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Abstract The behavior of a probabilistic automaton is essentially characterized by products of matrices selected from a given finite set of stochastic matrices. It is of interest to know under what conditions these matrix products are stable against perturbations of the entries in the matrices. 相似文献
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Jingyu Xiang Yuichi Tazaki Shinkichi Inagaki Tatsuya Suzuki 《Electrical Engineering in Japan》2014,186(4):59-69
This paper presents a method that allows simultaneous map building and path planning for mobile robots in unknown environments. A graphical representation of a workspace in variable resolutions is constructed using measurement data obtained by omnidirectional distance sensors. At the same time, a search for a feasible path to the target destination is executed using the constructed graph map. The proposed method is evaluated by performing simulations and experiments using an omnidirectional mobile robot equipped with laser range finders. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 59–69, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22493 相似文献
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Zirconia sphere particles were synthesized through the gelation process of Na-alginate, and cermet (ZrO2-Mo) pellets were fabricated under several conditions. In this process, a zirconia slurry was prepared by mixing oxide powders (ZrO2, Y2O3, Er2O3, CeO2), distilled water and Na-alginate, and subsequently dropped into CaCl2 solution. As a result, zirconia sphere particles coated with a gelled film were synthesized. The slurry density (zirconia content in slurry) of 30-64 wt.% and Na-alginate concentration of a few% were good for gelation for up to 10 wt.% CaCl2 solution. Sphere particles with smaller diameter were obtained by dropping slurry with a mechanical vibration. The prolongation of the ball milling time for mixture of oxide powders was effective to increase the sintered density of zirconia sphere particles, especially for higher CeO2 concentration. The dense cermet pellets were fabricated for max. 50% volume ratio of zirconia phase for Mo matrix using zirconia particles covered with Mo powder by a rotating granulation method. 相似文献
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Recently,small hydroelectric generators have gained attention as a further development in water turbine technology for ultra low head drops in open channels.The authors have evaluated the application of cross-flow water turbines in open channels as an undershot type after removing the casings and guide vanes to substantially simplify these water turbines.However,because undershot cross-flow water turbines are designed on the basis of cross-flow water turbine runners used in typical pipelines,it remains unclear whether the number of blades has an effect on the performance or flow fields.Thus,in this research,experiments and numerical analyses are employed to study the performance and flow fields of undershot cross-flow water turbines with varying number of blades.The findings show that the turbine output and torque are lower,the fluctuation is significantly higher,and the turbine efficiency is higher for runners with 8 blades as opposed to those with 24 blades. 相似文献
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Koshi Takenaka Masayoshi Ichigo Taisuke Hamada Atsushi Ozawa Takashi Shibayama Tetsuya Inagaki 《Science and Technology of Advanced Materials》2014,15(1)
Magnetostructural correlations in antiperovskite manganese nitrides were investigated systematically for stoichiometric and solid solution Mn3Cu1?xAxN (A = Co, Ni, Zn, Ga, Ge, Rh, Pd, Ag, In, Sn or Sb). This class of nitrides is attracting great attention because of their giant negative thermal expansion, which is achieved by doping Ge or Sn into the A site as a relaxant of the sharp volume contraction on heating (spontaneous volume magnetostriction ωs) because of the magnetovolume effects. The physical background of large ωs and mechanism of how the volume contraction becomes gradual with temperature are central concerns for the physics and applications of these nitrides. An entire dataset of thermal expansion, crystal structure and magnetization demonstrates that the cubic triangular antiferromagnetic state is crucial for large ωs. The intimate relationship between ωs and the magnetic structure is discussed in terms of geometrical frustration related to the Mn6N octahedron and magnetic stress concept. The results presented herein also show that ωs depends on the number of d electrons in the A atom, suggesting the important role of the d orbitals of the A atom. Not all the dopants in the A site, but the elements that disturb the cubic triangular antiferromagnetic state, are effective in broadening the volume change. This fact suggests that instability neighboring the phase boundary is related to the broadening. The relation between the gradual volume change and the local structure anomaly is suggested by recent microprobe studies. 相似文献
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Tetsuya OGAWA Hideki ISHIDA Nami MATSUDA Ayuko FUJIU Akiko MATSUDA Kyoko ITO Yoshitaka ANDO Kosaku NITTA 《Hemodialysis international. International Symposium on Home Hemodialysis》2009,13(3):301-306
Vascular calcification is associated with a poor prognosis in dialysis patients. It can be assessed with computed tomography but simple inoffice techniques may provide useful information. We compared the results obtained with a simple noninvasive technique with those obtained using multidetector computed tomography for aortic arch calcification volume (AoACV) in chronic hemodialysis (HD) patients. The enrolled study subjects were 63 (32 men and 31 women) maintenance HD patients. Calcification of the aortic arch was semiquantitatively estimated with a AoAC score (AoACS) on plain chest radiology. The AoACV was increased, with a mean value of 6.6 ranging from 0% to 36.5%. The coefficient of intraobserver variation was less than 2.5%. Aortic arch calcification score was highly correlated with AoACV (r=0.635, P<0.001). Multiple regression analysis showed age (F value=12.62, P<0.001) and pulse pressure (F value=4.54, P=0.037) to be significant independent determinants of AoACS. In conclusion, a simple measurement of AoACS may be useful for inoffice imaging to choose a therapeutic regimen in HD patients. 相似文献
9.
Noritsugu Hashimoto Seiji Niijima Jun-ichi Inagaki 《Journal of the European Ceramic Society》2009,29(14):3039-3043
Solid oxide fuel cells (SOFCs) are very attractive for their high energy conversion efficiency and low emissions. Generally, a supported layer of SOFCs is fabricated by tape casting, using an organic solvent. Recently, a slurry based on water instead of an organic solvent has been sought in order to avoid environmental pollution. In this study, the anode of SOFCs was fabricated by aqueous tape casting, and the electrolyte and the cathode were deposited by screen printing. The I–V characteristics of the cell thus obtained were evaluated. As a result, an 80 mm diameter-sized cell with a power density of 0.33 W/cm2 at 800 °C was successfully fabricated by controlling sintering conditions. 相似文献
10.
Zhi-xue Tian Akifumi Uozumi Ikutaro Hamada Susumu Yanagisawa Hidetoshi Kizaki Kouji Inagaki Yoshitada Morikawa 《Nanoscale research letters》2013,8(1):203
First-principles calculations were performed to investigate the effect of Pd concentration and oxygen vacancies on the stability of Pd at LaFeO3 surfaces. We found a much stronger tendency of Pd to segregate by taking the aggregation of Pd at LaFe1-xPdxO3-y surfaces into consideration, resulting in a pair of Pd-Pd around a vacancy. Moreover, we predicted that one oxygen-vacancy-containing FeO2-terminated surfaces would be stable at high temperatures by comparing the stability of LaFe1-xPdxO3-y surfaces, which further supports our previous conclusion that a Pd-containing perovskite catalyst should be calcined at 1,073 K or higher temperatures in air to enhance the segregation of Pd in the vicinity of surfaces to rapidly transform the Pd catalyst from oxidized to reduced states on the perovskite support. 相似文献