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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>A Forecast Model of Energy Security Level in The System of Managing Energy Efficiency at Enterprises</article-title>
      </title-group>
      <contrib-group>
        <aff id="aff0">
          <label>0</label>
          <institution>Comenius University in Bratislava</institution>
          ,
          <addr-line>Bratislava</addr-line>
          ,
          <country country="SK">Slovakia</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Khmelnytsky National University</institution>
          ,
          <addr-line>Khmelnytsky</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>State Enterprise”Novator”</institution>
        </aff>
      </contrib-group>
      <pub-date>
        <year>1978</year>
      </pub-date>
      <fpage>0000</fpage>
      <lpage>0002</lpage>
      <abstract>
        <p>.he paper emphasizes the importance of managing an energy-efficient development of enterprises by designing a forecast model of energy security level in the system of enterprise management. The paper aims to forecast likely scenarios for enhancing energy security, identify major priorities and discover new ways to ensure energy efficiency at enterprises. The paper employs the following research methods: synthesis and analysis - to identify the essence and value of scenario modelling; theoretical generalization - to determine the main components of energy security at enterprises; classification - to study the impact of each component of energy security at enterprises on the choice of optimal scenario development; logical generalization - to justify the relevance, aim and objectives of the research; the method of rising from the abstract to the concrete - to develop and substantiate forecast trends in the changes of energy security level. Results: weight coefficients of energy security components based on scenarios have been formed; an algorithm for forecasting energy security level at enterprises based on scenarios has been built; forecast trends in the changes of energy security level have been determined; forecast trend models of energy security level at enterprises based on the proposed scenarios have been designed.</p>
      </abstract>
      <kwd-group>
        <kwd>Model</kwd>
        <kwd>Forecast</kwd>
        <kwd>Scenario</kwd>
        <kwd>Energy Security</kwd>
        <kwd>Energy Efficiency</kwd>
        <kwd>Enterprise</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Today’s conditions of economic management encourage enterprises to be more
selfefficient and adapt to changes in external influences associated with rising energy
costs and destabilization in energy supply to realize their economic interests and
benefit from their competitive advantages. In this regard, the establishment of a system
for managing energy security at enterprises is an important condition for functioning
and improving the energy efficiency of socio-economic entities.</p>
      <p>It is vital to develop an effective system of managing energy security at industrial
enterprises since they take significant losses and are close to bankruptcy.</p>
      <p>
        It can be explained by the following factors: continuous interaction between
industrial enterprises and environmental factors as a major source of threats causing
destabilizing effects; certain unproductivity of industrial enterprises and the possibility of
taking measures for its timely elimination; energy security management is the only
way of optimizing industrial production; requirements of a market economy for
ensuring energy security as a factor in sustainable development of enterprises and
promotion of their competitiveness [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ].
      </p>
      <p>The use of forecast models is one of the important elements of a structural model
for the system of managing energy security at enterprises. Given this system seeks to
ensure enterprises’ safety management and, thus, ensure their energy-efficient
development, one can indicate about strategic intentions of senior management to achieve
these goals.</p>
      <p>Therefore, it refers to complex and multi-faceted processes of managing and
achieving strategic goals set by enterprises. Strategic planning is one of the most
important aspects of strategic management, being a promising tool for the scenario
method.</p>
      <p>
        The scenario method aims to identify several goals, which are different in content
but seek to realize the goals of strategic development [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. Two, three or more
scenarios are possible for strategic planning to increase energy security. Two scenarios allow
one to generate two opposite ideas about the future (pessimistic and optimistic). Three
scenarios indicate that one scenario serves as a forecast, being “optimal”. More than
three scenarios stimulate divergent thinking and can be used to form certain ideas [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>The scenarios of achieving an optimal level of energy security at enterprises can be
characterized as follows: 1) optimistic; 2) pessimistic; 3) realistic.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Related works</title>
      <p>
        Such scholars as [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] at work models energy security scenarios for Ireland using long
term macroeconomic forecasts to 2050, with oil production and price scenarios from
the International Monetary Fund, within the Irish TIMES energy systems model. The
analysis focuses on developing a least cost optimum energy system for Ireland under
scenarios of constrained oil supply.
