cover
Contact Name
Agus Suryanto
Contact Email
ijma@ub.ac.id
Phone
+628123304843
Journal Mail Official
ijma@ub.ac.id
Editorial Address
Faculty of Mathematics and Natural Sciences, Brawijaya University. Jl. Veteran, Malang City, East Java, Indonesia
Location
Kota malang,
Jawa timur
INDONESIA
Indonesian Journal of Mathematics and Applications
Published by Universitas Brawijaya
ISSN : -     EISSN : 29868149     DOI : https://doi.org/10.21776/ub.ijma
Core Subject : Science, Education,
The Indonesian Journal of Mathematics and Applications is a journal managed by Universitas Brawijaya, Malang, Indonesia, that is published twice a year (in March and September). IJMA is devoted to research articles of the highest quality in all areas of mathematics and its applications, statistics, and data science. The journal covers the following topics: Mathematical Analysis, Algebra, Biomathematics, Industrial Mathematics, Operasion Research, and Optimization, Data Sciences/Soft computing, Mathematical Physics, Financial Mathematics and Actuarial Sciences, Statictics. Upon its submission, the Editor-in-Chief decides on the suitability of the paper’s content for the aim and scope of the IJMA. If the Editor in Chief considers the paper is suitable, then the paper will be sent for peer reviewing by two peer reviewers. The Indonesian Journal of Mathematics and Applications maintains double anonymity, so neither the peer reviewers nor the author(s) can be identified by one another. The peer reviewers are respected scholars in the areas. The Indonesian Journal of Mathematics and Applications is an open access, peer-reviewed journal that considers articles describing novel computational algorithms and software, models and tools, including statistical methods, machine learning, and artificial intelligence, as well as systems biology.
Articles 55 Documents
Numerical Method for 1D Poisson-Boltzmann Equation Rizal Dian Azmi
Indonesian Journal of Mathematics and Applications Vol. 1 No. 2 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.02.4

Abstract

Poisson-Boltzmann is an equation which is used frequently to model a variety of electrostatic interactions problems in biomolecular computation. A value of atomic energy at the molecular movement becomes a singular value on the PBE. It affects the difficulty of solving this equation both analytically and numerically. In this article, this equation will be solved numerically. In this case, this equation is discretized using finite element method. The resulted system of equation is then solved with inexact backtracking Newton.
Some Basic Results in ν-Normed Spaces Rohman, Minanur; İlker Eryılmaz
Indonesian Journal of Mathematics and Applications Vol. 1 No. 1 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.01.1

Abstract

In this paper, we introduce the notion of a directed preserving generator (d.p.g.) from R into R. This d.p.g. can be used to construct new fields which generally have the same properties as R, except that some properties are affected by d.p.g. itself. With this new field, a ν-normed space will be formed. Some of the basic properties of this normed space are also discussed.
On the Inverse of a Square Matrix Using Logarithm Rellon, Louie Resti
Indonesian Journal of Mathematics and Applications Vol. 1 No. 1 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.01.2

Abstract

Assume that A is an n ‰ n matrix with real numbers as entries and the determinant of A ≠ 0. In this study, we established the results of getting the inverse of a matrix A using the logarithmic method and used some examples to discuss the necessity of getting the inverse of a matrix using the logarithm for both positive and negative determinants in terms of a given determinant of a matrix A. If the det A > 0, we have , where . However, if the det A < 0, we have , where .
Vector-Reservoir Transmission in A Japanese Encephalitis Model Lisa R. Sari; Puji Andayani; Sekarsari U. Wijaya
Indonesian Journal of Mathematics and Applications Vol. 1 No. 1 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.01.3

Abstract

In this paper, a model for characterizing the dynamics of vector-borne diseases is put out, emphasizing Japanese encephalitis. The susceptible-infectious-recovered (SIR) model for the host population and the susceptible-infectious (SI) model for the vector and reservoir populations are used to examine the role of host-vector-reservoir dynamics and their interplay. The standard incidence rate represents the probability of an actual disease contact. The model has two equilibrium points: an endemic equilibrium point that only exists under specific circumstances and a disease-free equilibrium point that always exists. The stability analysis of the model’s equilibrium point has been established. The basic reproduction number is calculated using the next-generation matrix method. A sensitivity analysis on models supported by numerical simulations is provided to demonstrate the critical parameter that affects the spread of disease.Our findings indicate that vector-reservoir transmission is the primary cause of endemic. Controlling vector-reservoir transmission lowers the likelihood of human infection and creates disease-free settings.
Application of Simulated Annealing Method on Tabarru-Fund Valuation using Inflator by Vasicek Model Approach Based on Profit and Loss Sharing Scheme Selvi Faristasari; Adhitya Ronnie Effendie
Indonesian Journal of Mathematics and Applications Vol. 1 No. 1 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.01.4

