A method of cross-point admittance based on ambient excitation to identify large engineering structures modal parameters was reported in this paper. 摘要提出了基于环境激励下，运用跨点导纳法识别大型工程结构模态参数的一种方法。
Further, the current quadrilateral and admittance quadrilateral, as well as their similarity to the power quadrilateral in non-sinusoidal alternating-current circuits were derived. 由功率四边形进一步确立了非正弦交流电路中的电流四边形和导纳四边形，以及它们和功率四边形的相似关系。
