Simulation Modelling Practice and Theory最新文献

{"title":"The impact of preschool children requiring adult assistance on evacuation efficiency","authors":"Hongliu Li ,&nbsp;Jacqueline Tsz Yin Lo ,&nbsp;Siuming Lo","doi":"10.1016/j.simpat.2024.103062","DOIUrl":"10.1016/j.simpat.2024.103062","url":null,"abstract":"<div><div>Preschool children, aged 3 to 6 years old, are a vulnerable group in emergencies due to their young age and limited self-protection abilities in kindergartens. Despite the critical role of kindergarten tutors in providing necessary aid and guidance, the adequacy of tutor-to-child ratios under increased assistance demands, and the efficacy of various evacuation guiding strategies, remain unexplored. This study modifies an agent-based model to simulate kindergarten evacuation, considering the proportion of children requiring assistance (ranging from 0 % to 100 %) and different guiding modes (instructing children in distinct regions: full circle, front semi-circle, and back semi-circle), with the aim of establishing ways to ensure effective evacuation. Through simulation, this study analyzes evacuation trajectories, evacuation time, flow, density distributions, and speed profiles to assess the impact of varying assistance needs and guiding strategies on evacuation efficiency. The findings reveal that an increase in the percentage of children needing assistance results in a gradual increase in evacuation time and a corresponding decrease in flow. Additionally, adopting the front semi-circle guiding mode speeds up evacuation compared to other guiding modes. These insights can provide valuable recommendations for kindergarten evacuation planning and crowd management for children.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"139 ","pages":"Article 103062"},"PeriodicalIF":3.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145587","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":"The Bevel Local Slope Approach: A method for mesh stiffness estimation in spur, helical and spiral bevel gears","authors":"Ala Eddin Chakroun,&nbsp;Mattia Battarra,&nbsp;Emiliano Mucchi","doi":"10.1016/j.simpat.2024.103047","DOIUrl":"10.1016/j.simpat.2024.103047","url":null,"abstract":"<div><div>The local slope approach proved to be very useful in recent studies as a method to generate the gear mesh stiffness of spur gears. This study seeks to adopt this approach and apply it to the analysis of the gear mesh stiffness of bevel gears. The objective therefore extends beyond the validation of results obtained with an updated version of the method named the bevel local slope approach. This approach is considered as a finite element method that is based on a first-order finite difference approximation using the non-linear force–deflection response of the gear pair. CADs are prepared and optimum FE meshing is generated to realize simulations for several increments dividing a single meshing period. The results obtained with this approach are compared to the analytical approach of Weber and Banascheck. The goal is to illuminate potential challenges associated with the aforementioned method. A key observation is the phenomena occurring in the body of the gear as a torsional deformation at a direction different to the direction of rotation. The method proved to be very useful not only for straight bevel gears, but also for helical and spiral shapes.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"139 ","pages":"Article 103047"},"PeriodicalIF":3.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A discrete-event simheuristic for enhancing urban mobility","authors":"Mohammad Peyman ,&nbsp;Xabier A. Martin ,&nbsp;Javier Panadero ,&nbsp;Angel A. Juan","doi":"10.1016/j.simpat.2025.103084","DOIUrl":"10.1016/j.simpat.2025.103084","url":null,"abstract":"<div><div>This paper addresses a rich variant of the team orienteering problem under uncertainty to improve urban mobility. Specifically, we conduct a case study using real-world data from urban transportation hubs in Barcelona, gathered from Open Data Barcelona. The study involves routing autonomous delivery drones operating within a university campus to deliver items to designated drop-off points. Traditional optimization techniques often fail to account for the stochastic fluctuations inherent in urban traffic and the complex interactions between various transportation activities. To address these challenges, this research employs a simheuristic framework that combines heuristic optimization with commercial simulation software to replicate the dynamic and uncertain nature of urban environments accurately. The efficiency and practical applicability of our simheuristic framework are demonstrated through comprehensive computational experiments in a real-world context.