12,057 research outputs found
Dissociating stimulus-stimulus and response-response effects in the Stroop task
The separate semantic and response competition interactions between colour and word processing in a manual Stroop task were evaluated by comparing three trial types. Identity trials are both semantically compatible and response compatible (e.g., BLUE in the colour blue), different response trials are both semantically incompatible and response incompatible (e.g., BLUE in the colour green, where blue and green have different response keys), and same response trials are semantically incompatible and response compatible (e.g., the word BLUE in the colour red, where blue and red have the same key press response). ink colours were embedded in two different word types, colour words, and colour associates. The results using colour words replicated the findings of De Houwer (2003) and demonstrated both a semantic effect (a difference between same response trials and identity trials) and response competition (a difference between same response trials and different response trials). in contrast, the results using colour associates provided evidence for only a semantic effect. These findings support interpretations of the colour associate Stroop effect that attribute the effect to semantics, but challenge Klein's (1964) response competition account and Sharma and McKenna's (1998) claim that the effect of colour associates is dependent on verbal responding. The results confirm that the Stroop colour-word task appears to involve at least two mechanisms, a semantic mechanism and a response competition mechanism
Play and Learn: Using Video Games to Train Computer Vision Models
Video games are a compelling source of annotated data as they can readily
provide fine-grained groundtruth for diverse tasks. However, it is not clear
whether the synthetically generated data has enough resemblance to the
real-world images to improve the performance of computer vision models in
practice. We present experiments assessing the effectiveness on real-world data
of systems trained on synthetic RGB images that are extracted from a video
game. We collected over 60000 synthetic samples from a modern video game with
similar conditions to the real-world CamVid and Cityscapes datasets. We provide
several experiments to demonstrate that the synthetically generated RGB images
can be used to improve the performance of deep neural networks on both image
segmentation and depth estimation. These results show that a convolutional
network trained on synthetic data achieves a similar test error to a network
that is trained on real-world data for dense image classification. Furthermore,
the synthetically generated RGB images can provide similar or better results
compared to the real-world datasets if a simple domain adaptation technique is
applied. Our results suggest that collaboration with game developers for an
accessible interface to gather data is potentially a fruitful direction for
future work in computer vision.Comment: To appear in the British Machine Vision Conference (BMVC), September
2016. -v2: fixed a typo in the reference
Gradient Photonic Materials Based on OneâDimensional Polymer Photonic Crystals
In nature, animals such as chameleons are wellâknown for the complex color patterns of their skin and the ability to adapt and change the color by manipulating sophisticated photonic crystal systems. Artificial gradient photonic materials are inspired by these color patterns. A concept for the preparation of such materials and their function as tunable mechanochromic materials is presented in this work. The system consists of a 1D polymer photonic crystal on a centimeter scale on top of an elastic poly(dimethylsiloxane) substrate with a gradient in stiffness. In the unstrained state, this system reveals a uniform red reflectance over the entire sample. Upon deformation, a gradient in local strain of the substrate is formed and transferred to the photonic crystal. Depending on the magnitude of this local strain, the thickness of the photonic crystal decreases continuously, resulting in a positionâdependent blue shift of the reflectance peak and hence the color in a rainbowâlike fashion. Using more sophisticated hardâsoftâhardâsoftâhard gradient elastomers enables the realization of stripeâlike reflectance patterns. Thus, this approach allows for the tunable formation of reflectance gradients and complex reflectance patterns. Envisioned applications are in the field of mechanochromic sensors, telemedicine, smart materials, and metamaterials
Flares in Open Clusters with K2. I. M45 (Pleiades), M44 (Praesepe) and M67
The presence and strength of a stellar magnetic field and activity is rooted
in a star's fundamental parameters such as mass and age. Can flares serve as an
accurate stellar "clock"?
To explore if we can quantify an activity-age relation in the form of a
flaring-age relation, we measured trends in the flaring rates and energies for
stars with different masses and ages.
