EXPERIMENTAL VERIFICATION OF OVERDISPERSION IN RADIOASSAY DATA
EXPERIMENTAL VERIFICATION OF OVERDISPERSION IN RADIOASSAY DATA
复制标题
放射分析数据过度分散的实验验证
作者：
T. Semkow
摘要：新的证据表明，相对于泊松分布，放射性数据经常过度分散。使用常用的检测系统测量了12例放射性数据。使用先前开发的过分散模型的有限版本分析数据。在该极限下，推导并讨论了三种过分散分布之间的关系：β -泊松分布、负二项分布和过分散高斯分布。在总共研究的13个病例中（12个测量病例加上1个文献病例），4个病例与泊松统计量在90%置信水平上一致，而其余9个病例被发现过度分散。这表明在放射性分析中，过色散是相当普遍的。所有三个过分散的分布都很好地拟合了数据。过度色散主要是由于探测系统的过度波动，在2个案例中，是由于连续的放射性衰变。
Abstract— New evidence is provided suggesting that radioassay data are frequently overdispersed with respect to the Poisson distribution. Twelve cases of radioassay data were measured using commonly available detection systems. The data were analyzed using a limited version of the overdispersion model developed earlier. In that limit, the relationships between three overdispersed distributions were derived and discussed: beta-Poisson, negative binomial, and overdispersed Gaussian. Out of a total of 13 cases studied (12 measured plus one from the literature), 4 were consistent with the Poisson statistics at 90% confidence level while the remaining 9 were found overdispersed. This shows that the overdispersion is rather prevalent in radioassay. All three overdispersed distributions fitted the data very well. The overdispersion was attributed mostly to the excess fluctuations of the detection systems or, in 2 cases, sequential radioactive decay.