Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS <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> en-US biljana.zlatanovska@ugd.edu.mk (D-r Biljana Zlatanovska) igor.stojanovik@ugd.edu.mk (D-r Igor Stojanovic) Thu, 11 May 2017 00:00:00 +0000 OJS 3.1.2.4 http://blogs.law.harvard.edu/tech/rss 60 Практична примена на едно – димензионалната бранова равенка https://js.ugd.edu.mk/index.php/YFCS/article/view/1828 <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> Mirjana Kocaleva, Aleksandra Risteska Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1828 Thu, 11 May 2017 07:03:26 +0000 MATHEMATICAL MODELING AND USING OF THE MATLAB DEVELOPED TOOLS FOR INDUSTRIAL PRODUCTION AND KINETIC FLOTATION MODELLING https://js.ugd.edu.mk/index.php/YFCS/article/view/1830 <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> Aleksandar Boris Krstev, Boris Kiril Krstev Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1830 Thu, 11 May 2017 07:23:12 +0000 STABILITY RESULTS FOR FIXED POINT ITERATION PROCEDURES https://js.ugd.edu.mk/index.php/YFCS/article/view/1780 <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> Rumen Marinov, Diana Nedelcheva Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1780 Thu, 11 May 2017 07:28:35 +0000 Споредба на алгоритми за класификација https://js.ugd.edu.mk/index.php/YFCS/article/view/1802 <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> Mirjana Kocaleva, Cveta Martinovska - Bande Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1802 Thu, 11 May 2017 07:08:20 +0000 Service for controlling household electrical devices through the internet https://js.ugd.edu.mk/index.php/YFCS/article/view/1829 <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> Darko Cebov, Ilija Mihajlov, Borjana Arsova, Zoran Zdravev Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1829 Thu, 11 May 2017 11:15:39 +0000 INVERSE FUNCTION THEOREM WITH STRONG METRIC REGULARITY https://js.ugd.edu.mk/index.php/YFCS/article/view/1779 <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> Rumen Marinov, Diana Nedelcheva Copyright (c) 2017 Yearbook - Faculty of Computer Science https://js.ugd.edu.mk/index.php/YFCS/article/view/1779 Thu, 11 May 2017 11:17:36 +0000