3,160 research outputs found
Turing Completeness of Finite, Epistemic Programs
In this note, we show the class of finite, epistemic programs to be Turing
complete. Epistemic programs is a widely used update mechanism used in
epistemic logic, where it such are a special type of action models: One which
does not contain postconditions
Pointwise intersection in neighbourhood modal logic
We study the logic of neighbourhood models with pointwise intersection, as a
means to characterize multi-modal logics. Pointwise intersection takes us from
a set of neighbourhood sets (one for each member of a set
, used to interpret the modality ) to a new neighbourhood set
, which in turn allows us to interpret the operator .
Here, is in the neighbourhood for if and only if equals the
intersection of some . We show that the
notion of pointwise intersection has various applications in epistemic and
doxastic logic, deontic logic, coalition logic, and evidence logic. We then
establish sound and strongly complete axiomatizations for the weakest logic
characterized by pointwise intersection and for a number of variants, using a
new and generally applicable technique for canonical model construction.Comment: Submitted to Advances in Modal Logic 201
Exploring Human Vision Driven Features for Pedestrian Detection
Motivated by the center-surround mechanism in the human visual attention
system, we propose to use average contrast maps for the challenge of pedestrian
detection in street scenes due to the observation that pedestrians indeed
exhibit discriminative contrast texture. Our main contributions are first to
design a local, statistical multi-channel descriptorin order to incorporate
both color and gradient information. Second, we introduce a multi-direction and
multi-scale contrast scheme based on grid-cells in order to integrate
expressive local variations. Contributing to the issue of selecting most
discriminative features for assessing and classification, we perform extensive
comparisons w.r.t. statistical descriptors, contrast measurements, and scale
structures. This way, we obtain reasonable results under various
configurations. Empirical findings from applying our optimized detector on the
INRIA and Caltech pedestrian datasets show that our features yield
state-of-the-art performance in pedestrian detection.Comment: Accepted for publication in IEEE Transactions on Circuits and Systems
for Video Technology (TCSVT
Generalized Trust in the Mirror: An Agent-Based Model on the Dynamics of Trust
High levels of trust have been linked to a variety of benefits including the well-functioning of markets and political institutions or the ability of societies to solve public goods problems endogenously. While there is extensive literature on the macro-level determinants of trust, the micro-level processes underlying the emergence and stability of trust are not yet sufficiently understood. We address this lacuna by means of a computer model. In this paper, conditions under which trust is likely to emerge and be sustained are identified. We focus our analysis mainly on the individual characteristics of agents: their social or geographical mobility, their attitude towards others or their general uncertainty about the environment. Contrary to predictions from previous literature, we show that immobile agents are detrimental to both, the emergence and robustness of trust. Additionally, we identify a hidden link between trusting others and being trustworthy
Hierarchical Salient Object Detection for Assisted Grasping
Visual scene decomposition into semantic entities is one of the major
challenges when creating a reliable object grasping system. Recently, we
introduced a bottom-up hierarchical clustering approach which is able to
segment objects and parts in a scene. In this paper, we introduce a transform
from such a segmentation into a corresponding, hierarchical saliency function.
In comprehensive experiments we demonstrate its ability to detect salient
objects in a scene. Furthermore, this hierarchical saliency defines a most
salient corresponding region (scale) for every point in an image. Based on
this, an easy-to-use pick and place manipulation system was developed and
tested exemplarily.Comment: Accepted for ICRA 201
3D model of magnetic fields evolution in dwarf irregular galaxies
Radio observations show that magnetic fields are present in dwarf irregular
galaxies (dIrr) and its strength is comparable to that found in spiral
galaxies. Slow rotation, weak shear and shallow gravitational potential are the
main features of a typical dIrr galaxy. These conditions of the interstellar
medium in a dIrr galaxy seem to unfavourable for amplification of the magnetic
field through the dynamo process. Cosmic-ray driven dynamo is one of the
galactic dynamo model, which has been successfully tested in case of the spiral
galaxies. We investigate this dynamo model in the ISM of a dIrr galaxy. We
study its efficiency under the influence of slow rotation, weak shear and
shallow gravitational potential. Additionally, the exploding supernovae are
parametrised by the frequency of star formation and its modulation, to
reproduce bursts and quiescent phases. We found that even slow galactic
rotation with a low shearing rate amplifies the magnetic field, and that rapid
rotation with a low value of the shear enhances the efficiency of the dynamo.
Our simulations have shown that a high amount of magnetic energy leaves the
simulation box becoming an efficient source of intergalactic magnetic fields.Comment: 4 pages, 4 figures, to appear in Proceedings of IAU Symp. 274,
Advances in Plasma Astrophysics, ed. A. Bonanno, E. de Gouveia dal Pino and
A. Kosoviche
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