To improve the reliability of coal mine safety monitoring systems we have analyzed the characteristics of a methane sensor, an important component of the monitoring system of production safety in a coal mine and studi...To improve the reliability of coal mine safety monitoring systems we have analyzed the characteristics of a methane sensor, an important component of the monitoring system of production safety in a coal mine and studied the main type and mode of faults when the sensor was used on-line. We introduced a new method based on artificial neural network to detect faults of methane sensors. In addition, using the output information of a single methane sensor, we established a sensor output model of a dynamic non-linear neural network for on-line fault detection. Finally, the fault of the heating wire of the sensor was simulated, indicating that, when the methane sensor had a fault, the predicted output of the neural network clearly deviated from the actual output, exceeding the pre-set threshold and showing that a fault had occurred in the methane sensor. The result shows that the model has good convergence and stability, and is quite capable of meeting the requirements for on-line fault detection of methane sensors.展开更多
目的探讨骶髂关节周围韧带钙化的分布规律,以期为脊柱韧带钙化机制的研究提供更多依据。方法回顾分析2022年1月我院影像归档和通讯系统(picture ar-chiving and communication system,PACS)上包含骶髂关节的腹盆腔检查及腰骶部检查的患...目的探讨骶髂关节周围韧带钙化的分布规律,以期为脊柱韧带钙化机制的研究提供更多依据。方法回顾分析2022年1月我院影像归档和通讯系统(picture ar-chiving and communication system,PACS)上包含骶髂关节的腹盆腔检查及腰骶部检查的患者的CT影像资料,通过纳入及排除标准入组连续病例1266例,男702例,女564例,年龄18~95岁。按照骶髂关节韧带钙化位置分为前方、中间、后方及上下部4组;按照10岁间隔分为7个年龄段组,其中20岁以下患者纳入18~29岁组,90岁以上患者纳入>80岁组。应用SPSS 25.0统计软件行χ^(2)检验及Spearman相关分析,统计分析骶髂关节周围韧带钙化的患病率及其与患者年龄、性别的相关性,各组间比较使用t检验。结果骶髂关节周围韧带钙化的患病率在不同性别间差异有统计学意义(P<0.05),女性(82.45%)高于男性(73.79%),且钙化数量在不同性别间差异亦有统计学意义(P<0.05);骶髂关节后方韧带钙化的患病率在不同性别间差异有统计学意义(P<0.05),钙化数量差异有统计学意义(P<0.05);在不同性别间,40~59岁年龄段人群骶髂关节后方韧带钙化的患病率差异有统计学意义(P<0.05);骶髂关节其余位置韧带钙化的患病率在各年龄段中无性别差异。结论骶髂关节周围韧带钙化在发生概率及数量上女性高于男性,高发年龄段女性为40~49岁,男性为70~79岁,钙化更易发生于骶髂关节后方韧带。展开更多
基金Projects 50534080 supported by the National Natural Science Foundation of ChinaNCET-05-0602 by the Program for New Century Excellent Talents in Universities of China2006KJ019B by the National Natural Science Foundation of Anhui Province Education Office
文摘To improve the reliability of coal mine safety monitoring systems we have analyzed the characteristics of a methane sensor, an important component of the monitoring system of production safety in a coal mine and studied the main type and mode of faults when the sensor was used on-line. We introduced a new method based on artificial neural network to detect faults of methane sensors. In addition, using the output information of a single methane sensor, we established a sensor output model of a dynamic non-linear neural network for on-line fault detection. Finally, the fault of the heating wire of the sensor was simulated, indicating that, when the methane sensor had a fault, the predicted output of the neural network clearly deviated from the actual output, exceeding the pre-set threshold and showing that a fault had occurred in the methane sensor. The result shows that the model has good convergence and stability, and is quite capable of meeting the requirements for on-line fault detection of methane sensors.
文摘目的探讨骶髂关节周围韧带钙化的分布规律,以期为脊柱韧带钙化机制的研究提供更多依据。方法回顾分析2022年1月我院影像归档和通讯系统(picture ar-chiving and communication system,PACS)上包含骶髂关节的腹盆腔检查及腰骶部检查的患者的CT影像资料,通过纳入及排除标准入组连续病例1266例,男702例,女564例,年龄18~95岁。按照骶髂关节韧带钙化位置分为前方、中间、后方及上下部4组;按照10岁间隔分为7个年龄段组,其中20岁以下患者纳入18~29岁组,90岁以上患者纳入>80岁组。应用SPSS 25.0统计软件行χ^(2)检验及Spearman相关分析,统计分析骶髂关节周围韧带钙化的患病率及其与患者年龄、性别的相关性,各组间比较使用t检验。结果骶髂关节周围韧带钙化的患病率在不同性别间差异有统计学意义(P<0.05),女性(82.45%)高于男性(73.79%),且钙化数量在不同性别间差异亦有统计学意义(P<0.05);骶髂关节后方韧带钙化的患病率在不同性别间差异有统计学意义(P<0.05),钙化数量差异有统计学意义(P<0.05);在不同性别间,40~59岁年龄段人群骶髂关节后方韧带钙化的患病率差异有统计学意义(P<0.05);骶髂关节其余位置韧带钙化的患病率在各年龄段中无性别差异。结论骶髂关节周围韧带钙化在发生概率及数量上女性高于男性,高发年龄段女性为40~49岁,男性为70~79岁,钙化更易发生于骶髂关节后方韧带。
