Journal archive
IT management |
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Performance management |
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The introduction of information systems (IS) in enterprise management, as experience shows,
quite rarely leads to increase in nomenclature of processed data. The obtained IS-related economic
effectiveness is usually lower than for other innovations in production. For the first time it was noted
by Academician V. A. Trapeznikov, who showed that the causes of this are not temporary or technology-
related, but have fundamental basis, defined by the nature of information processes. The work
proposes the common approach for estimating the effectiveness and optimization of main parameters
of production-technological information systems; we also put forward a method for estimating
the maximum (economically feasible) dimensions of mathematical programming problems that implement
the strategic functions of enterprise management. We also show major dependencies both
for optimization of parameters and estimation of IS local functions efficiency, as well as IS strategic
functions. The proposed methods are probably of most interest for the enterprises in machine-building
industry, which manufacture high-complexity products. The experience of creating IS for such
objects showed that the customer is unable to formulate complete and accurate requirements for the
future system. That is why the process of task setting and software development inevitably becomes
iterative. The analysis of the results of the current stage may lead to changes in any previous ones,
to the extent of creating new versions. To manage such an unpredictable process, it is necessary to
estimate full project cost and its effectiveness based on express-inspection of the enterprise. This
method, which is using advantages of macro-approach to describing complex objects, in fact allows
the completion of this goal even before any works have started. In addition, quite limited amount of
available data is required for calculations.
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IT and education |
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Training technologies |
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We discuss the problem of evidentiary selection senior students — applicants for a job in an organization,
institution, company, that ask for work in his senior students with an indication of the preferred
professional abilities, ranked in order of importance of these skills to the employer. The problem
is reduced to the ranking of training graduate students on the basis of testing, and the subsequent
calculation of the integral of Choquet according to testing. Choquet integral is used to form
a complex criterion of training students aggregation of several partial criteria. Particular criteria are
formed as the evaluation of test results on certain sections of the test, which correspond to the main
areas of vocational training students.
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Software engineering |
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Algorithmic efficiency |
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This paper is devoted to synchronization algorithms of agent-based parallel discrete-event simulation.
There are a lot of algorithms for such distributed simulation modeling, and most of them are
fallen into two groups: conservative and optimistic ones.
However the sphere of the research is simulation of agent-based systems. The agents are known
to be «smart»: they have some kind of knowledge that helps them reasoning in different situations.
So the idea is that we could use this knowledge base not only for artificial intelligence, but also for
synchronization algorithms in parallel simulation.
This paper provides the family of algorithms called KBASA (Knowledge Based Agent Synchronization
Algorithms) that result to significant improvement of standard optimistic algorithms. They are
designed exclusively on agent-based systems and are not compatible with usual distributed simulation
because of lack of knowledge.
Ontology was introduced as a knowledge base of an agent. The specification of the ontology
is also provided in the paper.
Eventually KBASA were designed and implemented on Akka (for Scala programming language)
and tested on real models. Theoretical description and practical results are also provided as well as
comparison with the standard optimistic algorithms on the same model.
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Network Technologies |
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The article examines the development process of the BML interpreter and the high-performance
cluster building with BML support. The language allows to modeling a web-interfaces and their business
logic in a declarative form. The article contains the comparative analysis of some critical components
in the system. In particularly there is a comparison of efficiency of the Web platforms in static
and dynamic environments between CGI, FastCGI and traditional PHP programming. Efficiency of
compiling and interpreting languages also considered. According to study, the FastCGI platform with
the C++ language gives the best result of performance. Detailed architecture with the base system
components is considered. The interpreter contains low-level programming elements and requires
performing the following tasks: HTTP requests parsing, store and retrieve user sessions, interact with
DBMS, parsing of XML-like documents, processing a regular expressions, provide the computed data
to templates and etc. There are some resource-intensive processes in the interpreter and they are
also requiring detailed analysis. The BML language based on XML syntax therefore its interpreter require
a proper XML-parser. Authors chose libxml2 as the best way for the fast development although
it shown not highest efficiency. Some of components are developed independently: HTTP-parser,
configuration files parser, session manager, all interface classes and more. In the article presented the
development process of the interpreter in high-performance systems as complex engineering solution.
Keywords: Web, backend, server programming, highload systems, cloud computing, clusters, servers, interpreter, declarative
programming, CGI, FastCGI, BML, BlockSet, HTML, XML, MVC, C++.
