RT&A EditorIal Board Members
Open Memorial Table of Academic of Boris Vladimirovich
Gendenko
On January 15, 2013, at the Faculty of Mechanics and
Mathematics of the Ivan Franko National University of Lviv,
the solemn opening of a memorial plaque was held in honor of
Academician Boris Gnedenko, the founder of the Ukrainian
probabilistic-statistical scientific school. The celebration
of the memory of an outstanding scientist has become a major
event in the scientific and cultural life of the University,
as well as for the whole school of probability theory,
represented by the bunch of followers and students of
Academician Boris Gnedenko both in Ukraine and abroad. The
memorial plaque was produced by Honored Art Worker,
professor of Lviv National Academy of Arts Vasyl Gogol,
well-known sculptor-portraitist in Ukraine.
DOI:
https://doi.org/10.24411/1932-2321-2018-12008
(M, MAP)/(PH, PH)/1 queue with Nonpremptive Priority,
Working Interruption and Protection
A. Krishnamoorthy Divya V .
In this paper we consider a (M,MAP)/(PH,PH)/1 queue with
nonpremptive priority, working interruption and protection.
Two types of priority classes of customers where type I
customers arrive according to a Poisson process and type II
customers arrive according to Markovian Arrival Process are
considered. Service time of both type I and type II
customers follow mutually independent phase type
distributions. The number of type I customers in the system
is restricted to a maximum of L. Also type I customers are
assumed to have a non-premptive priority over type II
customers. Customer services are subject to interruption by
a self induced mechanism. The interruptions occur according
to Poisson process. Instead of stopping service completely,
the service continues at slower rate during interruption.
Also we assume that an interruption occuring while customer
is already under interruption will not affect the
customer.The server continues to serve at this lower rate
until interruption is fixed. The duration of interruption is
assumed to be exponentially distributed. A protection
mechanism to diminish the effect of interruptions on type I
customers service is arranged.The protection for the service
of type I customers is provided at the epoch of realization
of the clock which starts ticking up the moment a type I
customer is taken for service. Type II customers are not
provided protection against interruption during their
service. Also we assume that type I customers get service at
a faster rate starting from the epoch of providing service
protection. We analyse the distribution of service time
duration of both type I and type II customers and the
distribution of a p-cycle. Also we provide LSTs of busy
cycle, busy period of type I customers generated during the
service time of a type II customer and LSTs of waiting time
distributions of type I and type II customers. Also we
compute the expected number of interruptions during a type I
and a type II service. We perform numerical computations to
evaluate important system characteristics and also optimal
system cost using a cost function .
DOI:
https://doi.org/10.24411/1932-2321-2018-12003
Phasor Measurement Unit Diagnosing
Mikhail Uspensky
Based
on the global navigation system timestamp an equipment is
applied to synchronize the measurement
moment in various power buses, which are remote from each
other, to measure the current and voltage phasors for the
power system control. It is named phasor measurement unit (PMU).
This is complex device and it should support the necessary
level of reliability for safe power system control. An
enhancement of PMU functioning reliability can be obtained
by redundancy of its assembled components. Aside from
redundancy there is a failure identification task of
components for ones from two devices and a concretization of
this unit for its replacement. In the paper the failure
identification issues are considered for redundancy, and the
diagnosing algorithm, which solves these issues, is offered.
DOI:
https://doi.org/10.24411/1932-2321-2018-12007
Crowd Sourcing Rules in Agile Software Engineering to
Improve Efficiency using Ontological Framework
Himanshu Pandey, Santosh Kumar, Manuj Darbari
Business Rule Management System provides the necessary seeds
for the planning, implementing, verifying and validating the
Agile Requirements. The BRMS model needs to be modified in a
way that organizational growth runs parallel with the
intrinsic expansion in the number of User Requirements in
Agile Development. This growth in Requirements or Rules in
Agile Software Development is an obvious overhead that needs
to be managed properly considering its sprint nature. A
Semantic approach is followed by design and maintenance of
an Ontology called RAgile. The ontology is developed in
‘Protégé 5 having inherent capability f Ontology Merging in
case of disparate Rule files. User requirements that are
drawn into the Rules or Policies depend upon the features
users expect of the Agile System.
