Rolling and swaying motion estimation for a mobile robot by using omnidirectional optical flows

Described here is a method for estimating rolling and swaying motions of a mobile robot using optical flow. We have proposed an image sensor with a hyperboloidal mirror for the vision-based navigation of a mobile robot. Its name is HyperOmni Vision. The radial component of optical flow in HyperOmni Vision has a periodic characteristic. The circumferential component of optical flow has a symmetric characteristic. The proposed method makes use of these characteristic to estimate robustly the rolling and swaying motion of the mobile robot. Correspondence to: Y. Yagi e-mail: y-yagi@sys.es.osaka-u.ac.jp     

Gait-based human age estimation using age group-dependent manifold learning and regression

Multimedia Tools and Applications - Human age estimation from gait is expected to be an important technology for a variety of applications such as automatic customer counting for marketing research...     

Catalytic cycle of cytochrome-c3 hydrogenase,a [NiFe]-enzyme,deduced from the structures of the enzyme and the enzyme mimic

Hydrogenases catalyze uptake and production of H₂. Heterolytic cleavage of H₂ bound on [NiFe]-hydrogenase (E) produces two unequal H species to form E:H_aH_b, where H_a and H_b behave differently. The structures of various states of the enzyme established by crystallography and spectroscopy were used to construct a catalytic cycle of the enzyme. The Ni–Fe center of the active enzyme has the Ni–Fe bridging site vacant. The enzyme is suggested to bind H₂ either at Ni or Fe atom. In E:H_aH_b, H_a is considered to be a protein-bound hydron (proton or deuteron) at the entrance to the hydrophobic gas tunnel. The structure of a synthetic hydrogenase-mimic suggests H_b to be the 6th ligand to Fe. Two successive one-electron processes from E:H_aH_b complete the catalytic cycle of H₂ uptake. The reverse of the cycle operates in the H₂ production. The proposed catalytic cycle is consistent with the kinetic, crystallographic and spectroscopic studies.     

Attentional modulation of the mere exposure effect.

The mere exposure effect refers to the phenomenon where previous exposures to stimuli increase participants’ subsequent affective preference for those stimuli. This study explored the effect of selective attention on the mere exposure effect. The experiments manipulated the to-be-attended drawings in the exposure period (either red or green polygons in Experiments 1 and 2; both red and green polygons in Experiments 3 and 4) and black to-be-evaluated drawings in the affective judgment period (morphologically identical to the red or green polygons in Experiments 1 and 4; morphologically identical to the composite drawings in Experiments 2 and 3). The results showed a significant mere exposure effect only for the target shapes involved in attentional selection, even when the participants could recognize the nontarget shapes. This indicates that selective attention modulated the mere exposure effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Calibration of multiple kinects with little overlap regions

When using multiple Kinects, there must be enough distances among neighboring Kinects to avoid spoiled range data caused by the interference of their infrared speckle patterns. In the arrangement, their overlapped regions are too small to apply existing calibration methods using correspondences between their observations straightforwardly. Therefore, we propose a method to calibrate Kinects without large overlapped regions. In our method, first, we add extra RGB cameras in an environment to compensate overlapped regions. Thanks to them, we can estimate their camera parameters by obtaining correspondences between color images. Next, for accurate calibration, which considers range data as well as color images of Kinects, we optimize the estimated parameters by minimizing both the errors of correspondences between color images and those of range data of planar regions, which exist in a general environment such as walls and floors. Although our method consists of conventional techniques, its combination is optimized to achieve the calibration. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

On-off switching properties of one-dimensional photonic crystals consisting of azo-functionalized polymer liquid crystals having different methylene spacers and polyvinyl alcohol

In this paper, photoresponsive behavior of multi-bilayered films having precisely controlled layer thickness prepared by stacking an azo-functionalized polymer liquid crystal, PMAzXAc, and polyvinyl alcohol alternatively, PVA, is described. The multi-bilayered films were found to reflect a light of specific wavelength depending on the layer thickness and refractive index, and showed the reversible change in the reflection intensity by irradiation with visible and UV lights. The change in the reflection intensity was brought about by change in the molecular orientation of PMAzXAc between an out-of-plane orientation and a photo-induced isotropic state, and was strongly dependent on the number of methylene spacer of PMAzXAc linking the azobenzene side group with the acrylate polymer main chain. PMAz6Ac with hexa-methylene spacer showed the largest change in the reflection intensity, while smaller change in the reflection intensity was observed for PMAzXAc having shorter or longer methylene spacer than 6. The effect of the methylene spacers on the photochemical change in the molecular orientation of azobenzene chromophores in the multi-bilayered films will be discussed.     

Synthesis and optical properties of azobenzene side chain polymers derived from the bifunctional fumaric acid and itaconic acid

Three type polymers containing the same azobenzene side chain group with different backbone structures, poly(DMAz6Fm), poly(DMAz6It) and poly(MAz6Ac) derived respectively from fumaric acid, itaconic acid and acrylic acid, were synthesized. The dependence of photo-response properties on the polymeric architecture was investigated for the solutions and films. By irradiation of the linearly polarized light (436 nm), uniaxial orientations of the thin films were induced and anisotropic properties were investigated by measurements of the order parameters and birefringence values.     

Investigation of continuous-wave and Q-switched microchip laser characteristics of Yb:YAG ceramics and crystals

Continuous-wave and passively Q-switched microchip laser performance of Yb:YAG ceramics and single-crystals was investigated. Highly efficient continuous-wave Yb:YAG laser performance was observed at 1030 nm and 1049 nm for both Yb:YAG ceramics and crystals with different transmissions of output couplers. The laser performance of Yb:YAG ceramic is comparable to that of Yb:YAG single crystal. Meanwhile, the laser performance of laser-diode pumped Yb:YAG/Cr⁴⁺:YAG all-ceramics- and all-crystals-combination passively Q-switched microchip lasers were investigated. Sub-nanosecond laser pulses with peak power over 150 kW were obtained with different Yb:YAG/Cr⁴⁺:YAG combinations. Linearly polarized laser was observed in Yb:YAG/Cr⁴⁺:YAG all-crystals combination and circular polarized laser was obtained in Yb:YAG/Cr⁴⁺:YAG all-ceramics combination. The best laser performance was obtained with Yb:YAG/Cr⁴⁺:YAG all-crystals combination.     

Molecular analysis of mutations induced by acrolein in human fibroblast cells using supF shuttle vector plasmids

Types of mutations induced by acrolein in the supF gene on the shuttle vector plasmid pMY189 replicated in normal human fibroblast cells were examined. Base sequence analysis of 92 plasmids with mutations in the supF gene revealed that the majority of the mutations were base substitutions (76%) and the others were deletions and insertions (24%). Single base substitutions were most frequently found (46%), while multiple base substitutions were 18% and tandem (two adjacent) base substitutions were 12% of the mutations. Of the base substitution mutations, G:C to T:A transversions were 44% and G:C to A:T transitions were 24%. The mutations were distributed not randomly but located at several hotspots. Acrolein produced DNA intra-strand cross-links between guanine residues, which might be responsible for rather high induction of the tandem base substitution mutations.