=Paper= {{Paper |id=Vol-3392/paper20 |storemode=property |title=Approach to Search Result Rankings Based on User Ratings |pdfUrl=https://ceur-ws.org/Vol-3392/paper20.pdf |volume=Vol-3392 |authors=Viacheslav Zosimov,Oleksandra Bulgakova |dblpUrl=https://dblp.org/rec/conf/cmis/ZosimovB23 }} ==Approach to Search Result Rankings Based on User Ratings== https://ceur-ws.org/Vol-3392/paper20.pdf
Approach to Search Result Rankings Based on User Ratings
Viacheslav Zosimov a, Oleksandra Bulgakova a
a
    Taras Shevchenko National University of Kyiv, Bohdan Hawrylyshyn str. 24, Kyiv, 04116, Ukraine


                 Abstract
                 This paper proposed an approach to rank search results based on user ratings, with a
                 subjective approach to the ranking process. Expert groups unique to each user are created to
                 achieve this effect. When no common ratings are available, the expert group is formed based
                 on a model built on the user's social profile, utilizing inductive algorithms such as a
                 polynomial neural network with active neurons.
                 The approach of ranking search results provides a unique order of elements for each user's
                 list of web resources. This effect is achieved by using evaluations from an expert group that
                 is unique to each user, as well as by incorporating each evaluation into the model for
                 calculating final rankings of web resources with its unique weight, calculated based on their
                 previous activity in the system. The resulting ranking model is much more difficult to falsify
                 because it is based on subjective factors. The ranking model will be unique for each user.
                 Falsifying it would require reproducing the preferences of each user, which is much more
                 difficult than acquiring links to one's web resource from authoritative sources.

                 Keywords 1
                 Ranking, search results, user ratings, expert groups, social profile, inductive algorithms,
                 polynomial neural network, active neurons

1. Introduction

    Currently, online advertising is the most effective way of promoting a business. This has resulted
in search engines no longer being a tool for obtaining information, but rather becoming advertising
platforms that display to the user not the pages that are most relevant to their informational needs, but
rather those for which more money has been invested in their promotion. Search engines benefit from
artificially lowering the quality of organic search results, as contextual advertising, which is often
irrelevant to the search query, appears more appropriate against that backdrop.
    The ranking algorithms of search engines take into account a large number of factors, but the main
weight is given to the page ranking, which is calculated based on the analysis of the quantity and
quality of external links to the page. Such evaluation methods are objective, but they can be easily
falsified with a certain advertising budget by purchasing the necessary amount of high-quality links
from external sources. This implies that they are oriented towards satisfying the needs of advertisers
rather than users.
    In [1], described learning-based ranking model is proposed to improve recommendation systems
with implicit user feedback. In [2], a ranking model is described that uses adaptive learning to
improve content-based recommendation systems. In [3] develops a hybrid ranking model for
scientific articles that combines content-based and citation-based methods. The ranking model using
neural networks and weak supervision is described in [4-5]. It can work with incomplete data, making
it more universal and convenient to use. However, the drawback is the complexity of understanding
the principles of neural network operation. [6] is dedicated to using BERT (Bidirectional Encoder
Representations from Transformers) for ranking in search engines. Research results have shown that

