Pub Date : 2025-09-12DOI: 10.1016/j.simpat.2025.103205
Daniele Baccega , Irene Terrone , Peter Heywood , Robert Chisholm , Paul Richmond , Sandro Gepiro Contaldo , Lorenzo Bosio , Simone Pernice , Marco Beccuti
Agent-based models are computational models that simulate the dynamic interactions, behaviours, and communication protocols among agents in a shared environment. The use of such models in the field of epidemiology has attracted much attention, allowing the evaluation of the effectiveness of possible interventions and vaccination strategies. However, setting up these environments typically requires a manual and technical process that can be both time-consuming and complex. To address this challenge, we introduce Forge4Flame, a novel and user-friendly dashboard that simplifies the definition of agent-based models for FLAME GPU 2. Our goal is to make this modelling framework more accessible to a broader audience of researchers and public health professionals. Specifically, the tool streamlines model design, execution, and analysis by automatically generating the required FLAME GPU 2 code and incorporating valuable visualisation and post-processing features. Moreover, the integration of two different levels of population model was explored, allowing a detailed analysis of disease dynamics. This shows the tool’s potential to enhance both the accessibility and scalability of agent-based models through Docker and Slurm for efficient distributed computing on high-performance computing systems. Finally, the effectiveness of this tool is demonstrated through a case study that investigates the COVID-19 emergency in a generic Italian middle school.
{"title":"Forge4Flame: An intuitive dashboard for designing GPU agent-based models to simulate infectious disease spread","authors":"Daniele Baccega , Irene Terrone , Peter Heywood , Robert Chisholm , Paul Richmond , Sandro Gepiro Contaldo , Lorenzo Bosio , Simone Pernice , Marco Beccuti","doi":"10.1016/j.simpat.2025.103205","DOIUrl":"10.1016/j.simpat.2025.103205","url":null,"abstract":"<div><div>Agent-based models are computational models that simulate the dynamic interactions, behaviours, and communication protocols among agents in a shared environment. The use of such models in the field of epidemiology has attracted much attention, allowing the evaluation of the effectiveness of possible interventions and vaccination strategies. However, setting up these environments typically requires a manual and technical process that can be both time-consuming and complex. To address this challenge, we introduce <em>Forge4Flame</em>, a novel and user-friendly dashboard that simplifies the definition of agent-based models for FLAME GPU 2. Our goal is to make this modelling framework more accessible to a broader audience of researchers and public health professionals. Specifically, the tool streamlines model design, execution, and analysis by automatically generating the required FLAME GPU 2 code and incorporating valuable visualisation and post-processing features. Moreover, the integration of two different levels of population model was explored, allowing a detailed analysis of disease dynamics. This shows the tool’s potential to enhance both the accessibility and scalability of agent-based models through Docker and Slurm for efficient distributed computing on high-performance computing systems. Finally, the effectiveness of this tool is demonstrated through a case study that investigates the COVID-19 emergency in a generic Italian middle school.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"145 ","pages":"Article 103205"},"PeriodicalIF":3.5,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105930","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}
Pub Date : 2025-09-09DOI: 10.1016/j.simpat.2025.103203
Haoran Xu , Yongsheng Liu , Fei Li , Shuaipeng Wang , Shangyu Yang
Borehole instability is a critical challenge that affects safety and efficiency in deep drilling. Classical continuum mechanics struggles to accurately capture the discontinuous processes of crack initiation and propagation around boreholes. This paper develops and validates a nonlocal borehole damage model based on peridynamics. The borehole collapse mechanism is explored, and the regulatory role of drilling fluid pressure in maintaining borehole stability is evaluated. The results show that borehole collapse initiates along the direction of minimum horizontal pressure, characterized by a crescent-shaped shear failure accompanied by tensile fractures. The borehole eventually evolves into a butterfly-shaped damage pattern with a central fragmented zone. Increasing the elastic modulus of the surrounding rock and reducing the borehole radius effectively inhibits damage propagation. As the elastic modulus increases from 6 to 30 GPa, the areas of the collapse zones are reduced by 87.50%, indicating a substantial enhancement in the material’s resistance to both microcrack initiation and macroscopic instability. Low-modulus rocks are more prone to form continuous shear-fracture zones. In contrast, the horizontal pressure difference emerges as the primary driver of damage evolution; once it exceeds 30 MPa, the crack growth resistance deteriorates rapidly, leading to accelerated crack coalescence and the formation of a connected fracture network. An optimal drilling fluid pressure window can suppress up to 85.05% of the damaged area. However, excessive pressure may induce radial tensile fractures. The findings revealed the mechanisms of borehole collapse and confirmed the superiority of the peridynamics model in predicting borehole instability. This study provides theoretical insight and methodological support for stability control in deep drilling operations.
