Simulation Modelling Practice and Theory最新文献

{"title":"On the modeling of dynamic queue formation and decision-making in pedestrian dynamics simulations","authors":"Ander García ,&nbsp;Dariel Hernández-Delfin ,&nbsp;Dae-Jin Lee ,&nbsp;Marco Ellero","doi":"10.1016/j.simpat.2025.103130","DOIUrl":"10.1016/j.simpat.2025.103130","url":null,"abstract":"<div><div>This work presents two distinct and novel approaches to simulating dynamic queue formation and route decision-making in pedestrian systems. Queue formation is modeled by detecting pedestrians within a specific cutoff distance from others already in line, altering movement forces and leading to organized queuing behavior. Two distinct methodologies are introduced to simulate dense, compressed formations and elongated, thin lines. A parametric analysis assesses how queue dimensions depend on model parameters. Additionally, we introduce a simple criterion for route selection based on the identification of queuing agents, prioritizing the most time-efficient route while accounting for delays caused by queues. Dynamic route changes are modeled by shifting between multiple pre-calculated velocity maps for each potential exit. Finally, both queuing and decision-making approaches are combined to study how queues affect route choice. Our results predict that pedestrian decision is influenced by the type of queue forming before the gates.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103130"},"PeriodicalIF":3.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144083693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study on blasting response of rock mass considering in-situ stress and joint inclination","authors":"Qianxi Gao ,&nbsp;Zhiliang Wang ,&nbsp;Yu Ni ,&nbsp;Jianguo Wang","doi":"10.1016/j.simpat.2025.103144","DOIUrl":"10.1016/j.simpat.2025.103144","url":null,"abstract":"<div><div>This paper investigates the influence of in-situ stress on the damage and vibration of jointed rock mass by double-hole blasting. Firstly, the hoop stress distribution around the blasthole under static load was explored. Then, six rock mass models with joint inclinations of 15°, 30°, 45°, 60°, 75°, and 90° were respectively established in the middle of the two blastholes. Finally, the blasting-induced damage and attenuation behavior of peak particle velocity (PPV) under different in-situ stress conditions were numerically simulated. The results indicate that under hydrostatic pressure, the proportion of crushed elements and the length of main cracks are negatively correlated with the magnitude of in-situ stress. The PPV initially increases and subsequently decreases as the in-situ stress rises. Under the action of non-hydrostatic pressure, when the vertical in-situ stress is constant, the proportion of the crushed elements and the length of the main cracks in the vertical direction decrease with the increase of the horizontal in-situ stress. When the horizontal in-situ stress increases and the joint inclination is between 0° and 75°, the PPV in the horizontal direction first increases and then decreases. When the joint inclination is 90°, the PPV in the horizontal direction consistently increases with the increase of the horizontal in-situ stress. These results can provide reference for the estimation of rock fragmentation in blasting operations.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"143 ","pages":"Article 103144"},"PeriodicalIF":3.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Digital twin for magnetic levitation systems: General architecture design and uncertainty analysis","authors":"Yang Wang,&nbsp;Yufeng Huang,&nbsp;Sebastian Viancha,&nbsp;Mir Behrad Khamesee","doi":"10.1016/j.simpat.2025.103134","DOIUrl":"10.1016/j.simpat.2025.103134","url":null,"abstract":"<div><div>Digital twins (DTs) are widely used for actuator design, virtual prototyping, simulations, and analysis of model-based system engineering. DT technology is promising for magnetic levitation (maglev) systems, as illustrated by the mover design with high-strength neodymium magnets, the Lorentz force and torque (wrench) model comparison, and motion control verification. Digitalized maglev planar actuators (MLPAs) are time-, material-, labor-, and cost-efficient to develop, and the proposed DT is constructed using an open-source PyBullet module and assisted with a parallel-operated graphic user interface (GUI) using the PyQt5 module. Data transfer between physical systems and DTs is available using socket connections. After comparing the physical and virtual experimental results, the complete DT is verified using a 2-dimensional (2-D) Halbach array and single-disc magnet movers. The uncertainties of the MLPAs are implemented using white noise and system delay models. The ignored uncertainty features are introduced and analyzed for experimental deviations. The proposed DT provides a virtual safeguard environment for the next stage of machine learning research and multiple magnet-mover motion control studies. The <em>first</em> MLPA DT is established with a real-time wrench physics engine, which enables research opportunities for multi-mover motion, robotic collaboration, and artificial intelligence applications. This study is also beneficial for the design and analysis research of MLPAs.