We investigated the time-domain photometry provided by Kepler's follow-up
mission K2 and searched for flares in three solar metallicity open clusters
with well-known ages, M45 (0.125 Gyr), M44 (0.63 Gyr), and M67 (4.3 Gyr). We
updated and employed the automated flare finding and analysis pipeline
Appaloosa, originally designed for Kepler. We introduced a synthetic flare
injection and recovery subroutine to ascribe detection and energy recovery
rates for flares in a broad energy range for each light curve. We collected a
sample of 1 761 stars, mostly late-K to mid-M dwarfs and found 751 flare
candidates with energies ranging from erg to
erg, of which 596 belong to M45, 155 to M44, and none to M67.
We find that flaring activity depends both on , and age. But
all flare frequency distributions have similar slopes with , supporting a universal flare generation process. We discuss
implications for the physical conditions under which flares occur, and how the
sample's metallicity and multiplicity affect our results.Comment: 17 pages, 11 figures, appendix. Accepted to A&
Type Ia supernova diversity: Standardizing the candles
Future use of type Ia supernovae for cosmology aims not only to determine the
equation of state of dark energy, but also to constrain possible variations in
its value. To achieve this goal, supernovae need to become better calibrated
standard candles - not only to improve the precision of the measurement, but
more importantly to gain better control over systematic uncertainties in order
to ensure the accuracy of the result.
Here we report on a project to quantify the diversity in type Ia supernovae,
and to look for trends and/or sub-types that can be used to improve their
calibration as standard candles. We implement a version of principal component
analysis on type Ia supernova spectra. Although the quantity of data is not
sufficient to draw any firm conclusions we show that this method holds promise
for, at the very least, effectively separating peculiar supernovae. Whether it
can be further used to improve the calibration of normal type Ia's remains a
project for future study.Comment: Conference Proceedings. Cefalu 2006, The multicoloured landscape of
compact objects and their explosive origins. Six pages, three figure
Supersonic through-flow fan design
The NASA Lewis Research Center has embarked on a program to experimentally prove the concept of a supersonic through-flow fan which is to maintain supersonic velocities throughout the compression system with only weak shock-wave flow losses. The detailed design of a supersonic through-flow fan and estimated off-design performance with the use of advanced computational codes are described. A multistage compressor facility is being modified for the newly designed supersonic through-flow fan and the major aspects of this modification are briefly described
Cosmic Shear Results from the Deep Lens Survey - II: Full Cosmological Parameter Constraints from Tomography
We present a tomographic cosmic shear study from the Deep Lens Survey (DLS),
which, providing a limiting magnitude r_{lim}~27 (5 sigma), is designed as a
pre-cursor Large Synoptic Survey Telescope (LSST) survey with an emphasis on
depth. Using five tomographic redshift bins, we study their auto- and
cross-correlations to constrain cosmological parameters. We use a
luminosity-dependent nonlinear model to account for the astrophysical
systematics originating from intrinsic alignments of galaxy shapes. We find
that the cosmological leverage of the DLS is among the highest among existing
>10 sq. deg cosmic shear surveys. Combining the DLS tomography with the 9-year
results of the Wilkinson Microwave Anisotropy Probe (WMAP9) gives
Omega_m=0.293_{-0.014}^{+0.012}, sigma_8=0.833_{-0.018}^{+0.011},
H_0=68.6_{-1.2}^{+1.4} km/s/Mpc, and Omega_b=0.0475+-0.0012 for LCDM, reducing
the uncertainties of the WMAP9-only constraints by ~50%. When we do not assume
flatness for LCDM, we obtain the curvature constraint
Omega_k=-0.010_{-0.015}^{+0.013} from the DLS+WMAP9 combination, which however
is not well constrained when WMAP9 is used alone. The dark energy equation of
state parameter w is tightly constrained when Baryonic Acoustic Oscillation
(BAO) data are added, yielding w=-1.02_{-0.09}^{+0.10} with the DLS+WMAP9+BAO
joint probe. The addition of supernova constraints further tightens the
parameter to w=-1.03+-0.03. Our joint constraints are fully consistent with the
final Planck results and also the predictions of a LCDM universe.Comment: Accepted for publication in Ap
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