{"title":"Peridynamics modeling of underground borehole instability: Collapse mechanism and stabilization strategy","authors":"Haoran Xu , Yongsheng Liu , Fei Li , Shuaipeng Wang , Shangyu Yang","doi":"10.1016/j.simpat.2025.103203","DOIUrl":"10.1016/j.simpat.2025.103203","url":null,"abstract":"<div><div>Borehole instability is a critical challenge that affects safety and efficiency in deep drilling. Classical continuum mechanics struggles to accurately capture the discontinuous processes of crack initiation and propagation around boreholes. This paper develops and validates a nonlocal borehole damage model based on peridynamics. The borehole collapse mechanism is explored, and the regulatory role of drilling fluid pressure in maintaining borehole stability is evaluated. The results show that borehole collapse initiates along the direction of minimum horizontal pressure, characterized by a crescent-shaped shear failure accompanied by tensile fractures. The borehole eventually evolves into a butterfly-shaped damage pattern with a central fragmented zone. Increasing the elastic modulus of the surrounding rock and reducing the borehole radius effectively inhibits damage propagation. As the elastic modulus increases from 6 to 30 GPa, the areas of the collapse zones are reduced by 87.50%, indicating a substantial enhancement in the material’s resistance to both microcrack initiation and macroscopic instability. Low-modulus rocks are more prone to form continuous shear-fracture zones. In contrast, the horizontal pressure difference emerges as the primary driver of damage evolution; once it exceeds 30 MPa, the crack growth resistance deteriorates rapidly, leading to accelerated crack coalescence and the formation of a connected fracture network. An optimal drilling fluid pressure window can suppress up to 85.05% of the damaged area. However, excessive pressure may induce radial tensile fractures. The findings revealed the mechanisms of borehole collapse and confirmed the superiority of the peridynamics model in predicting borehole instability. This study provides theoretical insight and methodological support for stability control in deep drilling operations.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"145 ","pages":"Article 103203"},"PeriodicalIF":3.5,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049318","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}
Pub Date : 2025-09-02DOI: 10.1016/j.simpat.2025.103202
Xiaoting Yuan , Tieqiao Tang , Tao Wang , Nikolai Bode
Modeling pedestrian flow through security checkpoints is critical for efficient airport operations. In this study, we develop a discrete event simulation model to describe queue dynamics at security screening checkpoints. Focusing on queue lengths, waiting times, and passenger arrival rates, we investigate how dynamically changing the number of open checkpoints affects system performance. Building on these insights, we formulate a mixed-integer linear programming model that incorporates system performance states derived from simulations to optimize checkpoint planning over time. Finally, we validate our approach through simulations based on arrival data from Guangzhou Baiyun International Airport, China. Compared with a stand-alone mixed-integer linear programming formulation, the simulation-enhanced method achieves fewer total and peak lanes while meeting the same service-level targets. By providing an accurate representation of pedestrian flows, this research offers airports a practical decision tool for dynamic resource allocation and improved checkpoint performance.