      </p>
      <p>
        In [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], studies the first, there is a need to better understand how sources of
insecurity can develop over time and how they are affected by the development of the energy
system. Second, the current tendency to study the security of supply for each energy
carrier separately needs to be complemented by comparisons of different energy
carrier's supply chains.
      </p>
      <p>
        As a result [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] three distinct perspectives on energy security have emerged: the
“sovereignty” perspective with its roots in political science; the “robustness”
perspective with its roots in natural science and engineering; and the ‘resilience’ perspective
with its roots in economics and complex systems analysis.
      </p>
      <p>At present, the energy security challenges are increasingly entangled so that they
cannot be analyzed within the boundaries of any single perspective. To respond to
these challenges, the energy security studies should not only achieve mastery of the
disciplinary knowledge underlying all three perspectives but also weave the theories,
methods and knowledge from these different mindsets together in a unified
interdisciplinary effort.</p>
      <p>
        In the paper [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] compares three different indices, “Energy Sustainability Index”,
“International Index of Energy Security Risk” and “Energy Architecture Performance
Index” along with their variants to examine if they provide consistent results for
various countries. A comparative assessment reveals that the three indices provide
different country rankings, which are inconsistent.
      </p>
      <p>
        This situation is akin to three blind men groping the elephant with each one
measuring a different part of the body and asserting that only their assessment is true.
Further analysis reveals that countries which rank in the top of the list of different indices
are insensitive to differences in construction of the index and it can be inferred that
they have robust energy systems, which partly resolves the conflict [
        <xref ref-type="bibr" rid="ref10 ref11 ref12 ref8 ref9">8-12</xref>
        ].
3
      </p>
    </sec>
    <sec id="sec-3">
      <title>The model of energy security level</title>
      <p>The paper presents the authors’ scenarios under which they reflect changes in the
priority components of energy security to simulate the level of energy security at
enterprises under study. These components include resources and energy (Р1),
equipment and technologies (Р2), environment and society (Р3), finances and economy
(Р4), organization and management (Р5).</p>
      <p>
        Using the scenario method, one can determine the impact of each component of
energy security at enterprises and achieve an optimal level of energy security under
certain conditions [
        <xref ref-type="bibr" rid="ref13 ref14 ref15 ref16 ref17 ref18">13-18</xref>
        ].
      </p>
      <p>Table 1 shows weight coefficients of components of energy security at enterprises
for each of the five possible scenarios based on expert assessment.</p>
      <p>Such components as resources and energy (Р1) and equipment and technologies
(Р2) become the most important ones under scenario 1 (0.352 and 0.242). Under
scenario 2, such a component as equipment and technologies (Р2) is more significant
than resources and energy (Р1). At the same time, organization and management (Р5)
can be valued more than environment and society (Р3) (0.187 and 0.121). Under
scenario 3, more importance is given to environment and society (Р3) and finances and
economy (Р4), whereas less importance − to organization and management (Р5)
(0.099). As evidenced by scenario 4, such components of energy security as finances
and economy (Р4) and organization and management (Р5) are characterized by top
positions among all the components. Scenario 5 focuses on organization and
management (Р5).</p>
      <p>Consequently, these scenarios allow one to analyze changes in energy security
level at enterprises under study, taking into account the changes in weight coefficients of
each component.</p>
      <p>The paper employs an economic and mathematical dynamic model, reflecting the
development of the modelled system through trends, to forecast the level of the
integrated indicator in future periods and obtain the necessary information. It is required
to assess and forecast the impact of internal and external threats on the energy
security of enterprises.</p>
      <p>Forecasting based on a time series of certain economic indicators belongs to
onedimensional forecasting methods, at the core of which is extrapolation, that is, a
continuation of trends observed in previous periods towards future periods. Such as
approach assumes that a forecasted indicator is shaped by many factors one cannot
identify or investigate. Under these conditions, the dynamics of changes in this indicator is
associated not with factors but the passage of time, manifested in the creation of
onedimensional time series.</p>
      <p>
        The paper employs statistical methods of forecasting based on the use of historical
information presented through time series, that is, dynamics series structured by
temporal attributes. The main idea behind time series analysis lies in building a trend
based on past data and further extrapolation of this line into the future. However, in
doing so, complex mathematical procedures are used to obtain the exact value of the
trend line and trace any fluctuations [
        <xref ref-type="bibr" rid="ref19 ref20 ref21 ref22 ref23 ref24 ref25">19-25</xref>
        ].
