The paper proposes four indicators to guide sensors layout in practical experiment on explosion overpressure filed construction based on tomographic method with high reconstruction accuracy and the least sensors. Firs...The paper proposes four indicators to guide sensors layout in practical experiment on explosion overpressure filed construction based on tomographic method with high reconstruction accuracy and the least sensors. First, genetic algorithm is adopted to conduct global search and sensor layout optimization method is selected to satisfy four indicators. Then, by means of Matlab, the variation of these four indicators with different sensor layouts and reconstruction accuracy are analyzed and discussed. The results indicate that the sensor layout method proposed by this paper can reconstruct explosion overpressure field at the highest precision by a minimum number of sensors. It will guide actual explosion experiments in a cost-effective way.展开更多
Nowadays, chemical safety has attracted considerable attention, and chemical gas leakage monitoring and source term estimation(STE) have become hot spots. However, few studies have focused on sensor layouts in scenari...Nowadays, chemical safety has attracted considerable attention, and chemical gas leakage monitoring and source term estimation(STE) have become hot spots. However, few studies have focused on sensor layouts in scenarios with multiple potential leakage sources and wind conditions, and studies on the risk information(RI) detection and prioritization order of sensors have not been performed. In this work, the monitoring area of a chemical factory is divided into multiple rectangles with a uniform mesh. The RI value of each grid node is calculated on the basis of the occurrence probability and normalized concentrations of each leakage scenario. A high RI value indicates that a sensor at a grid node has a high chance of detecting gas concentrations in different leakage scenarios. This situation is beneficial for leakage monitoring and STE. The methods of similarity redundancy detection and the maximization of sensor RI detection are applied to determine the sequence of sensor locations. This study reveals that the RI detection of the optimal sensor layout with eight sensors exceeds that of the typical layout with 12 sensors. In addition, STE with the optimized placement sequence of the sensor layout is numerically simulated. The statistical results of each scenario with various numbers of sensors reveal that STE is affected by sensor number and scenarios(leakage locations and winds). In most scenarios, appropriate STE results can be retained under the optimal sensor layout even with four sensors. Eight or more sensors are advised to improve the performance of STE in all scenarios. Moreover, the reliability of the STE results in each scenario can be known in advance with a specific number of sensors. Such information thus provides a reference for emergency rescue.展开更多
为了进一步提高传统无线传感网络覆盖布局的效率,设计了一种基于条件风险价值(Conditional Value at Risk,CVaR)布局的无线传感网络覆盖优化方法。通过惰性赋值方式实现快速搜索的功能,并对算法进行评价。研究结果表明:通过增加Γ可以...为了进一步提高传统无线传感网络覆盖布局的效率,设计了一种基于条件风险价值(Conditional Value at Risk,CVaR)布局的无线传感网络覆盖优化方法。通过惰性赋值方式实现快速搜索的功能,并对算法进行评价。研究结果表明:通过增加Γ可以得到更好结果,τ搜索上限设置为50能够对各种可信度的程度进行检索,获得一个全局最佳解决方案,建立置信水平α=0.9条件下的集合。基于CVaR优化布置方法可以降低系统失效概率,在不确定环境下建立更好的布置结构,大幅提高了系统的稳健性。该研究有助于提高网络通信效率,为后续的性能优化奠定一定的理论基础。展开更多
基金Natural Science Foudation of Shanxi Province of China(No.2013011017-8)
文摘The paper proposes four indicators to guide sensors layout in practical experiment on explosion overpressure filed construction based on tomographic method with high reconstruction accuracy and the least sensors. First, genetic algorithm is adopted to conduct global search and sensor layout optimization method is selected to satisfy four indicators. Then, by means of Matlab, the variation of these four indicators with different sensor layouts and reconstruction accuracy are analyzed and discussed. The results indicate that the sensor layout method proposed by this paper can reconstruct explosion overpressure field at the highest precision by a minimum number of sensors. It will guide actual explosion experiments in a cost-effective way.
基金supported by National Natural Science Foundation of China (61988101)National Natural Science Fund for Distinguished Young Scholars (61725301)Fundamental Research Funds for the Central Universities。
文摘Nowadays, chemical safety has attracted considerable attention, and chemical gas leakage monitoring and source term estimation(STE) have become hot spots. However, few studies have focused on sensor layouts in scenarios with multiple potential leakage sources and wind conditions, and studies on the risk information(RI) detection and prioritization order of sensors have not been performed. In this work, the monitoring area of a chemical factory is divided into multiple rectangles with a uniform mesh. The RI value of each grid node is calculated on the basis of the occurrence probability and normalized concentrations of each leakage scenario. A high RI value indicates that a sensor at a grid node has a high chance of detecting gas concentrations in different leakage scenarios. This situation is beneficial for leakage monitoring and STE. The methods of similarity redundancy detection and the maximization of sensor RI detection are applied to determine the sequence of sensor locations. This study reveals that the RI detection of the optimal sensor layout with eight sensors exceeds that of the typical layout with 12 sensors. In addition, STE with the optimized placement sequence of the sensor layout is numerically simulated. The statistical results of each scenario with various numbers of sensors reveal that STE is affected by sensor number and scenarios(leakage locations and winds). In most scenarios, appropriate STE results can be retained under the optimal sensor layout even with four sensors. Eight or more sensors are advised to improve the performance of STE in all scenarios. Moreover, the reliability of the STE results in each scenario can be known in advance with a specific number of sensors. Such information thus provides a reference for emergency rescue.
文摘为了进一步提高传统无线传感网络覆盖布局的效率,设计了一种基于条件风险价值(Conditional Value at Risk,CVaR)布局的无线传感网络覆盖优化方法。通过惰性赋值方式实现快速搜索的功能,并对算法进行评价。研究结果表明:通过增加Γ可以得到更好结果,τ搜索上限设置为50能够对各种可信度的程度进行检索,获得一个全局最佳解决方案,建立置信水平α=0.9条件下的集合。基于CVaR优化布置方法可以降低系统失效概率,在不确定环境下建立更好的布置结构,大幅提高了系统的稳健性。该研究有助于提高网络通信效率,为后续的性能优化奠定一定的理论基础。