{"title":"From pedestrian simulation to security screening checkpoint planning: Simulation-enhanced optimization method","authors":"Xiaoting Yuan , Tieqiao Tang , Tao Wang , Nikolai Bode","doi":"10.1016/j.simpat.2025.103202","DOIUrl":"10.1016/j.simpat.2025.103202","url":null,"abstract":"<div><div>Modeling pedestrian flow through security checkpoints is critical for efficient airport operations. In this study, we develop a discrete event simulation model to describe queue dynamics at security screening checkpoints. Focusing on queue lengths, waiting times, and passenger arrival rates, we investigate how dynamically changing the number of open checkpoints affects system performance. Building on these insights, we formulate a mixed-integer linear programming model that incorporates system performance states derived from simulations to optimize checkpoint planning over time. Finally, we validate our approach through simulations based on arrival data from Guangzhou Baiyun International Airport, China. Compared with a stand-alone mixed-integer linear programming formulation, the simulation-enhanced method achieves fewer total and peak lanes while meeting the same service-level targets. By providing an accurate representation of pedestrian flows, this research offers airports a practical decision tool for dynamic resource allocation and improved checkpoint performance.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"145 ","pages":"Article 103202"},"PeriodicalIF":3.5,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989364","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}
Pub Date : 2025-08-30DOI: 10.1016/j.simpat.2025.103204
Xingyu Zhao , Changhe Li , Pengzhi Lu , Wei Li , Weiwei Qiu , Wuchang Wang , Yuxing Li
Injection compressors, as the core equipment in the gas injection process of underground gas storage (UGS) facilities, play a vital role in ensuring the safe and efficient operation of UGS systems. However, traditional optimization methods often struggle to adapt dynamically under complex operating conditions and may lead to excessive energy consumption. To address these challenges, this study proposes a deep reinforcement learning (DRL)-based approach to optimize compressor start-up strategies. First, a high-fidelity hybrid simulation model is developed by integrating thermodynamic equations of reciprocating compressors with a residual correction network based on a multilayer perceptron, forming a Mechanism-Data fusion Model framework. This model achieves prediction errors of <5 % for power and <3 % for discharge flow rate. Based on the accurate simulation model, an optimization framework is constructed using the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm. Within this framework, continuous control variables—such as the number of operating compressors, inlet throttling levels, and relative clearance volume adjustments—are mapped to the action space of the reinforcement learning agent. A multi-objective reward function is designed to incorporate penalties for gas injection deviations, the number of active compressors, inlet pressure constraints, and clearance volume limits. By introducing delayed updates to the target network and applying an adaptive noise clipping mechanism, the proposed strategy ensures optimal parameter control across the entire gas injection cycle while satisfying operational and safety requirements. Experimental results demonstrate that the proposed method reduces compressor energy consumption by 5.18 %, offering a precise, adaptive, and intelligent decision-making solution for dynamic optimization of UGS compressor operations.
{"title":"Optimization of start-up strategies of gas injection compressor in underground gas storage using deep reinforcement learning","authors":"Xingyu Zhao , Changhe Li , Pengzhi Lu , Wei Li , Weiwei Qiu , Wuchang Wang , Yuxing Li","doi":"10.1016/j.simpat.2025.103204","DOIUrl":"10.1016/j.simpat.2025.103204","url":null,"abstract":"<div><div>Injection compressors, as the core equipment in the gas injection process of underground gas storage (UGS) facilities, play a vital role in ensuring the safe and efficient operation of UGS systems. However, traditional optimization methods often struggle to adapt dynamically under complex operating conditions and may lead to excessive energy consumption. To address these challenges, this study proposes a deep reinforcement learning (DRL)-based approach to optimize compressor start-up strategies. First, a high-fidelity hybrid simulation model is developed by integrating thermodynamic equations of reciprocating compressors with a residual correction network based on a multilayer perceptron, forming a Mechanism-Data fusion Model framework. This model achieves prediction errors of <5 % for power and <3 % for discharge flow rate. Based on the accurate simulation model, an optimization framework is constructed using the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm. Within this