=Paper= {{Paper |id=Vol-3360/p07 |storemode=property |title=Enhancing Movie Recommenders by means of KNN-based Algorithms |pdfUrl=https://ceur-ws.org/Vol-3360/p07.pdf |volume=Vol-3360 |authors=Kamil Rojek,Rafał Ochorok,Maciej Wiencis |dblpUrl=https://dblp.org/rec/conf/system/RojekOW22 }} ==Enhancing Movie Recommenders by means of KNN-based Algorithms== https://ceur-ws.org/Vol-3360/p07.pdf
Enhancing Movie Recommenders by means of KNN-based
Algorithms
Kamil Rojek1 , Rafał Ochorok1 and Maciej Wiencis1
1
    Faculty of Applied Mathematics, Silesian University of Technology, Kaszubska 23, 44-100 Gliwice, Poland


                                          Abstract
                                          The project concerns a system recommending films using the KNN algorithm. The program in order to find movies, is based
                                          on the history of viewed items. Movie Recommender initially chooses the best ones from the history of films, in order
                                          to finally give the proposals best suited to the user’s preferences. The model works with data from IMDB [? ] data set
                                          downloaded from datasets.imdbws.com.

                                          Keywords
                                          Movies, Prediction model, Classification algorithms, Personalized movie prediction, Python



1. Introduction                                                                                    2. Assumptions for algorithms
Currently, the most dynamically developing IT tools are                                            Each of the algorithms should be prepared to meet the
methods of artificial intelligence [1, 2]. Algorithms sup-                                         following criteria:
porting decision-making or supporting inference based
                                                                                                       1. Prepared according to the mathematical descrip-
on fuzzy sets [3, 4] find a number of applications, among
                                                                                                          tion of the algorithm;
others, in the detection of anomalies on roads [5] or in the
control of intelligent home management systems [6, 7].                                                 2. Optimized for the performance on our data set;
At this point, one cannot fail to mention a wide class of                                              3. Returns an array containing information about
heuristic algorithms based on the observation of animal                                                   top k (number of predicted movies) movies, bas-
behavior [8, 9, 10], which are widely used. The energy                                                    ing on top 3 movies from our watch-list.
reduction applications [11, 12, 13, 14, 15] are very im-
portant. The most common applications relate to the                                                3. Program description
use of [16] neural networks in a wide variety of applica-
tions that affect almost every area of life [17, 18, 19, 20].                                      The task of our project is to create a system recommend-
Very interesting applications concern the care of the el-                                          ing films using the KNN algorithm. The program in order
derly [21, 22, 23, 24]. Often, neural networks are used                                            to find movies, is based on the history of viewed items.
in various types of detection tasks for certain features                                           Movie Recommender initially chooses the best ones from
[25, 26, 27, 28]. The use of neural networks also plays a                                          the history of films. Then each video goes through the
very important role in machine learning [29, 30].                                                  algorithm so that the program finally gives the proposals
   Due to digitization of our modern world prediction                                              best suited to the user’s preferences. (Including watch
models are extremely crucial in these days. That’s be-                                             history). In this particular cases, KNN uses three metrics:
cause they can optimize some of the user’s processes, that                                         Taxi cab, Cosine distances and Euclidean.
would facilitate comfort of using a given app. Movies
are extremely complex thanks to a lot of variables into
which they can be divided. People struggle with choosing                                           4. KNN history
a movie to watch, because they not only might not be
aware of their preferences, but also they may not have                                                The origins of KNN can be traced to research conducted
enough time to check and compare all data[31]. Whole                                                  for the U.S armed forces. Evelyn Fix (1904-1965) was
problem could be solved by a program doing all the neces-                                             a mathematician and statistician who taught at Berke-
sary calculations for you, basing on user’s watch history                                             ley. Joseph Lawson Hodges Jr. (1922-2000) was a Berke-
and reviews.                                                                                          ley statistician who worked with the 20 United States
                                                                                                      Air Forces (USAF) from 1944. Combining their brilliant
                                                                                                      minds, in 1951 they wrote a technical analysis report for
SYSYEM 2022: 8th Scholar’s Yearly Symposium of Technology, Engi- the USAF. He introduced a discriminant analysis, non-
neering and Mathematics, Brunek, July 23, 2022
" kamiroj@polsl.pl (K. Rojek); rafaoch606@polsl.pl (R. Ochorok);
                                                                                                      parametric classification method. However, the newspa-
maciwie234@polsl.pl (M. Wiencis)                                                                      per was never officially published - most likely due to
         © 2022 Copyright for this paper by its authors. Use permitted under Creative Commons License
         Attribution 4.0 International (CC BY 4.0).
                                                                                                      confidentiality in the aftermath of World War II.
    CEUR
    Workshop
    Proceedings
                  http://ceur-ws.org
                  ISSN 1613-0073
                                       CEUR Workshop Proceedings (CEUR-WS.org)




