Information Systems & Grid Technologies
      Twelfth International Conference
                  ISGT’2018
      Sofia, Bulgaria, Nov. 16 – 17, 2018
                 Proceedings
organized by

       Faculty on Mathematics and Informatics, University of Sofia St. Kliment Ohridski
       Bulgarian Chapter of the Association for Information Systems (BulAIS)

ISGT’2018 Conference Committees
Chair

       Prof. Vladimir DIMITROV

Program Committee

       Míchéal Mac an AIRCHINNIGH, Trinity College, University of Dublin
       Pavel AZALOV, Pennsylvania State University
       Marco DE MARCO, Catholic University of Milan
       Milena DOBREVA, University of Malta
       Vladimir GETOV, University of Westminster
       Seifedine KADRY, American University of the Middle East, Kuwait
       Kalinka KALOYANOVA, University of Sofia “St. Kliment Ohridski”
       Angelika KOKKINAKI, University of Nicosia
       Violeta MANEVSKA, University of Bitola “St. Kliment Ohridski”
       Maria NISHEVA, University of Sofia “St. Kliment Ohridski”
       Dov TE’ENI, Tel-Aviv University
       Stanislaw WRYCZA, University of Gdansk
       Fani ZLATAROVA, Elizabethtown College

Organizing Committee

       Vasil GEORGIEV
       Maria KOLEVA
Preface
This conference was being held for the twelfth time on 16–17 November 2018 in the Faculty of
Mathematics and Informatics in Sofia, Bulgaria. It is supported by the Science Fund of the University of
Sofia “St. Kliment Ohridski” and by the Bulgarian Chapter of the Association for Information Systems
(BulAIS).

Total number of papers submitted for participation in ISGT’2017 was 23. They undergo the due selection
by at least two members of the Program Committee.

This Proceeding comprise 11 papers of 12 Bulgarian and 12 foreign authors.

The conference papers are available also on the ISGT web page http://isgt.fmi.uni-sofia.bg/ (under
“Previous conferences” tab).

Responsibility for the accuracy of all statements in each peer-reviewed paper rests solely with the
author(s). Permission is granted to photocopy or refer to any part of this book for personal or academic
use providing credit is given to the conference and to the authors.

                                                                                               The editors