Generation of adaptive gait patterns for quadruped robot with CPG network including motor dynamic model

This paper describes the generation of adaptive gait patterns using new Central Pattern Generators (CPGs) including motor dynamic models for a quadruped robot under various environments. The CPGs act as the flexible oscillators of the joints and adjust joint angles to required values. The CPGs are interconnected with each other and sets of their coupling parameters are adjusted by a genetic algorithm so that the quadruped robot can realize stable and adequate gait patterns. Generation of gait patterns results in the formation of the CPG networks suitable for the formation of not only a straight walking pattern but also of rotating gait patterns. Experimental results demonstrate that the proposed CPG networks are effective for the automatic adjustment of the adaptive gait patterns for the tested quadruped robot under various environments. Furthermore, the target tracking control based on image processing is achieved by combining the general gait patterns. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(1): 35–43, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20225     

Phase equilibria of quasi-binary systems consisting of multicomponent polymers 1 and 2. IV: Poly(ethylene oxide)/poly(propylene oxide) systems

To confirm the reliability of the theory of phase equibria of multicomponent polymer 1/multicomponent polymer 2 systems (i.e. quasi-binary systems) and the method of computer experiment based on this theory (Brit. Polym. J., 23 (1990)285; 23 (1990)299; Polym. Int., 29 (1992)219), could point curves (CPC), two-phase volume ratios ( R ) and critical solution points (CSP) have been determined experimentally for the quasi-binary mixtures of poly(ethylene oxide) (M¯_w = 647, M¯_w/M¯_n = 1.15; M¯_w and M¯_n, the weight-average and numberaverage molecular weights, respectively) and poly(propylene oxide) (M¯_w = 2028, M¯_w/M¯_n = 1.08; and M_w = 2987, M_w/M_n = 1.13). The hydroxyl end groups of both polymers were methoxylated in advance by the Cooper & Booth method (Polymer, 18 (1977)164). The thermodynamic interaction parameter between both polymers, χ₁₂, and the concentration dependence parameters for the above quasi-binary systems were determined by the method proposed in a previous paper (Brit. Polym. J., 23 (1990)299). CPC, R and CSP values calculated on the basis of the theory are in good agreement with the values determined experimentally.     

Stromal CCL5 Promotes Breast Cancer Progression by Interacting with CCR3 in Tumor Cells

Chemokines secreted from stromal cells have important roles for interactions with carcinoma cells and regulating tumor progression. C-C motif chemokine ligand (CCL) 5 is expressed in various types of stromal cells and associated with tumor progression, interacting with C-C chemokine receptor (CCR) 1, 3 and 5 expressed in tumor cells. However, the expression on CCL5 and its receptors have so far not been well-examined in human breast carcinoma tissues. We therefore immunolocalized CCL5, as well as CCR1, 3 and 5, in 111 human breast carcinoma tissues and correlated them with clinicopathological characteristics. Stromal CCL5 immunoreactivity was significantly correlated with the aggressive phenotype of breast carcinomas. Importantly, this tendency was observed especially in the CCR3-positive group. Furthermore, the risk of recurrence was significantly higher in the patients with breast carcinomas positive for CCL5 and CCR3 but negative for CCR1 and CCR5, as compared with other patients. In summary, the CCL5-CCR3 axis might contribute to a worse prognosis in breast cancer patients, and these findings will contribute to a better understanding of the significance of the CCL5/CCRs axis in breast carcinoma microenvironment.     

Magnesium interlayered diamond coating on silicon

Diamond thin films have been deposited using hot filament chemical vapour deposition technique on manually scratched p-Si(1 0 0) substrate, with and without magnesium interlayer. In spite of magnesium melting point being lower (T_m = 649 °C) than the growth temperature of the substrate (T_s  750 °C) used in these experiments, it was found that high quality diamond films could be grown on Mg covered substrate. A liquid substrate is probably generated during the diamond film growth. Raman spectroscopy analysis exhibited only the triply degenerate, zone centre optical phonon peak at 1333 cm⁻¹ indicating that nearly stress free crystallites were present. Broadening of the Raman peak (11.76 cm⁻¹) indicates that some small crystallites also are present. Scanning electron and atomic force microscopy accompanied by X-ray diffraction analysis where used to compare the details of diamond film growth directly on scratched Si(1 0 0) and Mg interlayered scratched Si(1 0 0) substrates.     

