Gümgüm, Sevin
Loading...
Profile URL
Name Variants
Turhan, Sevin Gümgüm
Gumgum, S.
Gümgüm, S.
Gumgum, Sevin
Gumgum, S.
Gümgüm, S.
Gumgum, Sevin
Job Title
Email Address
sevin.gumgum@ieu.edu.tr
Main Affiliation
02.02. Mathematics
Status
Current Staff
Website
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Sustainable Development Goals
1NO POVERTY
0
Research Products
2ZERO HUNGER
0
Research Products
3GOOD HEALTH AND WELL-BEING
3
Research Products
4QUALITY EDUCATION
0
Research Products
5GENDER EQUALITY
0
Research Products
6CLEAN WATER AND SANITATION
1
Research Products
7AFFORDABLE AND CLEAN ENERGY
1
Research Products
8DECENT WORK AND ECONOMIC GROWTH
0
Research Products
9INDUSTRY, INNOVATION AND INFRASTRUCTURE
0
Research Products
10REDUCED INEQUALITIES
0
Research Products
11SUSTAINABLE CITIES AND COMMUNITIES
0
Research Products
12RESPONSIBLE CONSUMPTION AND PRODUCTION
0
Research Products
13CLIMATE ACTION
0
Research Products
14LIFE BELOW WATER
1
Research Products
15LIFE ON LAND
0
Research Products
16PEACE, JUSTICE AND STRONG INSTITUTIONS
0
Research Products
17PARTNERSHIPS FOR THE GOALS
0
Research Products
Documents
13
Citations
199
h-index
8
Documents
0
Citations
0
Scholarly Output
18
Articles
18
Views / Downloads
37/82
Supervised MSc Theses
0
Supervised PhD Theses
0
WoS Citation Count
174
Scopus Citation Count
199
Patents
0
Projects
0
WoS Citations per Publication
9.67
Scopus Citations per Publication
11.06
Open Access Source
10
Supervised Theses
0
| Journal | Count |
|---|---|
| Balıkesir Üniversitesi Fen Bilimleri Enstitüsü Dergisi | 2 |
| Engıneerıng Analysıs Wıth Boundary Elements | 2 |
| Journal of Computatıonal And Applıed Mathematıcs | 2 |
| Hacettepe Journal of Mathematıcs And Statıstıcs | 1 |
| International Journal of Biomathematics | 1 |
Current Page: 1 / 3
Scopus Quartile Distribution
Competency Cloud
18 results
Scholarly Output Search Results
Now showing 1 - 10 of 18
Article Citation - WoS: 15Citation - Scopus: 17Drbem Solution of Mixed Convection Flow of Nanofluids in Enclosures With Moving Walls(Elsevier Science Bv, 2014) Gümgüm, Sevin; Tezer-Sezgin, M.This paper presents the results of a numerical study on unsteady mixed convection flow of nanofluids in lid-driven enclosures filled with aluminum oxide and copper-water based nanofluids. The governing equations are solved by the Dual Reciprocity Boundary Element Method (DRBEM), and the time derivatives are discretized using the implicit central difference scheme. All the convective terms and the vorticity boundary conditions are evaluated in terms of the DRBEM coordinate matrix. Linear boundary elements and quadratic radial basis functions are used for the discretization of the boundary and approximation of inhomogeneity, respectively. Solutions are obtained for several values of volume fraction (phi), the Richardson number (Ri), heat source length (B), and the Reynolds number (Re). It is disclosed that the average Nusselt number increases with the increase in volume fraction, and decreases with an increase in both the Richardson number and heat source length. (C) 2013 Elsevier B.V. All rights reserved.Article Citation - WoS: 6Citation - Scopus: 8Numerical Solutions of the Hiv Infection Model of Cd4(+) Cells by Laguerre Wavelets(Elsevier, 2023) Beler, Ayse; Özaltun, Gökçe; Gümgüm, Sevin; Özaltun Şimşek, GökçeIn this study, we analyze the numerical solutions of the Human Immunodeficiency Virus (HIV) infection on helper T cells by using the Laguerre wavelet method. Our goal is to find accurate approximate results of the models that measure the number of helper infected and uninfected T cells as well as the number of free virus particles at a given time. We present two different models which are governed by three first order nonlinear differential equations with different parameters. We include an error analysis in order to compare the results with other methods available in the literature, and observe that the Laguerre wavelet method gives highly accurate results, is very easy to implement, hence efficient, in the solution of the type of problems indicated.