Abstract

Currently, the financial services industry is dominated by conventional banks and individuals that apply the system of interest or an excess of loans. In Islam, this excess is referred to as usury, which is prohibited by Islamic law because, in practice, usury makes borrowers poorer as they cannot pay such high-interest installments. Not to mention, late payments are subject to penalties that will continue to accumulate if the borrower is unable to pay the next installment. From these facts, this system is prohibited by Islamic Law because there are harmed parties. Therefore, this research discusses mathematical models in the form of Islamic investment business loans for micro-economic traders by implementing a profit and loss sharing system. Tabarru-fund is a set of funds derived from borrowers’ contributions used to overcome conditions when they experience losses in certain conditions. In this mathematical model, the tabarru-fund acts as the premium that must be paid if the borrower is still profitable after the principal installments have paid off. This sharia model with tabarru funds is obtained by calculating the premium which involves the problem of minimizing the remaining tabarru funds in a certain period. The future value of the trader's profit rate will be projected using the Vasicek Model approach which previously determined the parameter estimation using OLS regression and then the data is generated using Monte Carlo simulation so that the sharia inflator is obtained. This sharia inflator plays a role in the optimization process of minimizing the remaining tabarru-fund which will be solved by the Simulated Annealing (SA) algorithm.
Implementation of Holt-Winter Exponential Smoothing Method to Forecast The Spread of Covid-19 Pangestu, Adhitama Ihza; Andayani, Puji
Indonesian Journal of Mathematics and Applications Vol. 1 No. 2 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.02.2

Abstract

This research examines the Holt winters exponential smoothing method to solve forecasting problems using case studies of the spread of Covid-19. The data source uses the transmission of Covid-19 in Indonesia. MAPE is used to measure errors in data forecasting. The results are structured to serve as a recommendation for other researchers in choosing a method for predicting the spread of the disease. Based on the results, forecasting with the Holt-Winters model in positive cases produces a MAPE value of 9.21% using the Multiplicative model and the best parameter values of alpha, beta and gamma (0.4, 0.05, 0.25). Whereas in the case of human recovery, the MAPE value was 11.86% using the Multiplicative model and the best values for the parameters alpha, beta and gamma (0.4, 0.03, 0.1). And in the case of death it produces a MAPE of 17.97% using the Multiplicative model and the parameter values alpha, beta and gamma (0.4, 0.01, 0.1). So, it can be concluded that the Holt-Winters method on human positive case data shows a good outcome performance while recovered and deceased cases produce a well-being analysis performance.
Finite Difference Scheme for Nonlinear Finite Grating without and with Defect Purnomo, Reymond
Indonesian Journal of Mathematics and Applications Vol. 1 No. 1 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.01.5

Abstract

We present a simple numerical scheme based on finite difference method (FDM) with different boundary treatments to study the nonlinear optical response of finite one-dimensional grating with Kerr medium. For linear and nonlinear case, we use the second order numerical scheme for interior with different treatments of boundary conditions. The resulting of nonlinear system of equations is solved using Newton method with continuation method. To illustrate this method, we consider a periodic medium with and without defect. As the result, this method is able to show the bandgap and optical bistability phenomena for both mediums.
Numerical Solution of Burgers Equation using Cubic B-Spline Collocation Method and Neumann Boundary Condition Mulya Lezani, Nadine; Habibah, Ummu
Indonesian Journal of Mathematics and Applications Vol. 1 No. 2 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.02.3

Abstract

Burgers equation is one of the nonlinear differential equations which is generally difficult to determine its analytical solution, so it is necessary to do a numerical approach. This article discusses the numerical solution of the Burgers equation using the Cubic B-Spline Collocation method. The first step is to derive the numerical scheme using the Cubic B-Spline Collocation method for the space variable and the Crank-Nicholson method for the time variable. Furthermore, based on von Neumann stability analysis, it is obtained that the numerical scheme of Burgers equation is unconditionally stable. By performing numerical simulations using different  and    step sizes, it can be shown that the absolute value of the resulting error will be smaller for the step sizes of   and which is getting smaller.
Comparison of Random Forest, XGBoost, and LightGBM Methods in Estimating Airbnb Accommodation Rental Prices Based on Customers in New York City Tauryawati, meylista
Indonesian Journal of Mathematics and Applications Vol. 1 No. 2 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.02.5

Abstract

The research data was taken from a dataset provided by Inside Airbnb, and the analysis was conducted using machine learning techniques with Random Forest, XGBoost, and LightGBM algorithms. The research stages include data understanding, data preprocessing, data analysis, modeling, model evaluation, and rental price estimation. It is expected that the results of this study can help customers estimate the rental price of Airbnb rooms.
Neutral Caputo-Fabrizio Fractional Differential Equation with Hyers-Ulam Stability Rohman, Minanur; Eryilmaz, Ilker; Huda, M. N.
Indonesian Journal of Mathematics and Applications Vol. 1 No. 2 (2023): Indonesian Journal of Mathematics and Applications (IJMA)
Publisher : Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.ijma.2023.001.02.1

Abstract

In this paper, we will discuss the existence and uniqueness of a neutral Caputo-Fabrizio differential equation which fulfills several required conditions. Furthermore, using the Picard operator, we show that the problem has Hyers-Ulam type stability.