framework, continuous control variables—such as the number of operating compressors, inlet throttling levels, and relative clearance volume adjustments—are mapped to the action space of the reinforcement learning agent. A multi-objective reward function is designed to incorporate penalties for gas injection deviations, the number of active compressors, inlet pressure constraints, and clearance volume limits. By introducing delayed updates to the target network and applying an adaptive noise clipping mechanism, the proposed strategy ensures optimal parameter control across the entire gas injection cycle while satisfying operational and safety requirements. Experimental results demonstrate that the proposed method reduces compressor energy consumption by 5.18 %, offering a precise, adaptive, and intelligent decision-making solution for dynamic optimization of UGS compressor operations.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"145 ","pages":"Article 103204"},"PeriodicalIF":3.5,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010686","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}
Pub Date : 2025-08-23DOI: 10.1016/j.simpat.2025.103201
Chun Sheng , Qize He , Liping Yu , Jiacheng Wang , Haoming Xie , Zhiming Fang , Zhongyi Huang
Emergency evacuation planning requires balancing multiple objectives like minimizing time, avoiding hazards, and ensuring fairness. Traditional methods struggle to strike a balance between macroscopic efficiency and microscopic realism. This study proposes a new multi-objective optimization framework based on an improved Matrix Translation Model (MTM) and Exit Balance Algorithm (EBA): the improved MTM efficiently simulates the evacuation process and obtains individual objectives, thereby deriving group evacuation time objective , detour objective ; crowding objective , injury objective and fatality objective . , , and are converted into penalty terms for , and the improved EBA algorithm balances evacuation times across different exits to solve the multi-objective problem. This framework ensures precise statistical analysis of individual evacuation parameters while guaranteeing that each iteration moves closer to the optimal solution, enabling rapid convergence. Optimization results from a scenario with 2 floors, 42 rooms, and 1688 evacuees demonstrate that the algorithm can complete the simulation within 8–15 s, and the evacuation time reduced by 16 % while controlling detour and crowding duration in the scenario without fire, and the cumulative injury probability cut by 42 % in the fire scenario. This work bridges macroscopic efficiency and microscopic realism, offering a practical solution for dynamic evacuation planning.
{"title":"Multi-objectives optimization of evacuation path based on improved matrix translation model and exit balance algorithm","authors":"Chun Sheng , Qize He , Liping Yu , Jiacheng Wang , Haoming Xie , Zhiming Fang , Zhongyi Huang","doi":"10.1016/j.simpat.2025.103201","DOIUrl":"10.1016/j.simpat.2025.103201","url":null,"abstract":"<div><div>Emergency evacuation planning requires balancing multiple objectives like minimizing time, avoiding hazards, and ensuring fairness. Traditional methods struggle to strike a balance between macroscopic efficiency and microscopic realism. This study proposes a new multi-objective optimization framework based on an improved Matrix Translation Model (MTM) and Exit Balance Algorithm (EBA): the improved MTM efficiently simulates the evacuation process and obtains individual objectives, thereby deriving group evacuation time objective <span><math><msub><mi>f</mi><mi>t</mi></msub></math></span>, detour objective <span><math><msub><mi>f</mi><mi>d</mi></msub></math></span>; crowding objective <span><math><msub><mi>f</mi><mi>c</mi></msub></math></span>, injury objective <span><math><msub><mi>f</mi><mi>i</mi></msub></math></span> and fatality objective <span><math><msub><mi>f</mi><mi>f</mi></msub></math></span>. <span><math><msub><mi>f</mi><mi>d</mi></msub></math></span>, <span><math><msub><mi>f</mi><mi>c</mi></msub></math></span>, <span><math><msub><mi>f</mi><mi>i</mi></msub></math></span> and <span><math><msub><mi>f</mi><mi>f</mi></msub></math></span> are converted into penalty terms for <span><math><msub><mi>f</mi><mi>t</mi></msub></math></span>, and the improved EBA algorithm balances evacuation times across different exits to solve the multi-objective problem. This framework ensures precise statistical analysis of individual evacuation parameters while guaranteeing that each iteration moves closer to the optimal solution, enabling rapid convergence. Optimization results from a scenario with 2 floors, 42 rooms, and 1688 evacuees demonstrate that the algorithm can complete the simulation within 8–15 s, and the evacuation time reduced by 16 % while controlling detour and crowding duration in the scenario without fire, and the cumulative injury probability cut by 42 % in the fire scenario. This work bridges macroscopic efficiency and microscopic realism, offering a practical solution for dynamic evacuation planning.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"145 ","pages":"Article 103201"},"PeriodicalIF":3.5,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907974","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}
