Journal of Mathematical Sciences and Optimization

A SIXTH-ORDER PREDICTOR-CORRECTOR METHOD FOR INITIAL VALUE PROBLEMS

2025-05-06T14:17:18+00:00

This article discusses the sixth-order predictor-corrector method by changing the integral limit of 
$[t_n,t_{n+1}]$ to $[t_{n-3},t_{n+1}]$. This method combines the explicit Adam-Bashforth approach 
as a predictor and the implicit Adam-Moulton approach as corrector. The results obtained show that 
the numerical solution is close to the exact solution and the selection of a small \textit{stepsize}
 $h$ makes this method an alternative method in solving various initial value problems.

Exploring Multiple Seasonal MA Models for Short-Term Load Forecasting

2025-03-04T08:02:35+00:00

This study explores the use of multiple seasonal Moving Average (MA) models for short-term load forecasting, focusing on identifying the most suitable model order, which may involve subset, multiplicative, or additive components. While many seasonal MA models for time series forecasting tend to assume non-multiplicative structures, often without performing statistical tests, this research introduces a new procedure to determine the most appropriate multiple MA order. The study includes a case analysis of short-term load forecasting in a specific country. The findings of the study indicate that incorporating multiple multiplicative parameters can significantly improve model accuracy.

THE CHROMATIC NUMBER FOR DELONIX REGIA AND PLUMERIA FLOWER GRAPHS

2025-05-07T02:02:12+00:00

Let be a simple graph. A vertex k-coloring of a graph is a labeling function , where and it is proper if the adjacent vertices have different labels. A graph is colorable if it has a proper coloring. The chromatic number is the smallest such that such that there exist a proper coloring of . This article investigated the chromatic number for Delonix Regia Flower ( and Plumeria Flower (PLF_n). The results showed that the chromatic number for Delonix regia flower () is for . Furthermore, the chromatic number for Plumeria Flower Graph for is odd, and for is even.

ANALYSIS OF TIME COST TRADE-OFF APPROACH ON CRITICAL PATH METHOD TO ACCELERATE CONSTRUCTION PROJECT COMPLETION

2025-03-25T08:20:36+00:00

The article discusses the analysis of project scheduling using the critical path method (CPM) to identify the project's critical path, allowing for the determination of the overall project completion time. This is further analyzed using the time cost trade off (TCTO) approach to evaluate the duration and costs after adding two hours of overtime on the critical path, with the assistance of Microsoft Excel software. The objective of this problem is to optimize project completion time and minimize delays based on the duration and costs of project activities. The calculation results indicate the optimal time and cost for project completion, and suggest that project acceleration can be achieved by selecting activities that can be expedited through the addition of overtime hours.

DETERMINING THE CHROMATIC NUMBER OF A MODIFIED ADENOVIRUS GRAPH USING GREEDY ALGORITHM

2025-05-08T06:47:12+00:00

One of the vertex colorings that is a well-known research topic is chromatic number which requires that any two adjacent vertices have different colors. Adenovirus is a DNA virus that causes infections in the upper or lower respiratory tract, pharynx, gastrointestinal tract, and conjunctiva. Let be the modified adenovirus graph. This graph is constructed from molecular biology data, where represents a set of vertices that represented the elements such as virus DNA genes, DNA segments, and their variants, while is the set of edges that describe overlapping interactions between segments or conflicts among them. This article discusses vertex coloring on the modified adenovirus graph using greedy. The chromatic number is the minimum number of colors used to solve the vertex coloring problem on the graph and is denoted by . This study aims to construct the graph and determine the chromatic number of the graph using the greedy algorithm. The results show that greedy algorithm give the chromatic number for the modified adenovirus graph with for even n is .