Hebbian learning rule restraining catastrophic forgetting in pulse neural network

In this paper, a Hebbian learning rule restraining “catastrophic forgetting” is proposed on a pulsed neural network (PNN) with leaky integrate‐and‐fire neurons. The strong point of this learning rule is that a learning of new pattern does not destroy past ones, and that an efficient use of synapses is enabled. First, in order to consider the function of the learning rule, a fundamental experiment is carried out. Next, to compare the performance between the proposed learning rule and conventional ones on the application, simulation experiments are examined using autonomous behavior robots which are forced to learn concurrently two different environments. The results of the experiments show that the proposed learning rule clearly restrains “catastrophic forgetting” and enables working of more efficient than conventional PNN learning. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(3): 50–60, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10343     

Dissolution of coal with NaOH-alcohol: Effect of alcohol species

Methanol, ethanol, straight-chain propanol, isopropanol, straight-chain butanol, sec-butanol, tert-butanol, straight-chain pentanol, and iso-pentanol were used for the reaction of coal with NaOH-alcohol at 290 °C for 1 h. All the products dissolved in pyridine with an extraction yield > 80 wt%. Straight-chain alcohols are less reactive than the secondary alcohols owing to the differences in hydrogen donating ability.     

Mechanism of the Photofading of Stilbene–fluorescent Dyes. Contribution of Singlet Oxygen to the Photofading of 4, 4‘–Bisacetamidostilbene

Self—sensitized and Rose Bengal—sensitized photo—oxidation of 4, 4′-bisacetamidostilbene (BAAS) in solution gives p—acetamidobenzaldehyde and p—acetamidobenzoic acid via the reaction of singlet oxygen with the trans isomer (la). The rate of the photo—oxidation is retarded in the presence of effective singlet oxygen quenchers. On the other hand, cls—BAAS (lb) is more stable to visible light under the conditions of Rose Bengal—sensitized photo—oxidation than trans—stilbene.     

Significance of deformation rate softening of memory in viscoelastic fluid mechanics and polymer processing

It is pointed out that in viscoelastic fluid constitutive equations, non-linear response to deformation rate and strain beyond the second order is usually interpreted in terms of the deformation rate or strain dependence of the memory function. These non-linearities act to decrease the extent of the memory. The dependence may be characterized by one or more dimensionless material parameters. A new dimensionless group based on the primary material parameters describing the intensity of the deformation rate dependence of the memory function is introduced and its significance is discussed. This is called the Yamamoto number. The solutions of viscoelastic fluid mechanics problems are considered to depend upon both the Weissenberg and Yamamoto numbers. Such problems include topics of interest in polymer melt processing such as uniaxial elouigatioiial flow, fiber spinning and vortex development in extrusion through a die entry.     

Extraction mechanism of copper by versatic 10

The extraction mechanism of copper from an aqueous ammonia-ammonium nitrate mixture by an n-hexane solution of Versatic 10 was studied from the standpoints of the equilibrium distribution of copper between aqueous and organic phases, the aqueous solubility and interfacial adsorption equilibrium of Versatic 10 and the extraction rate of copper.The equilibrium relations of the distribution of copper and the aqueous solubility and the interfacial adsorption of Versatic 10 were interpreted quantitatively and these equilibrium constants were evaluated.The extraction rate of copper was found to be proportional to the copper concentration in the aqueous phase, inversely proportional to the hydrogen ion concentration and independent of the Versatic 10 concentration in the organic phase. From the experimental results of the extraction rate and the interfacial adsorption equilibrium, it was inferred that the extraction rate was controlled by the elementary reaction between the copper ion in the aqueous phase and the anionic species of Versatic 10 adsorbed at the interface.