کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1898654 | 1044753 | 2012 | 9 صفحه PDF | دانلود رایگان |

We consider the family of regular plane closed strictly convex curves and the family of differential equations of special type associated to positive-valued, periodic and continuous functions. Each curve and the solutions of a fixed differential equation determine a family of disjoint closed curves called φφ-optics. In particular cases we obtain the family of αα-isoptics and the family of arc-optic curves. The family of arc-optic curves is closely related to the solutions of the Ulam problem. We generalize the Bianchi–Auerbach equation derived for the problem of floating body to general case of φφ-optics and we give some of its applications. We present the necessary and sufficient conditions for some geometric quantities connected in a natural way to φφ-optics to be constant.
Journal: Journal of Geometry and Physics - Volume 62, Issue 12, December 2012, Pages 2337–2345