      </p>
      <p>Thus, the time series implies the sequence of levels of the series:
{  } =  1,  2,…  
(1)
where  – natural numbers that correspond to the moments or intervals for
measuring the value under study.</p>
      <p>– levels of the series.</p>
      <p>Measurements are made at regular intervals.</p>
      <p>Such a method of forecasting can be presented through the following mathematical
model:
  +1 =   ,   , …   − ,  
(1)</p>
      <p>(1)
,   − 1,  
(2)</p>
      <p>(2)
, … ,   − 2, 
( )</p>
      <p>( )
, … ,   − 
(2)
 ;
where   – the value of the indicator being forecasted at a certain moment of time
 ( ) – the value of i factor at a certain moment of time  , which affects  ;
 ,  1,   – memory length of the series used during forecasting.</p>
      <p>
        The differences between different methods are related to the structure of the input 
and the type of function  (… ). Therefore, the paper uses one of the types of
dependencies used in modern forecasting methods, namely polynomial dependence. Time series
models in which the dynamics of the mean value of the series are described by
analytical dependence on time only are called trend models [
        <xref ref-type="bibr" rid="ref26 ref27 ref28 ref29 ref30">26-30</xref>
        ]. The trend model implies
the analytic function of the form below:
      </p>
      <p>=  ( ,  ⃗)
where  – the time set in certain units (years);
 ⃗ − a vector of parameters under which the model most accurately describes the
dependence of the series {  } on time  and ensures minimum fluctuations in actual
and modelled levels:</p>
      <p>( ⃗) = ‖  −  ( ,  )⃗
at a certain time interval  :     &lt;  &lt;    .</p>
      <p>It must be acknowledged that the function  ( ,  ⃗) can be not only a traditional
analytical (polynom) but also harmonic complex neural network.</p>
      <p>The input data for forecasting the level of energy security at enterprises are
calculated actual values of the level of this indicator under the proposed scenarios of ten
machine-building enterprises. Here is an algorithm that can forecast the level of
energy security at enterprises under study (Fig. 1).</p>
      <p>It is necessary to graphically represent the levels of the dynamic series, which is taken
as the basis for making forecasts, to establish the form of the mathematical equation
according to which they should be made.</p>
      <p>Visual analysis of the diagram can show what most accurately reflects a smooth
trend of the series, namely straight or curved lines. At the same time, the analysis of
coefficient values of correlation and approximation of different models proves that it
is essential to choose a polynomial trend model.
4</p>
    </sec>
    <sec id="sec-4">
      <title>Experiments</title>
      <p>The paper applies an algorithm for forecasting energy security level at enterprises and
reveals probable dependencies by using a forecast trend model for enterprises under
study. Table 2 shows forecast trends under five scenarios.
(3)
(4)
Building a forecast trend model</p>
      <p>=  ( ,  ⃗)
Analyzing the studied dependencies based on
the value of approximation reliability  2</p>
      <p>Constructing scenarios for changing
en</p>
      <p>ergy security level at enterprises</p>
      <p>Optimistic scenario
 ( 1,  2,  3,  4,  5)→</p>
      <p>Realistic
scenario
 &gt; &gt;</p>
      <p>Pessimistic
scenario
 ( 1,  2,  3,  4,  5)→ 
Years</p>
      <p>Thus, table 2 shows that the expected values of energy security level under these
scenarios are characterized by an increasing trend. Besides, some positive dynamics
proves a success in enterprises’ activities, as well as senior management’s ability to
deal with problematic situations, eliminate obstacles and threats to the external and
internal environment under unstable conditions. However, one should take into
account the maximum expected values of energy security level at enterprises under a
certain scenario to achieve maximum results in future periods. The paper also
attempts to demonstrate trend models under each scenario of enterprises under study
and calculate the values of approximation reliability  2 to determine optimal, real and
pessimistic scenarios. Figure 2 shows the forecast trend model of energy security
level at enterprises under study under scenario 1.