The optimized performance of rock blasting heavily relies on the presence of discontinuities. These geological features play an important role in wave and fracture propagation in rocks and can be considered a barrier against the blast wave and fracture propagation. Blasting has many applications, but one of the important aspects is presplitting blasting, in which light blasts are operated to create a continuous plane prior to the main blasting. The goal of this particular blast operation is mainly to inhibit damage to the reserved rock. In the presplit blastingin underground rocks, the magnitude of the ground in-situ stresses plays a vital role and dominates the performance of the presplitting, which can lead to an unsuccessful detonation if mismeasured. There is much evidence that, in many cases, the joints are not closed but instead are filled with a different material. Thus, in this study, the performance of presplit blasting in a rock domain with a closed or filled joint is analysed using the combined finite-discrete element method (FDEM) with a gas in fracture logic. First, the applicability of the method is verified against some experiments. Once verified, 2D FDEM models are analysed to evaluate the influence of an inclined closed or filled flaw on blast-induced fracture development. The FDEM results confirm the strong impact of joint inclination angle on the fragmentation degree. Furthermore, it is shown that the performance of the presplit blasting is remarkably dependent on the magnitude of ground in-situ stresses. The results also show that the filling material and its orientation angle with respect to the maximum principal stress have an imposing effect on the success of the presplitting blasting. Also, it is revealed that in the presplit blasting with filled joint, the failure of the filling is a mode failure, while the connecting fractures are of tensile mode.
{"title":"Numerical study of presplit blasting in rock masses with a closed and filled joint using coupled finite-discrete element method","authors":"Mansour Sharafisafa , Zeinab Aliabadian , Luming Shen","doi":"10.1016/j.simpat.2025.103199","DOIUrl":"10.1016/j.simpat.2025.103199","url":null,"abstract":"<div><div>The optimized performance of rock blasting heavily relies on the presence of discontinuities. These geological features play an important role in wave and fracture propagation in rocks and can be considered a barrier against the blast wave and fracture propagation. Blasting has many applications, but one of the important aspects is presplitting blasting, in which light blasts are operated to create a continuous plane prior to the main blasting. The goal of this particular blast operation is mainly to inhibit damage to the reserved rock. In the presplit blastingin underground rocks, the magnitude of the ground in-situ stresses plays a vital role and dominates the performance of the presplitting, which can lead to an unsuccessful detonation if mismeasured. There is much evidence that, in many cases, the joints are not closed but instead are filled with a different material. Thus, in this study, the performance of presplit blasting in a rock domain with a closed or filled joint is analysed using the combined finite-discrete element method (FDEM) with a gas in fracture logic. First, the applicability of the method is verified against some experiments. Once verified, 2D FDEM models are analysed to evaluate the influence of an inclined closed or filled flaw on blast-induced fracture development. The FDEM results confirm the strong impact of joint inclination angle on the fragmentation degree. Furthermore, it is shown that the performance of the presplit blasting is remarkably dependent on the magnitude of ground in-situ stresses. The results also show that the filling material and its orientation angle with respect to the maximum principal stress have an imposing effect on the success of the presplitting blasting. Also, it is revealed that in the presplit blasting with filled joint, the failure of the filling is a mode failure, while the connecting fractures are of tensile mode.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"144 ","pages":"Article 103199"},"PeriodicalIF":3.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902297","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}
Pub Date : 2025-08-20DOI: 10.1016/j.simpat.2025.103198
Mohammad Seyfaddini , Mojtaba Bahaaddini , Saeed Karimi Nasab , Mohammad Hossein Khosravi , Hossein Masoumi
