The position of knee point of Phase-frequency characteristic mean value curve is invariant, but the kurtosis of the curve near the knee point decreases.
刚度与质量参数随机时相频特性均值曲线的拐点位置不变，只是拐点附近曲线陡峭度减小。
2
The position of T2-6 anterior cutaneous branch of intercostals nerve (ACIN) perforating were invariant.
第2~6肋间神经前皮支（ACIN）在胸骨旁穿出点位置恒定。
3
Invariant moments are important measure in the pattern recognition. Invariant moments are independent of position, scale and orientation.