Phonetic analysis of speech and memory codes in beginning readers

Two experimental tasks, a speech segmentation and a short-term memory task, were presented to children who began to learn to read following either the "phonic" or the "wholeword" method. The segmentation task required the child to reverse two segments (either two phones or two syllables) in an utterance. The phonic group performed significantly better than the whole-word group in the "phonic reversal" task, but no difference appeared in the "syllable reversal" task. This indicated (1) that most children by the age of 6 years are ready to discover that speech consists of a sequence of phones and (2) that the moment at which they do it is influenced by the way they are taught to read. In the memory task, the children recalled series of visually presented items whose names either rhymed or did not. The difference in performance for the rhyming and nonrhyming series was significant in both groups. It was no greater for the phonic than for the whole-word group and was uncorrelated with the "phonic reversal" task. These results are discussed in connection with the distinction between ways of lexical access and ways of representing verbal information in short-term memory. © 1982 Psychonomic Society, Inc.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Reduction of quantization error in position encoders

The paper describes estimate of the quantization error of a real position encoder taking into account the factors specified above, and the method of minimization of this error by an additional adjustment of the scale is proposed. © Published under licence by IOP Publishing Ltd

Comparative analysis of digital data conversion algorithms in NC systems of machine tools

The research is aimed at studying the selection of instruments to encode, convert and compress digital data for various purposes. Hardware and software approaches to data conversion are considered. Two approaches are distinguished and described among many hardware realizations as most suitable for control systems - matrix-based and pulse-counting methods and corresponding circuits, with their advantages and disadvantages highlighted. Software-based algorithmic solutions are recommended as providing more flexible, reliable, compact and fast-response functioning in many aspects. Computational and table-based software algorithms for NC systems of machine tools (lathes and mills) are analysed and compared using a computer program developed for that purpose. The analysis is aimed at checking whether the differences between the algorithms are significant and finding an algorithm which would provide a higher operation speed in control systems of lathes and mills. The computational algorithm is concluded to be more suitable for NC systems of those machine tools, but it is stressed that the table-based method is more appropriate for certain purposes and applications. © 2021 Author(s).Ministry of Education and Science of the Russian Federation, Minobrnauka, (075-02-2022-877)Russian Science Foundation, RSF, (21-71-00044)The present research work consists of theoretical and computational parts, which were supported by different financial sources. E.A.T. acknowledges the Russian Science Foundation (Project No. 21-71-00044) for the development of the boundary integral method. L.V.T. is grateful to the financial support from the Ministry of Science and Higher Education of the Russian Federation (Project 075-02-2022-877 for the development of the regional scientific and educational mathematical center “Ural Mathematical Center”) for the development of the selection criteria, computer simulations, and numerical examples

Study on Methods of Adaptive Vibration Damping in Mechanical Systems

It is commonly known that operation of miscellaneous technological machines and vehicles, steel structures of construction facilities and other mechanical systems often results in dynamic loads, which cause undesired vibrations. A change in operating conditions brings about a change in vibration frequencies, and for this reason an effective means to eliminate them is adaptive absorbing of vibration. The article discusses the methods of adaptive vibration damping and various design schemes of adaptive vibration dampers. The comparison criteria were determined and a comparative study was carried out to determine the best method or scope of appropriate application of one or another of them. The dependences of the sensitivity and frequency of natural vibrations of vibration dampers that implement various control methods are determined. Recommendations on the feasibility of using different types of vibration dampers for vibration damping in the high, medium and low frequencies are given. © 2022 American Institute of Physics Inc.. All rights reserved

On selection of optimal stop position and spatial orientation of mobile robot

The paper analyses the problem of finding optimal coordinates of a mobile robot equipped with a manipulator. An optimization criterion is proposed and validated, and a method for calculating most rational coordinates of the robot is described. © Published under licence by IOP Publishing Ltd

Berry effect in acoustical polarization transport in phononic crystals

We derive the semiclassical equations of motion of a transverse acoustical wave packet propagating in a phononic crystal subject to slowly varying perturbations. The formalism gives rise to Berry effect terms in the equations of motion, manifested as the Rytov polarization rotation law and the polarization-dependent Hall effect. We show that the formalism is also applicable to the case of non-periodic inhomogeneous media, yielding explicit expressions for the Berry effect terms.Comment: To appear in JETP Let