Toppling failure is a common instability in natural rock slopes. The common approaches for investigating toppling failure mechanisms are physical and analytical methods, which encounter special difficulties for the test set-up and limitation in the number of physical experiments as well as complicated governing equations in analytical models. Recent advances in numerical modeling, particularly the discrete element method (DEM), have opened new avenues for understanding the complex mechanisms behind toppling failure. In this work, the ability of numerical method in reproducing toppling mechanism was first investigated through an extensive comparative analysis with physical and analytical methods. Hence, the validated numerical models were employed to statistically examine the individual and interactive effects of different parameters on the block-flexural toppling failure mechanism using the response surface methodology (RSM). To explore the statistical significance of effective parameters, the central composite design (CCD) was employed. The analysis revealed that aspect ratio constitutes the most influential parameter governing block-flexural toppling failure, while block unit weight found to be the least significant factor. Also, it was found out that the block unit weight and the block aspect ratio can cause a decrease in the failure initiation angle. It was concluded that an increase in the joint friction angle and block tensile strength can increase the stability of slope where the joint friction angle can change the shape and location of failure surface. Finally, evaluation of interaction effects showed that the impact of block tensile strength on block-flexural failure increases with an increase in block slenderness.
{"title":"Failure mechanisms of block-flexural toppling: An extensive numerical study","authors":"Mohammad Seyfaddini , Mojtaba Bahaaddini , Saeed Karimi Nasab , Mohammad Hossein Khosravi , Hossein Masoumi","doi":"10.1016/j.simpat.2025.103198","DOIUrl":"10.1016/j.simpat.2025.103198","url":null,"abstract":"<div><div>Toppling failure is a common instability in natural rock slopes. The common approaches for investigating toppling failure mechanisms are physical and analytical methods, which encounter special difficulties for the test set-up and limitation in the number of physical experiments as well as complicated governing equations in analytical models. Recent advances in numerical modeling, particularly the discrete element method (DEM), have opened new avenues for understanding the complex mechanisms behind toppling failure. In this work, the ability of numerical method in reproducing toppling mechanism was first investigated through an extensive comparative analysis with physical and analytical methods. Hence, the validated numerical models were employed to statistically examine the individual and interactive effects of different parameters on the block-flexural toppling failure mechanism using the response surface methodology (RSM). To explore the statistical significance of effective parameters, the central composite design (CCD) was employed. The analysis revealed that aspect ratio constitutes the most influential parameter governing block-flexural toppling failure, while block unit weight found to be the least significant factor. Also, it was found out that the block unit weight and the block aspect ratio can cause a decrease in the failure initiation angle. It was concluded that an increase in the joint friction angle and block tensile strength can increase the stability of slope where the joint friction angle can change the shape and location of failure surface. Finally, evaluation of interaction effects showed that the impact of block tensile strength on block-flexural failure increases with an increase in block slenderness.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"144 ","pages":"Article 103198"},"PeriodicalIF":3.5,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902502","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}
Pub Date : 2025-08-09DOI: 10.1016/j.simpat.2025.103194
Andreas Müller , Stefan Mueller , Tobias Brixner , Sebastian von Mammen
femtoPro is an interactive virtual reality (VR) laser laboratory balancing the contrasting challenges of accuracy and computational efficiency in optics simulations. It can simulate linear and nonlinear optical phenomena in real time, a task that pushes the boundaries of current consumer hardware. This paper details the concept, implementation, and evaluation of a dynamic graph-based solution tailored to the specific requirements and challenges of the simulation. Resource usage is optimized through a selective updating strategy that identifies and preserves laser paths unchanged between simulation frames, eliminating the need for unnecessary recalculations. Benchmarking of real-world scenarios confirms that our approach delivers a smooth user experience, even on mobile VR platforms with limited computing power. The methodologies, solutions and insights outlined in this paper may be applicable to other interactive, dynamic graph-based real-time simulations.
