cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota bandung,
Jawa barat
INDONESIA
Journal of the Indonesian Mathematical Society
Published by Indonesian Mathematical Society
ISSN : 20868952     EISSN : 24600245     DOI : -
Core Subject : Education,
Mathematics
Journal of the Indonesian Mathematical Society disseminates new research results in all areas of mathematics and their applications. Besides research articles, the journal also receives survey papers that stimulate research in mathematics and their applications.
Arjuna Subject : -
Articles 12 Documents
 1   2 
Search results for , issue "Vol. 31 No. 1 (2025): MARCH" : 12 Documents clear
On Generalized Space Matter Tensor Das, Bikiran; Jana, Sanjib Kumar; Ghosh, Sanjoy Kumar; Baishya, Kanak Kanti
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1184

Abstract

Extending the concept of Petrov tensor, in this article we attempt to introduce generalised space matter tensor [1],[2], [3], [4]. In the Riemannian manifold, it is found that the second Bianchi identity for the generalized space-matter tensor is satisfied if the energy-momentum tensor is of Codazzi type [5]. We study the nature of Riemannian manifolds by imposing curvature restrictions like symmetry, recurrent, weakly symmetry [6], [7], [8] etc. on this generalized Petrov space-matter tensor. We obtain the eigen values of the Ricci tensor S corresponding to the vector fields associated with the various 1− forms.
Double Intervention Analysis on The Arima Model of Covid-19 Cases in Bali Imro'ah, Nurfitri; Huda, Nur'ainul Miftahul
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1347

Abstract

The time series process is not only influenced by previous observations, but some phenomena result in drastic changes to observations in the time series process so that there is a change in the average or only a temporary change in observations. For example, there is a policy from the government towards handling a case. This is referred to as an intervention. Therefore, it is necessary to do time series modeling with intervention factors. One form of intervention in the current pandemic era is a policy issued by the government. In this study, the time series model used is ARIMA. This study aimed to analyze the effect of an intervention on the ARIMA model on Covid-19 cases in Bali. This study uses data on the number of new Covid-19 cases in Bali from 24 April 2020 to 31 May 2021. There are two interventions used in this study, namely restrictions on activities for the Panca Yadnya ceremony and crowds in Bali and restrictions on traveling outside the area and/or going home and/or leaving for employees of the State Civil Apparatus during the Covid-19 pandemic. The results of this study show that two policies issued by the Bali provincial government can handle the addition of new cases of Covid-19. It can be seen from the decline in the number of new Covid-19 cases in Bali until the end of May 2021.
Predicting Stock Price Using Convolutional Neural Network and Long Short Term Memory (Case Study: Stock of BBCA) Pangestika, Zubaidah; Josaphat, Bony Parulian
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1512

Abstract

Stocks are capital market instruments capable of creating profits for investors. However, stocks have a fluctuating nature that can lead to risk, so price predictions are needed to reduce this risk. Stock price prediction can use various methods such as deep learning. This study aims to predict stock price using Convolution Neural Network (CNN) and Long Short Term Memory (LSTM), with the application carried out at the stock price of Bank Central Asia (BBCA) for the period between July 1, 2005 and December 30, 2022. Data division uses a ratio of 70% for training and 30% for testing. To maximize prediction results, we select the best hyperparameter combinations using Grid Search. The prediction results show that CNN is better to LSTM, where CNN produces RMSE values of 488.992, R2 83.8%, and MAPE 6.5%.
The Locating-Chromatic Number of Some Jellyfish Graphs Arfin, Arfin
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1627

Abstract

Let c be a proper coloring of a graph G = (V, E) with k colors which induces a partition Π of V (G) into color classes L1, L2, . . . , Lk . For each vertex v in G, the color code cΠ(v) is defined as the ordered k-tuple (d(v, L1), d(v, L2), . . . , d(v, Lk )), where d(v, Li) represents the minimum distance from v to all other vertices u in Li(1 ≤ i ≤ k). If every vertex possesses unique color codes, then c is called a locating-k-coloring in G. If k is the minimum number such that c is a locating-k-coloring in G, then the locating-chromatic number of G is χL(G) = k. In this paper, the author determine the locating-chromatic number of some Jellyfish Graphs.
On Energy of Prime Ideal Graph of A Commutative Ring Associated with Seidel-Based Matrices Romdhini, Mamika Ujianita
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1713