0,155
0,3
0,25
0,2
0,15
0,1
0,05</p>
      <p>Analyzing the obtained results, one can see that scenario 2 allows the trend model
of energy security level at enterprises under study to acquire the maximum value of  2
under these conditions.</p>
      <p>If  2 is equal to 0.9198, it implies certain close links and indicates that 91.98% of
the variation in energy security level at enterprises under study may be caused by the
variation in such a component as equipment and technologies. The coefficient of
remaining determination (1-0.9198) demonstrates that 8.02% of the variation in energy
security level is attributable to other causes.</p>
      <p>Figure 4 shows the forecast trend model of energy security level at enterprises
under study under scenario 3. It proves that the forecast increasing trends for the indicator
under scenario 3 are slightly slower than under the previous scenarios.
y = 0,0042x2 - 16,978x + 17101</p>
      <p>R² = 0,7078
0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021</p>
      <p>Thus, the level of energy security at enterprises under study is much less dependent
on the impact of such a component as environment and society compared to other
ones (resources and energy, equipment and technologies). If  2 is equal to 0.7078, it
interprets the impact of other factors at the level of 29.2%.</p>
      <p>Under these conditions, the forecast trend model of energy security level at
enterprises under study under scenario 3 has lower indicators of the energy security level
of at enterprises under study in future periods compared to the forecasts under
scenarios 1 and 2.</p>
      <p>Figure 5 shows the forecast trend model of energy security level at enterprises
under study under scenario 4.</p>
      <p>0,35
0,3
0,25
0,2
0,15
0,1
0,05
y = 0,0049x2 - 19,568x + 19709</p>
      <p>R² = 0,8264
0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Thus, one can conclude that the forecast is optimal since the obtained coefficient of  2
is now equal to 0.8264. It proves that the level of energy security depends on the
economic component by 82.64%, other components – by 17.36%. One should also pay
particular attention to some similarities between the conditions of scenarios 1 and 4
since  2 becomes 0.8313 if the priority is given to resources and energy and 0.8264 –
in case of the priority of the economic component. It confirms the complexity and
close links between certain components when achieving the maximum level of energy
security at enterprises under study.
0,3
0,25
0,2
0,15
0,1
0,05</p>
      <p>Table 3 shows the results obtained from the constructed forecast trend models and
presents optimistic, realistic and pessimistic scenarios for enterprises under study
Analyzing these calculations, it is possible to confirm the existence of the revealed
optimistic, realistic and pessimistic scenarios and expected values of energy security
level according to each of them.</p>
      <p>According to the proposed algorithm for forecasting the level of energy security at
enterprises by scenarios, three scenarios for the possible development of the indicator
under study have been developed. The obtained results allow one to conclude that this
algorithm reflects rather high-quality forecast trends. Regarding the studied
enterprises, the obtained forecast values for optimistic, realistic and pessimistic scenarios for
achieving the level of energy security are reliable.</p>
      <p>Therefore, the proposed methodical approach to determining the level of energy
security based on forecast trend modelling makes it possible to identify the impact of
individual components of energy security on its overall level and, thus, create
scenarios for achieving the expected value following the optimality of each scenario under
these conditions. The proposed methodical approach can be useful for enterprises
since it contributes to thorough integrated assessment of the overall level of their
energy security, its forecasting for future periods, which, in turn, will positively affect
energy supply and energy efficiency of production and economic activities.
