1,668 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’
Summary of the Sussex-Huawei Locomotion-Transportation Recognition Challenge
In this paper we summarize the contributions of participants to the Sussex-Huawei Transportation-Locomotion (SHL) Recognition Challenge organized at the HASCA Workshop of UbiComp 2018. The SHL challenge is a machine learning and data science competition, which aims to recognize eight transportation activities (Still, Walk, Run, Bike, Bus, Car, Train, Subway) from the inertial and pressure sensor data of a smartphone. We introduce the dataset used in the challenge and the protocol for the competition. We present a meta-analysis of the contributions from 19 submissions, their approaches, the software tools used, computational cost and the achieved results. Overall, two entries achieved F1 scores above 90%, eight with F1 scores between 80% and 90%, and nine between 50% and 80%
文學的對比の諸問題
比喩-比喩の意味と文中での位置-優れた比喩。對比と諷刺-優れた文學は諷刺的である-暴露文學と諷刺-イギリス的諷喩文學-それは必ずしも時代の産物ではない。諷刺とイギリス的性格-イギリス的現實主義-オーウェルの諷刺文學
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