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随着新冠肺炎疫情在全世界各地传播,通过对其数据和传播机理的分析,已有SEIRD模型的基础上构建SEIiRD模型,将感染人群分为无症状感染者、轻症感染者、重症感染者和危重症感染者,分析不同感染人群的传播率对疫情发展的影响。在拟合现实数据的基础上进行仿真实验,研究发现影响疫情发展的主要感染人群是无症状感染者和轻症感染者。在此基础上进一步分析了不同的无症状和轻症感染者的传播速率所造成感染人数和死亡人数的变化情况。针对介入干预时间对感染人数和死亡人数的影响进行了仿真分析。实验结果表明该模型能有效模拟新冠肺炎疫情传播规律,有助于防控职能部门实施相应的疫情防控策略提供决策支持。 相似文献
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为了更好地揭示新冠肺炎(COVID-19)的传播机理,通过分析新冠病毒(2019-nCoV)的传播特性,考虑隐性潜伏者的自愈以及潜伏者的提前隔离,引入“入院隔离状态”,“隐性治愈状态”,考虑防控强度的变化,引入“发病状态”,提出了SEAIHR动力学模型。利用真实疫情数据,考虑不同阶段参数的变化,进行了多模型对比试验。实验结果表明,SEAIHR模型拟合和预测精度有明显提升,较经典模型在疫情前中期降低了34.4%~72.8%拟合误差,为疫情防控提供了参考与指导。 相似文献
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多级缸起竖系统运动过程的建模与仿真 总被引:4,自引:2,他引:4
讨论了含多级油缸起竖液压系统的特点,运用多体系统动力学理论分析了起竖系统的多刚体模型,采用“分离-碰撞”两状态模型和非线性弹簧-阻尼力函数对活塞杆间的碰撞过程进行等效,建立了考虑碰撞的起竖多刚体系统动力学模型,对多级油缸的运动过程进行了仿真。仿真结果表明多级缸活塞杆运动过程中的碰撞是影响大型装置起竖过程平稳性的主要因素,模型和仿真结果可用于快速起竖系统的设计。 相似文献
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基于演化的复杂系统建模与仿真研究 总被引:8,自引:7,他引:8
系统仿真技术正面临着新的挑战,即:如何建立基于演化的复杂系统动力学的建模与仿真方法学。本文讨论和综述了这一领域目前的工作和发展,主要内容包括:复杂性问题的提出;主要命题;复杂系统的动力学特征;复杂系统建模与仿真的理论研究、方法和软件。 相似文献
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突发事件发生时,应急资源的合理调度问题尤为重要。如何解决单一城市应急资源供应不足,如何将更多的资源进行整合,选择哪些救援点进行救援,什么时候进行救援,这些都是需要讨论的问题。通过建立虚拟协调中心,将分布式系统的理论应用到整合城市之间应急资源的协同调度管理中,从应急系统成本费用和因施救不及时造成损失的双重角度考虑,将救援成本最小和出救点数量最少作为应急优化目标,建立了针对多救援点事故灾害下的应急资源调度模型,并对资源的动态调度模型及协同过程进行仿真与研究分析。 相似文献
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作战系统仿真中的雷达建模与仿真研究 总被引:4,自引:2,他引:4
以舰艇防空作战中雷达单元的仿真为背景,按照搜索雷达和精跟踪雷达的功能及工作流程,将作战系统中的雷达仿真分成目标探测、捕获、非精确跟踪及精确跟踪等步骤,对各个步骤中需完成的工作进行了较为完整的介绍,并给出了相关流程图。 相似文献
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Weiwei Zhang Shiyong Liu Nathaniel Osgood Hongli Zhu Ying Qian Peng Jia 《Systems Research and Behavioral Science》2023,40(1):207-234
This study systematically reviews applications of three simulation approaches, that is, system dynamics model (SDM), agent-based model (ABM) and discrete event simulation (DES), and their hybrids in COVID-19 research and identifies theoretical and application innovations in public health. Among the 372 eligible papers, 72 focused on COVID-19 transmission dynamics, 204 evaluated both pharmaceutical and non-pharmaceutical interventions, 29 focused on the prediction of the pandemic and 67 investigated the impacts of COVID-19. ABM was used in 275 papers, followed by 54 SDM papers, 32 DES papers and 11 hybrid model papers. Evaluation and design of intervention scenarios are the most widely addressed area accounting for 55% of the four main categories, that is, the transmission of COVID-19, prediction of the pandemic, evaluation and design of intervention scenarios and societal impact assessment. The complexities in impact evaluation and intervention design demand hybrid simulation models that can simultaneously capture micro and macro aspects of the socio-economic systems involved. 相似文献
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The purpose of this paper is to demonstrate through practical application how a system dynamics (SD) patient flow model of an emergency department (ED) can show which levers effectively reduce backlogs to improve access to care. Overcrowded EDs are struggling to meet demand and access targets. In 2016 and 2017, in the UK and Australia, respectively, 15% and 28% of arrivals waited longer than the targeted 4-hr treatment time. Historically, simulation models that have informed access to emergency care have ignored the wider systems impacts. There is a growing awareness of the value of systems analysis tools for informing interventions and policy. In this study, we constructed a pilot system dynamics patient flow model, where the scope was the ambulatory and ambulance patient arrivals, the ED