5</p>
    </sec>
    <sec id="sec-5">
      <title>Conclusion</title>
      <p>Thus, an optimistic scenario is underpinned by the priority of organization and
management since the indicators of energy security level at enterprises can be maximized
for the next three years in case of its realization. Under scenario 5, enterprises can
reach the energy security level of 0.248 in 2020. A realistic scenario depends on the
presence of priority ( 1) and can help to reach the energy security level of 0.211 in
2019 and 0.244 in 2020. A pessimistic scenario ( 2) is characterized by the lowest
level of energy security. If such a scenario is chosen as the main one in maximizing
the value of energy security level, enterprises will not be able to increase this
indicator to the maximum achievable level.</p>
      <p>All the constructed models can help to reach rather high values of determination
coefficients, which indicates the high quality of these models. This situation is linked
to the lack of drastic changes in energy security level. Therefore, this forecasting
method is quite successful for the enterprise, and the results of this approach are
accurate.</p>
      <p>Therefore, the paper proves that energy security level at enterprises under study
should be modelled employing the scenario method, which can analyze the priority
components of the integrated indicator of energy security. It also presents the author’s
economic and mathematical dynamic model in which the development of the
modelled system can be represented as a trend to forecast the level of the integrated
indicator of energy security in future periods. Besides, it applies the method of statistical
forecasting based on the use of historical information presented in time series.</p>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgements</title>
      <p>The authors are grateful to their families for their patience and support in their
striving to study the current issues related to energy-efficient development and energy
security, as well as scientific advisers for believing in them and inspiration.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          1.
          <string-name>
            <surname>Ang</surname>
            ,
            <given-names>B. W.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Choong</surname>
            ,
            <given-names>W. L.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Ng</surname>
            ,
            <given-names>T. S.</given-names>
          </string-name>
          <article-title>Energy security: Definitions, dimensions, and indexes</article-title>
          .
          <source>Renewable and Sustainable Energy Reviews</source>
          ,
          <volume>42</volume>
          ,
          <fpage>1077</fpage>
          -
          <lpage>1093</lpage>
          (
          <year>2015</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          2.
          <string-name>
            <surname>Kharlamova</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Nate</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Chernyak</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          <article-title>Renewable energy and security for Ukraine: challenge or smart way</article-title>
          .
          <source>Journal of International Studies</source>
          ,
          <volume>9</volume>
          (
          <issue>1</issue>
          ),
          <fpage>88</fpage>
          -
          <lpage>115</lpage>
          (
          <year>2016</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          3.
          <string-name>
            <surname>Asaul</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Voynarenko</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Dzhulii</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Yemchuk</surname>
            ,
            <given-names>L</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Skorobohata</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Mykoliuk</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          <article-title>The latest information systems in the enterprise management and trends in their development</article-title>
          .
          <source>The 9th International Conference Advanced computer information technologies IEEE</source>
          ,
          <string-name>
            <surname>Ceske</surname>
            <given-names>Budejovice</given-names>
          </string-name>
          , Czech Republic, pp.
          <fpage>362</fpage>
          -
          <lpage>365</lpage>
          , (ACIT`
          <year>2019</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          4.
          <string-name>
            <surname>Glynn</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Chiodi</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Gargiulo</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Deane</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Bazilian</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>ÓGallachóir</surname>
            ,
            <given-names>B. Energy Security</given-names>
          </string-name>
          <article-title>Analysis: The case of constrained oil supply for Ireland</article-title>
          .
          <source>Energy Policy</source>
          ,
          <volume>66</volume>
          , pp.
          <fpage>312</fpage>
          -
          <lpage>325</lpage>
          (
          <year>2014</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          5.
          <string-name>
            <surname>Månsson</surname>
          </string-name>
          , А.,
          <string-name>
            <surname>Johansson</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Nilsson</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          <article-title>Assessing energy security: An overview of commonly used methodologies</article-title>
          ,
          <source>Energy</source>
          ,
          <volume>73</volume>
          , pp.
          <fpage>1</fpage>
          -
          <lpage>14</lpage>
          (
          <year>2014</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          6.