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103084"},"PeriodicalIF":3.5,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094586","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":"Simulation-based framework for authenticating SCADA systems and cyber threat security in edge-based autonomous environments","authors":"Ala Mughaid ,&nbsp;Shadi Alzu’bi ,&nbsp;Ahmad A.A. Alkhatib ,&nbsp;Adel AlZioud ,&nbsp;Alaa Al Ghazo ,&nbsp;Issa AL-Aiash","doi":"10.1016/j.simpat.2025.103078","DOIUrl":"10.1016/j.simpat.2025.103078","url":null,"abstract":"<div><div>Supervisory Control and Data Acquisition (SCADA) systems are pivotal to critical industries, such as oil and gas, water treatment, and power generation, where they enable real-time monitoring and control over complex industrial processes. These systems commonly use protocols like Modbus/RTU, Modbus TCP/IP, DNP3, and IEC60870, each chosen to meet specific operational requirements. However, vulnerabilities in protocols like Modbus TCP/IP, especially in access control, authentication, and data integrity leave SCADA networks susceptible to cyber threats, with risks ranging from process disruption to data breaches or potential physical harm to infrastructure. This study proposes a simulation-based security framework for SCADA environments using the Modbus TCP/IP protocol, incorporating authentication through unique identification bytes, robust encryption to secure communications, and a layered Intrusion Detection and Prevention System (IDS/IPS) to detect and counteract malicious activities. The framework’s effectiveness is demonstrated through simulated scenarios and a real-world case study, showcasing significant resilience against common cyber threats faced by SCADA systems.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103078"},"PeriodicalIF":3.5,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094700","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":"Scheduling bag-of-task jobs with security requirements and dual-criteria partial computations in a fog – cloud system","authors":"Helen D. Karatza","doi":"10.1016/j.simpat.2025.103082","DOIUrl":"10.1016/j.simpat.2025.103082","url":null,"abstract":"<div><div>Internet of Things (IoT) applications have become integral to daily life, but they often impose stringent security and timing constraints. Fog computing, a modern computing paradigm, extends the capabilities of cloud resources to the edge of the network, offering potential solutions to these challenges. In these collaborative computing environments, workloads are composed of tasks with varying security requirements. Consequently, implementing security-aware scheduling schemes is crucial to ensure the proper execution of applications and to achieve the desired Quality of Service (QoS). This study explores security-conscious scheduling methodologies specifically designed for Bag-of-Tasks (BoT) applications within a fog-cloud computing framework. Fog resources are suitable for processing BoT tasks with specific security requirements, referred to as “fog jobs”. Conversely, BoT applications without specific security requirements, referred to as “cloud jobs”, can be processed on either cloud or fog resources. To expedite the execution of fog jobs, a method that utilizes partial computations for cloud job tasks is employed. This study provides valuable insights into the effects of approximations on system performance through simulation-based evaluations. It considers partial computations based on delay levels in relation to service demands and the size of cloud jobs. This approach enhances system performance with only a minor trade-off in results accuracy.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103082"},"PeriodicalIF":3.5,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094698","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":"New insights on the downward evacuation speed on long-distance stairs by experiment and modelling","authors":"Yayun You ,&nbsp;Zhiming Fang ,&nbsp;Shaocong Xie ,&nbsp;Qize He ,&nbsp;Jun Zhang ,&nbsp;Tianyu Tang","doi":"10.1016/j.simpat.2025.103083","DOIUrl":"10.1016/j.simpat.2025.103083","url":null,"abstract":"<div><div>Current evacuation models for super high-rise buildings typically assume a fixed speed or a decrease in speed with distance traveled, which overlooks the combined effects of physical exertion, recovery after rest, and partnering behavior. In this study, we present new insights on the downward evacuation speed on long-distance stairs by experiment and modelling. First, long-distance down stairs experiments are carried out, in which the goal distance, rest, and partnering or not