Deterministic convergence of conjugate gradient method for feedforward neural networks

Conjugate gradient methods have many advantages in real numerical experiments, such as fast convergence and low memory requirements. This paper considers a class of conjugate gradient learning methods for backpropagation neural networks with three layers. We propose a new learning algorithm for almost cyclic learning of neural networks based on PRP conjugate gradient method. We then establish the deterministic convergence properties for three different learning modes, i.e., batch mode, cyclic and almost cyclic learning. The two deterministic convergence properties are weak and strong convergence that indicate that the gradient of the error function goes to zero and the weight sequence goes to a fixed point, respectively. It is shown that the deterministic convergence results are based on different learning modes and dependent on different selection strategies of learning rate. Illustrative numerical examples are given to support the theoretical analysis.     

Determination of Analytical Wavelength in Derivative Spectrophotometry

Abstract

The work presents two methods for preliminary determination of analytical wavelength when a binary system is analysed by derivative spectrophotometry. “The method of disturbing effect” involves the recording of derivative spectra of a series of two-component solutions where the concentration of one component of the mixture remains unchanged, whereas the concentration of the other changes. “The method of sixteen solutions” involves the recording of derivative spectra of a series of 16 solutions, in which to four concentrations of the one component correspond four different concentrations of the other component of the mixture.     

A Chamber for Testing the Release of Volatile Substances Secreted by Animals,Especially Mammals,as Exemplified by Substances Released by Rats in Response to Stress

Abstract

The success of the testing of volatile organic compounds emitted by animals is dependent on the creation of appropriate conditions for air sampling subsequently used to assay and identify the compounds. These conditions play a particularly important role in the investigation of pheromones, which are secreted in extremely low concentrations. The authors have not come across any previous work which offers constructional solutions, which would allow avoidance of contamination of the air samples containing volatile substances secreted by animals.

A constructional solution was developed, which provides optimal conditions for their sampling and isolation. Its main advantages are as follows: the exposure chamber (the chamber in which the animal is studied) is filled with synthetic air; the exposure chamber is separated from the atmospheric air with a synthetic air “jacket”; the exposure chamber has been constructed using materials which do not release chemicals and absorb them in trace quantities.     

The Synthesis and Properties of Diazaphenanthrene Aldehydes and their Simple Analogues

The synthesis of seven diazaphenanthrene aldehydes and their oximes via oxidation of corresponding methylderivatives is given and the n.m.r. spectra of the aldehydes are discussed. The synthesis of three new methyl diazaphenanthrenes by the Skraup method is presented.     

Synthesis of Azafluorenones

Syntheses of azafluorenones from monoazaphenanthrenes and phenanthrolines has ben investigated. 1- and 4-monoazaphenanthrenes have been oxidized by J₂O₅ in acetic acid to give quinones which were converted to 4- and 1-azafluoren-9-ones in alkaline media. Phenanthrolines can be oxidized directly by means of permanganate in alkaline medium to 1,5-, 1,6-, 1,8-, 2,5- and 3,5-diazafluoren-9-ones. From 1-, 4-azaphenanthrene- and 1,8-phenanthrolinequinones new benzopyrido- and dipyridophenazines have been synthesized.     

Polythiophene nanoparticles in aqueous media

The article presents the data concerning the synthesis of polythiophene (PTh) nanoparticles in aqueous medium applying emulsion polymerization. The synthetic method was studied in variety of combinations of initiator and surfactant. It was found that application of potassium peroxydisulfate (KPS) as initiator and sodium dodecyl sulfate (SDS) as the surfactant gives the best product yields. The structure, morphology, and physicochemical properties have been analyzed showing that the resulting latex have conducting film forming properties. Resulting polymers were characterized via fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), thermogravimetry‐differential thermal analysis (TG‐DTA), differential scanning calorimetry (DSC), and electrochemical methods [e.g. current–voltage characteristics (I–V), activation energy of electric conductivity, and doping processes]. A mechanism of the polymerization reaction is also discussed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43495.     

The Effect of Fullerenol C60(OH)36 on the Antioxidant Defense System in Erythrocytes

Background: Fullerenols (water-soluble derivatives of fullerenes), such as C₆₀(OH)₃₆, are biocompatible molecules with a high ability to scavenge reactive oxygen species (ROS), but the mechanism of their antioxidant action and cooperation with endogenous redox machinery remains unrecognized. Fullerenols rapidly distribute through blood cells; therefore, we investigated the effect of C₆₀(OH)₃₆ on the antioxidant defense system in erythrocytes during their prolonged incubation. Methods: Human erythrocytes were treated with fullerenol at concentrations of 50–150 µg/mL, incubated for 3 and 48 h at 37 °C, and then hemolyzed. The level of oxidative stress was determined by examining the level of thiol groups, the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, and glutathione transferase), and by measuring erythrocyte microviscosity. Results: The level of thiol groups in stored erythrocytes decreased; however, in the presence of higher concentrations of C₆₀(OH)₃₆ (100 and 150 µg/mL), the level of -SH groups increased compared to the control. Extending the incubation to 48 h caused a decrease in antioxidant enzyme activity, but the addition of fullerenol, especially at higher concentrations (100–150 µg/mL), increased its activity. We observed that C₆₀(OH)₃₆ had no effect on the microviscosity of the interior of the erythrocytes. Conclusions: In conclusion, our results indicated that water-soluble C₆₀(OH)₃₆ has antioxidant potential and efficiently supports the enzymatic antioxidant system within the cell. These effects are probably related to the direct interaction of C₆₀(OH)₃₆ with the enzyme that causes its structural changes.     

Coupler force reduction method for multiple-unit trains using a new hierarchical control system

During traction and braking of multiple-unit trains,substantial longitudinal dynamic forces might occur in couplers due to the non-optimal distribution of tract...