Autonomous driving control for ITS by using learning automaton network with multiple environments

In this paper, the application of the learning automaton (LA) network with multiple environments is proposed for the adaptive controller for ITS autonomous driving. The LA network, which we introduced previously, has the ability to learn which deals with both multiple reinforcement signals and information of multiple environments at the same time. This feature is found to be useful for improving the response of adaptation in dynamic environments such as highways. In order to evaluate the practical advantage of using the network, we designed a simulational highway system, constructed an autonomous travel controller using the simple LA and the LA network, and executed comparative experiments evaluating the performance of adaptation response and collision avoidance. The results show that the performance of the LA network with multiple environments is superior to that using simple LA application with regard to stability and safety. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 150(4): 36–43, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10363     

Atomistic observation and simulation analysis of spatio-temporal fluctuations during radiation-induced amorphization

We performed a dynamical-atomistic study of radiation-induced amorphization in the NiTi intermetallic compound using in situ high-resolution high-voltage electron microscopy and molecular dynamics simulations in connection with image simulation. Spatio-temporal fluctuations as non-equilibrium fluctuations in an energy-dissipative system, due to transient atom-cluster formation during amorphization, were revealed by the present spatial autocorrelation analysis.     

Two-channel self-mixing laser Doppler measurement with carrier-frequency-division multiplexing

We demonstrate real-time two-channel self-mixing laser-Doppler measurement with extreme optical sensitivity using a laser-diode-pumped thin-slice LiNdP4O12 laser. Successful carrier-frequency-division-multiplexed two-channel operations are realized by using one laser, two sets of optical frequency shifters, and a two-channel frequency-modulated-wave demodulation circuit. Simultaneous independent measurements of vibrations of speakers and averaged motions of small Brownian particles in different scattering cells are demonstrated. Self-mixing photon correlation spectroscopy of particle size distributions is also discussed.     

Effect of age on plasma bile acids and lipid components in the rat

With increasing age, total plasma bile acid contents increased in rats over a period of 11 months, and also total plasma cholesterol and carcass fat contents increased in the same manner. Plasma showing high bile acid levels at 11 months was found by means of high performance liquid chromatography to contain cholic acid as one of the major components, chenodeoxycholic acid and trace deoxycholic acid. These results suggest that there are close relationships between the plasma bile acids and age-dependent changes of lipid components in the rat.     

New design of linear discrete-time predictor using covariance information

A discrete one-stage predictor algorithm using covariance information in linear systems is derived. The algorithm is obtained for white Gaussian observation noise. The signal is a nonstationary or stationary stochastic process. The auto-covariance function of the signal is expressed using a semi-degenerate kernel of discrete-time systems. The semi-degenerate kernel can represent general covariance functions of random processes by a finite sum of nonrandom functions.     

Time-averaged aerodynamic forces acting on a hemisphere immersed in a turbulent boundary

The time-averaged pressure distribution over the surface of a hemisphere immersed in a fully developed turbulent boundary layer developing along a smooth, plane wall has been measured for a number of hemispheres of differing diameter d in order to establish the relationship between the aerodynamic force acting on such a hemisphere and the characteristics of the boundary layer. It is found that the drag coefficients defined by $\text{C}{}_{\mathrm{<mtext>D</mtext><mtext>\tau </mtext>}}\text{= D/(}\text{1}\text{2}\text{πu}{}_{\mathrm{\tau }}{}^2\text{A}$ may be expressed as a function of u_τd/ν alone in the range $\text{d/δ ? 1.0}$, where D is the pressure drag, u_τ the shear velocity, ν the kinematic viscosity, A denotes the area of the hemisphere projected onto a plane normal to the main flow direction, and δ is the boundary-layer thickness.     

Properties of hydroxyapatite prepared by the hydrolysis of tricalcium phosphate

Non-stoichiometric hydroxyapatite was prepared by the hydrolysis of α-tricalcium phosphate. The apatite was obtained as a powder and hardened with and without stirring during the hydrolysis. The apatite had a general formula, characteristic dehydration and pyrolysis behaviour similar to that of precipitated non-stoichiometric hydroxyapatite. In addition, it exhibited some new phenomena (i.e. thermal reaction between lattice H₂O and PO₄^3? above 473 K, formation of ESR centres above 473 K and disappearance at 873–973 K, and a slight weight loss at 873–973 K). Apatite particles were composed of aggregates of cylindrical rods or thin blades grown along the c-axis or {100} faces of apatite structure. Hardened apatite materials with various porosities above 55% and bulk densities below 1.4 g cm^?3 were obtained by using different water-soluble additives. The strength of the hardened materials was 20–500 kg cm^?2 in compression and 10–120 kg cm^?2 in bending. The strengths were improved at least two to three times by impregnating the hardened materials with methyl methacrylate polymer.     

Critical light scattering in4He near the gas-liquid critical point

Scattered intensities of light were measured near the gas-liquid critical point of ⁴ He at scattering angles of 30, 60, and 90° as functions of the reduced temperature =|T–T _c |/T _c along the critical isochore (T>T _c ) and the coexistence curve (T>T _c ). The temperature range was 3×10 ^–5 <<1.5×10 ^–2 . Critical exponents and coefficients describing divergence of the generalized susceptibility and the correlation length are obtained as (T>T _c )=1.31±0.02, v(T>T _c )=0.66±0.02, ₀ (T>T _c )=4.2±0.6 Å, (T>T _c )=1.32±0.02, v(T>T _c )=0.68±0.02, _± (T>T _c )=2.6±0.7 Å, =0.06±0.06(T>T _c ), 0.05±0.05(T>T _c ), and ₀(T>T _c )/x_± (T>T _c )=3.6±0.4. It is pointed out that the quantal nature of ⁴ He has remarkable influence on the critical behavior of ⁴ He in the above-mentioned temperature region.     

In situ FTIR study on reaction pathways in Ni(CO)4/CH3OK catalytic system for low-temperature methanol synthesis in a liquid medium

An in situ infrared spectroscopic study was conducted to elucidate the reaction pathways for low-temperature methanol synthesis in a catalytic system composed of Ni(CO)₄ and CH₃OK (denoted as Ni(CO)₄/CH₃OK). The reaction was conducted in a liquid medium at 313–333 K with an initial pressure of 3.0 MPa. When CH₃OK was added to Ni(CO)₄ solution at 293 K, different carbonylnickelates, [Ni₅(CO)₁₂]²⁻, [Ni₆(CO)₁₂]²⁻ and [Ni(CO)₃(COOCH₃)]⁻, were immediately formed from Ni(CO)₄. The species and the composition of the carbonylnickel complexes varied with temperature. The variations in concentrations of methanol (MeOH) and methyl formate (MF) during the run, which were determined from their IR absorptions, indicated a pattern characteristic of consecutive reactions with MF as an intermediate. Thus, it was shown that methanol was produced through the carbonylation of MeOH to MF and the subsequent hydrogenation of MF to MeOH. Stable hydridocarbonylnickel anions, [HNi(CO)₃]⁻ and/or [HNi₂(CO)₆]⁻, were observed together with a small amount of Ni(CO)₄ throughout the methanol synthesis. Since Ni(CO)₄ alone showed no activity for the hydrogenation of MF, the hydridocarbonylnickel anions generated in the presence of CH₃OK must be responsible for the reaction. The dual role of CH₃OK in the catalytic system was stated.