Abstract

Some energies of the prime ideal graph are found for a commutative ring associated with Seidel-based matrices including Seidel, Seidel Laplacian, and Seidel signless Laplacian matrices.
Some Topological Indices of Order Divisor Graphs of Cyclic Groups Bawana, Agista Surya; Susanti, Yeni
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1717

Abstract

This study investigates order divisor graphs' structural and topological properties derived from cyclic groups. Focusing on the relationship between group order and graph topology, we explore key indices, including the Wiener index, the Harary index, the first Zagreb index, and the second Zagreb index. We use a case-based approach to analyze graphs for cyclic groups of varying orders, from prime powers to more general composite structures. This work extends the theoretical framework of order divisor graphs and provides explicit formulations for their topological indices, highlighting the interplay between algebraic and graph-theoretic properties. These findings contribute to the broader understanding of algebraic graph theory and its applications.
Joint-Life Insurance Premium Model Using Archimedean Copula: The Study of Mortality in Indonesia Ramadhan, Muhammad Akhirul; Zainuddin, Ahmad Fuad; Pasaribu, Udjianna Sekteria; Sari, RR Kurnia Novita
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1783

Abstract

Joint-life insurance pays a sum insured when the first death occurs. This insurance has a case based on the order of exit from the cohort, namely joint life and last survivor. The former means that one of the insured leaves the cohort, while the latter means the last member of the insured has left his or her cohort. For some reasons of simplicity, the insurance premium is usually calculated with the assumption that the husband and wife are mutually independent. However, this assumption is considered unrealistic. Couples are open to the same risks, hence explaining joint survival model should involve dependence structures between the distribution of spouse mortality. In line with this, to understand the dependence structure of multiple random variables, the approach used is Copula. In this context, Copula relates the marginal distribution function of these variables to the joint life distribution. One of the advantages from Copula is that the random variables do not have to come from the same distribution, hence Copula is considered good enough to explain the dependence of the mortality rate between husband and wife. This study aimed to develop a joint survival model for calculating joint life insurance premiums using the concept of Archimedean Copula to discover the minimum premium value by conducting the following steps: first, identifying the marginal distributions of mortality for genders using Indonesian Mortality Table IV (TMI/Tabel Mortalitas Indonesia IV); second, Archimedean copula function-based constructing survival models that captures the relationship between these variables; third, setting dependency parameter θ; fourth, calculating the joint life premium using Archimedean copula based survival modeled for each correlation dependency level; and carrying out optimization to find the minimum premium value. This can be achieved by formulating the problem as an optimization problem, considering an objective function that yields the lowest premium till satisfying the financial requirements of the insurance company.
Forgotten Topological Index of The Zero Divisor Graph for Some Rings of Integers Semil @ Ismail, Ghazali; Sarmin, Nor Haniza; Alimon, Nur Idayu; Maulana, Fariz
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1827

Abstract

A topological index is a numerical value that provides information about the structure of a graph. Among various degree-based topological indices, the forgotten topological index (F-index) is of particular interest in this study. The F-index is calculated for the zero divisor graph of a ring R. In graph theory, the zero divisor graph of R is defined as a graph with vertex set the zero-divisors of R, and for distinct vertices a and b are adjacent if a · b = 0. This research focuses on the zero divisor graph of the commutative ring of integers modulo 2ρn where ρ is an odd prime and n is a positive integer. The objectives are to determine the set of all zero divisors, analyze the vertex degrees of the graph, and then compute the F-index of the zero divisor graph. Using algebraic techniques, we derive the degree of each vertex, the distribution of vertex degrees, and the number of edges in the graph. The general expression for the F-index of the zero divisor graph for the ring is established. The results contribute to understanding topological indices for algebraic structures, with potential applications in chemical graph theory and related disciplines.
Limiting Spectral Distributions of Random Matrices Having Equi-Correlated Normal Structure husnaqilati, Atina
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1209