          <string-name>
            <surname>Cherp</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Jewell</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          <article-title>The three perspectives on energy security: intellectual history, disciplinary roots and the potential for integration</article-title>
          .
          <source>Current Opinion in Environmental Sustainability</source>
          ,
          <volume>3</volume>
          (
          <issue>4</issue>
          ), pp.
          <fpage>202</fpage>
          -
          <lpage>212</lpage>
          (
          <year>2011</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          7.
          <string-name>
            <surname>Narula</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Reddy</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          <article-title>Three blind men and an elephant: The case of energy indices to measure energy security and energy sustainability</article-title>
          ,
          <source>Energy</source>
          ,
          <volume>80</volume>
          , pp.
          <fpage>148</fpage>
          -
          <lpage>158</lpage>
          (
          <year>2015</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          8.
          <string-name>
            <surname>Byrne</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Taminiau</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          <article-title>A review of sustainable energy utility and energy service utility concepts and applications: realizing ecological and social sustainability with a community utility”</article-title>
          ,
          <source>Wiley Interdisciplinary Reviews: Energy and Environment</source>
          ,
          <volume>5</volume>
          (
          <issue>2</issue>
          ), pp.
          <fpage>136</fpage>
          -
          <lpage>154</lpage>
          (
          <year>2016</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          9.
          <string-name>
            <surname>Mykoliuk</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Bobrovnyk</surname>
            ,
            <given-names>V.</given-names>
          </string-name>
          <article-title>Strategic Guidelines on Development of Renewable Energy Sources</article-title>
          ,
          <source>Global Journal of Environmental Science and Management, 5(SI)</source>
          , pp.
          <fpage>61</fpage>
          -
          <lpage>71</lpage>
          (
          <year>2019</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          10.
          <string-name>
            <surname>Amarasinghe</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Marino</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Manic</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          <article-title>Deep neural networks for energy load forecasting, Industrial Electronics (ISIE)</article-title>
          ,
          <source>IEEE 26th International Symposium</source>
          , Edinburgh, UK, pp.
          <fpage>1483</fpage>
          -
          <lpage>1488</lpage>
          (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          11.
          <string-name>
            <surname>Fan</surname>
            ,
            <given-names>Z.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Che</surname>
            ,
            <given-names>Y.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Chen</surname>
            ,
            <given-names>Z.</given-names>
          </string-name>
          <article-title>Product sales forecasting using online reviews and historical sales data: A method combining the Bass model and sentiment analysis</article-title>
          ,
          <source>Journal of Business Research</source>
          ,
          <volume>74</volume>
          , pp.
          <fpage>90</fpage>
          -
          <lpage>100</lpage>
          (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          12.
          <string-name>
            <surname>Wei</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          <article-title>A hybrid ANFIS model based on empirical mode decomposition for stock time series forecasting</article-title>
          , Applied Soft Computing,
          <volume>42</volume>
          , pp.
          <fpage>368</fpage>
          -
          <lpage>376</lpage>
          (
          <year>2016</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          13.
          <string-name>
            <surname>Rubio-Herrero</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Chandan</surname>
            ,
            <given-names>V.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Siegel</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Vishnu</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Vrabie</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          <article-title>A Learning Framework for Control-Oriented Modeling of Buildings. Machine Learning and Applications (ICMLA),</article-title>
          16th IEEE International Conference, Cancun, Mexico, pp.
          <fpage>473</fpage>
          -
          <lpage>478</lpage>
          (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          14.
          <string-name>
            <surname>Islamutdinov</surname>
            <given-names>V.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Ustyuzhantseva</surname>
            <given-names>A</given-names>
          </string-name>
          .
          <article-title>The Model to Assess Economic Security of Fuel and Energy Complex Enterprises of the Northern Resource-Producing Region Taking into Account the Behavioral Aspect</article-title>
          ,
          <source>International Journal of Mechanical Engineering and Technology</source>
          ,
          <volume>9</volume>
          (
          <issue>8</issue>
          ), pp.
          <fpage>1161</fpage>
          -
          <lpage>1171</lpage>
          (
          <year>2018</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          15.
