基于主逻辑图的安全风险建模研究

概率风险评估已成为研究复杂系统安全风险较为成熟的方法,其风险模型的建立是基于故障树/事件树的,风险分析具有众多的静态特性.然而,大的复杂系统往往存在诸多动态因素,在风险研究需要考虑这些动态因素的情况下,基于传统故障树/事件树的模型则难以提供支持.笔者对此进行了分析,提出了基于主逻辑图的安全风险建模;主要介绍了主逻辑图的概念及其建模方法,并对模型进行了分析;在此基础上,基于主逻辑图分析事故场景,对场景风险的量化评估进行了简要介绍,并结合某核反应堆例子进行了分析.     

煤堆自燃原因分析与防治措施

煤氧化自燃既是重大的事故隐患 ,也降低了煤的经济价值。分析了煤堆自燃的原因 ,煤堆易发生自燃的部位 ,并提出防治措施     

风险不确定的海上应急物资储备库选址

为提升海上应急系统的救助服务能力,研究海上应急物资储备库的选址问题。首先根据海上应急特点,从及时性、有效性以及不同风险等级的事故对应急服务需求量的差异性等角度考虑,引入应急效率满意度的概念,并将最大化应急效率值作为目标,构建海上应急物资储备库选址模型;然后通过离散仿真情景分析海上事故风险整体分布的不确定性,并利用鲁棒理论构建关于储备库选址的鲁棒优化模型;最后采用遗传算法求得最终选址方案。结果表明:在风险分布具有显著差异的离散仿真情景中,鲁棒优化模型相比确定性模型而言具有较好的稳定性,能够确保选址方案的可靠性。     

近距煤层无煤柱协调开采布局研究与应用*

为了解决老母矿近距煤层的开采难题,通过理论分析并利用FLAC 3D数值模拟软件进行模拟,分析出煤层前后推进150 m是最合理的步距,侧向采动支撑压力在15~50 m内存在影响。基于这些理论数据,确定回采巷道的合理位置,进而确定以内错距离范围为30~60 m的内错式布置方式布置巷道和无煤柱协调开采布局,并进行井下工程应用。最后把无煤柱协调开采布局与双巷掘进开采布局对比,得出无煤柱协调开采布局的先进性和优势,研究结果可为同类条件下的工程应用提供借鉴。     

化工园区消防站多目标选址模型

为提高化工园区的应急能力,针对化工园区内消防站的选址问题,建立一个消防站多目标选址模型。分析影响消防站选址的经济、时间、距离及覆盖率等基本因素,利用潜在生命损失值(PLL)对化工园区进行风险评估;建立消防站选址的约束条件,进而通过计算实现消防站的选址;通过实例验证模型的有效性。结果表明:该模型能综合考虑潜在生命损失值和影响消防站选址的因素,确定化工园区消防站位置,完善园区消防安全体系。     

需求不确定下的应急物资储备库选址模型研究

为提高应急突发事件的预防和处置能力,探讨需求不确定条件下的应急物资储备库选址问题。首先通过基于联系数的区间灰数法预测不确定需求,然后构建包含最短应急时间、最大覆盖范围、最小成本的多目标应急物资储备库模型,并利用改进的非支配排序遗传算法(NSGA-II)求解模型。结果表明,用基于联系数的区间灰数预测法能在样本量较少的情况下保证预测的准确性,用所建模型经多次迭代能从多个候选库存中选取出精度较高的Pareto最优解集,保证解集的多样性和准确性。     

Modelling of concentrations along a moving observer in an inhomogeneous plume. Biological application: model of odour-mediated insect flights

We develop a stochastic model for the time-evolution of scalar concentrations and temporal gradients in concentration experienced by observers moving within inhomogeneous plumes that are dispersing within turbulent flows. In this model, scalar concentrations and their gradients evolve jointly as a Markovian process. Underlying the model formulation is a natural generalisation of Thomson’s well mixed condition [Thomson DJ (1987) J Fluid Mech 180:529–556]. As a consequence model outputs are necessarily compatible with statistical properties of scalars observed in experiment that are used here as model input. We then use the model to examine how insects aloft within the atmospheric boundary-layer can locate odour sources by modulating their flight patterns in response to odour cues. Mechanisms underlying odour-mediated flights have been studied extensively at laboratory-scale but an understanding of these flights over landscape scales is still lacking. Insect flights are simulated by combining the stochastic model with a simple model of insect olfactory response. These simulations show the strong influence of wind speed on the distributions of the times taken by insects to locate the source. In accordance with experimental observations [Baker TC, Vickers NJ (1997) In: Insect pheromone research: new directions, pp 248–264; Mafra-Neto A, Cardé RT (1994) Nature 369:142–144], flight patterns are predicted to become straighter and shorter, and source location is predicted to become more likely as the mean wind speed increases. The most probable arrival time to the source decreases with the mean wind speed. It is shown that scale-free movement patterns arising from olfactory-driven foraging stem directly from the power-law distribution of concentration excursion times above/below a threshold level and are robust with respect to variations in Reynolds number. Flight lengths are well represented by a power law distribution in agreement with the observed patterns of foraging bumblebees [Heinrich B (1979) Oecologia 40(3):235–245].