262 research outputs found
Evaluation of the softness and its impression of visual stimuli in VR space
To examine the softness and impression of visual objects in VR (Virtual Reality) space, the impression of the visual stimuli in VR space was measured using the subjective evaluation of a seven-rank scale by changing with each the value of the deformation resistance of the stimuli, of shapes, and colors. The value of the deformation resistance of the stimuli expresses the degree of deformation to return to the original of the object when touching it in VR space. The lower value indicates the larger deformation like pudding and the higher one is the smaller one like thick rubber they were used three types of values lower and higher, and no-deformation of the objects. The shapes of objects as the stimuli were three shapes (sphere, cube, pyramid). The colors of the stimuli were selected from five colors (red, green, green, gray, and white) and they have used two types of the feeling of materials (matte and metallic) in each color. Ten participants were asked to subjectively evaluate the softness and impression of the stimulus. In the results, the evaluation changes from soft to hard by increasing the values of deformation resistance in all the stimuli in VR space. It is suggested that the degree of the deformation to return to the original can express the softness of objects when touching them in VR space even though the user does not touch them physically. It also discussed the relationship between softness and its impression of the stimuli in VR space
Lightning-Fast Dual-Layer Lossless Coding for Radiance Format High Dynamic Range Images
This paper proposes a fast dual-layer lossless coding for high dynamic range
images (HDRIs) in the Radiance format. The coding, which consists of a base
layer and a lossless enhancement layer, provides a standard dynamic range image
(SDRI) without requiring an additional algorithm at the decoder and can
losslessly decode the HDRI by adding the residual signals (residuals) between
the HDRI and SDRI to the SDRI, if desired. To suppress the dynamic range of the
residuals in the enhancement layer, the coding directly uses the mantissa and
exponent information from the Radiance format. To further reduce the residual
energy, each mantissa is modeled (estimated) as a linear function, i.e., a
simple linear regression, of the encoded-decoded SDRI in each region with the
same exponent. This is called simple linear regressive mantissa estimator.
Experimental results show that, compared with existing methods, our coding
reduces the average bitrate by approximately - % and significantly
reduces the average encoder implementation time by approximately
- %
Fermi surface with Dirac fermions in CaFeAsF determined via quantum oscillation measurements
Despite the fact that 1111-type iron arsenides hold the record transition
temperature of iron-based superconductors, their electronic structures have not
been studied much because of the lack of high-quality single crystals. In this
study, we completely determine the Fermi surface in the antiferromagnetic state
of CaFeAsF, a 1111 iron-arsenide parent compound, by performing quantum
oscillation measurements and band-structure calculations. The determined Fermi
surface consists of a symmetry-related pair of Dirac electron cylinders and a
normal hole cylinder. From analyses of quantum-oscillation phases, we
demonstrate that the electron cylinders carry a nontrivial Berry phase .
The carrier density is of the order of 10 per Fe. This unusual metallic
state with the extremely small carrier density is a consequence of the
previously discussed topological feature of the band structure which prevents
the antiferromagnetic gap from being a full gap. We also report a nearly
linear-in- magnetoresistance and an anomalous resistivity increase above
about 30 T for , the latter of which is likely related to the
quantum limit of the electron orbit. Intriguingly, the electrical resistivity
exhibits a nonmetallic temperature dependence in the paramagnetic tetragonal
phase ( 118 K), which may suggest an incoherent state. Our study provides
a detailed knowledge of the Fermi surface in the antiferromagnetic state of
1111 parent compounds and moreover opens up a new possibility to explore
Dirac-fermion physics in those compounds.Comment: 11 pages, 7 figures, 1 tabl
Phase Diagram of Pressure-Induced Superconductivity in EuFe2As2 Probed by High-Pressure Resistivity up to 3.2 GPa
We have constructed a pressuretemperature () phase diagram of
-induced superconductivity in EuFeAs single crystals, via
resistivity () measurements up to 3.2 GPa. As hydrostatic pressure is
applied, an antiferromagnetic (AF) transition attributed to the FeAs layers at
shifts to lower temperatures, and the corresponding resistive
anomaly becomes undetectable for 2.5 GPa. This suggests that the
critical pressure where becomes zero is about 2.5
GPa. We have found that the AF order of the Eu moments survives up to
3.2 GPa without significant changes in the AF ordering temperature
. The superconducting (SC) ground state with a sharp transition
to zero resistivity at 30 K, indicative of bulk
superconductivity, emerges in a pressure range from 2.5
GPa to 3.0 GPa. At pressures close to but outside the SC phase, the
curve shows a partial SC transition (i.e., zero resistivity is not
attained) followed by a reentrant-like hump at approximately
with decreasing temperature. When nonhydrostatic pressure with a uniaxial-like
strain component is applied using a solid pressure medium, the partial
superconductivity is continuously observed in a wide pressure range from 1.1
GPa to 3.2 GPa.Comment: 7 pages, 6 figures, accepted for publication in Physical Review B,
selected as "Editors' Suggestion
Design and synthesis of gene-directed caged cyclic nucleotides exhibiting cell type selectivity
We designed a new caging group that can be photoactivated only in the presence of a non-endogenous enzyme when exposed to 405 nm light. Because cells or tissues can be genetically tagged by an exogenously expressed enzyme, this novel method can serve as a strategy for adding targeting abilities to photocaged compounds
Pressure-Induced Antiferromagnetic Bulk Superconductor EuFeAs
We present the magnetic and superconducting phase diagram of EuFeAs
for and . The antiferromagnetic phase of the
Eu moments is completely enclosed in the superconducting phase. The
upper critical field vs. temperature curves exhibit strong concave curvatures,
which can be explained by the Jaccarino-Peter compensation effect due to the
antiferromagnetic exchange interaction between the Eu moments and
conduction electrons.Comment: submitted to the proceedings of the M2S-IX Toky
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