Claim Missing Document
Check
Articles

Found 6 Documents
Search
Journal : Journal of Research in Mathematics Trends and Technology

Implementation of Finite Element Method for Structural Analysis of Bridge Resistance Erwin; Joni Joni; Jonathan Liviera Marpaung
Journal of Research in Mathematics Trends and Technology Vol. 3 No. 2 (2021): Journal of Research in Mathematics Trends and Technology
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jormtt.v3i2.8362

Abstract

The bridge problem is on of the structural phenomenon in physical structural analysis. One of the problems of bridge is how to analyze the fatigue of bridge model so that the the resistance of the bridge may be estimate. In this paper the bridge problem will be explained using Finite Element Method in displacement function analysis. The stress-strain number will be written in parameters of bridge model. the displacement function is clearly influenced by the stress-strain value so that the initialization of the initial value will follow the value of the specified parameter. In this paper the displacement function of the bridge will be explained in simulation model. The result of this research is the difference about initial model to the simulation model so that the resistance of the model can be analyze caused of the initial parameters.
Modeling Arterial Blood Flow under Stenosis: A Comparative Study of Newtonian and Carreau-Yasuda Non-Newtonian Approaches Erwin; Marpaung, Jonathan Liviera
Journal of Research in Mathematics Trends and Technology Vol. 6 No. 2 (2024): Journal of Research in Mathematics Trends and Technology (JoRMTT)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jormtt.v6i2.18754

Abstract

This study investigates the simulation of blood flow within arteries experiencing stenosis using both Newtonian and non-Newtonian models. The Newtonian model employs standard fluid dynamics assumptions, while the non-Newtonian Carreau-Yasuda model accounts for the unique viscoelastic properties of blood, providing a more accurate representation of its flow behavior under various shear rates. By utilizing COMSOL Multiphysics, the simulations are conducted with parameters including blood velocity, viscosity, and pressure in normal and narrowed artery conditions. Results reveal that while the Newtonian model predicts general flow patterns, it lacks the precision needed to reflect the complexities of blood behavior in stenosed regions. Conversely, the Carreau-Yasuda model demonstrates enhanced accuracy by capturing viscosity variations and pressure differentials, particularly in the narrowed artery sections, showing the significance of non-Newtonian characteristics in modeling blood flow. These findings underscore the potential of non-Newtonian models in improving diagnostic and therapeutic approaches for vascular conditions.
Model for Working Capital Management of Micro, Small and Medium Enterprises in Indonesia by Using Multiple Objective Stochastic Programming Gultom, Parapat; Widyasari, Rina; Suyanto; Marpaung, Jonathan Liviera
Journal of Research in Mathematics Trends and Technology Vol. 5 No. 2 (2023): Journal of Research in Mathematics Trends and Technology (JoRMTT)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jormtt.v5i2.15937

Abstract

Micro, small and medium enterprises (MSME) have a big influence for the economy in Indonesia. But almost of this company don’t have an optimal working capital management because less knowledge and limitation of financial not only from the owner but also financial credit from bank. Working capital management plays an important role in the success or failure of a company its business activities. To achieve optimal use of working capital management managers the company must accurately control the trade-off between profitability and liquidity. The purpose of this research is to develop a model of working capital management where the sales are under uncertainty and the company has a limit financial. This study was tested using multiple linear regression analysis to see the correlation between profitability and liquidity with x1, x2, x3, x4, and x5 then find optimal solution by stochastic multi objective programming because we consider that sales is in under certainty. The main variables used in the analysis of return on assets to measure profitability, receivable turnover to measure liquidity, inventory turnover, accounts payable days, cash conversion. The results showed that account payable, inventory turnover, and cash turn over have a positive correlation for liquidity but inventory turnover and cash turnover have negative correlation to profitability.
Location Models with Multy Criterious Networks (Case Study: The Industrial of Rice Processing in The Batubara District) Gultom, Parapat; Nababan, Esther Sorta Mauli; Marpaung, Jonathan Liviera
Journal of Research in Mathematics Trends and Technology Vol. 4 No. 2 (2022): Journal of Research in Mathematics Trends and Technology (JoRMTT)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jormtt.v4i2.16121