Abstract

By rank inequalities, we show that the limiting spectral distribution of random matrices, which are Fisher matrices and Beta matrices composed of two independent samples from independent p-dimensional, centered normal populations such that all entries have unit variance and any correlation coefficient between different variables are fixed nonnegative r1, r2 < 1. Moreover, by similar method, we also present the limiting spectral distribution of Wigner matrices, Toeplitz matrices, and Hankel matrices of order p, where all entries are standard normal random variables and mutually correlated with a fixed nonnegative r < 1. However, the rank inequality for empirical spectral distributions is unable to show the limiting spectral distributions of Markov matrices and banded Toeplitz matrices because the perturbation matrices of those matrices have a rate rank 1.
Monophonic Polynomial of the Join of Graphs Paluga, Rolando N.
Journal of the Indonesian Mathematical Society Vol. 31 No. 1 (2025): MARCH
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.v31i1.1686

Abstract

The monophonic polynomial of a graph $G$, denoted by $M(G,x)$, is the polynomial $M(G,x) = \sum_{k=m(G)}^{|G|}M(G, k)x^k $, where $|G|$ is the order of $G$ and $M(G, k)$ is the number of monophonic sets in $G$ with cardinality $k$. In this paper, we delve into some characterizations of monophonic sets in the join of two graphs and use it to determine its corresponding monophonic polynomial. Moreover, we also present the monophonic polynomials of the complete graph $K_n$ $(n \geq 1)$, the path $P_n$ $(n \geq 3)$, the cycle $C_n$ $(n \geq 4)$, the fan $F_n$ $(n \geq 3)$, the wheel $W_n$ $(n \geq 4)$, the complete bipartite $K_{m,n}$ $(m, n \geq 1)$, $P_m + P_n$ ($m, n \geq 3$), $C_m + C_n$ ($m, n \geq 4$), $P_m + C_n$ ($m \geq 3$ and $n \geq 4$), $P_m + \overline{K_n}$ ($m \geq 3$ and $n \geq 2$), and $C_m + \overline{K_n}$ ($m \geq 4$ and $n \geq 2$). In general, we obtain the monophonic polynomial of the join of two graphs.

Page 1 of 2 | Total Record : 12

 1   2 

Filter by Year

2025 2025


Reset
Filter By Issues
All Issue Vol. 32 No. 1 (2026): MARCH Vol. 31 No. 4 (2025): DECEMBER Vol. 31 No. 3 (2025): SEPTEMBER Vol. 31 No. 2 (2025): JUNE Vol. 31 No. 1 (2025): MARCH Vol. 30 No. 3 (2024): NOVEMBER Vol. 30 No. 2 (2024): JULY VOLUME 30 NUMBER 1 (MARCH 2024) VOLUME 29 NUMBER 3 (NOVEMBER 2023) VOLUME 29 NUMBER 2 (JULY 2023) VOLUME 29 NUMBER 1 (MARCH 2023) VOLUME 28 NUMBER 3 (NOVEMBER 2022) VOLUME 28 NUMBER 2 (JULY 2022) VOLUME 28 NUMBER 1 (MARCH 2022) VOLUME 27 NUMBER 3 (November 2021) VOLUME 27 NUMBER 2 (July 2021) VOLUME 27 NUMBER 1 (MARCH 2021) VOLUME 26 NUMBER 3 (NOVEMBER 2020) Volume 26 Number 2 (July 2020) Volume 26 Number 1 (March 2020) Volume 25 Number 3 (November 2019) Volume 25 Number 2 (July 2019) Volume 25 Number 1 (March 2019) Volume 24 Number 2 (October 2018) Volume 24 Number 1 (April 2018) Volume 23 Number 2 (October 2017) Volume 23 Number 1 (April 2017) Volume 22 Number 2 (October 2016) Volume 22 Number 1 (April 2016) Volume 21 Number 2 (October 2015) Volume 21 Number 1 (April 2015) Volume 20 Number 2 (October 2014) Volume 20 Number 1 (April 2014) Volume 19 Number 2 (October 2013) Volume 19 Number 1 (April 2013) Volume 18 Number 2 (October 2012) Volume 18 Number 1 (April 2012) Volume 17 Number 2 (October 2011) Volume 17 Number 1 (April 2011) Special Edition, Year 2011 Volume 16 Number 2 (October 2010) Volume 16 Number 1 (April 2010) Volume 15 Number 2 (October 2009) Volume 15 Number 1 (April 2009) Volume 14 Number 2 (October 2008) Volume 14 Number 1 (April 2008) Volume 13 Number 2 (October 2007) Volume 13 Number 1 (April 2007) More Issue