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Kamil Rojek et al. CEUR Workshop Proceedings                                                                          49–54



5. Euclidean metrics history                                 The next step is to create a person’s profile to keep
                                                           a history of the videos watched along with the user’s
Euclidean distance is the distance in Euclidean space; rating. Before starting the algorithm, the program selects
both concepts are named after ancient Greek mathemati- three top movies according to the user’s rating. Then,
cian Euclid, whose Elements became a standard textbook based on this data, it performs calculations to find the
in geometry for many centuries.Concepts of length and best matching items in our database.
distance are widespread across cultures, can be dated to The metric used in the KNN algorithm is the sum of the
the earliest surviving "protoliterate" bureaucratic doc- cosine, taxicab and euclidean distances,between the val-
uments from Sumer in the fourth millennium BC (far ues of the film elements we compare, i.e. genres, writers,
before Euclid),and have been hypothesized to develop in directors. We use previously created numerical values.
children earlier than the related concepts of speed and Formulas used to determine distances between successive
time.But the notion of a distance, as a number defined parameters looks like this:
from two points, does not actually appear in Euclid’s Ele-
                                                                • Cosine distance
ments. Instead, Euclid approaches this concept implicitly,                            𝑢·𝑣
through the congruence of line segments, through the                           1−             ,                 (1)
                                                                                    ‖𝑢‖2 ‖𝑣‖2
comparison of lengths of line segments, and through the
concept of proportionality.                                     • Taxi cab distance
                                                                                   |𝑢 − 𝑣|                      (2)
6. Taxi Cab metrics history                                            • Euclidean distance
                                                                                     ⎯
                                                                                     ⎸ 𝑛
Taxicab Geometry is a non-Euclidean Geometry that mea-
                                                                                     ⎸∑︁
                                                                                     ⎷ (𝑢 − 𝑣)2                         (3)
sures distance on horizontal and vertical lines. According                               𝑖=1
to Taxicab Geometry - History, the taxicab metric was                    where u i v are the arrays to be compared
first introduced by Hermann Minkowski (1864-1909) over
100 years ago; however, it did not get its name until 1952.
Taxicab is unique in that it is only one axiom away from          The next step is to use the KNN algorithm, which will
being a Euclidean metric. In Euclidean Geometry the               use the previously described metric, in order to find the
minimum distance between two points is the shortest               k-nearest neighbors of a given movie. In the algorithm it-
line segment between those two points. However, in Taxi-          self, we predict finding k neighbors. As the algorithm can
cab Geometry there can be multiple minimal distances or           receive a maximum of 3 user top videos, it will therefore
‘shortest paths’ made up of line segments perpendicular           return a top 3k of the proposed positions. For example,
or parallel to the x-axis. Taxicab Geometry - History             if we add movies to the history:
suggests that modern research on taxicab did not occur                 • Coffee & Kareem, rating: 8
until as recent as the 1980s. The measurement of distance              • Das Cabinet des Dr. Caligari, rating: 9
using vertical and horizontal lines rather than diagonal               • The Kid, rating: 8.5
lines has sparked questions about its applications and            Program would output:
encouraged more research and exploration of this simple            Recommended Movies basing on: Coffee & Kareem
yet unique metric

                                                                       • The F word
7. Description of the program’s                                        • It’s All Gone Pete Tong
   operation                                                      Recommended Movies basing on: Das Cabinet des Dr.
                                                                  Caligari
Initially, we started the project by preparing the data in
such a way that we could then carry out calculations                   • Psycho
on them. For this purpose, we downloaded the IMDB                      • 6 donne per 1’assassino
database, which consisted of four files containing data           Recommended Movies basing on: The Kid
on:
                                                                       • The Circus
     • Data on the movie itself.                                       • Modern Times
     • Ratings for individual videos.
     • The cast of the movie.
     • Personal data of people participating in the film.         8. Algorithms
In order to optimize the algorithm, we do not use the full        In this section we will present pseudocodes of the most
names of the cast at this stage of operation.                     important algorithms used by us.



