International Journal of Simulation and Process Modelling (9 papers in press)

Regular Issues

• Prediction of environmental factors in seafood cold chain transportation based on IAGA-ELM algorithm  
  by Yang Wang, Yujia Jin, Yinong Chen, Shenghui Zhao, Xu E 
  Abstract: Cold chain transportation is often used to ensure the quality of seafood. In order to reduce the impact of environmental factors on product quality during cold chain transportation, an environmental factor prediction method based on improved adaptive genetic algorithm (IAGA) and extreme learning machine (ELM) is developed to predict the environmental factors generated in cold chain transportation. The environmental factor data composed of the gases released in the decay mechanism of cold fresh seafood is collected for training ELM with fast training speed and strong generalisation ability. Furthermore, the prediction model of environmental factors in the process of seafood cold chain transportation is established. Because initial connection weights and threshold values of traditional ELM have the characteristics of randomness, IAGA is used to address this issue. Compared with the existing ELM, GA-ELM, AGA-ELM and other models, our experimental results show that the proposed model obtains higher prediction accuracy and lower error rate.
  Keywords: IAGA; ELM; cold chain transportation; environmental factors; prediction.
  
  
• Performance optimisation of the feed water system of a thermal power plant using stochastic Petri nets with comparative analysis using PSO  
  by Sudhir Kumar, P.C. Tewari 
  Abstract: This study applies the stochastic Petri nets method for the performance evaluation of the feed water system of a thermal power plant. The availability analysis of subsystems has been used to determine the maintenance priorities. Further, the particle swarm optimisation (PSO) technique has been applied for the comparative analysis and optimised results. A licensed software package is used to examine the effects of different failure and repair rates, as well as the availability of repair facilities, on the performance behaviour and availability of the system. An algorithm has been applied in MATLAB software for optimisation using PSO. On the basis of the availability matrices obtained by Petri nets a decision support system for maintenance order priority is proposed, which will help the maintenance personnel to identify the criticality among various subsystems and to plan the maintenance policies and schedule.
  Keywords: Petri nets; performance modelling; availability assessment; decision support system; feed water system.
  DOI: 10.1504/IJSPM.2023.10054083
   
  
• Patient waiting time analysis in a multispecialty ophthalmic outpatient clinic using data analysis and discrete event simulation  
  by Shanmugam Prasanna Venkatesan, Lalwani Saurabh, Naveen Thomas, Sumanta Roy 
  Abstract: The demand for outpatient services is rapidly growing, resulting in multifaceted challenges due to capacity limitations. This research aims to analyse the patient waiting time in a multi-specialty ophthalmic outpatient clinic using data analysis and discrete event simulation (DES). The patient arrivals, the duration for pre-consultation and post-consultation services are highly uncertain. At first, a linear regression analysis is performed using electronic health record (EHR) log data, and the significant factors that affect patient waiting time are found. Further, a discrete event simulation model of the outpatient clinic is built using FlexSim Healthcare software (5.3) and validated. Improvement scenarios, namely: 1) adding resources; 2) introducing fixed interval appointment scheduling; 3) combining scenarios 1 and 2, are proposed for reducing the patient waiting time and evaluated. From the simulation results, it is inferred that scenario 3 reduces the average waiting time of the patients to 12.45 minutes from 38.37 minutes.
  Keywords: healthcare simulation; outpatient clinic; ophthalmology; data analysis; regression; waiting time.
  DOI: 10.1504/IJSPM.2023.10056150
   
  
• Study of vehicle dynamics response to collision in windrows of mine access roads through computer simulation  
  by Elyton Naves, João Lucas Diniz Oliveira, André Rebello Horta Novais 
  Abstract: The study presents an ore transport vehicle in simulated collision against the protection windrow (berm), located on the side of the roads, in order to prevent the vehicle from escaping in transit on the road. The work presents a study developed through computer simulation to validate the safety of access roads to mines owned by MRN. The objective is to dimension a windrow that it guarantees the safety of employees who travel with heavy-duty vehicles within the mine's operating fields. The computational simulations were carried out using the software EDEM and Motion View to simulate granular particles through the DEM methodology (Discrete Element Method) and the theory of vehicle dynamics, respectively. The information for the elaboration of the works were provided by MRN and complemented through scientific studies developed by the Naves Engenharia team. The results presented satisfactory data to the conditions required initially.
  Keywords: simulation; computer aided engineering; discrete element method; vehicular collision simulation.
  
