Asymptotic Stability Conditions and Estimates of Solutions for Nonlinear Multiconnected Time-Delay Systems

This paper examines certain classes of multiconnected (complex) systems with time-varying delay. Delay-independent stability conditions and estimates of the convergence rate of solutions to the origin for those systems are derived. It is shown that the exponents in the obtained estimates depend on the parameters of Lyapunov functions constructed for the corresponding isolated subsystems. The problem of computing parameter values that provide the most precise estimates is investigated. Some examples are presented to demonstrate the effectiveness of the proposed approaches.     

Physicochemical principles behind the preparation of high-purity arsenic compounds from lewisite detoxification products

High-purity arsine suitable for the growth of gallium arsenide-based epitaxial heterostructures has been prepared by processing a lewisite detoxification product: hydrolytic sodium arsenite. The proposed method involves the dissolution of hydrolytic sodium arsenite in water; electrolysis of the solution, resulting in the formation of arsenic acid and sodium hydroxide, which is subsequently used to absorb released chlorine; electrochemical arsine synthesis from the arsenic acid; and arsine purification by fractionation to a level of 99.9999%.     

Using Ideas of Kolmogorov Complexity for Studying Biological Texts

Kolmogorov complexity furnishes many useful tools for studying different natural processes that can be expressed using sequences of symbols from a finite alphabet (texts), such as genetic texts, literary and music texts, animal communications, etc. Although Kolmogorov complexity is not algorithmically computable, in a certain sense it can be estimated by means of data compressors. Here we suggest a method of analysis of sequences based on ideas of Kolmogorov complexity and mathematical statistics, and apply this method to biological (ethological) ??texts.?? A distinction of the suggested method from other approaches to the analysis of sequential data by means of Kolmogorov complexity is that it belongs to the framework of mathematical statistics, more specifically, that of hypothesis testing. This makes it a promising candidate for being included in the toolbox of standard biological methods of analysis of different natural texts, from DNA sequences to animal behavioural patterns (ethological ??texts??). Two examples of analysis of ethological texts are considered in this paper. Theses examples show that the proposed method is a useful tool for distinguishing between stereotyped and flexible behaviours, which is important for behavioural and evolutionary studies.     

A general simulation procedure for the electrical characteristics of metal-insulator-semiconductor tunnel structures

The algorithm is suggested for calculating the I–V characteristics of a voltage- or current-controlled metal-tunnel-thin insulator-semiconductor system. The basic underlying physical models are discussed. Applicability of the algorithm is confirmed by a comparison of the simulation results with the measurement data obtained by the authors and borrowed from the literature, for several different structures. The presented information is supposed to suffice for calculating the electrical characteristics of the investigated structures with the various combinations of materials: metal or polysilicon gate, single-layer or stacked insulator, and semiconductor with any doping type and level.