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Kamil Rojek et al. CEUR Workshop Proceedings                                                                 49–54




                                                             Data: Input: Id of the first movie 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1, Id of
  Data: Input: Id of the first movie 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1, Id of               the second movie 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2
        the second movie 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2                            Result: The lack of data
  Result: The lack of data
                                                             genresA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1
  genresA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1                                genresB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2
  genresB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2                                genreDistance = the euclidean distance between
  genreDistance = the cosine distance between two             two values.
   values.
                                                             directorA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1
  directorA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1                              directorB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2
  directorB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2                              directorDistance = the euclidean distance between
  directorDistance = the cosine distance between              two values.
   two values.
                                                             writerA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1
  writerA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1
                                                             writerB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2
  writerB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2
                                                             writerDistance = the euclidean distance between
  writerDistance = the cosine distance between two
                                                              two values.
   values.
  return genreDistance + directorDistance +                  return genreDistance + directorDistance +
   writerDistance                                             writerDistance
 Algorithm 1: Cosine distance metric pseudocode               Algorithm 3: Euclidean metric pseudocode




                                                             Data: Input: The name of the movie 𝑛𝑎𝑚𝑒,
                                                                   Amount 𝑘, User Name 𝑢𝑠𝑒𝑟
                                                             Result: Featured Videos
  Data: Input: Id of the first movie 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1, Id of
        the second movie 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2                            newMovie = movie name
  Result: The lack of data                                   distances=[]
                                                             neighbors = []
  genresA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1
  genresB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2                                for 𝑚𝑜𝑣𝑖𝑒 in 𝑚𝑜𝑣𝑖𝑒𝑠 do
  genreDistance = the taxi cab distance between                  if movie not in history then
   two.                                                              Add distances to the distances array using
                                                                      the ’Similarities’ metric between the
  directorA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1                                       given movie and the rest of the movies
  directorB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2                                       in the database.
  directorDistance = the taxi cab distance between               end
   two values.                                               end
                                                             distances.sort()
  writerA = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑1
                                                             for 𝑥 in 𝑘 do
  writerB = genre of 𝑚𝑜𝑣𝑖𝑒𝐼𝑑2
                                                                 Add to 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟𝑠 calculated distances.
  writerDistance = the taxi cab distance between
                                                             end
   two values.
                                                             for 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟 in 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟𝑠 do
  return genreDistance + directorDistance +                      View featured video data 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟
   writerDistance                                            end
     Algorithm 2: Taxicab metric pseudocode                 Algorithm 4: An algorithm that returns Recom-
                                                            mended Videos based on user preferences.




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Kamil Rojek et al. CEUR Workshop Proceedings                                                                      49–54



  Data: Input: movie’s name,                                        6. Genres_bin - Converted column ’Genres’ to a
  k - number of films searched                                         numerical form.
  Result: Prediction: k - movies’ name                              7. Writers_bin - Converted column ’Writers’ to a
  movie = movie information database row                               numerical form.
  neighbors = KNN algorithm using the taxi metric,                  8. Directors_bin - Converted column ’Directors’
  given k - amount of movies to be found                               to a numerical form.

  for 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟 in 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟𝑠 do                                  Based on the data base above, we have created several
      neighbors = KNN algorithm using the Cosine                rankings that show the popularity ratio of the data that
       distance metric                                          was used in the KNN algorithm:
  end
  for 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟 in 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟𝑠 do
      neighbors = KNN algorithm using the
       Euclidean metric
  end
  𝑟𝑒𝑐𝑜𝑚𝑚𝑒𝑛𝑑𝑒𝑑𝑀 𝑜𝑣𝑖𝑒𝑠 = []
  for 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟 in 𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟𝑠 do
      𝑎𝑣𝑔𝑅𝑎𝑡𝑖𝑛𝑔 = average rating of the movie
       (additional information from knn)
       𝑟𝑒𝑐𝑜𝑚𝑚𝑒𝑛𝑑𝑒𝑑𝑀 𝑜𝑣𝑖𝑒𝑠 += [𝑛𝑒𝑖𝑔ℎ𝑏𝑜𝑟,
       𝑎𝑣𝑔𝑅𝑎𝑡𝑖𝑛𝑔]
  end
   return 𝑟𝑒𝑐𝑜𝑚𝑚𝑒𝑛𝑑𝑒𝑑𝑀 𝑜𝑣𝑖𝑒𝑠
 Algorithm 5: An algorithm containing various met-
 rics to find the best matches for the user.
                                                                Figure 1: Top genres



9. Data base
9.1. Used Database
The following database was used for demonstration pur-
poses in a non-commercial, scientific manner - IMDB [32]
data set downloaded from datasets.imdbws.com. Tables
used:
     • name.basics.tsv
     • title.basics.tsv
     • title.crew.tsv
     • title.ratings.tsv
The database, after our simplifications and prior prepara-
tion, contains a collection of 9,827 films with information:
                                                                Figure 2: Top writers

9.2. Description of the columns
The set consists of 6000 rows and 7 columns.
A detailed description is provided below:
    1. OriginalTitle - Original title of a movie.
    2. Genres - List of movie genres.
    3. AverageRating - Average rating of a movie.
    4. Writers - A list of writers of a given movie.
    5. Directors - A list of directors of a given movie.



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Kamil Rojek et al. CEUR Workshop Proceedings                                                                              49–54



                                                                     [7] F. Bonanno, G. Capizzi, A. Gagliano, C. Napoli, Op-
                                                                         timal management of various renewable energy
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