DEPENDABILITY, №1(56)-2016
Structural reliability. The theory and practice
- Schäbe H., Shubinsky I.B.
LIMIT RELIABILITY OF STRUCTURAL REDUNDANCY
In many cases, reliability can be improved by using the redundancy of system components. This is an approach that is applied especially in information systems. In this paper we study redundant systems with imperfect switches. We show that there exists a limit as the number of redundant components tends to infinity. This limit is defined for typical exponential time distribution to a failure of digital equipment in information systems. Bound estimates are given for the system elements with distributions belonging to the NBUE (new better than used in expectation) or NWUE (new worse than used in expectation).
Keywords: structural redundancy, classification of types of structural redundancy, parallel system, failure free operation, bound estimates, hot standby, cold standby, probability of a failure in standby switching.
- Varzhapetyan A.G., Gluschenko P.V., Gusman Y.А., Pichugin Y.А.
PROBABILISTIC ESTIMATES OF OPERATION OF DYNAMIC SYSTEMS SPECIFIED BY A LARGE AMOUNT OF PARAMETERS
This article offers an algorithm of probabilistic estimation of reliability of multi-parameter dynamic systems. Probabilistic estimates are based on multivariable distributions statistically received from the results of experimental testing. For this purpose we consider two separate cases – direct and indirect measurement of parameters. Reliability of dynamic systems is also considered in terms of validation of statistical hypotheses. The statistics used to validate hypotheses are based on the assessment of distribution parameter received
experimentally.
Keywords: direct and indirect measurement of parameters, assessment of distribution parameters, statistical hypotheses.
- Pokhabov Yu. P.
APPROACH TO ENSURING OF DEPENDABILITY OF UNIQUE SAFETY CRITICAL SYSTEMS EXAMPLIFIED BY LARGE TRANSFORMABLE STRUCTURES
This paper describes the approach to ensuring of reliability, capable of identifying and preventing potential failures of unique safety critical systems at the earliest stages of the life cycle by the example of large transformable spacecraft structures. Among other things, this approach gives a possibility to take account of design and technological factors affecting reliability.
Keywords: unique safety critical systems, large transformable structure, spacecraft, reliability, failure-free operation, property, ability, parameter, index.
- Litvinenko R.S.
SIMULATION MODEL OF FUNCTIONING PROCESS OF AN ELECTRICAL FACILITY WITH CONSIDERATION OF RELIABILITY OF ITS ELEMENTS.
This article offers a variant of a simulating model to estimate reliability of electrical facility early at development
stage, using the information about a scope and reliability of its elements.
Keywords: element, facility, reliability, unit, time to failure, simulation.
- Ivanov V.V., Panchenko V.N., Shepelin P.V.
WEAR OF TYRE AND RAILS IN CURVES AND METHODS OF ITS REDUCTION
Development of railway transport provides for a further increase of train speed, carrying and crossing capacity of railways. That is why transport mechanics faces vital tasks in the field of train operation, interoperation of a rolling stock and a track, strength of components and nodes of a rolling stock, proper use of railway equipment turned out to operate in extreme conditions.
Keywords: wear of tires, interoperation of wheel and rail, movement in curves.
Functional reliability. The theory and practice
- Poltavsky А.V., Semenov S.S.
MODELS OF A COHERENT CONTROL OF THE PARAMETERS OF AN UNMANNED AERIAL VEHICLE
This article offers models and a method of implementation of coherent control of node modules of a phased array antenna (PA) and a movable object. Application of the offered method and models is radar systems of an increased spatial selectivity in the systems of detection of stealthy objects and monitoring of the environment of the advanced multi-operated unmanned aerial vehicles (UAV). Models and a device for a selective detection of stealthy objects in radar systems of the onboard control system of UAV are analyzed. Complicated complexes with UAV today are widely applied in different areas of the national economy. A market of such complicated technical systems is constantly growing and expanding. Modeling of such systems is particularly essential at an early stage of their experimental testing. In order to detect major characteristics of UAV in the sphere of incipient technologies the most essential indices of the operation of complexes with UAV are described. Indices of coherent systems in
such complexes are the most sensitive and their criticality can be estimated by the known identification methods.
Keywords: complicated technical systems; complexes of unmanned aerial vehicles; technical level; integral
and singular estimates; life cycle.
Functional safety. The theory and practice
- Kharlap S.N., Sivko B.V.
DEVELOPMENT OF HIGH-RELIABLE SYSTEMS BASED ON THE METHOD OF CROSS CHECK OF AXIOMATIC BASES
Based on the method of cross check of axiomatic bases, there have been developed reliable fail-safe microprocessor systems. They have been tested for reliability and fail-safety by using a set of simulation safety tests (SST). It has been revealed that reinforcement of the checking axiomatic basis allows us to improve fail-safety parameters. It has been shown that the cross check of axiomatic bases enables to develop fail-safe and reliable systems with target properties.
Keywords: functional safety, formal methods, fail-safety, failure detection, IT critical objects.
Reports
- Popova M.S.
PROVIDING A MULTILINGUAL ACCESS TO AN INFORMATION RESOURCE OF THE SPECIFIED SUBJECT DOMAIN AND ITS CATEGORIZED KNOWLEDGE
This paper describes an approach to provide a substantive multilingual access to a knowledge portal integrating knowledge, as well as to information resources which are relative to the specified subject domain based on ontologies. The requirements for a conceptual structure of ontologies are laid down. The analysis was performed in relation to directions of integration of semantic retrieval systems with ontologies
for the description of a search subject domain, as well as the requirements set by retrieval systems for the standards of ontological metadata and forms of their representation.
Practical realization of these requirements shall provide users with the most applicable tools to solve the urgent tasks of multilingual access to information resources of the specified subject domain, and to complete the task of definition of different types of information objects, identified by a retrieval system.
Keywords: information systems, ontologies, knowledge portal, thesaurus, multilingual thesaurus, information resource.