Abstract

Determining location is a problem encountered in many areas of everyday life. Determining this location becomes complex when many factors are taken into consideration, where one factor and another can conflict. One of the issues that will be discussed in this research is determining the location of the rice processing industry. This problem needs to be studied considering that the opportunity to establish a rice industry in several regions in Indonesia is very high considering that the potential for the main raw material (rice) is very large, as is the rice market where the largest population of the Indonesian nation makes rice the main food ingredient. The case study that will be discussed in this research is the rice processing industry in Batu Bara Regency. Batu Bara Regency is one of the districts/cities in North Sumatra Province which has enormous rice potential. In order to improve the welfare of farmers and provide good quality rice for the community, a Rice Processing Industry is needed. The problem in the rice processing industry is very complex, apart from the seasonal availability of rice raw materials, is the location where the rice processing factory is located. Various criteria need to be considered in this determination relating to the distance of the rice processing industry factory to each source of the main raw material (rice). Determining this location is very complex because it involves multiple criteria. This research will provide a location determination model using a Multi Criteria Network. The criteria used to determine the location of the rice processing industry in Batu Bara Regency are the transportation distance from the raw material center, travel time, and the condition of the road connecting the raw material center to the factory location. Based on the criteria for distance between rice centers and rice processing industrial factories, a route with a total minimum distance score of 0.71 is obtained. Meanwhile, based on travel time, the best route was obtained with a minimum total time score of 1.61. Based on the quality of the road taken, the best route was obtained with a maximum total score of 0.25. By considering the three criteria, the best route was obtained with a total optimum score of 2.96.
A Decision-Support Model for Football Squad Optimization: Integrating AHP-WASPAS and Binary Programming Gultom, Parapat; Ezra, Posman; Marpaung, Jonathan Liviera; Weber, Gerhard Wilhelm; Sentosa, Ilham
Journal of Research in Mathematics Trends and Technology Vol. 7 No. 1 (2025): Journal of Research in Mathematics Trends and Technology (JoRMTT)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jormtt.v7i1.18531

Abstract

Team composition in professional football remains a critical challenge due to subjective biases and the complexity of player performance metrics. This study proposes a multi-criteria decision-making (MCDM) approach to optimize the starting lineup of PSIS Semarang. The Analytical Hierarchy Process (AHP) was used to determine the importance of positional attributes, followed by the Weighted Aggregated Sum Product Assessment (WASPAS) to evaluate individual player preferences. A binary integer programming model was developed to construct the optimal eleven-player formation. The proposed formation was validated through simulation in Football Manager 2023. Results showed that a 4-3-3 formation consistently outperformed alternatives, leading to first-place rankings and a President’s Cup win in simulation trials. This integrated decision-support model demonstrates effectiveness in enhancing team selection strategies in professional football.
Review of Logistics Models for Perishable Goods: Comparative Analysis of Location Planning and Inventory Management under Supply Chain Disruptions Napitupulu, Normalina; Marpaung, Jonathan Liviera; Sirimavo, Yana; Ayu Dhisa Faradiba Siregar
Journal of Research in Mathematics Trends and Technology Vol. 7 No. 1 (2025): Journal of Research in Mathematics Trends and Technology (JoRMTT)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jormtt.v7i1.19239

Abstract

This study reviews and compares two logistics models tailored to perishable goods, focusing on the spatial and temporal dimensions of supply chain optimization. The first model proposes a population-density-based location planning framework that applies network centrality measures to determine optimal order fulfillment center locations. The second model introduces a two-warehouse inventory policy designed to handle disruption scenarios, such as lockdowns, by balancing demand variation and spoilage rates. Both models were evaluated for their methodological approaches, performance under disruption, and adaptability. The integrated review underscores the necessity of combining spatial efficiency with dynamic stock resilience to improve supply chain effectiveness for perishable goods. Findings suggest that hybrid models leveraging both geographic and temporal decision layers can significantly strengthen logistics adaptability.