The fiber optic sensors measuring accuracy depends on such destabilizing factors influence, as light emitter power variations, different research surface reflecting and scattering properties, photoreceiver parameters alterations and etc. Sometimes it is necessary to transform the measuring displacement into time interval, which duration is in proportionality to measurement value and is independent to destabilizing factors influence also. The mathematical model of the invariant transformation method of measuring displacement into time interval was elaborated for two channel fiber optic sensor. Using two measuring channels with mutual involuting adjustment permits to compensate the error components of the transfer functions and time dependences errors, gives the opportunity to make linear of the both channels transfer functions operating sections. Besides this the pulses generator circuit becomes more simple, because frequency instability of excitation voltages doesn't influence at the transformation results. Considered method permits to increase of the device quick-action, to simplify of displacement analog-digital conversation and to decrease of the comparator's error on account of contrary changing voltages comparison. The two-channel fiber optic sensor with modulated emission for precision positioning was elaborated in which research object surface is illuminated by modulated emission with the help of semiconductor laser, laser pulses duration is chosen divisible to 1/50 Hz. The two-channel fiber optic sensor with modulated emission for precision positioning operates in the structure of laser microscope positioning system. The device output signal sign is defined identically by fiber optic guide face plane shift direction. Its value is in proportionality to deflection value.Schematic diagrams of method realized devices are shown and the main concerned to these method and devices correlations are discussed.
The relevance of the work lies in the fact that the pace of development of the field of information security does not correspond to progress in the development of data processing methods, resulting in a serious lack of practical knowledge of the subject area, which prevents the creation of conditions for secure recording, processing and storage of data. In the process of writing the article, modern methods and principles of ensuring information security, including a mandatory approach, were studied, and a brief description of software products supporting this approach was given. The mandatory method of information protection implies granting access rights to certain actions in accordance with the user’s status. Such actions can be, for example, writing, reading and changing data. Examples of user statuses are ‘administrator’ and ‘reader’, where the administrator, as a rule, is provided with the entire list of available actions, and the reader is provided with only a minimum, sufficient for familiarization activities. In its architecture, the mandatory approach often contains tools for conducting cluster analysis. Cluster analysis can be used both to carry out work on risk analysis and assessment, and to determine the degree of protection of an object. In any case, when building a cluster, it should be taken into account that some levels of protection may be represented by more objects than others. There are software products on the information security market that allow the use of a mandatory method of ensuring information security. One of the striking examples is the PostgreSQL database management system, which has an apparatus of labels assigned according to the user’s level of rights: the higher the level of rights, the higher the access level.
One of the global environmental problems of our time is the reduction of biological diversity — the extinction of species or individual subspecies of animals. The aim of this work is to develop a generalized deterministic model with discrete time, designed to analyze the nature and mechanisms of the dynamics of the number of biological populations characterized by the presence of a complex age structure.
This article describes the information system, which is an electronic version of the laboratory journal of chemist-synthetics. An overview of the basic functionality of the program is presented.
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