Measurement of self-diffusion coefficients in Li ionic conductors by using the short-lived radiotracer of 8Li

For the effective use of short-lived radioactive beams, soon to be available at the Tokai Radioactive Ion Accelerator Complex, the authors have developed a radiotracer method for diffusion studies in solids. The experimental test was performed by the measurement of the diffusion coefficients of Li in a sample of the compound βLiAl using an α-emitting radiotracer of ⁸Li (T_1/2=0.84 s). It was found that the time-dependent yields of the α particles from the diffusing ⁸Li that was initially implanted in the sample could be used as a measure of the diffusivity of the tracer in a nondestructive way. The method was applied to measure the self-diffusion coefficients of Li in βLiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects (i.e., the existence of the atomic vacancies of Li and the defects in Ga sites that are replaced by Li).     

A multi-spectral non-local method for retrieval of boundary layer cloud properties from optical remote sensing data

A multi-spectral non-local (MSN) method is developed for advanced retrieval of boundary layer cloud properties from remote sensing data, as an alternative to the independent pixel approximation (IPA) method. The non-local method uses data at both the target pixel and neighboring pixels to retrieve cloud properties such as pixel-averaged cloud optical thickness and effective droplet radius. Radiance data to be observed from space were simulated by a three-dimensional (3D) radiation model and a stochastic boundary layer cloud model with two-dimensional (horizontal and vertical) variability in cloud liquid water and effective radius. An adiabatic assumption is used for each cloud column to model the geometrical thickness and vertical profiles of cloud liquid water content and effective droplet radius, neglecting drizzle and cloud brokenness for simplicity. The dependence of radiative smoothing and roughening on horizontal scale, optical thickness and single scattering albedo are investigated. Then, retrieval methods using 250-m horizontal resolution data onboard new generation satellites are discussed. The regression model for the MSN method was trained based on datasets from numerical simulations. The training was performed with respect to various domain averages of optical thickness and effective radius, because smoothing and roughening effects are strongly dependent on the two variables. Retrieval accuracy is discussed here with datasets independent of those used in the training, towards assessing the generality of the technique. It is demonstrated that retrieval accuracy of cloud optical thickness, which is often retrieved from single-spectral visible-wavelength data, is improved the most using neighboring pixel data and secondly using multi-spectral data, and ideally with both. When the IPA retrieval method is applied to optical thickness and effective radius, the root-mean-square relative errors can be 15-90%, depending on solar and view directions. In contrast, the MSN method has errors of 4-10%, which is smaller than IPA by a factor of 2-10. It is also suggested that the accuracy of the MSN method is insensitive to some assumptions in the inhomogeneous cloud input data used to train the regression model.     

关于太阳放射特性与地球能源的调查与研究

叙述了太阳对地球的放射及能源热收支等关系,同时还对世界各国在化石燃料的开发、配置、使用、价格等关系及人类 在现代建筑中对太阳放射的利用等方面作了一些调查,阐述了它们之间的一些关系。论述了人类在开发太阳能技术方面的重要 性和必要性。     

Destruction of percolative network using green synthesized gold nanoparticles: Formation of high dielectric material

Gold nanoparticles (AuNPs) of about 5 nm in diameter were biosynthesized at room temperature (300 K). The PVA/2.5 wt% KH₂PO₄ or KDP composite film and PVA/2.5 wt% KDP/AuNPs nanocomposite films with different concentrations of AuNPs were prepared. Interestingly, addition of 0.05 wt% of AuNPs to the PVA/2.5 wt% KDP percolative composite film destroys percolative behavior of this composite film. Furthermore, the PVA/2.5 wt% KDP/0.05 wt% AuNPs nanocomposite film exhibited high room temperature dielectric permittivity (ε′ ∼ 590 at 1 kHz). The behavior of AC conductivity (σ_ac) of the nanocomposite films indicated correlated barrier hopping type of conduction mechanism. The Cole–Davidson dielectric response becomes evident as the interfacial polarization process acquires a more symmetric form, tending to Debye relaxation. High value of ε′ promises direct application in capacitors. Moreover, the novel feature of destroying the percolative behavior by AuNPs may be applied even in other systems.     

The relationship between electropermeabilization and cell cycle and cell size of Saccharomyces cerevisiae

Yeast cells (Sacchromyces cerevisiae) in 0.9% NaCl solution containing phloxine B (dye) were treated by an application of a rectangular electric pulse. We input microscopic images of the yeast suspensions after the application into a computer, and measured whether each cell dyes or not, the phase in the cell cycle, and each cell size, using the software we had developed. After those measurements, we discussed the relationship between the yield of electropermeabilization (the ratio of dyed cells to the total cell number) and the phase in the cell cycle, and cell size. From the results, it was found that the yeast cells from S-phase to M-phase (S-M phase) in the cell cycle tend to be more permeated than G1-phase yeast cells, and in both phases the yield decreases with the increase in cell size.