[经] operational econometric model
yíng yùn jīng jì jì liáng mó xíng ㄧㄥˊ ㄩㄣˋ ㄐㄧㄥ ㄐㄧˋ ㄐㄧˋ ㄌㄧㄤˊ ㄇㄛˊ ㄒㄧㄥˊ