          <string-name>
            <surname>Hortal</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          <article-title>Empiricism in Herbert Simon: Administrative behavior within the evolution of the models of bounded and procedural rationality</article-title>
          ,
          <source>Brazilian Journal of Political Economy</source>
          ,
          <volume>37</volume>
          (
          <issue>4</issue>
          ), pp.
          <fpage>719</fpage>
          -
          <lpage>733</lpage>
          (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          16.
          <string-name>
            <surname>Alier</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Pascual</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Vivien</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Zaccai</surname>
            <given-names>E.</given-names>
          </string-name>
          <article-title>Sustainable degrowth: Mapping the context, criticisms and futureprospects of an emergent paradigm</article-title>
          ,
          <source>Ecological Economics</source>
          ,
          <volume>69</volume>
          (
          <issue>9</issue>
          ), pp.
          <fpage>1741</fpage>
          -
          <lpage>1747</lpage>
          (
          <year>2010</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          17.
          <string-name>
            <surname>Steinmann</surname>
            ,
            <given-names>Z.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Schipper</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Hauck</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Huijbregts</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          <article-title>How many environmental impact indicators are needed in the evaluation of product life cycles? Environmental Science</article-title>
          and Technology,
          <volume>50</volume>
          (
          <issue>7</issue>
          ) pp.
          <fpage>3913</fpage>
          -
          <lpage>3919</lpage>
          (
          <year>2016</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          18.
          <string-name>
            <surname>Wiedenhofer</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Fishman</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Lauk</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Haas</surname>
            ,
            <given-names>W.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Krausmann</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          <string-name>
            <surname>Integrating Material Stock Dynamics Into Economy-Wide Material Flow Accounting: Concepts</surname>
          </string-name>
          ,
          <source>Modelling, and Global Application for 1900-2050</source>
          , Ecological Economics,
          <volume>10</volume>
          , pp.
          <fpage>121</fpage>
          -
          <lpage>133</lpage>
          (
          <year>2019</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          19.
          <string-name>
            <surname>Kvon</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Prokopyev</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Shestak</surname>
            ,
            <given-names>V.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Ivanova</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Vodenko K. Energy Saving</surname>
          </string-name>
          <article-title>Projects as Energy Security Factors</article-title>
          .
          <source>International Journal of Energy Economics and Policy</source>
          ,
          <volume>8</volume>
          (
          <issue>6</issue>
          ), pp.
          <fpage>155</fpage>
          -
          <lpage>160</lpage>
          (
          <year>2018</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          20.
          <string-name>
            <surname>Mocanu</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Nguyen</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Gibescu</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Kling</surname>
            ,
            <given-names>W.</given-names>
          </string-name>
          <article-title>Deep learning for estimating building energy consumption Sustainable Energy</article-title>
          ,
          <source>Grids and Networks</source>
          ,
          <volume>6</volume>
          , pp.
          <fpage>91</fpage>
          -
          <lpage>99</lpage>
          (
          <year>2016</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation>
          21.
          <string-name>
            <surname>Zame</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Brehm</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Nitica</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Richard</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Schweitzer</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          <article-title>Smart grid and energy storage: Policy recommendations</article-title>
          ,
          <source>Renewable and Sustainable Energy Reviews</source>
          ,
          <volume>82</volume>
          , pp.
          <fpage>1646</fpage>
          -
          <lpage>1654</lpage>
          (
          <year>2018</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation>
          22.
          <string-name>
            <surname>Ang</surname>
            ,
            <given-names>B. W.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Choong</surname>
            ,
            <given-names>W. L.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Ng</surname>
            ,
            <given-names>T. S.</given-names>
          </string-name>
          <article-title>Energy security: Definitions, dimensions, and indexes</article-title>
          .
          <source>Renewable and Sustainable Energy Reviews</source>
          ,
          <volume>42</volume>
          ,
          <fpage>1077</fpage>
          -
          <lpage>1093</lpage>
          (
          <year>2015</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation>
          23.
