ตัวปิดล้อมที่สั้นที่สุดสำหรับสี่อาณาบริเวณซึ่งมีพื้นที่ตามที่กำหนด / อรรณพ แก้วขาว = Shortest enclosure for four regions of given areas / Annop Kaewkhao
In this thesis, we find necessary conditions of the shortest enclosure for four regions of given areas in case P[subscript 1] = P[subscript 2] = P[subscript 3] > P[subscript 4] where P[subscript i] is the pressure of region i, We obtain the following results (1) each cell of the forth region in the shortest enclosure may have at most 9 sides; (2) if the forth region is connected, then it must be an external cell