RT&A
2017,
# 2(45) Vol.12

Dimitrov, Boyan

**
Why
We Need Probability Distributions With Periodic Failure Rates In
Reliability And Risk **

We discuss situations in real life
where probability distributions with periodic failure rates
should be considered. This discussion leads us to a new
class, called Almost-Lack-of-Memory (ALM) probability
distributions. We explain the structure of these
distributions, and list some of their important properties.
One of the main properties is its periodic failure rate.
Throughout this article we notice some areas of possible
applications of these distributions, and relate applications
to the properties of these distributions. However, periodic
variability also is observed. This may be another
interesting continuation of this study.

**Keywords:** ALM class of probability distributions;
Periodic failure rate functions; Non-homogeneous Poisson
Process; periodic random environment

Farhadzadeh, E.M., Muradaliyev, A.Z.,
Farzaliyev, Y.Z.,

Rafiyeva, T.K. Abdullayeva, S.A.

**
Reliability of the
Estimate of Interrelation of Parameters Efficienty Their Work of
Objects of Ees **

Given is computational method of
statistical distribution function of possible realizations
of coefficients of linear correlation of Pearson and grade
correlation of Spirmen for dependent random quantities.
Dependence provided with ranging of random quantities of
selections. Random quantities are modeled and have uniform
distribution in the range of [0,1]. These distributions
allow to evaluate the error of II type and to compare it
with the error of I type. The error of II type established
on statistical distribution function of coefficient
correlation of independent selections. These distributions
are in a basis of criteria for estimate of the importance of
coefficients of correlation of technical and economic
parameters of objects of electrical power systems.

**Keywords:** Correlation coefficient, selection,
ranging, distribution, technical and economic indicator

**
**

Paramonov, Yuri

**
Modeling of Fatigue
Life of Unidirectional Fibrous Composite by Daniels'
Epsilon-Sequence Under Random Loading**

The modified Daniels' epsilon sequence
(DeS) is used for an analysis of a residual static
strength, a fatigue life, a fatigue strength of an
unidirectional fiber composite (UFC) considered as some
parallel system subjected to cycling loading with a random
value of a cycle parameter. Some example of the processing
of data set of a carbon-fiber reinforced composite is
given.

**Keywords:**
Daniels’ sequence, strength, fatigue life, composite

**
**

Rykov, V.

**
Controllable Queueing
Systems: From the Very Beginning up to Nowadays**

The present paper represents a review
of the Controllable Queueing Systems theory development from
the very beginning up to nowadays. The main stages of this
theory development are considered. Some new problems are
mentioned. The review is devoted to those, who are
interested in the creation and the development of the
Controllable Queueing Systems theory from its generation up
to nowadays, and who want to understand the tendency of its
development and the new directions and problems of its
study.

**Keywords:**
Controllable queueing systems, Markov decision processes,
Optimality principle, monotonicity of optimal policies

Gadolina, I., Lisachenko, N.

**
Percentiles Confidence
Intervals Building Using Bootstrap-Modeling: Application for
High-Tech Production Quality Control **

We propose a method for building
confidence intervals for percentiles with application to
quality control of the random properties of composite
polymer materials strength. The basises (i.e. lower
confidence limits for percentiles) are analyzed. The new
developed method employs the statistical bootstrap modeling
method. For the explanation of bootstrap procedure, the
problem of building confidence interval for the mean value
for the random values of composite material strength is
presented. The result is compared with classical one. Due to
bootstrap, it is possible to overcome some problems of
classical statistical constraints. There is no need in
postulating some type of distribution (normal or Weibull).
Some real problems are presented with the comparison of the
results by standard procedures and by the new method. It is
shown that the agreement is satisfactory.

**Keywords: **percentile, bootstrap-modeling, composite
material, strength

Deepak, T.G.

**
A Queueing Network Model
for Delay and Throughput Analysis in Multihop Wireless Ad Hoc
Networks **

In this paper we present a queueing
network model for computing average end-to-end delay, and
maximum throughput that can be attained in random access
multi-hop wireless ad hoc networks with stationary nodes
under two popular contention resolution schemes namely,
Binary Exponential Back-off (BEB) and Double Increment
Double Decrement (DIDD) rules. This model takes into
consider some realistic features of the system like (i) the
generation of different classes of packets at nodes, and
(ii) the dependence of the transmission time and
transmission probability on the distance between the
transmitter and receiver. Probability distributions and the
associated measures of characteristics of the time spent by
a packet at arbitrary node are analytically derived by using
phase type random variate theory, which in turn are used for
the computation of average end-to-end delay and maximum
achievable throughput. Theoretical results are numerically
illustrated.

**Keywords:** queue, network, phase type distribution,
Markov chain

Gnedenko, E., Rice, D.

**
The Economics and
Management of Nuclear Energy Industry: Supply Chain Reliability
and Safety**

Nuclear
energy safety is a critical issue as the world increasingly
turns to nuclear energy to meet our growing needs for power
and decreasing dependence on fossil fuels. Major nuclear
disasters like Chernobyl (1986) and Fukushima Daiichi (2001)
demonstrate
the need for improved controls of these systems. The nuclear
power supply chain is a critical component of the highly
interconnected nuclear energy system. This paper introduces
industry best practices and how these relate to the nuclear
energy industry safety and reliability.

**Keywords:** Nuclear energy, safety, supply chain,
reliability, operations costs

Gnedenko, D.

**
B. V. Gnedenko.
Bibliography**

#
The bibliography, which we present
below, includes everything that could be found from the
written and published B.V. Gnedenko, starting with books and
ending with newspaper articles. This includes also published
interviews. The bibliography is broken down by years, and
for each year everything that was published during this
year, including reprints, is presented. The work for each
year is arranged in one definite order: books, scientific
articles, articles on various aspects of teaching, reviews,
articles from general journals, newspaper publications,
interviews. If the same article was published during the
year in different places, then it is indicated under the
same number, listing the output of all publications.
Sometimes during the year there are articles with the same
name, but different content. They are listed under different
numbers, if possible, nearby.

**Keywords: **Gnedenko, bibliography, memory, history