3,405 research outputs found
The silicate model and carbon rich model of CoRoT-7b, Kepler-9d and Kepler-10b
Possible bulk compositions of the super-Earth exoplanets, CoRoT-7b,
Kepler-9d, and Kepler-10b are investigated by applying a commonly used silicate
and a non-standard carbon model. Their internal structures are deduced using
the suitable equation of state of the materials. The degeneracy problems of
their compositions can be partly overcome, based on the fact that all three
planets are extremely close to their host stars. By analyzing the numerical
results, we conclude: 1) The iron core of CoRoT-7b is not more than 27% of its
total mass within 1 mass-radius error bars, so an Earth-like
composition is less likely, but its carbon rich model can be compatible with an
Earth-like core/mantle mass fraction; 2) Kepler-10b is more likely with a
Mercury-like composition, its old age implies that its high iron content may be
a result of strong solar wind or giant impact; 3) the transiting-only
super-Earth Kepler-9d is also discussed. Combining its possible composition
with the formation theory, we can place some constraints on its mass and bulk
composition.Comment: 20 pages, 8figures, accepted for publication in RAA. arXiv admin
note: text overlap with arXiv:0707.289
Sexual Dimorphism, Female Reproductive Characteristics and Egg Incubation in an Oviparous Forest Skink (Sphenomorphus incognitus) from South China
We studied sexual dimorphism and female reproduction in an oviparous forest skink (Sphenomorphus incognitus) from South China. We incubated eggs under five thermal regimes (22, 25, 28, 25 ± 3 and 27 ± 5 °C) to examine the effects of constant versus fluctuating temperatures on incubation length and hatchling morphology. In our sample the largest male and female were 110 mm and 108 mm snout-vent length (SVL), respectively. Adult males and females did not differ in mean SVL; adult males were larger in head size (both length and width), longer in fore- and hind-limb lengths and shorter in abdomen length than females of the same SVL. Accordingly, we conclude that S. incognitus is a sexually monomorphic species in terms of SVL but shows sexual dimorphism in head size, abdomen length and appendage length. Females laid a single clutch of 3−10 eggs per breeding season from early May to mid-August, with larger females generally laying more (but not always larger) eggs per clutch than did smaller ones. Embryonic stages at laying ranged from Dufaure and Hubert’s (1961) stage 31 to 32, with a mean stage of 31.3. The positive relationship between clutch mass and female SVL was not significant. The offspring size-number trade-off does not exist in S. incognitus, as revealed by the fact that egg mass was independent of relative fecundity. Incubation length decreased as temperature increased, and stable temperatures resulted in delayed hatching. Hatchlings incubated under the five thermal regimes did not differ from each other in any examined trait, suggesting that S. incognitus is among oviparous reptilian species where incubation temperature has no role in modifying hatchling morphology as long as eggs are not exposed to extreme temperatures for prolonged periods of time
Neural Global Shutter: Learn to Restore Video from a Rolling Shutter Camera with Global Reset Feature
Most computer vision systems assume distortion-free images as inputs. The
widely used rolling-shutter (RS) image sensors, however, suffer from geometric
distortion when the camera and object undergo motion during capture. Extensive
researches have been conducted on correcting RS distortions. However, most of
the existing work relies heavily on the prior assumptions of scenes or motions.
Besides, the motion estimation steps are either oversimplified or
computationally inefficient due to the heavy flow warping, limiting their
applicability. In this paper, we investigate using rolling shutter with a
global reset feature (RSGR) to restore clean global shutter (GS) videos. This
feature enables us to turn the rectification problem into a deblur-like one,
getting rid of inaccurate and costly explicit motion estimation. First, we
build an optic system that captures paired RSGR/GS videos. Second, we develop a
novel algorithm incorporating spatial and temporal designs to correct the
spatial-varying RSGR distortion. Third, we demonstrate that existing
image-to-image translation algorithms can recover clean GS videos from
distorted RSGR inputs, yet our algorithm achieves the best performance with the
specific designs. Our rendered results are not only visually appealing but also
beneficial to downstream tasks. Compared to the state-of-the-art RS solution,
our RSGR solution is superior in both effectiveness and efficiency. Considering
it is easy to realize without changing the hardware, we believe our RSGR
solution can potentially replace the RS solution in taking distortion-free
videos with low noise and low budget.Comment: CVPR2022, https://github.com/lightChaserX/neural-global-shutte
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