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103134"},"PeriodicalIF":3.5,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144105417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning solutions with supervised adaptive neural networks for countermeasure competing strategy of computer virus models","authors":"Nabeela Anwar ,&nbsp;Saba Naz ,&nbsp;Muhammad Asif Zahoor Raja ,&nbsp;Iftikhar Ahmad ,&nbsp;Muhammad Shoaib ,&nbsp;Adiqa Kausar Kiani","doi":"10.1016/j.simpat.2025.103141","DOIUrl":"10.1016/j.simpat.2025.103141","url":null,"abstract":"<div><div>The rapid and uncontrolled proliferation of computer viruses in recent years has emerged as a critical challenge, posing significant threats to individual cybersecurity, financial assets, and the stability of industrial systems. This alarming trend underscores the urgent need for advanced and effective strategies to mitigate the spread of such viruses. Motivated by this persistent concern, the current study introduces a robust methodology utilizing supervised adaptive neural networks, backpropagated with the Levenberg-Marquardt method (ANNs-LMM), to model and predict the dynamic interaction between computer viruses and their countermeasures within the nonlinear SIC framework. The nonlinear SIC framework mimics the time-varying dynamic trends of the average values of susceptible, infected, and non-infected internal computers. The referenced solutions for analyzing the dynamic interactions for all three classes of the SIC model are determined for critical significant parameters including the variability in the infection rate of susceptible computers, the acquisition of countermeasures by each susceptible or infected computer, the recovery rate of infected computers, the immunity loss of uninfected computers upon the invalidation of countermeasures, and the distinction between internal and external computers that are not connected to the network by implementing the Adams method. The approximate prediction model for each classification of the nonlinear SIC system is computed using the generated data in ANNs-LMM as responses and predictions for train, validation, and test sampling. Exhaustive simulated scenarios are executed to ascertain the reliability of the presented model for comprehensive advanced resilient threat attacks intended to target key industrial systems. The ANNs-LMM results closely match the observed data, and further assessment using the regression measures, mean squared errors and histogram errors endorses the worth and reliability of the proposed methodology.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103141"},"PeriodicalIF":3.5,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144105416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing evacuation efficiency: Investigating how luggage influences exit strategies and crowd dynamics","authors":"Zhigang Shang ,&nbsp;Jun Zhang ,&nbsp;Zhigang Shi ,&nbsp;Xiaolian Li ,&nbsp;Weiguo Song","doi":"10.1016/j.simpat.2025.103142","DOIUrl":"10.1016/j.simpat.2025.103142","url":null,"abstract":"<div><div>Luggage carriers as an important part of pedestrians in public transportation hubs may greatly affect the crowd movement especially in emergencies, but have been seldom considered in existing evacuation models. In this work, we adjusted the spatial structure of pedestrians and the forces from luggage to simulate luggage-laden pedestrians. By introducing an exit selection model and rules for luggage-laden pedestrians, it can reflect the exit selection strategy of the crowd with luggage. The effectiveness and performance of the model was evaluated by comparing the simulation results with experimental data and those from other evacuation models. Subsequently, the model was used to simulate the evacuation process in different scenarios. It was found that setting a dedicated exit for luggage-laden pedestrians is unnecessary and will exacerbate the degree of conflict when there is no crowd diversion before the exit. As the passenger flow increases, the impact of luggage on crowd evacuation becomes more and more obvious, resulting in a longer evacuation time for higher proportion of luggage under the same pedestrian numbers. When the passenger flow is high, smaller distance between two exits will reduce the evacuation efficiency. Besides, frequent change on the expected exit during the movement process is not conducive to crowd evacuation. If pedestrians can complete the exit selection at a position from where the distance to the exit is larger than a certain value, the total evacuation time can be reduced. The larger the passenger flow is, the farther this distance should be. It is hoped that the relevant findings of this work can provide guidance and reference for public safety and emergency management in transportation hubs.