198 research outputs found
Interval Methods of Newton Type for Nonlinear Equations
No full text[Dimitrova Neli S.; Димитрова Нели С.]; [Markov Svetoslav M.; Марков Светослав М.]Two interval iteration methods of Newton type for finding real zeros of nonlinear equations are formulated and their convergence is investigated. A realization of the methods in computer arithmetic is obtained and some computer experiments are presented
Mathematics Curricula and Their Role for Formation of Mathematical Competence for Students in Specialties “Programmer” and “System Programmer”
No full text[Sirakov Nikolaj Marinov; Сираков Николай Маринов]; [Sirakova Neli Dimitrova; Сиракова Нели Димитрова]В статията се разглежда връзката на обучението по математика с обучаващите се в специалностите ”програмист“ и ”системен програмист“ в горен курс. Посочват се проблеми и се дават насоки за повишаване мотивацията и формиране на математическа компетентност у учениците, за да се реализират успешно на пазара на труда
Числени алгоритми с верификация на резултата за нелинейни алгебрични уравнения и системи нелинейни алгебрични уравнения
No full textСпециализиран научен съвет по математика, механика и информатика при ВАК, катедра „Числени методи и алгоритми“ при ФМИ на СУ „Св. Климент Охридски“, ЦЛПОИ и ИМИ на БАН, 1998 г., присъждане на образователна и научна степен "доктор" на Нели Стоянова Димитрова по научна специалност 01.01.09. [Dimitrova Neli Stoyanova; Димитрова Нели Стоянова
What a Difference Context Makes: Comparing Communication Strategies of Migration NGOs in Two Neighboring Countries
No full textThis research study compared non-governmental organizations (NGOs) working in the area of migration in two neighboring countries – Bulgaria and Turkey. Utilizing in-depth interviews with 39 NGO professionals in both countries, the analysis identified critical differences in public opinion dynamics, organizational structures and interdependencies, and government relationships. Further analysis unveiled how the local socio-economic and political context had impacted NGO communication strategies as well as the specific communication channels, public engagement activities, and social media campaigns in each country. Implications for communication scholarship during times of increasing migration flows and globalization are discussed.This article is published as Dimitrova, D., Ozdora-Aksak, E., What a Difference Context Makes: Comparing Communication Strategies of Migration NGOs in Two Neighboring Countries. Journal of Borderlands Studies. 31 Dec 2022. Latest Articles. https://doi.org/10.1080/08865655.2022.2161065. Posted with permission. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.<br
Local Bifurcations in a Nonlinear Model of a Bioreactor
No full textThis paper is partially supported by the Bulgarian Science Fund under grant Nr. DO 02–
359/2008.We consider a nonlinear model of a continuously stirred bioreactor
and study the stability of the equilibrium points with respect to practically
important model parameters. We determine regions in the parameter
space where the steady states undergo transcritical and Hopf bifurcations.
In the latter case, the stability of the emerged limit cycles is also studied.
Numerical simulations in the computer algebra system Maple are presented
to illustrate the theoretical results
Global Analysis of a Nonlinear Model for Biodegradation of Toxic Compounds in a Wastewater Treatment Process
No full textAchievement on Hyperspatial Resolution over Past and Present Satellite or Airborn Images
No full textGlobal Stability Analysis of a Bioreactor Model for Phenol and Cresol Mixture Degradation
No full textWe propose a mathematical model for phenol and p-cresol mixture degradation in a continuously stirred bioreactor. The model is described by three nonlinear ordinary differential equations. The novel idea in the model design is the biomass specific growth rate, known as sum kinetics with interaction parameters (SKIP) and involving inhibition effects. We determine the equilibrium points of the model and study their local asymptotic stability and bifurcations with respect to a practically important parameter. Existence and uniqueness of positive solutions are proved. Global stabilizability of the model dynamics towards equilibrium points is established. The dynamic behavior of the solutions is demonstrated on some numerical examples
One-Parameter Bifurcation Analysis of Dynamical Systems using Maple
No full textThis paper presents two algorithms for one-parameter local
bifurcations of equilibrium points of dynamical systems.
The algorithms are implemented in the computer algebra system Maple 13 © and designed as a package. Some examples are reported to demonstrate the package’s facilities.* This paper is partially supported by the Bulgarian Science Fund under grant Nr. DO 02–359/2008
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