  
• Finite element modelling for electrical discharge of Ti-6Al-4V Alloy and multi-objective optimisation using response surface modelling  
  by Diksha Jaurker, Mohan Kumar Pradhan 
  Abstract: Electrical discharge machining (EDM) is a non-traditional precision machining method that thermally erodes hard materials and complicated geometries with excellent accuracy, but it also creates residual stress and fractures. Finite element modelling (FEM) was performed for an axially symmetric two-dimensional model of the EDM method, taking into account plausible factors such as Gaussian heat flux distribution, thermally sensitive material properties, the proportion of heat distribution to the workpiece, plasma flushing efficiency (PFE), and so on, to assess the consequence of process variables on the temperature field during the heating stage, and then material removal rate (MRR) and residual stresses. Using the response surface modelling (RSM) approach, multi-objective optimisation was performed to maximise the MRR and minimise tensile residual stresses, and an optimum solution was found by assigning equal weightage to all objective functions.
  Keywords: electrical discharge machining; finite element method; simulation modelling; response surface methodology.
  DOI: 10.1504/IJSPM.2023.10056573
   
  
• Numerical study of sago pith waste drying process in a fluidized bed dryer  
  by Angnes Ngieng Tze Tiong, Eunice Ke Xin Lou 
  Abstract: Research on the drying of sago pith waste (SPW) using a fluidised bed dryer (FBD) is relatively scarce. Therefore, it was the aim of this study to scrutinise the drying of SPW in the FBD with varying diameter and height through computational fluid dynamic modelling. The simulations were conducted by using the multiphase Eulerian-Eulerian approach. The effects of bed dimensions, air velocity, and air temperature on the drying performance of SPW were investigated. Better drying of SPW is attained in FBD with a larger height and smaller diameter. Besides, the drying performance is better when the air temperature increases from 50? to 100?. Higher inlet velocities of 3 m/s to 4 m/s are not recommended. The recommended diameter and height for FBD are 180 mm and 190 mm, respectively. The optimum operating conditions to achieve the desired final moisture content are 12 m/s of air inlet velocities and an inlet temperature of 50.
  Keywords: computational fluid dynamics; CFD; drying; fluidised bed dryer; FBD; sago pith waste; SPW.
  DOI: 10.1504/IJSPM.2023.10057078
   
  
• Autonomous entities: a comparison between simulation models  
  by João Paulo Barbieri, Alexandre Ferreira Pinho, José Arnaldo Barra Montevechi 
  Abstract: Manufacturing systems, even with technological advances, are affected by factors linked to human decisions, especially in manufacturing systems with a high proportion of manual labour, such as an assembly line. In the simulation and modelling process, attributing greater autonomy to entities generates effects on the model. Such effects need to be considered by the modeller. To explore these effects, this article presents a method, whose name is iDAV, in which it is possible to analyse the elements of a simulation model and the nature of the connections between these elements. The iDAV method was applied to two Discrete-Event Simulation (DES) models. Both models represent the same assembly line. The difference between them lies in the degree of autonomy of the entities. Through the graphs, it was possible to verify the increase in complexity and variability of responses between the two DES models.
  Keywords: discrete-event simulation; autonomous entities; simulation and modelling.
  
  
• Decision-making on the agricultural products supply chain based on blockchain technology  
  by Guangdong Liu, Ziyang Li, Jinggui Chen 
  Abstract: Blockchain technology can regulate and trace the various nodes in the circulation of agricultural products, which can effectively improve circulation efficiency and reduce transportation losses but also bring corresponding costs. Based on this, we construct two theoretical models before and after investing in blockchain, study blockchain pricing and channel selection for APSC participants, and propose blockchain investment thresholds. The main results show the following: 1) investing in blockchain may harm the profits of APSC participants when the potential market demand is too low and the level of channel competition is too high. The FPS develops the same pricing strategies in both channels before investing in blockchain, but they are no longer consistent after investing in blockchain; 2) the e-retailing channel encroaches on the demand of the direct sales channel after investing in blockchain, but the total demand increases; 3) the fresh product supplier will only invest in blockchain if the blockchain fixed cost is low enough, and investing in blockchain is always beneficial to the e-retailer.
  Keywords: blockchain technology; agricultural product supply chain; dual-supply chain; quantity loss.
  DOI: 10.1504/IJSPM.2023.10058630
   
  
• Research on cooperative game model for distributed photovoltaic microgrid based on blockchain  
  by Liang-jiang Wei, Wei Jian, Shunkai Lu, Baochuan Fu, Baoping Jiang, Xin Zhang 
  Abstract: In recent years, as the dual-carbon target has been proposed, the installed capacity of distributed photovoltaic (PV) systems has been increasing annually. As a novel networking approach, a microgrid can integrate distributed energy resources and enable the effective grid connection and use of distributed PV energy. Based on this, a distributed PV microgrid group power trading model is proposed, which is based on blockchain technology and game theory. This provides a new approach to optimise the electricity market of microgrids. The cooperative game model of microgrid groups can effectively solve the interest issues of microgrid users. The simulation results demonstrate that, owing to the transparent and open nature of blockchain, microgrids can effectively engage in dynamic games, achieve the nearby consumption of distributed PV energy, and verify the feasibility and effectiveness of the model.
  Keywords: blockchain; cooperative game; microgrid; distributed photovoltaic system.
  DOI: 10.1504/IJSPM.2023.10058914