202 research outputs found
Preliminary Test of Affective Virtual Reality Scenes with Head Mount Display for Emotion Elicitation Experiment
Emotion elicitation experiments are conducted to collect biological signals from a subject who is in a stateăof emotion. The recorded signals are used as training/test dataset for constructing an emotion recognition system byămeans of machine learning. In conventional emotion elicitation experiments, affective images or videos were providedăfor a subject to draw out an emotion from them. However, the authors have concerns about the effectiveness. To surelyăevoke a specific emotion from subjects, we have produced several Virtual Reality (VR) scenes and provided theăsubjects with the scenes through a Head Mount Display (HMD) in emotion elicitation experiments. Usability andăeffectiveness of the VR scenes with the HMD for emotion elicitation were experimentally verified. It was confirmedăthat experience of the VR scenes with the HMD was effective in evoking emotions, but we have to improve howăsubjects learn a way of playing VR scenes and provide measures against VR sickness at any cost. Moreover, SupportăVector Machine classifiers as an emotion recognition system were constructed using the biological signals measuredăfrom the subjects in the emotion elicitation experiments.2017 17th International Conference on Control, Automation and Systems (ICCAS 2017), Oct. 18-21, 2017, Ramada Plaza, Jeju, Kore
Enrichment of r-process elements in dwarf spheroidal galaxies in chemo-dynamical evolution model
The rapid neutron-capture process (r-process) is a major process to
synthesize elements heavier than iron, but the astrophysical site(s) of
r-process is not identified yet. Neutron star mergers (NSMs) are suggested to
be a major r-process site from nucleosynthesis studies. Previous chemical
evolution studies however require unlikely short merger time of NSMs to
reproduce the observed large star-to-star scatters in the abundance ratios of
r-process elements relative to iron, [Eu/Fe], of extremely metal-poor stars in
the Milky Way (MW) halo. This problem can be solved by considering chemical
evolution in dwarf spheroidal galaxies (dSphs) which would be building blocks
of the MW and have lower star formation efficiencies than the MW halo. We
demonstrate that enrichment of r-process elements in dSphs by NSMs using an
N-body/smoothed particle hydrodynamics code. Our high-resolution model
reproduces the observed [Eu/Fe] by NSMs with a merger time of 100 Myr when the
effect of metal mixing is taken into account. This is because metallicity is
not correlated with time up to ~ 300 Myr from the start of the simulation due
to low star formation efficiency in dSphs. We also confirm that this model is
consistent with observed properties of dSphs such as radial profiles and
metallicity distribution. The merger time and the Galactic rate of NSMs are
suggested to be <~ 300 Myr and ~ yr, which are consistent with
the values suggested by population synthesis and nucleosynthesis studies. This
study supports that NSMs are the major astrophysical site of r-process.Comment: 16 pages, 16 figures, accepted for publication in Ap
Dark matter sterile neutrinos in stellar collapse: alteration of energy/lepton number transport and a mechanism for supernova explosion enhancement
We investigate matter-enhanced Mikheyev-Smirnov-Wolfenstein (MSW)
active-sterile neutrino conversion in the
channel in the collapse of the iron core of a pre-supernova star. For values of
sterile neutrino rest mass and vacuum mixing angle
(specifically, ) which include those required for viable sterile neutrino
dark matter, our one-zone in-fall phase collapse calculations show a
significant reduction in core lepton fraction. This would result in a smaller
homologous core and therefore a smaller initial shock energy, disfavoring
successful shock re-heating and the prospects for an explosion. However, these
calculations also suggest that the MSW resonance energy can exhibit a minimum
located between the center and surface of the core. In turn, this suggests a
post-core-bounce mechanism to enhance neutrino transport and neutrino
luminosities at the core surface and thereby augment shock re-heating: (1)
scattering-induced or coherent MSW conversion occurs deep in
the core, at the first MSW resonance, where energies are large ( MeV); (2) the high energy stream outward at near light speed; (3)
they deposit their energy when they encounter the second MSW resonance
just below the proto-neutron star surface.Comment: 13 pages, 9 figure
Sterile Neutrino-Enhanced Supernova Explosions
We investigate the enhancement of lepton number, energy, and entropy
transport resulting from active-sterile neutrino conversion
deep in the post-bounce supernova core followed by re-conversion
further out, near the neutrino sphere. We explicitly take
account of shock wave and neutrino heating modification of the active neutrino
forward scattering potential which governs sterile neutrino production. We find
that the luminosity at the neutrino sphere could be increased by
between and during the crucial shock re-heating epoch
if the sterile neutrino has a rest mass and vacuum mixing parameters in ranges
which include those required for viable sterile neutrino dark matter. We also
find sterile neutrino transport-enhanced entropy deposition ahead of the shock.
This `` pre-heating\rq\rq can help melt heavy nuclei and thereby reduce the
nuclear photo-dissociation burden on the shock. Both neutrino luminosity
enhancement and pre-heating could increase the likelihood of a successful core
collapse supernova explosion.Comment: 12 pages, 4 figure
A connectionist account of ontological boundary shifting
Abstract. Previous research on children's categorizations has suggested that children use perceptual and conceptual knowledge to generalize object names. Especially, the relation between ontological categories and linguistic categories appears to be a critical cue to learning object categories. However, its underlying mechanism remains unclear. In this paper, we propose a connectionist model that can acquire ontological knowledge by learning linguistic categories of entities. The results suggest that linguistic cues help children attend to specific perceptual properties
- âŚ