Fuzzy Sets and Systems ( IF 3.9 ) Pub Date : 2021-04-15 , DOI: 10.1016/j.fss.2021.04.004 Huan Huang
This paper discusses the properties of Skorokhod metric on normal and upper semi-continuous fuzzy sets on metric space. All fuzzy sets mentioned below refer to this type of fuzzy sets. We confirm that the Skorokhod metric and the enhanced-type Skorokhod metric are equivalent on compact fuzzy sets. However, the Skorokhod metric and the enhanced-type Skorokhod metric need not be equivalent on -integrable fuzzy sets, which include compact fuzzy sets. We point out that the -type metric, , is well-defined in common cases but the metric is not always well-defined on all fuzzy sets. We introduce the metric which is an expansion of the metric, and write as in the sequel. Then, we investigate the relationship between these two Skorokhod-type metrics and the metric. We show that the relationship can be divided into three cases. On compact fuzzy sets, the Skorokhod metric is stronger than the metric. On -integrable fuzzy sets, the Skorokhod metric is not necessarily stronger than the metric, but the enhanced-type Skorokhod metric is still stronger than the metric. On all fuzzy sets, even the enhanced-type Skorokhod metric is not necessarily stronger than the metric. We also show that the Skorokhod metric is stronger than the sendograph metric. At last, we give a simple example to answer some recent questions involved the Skorokhod metric.
中文翻译:
模糊集上Skorokhod度量的某些性质
本文讨论了度量空间上正态和上半连续模糊集上Skorokhod度量的性质。下文提到的所有模糊集均指这种类型的模糊集。我们确认,紧致模糊集上的Skorokhod度量和增强型Skorokhod度量是等效的。但是,Skorokhod指标和增强型Skorokhod指标不需要等效于-可积分模糊集,其中包括紧凑型模糊集。我们指出-类型 指标, 在常见情况下定义明确,但 度量标准并非总是在所有模糊集上都得到很好的定义。我们介绍 指标,是 度量并编写 作为 在续集中。然后,我们调查这两个Skorokhod类型指标与指标。我们证明这种关系可以分为三种情况。在紧致模糊集上,Skorokhod度量比指标。上-可积分模糊集,则Skorokhod指标不一定强于 指标,但增强型Skorokhod指标仍然比 指标。在所有模糊集上,即使增强型Skorokhod指标也不一定比指标。我们还显示Skorokhod指标比发送器指标更强。最后,我们给出一个简单的示例来回答一些最近的有关Skorokhod指标的问题。