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Simulation |
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Theory and practice |
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Modeling and simulation have arisen as a result of computing and information technology emerging,
now belong to one of the most popular tools in scientific research, management activities, training,
and other areas. The degree of penetration of technologies in various spheres of human activity is so
high that makes urgent the establishment of a regulatory framework as scientific, methodological, organizational
and administrative measures which will make possible transforming the activity of building
systems simulation and there practical use from the matter of art and science to in engineering task. In
this regard, it may be useful experience gained abroad, where the managerial and technical support
level currently reached a higher level of satisfaction then domestic where the M & S are also widely
used. The article provides a brief overview of the state in this area overseas aimed to help in overcoming
this gap. We point out the main M & S standards groups as well the leading institutions (both governmental
and none governmental) evolved in the standards development. After that the approaches
adopted in large bodies, mainly in the field of defense, to building the management environment for
M & S acquisition (including technical and management rules, standards and guides) are considered.
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Actor modeling |
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The article presents possibilities of Pilgrim Packed application in modelling ecological-economic
system of the region. Principal attention is paid to long-term economic calculations and to raising
precision and reliability of calculations by means of more detailed elaboration of mathematical
modelling process. There exist several ways of research depending on precision, reliability, value of
planning horizon (at macrolevel). In our opinion, in connection with this steadiness management is
the most efficient tool for preservation the environment. That’s why in this paper the authors pay special
attention to problems of ecological-economic stability (EES) in the region. The EES calculation
results «Floating at Road-stead» with application of CASE-technology in designing models «with no
programming» Pilgrim (with Visual Studio) are given as an example.
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Laboratory |
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Study of processes and systems |
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Temperature fields in real technical systems are interval and stochastic, that caused by interval
stochastic uncertain parameters. However existing methods for modeling of temperature fields in
technical system are based on the assumption that parameters determining the thermal regimes are
deterministic, meanwhile, an actual practice shows that such assumption is very far from the reality
and leads to low adequacy of modeling. An interval stochastic nature of temperature fields in technical
system is due to such random factors as: manufacturing tolerances; environmental characteristics;
external environment of operation; design parameters of system (contact gap, sizes, shape,
distance between elements, etc). All random factors determining thermal regimes of systems are
changed within intervals of their random tolerance values. Therefore uncertainty of these factors as
well as uncertainty of temperature distribution are interval stochastic too. But in the meantime at present
there are no adequate and effective mathematical and computer simulation methods for modeling
of interval stochastic temperature fields in complex technical systems. In this paper the mathematical
and computer simulation method for modeling of interval-stochastic temperature fields in
technical (electronic) systems, are developed. The temperature fields depend on interval character
of thermal input parameters of technical system and operational conditions. The modeling computer
simulation algorithm realized by computer program (STF-ElectronMod). Applying of these methods
and algorithm to an electronic system, are shown.
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Models and Methods |
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The paper describes an approach for constructing fuzzy linguistic variables, based on the use of
cluster analysis. The basic assumption in this method is the fact that the distance from the center of
the cluster element degree of membership fuzzy set is reduced. The maximum value of membership
will have a core (average) of cluster. Degree of membership of the other elements decreases
linearly with distance from the cluster core. The initial set of data is divided into clusters. Each cluster
corresponds to a linguistic (verbal) characteristic, which corresponds to a fuzzy linguistic variable.
The normalized distance from the cluster members to its center corresponds to the degree accessory
to the term: the greater the distance, the lower the degree of membership. The analytical form
of the membership functions is obtained by fitting the results of cluster analysis. This approach allows
you to automate the process of developing management systems with fuzzy logic.
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Point of view |
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Methodology of science |
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This article is devoted to a problem of formation of criteria for allocation from a set of the program
systems of the life imitating machines, which are received as result of modeling of intellect, but not
intellectual behavior of the subject. The main attention is paid to that fact that not all characteristics of
live essence but only some (not less than one) have to be inherent in the life imitating machine. And
also we can easily distinguish live essence not only from a stone, but also from the lifeless machine
gun. The variant of the architect program systems is revealed, which are reasonably classified in the
status of results of modeling of several sides multilaterally interpreted intellect of the subject. In article
the example of improvement of concrete program system on giving of the characteristics corresponding
to the status of the life imitating machine to it figures prominently. Thereby reader can form unambiguity
for distinction of processes of intellectual modeling and intellectual behavior of the subject.
Also it is noted that the lack of accurate distinction of components of triune essence (subject,
its intellect and intellectual behavior) completely brought out now questions of intellectual modeling
from the area of researches. Scale of a problem of research and intellectual modeling, its relevance,
the theoretical and practical importance are shown. It is emphasized that a long-term demand of the
solution of questions of research and intellectual modeling in a combination to complexity of their
decision led to conscious or unconscious substitution in scientific literature of the concept «modeling
of intellect» by the concept «modeling of intellectual behavior». Some standard cases in which
program systems obviously are in a false manner declared in the status of the imitating machines
are given in the conclusion.
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