477,173 research outputs found
Sellars' Argument for an Ontology of Absolute Processes
Scholars have rejected Wilfrid Sellars’ argument for an ontology of absolute processes on the grounds that it relies on a dubious and dogmatic appeal to the homogeneity of color. Borrowing from Rosenthal’s recent defense, but ultimate rejection of homogeneity, I defend this claim of on Sellarsian/Kantian transcendental grounds, and reconstruct the remainder of his argument. I argue that Sellars has good reason to suppose that homogeneity is a necessary condition of any possible experience, including indirect experience of theoretical-explanatory posits, and therefore good reason to hold that Reductive Materialism, as he conceives it, is an untenable account of color. The remainder of his argument aims to answer the question of what the metaphysical relation is between the state of an experiencing subject that we take color to be and the colorless microphysical particles that we take to constitute that subject. After rejecting Substance Dualism, Epiphenomenalism, and Wholistic or Emergent Materialism as explanatorily inadequate, Sellars proposes that both color-states and micro-physical particles should be understood as manifestations of an underlying ontology on absolute processes
Evaluating color texture descriptors under large variations of controlled lighting conditions
The recognition of color texture under varying lighting conditions is still
an open issue. Several features have been proposed for this purpose, ranging
from traditional statistical descriptors to features extracted with neural
networks. Still, it is not completely clear under what circumstances a feature
performs better than the others. In this paper we report an extensive
comparison of old and new texture features, with and without a color
normalization step, with a particular focus on how they are affected by small
and large variation in the lighting conditions. The evaluation is performed on
a new texture database including 68 samples of raw food acquired under 46
conditions that present single and combined variations of light color,
direction and intensity. The database allows to systematically investigate the
robustness of texture descriptors across a large range of variations of imaging
conditions.Comment: Submitted to the Journal of the Optical Society of America
Color naming reflects both perceptual structure and communicative need
Gibson et al. (2017) argued that color naming is shaped by patterns of
communicative need. In support of this claim, they showed that color naming
systems across languages support more precise communication about warm colors
than cool colors, and that the objects we talk about tend to be warm-colored
rather than cool-colored. Here, we present new analyses that alter this
picture. We show that greater communicative precision for warm than for cool
colors, and greater communicative need, may both be explained by perceptual
structure. However, using an information-theoretic analysis, we also show that
color naming across languages bears signs of communicative need beyond what
would be predicted by perceptual structure alone. We conclude that color naming
is shaped both by perceptual structure, as has traditionally been argued, and
by patterns of communicative need, as argued by Gibson et al. - although for
reasons other than those they advanced
Pixelated Semantic Colorization
While many image colorization algorithms have recently shown the capability
of producing plausible color versions from gray-scale photographs, they still
suffer from limited semantic understanding. To address this shortcoming, we
propose to exploit pixelated object semantics to guide image colorization. The
rationale is that human beings perceive and distinguish colors based on the
semantic categories of objects. Starting from an autoregressive model, we
generate image color distributions, from which diverse colored results are
sampled. We propose two ways to incorporate object semantics into the
colorization model: through a pixelated semantic embedding and a pixelated
semantic generator. Specifically, the proposed convolutional neural network
includes two branches. One branch learns what the object is, while the other
branch learns the object colors. The network jointly optimizes a color
embedding loss, a semantic segmentation loss and a color generation loss, in an
end-to-end fashion. Experiments on PASCAL VOC2012 and COCO-stuff reveal that
our network, when trained with semantic segmentation labels, produces more
realistic and finer results compared to the colorization state-of-the-art
Anomalous Soft Photons in Hadron Production
Anomalous soft photons in excess of what is expected from electromagnetic
bremsstrahlung have been observed in association with the production of
hadrons, mostly mesons, in high-energy (K+)p, (pi+)p, (pi-)p, pp, and (e+)(e-)
collisions. We propose a model for the simultaneous production of anomalous
soft photons and mesons in quantum field theory, in which the meson production
arises from the oscillation of color charge densities of the quarks of the
underlying vacuum in the flux tube. As a quark carries both a color charge and
an electric charge, the oscillation of the color charge densities will be
accompanied by the oscillation of electric charge densities, which will in turn
lead to the simultaneous production of soft photons during the meson production
process. How the production of these soft photons may explain the anomalous
soft photon data will be discussed. Further experimental measurements to test
the model will be proposed.Comment: 19 pages, 2 figures, to be published in Physical Review
Studies of Variability in Proto-Planetary Nebulae: II. Light and Velocity Curve Analyses of Iras 22272+5435 and 22223+4327
We have carried out a detailed observational study of the light, color, and
velocity variations of two bright, carbon-rich proto-planetary nebulae, IRAS
22223+4327 and 22272+5435. The light curves are based upon our observations
from 1994 to 2011, together with published data by Arkhipova and collaborators.
They each display four significant periods, with primary periods for IRAS
22223+4327 and 22272+5435 being 90 and 132 days, respectively. For each of
them, the ratio of secondary to primary period is 0.95, a value much different
from that found in Cepheids, but which may be characteristic of post-AGB stars.
Fewer significant periods are found in the smaller radial velocity data sets,
but they agree with those of the light curves. The color curves generally mimic
the light curves, with the objects reddest when faintest. A comparison in
seasons when there exist contemporaneous light, color, and velocity curves
reveals that the light and color curves are in phase, while the radial velocity
curves are 0.25 out of phase with the light curves. Thus they differ from what
is seen in Cepheids, in which the radial velocity curve is 0.50 P out of phase
with the light curve. Comparison of the observed periods and amplitudes with
those of post-AGB pulsation models shows poor agreement, especially for the
periods, which are much longer than predicted. These observational data,
particularly the contemporaneous light, color, and velocity curves, provide an
excellent benchmark for new pulsation models of cool stars in the post-AGB,
proto-planetary nebula phase.Comment: 15 Figures plus Erratu
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