用集合的近似凸性研究函数的拟凸性。在较弱假设下，获得了拟凸性的一些等价条件。

Quasiconvex functions are studied by applying nearly convexity of sets. Under weaker assumptions, some equivalent conditions for quasiconvexity are derived.

youdao

用集合的近似凸性研究函数的预不变凸性，在较弱的假设下获得了预不变凸性的一些等价条件。

Preconvex functions are studied by applying nearly convexity of sets in this paper. Under weaker assumptions, some equivalent conditions for preconvexity are derived.

youdao

从几何和凸集的角度，系统地给出了平面闭参数曲线全局凸和局部凸定义，并且证明了这两个定义是等价的。

Based on geometry and convex set methods, this paper gives systemically the definitions of global and local convexity for planar closed parametric curve, and proves the two definitions are equivalent.

youdao

Recognizing fine patterns, and you have in fact a very specialization of your brain in the centre called the fovea.

识别精细图案，实际上你的大脑中心,有一个叫做中央凸的部具有特殊的作用。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选