E.M. Farhadzadeh, A.Z. Muradaliyev, Y.Z. Farzaliyev
CRITERION OF THE SUPERVISION ACCURACY OF
INDEXES RELIABILITY OF POWER-GENERATING
UNITS A STATE
DISTRICT POWER STATION
The
atomized system is developed, allowing to determine and
compare indexes of individual reliability of complex
plants in view of a random in character of an initial
conditions.
Mikhail Yastrebenetsky
HOW PROFESSOR B.V. GNEDENKO GOT CAUGHT ON
A HOOK IN KHARKOV
For the first time, I met B.V. Gnedenko in the Fall of
1970 at the USSR conference-school on queueing theory.
The conference was organized by the Moscow State
University. Boris Vladimirovich Gnedenko was a head of
the conference. The conference took place at the
fantastic city resort Dilizhan insite the Caucasus
mountains in Armenia, in the house of composers. I would
have to say that I never attended a more interesting
conference in my life. The music was constantly playing
from the open windows of the cottages nearby; there was
a fascinating harmony of mountains, mathematics and
music...
G.Sh. Tsitsiashvili, M.A. Osipova
DIRECT CALCULATIONS OF A REACHING MOMENT
DISTRIBUTION FOR AN AUTOREGRESSIVE
RANDOM SEQUENCE BY RECCURENT INTEGRAL EQUALITIES
In this paper we consider an autoregressive random
sequence Xk = RXk−1 +ηk−1. Our problem is to calculate a
distribution of a reaching moment τ = inf (k : Xk ≥ X )
. This problem origins in the risk theory, in the
financial mathematics, in the statistics of random
processes and in the reliability theory. Interest to
mixtures of exponentials as approximations of
distributions with heavy tails is initiated by papers.
V. Raizer
RELIABILITY ASSESSMENT DUE TO WEAR
Evaluation of structural reliability under processes of
deterioration presents very important problem in design.
The structure's wear shows a reduction of bearing
capacity in time that for one's turn leads to increasing
the probability of failure. The reasons for long
duration and irreversible change of structural features
can be corrosion in steel structures, decomposition in
wood structures, ageing in polymer structures, and
processes of abrasion or erosion also. The problem of
defects accumulation should be mentioned too, when
reduction of the bearing capacity connects with load's
value and its duration. The models and peculiarities of
corrosion wear and its influence on bearing capacity are
discussed in this paper.
G.Sh. Tsitsiashvili, M.A. Osipova
ACCURACY SOLUTION OF A.A. NOVIKOV PROBLEM
O.V.Abramov, Y.V.Katueva and D.A.Nazarov
DISTRIBUTED COMPUTING ENVIRONMENT FOR
RELIABILITY-ORIENTED DESIGN
A
theoretical approach and applied techniques for
designing analogous electronic devices and systems with
due account of random variations in system parameters
and reliability specifications are considered. The paper
discusses the problem of choosing nominal values of
parameters of electronic devices and systems for which
the system survival probability or the performance
assurance probability for the predetermined time period
is maximized. Several algorithms for region of
acceptability location, modelling and discrete
optimization using parallel and distributed processing
are discussed. For seeking a numerical solution of the
parametric design problem a distributed computer-aided
reliability-oriented design system is proposed.
N.N. Radaev, A.V. Bochkov
DETERMINING A PRIORI DISTRIBUTION OF
ERROR-FREE RUNNING TIME FOR HIGH-RELIABILITY
COMPONENTS BY
DELPHI METHOD
We have
considered the approach to determining a priori
distribution of error-free running time for
high-reliability components by the method of paired
comparisons useful for the increase of their reliability
indicators. We have introduced the distinct variables,
whose grades of membership are interpreted as subjective
probabilities of finding the error-free running time and
its characteristics at various time intervals. The
method of recording the expert evaluation accuracy has
been suggested.
T. Aven
RISK ANALYSIS AND MANAGEMENT. BASIC
CONCEPTS AND PRINCIPLES
This
paper reviews and discusses some key concept and
principles of risk analysis and risk management, based
on a set of statements, formulated as myths about risk.
Examples of such myths are: risk is equal to the
expected value, risk equals uncertainty, risk can be
expressed by probabilities, risk is equal to an event,
risk acceptance criteria contribute to obtaining a high
safety standard, and ALARP can be verified by
cost-benefit analyses. It is concluded that risk needs
to address both the consequences and the uncertainties
about the consequences, and that it is necessary to see
beyond expected values and probabilities.
R. Guo, D. Guo
CREDIBILISTIC FUZZY REGRESSION
In
reliability, quality control and risk analysis, fuzzy
methodologies are more and more involved and inevitably
introduced difficulties in seeking fuzzy functional
relationship between factors. In this paper, we propose
a scalar variable formation of fuzzy regression model
based on the credibility measure theoretical foundation.
It is expecting our scalar variable treatments on fuzzy
regression models will greatly simplify the efforts to
seeking fuzzy functional relationship between fuzzy
factors. An M-estimator for the regression coefficients
is obtained and accordingly the properties and the
variance-covariance for the coefficient M-estimators are
also investigated in terms of weighted least-squares
arguments. Finally, we explore the asymptotic membership
function for the coefficient M-estimators.
Krzysztof Kolowrocki
RELIABILITY AND RISK ANALYSIS OF MULTI-STATE SYSTEMS WITH
DEGRADING COPONENTS
Applications of multi-state approach to the reliability
evaluation of systems composed of independent components
are considered. The main emphasis is on multi-state
systems with degrading components because of the
importance of such an approach in safety analysis,
assessment and prediction, and analysing the
effectiveness of operation processes of real technical
systems. The results concerned with multi-state series
systems are applied to the reliability evaluation and
risk function determination of a homogeneous bus
transportation system. Results on homogeneous
multi-state "m out of n" systems are applied to
durability evaluation of a steel rope. A non-homogeneous
series-parallel pipeline system composed of several
lines of multi-state pipe segments is estimated as well.
Moreover, the reliability evaluation of the model
homogeneous multi-state parallel-series electrical
energy distribution system is performed.
S. Guze
TRELIABILITY ANALYSIS OF TWO-STATE CONSECUTIVE "M OUT OF L:
F"-SERIES SYSTEMS
A non-stationary approach to reliability analysis of
two-state series and consecutive "m out of k: F" systems
is presented. Further, the consecutive "m out of k:
F"-series system is defined and the recurrent formulae
for its reliability function evaluation are proposed.
Paramonov Yuri, Andersons Janis, Kleinhofs Martinsh
MINMAXDM DISTRIBUTION FAMILY FOR TENSILE STRENGTH OF
COMPOSITE
Generalization of extended family of weakest-link
distributions with application to the composite specimen
strength analysis is presented. Composite (specifically,
monolayer) specimen for tensile strength is modeled as
series system but every "link" of this system is modeled
as parallel system. Results of successful attempts of
using some specific distribution from this family for
fitting of experimental dataset of strength of some
carbon fiber reinforced specimens are presented.
Viorel Gh. Voda
SOME COMMENTS ON STATISTICAL RISKS
In this work we make a detailed analysis of the concept
of risk, the stress being focused then on various kinds
of statistical risks: producer and consumer risks,
technical risk, Taguchi`s risk (making a connection with
Cpm capability index) and a risk arising in SPC practice.