Linear stability of planar premixed flames: reactive Navier-Stokes equations with finite activation energy and arbitrary Lewis number

A numerical shooting method for performing linear stability analyses of travelling waves is described and applied to the problem of freely propagating planar premixed flames. Previous linear stability analyses of premixed flames either employ high activation temperature asymptotics or have been performed numerically with finite activation temperature, but either for unit Lewis numbers (which ignores thermal-diffusive effects) or in the limit of small heat release (which ignores hydrodynamic effects). In this paper the full reactive Navier-Stokes equations are used with arbitrary values of the parameters (activation temperature, Lewis number, heat of reaction, Prandtl number), for which both thermal-diffusive and hydrodynamic effects on the instability, and their interactions, are taken into account. Comparisons are made with previous asymptotic and numerical results. For Lewis numbers very close to or above unity, for which hydrodynamic effects caused by thermal expansion are the dominant destablizing mechanism, it is shown that slowly varying flame analyses give qualitatively good but quantitatively poor predictions, and also that the stability is insensitive to the activation temperature. However, for Lewis numbers sufficiently below unity for which thermal-diffusive effects play a major role, the stability of the flame becomes very sensitive to the activation temperature. Indeed, unphysically high activation temperatures are required for the high activation temperature analysis to give quantitatively good predictions at such low Lewis numbers. It is also shown that state-insensitive viscosity has a small destabilizing effect on the cellular instability at low Lewis numbers

Nucleus-Electron Model for States Changing from a Liquid Metal to a Plasma and the Saha Equation

We extend the quantal hypernetted-chain (QHNC) method, which has been proved to yield accurate results for liquid metals, to treat a partially ionized plasma. In a plasma, the electrons change from a quantum to a classical fluid gradually with increasing temperature; the QHNC method applied to the electron gas is in fact able to provide the electron-electron correlation at arbitrary temperature. As an illustrating example of this approach, we investigate how liquid rubidium becomes a plasma by increasing the temperature from 0 to 30 eV at a fixed normal ion-density $1.03 \times 10^{22}/cm^3$. The electron-ion radial distribution function (RDF) in liquid Rb has distinct inner-core and outer-core parts. Even at a temperature of 1 eV, this clear distinction remains as a characteristic of a liquid metal. At a temperature of 3 eV, this distinction disappears, and rubidium becomes a plasma with the ionization 1.21. The temperature variations of bound levels in each ion and the average ionization are calculated in Rb plasmas at the same time. Using the density-functional theory, we also derive the Saha equation applicable even to a high-density plasma at low temperatures. The QHNC method provides a procedure to solve this Saha equation with ease by using a recursive formula; the charge population of differently ionized species are obtained in Rb plasmas at several temperatures. In this way, it is shown that, with the atomic number as the only input, the QHNC method produces the average ionization, the electron-ion and ion-ion RDF's, and the charge population which are consistent with the atomic structure of each ion for a partially ionized plasma.Comment: 28 pages(TeX) and 11 figures (PS

Study of the influence of the design of the turning tool on the removal of thermal energy from the cutting zone

In this work, we performed a study and developed the design of through-cutters that provide accelerated heat removal from the cutting zone with external turning. Using SolidWorks Simulation engineering analysis and SolidWorks Flow Simulation gas-hydrodynamic analysis modules as a research tool, we created a basic 3D model of a precast cutter and carried out a thermal analysis of the transition process to determine the distribution of temperature fields in the body of the cutter throughout time during the cutting process. After that, we made changes to the design of the cutter, specifically, created a cavity in the holder body in which the copper core was placed. We then re-performed the studies described above, which showed that when using a copper core, the temperature in the cutting zone decreases by 246 C within 15 minutes from the start of the work. To obtain a greater effect, we added a hole in the copper core and used air cooling, which allowed reducing the temperature in the cutting zone by 313 C. © Published under licence by IOP Publishing Ltd