{"title":"A graph-based laser path solver algorithm for virtual reality laboratory simulations","authors":"Andreas Müller , Stefan Mueller , Tobias Brixner , Sebastian von Mammen","doi":"10.1016/j.simpat.2025.103194","DOIUrl":"10.1016/j.simpat.2025.103194","url":null,"abstract":"<div><div>femtoPro is an interactive virtual reality (VR) laser laboratory balancing the contrasting challenges of accuracy and computational efficiency in optics simulations. It can simulate linear and nonlinear optical phenomena in real time, a task that pushes the boundaries of current consumer hardware. This paper details the concept, implementation, and evaluation of a dynamic graph-based solution tailored to the specific requirements and challenges of the simulation. Resource usage is optimized through a selective updating strategy that identifies and preserves laser paths unchanged between simulation frames, eliminating the need for unnecessary recalculations. Benchmarking of real-world scenarios confirms that our approach delivers a smooth user experience, even on mobile VR platforms with limited computing power. The methodologies, solutions and insights outlined in this paper may be applicable to other interactive, dynamic graph-based real-time simulations.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"144 ","pages":"Article 103194"},"PeriodicalIF":3.5,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828928","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}
Pub Date : 2025-08-07DOI: 10.1016/j.simpat.2025.103193
Yueting Wang, Zhiqun Hu, Zhaoming Lu, Qinrui An, Xiangming Wen
Adverse weather conditions significantly degrade the environmental perception capabilities of autonomous vehicles (AVs), thereby compromising both traffic safety and operational efficiency. Connected autonomous vehicles (CAVs), leveraging vehicle-to-vehicle (V2V) communication technology, have the potential to mitigate these challenges through cooperative perception mechanisms. Before large-scale deployment of CAVs, it is essential to understand the significant impacts of CAV application on urban traffic characteristics, especially in adverse weather conditions. However, building a realistic simulation for CAV traffic system in adverse weather conditions can be challenging. On the one hand, adverse weather, with chaotic atmosphere behaviors and rapid complex interactions with electromagnetic waves, imposes unpredictable effects on automotive sensors. On the other hand, the dynamic interplay between sensor physics, communication networks, and multi-agent data fusion contributes to uncertainty in CAV driving decisions. To address the challenges, this paper firstly introduces radar theories and builds a physics-based model to realistically simulate weather impacts on sensors at scale. Then, a novel simulation model is proposed for CAV traffic system in rainy conditions, which includes weather-related degraded sensor, unreliable V2V communication, and cooperative perception-based decision making module. Finally, simulations in different levels of rainy conditions are conducted based on a large-scale road network (in the City of Luxembourg) with real traffic data. Results show that CAVs are more effective in improving traffic safety and efficiency under challenging weather conditions. The limits of CAVs in adverse weather are also discussed.