The Sixth International Workshop on Computer Modeling and Intelligent Systems (CMIS-2023), May 3, 2023, Zaporizhzhia, Ukraine
EMAIL: zosimovvv@gmail.com (A. 1); sashabulgakova2@gmail.com (A. 2)
ORCID: 0000-0003-0824-4168 (A. 1); 0000-0002-6587-8573 (A. 2);
            © 2023 Copyright for this paper by its authors.
            Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
            CEUR Workshop Proceedings (CEUR-WS.org) Proceedings
BERT provides high accuracy compared to traditional ranking methods. However, its implementation
requires significant computational resources. [7] proposed a new approach to ranking that uses
reinforcement learning to aggregate different page ratings. Results have shown improvement in
ranking accuracy. However, the drawback is the need for significant computational resources and
implementation complexity.
    In [8] authors discuss sentiment analysis methods, including rule-based and machine learning-
based methods, and provide examples of their applications in various domains, such as social media
monitoring and product review analysis. In conclusion, the authors highlight the importance of
integrating recommender systems and sentiment analysis for creating more effective and personalized
recommendation systems.
    The development describes in [9] is designed to improve the relevance of search within
organizations and enterprises by automatically identifying and capturing the knowledge and expertise
of their employees. This can provide more accurate and relevant search results by linking search
queries to employees who possess the necessary expertise.
    However, one potential drawback of this system is its potential inefficiency in using contextual
information. It's important to consider not only the keywords but also the context in which they are
used and other related factors when conducting searches. If the system doesn't account for context and
can't adapt to changing user requirements, it can lead to irrelevant or incomplete results.
    Brytsov R.A. researches this problem. In his work [10], he presented a theoretical ranking model
based on web resource visit statistics and document viewing time. However, it does not take into
account the opinions of users about the web resources, as well as the level of agreement between users
and experts. Ranking methods based on user ratings are widely used for ranking products in online
stores. However, they are also based solely on the number of ratings and their numerical values.
    Overall, recent research has shown that the use of neural networks and reinforcement learning can
improve ranking accuracy in search engines. However, these approaches require significant
computational resources.
    Information retrieval is the process of searching for unstructured documentary information that
satisfies the user's information needs [11]. Given that user information needs are individual and
subjective, this definition suggests that search result ranking algorithms should be based on subjective
factors specific to each user.
    Therefore, the development of methods for personalizing search engine results by providing users
with search management tools and the development of new ranking models based on subjective user
information needs is a pressing task.
    In this paper proposed an approach to ranking search results based on user ratings. The main
difference of this method is the subjective approach to the ranking process. This effect is achieved by
creating expert groups unique to each user. In the absence of any common ratings, the expert group is
formed based on a model built on the user's social profile using inductive algorithms, namely a
polynomial neural network with active neurons.

2. Formation of expert groups
   In the real task of ranking search results, user ratings are used as input data for which their status
as an expert is not defined. Obviously, accepting the opinions of all users who have rated a web
resource as expert would be incorrect. It is also evident that the ratings and personal data provided
during registration are not sufficient to unambiguously identify a user as an objective expert in the
subject area. However, this data is sufficient to determine subjective expert groups for each user based
on the criterion of proximity of the user's ratings to those of each expert.
   In this work, for the search query of the current user, the ranks of web resources from the search
output are calculated as the weighted harmonic mean of all ratings from the members of the expert
group. Expert groups for each network user are unique and are formed in the background mode of the
system using three methods, depending on the presence of common ratings on a certain set of web
resources between the current user and a potential expert. For convenience of presentation, experts are
divided into three levels according to the method of calculating their weight. The division into levels
is only of a logical nature. The weight of experts from all levels is equivalent and is taken into account
when ranking search results without additional coefficients.
    To establish clarity in the definitions, the following terms are proposed within the framework of
the research:
    Current user U0 - the user for whom the group of experts is formed and for whom the ranking of
search results is carried out.
    Expert weight - a measure of the agreement between the expert's opinion and the current user's
opinion, calculated based on the similarity of their assessments for a certain set of web resources.
    First-level potential expert Ui - a user who shares ratings with the current user, but whose level of
agreement has not yet been calculated.
    Second-level potential expert Û j - a user who does not share ratings with the current user, but
shares ratings with a first-level expert.
   Third-level potential expert U~k - a user who does not share ratings with the current user or first-
level experts.

2.1.     Calculating the weight of first‐level experts

    Direct calculation can be applied in case the current user shares ratings with a set of potential
experts X for some set of web resources. It allows calculating the similarity of ratings for each pair of
“current user - potential expert” d(U0, Ui) separately. User ratings have values from 1 to 10, where 10
represents the most acceptable option. The expert's weight value is determined as the arithmetic mean
of the absolute differences between each pair of the user's and potential expert's ratings:
                                                        m     U 0j  U ij
                                          d(U 0 ,U i )                                                   (1)
                                                       j 1       m
where m is the number of common ratings that the current user has with the i-th potential expert from
the set X, and j is the ordinal number of the rating. The quality of the connection is evaluated using the
Shewhart chart. Candidates with high and very high connection strength are selected as experts. The
weight of expert Ui relative to the current user U0 is expedient to consider as a metric d(U0, Ui) in the
metric space (X, d), where X[U0, …, Un] is the set of all system users. The function d satisfies the
axioms of identity, symmetry, and triangle, but it cannot be defined for every pair of elements in the
set X, since not all users have common ratings. Therefore, in the context of this problem, it is incorrect
to use the term metric space, so in the future, we will refer to the function d(U0, Ui) for determining
the weight of the expert as an analogue of a metric. Expert weight values are numbers within the
interval d(U 0 ,U i )  0 ,... ,0.9  , therefore, to determine a qualitative assessment, the result of a
normalizing function is used, rather than the value itself:
                                                                d(U 0 ,U i ) 
                                           W ( d )  1   1,1                                        (2)
                                                                   10        