processes for acute and fast-track pathways, pathology and radiology services, the ED short-stay unit, and the Medical Assessment Planning Inpatient Unit. Patients queued to access constrained ED resources (doctors and beds) and diagnostic services (pathology and X-ray). The model was tested on actual data from five separate historical periods spanning 3 years. The resultant daily pattern of peaks and troughs in patient flow and system delays accurately replicated patterns in actual patient flows, resource use, and the location of delays. “What if” scenario analysis (b) simulated how access would have looked in the sample weeks with different intervention strategies, (b) simulated system limits on the basis of current resources, (c) accurately identified levers that historically have been most effective at minimizing ambulance ramping, and (d) identified when additional staffing would fail to improve flow. 相似文献
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This paper establishes a simulation decision system for both emergency resource preparation and emergency resource replenishment. The decision system uses both system dynamics and goal programming. A system dynamics model is then developed and validated with real case data as simulation decision support to emergency resource replenishment. An optimization simulation using the data from the emergency resource preparation process in the Ya'an earthquake in China is reported. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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磁轴承柔性转子系统动力特性建模与优化仿真 总被引:5,自引:0,他引:5
建立了电磁轴承柔性有质转子系统计入陀螺、阻尼、轴-径向动力耦合及机械-电磁-控制系统耦合等影响的动力特性分析计算数学模型,导出了多变量控制系统的标准化系统矩阵向量方程。以系统仿真响应为目标,通过复合寻优方法实现了系统最佳工作区(点)的求解。对优化仿真结果与试验现场调试结果进行了对比分析。 相似文献
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新冠疫情的爆发,使许多地区成为灾区,为了及时对灾区进行救援,灾后应急资源精准供给成为保障灾区人民安全的首要因素。本文利用SEIR预测决策时刻各灾区感染人数,由此计算灾区紧迫程度权重与物资需求量。基于紧迫程度构建以灾民满意度最大化、总成本最小化和考虑分配公平的应急资源调度多目标优化模型。提出多目标人工蜂群算法。针对人工蜂群算法易早熟等缺点,利用动态参数思想与Pareto解集来定义新的蜂群位置更新公式,利用教学优化思想对蜂群位置进行扰动,以避免算法陷入局部极值。通过算例进行模拟实验,结果表明,所提出的模型和算法可以有效解决疫情事件下多灾点应急资源最优化配置问题,且改进算法的性能更优。 相似文献
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Chih-Tung Hsiao Chun-Cheng Chen Lee-Kai Lin Chung-Shu Liu 《Systems Research and Behavioral Science》2023,40(1):194-206
Since the worldwide outbreak of the COVID-19 pandemic in December 2019, Taiwan has successfully stopped the spread of COVID-19. The policies and works of the epidemic control are a complex and dynamic process. This study applied the methodology of system dynamics to explore the structure of the COVID-19 epidemic control system in Taiwan and analysed its system behaviours. The results show that the system is composed of key subsystems, such as national health insurance and quarantine, combined with government policies. Joint efforts among the central and local governments and the general public have been made to strengthen the quarantine of border entrants, encourage the public to wear masks and employ technology for contact tracing and tracking down those being tested positive with COVID-19. Together with the efficient increase in the capacity of testing and medical treatments, these measures can effectively reach a balance between epidemic control and economic activities. 相似文献
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供应链系统的动力学和复杂性问题正在成为供应链设计、分析、优化和管理研究的一个热点。然而,相当多的研究侧重于定性的分析或简化的模型,而且不同领域的学者一般采用不同的理论和方法。通过对该领域相关研究文献的分析和归纳,在系统科学、复杂性科学和非线性科学理论的基础上,总结出供应链系统动力学和复杂性研究的建模仿真理论和方法的基本框架以及这些理论方法的相互联系,力图为供应链系统的动力学和复杂性建模仿真问题提供系统的研究思路。 相似文献
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如何采用数学规划方法优化应急组织指派策略,提高大规模自然灾害中人力资源的利用率,减少各种损失是当前亟待解决的重要课题。在应急组织指派优化决策框架的基础上,从任务顺序和目标数量2个维度,梳理了应急组织指派数学规划模型的研究现状;梳理了应急组织指派优化模型求解算法的进展;总结并指出了应急组织指派优化仿真建模中亟待深入研究的问题。 相似文献