random deviations always have bounded support and have marginal
distributions that are absolutely continuous with respect to Lebesgue measure.Comment: 15 pages, 1 figure. v2 has minor revision
Price competition, level-k theory and communication
This paper analyzes communication in a price competition game using the level- theory of bounded rationality. The level-k analysis predicts prices to be higher with communication than without. Our experimental evidence lends support to the view that communication affects subjects in a way that is compatible with the level-k model, indicating that people lie in order to fool other players that they believe do less thinking. Moreover, the results indicate that the predictive power of the level-k model does crucially depend on the possibility for high level players to form homogenous beliefs about the behavior of the level-0 players.Noncooperative Game Theory Communication Bounded Rationality Experiments
Moving boundary and photoelastic coupling in GaAs optomechanical resonators
Chip-based cavity optomechanical systems are being considered for
applications in sensing, metrology, and quantum information science. Critical
to their development is an understanding of how the optical and mechanical
modes interact, quantified by the coupling rate . Here, we develop GaAs
optomechanical resonators and investigate the moving dielectric boundary and
photoelastic contributions to . First, we consider coupling between the
fundamental radial breathing mechanical mode and a 1550 nm band optical
whispering gallery mode in microdisks. For decreasing disk radius from
m to m, simulations and measurements show that changes
from being dominated by the moving boundary contribution to having an equal
photoelastic contribution. Next, we design and demonstrate nanobeam
optomechanical crystals in which a GHz mechanical breathing mode couples
to a 1550 nm optical mode predominantly through the photoelastic effect. We
show a significant (30 ) dependence of on the device's in-plane
orientation, resulting from the difference in GaAs photoelastic coefficients
along different crystalline axes, with fabricated devices exhibiting
as high as 1.1 MHz for orientation along the [110] axis.
GaAs nanobeam optomechanical crystals are a promising system which can combine
the demonstrated large optomechanical coupling strength with additional
functionality, such as piezoelectric actuation and incorporation of optical
gain media
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