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103142"},"PeriodicalIF":3.5,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive offloading scheme of fine-grained tasks based on reinforcement learning in multi-access edge computing","authors":"Jie Li ,&nbsp;Ge Chen ,&nbsp;Kansong Chen","doi":"10.1016/j.simpat.2025.103139","DOIUrl":"10.1016/j.simpat.2025.103139","url":null,"abstract":"<div><div>In the context of multi-access edge computing, the constraints on device resources and energy pose a challenge in meeting the requirements of delay-sensitive and high-resource demand tasks. In order to address this issue, this paper puts forth an adaptive offloading decision based on fine-grained task sequencing (AOD-FTS). To enhance task execution efficiency and resource utilization, we design scheduling optimization for subtasks algorithm within the fine-grained task model to optimize the execution order of subtasks and improve subtask parallelism. Additionally, to reduce task delay and energy consumption, we propose an adaptive multi-objective reinforcement learning offloading algorithm based on ordered subtasks, formulated through multi-objective Markov decision processes. The scheme dynamically adjusts optimization preferences according to environmental changes and task completion states to make offloading decisions. Simulation results demonstrate that compared with two benchmark algorithms, the proposed AOD-FTS scheme achieves: (1) higher task completion rates, (2) improved resource utilization efficiency, (3) 81.66 % and 51.53 % reductions in delay respectively, and (4) 39.72 % and 71.36 % reductions in energy consumption respectively.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"143 ","pages":"Article 103139"},"PeriodicalIF":3.5,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144115817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MASS-GT: An empirical model for the simulation of freight policies","authors":"Michiel de Bok ,&nbsp;Lóránt Tavasszy ,&nbsp;Sebastiaan Thoen ,&nbsp;Larissa Eggers ,&nbsp;Ioanna Kourounioti","doi":"10.1016/j.simpat.2025.103140","DOIUrl":"10.1016/j.simpat.2025.103140","url":null,"abstract":"<div><div>Despite the importance of urban freight transportation for the accessibility and livability of cities, few systematic, quantitative and empirical methods exist which allow an impact assessment of urban freight transportation solutions or policies. There is a lack of transparent literature on the full specification and estimation of these models, which not only hampers continued research, but also the development of evidence-based urban freight transport policies. We present the urban freight simulator Multi-Agent Simulation System for Goods Transport (MASS-GT) with its full specification and empirical implementation for a study area in The Netherlands. It concerns an agent-based model based on a framework of discrete choice and optimization models, which describes logistic choices of shippers, carriers, producers and consumers. The disaggregate level of detail allows the analysis of a wide variety of logistic developments and policies across all or specific logistic segments. The model is estimated and validated using a variety of data sources: truck trip diaries, supply/use statistics, an e-commerce demand survey, traffic counts and other relevant statistics. The article presents the full specifications of the model and their empirical estimation, including the data sources used. Also, the validity of the model is evaluated using road freight traffic counts. Finally, examples of applications of the model to case studies are provided.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103140"},"PeriodicalIF":3.5,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of electro-magnets on enhanced hall-effect amplifier nanoscale device (HAND) – part 1: Modelling & simulations","authors":"Raz Mottes ,&nbsp;Avi Karsenty","doi":"10.1016/j.simpat.2025.103133","DOIUrl":"10.1016/j.simpat.2025.103133","url":null,"abstract":"<div><div>A new version of a nanoscale device, based on the famous Hall Effect, and named HAND (Hall Amplifier Nanoscale Device), was designed and analytically modelled, with the goal of implementing the macro-Hall effect on the nano scale. Following the physics of the Hall effect, the device receives a current as an input and creates a voltage as an output, which means it possesses a low input impedance and a high output impedance. While most other nanoscale devices based on the Hall effect are sensors, HAND operates as both an amplifier and a modulator, and it can be expected to find use in electronic circuits at very high frequencies (tens of THz). The first generation of the device required several improvements in advance of future fabrication of the second generation. One of these was enabling an increase of the applied magnetic field to higher values while preventing undesirable overheating of the device. Several approaches were taken toward this end, including changes to the material composition, device geometry, and other physical parameters of the HAND. A renewed mathematical description of the device behavior in DC condition was developed, as well as thorough analytical models for classical Hall Effect, in order to accurate forecast the behavior of the re-designed HAND. The analytical and numerical simulation results matched fully, validating the mathematical model for the case of a spiral coil geometry. This improved device, combining high frequency operation, amplification, the Hall effect, and nanoscale dimensions, is capable of revolutionizing microelectronic circuitry.