(c) 2023 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 22Citation - Scopus: 25Drbem Solution of Natural Convection Flow of Nanofluids With a Heat Source(Elsevier Sci Ltd, 2010) Gümgüm, Sevin; Tezer-Sezgin, M.This paper presents the dual reciprocity boundary element method (DRBEM) solution of the unsteady natural convective flow of nanofluids in enclosures with a heat source. The implicit Euler scheme is used for time integration. All the convective terms are evaluated in terms of DRBEM coordinate matrix. The vorticity boundary conditions are obtained from the Taylor series expansion of stream function equation. The results report that the average Nusselt number increases with the increase in both volume fraction and Rayleigh number. It is also observed that an increase in heater length reduces the heat transfer. The average Nusselt number of aluminum oxide-water based nanofluid is found to be smaller than that of copper-water based nanofluid. Results are given in terms of streamlines, isotherms, vorticity contours, velocity profiles and tables containing average Nusselt number for several values of Rayleigh number, heater length, volume fraction, and number of iterations together with CPU times. (C) 2010 Elsevier Ltd. All rights reserved.Article Citation - Scopus: 1Gegenbauer Wavelet Solutions of the Sir and Sitr Systems of the Covid-19 Disease(World Scientific Publ Co Pte Ltd, 2024) Simsek, Gokce ozaltun; Beler, Ayse; Gumgum, SevinThis study aimed to investigate the influence of various parameters on the solutions of the susceptible-infected-recovered (SIR) and susceptible-treated-infectious-recovering (SITR) models to describe the spread of COVID-19. To achieve this, we employ the Gegenbauer wavelet technique to convert the system of nonlinear differential equations into a system of nonlinear algebraic equations. This approach has the advantage of not requiring the linearization of the nonlinear expressions, which significantly reduces truncation errors commonly associated with other methods. We conduct a thorough comparison of the absolute and residual errors generated by this technique against those produced by other numerical methods, finding that our results demonstrate a high level of accuracy. Additionally, the Gegenbauer wavelet technique is not only efficient but also straightforward to implement, contributing to a lower CPU time requirement. Overall, this study highlights the effectiveness of the Gegenbauer wavelet technique in accurately modeling the dynamics of COVID-19 transmission while offering practical computational advantages.Article Citation - WoS: 4Citation - Scopus: 5Drbem Formulation for Transient Stokes Flow With Slip Boundary Condition(Elsevier Sci Ltd, 2017) Gümgüm, Sevin; Wrobel, Luiz C.In this study, the effect of linear and nonlinear slip boundary conditions on the flow of a slow viscous fluid is investigated numerically. The boundary integral representation of the transient Stokes equations is given in primitive variables form. The fundamental solution to the steady Stokes equations is employed in the boundary element method (BEM) formulation. The time derivative is taken to the boundary with the dual reciprocity method and approximated by the finite difference method (FDM) until a steady-state is achieved. It is assumed that the fluid is capable of slip, with the slip velocity expressed as a function of shear rate at the wall. In the numerical tests, the fluid is initially assumed to be stationary; at each time step, the velocity boundary conditions along the walls are updated as the shear forces vary with time.Article Modeling the Impact of Public and Private Treatment on Alcohol Addiction: A Spectral Methods Approach(Birkhäuser, 2026) Türe, C.E.; Gümgüm, S.Effective public health policy for alcohol addiction requires a quantitative understanding of treatment efficacy. In this study, we introduce a parameter investigation of a mathematical model governed by a system of six non-linear ordinary differential equations and discuss the impact of public and private treatment. We solve the model using Chebyshev and Laguerre spectral methods. Application of these methods convert the system of differential equations into a system of algebraic equations. We compare our numerical results with the results of the Runge–Kutta method and observe that they agree very well. We further validate the results by calculating residual errors and show that