null adj. 1.無效力的,無束縛力的。 2.無效的,無用的,無益的;無價值的。 3.沒特征[個性]的,沒表情的。 4.〔罕用語〕不存在的,沒有的;零(位)的;空的。 n. 【數(shù)學(xué)】零,零位;空;【無線電】零訊號,微弱訊號。 a null indicator 零示器;零位指示器。 the null method 衡消法。 null and void 【律】無效;失效(This check is null and void. 本支票無效)。 vt. 使無效。
It redefines the between - class scatter by adding a weight function according to the between - class distance . therefore , it can separate the classes as much as possible . at the same time , it projects the between - class scatter into the null space of the within - class scatter that contains the most discriminant information 新方法重新定義了樣本類間離散度矩陣,在原始定義的基礎(chǔ)上增加一個由類間距離決定的可變權(quán)函數(shù),使得在選擇投影方向時,能夠更好地分開各個類的樣本。
First , we do not know what kind of bifurcation will happen in advance , it is difficult to choose what kind of regular extended system for detecting them . second , if there are higher order singularities , even the multi - dimensional null space , one parameter is not enough for establishing a regular extended system 首先考慮單參數(shù)非線性問題,如果參數(shù)的個數(shù)足夠多,在延拓過程中通過求解各種正則的擴展系統(tǒng)可以求出方程解枝上存在的各種高階奇異點,例如高階折疊點、橫截式分歧點、音叉式分歧點等。