524 research outputs found
Collaboration Development through Interactive Learning between Human and Robot
In this paper, we investigated interactive learning between human subjects and robot experimentally, and its essential characteristics are examined using the dynamical systems approach. Our research concentrated on the navigation system of a specially developed humanoid robot called Robovie and seven human subjects whose eyes were covered, making them dependent on the robot for directions. We compared the usual feed-forward neural network (FFNN) without recursive connections and the recurrent neural network (RNN). Although the performances obtained with both the RNN and the FFNN improved in the early stages of learning, as the subject changed the operation by learning on its own, all performances gradually became unstable and failed. Results of a questionnaire given to the subjects confirmed that the FFNN gives better mental impressions, especially from the aspect of operability. When the robot used a consolidation-learning algorithm using the rehearsal outputs of the RNN, the performance improved even when interactive learning continued for a long time. The questionnaire results then also confirmed that the subject's mental impressions of the RNN improved significantly. The dynamical systems analysis of RNNs support these differences and also showed that the collaboration scheme was developed dynamically along with succeeding phase transitions
Compressibility of Liquefied Sand
Laboratory measurement using CCD camera was conducted to trace the sedimentation process of sand grains in a liquefied model layer. The purpose of this measurement was basically intended to obtain a visual evidence of appearance of suspended state in upper part of the liquefied soil. For this purpose, glass bead particles were used as model ground material. The test results prevailed that the glass bead grains were suspended in pore water at the instant when complete liquefaction was brought about to the layer, then they began to settle in the water. The measured pore water kept high value until grains ceased moving. And the moving velocity was far slower than that estimated by Stokes equation for sedimentation of single particle. From these findings, a predicting method was proposed to obtain the compressibility of liquefied sand layer and the continuation time of suspended state of grains
Oceanographic Data of the 46th Japanese Antarctic Research Expedition from December 2004 to March 2005
Oceanographic Data of the 45th Japanese Antarctic Research Expedition from December 2003 to March 2004
A novel symmetry in nanocarbons: pre-constant discrete principal curvature structure
Since the first-principles calculations in quantum chemistry precisely
provide possible configurations of carbon atoms in nanocarbons, we have
analyzed the geometrical structure of the possible carbon configurations and
found that there exists a novel symmetry in the nanocarbons, i.e., the
pre-constant discrete principal curvature (pCDPC) structure. In terms of the
discrete principal curvature based on the discrete geometry for trivalent
oriented graphs developed by Kotani, Naito, and Omori (Comput. Aided Geom.
Design, , (2017), 24-54), we numerically investigated discrete
principal curvature distribution of the nanocarbons, C, carbon
nanotubes, C (C dimer), and C-polymers (peanut-shaped
fullerene polymers). While the C and nanotubes have the constant
discrete principal curvature (CDPC) as we expected, it is interesting to note
that the C-polymers and C dimer also have the almost constant
discrete principal curvature, i.e., pCDPC, which is surprising. A nontrivial
pCDPC structure with revolutionary symmetry is available due to discreteness,
though it has been overlooked in geometry. In discrete geometry, there appears
a center axisoid which is the discrete analogue of the center axis in the
continuum differential geometry but has three-dimensional structure rather than
a one-dimensional curve due to its discrete nature. We demonstrated that such
pCDPC structure exists in nature, namely in the C-polymers. Furthermore,
since we found that there is a positive correlation between the degree of the
CDPC structure and stability of the configurations for certain class of the
C-polymers, we also revealed the origin of the pCDPC structure from an
aspect of materials science.Comment: 18 page
Long-term effects of school barefoot running program on sprinting biomechanics in children: A case-control study
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