DOI:
https://doi.org/10.24411/1932-2321-2018-12001
The FCFS-RQ system by Laslo Lacatos and its modifications
Igor N. Kovalenko
The A. is proud of his being a disciple and co-worker of the
world-wide known scholar Boris Vladimirovich Gnedenko and of
being a participant of his scientific school, especially in
the scope of queueing and reliability. The attempt is made
to outline the contribution of prominent Gnedenko’s
colleagues Professors M.A. Fedotkin, L.G. Afanasyeva and
G.I. Falin to the theory and practice of transportation
processes. In 1994, a talented Hungarian probabilist Laslo
Lakatos invented a new class of queueing systems, FCFS RQ
systems motivated by an aviation problem. Such models were
generalized by the Author’s disciple E.V. Koba. The A. makes
a further step in the study of this problem considering a
Lakatos type system with hyper-Erlangian inter-arrival and
service times.
DOI:
https://doi.org/10.24411/1932-2321-2018-12002
The Problem of large deviations. Comparison of the classical
and alternative representations, p.1
S.V. Zhulenev
This year marks the 80th anniversary of the origin of the
research problem (see [1]), later called the problem of
large deviations. And after the appearance in early 2000 of
its alternative (see [4]-[6]), the original version it was
natural to call it a classic. In this work, it is proposed
to resume the study of both options in the simplest,
one-dimensional case, i.e. take the first step in a certain
direction. More precisely, In this and subsequent work of M.
V. Maslikhin, a comparison of representations of large
deviations obtained in the classical (in the style [3]) and
alternative (in the style [6]) cases for the normalized sums
of the i.i.d.r.v’s. and 10 (5 in each work) of different
distributions of the summands of these sums is carried out.
To conduct this analysis has proven difficult, but the
conclusions that they allowed us to make were very
interesting.
DOI:
https://doi.org/10.24411/1932-2321-2018-12010
The problem of large deviations. Comparison of the classical
and alternative representations, p.2
M. V. Maslikhin
This work is a continuation of the previous article (see
[1]). Therefore, I note only that here are considered
representations of large deviations for 5 other
distributions of the summands of the mentioned normalized
sums. In addition, if [1] explains what views are compared
and how to get them, here the introduction
clarifies the main results of analysis, i.e. whether
it is difficult to get them and how they are practically
useful.
DOI:
https://doi.org/10.24411/1932-2321-2018-12005
On another approach to the analysis of the known problem of
optimal stopping, p.1
S.V. Zhulenev
In the well-known optimal stopping problem, it was always
clear that there must be a connection between the type of
the objective function or, in other words, the type of
surface in three-dimensional space and the specific optimum
stopping time. But it was unclear how this relationship
discover. In this work and the following two, a simple idea
is realized to establish this connection. It comes down to
replacing of the initial and very large stop set consisting
of Markov moments with respect to the flow of Sigma algebras
generated by the random walk under consideration to a
simplified stop set consisting of integer random variables.
Moreover, in this part 1, the domain of the new objective
function definition on the integer lattice of the plane is
specified, the condition is given, when the optimal moment
is 0, and also mention the known results from the
combinatorics used in other parts. The following two parts
explain what this relationship is for small horizons n.
DOI:
https://doi.org/10.24411/1932-2321-2018-12009
On another approach to the analysis of the known problem of
optimal stopping, p.2
S.V. Zhulenev
Part 2 implements the idea mentioned earlier in part 1 in
the case of the small and odd horizon n = 5.
Again, the desired relationship between the objective
function of the problem and the optimal moment of
stopping time was very interesting and simple.
DOI:
https://doi.org/10.24411/1932-2321-2018-12004
On another approach to the analysis of the known problem of
optimal stopping, p.3
A.S. Filatov
Part 3 implements the idea mentioned earlier in part 1 in
the case of the small and even horizon n = 6: Again, the
desired relationship between the objective function of the
problem and the optimal moment of stopping time was very
interesting and simple.
DOI:
https://doi.org/10.24411/1932-2321-2018-12006
