But the practical usefulness of implicitization is hampered by the complex representation of the implicit equations of high degree rational curves and surfaces. 這方面的研究已經(jīng)取得了很大的進(jìn)展，然而由于高次曲線(xiàn)的隱式表示極其復雜，其實(shí)際應用價(jià)值受到嚴峻的挑戰。
An approximate quadratic curve has been found to suit the relationship between the tolerances of roundness and their logarithmic fatigue lives with given survivability. 在相同存活率下，孔的圓度公差與孔的對數疲勞壽命呈二次曲線(xiàn)關(guān)系。