are used as control factors. Second, a speed formula that indicates how the speed decreases as accumulated distance and how much does the speed increase after the rest is defined according to the experimental results. Furthermore, an evacuation model with dynamic speed (Evac-DS model) for super high-rise buildings is built, in which the pedestrian's speed is determined by the factors considered in the defined formula, such as expected evacuation distance, evacuation time, rest time, goal distance, and partnering or not. The results show that whether in scenarios where pedestrians move alone or in pairs, the trend of speed changes in the evacuation process on long-distance stairs predicted by the Evac-DS model closely matches the experiment. Finally, the Evac-DS model is used to simulate the evacuation process in Shanghai Tower with 580m height, and the predicted speed is compared with the evacuation drill data, as well as two other models: one assuming a constant speed and another where speed decreases linearly with distance. The results indicate that the Evac-DS model can effectively predict the evacuation time and the variation of pedestrian's evacuation speed in actual super high-rise buildings. This study may be a key step in understanding the nonlinear changes in speed during long-distance stairs evacuation, and provide scientific reference and support for both theoretical research and model applications related to pedestrian evacuation in the stairwells of super high-rise buildings.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103083"},"PeriodicalIF":3.5,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094699","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 application of a 3D GPU-parallelized CDEM for blasting induced rock fractures","authors":"Huanning Hu ,&nbsp;Liyun Yang ,&nbsp;Chun Feng ,&nbsp;Junguang Huang ,&nbsp;Xinguang Zhu","doi":"10.1016/j.simpat.2025.103081","DOIUrl":"10.1016/j.simpat.2025.103081","url":null,"abstract":"<div><div>The study has developed a three-dimensional, GPU-parallelized Continuum-Discontinuum Element Method (CDEM) program, utilizing the CUDA C/C++ programming model on GPUs to simulate rock deformation, fracturing, and movement. Initially, the paper outlines the theory and algorithms of the 3D Graphics Processing Units (GPU) - parallelized CDEM, focusing particularly on parallelization and optimization. Performance tests indicate that the 3D GPU-parallelized CDEM achieves a computational speed 645.31 times faster than a single-core serial CDEM code, significantly boosting computational efficiency. The simulation results of rock fracturing were demonstrated through a single-borehole blasting simulation in granite. Material parameters for granite were calibrated using 3D Brazilian and uniaxial compression tests. Comparisons with experimental data demonstrated that the simulation effectively replicated the observed crack patterns. However, discrepancies were noted in stress wave attenuation, and significant errors in crack density were observed across different sections, which may be attributed to variations in loading methods. These comparisons indicate that the proposed model can simulate the entire process of explosive-induced fracturing with substantial improvements in computational efficiency. Nonetheless, further enhancements in accuracy are necessary. These findings underscore the advantages of the 3D GPU-parallelized CDEM in enhancing computational speeds and its potential in geotechnical engineering, especially for simulating rock fractures under quasi-static and explosive dynamic conditions.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103081"},"PeriodicalIF":3.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094697","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":"PyAdMesh: A novel high-performance software for adaptive finite element analysis","authors":"S. Asil Gharebaghi,&nbsp;A.H. Khatami","doi":"10.1016/j.simpat.2025.103074","DOIUrl":"10.1016/j.simpat.2025.103074","url":null,"abstract":"<div><div>This study introduces <span>PyAdMesh</span>, an open-source software for reducing discretization errors in finite element analysis using an h-adaptive method. Adaptive approaches iteratively refine meshes to minimize errors but require substantial computational resources due to repeated analyses. <span>PyAdMesh</span> addresses this challenge by employing efficient data transfer operators for displacement, stress, and strain, avoiding full reanalysis. The software achieves performance gains through parallel processing on CPU and GPU, leveraging <span>CuPy</span>, <span>Numba</span>, and Python’s <span>multiprocessing</span> library. GPU parallelization achieves speed-ups of 30 times compared to serial execution, while CPU parallelization yields an 8-fold improvement. <span>PyAdMesh</span> reduces discretization error from <span>5.5</span>% to <span>0.07</span>% using a recovery-based error estimation method. Despite low-end hardware, including an <em>Intel Xeon 6148</em> CPU and <em>NVIDIA Quadro P4000</em> GPU, the software demonstrates significant potential for adaptive finite element analysis. Future studies should explore its performance on high-end hardware. This work highlights <span>PyAdMesh</span>’s potential for large-scale engineering simulations, balancing computational efficiency and accuracy.