ISSN 2738-0971 | eISSN 2738-1013
Bulletin of Natural Sciences Research
Open access journal | Double-blind peer review

Vladica Stojanović

Faculty of Sciences and Mathematics

Articles

Open Access Original Scientific Paper

INTERPOLATION LOGISTIC FUNCTION IN THE SURFACE POTENTIAL BASED MOSFET MODELING

by Tijana Kevkić, Vladica Stojanović

Introduction of the Interpolation Logistic (IL) function in an approximate Surface-Potential-Based MOSFET model has been proposed in this paper. This function can be precisely determined in accordance with different MOSFET device characteristics. The IL function also provides continual behavior of the surface potential in entire useful region of MOSFET operation. Unlike the approximate analytical models which can meet in literature, continual and smooth transition of the surface potential between weak and strong inversion region here is achieved without using of any empirical parameter. Furthermore, thanks to the IL function, speed and manner of that transition are controlled. The values obtained for the surface potential are verified extensively with the numerical data, and a great agreement is found for the MOSFET devices from different technology generations.

View Full-Text DOI 10.5937/univtho8-17067 Published: 08 Dec 2018
Open Access Original Scientific Paper

HOMOTOPY PERTURBATIONS METHOD: THEORETICAL ASPECTS & APPLICATIONS

by Vladica Stojanović, Tijana Kevkić

The application of the homotopy perturbation method (HPM) in two different research's area has been proposed in this paper. First, the HPM has been used for approximate solving of the well-known implicit equation for electrostatic surface potential of MOSFET transistor. The approximate analytical solution obtained in this case has relative simple mathematical form, and simultaneously high degree of accuracy. Next, HPM has been applied in determination of the invariant measures (IMs) of the non-linear dynamical systems with chaotic behavior. The convergence and efficiency of this method have been confirmed and illustrated in some characteristic examples of chaotic mappings.

View Full-Text DOI 10.5937/univtho8-17290 Published: 30 Jun 2018
Open Access Original Scientific Paper

CAN THE TRANSFORMATION OF INSTRUCTION PROCESS INTO A VIRTUAL PLACE INDUCE A SHIFT IN BEHAVIORAL PATTERNS OF TEACHERS AND STUDENTS?

by Eugen Ljajko, Vladica Stojanović, Dragana Valjarević, Tanja Jovanović

The goal of this study is to reveal possible influence that the participants’ age and Information and Communications Technologies (ICT) usage in the instruction process can have on behavior that defines whether students and teachers belong to one of the Digital Native/Immigrant or Visitor/Resident groups. We collected data through two surveys that covered a total of 1273 students and 382 teachers from southern regions of Serbia. The surveys consisted of questions about availability of computers and internet, ICT use in the instruction process, and communication habits in the ICT-empowered instruction process. The first survey covered both, students and teachers that were involved in the instruction process mostly deprived of the ICT usage. The second survey covered participants of an instruction process that was successfully improved by an ICT usage. Data analysis shows a shift in communication patterns of teachers and a sharp improvement in computer use for educational purposes for both groups included in the surveys. The change is induced by a proper ICT usage in the instruction process. Conclusions that followed the data analysis lead us to better approaches in organizing ICT usage in the instruction process that enable participants fully employ their resources in order to improve teaching techniques and learning.

View Full-Text DOI 10.5937/univtho6-11953 Published: 31 Dec 2016
Open Access Original Scientific Paper

MODIFICATION OF TRANSITION'S FACTOR IN THE COMPACT SURFACE-POTENTIAL- BASED MOSFET MODEL

by Tijana Kevkić, Vladica Stojanović, Dragan Petković

The modification of an important transition’s factor which enables continual behavior of the surface potential in entire useful range of MOSFET operation is presented. The various modifications have been made in order to obtain an accurate and computationally efficient compact MOSFET model. The best results have been achieved by introducing of the generalized logistic function (GL) in fitting of considered factor. The smoothness and speed of the transition of the surface potential from the depletion to the strong inversion region can be controlled in this way. The results of the explicit model with this GL functional form for transition's factor have been verified extensively with the numerical data. A great agreement was found for a wide range of substrate doping and oxide thickness. Moreover, the proposed approach can be also applied on the case where quantum mechanical effects play important role in inversion mode.

View Full-Text DOI 10.5937/univtho6-11360 Published: 25 Dec 2016