短語詞組短語trend surface analysis method 趨勢麪方法grey trend relational analysis method 灰色趨勢關(guān)聯(lián)分析periodic trend analysis method 周期趨勢分析法gray trend analysis method 灰色gm模型Similarity -difference connection trend analysis method 同異聯(lián)系勢分析 返回 trend analysis method