2.2.     Calculating the weight of second‐level experts

   Forming expert groups only from those users who have common ratings with the current user
significantly narrows down the circle of potential experts. To solve this problem, a method for
calculating the weight of experts in the absence of common ratings with the current user has been
proposed. It assumes the presence of common ratings with first-level experts and determines the
overall weight of a potential second-level expert with respect to the current user d(U 0 ,Û j ) taking into
account their weight relative to the first-level expert d(U i ,Û j ) and the weight of the first-level expert
relative to the current user d(U i ,Û j ) .
   The weight of second-level experts relative to the current user is expedient to calculate as the
product of the weight of the first-level expert relative to the second-level potential expert who has
common ratings and the weight of the first-level expert relative to the current user:
                                    W(d(U 0 ,Û j ))  W ( d(U i ,Û j ))  W ( d(U 0 ,U i ))                                    (3)
   The expert group includes second-level potential experts whose weight relative to the current user
is W(d(U0 ,Û j )) > 0.7.


2.3.     Calculating the weight of third‐level experts

   The proposed method can be applied when there are a low number or absence of shared ratings,
based on a model for calculating the weight of potential experts constructed from personal social
profiles. The calculation of the weight of potential experts based on their past activity always yields
the most accurate results. However, during the implementation and early stages of system operation,
there will inevitably be situations where there is insufficient data to apply this method. Accumulating
a certain base of ratings, i.e., the presence of shared ratings in the database in sufficient quantities to
form expert groups for most system users, is necessary for its application. Therefore, to ensure correct
system operation at an early stage of implementation, a method for determining the weight of users
who have no shared ratings was developed. The user's social profile is formed based on the
information they provide during registration in the system [12]. To build a model for calculating the
weight of experts, a number of subjective features xm were selected, which may directly or indirectly
affect the visitor's evaluation.
   For modeling the degree of consensus among experts, a generalized iterative algorithm (GIA) of
inductive modeling was chosen - a polynomial network with active neurons [13].
   Formally, in the general case, the GIAI for a layer r is defined:

   1.    The input matrix is X r 1  ( y1r ,..., y Fr , x1 ,, xm ) .
   2.    Transition        operators        of      the      form         ylr 1  f ( yir , y rj ), l  1,2,, CF2 , i, j  1, F and
   ylr 1  f ( yir , x j ), l  1,2,, Fm, i  1, F , j  1, m with a quadratic partial description are applied.
   3. For                 each                description,                  the                  optimal          structure
    f (u, v)  a0 d1  a1 d 2 u  a2 d3 v  a3 d 4 uv  a4 d5 u 2  a5 d 6 v 2 ,         d opt    arg min CR , q  2 p  1 ,
                                                                                                                 l
                                                                                                       l 1, q

   d k  {0, 1} , f opt (u , v )  f (u , v , d opt ) is found;
   4. The algorithm stops when CRmin                    r 1     r and the optimal model corresponds to the value
                                                              CRmin
     r
   CRmin for the r-th layer. Usually, the criterion of regularity is applied:
                                                                     2                 2
                                               ARB A  y B  yˆ B         y B  X BˆA ,                                        (4)
   based on dividing the data sample into two non-overlapping sub-samples - training set A and
   validation set B, W T  ( AT BT ) where ŷ B is the estimate of the output on B by a model, ˆA vector
   of parameters of which is calculated on A.
   Figure 1 represents a system that takes an input X and uses it to generate different models on next
layer r. The generated models are passed to an active neuron block that optimizes their complexity
using combinatorial optimization and selects F best models. The system then computes the error for
each model, selects F best models again, and repeats the process until only one model is left. The final
model is selected based on having the lowest error. Finally, the system outputs the value of y.
Figure 1: GIA scheme


3. Results
    For comparing the results of the coherence of experts' opinions using the methods described above,
a data sample was used in which 20 users evaluated 20 web resources based on the quality of
presented information and ease of use. The evaluation scale ranged from 1 to 10, where 10 is the best
score. Expert #0 is the current user, and a group of experts is selected based on their ratings. For ease
of understanding, the web resources will be denoted by capital Latin letters with a digital index equal
to the number of the data sample, and the user numbers will be represented by digits.
    For each potential expert paired with user #0, a measure of consensus of opinions was calculated
(Table 1).