          <article-title>The Ukraine's Energy Strategy for 2035 «Safety, Energy Efficiency</article-title>
          ,
          <article-title>Competitiveness» approved by the Cabinet of Ministers of Ukraine as of August 18,</article-title>
          <year>2017</year>
          №
          <fpage>605</fpage>
          -
          <lpage>r</lpage>
          . Retrieved from http://zakon0.rada.gov.ua/laws/show/605-2017-%D1%
          <fpage>80</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation>
          24.
          <string-name>
            <surname>Ukraine</surname>
          </string-name>
          <article-title>'s New Energy Strategy by 2020: Security, Energy Efficiency</article-title>
          , Competition. Retrieved from http://www.razumkov.org.ua/ua/upload/Draft%20Strategy_
          <fpage>00</fpage>
          %
          <issue>20</issue>
          (
          <issue>7</issue>
          ).pdf.
        </mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation>
          25. Ukraine-2020
          <source>Sustainable Development Strategy, approved by Decree of the President of Ukraine dated January 12</source>
          ,
          <year>2015</year>
          № 5. Retrieved from http://zakon5.rada.gov.ua/laws/show/5/2015.
        </mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation>
          26.
          <string-name>
            <surname>Zlotenko</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Rudnichenko</surname>
            ,
            <given-names>Y.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Illiashenko</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Voynarenko</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Havlovska</surname>
            ,
            <given-names>N.</given-names>
          </string-name>
          <article-title>Optimization of the sources structure of financing the implementation of strategic guidelines for ensuring the economic security of investment activities of an industrial enterprise</article-title>
          , Technology, Education, Management, Informatics,
          <volume>8</volume>
          , (
          <issue>2</issue>
          ), pp.
          <fpage>498</fpage>
          -
          <lpage>506</lpage>
          (
          <year>2019</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref27">
        <mixed-citation>
          27.
          <string-name>
            <surname>Hovorushchenko</surname>
          </string-name>
          ,
          <source>T. Information Technology for Assurance of Veracity of Quality Information in the Software Requirements Specification, Advances in Intelligent Systems and Computing</source>
          ,
          <volume>689</volume>
          , pp.
          <fpage>166</fpage>
          -
          <lpage>185</lpage>
          (
          <year>2018</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref28">
        <mixed-citation>
          28.
          <string-name>
            <surname>Elbassoussy</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <article-title>"European energy security dilemma: major challenges and confrontation strategies"</article-title>
          ,
          <source>Review of Economics and Political Science</source>
          , Vol.
          <volume>4</volume>
          No.
          <issue>4</issue>
          , pp.
          <fpage>321</fpage>
          -
          <lpage>343</lpage>
          . (
          <year>2019</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref29">
        <mixed-citation>
          29.
          <string-name>
            <surname>Bublyk</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Koval</surname>
            ,
            <given-names>V.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Redkva</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          <article-title>Analysis impact of the structural competition preconditions for ensuring economic security of the machine building complex</article-title>
          .
          <source>Marketing and Management of Innovations</source>
          ,
          <volume>4</volume>
          ,
          <fpage>229</fpage>
          -
          <lpage>240</lpage>
          (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref30">
        <mixed-citation>
          30.
          <string-name>
            <surname>Izonin</surname>
            <given-names>I.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Tkachenko</surname>
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Kryvinska</surname>
            <given-names>N.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Tkachenko</surname>
            <given-names>P.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Greguš</surname>
            <given-names>ml. M.</given-names>
          </string-name>
          (
          <year>2019</year>
          )
          <article-title>Multiple Linear Regression Based on Coefficients Identification Using Non-iterative SGTM Neural-like Structure</article-title>
          . In:
          <string-name>
            <surname>Rojas</surname>
            <given-names>I.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Joya</surname>
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Catala</surname>
            <given-names>A</given-names>
          </string-name>
          . (eds)
          <article-title>Advances in Computational Intelligence</article-title>
          .
          <source>IWANN 2019. Lecture Notes in Computer Science</source>
          , vol
          <volume>11506</volume>
          . Springer, Chan.
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>