Influence of overload on low-frequency instability of working process in the combustion chamber of the solid propellant rocket engine

In the paper the real oscillatory process is reproduced by statement of direct numerical experiment and the mechanism of occurrence and refill of low-frequency acoustic instability in the combustion chamber of the solid propellant rocket engine with the account of flight overload is investigated for the first time. The direct numerical modeling of low-frequency acoustic instability is carried out by means of Davydov’s method (method of large particles), which is well-suited for the solutions of many problems of mechanics of the continuous media. The results of numerical modeling are presented here. The hydrodynamic highly nonlinear nature of low-frequency fluctuations connected to structure and character of current in the combustion chamber of the rocket engine on firm fuel are proved to be tru

The Innovative Management of the Development of Enterprises of Hotel and Restaurant Industry: the Conceptual Aspect

The article is aimed at forming the concept of innovative management of the development of enterprises hotel and restaurant industry as economic systems in modern market conditions. It is determined that the driving force of transformations within the enterprise is the innovative management of its development, the efficiency of which is defined by the nature of changes in the environment, the ability of the enterprise to adequately perceive these processes, and be able to readjust in accordance with objective regularities. The carried out theoretical analysis made possible to allocated the main features of adaptation from the standpoint of systemic, situational, and process approaches, and to present the basic elements of adaptation. It has been determined that the innovativeness of management of economic processes is a complex and underrated phenomenon, which includes change management, orientation towards both result and capability. According to results of the research, the conception of innovative management of the development of enterprises of hotel and restaurant industry as economic systems is proposed

Estimating the Components of Innovative Management of Development of Enterprises of Hotel and Restaurant Industry: Methodical Aspects

The article is aimed at formation of methodical approach to estimation of components of innovative management of development of hotel and restaurant enterprises in the current market conditions. An algorithm of methodical approach to diagnostics of innovative management of development of enterprises of hotel and restaurant industry is elaborated, the purpose of which is formation of analytical basis for making effective managerial decisions for overcoming crisis and further adaptive development. Components of innovative management of development of hotel and restaurant enterprises as well as their essence are suggested, their necessary quantity to obtain an efficient result of analysis is determined. An aggregate of indicators of the components for carrying out a complex diagnostics of innovative management of development of enterprises of hotel and restaurant industry is formed and the results of calculations of the general integral indicator of the innovative management of development of hotel and restaurant industry enterprises in 2007–2016 are provided

New types of stable nonlinear whistler waveguides

International audienceThe stationary self-focusing of whistler waves with frequencies near half of the electron-cyclotron frequency in the ionospheric plasma is considered in the framework of a two-dimensional generalized nonlinear Schrödinger equation including fourth-order dispersion effects and nonlinearity saturation. New types of soliton-like (with zero topological charge) and vortex-like nonlinear waveguides are found, and their stability confirmed both analytically and numerically

Marine particles investigation by underwater digital holography

A hardware-software complex for non-contact investigation of marine particles is presented. The complex is based on digital holography principles and can be immersed in water, for example, to study plankton in a habitat. Special features of a submersible holocamera (or DHC sensor) are considered. Results of approbation of the complex during the Mission in the Kara Sea are presented. A new DHC sensor design is discusse

Fast recognition of marine particles in underwater digital holography

The issue of fast recognition of marine particles in situ by digital holography methods is considered. An algorithm for the classification of marine particles by morphological features is proposed. Preliminary results and estimation of accuracy of the proposed algorithm are presented

Stable multiple-charged localized optical vortices in cubic-quintic nonlinear media

The stability of two-dimensional bright vortex solitons in a media with focusing cubic and defocusing quintic nonlinearities is investigated analytically and numerically. It is proved that above some critical beam powers not only one- and two-charged but also multiple-charged stable vortex solitons do exist. A vortex soliton occurs robust with respect to symmetry-breaking modulational instability in the self-defocusing regime provided that its radial profile becomes flattened, so that a self-trapped wave beam gets a pronounced surface. It is demonstrated that the dynamics of a slightly perturbed stable vortex soliton resembles an oscillation of a liquid stream having a surface tension. Using the idea of sustaining effective surface tension for spatial vortex soliton in a media with competing nonlinearities the explanation of a suppression of the modulational instability is proposed.Comment: 4 pages, 3 figures. Submitted to Journal of Optics A. The proceedings of the workshop NATO ARW, Kiev 2003 Singular Optics 200

Digital holographic camera for plankton monitoring

A submersible digital holographic camera for measuring plankton and other particles is described. The camera provides underwater recording of digital holograms of water volume containing plankton followed by automatic restoration of holographic images of plankton species, determination of their sizes, shapes, and concentrations, and their recognition and classification. Particles with sizes of 200 μm and larger are analyzed. The water volume registered per exposure is about 1 L. The special features of the software for automatic information retrieval from digital holograms are discussed. Examples of application of the camera as an integral part of the hardware-software complex for field measurements are given. Prospects for application of this complex for ecological monitoring are discussed. The recognition criterion of the digital holographic camera and the data volume and the averaging time required for obtaining statistically reliable data on plankton species are also given

The Hierarchical System of Strategies for Innovative Management of the Development of Hotels and Catering Enterprises on an Active Adaptive Basis

The aim of the article is forming a hierarchical system of strategies for innovative management of the development of hotels and restaurant enterprises on an active adaptive basis under modern market conditions. The article considers the content of the analysis of the economic activity of hotels and restaurant enterprises and the intrinsic characteristic of intuitionism, which is an analytical and intuitive platform for the formation of a hierarchical system of strategies for innovative management of the development of hotels and restaurant enterprises. A set of components of the functional strategy of innovative management of the development of hotels and restaurant enterprises and a list of their alternatives is formed. The stages of choosing alternatives to the strategy of innovative management of the development of hotels and restaurant enterprises are determined. Based on the results of the study, an active adaptive hierarchical system of strategies for innovative management of the development of hotels and restaurant facilities is formed