Table 1
Measures of concordance of user #0's opinions with each of the potential experts
                             User                     The weight value of the
                                                   potential expert | correlation
                                                           strength >0.7
                               1                             0.9285 | +
                               2                             0.8735 | +
                               3                             0.9010 | +
                               4                             0.9120 | +
                               5                             0.6370 | ‐
                               6                             0.9120 | +
                                  7                             0.5765 | ‐
                                  8                             0.8955 | +
                                  9                             0.8955 | +
                                 10                             0.9010 | +
                                 11                             0.9285 | +
                                 12                             0.9175 | +
                                 13                             0.6975 | ‐
                                 14                             0.8570 | +
                                 15                             0.6315 | ‐
                                 16                             0.5600 | ‐
                                 17                             0.5270 | ‐
                                 18                             0.7580 | +
                                 19                             0.7195 | +
                                 20                             0.7525 | +


    To develop a methodology for considering the weight of second-level experts in ranking, it is
necessary to choose criteria for assessing the ratio of the weight of second-level experts to the current
user, expressed through the weight of first-level experts. Fig. 2-3 shows the modules of the
differences in weight of second-level experts and their weights relative to the current user.
    The diagram in Fig. 2 shows the dependence of the average difference in weight of second-level
experts relative to the weight of first-level experts. The graph shows that the weight deviation
significantly increases when the weight values of first-level experts are less than 0.8.
   Potential second-level experts whose weight relative to the current user is W(d(U0 ,Û j )) > 0.7 are
selected for the expert group.




Figure 2: The dependence of the average difference in weight of a second‐level user on the weight
of a first‐level expert
Figure 3: The weight differences in of second level users


    The calculation of the weight of potential experts based on the analysis of their previous activities
always gives the most accurate results. However, during the system's introduction and the period from
the beginning of its operation until a certain database of ratings has accumulated, situations will
inevitably arise where there is not enough data for its application. By accumulating a certain database
of ratings, it is meant having a sufficient number of shared ratings in the database to form expert
groups for most users of the system. Therefore, to ensure the proper functioning of the system at an
early stage of its operation, the GIA algorithm is used at the third level to determine the weight of
users who have no shared ratings at all. The generalized iterative algorithm is a set of iterative and
iterative-combinatorial algorithms defined by the components of a vector of three index sets: DM
(Dialogue Mode), IC (Iterative-Combinatorial), MR (Multilayered-Relaxative), where any iterative
algorithm is defined as a specific case of the generalized UIA = {DM, IC, MR}. DM can take three
values: 1 - standard automatic mode; 2 - planned automatic mode; 3 - interactive mode; IC can take
two values: 1 - iterative and 2 - iterative-combinatorial algorithms; MR can take three values: 1 -
classical multilayered, 2 - relaxative, 3 - combined algorithms [13].
    The input data consisted of social profiles of users (U0-U60) who participated in previous
experiments. Since their weight relative to user U0 had already been calculated on the rating data
samples, the same expert groups were used for building the model.
    To determine in terms of users who have no common ratings with both the current user and the
members of the expert group U0,exp, we will refer to them as potential third-level experts. It is
necessary to build a model of the influence of socio-personal factors of Internet users on the degree of
agreement of opinions between the potential third-level expert and the current user. The sample was
randomly divided into two sub-samples in the following proportions: 70% - testing, 30% - validation.
The obtained model is an intermediate stage for solving the given task under time constraints. Table 2
shows the values of actual and modeled results on samples A and B for GIA. In Figure 4 the
generalized iterative algorithm reaches a minimum on the 7th layer.
    The proposed methodology is applied to the task of ranking search results in the search engine
Google.com.ua. At first glance, this task seems very laborious, considering the large number of
results, which in most cases reaches hundreds of thousands, or even several million. However, upon
closer analysis of the algorithms used by search engines, it turns out that the computational
complexity of the task is several orders of magnitude lower [14]. The actual number of search results
that a user has access to be much smaller than what the system claims when performing a search
query.

