中文摘要：

We discuss how to determine and combine upper limits based on observed events and estimated backgrounds with a Bayesian method,when insignificant signals are observed in independent measurements.In addition to some general features deduced from the analytical formulae,systematic numerical results are obtained by a C++program(CULBA) for low-count experiments,which can be used as a reference to combine two upper limits.

英文摘要：

We discuss how to determine and combine upper limits based on observed events and estimated back- grounds with a Bayesian method, when insignificant signals are observed in independent measurements. In addition to some general features deduced from the analytical formulae, systematic numerical results are obtained by a C＋＋ program （CULBA） for low-count experiments, which can be used as a reference to combine two upper limits.