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103074"},"PeriodicalIF":3.5,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094694","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":"Prediction of casted muck pile profiles using discrete element modeling and the Monte Carlo approach","authors":"R. Lamont ,&nbsp;S. Schafrik ,&nbsp;B. Diddle ,&nbsp;J. Silva ,&nbsp;J. Calnan ,&nbsp;Z. Agioutantis","doi":"10.1016/j.simpat.2025.103077","DOIUrl":"10.1016/j.simpat.2025.103077","url":null,"abstract":"<div><div>In applicable orebodies, well-designed cast blasting has proven to be a more efficient method of material transportation than traditional options. Cast blast design has historically been based upon the modification of previous field observations. More recently, numerical models have been developed to predict blasting effects such as vibration and sound, among many. The Discrete Element Modeling method, which creates a large quantity of individual particles, has experienced successful application in modeling blasted rock movement. This work examined several potential improvements to the prediction of muck pile profiles and evaluated their effect based on measured results. Model element shapes, sizes, and distributions were found to have little effect on predictive ability. A stochastic approach was taken to simplify the effect of several pre-blast variables into only initial velocity, which proved to be a valid assumption. A modest central portion of the bench was found to represent the entire bench accurately. Several factors were found to have a high impact on final muck pile profiles, including friction, pit floor variation, and timing. The results illuminate the effects of several parameters crucial to increasing the ability of operators to optimize cast blasts.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103077"},"PeriodicalIF":3.5,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094695","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":"Peridynamics simulating of dynamics crack propagation in rock mass under blasting load","authors":"Liping Li ,&nbsp;Xiaochu Chen ,&nbsp;Chenglu Gao ,&nbsp;Zongqing Zhou ,&nbsp;Minghao Li ,&nbsp;Daosheng Zhang ,&nbsp;Jinbo Chen","doi":"10.1016/j.simpat.2025.103079","DOIUrl":"10.1016/j.simpat.2025.103079","url":null,"abstract":"<div><div>It is important to study the crack propagation and failure criterion of fractured rock masses under dynamic blasting loads to ensure the safety and stability of tunnels constructed using the drill-and-blast method. Based on the idea of conventional peridynamics, a peridynamics constitutive model of the pull-compression composite failure of rock materials and a peridynamics simulation method for crack propagation in a fractured rock mass under a blasting load were established. In addition, the criterion for the stress wave incident angle and in-situ stress state for crack propagation in a rock mass were investigated. The incident angle of the stress waves was found to affect the crack propagation. When the incident angle was 0°, new cracks propagated parallel to prefabricated cracks. When the incident angle was 15°-75°, wing cracks formed at the tips on both sides of a prefabricated crack, and the initiation and propagation angles of these new cracks increased with the incident angle. The in-situ stress affected the propagation direction of an explosive-generated crack and the range of the fracture zone. When unidirectional stress was applied, the radial main crack expanded along the direction of the stress, and the range of the fracture zone decreased with an increase in stress. The applicability and accuracy of the proposed dynamic disturbance peridynamics simulation method for solving the problem of dynamic failure and crack growth in a rock mass were verified based on previous physical and model test results.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"140 ","pages":"Article 103079"},"PeriodicalIF":3.5,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094696","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}