Table 2
The values of actual and modeled results on samples A and B for GIA
     Sub‐samples               Real data, y            Model data, ŷ
                                      1                         0,904
                                   0,9285                       0,895
                                   0,8735                       0,752
                                   0,901                        0,882
                                   0,912                        0,810
                                   0,637                        0,628
                                   0,912                        0,865
           А                       0,5765                       0,637
                                   0,8955                       0,818
                                   0,8955                       0,961
                                   0,901                        0,911
                                   0,9285                       0,886
                                   0,9175                       0,928
                                   0,6975                       0,737
                                   0,857                        0,856
                                   0,6315                       0,730
                                    0,56                        0,680
           В                       0,527                        0,574
                                   0,758                        0,788
                                   0,7195                       0,814
                                   0,7525                       0,750




Figure 4: The values of the evaluation criterion (AR criterion) for the layers R

   To verify the effectiveness and correctness of the methods presented above for solving the problem
of ranking web resources based on user ratings, four experiments were conducted. Four data samples
were formed, one for each experiment (Table 1-2). In each sample, 20 users rated 20 web resources
based on the quality of the presented information and ease of use. A total of 60 users were involved in
forming the four samples. Some users participated in rating web resources in more than one sample.
However, the same users were denoted with the same numbers in all four experiments, for example,
user #1 in each experiment is the same person. Each experiment involved several experts from the
previous experiment and new users. This was done to be able to trace the weight values of the same
experts in different data samples. Before starting the ranking of web resources according to the chosen
methods, it is necessary to obtain a reference ranking against which the results will be compared.
Simple sorting of web resources in decreasing order of user 0's ratings only provides approximate
results. Such a method only orders a group of web resources with the same ratings in decreasing
order. The true order of web resources within each group remains unknown. Therefore, to construct a
reference ranking, user 0 assigned a rank from 1 to 20 to each web resource, where 1 is the highest
rank.
   Manual ranking was used to create the reference ranking for the current user. The next step is to
construct a ranking based on median values and assign new ranks. The new rank for a web resource
with a unique value is equal to its position in the ordered list. In case several web resources have the
same ranks based on median values, their new ranks are the arithmetic means of their positions in the
ordered list. As some web resources received the same score, they are considered equivalent and are
grouped into an equivalence class. To evaluate the efficiency of the aforementioned methods for
calculating average scores, the average deviation from the reference ranking is used. It is calculated as
the arithmetic mean of the differences between the positions of web resources.
   The summarized results of the conducted experiments are presented in Table 3.

Table 3
Measures of concordance of user #0's opinions with each of the potential experts
                     Experiment number              Weighted harmonic mean
                   #1 The sum of deviations                     18
                  Average value of deviation:                   0,9
                   #2 The sum of deviations                     24
                  Average value of deviation:                   1.2
                   #3 The sum of deviations                     22
                  Average value of deviation:                   1.1
                   #4 The sum of deviations                     20
                  Average value of deviation:                    1
                         Best results                            4

   The last row of the Table 3 shows the number of times the determined method provided the best
ranking results. If more than one method showed the best results during the experiment, they are all
considered the best.
   The methodology for building a personalized web ranking model based on user ratings has shown
high effectiveness, indicating the potential for developing this direction further.
   The developed method for ranking search results generates a unique ordering of web resources for
each user. This is achieved by using ratings from expert groups unique to each user, and by assigning
each rating a unique weight calculated based on the user's previous activity in the system.
   The resulting ranking model is much more difficult to falsify because it is based on subjective
factors. Each user will have a unique ranking model, and falsifying it would require reproducing each
user's preferences, which is much more difficult than acquiring links to their website from
authoritative sources.

4. Conclusions

    An approach to ranking search results based on user ratings is proposed. The main difference of
this method is the subjective approach to the ranking process. This effect is achieved by forming
expert groups unique to each user. Experts are selected based on the degree of agreement with the
current user, calculated based on the common ratings for a certain set of web resources. Selection of
users for the expert group is based on their weight relative to the current user, which is a measure of
their agreement.
    A methodology for forming unique expert groups for each user is proposed, which includes three
levels depending on the presence of common ratings for a certain set of web resources between the
current user and potential experts. The first level involves selecting potential experts based on their
common ratings with the current user for a certain set of web resources. The second level involves
selecting potential experts based on their agreement with the current user on a certain set of web
resources. The third level involves selecting potential experts based on their weight relative to the
current user, which is a measure of their agreement.
    The proposed method has several advantages over traditional ranking methods. First, it takes into
account the subjective nature of user preferences. Second, it allows for the formation of unique expert
groups for each user, which can improve the accuracy of the ranking results. Third, it provides users
with tools to manage their search results.
    The next step in the development of this approach could be to construct ranking models based on a
large number of factors, similar to modern search engines. By incorporating additional factors such as
click-through rates, time spent on a page, and other user behavior data, it may be possible to further
improve the accuracy of the ranking results.

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