2,037 research outputs found
Excellent daytime seeing at Dome Fuji on the Antarctic plateau
Context. Dome Fuji, the second highest region on the Antarctic plateau, is
expected to have some of the best astronomical seeing on Earth. However, site
testing at Dome Fuji is still in its very early stages.
Aims. To investigate the astronomical seeing in the free atmosphere above
Dome Fuji, and to determine the height of the surface boundary layer.
Methods. A Differential Image Motion Monitor was used to measure the seeing
in the visible (472 nm) at a height of 11 m above the snow surface at Dome Fuji
during the austral summer of 2012/2013.
Results. Seeing below 0.2'' has been observed. The seeing often has a local
minimum of ~0.3'' near 18 h local time. Some periods of excellent seeing, 0.3''
or smaller, were also observed, sometimes extending for several hours at local
midnight. The median seeing is higher, at 0.52''---this large value is believed
to be caused by periods when the telescope was within the turbulent boundary
layer.
Conclusions. The diurnal variation of the daytime seeing at Dome Fuji is
similar to that reported for Dome C, and the height of the surface boundary
layer is consistent with previous simulations for Dome Fuji. The free
atmosphere seeing is ~0.2'', and the height of the surface boundary layer can
be as low as ~11 m.Comment: 4 pages, 6 figures, Submitted to Astronomy & Astrophysics (letter
Structure Transformation between Perovskite-type and B-type Rare Earth Structures
AbstractLaLnO3 (Ln = Dy, Ho, Y, Er, and Yb) and La(Ln, Ln’)O3 (Ln, Ln’ = Dy, Ho, Er, and Yb) systems were synthesized by solid state reaction method and characterized by X-ray diffraction. When Ln = Er or Yb which has smaller ionic radius than that of Y3+ (0.900Å), the LaLnO3 showed an orthorhombic perovskite structure, while when Ln = Dy or Ho which has larger ionic radius than that of Y3+, it showed a monoclinic B-type rare earth structure. Next, the solid solution system of LaHoxYb1-xO3 was investigated in order to clarify the crystallochemical factor affecting the structural transformation. The XRD experiments revealed that the samples with x = 0.90 (rav.=0.8977Å) showed the orthorhombic perovskite structure, changed to the mixed phases of monoclinic B-type rare earth, and orthorhombic perovskite structures with increasing x, and then the samples with x ≥ 0.95 (rav.=0.8994Å) showed the monoclinic B-type rare earth structures, where rav. represents the average ionic radii of Ln and Ln’
WWP1 knockout in mice exacerbates obesity-related phenotypes in white adipose tissue but improves whole-body glucose metabolism
MITSuME--Multicolor Imaging Telescopes for Survey and Monstrous Explosions
Development of MITSuME is reported. Two 50-cm optical telescopes have been
built at Akeno in Yamanashi prefecture and at Okayama Astrophysical Observatory
(OAO) in Okayama prefecture. Three CCD cameras for simultaneous g'RcIc
photometry are to be mounted on each focal plane, covering a wide FOV of about
30" x 30". The limiting magnitude at V is fainter than 18. In addition to these
two optical telescopes, a 91-cm IR telescope with a 1 deg x 1 deg field of view
is being built at OAO, which performs photometry in YJHK bands. These robotic
telescopes can start the observation of counterparts of a GRB within a minute
from an alert. We aim to obtain photometric redshifts exceeding 10 with these
telescopes. The performance and the current construction status of the
telescopes are presented.Comment: 4 pages, 3 figures, 4th Workshop on Gamma-Ray Burst in the Afterglow
Era, Roma, October 18-22, 200
Summary of the Sussex-Huawei Locomotion-Transportation Recognition Challenge 2019
In this paper we summarize the contributions of participants to the third Sussex-Huawei Locomotion-Transportation (SHL) Recognition Challenge organized at the HASCAWorkshop of UbiComp/ISWC 2020. The goal of this machine learning/data science challenge is to recognize eight locomotion and transportation activities (Still, Walk, Run, Bike, Bus, Car, Train, Subway) from the inertial sensor data of a smartphone in a user-independent manner with an unknown target phone position. The training data of a “train” user is available from smartphones placed at four body positions (Hand, Torso, Bag and Hips). The testing data originates from “test” users with a smartphone placed at one, but unknown, body position. We introduce the dataset used in the challenge and the protocol of the competition. We present a meta-analysis of the contributions from 15 submissions, their approaches, the software tools used, computational cost and the achieved results. Overall, one submission achieved F1 scores above 80%, three with F1 scores between 70% and 80%, seven between 50% and 70%, and four below 50%, with a latency of maximum of 5 seconds
Summary of the Sussex-Huawei locomotion-transportation recognition challenge 2020
In this paper we summarize the contributions of participants to the third Sussex-Huawei Locomotion-Transportation (SHL) Recognition Challenge organized at the HASCAWorkshop of UbiComp/ISWC 2020. The goal of this machine learning/data science challenge is to recognize eight locomotion and transportation activities (Still, Walk, Run, Bike, Bus, Car, Train, Subway) from the inertial sensor data of a smartphone in a user-independent manner with an unknown target phone position. The training data of a “train” user is available from smartphones placed at four body positions (Hand, Torso, Bag and Hips). The testing data originates from “test” users with a smartphone placed at one, but unknown, body position. We introduce the dataset used in the challenge and the protocol of the competition. We present a meta-analysis of the contributions from 15 submissions, their approaches, the software tools used, computational cost and the achieved results. Overall, one submission achieved F1 scores above 80%, three with F1 scores between 70% and 80%, seven between 50% and 70%, and four below 50%, with a latency of maximum of 5 seconds
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Modified Rate-Theory Predictions in Comparison to Microstructural Data
Standard rate theory methods have recently been combined with experimental microstructures to successfully reproduce measured swelling behavior in ternary steels around 400 C. Fit parameters have reasonable values except possibly for the recombination radius, R{sub c}, which can be larger than expected. Numerical simulations of void nucleation and growth reveal the importance additional recombination processes at unstable clusters. Such extra recombination may reduce the range of possible values for R{sub c}. A modified rate theory is presented here that includes the effect of these undetectably small defect clusters. The fit values for R{sub c} are not appreciably altered, as the modification has little effect on the model behavior in the late steady state. It slightly improves the predictions for early transient times, when the sink strength of stable voids and dislocations is relatively small. Standard rate theory successfully explains steady swelling behavior in high purity stainless steel
Optical Spectropolarimetry of SN 2002ap: High Velocity Asymmetric Explosion
We present spectropolarimetry of the Type Ic supernova SN 2002ap and give a
preliminary analysis: the data were taken at two epochs, close to and one month
later than the visual maximum (2002 February 8). In addition we present June 9
spectropolarimetry without analysis. The data show the development of linear
polarization. Distinct polarization profiles were seen only in the O I \lambda
7773 multiplet/Ca II IR triplet absorption trough at maximum light and in the
Ca II IR triplet absorption trough a month later, with the latter showing a
peak polarization as high as ~2 %. The intrinsic polarization shows three clear
position angles: 80 degs for the February continuum, 120 degs for the February
line feature, and 150 degs for the March data. We conclude that there are
multiple asymmetric components in the ejecta. We suggest that the supernova has
a bulk asymmetry with an axial ratio projected on the sky that is different
from 1 by of order 10 %. Furthermore, we suggest very speculatively that a high
velocity ejecta component moving faster than ~0.115c (e.g., a jet) contributes
to polarization in the February epoch.Comment: 7 pages, 3 figures, accepted for publication in the Astrophysical
Journal (Letters
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