{"title":"Modeling proactive effects of connected autonomous vehicles on urban traffic in adverse weather","authors":"Yueting Wang, Zhiqun Hu, Zhaoming Lu, Qinrui An, Xiangming Wen","doi":"10.1016/j.simpat.2025.103193","DOIUrl":"10.1016/j.simpat.2025.103193","url":null,"abstract":"<div><div>Adverse weather conditions significantly degrade the environmental perception capabilities of autonomous vehicles (AVs), thereby compromising both traffic safety and operational efficiency. Connected autonomous vehicles (CAVs), leveraging vehicle-to-vehicle (V2V) communication technology, have the potential to mitigate these challenges through cooperative perception mechanisms. Before large-scale deployment of CAVs, it is essential to understand the significant impacts of CAV application on urban traffic characteristics, especially in adverse weather conditions. However, building a realistic simulation for CAV traffic system in adverse weather conditions can be challenging. On the one hand, adverse weather, with chaotic atmosphere behaviors and rapid complex interactions with electromagnetic waves, imposes unpredictable effects on automotive sensors. On the other hand, the dynamic interplay between sensor physics, communication networks, and multi-agent data fusion contributes to uncertainty in CAV driving decisions. To address the challenges, this paper firstly introduces radar theories and builds a physics-based model to realistically simulate weather impacts on sensors at scale. Then, a novel simulation model is proposed for CAV traffic system in rainy conditions, which includes weather-related degraded sensor, unreliable V2V communication, and cooperative perception-based decision making module. Finally, simulations in different levels of rainy conditions are conducted based on a large-scale road network (in the City of Luxembourg) with real traffic data. Results show that CAVs are more effective in improving traffic safety and efficiency under challenging weather conditions. The limits of CAVs in adverse weather are also discussed.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"144 ","pages":"Article 103193"},"PeriodicalIF":3.5,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144866658","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}
Pub Date : 2025-08-06DOI: 10.1016/j.simpat.2025.103192
Sven Watzinger , David Olave-Rojas , Janina Bathe , Hanna-Joy Renner , Jan Wnent , Leonie Hannappel , Jan-Thorsten Gräsner , Stefan Nickel
The global pandemic provoked by the SARS-CoV-2 virus in recent years has presented new challenges to health care systems. One major issue is the risk of overloading hospital capacities during regional surges, especially in intensive care units. Strategic patient transfers between regions with different loads can mitigate this risk. To coordinate such nationwide strategic patient transfers in Germany, the clover-leaf system was initiated. The transfer decision consists of allocating patients to destination hospitals as well as scheduling patients on transport vehicles which includes the possibility of combining different modes of transport, for instance ground-based with an ambulance and air-based with a helicopter, during one transfer. As potentially conflicting objective dimensions the impact of the transfers on the transferred patients and the impact on loads in intensive care units have to be considered. To support the decision makers a hybrid simulation model combining agent-based and discrete-event modeling is developed by an interdisciplinary team of medical and operations research experts. The main contribution of the simulation model is the modeling of multimodal patient transfers which to the best of our knowledge has not been considered in the existing literature. Next to the simulation model, several transfer strategies in the form of decision rules are proposed. These transfer strategies are used to benchmark transfer plans created by the decision makers in a test scenario based on nationwide data of the German health care system. Using simulation allowed to evaluate the transfer plans in different objective dimensions and informed the decision-making process.
{"title":"A flexible hybrid simulation model for hospital capacity management through multimodal transfers of COVID-19 patients","authors":"Sven Watzinger , David Olave-Rojas , Janina Bathe , Hanna-Joy Renner , Jan Wnent , Leonie Hannappel , Jan-Thorsten Gräsner , Stefan Nickel","doi":"10.1016/j.simpat.2025.103192","DOIUrl":"10.1016/j.simpat.2025.103192","url":null,"abstract":"<div><div>The global pandemic provoked by the SARS-CoV-2 virus in recent years has presented new challenges to health care systems. One major issue is the risk of overloading hospital capacities during regional surges, especially in intensive care units. Strategic patient transfers between regions with different loads can mitigate this risk. To coordinate such nationwide strategic patient transfers in Germany, the clover-leaf system was initiated. The transfer decision consists of allocating patients to destination hospitals as well as scheduling patients on transport vehicles which includes the possibility of combining different modes of transport, for instance ground-based with an ambulance and air-based with a helicopter, during one transfer. As potentially conflicting objective dimensions the impact of the transfers on the transferred patients and the impact on loads in intensive care units have to be considered. To support the decision makers a hybrid simulation model combining agent-based and discrete-event modeling is developed by an interdisciplinary team of medical and operations research experts. The main contribution of the simulation model is the modeling of multimodal patient transfers which to the best of our knowledge has not been considered in the existing literature. Next to the simulation model, several transfer strategies in the form of decision rules are proposed. These transfer strategies are used to benchmark transfer plans created by the decision makers in a test scenario based on nationwide data of the German health care system. Using simulation allowed to evaluate the transfer plans in different objective dimensions and informed the decision-making process.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"144 ","pages":"Article 103192"},"PeriodicalIF":3.5,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828927","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}