Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Graphical representation of O y∩Ω i. The dashed circle denotes the circular neighborhood O y centered on y. The image domain Ω is divided into three disjoint regions Ω 1, Ω 2, and Ω 3, which partition the neighborhood O y into three subregions O y∩Ω 1, O y∩Ω 2, and O y∩Ω 3.