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103133"},"PeriodicalIF":3.5,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of step-path failure mechanisms in rock slopes with en-echelon joints based on FDEM simulation","authors":"Haoyu Han ,&nbsp;Xuantao Liu ,&nbsp;Hongyuan Liu ,&nbsp;Daisuke Fukuda ,&nbsp;Lingyu Zeng ,&nbsp;Zicheng Xiong ,&nbsp;Yuxing Wang ,&nbsp;Yangtian Ye ,&nbsp;Andrew Chan","doi":"10.1016/j.simpat.2025.103138","DOIUrl":"10.1016/j.simpat.2025.103138","url":null,"abstract":"<div><div>In this study, an in-house combined finite-discrete element method (FDEM) is implemented to simulate and analyze the entire step-path failure process in rock slopes with en-echelon joints under natural conditions. Based on the Longmenqiao Reservoir slope in Chongqing, China, numerical models of the slope with and without en-echelon joints are established, and a comparative analysis is first conducted to explore the effects of the en-echelon joints on the slope failure mode. Then, to further investigate the slope failure mechanisms due to various influencing factors on site, a series of parametric analyses is conducted following an orthogonal experimental design with six factors at three levels. Through range and variance analyses of the computation results from 18 numerical models, the sensitivities of the slope stability to slope angle, slope height, joint angle, joint length, rock bridge angle, and rock bridge length are evaluated. Furthermore, a single-variable analysis method is adopted to build 24 numerical models with a focus on the aforementioned six key influencing factors to investigate the specific impacts of each factor on the slope stability, slope failure mode, and kinetic energy variation during the slope failure process. It is found that the fracture of the slopes with the en-echelon joints emerges sequentially along the joints and rock bridges from the bottom to top during the small deformation stage and reversals in shear stress direction are observed within the rock bridges during the detachment stage. The slope stability is found to be sensitive to the following six key influencing factors in descending order: joint angle, slope angle, slope height, joint length, rock bridge angle, and rock bridge length. A negative correlation is identified between the slope stability and the slope angle, slope height as well as joint angle while no clear linear relationship exists with the other three parameters. The numerical findings not only deepen the understanding of the mechanisms of step-path failure in rock slopes but also provide solid theoretical and data foundations for landslide risk assessment and prediction under complex environmental conditions.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103138"},"PeriodicalIF":3.5,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and evaluation of digital twin model for rack and pinion drive vegetable seedling transmission device using Adams/MATLAB co-simulation","authors":"Ibrar Ahmad ,&nbsp;Bushra Siddique ,&nbsp;Muhammad Adnan Islam ,&nbsp;Zia Ul Haq ,&nbsp;Ziang Niu ,&nbsp;Muhammad Mohsin Waqas ,&nbsp;Qizhi Yang ,&nbsp;Zhengjun Qiu","doi":"10.1016/j.simpat.2025.103132","DOIUrl":"10.1016/j.simpat.2025.103132","url":null,"abstract":"<div><div>A sustainable design and optimized control system for the vegetable seedling transmission device is crucial for enhancing the operational speed and precision of fully automatic vegetable seedling transplanters. The incorporation of virtual prototype modeling for optimizing the design and control of these seedling devices has not been sufficiently explored in prior studies. Goal of this research is to develop and validate a digital twin model that will serve as a foundation for optimizing the design and control of seedling devices used in robotic transplanters. This study presents a state-of-the-art digital twin model of rack and pinion drive seedling transmission device utilizing Adams/MATLAB co-simulation. The findings demonstrate a robust correspondence between digital twin model and physical prototype, exhibiting a maximum linear positioning error discrepancy of 0.95 mm, a maximum relative positioning error of 3.17 and coefficient of determination (<span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span>) values approximately equal to 1. Angular positioning error ranged from 3.73° to 7.98° as seedling rates increased from 90 to 140 seedlings/mi. Furthermore, precise activation and deactivation of the seedling cups opening mechanism was observed during the seedling transmission schedule. This digital twin model accurately represents the physical model of seedling device which can be utilized for design and control optimization. Potential future applications of this digital twin model include enhancing efficiency of robotic transplanters and mitigating environmental impacts.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"142 ","pages":"Article 103132"},"PeriodicalIF":3.5,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}