CUSUM ANALYSES OF TIME-INTERVAL DATA FOR ONLINE RADIATION MONITORING
CUSUM ANALYSES OF TIME-INTERVAL DATA FOR ONLINE RADIATION MONITORING
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DOI：
10.1097/hp.0b013e3182430106
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发表时间：
2012-06-01
期刊：
影响因子：
2.2
通讯作者：
Sharp, Julia L.
中科院分区：
文献类型：
--
作者：
Luo, Peng;DeVol, Timothy A.;Sharp, Julia L.
三个统计控制图方法进行了研究，以确定一个具有最高的检测概率和最佳的平均运行长度（ARL）。这三种控制图包括计数数据的Shewhart控制图、计数数据的累积和（Cumulative sum，Cumulative sum）分析（Poisson Cumulative sum，Cumulative sum）分析（Poisson Cumulative sum）和时间间隔（两个连续辐射脉冲之间的时间差）数据的Cumulative sum分析（time-interval Cumulative sum）分析（time-interval Cumulative sum）分析（time-interval Cumulative sum）。用实验数据和模拟数据比较了时间间隔控制图、泊松控制图和休哈特控制图。实验数据用DGF-4C（XIA，Inc.）列表模式下的系统。模拟数据是通过使用蒙特卡罗技术获得的泊松过程的随机抽样。所有统计算法均使用R（R开发核心团队）开发。比较了三种方法的检测概率和ARL。时间间隔CUSUM控制图的检测概率与Poisson CUSUM控制图相似，但在相对较高的辐射水平下具有最短的ARL;例如，在每秒10.0次计数（cps）下（比背景计数率高五倍），比泊松计数短约40%。两种EQUIUM控制图的检出概率均高于Shewhart控制图;例如，在4.0 cps时比Shewhart对照方法高100%（高于背景计数率两倍）。此外，当使用时间间隔信息时，与修改的运行规则（mrcumUM（ti））相结合的Cumulum控制图显示出进一步减少响应辐射水平变化所需的时间并将假阳性率保持在所需水平的能力。健康物理学102（6）：637-645;2012
Three statistical control chart methods were investigated to determine the one with the highest detection probability and the best average run length (ARL). The three control charts include the Shewhart control chart of count data, cumulative sum (CUSUM) analysis of count data (Poisson CUSUM), and CUSUM analysis of time-interval (time difference between two consecutive radiation pulses) data (time-interval CUSUM). The time-interval CUSUM (CUSUMti) control chart was compared with the Poisson CUSUM (CUSUMcnt) and the Shewhart control charts with experimental and simulated data. The experimental data were acquired with a DGF-4C (XIA, Inc.) system in list mode. Simulated data were obtained by using Monte Carlo techniques to obtain a random sampling of a Poisson process. All statistical algorithms were developed using R (R Development Core Team). Detection probabilities and ARLs for the three methods were compared. The time-interval CUSUM control chart resulted in a similar detection probability as that of the Poisson CUSUM control chart but had the shortest ARL at relatively higher radiation levels; e.g., about 40% shorter than the Poisson CUSUM at 10.0 counts per second (cps) (five times above the background count rate). Both CUSUM control charts resulted in a higher detection probability than that of the Shewhart control chart; e.g., 100% greater than the Shewhart control method at 4.0 cps (two times above the background count rate). In addition, when time-interval information was used, the CUSUM control chart coupled with a modified runs rule (mrCUSUM(ti)) showed the ability to further reduce the time needed to respond to changes in radiation levels and keep the false positive rate at a required level. Health Phys. 102(6):637-645;2012