both methods are accurate, efficient and reliable. We also observe that treatment accessibility (admission rates) and treatment quality (recovery efficacy) are the most important factors for reducing addiction in the long term. The numerical results demonstrate that structured care is important for combating alcohol addiction. © The Author(s) 2026.Article Göl Kirliliği Probleminin Çözümü için Hızlı ve Güvenilir Bir Sayısal Yaklaşım(2025) Gümgüm, SevinSu, hava gibi çevrenin temel bileşenlerinden biridir ve su kaynaklarının bozulması tüm canlı organizmaları tehdit etmektedir. Bu nedenle su kirliliği sorununu araştırmak büyük önem taşımaktadır. Göller, su kaynaklarının büyük bir bölümünü oluşturmaktadır. Bu çalışmanın amacı, üç adet birbiriyle bağlantılı gölden oluşan bir sistemdeki kirlilik dinamiklerini Gegenbauer dalgacık yöntemi ile analiz etmektir. Problem, her bir göldeki kirlilik oranının zamana göre değişimini temsil eden üç doğrusal diferansiyel denklem sistemi ile modellenmiştir. Zaman türevlerine, kesikli Gegenbauer dalgacık serisiyle yaklaşılmış ve diferansiyel denklem sistemi, cebirsel denklem sistemine dönüştürülmüştür. Elde edilen sayısal sonuçlar, literatürde mevcut diğer sayısal sonuçlarla karşılaştırılarak önerilen tekniğin güvenilir ve hızlı olduğu gösterilmiştir. Ayrıca, yöntemin yüksek doğruluk sağladığı ve bu nedenle diğer ekolojik olayların çözümünde de kullanılabileceği ortaya konmuştur.Article Citation - WoS: 10Citation - Scopus: 11Gegenbauer Wavelet Solutions of Fractional Integro-Differential Equations(Elsevier, 2023) Ozaltun, Gokce; Konuralp, Ali; Gumgum, SevinThe aim of this study is to use Gegenbauer wavelets in the solution of fractional integrodifferential equations. The method is applied to several problems with different values of resolution parameter and the degree of the truncated polynomial. The results are compared with those obtained from other numerical methods. We observe that the current method is very effective and gives accurate results. One of the reasons for that is it enables us to improve accuracy by increasing resolution parameter, while keeping the degree of polynomial fixed. Another reason is nonlinear terms do not require linearization. Hence the method can be directly implemented and results in the system of algebraic equations which solved by Wolfram Mathematica. It can be asserted that this is the first application of the Gegenbauer wavelet method to the aforementioned types of problems. (C) 2022 Elsevier B.V. All rights reserved.Article Citation - WoS: 6Citation - Scopus: 8Numerical Solutions of Troesch and Duffing Equations by Taylor Wavelets(Hacettepe University, 2023) Özaltun, Gökçe; Gümgüm, Sevin; Şimşek, Gökçe ÖzaltunThe aim of this study is to obtain accurate numerical results for the Troesch and Duffing equations by using Taylor wavelets. Important features of the method include easy imple-mentation and simple calculation. The effectiveness and accuracy of the applied method is illustrated by solving these problems for several variables. One of the important vari-able is the resolution parameter which enables to use low degree polynomials and decrease the computational cost. Results show that the proposed method yields highly accurate solutions by using quite low degree polynomials. © 2023, Hacettepe University. All rights reserved.Article Citation - WoS: 11Citation - Scopus: 14Legendre Wavelet Solution of High Order Nonlinear Ordinary Delay Differential Equations(Scientific Technical Research Council Turkey-Tubitak, 2019) Gumgum, Sevin; Ersoy Ozdek, Demet; Ozaltun, GokceThe purpose of this paper is to illustrate the use of the Legendre wavelet method in the solution of high-order nonlinear ordinary differential equations with variable and proportional delays. The main advantage of using Legendre polynomials lies in the orthonormality property, which enables a decrease in the computational cost and runtime. The method is applied to five differential equations up to sixth order, and the results are compared with the exact solutions and other numerical solutions when available. The accuracy of the method is presented in terms of absolute errors. The numerical results demonstrate that the method is accurate, effectual and simple to apply.
