https://js.ugd.edu.mk/index.php/YFCS/issue/feed Yearbook - Faculty of Computer Science 2017-05-11T11:17:36+00:00 D-r Biljana Zlatanovska biljana.zlatanovska@ugd.edu.mk Open Journal Systems <p>The Yearbook of the Faculty of Computer Science from "Goce Delcev" University - Stip is a collection of achievements in computer science and technology, mathematics and applied mathematics.</p> https://js.ugd.edu.mk/index.php/YFCS/article/view/1828 Практична примена на едно – димензионалната бранова равенка 2017-05-11T07:06:26+00:00 Mirjana Kocaleva mirjana.kocaleva@ugd.edu.mk Aleksandra Risteska aleksandra.risteska@ugd.edu.mk <p>Во овој труд ги разгледуваме парцијалните диференцијални равенки, а посебен акцент ставаме на хиперболичните равенки и на брановата равенка како посебен вид на овие равенки. Исто така користиме компјутерска симулација со која го прикажуваме проблемот на пропагирање на бран на конкретен нумерички модел. Користиме формулација на равенката на бранот изразена преку брзината, деформацијата и напонот. Со интегрирање на брзината во однос на времето, добиваме преместувања на просторните точки. Главната цел на ова истражување е да ги проучиме феномените кои се случуваат кога имаме Dirichlet гранични услови кога имаме пропагирање на бранот во форма на полу-синусен пулс.</p> 2017-05-11T07:03:26+00:00 Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1830 MATHEMATICAL MODELING AND USING OF THE MATLAB DEVELOPED TOOLS FOR INDUSTRIAL PRODUCTION AND KINETIC FLOTATION MODELLING 2017-05-11T07:23:12+00:00 Aleksandar Boris Krstev aleksandar.krstev@ugd.edu.mk Boris Kiril Krstev boris.krstev@ugd.edu.mk <p>To improve kinetic flotation models, many first-order flotation kinetics models with distributions of flotation rate constants were redefined so that they could all be represented by the same set of three model parameters. As a result, the width of the distribution become independent of its mean, and parameters of the model and the curve fitting errors, became virtually the same, independent of the chosen distribution function. In our case, investigations of the chalcopyrite ores are carried out using mathematical modeling and using of the matlab developed tools for industrial production &nbsp;- Classical model, Klimpel Model and fully mixed model. According to the experimental results obtained in laboratory, the Classical model is most appropriate for presentation of kinetic flotation, especially by means of MATLAB modeling.</p> 2017-05-11T07:23:12+00:00 Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1780 STABILITY RESULTS FOR FIXED POINT ITERATION PROCEDURES 2017-05-11T07:28:35+00:00 Rumen Marinov marinov_r@yahoo.com Diana Nedelcheva dkondova@abv.bg <p>While solving inclusions numerically by an iterative procedure, usually we follow some theoretical model and deal with an approximate numerical sequence. If the numerical sequence converges to a point anticipated by the theoretical sequence, then we say that the iterative procedure is stable. This kind of study plays a vital role in computational analysis, game theory and computer programming. The purpose of this paper is to discuss stability of the Picard iterative procedure for pseudo-Lipschitz&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; multivalued operators in metric spaces.</p> 2017-05-11T07:28:35+00:00 Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1802 Споредба на алгоритми за класификација 2017-05-11T07:08:20+00:00 Mirjana Kocaleva mirjana.kocaleva@ugd.edu.mk Cveta Martinovska - Bande cveta.martinovska@ugd.edu.mk <p>Денес бројот на нови технологии секојдневно расте. Податочното рударење е една од поновите технологии која се уште е актуелна за проучување. За таа цел во овој труд прво ги разгледуваме податочното рударење и класификацијата, а потоа се задржуваме на дрвата за одлучување како еден од начините за имплементација на класификацијата. Исто така ги разгледуваме перформансите на алгоритмите за градење на дрва за одлучување, како и ентропијата, Gini коефициентот, грешката при класификација, прецизност и recall, ROC криви... Понатаму, правиме споредба на едни од најпознатите алгоритми за класификација и ги презентираме резултатите добиени со примена на ID3 и J48 алгоритмите (Ј48 и Ј48 graft) на наша база на податоци. Заклучуваме дека најдобри предвидувања се добиваат со употреба на Ј48 алгоритмот кога користиме 10-fold cross-validation и со употреба на ID3 кога користиме training set.</p> 2017-05-11T07:08:20+00:00 Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1829 Service for controlling household electrical devices through the internet 2017-05-11T11:15:39+00:00 Darko Cebov darko.101790@student.ugd.edu.mk Ilija Mihajlov ilija.101746@student.ugd.edu.mk Borjana Arsova borjana.101783@student.ugd.edu.mk Zoran Zdravev zoran.zdravev@ugd.edu.mk <p>This paper provides description of service which offers controlling household electrical devices through the Internet, remotely. The concept of the service in this format is designed as a student’s project and it gives the basic idea which can be improved.<br>At the beginning, importance of the problem of electrical energy consumption is explained. Some illustrative examples for improving energy consumption of the devices are given. The idea of IoT (Internet of Things) internetworking is analyzed as potential solution for the problem. Our service is based on the IoT and it is combination of some simple hardware and software components which are specified and explained separately. The business potential of developing service of this kind is mentioned. Finally, we summarize the benefits that users can obtain by implementing this system in their households.</p> 2017-05-11T11:15:39+00:00 Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1779 INVERSE FUNCTION THEOREM WITH STRONG METRIC REGULARITY 2017-05-11T11:17:36+00:00 Rumen Marinov marinov_r@yahoo.com Diana Nedelcheva dkondova@abv.bg <p><strong>Abstract.</strong> In this paper we prove an extension of the contraction mapping principle for single-valued mappings dealing with more general assumptions containing modulus instead of pseudo-contractive functions. In [4] A. L. Dontchev and R.T. Rockaffelar supposethe strong metric regularity of set-valued mapping &nbsp;and the Lipschitz continuity of the function &nbsp;with given nonnegative constants and prove the strong metric regularity of &nbsp;while we assume the properties of &nbsp;and &nbsp;with modulus functions and prove a generalization of their result.</p> 2017-05-11T11:17:36+00:00 Copyright (c) 2017 Yearbook - Faculty of Computer Science